Abstract S01-01: Therapeutic targeting of TMPRSS2 and ACE2 as a potential strategy to combat COVID-19
Authors: Deng Qu , Rasool Reyaz Ur , Natesan Ramakrishnan , Asangani Irfan A. 
Published: December 2020

Abstract
The novel SARS-CoV-2 infection responsible for the COVID-19 pandemic is expected to have an adverse effect on the progression of multiple cancers, including prostate cancer, due to the ensuing cytokine storm associated oncogenic signaling. A better understanding of the host cell factors and their regulators will help identify potential therapies to block SARS-CoV-2 infection at an early stage and thereby prevent cancer progression. Host cell infection by SARS-CoV-2 requires the binding of the viral spike S protein to ACE2 receptor and priming by the serine protease TMPRSS2—encoded by a well-known androgen response gene and highly expressed in patients diagnosed with prostate cancer. Epidemiologic data showing increased severity and mortality of SARS-CoV-2 disease in men suggest a possible role for androgen in the transcriptional activation of ACE2 and TMPRSS2 in the lungs and other primary infection sites. Here, by performing in vivo castration in mice, RT-PCR, immunoblotting, Co-IP, and pseudovirus infection assays in multiple cell lines, we present evidence for the transcriptional regulation of TMPRSS2 and ACE2 by androgen, their endogenous interaction, as well as a novel combination of drugs in blocking viral infection. In adult male mice, castration led to a significant loss in the expression of ACE2 and TMPRSS2 at the transcript and protein levels in the lung, heart, and small intestine. Intriguingly, castrated mice displayed a substantial increase in ACE2 in the kidney, which could potentially be due to the low blood pressure resulting from androgen deprivation. Endogenous TMPRSS2 and ACE2 were found to be physically interacting, as observed by reciprocal immunoprecipitation followed by immunoblotting. Importantly, along with full-length zymogen form, a prominent novel small isoform of TMPRSS2 was found to be associated with ACE2 in lung and prostate cells. In an overexpression system, camostat—a serine protease inhibitor specific to TMPRSS2—inhibited the cleavage of spike S, suggesting a direct role of this serine protease in priming the viral spike S protein, a prerequisite for an active infection. Furthermore, a combination of camostat, antiandrogen, and epigenetic drugs at sublethal concentrations blocked SARS-CoV-2 pseudovirus infection in multiple cell types. Together, our preclinical data provide a strong rationale for clinical evaluation of TMRPSS2 inhibitors, antiandrogens, and epigenetic drug combinations along with antiviral drug remdesivir as early as clinically possible to prevent progression to pneumonia and multiorgan failure as a result of hyperinflammatory responses in COVID-19 patients.
Citation Format: Qu Deng, Reyaz Ur Rasool, Ramakrishnan Natesan, Irfan A. Asangani. Therapeutic targeting of TMPRSS2 and ACE2 as a potential strategy to combat COVID-19 [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2020 Jul 20-22. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(18_Suppl):Abstract nr S01-01.