Differential expression and preliminary function study of a novel tumor related gene pp4519

Objective To explore the differential expression of a novel tumor related gene pp4519 in lung cancer lines, human lung cancer and noncancerous lung tissues as well as its preliminary biological function. Methods Specific oligopeptide (22 AAs) of PP4519 was synthesized and conjugated to KLH, polyclonal rabbit anti PP4519 antibody was prepared. The biological function and differential expression of PP4519 were studied by in vitro colony formation assay, growth curve of transfected cells, ectopic tumor formation assay of transfected SPC A1 cell line, semi Q RT PCR, western blot, immunocytochemistry immunohistochemistry, and so forth. Results Compared to vector, PP4519 inhibited the colony formation of transfected SPC A1 cells in vitro ( P 0.05); PP4519 also inhibited significantly the ectopic tumor formation of transfected SPC A1 cells in nude Balb/C mice ( P 0.01). Apoptotic ratio both of SPC A1 and COS 7 cells were increased by transiently transfecting pp4519 gene. No significant different expression was observed in lung cancer and noncancerous lung tissues as measured by semi Q RT PCR, western blot( P 0.05, P 0.05). However, the result of immunohistochemistry showed that PP4519 was up expressed in noncancerous lung tissues than normal lung tissues. Conclusion pp4519 was a novel lung cancer related gene with the function of inhibiting its growth.