Expression and Clinical Significance of SARS-CoV-2 Human Targets in Neoplastic and Non-Neoplastic Lung Tissues

HDAC1-3 inhibition increases SARS-CoV-2 replication and productive infection in lung mesothelial and epithelial cells

Background

Despite the significant progress achieved in understanding the pathology and clinical management of SARS-CoV-2 infection, still pathogenic and clinical issues need to be clarified. Treatment with modulators of epigenetic targets, i.e., epidrugs, is a current therapeutic option in several cancers and could represent an approach in the therapy of viral diseases.

Results

Aim of this study was the analysis of the role of histone deacetylase (HDAC) inhibition in the modulation of SARS-CoV-2 infection of mesothelial cells (MCs).MeT5A cells, a pleura MC line, were pre-treated with different specific class I and IIb HDAC inhibitors. Unexpectedly, treatment with HDAC1-3 inhibitors significantly increased ACE2/TMPRSS2 expression, suggesting a role in favoring SARS-CoV-2 infection. We focused our analysis on the most potent ACE2/TMPRSS2 inducer among the inhibitors analysed, MS-275, a HDAC1-3 inhibitor. ACE2/TMPRSS2 expression was validated by Western Blot (WB) and immunofluorescence. The involvement of HDAC inhibition in receptor induction was confirmed by HDAC1/HDAC2 silencing. In accordance to the ACE2/TMPRSS2 expression data, MS-275 increased SARS-CoV-2 replication and virus propagation in Vero E6 cells.Notably, MS-275 was able to increase ACE2/TMPRSS2 expression and SARS-CoV-2 production, although to a lesser extent, also in the lung adenocarcinoma cell line Calu-3 cells.Mechanistically, treatment with MS-275 increased H3 and H4 histone acetylation at ACE2/TMPRSS2 promoters, increasing their transcription.

Conclusion

This study highlights a previously unrecognized effect of HDAC1-3 inhibition in increasing SARS-CoV-2 cell entry, replication and productive infection correlating with increased expression of ACE2 and TMPRSS2. These data, while adding basic insight into COVID-19 pathogenesis, warn for the use of HDAC inhibitors in SARS-CoV-2 patients.

Chemotherapy induces ACE2 expression in breast cancer via the ROS-AKT-HIF-1α signaling pathway: a potential prognostic marker for breast cancer patients receiving chemotherapy

Background

Angiotensin-converting enzyme 2 (ACE2) is a key enzyme of the renin-angiotensin system and a well-known functional receptor for the entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) into host cells. The COVID-19 pandemic has brought ACE2 into the spotlight, and ACE2 expression in tumors and its relationship with SARS-COV-2 infection and prognosis of cancer patients have received extensive attention. However, the association between ACE2 expression and tumor therapy and prognosis, especially in breast cancer, remains ambiguous and requires further investigation. We have previously reported that ACE2 is elevated in drug-resistant breast cancer cells, but the exact function of ACE2 in drug resistance and progression of this malignant disease has not been explored.

Methods

The expression of ACE2 and HIF-1α in parental and drug-resistant breast cancer cells under normoxic and hypoxic conditions was analyzed by Western blot and qRT-PCR methods. The protein levels of ACE2 in plasma samples from breast cancer patients were examined by ELISA. The relationship between ACE2 expression and breast cancer treatment and prognosis was analyzed using clinical specimens and public databases. The reactive oxygen species (ROS) levels in breast cancer cells were measured by using a fluorescent probe. Small interfering RNAs (siRNAs) or lentivirus-mediated shRNA was used to silence ACE2 and HIF-1α expression in cellular models. The effect of ACE2 knockdown on drug resistance in breast cancer was determined by Cell Counting Kit 8 (CCK-8)-based assay, colony formation assay, apoptosis and EdU assay.

Results

ACE2 expression is relatively low in breast cancer cells, but increases rapidly and specifically after exposure to anticancer drugs, and remains high after resistance is acquired. Mechanistically, chemotherapeutic agents increase ACE2 expression in breast cancer cells by inducing intracellular ROS production, and increased ROS levels enhance AKT phosphorylation and subsequently increase HIF-1α expression, which in turn upregulates ACE2 expression. Although ACE2 levels in plasma and cancer tissues are lower in breast cancer patients compared with healthy controls, elevated ACE2 in patients after chemotherapy is a predictor of poor treatment response and an unfavorable prognostic factor for survival in breast cancer patients.

Conclusion

ACE2 is a gene in breast cancer cells that responds rapidly to chemotherapeutic agents through the ROS-AKT-HIF-1α axis. Elevated ACE2 modulates the sensitivity of breast cancer cells to anticancer drugs by optimizing the balance of intracellular ROS. Moreover, increased ACE2 is not only a predictor of poor response to chemotherapy, but is also associated with a worse prognosis in breast cancer patients. Thus, our findings provide novel insights into the spatiotemporal differences in the function of ACE2 in the initiation and progression of breast cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03716-w.

Molecular Landscape of Lung Epithelium Contributes to High Severity and Comorbidities for COVID-19 and Lung Cancer

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The heterogeneous and complex nature of cancer is extensively revealed at molecular, genetic, and tissue microenvironment levels. Currently, co-occurrence of coronavirus disease 2019 (COVID-19) to lung cancer patients and severity of infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been understood at preclinical and clinical levels. However, molecular and cellular insights are not discussed in those papers that support the increased COVID-19 severity and comorbidities in several cancer types, including lung cancer patients. Therefore, this perspective highlights the basis of high severity and comorbidities among lung cancer patients infected by COVID-19 with an emphasis on translational aspects.

Lung Cancer and Severe Acute Respiratory Syndrome Coronavirus 2 Infection: Identifying Important Knowledge Gaps for Investigation

Patients with lung cancer are especially vulnerable to coronavirus disease 2019 (COVID-19) with a greater than sevenfold higher rate of becoming infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) COVID-19, a greater than threefold higher hospitalization rate with high complication rates, and an estimated case fatality rate of more than 30%. The reasons for the increased vulnerability are not known. In addition, beyond the direct impact of the pandemic on morbidity and mortality among patients with lung cancer, COVID-19, with its disruption of patient care, has also resulted in substantial impact on lung cancer screening and treatment/management.COVID-19 vaccines are safe and effective in people with lung cancer. On the basis of the available data, patients with lung cancer should continue their course of cancer treatment and get vaccinated against the SARS-CoV-2 virus. For unknown reasons, some patients with lung cancer mount poor antibody responses to vaccination. Thus, boosting vaccination seems urgently indicated in this subgroup of vulnerable patients with lung cancer. Nevertheless, many unanswered questions regarding vaccination in this population remain, including the magnitude, quality, and duration of antibody response and the role of innate and acquired cellular immunities for clinical protection. Additional important knowledge gaps also remain, including the following: how can we best protect patients with lung cancer from developing COVID-19, including managing care in patient with lung cancer and the home environment of patients with lung cancer; are there clinical/treatment demographics and tumor molecular demographics that affect severity of COVID-19 disease in patients with lung cancer; does anticancer treatment affect antibody production and protection; does SARS-CoV-2 infection affect the development/progression of lung cancer; and are special measures and vaccine strategies needed for patients with lung cancer as viral variants of concern emerge.

Factors regulating dynamics of angiotensin-converting enzyme-2 (ACE2), the gateway of SARS-CoV-2: Epigenetic modifications and therapeutic interventions by epidrugs

Angiotensin-converting enzyme-2 (ACE2) is one of the major components of the renin-angiotensin system (RAS) and participates in the physiological functions of the cardiovascular system and lungs. Recent studies identified ACE2 as the receptor for the S-protein of the novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and thus acts as the gateway for viral entry into the human body. Virus infection causes an imbalance in the RAS axis and induces acute lungs injury and fibrosis. Various factors regulate ACE2 expression patterns as well as control its epigenetic status at both transcription and translational levels. This review is mainly focused on the impact of environmental toxicants, drugs, endocrine disruptors, and hypoxia as controlling parameters for ACE2 expression and its possible modulation by epigenetic changes which are marked by DNA methylation, histone modifications, and micro-RNAs (miRNAs) profile. Furthermore, we have emphasized on interventions of various phytochemicals and bioactive compounds as epidrugs that regulate ACE2-S-protein interaction and thereby curb viral infection. Since ACE2 is an important component of the RAAS axis and a crucial entry point of SARS-CoV-2, the dynamics of ACE2 expression in response to various extrinsic and intrinsic factors are of contemporary relevance. We have collated updated information on ACE2 expression modulated by epidrugs, and urge to take over further studies on these important physiological regulators to unravel many more systemic linkages related to both metabolic and infectious diseases, in general and SARS-CoV-2 in particular for further development of targeted interventions.

Expression of SARS-COV-2 cell receptor gene ACE2 is associated with immunosuppression and metabolic reprogramming in lung adenocarcinoma based on bioinformatics analyses of gene expression profiles

The aberrant expression level of SARS-CoV-2 cell receptor gene ACE2 was reported in lung adenocarcinoma (LUAD) comorbidity of COVID-19. However, the association of ACE2 expression levels with immunosuppression and metabolic reprogramming in LUAD remains lacking. We investigated the expression level of ACE2, an association of ACE2 expression level with various types of immune signatures, immune ratios, and pathways. We employed a weighted gene co-expression network analysis (WGCNA) R package to identify the gene modules and investigated prognostic roles of hub genes in LUAD. Overexpression of ACE2 level was found in LUAD and ACE2 expression was negatively associated with various types of immune signatures including CD8⁺ T cells, CD4⁺ regulatory T cells, NK cells, and T cell activation. Besides, ACE2 upregulation was not only associated with CD8⁺ T cell/CD4+ regulatory T cell ratios but also linked with downregulation of immune-markers including CD8A, KLRC1, GZMA, GZMB, NKG7, CCL4, and IFNG. Moreover, the ACE2 expression level was found to be associated with the enrichment level of various metabolic pathways and it was also found that the metabolic pathways are directly positively correlated with the increased expression levels of ACE2, indicating that the overexpression of ACE2 is associated with metabolic reprogramming in LUAD. Furthermore, WGCNA based analysis revealed the gene modules in the high-ACE2-expression-level group of LUAD and identified GCLC and SLC7A11 hub genes which are not only highly expressed in lung adenocarcinoma but also correlated with the poor survival prognosis. Our analysis of ACE2 in LUAD tissues suggests that ACE2 is not only a receptor but is also associated with immunosuppression and metabolic reprogramming. This study underlines the clue for understanding the clinical significance of ACE2 in COVID-19 patients with LUAD comorbidity.

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The expression level of ACE2 is negatively associated with the immune signatures.

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ACE2 upregulation also linked with the downregulation of immune-markers.

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The ACE2 expression level is positively associated with the metabolic pathways.

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WGCNA based analysis revealed the gene modules in a high-ACE2-expression-level group.

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Highly expressed GCLC and SLC7A11 hub genes are correlated with the poor prognosis.