Plasmacytoma variant translocation1 (PVT1) is a very important long nocoding RNA,which located at chromosome 8q24.21 in human beings.Aberrant expression and polymorphism of PVT1 was closely associated with various kinds of cancers such as malignant lymphoma,breast cancer,colorectal cancer,pancreatic cancer,and affected survival and prognosis of cancer patients.This mainly attribute to its interactin with myc,miRNAs and other proteins,and also gene polymorphism.Further study of PVT1 is expected to provide a new target for the diagnosis and treatment of cancer.

Background:Recent studies have shown that long non-coding RNAs(lncRNAs)play important roles in carcinogenesis and cancer biology and the related context has attracted more and more attentions. PVT1,which encodes a lncRNA,is reported to be up-regulated and exhibit pro-oncogenic activity in a wide variety of human cancers. Aims:To investigate the expression of PVT1 in human pancreatic cancer cells and its effect on proliferation and apoptosis of HPAF-Ⅱ cells. Methods:One target siRNA against PVT1 was synthesized and transfected into HPAF-Ⅱ cells by using lipofactamine technique. PVT1 mRNA expression was detected by real-time PCR;capability of cell proliferation was examined by MTS and colony formation assays;cell cycle progression and apoptosis were measured by flow cytometry;and Western blotting was performed to determine the expressions of apoptosis-related proteins and proto-oncogene protein c-Myc. Results:The mRNA expression of PVT1 in several human pancreatic cancer cell lines,especially HPAF-Ⅱ cells was significantly higher than that in H6c7,a human immortalization normal pancreatic ductal epithelial cell line. Compared with HPAF-Ⅱ cells transfected with negative control siRNA or without transfection,silencing of PVT1 by siRNA-PVT1 resulted in remarkable reduction in cell proliferation,cell cycle G1 phase arrest,and notable apoptosis;meanwhile,the expressions of apoptosis-related proteins(cleaved-caspase-3 and cleaved-PARP)were up-regulated,the ratio for Bcl-2 / Bax was decreased,and the expression of c-Myc protein was down-regulated. Conclusions:LncRNA-PVT1 is highly expressed in human pancreatic cancer cell line HPAF-Ⅱ. It may affect the proliferation and apoptosis of HPAF-Ⅱ cells partially through regulating c-Myc expression.