A gene normally involved in the regulation of embryonic development can trigger the transition of cells into more mobile types that can spread without regard for the normal biological controls that restrict metastasis, the new study shows. …
Biologists have previously found that this kind of transformation, which often occurs in cancer cells as well as during embryonic development, is controlled by transcription factors — proteins that turn genes on and off. However, the new MIT research reveals that RNA-binding proteins also play an important role. Human cells have about 500 different RNA-binding proteins, which influence gene expression by regulating messenger RNA, the molecule that carries DNA’s instructions to the rest of the cell. “Recent discoveries show that there’s a lot of RNA-processing that happens in human cells and mammalian cells in general,” says Yarden Katz, a recent MIT PhD recipient and one of the lead authors of the new paper…
Mariana Chavez Mac Gregor, M.D., assistant professor, health services research and breast medical oncology, will present the findings at a poster session of the 2014 San Antonio Breast Cancer Symposium. Oncotype DX is a 21-gene assay used to help estimate the likelihood of recurrence in women with early-stage breast cancer and, thus, determine those who may or may not benefit from adjuvant chemotherapy. The National Comprehensive Cancer Network includes its use for women with lymph node-negative, hormone receptor (HR)-positive and HER2-negative disease. …
For years, controversy has surrounded the CYP2D6 gene test for breast cancer. Women with certain inherited genetic deficiencies in the CYP2D6 gene metabolize tamoxifen less efficiently, and thus have lower levels of tamoxifen’s active cancer-fighting metabolite endoxifen. Numerous studies have shown that these women gain less benefit from tamoxifen therapy and have higher rates of recurrence. However, two large clinical trials found no link between the CYP2D6 genotype and tamoxifen effectiveness, prompting recommendations against testing…
The study suggests that attacking those subsets with targeted drugs may degrade the disease’s ability to spread throughout the bone marrow of affected patients, the authors say. The discovery was made by developing a mouse model of the disease that enabled researchers to track which of 15 genetic groups — or subclones — of myeloma cells spread beyond their initial site in the animals’ hind legs. By labeling the different subgroups with fluorescent dyes, researchers determined that just one of the subclones was responsible for the disease metastasis. They then compared the pattern of gene abnormalities in the initial myeloma tissue and the metastatic tumors. …
Cancer Research UK scientists have discovered that bowel cancer may not be restricted to starting its journey in the stem cells in the lining of the intestines as previously thought. The researchers, based at the Wellcome Trust Centre for Human Genetics, studied a hereditary faulty gene which can cause bowel cancer in middle age. The faulty gene causes normal cells to behave like immortal stem cells and develop tumours of their own- challenging the theory that normal cells have a fixed fate and limited lifespan. The cells lining the bowel are continuously replaced — new ‘daughter’ cells are produced by immortal stem cells to replace those that have worn out. …
The research, published in the Proceedings of the National Academy of Sciences, shows how the common chemotherapy drug topotecan can drastically suppress the expression of Topoisomerase-1, a gene that triggers the creation of proteins essential for normal brain function. Specifically, the drug tamps down the proteins that are necessary for neurons to communicate through synapses. However, the researchers found that the protein levels and synaptic communication return to normal when the drug is removed. …
Lung cancer, which affects nonsmokers as well as smokers, is the most common cancer worldwide, causing 1.6 million deaths a year, far more than pancreatic, breast and colon cancer combined. About 30 percent of the most common type of lung cancer (non-small) contains a mutation in a gene called KRAS. …
The findings are published online in Lancet Oncology. Study co-leads Dr. Robert Bristow, a clinician-scientist at Princess Margaret Cancer Centre, and Dr. Paul Boutros, an investigator at the Ontario Institute for Cancer Research, report that the gene test provides a much-needed quick and accurate tool to determine with greater precision the men who will do well with local treatment only (surgery or radiation), and those who will need extra treatment (chemotherapy and hormone therapy) to ensure the cancer is completely eradicated. …
The gene, called MACROD2, might also be useful in screening for some aggressive forms of breast cancers, and, someday, offering a new target for therapy, says Ben Ho Park, M.D., Ph.D., an associate professor of oncology in the Kimmel Cancer Center’s Breast Cancer Program and a member of the research team. The drug tamoxifen is used to treat estrogen receptor-positive breast cancers. Cells in this type of breast cancer produce protein receptors in their nuclei which bind to and grow in response to the hormone estrogen. Tamoxifen generally blocks the binding process of the estrogen-receptor, but some estrogen receptor-positive cancers are resistant or become resistant to tamoxifen therapy, finding ways to elude its effects…