Cis-dichlorodiammineplatinum upregulates angiotensin II type 1 receptors through reactive oxygen species generation and enhances VEGF production in bladder cancer

Impact of Angiotensin Converting Enzyme Inhibitors on Pathologic Complete Response With Neoadjuvant Chemotherapy for Muscle Invasive Bladder Cancer

INTRODUCTION

The renin-angiotensin system (RAS) has been demonstrated to modulate cell proliferation, desmoplasia, angiogenesis and immunosuppression. We examined the association of RAS inhibitors (RASi)-namely angiotensin converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB)-with neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) preceding radical cystectomy (RC).

PATIENTS AND METHODS

We retrospectively investigated concurrent RASi use with NAC prior to RC in 302 patients with MIBC from 3 academic institutions. Outcomes included pathologic complete response (pCR) and overall survival (OS). Pathologic features, performance status (PS), clinical stage, type/number of cycles of NAC, and toxicities were collected.

RESULTS

Overall pCR rate was 26.2% and 5-year OS was 62%. Concurrent ACEi intake with NAC approached significance for association with pCR (odds ratio [OR] = 1.71; 95% CI, 0.94-3.11; P = .077). Patients with cT3/4N0-N1 disease receiving ACEi had higher pCR rates (30.8% vs. 17.7%, P = .056) than those not on ACEi. Female sex had a statistically significant favorable interaction for pCR with ACEi intake (P = .044). ACEi intake was not associated with OS, while pCR, PS and lower clinical stage were significantly associated with improved OS.

CONCLUSION

ACEi intake is potentially associated with increased pCR in patients with MIBC receiving NAC prior to RC, and this association is more pronounced in patients with higher clinical stage of disease at the initiation of therapy and female sex. Our data suggest the potential relevance of the RAS as a therapeutic target in aggressive MIBC.

Cisplatin treatment reduces contraction to angiotensin II by altering expression of angiotensin II receptors: a pilot study

The renin angiotensin system is a key regulator of blood pressure homeostasis. Angiotensin type 1 (AT1R) and 2 receptors (AT2R) have been investigated as targets for cisplatin-induced acute kidney injury; however, their therapeutic potential remains inconclusive. This pilot study aimed to determined the effect that acute cisplatin treatment had on angiotensin II (AngII)-induced contraction in blood vessels and expression profiles of AT1R and AT2R in mouse arteries and kidneys. Male C57BL/6 mice at 18 week of age (n = 8) were treated with vehicle or bolus dose of cisplatin (12.5 mg/kg). Thoracic aorta (TA), adnominal aorta (AA), brachiocephalic arteries (BC), iliac arteries (IL) and kidneys were collected for isometric tension and immunohistochemistry analysis. Cisplatin treatment reduced IL contraction to AngII at all doses (p < 0.01, p < 0.001, p < 0.0001); however, AngII did not induce contraction in TA, AA or BC in either treatment group. Following cisplatin treatment, AT1R expression was significantly upregulated in the media of TA (p < 0.0001) and AA (p < 0.0001), and in the endothelium (p < 0.05) media (p < 0.0001) and adventitia (p < 0.01) of IL. Cisplatin treatment significantly reduced AT2R expression in the endothelium (p < 0.05) and media (p < 0.05) of TA. In renal tubules, both AT1R (p < 0.01) and AT2R (p < 0.05) were increased following cisplatin treatment. Herein, we report that cisplatin reduces AngII-mediated contraction in IL and may be explained by an absence of normal counterregulatory expression of AT1R and AT2R, indicating other factors are involved.

Antihypertensive Drugs and Cancer Risk

Hypertension is the most prevalent comorbidity in cancer patients. Consequently, many cancer patients are prescribed antihypertensive drugs before cancer diagnosis or during cancer treatment. However, whether antihypertensive drugs affect the incidence, treatment efficacy, or prognosis of cancer remains unanswered. For instance, renin-angiotensin and β-adrenergic signaling may be involved not only in blood pressure elevation but also in cell proliferation, angiogenesis, and tissue invasion. Therefore, the inhibition of these pathways may have beneficial effects on cancer prevention or treatment. In this article, we reviewed several studies regarding antihypertensive drugs and cancer. In particular, we focused on the results of clinical trials to evaluate whether the use of antihypertensive drugs affects future cancer risk and prognosis. Unfortunately, the results are somewhat inconsistent, and evidence demonstrating the effect of antihypertensive drugs remains limited. We indicate that the heterogeneity in the study designs makes it difficult to clarify the causal relationship between antihypertensive drugs and cancer. We also propose that additional experimental studies, including research with induced pluripotent cells derived from cancer patients, single-cell analyses of cancer cell clusters, and clinical studies using artificial intelligence electronic health record systems, might be helpful to reveal the precise association between antihypertensive drugs and cancer risk.

Circ_0058063 contributes to cisplatin-resistance of bladder cancer cells by upregulating B2M through acting as RNA sponges for miR-335-5p

Bladder cancer (BC) is one of the most common malignant tumors of the urinary system, and cisplatin (CDDP) is a critical chemical drug for the treatment of BC. However, CDDP-resistance seriously limits the therapeutic efficacy of this drug for clinical utilization. Thus, identification of pivotal molecule targets that regulate CDDP-resistance in BC become urgent and necessary. In this study, we firstly identified a novel BC-associated circular RNA circ_0058063 that participates in the regulation of CDDP-resistance in BC. Specifically, circ_0058063 was significantly overexpressed in CDDP-resistant tissue and cells, in contrast with the corresponding CDDP-sensitive counterparts. Further loss-of-function experiments validated that downregulation of circ_0058063 suppressed cell proliferation and tumor growth, whereas induced cell apoptosis in the CDDP-resistant BC cells in vitro and in vivo. In addition, we disclosed that circ_0058063 acts as a sponge for miR-335-5p to positively regulate B2M expression, and further rescuing experiments verified that the enhancing effects of sh-circ_0058063 on CDDP-sensitivity in the CDDP-resistant BC cells were abrogated by silencing miR-335-5p. Taken together, our results demonstrated that circ_0058063 contributed to CDDP resistance of bladder cancer cells via sponging miR-335-5p, and B2M might be the downstream effector gene. This study firstly evidenced that targeting circ_0058063 might be an effective strategy to improve CDDP-sensitivity in BC.

Synthesis and Evaluation of [18F]FEtLos and [18F]AMBF3Los as Novel 18F-Labelled Losartan Derivatives for Molecular Imaging of Angiotensin II Type 1 Receptors

Losartan is widely used in clinics to treat cardiovascular related diseases by selectively blocking the angiotensin II type 1 receptors (AT₁Rs), which regulate the renin-angiotensin system (RAS). Therefore, monitoring the physiological and pathological biodistribution of AT₁R using positron emission tomography (PET) might be a valuable tool to assess the functionality of RAS. Herein, we describe the synthesis and characterization of two novel losartan derivatives PET tracers, [¹⁸F]fluoroethyl-losartan ([¹⁸F]FEtLos) and [¹⁸F]ammoniomethyltrifluoroborate-losartan ([¹⁸F]AMBF₃Los). [¹⁸F]FEtLos was radiolabeled by ¹⁸F-fluoroalkylation of losartan potassium using the prosthetic group 2-[¹⁸F]fluoroethyl tosylate; whereas [¹⁸F]AMBF₃Los was prepared following an one-step ¹⁸F-¹⁹F isotopic exchange reaction, in an overall yield of 2.7 ± 0.9% and 11 ± 4%, respectively, with high radiochemical purity (>95%). Binding competition assays in AT₁R-expressing membranes showed that AMBF₃Los presented an almost equivalent binding affinity (K_i 7.9 nM) as the cold reference Losartan (K_i 1.5 nM), unlike FEtLos (K_i 2000 nM). In vitro and in vivo assays showed that [¹⁸F]AMBF₃Los displayed a good binding affinity for AT₁R-overexpressing CHO cells and was able to specifically bind to renal AT₁R. Hence, our data demonstrate [¹⁸F]AMBF₃Los as a new tool for PET imaging of AT₁R with possible applications for the diagnosis of cardiovascular, inflammatory and cancer diseases.

Antihypertensive medications are associated with the risk of kidney and bladder cancer: a systematic review and meta-analysis

Several studies have indicated that the use of antihypertensive medications may influence the incidence of bladder/kidney cancer, with some scholars refuting any such association. Hence, a systematic review is needed to verify this linkage. we comprehensively searched PubMed, Embase, Web of Science, and the Cochrane Library for original studies reporting a relationship between antihypertensive medications and risk of bladder/kidney cancer. We included 31 articles comprising 3,352,264 participants. We found a significant association between the risk of kidney cancer and any antihypertensive medications use (relative risk (RR) = 1.45, 95% CI 1.20-1.75), as well as angiotensin-converting enzyme inhibitors (RR = 1.24, 95% CI 1.04-1.48), angiotensin II receptor blockers (ARB) (RR = 1.29, 95% CI:1.22-1.37), beta-blockers (RR = 1.36, 95% CI 1.11-1.66), calcium-channel blockers (RR = 1.65, 95% CI 1.54-1.78) and diuretics (RR = 1.34, 95% CI 1.19-1.51). In case of bladder cancer, a statistical significance was observed with the use of ARB (RR = 1.07, 95% CI 1.03-1.11) but not with the other antihypertensive medications. There was a linear association between the duration of antihypertensive medications and the risk of kidney cancer (P = 0.061 for a non-linear trend) and the pooled RR for the per year increase in antihypertensive medications duration of use was 1.02 (95% CI: 1.01-1.02). Our results indicate that there is a significant association between each class of antihypertensive medications and the risk of kidney cancer, and this trend presented as a positive linear association. Furthermore, the use of ARB has been linked to the risk of bladder cancer.

Targeting the renin-angiotensin system to improve cancer treatment: Implications for immunotherapy

Renin-angiotensin system (RAS) inhibitors (RASi)-widely prescribed for the treatment of cardiovascular diseases-have considerable potential in oncology. The RAS plays a crucial role in cancer biology and affects tumor growth and dissemination directly and indirectly by remodeling the tumor microenvironment. We review clinical data on the benefit of RASi in primary and metastatic tumors and propose that, by activating immunostimulatory pathways, these inhibitors can enhance immunotherapy of cancer.

Exploring the role of paraoxonase-2 in bladder cancer: analyses performed on tissue samples, urines and cell cultures

The enzyme paraoxonase-2 (PON2) is ubiquitously expressed and exerts its antiapoptotic and antioxidative functions in several intracellular compartments.The aim of this study is to investigate the role of PON2 in bladder cancer (BC). The expression levels of PON2 in paired tumor and normal bladder tissue samples and in urinary exfoliated cells from patients affected with BC and healthy donors were evaluated. Moreover, the effect of PON2 overexpression on tumor cell proliferation and susceptibility to oxidative stress was investigated in human bladder cancer cell line T24.Our results showed that PON2 expression levels were significantly higher in BC compared with non-tumor tissue. In urinary exfoliated cells from BC patients, PON2 mRNA levels showed an inverse correlation with tumor stage (pT). Moreover, PON2 overexpression in T24 cells led to a significant increase in tumor cell proliferation and resistance to oxidative stress.The results obtained showed that PON2 could represent a molecular biomarker for bladder cancer and suggest a potential role of the enzyme as a prognostic factor for this neoplasm.

A Mini-Review of Reactive Oxygen Species in Urological Cancer: Correlation with NADPH Oxidases, Angiogenesis, and Apoptosis

Oxidative stress refers to elevated reactive oxygen species (ROS) levels, and NADPH oxidases (NOXs), which are one of the most important sources of ROS. Oxidative stress plays important roles in the etiologies, pathological mechanisms, and treatment strategies of vascular diseases. Additionally, oxidative stress affects mechanisms of carcinogenesis, tumor growth, and prognosis in malignancies. Nearly all solid tumors show stimulation of neo-vascularity, termed angiogenesis, which is closely associated with malignant aggressiveness. Thus, cancers can be seen as a type of vascular disease. Oxidative stress-induced functions are regulated by complex endogenous mechanisms and exogenous factors, such as medication and diet. Although understanding these regulatory mechanisms is important for improving the prognosis of urothelial cancer, it is not sufficient, because there are controversial and conflicting opinions. Therefore, we believe that this knowledge is essential to discuss observations and treatment strategies in urothelial cancer. In this review, we describe the relationships between members of the NOX family and tumorigenesis, tumor growth, and pathological mechanisms in urological cancers including prostate cancer, renal cell carcinoma, and urothelial cancer. In addition, we introduce natural compounds and chemical agents that are associated with ROS-induced angiogenesis or apoptosis.

Prognostic Impact of Renin-Angiotensin Inhibitors in Patients with Bladder Cancer Undergoing Radical Cystectomy

BACKGROUND

Renin-angiotensin system blockade has been effective for the treatment of patients with several types of malignancy. This study evaluated the prognostic impact of renin-angiotensin system inhibitors, including angiotensin-2 converting enzyme inhibitors and angiotensin 2 receptor blockers, in patients with bladder cancer undergoing radical cystectomy.

METHODS

This retrospective study included 269 patients who had undergone radical cystectomy. The oncologic outcomes of patients treated or not treated with renin-angiotensin system inhibitors after surgery were evaluated. Overall survival and cancer-specific survival were assessed by the Kaplan-Meier method and by Cox regression analysis.

RESULTS

The median follow-up duration after radical cystectomy in survivors was 44.5 months. The 5-year, cancer-specific survival rates in patients who did and did not receive renin-angiotensin system inhibitors were 79.0 and 66.4 %, respectively (P = 0.011). Similarly, the 5-year overall survival rates were 76.1 and 61.4 %, respectively (P = 0.0097). Multivariable analyses showed that use of renin-angiotensin system inhibitors was an independent prognostic factor for cancer-specific survival (hazard ratio 0.47, P = 0.036) and for overall survival (hazard ratio 0.36, P = 0.022).

CONCLUSIONS

Renin-angiotensin system inhibitors significantly reduced the risks of cancer-specific and overall mortality after radical cystectomy in patients with bladder cancer. Renin-angiotensin system inhibitors may improve oncologic outcomes in high-risk patients with bladder cancer.

Renin-angiotensin system blockade: Its contribution and controversy

Angiotensin II is a key biological peptide in the renin-angiotensin system that regulates blood pressure and renal hemodynamics, and extensive experimental studies have shown that angiotensin II promotes diverse fibrotic changes and induces neovascularization in several inflammatory diseases. It is known that angiotensin II can be controlled using renin-angiotensin system blockade when angiotensin II is the main factor inducing a particular disease, and renin-angiotensin system blockade has assumed a central role in the treatment of inflammatory nephritis, cardiovascular disorders and retinopathy. In contrast, renin-angiotensin system blockade was found to have not only these effects but also other functions, such as inhibition of cancer growth, angiogenesis and metastasis. Numerous studies have sought to elucidate the mechanisms and support these antitumor effects. However, a recent meta-analysis showed that renin-angiotensin system blockade use might in fact increase the incidence of cancer, so renin-angiotensin system blockade use has become somewhat controversial. Although the renin-angiotensin system has most certainly made great contributions to experimental models and clinical practice, some issues still need to be resolved. The present review discusses the contribution and controversy surrounding the renin-angiotensin system up to the present time.

Renin-angiotensin system regulates neurodegeneration in a mouse model of normal tension glaucoma

Glaucoma, one of the leading causes of irreversible blindness, is characterized by progressive degeneration of optic nerves and retinal ganglion cells (RGCs). In the mammalian retina, excitatory amino acid carrier 1 (EAAC1) is expressed in neural cells, including RGCs, and the loss of EAAC1 leads to RGC degeneration without elevated intraocular pressure (IOP). In the present study, we found that expressions of angiotensin II type 1 receptor (AT1-R) and Toll-like receptor 4 (TLR4) are increased in RGCs and retinal Müller glia in EAAC1-deficient (KO) mice. The orally active AT1-R antagonist candesartan suppressed TLR4 and lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) expressions in the EAAC1 KO mouse retina. Sequential in vivo retinal imaging and electrophysiological analysis revealed that treatment with candesartan was effective for RGC protection in EAAC1 KO mice without affecting IOP. In cultured Müller glia, candesartan suppressed LPS-induced iNOS production by inhibiting the TLR4-apoptosis signal-regulating kinase 1 pathway. These results suggest that the renin–angiotensin system is involved in the innate immune responses in both neural and glial cells, which accelerate neural cell death. Our findings raise intriguing possibilities for the management of glaucoma by utilizing widely prescribed drugs for the treatment of high blood pressure, in combination with conventional treatments to lower IOP.

Synergistic induction of cancer cell death and reduction of clonogenic resistance by cisplatin and FK228

Human urinary bladder cancer is the fifth most common cancer in the United States, and the long-term disease-free survival in patients is still suboptimal with current chemotherapeutic regimens. Development of effective chemotherapeutic regimens is crucial to decrease the morbidity and mortality of this cancer. The goal of this study was to investigate the effectiveness of FK228 in increasing cisplatin's ability to induce bladder cancer cell death and reduce drug resistance. Our study revealed that FK228 combined with cisplatin synergistically induced cell death and reduced clonogenic survival of human urinary bladder cancer cells. The Erk-Nox pathway played an important role in mediating signals highly increased by this combined treatment to induce significantly-elevated levels of reactive oxygen species, leading to substantially-induced caspase activation and synergistically-increased death in cancer cells. Cisplatin was able to enhance the ability of FK228 to significantly reduce glutathione, indicating a novel activity of combined FK228 and cisplatin in reducing drug resistance. The ability of combined FK228 and cisplatin to synergistically induce cell death and reduce clonogenic survival was also applicable to colon cancer cells. Hence, combined use of FK228 with cisplatin should be considered in development of therapeutic strategies to control urinary bladder cancer and other cancer development and recurrence.

Prognonstic impact of renin-angiotensin system blockade in localised upper-tract urothelial carcinoma

Background:

The potential role of the renin-angiotensin system (RAS) in the promotion of tumour growth has been investigated, and the administration of RAS inhibitors, such as angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs), may improve disease control in malignancy. We investigated the prognostic impact of RAS inhibitors by analysing data from patients with upper-tract urothelial carcinoma (UTUC).

Methods:

A total of 279 patients who underwent nephroureterectomy for localised UTUC (pTa-3N0M0) were identified at our three institutions. We retrospectively investigated the prognostic outcomes following nephroureterectomy in patients administered or not administered ACEIs or ARBs.

Results:

The median follow-up period was 3.4 years. RAS inhibitors were administered to 48 patients (17.2%). Multivariate analysis showed that the appearance of pathological T3, positive lymphovascular invasion, and no RAS inhibitor administration (P=0.027 HR=3.14) were independent risk factors for a decrease in subsequent metastasis-free survival. The 5-year metastasis-free survival rate was 93.0% in patients who administered RAS inhibitors, and 72.8% in their counterparts who did not (P=0.008).

Conclusion:

The absence of RAS inhibitor administration was an independent risk factor for subsequent tumour metastasis in patients with localised UTUC. We propose RAS inhibitors may be a potent choice as an effective treatment following nephroureterectomy.

Acquired platinum resistance enhances tumour angiogenesis through angiotensin II type 1 receptor in bladder cancer

BACKGROUND

We investigated the changes in reactive oxygen species (ROS) and angiogenesis through angiotensin II (Ang II) type 1 receptor (AT1R) after the development of acquired platinum resistance in bladder cancer.

METHODS

Four invasive human bladder cancer cell lines, T24, 5637, T24PR, and 5637PR, were used in vitro, whereas in vivo, T24 and T24PR cells were used. T24PR and 5637PR cells were newly established at our institution as acquired platinum-resistant sublines by culturing in cisplatin (CDDP)-containing conditioned medium for 6 months.

RESULTS

Ang II induced significantly higher vascular endothelial growth factor (VEGF) production in T24PR and 5637PR cells than in their corresponding parent cells in vitro, whereas Ang II induced a further increase in VEGF production. These platinum-resistant cells also showed significantly higher AT1R expression than their corresponding parent cells. ROS was also significantly upregulated in T24PR and 5637PR cells, whereas increased AT1R expression was significantly downregulated by scavenging free radicals. We also demonstrated the efficacy of AT1R blockade at suppressing the growth of platinum-resistant xenograft model.

CONCLUSION

Our findings indicate a new molecular mechanism for upregulated AT1R signalling through increased ROS when tumours progressed after the CDDP-based regimens, and shed light on the importance of AT1R blockade for platinum-resistant bladder cancers.

LOX-1 and angiotensin receptors, and their interplay

The renin-angiotensin system (RAS) plays an important role in regulating blood pressure, water-salt balance and the pathogenesis of cardiovascular diseases. Angiotensin II (Ang II) is the physiologically active mediator and mediates the main pathophysiological actions in RAS. Ang II exerts the effects by activating its receptors, primarily type 1 (AT1R) and type 2 (AT2R). Most of the known pathophysiological effects of Ang II are mediated by AT1R activation. The precise physiological function of AT2R is still not clear. Generally, AT2R is considered to oppose the effects of AT1R. Lectin-like oxidized low-density lipoprotein scavenger receptor-1 (LOX-1) is one of the major receptors responsible for binding, internalizing and degrading ox-LDL. The activation of LOX-1 has been known to be related to many pathophysiological events, including endothelial dysfunction and injury, fibroblast growth, and vascular smooth muscle cell hypertrophy. Many of these alterations are present in atherosclerosis, hypertension, and myocardial ischemia and remodeling. A growing body of evidence suggests the existence of a cross-talk between LOX-1 and Ang II receptors. Their interplays are embodied in the reciprocal regulation of their expression and activity. Their interplays are involved in a series of signals. Recent studies suggests that reactive oxygen species (ROS), nitric oxide (NO), protein kinase C (PKC) and mitogen activated protein kinases (MAPKs) are important signals responsible for their cross-talk. This paper reviews these aspects of dyslipidemia and RAS activation.

Angiotensin II type 1 receptor expression and microvessel density in human bladder cancer

OBJECTIVES

To determine whether angiotensin II type 1 receptor (AT1R) expression and tumor angiogenesis in human bladder cancer (BCa) specimens acquired by transurethral resection (TUR). It has recently been reported that AT1R is expressed in several tumors and is involved in tumor angiogenesis. However, no study has investigated AT1R expression in association with angiogenesis in clinical specimens of bladder cancer.

METHODS

Surgical specimens were obtained from 108 patients who had undergone TUR for bladder cancer. All specimens were pathologically diagnosed as urothelial carcinoma. AT1R expression and microvessel density (MVD) were determined by immunostaining. The clinical and pathologic characteristics were retrospectively reviewed.

RESULTS

The MVD was greater in muscle-invasive BCa (MIBC; 29 cases, 34.4 ± 4.1/0.25 mm(2)) than in non-MIBC (NMIBC; 79 cases, 17.4 ± 1.1/0.25 mm(2), P < .0001). AT1R expression was greater in the MIBC (P = .0004) and high-grade (P = .0063) specimens than in the NMIBC and low-grade specimens. In addition, the greater expression of AT1R was significantly associated with MVD (P < .05). In NMIBC, the factors significantly affecting recurrence-free survival on univariate analysis were AT1R (P = .02), MVD (P < .0001), tumor multiplicity (P = .0007), and bacille Calmette-Guérin intravesical instillation after TUR (P = .0026). Multivariate analysis revealed that tumor multiplicity and no BCG intravesical instillation after TUR were independent predictors of 5-year recurrence-free survival, and AT1R and MVD were independent predictors of 1-year recurrence-free survival (P < .01).

CONCLUSIONS

AT1R expression and MVD were related to early intravesical recurrence in NMIBC. The results suggest that AT1R could become a new molecular target and a prognostic factor for NMIBC.