Abstract 5730: Targeting intrinsically disordered protein βII-spectrin prevents metabolic syndrome and hepatocellular carcinoma on a sex-based bias
Authors: Yang Xiaochun , Bhowmick Krishanu , Xiang Xiyan , Ohshiro Kazufumi , Vegesna Anil , Mishra Lopa 
Published: April 2023

Abstract
Background: Hepatocellular carcinoma (HCC) is a lethal cancer that affects males 2-4 times more than females. HCC incidence is rising in parallel with risk factors such as non-alcoholic steatohepatitis (NASH) and alcohol induced cirrhosis. A major enzyme in alcohol metabolism, aldehyde dehydrogenase 2 (ALDH2) deficiency affects ~560 million people globally. In males, different ALDH2 genotypes exhibit significant metabolic differences from females. Yet the mechanism for the sex differences remains unclear. We have found that targeting an intrinsically disordered protein and TGF-β signaling Smad3/4 adaptor, βII-spectrin (Sptbn1) blocks NASH and HCC in a liver-specific knockout (LSKO) mice and siRNA to human NASH microfluidic cultures (Sci Transl Med. 2021. 13(624): eabk2267). In mouse mutants of Smad3/Sptbn1 with HCC, stem cell proteins are markedly altered. Here, we sought to examine this further by intercrossing Sptbn1 deficient mice with ALDH2 deficient mice.
Methods: Global heterozygous knockout of Sptbn1 mice were intercrossed with Aldh2 knockout mice (ASKO) to explore the role of βII-spectrin in aldehyde-related liver injury. LSKO mice were intercrossed with ALDH2 deficient mice (ALSKO) and siRNA treatment to explore the therapeutic effects of targeting Sptbn1 during the progression of metabolic syndrome (MetS) or HCC induced by Western diet (WD)/chemical (DEN) in the context of ALDH2 deficiency in both male and female mice. We performed phenotypic analyses of metabolic state, liver pathology, intestinal pathology, and gut microbiomes.
Results: LSKO displayed obvious therapeutic effects against liver steatosis in male mice, whereas female mice did not. ASKO mice developed NASH spontaneously and showed impaired glucose handling, disordered lipids metabolism, with increased intestinal permeability and pro-inflammatory species of Bacteroidetes and Firmicutes. ALDH2 deficiency exacerbated toxic reactive aldehydes accumulation. LSKO mice were protected from WD induced MetS and NASH, including decreased body weight and fat weight, decreased serum triglyceride and AST/ALT, downregulated expression of proinflammatory genes and profibrotic genes and improved NAS Score. LSKO mice were also protected from WD/DEN-induced HCC: mice had less tumor number, smaller tumor size and less proliferation. siRNA targeting Sptbn1 also showed similar therapeutic effects as LSKO. Further, LSKO and siRNA targeting Sptbn1 also improved NASH phenotypes resembling MetS in Aldh2−/− mice: decreased liver fat accumulation, improved glucose handling and reduced inflammatory cell infiltration.
Conclusions: Our data suggest that βII-spectrin, an intrinsically disordered protein, is a potential therapeutic target for diet/chemical-induced Mets/NASH and preventing HCC development and could provide new insight into sex-based differences in HCC.
Citation Format: Xiaochun Yang, Krishanu Bhowmick, Xiyan Xiang, Kazufumi Ohshiro, Anil Vegesna, Lopa Mishra. Targeting intrinsically disordered protein βII-spectrin prevents metabolic syndrome and hepatocellular carcinoma on a sex-based bias. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5730.