Activated Ras proteins interact with a broad range of effector proteins to induce a diverse series of biological consequences. Although typically associated with enhanced growth and transformation, activated Ras may also induce growth antagonistic effects such as senescence or apoptosis. It is now apparent that some of the growth-inhibitory properties of Ras are mediated via the RASSF family of...

BACKGROUND The function of the tumor suppressor gene RASSF1A in cancer cells has been detailed in many studies. However, due to the methylation of its promoter, the expression of RASSF1A is missing in most cancers. In the literature, we found that the conclusion regarding the relationship between RASSF1A gene promoter methylation and the susceptibility and prognosis of melanoma was not unified....

Increasing evidence has been accumulated indicating the important role of epigenetic regulation in tumor genesis. Previously, we observed that the transfection of hepatitis C virus core (HCVc) protein led to malignant transformation in normal biliary cells, and that tumor suppressor gene RASSF1A was downregulated in many hilar cholangiocarcinoma patients by hypermethylation in the promoter regi...

Recent advances in the study of RASSF1A, the candidate tumor suppressor gene, indicate a possible role of RASSF1A in cell cycle regulation; however, very little is known regarding molecular mechanisms underlying this control. Using small interfering RNA to knockdown endogenous RASSF1A in the breast tumor cell line HB2 and in the cervical cancer cell line HeLa, we identify that a key player in c...

Physical activity reduces breast cancer risk. Promoter hypermethylation of the tumor suppressor genes APC and RASSF1A , which is potentially reversible, is associated with breast cancer risk. We conducted a cross-sectional study in 45 women without breast cancer to determine the association of physical activity with promoter hypermethylation of APC and RASSF1A in breast tissue. We used quantita...

Some oncogenes, such as activated Ras, cause the malignant transformation of lung cells. c-Jun-NH2-kinase (JNK) activation is essential for the oncogenic function of these cells. In this study, we show that RASSF1A inhibits the growth of lung cancer cells by blocking the JNK pathway. The exogenous expression of RASSF1A suppressed JNK phosphorylation, and cells stably transfected with RASSF1A sh...

Hypermethylation of tumor suppressor genes (TSGs) promoters by DNA methyltransferase (DNMT) can be observed in almost all cancers which represent a hallmark of carcinogenesis, including lung cancer. DNMT inhibitors (e.g.5-Aza-CR/CdR) reactivate TSGs to exert anti-cancer activity and have been applied into the clinical. However, it is cytotoxic even at low concentrations, which might be not dire...

Ras association domain family (RASSF) 6 is a member of the C-terminal RASSF proteins such as RASSF1A and RASSF3. RASSF6 is involved in apoptosis in various cells under miscellaneous conditions, but it remains to be clarified how RASSF6 exerts tumor-suppressive roles. We reported previously that RASSF3 facilitates the degradation of MDM2, a major E3 ligase of p53, and stabilizes p53 to function ...