Research Projects

Hepatocellular carcinoma (HCC), leading cause of cancer-related mortality globally, is driven by risk factors like chronic hepatitis B infection and non-alcoholic fatty liver disease [1,2]. Orphan nuclear receptor, small heterodimer partner (SHP or NR0B2), involved in cholesterol-bile acid homeostasis functions as transcriptional repressor and tumor suppressor in liver cancer [18]. While, hyaluronan-binding protein 1 (HABP1) promotes tumor progression, extracellular matrix remodelling, and autophagy modulation in HCC [13,14]. Preliminary in silico analysis revealed inverse co-relation between SHP and HABP1 expression in primary HCC samples, corroborated by wet lab experiments. Stable SHP overexpression in HepG2 (HepSHP) ensued HABP1 downregulation and enhanced autophagic degradation, concomitant with reduced proliferation suggesting SHP-HABP1 crosstalk. The rationale is based on established literature and preliminary findings, supporting its feasibility. SHP reportedly recruits histone deacetylases (HDACs) to repress gene expression in metabolic pathways [15], demonstrating its epigenetic regulatory capacity. As epigenetic corepressor, it sequentially recruits HDACs, histone methyltransferase G9a, mSin3A/Swi–Snf chromatin‐remodeling complex to target promoters thereby affecting H3K9 deacetylation and methylation to establish repressive chromatin and silence genes e.g. CYP7A1 in hepatocytes [51]. In HCC, SHP is frequently silenced by promoter CpG hypermethylation, leading to enhanced tumor growth and poorer prognosis; conversely, restoration of SHP expression inhibits HCC cell proliferation by suppression of oncogenic pathways [24]. SHP deficiency causes widespread alterations in DNA methylation patterns, highlighting potential role in epigenetic regulation in HCC [28]. Meanwhile, HABP1 overexpression in HepG2 (HepR21) ensued SHP downregulation, concomitant with increased proliferation (preliminary data); suggesting SHP-mediated HABP1 repression could counteract these effects. This project aims to investigate a significant gap: epigenetic interplay between SHP and HABP1 to regulate HCC progression, addressing a yet underexplored regulatory axis in tumor biology. Prior research documented SHP’s epigenetic roles and tumor-suppressive functions and HABP1’s tumor proliferative function independently, but their combined genetic and epigenetic interactions—particularly how SHP potentially modulates HABP1 expression and downstream oncogenic processes—remain uncharted. Testable Hypothesis: SHP overexpression ensues reduced tumorigenic potential in HCC through epigenetic regulation of HABP1. The project is structured around three specific aims utilizing HepG2, HepSHP and HepR21 cells: 1st objective aims to analyze epigenetic modifications at HABP1 locus in response to SHP overexpression using ChIP seq to assess histone modifications and bisulfite sequencing to evaluate DNA methylation at the HABP1 promoter. 2nd objective focuses on identifying co-regulatory complexes at HABP1 locus utilizing Co-immunoprecipitation prior to mass spectrometry to identify SHP-interacting proteins (epigenetic modifiers like HDACs) and ChIP-qPCR to validate their recruitment at HABP1 locus. 3rd objective will access functional implications of SHP-HABP1 crosstalk at both epigenetic and protein levels upon autophagy, survivability and metastasis through SHP knockdown and HABP1 inhibition approaches. The project is expected to provide insight on specific SHP driven epigenetic modifications (e.g. histone acetylation, DNA methylation) at the HABP1 locus, potentially revealing previously unrecognized tumor-suppressive mechanism. Integration of the findings with functional outcomes like autophagy and metastasis, could uncover therapeutic targets, offering a transformative perspective on HCC biology and treatment strategies applicable to other cancers with dysregulated SHP and HABP1.