Effect of angiotensin receptor blockade on prevention and reversion of tamoxifen-resistant phenotype in MCF-7 cells

Impact on clinical outcomes of renin-angiotensin system inhibitors against doxorubicin-related toxicity in patients with breast cancer and hypertension: A nationwide cohort study in South Korea

BACKGROUND

Although doxorubicin (DOX) is a commonly used potent chemotherapeutic agent in patients with breast cancer, its cardiotoxic effect is a concern, particularly in patients with hypertension. Antihypertensive renin-angiotensin system (RAS) inhibitors may potentially play a role in preventing overt heart failure (HF) due to DOX toxicity. This study aimed to evaluate whether the use of RAS inhibitors improves clinical outcomes in patients with hypertension and breast cancer undergoing DOX-containing chemotherapy.

METHODS

A total of 54,344 female patients who were first diagnosed with breast cancer and initiated into DOX therapy between 2008 and 2015 were recruited from a nationwide Korean cohort. Patients were divided into two groups: with and without hypertension (HT, n = 10,789; non-HT, n = 43,555), and the RAS inhibitor group (n = 1,728) was sub-classified from the HT group. Two propensity score-matched cohorts were constructed to compare the clinical outcomes between non-HT and HT groups and between non-HT and RAS inhibitor groups. The primary outcome was the composite of HF and death.

RESULTS

After propensity score matching, the HT group had a higher risk for HF (adjusted hazard ratio [HR] = 1.30, 95% confidence intervals [95% CI] = 1.09-1.55) compared to the non-HT group, but there was no significant difference in primary outcome between the two groups. The RAS inhibitor group had a lower risk for primary outcome (adjusted HR = 0.78, 95% CI = 0.65-0.94) and death (adjusted HR = 0.81, 95% CI = 0.66-0.99) compared to the non-HT group.

CONCLUSIONS

Hypertension is a risk factor for HF in patients with breast cancer undergoing DOX chemotherapy. However, the RAS inhibitors used to treat hypertension may contribute to decreased mortality and improved clinical outcomes.

Estrogen and Estrogen Receptor Modulators: Potential Therapeutic Strategies for COVID-19 and Breast Cancer

Owing to the ongoing coronavirus disease 2019 (COVID-19) pandemic, we need to pay a particular focus on the impact of coronavirus infection on breast cancer patients. Approximately 70% of breast cancer patients express estrogen receptor (ER), and intervention therapy for ER has been the primary treatment strategy to prevent the development and metastasis of breast cancer. Recent studies have suggested that selective estrogen receptor modulators (SERMs) are a potential therapeutic strategy for COVID-19. With its anti-ER and anti-viral combined functions, SERMs may be an effective treatment for COVID-19 in patients with breast cancer. In this review, we explore the latent effect of SERMs, especially tamoxifen, and the mechanism between ER and virus susceptibility.

The potential role of abnormal angiotensin-converting enzyme 2 expression correlated with immune infiltration after SARS-CoV-2 infection in the prognosis of breast cancer

The potential role of abnormal ACE2 expression after SARS-CoV-2 infection in the prognosis of breast cancer is still ambiguous. In this study, we analyzed ACE2 changes in breast cancer and studied the correlation between ACE2 and the prognosis and further analyzed the relationship between immune infiltration and the prognosis of different breast cancer subtypes. Finally, we inferred the prognosis of breast cancer patients after SARS-CoV-2 infection. We found that ACE2 expression decreased significantly in breast cancer, except for basal-like subtype. Decreased ACE2 expression level was correlated with abnormal immune infiltration and poorer prognosis of luminal B breast cancer (RFS: HR 0.76, 95%CI=0.63-0.92, p=0.005; DMFS: HR 0.70, 95%CI=0.49-1.00, p=0.046). The expression of ACE2 was strongly positively correlated with the immune infiltration level of CD8⁺ T cell (r=0.184, p<0.001), CD4⁺ T cell (r=0.104, p=0.02) and neutrophils (r=0.101, p=0.02). ACE2 expression level in the luminal subtype was positively correlated with CD8A and CD8B markers in CD8+ T cells, and CEACAM3, S100A12 in neutrophils. In conclusion, breast tumor tissues might undergo a further decrease in the expression level of ACE2 after SARS-CoV-2 infection, which could contribute to further deterioration of immune infiltration and worsen the prognosis of luminal B breast cancer after SARS-CoV-2 infection.

The Effect of Local Renin Angiotensin System in the Common Types of Cancer

The Renin Angiotensin System (RAS) is a hormonal system that is responsible for blood pressure hemostasis and electrolyte balance. It is implicated in cancer hallmarks because it is expressed locally in almost all of the body's tissues. In this review, current knowledge on the effect of local RAS in the common types of cancer such as breast, lung, liver, prostate and skin cancer is summarised. The mechanisms by which RAS components could increase or decrease cancer activity are also discussed. In addition to the former, this review explores how the administration of AT1R blockers and ACE inhibitors drugs intervene with cancer therapy and contribute to the outcomes of cancer.

COVID-19 infection can cause chemotherapy resistance development in patients with breast cancer and tamoxifen may cause susceptibility to COVID-19 infection

Breast cancer is the most common cancer in women and is the second most common cause of death in women. Estrogen plays an important role in breast tumor etiopathogenesis. Tamoxifen and other anti-estrogen drugs are used in breast cancer patients who have a positive estrogen receptor (ER). While angiotensin II plays a key role in breast cancer etiology and causes tamoxifen resistance, angiotensin 1-7 has been reported to may reduce the spread and invasion of breast cancer. During the COVID-19 infection, the virus blocks ACE2, and angiotensin 1-7 production discontinued. Angiotensin III production may increase as angiotensin II destruction is reduced. Thus, aminopeptidase upregulation may occur. Increased aminopeptidase may develop resistance to chemotherapy in breast cancer patients receiving chemotherapy. Estrogen can have a protective effect against COVID-19. Estrogen increase causes ER-α upregulation in T lymphocytes. Thus, estrogen increases the release of interferon I and III from T lymphocytes. Increasing interferon I and III alleviates COVID-19 infection. Tamoxifen treatment causes down-regulation, mutation, or loss in estrogen receptors. In the long-term use of tamoxifen, its effects on estrogen receptors can be permanent. Thus, since estrogen receptors are damaged or downregulated, estrogen may not act by binding to these receptors. Tamoxifen is a P-glycoprotein inhibitor, independent of its effect on estrogen receptors. It suppresses T cell functions and interferon release. We think tamoxifen may increase the COVID-19 risk due to its antiestrogen and P-glycoprotein inhibitory effects.

The Network of Angiotensin Receptors in Breast Cancer

The renin-angiotensin system (RAS) is a network of proteins regulating many aspects of human physiology, including cardiovascular, pulmonary, and immune system physiology. The RAS is a complicated network of G-protein coupled receptors (GPCRs) (i.e., AT1R, AT2R, MASR, and MRGD) orchestrating the effects of several hormones (i.e., angiotensin II, angiotensin (1-7), and alamandine) produced by protease-based transmembrane receptors (ACE1 and ACE2). Two signaling axes have been identified in the RAS endocrine system that mediate the proliferative actions of angiotensin II (i.e., the AT1R-based pathway) or the anti-proliferative effects of RAS hormones (i.e., the AT2R-, MAS-, and MRGD-based pathways). Disruption of the balance between these two axes can cause different diseases (e.g., cardiovascular pathologies and the severe acute respiratory syndrome coronavirus 2- (SARS-CoV-2)-based COVID-19 disease). It is now accepted that all the components of the RAS endocrine system are expressed in cancer, including cancer of the breast. Breast cancer (BC) is a multifactorial pathology for which there is a continuous need to identify novel drugs. Here, I reviewed the possible roles of both axes of the RAS endocrine network as potential druggable pathways in BC. Remarkably, the analysis of the current knowledge of the different GPCRs of the RAS molecular system not only confirms that AT1R could be considered a drug target and that its inhibition by losartan and candesartan could be useful in the treatment of BC, but also identifies Mas-related GPCR member D (MRGD) as a druggable protein. Overall, the RAS of GPCRs offers multifaceted opportunities for the development of additional compounds for the treatment of BC.

AGTR1 promoter hypermethylation in lung squamous cell carcinoma but not in lung adenocarcinoma

Aberrant DNA methylation is associated with non-small cell lung cancer (NSCLC), suggesting that gene promoter methylation may be a potential biomarker for the detection or risk prediction of NSCLC. The present study aimed to evaluate the potential usage of angiotensin II receptor type 1 (AGTR1) methylation in two major pathologic subtypes: Lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). Quantitative methylation-specific polymerase chain reaction was used to investigate the effect of AGTR1 promoter methylation in the tumor and the paired adjacent non-tumor tissue samples from 42 patients with LUSC, and 69 with LUAD. The percentage of methylated reference was calculated and presented as the median (interquartile range 25th-75th percentile). The results of the current study revealed that there was significantly increased AGTR1 promoter methylation in the tumor tissues compared with the paired adjacent non-tumor tissue [97.4 (57.22-130.5) vs. 85 (48.25-123); P=0.024]. Furthermore, higher AGTR1 promoter methylation was observed in patients with LUSC compared with LUAD (odds ratio=2.483; 95% confidence interval=1.125-5.480; P=0.023). Significant differences were identified in AGTR1 methylation between non-tumor and the tumor tissues in LUSC [113.5 (68.33-148.73) vs. 93.04 (45.94-140); P=0.008]. In addition, the Cancer Genome Atlas data of 378 patients with LUSC and 477 with LUAD revealed an inverse correlation between gene expression and the methylation status of AGTR1 promoter.. These data suggest that AGTR1 hypermethylation is a promising biomarker to assist in LUSC detection and diagnosis.

G-protein coupled receptors of the renin-angiotensin system: new targets against breast cancer?

G-protein coupled receptors (GPCRs) constitute the largest family of membrane receptors, with high potential for drug discovery. These receptors can be activated by a panel of different ligands including ions, hormones, small molecules, and vasoactive peptides. Among those, angiotensins [angiotensin II (AngII) and angiotensin 1–7] are the major biologically active products of the classical and alternative renin-angiotensin system (RAS). These peptides bind and activate three different subtypes of GPCRs, namely AT1, AT2, and Mas receptors, to regulate cardiovascular functions. Over the past decade, the contribution of several RAS components in tumorigenesis has emerged as a novel important concept, AngII being considered as harmful and Ang1–7 as protective against cancer. Development of selective ligands targeting each RAS receptor may provide novel and efficient targeted therapeutic strategies against cancer. In this review, we focus on breast cancer to summarize current knowledge on angiotensin receptors (AT1, AT2, and Mas), and discuss the potential use of angiotensin receptor agonists and antagonists in clinics.

Loss of angiotensin-converting enzyme 2 promotes growth of gallbladder cancer

The aim of this study is to investigate the role of angiotensin-converting enzyme 2 (ACE2) in gallbladder cancer (GBC) and the therapeutic potential of angiotensin receptor blocker in GBC. Human gallbladder epithelial cells (HGBEC) together with GBC cells and tissue samples were used. In vitro studies were carried out to investigate the role of ACE2 in GBC cells. ACE2 levels were studied in in vivo GBC mouse models subject to ARB treatment. ACE2 level was decreased in GBC cells compared with that in normal gallbladder cells. Replenishment of angiotensin II (A2) promoted tumour cell growth, which could be mitigated by ACE2 supplement. ARB blocked A2-induced GBC cell growth and activated ERK. Activity of mTOR was not altered with different ACE2 status. ARB inhibited tumour growth in xenograft mouse models. In vivo study also showed that decreased expression of ACE2 was associated with enlarged tumour size. By genetic replenishment of ACE2 and pharmaceutical use of ARB, restored ACE2 level mitigated GBC growth. Our results supported the rationale for the use of ARB in GBC patients for potential therapeutic benefit.