Nuclear factor IA-mediated transcriptional regulation of crystallin αB inhibits hepatocellular carcinoma progression.

Hepatocellular carcinoma (HCC) is a highly invasive malignant tumor with limited therapeutic options. In the present study, bioinformatics analysis, including differential expression analysis, functional enrichment, protein-protein interaction network construction, survival analysis and risk model evaluation, identified CRYAB as a central prognostic gene in HCC. Additionally, motif analysis using JASPAR revealed nuclear factor IA (NFIA), as a potential transcriptional regulator of CRYAB. Further in vitro experiments were conducted to explore the roles of CRYAB and NFIA in HCC, suggesting that these molecules may serve as promising therapeutic targets for future research. Differentially expressed genes (DEGs) from the Cancer Genome Atlas-liver hepatocellular carcinoma (LIHC) and GSE113996 datasets were identified using the 'limma' package, with Biological Process and Kyoto Encyclopedia of Genes and Genomes enrichment analysis conducted. Overlapping DEGs underwent Protein-protein interaction and prognostic analysis. Key prognostic genes were selected through Kaplan-Meier survival analysis and Least Absolute Shrinkage and Selection Operator regression before they were incorporated into a predictive risk model, which was evaluated by receiver operating characteristic analysis. JASPAR motif analysis identified NFIA as a potential transcriptional regulator of CRYAB, with the TIMER database used to further examine the NFIA expression profile among other cancers. In vitro assays using MHCC97H and Huh7 cells were used to examine the roles of CRYAB and NFIA in HCC. Cell counting kit-8 (CCK-8) assay was used to assess proliferation, whilst Transwell assay was used to measure migration and invasion. To investigate the reciprocal regulation, rescue experiments combining NFIA overexpression and CRYAB knockdown were performed to compare their effects on cell proliferation, migration and invasion. Additionally, dual-luciferase assay was used to examine the regulatory effect of NFIA on the CRYAB promoter by comparing the wild-type and mutant constructs. Bioinformatics analyses revealed CRYAB to be a hub gene. CRYAB upregulation was found to be associated with poor prognosis in patients with LIHC. In vitro, elevated CRYAB expression was observed in HCC cell lines compared with that in the huma liver immortalized cell line THLE-2. CRYAB knockdown was found to significantly inhibit MHCC97H and Huh7 cell proliferation, migration and invasion. By contrast, NFIA expression was found to be downregulated in LIHC compared with that in normal liver tissues, where its expression showed an inverse association with that of CRYAB. Direct interaction between NFIA and the CRYAB promoter region was confirmed through dual-luciferase assays. Furthermore, low NFIA expression markedly enhanced HCC cell proliferation, invasion and migration. This pro-tumor effect was reversed in the si-NFIA + si-CRYAB group, where simultaneous downregulation of CRYAB significantly reduced cell proliferation, migration and invasion, suggesting that CRYAB downregulation can counteract the effects induced by low NFIA expression. To conclude, these results suggest that NFIA can inhibit the malignant proliferation of HCC cells by activating CRYAB expression, which further suggest that CRYAB and NFIA are promising avenues for the development of novel HCC treatment strategies.