Open AccessDownregulation of p16ink4a inhibits cell proliferation and induces G1 cell cycle arrest in cervical cancer cells
Author(s) -
Chu Yue Zhang,
Bao Wang,
Li Hua Wang
Publication year - 2014
Publication title -
international journal of molecular medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.048
H-Index - 90
eISSN - 1791-244X
pISSN - 1107-3756
DOI - 10.3892/ijmm.2014.1731
Subject(s) - cell cycle , cyclin d1 , cancer research , hela , cell growth , downregulation and upregulation , retinoblastoma protein , apoptosis , cyclin b1 , biology , western blot , cell , cancer , carcinogenesis , mtt assay , cyclin dependent kinase 1 , biochemistry , genetics , gene
Studies have suggested that p16(ink4a) may be a surrogate biomarker for the diagnosis of cervical cancer; however, the function of p16(ink4a) in human cervical cancer cells remains largely unknown. Therefore, in this study, we aimed to investigate the role of p16(ink4a) in human cervical cancer cells. Immunocytochemistry was used to examine invasive squamous cell carcinoma and its precancerous lesions. p16(ink4a)-siRNA was transfected into SiHa and HeLa cells to deplete its expression. The cellular levels of p16(ink4a) mRNA and protein were detected by qRT-PCR and western blot analysis. Proliferation rates were assessed by methyl thiazolyl tetrazolium (MTT) and plate colony formation assays. Cellular migration and invasion ability were assessed by a wound healing assay and Transwell assay. Cellular apoptosis and the cell cycle were measured by flow cytometry. The protein levels of retinoblastoma (Rb), phosphorylated Rb (phospho-Rb), cyclin D1 and caspase-3 were determined by western blot analysis. The results revealed that p16(ink4a) was overexpressed in the cervical cancer and precancerous lesions (P<0.05). The downregulation of p16(ink4a) in the SiHa and HeLa cells inhibited their proliferation, migration and invasion. In the SiHa cells, p16(ink4a)-siRNA also induced G1 cell cycle arrest and apoptosis. Western blot analysis revealed that the downregulation of p16(ink4a) in the SiHa cells markedly induced caspase-3 activation and decreased cyclin D1 expression. These data suggest that the overexpression of p16(ink4a) appears to be useful in monitoring cervical precancerous lesions, which supports that the hypothesis that p16(ink4a) is a surrogate biomarker for the diagnosis of cervical cancer. The therapeutic targeting of overexpressed p16(ink4a) in the p16(ink4a)-cyclin-Rb pathway may be a useful strategy in the treatment of cervical cancer.