β-blockers: a novel class of antitumor agents

The multifaceted role of beta-blockers in overcoming cancer progression and drug resistance: Extending beyond cardiovascular disorders

Beta-blockers are commonly used medications that antagonize β-adrenoceptors, reducing sympathetic nervous system activity. Emerging evidence suggests that beta-blockers may also have anticancer effects and help overcome drug resistance in cancer treatment. This review summarizes the contribution of different isoforms of beta-adrenoceptors in cancer progression, the current preclinical and clinical data on associations between beta-blockers use and cancer outcomes, as well as their ability to enhance responses to chemotherapy and other standard therapies. We discuss proposed mechanisms, including effects on angiogenesis, metastasis, cancer stem cells, and apoptotic pathways. Overall, results from epidemiological studies and small clinical trials largely indicate the beneficial effects of beta-blockers on cancer progression and drug resistance. However, larger randomized controlled trials are needed to firmly establish their clinical efficacy and optimal utilization as adjuvant agents in cancer therapy.

Investigating Carvedilol's Repurposing for the Treatment of Non-Small Cell Lung Cancer via Aldehyde Dehydrogenase Activity Modulation in the Presence of β-Adrenergic Agonists

Repurposing existing drugs appears to be a potential solution for addressing the challenges in the treatment of non-small cell lung cancer (NSCLC). β-adrenoceptor antagonist drugs (β-blockers) have tumor-inhibiting effects, making them promising candidates for potential NSCLC treatment. This study investigates the anticancer potential of a subset of β-blockers in NSCLC cell lines; A549 and H1299. Additionally, it investigates the underlying mechanism behind β-blockers' anticancer effect by influencing a potential novel target named aldehyde dehydrogenase (ALDH). The MTT assay assessed β-blockers' cytotoxicity on both cell lines, while Western blot and NADH fluorescence assays evaluated their influence on ALDH protein expression and activity. Carvedilol (CAR) was the most effective blocker in reducing cell survival of A549 and H1299 with IC50 of 18 µM and 13.7 µM, respectively. Significantly, CAR led to a 50% reduction in ALDH expression and 80% decrease in ALDH activity in A549 cells, especially when combined with β-agonists, in comparison to the control. This effect might be attributed to β-agonist blockade or an alternative pathway. This novel finding adds to our understanding of CAR's multifaceted anticancer properties, implying that combining CAR with β-agonists could be a useful strategy for lung cancer treatment.

Drug Repurposing in Oncology: A Systematic Review of Randomized Controlled Clinical Trials

Quality pharmacological treatment can improve survival in many types of cancer. Drug repurposing offers advantages in comparison with traditional drug development procedures, reducing time and risk. This systematic review identified the most recent randomized controlled clinical trials that focus on drug repurposing in oncology. We found that only a few clinical trials were placebo-controlled or standard-of-care-alone-controlled. Metformin has been studied for potential use in various types of cancer, including prostate, lung, and pancreatic cancer. Other studies assessed the possible use of the antiparasitic agent mebendazole in colorectal cancer and of propranolol in multiple myeloma or, when combined with etodolac, in breast cancer. We were able to identify trials that study the potential use of known antineoplastics in other non-oncological conditions, such as imatinib for severe coronavirus disease in 2019 or a study protocol aiming to assess the possible repurposing of leuprolide for Alzheimer's disease. Major limitations of these clinical trials were the small sample size, the high clinical heterogeneity of the participants regarding the stage of the neoplastic disease, and the lack of accounting for multimorbidity and other baseline clinical characteristics. Drug repurposing possibilities in oncology must be carefully examined with well-designed trials, considering factors that could influence prognosis.

The β2-adrenergic receptor in the apical membrane of intestinal enterocytes senses sugars to stimulate glucose uptake from the gut

The presence of sugar in the gut causes induction of SGLT1, the sodium/glucose cotransporter in intestinal epithelial cells (enterocytes), and this is accompanied by stimulation of sugar absorption. Sugar sensing was suggested to involve a G-protein coupled receptor and cAMP - protein kinase A signalling, but the sugar receptor has remained unknown. We show strong expression and co-localization with SGLT1 of the β2-adrenergic receptor (β ₂-AR) at the enterocyte apical membrane and reveal its role in stimulating glucose uptake from the gut by the sodium/glucose-linked transporter, SGLT1. Upon heterologous expression in different reporter systems, the β ₂-AR responds to multiple sugars in the mM range, consistent with estimated gut sugar levels after a meal. Most adrenergic receptor antagonists inhibit sugar signaling, while some differentially inhibit epinephrine and sugar responses. However, sugars did not inhibit binding of I¹²⁵-cyanopindolol, a β ₂-AR antagonist, to the ligand-binding site in cell-free membrane preparations. This suggests different but interdependent binding sites. Glucose uptake into everted sacs from rat intestine was stimulated by epinephrine and sugars in a β ₂-AR-dependent manner. STD-NMR confirmed direct physical binding of glucose to the β ₂-AR. Oral administration of glucose with a non-bioavailable β ₂-AR antagonist lowered the subsequent increase in blood glucose levels, confirming a role for enterocyte apical β ₂-ARs in stimulating gut glucose uptake, and suggesting enterocyte β ₂-AR as novel drug target in diabetic and obese patients. Future work will have to reveal how glucose sensing by enterocytes and neuroendocrine cells is connected, and whether β ₂-ARs mediate glucose sensing also in other tissues.

Β-blockers activate autophagy on infantile hemangioma-derived endothelial cells in vitro

The mechanisms underlying the success of propranolol in the treatment of infantile hemangioma (IH) remain elusive and do not fully explain the rapid regression of hemangiomatous lesions following drug administration. As autophagy is critically implicated in vascular homeostasis, we determined whether β-blockers trigger the autophagic flux on infantile hemangioma-derived endothelial cells (Hem-ECs) in vitro.

MATERIAL AND METHODS

Fresh tissue specimens, surgically removed for therapeutic purpose to seven children affected by proliferative IH, were subjected to enzymatic digestion. Cells were sorted with anti-human CD31 immunolabeled magnetic microbeads. Following phenotypic characterization, expanded Hem-ECs, at P2 to P6, were exposed to different concentrations (50 μM to 150 μM) of propranolol, atenolol or metoprolol alone and in combination with the autophagy inhibitor Bafilomycin A1. Rapamycin, a potent inducer of autophagy, was also used as control. Autophagy was assessed by Lysotracker Red staining, western blot analysis of LC3BII/LC3BI and p62, and morphologically by transmission electron microscopy.

RESULTS

Hem-ECs treated with either propranolol, atenolol or metoprolol displayed positive LysoTracker Red staining. Increased LC3BII/LC3BI ratio, as well as p62 modulation, were documented in β-blockers treated Hem-ECs. Abundant autophagic vacuoles and multilamellar bodies characterized the cytoplasmic ultrastructural features of autophagy in cultured Hem-ECs exposed in vitro to β-blocking agents. Importantly, similar biochemical and morphologic evidence of autophagy were observed following rapamycin while Bafilomycin A1 significantly prevented the autophagic flux promoted by β-blockers in Hem-ECs.

CONCLUSION

Our data suggest that autophagy may be ascribed among the mechanisms of action of β-blockers suggesting new mechanistic insights on the potential therapeutic application of this class of drugs in pathologic conditions involving uncontrolled angiogenesis.

Beta-adrenergic receptor blockers and hepatocellular carcinoma survival: a systemic review and meta-analysis

INTRODUCTION

Preclinical data have revealed that beta-adrenergic stimulation can affect the growth and progression of different types of malignancies. Beta-adrenergic receptor blockers have been associated with improved survival in patients with many types of cancer. We performed a meta-analysis to investigate the association between beta-blocker use and hepatocellular carcinoma (HCC) prognosis.

METHODS

In this meta-analysis, a full search was conducted using PubMed, the Cochrane library and Embase to identify all relevant studies published up to May 2021. Available hazard ratios (HRs) were extracted for overall survival (OS), cancer-specific survival (CSS) and pooled using a random-effects meta-analysis.

RESULTS

Four studies involving 7252 patients with HCC met the inclusion criteria and were included in the systemic review. Three studies that reported OS data of 5148 patients were included in the meta-analysis. The random-effects model showed that beta-blocker use was associated with significantly improved OS in HCC (HR = 0.69, 95% CI = 0.54-0.88, P = 0.0031), without significant heterogeneity (I² = 41%; Q = 6.42, P = 0.18).

CONCLUSION

This meta-analysis suggested that beta-blocker use can be associated with prolonged OS of patients with HCC.

Subclinical cardiac damage in cancer patients before chemotherapy

Cancer and cardiovascular diseases, including heart failure (HF), are the main causes of death in Western countries. Several anticancer drugs and radiotherapy have adverse effects on the cardiovascular system, promoting left ventricular dysfunction and ultimately HF. Nonetheless, the relationship between cancer and HF is likely not unidirectional. Indeed, cancer and HF share common risk factors, and both have a bidirectional relationship with systemic inflammation, metabolic disturbances, and neurohormonal and immune activation. Few studies have assessed the impact of untreated cancer on the heart. The presence of an active cancer has been associated with elevated cardiac biomarkers, an initial impairment of left ventricular structure and function, autonomic dysfunction, and reduced exercise tolerance. In turn, these conditions might increase the risk of cardiac damage from chemotherapy and radiotherapy. HF drugs such as beta-blockers or inhibitors of the renin–angiotensin–aldosterone system might exert a protective effect on the heart even before the start of cancer therapies. In this review, we recapitulate the evidence of cardiac involvement in cancer patients naïve from chemotherapy and radiotherapy and no history of cardiac disease. We also focus on the perspectives for an early diagnosis and treatment to prevent the progression to cardiac dysfunction and clinical HF, and the potential benefits of cardioactive drugs on cancer progression.

Beta1- and Beta2-Adrenoceptors Expression Patterns in Human Non-small Cell Lung Cancer: Relationship with Cancer Histology

Assessment of Beta-AR protein expression on tumour tissues might be a plausible strategy to select cancer patients who can benefit from Beta-blockers therapy. The aim of this study is to evaluate the differences between resected tissue specimens from primary lung cancer (adenocarcinoma (ADC) and squamous cell carcinoma (SCC)) in terms of expression pattern of Beta1- and Beta2-AR in both tumour and adjacent surrounding non-tumour tissue. This retrospective study was based on the analysis of 80 patients with histologically confirmed diagnosis of primary Non-Small Cell Lung Cancer (NSCLC) who received surgical treatment. The cases were carefully selected in order to obtain the most homogeneous sample in terms of histologic subtype (40 ADCs and 40 SCCs) and clinical stage (10 each). Beta1- and Beta2-AR expression was determined by immunohistochemistry and the staining evaluated by semi-quantitative scoring using the H-score method. In our NSCLC series, Beta1- and Beta2-AR are differentially expressed. Beta1-AR expression is present at low levels in both SCC and ADC. Likewise, when compared with the matched surrounding non-tumour tissues, Beta1-AR expression level was significantly lower in both histologic subtypes. Conversely, Beta2-AR is highly expressed in both histologic subtypes, but clearly highly expressed in ADC when compared with SCC and with their matched surrounding non-tumour tissue. Overall, this clinicopathological study highlights the differential expression of Beta1- and Beta2-AR in ADC and SCC. Repurposing non-selective Beta-blockers in oncologic setting might be a suitable therapeutic strategy for lung ADC. Graphical abstract.

Use of Antihypertensive Medications and Survival Rates for Breast, Colorectal, Lung, or Stomach Cancer

Using time-dependent Cox regression models, we examined associations of common antihypertensive medications with overall cancer survival (OS) and disease-specific survival (DSS), with comprehensive adjustment for potential confounding factors. Participants were from the Shanghai Women's Health Study (1996-2000) and Shanghai Men's Health Study (2002-2006) in Shanghai, China. Included were 2,891 incident breast, colorectal, lung, and stomach cancer cases. Medication use was extracted from electronic medical records. With a median 3.4-year follow-up after diagnosis (interquartile range, 1.0-6.3), we found better outcomes among users of angiotensin II receptor blockers with colorectal cancer (OS: adjusted hazard ratio (HR) = 0.62, 95% confidence interval (CI): 0.44, 0.86; DSS: adjusted HR = 0.61, 95% CI: 0.43, 0.87) and stomach cancer (OS: adjusted HR = 0.62, 95% CI: 0.41, 0.94; DSS: adjusted HR = 0.63, 95% CI: 0.41, 0.98) and among users of β-adrenergic receptor blockers with colorectal cancer (OS: adjusted HR = 0.50, 95% CI: 0.35, 0.72; DSS: adjusted HR = 0.50, 95% CI: 0.34, 0.73). Better survival was also found for calcium channel blockers (DSS: adjusted HR = 0.67, 95% CI: 0.47, 0.97) and diuretics (OS: adjusted HR = 0.66, 95% CI: 0.45, 0.96; DSS: adjusted HR = 0.57, 95% CI: 0.38, 0.85) with stomach cancer. Our findings suggest angiotensin II receptor blockers, β-adrenergic receptor blockers, and calcium channel blockers might be associated with improved survival outcomes of gastrointestinal cancers.

Cardiovascular, antidepressant and immunosuppressive drug use in relation to risk of cutaneous melanoma: a protocol for a prospective case-control study

INTRODUCTION

The incidence of cutaneous melanoma (hereafter melanoma) has increased dramatically among fair-skinned populations worldwide. In Norway, melanoma is the most rapidly growing type of cancer, with a 47% increase among women and 57% among men in 2000-2016. Intermittent ultraviolet exposure early in life and phenotypic characteristics like a fair complexion, freckles and nevi are established risk factors, yet the aetiology of melanoma is multifactorial. Certain prescription drugs may have carcinogenic side effects on the risk of melanoma. Some cardiovascular, antidepressant and immunosuppressive drugs can influence certain biological processes that modulate photosensitivity and immunoregulation. We aim to study whether these drugs are related to melanoma risk.

METHODS AND ANALYSIS

A population-based matched case-control study will be conducted using nation-wide registry data. Cases will consist of all first primary, histologically verified melanoma cases diagnosed between 2007 and 2015 identified in the Cancer Registry of Norway (14 000 cases). Ten melanoma-free controls per case (on date of case melanoma diagnosis) will be matched based on sex and year of birth from the National Registry of Norway. For the period 2004-2015, and by using the unique personal identification numbers assigned to all Norwegian citizens, the case-control data set will be linked to the Norwegian Prescription Database for information on drugs dispensed prior to the melanoma diagnosis, and to the Medical Birth Registry of Norway for data regarding the number of child births. Conditional logistic regression will be used to estimate associations between drug use and melanoma risk, taking potential confounding factors into account.

ETHICS AND DISSEMINATION

The project is approved by the Regional Committee for Medical Research Ethics in Norway and by the Norwegian Data Protection Authority. The study is funded by the Southeastern Norway Regional Health Authority. Results will be published in peer-reviewed journals and disseminated further through scientific conferences, news media and relevant patient interest groups.

Propranolol inhibits proliferation and invasion of hemangioma-derived endothelial cells by suppressing the DLL4/Notch1/Akt pathway

Infantile hemangioma (IH) is one of the most common benign vascular tumors of infancy. Propranolol has been recently introduced for the treatment of IH. However, the mechanism of protective effect has not been fully understood. In this study, hemangioma-derived endothelial cells (HemECs) were isolated and treated with propranolol. The cell viability was measured by MTT assay, and the cell cycle arrest was detected using flow cytometry. Cell invasion was determined using transwell assay. The expressions of matrix metalloproteinase (MMP)-2, MMP-9, Delta-like 4 (DLL4), Notch1, Akt, p-Akt, and vascular endothelial growth factor (VEGF) were detected using western blot. HemECs were incubated with recombinant human DLL4 (rhDLL4) to investigate the role of DLL4/Notch1 in the effect of propranolol. The results showed that propranolol inhibited cell viability of HemECs in a time-dependent manner. Propranolol suppressed cell proliferation of HemECs by arresting cell progression at G0/G1 phase. Propranolol inhibited the invasion ability of HemECs and reduced the expression levels of MMP-2 and MMP-9 in HemECs. Besides, propranolol treatment blocked the DLL4/Notch1 and Akt signaling and inhibited VEGF expression in HemECs. Treatment with rhDLL4 activated the Akt signaling and attenuated the effect of propranolol on HemECs. Our data indicated that propranolol inhibited the cell proliferation and invasion of HemECs. The effect was possibly involved in the DLL4/Notch1/Akt signaling pathway.

Beta-blockers improve survival outcomes in patients with multiple myeloma: a retrospective evaluation

A preclinical study demonstrated anti-proliferative and apoptotic effect of propranolol on multiple myeloma (MM) cell. Clinical studies suggested that beta-blocker (BB) might impact the prognosis of breast, prostate, colorectal, ovarian, lung, and skin cancer. This retrospective study evaluated the effect of BB in MM disease-specific survival (DSS) and overall survival (OS). Among 1,971 newly diagnosed MM patients seen at Mayo Clinic between 1995 and 2010, usage of BB and other cardiac (or antihypertensive) medications were abstracted. Cumulative incidence function and Kaplan-Meier method were used to estimate 5-year cumulative incidence rate (CIR) of MM death and OS rate, respectively. Nine hundred and thirty (47.2%) patients had no intake of cardiac medications; 260 (13.2%) used BB alone; 343 (17.4%) used both BB/non-BB cardiac medications; and 438 (22.2%) had non-BB cardiac drugs. Superior MM DSS was observed in BB only users, compared to patients without any cardiac drugs ( HRadj.CS, 0.53, 95% confidence interval [CI], 0.42-0.67, P_adj. <0.0001) and non-BB cardiac drugs users ( HRadj.CS, 0.49, 95% CI, 0.38-0.63, P_adj. <0.0001). Patients on both BB and other cardiac drugs showed superior DSS than non-cardiac drugs users ( HRadj.CS, 0.54, 95% CI, 0.44-0.67, P_adj. <0.0001) and non-BB cardiac drug users. ( HRadj.CS, 0.50, 95% CI, 0.40-0.62, P_adj. <0.0001). MM DSS did not differ between BB users with and without other cardiac drugs (P_adj. =0.90). Multivariable analysis showed the same pattern for OS. In patients with MM, BB intake is associated with a reduced risk of disease-specific death and overall mortality in comparison to non-BB or no use of cardiac drugs. Am. J. Hematol. 92:50-55, 2017. © 2016 Wiley Periodicals, Inc.

β-Adrenergic modulation of cancer cell proliferation: available evidence and clinical perspectives

PURPOSE

In this review, we aimed to present and discuss the available preclinical and epidemiological evidences regarding the modulation of cancer cell proliferation by β-adrenoceptors (β-AR), with a specific focus on the putative effects of β-blockers according to their pharmacological properties.

METHODS

A comprehensive review of the published literature was conducted, and the evidences concerning the involvement of β-AR in cancer as well as the possible role of β-blockers were selected and discussed.

RESULTS

The majority of reviewed studies show that: (1) All the cancer types express both β1- and β2-AR, with the exception of neuroblastoma only seeming to express β2-AR; (2) adrenergic agonists are able to increase proliferation of several types of cancers; (3) the proliferative effect seems to be mediated by both β1- and β2-AR; (4) binding to β-AR results in a cAMP transient flux which activates two major downstream effector systems: protein kinase A and EPAC and (5) β-blockers might be putative adjuvants for cancer treatment.

CONCLUSIONS

Overall, the reviewed studies show strong evidences that β-AR activation, through several intracellular mechanisms, modulate tumor cell proliferation suggesting β-blockers can be a feasible therapeutic approach to antagonize β-adrenergic response or have a protective effect per se. This review highlight the need for intensifying the research not only on the molecular mechanisms underlying the β-adrenergic influence in cancer, but also on the implications of biased agonism of β-blockers as potential antitumor agents.

Role of β2 adrenergic receptor signaling pathway in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancies characterized by insidious onset and poor prognosis. Studies have shown that β adrenergic receptor signaling, especially β2 adrenergic receptor (β2-AR) signaling, regulates multiple cellular processes that contribute to the initiation and progression of cancer, including differentiation, proliferation and apoptosis. β2-AR signaling is also involved in tumor angiogenesis, progression and metastasis in HCC. Therefore, understanding of the role of the β2 adrenergic receptor signaling pathway in HCC progression and metastasis will be of great value in developing therapeutic strategies for this maliganancy. In this paper, we will discuss the role of β2 adrenergic receptor signaling pathway in HCC.

Clinical features and management of multifocal hepatic hemangiomas in children: a retrospective study

Multifocal hepatic hemangioma (MHH) is a benign hepatic tumor that is commonly diagnosed in children with multiple cutaneous infantile hemangiomas (IHs). We present a review of all children with MHH at our institutions. Of the 42 patients, the median age at presentation of MHH was 2.5 months. Thirty-six (85.7%) patients had cutaneous IHs. Twelve (28.6%) patients were symptomatic at presentation. There was no significant association between the number of hepatic hemangiomas and the number of cutaneous IHs. Fourteen (33.3%) patients received some form of treatment for hepatic hemangiomas. The most common type of treatment was oral prednisone in 8 patients, followed by oral propranolol in 6 patients. Two patients were totally resistant to prednisone treatment. They died from congestive heart failure or respiratory distress and coagulopathy. Two patients with problematic facial IH were treated with intralesional triamcinolone injection. The remaining 26 patients were managed with imaging surveillance. On follow-up, all of the survivors had a favorable outcome. Our study suggests that the clinical features of MHH are variable. Our data emphasize the treatment strategy that aggressive treatment is indicated in symptomatic or progressive MHHs, whereas observation management of asymptomatic patients with a few small lesions is safe and appropriate.

Non-selective beta-blockers in cirrhosis: Current concepts and controversies

Non-selective beta-blockers (NSBBs) have been at the forefront in the management of portal hypertension in liver cirrhosis for the last three decades, a trusty component in the armamentarium of the Hepatologist. The role of beta-blockers has been cemented for years in cardiac disease including angina, hypertension and in heart failure, however NSBBs with their non-selective effects on β1 and β2 receptors have led to them fondly being termed “the hepatologist’s aspirin”. NSBBs’ role in reduction of portal pressure in the setting of primary and secondary prophylaxis for variceal haemorrhage has been well established. NSBBs include propranolol, nadolol and carvedilol - with the latter having been shown to be effective in patients who often fail to demonstrate a haemodynamic response to propranolol. Recent observational studies however have served for the Hepatology community to question the beneficial role of NSBBs in portal hypertension, especially in advanced cases with refractory ascites. The deleterious effect in patients with refractory ascites in a few studies led to a U-turn in clinical practice, with some in the Hepatology community withdrawing their usage in patients with advanced cirrhosis. This also led to the “window hypothesis” suggesting there may be only be a finite time frame when NSBBs have a beneficial effect in portal hypertension. The window hypothesis proposed the window for the benefits of NSBBs is closed in early portal hypertension, opening as portal hypertension progresses with it closing in advanced liver disease. The window was proposed to close in conditions such as refractory ascites or spontaneous bacterial peritonitis when patients may not necessarily mount a compensatory haemodynamic response when on NSBBs. Some centres however have continued the practice of NSBBs in advanced cirrhosis with published data challenging the scepticisms of other groups who stop NSBBs. Thus the debate, like the window hypothesis has opened, with more questions to be answered about NSBB’s mechanism of action not only in reducing portal hypertension but also their effects on systemic haemodynamics and on the pro-inflammatory pathways often activated in cirrhosis especially in advanced disease. This article serves to review the role of NSBBs in the management of portal hypertension/cirrhosis and concentrate on current concepts and controversies in this field.

Upregulated autocrine vascular endothelial growth factor (VEGF)/VEGF receptor-2 loop prevents apoptosis in haemangioma-derived endothelial cells

BACKGROUND

The autocrine vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)-2 loop is required to maintain the transformed phenotype of many tumours, in part, by preventing apoptotic cell death in response to many different stimuli. However, it is unclear whether constitutive VEGF/VEGFR-2 activation in haemangioma-derived endothelial cells (HaemECs) can lead to a general suppression of apoptosis.

OBJECTIVES

The objective of this study was to investigate whether the autocrine VEGF loop promotes HaemEC survival via its receptor, VEGFR-2.

METHODS

HaemECs and human umbilical vein endothelial cells (HUVECs) were serum-starved for 12-48 h. Cell apoptosis was measured. The potential mechanisms of VEGF/VEGFR-2-induced HaemEC survival were investigated, and the role of the autocrine VEGF/VEGFR-2 loop in preventing propranolol-induced apoptotic HaemEC death was also analysed.

RESULTS

Compared with HUVECs, HaemECs showed increased resistance to apoptosis induced by serum starvation. Upregulated VEGF/VEGFR-2 signalling in HaemECs induced an autocrine signalling loop, which resulted in Akt activation. Furthermore, this activation of Akt was necessary for VEGF/VEGFR-2-induced protection against serum deprivation-induced HaemEC apoptosis. In addition, Bcl-2, which functions as an anti-apoptotic factor and direct downstream target of PI3K/Akt, was decreased by the inhibition of VEGF/VEGFR-2, which led to an increase in caspase-3 activity, caspase-9 activity and HaemEC apoptosis. Moreover, HaemECs acquired greater resistance to propranolol treatment than HUVECs, whereas inhibition of VEGF/VEGFR-2 signalling in HaemECs sensitized these cells to propranolol-induced apoptosis.

CONCLUSIONS

Our results demonstrate that upregulation of the autocrine VEGF/VEGFR-2 loop can induce general resistance to apoptotic stimuli in HaemECs.

The use of propranolol in the treatment of infantile haemangiomas: an update on potential mechanisms of action

Currently, propranolol is the preferred treatment for problematic proliferating infantile haemangiomas (IHs). The rapid action of propranolol has been shown to be especially dramatic in IHs involving dyspnoea, haemodynamic compromise, palpebral occlusion or ulceration. Another remarkable aspect of propranolol treatment revealed that the growth of the IHs was not only stabilized, but also that the improvement continued until complete involution was achieved, leading to a considerable shortening of the natural course of IH. However, the mechanisms underlying the effects of propranolol have not been fully elucidated. Recent studies have offered evidence of a variety of mechanisms. These include the promotion of pericyte-mediated vasoconstriction, the inhibition of vasculogenesis and catecholamine-induced angiogenesis, the disruption of haemodynamic force-induced cell survival, and the inactivation of the renin-angiotensin system. This review summarizes these mechanisms and the new concepts that are emerging in this area of research. Moreover, several molecular mechanisms by which propranolol may modify neovascularization in IH have also been proposed. The antihaemangioma effect of propranolol may not be attributable to a single mechanism, but rather to a combination of events that have not yet been elucidated or understood. Further studies are needed to evaluate and verify these mechanisms to gain a greater understanding of the effects of the intake of propranolol on haemangioma involution.

Role of adrenergic receptor signaling pathway in colorectal cancer

Colorectal cancer is one of the most common malignancies. During the past decades, studies have continued to shed light on the role of adrenergic receptor signaling in cancer. Preclinical studies have shown that adrenergic receptor signaling is involved in colon cancer progression and metastasis and have implicated that stress hormones or behavioral changes are highly associated with tumor formation and progression. Therefore, further understanding of the role of the adrenergic receptor (AR) signaling pathway in colorectal cancer progression and metastasis will be of great value in developing therapeutic strategies for this malignancy.

Role of G protein-coupled receptor kinase 2 in tumoral angiogenesis

Downregulation of G protein-coupled receptor kinase 2 (GRK2) in endothelial cells has recently been identified as a relevant event in the tumoral angiogenic switch. Based on the effects of altering GRK2 dosage in cell and animal models, this kinase appears to act as a hub in key signaling pathways involved in vascular stabilization and remodeling. Accordingly, decreased GRK2 expression in endothelial cells accelerates tumor growth in mice by impairing the pericytes ensheathing the vessels, thereby promoting hypoxia and macrophage infiltration. These results raise new questions regarding the mechanisms by which transformed cells trigger the decrease in GRK2 observed in human breast cancer vessels and how GRK2 modulates the interactions between different cell types that occur in the tumor microenvironment.

The risk of cancer in patients with rheumatoid arthritis taking tumor necrosis factor antagonists: a nationwide cohort study

Introduction

The association between cancer and use of biologic therapy among rheumatoid arthritis (RA) patients remains controversial. We aimed to compare the relative risk of cancer development between RA patients taking tumor necrosis factor α (TNFα) antagonists and those taking nonbiologic disease-modifying anti-rheumatic drugs (nbDMARDs).

Methods

We conducted a nationwide cohort study between 1997 and 2011 using the Taiwan National Health Insurance Research Database. The risk of newly diagnosed cancer was compared between patients starting TNF-α antagonists (biologics cohort) and matched subjects taking nbDMARDs only (nbDMARDs cohort). Cumulative incidences and hazard ratios (HR) were calculated after adjusting for competing mortality. Standardized incidence ratio (SIR) was calculated for cancer risk. Multivariate analyses were performed using Cox proportional hazards model.

Results

We compared 4426 new users of TNF-α antagonists and 17704 users of nbDMARDs with similar baseline covariate characteristics. The incidence rates of cancer among biologics and nbDMARDs cohorts were 5.35 (95% confidence interval (CI) 4.23 to 6.46) and 7.41 (95% CI 6.75 to 8.07) per 1000 person-years, respectively. On modified Cox proportional hazards analysis, the risk of cancer was significantly reduced in subjects in biologics cohort (adjusted HR 0.63, 95% CI 0.49 to 0.80, P < .001), after adjusting for age, gender, disease duration, major co-morbidities, and prior use of DMARDs and corticosteroids. However, there was an increased risk for hematologic cancers in biologics cohort, yet without statistical significance. The effect of biologics was consistent across all multivariate stratified analyses and the association between biologics use and cancer risk was independent of dosage of concomitant nbDMARDs.

Conclusion

These findings suggested that RA patients taking TNF-α antagonist are associated with a lower risk of cancer, but not for hematologic cancers, than RA patients taking nbDMARDs alone.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-014-0449-5) contains supplementary material, which is available to authorized users.

A role for cAMP-driven transactivation of EGFR in cancer aggressiveness - therapeutic implications

In many common cancers, production of cAMP boosts cancer proliferation, survival, and aggressiveness, reflecting the fact that, through mechanisms that require further clarification, cAMP can promote tyrosine phosphorylation, notably transactivation of the epidermal growth factor receptor (EGFR). Hormones which activate adenylate cyclase in many cancers include PGE2 - often produced by cox-2 activity within tumors - and adrenergic hormones, acting on beta2 receptors. NSAID cyclooxygenase inhibitors, including low-dose aspirin, clearly reduce risk for many adenocarcinomas, but the impact of cox-2 inhibitors in clinical cancer therapy remains somewhat equivocal. There is increasing evidence that increased sympathetic drive, often reflecting psychic stress or tobacco usage, increases risk for, and promotes the aggressiveness of, many cancers. The non-specific beta antagonist propranolol shows cancer-retardant activity in pre-clinical rodent studies, especially in stressed animals, and a limited amount of epidemiology concludes that concurrent propranolol usage is associated with superior prognosis in breast cancer, ovarian cancer, and melanoma. Epidemiology correlating increased resting heart rate with increased total cancer mortality can be interpreted as compelling evidence that increased sympathetic drive encourages the onset and progression of common cancers. Conversely, hormones which inhibit adenylate cyclase activity in cancers may have potential for cancer control; GABA, which can be administered as a well-tolerated nutraceutical, has potential in this regard. Combination regimens intended to down-regulate cancer cAMP levels, perhaps used in conjunction with EGFR inhibitors, may have considerable potential for suppressing the contribution of cAMP/EGFR to cancer aggressiveness. This model also predicts that certain other hormones which activate adenylate cylase in various tissue may play a yet-unsuspected role in cancer induction and spread.

'Reduced malignancy as a mechanism for longevity in mice with adenylyl cyclase type 5 disruption'

Disruption of adenylyl cyclase type 5 (AC5) knockout (KO) is a novel model for longevity. Because malignancy is a major cause of death and reduced lifespan in mice, the goal of this investigation was to examine the role of AC5KO in protecting against cancer. There have been numerous discoveries in genetically engineered mice over the past several decades, but few have been translated to the bedside. One major reason is that it is difficult to alter a gene in patients, but rather a pharmacological approach is more appropriate. The current investigation employs a parallel construction to examine the extent to which inhibiting AC5, either in a genetic knockout (KO) or by a specific pharmacological inhibitor protects against cancer. This study is unique, not only because a combined genetic and pharmacological approach is rare, but also there are no prior studies on the extent to which AC5 affects cancer. We found that AC5KO delayed age-related tumor incidence significantly, as well as protecting against mammary tumor development in AC5KO × MMTV-HER-2 neu mice, and B16F10 melanoma tumor growth, which can explain why AC5KO is a model of longevity. In addition, a Food and Drug Administration approved antiviral agent, adenine 9-β-D-arabinofuranoside (Vidarabine or AraAde), which specifically inhibits AC5, reduces LP07 lung and B16F10 melanoma tumor growth in syngeneic mice. Thus, inhibition of AC5 is a previously unreported mechanism for prevention of cancers associated with aging and that can be targeted by an available pharmacologic inhibitor, with potential consequent extension of lifespan.

Signaling pathways in the development of infantile hemangioma

Infantile hemangioma (IH), which is the most common tumor in infants, is a benign vascular neoplasm resulting from the abnormal proliferation of endothelial cells and pericytes. For nearly a century, researchers have noted that IH exhibits diverse and often dramatic clinical behaviors. On the one hand, most lesions pose no threat or potential for complication and resolve spontaneously without concern in most children with IH. On the other hand, approximately 10% of IHs are destructive, disfiguring and even vision- or life-threatening. Recent studies have provided some insight into the pathogenesis of these vascular tumors, leading to a better understanding of the biological features of IH and, in particular, indicating that during hemangioma neovascularization, two main pathogenic mechanisms prevail, angiogenesis and vasculogenesis. Both mechanisms have been linked to alterations in several important cellular signaling pathways. These pathways are of interest from a therapeutic perspective because targeting them may help to reverse, delay or prevent hemangioma neovascularization. In this review, we explore some of the major pathways implicated in IH, including the VEGF/VEGFR, Notch, β-adrenergic, Tie2/angiopoietins, PI3K/AKT/mTOR, HIF-α-mediated and PDGF/PDGF-R-β pathways. We focus on the role of these pathways in the pathogenesis of IH, how they are altered and the consequences of these abnormalities. In addition, we review the latest preclinical and clinical data on the rationally designed targeted agents that are now being directed against some of these pathways.