A Way to Kill Chemo-Resistant Ovarian Cancer Cells: Cut Down Their Protector

A recent study provides new insight into why ovarian cancer is often resistant to chemotherapy, as well as a potential way to improve its diagnosis and treatment.

Protein Data Base 3-D rendering of the Gelsolin protein. (Photo: Wikipedia)

Protein Data Base 3-D rendering of the gelsolin protein. (Photo: Wikipedia)

Ovarian cancer is the most lethal gynecological cancer, claiming the lives of more than 60% of women who are diagnosed with the disease. A study involving Ottawa and Taiwan researchers, published in the influential Proceedings of the National Academy of Sciences (PNAS), provides new insight into why ovarian cancer is often resistant to chemotherapy, as well as a potential way to improve its diagnosis and treatment.

It is estimated that 2,700 Canadian women will be diagnosed with ovarian cancer in 2014 and that 1,750 Canadian women will die from the disease, according to Ovarian Cancer Canada. This cancer is often diagnosed late and develops a resistance to chemotherapy.

tsang_ben

Dr. Ben Tsang

“What we’ve discovered will help clinicians to better treat women with ovarian cancer,” says Dr. Ben Tsang, senior scientist at the Ottawa Hospital Research Institute and professor at the University of Ottawa. “The key is understanding the role of a protein called “gelsolin.” With our colleagues from National Cheng Kung University in Taiwan, we found that an increased level of this protein is associated with aggressive forms of ovarian cancer that are more likely to be resistant to chemotherapy and lead to death.”

The researchers showed how gelsolin works at the molecular level to protect cancer cells against a widely used chemotherapy drug called “cisplatin.”

The findings are important because they will help clinicians to determine the most effective treatment plan based on the level of gelsolin. Work still needs to be done to determine exactly how much gelsolin indicates a cancer that is chemo-resistant and would require different treatment options.

In addition, this same protein that makes ovarian cancer cells resistant to chemotherapy can be used to overcome this treatment obstacle. By cutting gelsolin down to a specific fragment and putting it into chemo-resistant cancer cells, the international team discovered they could make these cells susceptible to the cancer-killing effects of cisplatin.

Shieh

Dr. Dar-Bin Shieh

“We believe this discovery is a promising avenue for developing a new therapy to reduce chemo-resistance in women with this deadly disease,” said Dr. Dar-Bin Shieh, collaborative partner from National Cheng Kung University of Taiwan. Shieh is currently leading the International Institute of Macromolecular Analysis and Nanomedicine Innovation (IMANI), which is focused on translating molecular discoveries to the clinic.

Based on 2009 estimates, approximately one in 72 Canadian women will develop ovarian cancer in her lifetime and one in 93 will die from it.

This study was supported by the Canadian Institutes of Health Research and the National Science Council of Taiwan.

Ottawa Hospital Research Institute
The Ottawa Hospital Research Institute is the research arm of The Ottawa Hospital and is an affiliated institute of the University of Ottawa, closely associated with its faculties of Medicine and Health Sciences. The Ottawa Hospital Research Institute includes more than 1,700 scientists, clinical investigators, graduate students, postdoctoral fellows and staff conducting research to improve the understanding, prevention, diagnosis and treatment of human disease. Research at Ottawa Hospital Research Institute is supported by The Ottawa Hospital Foundation.

University of Ottawa: A crossroads of cultures and ideas
The University of Ottawa is home to almost 50,000 students, faculty and staff, who live, work and study in both French and English. The campus is a crossroads of cultures and disciplines, where bold minds come together to inspire game-changing ideas. The University of Ottawa is one of Canada’s top 10 research universities — our professors and researchers explore new approaches to today’s challenges. One of a handful of Canadian universities ranked among the top 200 in the world, we attract exceptional thinkers and welcome diverse perspectives from across the globe.

National Cheng Kung University
National Cheng Kung University (NCKU) is a research-led comprehensive university in Tainan City, Taiwan. Since its establishment in 1931, NCKU has nurtured countless social elites and leaders under the trailblazing efforts of its former faculties and staffs. NCKU is one of the most prestigious universities in Taiwan, with a high reputation in science, engineering, medicine, management, planning and design. The university is a role model for the transformation of Taiwan’s higher-educational institutes, and is also an important pillar of the country’s economic and industrial structure.

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WIH Researchers Examine Role of Hormone HE4 in Patient Responses to Ovarian Cancer Treatment

Researchers at Women & Infants’ Hospital of Rhode Island recently published the results of an investigation into the role of hormone HE4 in patient responses to ovarian cancer treatment.

Researchers at Women & Infants’ Hospital of Rhode Island recently published the results of an investigation into how we might better tailor therapy for ovarian cancer.

The work comes out of the molecular therapeutic laboratory directed by Richard G. Moore, M.D., of Women & Infants’ Program in Women’s Oncology. Entitled “HE4 expression is associated with hormonal elements and mediated by importin-dependent nuclear translocation,” the research was recently published in the international science journal Scientific Reports, a Nature publishing group.

The goal of the study was to investigate the role of the hormone HE4 (Human epididymis protein 4) in modulating ovarian cancer’s response to hormones and hormonal therapies. HE4 is a biomarker that is elevated in ovarian cancer and is known to play a role in resistance to chemotherapy.

Richard G. Moore, M.D.

Richard G. Moore, M.D.

“There is little known about the biologic functions of HE4 but we did know that there were hormonal responsive elements within the promoter region of the HE4 gene, which regulates gene expression. For this reason, we hypothesized that steroid hormones could influence expression of HE4 in ovarian cancer,” Moore explains.

The study resulted in multiple findings:

  • Hormonal therapies like tamoxifen (Nolvadex) and fulvestrant (Faslodex) are effective because they bind the estrogen receptor. If cells have less estrogen receptor expression, these drugs can’t do their job. This, the researchers believe, is due to epigenetic modifications which modify the DNA structure but not the DNA sequence itself. Overexpression led to the epigenetic modification known as decreased DNA methylation in cell culture and in human tissue samples.
  • Treatment of ovarian cancer cells with tamoxifen and fulvestrant all cause HE4 to translocate to the cell nucleus, where it can then effect further gene expression in cancer cells.
  • Using the drug ivermectin (broad-spectrum antiparasitic agent), the researchers were able to inhibit the protein import in-4, which then inhibited HE4 from translocating to the nucleus. If HE4 can’t enter the nucleus, it cannot affect gene expression. The ability to block HE4 from entering the nucleus restored sensitivity to hormonal therapy.

“We are not certain but believe this might mean there could be a subset of women whose tumors are more likely to respond to hormonal therapy. Moreover, we might be able to eventually identify which tumors these are and target treatment,” Moore says.

Dr. Moore’s lab will continue to investigate the expression of estrogen receptors in both primary and recurrent ovarian cancers and how that relates to HE4 expression. In addition, Dr. Moore and other researchers will investigate how importin inhibitors may play a role in addressing chemoresistance to standard therapeutics, particularly in HE4 overexpressing tumors.

About Women & Infants Hospital

Women & Infants’ Hospital of Rhode Island, a Care New England hospital, is one of the nation’s leading specialty hospitals for women and newborns. The primary teaching affiliate of The Warren Alpert Medical School of Brown University for obstetrics, gynecology and newborn pediatrics, as well as a number of specialized programs in women’s medicine, Women & Infants’ is the eighth largest stand-alone obstetrical service in the country with nearly 8,400 deliveries per year.In 2009, Women & Infants opened the country’s largest, single-family room neonatal intensive care unit.

New England’s premier hospital for women and newborns, Women & Infants’ and Brown offer fellowship programs in gynecologic oncology, maternal-fetal medicine, urogynecology and reconstructive pelvic surgery, women’s mental health, neonatal-perinatal medicine, pediatric and perinatal pathology, gynecologic pathology and cytopathology, and reproductive endocrinology and infertility. It is home to the nation’s only mother-baby perinatal psychiatric partial hospital, as well as the nation’s only fellowship program in obstetric medicine.

Women & Infants’ Hospital has been designated as a Breast Center of Excellence from the American College of Radiography; a Center for In Vitro Maturation Excellence by SAGE In Vitro Fertilization; a Center of Biomedical Research Excellence by the National Institutes of Health; and a Neonatal Resource Services Center of Excellence. It is one of the largest and most prestigious research facilities in high risk and normal obstetrics, gynecology and newborn pediatrics in the nation, and is a member of the National Cancer Institute’s Gynecologic Oncology Group and the National Institutes of Health’s Pelvic Floor Disorders Network.

Sources:

  • Lokich E et al. “HE4 expression is associated with hormonal elements and mediated by importin-dependent nuclear translocation.” Sci Rep. 2014 Jun 30;4:5500. doi: 10.1038/srep05500. [PMID:24975515] [PMCID:PMC4074789]

Related Posts:

  • Small Phase II Study Tests the Use of Fulvestrant in the Treatment of Recurrent Epithelial Ovarian Cancer (March 15, 2009).
  • European Researchers Find Estrogen Receptor Gene Amplification Occurs Rarely in Ovarian Cancer (February 24, 2009).
  • Working Smarter, Not Harder: Use of Anti-Estrogen Therapy to Battle Recurrent Ovarian Cancer (August 18, 2008).

Glutamine Ratio is Key Ovarian Cancer Indicator

Glutamine plays an important role in cellular growth in several cancers. A Rice University-led study shows how ovarian cancer metabolism changes between early and late stages. In this study, a further link between glutamine dependency and tumor invasiveness is established in ovarian cancer.

A Rice University-led analysis of the metabolic profiles of hundreds of ovarian tumors has revealed a new test to determine whether ovarian cancer cells have the potential to metastasize, or spread to other parts of the body. The study also suggests how ovarian cancer treatments can be tailored based on the metabolic profile of a particular tumor.

The research, which appears online this week in Molecular Systems Biology, was conducted at the Texas Medical Center in Houston by researchers from Rice University, the University of Texas M.D. Anderson Cancer Center, and the Baylor College of Medicine.

Deepak Nagrath

Deepak Nagrath, Assistant Professor of Chemical and Biomolecular Engineering at Rice University

“We found a striking difference between the metabolic profiles of poorly aggressive and highly aggressive ovarian tumor cells, particularly with respect to their production and use of the amino acid glutamine,” said lead researcher Deepak Nagrath Ph.D. of Rice University. “For example, we found that highly aggressive ovarian cancer cells are glutamine-dependent, and in our laboratory studies, we showed that depriving such cells of external sources of glutamine — as some experimental drugs do — was an effective way to kill late-stage cells.

“The story for poorly aggressive cells was quite different,” said Nagrath, Assistant Professor of Chemical and Biomolecular Engineering at Rice. “These cells use an internal metabolic pathway to produce a significant portion of the glutamine that they consume, so a different type of treatment — one aimed toward internal glutamine sources — will be needed to target cells of this type.”

The research is part of a growing effort among cancer researchers worldwide to create treatments that target the altered metabolism of cancer cells. It has long been known that cancer cells adjust their metabolism in subtle ways that allow them to proliferate faster and survive better. In 1924, Otto Warburg showed that cancer cells produced far more energy from glycolysis than did normal cells. The Nobel Prize-winning discovery became known as the “Warburg effect,” and researchers long believed that all cancers behaved in this way. Intense research in recent decades has revealed a more nuanced picture.

“Each type of cancer appears to have its own metabolic signature,” Nagrath said. “For instance, kidney cancer does not rely on glutamine, and though breast cancer gets some of its energy from glutamine, it gets even more from glycolysis. For other cancers, including glioblastoma and pancreatic cancer, glutamine appears to be the primary energy source.”

Rice University Researchers

Researchers at Rice University’s Laboratory for Systems Biology of Human Diseases analyzed the metabolic profiles of hundreds of ovarian tumors and discovered a new test to determine whether ovarian cancer cells have the potential to metastasize. Study co-authors include, from left, Julia Win, Stephen Wahlig, Deepak Nagrath, Hongyun Zhao, Lifeng Yang and Abhinav Achreja.

Nagrath, director of Rice University’s Laboratory for Systems Biology of Human Diseases, said the new metabolic analysis indicates that ovarian cancer may be susceptible to multidrug cocktails, particularly if the amounts of the drugs can be tailored to match the metabolic profile of a patient’s tumor.

The research also revealed a specific biochemical test that pathologists could use to guide such treatments. The test involves measuring the ratio between the amount of glutamine that a cell takes up from outside and the amount of glutamine it makes internally.

“This ratio proved to be a robust marker for prognosis,” said University of Texas M.D. Anderson Cancer Center co-author Anil Sood, M.D., Professor of Gynecologic Oncology and Reproductive Medicine and co-director of the Center for RNA Interference and Non-Coding RNA. “A high ratio was directly correlated to tumor aggression and metastatic capability. Patients with this profile had the worst prognosis for survival.”

The three-year study included cell culture studies at Rice as well as a detailed analysis of gene-expression profiles of more than 500 patients from the Cancer Genome Atlas and protein-expression profiles from about 200 M.D. Anderson patients.

“The enzyme glutaminase is key to glutamine uptake from outside the cell, and glutaminase is the primary target that everybody is thinking about right now in developing drugs,” Nagrath said. “We found that targeting only glutaminase will miss the less aggressive ovarian cancer cells because they are at a metabolic stage where they are not yet glutamine-dependent.”

Lifeng

Lifeng Yang, Study Lead Author & Graduate Student, Systems Biology of Human Diseases, Rice University

Rice University graduate student Lifeng Yang, lead author of the study, designed a preclinical experiment to test the feasibility of a multidrug approach, involving the use of a JAK inhibitor and a glutaminase inhibitor. This “drug cocktail” approach inhibited the early stage production of internal glutamine, while also limiting the uptake of external glutamine.

“That depleted all sources of glutamine for the cells, and we found that cell proliferation decreased significantly,” Yang said.

Nagrath said the study also revealed another key finding — a direct relationship between glutamine and an ovarian cancer biomarker called “STAT3” (Signal Transducer And Activator Of Transcription 3).

“A systems-level understanding of the interactions between metabolism and signaling is vital to developing novel strategies to tackle cancer,” said M.D. Anderson co-author Prahlad Ram Ph.D., Associate Professor of Systems Biology and co-director of the M.D. Anderson Cancer Center’s Systems Biology Program. “STAT3 is the primary marker that is used today to ascertain malignancy, tumor aggression and metastasis in ovarian cancer.”

Nagrath said, “The higher STAT3 is, the more aggressive the cancer. For the first time, we were able to show how glutamine regulates STAT3 expression through a well-known metabolic pathway called the TCA cycle, which is also known as the ‘Krebs cycle.’”

Nagrath said the research is ongoing. Ultimately, Dr. Nagrath hopes the investigations will lead to new treatment regimens for cancer as well as a better understanding of the role of cancer-cell metabolism in metastasis and drug resistance.

Co-authors include Hongyun Zhao, Stephen Wahlig, Abhinav Achreja and Julia Win (all affiliated with Rice University); Tyler Moss, Lingegowda Mangala, Guillermo Armaiz-Pena, Dahai Jiang, Rajesha Roopaimoole, Cristian Rodriguez-Aguayo, Imelda Mercado-Uribe, Gabriel Lopez-Berestein and Jinsong Liu (all affiliated with M.D. Anderson Cancer Center); Juan Marini of Baylor College of Medicine; and Takashi Tsukamoto of Johns Hopkins University.

The research was supported by seed funding from (i) the Collaborative Advances in Biomedical Computing Program at Rice Univesity’s Ken Kennedy Institute for Information Technology, (ii) Rice University’s John and Ann Doerr Fund for Computational Biomedicine, (iii) the Odyssey Fellowship Program at the MD Anderson Cancer Center, (iv) the estate of C.G. Johnson Jr., (v) the National Institutes of Health, (vi) the Cancer Prevention and Research Institute of Texas, (v) the Ovarian Cancer Research Fund, (vi) the Blanton-Davis Ovarian Cancer Research Program, (vii) the Gilder Foundation, and (viii) the MD Anderson Cancer Center.

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Ovarian Cancer Cells Are More Aggressive On Soft Tissues

When ovarian cancer spreads from the ovaries it almost always does so to a layer of fatty tissue that lines the gut. A new study has found that ovarian cancer cells are more aggressive on these soft tissues due to the mechanical properties of this environment. The finding is contrary to what is seen with other malignant cancer cells that seem to prefer stiffer tissues.

Model Release-YES

Professor Michelle Dawson and graduate student Daniel McGrail used traction force microscopy to measure the forces exerted by cancer cells on soft and stiff surfaces. (Photo Credit: Rob Felt, Georgia Institute of Technology)

“What we found is that there are some cancer cells that respond to softness as opposed to stiffness,” said Michelle Dawson, an assistant professor in the School of Chemical and Biomolecular Engineering at the Georgia Institute of Technology. “Ovarian cancer cells that are highly metastatic respond to soft environments by becoming more aggressive.”

Ovarian cancer cells spread, or metastasize, by a different method than other cancer cells. Breast cancer cells, for example, break off from a solid tumor and flow through the blood until they arrest in small blood vessels. The cancer cells then penetrate the vessel surface to form a tumor. Because ovarian tumors are in the abdomen, these cancer cells are shed into the surrounding fluid and not distributed through the blood. They must be able to adhere directly to the fatty tissue that lines the gut, called the omentum, to begin forming a tumor. The new study discovered details about how ovarian cancer cells seem to prefer the mechanical properties of this soft tissue.

The study was published in a recent advance online edition of the Journal of Cell Science and was sponsored by the National Science Foundation and the Georgia Tech and Emory Center for Regenerative Medicine.

The research team, led by Daniel McGrail, a graduate student in the Dawson lab, found that ovarian cancer cells in vitro were more adherent to a layer of soft fat cells than a layer of stiffer bone cells, and that this behavior was also repeated using gels of similar rigidities.

“All the behaviors that we associate with breast cancer cells on these more rigid environments are flipped for ovarian cancer cells,” Dawson said.

After adhering to these soft surfaces, metastatic ovarian cancer cells became more aggressive. Their proliferation increased and they were less responsive to chemotherapeutics. The ovarian cancer cells were also more motile on soft surfaces, moving nearly twice as fast as on rigid surfaces.

The team also found that less aggressive cells that do not metastasize do not exhibit any of these changes.

The researchers used techniques that haven’t been traditionally used in the study of ovarian cancer. They measured the force exerted by the cells by tracking the displacement of beads in the environment around the cells. The researchers found that the metastatic cells increased their traction forces – used to generate motion – by three-fold on soft surfaces, but no such change was present in the less aggressive cells.

“We think the behavior that metastatic ovarian cancer cells exert on these soft surfaces is representative of the mechanical tropism that they have for these softer tissues in the gut,” Dawson said.

In future work, the researchers will investigate whether ovarian cancer cells have some natural inclination towards this uniquely more aggressive behavior in softer environments.

“We’re trying to find out whether there is some internal programming that leads to this aggressive behavior,” Dawson said.

This research is supported by the National Science Foundation under award number 1032527, and the Georgia Tech and Emory Center for Regenerative Medicine under award number 1411304. Any conclusions or opinions are those of the authors and do not necessarily represent the official views of the sponsoring agencies.

Source:  McGrail DJ, et al., The malignancy of metastatic ovarian cancer cells is increased on soft matrices through a mechanosensitive Rho-ROCK pathway. (Journal of Cell Science, 2014). http://dx.doi.org/10.1242/?jcs.144378.

TGen-led Study Discovers Genetic Cause of a Rare Type of Ovarian Cancer

TGen-led study discovers genetic cause of a rare type of ovarian cancer. Scientific breakthrough could lead to new cancer treatments; study inspired by the memory of Taryn Ritchey, a 22-year-old patient who lost her battle to the disease.

The cause of a rare type of ovarian cancer that most often strikes girls and young women has been uncovered by an international research team led by the Translational Genomics Research Institute (TGen), according to a study published online recently by the renowned scientific journal, Nature Genetics. [1] In a scientific rarity, two additional studies with similar results were also published online on the same day in Nature Genetics, producing immediate validation and reflecting a scientific consensus that usually takes months or even years to accomplish. [2-3]

By applying its groundbreaking work in genomics, TGen led a study that included: Scottsdale Healthcare, Mayo Clinic, Johns Hopkins University, St. Joseph’s Hospital and Medical Center; Evergreen Hematology and Oncology, Children’s Hospital of Alabama, the Autonomous University of Barcelona, British Columbia Cancer Agency, University of British Columbia, and the University Health Network-Toronto.

The findings revealed a “genetic superhighway” mutation in a gene found in the overwhelming majority of patients with small cell carcinoma of the ovary, hypercalcemic type, also known as “SCCOHT.” This rare type of ovarian cancer is usually not diagnosed until it is in its advanced stages. It does not respond to standard chemotherapy, and 65 percent of patients with the disease die within 2 years. SCCOHT can affect girls as young as 14 months, and women as old as 58 years – with a mean age of only 24 years old. In this study, the youngest patient was 9 years old.

The three separate groups of international researchers reported strikingly similar scientific findings related to SCCOHT, as provided below.

  • Identification of germline (i.e., inherited) and somatic (lifetime acquired) inactivating mutations in the SWI/SNF chromatin-remodeling gene SMARCA4 in 75% (9/12) of SCCOHT cases, in addition to SMARCA4 protein loss in 82% (14/17) of the SCCOHT tumors. Notably, only 0.4% (2/485) of the other primary ovarian tumors tested possessed similar genomic characteristics. [Ref. 1]
  • Identification of recurrent inactivating mutations in the SMARCA4 gene in 12 of 12 SCCOHT tumor samples. [Ref. 2]
  • Indentification of germline inactivating mutations in familial cases of SCCOHT. Through additional analysis of non-familial tumors, the researchers determined that nearly 100% of tumors carry SMARCA4 mutations, and 38 of 40 lack protein expression.[Ref. 3]

Collectively, these findings implicate inactivating mutations in the SMARCA4 gene as a major cause of SCCOHT, and may lead researchers to improvements in genetic counseling, as well as the development of new targeted therapy treatment approaches.

Dr. Jeffrey Trent, President and Research Director of TGen, is the study's senior author.

Dr. Jeffrey Trent, President and Research Director of TGen, is the study’s senior author.

“This is a thoroughly remarkable study. Many genetic anomalies can be like a one-lane road to cancer; difficult to negotiate. But these findings indicate a genetic superhighway that leads right to this highly aggressive disease,” said Dr. Jeffrey Trent, President and Research Director of TGen, and the study’s senior author. “The correlation between mutations in SMARCA4 and the development of SCCOHT is simply unmistakable.”

Dr. Trent added that while the breakthrough is for a relatively rare cancer, discovering the origins of this type of ovarian cancer could have implications for more common diseases.

Much of the work in this study was inspired by the memory of Taryn Ritchey, a 22-year-old TGen patient who in 2007 lost her battle with ovarian cancer, the 5th leading cause of cancer death among American women.

“Taryn would be incredibly excited about this amazing new study, and she would be glad and thankful that other young women like her might now be helped because of TGen’s ongoing research,” said Taryn’s mother Judy Jost of Cave Creek, Arizona. “My daughter never gave up, and neither has TGen.”

The SMARCA4 gene – previously associated with lung, brain and pancreatic cancer – was the only recurrently mutated gene in the study’s samples. The implications of this discovery, therefore, may be widespread.

“The findings in this study represent a landmark in the field. The work identifies SMARCA4 mutations as the culprit, and most future research on this disease will be based on this remarkable discovery,” said Dr. Bert Vogelstein, Director of the Ludwig Center at Johns Hopkins University, Investigator at the Howard Hughes Medical Institute, and pioneer in the field of cancer genomics. He did not participate in the study but is familiar with its findings.

“The past decade of research has taught us that cancer is a vastly complex disease. Profound patient-to-patient variability has made treatment and diagnosis for many tumor types at times very difficult. In this case, however, we have found a single genetic event driving SCCOHT in nearly every patient,” said Dr. William Hendricks, a TGen Staff Scientist and another author of the study.

“We have shown that loss of SMARCA4 protein expression is extremely specific to SCCOHT and can facilitate the diagnosis of SCCOHT,” said Dr. Anthony N. Karnezis, a fellow at the British Columbia Cancer Agency located in Vancouver, Canada, and one of the study’s authors.

Pilar Ramos, a TGen Research Associate, is the study's lead author.

Pilar Ramos, a TGen Research Associate, is the study’s lead author. “By definitively identifying the relationship between SMARCA4 and SCCOHT, we have high confidence that we have set the stage for clinical trials that could provide patients with immediate benefit.”

“By definitively identifying the relationship between SMARCA4 and SCCOHT, we have high confidence that we have set the stage for clinical trials that could provide patients with immediate benefit.”

“We set out to uncover any small sliver of hope for women afflicted with this rare cancer. What we found instead are the nearly universal underpinnings of SCCOHT,” said Pilar Ramos, a TGen Research Associate, and the study’s lead author. “By definitively identifying the relationship between SMARCA4 and SCCOHT, we have high confidence that we have set the stage for clinical trials that could provide patients with immediate benefit.”

The TGen-led study was supported by grants from: the Marsha Rivkin Center for Ovarian Cancer Research, the Anne Rita Monahan Foundation, the Ovarian Cancer Alliance of Arizona, the Small Cell Ovarian Cancer Foundation, and philanthropic support to the TGen Foundation. Further support was provided by the Terry Fox Research Initiative’s New Frontiers Program in Cancer, and the Canadian Institutes of Health Research.

For more information about TGen’s research into small cell carcinoma of the ovary (SCCO), or to participate in a future study, visit: www.tgen.org/scco.

About TGen

Translational Genomics Research Institute (TGen) is a Phoenix, Arizona-based non-profit organization dedicated to conducting cutting-edge genomic research to accelerate breakthroughs in healthcare. TGen is focused on helping patients with cancer, neurological disorders and diabetes, through cutting edge translational research (the process of rapidly moving research towards patient benefit). TGen physicians and scientists work to unravel the genetic components of both common and rare complex diseases in adults and children. Working with collaborators in the scientific and medical communities literally worldwide, TGen makes a substantial contribution to help our patients through efficiency and effectiveness of the translational process. For more information, visit: www.tgen.org.

References:

1./ Ramos P, et al.  Small cell carcinoma of the ovary, hypercalcemic type, displays frequent inactivating germline and somatic mutations in SMARCA4. Nature Genetics (published online 23 March 2014) doi:10.1038/ng.2928.

2./ Jelinic P, et al. Recurrent SMARCA4 mutations in small cell carcinoma of the ovaryNature Genetics (published online 23 March 2014) doi:10.1038/ng.2922.

3./ Witkowski L, et al.  Germline and somatic SMARCA4 mutations characterize small cell carcinoma of the ovary, hypercalcemic type.  Nature Genetics (published online 23 March 2014) doi:10.1038/ng.2931

Additional Information:

 

Novel “Jantibody Fusion Protein” Cancer Vaccine Holds Promise Against Ovarian Cancer

A novel approach to cancer immunotherapy – strategies designed to induce the immune system to attack cancer cells – may provide a new and cost-effective weapon against some of the most deadly tumors, including ovarian cancer and mesothelioma.

A novel approach to cancer immunotherapy – strategies designed to induce the immune system to attack cancer cells – may provide a new and cost-effective weapon against some of the most deadly tumors, including ovarian cancer and mesothelioma. Investigators from the Massachusetts General Hospital (MGH) Vaccine and Immunotherapy Center (VIC) report in the Journal of Hematology & Oncology that a protein engineered to combine a molecule targeting a tumor-cell-surface antigen with another protein that stimulates several immune functions prolonged survival in animal models of both tumors.

“Some approaches to creating cancer vaccines begin by extracting a patient’s own immune cells, priming them with tumor antigens and returning them to the patient, a process that is complex and expensive,” says Mark Poznansky, M.D., Ph.D., director of the MGH Vaccine and Immunotherapy Center and senior author of the report. “Our study describes a very practical, potentially broadly applicable and low-cost approach that could be used by oncologists everywhere, not just in facilities able to harvest and handle patient’s cells.”

The MGH team’s vaccine stimulates the patient’s own dendritic cells, a type of immune cell that monitors an organism’s internal environment for the presence of viruses or bacteria, ingests and digests pathogens encountered, and displays antigens from those pathogens on their surface to direct the activity of other immune cells. As noted above, existing cancer vaccines that use dendritic cells require extracting cells from a patient’s blood, treating them with an engineered protein or nucleic acid that combines tumor antigens with immune-stimulating molecules, and returning the activated dendritic cells to the patient.

Fusion protein activates immune cells against tumors The Jantibody fusion protein, combining an antibody fragment targeting an antigen found on tumor cells with an immune-response-inducing protein (MTBhsp70), activates dendritic cells against several tumor antigens and induces a number of T-cell-based immune responses. (Jianping Yuan, PhD, MGH Vaccine and Immunotherapy Center)

Fusion protein activates immune cells against tumors. The Jantibody fusion protein, combining an antibody fragment targeting an antigen found on tumor cells with an immune-response-inducing protein (MTBhsp70), activates dendritic cells against several tumor antigens and induces a number of T-cell-based immune responses. (Jianping Yuan, PhD, MGH Vaccine and Immunotherapy Center)

The approach developed by the MGH team starts with the engineered protein, which in this case fuses an antibody fragment targeting a protein called mesothelin – expressed on the surface of such tumors as mesothelioma, ovarian cancer and pancreatic cancer – to a protein from the tuberculosis bacteria that stimulates the activity of dendritic and other immune cells. In this system, the dendritic cells are activated and targeted against tumor cells while remaining inside the patient’s body.

In the experiments described in the paper, the MGH team confirmed that their mesothelin-targeting fusion protein binds to mesothelin on either ovarian cancer or mesothelioma cells, activates dendritic cells, and enhances the cells’ processing and presentation of several different tumor antigens, inducing a number of T-cell-based immune responses. In mouse models of both tumors, treatment with the fusion protein significantly slowed tumor growth and extended survival, probably through the activity of cytotoxic CD8 T cells.

“Many patients with advanced cancers don’t have enough functioning immune cells to be harvested to make a vaccine, but our protein can be made in unlimited amounts to work with the immune cells patients have remaining,” explains study co-author Jeffrey Gelfand, MD, senior scientist at the Vaccine and Immunotherapy Center. “We have created a potentially much less expensive approach to making a therapeutic cancer vaccine that, while targeting a single tumor antigen, generates an immune response against multiple antigens. Now if we can combine this with newly-described ways to remove the immune system’s “brakes” – regulatory functions that normally suppress persistent T-cell activity – the combination could dramatically enhance cancer immunotherapy.”

Poznansky adds that the tumors that might be treated with the mesothelin-targeting vaccine – ovarian cancer, pancreatic cancer and mesothelioma – all have poor survival rates. “Immunotherapy is generally nontoxic, so this vaccine has the potential of safely extending survival and reducing the effects of these tumors, possibly even cutting the risk of recurrence. We believe that this approach could ultimately be used to target any type of cancer and are currently investigating an improved targeting approach using personalized antigens.” The MGH team just received a two-year grant from the Department of Defense Congressionally Directed Medical Research Program to continue their research.

Poznansky is an associate professor of Medicine, and Gelfand is a clinical professor of Medicine at Harvard Medical School. Jianping Yuan, Ph.D., of the MGH Vaccine and Immunotherapy Center (VIC) is the lead author of the Journal of Hematology and Oncology report. Additional co-authors include Pierre LeBlanc, Ph.D., Satoshi Kashiwagi M.D., Ph.D., Timothy Brauns, and Svetlana Korochkina, Ph.D., MGH VIC; and Nathalie Scholler, M.D., Ph.D., University of Pennsylvania School of Medicine.

The authors dedicate their report to Janet Gelfand, the wife of Jeffrey Gelfand, who died of ovarian cancer in 2006 and inspired their investigation. In her honor they named their tumor-targeting fusion protein “Jantibody.” Support for the study includes grants from the Edmund Lynch Jr. Cancer Fund, Arthur Luxenberg Esq., Perry Weitz Esq., the VIC Mesothelioma Research and Resource Program, and the Friends of VIC Fund.

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $775 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, reproductive biology, systems biology, transplantation biology and photomedicine.

Sources:

  • Novel cancer vaccine holds promise against ovarian cancer, mesothelioma — Antigen-targeting fusion protein should be less expensive, more accessible than current approaches, Massachusetts General Hospital, Press Release, March 5, 2014.
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Glimmer of Hope: Johns Hopkins Uses Pap Smear Test Cervical Fluid to Detect Ovarian & Endometrial Cancers

Using cervical fluid obtained during routine Pap tests, scientists at the Johns Hopkins Kimmel Cancer Center have developed a test to detect ovarian and endometrial cancers. The investigators note that larger-scale studies are needed prior to clinical use on women. 

Using cervical fluid obtained during routine Pap tests, scientists at the Johns Hopkins Kimmel Cancer Center have developed a test to detect ovarian and endometrial cancers. Results of the experiments are published in the January 9 issue of the journal Science Translational Medicine.

In a pilot study, the “PapGene” test, which relies on genomic sequencing of cancer-specific mutations, accurately detected all 24 (100 percent) endometrial cancers and nine of 22 (41 percent) ovarian cancers. The endometrial cancers may have been easier to find because cells from those tumors do not have as far to travel as ovarian cancer cells. The Hopkins researchers will study whether inserting the Pap brush deeper, testing during different times of the menstrual cycle, or other factors might improve detection of ovarian cancer.

The investigators note that larger-scale studies are needed prior to clinical use on women, but they believe the test has the potential to pioneer genomic-based, cancer screening tests. [Emphasis added]

The Papanicolaou (Pap) test, during which cells collected from the cervix are examined for microscopic signs of cancer, is widely and successfully used to screen for cervical cancers. Today, many women’s Paps undergo an additional DNA-based test to see if they harbor the human papillomavirus (HPV), which can spur cervical cancer. However, no routine screening method is available for ovarian or endometrial cancers.

 Luis Diaz, M.D.

Luis Alberto Diaz, M.D.

Since the Pap test occasionally contains cells shed from the ovaries or endometrium, cancer cells arising from these organs could be present in the fluid as well, says Luis Diaz, M.D., associate professor of oncology at Johns Hopkins, as well as director of translational medicine at the Ludwig Center for Cancer Genetics and Therapeutics and director of the Swim Across America Laboratory, also at Johns Hopkins. The laboratory is sponsored by a volunteer organization that raises funds for cancer research through swim events. “Our genomic sequencing approach may offer the potential to detect these cancer cells in a scalable and cost-effective way,” adds Diaz.

Hear Dr. Diaz discuss the PapGene test research in this hyperlinked podcast, courtesy of the American Association for the Advancement of Science.

Cervical fluid of patients with gynecologic cancer carries normal cellular DNA mixed together with DNA from cancer cells, according to the investigators. The investigators’ task was to use genomic sequencing to distinguish cancerous from normal DNA.

The scientists had to determine the most common genetic changes in ovarian and endometrial cancers in order to prioritize which genomic regions to include in their test. They searched publicly available genome-wide studies of ovarian cancer, including those done by other Johns Hopkins investigators, to find mutations specific to ovarian cancer. Such genome-wide studies were not available for the most common type of endometrial cancer, so they conducted genome-wide sequencing studies on 22 of these endometrial cancers.

From the ovarian and endometrial cancer genome data, the Johns Hopkins-led team identified 12 of the most frequently mutated genes in both cancers and developed the PapGene test with this insight in mind.

The investigators then applied PapGene on Pap test samples from ovarian and endometrial cancer patients at The Johns Hopkins Hospital, Memorial Sloan-Kettering Cancer Center, the University of São Paulo in Brazil and ILSbio, a tissue bank. The new test detected both early- and late-stage disease in the endometrial and ovarian cancers tested. No healthy women in the control group were misclassified as having cancer.

Animation of PapGene:

Looking ahead, the investigators’ next steps include applying PapGene on more samples and working to increase the test’s sensitivity in detecting ovarian cancer. “Performing the test at different times during the menstrual cycle, inserting the cervical brush deeper into the cervical canal, and assessing more regions of the genome may boost the sensitivity,” says Chetan Bettegowda, M.D., Ph.D., assistant professor of neurosurgery at Johns Hopkins and a member of the Ludwig Center as well.

Together, ovarian and endometrial cancers are diagnosed in nearly 70,000 women in the United States each year, and about one-third of them will die from it. “Genomic-based tests could help detect ovarian and endometrial cancers early enough to cure more of them,” says graduate student Yuxuan Wang, who notes that the cost of the test could be similar to current cervical fluid HPV testing, which is less than $100.

PapGene is a high-sensitivity approach for the detection of cancer-specific DNA mutations, according to the investigators; however, false mutations can be erroneously created during the many steps — including amplification, sequencing and analysis — required to prepare the DNA collected from a Pap test specimen for sequencing. This required the investigators to build a safeguard into PapGene’s sequencing method, designed to weed out artifacts that could lead to misleading test results.

“If unaccounted for, artifacts could lead to a false positive test result and incorrectly indicate that a healthy person has cancer,” says graduate student Isaac Kinde.

Kinde added a unique genetic barcode — a random set of 14 DNA base pairs — to each DNA fragment at an initial stage of the sample preparation process. Although each DNA fragment is copied many times before eventually being sequenced, all of the newly copied DNA can be traced back to one original DNA molecule through their genetic barcodes. If the copies originating from the same DNA molecule do not all contain the same mutation, then an artifact is suspected and the mutation is disregarded. However, bonafide mutations, which exist in the sample before the initial barcoding step, will be present in all of the copies originating from the original DNA molecule.

The Johns Hopkins test results demonstrate that DNA from most endometrial and a fraction of ovarian cancers can be detected in a standard liquid-based Pap smear specimen obtained during routine pelvic examination. Although improvements need to be made before applying this test in a routine clinical manner, it represents a promising first step toward a broadly applicable screening methodology for the early detection of gynecologic malignancies.

“This is very encouraging, and it shows great potential,” said American Cancer Society genetics expert Michael Melner.

“We are a long way from being able to see any impact on our patients,” cautioned Dr. Shannon N. Westin of the University of Texas MD Anderson Cancer Center. Dr. Westin reviewed the research in an accompanying editorial, and said the ovarian cancer detection would need improvement if the test is to work. But Dr. Westin noted that ovarian cancer has poor survival rates because it’s rarely caught early. “If this screening test could identify ovarian cancer at an early stage, there would be a profound impact on patient outcomes and mortality,” Westin said.

More than 22,000 U.S. women are diagnosed with ovarian cancer each year, and more than 15,000 die. Symptoms such as bloating and pelvic or abdominal pain are seldom obvious until the cancer is more advanced, and numerous attempts at screening tests have failed.

Endometrial cancer affects about 47,000 U.S. women a year, and kills about 8,000. There is no screening test for it either, but most women are diagnosed early because of postmenopausal bleeding.

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Funding for the research was provided by Swim Across America, the Commonwealth Fund, the Hilton-Ludwig Cancer Prevention Initiative, the Virginia & D.K. Ludwig Fund for Cancer Research, the Experimental Therapeutics Center of the Memorial Sloan-Kettering Cancer Center, the Chia Family Foundation, The Honorable Tina Brozman Foundation, the United Negro College Fund/Merck Graduate Science Research Dissertation Fellowship, the Burroughs Wellcome Career Award for Medical Scientists, the National Colorectal Cancer Research Alliance and the National Institutes of Health’s National Cancer Institute (N01-CN-43309, CA129825, CA43460).

In addition to Kinde, Bettegowda, Wang and Diaz, investigators participating in the research include Jian Wu, Nishant Agrawal, Ie-Ming Shih, Robert Kurman, Robert Giuntoli, Richard Roden and James R. Eshleman from Johns Hopkins; Nickolas Papadopoulos, Kenneth Kinzler and Bert Vogelstein from the Ludwig Center at Johns Hopkins; Fanny Dao and Douglas A. Levine from Memorial Sloan-Kettering Cancer Center; and Jesus Paula Carvalho and Suely Kazue Nagahashi Marie from the University of São Paulo.

Papadopoulos, Kinzler, Vogelstein and Diaz are co-founders of Inostics and Personal Genome Diagnostics. They own stocks in the companies and are members of their Scientific Advisory Boards. Inostics and Personal Genome Diagnostics have licensed several patent applications from Johns Hopkins. These relationships are subject to certain restrictions under The Johns Hopkins University policy, and the terms of these arrangements are managed by the university in accordance with its conflict-of-interest policies.

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Citations:

I. Kinde, C. Bettegowda, Y. Wang, J. et. al. Evaluation of DNA from the Papanicolaou Test to Detect Ovarian and Endometrial Cancers. Sci. Transl. Med. 5, 167ra4 (2013).

S. N. Westin, G. B. Mills, A. P. Myers, Repurposing the Pap Smear: One Step Closer to Gynecologic Cancer Screening. Sci. Transl. Med. 5, 167ps1 (2013).

Additional Sources:

Johns Hopkins Scients Use Pap Test Fluid to Detect Ovarian, Endometrial Cancers, John Hopkins Medicine, Press Release, January 9, 2013.

Retooling Pap Test To Spot More Kinds Of Cancer, The Associated Press via National Public Radio, January 9, 2013.