Monthly Archives: April 2009

Synergistic Anti-Tumor Effect of CRM197 & Paclitaxel in Ovarian Cancer

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CRM197, an inhibitor of heparin-binding EGF-like growth factor (HB-EGF), produces a synergistic ovarian cancer anti-tumor effect when combined with paclitaxel, according to study results published in the March 15th issue of the International Journal of Cancer.  The investigators, Dr. Shingo Miyamoto and his colleagues, are affiliated with the Fukuoka University in Japan.  “The treatment of CRM197 in conjunction with paclitaxel results in a marked synergistic anti-tumor effect in ovarian cancer cells in vivo, suggesting a novel combination therapy for ovarian cancer patients including those showing chemo-resistance.”  Accordingly, the investigators generally concluded that inhibitory agents against HB-EGF, such as CRM197, represent possible chemotherapeutic and chemosensitizing agents for ovarian cancer. …

CRM197, an inhibitor of heparin-binding EGF-like growth factor (HB-EGF), produces a synergistic ovarian cancer anti-tumor effect when combined with paclitaxel, according to study results published in the March 15th issue of the International Journal of Cancer.  The investigators, Dr. Shingo Miyamoto and his colleagues, are affilitated with the Fukuoka University in Japan.

According to the researchers, HB-EGF plays a pivotal role in tumor growth and clinical outcomes in patients with ovarian cancer, thereby making it a target for future ovarian cancer therapy. CRM197 is a non-toxic variant of the diphtheria toxin.  The investigators conducted studies in which CRM197 and paclitaxel (Taxol®) were tested against ovarian cancer cell cultures (in vitro) and overexpressing HB-EGF ovarian cancer cells which were injected into mice.

The investigators discovered that paclitaxel induced transient ERK activation and sustained activation of JNK and p38 MAPK, effects that were reduced by overexpression of HB-EGF. CRM197 effectively suppressed the paclitaxel-induced anti-apoptotic signals mediated by ERK and Akt and enhanced the pro-apoptotic signals JNK and p38 MAPK.

The investigators also noted that in the mice with ovarian cancer xenografts, paclitaxel and CRM197 completely blocked tumor formation at doses of 10 mg/kg paclitaxel and 5 mg/kg CRM197.

Based on the foregoing, Miyamoto et. al. concluded that “the enhancement of HB-EGF expression abrogates the antitumor effect of paclitaxel by altering the balance of anti-apoptotic and pro-apoptotic signals induced by paclitaxel. The treatment of CRM197 in conjunction with paclitaxel results in a marked synergistic anti-tumor effect in ovarian cancer cells in vivo, suggesting a novel combination therapy for ovarian cancer patients including those showing chemo-resistance.”  Accordingly, the investigators generally concluded that inhibitory agents against HB-EGF, such as CRM197, represent possible chemotherapeutic and chemosensitizing agents for ovarian cancer.

“Phase 1 [clinical] study of the use of CRM197 has already started at Fukuoka University for patients with advanced ovarian cancer under the approval of the ethical committee,” the investigators added.

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Johns Hopkins Discovers a Protein That Contributes to Ovarian Cancer Recurrence By Causing Chemoresistance

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” … Ground-breaking work on an ovarian cancer-related protein in the lab of Ie-Ming Shih at the [Johns Hopkins] School of Medicine is leading to new insights into cancer biology. … They have revealed a novel protein that creates cancer cells that are resistant to traditional cancer chemotherapies and partially revealed its mechanism of action. With all of this information, the team hopes to create drugs that can target these proteins or find out which chemotherapies currently on the market do not function in this pathway to create resistant cancer cells.”

“Ovarian cancer is a growing concern with more than 15,000 deaths occurring in 2007, making it the leading cause of death in gynecological diseases.

Ie-Ming Shih, M.D., Ph.D., Professor, Pathobiology Graduate Program, Department of Pathology, Johns Hopkins University, Baltimore, Maryland

Ie-Ming Shih, M.D., Ph.D., Professor, Pathobiology Graduate Program, Department of Pathology, Johns Hopkins University, Baltimore, Maryland

Ground-breaking work on an ovarian cancer-related protein in the lab of Ie-Ming Shih at the School of Medicine is leading to new insights into cancer biology.

The protein is nucleus accumbens-1, NAC-1, which is a transcription factor that regulates the expression of genes. Previous work has shown NAC-1 to be overexpressed in many types of cancer, specifically ovarian cancer that is resistant to chemotherapy.

A deeper understanding of its mechanism of action would allow scientists and physicians to make inroads into possibly curing the diseases.

In many cases, the first round of chemotherapy or treatment shrinks the tumor but does not cure the patient of the diseases. The cancer then grows back and can be resistant to a second round of the initial therapy.

Ovarian cancer cells that are resistant to chemotherapy have higher than normal levels of NAC-1. Shih and her [sic] team showed that the ovarian cancer cells, when exposed to a particular chemotherapy drug, were resistant compared to cancer cells with normal expression of NAC-1.

Upon further investigation into the biological pathways of interacting proteins in the nucleus, the team found that another protein [Gadd45-gamma-interacting protein 1 (Gadd45gip1)] is the target of NAC-1’s mechanism of action.

NAC-1 works by interacting with this other protein and stopping it from working and decreasing its expression inside the cell. So when NAC-1 expression is increased, the cancer cells are resistant to treatment, and the downstream target protein of NAC-1 is downregulated.

Performing further experiments, the researchers found that by making normal cancer cells overexpress the NAC-1 protein the cells were resistant to the chemotherapy drug, where previously they were not before the induced expression.

Also, the downstream target protein had reduced expression.

Conversely, if the researchers knocked down the expression of NAC-1 or increased the expression of its downstream target protein, then the cells were sensitive to cancer treatment, more so than normal cancer cells.

The scientists also wanted to uncover how the proteins interact structurally. Their work has revealed that NAC-1 is a homodimer protein, meaning it self-dimerizes – two copies of the protein come together to form the working product.

If the researchers formed a NAC-1 protein with only one of the units working properly, then the entire protein would not function and the ovarian cancer cells were sensitive to chemotherapy treatment.

Also, in this non-functional protein, it would induce the expression of its downstream target protein and increase that protein’s expression, thereby sensitizing the cells to chemotherapy.

Taken together, the researchers have paved new roads into the ever-complicating fight against cancer.

They have revealed a novel protein that creates cancer cells that are resistant to traditional cancer chemotherapies and partially revealed its mechanism of action.

With all of this information, the team hopes to create drugs that can target these proteins or find out which chemotherapies currently on the market do not function in this pathway to create resistant cancer cells.”

Source: Resistance to cancer chemotherapy is studied, by Neil Neumann, Science Section, The Johns Hopkins Newsletter, April 2, 2009 (discussing Jinawath N, Vasoontara C, Yap KL et al.  NAC-1, a potential stem cell pluripotency factor, contributes to paclitaxel resistance in ovarian cancer through inactivating Gadd45 pathway.  Oncogene. 2009 Mar 23. [Epub ahead of print]).

PhRMA Report Shows Record Number of Development Drugs to Treat Cancer; 63 Ovarian Cancer & 203 Solid Tumor Drugs Listed

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“Responding to President Obama’s call for ‘a cure for cancer in our time,’ the Pharmaceutical Research and Manufacturers of America (PhRMA) delivered a new report today on medicines in the research pipeline for cancer. The report shows that America’s pharmaceutical research and biotechnology companies are testing a record 861 new cancer medicines and vaccines. The medicines listed in the report are being tested in human clinical trials or are awaiting approval by the U.S. Food and Drug Administration. [Libby’s H*O*P*E*™ : 63 Ovarian Cancer Drugs & 203 Solid Tumor Drugs are listed in the 2009 PhRMA report (pp. 51 – 55)]. …”

“New Report Shows Record Number of Medicines In Development to Treat Leading Causes of Cancer

phrmalogoDenver, CO (April 1, 2009) – Responding to President Obama’s call for ‘a cure for cancer in our time,’ the Pharmaceutical Research and Manufacturers of America (PhRMA) delivered a new report today on medicines in the research pipeline for cancer. The report shows that America’s pharmaceutical research and biotechnology companies are testing a record 861 new cancer medicines and vaccines. The medicines listed in the report are being tested in human clinical trials or are awaiting approval by the U.S. Food and Drug Administration. [Libby’s H*O*P*E*™ Note: 63 Ovarian Cancer Drugs & 203 Solid Tumor Drugs are listed in the 2009 PhRMA report (pp. 51-55)].

Nationwide, cancer is the second leading cause of death, affecting more than 10 million Americans, according to the National Cancer Institute. This year, more than half a million Americans are expected to die of cancer-more than 1,500 a day. In Colorado, the lifetime risk of cancer is 1 in 2 for males and 2 in 5 for females. The most commonly diagnosed cancer in the state is breast cancer, followed by prostate and lung cancer.

‘We released this report in Denver because of Colorado’s growing role in developing cancer medicines,’ said PhRMA Senior Vice President Ken Johnson, who unveiled the report at the State Capitol Building.

‘Oncology is one of Colorado’s core research competencies, so the President’s call to cure cancer resonates powerfully in our state,’ said Colorado Lt. Governor Barbara O’Brien. ‘We are proud that the cancer medicines now in the research pipeline in Colorado are contributing substantially to the incredible progress made in the last five years by biopharmaceutical companies in developing new and more effective cancer treatments. The nation must continue its strong commitment to the cutting-edge pharmaceutical research that will enable cancer patients to live longer, healthier, and more productive lives.’

billytauzin

Billy Tauzin, President and Chief Executive Officer, The Pharmaceutical Research and Manufacturers of America (PhRMA). PhRMA's mission is to conduct effective advocacy for public policies that encourage discovery of important new medicines for patients by pharmaceutical & biotechnology research companies.

‘I am one of those patients who was diagnosed with cancer and was given a new treatment that brought me from the brink of death back to life,’ says PhRMA President and CEO Billy Tauzin. ‘The men and women working for America’s pharmaceutical research companies are committed to developing new cancer medicines that, one day, could eradicate cancer all together.’

Cancer medicines being developed include 122 for lung cancer, the leading cause of cancer death in the United States; 107 for breast cancer, which is expected to strike more than 180,000 American women this year; 70 for colorectal cancer, which is the third most common cancer in both men and women; and 103 for prostate cancer, which this year is expected to kill 28,000 American men. Additional medicines target brain cancer, kidney cancer, ovarian cancer, pancreatic cancer, skin cancer, and others.

The medicines represent many cutting-edge approaches, including a drug that delivers a synthetic version of a substance derived from scorpions directly to brain tumor cells; a number of cancer vaccines; medicines that target and kill specific cancer cells; and treatments that activate the patient’s general immune system to destroy cancer.

‘Researchers are making exciting progress in the search for new cures and treatments for cancer. But these efforts are wasted if the medicines we develop aren’t accessible to patients who need them,’ said Johnson.

Help is available to patients in need through the Partnership for Prescription Assistance (PPA), a program sponsored by America’s pharmaceutical research companies. To date, the PPA has helped more than 5.7 million patients nationwide, including more than 72,000 people in Colorado. Since its launch in April 2005, the PPA bus tour has visited all 50 states and more than 2,500 cities to educate people about patient assistance programs.

The “Help is Here Express” is staffed by trained specialists able to quickly help uninsured and financially struggling patients access information on more than 475 patient assistance programs, including nearly 200 programs offered by pharmaceutical companies. When the “Help is Here Express” moves on, patients can visit PPA’s easy-to-use Web site (www.pparx.org) or call the toll-free phone number (1-888-4PPA-NOW).

Click here to read Medicines in Development for Cancer 2009. [Adobe Reader PDF Doc.]

Read the backgrounder fact sheet here.

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Pharmaceutical Research & Manufacturers of America

The Pharmaceutical Research and Manufacturers of America (PhRMA) represents the country’s leading pharmaceutical research and biotechnology companies, which are devoted to inventing medicines that allow patients to live longer, healthier, and more productive lives. PhRMA companies are leading the way in the search for new cures. PhRMA members alone invested an estimated $50.3 billion in 2008 in discovering and developing new medicines. Industry-wide research and investment reached a record $65.2 billion in 2008.

PhRMA Internet Address: www.phrma.org

For information on stories of hope and survival, visit: http://sharingmiracles.com/

PhRMA en Español: www.nuestraphrma.org

For information on how innovative medicines save lives, visit: www.innovation.org

For information on the Partnership for Prescription Assistance, visit: www.pparx.org

For information on the danger of imported drugs, visit: www.buysafedrugs.info”

Source:  New Report Shows Record Number of Medicines In Development to Treat Leading Causes of Cancer, Press Release, Pharmaceutical Research and Manufacturers of America, April 1, 2009.