Nicotine induces resistance to chemotherapy by modulating mitochondrial signaling in lung cancer

Type of neoadjuvant treatment strategy is associated with differential pathologic responses in pancreatic ductal adenocarcinoma

BACKGROUND

Tumor fibrosis after neoadjuvant treatment (NAT) for pancreatic ductal adenocarcinoma (PDAC) correlates with treatment response. Herein we assessed how different NAT strategies influence pathologic responses and survival.

METHODS

Patients with surgically resected PDAC who received NAT (1991-2020) were included. Descriptive statistics compared outcomes amongst fibrosis groups (none, minor <50 ​%, partial 51%-94 ​%, major ≥95 ​%) and NAT (chemotherapy alone, chemoradiation, or chemotherapy ​+ ​chemoradiation (total neoadjuvant therapy, TNT)).

RESULTS

Patients with major fibrosis most often received TNT (65.8 ​%, p ​< ​0.001). Major fibrosis was associated with the greatest rate of downstaging (77.8 ​%, p ​< ​0.001), highest R0 margin rate (100 ​%, p ​< ​0.01), and lowest mean positive lymph node ratio (0.80, p ​< ​0.01). Amongst complete responders, 11/14 (78.6 ​%) received TNT. Median overall (66.3 months, p ​= ​0.003) and disease-free (54.7months, p ​= ​0.05) survival were highest with major fibrosis.

CONCLUSIONS

Major fibrosis and complete pathologic responses after NAT are most frequent with a TNT strategy and are associated with improved outcomes.

Smoking history is associated with reduced efficacy of neoadjuvant therapy in pancreatic adenocarcinoma

BACKGROUND

Differential responses to neoadjuvant therapy (NAT) exist in pancreatic ductal adenocarcinoma (PDAC); however, contributing factors are poorly understood. Tobacco smoke is a common risk factor for PDAC, with nicotine-induced chemoresistance observed in other cancers. This study aimed to explore the potential association between tobacco use and NAT efficacy in PDAC.

METHODS

A single-center, retrospective analysis was conducted that included all consecutive patients with PDAC who underwent surgical resection after NAT with a documented smoking history (N = 208). NAT response was measured as percentage fibrosis in the surgical specimen. Multivariable models controlled for covariates and survival were modeled using the Kaplan-Meier method.

RESULTS

Postoperatively, major responses to NAT (>95% fibrosis) were less frequently observed in smokers than in nonsmokers (13.7% vs 30.4%, respectively; P = .021). Pathologic complete responses were similarly less frequent in smokers than in nonsmokers (2.1% vs 9.9%, respectively; P = .023). On multivariate analysis controlling for covariates, smoking history remained independently associated with lower odds of major fibrosis (odds ratio [OR], 0.25; 95% CI, 0.10-0.59; P = .002) and pathologic complete response (OR, 0.21; 95% CI, 0.03-0.84; P = .05). The median overall survival was significantly longer in nonsmokers than in smokers (39.1 vs 26.6 months, respectively; P = .05).

CONCLUSION

Tobacco use was associated with diminished pathologic responses to NAT. Future research to understand the biology underlying this observation is warranted and may inform differential NAT approaches or counseling among these populations.

Nicotinic acetylcholine receptors in cancer: Limitations and prospects

Nicotinic acetylcholine receptors (nAChRs) have long been considered to solely mediate neurotransmission. However, their widespread distribution in the human body suggests a more diverse physiological role. Additionally, the expression of nAChRs is increased in certain cancers, such as lung cancer, and has been associated with cell proliferation, epithelial-to-mesenchymal cell transition, angiogenesis and apoptosis prevention. Several compounds that interact with these receptors have been identified as potential therapeutic agents. They have been tested as drugs for treating nicotine addiction, alcoholism, depression, pain and Alzheimer's disease. This review focuses on nAChR-mediated signalling in cancer, presenting opportunities for the development of innovative nAChR-based anticancer drugs. It displays the differences in expression of each nAChR subunit between normal and cancer cells for selected cancer types, highlighting their possible involvement in specific cases. Antagonists of nAChRs that could complement existing cancer therapies are summarised and critically discussed. We hope that this review will stimulate further research on the role of nAChRs in cancer potentially leading to innovative cancer therapies.

Tobacco nicotine promotes TRAIL resistance in lung cancer through SNHG5

Tobacco nicotine use is carcinogenic and a well-known risk factor for lung cancer. However, whether tobacco nicotine can induce drug resistance in lung cancer is not clear. The objective of the present study was to identify the TNF-related apoptosis-inducing ligand (TRAIL) resistance of long noncoding RNAs (lncRNAs) that are differentially expressed in smokers and nonsmokers with lung cancer. The results suggested that the nicotine upregulated small nucleolar RNA host gene 5 (SNHG5) and markedly decreased the levels of cleaved caspase-3. The present study found that cytoplasm lncRNA SNHG5 overexpression was associated with TRAIL resistance in lung cancer and that SNHG5 can interact with X-linked inhibitor of apoptosis protein to promote TRAIL resistance. Therefore, nicotine promoted TRAIL resistance in lung cancer through SNHG5/X-linked inhibitor of apoptosis protein.

Reporting of tobacco use and tobacco-related analyses in cancer cooperative group clinical trials: a systematic scoping review

BACKGROUND

Continued smoking after a diagnosis of cancer negatively impacts cancer outcomes, but the impact of tobacco on newer treatments options is not well established. Collecting and evaluating tobacco use in clinical trials may advance understanding of the consequences of tobacco use on treatment modalities, but little is known about the frequency of reporting and analysis of tobacco use in cancer cooperative clinical trial groups.

PATIENTS AND METHODS

A comprehensive literature search was conducted to identify cancer cooperative group clinical trials published from January 2017-October 2019. Eligible studies evaluated either systemic and/or radiation therapies, included ≥100 adult patients, and reported on at least one of: overall survival, disease/progression-free survival, response rates, toxicities/adverse events, or quality-of-life.

RESULTS

A total of 91 studies representing 90 trials met inclusion criteria with trial start dates ranging from 1995 to 2015 with 14% involving lung and 5% head and neck cancer patients. A total of 19 studies reported baseline tobacco use; 2 reported collecting follow-up tobacco use. Seven studies reported analysis of the impact of baseline tobacco use on clinical outcomes. There was significant heterogeneity in the reporting of baseline tobacco use: 7 reported never/ever status, 10 reported never/ex-smoker/current smoker status, and 4 reported measuring smoking intensity. None reported verifying smoking status or second-hand smoke exposure. Trials of lung and head and neck cancers were more likely to report baseline tobacco use than other disease sites (83% versus 6%, P < 0.001).

CONCLUSIONS

Few cancer cooperative group clinical trials report and analyze trial participants' tobacco use. Significant heterogeneity exists in reporting tobacco use. Routine standardized collection and reporting of tobacco use at baseline and follow-up in clinical trials should be implemented to enable investigators to evaluate the impact of tobacco use on new cancer therapies.

The Association between Smoking and Mortality in Women with Breast Cancer: A Real-World Database Analysis

Smoking increases the cancer-specific and overall mortality risk in women with breast cancer (BC). However, the effect of smoking cessation remains controversial, and detailed research is lacking in Asia. We aimed to investigate the association between smoking status and mortality in women with BC using the population-based cancer registry. The Taiwan Cancer Registry was used to identify women with BC from 2011 to 2017. A total of 54,614 women with BC were enrolled, including 1687 smokers and 52,927 non-smokers. The outcome, mortality, was identified using Taiwan’s cause-of-death database. The association between smoking status and mortality was estimated using Cox proportional regression. Women with BC who smoked had a 1.25-fold higher (95% C.I.: 1.08–1.45; p = 0.0022) risk of overall mortality and a 1.22-fold higher (95% C.I.: 1.04–1.44; p = 0.0168) risk of cancer-specific mortality compared with non-smokers. The stratified analysis also indicated that women with BC who smoked showed a significantly higher overall mortality risk (HR: 1.20; 95% CI: 1.01–1.43; p = 0.0408) than women with BC who did not smoke among women without comorbidities. Additionally, current smokers had a 1.57-fold higher risk (95% CI: 1.02–2.42; p = 0.0407) of overall mortality compared with ever smokers among women with BC who smoked. It was shown that a current smoking status is significantly associated with an increase in overall and cancer-specific mortality risk in women with BC. Quitting smoking could reduce one’s mortality risk. Our results underscore the importance of smoking cessation for women with BC.

β-Caryophyllene Counteracts Chemoresistance Induced by Cigarette Smoke in Triple-Negative Breast Cancer MDA-MB-468 Cells

Exposure to cigarette smoke (CS) has been associated with an increased risk of fatal breast cancers and recurrence, along with chemoresistance and chemotherapy impairment. This strengthens the interest in chemopreventive agents to be exploited both in healthy and oncological subjects to prevent or repair CS damage. In the present study, we evaluated the chemopreventive properties of the natural sesquiterpene β-caryophyllene towards the damage induced by cigarette smoke condensate (CSC) in triple negative breast cancer MDA-MB-468 cells. Particularly, we assessed the ability of the sesquiterpene to interfere with the mechanisms exploited by CSC to promote cell survival and chemoresistance, including genomic instability, cell cycle progress, autophagy/apoptosis, cell migration and related pathways. β-Caryophyllene was found to be able to increase the CSC-induced death of MDA-MB-468 cells, likely triggering oxidative stress, cell cycle arrest and apoptosis; moreover, it hindered cell recovery, autophagy activation and cell migration; at last, a marked inhibition of the signal transducer and activator of transcription 3 (STAT3) activation was highlighted: this could represent a key mechanism of the chemoprevention by β-caryophyllene. Although further studies are required to confirm the in vivo efficacy of β-caryophyllene, the present results suggest a novel strategy to reduce the harmful effect of smoke in cancer patients and to improve the survival expectations in breast cancer women.

Nicotine-induced miR-21-3p promotes chemoresistance in lung cancer by negatively regulating FOXO3a

Lung cancer is the leading cause of cancer-related mortality worldwide and cigarette smoking is reported to contribute to the lung cancer-related mortality. The present study aimed to investigate the molecular mechanism underlying nicotine-induced chemoresistance in lung cancer. The expression of microRNA (miR)-21-3p and its predicted target FOXO3a in lung cancer cells was detected via reverse transcription-quantitative PCR, in the presence or absence of nicotine. The regulatory effect of miR-21-3p and FOXO3a on lung cancer cell proliferation and apoptosis induced by docetaxel or cisplatin treatment was evaluated by performing Cell Counting Kit-8 and Annexin V/PI staining assays, respectively. The interaction between miR-21-3p and FOXO3a was analyzed by performing luciferase reporter assays and western blotting. FOXO3a overexpression rescue experiments were conducted in vitro and in vivo using a xenograft mouse model to assess the function of miR-21-3p/FOXO3a in lung cancer. Nicotine induced miR-21-3p expression in lung cancer cells in a dose-dependent manner. miR-21-3p downregulated FOXO3a expression by directly binding to the 3′-untranslated region of FOXO3a. Moreover, miR-21-3p knockdown sensitized lung cancer cells to docetaxel or cisplatin treatment. Mechanistically, FOXO3a was predicted as a direct target of miR-21-3p. FOXO3a overexpression promoted the chemosensitivity of lung cancer cells to docetaxel or cisplatin treatment. Furthermore, FOXO3a overexpression antagonized the regulatory function of miR-21-3p on docetaxel- or cisplatin-treated lung cancer cells. In the docetaxel- or cisplatin-treated lung cancer xenograft mouse model, miR-21-3p promoted chemoresistance via negatively regulating FOXO3a. Therefore, the present study demonstrated that nicotine-induced miR-21-3p promoted chemoresistance to docetaxel or cisplatin treatment via negatively regulating FOXO3a, which may serve as a novel therapeutic strategy for the treatment of patients with chemoresistant lung cancer.

Study protocol for a hybrid type 1 effectiveness-implementation trial testing virtual tobacco treatment in oncology practices [Smokefree Support Study 2.0]

BACKGROUND

Persistent smoking among patients diagnosed with cancer is associated with adverse clinical outcomes, yet an evidence-based tobacco use intervention has not been well-integrated into cancer care in community oncology settings. This paper describes the protocol of a nation-wide clinical trial conducted by the ECOG-ACRIN National Cancer Institute (NCI) Community Oncology Research Program (NCORP) Research Base to assess the effectiveness of a virtual tobacco treatment intervention and the process of implementing tobacco treatment in NCORP community oncology settings.

METHODS/DESIGN

This two-arm, multisite (n: 49 NCORP sites) hybrid type 1 effectiveness-implementation randomized controlled trial compares the effectiveness of a Virtual Intervention Treatment (VIT) versus an Enhanced Usual Control (EUC) among English and Spanish speaking patients recently diagnosed with cancer, reporting current smoking and receiving care at a participating NCORP Community or Minority/Underserved Site. The VIT includes up to 11 virtual counseling sessions with a tobacco treatment specialist and up to 12 weeks of nicotine replacement therapy (NRT). The EUC arm receives a referral to the NCI Quitline. The primary study outcome is biochemically confirmed 7-day point prevalence smoking abstinence. Moderators of treatment effect will be assessed. The study evaluates implementation processes from participating NCORP site staff via survey, administrative, and focus group data, including reach, acceptability, appropriateness, fidelity, feasibility, adoption, cost and sustainability outcomes.

DISCUSSION

This trial will generate findings about the effectiveness of an evidence-based virtual tobacco treatment intervention targeting patients diagnosed with cancer and illuminate barriers and facilitators that influence implementing tobacco treatment into community oncology settings nationally. In the era of COVID-19, virtual care solutions are vital for maximizing access and utilization of tobacco treatment delivery.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03808818) on January 18th, 2019; Last update posted: May 21st, 2020.

New Implications of Patients’ Sex in Today’s Lung Cancer Management

Simple Summary

We aim to raise awareness that sex is an important factor to take into account in modern-day thoracic oncology practice. Summarized, women should be specifically targeted in smoking cessation campaigns and sex-specific barriers should be addressed. Women present more often with adenocarcinoma histology and EGFR/ALK alterations, as lung cancer in never-smokers is more common in women compared to men. Lung cancer in female patients may show a poorer response to immune checkpoint inhibition; therefore, the addition of chemotherapy should be considered. On the other hand, women experience more benefits from targeted therapy against EGFR. In general, prognosis for women is better compared to that in men. Lung cancer screening trials report that women derive more benefit from screening, although they have not been designed for women. Future trial designs should take this into account and encourage participation of women.

Abstract

This paper describes where and how sex matters in today’s management of lung cancer. We consecutively describe the differences between males and females in lung cancer demographics; sex-based differences in the immune system (including the poorer outcomes in women who are treated with immunotherapy but no chemotherapy); the presence of oncogenic drivers and the response to targeted therapies according to sex; the greater benefit women derive from lung cancer screening and why they get screened less; and finally, the barriers to smoking cessation that women experience. We conclude that sex is an important but often overlooked factor in modern-day thoracic oncology practice.

Nicotinic receptors modulate antitumor therapy response in triple negative breast cancer cells

BACKGROUND

Triple negative breast cancer is more aggressive than other breast cancer subtypes and constitutes a public health problem worldwide since it has high morbidity and mortality due to the lack of defined therapeutic targets. Resistance to chemotherapy complicates the course of patients’ treatment. Several authors have highlighted the participation of nicotinic acetylcholine receptors (nAChR) in the modulation of conventional chemotherapy treatment in cancers of the airways. However, in breast cancer, less is known about the effect of nAChR activation by nicotine on chemotherapy treatment in smoking patients.

AIM

To investigate the effect of nicotine on paclitaxel treatment and the signaling pathways involved in human breast MDA-MB-231 tumor cells.

METHODS

Cells were treated with paclitaxel alone or in combination with nicotine, administered for one or three 48-h cycles. The effect of the addition of nicotine (at a concentration similar to that found in passive smokers’ blood) on the treatment with paclitaxel (at a therapeutic concentration) was determined using the 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The signaling mediators involved in this effect were determined using selective inhibitors. We also investigated nAChR expression, and ATP “binding cassette” G2 drug transporter (ABCG2) expression and its modulation by the different treatments with Western blot. The effect of the treatments on apoptosis induction was determined by flow cytometry using annexin-V and 7AAD markers.

RESULTS

Our results confirmed that treatment with paclitaxel reduced MDA-MB-231 cell viability in a concentration-dependent manner and that the presence of nicotine reversed the cytotoxic effect induced by paclitaxel by involving the expression of functional α7 and α9 nAChRs in these cells. The action of nicotine on paclitaxel treatment was linked to modulation of the protein kinase C, mitogen-activated protein kinase, extracellular signal-regulated kinase, and NF-κB signaling pathways, and to an up-regulation of ABCG2 protein expression. We also detected that nicotine significantly reduced the increase in cell apoptosis induced by paclitaxel treatment. Moreover, the presence of nicotine reduced the efficacy of paclitaxel treatment administered in three cycles to MDA-MB-231 tumor cells.

CONCLUSION

Our findings point to nAChRs as responsible for the decrease in the chemotherapeutic effect of paclitaxel in triple negative tumors. Thus, nAChRs should be considered as targets in smoking patients.

Nicotinic acetylcholine receptors in chemotherapeutic drugs resistance: An emerging targeting candidate

There is no definitive cure for cancer, and most of the current chemotherapy drugs have limited effects due to the development of drug resistance and toxicity at high doses. Therefore, there is an ongoing need for identifying the causes of chemotherapeutic resistance, and it will be possible to develop innovative treatment approaches based on these novel targeting candidates. Cigarette smoking is known to be one of the main causes of resistance to chemotherapeutic agents. Nicotine as a component of cigarette smoke is an exogenous activator of nicotinic acetylcholine receptors (nAChRs). It can inhibit apoptosis, increase cell proliferation and cell survival, reducing the cytotoxic effects of chemotherapy drugs and cause a reduced therapeutic response. Recent studies have demonstrated that nAChRs and their downstream signaling pathways have considerable implications in different cancer's initiation, progression, and chemoresistance. In some previous studies, nAChRs have been targeted to obtain better efficacies for chemotherapeutics. Besides, nAChRs-based therapies have been used in combination with chemotherapy drugs to reduce the side effects. This strategy requires lower doses of chemotherapy drugs compared to the conditions that must be used alone. Here, we discussed the experimental and clinical studies that show the nAChRs involvement in response to chemotherapy agents. Also, controversies relating to the effects of nAChR on chemotherapy-induced apoptosis are in our focus in this review article. Delineating the complex influences of nAChRs would be of great interest in establishing new effective chemotherapy regimens.

Nicotine Changes Airway Epithelial Phenotype and May Increase the SARS-COV-2 Infection Severity

(1) Background: Nicotine is implicated in the SARS-COV-2 infection through activation of the α7-nAChR and over-expression of ACE2. Our objective was to clarify the role of nicotine in SARS-CoV-2 infection exploring its molecular and cellular activity. (2) Methods: HBEpC or si-mRNA-α7-HBEpC were treated for 1 h, 48 h or continuously with 10-7 M nicotine, a concentration mimicking human exposure to a cigarette. Cell viability and proliferation were evaluated by trypan blue dye exclusion and cell counting, migration by cell migration assay, senescence by SA-β-Gal activity, and anchorage-independent growth by cloning in soft agar. Expression of Ki67, p53/phospho-p53, VEGF, EGFR/pEGFR, phospho-p38, intracellular Ca2+, ATP and EMT were evaluated by ELISA and/or Western blotting. (3) Results: nicotine induced through α7-nAChR (i) increase in cell viability, (ii) cell proliferation, (iii) Ki67 over-expression, (iv) phospho-p38 up-regulation, (v) EGFR/pEGFR over-expression, (vi) increase in basal Ca2+ concentration, (vii) reduction of ATP production, (viii) decreased level of p53/phospho-p53, (ix) delayed senescence, (x) VEGF increase, (xi) EMT and consequent (xii) enhanced migration, and (xiii) ability to grow independently of the substrate. (4) Conclusions: Based on our results and on evidence showing that nicotine potentiates viral infection, it is likely that nicotine is involved in SARS-CoV-2 infection and severity.

SNHG9 was upregulated in NSCLC and associated with DDP-resistance and poor prognosis of NSCLC patients

Lung cancer, a leading cause of cancer-related mortalities worldwide and non-small cell lung cancer (NSCLC) is the main subtype of lung cancer. As a first-line chemotherapeutic drug used for NSCLC, acquired resistance retarded the clinical application of cisplatin (DDP). We herein reported long non-coding RNA SNHG9 was over-expressed in NSCLC tissues and cell lines compared with normal lung tissues and cell line; Increased SNHG9 was also observed in DDP resistant NSCLC tissues and cell lines compared with their DDP sensitive counterparts. Elevated expression of SNHG9 was associated with lower overall survival (OS) rate in NSCLC patients. Besides, silence of SNHG9 suppressed DDP resistance of NSCLC cells. Furthermore, CAPRIN1 was positively regulated by SNHG9 and mediated the promoting role of SNHG9 in DDP resistance of NSCLC cells. SNHG9 could be used as a potential target for DDP resistant NSCLC therapy.

Can Cancer Diagnosis Help in Quitting Tobacco? Barriers and Enablers to Tobacco Cessation Among Head and Neck Cancer Patients from a Tertiary Cancer Center in South india

BACKGROUND

Tobacco use contributes to almost 40% of the cancers in India. Considering the potential threat, many preventive measures have been instigated in the country. However, tobacco cessation for hospitalized cancer patients is an unexplored territory in India. This study aims to understand the quit status and to explore the reasons to quit or continue the use of tobacco after the diagnosis of head and neck cancer (HNC).

METHODS

HNC patients admitted between February and April 2016 were assessed for their tobacco use status. A DT was used to assess the psychological distress. Users were assessed for their readiness to quit and dependence on tobacco. An in-depth interview was conducted among 25 patients (seven current users and 18 recent quitters), and themes that emerged were discussed.

RESULTS

Of the 119 HNC patients, 71 were tobacco users and 48 had quit tobacco after the diagnosis. The reasons to quit were the perceived benefits of quitting, advice from the physicians, and awareness about cancer and its association with tobacco. In contrast, the reasons to continue the use of tobacco were attributed to coping mechanisms, nihilistic perception about the outcome of the cancer, and a lack of understanding about cancer and its association with tobacco.

CONCLUSION

The recent quitters comprehended the benefits of quitting and were able to prioritize their needs after the diagnosis. However, one-third of the HNC patients continued to use tobacco even after the diagnosis of cancer. Hence, tobacco cessation services need to be integrated into oncology services for achieving better treatment outcomes.

Impact of the APE1 Redox Function Inhibitor E3330 in Non-small Cell Lung Cancer Cells Exposed to Cisplatin: Increased Cytotoxicity and Impairment of Cell Migration and Invasion

Elevated expression levels of the apurinic/apyrimidinic endonuclease 1 (APE1) have been correlated with the more aggressive phenotypes and poor prognosis of non-small cell lung cancer (NSCLC). This study aimed to assess the impact of the inhibition of the redox function of APE1 with E3330 either alone or in combination with cisplatin in NSCLC cells. For this purpose, complementary endpoints focusing on cell viability, apoptosis, cell cycle distribution, and migration/invasion were studied. Cisplatin decreased the viability of H1975 cells in a time- and concentration-dependent manner, with IC₅₀ values of 9.6 µM for crystal violet assay and 15.9 µM for 3-(4,5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. E3330 was clearly cytotoxic for concentrations above 30 µM. The co-incubation of E3330 and cisplatin significantly decreased cell viability compared to cisplatin alone. Regarding cell cycle distribution, cisplatin led to an increase in sub-G1, whereas the co-treatment with E3330 did not change this profile, which was then confirmed in terms of % apoptotic cells. In addition, the combination of E3330 and cisplatin at low concentrations decreased collective and chemotactic migration, and also chemoinvasion, by reducing these capabilities up to 20%. Overall, these results point to E3330 as a promising compound to boost cisplatin therapy that warrants further investigation in NSCLC.

An okadaic acid fragment analogue prevents nicotine-induced resistance to cisplatin by recovering PP2A activity in non-small cell lung cancer cells

We herein report the design, synthesis, and functional impact of an okadaic acid (OA) small analogue, ITH12680, which restores the activity of phosphoprotein phosphatase 2A (PP2A), whose deficient activity has been implicated in nicotine-mediated tumor progression and chemoresistance in non-small cell lung cancer (NSCLC). For its design, we paid attention to the structure of the PP2A-OA complex, where the C16-C38 OA fragment confers PP2A affinity and selectivity, but it is not involved in the inhibitory effect. Confirming this hypothesis, PP2A activity was not inhibited by ITH12680. By contrast, the compound partially restored OA-exerted PP2A inhibition in vitro. Moreover, flow cytometry and immunoblotting experiments revealed that ITH12680 reversed nicotine-induced cisplatin resistance in NSCLC cells, as it prevented nicotine-induced reduction of Bax expression and inhibited nicotine-mediated activation of cell survival and proliferation kinases, Akt and ERK1/2. Our findings suggest that the rescue of nicotine-inhibited PP2A activity could diminish the resistance to cisplatin treatment observed in NSCLC patients who continue smoking.

Nicotine exposure potentiates lung tumorigenesis by perturbing cellular surveillance

BACKGROUND

Nicotine is a major tobacco component and found at circulating concentrations in smokers' bloodstreams. Although considered a non-carcinogenic substance, nicotine rapidly defuses to tissues after being inhaled, inviting effects on cellular physiology, particularly in the lung. Widespread increased use of nicotine-based e-cigarettes, especially in younger adults, creates an urgent need for improved understanding of nicotine's potential to impact human health.

METHODS

Biological and biochemistry methods were used to interrogate the potential for nicotine to weaken the genetic integrity of murine and human-lung epithelial cells.

RESULTS

We demonstrate that nicotine potentiates the growth of the lung epithelial cells in a dose-response fashion. Nicotine elicits an acute increase in reactive oxygen species (ROS), which persists at moderately high levels throughout the duration of nicotine exposure. The aberrant increases in ROS appear to induce ER stress and UPR activation, as reflected by BIP upregulation and PERK phosphorylation. Furthermore, prolonged nicotine exposure interferes with p53 function triggered by sodium arsenite. Unless p53 is suppressed, persistent nicotine exposure does not induce colony formation by lung epithelial cells in soft agar.

CONCLUSION

The data suggest that nicotine treatment, by perturbing intracellular redox state and altering p53 function, can create a pro-tumorigenic environment in lung epithelium. The results suggest caution in using nicotine replacement therapies and e-cigarettes.

Small interfering RNA targeting alpha7 nicotinic acetylcholine receptor sensitizes hepatocellular carcinoma cells to sorafenib

AIMS

It has been demonstrated that reduced expression of alpha7 nicotinic acetylcholine receptor (α7nAChR) led to reduced chemotherapeutic drugs resistance in various cancer cells. However, whether small interfering RNA (siRNA) mediated knockdown of α7nAChR can reduce sorafenib (SOR) resistance in HCC cells remains to be determined.

MATERIALS AND METHODS

The effects of α7nAChR-siRNA in combination with SOR treatment was analyzed in human (HepG2) and mouse (Hepa 1-6) HCC cell lines. The MTT, DAPI staining and flow cytometry assays were applied to measure the cell viability, apoptosis and cell cycle progression of the cells. Also, the changes in the mRNA and protein levels of the α7nAChR were measured by quantitative real-time PCR and western blot analysis, respectively.

KEY FINDINGS

The results revealed that SOR increased both mRNA and protein levels of α7nAChR in HCC cells. Treatment with α7nAChR-siRNA abolished these effects. Also, SOR treatment in combination with α7nAChR-siRNA significantly sensitizes HCC cells to SOR cytotoxicity. This combination therapy significantly induced HCC cells apoptosis compared to SOR alone.

SIGNIFICANCE

These experimental results indicate that knockdown of α7nAChR by siRNA increased the SOR antitumor activity of HCC cells and suggests that this additive combination is a promising drug candidate for HCC therapy.

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.

Positive plasma cotinine during platinum-based chemotherapy is associated with poor response rate in advanced non-small cell lung cancer patients

INTRODUCTION

Patients with advanced non-small cell lung cancer (NSCLC) are most of the time treated with a first-line cytotoxic chemotherapy. Tobacco use is responsible for 90% of lung cancer. The aim of this study was to evaluate the impact of smoking continuation during first-line chemotherapy on tumor response in advanced-stage NSCLC.

MATERIALS AND METHODS

All patients with an advanced-stage NSCLC (IIIb or IV), treated with first-line platinum-based chemotherapy in our Department between June 2013 and July 2017 were included. Smoking status was assessed at inclusion by self-report, then at the tumor assessment consultation after 2 months of treatment, by both self-report and plasmatic cotinine measurement. Chemotherapy response, progression-free survival (PFS), overall survival (OS) and stage 3-4 toxicity were registered.

RESULTS

Ninety-seven patients were included: 8 (8%) declared to be non-smokers, 56 (58%) current smokers and 33 (34%) former smokers at diagnosis. At the first tumor evaluation, 24 (25%) self-reported as active smokers and 73 (75%) as non-smokers; overall response rate (ORR) was respectively 38% and 48% (p = 0.373). Fifty-four patients had a plasmatic cotinine evaluation at the first tumor evaluation. Seventeen patients (32%) had a positive cotinine rate (median 108ng/mL, IQR 31-236). Six patients (35%) had positive cotinine rate whereas declaring to be non-smokers at the first tumor evaluation. ORR was 18% in case of positive cotinine rate, and 57% when negative (p = 0.007). Regardless of the method for smoking status evaluation, PFS, OS and grade 3-4 toxicities were similar between smoker and non-smoker patients at the first tumor evaluation.

CONCLUSION

Smoking continuation during platinum-based chemotherapy, reflected by positive plasma cotinine rate, was associated with a poor ORR.

Chronic nicotine exposure affects programmed death-ligand 1 expression and sensitivity to epidermal growth factor receptor-tyrosine kinase inhibitor in lung cancer

Background

Smoking histories are independently associated with poor response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients with activating EGFR mutations. The aim of the present study was to determine the effect of nicotine exposure on programmed death-ligand 1 (PD-L1) expression in EGFR mutant lung cancer cells.

Methods

Human lung adenocarcinoma PC9 cells were exposed to 1 µM nicotine for 3 months designated as PC9/N, and cells were stimulated with gefitinib (0, 0.1, or 1 µM) for 48 hrs. Cell viability by the MTT assay and morphological changes by immunofluorescence staining were assessed. The protein expression of EGFR, mTOR, AKT, α1-nicotine acetylcholine receptor (nAchR) and PD-L1 were measured by Western blot. Gene expression of α1-nAchR and PD-L1 were examined by RT-PCR. Intratumoral levels of PD-L1 expression were compared according to the burden of smoking dosage in 54 EGFR mutant lung cancer patients.

Results

Cellular growth was inhibited by treatment with gefitinib, and PC9 cells were significantly more sensitive to gefitinib than PC9/N cells. Pleomorphic appearance with atypical nuclei and to be detached and shrunken with condensed nuclei in PC9 than PC9/N cells. The gene expression level of α1-nAchR and PD-L1 gene were higher in PC9/N cells compared to those in PC9 cells after treatment with gefitinib. Phosphorylation levels of EGFR, mTOR, AKT and PD-L1 level were decreased by gefitinib in PC9/N cells, which was to a lesser extent than that in PC9 cells. In tumors, heavy smokers (≥30 PY) showed 28.5% of ≥50% PD-L1 tumor proportion score (TPS) while light smoker and never smokers had 12.5% and 9.7% of ≥50% PD-L1 TPS, respectively. However, there was no statistical significance (P value =0.628).

Conclusions

Chronic nicotine exposure could increase PD-L1 expression related to intrinsic resistance to EGFR-TKI in NSCLC patients harboring activating EGFR mutation. Considering the clinical importance of inevitable EGFR resistance, further studies regarding the role of anti-PD-1/PD-L1 treatment are needed, especially in EGFR mutant smokers.

Mitochondria as a possible target for nicotine action

Mitochondria are multifunctional and dynamic organelles deeply integrated into cellular physiology and metabolism. Disturbances in mitochondrial function are involved in several disorders such as neurodegeneration, cardiovascular diseases, metabolic diseases, and also in the aging process. Nicotine is a natural alkaloid present in the tobacco plant which has been well studied as a constituent of cigarette smoke. It has also been reported to influence mitochondrial function both in vitro and in vivo. This review presents a comprehensive overview of the present knowledge of nicotine action on mitochondrial function. Observed effects of nicotine exposure on the mitochondrial respiratory chain, oxidative stress, calcium homeostasis, mitochondrial dynamics, biogenesis, and mitophagy are discussed, considering the context of the experimental design. The potential action of nicotine on cellular adaptation and cell survival is also examined through its interaction with mitochondria. Although a large number of studies have demonstrated the impact of nicotine on various mitochondrial activities, elucidating its mechanism of action requires further investigation.

Potential effects of nicotine on glioblastoma and chemoradiotherapy: a review

Introduction: Glioblastoma multiforme (GBM) has a poor prognosis despite maximal surgical resection with subsequent multi-modal radiation and chemotherapy. Use of tobacco products following diagnosis and during the period of treatment for non-neural tumors detrimentally affects treatment and prognosis. Approximately, 16-28% of patients with glioblastoma continue to smoke after diagnosis and during treatment. The literature is sparse for information-pertaining effects of smoking and nicotine on GBM treatment and prognosis. Areas covered: This review discusses cellular pathways involved in GBM progression that might be affected by nicotine, as well as how nicotine may contribute to resistance to treatment. Similarities of GBM pathways to those in non-neural tumors are investigated for potential effects by nicotine. English language papers were identified using PubMed, Medline and Scopus databases using a combination of keywords including but not limited to the following: nicotine, vaping, tobacco, e-cigarettes, smoking, vaping AND glioblastoma or brain cancer OR/AND temozolomide, carmustine, methotrexate, procarbazine, lomustine, vincristine, and neural tumor cell lines. Expert opinion: Understanding the impact of nicotine on treatment and resistance to chemotherapeutics should allow physicians to educate their patients with GBM with evidence-based recommendations about the effects of continuing to use nicotine-containing products after diagnosis and during treatment.

Tobacco smoking after diagnosis of cancer: clinical aspects

Tobacco smoking accounts for at least 30% of all cancer deaths and nearly 90% of lung cancer deaths. Smoking cessation significantly reduces the risk of developing tobacco-related malignancies. Smoking after cancer diagnosis is also associated with multiple risks, including worse tolerance of treatment, higher risk of a failure and second primary tumors, and poorer quality of life. Apart from disease site and stage, continued smoking is considered the strongest adverse predictor of survival in cancer patients. However, the benefits of smoking cessation are undervalued: many patients are not aware of harms related to continued tobacco use after cancer diagnosis. Furthermore, health care professionals often do not encourage their patients to quit, and do not provide tobacco cessation assistance for continuing tobacco users. Despite the apparent impact of tobacco use on treatment outcomes, data on current smoking status is only rarely captured in clinical trials This article reviews the most important clinical aspects of smoking after the diagnosis of cancer.

Nicotine Induces Resistance to Erlotinib Therapy in Non-Small-Cell Lung Cancer Cells Treated with Serum from Human Patients

Previously, we reported that nicotine reduces erlotinib sensitivity in a xenograft model of PC9, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-sensitive non-small-cell lung cancer cell line. The present study examined whether smoking induces erlotinib resistance in vitro. We assessed resistance to EGFR-TKIs by treating cancer cell lines with erlotinib, afatinib, or osimertinib, and serum collected from smokers within 30 min of smoking and that from a non-smoker as a control. We also assessed erlotinib resistance by treating PC9 cells exposed to serum from a smoker or a non-smoker, or serum from an erlotinib user. Treatment of the cancer cell lines with serum from smokers induced significant erlotinib resistance, compared with the control (p < 0.05). Furthermore, serum samples with a high concentration of cotinine (a nicotine exposure indicator) demonstrated stronger erlotinib resistance than those with low concentrations. Similar to the observations with erlotinib treatment of cell lines, the analysis of serum from erlotinib users revealed that smokers demonstrated significantly reduced sensitivity to erlotinib (p < 0.001). In conclusion, our present results support the hypothesis that smoking contributes to resistance to erlotinib therapy in non-small-cell lung cancer.

Guidelines for the Surgical Management of Oral Cancer: Korean Society of Thyroid-Head and Neck Surgery

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient’s treatment goals.

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.

Supportive Care for the Head and Neck Cancer Patient

Patients with head and neck cancers (HNC) face multiple psychosocial and physical challenges that require multidisciplinary attention and care throughout their disease process. The psychoemotional symptoms may be triggered by cosmetic disfigurement and/or functional deficits related to the cancer itself or cancer-directed treatments. These physical and emotional symptoms can be demoralizing and require acute and long-term professional assistance throughout a patient's lifespan. HNC remains one of the most challenging cancers to treat due to disfigurement, emotional suffering, social isolation, and loss of self-esteem. The emotional and physical symptoms a supportive care team can address are discussed in this chapter.

SNP rs16969968 as a Strong Predictor of Nicotine Dependence and Lung Cancer Risk in a North Indian Population

Background:

The 15q24-25 loci contain genes (CHRNA5 and CHRNA3) encoding nicotinic acetylcholine receptor subunits. We here determined for the first time the association of genetic variants rs16969968 and rs3743074 in CHRNA5 and CHRNA3, respectively, on nicotine dependence and lung cancer risk in a North Indian population by a case-control approach.

Methods:

Venous blood samples were obtained from 324 participants (108 lung cancer patients and 216 healthy individuals). DNA was extracted and PCR amplified with primers flanking the SNPs rs16969968 and rs3743074. Amplicons were subjected to sequencing and logistic regression was used to analyze association between variables.

Results:

The risk variant SNP rs16969968 in both heterozygous and homozygous forms appeared to exert a significant effect on nicotine dependence [GA (OR=2.77) and AA (OR=2.53)]. As expected, smoking was strongly associated with lung cancer (OR= 2.62). Risk allele rs16969968 in CHRNA5 also showed a significant association with increased lung cancer risk in our cohort, alone (OR= 4.99) and with smoking as a co-variable (OR= 4.28). Comparison of our analysis with other populations suggested that individuals with rs16969968 risk allele in the Indian population are more susceptible to lung cancer.

Conclusion:

Overall, the results strongly indicated that, in our cohort North Indian population, the genetic variant rs16969968, but not rs3743074, is significantly associated with both nicotine dependence and increased risk of lung cancer. While the results are significant, there is further need to increase the sample size and improve precision of our risk prediction.

Nicotine Prevents and Reverses Paclitaxel-Induced Mechanical Allodynia in a Mouse Model of CIPN

Chemotherapy-induced peripheral neuropathy (CIPN), a consequence of peripheral nerve fiber dysfunction or degeneration, continues to be a dose-limiting and debilitating side effect during and/or after cancer chemotherapy. Paclitaxel, a taxane commonly used to treat breast, lung, and ovarian cancers, causes CIPN in 59-78% of cancer patients. Novel interventions are needed due to the current lack of effective CIPN treatments. Our studies were designed to investigate whether nicotine can prevent and/or reverse paclitaxel-induced peripheral neuropathy in a mouse model of CIPN, while ensuring that nicotine will not stimulate lung tumor cell proliferation or interfere with the antitumor properties of paclitaxel. Male C57BL/6J mice received paclitaxel every other day for a total of four injections (8 mg/kg, i.p.). Acute (0.3-0.9 mg/kg, i.p.) and chronic (24 mg/kg per day, s.c.) administration of nicotine respectively reversed and prevented paclitaxel-induced mechanical allodynia. Blockade of the antinociceptive effect of nicotine with mecamylamine and methyllycaconitine suggests that the reversal of paclitaxel-induced mechanical allodynia is primarily mediated by the α7 nicotinic acetylcholine receptor subtype. Chronic nicotine treatment also prevented paclitaxel-induced intraepidermal nerve fiber loss. Notably, nicotine neither promoted proliferation of A549 and H460 non-small cell lung cancer cells nor interfered with paclitaxel-induced antitumor effects, including apoptosis. Most importantly, chronic nicotine administration did not enhance Lewis lung carcinoma tumor growth in C57BL/6J mice. These data suggest that the nicotinic acetylcholine receptor-mediated pathways may be promising drug targets for the prevention and treatment of CIPN.

Final data of an Italian multicentric survey about counseling for smoking cessation in patients with diagnosis of a respiratory disease

INTRODUCTION

Smoking is the major risk factor for cancer and several respiratory diseases. Quitting smoking at any point of life may increase the effectiveness of treatments and improve prognosis of patients with any pulmonary disease, including lung cancer. However, few institutions in Europe offer to patients adequate counseling for smoking cessation.

OBJECTIVES

Aim of this study was to investigate the level of counseling for smoking cessation offered by healthcare professionals to patients and their appreciation towards the intervention itself.

METHODS

Between January 2013 and February 2016, 490 patients, diagnosed with a respiratory diseases, were prospectively evaluated with an anonymous survey developed by WALCE (Women Against Lung Cancer in Europe).

RESULTS

The majority of patients enrolled (76%) declared to have stopped smoking after the diagnosis of a respiratory disease, 17% to smoke less, 7% to continue smoking. Patients who reported to have never received any counseling for smoking cessation were 38%. Almost 73% of the other patients reported a positive judgment about the quality of healthcare's intervention. Despite these favorable considerations, 83% of patients have disclosed they simply quit smoking overnight without help, 5% have used electronic cigarettes, 5% nicotine replacement treatments, 4% dedicated books, 3% have attended a referral clinic.

CONCLUSIONS

Considering all the smoking-related side effects, greater efforts should be made in order to better support patients in smoking cessation. Smoking should be considered as a real physical disorder and similar surveys should be encouraged with the aim to fight the 'stigma' of smoking that still exists among patients.

Helping patients to reduce tobacco consumption in oncology: a narrative review

The present overview focuses on evidence of smoking cessation approaches in oncology settings with the aim to provide health personnel a critical perspective on how to help their patients. This narrative review is structured in two main sections: the first one describes the psycho-cognitive variables involved in the decision to continue smoking after a cancer diagnosis and during the treatment; the second section relates methods and tools may be recommended, being evidence-based, to support smoking cessation in oncology settings. Active smoking increases not only susceptibility to common cancers in the general population, but also increases disease severity and comorbidities in cancer patients. Nowadays, scientific evidence has identified many strategies to give up smoking, but a lack of knowledge exists for treatment of nicotine dependence in the cancer population. Health personnel is often ambiguous when approaching the problem, while their contribution is essential in guiding patients towards healthier choices. We argue that smoking treatments for cancer patients deserve more attention and that clinical features, individual characteristics and needs of the patient should be assessed in order to increase the attempts success rate. Health personnel that daily work and interact with cancer patients and their caregivers have a fundamental role in the promotion of the health changing. For this reason, it is important that they have adequate knowledge and resources in order to support cancer patients to stop tobacco cigarette smoking and promoting and healthier lifestyle.

Integrating tobacco treatment into cancer care: Study protocol for a randomized controlled comparative effectiveness trial

BACKGROUND

Despite the well-established risks of persistent smoking, 10-30% of cancer patients continue to smoke after diagnosis. Evidence-based tobacco treatment has yet to be integrated into routine oncology care. This paper describes the protocol, manualized treatment, evaluation plan, and overall study design of comparing the effectiveness and cost of two treatments across two major cancer centers.

METHODS/DESIGN

A two-arm, two-site randomized controlled comparative effectiveness trial is testing the hypothesis that an Intensive Treatment (IT) intervention is more effective than a Standard Treatment (ST) intervention in helping recently diagnosed cancer patients quit smoking. Both interventions include 4 weekly counseling sessions and FDA-approved smoking cessation medication advice. The IT includes an additional 4 biweekly and 3 monthly booster sessions as well as dispensal of the recommended FDA-approved smoking cessation medication at no cost. The trial is enrolling patients with suspected or newly diagnosed cancer who have smoked a cigarette in the past 30days. Participants are randomly assigned to receive the ST or IT condition. Tobacco cessation outcomes are assessed at 3 and 6months. The primary study outcome is 7-day point prevalence biochemically-validated tobacco abstinence. Secondary study outcomes include the incremental cost-effectiveness of the IT vs. ST.

DISCUSSION

This trial will answer key questions about delivering tobacco treatment interventions to newly diagnosed cancer patients. If found to be efficacious and cost-effective, this treatment will serve as a model to be integrated into oncology care settings nation-wide, as we strive to improve treatment outcomes and quality of life for cancer patients.

Impact of smoking on lung cancer treatment effectiveness: a review

Tobacco smoke contains more than 4000 detectable substances, such as polycyclic aromatic hydrocarbons, nicotine, carbon monoxide and heavy metals, which are considered powerful enzymatic inducers that have notable influence on the efficacy and tolerability of many medications through complex pharmacokinetic and pharmacodynamic interactions. As a result, adjustments of drug dosages are required in smokers, both if they continue to smoke or if they quit after smoking cessation treatment. The purpose of this review is to examine the main drug interactions with tobacco smoke clinically relevant, with a closer look on patients developing oncologic diseases.

American Cancer Society Head and Neck Cancer Survivorship Care Guideline

Answer questions and earn CME/CNE The American Cancer Society Head and Neck Cancer Survivorship Care Guideline was developed to assist primary care clinicians and other health practitioners with the care of head and neck cancer survivors, including monitoring for recurrence, screening for second primary cancers, assessment and management of long-term and late effects, health promotion, and care coordination. A systematic review of the literature was conducted using PubMed through April 2015, and a multidisciplinary expert workgroup with expertise in primary care, dentistry, surgical oncology, medical oncology, radiation oncology, clinical psychology, speech-language pathology, physical medicine and rehabilitation, the patient perspective, and nursing was assembled. While the guideline is based on a systematic review of the current literature, most evidence is not sufficient to warrant a strong recommendation. Therefore, recommendations should be viewed as consensus-based management strategies for assisting patients with physical and psychosocial effects of head and neck cancer and its treatment. CA Cancer J Clin 2016;66:203-239. © 2016 American Cancer Society.

Effect of Cigarette Smoking on Epithelial to Mesenchymal Transition (EMT) in Lung Cancer

Epithelial to mesenchymal transition (EMT) is a process that allows an epithelial cell to acquire a mesenchymal phenotype through multiple biochemical changes resulting in an increased migratory capacity. During cancer progression, EMT is found to be associated with an invasive or metastatic phenotype. In this review, we focus on the discussion of recent studies about the regulation of EMT by cigarette smoking. Various groups of active compounds found in cigarette smoke such as polycyclic aromatic hydrocarbons (PAH), nicotine-derived nitrosamine ketone (NNK), and reactive oxygen specicies (ROS) can induce EMT through different signaling pathways. The links between EMT and biological responses to cigarette smoke, such as hypoxia, inflammation, and oxidative damages, are also discussed. The effect of cigarette smoke on EMT is not only limited to cancer types directly related to smoking, such as lung cancer, but has also been found in other types of cancer. Altogether, this review emphasizes the importance of understanding molecular mechanisms of the induction of EMT by cigarette smoking and will help in identifying novel small molecules for targeting EMT induced by smoking.

Calcium efflux from the endoplasmic reticulum regulates cisplatin-induced apoptosis in human cervical cancer HeLa cells

The function of calcium efflux from the endoplasmic reticulum (ER) in cisplatin-induced apoptosis is not fully understood in cancer cells. The present study used western blot analysis, flow cytometry, immunofluorescence and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay to investigate calcium signaling in human cervical cancer cells exposed to cisplatin. In the present study, treatment with cisplatin increased free Ca²⁺ levels in the cytoplasm and mitochondria of human cervical cancer HeLa cells, which further triggers the mitochondria-mediated and ER stress-associated apoptosis pathways. Notably, blocking calcium signaling using the calcium chelating agent bis-(o-aminophenoxy)ethane-N,N,N',N'-tetra-acetic acid acetoxymethyl ester inhibited cisplatin-induced apoptosis via downregulation of the calcium-dependent proteases, the calpains, and innate apoptosis proteins, such as caspsae-3, caspase-4 and C/EBP homologous protein (CHOP). In addition, use of the inositol triphosphate receptor inhibitor, 2-aminoethyl diphenylborinate, to inhibit calcium efflux from the ER resulted in similar effects. This data indicated that calcium efflux from the ER plays a significant role in cisplatin-induced apoptosis in human cervical cancer HeLa cells, which provides further mechanistic insights into the tumor cell-killing effect of cisplatin and potential therapeutic strategies to improve cisplatin chemotherapy.

Nicotine Inhibits Cisplatin-Induced Apoptosis via Regulating α5-nAChR/AKT Signaling in Human Gastric Cancer Cells

Gastric cancer incidence demonstrates a strong etiologic association with smoking. Nicotine, the major component in tobacco, is a survival agonist that inhibits apoptosis induced by certain chemotherapeutic agents, but the precise mechanisms involved remain largely unknown. Recently studies have indicated that α5-nicotinic acetylcholine receptor (α5-nAChR) is highly associated with lung cancer risk and nicotine dependence. Nevertheless, no information has been available about whether nicotine also affects proliferation of human gastric cancer cells through regulation of α5-nAChR. To evaluate the hypothesis that α5-nAChR may play a role in gastric cancer, we investigated its expression in gastric cancer tissues and cell lines. The expression of α5-nAChR increased in gastric cancer tissue compared with para-carcinoma tissues. In view of the results, we proceeded to investigate whether nicotine inhibits cisplatin-induced apoptosis via regulating α5-nAChR in gastric cancer cell. The results showed that nicotine significantly promoted cell proliferation in a dose and time-dependent manner through α5-nAChR activation in human gastric cells. Furthermore, nicotine inhibited apoptosis induced by cisplatin. Silence of α5-nAChR ablated the protective effects of nicotine. However, when co-administrating LY294002, an inhibitor of PI3K/AKT pathway, an increased apoptosis was observed. This effect correlated with the induction of Bcl-2, Bax, Survivin and Caspase-3 by nicotine in gastric cell lines. These results suggest that exposure to nicotine might negatively impact the apoptotic potential of chemotherapeutic drugs and that α5-nAChR/AKT signaling plays a key role in the anti-apoptotic activity of nicotine induced by cisplatin.

It's never too late: Smoking cessation after stereotactic body radiation therapy for non-small cell lung carcinoma improves overall survival

PURPOSE

As stereotactic body radiation therapy (SBRT) has emerged as a quick, effective, and well-tolerated treatment for early stage non-small cell lung carcinoma (NSCLC), it can be difficult to convince patients to quit smoking in follow-up. We evaluated whether there was a survival benefit to smoking cessation after SBRT.

METHODS AND MATERIALS

Patients with early-stage NSCLC treated from 2004 to 2013 who were still smoking tobacco at the time of SBRT were identified from a prospective institutional review board-approved registry. Peripheral tumors were treated to 54 Gy in 3 fractions and central tumors to 50 Gy in 5 fractions. Patients were reviewed for overall survival (OS) and disease progression. The log-rank and Cox regression tests were used to identify factors predictive of OS.

RESULTS

Thirty-two patients (27%) quit smoking after SBRT, and 87 (73%) continued smoking. Median follow-up was 22 months (range, 2-87). On multivariate analysis, smoking status (hazard ratio, 2.1; 95% confidence interval, 1.02-4.2; P = .045), increasing age-adjusted Charlson comorbidity score and larger tumor size were predictive of worse OS. The prior number of cigarette pack-years was not significant (P = .62). In a Kaplan-Meier comparison, smoking cessation after SBRT was associated with improved 2-year OS, 78% versus 69% (P = .014). There was no significant difference in 2-year progression-free survival (75% vs 55%, P = .23) or local control (97% vs 88%, P = .63).

CONCLUSION

OS is significantly improved in patients who stop smoking after SBRT for early-stage NSCLC, no matter their previous smoking history. Encouraging smoking cessation should be an important part of every posttreatment visit.

Nicotine mediates expression of genes related to antioxidant capacity and oxidative stress response in HIV-1 transgenic rat brain

Oxidative stress plays an important role in the progression of HIV-1 infection. Nicotine can either protect neurons from neurodegeneration or induce oxidative stress, depending on its dose and degree of oxidative stress impairment. However, the relationship between nicotine and oxidative stress in the HIV-1-infected individuals remains largely unknown. The purpose of this study was to determine the effect of nicotine on expression of genes related to the glutathione (GSH)-centered antioxidant system and oxidative stress in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of HIV-1 transgenic (HIV-1Tg) and F344 control rats. Adult HIV-1Tg and F344 rats received nicotine (0.4 mg/kg, base, s.c.) or saline injections once per day for 27 days. At the end of treatment, various brain regions including the NAc and VTA were collected from each rat. Following total RNA extraction and complementary DNA (cDNA) synthesis of each sample, quantitative reverse transcription PCR (RT-PCR) analysis was performed for 43 oxidative-stress-related genes. Compared with F344 control rats, HIV-1Tg rats showed a significant downregulation of genes involved in ATPase and cyctochrome oxidase at the messenger RNA (mRNA) level in both regions. Further, we found a significant downregulation of Gstm5 in the NAc and upregulation of Cox1, Cox3, and Gsta6 in the VTA of HIV-1Tg rats. HIV-1Tg rats showed brain-region-specific responses to chronic nicotine treatment. This response resulted in a change in the expression of genes involved in antioxidant mechanisms including the downregulation of genes such as Atp5h, Calml1, Gpx7, Gstm5, Gsr, and Gsta6 and upregulation of Sod1 in the NAc, as well as downregulation of genes like Cox5a, Gpx4, Gpx6, Gpx7, Gstm5, and Sod1 in the VTA of HIV-1Tg rats. Together, we conclude that chronic nicotine treatment has a dual effect on the antioxidant defense system and oxidative-stress-induced apoptosis signaling in HIV-1Tg rats. These findings suggest that nicotine has a negative effect on response to oxidative stress and antioxidant processes in HIV-1 Tg rat brain, especially in the VTA.

Nicotine Induces Tumor Growth and Chemoresistance through Activation of the PI3K/Akt/mTOR Pathway in Bladder Cancer

Continued smoking is highly associated with not only a higher incidence but also greater risk of tumor recurrence, progression, and acquired chemoresistance of urothelial carcinoma. We investigated whether nicotine affects urothelial carcinoma, and the detailed mechanism by which nicotine could induce tumor growth and any associated chemoresistance. Cell viability was evaluated in the human bladder cancer cell line T24 exposed to nicotine with or without cisplatin (CDDP) and NVP-BEZ235 as a PI3K/mTOR dual inhibitor by the WST-1 assay. Protein expression of the PI3K/Akt/mTOR pathway was investigated by Western blotting or immunohistochemical analysis. The influence of nicotine on tumor growth was also evaluated with or without CDDP and/or NVP-BEZ235 in a subcutaneous bladder tumor model. The result demonstrated that cell proliferation was increased in T24 cells after exposure to nicotine. Phospho-specific Akt (pAkt) and phospho-specific p70 S6 kinase (pS6) were significantly upregulated by nicotine exposure. Tumor growth in vivo was significantly induced by nicotine exposure in accordance with increased pS6 expression. Nicotine attenuated inhibition of T24 cell growth by CDDP and further upregulated pS6 expression in vitro and in vivo. NVP-BZE235 inhibited T24 cell proliferation and pAkt and pS6 expression induced after exposure to nicotine and/or CDDP. In conclusion, nicotine increases tumor growth and induces acquired chemoresistance through activation of the PI3K/Akt/mTOR pathway in bladder cancer.

Mechanisms of tumor-promoting activities of nicotine in lung cancer: synergistic effects of cell membrane and mitochondrial nicotinic acetylcholine receptors

Background

One of the major controversies of contemporary medicine is created by an increased consumption of nicotine and growing evidence of its connection to cancer, which urges elucidation of the molecular mechanisms of oncogenic effects of inhaled nicotine. Current research indicates that nicotinergic regulation of cell survival and death is more complex than originally thought, because it involves signals emanating from both cell membrane (cm)- and mitochondrial (mt)-nicotinic acetylcholine receptors (nAChRs). In this study, we elaborated on the novel concept linking cm-nAChRs to growth promotion of lung cancer cells through cooperation with the growth factor signaling, and mt-nAChRs — to inhibition of intrinsic apoptosis through prevention of opening of mitochondrial permeability transition pore (mPTP).

Methods

Experiments were performed with normal human lobar bronchial epithelial cells, the lung squamous cell carcinoma line SW900, and intact and NNK-transformed immortalized human bronchial cell line BEP2D.

Results

We demonstrated that the growth-promoting effect of nicotine mediated by activation of α7 cm-nAChR synergizes mainly with that of epidermal growth factor (EGF), α3 — vascular endothelial growth factor (VEGF), α4 — insulin-like growth factor I (IGF-I) and VEGF, whereas α9 with EGF, IGF-I and VEGF. We also established the ligand-binding abilities of mt-nAChRs and demonstrated that quantity of the mt-nAChRs coupled to inhibition of mPTP opening increases upon malignant transformation.

Conclusions

These results indicated that the biological sum of simultaneous activation of cm- and mt-nAChRs produces a combination of growth-promoting and anti-apoptotic signals that implement the tumor-promoting action of nicotine on lung cells. Therefore, nAChRs may be a promising molecular target to arrest lung cancer progression and re-open mitochondrial apoptotic pathways.

Effects of cigarette smoking on metabolism and effectiveness of systemic therapy for lung cancer

INTRODUCTION

Cigarette smoke associated polycyclic aromatic hydrocarbons can induce key drug-metabolizing enzymes of cytochrome P450 and isoforms of the glucuronyl transferases families. These enzymes metabolize several systemic therapies for lung cancer. Induction of these enzymes may lead to accelerated clearance with resultant impact on systemic therapy efficacy and toxicity in smokers compared with nonsmokers. This article reviews published literature regarding the influence of smoking as it relates to alteration of metabolism of systemic therapy in lung cancer.

METHODS

A structured search of the National Library of Medicine's PubMed/MEDLINE identified relevant articles. Data were abstracted and analyzed to summarize the findings.

RESULTS

Studies that analyzed pharmacokinetic data were prospective. Smokers receiving erlotinib exhibited rapid clearance, requiring a higher dose to reach equivalent systemic exposure compared with nonsmokers. Smokers receiving irinotecan also demonstrated increased clearance and lower systemic exposure. There was no difference in clearance of paclitaxel or docetaxel in smokers. Chemotherapy-associated neutropenia was worse in nonsmokers compared with smokers in patients treated with paclitaxel, docetaxel, irinotecan, and gemcitabine.

CONCLUSIONS

Systemic therapy for lung cancer has a narrow therapeutic index such that small changes in plasma concentrations or exposure in smokers may result in suboptimal therapy and poor outcomes. Smoking cessation must be emphasized at each clinical visit. However, prospective trials should take into consideration the effects of smoking history on drug pharmacokinetics and efficacy. The metabolizing enzyme phenotype in smokers may require individualized dose algorithms for specific agents.

Post-operative smoking status in lung and head and neck cancer patients: association with depressive symptomatology, pain, and fatigue

OBJECTIVE

An estimated 35-50% of lung and head and neck cancer patients are smoking at diagnosis; most try to quit; however, a substantial proportion resumes smoking. As cancer treatments improve, attention to the effects of continued smoking on quality of life in the survivorship period is increasing. The current study examines if smoking abstinence following surgical treatment is associated with better quality of life.

METHODS

Participants were 134 patients with head and neck or lung cancer who received surgical treatment. Smoking status and indices of quality of life (depressive symptoms, fatigue, and pain) were assessed at the time of surgery (baseline) and at 2, 4, 6, and 12 months post-surgery. Analyses were performed using a generalized estimating equations approach. A series of models examined the correlation between smoking status and post-surgery quality of life while adjusting for demographics, clinical variables, and baseline smoking status and quality of life.

RESULTS

Continuous post-surgery abstinence was associated with lower levels of depressive symptoms and fatigue; however, the relationship with fatigue became nonsignificant after adjusting for baseline fatigue and income. There was no significant relationship observed between smoking status and pain.

CONCLUSIONS

Findings add to a growing literature showing that smoking cessation is not associated with detrimental effects on quality of life and may have beneficial effects, particularly with regard to depressive symptoms. Such information can be used to motivate smoking cessation and continued abstinence among cancer patients and increase provider comfort in recommending cessation.

Oxymatrine induces mitochondria dependent apoptosis in human osteosarcoma MNNG/HOS cells through inhibition of PI3K/Akt pathway

The cytostatic drug from traditional Chinese medicinal herb has acted as a chemotherapeutic agent used in treatment of a wide variety of cancers. Oxymatrine, classified as a quinolizidine alkaloid, is a phytochemical product derived from Sophora flavescens, and has been reported to possess anticancer activities. However, the cancer growth inhibitory effects and molecular mechanisms in human osteosarcoma MNNG/HOS cell have not been well studied. In the present study, the cytotoxic effects of oxymatrine on MNNG/HOS cells were examined by MTT and bromodeoxyuridine (BrdU) incorporation assays. The percentage of apoptotic cells and the level of mitochondrial membrane potential (Δψ m) were assayed by flow cytometry. The levels of apoptosis-related proteins were measured by Western blot analysis or enzyme assay Kit. Our results showed that treatment with oxymatrine resulted in a significant inhibition of cell proliferation and DNA synthesis in a dose-dependent manner, which has been attributed to apoptosis. Furthermore, we found that oxymatrine considerably inhibited the expression of Bcl-2 whilst increasing that of Bax. This promoted mitochondrial dysfunction, leading to the release of cytochrome c from the mitochondria to the cytoplasm, as well as the activation of caspase-9 and -3. Moreover, addition of oxymatrine to MNNG/HOS cells also attenuated phosphatidylinositol 3-kinase (PI3K) ⁄Akt signaling pathway cascade, evidenced by the dephosphorylation of P13K and Akt. Likewise, oxymatrine significantly suppressed tumor growth in female BALB/C nude mice bearing MNNG/HOS xenograft tumors. In addition, no evidence of drug-related toxicity was identified in the treated animals by comparing the body weight increase and mortality. Therefore, these findings should be useful for understanding the apoptotic cellular mechanism mediated by oxymatrine and might offer a therapeutic potential advantage for human osteosarcoma chemoprevention or chemotherapy.