Tupa Basuroy, PhD

Pronouns

She/Her/Hers

Rank

Research Fellow

Institution

MGH

BWH-MGH Title

Associate Professor of Medicine

Department

Radiation Oncology

Authors

Tupa Basuroy*, Othon Iliopoulos

Nuclear acetate shapes the metabolic profile in renal cell carcinoma

WMSS 2022

My participation in the Women in Medicine & Science Symposium 2022 will translate the present-day societal thinking that is equipped to accept women as part of the medical profession. This is a good opportunity to identify me as one of the millions of women cancer researchers who partake in the development of the US economy that encourages private investments in drug discovery for the cure of several life-threatening diseases including cancer. My clinical interest in cancer research has been a wonderful journey, being blessed with amazing mentors, both men and women, who are top-notch clinicians and scientists as well.

Background

Inactivation of Von-Hippel Lindau (VHL) tumor suppressor gene accounts to over ninety percent of clear renal cell carcinoma (ccRCC) cases. VHL loss results in constitutive activation of hypoxia inducible factor 2 alphas (HIF2αs), and results in HIF2α-dependent reprogramming of cancer cell metabolism. Cells with active HIF2αs become glutamine addicted. Cancer cells rely on glutamine carbons as key source to generate energy, biomass and reducing equivalents and restore the Acetyl CoA pool.

Methods

Targeting Glutaminase 1 (GLS1), the obligatory enzyme that catalyzes the first step of exogenous glutamine utilization, kills preferentially VHL-null and HIF2α-expressing cells. We test the hypothesis that Acetyl CoA Synthetase 2 (ACSS2), an enzyme that converts free acetate to Acetyl CoA, may synergize with GLS1 inhibitors to suppress growth of ccRCC. We examine with genetic and metabolic experiments the role of ACSS2 in RCC biology.

Results

Inhibition of GLS1 decreases cellular Acetyl CoA. We showed that GLS1 inhibitor (CB-839) reduces Histone3 Lysine27 Acetylation (H3K27Ac) in vitro, preferentially in VHL-depleted cells, compared to their VHL-replete counterparts.

Conclusions

Preliminary experiments using an ACSS2 inhibitor support the hypothesis. We identified that nuclear ACSS2 recaptures free nuclear acetate and exogenous acetate as substrate to maintain nuclear Acetyl CoA pool for histone reacetylation in HIF2α-dependent manner.