HJURP Derived from Cancer-Associated Fibroblasts Promotes Glutamine Metabolism to Induce Resistance to Doxorubicin in Ovarian Cancer.

Abstract

Cancer-associated fibroblasts (CAFs) are closely associated with tumor drug resistance. This study intended to delineate how CAFs induced DOX resistance in ovarian cancer. Differential gene expression analysis of ovarian cancer CAFs was completed using Gene Expression Omnibus database. CAFs and normal fibroblasts (NFs) were isolated from ovarian cancer tissues and adjacent normal tissues. The expressions of Holliday Junction Recognition Protein (HJURP), α-smooth muscle actin (α-SMA), and fibroblast activation protein alpha (FAP) were assessed by quantitative reverse transcription polymerase chain reaction and Western blot (WB), α-SMA and FAP were detected by immunofluorescence. A2780 cells were treated with CAF or NF conditioned medium (CM), and protein expression of HJURP was assessed by WB. A2780-DOX cells were constructed and cultured with CAF or NF CM, and cell viability and IC₅₀ value of DOX were assayed by Cell Counting Kit-8. Kits were used to test glutamine metabolism and mitochondrial tricarboxylic acid (TCA) cycle products, while WB was utilized to assess expressions of amino acid transporters. mRNA and protein levels of HJURP in CAFs derived from ovarian cancer were significantly higher than those in NFs. Culturing ovarian cancer cells with CAF CM could increase protein expressions of HJURP. HJURP derived from CAFs significantly enhanced viability of A2780-DOX cells and DOX resistance. CAF-derived HJURP fostered glutamine metabolism and mitochondrial TCA cycle in ovarian cancer resistant cells ultimately leading to ovarian cancer DOX resistance. CAF-derived HJURP drove ovarian cancer glutamine metabolism and DOX resistance.