YueF Overexpression Inhibits Cell Proliferation Partly Through P21^WAF1/Cip1Upregulation In Renal Cell Carcinoma

Background Renal cell carcinoma (RCC) is the most common type of kidney cancer and follows an unpredictable disease course; it is the most malignant tumor of the kidney and accounts for approximately2-3%of all adult cancers in Western countries. Moreover, the morbidity and mortality associated with renal carcinoma has steadily increased over the past20years. Histopathologically, RCC is classified into four subtypes, with80%of cases consisting of the clear cell subtype. Due to its insidious onset, patients frequently exhibit advanced disease at the time of clinical diagnosis; drugs and newly discovered markers have been unable to significantly increase the survival of these patients. Therefore, additional research is required to identify specific genes that might play important roles in RCC carcinogenesis.YueF (GenBank accession number:BC006131) is a putative tumor suppressor gene that is expressed in hepatomas. It was initially discovered by Huang et al. using a yeast two-hybrid method aimed at identifying Hepatitis B virus X protein (HBx)-interacting proteins. YueF is highly expressed in the cytoplasm of normal cells and tissues, including liver, lung, bladder, myocardial tissue, and intestine; however, it is detected at low levels in corresponding tumor tissues, including liver, lung, and bladder cancers. Overexpression of YueF can inhibit the proliferation of hepatocellular carcinoma (HCC) cells, induce apoptosis in vitro and suppress the HCC tumorigenicity in nude mice in vivo, indicating that YueF might be a novel candidate gene for tumor suppression in tumorigenesis. However, the biological role and the mechanism of YueF action in renal cell carcinoma (RCC) are largely unknown.We investigated not only YueF expression in RCC tissues and corresponding normal tissues but also studied the role of YueF in the proliferation of RCC cells. Our data indicated that YueF expression decreased in RCC tissues and786-0cells. YueF overexpression resulted in increased levels of p53and p21WAF1/Cip1protein expression and a decreased level of cyclin D1expression and subsequently induced inhibition of cell growth in786-0cells. The proliferation defects caused by YueF overexpression can be partially rescued with p21siRNA. This study is the first to demonstrate that YueF modulates cell growth via the regulation of the p21WAF1/Cip1pathway in renal cell carcinoma.Objective To examined the expression of the YueF gene in RCC tissues and the effect of YueF on cell proliferation in RCC786-0cells.Methods Tissue samples from eight human renal cell carcinomas and adjacent normal tissues were obtained after nephrectomy in RCC patients (2females and6males) and examined by a pathologist. All the eight RCC samples are clear cell subtype, and all the adjacent tissue samples are normal, without fibrosis or other non-neoplastic changes. the lentiviral YueF plasmid was co-transfected into293FT cells (Invitrogen, USA) along with three different packaging plasmids, pLP1, pLP2, and pLP/VSV-G, to generate lentivirus.then The786-0cells were infected at a multiplicity of infection (MOI) of5with either lentivirus containing the YueF gene (pCDH-YueF) or empty virus (EV) containing6μg/mL of polybrene according to the manufacturer’s instructions. To examine the effect of YueF on cell growth,786-0cells were infected with either lentivirus containing the YueF gene (pCDH-YueF) or EV.we use Western Blot Analysis to text YueF protein.at last,we analysis cell cycle.Results Downregulated Expression of YueF Protein in Clinical RCC tissues and RCC786-0cells,and Overexpression of YueF in RCC786-0Cells with Lentivirus. YueF Overexpression Inhibits the Proliferation of786-0Cells,which Overexpression in786-0Cells Causes Cell Cycle Arrest at the G1Phase.YueF Overexpression Inhibits the Proliferation of786-0Cells Partly through p21Upregulation,Conclusion The results showed that YueF was expressed at high levels in normal kidney tissues and cell lines but was reduced or absent in RCC tissues and786-0cells. Lentivirus-mediated YueF overexpression in RCC786-0cells caused cell-cycle arrest in the G1phase and dramatically reduced proliferation in culture. YueF overexpression resulted in increased protein levels of p53and p21WAF1/Cip1, whereas the protein levels of cyclin D1and pRb were decreased.