SREBP1c Regulated The Expression Of PERK And Affected The Proliferation,apoptosis And Autophagy Through The PERK Signal Pathway In Osteosarcoma Cells

Objective: To investigate whether the steroid regulatory element binding protein 1c(SREBP1c)binds to the promoter of protein kinase-like endoplasmic reticulum kinase(PERK)gene and influence the mechanism of proliferation,apoptosis and autophagy in saos2 and RCS osteosarcoma cells by regulating the transcription and expression of PERK.Methods: The full-length and a series of truncated promoter of the PERK gene w as constructed.The pRL-SV40,pcDNA3.1-SREBP1 c and pcDNA3.1-SR EBP1 cm were co-transfected into osteosarcoma cells to detected lucifera se activity.The direct relationship between SREBP1 c and PERK promo ter sequences were validated by CHIP and EMSA methods.The lentivir al SREBP1 c,SREBP1cm and PERK were constructed and packaged by pWPT-GFP lentiviral vector system.The expression of PERK mRNA a nd protein in osteosarcoma cells was detected by RT-PCR and Western blotting.In order to investigated the possible molecular mechanisms of SREBP1 c,SREBP1cm and PERK on the proliferation,apoptosis and au tophagy of osteosarcoma cells in ERS state by using TM to constructed ERS model.Results:PcDNA3.1-SREBP1 c and pc DNA3.1-SREBP1 cm up-regulated the activity of PERK promoter;ChIP and EMSA demonstrated that SREBP1 c directly binds to the promoter region of PERK and regulates transcription and expression of PERK;The lentivirus SREBP1 c,SREBP1cm were used to increase the expression of PERK,SREBP1 c and SREBP1 cm in different levels(P <0.05).Overexpression of SREBP1 c,SREBP1cm and PERK could induce the endoplasmic reticulum stress in the absence of TM induction.In the ERs state,overexpression of SREBP1 c,SREBP1cm and PERK can inhibit the proliferation and promote apoptosis and autophagyin osteosarcoma cells.SREBP1 c / 1cm can up-regulated PERK expression and phosphorylation to enhance the inhibitory effect of PERK on cell proliferation,Promote PERK-mediated apoptosis and autophagy.The effect of SREBP1 cm on the biological function of PERK can be effectively reversed by PERK signal pathway inhibitor GSK2606414,that is,GSK2606414 can effectively reverse the inhibitory effect of PERK on cell proliferation and promote PERK-mediated apoptosis and Cell autophagy,demonstrated that SREBP1 c regulates cell proliferation,apoptosis and autophagy by upregulating PERK expression and phosphorylation activation of the corresponding signaling pathway to achieve.Conclusion:SREBP1c regulated the transcription and expression of PERK gene by directly binding to the PERK gene promoter;SREBP1c / 1cm enhances the inhibitory effect of PERK on cell proliferation and promotes PERK-mediated apoptosis and autophagy.The effect of SREBP1 c / 1cm depends on the PERK signal path.