The Critical Role Of B4GALT4 In Promoting Microtubule Spindle Assembly In HCC Through The Regulation Of PLK1 And RHAMM Expression

Background: Protein glycosylation is a common and important post-translational modification that regulates cell functions.Recent research has demonstrated that the aberrant glycosylation is a hallmark of cancer.Beta1,4 ‐ galactosyltransferase(B4GALT)family members are involved in numerous biological processes that promote cancer progression,including the regulation of cancer cell proliferation,apoptosis and metastasis.However,the expressions and pathological mechanisms of B4 GALTs in hepatocellular carcinoma(HCC)remain unclear.Currently,there are few studies lie on the B4 GALT family members,and only a few works have emphasized the importance of B4GALT4 in biological system.B4GALT4 plays a key role in the biosynthesis of short keratan sulfate(KS)chains in vitro,which strongly implied the influence of aberrant B4GALT4 expression on the production of KS-containing proteoglycans(e.g.,lumican,fibromodulin,CD44).Objective: This study systematically explored the expression levels of B4 GALTs in HCC compared with normal tissues,and comprehensively evaluated the prognostic value of B4 GALTs in HCC.The main signaling pathways affected by B4 GALTs in HCC were identified,and the molecular mechanism of B4GALT4 involved in regulating the assembly of microtubule spindles in HCC cells was further elucidated.Method:(1)B4GALTs exhibited significant expression alterations in tumor tissues were screened out from a combined study of public databases on multiple platforms;(2)Based on machine learning algorithms combined with known liver cancer markers,a risk regression model was established by comprehensively considering the expression levels of B4 GALTs,and the prognostic value of the model was evaluated;(3)Through GO and GSEA gene pathway enrichment analysis,the signaling pathways mainly affected by B4 GALTs were elucidated,and the correlation analysis of gene expression as well as the single-cell sequencing data analysis were used to reveal the main role of B4GALT;(4)WB and other biochemical experiments were applied to study the activation of cell signaling pathways that are regulated by B4 GALT,and the downstream molecular mechanisms were elucidated eventually.Results:(1)The expression of B4 GALT family members were up-regulated in tumor tissues;(2)There is a strong correlation between the up-regulations of B4 GALTs with poorer prognosis among HCC patients;(3)Cell microtubule and spindle assembly is the main signaling pathway affected by B4 GALT family members in HCC;(4)Knockdown of B4GALT4 down-regulated the production of lumican,and repressed the expressions of PLK1 and RHAMM through regulating the TGF-beta pathway.Conclusion: B4 GALT family members play critical roles in HCC.B4GALT4 acts as a critical factor promoting the pathological progression of HCC and is an important prognostic marker of HCC.These studies will provide valuable insight into the role of B4 GALT family members in HCC and lead to the development of new strategies to improve the outcomes for patients with HCC.