Blocking angiotensin II Type 1 receptor triggers apoptotic cell death in human pancreatic cancer cells

Several first-line anti-hypertensives act on fibrosarcoma progression and PD1ab blockade therapy

PURPOSE

Patients are typically diagnosed with both hypertension and fibrosarcoma. Medical oncologists must prescribe suitable anti-hypertensive medications while considering anti-tumor drugs. Recently, immunotherapy has become prominent in cancer treatment. Nonetheless, it is unknown what role anti-hypertensive medications will play in immunotherapy.

METHODS

We examined the effects of six first-line anti-hypertensive medications on programmed cell death protein 1 antibody (PD1ab) in tumor treatment using a mouse model of subcutaneous fibrosarcoma. The drugs examined were verapamil, losartan, furosemide, spironolactone, captopril, and hydrochlorothiazide (HCTZ). The infiltration of CD8+ T cells was examined by immunohistochemistry. Additionally, several in vitro and in vivo assays were used to study the effects of HCTZ on human fibrosarcoma cancer cells to explore its mechanism.

RESULTS

Verapamil suppressed tumor growth and showed an improved effect on the tumor inhibition of PD1ab. Captopril did not affect tumor growth but brought an unexpected benefit to PD1ab treatment. In contrast, spironolactone and furosemide showed no effect on tumor growth but had an offset effect on the PD1ab therapy. Consequently, the survival time of mice was also significantly reduced. Notably, losartan and HCTZ, especially HCTZ, promoted tumor growth and weakened the effect of PD1ab treatment. Consistent results were observed in vivo and in vitro using the human fibrosarcoma cell line HT1080. We determined that the Solute Carrier Family 12 Member 3 (SLC12A3), a known target of HCTZ, may be the principal factor underlying its effect-enhancing properties through mechanism studies employing The Cancer Genome Atlas (TCGA) data and in vivo and in vitro assays.

CONCLUSION

Verapamil and captopril potentiated the anti-tumor effect of PD1ab, whereas spironolactone and furosemide weakened the effect of PD1ab on tumor inhibition. Alarmingly, losartan and HCTZ promoted tumor growth and impaired the effect of PD1ab. Furthermore, we preliminarily found that HCTZ may promote tumor progression through SLC12A3. Based on this study, futher mechanism researches and clinical trials should be conducted in the future.

Clinically impactful metabolic subtypes of pancreatic ductal adenocarcinoma (PDAC)

Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease characterized by a diverse tumor microenvironment. The heterogeneous cellular composition of PDAC makes it challenging to study molecular features of tumor cells using extracts from bulk tumor. The metabolic features in tumor cells from clinical samples are poorly understood, and their impact on clinical outcomes are unknown. Our objective was to identify the metabolic features in the tumor compartment that are most clinically impactful. Methods: A computational deconvolution approach using the DeMixT algorithm was applied to bulk RNASeq data from The Cancer Genome Atlas to determine the proportion of each gene's expression that was attributable to the tumor compartment. A machine learning algorithm designed to identify features most closely associated with survival outcomes was used to identify the most clinically impactful metabolic genes. Results: Two metabolic subtypes (M1 and M2) were identified, based on the pattern of expression of the 26 most important metabolic genes. The M2 phenotype had a significantly worse survival, which was replicated in three external PDAC cohorts. This PDAC subtype was characterized by net glycogen catabolism, accelerated glycolysis, and increased proliferation and cellular migration. Single cell data demonstrated substantial intercellular heterogeneity in the metabolic features that typified this aggressive phenotype. Conclusion: By focusing on features within the tumor compartment, two novel and clinically impactful metabolic subtypes of PDAC were identified. Our study emphasizes the challenges of defining tumor phenotypes in the face of the significant intratumoral heterogeneity that typifies PDAC. Further studies are required to understand the microenvironmental factors that drive the appearance of the metabolic features characteristic of the aggressive M2 PDAC phenotype.

Cabozantinib, Vandetanib, Pralsetinib and Selpercatinib as Treatment for Progressed Medullary Thyroid Cancer with a Main Focus on Hypertension as Adverse Effect

This manuscript investigates cabozantinib, vandetanib, pralsetinib, and selpercatinib, four tyrosine kinase inhibitors (TKIs), which are used to treat advanced and/or metastatic medullary thyroid cancer (MTC). Data on efficacy and safety are presented with the main focus on treatment-related hypertension, a well-known adverse effect (AE) of these TKIs. Taken together, TKI-induced hypertension is rarely a dose-limiting side effect. However, with increasing survival times of patients under treatment, hypertension-associated complications can be expected to be on the rise without proper medication.

Angiotensin blockade therapy and survival in pancreatic cancer: a population study

BACKGROUND

Pancreatic cancer (PC) is one of the most aggressive and challenging cancer types to effectively treat, ranking as the fourth-leading cause of cancer death in the United States. We investigated if exposures to angiotensin II receptor blockers (ARBs) or angiotensin I converting enzyme (ACE) inhibitors after PC diagnosis are associated with survival.

METHODS

PC patients were identified by ICD-9 diagnosis and procedure codes among the 3.7 million adults living in the Emilia-Romagna Region from their administrative health care database containing patient data on demographics, hospital discharges, all-cause mortality, and outpatient pharmacy prescriptions. Cox modeling estimated covariate-adjusted mortality hazard ratios for time-dependent ARB and ACE inhibitor exposures after PC diagnosis.

RESULTS

8,158 incident PC patients were identified between 2003 and 2011, among whom 20% had pancreas resection surgery, 36% were diagnosed with metastatic disease, and 7,027 (86%) died by December 2012. Compared to otherwise similar patients, those exposed to ARBs after PC diagnosis experienced 20% lower mortality risk (HR=0.80; 95% CI: 0.72, 0.89). Those exposed to ACE inhibitors during the first three years of survival after PC diagnosis experienced 13% lower mortality risk (HR=0.87; 95% CI: 0.80, 0.94) which attenuated after surviving three years (HR=1.14; 95% CI: 0.90, 1.45).

CONCLUSIONS

The results of this large population study suggest that exposures to ARBs and ACE inhibitors after PC diagnosis are significantly associated with improved survival. ARBs and ACE inhibitors could be important considerations for treating PC patients, particularly those with the worst prognosis and most limited treatment options. Considering that these common FDA approved drugs are inexpensive to payers and present minimal increased risk of adverse events to patients, there is an urgent need for randomized clinical trials, large simple randomized trials, or pragmatic clinical trials to formally and broadly evaluate the effects of ARBs and ACE inhibitors on survival in PC patients.

Angiotensin II Receptor Antagonist, Valsartan, Has Beneficial Effect in Lung Metastasis of Colorectal Cancer Treated with Fluorouracil

PURPOSE

Lung metastasis is the main cause of death in patients with colorectal carcinoma (CRC). Angiotensin II has been confirmed to facilitate cancer cell progression and metastasis. In this study, the possible anti-metastatic effects of an angiotensin II receptor type 1 (AT1R) antagonist, valsartan, have been investigated in an experimental CRC lung metastasis model.

METHODS

An animal CRC lung metastasis model was used, involving intravenous injection of CRC cells. The experimental groups included (1) control group; (2) 5-FU (5-fluorouracil) group (5 mg/kg/every other day; ip); (3) valsartan group (40 mg/kg/day; po); and (4) valsartan + 5-FU group (combination group; valsartan 40 mg/kg/day, oral gavage, and 5-FU 5 mg/kg/every other day; ip). After 11 days, macroscopic and histological evaluations of lung tissues have been done for evaluation of lung metastatic nodules. In addition, inflammatory and angiogenic markers and oxidative stress index were measured in lung tissue.

RESULTS

Our results showed that administration of valsartan especially in combination with 5-FU significantly reduced lung metastatic nodule and metastatic area (p < 0.05) in macroscopic and histological evaluations stained by hematoxylin-eosin. Measurement of inflammatory, angiogenic, and oxidative/antioxidative markers in lung tissue indicated that the level of IL-6, angiogenic markers (VEGF and VEGFR-1), and antioxidative markers significantly reduced in combination group (p < 0.05) while the MDA as a marker of oxidative stress increased (p < 0.05).

CONCLUSION

These results suggest that valsartan in combination with standard chemotherapeutic agents can have a synergistic effect in treatment of lung metastasis of CRC.

Renin-Angiotensin-Aldosterone System Inhibitors and Risk of Cancer: A Population-Based Cohort Study Using a Common Data Model

Studies have reported conflicting results on the association between the use of renin-angiotensin-aldosterone system (RAAS) inhibitors and cancer development. We compared the incidence of cancer between patients using RAAS inhibitors and other antihypertensive drugs. This retrospective observational cohort study used data from seven hospitals in Korea that were converted for use in the Observational Medical Outcomes Partnership Common Data Model. A total of 166,071 patients on antihypertensive therapy across the databases of the seven hospitals were divided into two groups according to the use of RAAS inhibitors. The primary outcome was the occurrence of cancer. A total of 166,071 patients across the databases of the seven hospitals was included in the final analysis; 26,650 (16%) were in the RAAS inhibitors group and 139,421 (84%) in the other antihypertensive drugs group. The meta-analysis of the whole cohort showed a lower incidence of cancer occurrence in the RAAS inhibitor group (9.90 vs. 13.28 per 1000 person years; HR, 0.81; 95% confidence interval [CI], 0.75-0.88). After propensity-score matching, the RAAS inhibitor group consistently showed a lower incidence of cancer (9.90 vs. 13.28 per 1000 person years; HR, 0.86; 95% CI, 0.81-0.91). The patients using RAAS inhibitors showed a lower incidence of cancer compared with those using other antihypertensive drugs. These findings support the association between the use of RAAS inhibitors and cancer occurrence.

Angiotensin-converting Enzyme Inhibitors and Angiotensin Receptor Blockers as Potential Therapeutic Options for Pancreatic Cancer

The renin-angiotensin system (RAS) has been reported to have a role in carcinogenesis, and therefore it may be of value as a potential therapeutic target in inhibiting tumor growth. It has been shown that inhibition of RAS via angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor (ARBs) inhibitors may have a protective effect against several malignancies. Here, we provide an overview of the potential value of the RAS pathway and targeting via ACE/ARB inhibitors in pancreatic cancer. Whilst the potential role of RAS as a target for the treatment of pancreatic cancer has been reported, the use of candesartan with gemcitabine failed to improve outcomes in pancreatic cancer. Another study of 1-3 years using ARB was found to reduce the risk of pancreatic cancer. In line with these trials, others have demonstrated that the ARBs in combination with gemcitabine might improve clinical outcomes in patients with advanced pancreatic cancer. Prospective trials are warranted to investigate this hypothesis.

COVID-19, ferrosenescence and neurodegeneration, a mini-review

Exacerbation of cognitive, motor and nonmotor symptoms have been described in critically ill COVID-19 patients, indicating that, like prior pandemics, neurodegenerative sequelae may mark the aftermath of this viral infection. Moreover, SARS-CoV-2, the causative agent of COVID-19 disease, was associated with hyperferritinemia and unfavorable prognosis in older individuals, suggesting virus-induced ferrosenescence. We have previously defined ferrosenescence as an iron-associated disruption of both the human genome and its repair mechanisms, leading to premature cellular senescence and neurodegeneration. As viruses replicate more efficiently in iron-rich senescent cells, they may have developed the ability to induce this phenotype in host tissues, predisposing to both immune dysfunction and neurodegenerative disorders. In this mini-review, we summarize what is known about the SARS-CoV-2-induced cellular senescence and iron dysmetabolism. We also take a closer look at immunotherapy with natural killer cells, angiotensin II receptor blockers ("sartans"), iron chelators and dipeptidyl peptidase 4 inhibitors ("gliptins") as adjunct treatments for both COVID-19 and its neurodegenerative complications.

Angiotensin Receptor Blockers Are Not Just for Hypertension Anymore

Beyond blood pressure control, angiotensin receptor blockers reduce common injury mechanisms, decreasing excessive inflammation and protecting endothelial and mitochondrial function, insulin sensitivity, the coagulation cascade, immune responses, cerebrovascular flow, and cognition, properties useful to treat inflammatory, age-related, neurodegenerative, and metabolic disorders of many organs including brain and lung.

Angiotensin II receptor blockers valsartan and losartan improve survival rate clinically and suppress tumor growth via apoptosis related to PI3K/AKT signaling in nasopharyngeal carcinoma

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a common type of head and neck cancer in Asia. Adverse effects occur in over 90% of NPC patients treated with radiotherapy or chemoradiation. Angiotensin II receptor blockers (ARBs) are commonly used to treat hypertension without serious adverse effects. However, the anticancer activity of ARBs in NPC remains unclear.

METHODS

We investigated the survival impacts of ARBs among NPC patients in a retrospective study. The anticancer effects and related signaling pathways of the ARBs valsartan and losartan were also evaluated in vitro and in vivo.

RESULT

A total of 927 patients with NPC who had hypertension were enrolled in the study, 272 (29.3%) of whom received ARBs. Kaplan-Meier analysis revealed that patients who used ARBs had higher rates of 5-year overall survival (OS; 87.8% vs 75.1%; P = .002) and disease-specific survival (DSS; 95.4% vs 77.7%; P < .001) than those who did not receive this treatment. Additionally, ARBs inhibited cell proliferation and induced apoptosis by increasing levels of cleaved caspase-3, cleaved caspase-9, and cytochrome C; the cell population in the sub-G1 phase; and caspase-3 activity in NPC-TW01 cells. ARBs inhibited tumor growth and angiogenesis via apoptosis in an NPC xenografts model. Interestingly, ARBs inhibited phosphorylation of PI3K/AKT signaling in vitro and in vivo, which is markedly attributed to their antitumor effects in NPC.

CONCLUSION

These data indicate that ARBs not only improve 5-year OS and DSS among patients with NPC but also exert antiproliferative and antiangiogenesis effects by inducing apoptosis in NPC, supporting that ARBs may be promising agents for treatment of NPC.

Nox2 signaling and muscle fiber remodeling are attenuated by losartan administration during skeletal muscle unloading

Reduced mechanical loading results in atrophy of skeletal muscle fibers. Increased reactive oxygen species (ROS) are causal in sarcolemmal dislocation of nNOS and FoxO3a activation. The Nox2 isoform of NADPH oxidase and mitochondria release ROS during disuse in skeletal muscle. Activation of the angiotensin II type 1 receptor (AT1R) can elicit Nox2 complex formation. The AT1R blocker losartan was used to test the hypothesis that AT1R activation drives Nox2 assembly, nNOS dislocation, FoxO3a activation, and thus alterations in morphology in the unloaded rat soleus. Male Fischer 344 rats were divided into four groups: ambulatory control (CON), ambulatory + losartan (40 mg kg^-1  day^-1 ) (CONL), 7 days of tail-traction hindlimb unloading (HU), and HU + losartan (HUL). Losartan attenuated unloading-induced loss of muscle fiber cross-sectional area (CSA) and fiber-type shift. Losartan mitigated unloading-induced elevation of ROS levels and upregulation of Nox2. Furthermore, AT1R blockade abrogated nNOS dislocation away from the sarcolemma and elevation of nuclear FoxO3a. We conclude that AT1R blockade attenuates disuse remodeling by inhibiting Nox2, thereby lessening nNOS dislocation and activation of FoxO3a.

Elucidating the Association Between the Upregulation of Angiotensin Type 1-Receptors and the Development of Gastrointestinal Malignancies

The renin-angiotensin system (RAS) is a major regulator of body fluid hemostasis and blood pressure. Angiotensin type 1 receptors (AT1R) are one of the major components of this system and are widely expressed in different organs, including the gastrointestinal (GI) system. Very little known about the physiological roles of AT1R in GI tract but evidence has reported that local AT1Rs are upregulated in pathological conditions like GI malignancies and play role in stimulation of signaling pathways associated with GI cancers progression. AT1Rs axes signaling in tumor microenvironments stimulate inflammation and facilitate vascularization around the tumor cell to display invasive behavior. AT1Rs in stroma cells promote tumor-associated angiogenesis by upregulated of vessel endothelial growth factor (VEGF). Also, AT1Rs by the activation of molecular mechanisms such as PI3/Akt/NF-κB pathways increase the invasion of tumor cells. Experimental and clinical studies have reported that AT1R antagonists have beneficial influences by increasing the survival of patients with GI malignancies and reduction in the proliferation of GI cancer cell lines in vitro, and the growth and metastasis of tumors in vivo, therefore, AT1Rs antagonist have the potential for future anticancer strategies. This review focuses on the pathological roles of AT1Rs in GI malignancies.

Renin-angiotensin system and cancer: epidemiology, cell signaling, genetics and epigenetics

Day by day, the health and economical burden of cancer increases globally. Indeed it can be considered that there is ''cancer pandemic''. Blocking the renin-angiotensin system (RAS) by angiotensin-converting enzyme (ACE) inhibitors (ACEI) or angiotensin-receptor blockers (ARB) are widely used measures to treat hypertension and heart failure. It has been recently suggested the activation and blocking of RAS has been associated with various types of cancer in epidemiological and experimental studies. Various studies have shown that RAS blockage is protective in some cancers. However, although fewer, contradictory data also showed that RAS blockage is either not related or adversely related to cancer. Although the reasons for these findings are not exactly known, different types of receptors and effectors in RAS may account for these findings. In the current review, we summarize the different RAS receptors and cancer development with regard to epidemiology, and pathogenesis including cell signaling pathways, apoptosis, genetic and epigenetic factors.

GPCRs in pancreatic adenocarcinoma: Contributors to tumour biology and novel therapeutic targets

Pancreatic cancer has one of the highest mortality rates (5-year survival ~9%) among cancers. Pancreatic adenocarcinoma (PAAD) is the most common (>80%) and the most lethal type of pancreatic cancer. A need exists for new approaches to treat pancreatic adenocarcinoma. GPCRs, the largest family of cell-surface receptors and drug targets, account for ~35% of approved drugs. Recent studies have revealed roles for GPCRs in PAAD cells and cells in the tumour micro-environment. This review assesses current information regarding GPCRs in PAAD by summarizing omics data for GPCRs expression in PAAD. The PAAD "GPCRome" includes GPCRs with approved agents, thereby offering potential for their repurposing/repositioning. We then reviewed the evidence for functional roles of specific GPCRs in PAAD. We also highlight gaps in understanding the contribution of GPCRs to PAAD biology and identify several GPCRs that may be novel therapeutic targets for future work in search of GPCR-targeted drugs to treat PAAD tumours.

Association between Angiotensin-Converting Enzyme Inhibitors and Lung Cancer-A Nationwide, Population-Based, Propensity Score-Matched Cohort Study

Background: Direct evidence of lung cancer risk in Asian users of angiotensin-converting enzyme inhibitors (ACEIs) is lacking. Methods: The ACEI cohort comprised 22,384 patients aged ≥ 18 years with a first prescription of ACEI. The comparison angiotensin receptor blocker (ARB) cohort consisted of age-, sex- and comorbidity-matched patients at a ratio of 1:1. The primary outcome was the incidence of lung cancer, which was evaluated using a proportional hazard model. Results: The overall incidence rates of lung cancer in the ACEI and ARB cohorts were 16.6 and 12.2 per 10,000 person-years, respectively. The ACEI cohort had a significantly higher risk of lung cancer than the ARB cohort (adjusted hazard ratio [aHR]. = 1.36; 95% confidence interval [CI]. = 1.11–1.67). Duration–response and dose–response analyses revealed that compared with patients who did not receive ACEIs, patients who received ACEIs for more than 45 days per year (aHR = 1.87; 95% CI = 1.48–2.36) and patients who received more than 540 defined daily doses of ACEIs per year (aHR =1.80; 95% CI = 1.43–-2.27) had a significantly higher risk of lung cancer. The cumulative incidence of lung cancer was also significantly higher in the ACEI cohort than in the ARB cohort (log-rank test, p = 0.002). Conclusions: ACEI use is associated with an increased risk of lung cancer compared with ARB use. Patients using ARBs have a significantly lower risk of lung cancer than non-ARB users.

Evaluating the benefits of renin-angiotensin system inhibitors as cancer treatments

G-protein-coupled receptors (GPCRs) are the largest and most diverse group of cellular membrane receptors identified and characterized. It is estimated that 30 to 50% of marketed drugs target these receptors. The angiotensin II receptor type 1 (AT1R) is a GPCR which signals in response to systemic alterations of the peptide hormone angiotensin II (AngII) in circulation. The enzyme responsible for converting AngI to AngII is the angiotensin-converting enzyme (ACE). Specific inhibitors for the AT1R (more commonly known as AT1R blockers or antagonists) and ACE are well characterized for their effects on the cardiovascular system. Combined with the extensive clinical data available on patient tolerance of AT1R blockers (ARBs) and ACE inhibitors (ACEIs), as well as their non-classical roles in cancer, the notion of repurposing this class of medications as cancer treatment(s) is explored in the current review. Given that AngII-dependent AT1R activity directly regulates angiogenesis, remodeling of vasculature, pro-inflammatory responses, stem cell programming and hematopoiesis, and electrolyte balance; the modulation of these processes with pharmacologically well characterized medications could present a valuable complementary treatment option for cancer patients.

Impact of Angiotensin Receptor Blockers, Beta Blockers, Calcium Channel Blockers and Thiazide Diuretics on Survival of Ovarian Cancer Patients

Purpose

We investigated the impact of four types of antihypertensive medications, angiotensin receptor blockers (ARBs), beta blockers (BBs; both selective and non-selective), calcium channel blockers (CCBs), and thiazide diuretics (TDs) on survival outcomes in epithelial ovarian cancer (EOC).

Materials and Methods

A single-institutional retrospective chart review of 878 patients with EOC was performed. Survival was compared according to use of the four antihypertensive medications during primary treatment. Propensity score matching (ratio 1:3) was performed to control possible associated covariates, such as age, International Federation of Gynecology and Obstetrics stage, residual status after primary debulking surgery, and co-morbidity.

Results

Among 878 patients, 56 patients (6.4%) were ARB users, 62 (7.1%) were BB users, 107 (12.2%) were CCBs users and 32 (3.6%) used TDs. Median progression-free survival (PFS) for ARB, BB, and CCB users was 37.8, 27.2, and 23.6 months compared with 33.6 months for non-users. ARB was associated with 35% decreased risk of disease progression (hazard ratio [HR], 0.65; 95% confidence interval [CI], 0.42 to 0.99; p=0.046) in multivariate analysis. After propensity score matching, median PFS for ARB users was 37.8 months and ARB use remained to be associated with lower recurrence rate in univariate (p=0.035) and multivariate analysis (HR, 0.60; 95% CI, 0.39 to 0.93; p=0.022).

Conclusion

In this study, ARBs use during primary treatment is associated with lower recurrence in EOC patients. However, CCBs, BBs, and TDs did not show beneficial impact.

The Therapeutic Potential of Angiotensin-converting Enzyme and Angiotensin Receptor Inhibitors in the Treatment of Colorectal Cancer: Rational Strategies and Recent Progress

Colorectal cancer (CRC) is one of the most common causes of cancer-related death in the world. There is a document that angiotensin (AT) which is found to be involved in the progression of CRC. Furthermore, Angiotensin receptor inhibitors (ARIs) and angiotensin-converting enzyme Inhibitors (ACE-Is) demonstrate activity in CRC by their inhibition of both Insulin-like growth factor 1 (IGF-1) and Vascular endothelial growth factor (VEGF), and therefore present a potentially novel therapeutic strategy in colorectal cancer, which have summarized in the current review. Preclinical studies have illustrated the direct effect of major active mediator angiotensin II (ATII) on the promotion of angiogenesis through VEGF and other proliferative mediators. Suppression of the angiotensin II type I receptor (AT1R) via ACE-Is has shown a reduction in the development of solid tumor and metastasis, particularly CRC incidence, polyp formation, and distant metastasis. MicroRNAs (miRs) are a family of small nucleotides without coding that plays an important role after transcribing hundreds to thousands of non-coding and coding gene. Against this background, the application of anti-hypertensive medications such as losartan might have a therapeutic impact, although further preclinical and clinical studies might provide novel insight into the potentially beneficial effect of ACE-Is in the treatment of colorectal cancer patients.

The impact of At1r inhibition via losartan on the anti-leukaemic effects of doxorubicin in acute myeloid leukaemia

Introduction:

Bone marrow renin–angiotensin system(RAS) modulates acute myeloid leukaemia(AML).The aim of this study is to clarify the relationships between RAS and AML, and to show the effect of losartan and doxorubicin treatment in AML cell lines.

Methods:

AML cell lines including CESS, HL-60, MO-1, P31/FUJ, GDM-1 and KASUMI-3 were used as models in this study.

Results:

After treating the six AML cell lines with a combination of losartan and doxorubicin, they were divided into two groups based on their behaviour: one became more sensitive to drug treatment (Group A) and the other had no change observed in behaviour after drug treatment (Group B). In silico analyses showed that Group A is involved in cellular apoptosis, while Group B is involved in tumour angiogenesis further supporting the in vitro results.

Conclusion:

The combined treatment of the AML cell lines with losartan and doxorubicin resulted in an increase in sensitivity of some of the cell lines. Those leukaemic cells are modulated via the induction of apoptosis, whereas the other cells resistant to the drug treatment are closely related to tumour angiogenesis indicating that RAS-AT1R seems to be differently expressed in different leukaemic blast cells and tumour microenvironments. Pharmaco-biological actions of RAS inhibitors may be different in distinct leukaemic cells based on the pathological behaviour of AML genomic subtypes.

Impact of Angiotensin Receptor Blocker Use on Overall Survival Among Patients Undergoing Resection for Pancreatic Cancer

BACKGROUND

Pancreatic cancer has higher concentrations of angiotensin II compared with other cancers. This study sought to assess the effect of angiotensin II receptor blockers (ARBs) on survival of patients undergoing resection using a large, nationally representative dataset.

METHODS

Patients undergoing pancreatic cancer resection were identified in the Truven Health MarketScan database. Multivariable Cox proportional hazards regression was used to assess the effect of ARB use on overall survival.

RESULTS

A total of 4299 patients were identified, among whom 479 (11.1%) filled a prescription for an ARB. Mean patient age was 54.5 years (SD = 8.6 years); 2187 (51.1%) were female. Exactly 49.4% (n = 2125) of patients had a Charlson comorbidity index >2 at the time of surgery (n = 2125, 49.4%) and 59.6% (n = 2563) underwent a pancreaticoduodenectomy. Kaplan-Meier estimates of survival at 1, 2, and 4 years were 62.8% (95% CI: 61.3-64.2%), 38.2% (95% CI: 36.6-39.8%), and 19.0% (95% CI: 17.1-21.0%), respectively. On multivariable analysis, ARB use was associated with a 24% decreased risk of death over the 5-year period in which patients were under observation (HR = 0.76, 95% CI: 0.67-0.87, p < 0.001).

CONCLUSIONS

ARB use was associated with improved survival in patients undergoing resection of pancreatic cancer. Further research is required into the differential effect of ARBs in the treatment of pancreatic cancer.

Management of Adverse Events Associated with Cabozantinib Therapy in Renal Cell Carcinoma

Cabozantinib was recently approved for the treatment of advanced renal cell carcinoma (RCC) after treatment with vascular endothelial growth factor (VEGF)-targeted therapy. Cabozantinib is a multikinase inhibitor targeting VEGF receptor (VEGFR) 2, mesenchymal-epithelial transition receptor, and "anexelekto" receptor tyrosine kinase. A 60-mg daily dose led to improved overall survival and progression-free survival (PFS) versus everolimus in advanced RCC patients as a second- or later-line treatment in the METEOR trial. Improved PFS with cabozantinib versus sunitinib has also been demonstrated in the first-line setting in CABOSUN. However, cabozantinib, like other VEGFR inhibitors, is associated with toxicity that may affect the patient's quality of life. The most frequent adverse events (AEs) are diarrhea, fatigue, hypertension, hand-foot syndrome, weight loss, nausea, and stomatitis. This article summarizes the safety profile of cabozantinib in RCC patients and offers guidance for the management of these AEs. We discuss the underlying mechanisms of these AEs and, based on our experiences with cabozantinib and other multikinase inhibitors, we present approaches to manage toxicity. Prophylactic and therapeutic solutions are available to help with the management of toxicity associated with cabozantinib, and adequate interventions can ensure optimum adherence and maximize patient outcomes.

IMPLICATIONS FOR PRACTICE

Cabozantinib leads to improved survival outcomes in renal cell carcinoma patients compared with everolimus. However, management of the adverse event profile is crucial to achieve optimum adherence and outcomes with the use of cabozantinib. This review aims to provide appropriate guidance that will minimize the impact of adverse events and help to maximize the utility of this agent in patients with advanced renal cell carcinoma.

Angiotensin receptor blocker use and gastro-oesophageal cancer survival: a population-based cohort study

BACKGROUND

Angiotensin receptor blockers (ARBs; including candesartan, losartan, olmesartan and valsartan) are widely used to treat hypertension, heart failure and diabetic neuropathy. There is considerable pre-clinical evidence that ARBs can reduce cancer progression, particularly for gastric cancer. Despite this, epidemiological studies have yet to assess the impact of ARB use on gastro-oesophageal cancer survival.

AIM

To investigate the association between post-diagnosis ARB use and gastro-oesophageal cancer survival.

METHODS

We selected a cohort of patients with newly-diagnosed gastro-oesophageal cancer between 1998 and 2012 from English cancer registries. We linked to prescription and clinical records from the Clinical Practice Research Datalink, and to death records from the Office for National Statistics. We used time-dependant Cox-regression models to calculate hazard ratios (HRs) comparing gastro-oesophageal cancer-specific mortality between post-diagnosis ARB users and non-users, after adjusting for demographics, comorbidities and post-diagnosis aspirin or statin use.

RESULTS

Our cohort included 5124 gastro-oesophageal cancer patients, of which 360 used ARBs, and 3345 died due to their gastro-oesophageal cancer during follow-up. After adjustment, ARB users had moderately lower risk of gastro-oesophageal cancer mortality than the non-users (HR = 0.83, 95% CI 0.71-0.98). There was evidence of a dose-response relationship with the lowest HRs observed among patients receiving at least 2 years of prescriptions (HR = 0.42, 95% CI 0.25-0.72).

CONCLUSIONS

In this large population-based gastro-oesophageal cancer cohort, we found moderately reduced cancer-specific mortality among ARB users. However, confirmation in further independent epidemiological studies with sufficient staging information is required.

A precision-guided MWNT mediated reawakening the sunk synergy in RAS for anti-angiogenesis lung cancer therapy

Multi-walled carbon nanotube (MWNT) with its versatility has exhibited tremendous superiority in drug delivery. Despite plenty of researches on MWNT based delivery systems, precision-guided assistances to maximize their profitable properties are still lacking in substantive progress. We developed here a dual-targeting and co-delivery system based on MWNT for antiangiogenesis therapy in lung cancer which aimed at renin-angiotensin system (RAS) dysregulation by synergistically conducting angiotensin II type 1 receptor (AT₁R) and type 2 receptor (AT₂R) pathway. In this work, iRGD peptide connected to polyethyleneimine (PEI) was linked to MWNT skeleton, accompanying with candesartan (CD) conjugated to MWNT mediated by cystamine (SS). The functionalized MWNT is assembled with plasmid AT₂ (pAT₂) to form iRGD-PEI-MWNT-SS-CD/pAT₂ complexes. iRGD and CD act as pilots for complexes to dually target symbolic ανβ3-integrin and AT₁R both overexpressed on tumor angiogenic endothelium and lung cancer cell. CD as chemotherapy showed synergistic downregulation of VEGF when combining of pAT₂ and efficiently inhibited angiogenesis. iRGD-PEI-MWNT-SS-CD/pAT₂ complexes greatly appreciated drug activities by changing drug distribution and exhibited remarkable tumor growth suppression in A549 xenograft nude mice. Our work presents that such dual-targeting strategy highly improves the delivery performance of MWNT and open a new avenue for RAS related lung cancer therapy.

The prognostic significance of hypertension at diagnosis in children with wilms tumor

Objectives:

To determine the prognostic effect of hypertension at diagnosis on outcomes of children with Wilms tumor (WT).

Methods:

A single center retrospective analysis was conducted on 85 consecutive children with WT diagnosed between January 2000 and August 2013. Patients were classified as hypertensive or normotensive at diagnosis. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Cox regression was used to determine the predictive significance of hypertension and other clinical factors.

Results:

Seventy-one patients had complete data. Of this, 25 (35.2%) were hypertensive and 46 (64.8%) normotensive with corresponding remission rates of 56.0% versus 82.6%, p=0.032; and death as first event of 7% versus 0%, p=0.004. The 5-year OS in the hypertensive versus normotensive patients were (67.1±10.3% versus 89.6±4.9%, p=0.009) and the corresponding 5-year PFS were (53.4±10.4% versus 79.1±6.2%, p=0.007). With univariate analysis, hypertension and local stage were predictors of OS (p=0.012 and p=0.029) and PFS (p=0.030 and p=0.008). In the multivariate analysis, hypertension, local stage, and histopathology were identified as independent prognostic factors of OS (p=0.004, p=0.034, and p=0.038); and hypertension and local stage as prognostic for PFS (p=0.010 and p=0.012).

Conclusion:

Hypertension at diagnosis is a prognostic predictor of poor outcome in WT and may signify tumor resistance.

The use of drugs acting on the renin-angiotensin system and the incidence of pancreatic cancer

Background:

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are commonly used antihypertensives. Recently, these drugs have been associated with a protective effect against pancreatic cancer, but data on this putative association remain limited. Thus, the objective of this study was to determine whether the use of ACEIs and/or ARBs is associated with a decreased risk of pancreatic cancer.

Methods:

We conducted a population-based cohort study, using a nested case–control analysis within the UK Clinical Practice Research Datalink population. The cohort consisted of all patients newly treated with antihypertensive drugs between 1 January 1995 and 31 December 2009, with follow-up until 31 December 2010. Cases were patients with newly diagnosed pancreatic cancer, which were matched with up to 10 controls on age, sex, calendar year of cohort entry, and duration of follow-up. Conditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of pancreatic cancer incidence associated with ever use of ACEIs and ARBs. A secondary analysis was conducted to assess whether the incidence of pancreatic cancer varied with cumulative duration of use of these drugs.

Results:

A cohort of 547 566 was assembled. During 3 040 332 person-years of follow-up, a total of 866 patients were newly diagnosed with pancreatic cancer (rate: 3/10 000 per year) and matched to 8636 controls. Overall, when compared with other antihypertensive drugs, the use of ACEIs was not associated with a decreased risk of pancreatic cancer overall (OR: 1.01, 95% CI: 0.86–1.17) or according to cumulative duration of use. The use of ARBs was not associated with a decreased risk of pancreatic cancer overall (OR: 0.93, 95% CI: 0.75–1.15), whereas a cumulative duration of use of 1–3 years was associated with a 38% decrease (OR: 0.62, 95% CI: 0.41–0.94), which returned to the null after >3 years of use (OR: 1.04, 95% CI: 0.74–1.46).

Conclusions:

The use of ARBs and ACEIs was not associated with an overall decreased risk of pancreatic cancer when compared with patients using other antihypertensive drugs. Additional research is needed to determine whether ARBs may confer a short-term protective effect.

Angiotensin II type-1 receptor blockers enhance the effects of bevacizumab-based chemotherapy in metastatic colorectal cancer patients

The local renin-angiotensin system promotes angiogenesis and vascular proliferation via expression of vascular endothelial growth factor or epidermal growth factor receptor. We hypothesized that angiotensin II type-1 receptor blockers (ARBs) in combination with bevacizumab (Bev) may improve clinical outcomes in patients with metastatic colorectal cancer (mCRC). A total of 181 patients with histopathologically confirmed mCRC treated with first-line oxaliplatin-based chemotherapy in combination with Bev were enrolled between June, 2007 and September, 2010. The patients were divided into two groups based on the presence or absence of treatment with ARBs prior to the initiation of second-line chemotherapy. Kaplan-Meier analysis and Cox proportional hazard modeling were used in the statistical analysis. The median progression-free survival (PFS) in patients undergoing second-line chemotherapy in combination with Bev and ARBs (n=56) vs. those treated in the absence of ARBs (n=33) was 8.3 vs. 5.7 months, respectively [hazard ratio (HR)=0.57, 95% confidence interval (CI): 0.35-0.94, P=0.028]. The median overall survival (OS) was 26.5 vs. 15.2 months, respectively (HR=0.47, 95% CI: 0.25-0.88, P=0.019). In the multivariate analysis, the use of ARBs was independently associated with prolongation of OS and PFS. In conclusion, the use of ARBs prolonged survival in mCRC patients.

[Oncology-related issues of angiotensin-receptor blockers]

Recently controversial data emerged regarding the cancer inducing activity of angiotensin-receptor blockers. There may be several reasons which may explain the controversial data published in the scientific literature including wrong trial design or misinterpretation of data. Considering the large number of patients receiving treatment for hypertension, it is essential to have a clear view of the cancer-related safety of these drugs. This paper tries to give an overview on this issue based on data available in the literature. According to our present knowledge, angiotensin-receptor blockers exert more likely anticancer activity rather than carcinogenesis inducing effect. In fact, some oncologic trials point to this direction, because angiotensin-receptor blockers are suggested as co-treatment to chemotherapy in cases of pancreatic, oesophageal and gastric cancers.

Telmisartan induces apoptosis and regulates Bcl-2 in human renal cancer cells

It has been well-characterized that the renin-angiotensin system (RAS) physiologically regulates systemic arterial pressure. However, RAS signaling has also been shown to increase cell proliferation during malignancy, and angiotensin receptor blockers (ARBs) are able to decrease pro-survival signaling by inhibiting anti-apoptotic molecules and suppressing caspase activity. In this study, the apoptotic effects of telmisartan, a type of ARB, was evaluated using a non-cancerous human renal cell line (HEK) and a human renal cell carcinoma (RCC) cell line (786). Both types of cells were treated with telmisartan for 4 h, 24 h, and 48 h, and then were assayed for levels of apoptosis, caspase-3, and Bcl-2 using MTT assays, flow cytometry, and immunostaining studies. Analysis of variance was used to identify significant differences between these data (P < 0.05). Following the treatment of 786 cells with 100 µM and 200 µM telmisartan, a marked inhibition of cell proliferation was observed. 50 µM cisplatin also caused high inhibition of these cells. Moreover, these inhibitions were both concentration- and time-dependent (P < 0.05). Various apoptotic effects were also observed compared with control cells at the 24 h and 48 h timepoints assayed (P < 0.001). Furthermore, positive caspase-3 staining and down-regulation of Bcl-2 were detected, consistent with induction of cell death. In contrast, treatment of HEK cells with telmisartan did not produce an apoptotic effect compared with control cells at the 24 h timepoint (P > 0.05). Treatment with cisplatin promoted in HEK cells high index of apoptosis (P < 0.001). Taken together, these results suggest that telmisartan induces apoptosis via down-regulation of Bcl-2 and involvement of caspase-3 in human RCC cells.

Antitumor effect of angiotensin II type 1 receptor blocker losartan for orthotopic rat pancreatic adenocarcinoma

OBJECTIVE

The aim of this study was to investigate the synergistic inhibitory effects of gemcitabine and losartan, angiotensin II type 1 (AT1) receptor blockers, on an orthotopic rat pancreatic cancer model.

METHODS

The rat orthotopic pancreatic cancer model was prepared using DSL-6A/C cells, a rat ductal pancreatic adenocarcinoma cell line. The rats were treated with gemcitabine alone (100 mg/kg per week), losartan alone (100 mg/kg per day), or gemcitabine plus losartan.

RESULTS

Survival was significantly improved by treatment with gemcitabine (89.6 ± 21.8 days) or losartan (76.9 ± 18.7 days) alone compared with that in the control group (59.6 ± 13.4 days; P < 0.05). Treatment with gemcitabine plus losartan further prolonged the survival time to 102.6 ± 16.5 days compared with that in the control group (P < 0.0001). Gemcitabine or losartan significantly and dose-dependently reduced the proliferation of DSL-6A/C cells in vitro. Both drugs inhibited pancreatic vascular endothelial growth factor expression compared with that in the control group (P < 0.05).

CONCLUSIONS

The results of this study indicate that combined treatment with gemcitabine and losartan significantly improved the survival of rats with orthotopic pancreatic cancer by inhibiting vascular endothelial growth factor synthesis and suppressing cancer cell proliferation via AT1 receptor blockade. Thus, an AT1 receptor blocker in combination with gemcitabine might improve the clinical outcomes of patients with advanced pancreatic cancer.

Sunitinib combined with angiotensin-2 type-1 receptor antagonists induces more necrosis: a murine xenograft model of renal cell carcinoma

Background. Angiotensin-2 type-1 receptor antagonists not are only antihypertensive drugs but also can inhibit VEGF production. We hypothesised that adding telmisartan to sunitinib could potentiate the antiangiogenic effects. Material and Methods. 786-O cell lines were injected in nude mice. After tumor development, mice were divided into 4 groups: the first was the control group (DMSO), the second group was treated with sunitinib alone, the third group was treated with telmisartan alone, and the fourth group was treated with the combination. Drugs were orally administered every day for four weeks. Animals were sacrificed after treatment. Blood and tumor tissues were collected for analysis by immunohistochemistry, Western Blot, and ELISA methods. Results. All animals developed a ccRCC and ten in each group were treated. Using a kinetic model, tumors tended to grow slower in the combination group compared to others (P = 0.06). Compared to sunitinib alone, the addition of telmisartan significantly increased tissue necrosis (P = 0.038). Central microvascular density decreased (P = 0.0038) as well as circulating VEGF (P = 0.003). There was no significant variation in proliferation or apoptosis markers. Conclusion. The combination of sunitinib and telmisartan revealed an enhancement of the blockage of the VEGF pathway on renal tumor resulting in a decrease in neoangiogenesis and an increase in necrosis.

Overexpressing TNF-alpha in pancreatic ductal adenocarcinoma cells and fibroblasts modifies cell survival and reduces fatty acid synthesis via downregulation of sterol regulatory element binding protein-1 and activation of acetyl CoA carboxylase

The effect of tumor necrosis factor-alpha (TNF-α) gene delivery has been suggested as a potentially useful therapeutic approach to improve the chemotherapeutic treatment of patients with pancreatic ductal adenocarcinoma (PDA), but the exact mechanism of its action is not clearly understood. In this study, we analyzed the expression profile of TNF-α in PDA tissue and explored its potential role in fatty acid synthase (FAS) regulation in PDA cells and in fibroblasts. Quantitative real-time polymerase chain reaction was used to examine the expression of TNF-α in PDA, matching adjacent tissues, and benign lesions. Logistic regression models with robust variance were used to analyze the gene expression levels, and Kaplan-Meier survival curves were generated. In vitro, we overexpressed the TNF-α gene in PDA cells and fibroblasts and analyzed its effect on cell survival, migration, and on members of the FAS signaling pathway. We also evaluated TNF-α effects on a panel of inflammation-, angiogenesis-, and metastasis-related markers. In the tumor tissue of PDA patients, compared with their matched adjacent tissue, expression levels of TNF-α were not statistically different and did not correlate with survival or any other examined clinicopathological features. Overexpression of TNF-α significantly (p < 0.05) reduced PDA and fibroblast cell migration. In PDA cells that highly overexpress TNF-α, this was associated with a significant reduction of FAS mRNA and protein expression levels and significant (p < 0.05) reduction of SREBP-1 and ACC mRNA. Reduction of FAS by TNF-α was inhibited when either SREBP-1 or ACC was knocked down by siRNA. PDA cells and fibroblasts that overexpress TNF-α displayed differential regulation of several inflammation-related markers and reduced levels of metastasis-related genes. Our data demonstrate a previously unknown multi-targeted involvement of TNF-α in PDA lipogenesis and inflammation and metastasis and suggest that intratumoral introduction of TNF-α may have the potential as a novel therapeutic approach in human PDA.

Olmesartan potentiates the anti-angiogenic effect of sorafenib in mice bearing Ehrlich's ascites carcinoma: role of angiotensin (1-7)

Local renin-angiotensin systems exist in various malignant tumor tissues; this suggests that the main effector peptide, angiotensin II, could act as a key factor in tumor growth. The underlying mechanisms for the anti-angiogenic effect of angiotensin II type 1 receptor blockers need to be further evaluated. The present study was carried out to investigate the anti-angiogenic effect of olmesartan alone or in combination with sorafenib, an angiotensin (1–7) agonist or an angiotensin (1–7) antagonist in Ehrlich's ascites carcinoma-bearing mice. The tumor was induced by intradermal injection of Ehrlich's ascites carcinoma cells into mice. Tumor discs were used to evaluate the microvessel density; the serum levels of vascular endothelial growth factor (VEGF) and serum insulin-like growth factor I (IGF-I); and their intratumoral receptors, VEGF receptor-2 and IGF-I receptor, respectively. All parameters were determined following the treatment course, which lasted for 21 days post-inoculation. Monotherapy with olmesartan and its combination with sorafenib resulted in a significant reduction in microvessel density and serum levels of VEGF and IGF-I, as well as their intratumoral receptors. In addition, the combination of olmesartan (30 mg/kg) with an angiotensin (1–7) agonist reduced the microvessel density, IGF-I serum levels and the levels of its intratumoral receptor. In conclusion, olmesartan reduced the levels of the angiogenesis markers IGF-I and VEGF and down-regulated the intratumoral expression of their receptors in a dose-dependent manner, and these effects were dependent on the angiotensin (1–7) receptor. These results suggest that olmesartan is a promising adjuvant to sorafenib in the treatment of cancer.

Expression and clinical significance of angiotensin II type 1 receptor in human hepatocellular carcinoma

This study aimed to investigate the expression of angiotensin II type 1 receptor (AT-1R) mRNA and the AT-1R protein in human primary hepatocellular carcinoma (PHC), and to attempt to elucidate their association with pathological and clinical characteristics. Fresh tumor and normal liver tissues were obtained from 44 patients with PHC following hepatectomies. AT-1R mRNA levels were quantitatively analyzed by quantitative polymerase chain reaction (qPCR) while the protein levels were assessed by immunohistochemistry. The expression levels of AT-1R were observed in hepatocellular carcinoma tissues and normal liver tissues. The level of AT-1R protein expression in normal liver tissues was higher compared with that in PHC tissues (P=0.0033). The AT-1R mRNA levels were higher in patients with negative hepatitis B virus surface antigen (HBsAg), normal α-fetoprotein (AFP) levels and high tumor differentiation, compared with those in patients with positive HBsAg (P=0.0005), upregulated AFP levels (P=0.0008) and poor tumor differentiation (P=0.0290). No significant correlation was identified between the expression levels of AT-1R mRNA and general characteristics such as gender, age, cirrhotic nodules, tumor size, tumor encapsulation, tumor number, carcinoma embolus, tumor metastasis or tumor recurrence. Downregulated levels of AT-1R mRNA and AT-1R protein may indicate a poor prognosis for patients with PHC.

A multicenter phase II trial of gemcitabine and candesartan combination therapy in patients with advanced pancreatic cancer: GECA2

BACKGROUND

Our retrospective study and phase I trial of gemcitabine and candesartan combination therapy suggested the inhibition of renin-angiotensin system potentially has a role in the treatment of advanced pancreatic cancer. The aim of this multicenter phase II trial was to assess the efficacy and toxicity of gemcitabine and candesartan combination therapy for advanced pancreatic cancer.

METHODS

Chemotherapy-naive patients with histologically or cytologically proven advanced pancreatic cancer were enrolled. Gemcitabine was administered at a dose of 1,000 mg/m(2) over 30 min on days 1, 8, and 15 and oral candesartan at a dose of 16 mg in normotensive patients, and 8 mg initially in hypertensive patients, with dose escalation to 16 mg allowed, from days 1 to 28, repeated every 4 weeks.

RESULTS

A total of 35 patients with advanced pancreatic cancer were enrolled. Overall response rate and disease control rate were 11.4 % and 62.9 %. The median PFS and OS were 4.3 and 9.1 months with 1-year survival rate of 34.2 %. The median PFS was significantly longer in patients receiving 16 mg compared with 8 mg of candesartan (4.6 vs. 3.5 months, p=0.031). Major severe toxicities were neutropenia (23 %), leukopenia (17 %) and thrombocytopenia (11 %). Grade 2 hypotension was observed in 3 patients (9 %) and candesartan was discontinued in 2 patients due to hypotension. Conclusions In this multicenter phase 2 trial, gemcitabine and candesartan combination therapy was tolerable but failed to demonstrate activity against advanced pancreatic cancer. (UMIN CTR: UMIN000005580).

The angiotensin II type I receptor blocker olmesartan inhibits the growth of pancreatic cancer by targeting stellate cell activities in mice

There is accumulating evidence that pancreatic stellate cells (PSCs), a major profibrogenic cell type in the pancreas, promote the progression of pancreatic cancer. The interactions between PSCs and pancreatic cancer have attracted substantial attention as a novel therapeutic target for the treatment of pancreatic cancer. We examined here the effects of olmesartan, an angiotensin II type I receptor blocker, on pancreatic cancer-associated fibrosis using a subcutaneous tumor model developed by co-injection of pancreatic cancer cells with PSCs in nude mice. Co-injection of pancreatic cancer cells AsPC-1 with PSCs increased the size of tumors compared with AsPC-1 cells alone. Olmesartan administrated at 10 mg/kg in drinking water inhibited the growth of subcutaneous tumors derived from the co-injection, but not those derived from mono-injection. This effect was accompanied by decreased expression of α-smooth muscle actin (a marker of activated PSCs) and collagen deposition. The inhibitory effect of olmesartan was also observed even if it was administrated after significant development of subcutaneous tumors. In addition, olmesartan decreased cell growth and type I collagen production in PSCs in vitro. These results suggest that olmesartan inhibited the growth of tumors by targeting stellate cell activities, and that olmesartan might be useful as an anti-fibrosis therapy in pancreatic cancer.

[Angiotensin-2 type 1 receptors (AT1R) and cancers]

Recently, several meta-analysis suggested an increased risk of cancers linked to the use of antagonists of angiotensin-2 receptors or inhibitors of angiotensinogen converting enzyme. The results of epidemiological studies are conflicting. Meta-analysis as well as retrospective studies are not reliable and biased, since they have never been designed to explore any pro- or antitumoral effect. We lack of prospective studies that could take off the doubt on these drugs. Nevertheless, all experimental researches pointed out potent antitumoral properties. Indeed, direct antiproliferative and neo-angiogenic inhibition have been described on tumor cell cultures as well as on animal models. Moreover, we are convinced that the use of antagonists of angiotensin-2 receptors and inhibitors of angiotensinogen converting enzyme may be then of clinical use in the near future in association with classical antitumor drugs. In this review, we proposed to explore these data by a thorough analysis of recent literature associating epidemiological and experimental studies.

Phase I trial of gemcitabine and candesartan combination therapy in normotensive patients with advanced pancreatic cancer: GECA1

Our retrospective study showed inhibition of the renin-angiotensin system was associated with better outcomes in patients with advanced pancreatic cancer receiving gemcitabine. The primary objective of this phase I study was to determine the recommended dose of candesartan in combination with gemcitabine in normotensive patients with advanced pancreatic cancer. Candesartan was given orally at an escalating dose (4, 8, 16, and 32 mg) q.d. daily, and gemcitabine was given 1000 mg/m(2) 30 min i.v. on days 1, 8, and 15, repeated every 4 weeks. Dose-limiting toxicity (DLT) was defined as grade 4 hematological toxicities, grade 2 hypotension, abnormal creatinine or potassium, and grade 3 or 4 other non-hematological toxicities. A standard "3+3" phase I dose-escalation design was used. A total of 14 patients (candesartan 4 mg, three patients; 8 mg, three patients; 16 mg, six patients; 32 mg, two patients) were enrolled. One of six patients at 16 mg showed DLT of grade 4 neutropenia and two of two patients at 32 mg showed DLT of grade 2 hypotension. Response rate and disease control rate were 0% and 79%, respectively. Progression-free survival and overall survival were 7.6 and 22.9 months, respectively. Candesartan 16 mg is the recommended dose in combination with gemcitabine in the treatment of advanced pancreatic cancer. (UMIN CTR: UMIN000002152).

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 system inhibitors and outcome of sunitinib treatment in patients with metastatic renal cell carcinoma: a retrospective examination

BACKGROUND

Sunitinib is a standard treatment for metastatic renal cell carcinoma. Angiotensin system inhibitors, including angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, are widely used in hypertension, kidney disease and heart failure. Data suggests that they may inhibit tumourigenesis.

AIMS

To study the effect of angiotensin system inhibitors on sunitinib treatment outcome in metastatic renal cell carcinoma.

METHODS

We performed a retrospective study of an unselected cohort of patients with metastatic renal cell carcinoma who were treated with sunitinib. Patients were divided into angiotensin system inhibitors users (group 1) and non-users (group 2). The effect of angiotensin system inhibitors on objective response, time to disease progression and overall survival, was tested with adjustment for known confounding risk factors through logistic regression model and Cox regression model.

RESULTS

Between 2004 and 2010, 127 patients with metastatic renal cell carcinoma were treated with sunitinib, 44 group 1 and 83 group 2. The groups were balanced regarding known clinicopathologic prognostic factors. Objective response was partial response/stable disease 86% versus 72% and progressive disease 14% versus 28% (p=0.07) in group 1 versus 2, respectively. Median progression free survival was 13 versus 6 months (HR 0.537, p=0.0055), and median overall survival 30 versus 23 months (HR 0.688, p=0.21), in favour of group 1.

CONCLUSIONS

Angiotensin system inhibitors may improve the outcome of sunitinib treatment in metastatic renal cell carcinoma. This should be investigated prospectively, and if validated applied in clinical practise and clinical trials.

Angiotensin receptor blockers and angiogenesis: clinical and experimental evidence

Angiotensin II type 1 receptor antagonists [ARBs (angiotensin receptor blockers)] are indicated for BP (blood pressure)-lowering, renal protection and cardioprotection in patients unable to tolerate ACEIs (angiotensin-converting enzyme inhibitors). A recent meta-analysis revealed an association between ARBs and tumour development, possibly due to enhancement of angiogenesis. However, published evidence is conflicting on the effects of ARBs on angiogenesis or the expansion of the existing vascular network. ARBs have been shown to exert primarily anti-angiogenic effects in basic science studies of cancer, retinopathy, peripheral artery disease and some models of cardiovascular disease. In animal and cellular models of myocardial infarction and stroke, however, ARB administration has been associated with robust increases in vascular density and improved recovery. The aim of the present review is to examine the angiogenic effects of ARBs in animal and cellular models of relevant disease states, including proposed molecular mechanisms of action of ARBs and the clinical consequences of ARB use.

Mesenchymal cell proliferation and programmed cell death: key players in fibrogenesis and new targets for therapeutic intervention

An exquisite equilibrium between cell proliferation and programmed cell death is required to maintain physiological homeostasis. In inflammatory bowel disease, and especially in Crohn's disease, enhanced proliferation along with defective apoptosis of immune cells are considered key elements of pathogenesis. Despite the relatively limited attention that has been given to research efforts devoted to intestinal fibrosis to date, there is evidence suggesting that enhanced proliferation along with defective programmed cell death of mesenchymal cells can significantly contribute to the development of excessive fibrogenesis in many different tissues. Moreover, some therapies have demonstrated potential antifibrogenic efficacy through the regulation of mesenchymal cell proliferation and programmed cell death. Further understanding of the pathways involved in the regulation of mesenchymal cell proliferation and apoptosis is, however, required.

Inhibition of renin-angiotensin system affects prognosis of advanced pancreatic cancer receiving gemcitabine

Background:

The renin–angiotensin system (RAS) is thought to have a role in carcinogenesis, and RAS inhibition may prevent tumour growth.

Methods:

We retrospectively investigated the impact of angiotensin I-converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs) in 155 patients with pancreatic cancer receiving gemcitabine monotherapy. Patients were divided into three groups: the ACEI/ARB group (27 patients receiving an ACEI or ARB for hypertension (HT)), the non-ACEI/ARB with HT group (25 patients receiving antihypertensive drugs other than ACEIs or ARBs), and the non-HT group (103 patients receiving no antihypertensive drugs).

Results:

Patient characteristics were not different, except for age and HT medications. Progression-free survival (PFS) was 8.7 months in the ACEI/ARB group, 4.5 months in the non-ACEI/ARB with HT group, and 3.6 months in the non-HT group. Overall survival (OS) was 15.1 months in the ACEI/ARB group, 8.9 months in the non-ACEI/ARB with HT group, and 9.5 months in the non-HT group. The use of ACEIs/ARBs was a significant prognostic factor for both PFS (P=0.032) and OS (P=0.014) in the multivariate analysis.

Conclusions:

The ACEIs/ARBs in combination with gemcitabine might improve clinical outcomes in patients with advanced pancreatic cancer. Prospective trials are needed to test this hypothesis.