Comprehensive pan-cancer analysis of heat shock protein 110, 90, 70 and 60 families

Abstract

Background: Heat shock proteins (HSPs) are a class of molecular chaperones that function in protein folding and maintain protein structure and function. No study has performed a comprehensive pan-cancer analysis of HSPs. Here we carried out a panoramic analysis of the expression and prognosis of HSP110, HSP90, HSP70 and HSP60 families in 33 tumors, with the aim of deepening the systematic understanding of HSPs in cancer. Materials and Methods: Next-generation sequencing data of multiple tumors were downloaded from TCGA, CCLE and Oncomine databases. RStudio 3.6.1 was used to analyze the expressions, mutations, copy number variations (CNVs), cancer-related signaling pathways, immune cell infiltration and prognosis profiles of HSP110, HSP90, HSP70, and HSP60 families in 33 tumors. Results: HSPA6 and HSPA7 were generally highly expressed while HSPA12A, HSPA12B, HSPA2 and HSPA4L were mainly expressed at low levels in different cancer tissues. The results revealed mainly positive correlations among the expressions of HSPs in different cancers. Expressions of HSP family members were generally associated with poor prognosis in respiratory, digestive, urinary, and reproductive system tumors and associated with good prognosis in cholangiocarcinoma, pheochromocytoma and paraganglioma. TCGA mutation analysis showed that HSP gene mutation rate in cancers was 0­%–23%. CCLE mutation analysis indicated that HSP gene mutation rate in 828 cell lines from 15 tumors was 0%–17%. CNV analysis revealed that HSPs have different degrees of gene amplifications and deletions in cancers. Gene mutations of 15 HSPs influenced their protein expressions in different cancers. Copy number amplifications and deletions of 22 HSPs also impacted protein expression levels in pan-cancer. HSP gene mutation was generally a poor prognosis factor in cancers, except for uterine corpus endometrial carcinoma. CNVs in 14 HSPs showed varying influences on survival status in different cancers. HSPs may be involved in the activation and inhibition of multiple cancer-related pathways. HSP expressions were closely correlated with 22 immune cell infiltrations in different cancers. Conclusion: Our results show that HSP families play an important role in the occurrence and development of various tumors and are potential tumor diagnostic and prognostic biomarkers as well as anti-cancer therapeutic targets.