Expression studies are directed to detect and quantify a specific gene's messenger RNA (mRNA) levels. Fibroblast growth factor receptors (FGFRs) are a family of five highly conserved transmembrane tyrosine kinase receptors (RTKs), which regulate a variety of cellular functions, such as proliferation, and migration, differentiation, and survival. Distorted expression of FGFRs is commonly detected in cancer patients. Various enrichment analysis has investigated the association of FGFR(s) expression with tumorigenicity. Till now, less has been investigated regarding their expression in esophageal cancer development.
We analysed the expression data of FGFR(s) in GEPIA (Gene Expression Profiling Interactive Analysis), TNM, and UALCAN databases. The correlation between the expression pattern of FGFR(s) and patient survival was analyzed using a Kaplan-Meier plot. FGFR4 and FGFRL1 expression profiles were also evaluated for patient clinicopathological features. To explore the downstream signalling partners for FGFR4 and FGFRL1, differential gene expression analysis available, was done through the Enrichr tool using Panther, Reactome, and KEGG Databases.
The mRNA expression level of FGFR4 and FGFRL1 was significantly upregulated in esophageal carcinoma whereas expression of FGFR1 and 3 was significantly downregulated. We also observed that expression levels of FGFRL1 significantly decreases at the initiation of the lymph node metastasis stage and then gradually increases towards the end of the metastasis. Hence, provided microarray dataset was reanalyzed to identify differential genes expressed in the FGFRL1 deficient esophageal carcinoma cell line, and their pathway analysis was reported to be involved in various cell regulating pathways such as Cadherin signaling, and TGF signaling pathways.
Each FGFR seem to have different expression and survival correlation profile in esophageal carcinoma. FGFR4 and FGFRL1 predict a better relapse-free survival in EC and can be regarded as diagnostic markers.FGFRL1 knockout seem to affect a wide range of cellular pathways which are major drivers for regulation of cell survival and proliferation.
The authors.
Faculty Research Grant Scheme (FRGS), Guru Gobind Singh Indraprastha University.
All authors have declared no conflicts of interest.