Melatonin Promotes Apoptosis Of Bladder Cancer Cells By Inhibiting Cellular Prion Protein Expression

[Background]Bladder cancer is one of the most common malignant tumors of the urinary system.In recent years,the incidence of bladder cancer in our country has increased year by year,and it is a disease that has no obvious symptoms and is prone to relapse.Melatonin is an indoleamine hormone secreted by the pineal gland.Previous studies have found that it can inhibit the growth of gastric cancer,colon cancer,and osteosarcoma in vitro and in vivo through different routes.There are few studies on bladder cancer.This study explored the regulatory effect of melatonin on the proliferation,apoptosis,invasion and migration of bladder cancer cells(T24 and UMUC-3).In addition,cellular prion protein(PrPC)is a glycosylphosphatidylinositol The cell surface proteins anchored on the cell membrane are highly expressed in cells of various tissues such as nerves,muscles and heart.Previous studies have shown that PrPC plays an important role in the proliferation,apoptosis,invasion,metastasis and drug resistance of various tumor cells.Studies have shown that melatonin inhibits colon cancer cell proliferation and promotes apoptosis by down-regulating PrPC.However,its mechanism of action in bladder cancer has not been fully elucidated.In conclusion,the main research purpose of this article is to further explore the effect of melatonin on bladder cancer cells and whether the LKB1-AMPK-m TOR signaling pathway has a regulatory role in this process,and bladder cancer cells on melatonin after PrPC knockout Changes after processing to explore the role of PrPC in this middle.[Methods]1.Cell culture bladder cancer cell lines T24 and UMUC-3 were cultured in DMEM medium.Cell lines were treated with melatonin at different concentrations,respectively,and the cell growth ability was measured.2.The degree of apoptosis was evaluated using the FITC Annexin V Apoptosis Detection Kit(Becton Dickinson).Briefly,cells were isolated with trypsin(Hyclone),then stained with FITC annexin V,and analyzed using a FACScanto II cytometer(Becton Dickinson).3.The Transwell chamber was used to perform relevant operations on the cells to investigate the ability of melatonin to migrate and invade cells.4.Plasmid construction and transient transfection.Specific PrPC-si RNA was used to transfect sugar T24 and UMUC-3 bladder cancer cell lines.5.Western blot was used to detect the expression of PrPC,LKB1,AMPK,m TOR,BAX,caspase3 and Bcl-2 proteins in melatonin-treated bladder cancer cells.[Result]1.After treatment of bladder cancer cells with melatonin,we found that melatonin significantly inhibited the growth ability of bladder cancer cells.Within a certain concentration range,as the concentration increased,the inhibitory capacity also increased.2.In order to study the effects of melatonin on the apoptosis of bladder cancer cells,we adopted flow cytometry to detect the apoptosis of bladder cancer cell lines.In addition,the expression of apoptotic protein in melanin-treated bladder cancer cells was stronger than that in untreated bladder cancer cells by Western blotting;3.In order to explore the effect of melatonin on the invasion and migration of bladder cancer cells,the Transwell chamber was used for operation,and it was found that theability of bladder cancer cells to invade and migrate was reduced after melatonin treatment.3.We further found that after melatonin treatment in bladder cancer cells,the expression of PrPC decreased and the LKB1-AMPK-m TOR pathway was activated.In order to study the underlying mechanism between the two,we used specific si RNA to knock down PrPC and found that The expression of LKB1 and AMPK also increased correspondingly,and the expression of m TOR decreased accordingly.The above results indicate that PrPC inhibits the activation of AMPK,indicating that PrPC promotes the growth and proliferation of bladder cancer cells through the LKB1-AMPK-m TOR signaling pathway,and melatonin can suppress this effect.[Conclusion]1.Melatonin can inhibit the growth,invasion and migration of bladder cancer and promote apoptosis.2.Melatonin can inhibit the growth of bladder cancer cells by inducing PrPC to down-regulate and activate the lkb1-ampk-mtor signaling pathway.