A Pan-cancer Analysis to Determine the Prognostic Analysis and Immune
Infiltration of HSPA5
Authors: Zhu Rong-Kun , Zhang Wei , Zhang Yi-Xing , hui Zeng , Wang Xiong-Wei 
Published: May 2023

Background:
Heat shock 70kDa protein 5 (HSPA5), also known as GRP78, is widely expressed in
most malignant cells and has been shown to have a significant role in the spread of most malignancies by
transferring them to the cell membrane. High-level HSPA5 may serve as an independent prognostic marker
for various malignancies due to its ability to accelerate tumor growth and migration, inhibit cell apoptosis
and closely connect to prognosis. Therefore, it is crucial to examine HSPA5 using pan-cancer research,
which might result in the discovery of novel cancer treatment targets.

Methods:
The GTEx and TCGA databases have both provided evidence of the expression of various amounts
of HSPA5 in various tissues. The Clinical Proteomics Tumor Analysis Consortium (CPTAC) evaluated the
levels of HSPA5 protein expression, while qPCR investigations also evaluated the expression of HSPA5
mRNA in certain tumors. HSPA5 was studied using the Kaplan-Meier method to examine how it influences
overall survival and disease-free survival in malignancies. GEPIA2 was used to investigate the correlation
between HSPA5 expression and the clinical stage of cancer. The tumor-immune system interaction database
(TISIDB) examined the expression of HSPA5 in association with molecular and tumor immune subtypes.
The co-expressed genes of HSPA5 were extracted from the STRING database, and the top 5 co-expressed
genes of HSPA5 in 33 cancers were identified using the TIMER database. Further research examined the relationship
between tumor mutations and HSPA5. Microsatellite Instability (MSI) and Tumor Mutation Burden
(TMB) were the primary areas of interest. The association between HSPA5 mRNA expression and immune
infiltration was also explored using the TIMER database. Additionally, through the Linkedomics database,
we examined the enrichment of GO and KEGG for HSPA5 in glioblastoma. Finally, the Cluster Analyzer
tool was used to carry out a GSEA functional enrichment investigation.

Results:
HSPA5 mRNA expression was found to be greater in all 23 tumor tissues than in the equivalent
normal tissues, and high HSPA5 expression appeared to be strongly related to a poor prognosis in the majority
of cancers, as observed by survival plots. In the tumour clinical stage display map, HSPA5 showed differential
expression in most tumours. HSPA5 is strongly associated with Tumor Mutation Burden (TMB) and
Microsatellite Instability (MSI). Cancer-associated Fibroblasts (CAFs) infiltration was strongly associated
with HSPA5, as were nine immunological subtypes of malignancy and seven molecular subtypes of malignancy.
According to the results of GO and KEGG enrichment analyses, HSPA5 in GBM is mostly involved
in neutrophil-mediated immunological and collagen metabolic activities. Additionally, GSEA enrichment
analyses of HSPA5 and associated genes demonstrated a substantial link between HSPA5 and the immunological
milieu of tumors, cell division and nervous system regulation. By using qPCR, we were able to further
corroborate the enhanced expression in the GBM, COAD, LUAD and CESC cell lines.

Conclusion:
Our bioinformatics research leads us to hypothesize that HSPA5 may be involved in immune
infiltration as well as tumor growth and progression. Additionally, it was found that differentially expressed
HSPA5 is linked to a poor prognosis for cancer, with the neurological system, the tumor immunological microenvironment
and cytokinesis being potential contributing factors. As a result, HSPA5 mRNA and the associated
protein might be used as therapeutic targets and possible prognostic markers for a range of malignancies.