In vitro sensitivity of leukemia cells to propranolol

Critical role of Aquaporin-1 and telocytes in infantile hemangioma response to propranolol beta blockade

Propranolol, a nonselective β-adrenergic receptor (ADRB) antagonist, is the first-line therapy for severe infantile hemangiomas (IH). Since the incidental discovery of propranolol efficacy in IH, preclinical and clinical investigations have shown evidence of adjuvant propranolol response in some malignant tumors. However, the mechanism for propranolol antitumor effect is still largely unknown, owing to the absence of a tumor model responsive to propranolol at nontoxic concentrations. Immunodeficient mice engrafted with different human tumor cell lines were treated with anti-VEGF bevacizumab to create a model sensitive to propranolol. Proteomics analysis was used to reveal propranolol-mediated protein alteration correlating with tumor growth inhibition, and Aquaporin-1 (AQP1), a water channel modulated in tumor cell migration and invasion, was identified. IH tissues and cells were then functionally investigated. Our functional protein association networks analysis and knockdown of ADRB2 and AQP1 indicated that propranolol treatment and AQP1 down-regulation trigger the same pathway, suggesting that AQP1 is a major driver of beta-blocker antitumor response. Examining AQP1 in human hemangioma samples, we found it exclusively in a perivascular layer, so far unrecognized in IH, made of telocytes (TCs). Functional in vitro studies showed that AQP1-positive TCs play a critical role in IH response to propranolol and that modulation of AQP1 in IH-TC by propranolol or shAQP1 decreases capillary-like tube formation in a Matrigel-based angiogenesis assay. We conclude that IH sensitivity to propranolol may rely, at least in part, on a cross talk between lesional vascular cells and stromal TCs.

The β-adrenergic receptor antagonist propranolol offsets resistance mechanisms to chemotherapeutics in diverse sarcoma subtypes: a pilot study

Standard chemotherapy for soft tissue sarcomas has shown limited efficacy. Here, we sought to evaluate whether β-adrenergic receptor (β-AR) signalling contributed to the progression of sarcomas and therapy resistance. To assess the translational potential of β-adrenergic receptors, we performed immunohistochemical detection of β1-AR, β2-AR and β3-AR in leiomyosarcoma, liposarcoma and angiosarcoma tissue specimens, reporting the results scored for the intensity. By using established and patient-derived sarcoma cells, we demonstrated the antitumour potential of the pharmacological targeting of β-ARs with the nonselective β-blocker propranolol in such sarcomas. Of note, pharmacological β-AR inhibition synergized with doxorubicin in inhibiting the cell viability of liposarcoma and leiomyosarcoma cells and increased the response to docetaxel in angiosarcoma- and solitary fibrous tumour (SFT)-patient-derived cells. Notably, the SFT patient was treated with the combination of propranolol and docetaxel, reporting prolonged disease control. Mechanistically, we found that propranolol reduced the activity of the multidrug resistance efflux pump P-gp, thereby increasing the intracellular doxorubicin concentration and antitumour activity. In addition, propranolol attenuated the Akt-dependent survival signal induced by doxorubicin and strongly reduced the activation of the NF-kB/COX-2 pathway, increasing cell sensitivity to docetaxel. Overall, our study highlighted the therapeutic potential of propranolol, alone or in rational combination therapies, for sarcoma treatment.

Repurposing Drugs in Oncology (ReDO)-Propranolol as an anti-cancer agent

Propranolol (PRO) is a well-known and widely used non-selective beta-adrenergic receptor antagonist (beta-blocker), with a range of actions which are of interest in an oncological context. PRO displays effects on cellular proliferation and invasion, on the immune system, on the angiogenic cascade, and on tumour cell sensitivity to existing treatments. Both pre-clinical and clinical evidence of these effects, in multiple cancer types, is assessed and summarised and relevant mechanisms of action outlined. In particular there is evidence that PRO is effective at multiple points in the metastatic cascade, particularly in the context of the post-surgical wound response. Based on this evidence the case is made for further clinical investigation of the anticancer effects of PRO, particularly in combination with other agents. A number of trials are on-going, in different treatment settings for various cancers.

In Vitro Effects of Propranolol on T Helper Type 1 Cytokine Profile in Human Leukemic T Cells

INTRODUCTION

Cytokines are a large group of proteins play a key role in inflammation. Down-regulation of pro-inflammatory cytokines has beneficial effect on heart function. Propranolol, as a non selective beta-adrenergic blocker, has been extensively used for treatment of many cardiovascular problems such as arrhythmias and heart malfunction. In addition anti-inflammatory effects of propranolol have been revealed. In this study the propranolol effect on T helper type 1 cytokine profile in human leukemic T cells has been assessed in vitro.

MATERIALS AND METHODS

Human leukemic T cells (Molt-4 and Jurkat) were cultured in complete RPMI medium. The cells were then incubated with different concentrations of propranolol (0.03- 30 µM) in the presence or absence of PHA (10 µg/ml) for 48 hours. The supernatants of cell culture media were collected and used for cytokines assay.

RESULTS

Propranolol significantly decreased the T helper type 1 cytokine profile [Interleukin-2 (IL-2) and Interferon- γ (IFN-γ)] production in PHA stimulated Molt-4 and Jurkat cells, after 48 hour of incubation time, dose-dependently compared to untreated control cells.

CONCLUSION

Our data showed a dose dependent inhibitory effect of propranolol on the IL-2 and IFN-γ production in human leukemic Molt-4 and Jurkat cells. The anti- inflammatory effect of propranolol reported by other investigators may be in part due to its suppressive effect on production of inflammatory cytokines such as IL-2 and IFN-γ. So, propranolol along with its chronic long-term usage in cardiovascular problems may have potential implication in treatment of inflammatory-based disorders.

Anti-tumor activity of the beta-adrenergic receptor antagonist propranolol in neuroblastoma

Neuroblastoma (NB) is a pediatric tumor of the sympathetic nervous system, which is often associated with elevated catecholamines. More than half of patients with metastatic NB relapse and survival is extremely poor with current therapies. In a high-throughput screen of FDA-approved drugs we identified anti-NB activity for the nonselective β-adrenergic receptor antagonist propranolol hydrochloride.

Propranolol inhibited growth of a panel of fifteen NB cell lines irrespective of MYCN status, and treatment induced apoptosis and decreased proliferation. Activity was dependent on inhibition of the β2, and not β1, adrenergic receptor, and treatment resulted in activation of p53 and p73 signaling in vitro. The majority of NB cell lines and primary tumors express β2 adrenergic receptor and higher mRNA levels correlate with improved patient survival, but expression levels did not correlate with in vitro sensitivity to propranolol. Furthermore, propranolol is synergistic with the topoisomerase I inhibitor SN-38 and propranolol inhibits growth of NB xenografts in vivo at doses similar to those used to treat infants with hemangiomas and hypertension. Taken together, our results suggest that propranolol has activity against NB and thus should be considered in combination treatments for patients with relapsed and refractory NB.

The effect of calcium channel blockers on the outcome of acute myeloid leukemia

The effect of calcium channel blockers (CCBs), beta blockers and angiotensin converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) on the prognosis of patients with acute myeloid leukemia (AML) is largely unknown. We collected data on the use of these medications in 1043 patients with AML, excluding promyelocytic leukemia, diagnosed and treated at M. D. Anderson Cancer Center between 2000 and 2012. Treatment with either amlodipine or diltiazem predicted a worse overall survival (hazard ratio [HR] 1.6, 95% confidence interval [CI] 1.22-2.06, p < 0.0001). There was no difference in survival depending on whether patients were taking beta blockers, ACE inhibitors or ARBs. The effect of CCBs on survival was independent from the National Comprehensive Cancer Network risk classification, age, performance status, response to treatment, year of diagnosis and CD34 levels, assessed by flow cytometry (HR 1.39, 95% CI 1.05-1.80, p = 0.02). Treatment with either amlodipine or diltiazem predicts worse survival in patients with AML independent of known prognostic factors.