IRE1α-TRAF2-ASK1 pathway is involved in CSTMP-induced apoptosis and ER stress in human non-small cell lung cancer A549 cells

BackgroundCSTMP, a Tetramethylpyrazine (TMP) analogue, is designed and synthesized based on the pharmacophores of TMP and resveratrol. Recent studies showed that CSTMP had strong protective effects in endothelial cells apoptosis by its anti-oxidant activity. However, the pharmacological function of CSTMP in cancer have not been elucidated to date. The objective of this study was to investigate the anti-cancer effect of CSTMP against human non-small cell lung cancer (NSCLC) A549 cells and the underlying mechanisms.MethodsThe cell proliferation and apoptosis were detected by MTT assay and flow cytometry. Caspases activity was determined spectrophotometricaly at 405 nm using a microtiter plate reader. Western blot and real-time PCR was used to assess the protein and mRNA expression. Immunoprecipitation was used to examine the protein–protein interactions.ResultsCSTMP inhibited the proliferation and induced cell cycle arrest and apoptosis of A549 cells. Caspase3, 8, 9 and PARP-1 activation, and Bax/Bcl-2 ratio analyses demonstrated that the anti-cancer effect of CSTMP in A549 cells was mediated by promoting caspase- and mitochondria-dependent apoptosis. Furthermore, CSTMP induced ER stress in A549 cells as evidenced by elevated levels of GRP78, GRP94, CHOP, IRE1α, TRAF2, p-ASK1 and p-JNK, activation of caspase12 and 4, and enhanced formation of an IRE1α-TRAF2-ASK1 complex. Knockdown of IRE1α by siRNA suppressed activation of IRE1α, TRAF2, p-ASK1 and p-JNK in CSTMP treated A549 cells. In addition, the effects of CSTMP on the formation of an IRE1α-TRAF2-ASK1 complex, caspase- and mitochondria-dependent apoptosis were also reversed by IRE1α siRNA in A549 cells.ConclusionsCollectively, we showed that CSTMP induced apoptosis of A549 cells were through IRE1α-TRAF2-ASK1 complex-mediated ER stress, JNK activation, and mitochondrial dysfunction. These insights on this novel compound CSTMP may provide a novel anti-cancer candidate for the treatment of NSCLC.     

Human interleukin-2 gene transfer into ovarian cancer cell lines SKOV3, decreased the proliferation, tumorigenesis and enhanced the immunity of the tumor cells

To study the effects of human interleukin-2 genetransfer on the morphology, proliferation, tumori-genesis, immunity, and oncogenes expression of tumorcells, the gene encoding human interleukin-2 (IL-2) wasintroduced via retroviral vectors pLXSN into ovariancancer cell lines SKOV3. A resistant clone with high IL-2activity (318 U/10~6cell/24 hours) in the culturesupernatants was cloned. The hIL-2 mRNA was detectedwith RT-PCR in SKOV3/IL2 cells. The IL2 secretinghas persisted for 23 weeks with 38 passanges. The hIL-2     

Inoculation with IL-2 and B7-1 co-transfected G422 murine glioblastoma cells resulting in enhanced antitumor immunity in vivo

It's well known that interleukin-2 (IL-2) plays animportant role in eliciting antitumor immunityparticularly mediated by T cells. In addition, theexpression of MHC can be enhanced by IL-2 genetransfection in tumor cells. Recent studies have indicatedthat at least two signals are required for the activation ofnaive T cells by antigen-bearing target cells: an antigen-sopific signal and a crystimulatory signal. B7-l is an