tumors
New research suggests that combining the chemotherapy drug paclitaxel with very low doses of the HIV-fighting drug AZT may shrink or even eradicate certain types of cancer tumors. Using both drugs in mice helped inhibit the enzyme telomerase, a component critical to the livelihood of some cancer cells. Telomerase helps to build and maintain telomeres ? protective strands of DNA at each end of a chromosome.
Researchers have developed a novel approach to genetically instruct human immune cells to recognize and kill cancer cells in a mouse model. The investigators plan to ultimately apply this strategy in a clinical trial setting for patients with certain forms of leukemias and lymphomas. Scientists at Memorial Sloan-Kettering Cancer Center (MSKCC) genetically engineered an antigen receptor, introduced it into cultured human T cells, and infused the T cells in mice that bear widespread tumor cells. The modified T cells, now able to recognize the targeted antigen present on the tumor cells, eradicated the cancer.
Researchers at Dana-Farber Cancer Institute have made a discovery that could help solve a mystery in cancer biology: how a sunburn acquired during a childhood day at the beach can develop into a deadly tumor decades later. The scientists report in the Feb. 4 Proceedings of the National Academy of Sciences that the sun's damaging ultraviolet (UV) rays target a series of biochemical signals inside the young skin cell, impairing the cell's ability to control its proliferation. The paper currently is available on the journal's web site.
A minimally invasive, experimental treatment is proving successful in removing small kidney tumors from appropriate patients, report researchers from Massachusetts General Hospital (MGH). In a study in the February 2003 issue of Radiology, the MGH team describes how a technique called radiofrequency ablation (RFA) destroyed all renal cell carcinoma (RCC) tumors less than 3 cm in size and some larger tumors, depending on their location. The most common form of kidney cancer, RCC will be diagnosed in almost 32,000 Americans this year and is most frequently treated with surgical removal through either an open or laparoscopic procedure.
A team of scientists has shrunk tumors or delayed their growth in animal studies by using radiation to enable a drug to "zero in" and block the tumor blood vessels. The work, reported in the January issue of the journal Cancer Cell, is a model for what might be achieved in patients by using radiation to activate drug targets in tumors. "We can now use combinations of chemotherapy and radiation to improve the anti-cancer effect for many of our patients, but the side effects can be great," said Dr. Dennis Hallahan, chair of Radiation Oncology at Vanderbilt- Ingram. "With this approach, we hope we can ultimately deliver drugs directly and selectively to the tumor alone, and reduce side effects."
Researchers at Washington University School of Medicine in St. Louis have found that a protein called cytidine uridine guanosine binding protein-2 (CUGBP2) can destroy several different types of cancer cells. When the team inserted the protein into cultured tumor cells, more than 70 percent self-destructed. The researchers found that CUGBP2 helps regulate production of cyclooxygenase-2, (COX-2), which is better known as a key culprit in arthritis.
Research conducted at Ohio State University suggests that cell biologists may be exposing the cell cultures they study to too much oxygen. This finding could have broad implications for cellular biology research, which receives billions of dollars of funding nationally, said Ohio State scientist Chandan Sen. He is the lead author of a study which suggests that cells act differently depending on how much oxygen they are exposed to, especially when it is too much.
The presence of tumor-infiltrating lymphocytes predicts the length of remission after chemotherapy and the overall survival of patients with ovarian cancer, according to researchers from the Abramson Cancer Center and the Center on Women's Health at the University of Pennsylvania School of Medicine. Their findings, which are presented in the January 16th issue of the New England Journal of Medicine, constitute the first proof that a spontaneous immune response against the tumor dramatically impacts the clinical course of ovarian cancer. These novel findings generate hope that immune therapies may significantly prolong the response to chemotherapy and improve the survival of patients with advanced ovarian carcinoma.
Scientists at the John Wayne Cancer Institute in Santa Monica, California have found a panel of molecular markers that could signal which patients might have the best results following vaccination for malignant melanoma. According to a study published in the January 15, 2003 issue of Cancer Research, a journal of the American Association for Cancer Research (AACR), the scientists showed that patient survival improved significantly if their tumors expressed higher levels for these markers, known as melanoma-associated antigens (MAAs).
Important disparities in breast-cancer diagnosis, treatment and survival among American women of various racial and ethnic backgrounds are documented in a new study by researchers in Seattle. The findings are based on the largest, most comprehensive study of its kind to evaluate the relationship between race/ethnicity and breast-cancer stage, treatment and survival. The study evaluated data from nearly 125,000 women representing all major racial/ethnic populations and subpopulations in the United States, the majority of which have only been tracked by national cancer registries since the late 1980s.
Researchers have identified or confirmed 490 proteins in human blood serum -- nearly doubling the number of known serum proteins, according to a paper accepted for publication in the December issue of Molecular and Cellular Proteomics. "We have performed the most extensive identification of proteins in serum to date," said Joel Pounds, corresponding author and a PNNL staff scientist. "We studied blood serum because it holds clues to all the major processes in our bodies. We need to know what proteins exist in that serum to know how they might be used to predict disease susceptibility, monitor disease progression or diagnose disease." These clues include proteins that "leak" from dead and dying cells, and proteins secreted into blood or released from tumors. Identifying these proteins allows scientists to conduct additional studies to define each protein's functional role in cells and the body.
Cancer patients undergoing chemotherapy often endure painful side effects caused by the powerful drugs as they course through their entire bodies, damaging healthy tissue and tumors alike. Utah researchers are reporting in the December issue "Cancer Research" that they have successfully tested a new method in laboratory animals that would concentrate the impact of cancer drugs on specific cancerous tissues, thus sparing the rest of the body from harm.
Using a novel gene therapy approach that boosts the body?s immune system, a researcher has cured cancer in laboratory mice. In experiments reported in the Dec. 15 issue of Cancer Research, Chung Lee and colleagues at the Feinberg School of Medicine at Northwestern University applied the gene therapy technique to render immune cells insensitive to transforming growth factor beta (TGF-beta), a powerful, naturally occurring substance in the body called an immunosuppressor that enables cancer cells to evade surveillance by the immune system. The approach boosted the mice?s immune system, which virtually eliminated cancerous tumors in the animals' lungs and prostate gland.
Breast cancer tumors that stop responding to the drug tamoxifen actually change their cellular characteristics and become responsive to other types of drugs, including Herceptin, according to oncologists at the Duke Comprehensive Cancer Center. "In the process of becoming resistant to tamoxifen, the tumors alter their qualities and become receptive to Herceptin and other drugs that target the HER-2 receptor," said Kimberly Blackwell, M.D., assistant professor of oncology at Duke.
Oncologists are testing a new technique called gene expression profiling that subtypes each breast cancer tumor by its genetic defects so that doctors can tailor their treatment to inhibit that particular tumor. The researchers believe the technique could spare millions of women from needlessly receiving toxic chemotherapy, and they are leading a national clinical trial to study gene profiling. "Currently, we have no predictive model to determine who will respond to hormonal therapies and who won't, so we prescribe chemotherapy as a backup measure to ensure the cancer's demise," said Matthew Ellis, M.D., Ph.D., director of the breast cancer program at Duke. "This one-treatment-fits-all approach leads to a huge amount of over treatment, with up to 50 percent of women unnecessarily receiving chemotherapy."
