Polymorphisms of CHRNA3 and CHRNA5: Head and neck cancer and cigarette consumption intensity in a Brazilian population

The expression of nicotinic acetylcholine receptor subunits and their associations with local immune cells and prognosis in oral squamous cell carcinoma

BACKGROUND

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels that may be responsible for cancer cell proliferation, epithelial-mesenchymal transition (EMT), and immune regulation. However, little is known about the associations of different nAChR subunits with tumor microenvironment in oral squamous cell carcinoma (OSCC).

METHODS

We retrospectively reviewed pathology samples from 75 OSCC patients by immunohistochemistry. In addition, a cohort of 307 OSCC patients in The Cancer Genome Atlas was analyzed.

RESULTS

Subunit α1 was specific to peri-OSCC skeletal muscle. Increased α1 was associated with increased CD44 (cancer stem cells), increased CD3 and 8 (T cells), increased CD56 and 16 (natural killer cells), a decreased T stage, and an increased N stage. Increased α3 was associated with increased CD56 and 16. Increased α5 was associated with decreased CD3, 8, and 56, a decreased T stage, an increased N stage, worse survival, and decreased epithelial features. Increased α7 was associated with increased CD3, 8, 56, and 16, decreased tumor/peritumor ratios of CD3, 8, and 56 immune cells, and increased epithelial features. Increased local immune cells were associated with a better prognosis.

CONCLUSIONS

α5 is the only subunit associated with decreased local immune cells and worse survival, while α1, α3, and α7 are associated with increased local immune cells in OSCC. α5 and α7 are correlated with different EMT states to be mesenchymal-like and epithelial-like OSCC, respectively. Protein expression data of the nAChR subunits, complementary to gene expression data, could provide meaningful information regarding the EMT status of OSCC associated with immune responses and prognosis.

Comprehensive analysis to identify the neurotransmitter receptor-related genes as prognostic and therapeutic biomarkers in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is a highly heterogeneous disease with high morbidity and mortality, which accounts for the fourth most common cause of cancer-related deaths. Reports suggest that the neurotransmitter receptor-related genes (NRGs) may influence the tumor microenvironment and the prognosis of patients with HCC.

Methods: The clinical information and RNA-seq data of patients with HCC were acquired from the ICGC-LIRI-JP dataset and the TCGA-LIHC dataset. Effects of 115 NRGs on the prognosis of HCC patients were analyzed in the ICGC-LIRI-JP dataset. The least absolute shrinkage and selection operator (LASSO) regression model was utilized to generate a risk score formula based on the critical NRGs. Next, the risk score effectiveness was validated both in the TCGA-LIHC dataset and in our clinical HCC samples. Based on the risk scores, patients with HCC were divided into two groups. Moreover, differentially expressed genes (DEGs) were screened. The gene ontology (GO) was used to analyze the functional enrichments of DEGs and to identify potential signaling pathways. To test the diagnostic effectiveness of our model, the receiver operator characteristic curve (ROC) analysis and nomogram were used. Finally, potential targeted drug prediction was performed based on DEGs of nine clinical HCC samples.

Results: Nine NRGs were correlated significantly with the prognosis of patients with HCC, and eight NRGs were successfully included in the LASSO regression model. The Kaplan-Meier analysis of overall survival (OS) suggested that patients in the high-risk score group had worse prognosis; on the other hand, ROC analysis revealed a high prognostic value of the risk score in HCC. Several critical signaling pathways, such as lipid metabolism, organic acid metabolism, cell migration, cell adhesion, and immune response, were enriched both in public datasets and clinical samples. Nomogram results also suggested that the risk scores correlated well with the patients’ prognosis. Potential targeted drugs prediction revealed that tubulin inhibitors might be the promising drugs for patients with HCC who have high risk scores based on the NRGs.

Conclusion: We established a prognostic model based on critical NRGs. NRGs show a promising prognostic prediction value in HCC and are potential therapeutic targets for the disease treatment.

Identification of the Nerve-Cancer Cross-Talk-Related Prognostic Gene Model in Head and Neck Squamous Cell Carcinoma

The incidence of head and neck squamous cell carcinoma (HNSC) is increasing year by year. The nerve is an important component of the tumor microenvironment, which has a wide range of cross-talk with tumor cells and immune cells, especially in highly innervated organs, such as head and neck cancer and pancreatic cancer. However, the role of cancer-nerve cross-talk-related genes (NCCGs) in HNSC is unclear. In our study, we constructed a prognostic model based on genes with prognostic value in NCCGs. We used Pearson’s correlation to analyze the relationship between NCCGs and immune infiltration, microsatellite instability, tumor mutation burden, drug sensitivity, and clinical stage. We used single-cell sequencing data to analyze the expression of genes associated with stage in different cells and explored the possible pathways affected by these genes via gene set enrichment analysis. In the TCGA-HNSC cohort, a total of 23 genes were up- or downregulated compared with normal tissues. GO and KEGG pathway analysis suggested that NCCGs are mainly concentrated in membrane potential regulation, chemical synapse, axon formation, and neuroreceptor-ligand interaction. Ten genes were identified as prognosis genes by Kaplan-Meier plotter and used as candidate genes for LASSO regression. We constructed a seven-gene prognostic model (NTRK1, L1CAM, GRIN3A, CHRNA5, CHRNA6, CHRNB4, CHRND). The model could effectively predict the 1-, 3-, and 5-year survival rates in the TCGA-HNSC cohort, and the effectiveness of the model was verified by external test data. The genes included in the model were significantly correlated with immune infiltration, microsatellite instability, tumor mutation burden, drug sensitivity, and clinical stage. Single-cell sequencing data of HNSC showed that CHRNB4 was mainly expressed in tumor cells, and multiple metabolic pathways were enriched in high CHRNB4 expression tumor cells. In summary, we used comprehensive bioinformatics analysis to construct a prognostic gene model and revealed the potential of NCCGs as therapeutic targets and prognostic biomarkers in HNSC.

The CHRNA5 Polymorphism (rs16969968) and its Association with Waterpipe Smoking Addiction among Jordanians

Waterpipe smoking is a form of tobacco use that causes nicotine/tobacco dependence and has become a global health problem. In the current study, the association of rs16969968 SNP in the CHRNA5 gene with waterpipe dependence was investigated. A total of 386 men and women who used a waterpipe to smoke tobacco were recruited and divided into less dependent and more dependent smokers based on their score on the Lebanon Waterpipe Dependence Scale (LWDS). Results showed a significant difference in the distribution of GG, GA, and AA genotypes by waterpipe dependence status (P<0.001). The more dependent group showed a higher frequency of the AA genotype than the less dependent smokers' group (38% versus 23% respectively). In addition, the more dependent smokers exhibited more A allele than less dependent smokers (53% versus 37% respectively, P<0.001). In conclusion, there is an association between the rs16969968 SNP and waterpipe dependence as assessed by the LWDS.

Polymorphisms of CHRNA3 and CHRNA5: Head and neck cancer and cigarette consumption intensity in a Brazilian population

Background

Cigarette consumption has been identified as the main non‐etiological factor in head and neck cancer (HNC) development. One of the main compounds in cigarettes is nicotine, which binds directly to nicotine acetylcholine receptors (nAchRs) in the body, which are encoded by different genes of the CHRNA family. Polymorphisms in some of these genes have been studied in relation to the risk of HNC and cigarette consumption intensity. The aim of this study was to evaluate whether there were associations between the CHRNA3 (rs578776) and CHRNA5 (rs16969968) polymorphisms and HNC risk and between the polymorphisms and the intensity of cigarette consumption.

Methods

A total of 1,067 individuals from Heliopolis Hospital in São Paulo were investigated, including 619 patients with HNC and 448 patients without diagnosed tumors. All participants answered a questionnaire about sociodemographic information and cigarette consumption data. The polymorphisms were determined by TaqMan genotyping by real‐time PCR.

Results

The polymorphisms studied, rs578776 (CHRNA3) and rs16969968 (CHRNA5), did not have an association with HNC risk, but the rs16969968 homozygous genotype was associated with increased cigarette consumption intensity (OR 1.93, 95% CI 1.05–3.58).

Conclusion

The polymorphism CHRNA5 can be considered an indirect risk factor for neoplasms in these Brazilian samples when cigarette consumption increased.