Mechanism Of SPARC Promoting Sunitinib Resistance In Renal Carcinoma Cells By Inhibiting Ferroptosis

Objective:Small-molecule targeted drugs are the main therapeutic strategies for patients with recurrent and advanced renal cancer,and the resistance of RCC to targeted drugs is the major contributors of death in patients with advanced RCC.Iron death is a novel cell death mode,which is widely involved in the regulation of small molecule targeted drug resistance in a variety of solid tumors.SPARC occupies a vital role in the occurrence,invasion and metastasis of kidney cancer,but drug resistance of cancer cells is rarely reported.Methods:1.Drug resistant strains of KIRC were gradually induced by increasing gradient concentration of Sunitinib,and cell viability was detected by CCK-8.The key genes affecting the drug resistance in KIRC were screened with bioinformatics,and the expression of SPARC in drug-resistant cell lines was detected by molecular biology.SPARC was clearly associated with targeted drug resistance in KIRC.2.Bioinformatics was used to analyze the pathways related to resistance of KIRC to small-molecule targeted drugs.By molecular biological methods,mRNA and protein levels of GPX4,NRF2 and SAPRC,the key molecules of iron death,were detected between the drug-resistant group and the control.The changes of oxidative stress levels between the two groups were detected.In combination with a rescue experiment designed by Fer-1,a ferroptosis inhibitor,ferroptosis was verified in human renal carcinoma cells treated with Sunitinib.To elucidate the effect of SPARC on targeted drug resistance in human renal cancer cells by regulating cell ferroptosis.3.Bioinformatics discovered the correlation between SPARC and PI3K/AKT pathway.In vitro and in vivo experiments,qPCR,Westernblot immunohistochemistry and other methods were used,and pathway inhibitor LY294002 was introduced.It was verified that the PI3K/AKT pathway can regulate the expression of SPARC and ferroptosis in KIRC,and lentivirus transfection was used to establish kidney cancer cell lines and nude mouse models with stable SPARC knockdown,so as to explore that SPARC can regulate ferroptosis in KIRC through PI3K/AKT pathway and enhance drug resistance of targeted drugs.4.Combined with the clinical database,it was verified that SPARC regulates the resistance of kidney cancer to targeted drugs by influencing cell ferroptosis.Results:1.SPARC gene abundance was higher in human renal carcinoma cells resistant to Sunitinib,which was significantly up-regulated.2.Sunitinib can increase the level of ferroptosis in KIRC cells,and this trend is inhibited after drug resistance,and the level of ferroptosis is significantly reduced.3.SPARC can regulate ferroptosis in renal carcinoma cells through PI3K/AKT pathway.4.PI3K/AKT pathway can regulate the expression of SPARC in RCC.Conclusion:In this study,we analyzed different databases through bioinformatics,relying on in vitro and in vivo experiments of molecular biology,combined with clinical practice.In human clear cell carcinoma cells resistant to small molecule targeted drugs,SPARC regulates ferroptosis of renal cancer cells through the PI3K/AKT feedback loop,thereby reversing the resistance of renal cancer cells to targeted drugs.