Tissue Non-specific Alkaline Phosphatase(TNALP) Promotes The Sensitivity Of Serous Ovarian Cancer To Cisplatin Through GRB10/MTORC1 Signaling Pathway

Objective: Previous studies found that ALPL can inhibit the EMT and invasive potential of serous ovarian cancer(SOC)cells.This study aimed to investigate the function of the TNALP,which is encoded by ALPL,in the SOC's response to cisplatin and underlying mechanism.Methods: CCK-8 was used to detect the sensitivity of SOC cells(SKOV3,HEY)to cisplatin with or without ALPL overexpression.Spectrophotometric assay was utilized to measure the conversion rate of exogenous PLP to PL.i TRAQ was employed to screen the differentially expressed proteins in SKOV3-ALPL cells compared to control,and GRB10,which was reported to be involved in platinum resistance was identified.And the change of key molecules in mTOR signaling pathway and autophagy were detected through Western Blot in SKOV3-ALPL cells compared to control.Finally,the expression of ALPL and GRB10 was assessed through immunohistochemistry in tissue blocks from 92 patients with serous ovarian cancer(SOC),and 20 blocks of normal ovaries andfallopian tube were chosen as normal control.Results: 1.The sensitivity of SOC cells to cisplatin could be enhanced by ALPL overexpression,which could be partially inhibited by autophagy inhibitor chloroquine.2.ALPL could promote the expression of GRB10 and inhibit mTORC1 signaling pathway,and promote the expression of downstream autophagy-related protein.3.The conversion of pyridoxal phosphate PLP to PL was demonstrated to be faster in ALPL overexpression cells.4.GRB10 expression in SOC cells was increased after pyridoxal(PL)treatment,which is similar to ALPL overexpression.5.GRB10 knocked down in SOC cells with ALPL overexpression could attenuate the effect of ALPL on cisplatin sensitivity.6.Consistently low expression of GRB10 and ALPL was shown in 92 patients with SOC,which is associated with worse survival prognosis.Conclusion: TNALP may affect GRB10/mTORC1 signaling pathway by affecting vitamin B6 metabolism and then activate autophagy,which can enhance the response of SOC cells to cisplatin and improve patient prognosis.