A tumor suppressor that promotes cancer cell growth?October 09, 2006Berlin, Germany - Researchers have shown that the tumor suppressor gene H-REV107-1 may actually stimulate tumor progression in some non-small cell lung carcinomas. The related report by Nazarenko et al., "H-REV107-1 stimulates growth in non-small cell lung carcinomas via the activation of mitogenic signaling," appears in the October issue of The American Journal of Pathology. Tumor suppressor genes function by regulating normal cell growth and proliferation. When a tumor suppressor gene is turned off, by mutation, deletion, or blocked expression, cell growth can proceed without safeguards, contributing to cancer cell proliferation. However, this appears not to be the case in some non-small cell lung carcinomas (NSCLC), in which a tumor suppressor (H-REV107-1) actually promotes cancer cell growth. Nazarenko et al. found H-REV107-1 expression in a portion of human NSCLC samples examined. When they further characterized this expression in relation to normal lung tissue, H-REV107-1 was found in nonproliferating and proliferating cells in normal lung tissue, localized mainly to the nucleus. In cultured NSCLC cells, however, H-REV107-1 was found in either the cytoplasm or both the cytoplasm and nucleus. The group then examined whether cellular localization of H-REV107-1 in NSCLC tumor samples is linked with tumor behavior. Strikingly, cytoplasmic localization correlated with decreased patient survival (24 months versus 41 months for nuclear localization). These data suggested that cytoplasmic H-REV107-1 stimulates cell growth. This was then confirmed by suppression of H-REV107-1 RNA, which inhibited cell proliferation, and overexpression of H-REV107-1 protein, which stimulated cell growth pathways and increased proliferation. These data demonstrate that H-REV107-1 exerts pro-growth functions within a subset of NSCLC cells in a location-dependent manner. Similar reverse functions have been identified for other tumor suppressors, but the correlation between H-REV107-1 expression and NSCLC patient survival is quite striking. The exact mechanisms that regulate H-REV107-1 activity are currently being investigated. The possibility of using H-REV107-1 as a novel prognostic indicator of tumor aggressiveness is appealing. Lung cancer is responsible for more deaths than any other cancer, with only 15% of patients reaching 5-year survival, and non-small cell lung cancer accounts for 75% of all lung cancer. American Journal of Pathology |
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| Related Tumor Suppressor Current Events and Tumor Suppressor News Articles Discovery in worms by Queen's researchers points to more targeted cancer treatment Researchers at Queen's University have found a link between two genes involved in cancer formation in humans, by examining the genes in worms. The groundbreaking discovery provides a foundation for how tumor-forming genes interact, and may offer a drug target for cancer treatment. Loss of tumor supressor gene essential to transforming benign nerve tumors into cancers Researchers at UCLA's Jonsson Comprehensive Cancer Center showed for the first time that the loss or decreased expression of the tumor suppressor gene PTEN plays a central role in the malignant transformation of benign nerve tumors called neurofibromas into a malignant and extremely deadly form of sarcoma. KEAP1 Keeps major cancer-promoting protein at bay A tumor-suppressing protein snatches up an important cancer-promoting enzyme and tags it with molecules that condemn it to destruction, a research team led by scientists at The University of Texas M. D. Anderson Cancer Center reports this week in the journal Molecular Cell. Genes signal late-stage laryngeal cancer, poorer outcome Researchers at Henry Ford Hospital have identified tumor-suppressing genes that may provide a more accurate diagnosis of disease stage and survival for laryngeal cancer patients than current standards. New study resolves the mysterious origin of Merkel cells A new study resolves a 130-year-old mystery over the developmental origin of specialized skin cells involved in touch sensation. Natural compounds, chemotherapeutic drugs may become partners in cancer therapy Research in the Linus Pauling Institute at Oregon State University suggests that some natural food compounds, which previously have been studied for their ability to prevent cancer, may be able to play a more significant role in treating it - working side-by-side with the conventional drugs that are now used in chemotherapy. Tumor suppressor pulls double shift as reprogramming watchdog A collaborative study by researchers at the Salk Institute for Biological Studies uncovered that the tumor suppressor p53, which made its name as "guardian of the genome", not only stops cells that could become cancerous in their tracks but also controls somatic cell reprogramming. Researchers uncover potential mechanisms to protect against genetic alterations, diseases Peering into the DNA of tiny yeast, researchers at the Moores Cancer Center at the University of California, San Diego and the San Diego Branch of the Ludwig Institute for Cancer Research have pinpointed a large number of genes that can prevent a type of genetic rearrangement that may lead to cancer and other diseases. Tumor mutations can predict chemo success New work by MIT cancer biologists shows that the interplay between two key genes that are often defective in tumors determines how cancer cells respond to chemotherapy. Unraveling how cells respond to low oxygen Gary Chiang, Ph.D., and colleagues at Burnham Institute for Medical Research (Burnham) have elucidated how the stability of the REDD1 protein is regulated. More Tumor Suppressor Current Events and Tumor Suppressor News Articles |
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