PinX1 regulation of telomerase activity and apoptosis in nasopharyngeal carcinoma cells

Background. human interacting protein x1 (pinx1) has been identified as a critical telomerase inhibitor and proposed to be a putative tumor suppressor gene. loss of pinx1 has been found in a large variety of malignancies,however,its function in inhibiting telomerase activity of tumor cells is not well documented. here we show that pinx1 is essential for down-regulation telomerase activity of nasopharyngeal carcinoma. methods. expression vectors of human pinx1 (pegfp-c3-pinx1) and its small interfering rna (pinx1-fam-sirna) were constructed and transfected into npc. their effects on mrna of telomerase catalytic subunit (htert),telomerase activity,cell proliferation,cell migration,wound healing,cell cycles and apoptosis were examined using semi-quantitative rt-pcr,stretch pcr,mtt assay,transwell,scratch assay and flow cytometry,respectively. results. transfection of pegfp-c3-pinx1 and pinx1-fam-sirna increased and reduced pinx1 mrna by 1.6-fold and 70%,respectively. over-expression of pinx1 decreased htert mrna by 21%,reduced telomerase activity,inhibited cell growth,migration and wound healing ability,arrested cells in g0/g1 phase,and increased apoptotic index. in contrast,down-regulation of pinx1 did not alter the above characteristics. conclusions. pinx1 may play important roles in npc proliferation,migration and apoptosis and has application potential in tumor-targeted gene therapy. © 2012 lai et al; licensee biomed central ltd.