Epithelial-to-Mesenchymal Transition (EMT) and Signal Transducers and Activators of Transcription (STAT3) Are a Novel Therapeutic Strategy for Hepatocellular Carcinoma (HCC) Prognosis

Abstract

Abstract Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death worldwide and is the second most common cancer in Egypt. Poor diagnosis of HCC is correlated with vascular invasion and metastasis. Epithelial-to-mesenchymal transition (EMT) is the main step in the tumor invasion process whereby epithelial cells lose cell polarity with each other and then undergo a dramatic remodeling of the cytoskeleton. Also, EMT plays a pivotal role in metastasis when epithelial cell layers lose cell-cell contacts in tumor progression due to the loss of E-cadherin and increasing the ability of the spread into surrounding tissues. Signal transducers and activators of transcription (STAT) play a different cellular function as signal transducers in the cytoplasm and transcription activators in the nucleus. STAT3 gene plays a crucial role to affect EMT in cancer progression by promoting cell proliferation and survival through its function as a transcription factor of the tumor. The aim of our study is to investigate the gene expression of STAT3 in HCC (HepG-2) cell lines and the expression of cell differentiation and proliferation markers. Western blotting was used to examine the protein expression of STAT3, E-cadherin, and β-catenin signaling. Our results showed that STAT3 expression levels were detected, as well as a significant increase in the expression of proliferation marker as β-catenin and a significant decrease of differentiation marker as E-cadherin protein expression levels in HepG-2 cell lines. Conclusion Our finding provides novel evidence for using a molecular gene therapy as STAT3, which showed an effect on EMT that plays a pivotal role in the prognosis of HCC. The loss of E-cadherin expression is a hallmark of EMT, because β-catenin is associated with the cytoplasmic domain of E-cadherin. We have emphasized the significant role of EMT and STAT3 in HCC progression, which could be a potential application as a novel therapeutic strategy for HCC treatment.