bioRxiv Science⌕ Search

Biology subjects

Hsieh, J. J.

Publications and source records attributed to Hsieh, J. J..

3 recordsLinked to original sources

Combined Loss of VHL and TSC1 Drives Clear Cell Renal Cell Carcinoma with Metabolic and Redox Reprogramming that Creates an NRF2 Dependency

Cancer genomics studies have implicated combined loss of VHL and TSC1 as sufficient to initiate clear cell renal cell carcinoma (ccRCC) in humans. Here, we engineered a mouse model with kidney-specific deletion of Vhl and Tsc1. VhlF/FTsc1F/FKsp-Cre+ mice developed multifocal renal cell carcinomas starting at 7 weeks of age with 100% penetrance, and the resulting Vhl-/-Tsc1-/- tumors recapitulated the histopathology of human VHL-/-TSC1-/- ccRCC. Integrated transcriptomic and metabolomic analyses of 4-week-old preneoplastic renal cortices deficient for Vhl and Tsc1 demonstrated heightened HIF and mTORC1 signaling and unexpectedly revealed activation of an antioxidant response regulated by NRF2 (NFE2L2). Biochemical, cell biological, multi-omic, and xenograft studies identified an NRF2 dependency in human VHL-/-TSC1-/- ccRCC cells. Altogether, we report a mouse model that recapitulates human VHL-/-TSC1-/- ccRCC, delineate metabolic and redox reprogramming driven by unrestrained HIF and mTORC1 activation in the renal cortex, and identify NRF2 as a potential therapeutic vulnerability.

cancer biology↗

Resource-efficient pooled sequencing expands translational impact in solid tumors

Intratumoral genetic heterogeneity (ITH) poses a significant challenge to utilizing sequencing for decision making in the management of cancer. Although sequencing of multiple tumor regions can address the pitfalls of ITH, it does so at a significant increase in cost and resource utilization. We propose a pooled multiregional sequencing strategy, whereby DNA aliquots from multiple tumor regions are mixed prior to sequencing, as a cost-effective strategy to boost translational value by addressing ITH while preserving valuable residual tissue for secondary analysis. Focusing on kidney cancer, we demonstrate that DNA pooling from as few as two regions significantly increases mutation detection while reducing clonality misattribution. This leads to an increased fraction of patients identified with therapeutically actionable mutations, improved patient risk stratification, and improved inference of evolutionary trajectories with an accuracy comparable to bona fide multiregional sequencing. The same approach applied to non-small-cell lung cancer data substantially improves tumor mutational burden (TMB) detection. Our findings demonstrate that pooled DNA sequencing strategies are a cost-effective alternative to address intrinsic genetic heterogeneity in clinical settings.

genomics↗

Sprouty2 limits intestinal tuft and goblet cell numbers through GSK3β-mediated restriction of epithelial IL-33.

Dynamic regulation of intestinal cell differentiation is crucial for both homeostasis and the response to injury or inflammation. Sprouty2, an intracellular signaling regulator, controls pathways including PI3K and MAPKs that are implicated in differentiation and are dysregulated in inflammatory bowel disease. Here, we asked whether Sprouty2 controls secretory cell differentiation and the response to colitis. We report that colonic epithelial Sprouty2 deletion led to expanded goblet and tuft cell populations. Sprouty2 loss induced PI3K/Akt signaling, leading to GSK3{beta} inhibition and epithelial interleukin (IL)-33 expression. In vivo, this resulted in increased stromal IL-13+ cells. IL-13 in turn induced tuft and goblet cell expansion in vitro and in vivo. Sprouty2 was downregulated by inflammation; this appeared to be a protective response, as VillinCre;Sprouty2F/F mice were resistant to DSS colitis. In contrast, Sprouty2 was elevated in colons of inflammatory bowel disease patients, suggesting that this protective epithelial-stromal signaling mechanism is lost in disease.

physiology↗