Cooperative regulation of non-small cell lung carcinoma by nicotinic and beta-adrenergic receptors: a novel target for intervention

Neurobiology of cancer: Adrenergic signaling and drug repurposing

Cancer neuroscience, as an emerging converging discipline, provides us with new perspectives on the interactions between the nervous system and cancer progression. As the sympathetic nervous system, in particular adrenergic signaling, plays an important role in the regulation of tumor activity at every hierarchical level of life, from the tumor cell to the tumor microenvironment, and to the tumor macroenvironment, it is highly desirable to dissect its effects. Considering the far-reaching implications of drug repurposing for antitumor drug development, such a large number of adrenergic receptor antagonists on the market has great potential as one of the means of antitumor therapy, either as primary or adjuvant therapy. Therefore, this review aims to summarize the impact of adrenergic signaling on cancer development and to assess the status and prospects of intervening in adrenergic signaling as a therapeutic tool against tumors.

A review on the effect of COX-2-mediated mechanisms on development and progression of gastric cancer induced by nicotine

Smoking is a documented risk factor for cancer, e.g., gastric cancer. Nicotine, the principal tobacco alkaloid, would exert its role of contribution to gastric cancer development and progression through nicotinic acetylcholine receptors (nAChRs) and β-adrenergic receptors (β-ARs), which then promote cancer cell proliferation, migration and invasion. As a key isoenzyme in conversion of arachidonic acid to prostaglandins, cyclooxygenase-2 (COX-2) has been demonstrated to have a wide range of effects in carcinogenesis and tumor development. At present, many studies have reported the effect of nicotine on gastric cancer by binding to nAChR, as well as indirectly stimulating β-AR to mediate COX-2-related pathways. This review summarizes these studies, and also proposes more potential COX-2-mediated mechanisms. These events might contribute to the growth and progression of gastric cancer exposed to nicotine through tobacco smoke or cigarette substitutes. Also, this review article has therefore the potential not only to make a significant contribution to the treatment and prognosis of gastric cancer for smokers but also to the clinical application of COX-2 antagonists. In addition, this work also discusses the considerable challenges of this field with special reference to the future perspective of COX-2-mediated mechanisms in development and progression of gastric cancer induced by nicotine.

Targeting Alpha7 Nicotinic Acetylcholine Receptors in Lung Cancer: Insights, Challenges, and Therapeutic Strategies

Alpha7 nicotinic acetylcholine receptor (α7 nAChR) is an ion-gated calcium channel that plays a significant role in various aspects of cancer pathogenesis, particularly in lung cancer. Preclinical studies have elucidated the molecular mechanism underlying α7 nAChR-associated lung cancer proliferation, chemotherapy resistance, and metastasis. Understanding and targeting this mechanism are crucial for developing therapeutic interventions aimed at disrupting α7 nAChR-mediated cancer progression and improving treatment outcomes. Drug research and discovery have determined natural compounds and synthesized chemical antagonists that specifically target α7 nAChR. However, approved α7 nAChR antagonists for clinical use are lacking, primarily due to challenges related to achieving the desired selectivity, efficacy, and safety profiles required for effective therapeutic intervention. This comprehensive review provided insights into the molecular mechanisms associated with α7 nAChR and its role in cancer progression, particularly in lung cancer. Furthermore, it presents an update on recent evidence about α7 nAChR antagonists and addresses the challenges encountered in drug research and discovery in this field.

Increased sympathetic nervous system impairs prognosis in lung cancer patients: a scoping review of clinical studies

Aim

To summarize current knowledge, gaps, quality of the evidence and show main results related to the role of the autonomic nervous system in lung cancer.

Methods

Studies were identified through electronic databases (PubMed, Scopus, Embase and Cochrane Library) in October 2023, and a descriptive analysis was performed. Twenty-four studies were included, and most were observational.

Results

Our data indicated an increased expression of β-2-adrenergic receptors in lung cancer, which was associated with poor prognosis. However, the use of β-blockers as an add-on to standard treatment promoted enhanced overall survival, recurrence-free survival and reduced metastasis occurrence.

Conclusion

Although the results herein seem promising, future research using high-quality prospective clinical trials is required to draw directions to guide clinical interventions.

Regulation of Vascular Endothelial Growth Factor Signaling by Nicotine in a Manner Dependent on Acetylcholine-and/or β-Adrenergic-Receptors in Human Lung Cancer Cells

Simple Summary

Nicotine, a highly addictive component in cigarette smoke, facilitates tumorigenesis and the accelerated development of non-small cell lung cancer (NSCLC), which is known to account for ~80% of all lung cancer cases. This study sheds light on how the nicotine treatment of NSCLC cells regulates vascular endothelial growth factor (VEGF) signaling, known to be important in the progression of vascular disease and cancer, by acting through nicotinic acetylcholine receptors and by leading to the activation of β-adrenergic receptors through increased levels of the stress neurotransmitters, norepinephrine/noradrenaline, and epinephrine/adrenaline. Nicotine-induced activation of VEGF promoted the function of proteins involved in increased cell survival and suppressed the function of a crucial tumor suppressor, blocking cell death. This work expands our scientific knowledge of mechanisms employed by nicotine in regulating VEGF signaling in a manner dependent on the acetylcholine and/or β-adrenergic receptors, leading to lung cancer cell survival, and also provides significant insights into novel future therapeutic strategies to combat lung cancer.

Abstract

In addition to binding to nicotinic acetylcholine receptors (nAChRs), nicotine is known to regulate the β-adrenergic receptors (β-ARs) promoting oncogenic signaling. Using A549 (p53 wild-type) and H1299 (p53-null) lung cancer cells, we show that nicotine treatment led to: increased adrenaline/noradrenaline levels, an effect blocked by treatment with the α7nAChR inhibitor (α-BTX) but not by the β-blocker (propranolol) or the α4β2nAChR antagonist (DhβE); decreased GABA levels in A549 and H1299 cell media, an effect blocked by treatment with DhβE; increased VEGF levels and PI3K/AKT activities, an effect diminished by cell co-treatment with α-BTX, propranolol, and/or DhβE; and inhibited p53 activity in A549 cells, that was reversed, upon cell co-treatment with α-BTX, propranolol, and/or DhβE or by VEGF immunodepletion. VEGF levels increased upon cell treatment with nicotine, adrenaline/noradrenaline, and decreased with GABA treatment. On the other hand, the p53 activity decreased in A549 cells treated with nicotine, adrenaline/noradrenaline and increased upon cell incubation with GABA. Knockdown of p53 led to increased VEGF levels in the media of A549 cells. The addition of anti-VEGF antibodies to A549 and H1299 cells decreased cell viability and increased apoptosis; blocked the activities of PI3K, AKT, and NFκB in the absence or presence of nicotine; and resulted in increased p53 activation in A549 cells. We conclude that VEGF can be upregulated via α7nAChR and/or β-ARs and downregulated via GABA and/or p53 in response to the nicotine treatment of NSCLC cells.

Regulation of Soluble E-Cadherin Signaling in Non-Small-Cell Lung Cancer Cells by Nicotine, BDNF, and β-Adrenergic Receptor Ligands

The ectodomain of the transmembrane protein E-cadherin can be cleaved and released in a soluble form referred to as soluble E-cadherin, or sE-cad, accounting for decreased E-cadherin levels at the cell surface. Among the proteases implicated in this cleavage are matrix metalloproteases (MMP), including MMP9. Opposite functions have been reported for full-length E-cadherin and sE-cad. In this study, we found increased MMP9 levels in the media of two non-small cell lung cancer (NSCLC) cell lines, A549 and H1299, treated with BDNF, nicotine, or epinephrine that were decreased upon cell treatment with the β-adrenergic receptor blocker propranolol. Increased MMP9 levels correlated with increased sE-cad levels in A549 cell media, and knockdown of MMP9 in A549 cells led to downregulation of sE-cad levels in the media. Previously, we reported that A549 and H1299 cell viability increased with nicotine and/or BDNF treatment and decreased upon treatment with propranolol. In investigating the function of sE-cad, we found that immunodepletion of sE-cad from the media of A549 cells untreated or treated with BDNF, nicotine, or epinephrine reduced activation of EGFR and IGF-1R, decreased PI3K and ERK1/2 activities, increased p53 activation, decreased cell viability, and increased apoptosis, while no effects were found using H1299 cells under all conditions tested.

Beta-blocker exposure and survival outcomes in patients with advanced pancreatic ductal adenocarcinoma: a retrospective cohort study (BETAPANC)

Introduction: Preclinical studies have demonstrated the possible role of beta-adrenergic receptors in pancreatic ductal adenocarcinoma (PDAC) tumor invasion and migration. The current study aimed to explore the possible association between survival outcomes and beta-blocker (BB) exposure in patients with advanced PDAC. Methods: This retrospective single-center study included 182 patients with advanced PDAC. Clinical [age, sex, BMI, cardiovascular condition, presence (SBB) or absence (NSBB) of beta-1 selectivity of BB, exposure duration, and multimorbidity], oncological (stage and anticancer treatment regimen), and biological (renal and liver function) data were collected. The endpoints were overall survival (OS) and progression-free survival (PFS). Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for survival outcomes associated with BB exposure were estimated using Cox regression model and propensity score (PS) methods. Results: Forty-one patients (22.5%) were exposed to BB. A total of 104 patients progressed (57.1%) to PDAC and 139 (76.4%) patients died at the end of follow-up (median, 320 days; IQR, 438.75 days). When compared to the non-exposed group, there was no increase in survival outcomes associated with BB use (OS: HR = 1.38, 95% CI = 0.80-2.39, p = 0.25; PFS: adjusted HR = 0.95, 95% CI = 0.48-1.88, p = 0.88). Similar results were obtained using the PS method. Compared to no BB usage, SBB use was associated with a significant decrease in OS (HR = 1.80, 95% CI = 1.16-2.80, p < 10^-2). Conclusion: BB exposure was not associated with improved PDAC survival outcomes. Beta-1-selectivity was not independently associated with any differences.

Landscape and clinical impact of metabolic alterations in non-squamous non-small cell lung cancer

Background

Metabolomics studies to date have described widespread metabolic reprogramming events during the development of non-squamous non-small cell lung cancer (NSCLC). Extending far beyond the Warburg effect, not only is carbohydrate metabolism affected, but also metabolism of amino acids, cofactors, lipids, and nucleotides.

Methods

We evaluated the clinical impact of metabolic reprogramming. We performed comparative analysis of publicly available data on non-squamous NSCLC, to identify concensus altered metabolic pathways. We investigated whether alterations of metabolic genes controlling those consensus metabolic pathways impacted clinical outcome. Using the clinically annotated lung adenocarcinoma (LUAD) cohort from The Cancer Genome Atlas, we surveyed the distribution and frequency of function-altering mutations in metabolic genes and their impact on overall survival (OS).

Results

We identified 42 metabolic genes of clinical significance, the majority of which (37 of 42) clustered across three metabolic superpathways (carbohydrates, amino acids, and nucleotides) and most functions (40 of 42) were associated with shorter OS. Multivariate analyses showed that dysfunction of carbohydrate metabolism had the most profound impact on OS [hazard ratio (HR) =5.208; 95% confidence interval (CI): 3.272 to 8.291], false discovery rate (FDR)-P≤0.0001, followed by amino acid metabolism (HR =3.346; 95% CI: 2.129 to 5.258), FDR-P≤0.0001 and nucleotide metabolism (HR =2.578; 95% CI: 1.598 to 4.159), FDR-P=0.0001. The deleterious effect of metabolic reprogramming on non-squamous NSCLC was observed independently of disease stage and across treatments groups.

Conclusions

By providing a detailed landscape of metabolic alterations in non-squamous NSCLC, our findings offer new insights in the biology of the disease and metabolic adaptation mechanisms of clinical significance.

Insights into the Mechanisms of Action of Proanthocyanidins and Anthocyanins in the Treatment of Nicotine-Induced Non-Small Cell Lung Cancer

In traditional medicine, different parts of plants, including fruits, have been used for their anti-inflammatory and anti-oxidative properties. Plant-based foods, such as fruits, seeds and vegetables, are used for therapeutic purposes due to the presence of flavonoid compounds. Proanthocyanidins (PCs) and anthocyanins (ACNs) are the major distributed flavonoid pigments in plants, which have therapeutic potential against certain chronic diseases. PCs and ACNs derived from plant-based foods and/or medicinal plants at different nontoxic concentrations have shown anti-non-small cell lung cancer (NSCLC) activity in vitro/in vivo models through inhibiting proliferation, invasion/migration, metastasis and angiogenesis and by activating apoptosis/autophagy-related mechanisms. However, the potential mechanisms by which these compounds exert efficacy against nicotine-induced NSCLC are not fully understood. Thus, this review aims to gain insights into the mechanisms of action and therapeutic potential of PCs and ACNs in nicotine-induced NSCLC.

Targeting ADRB2 enhances sensitivity of non-small cell lung cancer to VEGFR2 tyrosine kinase inhibitors

Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) tyrosine kinase inhibitors (TKIs) have achieved remarkable clinical progress in the treatment of non-small-cell lung cancer; however, resistance has limited their therapeutic efficacy. Therefore, understanding the mechanisms of VEGF-TKI and ICI resistance will help to develop effective treatment strategies for patients with advanced NSCLC. Our results suggested that treatment with VEGFR2-TKIs upregulated ADRB2 expression in NSCLC cells. Propranolol, a common ADRB2 antagonist, significantly enhanced the therapeutic effect of VEGFR2-TKIs by inhibiting the ADRB2 signaling pathway in NSCLC cells in vitro and in vivo. Mechanically, the treatment-induced ADRB2 upregulation and the enhancement of ADRB2/VEGFR2 interaction caused resistance to VEGFR2-TKIs in NSCLC. And the inhibition of the ADRB2/CREB/PSAT1 signaling pathway sensitized cells to VEGFR2-TKIs. We demonstrated that ADRB2 signaling is crucial in mediating resistance to VEGFR2-TKIs and provided a novel promising combinatory approach to enhance the antitumor effect of VEGFR2-TKIs in NSCLC combining with propranolol.

RNA splicing and aggregate gene expression differences in lung squamous cell carcinoma between patients of West African and European ancestry

OBJECTIVES

Despite disparities in lung cancer incidence and mortality, the molecular landscape of lung cancer in patients of African ancestry remains underexplored, and race-related differences in RNA splicing remain unexplored.

MATERIALS AND METHODS

We identified differentially spliced genes (DSGs) and differentially expressed genes (DEGs) in biobanked lung squamous cell carcinoma (LUSC) between patients of West African and European ancestry, using ancestral genotyping and Affymetrix Clariom D array. DSGs and DEGs were validated independently using the National Cancer Institute Genomic Data Commons. Associated biological processes, overlapping canonical pathways, enriched gene sets, and cancer relevance were identified using Gene Ontology Consortium, Ingenuity Pathway Analysis, Gene Set Enrichment Analysis, and CancerMine, respectively. Association with LUSC survival was conducted using The Cancer Genome Atlas.

RESULTS

4,829 DSGs and 267 DEGs were identified, including novel targets in NSCLC as well as genes identified previously to have relevance to NSCLC. RNA splicing events within 3 DSGs as well as 1 DEG were validated in the independent cohort. 853 DSGs and 29 DEGs have been implicated as potential drivers, oncogenes and/or tumor suppressor genes. Biological processes enriched among DSGs and DEGs included metabolic process, biological regulation, and multicellular organismal process and, among DSGs, ion transport. Overlapping canonical pathways among DSGs included neuronal signaling pathways and, among DEGs, cell metabolism involving biosynthesis. Gene sets enriched among DSGs included KRAS Signaling, UV Response, E2 F Targets, Glycolysis, and Coagulation. 355 RNA splicing events within DSGs and 18 DEGs show potential association with LUSC patient survival.

CONCLUSION

These DSGs and DEGs, which show potential biological and clinical relevance, could have the ability to drive novel biomarker and therapeutic development to mitigate LUSC disparities.

Effect of β-Blocker in Treatment-Naïve Patients With Advanced Lung Adenocarcinoma Receiving First-Generation EGFR-TKIs

Background

Through activation of adrenergic receptors, chronic stress can trigger the secretion of neurotransmitters and hormones that enhance tumor growth, increase angiogenesis, and promote drug resistance. This study aimed to evaluate the effect of β-blockers in patients receiving first-line epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) for lung adenocarcinoma.

Methods

This retrospective cohort study enrolled patients with advanced lung adenocarcinoma under first-line EGFR-TKIs between 2011 and 2014 in the National Health Insurance Research Database of Taiwan. The effects of β-blockers use, defined as ≥60 defined daily doses within 180 days before initiation of EGFR-TKI therapy, on the 2-year time-to-discontinuation (TTD) of EGFR-TKIs and 4-year overall survival (OS) were investigated using Cox regression analyses with inverse propensity score weighting and sensitivity analysis in subgroup with either hypertension or ischemic heart diseases.

Results

Among 4988 enrolled patients, 552 (11.1%) were in the β-blocker group. Patients in the β-blocker group were more likely to be older than 75 and had diabetes mellitus and cardiovascular comorbidities. In Cox regression analysis, β-blocker usage was associated with a longer TTD (hazard ratio, HR: 0.91 [0.86-0.96]) and OS (HR: 0.68 [0.64-0.72]). The results also favored β-blocker group in sensitivity analysis.

Conclusions

In treatment-naïve patients with advanced lung adenocarcinoma under first-line EGFR-TKIs, prior use of β-blocker was associated with a better outcome. The findings encourage further prospective clinical study to validate the possibility of β-blockers as adjuvant anticancer therapy.

Role of the parasympathetic nervous system in cancer initiation and progression

The nervous system plays an important role in cancer initiation and progression. Accumulated evidences clearly show that the sympathetic nervous system exerts stimulatory effects on carcinogenesis and cancer growth. However, the role of the parasympathetic nervous system in cancer has been much less elucidated. Whereas retrospective studies in vagotomized patients and experiments employing vagotomized animals indicate the parasympathetic nervous system has an inhibitory effect on cancer, clinical studies in patients with prostate cancer indicate it has stimulatory effects. Therefore, the aim of this paper is a critical evaluation of the available data related to the role of the parasympathetic nervous system in cancer.

Nicotinic-nAChR signaling mediates drug resistance in lung cancer

Lung cancer is the leading cause of cancer death worldwide. Cigarette smoking is the most common risk factor for lung carcinoma; other risks include genetic factors and exposure to radon gas, asbestos, secondhand smoke, and air pollution. Nicotine, the primary addictive constituent of cigarettes, contributes to cancer progression through activation of nicotinic acetylcholine receptors (nAChRs), which are membrane ligand-gated ion channels. Activation of nicotine/nAChR signaling is associated with lung cancer risk and drug resistance. We focused on nAChR pathways activated by nicotine and its downstream signaling involved in regulating apoptotic factors of mitochondria and drug resistance in lung cancer. Increasing evidence suggests that several sirtuins play a critical role in multiple aspects of cancer drug resistance. Thus, understanding the consequences of crosstalk between nicotine/nAChRs and sirtuin signaling pathways in the regulation of drug resistance could be a critical implication for cancer therapy.

β-Adrenergic Signaling in Lung Cancer: A Potential Role for Beta-Blockers

Lung cancer results in more patient deaths each year than any other cancer type. Additional treatment strategies are needed to improve clinical responses to approved treatment modalities and prevent the emergence of resistant disease. Catecholamines including norepinephrine and epinephrine are elevated as a result of chronic stress and mediate their physiological effects through activation of adrenergic receptors on target tissues. Lung cancer cells express β-adrenergic receptors (β-ARs), and numerous preclinical studies indicate that β2-AR signaling on lung cancer cells facilities cellular programs including proliferation, motility, apoptosis resistance, epithelial-to-mesenchymal transition, metastasis, and the acquisition of an angiogenic and immunosuppressive phenotype. Here, we review the preclinical and clinical evidence supporting a potential role for beta-blockers in improving the clinical outcome of lung cancer patients. Graphical Abstract Catecholamines including norepinephrine and epinephrine act of β-ARs expressed on NSCLC tumor cells and activate pathways regulating tumor progression.

Beta-Blocker Use and Lung Cancer Mortality in a Nationwide Cohort Study of Patients with Primary Non-Small Cell Lung Cancer

BACKGROUND

β-Adrenergic receptor blockers have been associated with improved survival among patients with different types of malignancies, but available data for patients with non-small cell lung cancer (NSCLC) are contradictory and limited to small hospital-based studies. We therefore aimed to investigate whether β-blocker use at the time of cancer diagnosis is associated with lung cancer mortality in the largest general population-based cohort of patients with NSCLC to date.

METHODS

For this retrospectively defined nationwide cohort study, we used prospectively collected data from Swedish population and health registers. Through the Swedish Cancer Register, we identified 18,429 patients diagnosed with a primary NSCLC between 2006 and 2014 with follow-up to 2015. Cox regression was used to estimate the association between β-blocker use at time of cancer diagnosis ascertained from the Prescribed Drug Register and cancer-specific mortality identified from the Cause of Death Register.

RESULTS

Over a median follow-up of 10.2 months, 14,994 patients died (including 13,398 from lung cancer). Compared with nonuse, β-blocker use (predominantly prevalent use, 93%) was not associated with lung cancer mortality [HR (95% confidence interval): 1.01 (0.97-1.06)]. However, the possibility that diverging associations for specific β-blockers and some histopathologic subtypes exist cannot be excluded.

CONCLUSIONS

In this nationwide cohort of patients with NSCLC, β-blocker use was not associated with lung cancer mortality when assessed in aggregate in the total cohort, but evidence for some β-blockers is less conclusive.

IMPACT

Our results do not indicate that β-blocker use at lung cancer diagnosis reduces the cancer-specific mortality rate in patients with NSCLC.

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.

The impact of smoking and the influence of other factors on lung cancer

Introduction: Smoking is the main preventable cause of lung cancer. This review summarizes preclinical and clinical data on the mechanisms of smoking-associated cancer development of the major histological lung cancer types small cell lung carcinoma squamous cell carcinoma and pulmonary adenocarcinoma (PAC) and the impact of several factors other than smoking on this process. Areas covered: The role of intracellular signaling induced by nicotinic receptors and beta-adrenergic receptors, the resulting increase in intracellular cyclic adenosine monophosphate (cAMP) as a key driver of PAC and the promoting effects of respiratory tract diseases and their therapeutics, psychological stress and global warming. Expert opinion: Smoking has deleterious effects on the regulation of lung epithelia by neurotransmitter receptors that are further enhanced by gene mutations. Sensitization of the alpha-7 nicotinic receptor (α7nAChR) by COPD enhances the carcinogenic effects of smoking and turns nicotine into a carcinogen. Nicotine vaping may, therefore, cause cancer in individuals with chronic obstructive pulmonary disease. The opposing effects of cAMP on the major lung cancer types indicate that patients with PAC of Clara cell phenotype (PAC-Cl) will benefit from treatment with cAMP reducers and suggest that global warming-induced respiratory tract diseases and their therapeutics cause the global increase in the incidence of PAC.

Are associations between psychosocial stressors and incident lung cancer attributable to smoking?

PURPOSE

To learn whether reported associations between major psychosocial stressors and lung cancer are independent of smoking history.

METHODS

Subjects were at least 25 years old and without lung cancer at enrollment in the United States Census Bureau's National Longitudinal Mortality Survey in 1995-2008. Follow-up via Surveillance Epidemiology and End Results and National Death Index continued until lung cancer diagnosis, death, or December 2011. Involuntary unemployment, widowhood, and divorce, stratified by sex, were tested for association with subsequent lung cancer using proportional hazards regression for competing risks. Smoking status, years smoked, cigarettes per day, and years since quitting were imputed when missing.

RESULTS

At enrollment, subjects (n = 100,733, 47.4% male, age 49.1(±15.8) years) included 17.6% current smokers, 23.5% former smokers. Of men and women, respectively, 11.3% and 15.0% were divorced/separated, 2.9% and 11.8% were widowed, and 2.9% and 2.3% were involuntarily unemployed. Ultimately, 667 subjects developed lung cancer; another 10,071 died without lung cancer. Adjusted for age, education, and ancestry, lung cancer was associated with unemployment, widowhood, and divorce/separation in men but not women. Further adjusted for years smoked, cigarettes per day, and years since quitting, none of these associations was significant in either sex.

CONCLUSIONS

Once smoking is accounted for, psychosocial stressors in adulthood do not independently promote lung cancer. Given their increased smoking behavior, persons experiencing stressors should be referred to effective alternatives to smoking and to support for smoking cessation.

Effects of β-Adrenergic Antagonists on Chemoradiation Therapy for Locally Advanced Non-Small Cell Lung Cancer

Introduction: Locally advanced non-small cell lung cancer (NSCLC) is highly resistant to chemoradiotherapy, and many cancer patients experience chronic stress. Studies that suggest stimulation of β-adrenergic receptors (β-AR) promotes tumor invasion and therapy resistance. We investigated whether β-AR inhibition with beta-blockers acts as a chemotherapy and radiation sensitizer in vitro and in patients treated with chemoradiation for locally advanced NSCLC. Methods: We investigated the effects of the non-selective beta-blocker propranolol on two human lung adenocarcinoma cell lines (PC9, A549) treated with radiation or cisplatin. We retrospectively evaluated 77 patients with Stage IIIA NSCLC who received induction chemoradiation followed by surgery. Pathological and imaging response, metastatic rate, and survival were analyzed using SPSS v22.0 and PrismGraphpad6. Results: Propranolol combined with radiation or cisplatin decreased clonogenic survival of PC9 and A549 cells in vitro (p < 0.05). Furthermore, propranolol decreased expression of phospho-protein kinase A (p-PKA), a β-adrenergic pathway downstream activation target, in both cell lines compared to irradiation or cisplatin alone (p < 0.05). In patients treated for Stage IIIA NSCLC, 16 took beta-blockers, and 61 did not. Beta-blockade is associated with a trend to improved overall survival (OS) at 1 year (81.3% vs 57.4%, p = 0.08) and distant metastasis-free survival (DMFS) (2.6 years vs. 1.3 years, p = 0.16). Although beta-blocker use was associated with decreased distant metastases (risk ratio (RR) 0.19; p = 0.03), it did not affect primary tumor pathological response (p = 0.40) or imaging response (p = 0.36). Conclusions: β-AR blockade enhanced radiation and cisplatin sensitivity of human lung cancer cells in vitro. Use of beta-blockers is associated with decreased distant metastases and potentially improved OS and DMFS. Additional studies are warranted to evaluate the role of beta-blockers as a chemoradiation sensitizer in locally advanced NSCLC.

The role of adrenergic receptors in lung cancer

Adrenergic receptors (ARs), especially β-ARs, are constitutively expressed in most mammalian cells and are associated with various malignancies including lung cancer. Epidemiologic studies have reported that activation of β-AR signalling promotes the development and progression of lung cancer and that pharmacological interference by β-AR blockers could partially reverse lung cancer progression. In this review, we mainly focus on the role of β-ARs in lung cancer and then reveal the possible application of AR blockers in anti-tumour therapy for lung cancer.

The Influence of Nicotine on Lung Tumor Growth, Cancer Chemotherapy, and Chemotherapy-Induced Peripheral Neuropathy

Studies in animal models have suggested that nicotine, an agonist of nicotinic acetylcholine receptors, may have the potential to prevent and/or reverse the peripheral neuropathy induced by cancer chemotherapeutic drugs, such as paclitaxel and oxaliplatin. However, a large body of evidence suggests that nicotine may also stimulate lung tumor growth and/or interfere with the effectiveness of cancer chemotherapy. Whereas the reported proliferative effects of nicotine are highly variable, the antagonism of antitumor drug efficacy is more consistent, although this latter effect has been demonstrated primarily in cell culture studies. In contrast, in vitro and in vivo studies from our own laboratory indicate that nicotine fails to enhance the growth of nonsmall cell lung cancer cells or attenuate the effects of chemotherapy (paclitaxel). Given the inconsistencies in the literature, coupled with our own findings, the weight of evidence suggests that caution may be warranted in proposing to use nicotine to mitigate chemotherapy-induced peripheral neuropathy in cancer patients receiving chemotherapy. Conversely, clinical trials could be performed in patients who have completed therapy and are considered to be disease-free to determine whether nicotine, in the form of commercially available patches or gum, is effective in alleviating peripheral neuropathy symptoms.

α7 nicotinic acetylcholine receptors in lung cancer

Lung cancer has one of the highest mortality rates among malignancies globally, and smoking has been documented as the main cause of lung cancer. Nicotinic acetylcholine receptors (nAChRs) were initially identified as notable regulators of the nervous system. In addition to their function in the brain, accumulating evidence indicates that nAChRs perform a host of diverse functions in almost all non-neuronal mammalian cells. The homomeric α7nAChR, a subtype of nAChRs, is responsible for the proliferative, pro-angiogenic and pro-metastatic effects of nicotine in lung cancer. Provided the association of cigarette smoking with several disease types such as cardiovascular disease, the α7nAChR-mediated signaling pathway has been implicated in the pathophysiology of lung cancer. Currently, strategies that target the α7nAChR including α7nAChR antagonists are considered to be potentially useful anticancer drugs for therapeutic purposes. Thus, the present review assesses current understanding of the function and underlying molecular mechanisms of α7nAChR in lung cancer and evaluates how targeting α7nAChR may result in novel therapeutic methods.

Inhaled corticosteroids have a protective effect against lung cancer in female patients with chronic obstructive pulmonary disease: a nationwide population-based cohort study

Whether the use of inhaled corticosteroids (ICS) protects patients with chronic obstructive pulmonary disease (COPD) from lung cancer remains undetermined. In this retrospective nationwide population-based cohort study, we extracted data of 13,686 female COPD patients (ICS users, n = 1,290, ICS non-users, n = 12,396) diagnosed between 1997 and 2009 from the Taiwan's National Health Insurance database. These patients were followed-up until 2011, and lung cancer incidence was determined. Cox regression analysis was used to estimate hazard ratios (HRs) for lung cancer incidence. The time to lung cancer diagnosis was significantly different between ICS users and non-users (10.75 vs. 9.68 years, P < 0.001). Per 100,000 person-years, the lung cancer incidence rate was 235.92 for non-users and 158.67 for users [HR = 0.70 (95% confidence interval {CI}: 0.46-1.09)]. After adjusting for patients' age, income, and comorbidities, a cumulative ICS dose > 39.48 mg was significantly associated with a lower risk of lung cancer [ICS users > 39.48 mg, HR = 0.45 (95% CI: 0.21-0.96)]. Age ≥ 60 years, pneumonia, diabetes mellitus, and hypertension decreased lung cancer risk, whereas pulmonary tuberculosis increased the risk. Our results suggest that ICS have a potential role in lung cancer prevention among female COPD patients.

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.

Cigarette smoke extracts induce overexpression of the proto-oncogenic gene interleukin-13 receptor α2 through activation of the PKA-CREB signaling pathway to trigger malignant transformation of lung vascular endothelial cells and angiogenesis

Cigarette smoking is a major cause of lung cancer. Tumor-associated endothelial cells (TAECs) play important roles in tumor angiogenesis and metastasis. However, whether cigarette smoking can trigger genesis of lung TAECs has not been reported yet. In the current study, we used lung endothelial cell (EC) lines as a model to study the pathological effect of cigarette smoke extracts (CSEs) on human lung ECs, and found that a lower dose of 4% CSEs obviously caused abnormal morphological changes in ECs, increased the permeability of endothelial monolayer, while a higher concentration of 8% CSEs caused EC apoptosis. Strikingly, CSEs induced a 117-fold overexpression of a pro-tumorigenic interleukin-13 receptor α2 gene (IL-13Rα2, also named as CT-19) through activation of the protein kinase A (PKA) and cAMP response element-binding protein (CREB) signaling pathway. A PKA specific inhibitor H89 completely abolished CSEs-induced IL-13Rα2 overexpression. The overexpression of IL-13Rα2 in lung ECs significantly increased the tumorigenic, migratory, and angiogenic capabilities of the cells, suggesting that IL-13Rα2 promotes genesis of lung TAECs. Together, our data show that CSEs activate the PKA, CREB, and IL-13Rα2 axis in lung ECs, and IL-13Rα2 promotes the malignant transformation of lung ECs and genesis of TAECs with robust angiogenic and oncogenic capabilities. Our study provides new insight into the mechanism of CSEs-triggered lung cancer angiogenesis and tumorigenesis, suggesting that the PKA-CREB-IL-13Rα2 axis is a potential target for novel anti-lung tumor angiogenesis and anti-lung cancer drug discovery.

Intraoperative use of dexmedetomidine is associated with decreased overall survival after lung cancer surgery

Background and Aims:

The aim is to evaluate the association between the use of intraoperative dexmedetomidine with an increase in recurrence-free survival (RFS) and overall survival (OS) after nonsmall cell lung cancer (NSCLC) surgery.

Material and Methods:

This was a propensity score-matched (PSM) retrospective study. Single academic center. The study comprised patients with Stage I through IIIa NSCLC. Patients were excluded if they were younger than 18 years. Primary outcomes of the study were RFS and OS. RFS and OS were evaluated using univariate and multivariate Cox proportional hazards models after PSM (n = 251/group) to assess the association between intraoperative dexmedetomidine use and the primary outcomes. The value of P < 0.05 was considered statistically significant.

Results:

After PSM and adjusting for significant covariates, the multivariate analysis demonstrated no association between the use of dexmedetomidine and RFS (hazard ratio [HR] [95% confidence interval (CI)]: HR = 1.18, 95% CI: 0.91–1.53; P = 0.199). The multivariate analysis also demonstrated an association between the administration of dexmedetomidine and reduced OS (HR = 1.28, 95% CI: 1.03–1.59; P = 0.024).

Conclusions:

This study demonstrated that the intraoperative use of dexmedetomidine to NSCLC patients was not associated with a significant impact on RFS and but worsening OS. A randomized controlled study should be conducted to confirm the results of this study.

Prognostic significance of β2-adrenergic receptor expression in non-small cell lung cancer

BACKGROUND

The β2-Adrenergic receptor (β2-AR) is associated with tumor growth and progression. However, the clinical significance of β2-AR expression in patients with non-small cell lung cancer (NSCLC) remains unclear.

METHODS

Three hundred twenty-eight patients with surgically resected NSCLC were retrospectively investigated. Tumor sections were stained by immunohistochemistry for assessing β2-AR and Ki-67 expression and microvessel density (MVD), which was using CD34 levels.

RESULTS

β2-AR was positively expressed in 27% of all patients, in 29% of adenocarcinoma (AC) patients, and in 24% of non-AC patients. In AC patients, β2-AR expression was significantly correlated with lymphatic permeation (r=0.240; P<0.001), vascular invasion (r=0.239; P<0.001), and Ki-67 expression (r=0.175; P=0.009). However, this correlation was not observed in non-AC patients. Positive β2-AR expression was identified as a negative predictor for worse outcomes in AC patients, particularly in those with stage I tumors. Multivariate analysis confirmed that β2-AR expression was an independent factor for predicting poor progression-free survival in stage I AC patients (HR=2.220; 95% CI, 1.077-4.573; P=0.031).

CONCLUSION

β2-AR expression is an independent prognostic factor for early-stage AC patients.

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.

The Role of Beta-Blockers in the Treatment of Hypertension

IMPORTANCE

Two major guide-line committees (JNC-8 and NICE UK) have dropped beta-blockers as first-line therapy in the treatment of hypertension. Also, recent meta-analyses (that do not take age into account) have concluded that beta-blockers are inappropriate first-line agents in the treatment of hypertension. This review seeks to shed some light on the "rights and wrongs" of such actions and conclusions.

OBJECTIVES

Because the pathophysiology of primary/essential hypertension differs in elderly and younger subjects, the latter being closely linked to obesity and increased sympathetic nerve activity, the author sought to clarify the efficacy of beta-blockers in the younger/middle-aged group in reducing the risk of death, and cardiovascular end-points.

EVIDENCE ACQUISITION

Four searches were undertaken, utilising PubMed up to 31st Dec 2015. One search was under the terms "hypertension AND obesity AND sympathetic nerve activity". A second was "hypertension AND plasma noradrenaline/norepinephrine AND survival". A third was "beta-blockers or adrenergic beta-antagonists AND hypertension AND age AND stroke or myocardial infarction or death". A fourth was "meta-analysis of beta-blockers AND hypertension AND age AND death, stroke, myocardial infarction" RESULTS: Diastolic (with or without systolic) hypertension, in contrast to isolated systolic hypertension, occurs primarily in younger subjects, and is linked to overweight/obesity and increased sympathetic nerve activity. In younger/middle-aged hypertensive subjects, high plasma norepinephrine levels are linked (independent of blood pressure) to an increased risk of future cardiovascular events and death. High resting heart rates (a surrogate for high sympathetic nerve activity) likewise predict premature all-cause death, coronary heart disease and cardiovascular events in younger hypertensive subjects. In this younger/middle-aged hypertensive group, antihypertensive agents that increase sympathetic nerve activity (diuretics, dihydropyridine calcium blockers, and angiotensin receptor blockers (ARBs)) do not decrease (and may increase) the risk of myocardial infarction, and are therefore inappropriate first-line agents in this age-group. By contrast, in younger/middle-aged hypertensive subjects (less than 60 years old), meta-analysis has shown that beta-blockers are significantly superior to randomised placebo, and at least as effective as randomised comparator agents, in reducing death/stroke/myocardial infarction. In this younger/middle-aged hypertensive group beta-blockers have been shown (vs randomised placebo or diuretics) to reduce the risk of myocardial infarction by 35-50 %, and stroke by 50-55 % (vs placebo), in non-smoker men. Atenolol was at least as effective as ACE-inhibition (captopril) in reducing all 7 cardiovascular endpoints (including stroke which was reduced by 50 %), vs less tight control of blood pressure, in obese hypertensive subjects with type-2 diabetes (UKPDS study); and after 20 years follow-up, atenolol was significantly (23 %) superior to the ACE-inhibitor in reducing the risk of all-cause death (beta-blockers have anti-cancer properties, which maybe relevant).

CONCLUSIONS AND RELEVANCE

Primary/essential hypertension in younger/middle-age is underpinned by high sympathetic nerve activity. In this age-group high resting heart rates and high plasma norepinephrine levels (independent of blood pressure) are linked to premature cardiovascular events and death. Thus, anti-hypertensive agents that increase sympathetic nerve activity ie diuretics, dihydropyridine calcium blockers, and ARBs, are inappropriate first-line choices in this younger age-group. Beta-blockers perform well vs randomised placebo and other antihypertensive agents regarding reduced risk of death/stroke/myocardial infarction in younger (<60 years) hypertensive subjects, and are a reasonable first-line choice of therapy (certainly in men). These facts should be reflected in the recommendations of guideline committees around the world.

Role of gross tumor volume in the prognosis of non-small cell lung cancer treated with 3D conformal radiotherapy: a meta-analysis

PURPOSE

Three-dimensional conformal radiotherapy (3D-CRT) has become widely applied in patients with non-small cell lung cancer (NSCLC), and gross tumor volume (GTV) is a reliable index for predicting prognosis in patients with NSCLC. This meta-analysis investigated the association between GTV and prognosis in patients with NSCLC after 3D-CRT.

METHODS

Electronic bibliographic databases were searched to identify articles related to NSCLC and 3D-CRT. The search results were carefully screened, using predetermined selection criteria, to select the most relevant studies. Newcastle-Ottawa Scale criteria were applied by 2 reviewers independently to evaluate the quality of the methodology of each included article., Based on GTV, each patient was assigned to either the study group (large GTV [≥112 cm(3)]) or the control group (small GTV [<112 cm(3)]), and the mean rates of overall survival (OS) and survival at 1, 3, and 5 years were calculated in each group. Summary hazard ratio (HR) with 95% CI was calculated.

FINDINGS

The data from 10 cohort studies were incorporated into the current meta-analysis (1473 patients; study group, 773; control group, 700). The OS in the study group was significantly less than that in the control group (HR = 1.52; 95% CI, 1.10-1.94; P < 0.01). The study and control groups also had significantly different survival rates at 1 year (HR = 1.27; 95% CI, 1.10-1.46, P = 0.01), 3 years (HR = 2.06; 95% CI, 1.63-2.61; P < 0.01), and 5 years (HR = 2.25; 95% CI, 1.63-3.10; P < 0.01). Findings from funnel plots and Egger tests of the OS and 3-year survival rate suggested no publication bias. With respect to the 1- and 5-year survival rates, however, the funnel plots and Egger tests demonstrated publication bias among the included studies.

IMPLICATIONS

The relatively small number of studies and small sample size, as well as the lack of a specific and standard method of defining small and large GTV, may have influenced the credibility and reliability of our results. The findings suggest that GTV influences prognosis in patients with NSCLC after 3D-CRT. However, further studies with larger sample sizes are needed to confirm our finding that a larger GTV is negatively associated with NSCLC prognosis after 3D-CRT.

Therapeutic Effects of Repurposed Therapies in Non-Small Cell Lung Cancer: What Is Old Is New Again

The recent emergence of targeted and immunotherapeutic agents has dramatically changed the management for patients with non-small cell lung cancer (NSCLC). Despite these advances, lung cancer is not exempt from the challenges facing oncology drug development, including the huge financial cost and the time required for drug implementation. Repositioning noncancer therapies with potential antineoplastic properties into new therapeutic niches is an alternative treatment strategy offering the possibility of saving money and time and improving outcomes. The goal of such a strategy is to deliver an effective drug with a favorable toxicity profile at a reduced cost. Preclinical models and observational data have demonstrated promising activity for many of these agents, and they are now being studied in prospective trials. We review the relevant published data regarding the therapeutic effects of metformin, statins, nonsteroidal anti-inflammatory drugs, β-blockers, and itraconazole in NSCLC, with a focus on the putative mechanisms of action and clinical data. As these drugs are increasingly being tested in clinical trials, we aim to highlight the salient challenges and future strategies to optimize this approach.

Antiproliferative effects of β-blockers on human colorectal cancer cells

Colon cancer is the fourth and third most common cancer, respectively in men and women worldwide and its incidence is on the increase. Stress response has been associated with the incidence and development of cancer. The catecholamines (CA), adrenaline (AD) and noradrenaline (NA), are crucial mediators of stress response, exerting their effects through interaction with α- and β-adrenergic receptors (AR). Colon cancer cells express β-AR, and their activation has been implicated in carcinogenesis and tumor progression. Interest concerning the efficacy of β-AR blockers as possible additions to cancer treatment has increased. The aim of this study was to investigate the effect of several AR agonists and β-blockers following cell proliferation of HT-29 cells, a human colon adenocarcinoma cell line. For this purpose, HT-29 cells were incubated in the absence (control) or in the presence of the AR-agonists, AD, NA and isoprenaline (ISO) (0.1-100 µM) for 12 or 24 h. The tested AR agonists revealed proliferative effects on HT-29 cells. In order to study the effect of several β-blockers following proliferation induced by AR activation, the cells were treated with propranolol (PRO; 50 µM), carvedilol (CAR; 5 µM), atenolol (ATE; 50 µM), or ICI 118,551 (ICI; 5 µM) for 45 min prior, and simultaneously, to incubation with each of the AR agonists, AD and ISO, both at 1 and 10 µM. The results suggested that adrenergic activation plays an important role in colon cancer cell proliferation, most probably through β-AR. The β-blockers under study were able to reverse the proliferation induced by AD and ISO, and some of these blockers significantly decreased the proliferation of HT-29 cells. The elucidation of the intracellular pathways involved in CA-induced proliferation of colon cancer cells, and in the reversion of this effect by β-blockers, may contribute to identifying promising strategies in cancer treatment.

Carvedilol use is associated with reduced cancer risk: A nationwide population-based cohort study

BACKGROUND

To investigate the effect of carvedilol on the incidence of cancer in a large population-based cohort study.

METHODS

Data were obtained from the Taiwan National Health Insurance Research Database. The cohort study included 6771 patients who received long-term carvedilol treatment between 2000 and 2010 (carvedilol cohort) and 6771 matched controls (noncarvedilol cohort). A Cox proportional hazards model was used to evaluate the risk of cancer in the patients treated with carvedilol.

RESULTS

With the mean follow-up period of 5.17 years and 4.93 years in the carvedilol and noncarvedilol cohorts, respectively, the patients in the carvedilol cohort had a 26% reduction of cancer risk compared with those in the noncarvedilol cohort (hazard ratio [HR]=0.74; 95% confidence interval [CI]=0.63-0.87; p<.001). The sex-specific carvedilol to noncarvedilol relative risk was lower for both women (HR=0.73; 95% CI=0.56-0.94) and men (HR=0.75; 95% CI=0.61-0.92). Moreover, stratified by cancer site, treatment with carvedilol in the carvedilol cohort resulted in significantly lower incidence of stomach and lung cancers than in the noncarvedilol cohort.

CONCLUSION

This nationwide population-based cohort study demonstrated that long-term treatment with carvedilol is associated with reduced upper gastrointestinal tract and lung cancer risk, indicating that carvedilol could be a potential agent in these cancers prevention.

Infantile hemangiomas, retinopathy of prematurity and cancer: a common pathogenetic role of the β-adrenergic system

The serendipitous demonstration that the nonselective β-adrenergic receptor (β-AR) antagonist propranolol promotes the regression of infantile hemangiomas (IHs) aroused interest around the involvement of the β-adrenergic system in angiogenic processes. The efficacy of propranolol was related to the β2-AR blockade and the consequent inhibition of the production of vascular endothelial growth factor (VEGF), suggesting the hypothesis that propranolol could also be effective in treating retinopathy of prematurity (ROP), a retinal pathology characterized by VEGF-induced neoangiogenesis. Consequent to the encouraging animal studies, a pilot clinical trial showed that oral propranolol protects newborns from ROP progression, even though this treatment is not sufficiently safe. Further, animal studies clarified the role of β3-ARs in the development of ROP and, together with several preclinical studies demonstrating the key role of the β-adrenergic system in tumor progression, vascularization, and metastasis, prompted us to also investigate the participation of β3-ARs in tumor growth. The aim of this review is to gather the recent findings on the role of the β-adrenergic system in IHs, ROP, and cancer, highlighting the fact that these different pathologies, triggered by different pathogenic noxae, share common pathogenic mechanisms characterized by the presence of hypoxia-induced angiogenesis, which may be contrasted by targeting the β-adrenergic system. The mechanisms characterizing the pathogenesis of IHs, ROP, and cancer may also be active during the fetal-neonatal development, and a great contribution to the knowledge on the role of β-ARs in diseases characterized by chronic hypoxia may come from research focusing on the fetal and neonatal period.

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.

Genetic susceptibility to lung cancer and co-morbidities

Lung cancer is a leading cause of cancer death and disease burden in many countries. Understanding of the biological pathways involved in lung cancer aetiology is required to identify key biomolecules that could be of significant clinical value, either as predictive, prognostic or diagnostic markers, or as targets for the development of novel therapies to treat this disease, in addition to smoking avoidance strategies. Genome-wide association studies (GWAS) have enabled significant progress in the past 5 years in investigating genetic susceptibility to lung cancer. Large scale, multi-cohort GWAS of mainly Caucasian, smoking, populations have identified strong associations for lung cancer mapped to chromosomal regions 15q [nicotinic acetylcholine receptor (nAChR) subunits: CHRNA3, CHRNA5], 5p (TERT-CLPTM1L locus) and 6p (BAT3-MSH5). Some studies in Asian populations of smokers have found similar risk loci, whereas GWAS in never smoking Asian females have identified associations in other chromosomal regions, e.g., 3q (TP63), that are distinct from smoking-related lung cancer risk loci. GWAS of smoking behaviour have identified risk loci for smoking quantity at 15q (similar genes to lung cancer susceptibility: CHRNA3, CHRNA5) and 19q (CYP2A6). Other genes have been mapped for smoking initiation and smoking cessation. In chronic obstructive pulmonary disease (COPD), which is a known risk factor for lung cancer, GWAS in large cohorts have also found CHRNA3 and CHRNA5 single nucleotide polymorphisms (SNPs) mapping at 15q as risk loci, as well as other regions at 4q31 (HHIP), 4q24 (FAM13A) and 5q (HTR4). The overlap in risk loci between lung cancer, smoking behaviour and COPD may be due to the effects of nicotine addiction; however, more work needs to be undertaken to explore the potential direct effects of nicotine and its metabolites in gene-environment interaction in these phenotypes. Goals of future genetic susceptibility studies of lung cancer should focus on refining the strongest risk loci in a wide range of populations with lung cancer, and integrating other clinical and biomarker information, in order to achieve the aim of personalised therapy for lung cancer.

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.

Impact of neuro-psychological factors on smoking-associated lung cancer

Smoking has been extensively documented as a risk factor for all histological types of lung cancer and tobacco-specific nitrosamines and polycyclic aromatic hydrocarbons reproducibly cause lung cancer in laboratory rodents. However, the most common lung cancer, non-small cell lung cancer (NSCLC), frequently develops in never smokers and is particularly common in women and African Americans, suggesting that factors unrelated to smoking significantly impact this cancer. Recent experimental investigations in vitro and in animal models have shown that chronic psychological stress and the associated hyperactive signaling of stress neurotransmitters via β-adrenergic receptors significantly promote the growth and metastatic potential of NSCLC. These responses were caused by modulation in the expression and sensitization state of nicotinic acetylcholine receptors (nAChRs) that regulate the production of stress neurotransmitters and the inhibitory neurotransmitter γ-aminobutyric acid (GABA). Similar changes in nAChR-mediated neurotransmitter production were identified as the cause of NSCLC stimulation in vitro and in xenograft models by chronic nicotine. Collectively, these data suggest that hyperactivity of the sympathetic branch of the autonomic nervous system caused by chronic psychological stress or chronic exposure to nicotinic agonists in cigarette smoke significantly contribute to the development and progression of NSCLC. A recent clinical study that reported improved survival outcomes with the incidental use of β-blockers among patients with NSCLC supports this interpretation.

Nicotine activates YAP1 through nAChRs mediated signaling in esophageal squamous cell cancer (ESCC)

Cigarette smoking is an established risk factor for esophageal cancers. Yes-associated protein 1 (YAP1), the key transcription factor of the mammalian Hippo pathway, has been reported to be an oncogenic factor for many cancers. In this study, we find nicotine administration can induce nuclear translocation and activation of YAP1 in ESCC. Consistently, we observed nuclear translocation and activation of YAP1 by knockdown of CHRNA3, which is a negative regulator of nicotine signaling in bronchial and esophageal cancer cells. Nicotine administration or CHRNA3 depletion substantially increased proliferation and migration in esophageal cancer cells. Interestingly, we find that YAP1 physically interacts with nAChRs, and nAChRs-signaling dissociates YAP1 from its negative regulatory complex composed with α-catenin, β-catenin and 14-3-3 in the cytoplasm, leading to upregulation and nuclear translocation of YAP1. This process likely requires PKC activation, as PKC specific inhibitor Enzastaurin can block nicotine induced YAP1 activation. In addition, we find nicotine signaling also inhibits the interaction of YAP1 with P63, which contributes to the inhibitory effect of nicotine on apoptosis. Using immunohistochemistry analysis we observed upregulation of YAP1 in a significant portion of esophageal cancer samples. Consistently, we have found a significant association between YAP1 upregulation and cigarette smoking in the clinical esophageal cancer samples. Together, these findings suggest that the nicotine activated nAChRs signaling pathway which further activates YAP1 plays an important role in the development of esophageal cancer, and this mechanism may be of a general significance for the carcinogenesis of smoking related cancers.

Perioperative beta-blocker use and survival in lung cancer patients

STUDY OBJECTIVE

To assess the effect of perioperative beta blockers on recurrence and overall survival after non-small cell lung cancer surgery.

DESIGN

Retrospective study.

SETTING

Academic medical center.

MEASUREMENTS

The medical records of patients with stage 1, 2, and 3a non-small cell lung cancer were divided into three different groups: those patients who never received beta blockers perioperatively, those receiving nonselective beta blockers within 60 days of surgery, and those taking selective beta blockers within 60 days of surgery. Recurrence-free survival and overall survival were the main clinical endpoints. Univariate log-rank tests and multivariate Cox proportional hazards models were used to assess the effects of selective beta blockers, nonselective beta blockers, or no beta blockers on recurrence-free survival and overall survival.

MAIN RESULTS

The analysis included records of 435 patients. Univariate analyses showed that the use of both selective and nonselective beta blockers was associated with decreased recurrence-free survival (P = 0.014) and overall survival (P = 0.009). However, these findings were not sustained after adjusting for possible confounding variables in the multivariate analysis. The hazard ratios for recurrence-free survival (selective beta blockers vs no beta blocker use were: 1.304; 95% confidence intervals [CI] 0.973 - 1.747; P = 0.075; for nonselective beta blockers vs no beta blockers: 0.989; 95% CI 0.639 - 1.532; P = 0.962. The hazard ratios for overall survival were: selective beta blocker use vs no beta blockers: 1.335; 95% CI 0.966 - 1.846; P = 0.080; nonselective beta blocker use vs no beta blocker use: 1.108; 95% CI 0.678 - 1.812; P = 0.682.

CONCLUSION

Administration of beta blockers during the perioperative period did not improve recurrence-free or overall survival in patients undergoing resection of non-small cell lung cancer.

Nicotine-mediated cell proliferation and tumor progression in smoking-related cancers

Tobacco smoke contains multiple classes of established carcinogens including benzo(a)pyrenes, polycyclic aromatic hydrocarbons, and tobacco-specific nitrosamines. Most of these compounds exert their genotoxic effects by forming DNA adducts and generation of reactive oxygen species, causing mutations in vital genes such as K-Ras and p53. In addition, tobacco-specific nitrosamines can activate nicotinic acetylcholine receptors (nAChR) and to a certain extent β-adrenergic receptors (β-AR), promoting cell proliferation. Furthermore, it has been demonstrated that nicotine, the major addictive component of tobacco smoke, can induce cell-cycle progression, angiogenesis, and metastasis of lung and pancreatic cancers. These effects occur mainly through the α7-nAChRs, with possible contribution from the β-ARs and/or epidermal growth factor receptors. This review article will discuss the molecular mechanisms by which nicotine and its oncogenic derivatives such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and N-nitrosonornicotine induce cell-cycle progression and promote tumor growth. A variety of signaling cascades are induced by nicotine through nAChRs, including the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway, phosphoinositide 3-kinase/AKT pathway, and janus-activated kinase/STAT signaling. In addition, studies have shown that nAChR activation induces Src kinase in a β-arrestin-1-dependent manner, leading to the inactivation of Rb protein and resulting in the expression of E2F1-regulated proliferative genes. Such nAChR-mediated signaling events enhance the proliferation of cells and render them resistant to apoptosis induced by various agents. These observations highlight the role of nAChRs in promoting the growth and metastasis of tumors and raise the possibility of targeting them for cancer therapy.

β-Adrenergic system, a backstage manipulator regulating tumour progression and drug target in cancer therapy

β-Adrenoceptors are broadly distributed in various tissues of the body. Stress hormones regulate a panel of important physiological functions and disease states including cancer. Nicotine and its derivatives could stimulate the release of stress hormones from cancer cells, leading to the promotion of cancer development. β-Blockers have been widely used to control hypertension for decades. Recently, these agents could have significant implications in cancer therapy through blockade of adrenoceptors in tumour tissues. In this review, we summarize recent advancements about the influence of stress hormones, nicotine and β-adrenoceptors on cancer cell proliferation, apoptosis, invasion and metastasis, and also tumour vasculature normalization. Relevant signal pathways and potential value of β-blockers in the treatment of cancer are also discussed in this review.

APS8, a polymeric alkylpyridinium salt blocks α7 nAChR and induces apoptosis in non-small cell lung carcinoma

Naturally occurring 3-alkylpyridinium polymers (poly-APS) from the marine sponge Reniera sarai, consisting of monomers containing polar pyridinium and nonpolar alkyl chain moieties, have been demonstrated to exert a wide range of biological activities, including a selective cytotoxicity against non-small cell lung cancer (NSCLC) cells. APS8, an analog of poly-APS with defined alkyl chain length and molecular size, non-competitively inhibits α7 nicotinic acetylcholine receptors (nAChRs) at nanomolar concentrations that are too low to be acetylcholinesterase (AChE) inhibitory or generally cytotoxic. In the present study we show that APS8 inhibits NSCLC tumor cell growth and activates apoptotic pathways. APS8 was not toxic for normal lung fibroblasts. Furthermore, in NSCLC cells, APS8 reduced the adverse anti-apoptotic, proliferative effects of nicotine. Our results suggest that APS8 or similar compounds might be considered as lead compounds to develop antitumor therapeutic agents for at least certain types of lung cancer.