Tobacco Smoking-Associated Alterations in the Immune Microenvironment of Squamous Cell Carcinomas

The Expression and Effection of MicroRNA-499a in High-Tobacco Exposed Head and Neck Squamous Cell Carcinoma: A Bioinformatic Analysis

Background: Few studies have directly investigated the differential expression of microRNAs (miRNAs) in head and neck squamous cell carcinoma (HNSCC) with low, medium, and high tobacco exposure. The purpose of this study is to screen the differentially expressed miRNAs and to investigate their clinical significance and potential biological mechanisms in the three groups of HNSCC.

Methods: The datasets of HNSCC were obtained from The Cancer Genome Atlas (TCGA). The edgeR package was used to determine differentially expressed miRNAs and genes among the three groups of HNSCC. Statistical methods were applied to assess the clinical significance of miRNA and its correlation with genes. The correlation between gene expression and clinical characteristics was analyzed using weighted gene co-expression network analysis (WGCNA). Three online databases were used to predict the target genes of miRNAs. More importantly, qRT-PCR was employed to verify the differential expression of miRNAs and genes in our patients.

Results: 32 differentially expressed miRNAs and 1,820 differentially expressed genes were found among the three groups of HNSCC. Patients with high expression of hsa-miR-499a had lower overall survival than the ones with low expression in high-tobacco exposed HNSCC. Cox regression analysis found that high expression of hsa-miR-499a and female were independent risk factors for prognosis in high-tobacco exposed HNSCC. Chi-square test found that hsa-miR-499a was associated with N stage in high-tobacco exposed HNSCC. WGCNA identified four gene modules associated with N stage in high-tobacco exposed HNSCC. Then three online databases were used to predict potential target genes for hsa-miR-499a, which were AEBP2 and ZNRF1. Pearson correlation analysis showed that hsa-miR-499a was negatively correlated with AEBP2 and ZNRF1. qRT-PCR supported bioinformatic results that hsa-miR-499a, AEBP2, and ZNRF1 were differentially expressed among the three groups of HNSCC in our patients.

Conclusion: 32 differentially expressed miRNAs and 1,820 differentially expressed genes were successfully identified in HNSCC with low, medium, and high tobacco exposure. The patients with high expression of hsa-miR-499a had poor prognoses compared with patients with low expression in high-tobacco exposed HNSCC. Hsa-miR-499a was associated with N stage in high-tobacco exposed HNSCC. AEBP2 and ZNRF1 were the potential target genes of hsa-miR-499a.

Association of two BRM promoter polymorphisms and smoking status with malignant pleural mesothelioma risk and prognosis

Brahma (BRM), of the SWI/SNF complex, has two 6 to 7 bp insertion promoter polymorphisms (BRM-741/BRM-1321) that cause epigenetic BRM suppression, and are associated with risk of multiple cancers. BRM polymorphisms were genotyped in malignant pleural mesothelioma (MPM) cases and asbestos-exposed controls. Multivariable logistic regression (risk) and Cox regression (prognosis) were performed, including stratified analyses by smoking status to investigate the effect of polymorphisms on MPM risk and prognosis. Although there was no significant association overall between BRM-741/BRM-1321 and risk in patients with MPM, a differential effect by smoking status was observed (P-interaction < .001), where homozygous variants were protective (aOR of 0.18-0.28) in ever smokers, while never smokers had increased risk when carrying homozygous variants (aOR of 2.7-4.4). While there was no association between BRM polymorphisms and OS in ever-smokers, the aHR of carrying homozygous-variants of BRM-741, BRM-1321 or both were 4.0 to 8.6 in never-smokers when compared to wild-type carriers. Mechanistically, lower mRNA expression of BRM was associated with poorer general cancer prognosis. Electrophoretic mobility shift assays and chromatin immunoprecipitation experiments (ChIP) revealed high BRM insertion variant homology to MEF2 regulatory binding sites. ChIP experimentation confirmed MEF2 binding only occurs in the presence of insertion variants. DNA-affinity purification assays revealed YWHA scaffold proteins as vital to BRM mRNA expression. Never-smokers who carry BRM homozygous variants have an increased chance of developing MPM, which results in worse prognosis. In contrast, in ever-smokers, there may be a protective effect, with no difference in overall survival. Mechanisms for the interaction between BRM and smoking require further study.

Association Between Smoking and Survival Benefit of Immunotherapy in Advanced Malignancies: A Systematic Review and Meta-Analysis

OBJECTIVES

Smoking is associated with an increased tumor mutational burden. As tumor mutational burden has been shown to correlate with response to immunotherapy (IO), we hypothesized that a history of smoking may be associated with better response to IO.

METHODS

We utilized a systematic review with stratified meta-analysis of randomized clinical trials of IO versus standard of care in patients with advanced solid organ malignancies.

RESULTS

Among 9 relevant studies, we found no significant difference in the benefit of IO, compared with other systemic therapies, between ever smokers (hazard ratio [HR], 0.77; 95% confidence interval [CI], 0.58-1.04; P=0.09) and never smokers (HR, 0.75; 95% CI, 0.67-0.86; P<0.0001) (test for difference P=0.83). We also observed no significant difference between current (HR, 0.92; 95% CI, 0.63-1.34; P=0.66; I=67%) and never smokers (HR, 0.74; 95% CI, 0.59-0.93; P=0.01; I=46%) (test for difference P=0.35).

CONCLUSIONS

Stratified meta-analysis demonstrates that smoking status is not significantly associated with the response to IO in the treatment of advanced solid organ malignancies.

Smoking history influences the prognostic value of peripheral naïve CD4+ T cells in advanced non-small cell lung cancer

Background

Considering the effect of smoking on tumor immunity, we attempted to investigate the impact of smoking history on the prognostic value of circulating naïve and memory CD4+ and CD8+ T cells in advanced non-small cell lung cancer (NSCLC) treated with chemo(radio)therapy.

Methods

Of 196 histologically confirmed advanced NSCLC, 98 eligible ones were enrolled. Naïve and memory CD4+ and CD8+ T cells from peripheral blood were measured by flow cytometry. Kaplan-Meier curves helped estimate patients' survival. The uni- and multivariate Cox proportional hazards regression model was employed in the assessment of the prognostic value of factors.

Results

Multivariate survival analyses showed that peripheral naïve CD4+ T cells independently predicted favorable overall survival (OS) in ever smokers with advanced NSCLC (P = 0.007), but unfavorable OS in never smokers with the same ailment (P = 0.012). Ever smokers presented a different distribution of naïve and memory T cells: low expression levels of naïve CD4+ T (P = 0.005), naïve CD8+ T (P = 0.031), CD4+ naïve/memory ratio (P = 0.020), and CD8+ naïve/memory ratio (P = 0.019), and high distributions of memory CD4 + T (P = 0.004), memory CD8 + T (P = 0.034), and naïve CD8/CD4 ratio (P = 0.020), when compared to never smokers.

Conclusions

We revealed the impact of cigarette-smoking on peripheral naïve CD4+ T cells' prognostic value in advanced NSCLC patients. These results could help in refining personalized treatment for advanced NSCLC patients.

Immunomodulatory and immunotherapeutic implications of tobacco smoking in squamous cell carcinomas and normal airway epithelium

The mutagenic effects of tobacco smoking increase the risk of the development of cancers of the lung, head and neck, and other anatomic sites. In a comparison of squamous cell carcinomas of the lung and the head and neck, we find that the immunomodulatory effects of smoking differ based on anatomic site. In both sites, the mutational signature of smoking is strongly associated with somatic mutational load. In head and neck squamous cell carcinoma, the mutational signature of tobacco exposure is associated with a strongly immunosuppressive tumor microenvironment. In contrast, in lung squamous cell carcinoma, the opposite effect is seen, with the tumor immune microenvironment significantly more inflamed. These effects are mirrored in rates of response to immune checkpoint inhibitor immunotherapy, which tend to be higher in smokers with lung cancer, but lower in smokers with head and neck cancer. We find a similarly strong immunosuppressive effect of smoking in non-cancerous lung epithelium. Taken together, our findings show that the effects of mutational signatures on the immune microenvironment and response to immunotherapy can be affected by context such as cancer type, anatomic site, and histology.

Prognostic Score Predicts Survival in HPV-Negative Head and Neck Squamous Cell Cancer Patients

Although patients having head and neck squamous cell carcinoma (HNSCC) have high mortality, standardized prognostic tools are unavailable. As such, having a validated simple prognostic scoring system to help predict mortality in these high-risk patients is urgently needed. The current study aimed to develop and internally validate a prognostic scoring system for overall mortality in human papillomavirus (HPV)-independent HNSCC patients. Data on 400 consecutive patients from the Cancer Genome Atlas database with a known HPV-RNA negative status were analyzed. A prognostic model to predict patient overall mortality was developed using the logistic regression beta coefficients and a simple risk score was created. The model was internally validated using bootstrap validation with 2000 replications. Five covariates (age, pT, pN, perineural invasion, and EAp53 score) were used in the development of the mortality risk score in the final model. Three risk groups were stratified based on the prognostic scores: low-risk (<96 points), medium-risk (96-121 points), and high-risk (≥122 points) with a survival of 76%, 62% and 35%, respectively. The proposed model presented good discrimination in both the development (AUC = 0.76; 95% CI 0.70, 0.81) and bootstrap validation (AUC = 0.76; 95% CI 0.70, 0.81) with a non-significant Hosmer-Lemeshow chi-square of 6.17 (p = 0.63). The proposed prognostic scoring system is easy to use to predict patient overall mortality and could also help in the appropriate allocation of medical resources while managing HNSCC patients. External validation (including re-calibration if needed) should be conducted to test the model's generalizability in different populations.

Resectable lung lesions malignancy assessment and cancer detection by ultra-deep sequencing of targeted gene mutations in plasma cell-free DNA

Background

Early detection of lung cancer to allow curative treatment remains challenging. Cell-free circulating tumour (ct) DNA (ctDNA) analysis may aid in malignancy assessment and early cancer diagnosis of lung nodules found in screening imagery.

Methods

The multicentre clinical study enrolled 192 patients with operable occupying lung diseases. Plasma ctDNA, white cell count genomic DNA (gDNA) and tumour tissue gDNA of each patient were analysed by ultra-deep sequencing to an average of 35 000× of the coding regions of 65 lung cancer-related genes.

Results

The cohort consists of a quarter of benign lung diseases and three quarters of cancer patients with all histopathology subtypes. 64% of the cancer patients are at stage I. Gene mutations detection in tissue gDNA and plasma ctDNA results in a sensitivity of 91% and specificity of 88%. When ctDNA assay was used as the test, the sensitivity was 69% and specificity 96%. As for the lung cancer patients, the assay detected 63%, 83%, 94% and 100%, for stages I, II, III and IV, respectively. In a linear discriminant analysis, combination of ctDNA, patient age and a panel of serum biomarkers boosted the overall sensitivity to 80% at a specificity of 99%. 29 out of the 65 genes harboured mutations in the patients with lung cancer with the largest number found in TP53 (30% plasma and 62% tumour tissue samples) and EGFR (20% and 40%, respectively).

Conclusion

Plasma ctDNA was analysed in lung nodule assessment and early cancer detection, while an algorithm combining clinical information enhanced the test performance.

Trial registration number

NCT03081741.

The Need to Prioritize and Re-prioritize Palliative Care Options: Smoking Cessation as a Case-in-Point

OPINION STATEMENT

Palliative care in cancer patients requires a continuous reprioritization of effort. This review describes the need for this reprioritization and uses smoking cessation as a case-in-point. The treatment of patients with metastatic non-small cell lung cancer has changed dramatically in the past few years. Interestingly, patients who had previously smoked now have an improved prognosis-for a variety of reasons. This review discusses this last observation in detail and raises the question of how forcefully we should advise smoking cessation in patients with incurable metastatic non-small cell lung cancer.

Effect of the thymine-DNA glycosylase rs4135050 variant on Saudi smoker population

Background

Thymine‐DNA glycosylase (TDG) is an essential DNA‐repair enzyme which works in both epigenetic regulation and genome maintenance. It is also responsible for efficient correction of multiple endogenous DNA lesions which occur commonly in mammalian genomes. Research of genetic variants such as SNPs, resulting in disease, is predicted to yield clinical advancements through the identification of sensitive genetic markers and the development of disease prevention and therapy. To that end, the main objective of the present study is to identify the possible interactions between cigarette smoking and the rs4135050 variant of the TDG gene, situated in the intron position, among Saudi individuals.

Methods

TDG rs4135050 (A/T) was investigated by genotyping 239, and 235 blood specimens were obtained from nonsmokers and smokers of cigarette respectively.

Results

T allele frequency was found which showed a significant protective effect on Saudi male smokers (OR = 0.64, p = 0.0187) compared to nonsmoking subjects, but not in female smokers. Furthermore, smokers aged less than 29 years, the AT and AT+TT genotypes decreased more than four times the risk of initiation of smoking related‐diseases compare to the ancestral AA homozygous genotype. Paradoxically, the AT (OR = 3.88, p = 0.0169) and AT+TT (OR = 2.86, p = 0.0420) genotypes were present at a higher frequency in smoking patients aged more than 29 years as compared to nonsmokers at the same ages.

Conclusion

Depending on the gender and age of patients, TDG rs4135050 may provide a novel biomarker for the early diagnosis and prevention of several diseases caused by cigarette smoking.

TNFSF15 promoter polymorphisms increase the susceptibility to small cell lung cancer: a case-control study

BACKGROUND

Tumor necrosis factor superfamily member 15 (TNFSF15) is closely related to tumorigenesis and development. This study aimed to investigate the correlations between TNFSF15 polymorphisms and genetic susceptibility to lung cancer.

METHODS

This case-control study included 209 small cell lung cancer patients (SCLC), 340 non- small cell lung cancer patients (NSCLC) and 460 health controls. TNFSF15-638 A > G and - 358 T > C polymorphisms were genotyped by polymerase chain reaction-restrictive fragment length polymorphism (PCR-RFLP) analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were estimated by unconditional logistic regression.

RESULTS

Our results showed that subjects carrying the TNFSF15-638GG genotype or -358CC genotype were more likely to develop SCLC (-638GG, OR = 1.84, 95%CI = 1.13-2.99; -358CC, OR = 2.44, 95%CI = 1.46-4.06), but not NSCLC (P > 0.05). In stratified analysis, -638GG genotype was related to SCLC among males (OR = 1.95, 95%CI = 1.09-3.45, P = 0.023) and older patients (OR = 2.93, 95%CI = 1.44-8.68, P = 0.006). However, -358CC genotype was associated with SCLC among females (OR = 8.42, 95%CI = 2.22-31.89, P = 0.002) and older subjects with OR (95%CI) of 11.04 (3.57-34.15) (P < 0.001). Moreover, TNFSF15 -358CC was linked with a higher risk of SCLC among non-smokers (OR = 2.54, 95%CI = 1.20-5.35, P = 0.015) but not among smokers (OR = 1.88, 95%CI = 0.92-3.84, P = 0.086).

CONCLUSION

These findings highlight the importance of TNFSF15 polymorphisms in the development of SCLC.

Immune biomarkers of response to immune-checkpoint inhibitors in head and neck squamous cell carcinoma

Anti-programmed cell death protein 1 (PD-1) agents have become the standard of care for platinum-refractory recurrent/metastatic head and neck squamous cell carcinoma (HNSCC) and are currently being evaluated in various disease settings. However, despite the gain in overall survival seen in some of the clinical trials, the majority of patients display primary resistance and do not benefit from these agents. Taking into consideration the potentially severe immune-related toxicities and their high cost, the search for predictive biomarkers of response is crucial. Besides Programmed death ligand-1 (PD-L1) expression, other biomarkers such as immune infiltration, tumor mutational burden or immune-gene expression profiling have been explored, but none of them has been validated in this disease. Among these, the microbiota has recently garnered tremendous interest since it has proven to influence the efficacy of PD-1 blockade in some tumor types. With the accumulating evidence on the effect of the microbiota in HNSCC tumorigenesis and progression, the study of its potential role as a predictive immune biomarker is warranted. This review examines the available evidence on emerging immune predictive biomarkers of response to anti-PD-1/PD-L1 therapy in HNSCC, introducing the microbiota and its potential use as a predictive immune biomarker in this disease.

Comprehensive analysis of the tumor immune micro-environment in non-small cell lung cancer for efficacy of checkpoint inhibitor

Characterizing the molecular immune subtype and micro-environment of lung cancer is necessary to understand immunogenic interactions between infiltrating immune and stromal cells, and how tumor cells overcome immune checkpoint blockades. This study seeks to identify computational methodologies for subtyping gene expression-based tumor-immune micro-environment interactions, which differentiate non-small cell lung cancer (NSCLC) into immune-defective and immune-competent subtypes. Here, 101 lung squamous cell carcinomas (LUSCs) and 87 lung adenocarcinomas (LUADs) tumor samples have been analyzed. Several micro-environmental factors differentially induce LUAD or LUSC immune subtypes, as well as immune checkpoint expression. In particular, tumor-associated macrophages (TAMs) are key immune cells play a vital role in inflammation and cancer micro-environments of LUSCs; whereas, regulatory B cells are immunosuppressive and tumorigenic in LUADs. Additionally, cytolytic activity upon CD8⁺ T cell activation is decreased by the abundance of B cells and macrophages in immune-competent subtypes. Therefore, identifying immune subtypes in lung cancer and their impact on tumor micro-environment will lead to clinical tools for assessing LUADs and LUSCs in patients, as well as maximize the efficacy of immune checkpoint inhibitors.

CSF1R-Expressing Tumor-Associated Macrophages, Smoking and Survival in Lung Adenocarcinoma: Analyses Using Quantitative Phosphor-Integrated Dot Staining

CSF1R-expressing tumor-associated macrophages (TAMs) induce a tumor-promoting microenvironment by regulating immunity. Evidence demonstrates that the expression and single nucleotide polymorphisms of CSF1R relate with survival and risk of lung cancer in never smokers. However, no previous studies have examined the association of CSF1R expression in TAMs with mortality or whether the prognostic association differs according to smoking status in lung adenocarcinoma. Quantitative phosphor-integrated dot staining was used to precisely assess CSF1R expression in TAMs. Using 195 consecutive cases of lung adenocarcinoma, we examined the association of CSF1R expression with mortality and whether the prognostic association differs according to smoking status. We observed high expression levels of CSF1R in TAMs in 65 of 195 (33%) cases of lung adenocarcinoma. High expression levels of CSF1R were associated with high lung cancer-specific mortality (log-rank p = 0.037; hazard ratio (HR) = 1.61, 95% confidence interval (CI) = 1.02−2.52, p = 0.043). This prognostic association differed according to smoking status (p for interaction = 0.049, between never-smoking and ever-smoking patients). The association between high expression levels of CSF1R and lung cancer-specific mortality was stronger in never-smoking patients (log-rank p = 0.0027; HR = 2.90, 95% CI = 1.41−6.11, p = 0.0041) than in ever-smoking patients (log-rank p = 0.73; HR = 1.11, 95% CI = 0.59−2.00, p = 0.73). The findings suggest that CSF1R-expressing TAMs may exert stronger tumor-promoting immunity in never-smoking patients with lung adenocarcinoma and serve as a therapeutic target in precision immunotherapies.

Differential Effect of Smoking on Gene Expression in Head and Neck Cancer Patients

Smoking is a well-known behavior that has an important negative impact on human health, and is considered to be a significant factor related to the development and progression of head and neck squamous cell carcinomas (HNSCCs). Use of high-dimensional datasets to discern novel HNSCC driver genes related to smoking represents an important challenge. The Cancer Genome Atlas (TCGA) analysis was performed in three co-existing groups of HNSCC in order to assess whether gene expression landscape is affected by tobacco smoking, having quit, or non-smoking status. We identified a set of differentially expressed genes that discriminate between smokers and non-smokers or based on human papilloma virus (HPV)16 status, or the co-occurrence of these two exposome components in HNSCC. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways classification shows that most of the genes are specific to cellular metabolism, emphasizing metabolic detoxification pathways, metabolism of chemical carcinogenesis, or drug metabolism. In the case of HPV16-positive patients it has been demonstrated that the altered genes are related to cellular adhesion and inflammation. The correlation between smoking and the survival rate was not statistically significant. This emphasizes the importance of the complex environmental exposure and genetic factors in order to establish prevention assays and personalized care system for HNSCC, with the potential for being extended to other cancer types.

Inflammatory signatures of smoking

Smoking is associated with distinct pro- and anti-inflammatory signatures in squamous cell carcinomas of the lung and the head and neck.