Genetics of lung-cancer susceptibility

Prevalence of pathogenic or likely pathogenic germline variants in cancer predisposition genes among selected patients with lung adenocarcinoma: The GERMLUNG study

INTRODUCTION

Pathogenic or likely pathogenic germline variants (PGVs) in cancer predisposition genes may play a role in lung cancer (LC) susceptibility. However, determining an eligible population for genetic testing remains uncertain. This study aimed to assess the prevalence of PGVs in a selected cohort of individuals with lung adenocarcinoma.

METHODS

A cross-sectional cohort study was conducted to assess the PGVs rate in lung adenocarcinoma patients with a family history of LC, young-onset presentation, history of never/light smoking, or actionable genomic alterations (AGAs). Sequencing was performed using Sophia Hereditary Cancer Solution panel F, including 144 cancer predisposition genes. Variants classified as pathogenic or likely pathogenic were included for further analysis.

RESULTS

Of 201 patients, 43 (21.4 %) exhibited PGVs, among which 64.5 % were DNA damage repair genes, and 86.1 % were clinically actionable. The main PGVs were in ATM (9.3 %), TP53 (6.9 %), BRCA2 (6.9 %), and CHEK2 (6.9 %) genes. PGVs were associated with male sex (adjusted odds ratio [aOR] 2.46, 95 % CI 1.15-5.32, p = 0.021), along with a trend toward association with AGAs (aOR 6.04, 95 % CI 0.77-49.74, p = 0.094).

CONCLUSIONS

In this study, a high PGVs prevalence was identified based on our selection criteria, which represents an effective strategy to identify candidates for germline genomic testing, potential screening strategies in close relatives, and personalized therapeutic modalities. Our results warrant further exploration in other populations to confirm them.

Biological and therapeutic implications of the cancer-related germline mutation landscape in lung cancer

Although smoking is the primary cause of lung cancer, only about 15% of lifelong smokers develop the disease. Moreover, a substantial proportion of lung cancer cases occur in never-smokers, highlighting the potential role of inherited genetic factors in the cause of lung cancer. Lung cancer is significantly more common among those with a positive family history, especially for early-onset disease. Therefore, the presence of pathogenic germline variants might act synergistically with environmental factors. The incorporation of next-generation sequencing in routine clinical practice has led to the identification of cancer-predisposing mutations in an increasing proportion of patients with lung cancer. This Review summarises the landscape of germline susceptibility in lung cancer and highlights the importance of germline testing in patients diagnosed with the disease, which has the potential to identify individuals at risk, with implications for tailored therapeutic approaches and successful prevention through genetic counselling and screening.

Feasibility and safety of EGFR-TKI neoadjuvant therapy for EGFR-mutated NSCLC: A meta-analysis

BACKGROUND

The role of neoadjuvant epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) targeted therapy for EGFR-mutated non-small cell lung cancer (NSCLC) is unclear. Previous studies have shown that EGFR-TKIs have excellent anti-tumor activity. However, almost all studies on neoadjuvant EGFR-TKI treatment for EGFR-mutated NSCLC have been non-randomized controlled trials with small sample sizes and different methods of statistical analysis, which may lead to a lack of valid metrics to assess the feasibility and safety of neoadjuvant EGFR-TKI treatment. This meta-analysis aimed to assess the efficacy and safety of neoadjuvant EGFR-TKI treatment for NSCLC patients with EGFR mutations.

METHODS

Relevant studies were systematically searched in PubMed, Embase, and Web of Science databases. Results including objective response rate (ORR), complete resection rate (R0), downstaging rate, pathological complete response (PCR), major pathological response (MPR), progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were used for further analysis.

RESULTS

This meta-analysis ultimately included 11 studies involving 344 patients with EGFR-positive mutations in NSCLC. In terms of tumor response, the pooled ORR was 57% (95% CI: 42%-73%), and in the Osimertinib subgroup, the pooled ORR was 80% (95% CI: 63%-98%). Analysis of studies that reported a downstaging rate showed the pooled downstaging rate of 41% (95% CI: 9%-74%) and the pooled downstaging rate of 74% (95% CI: 22%-100%) in the Osimertinib subgroup. In terms of surgical outcomes, the pooled pCR rate was 3% (95% CI: 0%-7%), the pooled MPR rate was 11% (95% CI: 6%-17%), and the pooled R0 resection rate was 91% (95% CI: 85%-95%). The most common adverse events associated with neoadjuvant therapy were rash and diarrhea. The pooled incidence of any grade of rash was 47.1% (95% CI: 25.4%-69.3%), and the pooled incidence of grade ≥ 3 rash was 0.6% (95% CI: 0.0%-2.5%). The pooled incidence of diarrhea of any grade was 28.8% (95% CI: 14.4%-45.4%), with the pooled incidence of grade ≥ 3 diarrhea of 0.2% (95% CI: 0.0%-1.6%). The pooled incidence of ≥ grade 3 adverse events was significantly lower.

CONCLUSIONS

Our meta-analysis confirmed the efficacy and safety of neoadjuvant EGFR-TKIs for the treatment of NSCLC patients with EGFR-positive mutations and that third-generation EGFR-TKIs were superior to first- and second-generation EGFR-TKIs in terms of shrinking tumor volume and lowering tumor stage; however, future large-scale and multicenter randomized controlled trials are needed to confirm this conclusion.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023466731.

Two-phase designs with failure time processes subject to nonsusceptibility

Epidemiological studies based on 2-phase designs help ensure efficient use of limited resources in situations where certain covariates are prohibitively expensive to measure for a full cohort. Typically, these designs involve 2 steps: In phase I, data on an outcome and inexpensive covariates are acquired, and in phase II, a subsample is chosen in which the costly variable of interest is measured. For right-censored data, 2-phase designs have been primarily based on the Cox model. We develop efficient 2-phase design strategies for settings involving a fraction of long-term survivors due to nonsusceptibility. Using mixture models accommodating a nonsusceptible fraction, we consider 3 regression frameworks, including (a) a logistic "cure" model, (b) a proportional hazards model for those who are susceptible, and (c) regression models for susceptibility and failure time in those susceptible. Importantly, we introduce a novel class of bivariate residual-dependent designs to address the unique challenges presented in scenario (c), which involves 2 parameters of interest. Extensive simulation studies demonstrate the superiority of our approach over various phase II subsampling schemes. We illustrate the method through applications to the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial.

Conducting polymer composite-based biosensing materials for the diagnosis of lung cancer: A review

The development of a simple and fast cancer detection method is crucial since early diagnosis is a key factor in increasing survival rates for lung cancer patients. Among several diagnosis methods, the electrochemical sensor is the most promising one due to its outstanding performance, portability, real-time analysis, robustness, amenability, and cost-effectiveness. Conducting polymer (CP) composites have been frequently used to fabricate a robust sensor device, owing to their excellent physical and electrochemical properties as well as biocompatibility with nontoxic effects on the biological system. This review brings up a brief overview of the importance of electrochemical biosensors for the early detection of lung cancer, with a detailed discussion on the design and development of CP composite materials for biosensor applications. The review covers the electrochemical sensing of numerous lung cancer markers employing composite electrodes based on the conducting polyterthiophene, poly(3,4-ethylenedioxythiophene), polyaniline, polypyrrole, molecularly imprinted polymers, and others. In addition, a hybrid of the electrochemical biosensors and other techniques was highlighted. The outlook was also briefly discussed for the development of CP composite-based electrochemical biosensors for POC diagnostic devices.

Mendelian randomization analyses explore the relationship between cathepsins and lung cancer

Lung cancer, a major contributor to cancer-related fatalities worldwide, involves a complex pathogenesis. Cathepsins, lysosomal cysteine proteases, play roles in various physiological and pathological processes, including tumorigenesis. Observational studies have suggested an association between cathepsins and lung cancer. However, the causal link between the cathepsin family and lung cancer remains undetermined. This study employed Mendelian randomization analyses to investigate this causal association. The univariable Mendelian randomization analysis results indicate that elevated cathepsin H levels increase the overall risk of lung cancer, adenocarcinoma, and lung cancer among smokers. Conversely, reverse Mendelian randomization analyses suggest that squamous carcinoma may lead to increased cathepsin B levels. A multivariable analysis using nine cathepsins as covariates reveals that elevated cathepsin H levels lead to an increased overall risk of lung cancer, adenocarcinoma, and lung cancer in smokers. In conclusion, cathepsin H may serve as a marker for lung cancer, potentially inspiring directions in lung cancer diagnosis and treatment.

Mapping Multi-factor-mediated Chromatin Interactions to Assess Dysregulation of Lung Cancer-related Genes

Studies on the lung cancer genome are indispensable for developing a cure for lung cancer. Whole-genome resequencing, genome-wide association studies, and transcriptome sequencing have greatly improved our understanding of the cancer genome. However, dysregulation of long-range chromatin interactions in lung cancer remains poorly described. To better understand the three-dimensional (3D) genomic interaction features of the lung cancer genome, we used the A549 cell line as a model system and generated high-resolution chromatin interactions associated with RNA polymerase II (RNAPII), CCCTC-binding factor (CTCF), enhancer of zeste homolog 2 (EZH2), and histone 3 lysine 27 trimethylation (H3K27me3) using long-read chromatin interaction analysis by paired-end tag sequencing (ChIA-PET). Analysis showed that EZH2/H3K27me3-mediated interactions further repressed target genes, either through loops or domains, and their distributions along the genome were distinct from and complementary to those associated with RNAPII. Cancer-related genes were highly enriched with chromatin interactions, and chromatin interactions specific to the A549 cell line were associated with oncogenes and tumor suppressor genes, such as additional repressive interactions on FOXO4 and promoter-promoter interactions between NF1 and RNF135. Knockout of an anchor associated with chromatin interactions reversed the dysregulation of cancer-related genes, suggesting that chromatin interactions are essential for proper expression of lung cancer-related genes. These findings demonstrate the 3D landscape and gene regulatory relationships of the lung cancer genome.

Associations of biomarkers for exposure to tobacco smoke with lung cancer risk in Korea

BACKGROUND

Nicotine metabolite ratio (NMR) can be used to predict total nicotine clearance. However, it is unknown whether NMR could be used as a marker of lung cancer risk.

OBJECTIVE

To evaluate the blood metabolites of nicotine relating to the risk of developing lung cancer and investigate the combined effects of NMR and cigarette per day on the risk of lung cancer.

METHODS

Among the 1,054 eligible subjects from the Korean Cancer Prevention Study-II biobank cohort, those with cotinine values below 0 ng/ml were excluded. Slow and fast metabolizer groups were defined using the median value of the NMR, calculated with the control group data, as the cut-point.

RESULTS

The multivariable Cox proportional hazard models demonstrated that, the fast metabolizer group had a significantly higher risk of lung cancer than the slow metabolizer group (Adjusted HR: 2.02, 95% CI: 1.32-3.10). Fast metabolizers who smoked more than 15 cigarettes per day had an even higher risk of lung cancer (Adjusted HR: 3.51, 95% CI: 1.96-6.29) than the slow metabolizers who smoked less than 15 cigarettes per day.

CONCLUSIONS

In summary, the NMR may be an effective marker for estimating tobacco-related disease risks such as lung cancer.

The Role of Genomics and Proteomics in Lung Cancer Early Detection and Treatment

Lung cancer is the leading cause of cancer-related death worldwide, with non-small-cell lung cancer (NSCLC) being the primary type. Unfortunately, it is often diagnosed at advanced stages, when therapy leaves patients with a dismal prognosis. Despite the advances in genomics and proteomics in the past decade, leading to progress in developing tools for early diagnosis, targeted therapies have shown promising results; however, the 5-year survival of NSCLC patients is only about 15%. Low-dose computed tomography or chest X-ray are the main types of screening tools. Lung cancer patients without specific, actionable mutations are currently treated with conventional therapies, such as platinum-based chemotherapy; however, resistances and relapses often occur in these patients. More noninvasive, inexpensive, and safer diagnostic methods based on novel biomarkers for NSCLC are of paramount importance. In the current review, we summarize genomic and proteomic biomarkers utilized for the early detection and treatment of NSCLC. We further discuss future opportunities to improve biomarkers for early detection and the effective treatment of NSCLC.

Comprehensive Analysis of NPSR1-AS1 as a Novel Diagnostic and Prognostic Biomarker Involved in Immune Infiltrates in Lung Adenocarcinoma

The incidence of lung adenocarcinoma (LUAD), the most common subtype of lung cancer, continues to make lung cancer the largest cause of cancer-related deaths worldwide. Long noncoding RNAs (lncRNAs) have been shown to have a significant role in both the onset and progression of lung cancer. In this study, we aimed to investigate the clinical significance and underlying mechanism of lncRNA NPSR1-AS1 (NPSR1-AS1) in LUAD. First, we performed an analysis on TCGA and identified 229 differentially expressed lncRNAs (DELs) (including 216 upregulated lncRNAs and 13 downregulated lncRNAs). Then, we carried out a screening of the lncRNAs associated with survival, and a total of 382 survival-related lncRNAs were found. 15 survival-related DELs were identified. Among them, our attention focused on NPSR1-AS1. We found that the expression of NPSR1-AS1 was much higher in LUAD specimens compared to nontumor tissues. According to the results of the ROC assays, high NPSR1-AS1 expression had an AUC value of 0.904 for LUAD, with a 95% confidence interval ranging from 0.881 to 0.927. The expression of NPSR1-AS1 was shown to be significantly elevated in a wide variety of cancers, according to the findings of a pancancer investigation. Functional enrichment analysis confirmed that NPSR1-AS1 was involved in LUAD progression via regulating several tumor-related pathways. Patients with high levels of NPSR1-AS1 expression were shown to have a shorter disease-specific survival (DSS) or overall survival (OS) than those with low levels of NPSR1-AS1 expression, according to the findings of a clinical investigation. It was determined by multivariate analysis that NPSR1-AS1 expressions served as an independent prognostic factor for the overall survival of LUAD patients. The results of immune cell infiltration revealed that the expressions of NPSR1-AS1 were negatively associated with CD8 T cells, pDC, cytotoxic cells, mast cells, iDC, neutrophils, NK CD56dim cells, DC, Th17 cells, Tgd, and macrophages, while they were positively associated with NK CD56bright cells and B cells. Overall, our findings revealed that NPSR1-AS1 could serve as a potential biomarker to assess the clinical outcome and immune infiltration level in LUAD.

Whole-genome sequencing of East Asian lung cancers reveals new germline pathogenic variants

In this issue of Cancer Cell, Wang et al. use whole-genome sequencing of lung cancer cases and controls with East Asian ancestry to comprehensively characterize both common and rare variants that predispose to lung cancer. Their findings suggest that rare promoter variants in BRCA2 are associated with increased lung cancer risk.

Positron emission tomography imaging of lung cancer: An overview of alternative positron emission tomography tracers beyond F18 fluorodeoxyglucose

Lung cancer has been the leading cause of cancer-related mortality in China in recent decades. Positron emission tomography-computer tomography (PET/CT) has been established in the diagnosis of lung cancer. ¹⁸F-FDG is the most widely used PET tracer in foci diagnosis, tumor staging, treatment planning, and prognosis assessment by monitoring abnormally exuberant glucose metabolism in tumors. However, with the increasing knowledge on tumor heterogeneity and biological characteristics in lung cancer, a variety of novel radiotracers beyond ¹⁸F-FDG for PET imaging have been developed. For example, PET tracers that target cellular proliferation, amino acid metabolism and transportation, tumor hypoxia, angiogenesis, pulmonary NETs and other targets, such as tyrosine kinases and cancer-associated fibroblasts, have been reported, evaluated in animal models or under clinical investigations in recent years and play increasing roles in lung cancer diagnosis. Thus, we perform a comprehensive literature review of the radiopharmaceuticals and recent progress in PET tracers for the study of lung cancer biological characteristics beyond glucose metabolism.

Common and distinguishing genetic factors for substance use behavior and disorder: an integrated analysis of genomic and transcriptomic studies from both human and animal studies

BACKGROUND AND AIMS

Genomic and transcriptomic findings greatly broaden the biological knowledge regarding substance use. However, systematic convergence and comparison evidence of genome-wide findings is lacking for substance use. Here, we combined all the genome-wide findings from both substance use behavior and disorder (SUBD) and identified common and distinguishing genetic factors for different SUBDs.

METHODS

Systemic literature search for genome-wide association (GWAS) and RNA-seq studies of alcohol/nicotine/drug use behavior (partially meets or not reported diagnostic criteria) and alcohol use behavior and disorder (AUBD), nicotine use behavior and disorder (NUBD) and drug use behavior and disorder (DUBD) was performed using PubMed and the GWAS catalog. Drug use was focused upon cannabis, opioid, cocaine and methamphetamine use. GWAS studies required case-control or case/cohort samples. RNA-seq studies were based on brain tissues. The genes which contained significant single nucleotide polymorphism (P ≤ 1 × 10^-6 ) in GWAS and reported as significant in RNA-seq studies were extracted. Pathway enrichment was performed by using Metascape. Gene interaction networks were identified by using the Protein Interaction Network Analysis database.

RESULTS

Total SUBD-related 2910 genes were extracted from 75 GWAS studies (2 773 889 participants) and 17 RNA-seq studies. By overlapping the genes and pathways of AUBD, NUBD and DUBD, four shared genes (CACNB2, GRIN2B, PLXDC2 and PKNOX2), four shared pathways [two Gene Ontology (GO) terms of 'modulation of chemical synaptic transmission', 'regulation of trans-synaptic signaling', two Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways of 'dopaminergic synapse', 'cocaine addiction'] were identified (significantly higher than random, P < 1 × 10^-5 ). The top shared KEGG pathways (Benjamini-Hochberg-corrected P-value < 0.05) in the pairwise comparison of AUBD versus DUBD, NUBD versus DUBD, AUBD versus NUBD were 'Epstein-Barr virus infection', 'protein processing in endoplasmic reticulum' and 'neuroactive ligand-receptor interaction', respectively. We also identified substance-specific genetic factors: i.e. ADH1B and ALDH2 were unique for AUBD, while CHRNA3 and CHRNA4 were unique for NUBD.

CONCLUSIONS

This systematic review identifies the shared and unique genes and pathways for alcohol, nicotine and drug use behaviors and disorders at the genome-wide level and highlights critical biological processes for the common and distinguishing vulnerability of substance use behaviors and disorders.

Germline Pathogenic Variants Impact Clinicopathology of Advanced Lung Cancer

BACKGROUND

The genetic factors that modulate risk for developing lung cancer have not been fully defined. Here, we sought to determine the prevalence and clinical significance of germline pathogenic/likely pathogenic variants (PV) in patients with advanced lung cancer.

METHODS

We studied clinical and tumor characteristics of germline PV in 5,118 patients who underwent prospective genomic profiling using paired tumor-normal tissue samples in 468 cancer genes.

RESULTS

Germline PV in high/moderate-penetrance genes were observed in 222 (4.3%) patients; of these, 193 patients had PV in DNA damage repair (DDR) pathway genes including BRCA2 (n = 54), CHEK2 (n = 30), and ATM (n = 26) that showed high rate of biallelic inactivation in tumors. BRCA2 heterozygotes with lung adenocarcinoma were more likely to be never smokers and had improved survival compared with noncarriers. Fourteen patients with germline PV in lung cancer predisposing genes (TP53, EGFR, BAP1, and MEN1) were diagnosed at younger age compared with noncarriers, and of tumor suppressors, 75% demonstrated biallelic inactivation in tumors. A significantly higher proportion of germline PV in high/moderate-penetrance genes were detected in high-risk patients who had either a family history of any cancer, multiple primary tumors, or early age at diagnosis compared with unselected patients (10.5% vs. 4.1%; P = 1.7e-04).

CONCLUSIONS

These data underscore the biological and clinical importance of germline mutations in highly penetrant DDR genes as a risk factor for lung cancer.

IMPACT

The family members of lung cancer patients harboring PV in cancer predisposing genes should be referred for genetic counseling and may benefit from proactive surveillance.

Associations of genetic risk, BMI trajectories, and the risk of non-small cell lung cancer: a population-based cohort study

BACKGROUND

Body mass index (BMI) has been found to be associated with a decreased risk of non-small cell lung cancer (NSCLC); however, the effect of BMI trajectories and potential interactions with genetic variants on NSCLC risk remain unknown.

METHODS

Cox proportional hazards regression model was applied to assess the association between BMI trajectory and NSCLC risk in a cohort of 138,110 participants from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. One-sample Mendelian randomization (MR) analysis was further used to access the causality between BMI trajectories and NSCLC risk. Additionally, polygenic risk score (PRS) and genome-wide interaction analysis (GWIA) were used to evaluate the multiplicative interaction between BMI trajectories and genetic variants in NSCLC risk.

RESULTS

Compared with individuals maintaining a stable normal BMI (n = 47,982, 34.74%), BMI trajectories from normal to overweight (n = 64,498, 46.70%), from normal to obese (n = 21,259, 15.39%), and from overweight to obese (n = 4,371, 3.16%) were associated with a decreased risk of NSCLC (hazard ratio [HR] for trend = 0.78, P < 2×10^-16). An MR study using BMI trajectory associated with genetic variants revealed no significant association between BMI trajectories and NSCLC risk. Further analysis of PRS showed that a higher GWAS-identified PRS (PRS_GWAS) was associated with an increased risk of NSCLC, while the interaction between BMI trajectories and PRS_GWAS with the NSCLC risk was not significant (P_sPRS= 0.863 and P_wPRS= 0.704). In GWIA analysis, four independent susceptibility loci (P < 1×10^-6) were found to be associated with BMI trajectories on NSCLC risk, including rs79297227 (12q14.1, located in SLC16A7, P_interaction = 1.01×10^-7), rs2336652 (3p22.3, near CLASP2, P_interaction = 3.92×10^-7), rs16018 (19p13.2, in CACNA1A, P_interaction = 3.92×10^-7), and rs4726760 (7q34, near BRAF, P_interaction = 9.19×10^-7). Functional annotation demonstrated that these loci may be involved in the development of NSCLC by regulating cell growth, differentiation, and inflammation.

CONCLUSIONS

Our study has shown an association between BMI trajectories, genetic factors, and NSCLC risk. Interestingly, four novel genetic loci were identified to interact with BMI trajectories on NSCLC risk, providing more support for the aetiology research of NSCLC.

TRIAL REGISTRATION

http://www.

CLINICALTRIALS

gov , NCT01696968 .

The Current Status of SSRP1 in Cancer: Tribulation and Road Ahead

Methods

We search PubMed and Web of Sciences with keywords “SSRP1” and “Cancer.” Only English literature was included, and conference papers and abstract were all excluded.

Results

Transcription factors are classified into three groups based on their DNA binding motifs: simple helix-loop-helix (bHLH), classical zinc fingers (ZF-TFs), and homeodomains. The tumor-suppressive miR-497 (microRNA-497) acted as an undesirable regulator of SSRP1 upregulation, which led to tumor growth. The siRNA (small interfering RNA) knockdown of SSRP1 hindered cell proliferation along with incursion and glioma cell migration. Through the AKT (also known as protein kinase B) signaling pathway, SSRP1 silencing affected cancer apoptosis and cell proliferation.

Conclusion

The MAPK (mitogen-activated protein kinase) signaling pathway's phosphorylation was suppressed when SSRP1 was depleted. The effect of curaxins on p53 and NF-B (nuclear factor-κB), and their toxicity to cancer cells, is attributable to the FACT (facilitates chromatin transcription) complex's chromatin trapping.

Signaling Pathway Inhibitors, miRNA, and Nanocarrier-Based Pharmacotherapeutics for the Treatment of Lung Cancer: A Review

Lung cancer is one of the most commonly diagnosed cancers and is responsible for a large number of deaths worldwide. The pathogenic mechanism of lung cancer is complex and multifactorial in origin. Thus, various signaling pathways as targets for therapy are being examined, and many new drugs are in the pipeline. However, both conventional and target-based drugs have been reported to present significant adverse effects, and both types of drugs can affect the clinical outcome in addition to patient quality of life. Recently, miRNA has been identified as a promising target for lung cancer treatment. Therefore, miRNA mimics, oncomiRs, or miRNA suppressors have been developed and studied for possible anticancer effects. However, these miRNAs also suffer from the limitations of low stability, biodegradation, thermal instability, and other issues. Thus, nanocarrier-based drug delivery for the chemotherapeutic drug delivery in addition to miRNA-based systems have been developed so that existing limitations can be resolved, and enhanced therapeutic outcomes can be achieved. Thus, this review discusses lung cancer's molecular mechanism, currently approved drugs, and their adverse effects. We also discuss miRNA biosynthesis and pathogenetic role, highlight pre-clinical and clinical evidence for use of miRNA in cancer therapy, and discussed limitations of this therapy. Furthermore, nanocarrier-based drug delivery systems to deliver chemotherapeutic drugs and miRNAs are described in detail. In brief, the present review describes the mechanism and up-to-date possible therapeutic approaches for lung cancer treatment and emphasizes future prospects to bring these novel approaches from bench to bedside.

A Functional Polymorphism in Accessible Chromatin Region Confers Risk of Non-Small Cell Lung Cancer in Chinese Population

Background

The disease-associated non-coding variants identified by genome-wide association studies (GWASs) were enriched in open chromatin regions (OCRs) and implicated in gene regulation. Genetic variants in OCRs thus may exert regulatory functions and contribute to non-small cell lung cancer (NSCLC) susceptibility.

Objective

To fine map potential functional variants in GWAS loci that contribute to NSCLC predisposition using chromatin accessibility and histone modification data and explore their functions by population study and biochemical experimental analyses.

Methods

We mapped the chromatin accessible regions of lung tissues using data of assay for transposase-accessible chromatin using sequencing (ATAC-seq) in The Cancer Genome Atlas (TCGA) and prioritized potential regulatory variants within lung cancer GWAS loci by aligning with histone signatures using data of chromatin immunoprecipitation assays followed by sequencing (ChIP-seq) in the Encyclopedia of DNA Elements (ENCODE). A two-stage case–control study with 1,830 cases and 2,001 controls was conducted to explore the associations between candidate variants and NSCLC risk in Chinese population. Bioinformatic annotations and biochemical experiments were performed to further reveal the potential functions of significant variants.

Results

Sixteen potential functional single-nucleotide polymorphisms (SNPs) were selected as candidates from bioinformatics analyses. Three variants out of the 16 candidate SNPs survived after genotyping in stage 1 case–control study, and only the results of SNP rs13064999 were successfully validated in the analyses of stage 2 case–control study. In combined analyses, rs13064999 was significantly associated with NSCLC risk [additive model; odds ratio (OR) = 1.17; 95%CI, 1.07–1.29; p = 0.001]. Functional annotations indicated its potential enhancer bioactivity, and dual-luciferase reporter assays revealed a significant increase in luciferase activity for the reconstructed plasmid with rs13064999 A allele, when compared to the one with wild-type G allele (p_A549 < 0.001, p_SK-MES-1 = 0.004). Further electrophoretic mobility shift assays (EMSA) and super-shift assays confirmed a stronger affinity of HP1γ for the binding motif containing SNP rs13064999 A allele.

Conclusion

These findings suggested that the functional variant rs13064999, identified by the integration of ATAC-seq and ChIP-seq data, contributes to the susceptibility of NSCLC by affecting HP1γ binding, while the exact biological mechanism awaits further exploration.

The association between dietary vitamin B12 and lung cancer risk: findings from a prospective cohort study

BACKGROUND

Since previous epidemiological studies reported inconsistent associations between dietary vitamin B12 intake and lung cancer risk, more studies are warranted to clarify this association in different populations.

METHODS

The association between dietary B12 intake and lung cancer risk was examined in the Singapore Chinese Health Study, an ongoing prospective cohort study of 63 257 Singaporean Chinese men and women, 45-74 years of age at enrollment during 1993-1998 and were followed up for incidence of lung cancer for up to 25 years. Dietary vitamin B12 intake was derived from a validated food frequency questionnaire. Cox proportional hazard regression method was used to estimate hazard ratio and 95% confidence interval (CI) of lung cancer associated with dietary vitamin B12 intake with adjustment for multiple potential confounders.

RESULTS

After a mean follow-up of 17.64 years, 2001 study participants developed lung cancer. High levels of vitamin B12 intake were associated with significantly increased risk of lung cancer (Ptrend = 0.03). Compared with the lowest quintile, hazard ratios (95% CIs) of lung cancer for quintile 2, 3, 4, and 5 of vitamin B12 intake were 1.09 (0.95-1.25), 1.11 (0.96-1.28), 1.11 (0.97-1.29) and 1.18 (1.03-1.35), respectively. This positive association was more apparent in men than in women, in adenocarcinoma patients, or in participants with equal or less than 2 years follow-up than those with longer duration of follow-up.

CONCLUSION

Higher intake of dietary vitamin B12 was associated with increased risk of lung cancer. This highlights the potential harmful effect of vitamin B12 supplementation for lung cancer.

Association between NEAT1 polymorphism and the risk of lung cancer: A protocol for systematic review and meta-analysis

BACKGROUND

Long noncoding RNAs play vital roles in development and progression of lung cancers. Nuclear paraspeckle assembly transcript 1 (NEAT1) polymorphisms were reported to be closely related to lung cancer susceptibility. Recently, numerous studies have been performed to detect the association between NEAT1 polymorphisms and lung cancer susceptibility. However, their results were inconsistent and controversial. So, we carried out a meta-analysis aiming to define the association exactly.

METHODS

Appropriate studies were retrieved from searching Web of Science, PubMed, Scopus, and Google scholar databases, updated January 31, 2021. The pooled odds ratios with 95% confidence intervals were calculated to estimate the strength of the association between NEAT1 polymorphisms and lung cancer risk. All of the data were analyzed with Stata 16.0.

RESULTS

The results of this meta-analysis will be submitted to a peer-reviewed journal for publication.

CONCLUSION

This meta-analysis will summarize the relationship between NEAT1 polymorphism and lung cancer.

Occupational Exposure to Pesticides and Lung Cancer Risk: A Propensity Score Analyses

Purpose

Occupational exposure to pesticides is thought to be associated with lung cancer, but studies have yielded conflicting results. We performed a propensity score (PS) based analyses to evaluate the relationship between occupational exposure to pesticides and lung cancer risk in the Korea National Cancer Center community-based cohort study (KNCCCS).

Materials and Methods

During the follow-up period, 123 incidental lung cancer cases were identified, of the 7,471 subjects in the final statistical analysis. Information about occupational exposure to pesticides and other factors was collected at enrollment (2003–2010). Cox proportional hazards regression analyses were conducted. Four PS-based approaches (i.e., matching, stratification, inverse probability-of-treatment weighting, and the use of the PS as a covariate) were adopted, and the results were compared. PS was obtained from the logistic regression model. Absolute standardized differences according to occupational exposure to pesticides were provided to evaluate the balance in baseline characteristics.

Results

In the Cox proportional hazards regression model, the hazard ratio (HR) for lung cancer according to occupational exposure to pesticides was 1.82 (95% confidence interval [CI], 1.11 to 2.98). With all the propensity score matching (PSM) methods, the HRs for lung cancer based on exposure to pesticides ranged from 1.65 (95% CI, 1.04 to 2.64) (continuous term with PSM) to 2.84 (95% CI, 1.81 to 4.46) (stratification by 5 strata of the PS). The results varied slightly based on the method used, but the direction and statistical significance remained the same.

Conclusion

Our results strengthen the evidence for an association between occupational exposure to pesticides and the risk of lung cancer.

Volatile organic compound breath testing detects in-situ squamous cell carcinoma of bronchial and laryngeal regions and shows distinct profiles of each tumour

Volatile organic compound (VOC) breath testing of lung and head and neck squamous cell carcinoma (SCC) has been widely studied, however little is known regarding VOC profiles of in-situ SCC. A prospective study of VOC in patients with histologically proven SCC, either in-situ or advanced, and controls. Breath samples were analysed using the E-nose Cyranose ^®320 and by gas chromatography/mass spectroscopy. Predictive models were developed using bootstrap forest using all 32 sensors. Data from 55 participants was analysed: 42 SCC cases comprising 20 bronchial (10 in-situ, 10 advanced) and 22 laryngeal (12 in-situ, 10 advanced), and 13 controls. There were 32 (76%) male SCC cases with mean age 63.6 (SD = 9.5) compared with 11 (85%) male controls with mean age 61.9 (SD = 10.1). Predictive models for in situ cases had good sensitivity and specificity compared to controls (overall, 95% and 69%; laryngeal, 100% and 85%; bronchial, 77% and 80%). When distinguishing in-situ and advanced tumours, sensitivity and specificity 82% and 75% respectively. For different tumour types (bronchial versus advanced laryngeal) sensitivity and specificity were 100% and 80% respectively. VOCs isolated from in-situ cancers included some previously demonstrated in advanced cancers and some novel VOCs. In-situ bronchial and laryngeal cancer can be detected by VOC analysis. Distinction from normal controls and between the two tumour types could allow screening in high risk groups for these curable lesions.

Polymorphisms in DNA repair genes in lung cancer patients living in a coal-mining region

Air pollutants and ionizing radiation are well-known carcinogens involved in the pathogenesis of lung cancer, and residents of coal-mining regions are exposed routinely to these agents. Polymorphisms in DNA repair genes may be associated with an increased risk of malignant transformation. We investigated associations between the risk of lung cancer in residents of the coal-mining region and polymorphisms in the genes APEX1 (rs1130409), hOGG1 (rs1052133), XRCC1 (rs25489, rs25487), XRCC2 (rs3218536), XRCC3 (rs861539), ADPRT/PARP1 (rs1136410), XPD/ERCC2 (rs13181), XPG/ERCC5 (rs17655), XPC (rs2228001), ATM (rs1801516), and NBS1 (rs1805794). Three hundred and forty residents of the Kemerovo Region (a coal-mining region of western Siberia) were lung cancer patients exposed to air pollutants and ionizing radiation (case) and 335 were healthy donors (control). Genotyping was performed by real-time PCR and allele-specific PCR. We discovered that polymorphisms in the XPD gene in men [log-additive model: odds ratio (OR) = 1.64, 95% confidence interval (CI): 1.17-2.31], the ATM gene in women and nonsmokers (codominant model: OR = 0.11, 95% CI: 0.02-0.49 and OR = 0.25, 95% CI: 0.08-0.72, respectively), the APEX1 gene for smokers (recessive model: OR = 2.55, 95% CI: 1.34-4.85), and the NBS1 gene for those who work in the coal industry (overdominant model: OR = 0.40, 95% CI: 0.21-0.75) are associated with an increased risk of lung cancer. Using the multifactor dimensionality reduction method, we found a model of gene-gene interactions associated with the risk of lung cancer: NBS1 (rs1805794)-XRCC1 (rs25487)-hOGG1 (rs1052133)-XPG (rs17655). These results indicate an association between combinations of polymorphisms in the studied genes and the risk of lung cancer in residents of a coal-mining region.

Long non-coding RNA-ZNF281 upregulates PTEN expression via downregulation of microRNA-221 in non-small cell lung cancer

A recent study reported that zinc finger protein (ZNF)281 is a tumor-suppressive long non-coding (lnc)RNA in glioma. The present study investigated the role of ZNF281 in non-small cell lung cancer (NSCLC). ZNF281 expression in paired cancer and non-cancerous tissues from patients with NSCLCs was analyzed by RNA extraction and reverse transcription-quantitative-PCR. A 5-year follow up on patients was performed to analyze the prognostic value of ZNF281 for NSCLC. Cell transfections of ZNF281 or phosphatase and tensin homolog (PTEN) expression vector and microRNA (miR)-221 mimic were performed to analyze the relationship between ZNF281, miR-221 and PTEN. Cell apoptosis and proliferation were analyzed using Cell Counting Kit-8 and flow cytometry, respectively. In patients with NSCLC, expression levels of ZNF281 were significantly lower in cancer tissues compared with in non-cancerous tissues, and lower levels of ZNF281 expression in cancerous tissues predicted poor survival. In NSCLC cells, ZNF281 overexpression resulted in upregulated PTEN and downregulated miR-221 expression, whereas cells with miR-221 overexpression exhibited downregulated PTEN expression and unaffected ZNF281 expression. In addition, ZNF281 and PTEN overexpression resulted in accelerated cell apoptosis and inhibited the cell proliferation of NSCLC cells. Notably, miR-221 overexpression exhibited an opposite effect and attenuated the functions of ZNF281 and PTEN overexpression. Therefore, ZNF281 may upregulate PTEN via downregulation of miR-221 in NSCLC, resulting in inhibition of cancer cell proliferation and the promotion of apoptosis.

LncRNA-KAT7 Negatively Regulates miR-10a Through an Epigenetic Pathway to Participate in Nonsmall Cell Lung Cancer

Objective: LncRNA-KAT7 is a recently identified tumor suppressor in colorectal cancer, whereas its roles in other malignancies remain unclear. This study aimed to investigate the roles of KAT7 in nonsmall cell lung cancer (NSCLC). Results: The results showed that KAT7 was downregulated in NSCLC and predicted poor survival. KAT7 negatively correlated with miR-10a in NSCLC. In NSCLC cells, overexpression of KAT7 led to downregulated miR-10a, whereas silencing of KAT7 led to upregulated miR-10a. Methylation-specific polymerase chain reaction revealed that KAT7 positively regulated the methylation of miR-10a. Cell proliferation assay showed that overexpression of miR-10a led to increased proliferation rate of NSCLC cells. In addition, overexpression of KAT7 played an opposite role and reduced the effects of the overexpression of miR-10a. Conclusion: In conclusion, KAT7 negatively regulates miR-10a through epigenetic mechanisms to participate in NSCLC cell proliferation.

TERT-rs33963617 and CLPTM1L-rs77518573 reduce the risk of non-small cell lung cancer in Chinese population

BACKGROUND

Genome-wide association studies (GWAS) have identified 5p15.33 as a susceptible locus for lung cancer. However, for non-small cell lung cancer (NSCLC), low-frequency risk variants in this region have not been systematically studied. We intended to explore the associations between low-frequency variants on 5p15.33 and NSCLC using a next-generation sequencing based approach in this study.

METHODS

We have acquisited the variation spectrum of 400 NSCLC patients on 5p15.33 by sequencing the targeted region before. Candidate variants were primarily selected by restricting the minor allele frequency (MAF 1-5%) and then by comparing their frequency in 400 NSCLC patients with 1008 East Asians from The genome Aggregation Database (gnomAD). The associations between candidate variants and NSCLC were discovered and replicated in two case-control sets: discovery stage with 960 cases and 916 controls, and replication stage with 1596 cases and 1614 controls in total.

RESULTS

Five low-frequency variants were selected as our candidates and subsequent association analyses showed that 2 polymorphisms were significantly associated with risk of NSCLC, including rs33963617 (OR = 0.63, 95% CI: 0.53-0.76, P = 3.80 × 10^-7) in TERT and rs77518573 (OR = 0.73, 95% CI: 0.63-0.84, P = 2.00 × 10^-5) in upstream of CLPTM1L. When stratified by histologic subtype, a significant association was only investigated in adenocarcinoma for rs77518573. We also observed an obvious cumulative effect of the two significant variants.

CONCLUSIONS

We newly identified two NSCLC related variants on chromosome 5p15.33. Both TERT-rs33963617 and CLPTM1L-rs77518573 conferred reduced risk for NSCLC in Chinese Han population.

LncRNA MAGI2-AS3 is downregulated in non-small cell lung cancer and may be a sponge of miR-25

BACKGROUND

This study aimed to investigate the role of lncRNA MAGI2-AS3 in non-small cell lung cancer (NSCLC).

METHODS

Expression levels of MAGI2-AS3 and RECK mRNA in two types of tissues (non-tumor and NCSLC) were measured by qPCR. To further investigate the interaction between MAGI2-AS3 and RECK, MAGI2-AS3 and RECK expression vectors were transfected into H1993 cells.

RESULTS

We found that MAGI2-AS3 and RECK were upregulated and positively correlated in NSCLC. In NSCLC cells, MAGI2-AS3 overexpression led to upregulated RECK. Bioinformatics analysis showed that MAGI2-AS3 may bind miR-25, which can directly target RECK. In NSCLC cells, miR-25 overexpression led to downregulated RECK and attenuated the effects of MAGI2-AS3 overexpression, while MAGI2-AS3 and miR-25 failed to affect each other. Cell invasion and migration analysis showed decreased NSCLC cell invasion and migration rates after MAGI2-AS3 and RECK overexpression. MiR-25 showed opposite role and reduced the effects of MAGI2-AS3 overexpression.

CONCLUSION

Therefore, MAGI2-AS3 may sponge miR-25 to upregulate RECK, thereby inhibiting NSCLC cell invasion and migration.

TRIAL REGISTRATION

HLJCM20163358592, registered by First Affiliated Hospital, Heilongjiang University of Chinese Medicine at March 3, 2016, prospectively.

Polymorphisms and rare variants identified by next-generation sequencing confer risk for lung cancer in han Chinese population

BACKGROUND

Lung cancer is one of the leading causes of cancer death worldwide, and genetic risk factors account for a large part of its carcinogenesis. The low economic requirements and high efficiency of next-generation sequencing (NGS) make it widely used in detecting genetic alterations in pathogenesis.

METHODS

We performed targeted panel sequencing in 780 Han Chinese lung cancer patients using a commercial probe, and the correlations between dozens of susceptible sites were verified in 1113 healthy controls. This study used Fisher's exact test and Benjamini-Hochberg FDR correction to analyze the mutual exclusion between mutated genes, and Pearson's p was used to verify the correlations between mutations and lung cancer susceptibility.

RESULTS

Our results determined the mutation spectrum and showed that each lung cancer patient carried at least one DNA mutation. The most frequently mutated gene was BRCA2 (mutation rate,10.6 %.). The co-occurrence and mutual exclusion analysis of DNA damage related genes showed that gene ATM was mutually exclusive from MSH6. We conducted a further case-control study in different subtypes of lung cancer and the results described 14 mutations associated with adenocarcinoma, 9 with squamous cell carcinoma, and 4 with small cell lung cancer. These variants were novel de-novo germline mutations in lung cancer. Particularly, rs3864017 in FANCD2 showed a protective effect of lung adenocarcinoma for carriers (OR = 0.146, 95 % CI = 0.052∼0.405, P_adjusted = 3.37 × 10^-4).

CONCLUSIONS

18 candidate mutations might alter the risk of lung cancer in the Han Chinese population, including polymorphisms rs3864017(FANCD2), rs55740729(MSH6) and 16 rare variants. The underlying mechanisms of candidate genes in lung cancer remain unclear and we suggest more functional studies on exploring how these genes affect the risk of lung cancer.

Inherited lung cancer: a review

Lung cancer is the most common cancer worldwide and has high rates of mortality. The major risk factor associated with this disease is tobacco smoke, but approximately 10%-25% of all lung cancer cases occur in patients who have never smoked. Data suggest that lung cancer in never-smokers has a different molecular profile, tumour microenvironment and epidemiology than that in smokers. Several risk factors have been associated with its occurrence, and the possibility of inherited predisposition is becoming clearer. A better understanding of this disease is essential for the future development of personalised screening, diagnosis and treatment approaches, with consequent reduction of mortality. In this review, we discuss historical studies of lung cancer in never-smokers and the currently available evidence of inherited predisposition to this disease.

Alternative and New Radiopharmaceutical Agents for Lung Cancer

BACKGROUND

FDG PET/CT imaging has an established role in lung cancer (LC) management. Whilst it is a sensitive technique, FDG PET/CT has a limited specificity in the differentiation between LC and benign conditions and is not capable of defining LC heterogeneity since FDG uptake varies between histotypes.

OBJECTIVE

To get an overview of new radiopharmaceuticals for the study of cancer biology features beyond glucose metabolism in LC.

METHODS

A comprehensive literature review of PubMed/Medline was performed using a combination of the following keywords: "positron emission tomography", "lung neoplasms", "non-FDG", "radiopharmaceuticals", "tracers".

RESULTS

Evidences suggest that proliferation markers, such as 18F-Fluorothymidine and 11CMethionine, improve LC staging and are useful in evaluating treatment response and progression free survival. 68Ga-DOTA-peptides are already routinely used in pulmonary neuroendocrine neoplasms (NENs) management and should be firstly performed in suspected NENs. 18F-Fluoromisonidazole and other radiopharmaceuticals show a promising impact on staging, prognosis assessment and therapy response in LC patients, by visualizing hypoxia and perfusion. Radiolabeled RGD-peptides, targeting angiogenesis, may have a role in LC staging, treatment outcome and therapy. PET radiopharmaceuticals tracing a specific oncogene/signal pathway, such as EGFR or ALK, are gaining interest especially for therapeutic implications. Other PET tracers, like 68Ga-PSMA-peptides or radiolabeled FAPIs, need more development in LC, though, they are promising for therapy purposes.

CONCLUSION

To date, the employment of most of the described tracers is limited to the experimental field, however, research development may offer innovative opportunities to improve LC staging, characterization, stratification and response assessment in an era of increased personalized therapy.

Telomere-associated genes and telomeric lncRNAs are biomarker candidates in lung squamous cell carcinoma (LUSC)

In the past decade, research efforts were made to identify molecular biomarkers useful as therapeutic targets in Non-Small Cell Lung Cancer (NSCLC), the most frequent type of lung carcinoma. NSCLC presents different histological subtypes being the most prevalent LUSC (Lung Squamous Cell Cancer) and LUAD (Lung Adenocarcinoma), and only a subset of LUAD patients' present tumors expressing known targetable genetic alterations. Telomeres and its components, including telomerase, the enzyme that replenishes telomeres, have been considered potential cancer biomarkers due to their crucial role in cell proliferation and genome stability. Our study aims to quantify expression changes affecting telomere-associated genes and ncRNAs associated with telomere regulation and maintenance in NSCLC. We first assessed the transcriptome (RNA-Seq) data of NSCLC patients from The Cancer Genome Atlas (TCGA) and then we tested the expression of telomere-associated genes and telomeric ncRNAs (TERC, telomerase RNA component, and TERRA, telomere repeat-containing RNA) in Brazilian NCSLC patient samples by quantitative RT-PCR, using matched normal adjacent tissue samples as the control. We also estimated the mean size of terminal restriction fragments (TRF) of some Brazilian NSCLC patients using telomeric Southern blot. The TCGA analysis identified alterations in the expression profile of TERT and telomere damage repair genes, mainly in the LUSC subtype. The study of Brazilian NSCLC samples by RT-qPCR showed that LUSC and LUAD express high amounts of TERT and that although the mean TRF size of tumor samples was shorter compared to normal cells, telomeres in NSCLC are probably maintained by telomerase. Also, the expression analysis of Brazilian NSCLC samples identified statistically significant alterations in the expression of genes involved with telomere damage repair, as well as in TERC and TERRA, mainly in the LUSC subtype. We, therefore, concluded that telomere maintenance genes are significantly deregulated in NSCLC, representing potential biomarkers in the LUSC subtype.

Lung Cancer in the Young

INTRODUCTION

Median age at diagnosis of lung cancer is 70 years. Its presentation in patients 40 or younger is uncommon and it has been proposed that maybe it is a different disease due to its clinical characteristics and genetic makeup. There are a limited number of studies in this population and they report different clinic-pathological characteristics in comparison with older patients.

METHODS

We described the incidence of lung cancer patients diagnosed at age 40 or younger at the Instituto Nacional de Enfermedades Neoplasicas (INEN), Lima-Peru; from 2009 to 2017 and evaluated the characteristic of NSCLC. Epidemiologic and clinic-pathological data was collected from clinical files. Analysis was carried out using SPSSvs19 software.

RESULTS

We identified 3823 patients with lung cancer seen at INEN during the study period. Among these, 166 (4.3%) patients were 40 years or younger, and 137/166 (82.5%) were NSCLC. Median age at diagnosis was 36 years (range 14-40 years) and 59.1% of patients were female. A smoking history was present in 14.4% of patients. Frequent symptoms at diagnosis were cough (62.0%), chest pain (51.8%) and dyspnea (40.9%). Adenocarcinoma was the most common histological type (63.3%). Most patients had advanced disease at diagnosis (84.7%). The median overall survival was 8.2 months.

CONCLUSIONS

The proportion of young patients with lung cancer in our population is higher than that reported in the most recent literature. Lung cancer in the young is mostly sporadic, more frequent in women, usually adenocarcinoma type and it presents with advanced disease, resulting in a very poor survival.

Association Between Nicotine-dependent Gene Polymorphism and Smoking Cessation in Patients With Lung Cancer

BACKGROUND

Patients with lung cancer continue to smoke owing to complex factors. Failure to quit smoking (defined as nicotine dependence) is significantly associated with genetic status. This study aimed to investigate the relationship between polymorphisms in nicotine dependence genes and smoking status after the diagnosis of lung cancer.

PATIENTS AND METHODS

A total of 240 patients with lung cancer were included from July 2017 to March 2018. According to the actual smoking condition after lung cancer diagnosis, eligible patients were divided into 3 groups: the never-smoking group, the failure to quit smoking group, and the successful smoking cessation group. Fagerstrom Test for Nicotine Dependence scores were used to evaluate the smoking status of each group. Three nicotine-dependent genes with 6 loci were detected.

RESULTS

Among the 240 patients, 86 were never-smokers, 51 failed to quit smoking, and 104 successfully quit smoking. The initial age of smoking in the failure to quit smoking group was significantly younger than those in the successful smoking cessation group (P = .001). There was a significant difference in the GG and AG and AA genotype distributions of CHRNA3 (rs578776) among the 3 groups (P = .003). There was also a significant difference in the distribution of CHRNA4 (rs2229959) genotypes among the 3 groups (P = .003). However, there was no significant difference in the genotype distribution of CHRNA5 (rs588765) among the 3 groups (P = .277).

CONCLUSIONS

Gene polymorphisms of CHRNA3 (rs578776) and CHRNA4 (rs1044396 and rs2229959) were associated with the success of smoking cessation after the diagnosis of lung cancer, which should be considered in the management of smoking cessation after patients are diagnosed with lung cancer.

Gene polymorphism of cytochrome P450 significantly affects lung cancer susceptibility

BACKGROUND

Cytochrome P450 (CYPs) are heme proteins involved in the metabolism of a variety of endogenous and exogenous substances and play an important role in the carcinogenesis mechanisms of environmental and hereditary factors. The objective of this study was to investigate how polymorphisms of CYPs correlate with lung cancer (LC) susceptibility.

METHODS

Six single nucleotide polymorphisms (SNPs) were genotyped in this study. The chi-square test and unconditional logistic regression model were used to evaluate the correlation between SNPs and LC susceptibility. The expressions and survival data of genes in patients with LC were mined using Oncomine and Kaplan-Meier Plotter database.

RESULTS

Four SNPs were found to be significantly associated with the risk of LC development (P < 0.05). The most significant correlation was that the A allele and AA genotype of CYP2D6 rs1065852 were associated with increased risk of LC development (adjusted odds ratio [OR] = 1.35, 95% confidence interval [95%CI] = 1.13-1.60, P = 9.04e-4; OR = 1.83, 95%CI = 1.29-2.59, P = 0.001 respectively). Similar association of this variant was also found in the subgroups of male patients, cases in III-IV stages, positive lymph node, squamous cell carcinomas and adenocarcinomas. Whereas rs1065852 was considered as protective factor in females (adjusted OR = 0.33, 95% CI = 0.16-0.70, P = 0.004). In stratified analyses, the association of CYP24A1 rs2762934, CYP24A1 rs6068816, CYP20A1 rs2043449 polymorphism with LC risk appeared stronger in some subgroups. CYP2D6, CYP24A1 and CYP20A1 are overexpressed in some pathological types of LC (P < 0.05), and high levels of CYP2D6 and CYP20A1 indicate poor and good prognosis of LC, respectively.

CONCLUSION

This study revealed that rs1065852, rs2043449, rs2762s934, and rs6068816 of CYPs were associated with LC susceptibility in the Northwestern Chinese Han population; CYP2D6 and CYP20A1 were overexpressed and correlated with prognosis of LC.

Association between Polymorphisms of Vitamin D Receptor and Lung Cancer Susceptibility: Evidence from an Updated Meta-analysis

Purpose: The aim of this meta-analysis was to investigate polymorphism of Bsm1, Apal, Taq1 and Cdx-2 in vitamin D receptor (VDR) associations in relation to lung cancer (LC) susceptibility.

Methods: 9 literatures were recruited into this meta-analysis from PubMed, PMC, Embase, Web of Science, Cochrane library and CNKI. STATA version 15.1 was used for statistical tests. The heterogeneity was tested using I² statistics. According to the value of I², the random-effect model (REM) or fixed-effect model (FEM) was selected to combine data from studies, respectively. Potential publication bias was evaluated by Egger's test. Sensitivity analysis was also performed to evaluate the stability and reliability in results.

Results: Decreased susceptibility of LC was found in all genetic models contrast in Bsm1 gene of VDR (a vs. A: OR = 0.62, 95 % CI = 0.44-0.87; aa vs. AA: OR = 0.76, 95 % CI = 0.60-0.96; Aa vs. AA: OR = 0.59, 95 % CI = 0.39-0.88; aa vs. AA+Aa: OR = 0.80, 95 % CI = 0.64-0.99; Aa+aa vs. AA: OR = 0.57, 95 % CI = 0.37-0.86). The similar results were also found in partial genetic models of Taq1 (a vs. A: OR = 0.88, 95 % CI = 0.79-0.98; aa vs. AA+Aa: OR = 0.84, 95 % CI = 0.73-0.98) and Cdx-2 (Aa vs. AA: OR = 0.80, 95 % CI = 0.66-0.98; Aa+aa vs. AA: OR = 0.79, 95 % CI = 0.65-0.96). Likewise, significant correlation between Bsm1, Taq1 polymorphism and LC risk was detected among Asians. Cdx-2 polymorphism was considered as a protective factor in Caucasians, whereas no association of Apal polymorphism with LC risk was observed in Asians and Caucasians for all genetic models.

Conclusion: The results of this meta-analysis suggested that Bsm1, Taq1 and Cdx-2 polymorphism may contribute to lung cancer susceptibility, more studies need be conducted to confirm in the future.

Mendelian Randomization and mediation analysis of leukocyte telomere length and risk of lung and head and neck cancers

BACKGROUND

Evidence from observational studies of telomere length (TL) has been conflicting regarding its direction of association with cancer risk. We investigated the causal relevance of TL for lung and head and neck cancers using Mendelian Randomization (MR) and mediation analyses.

METHODS

We developed a novel genetic instrument for TL in chromosome 5p15.33, using variants identified through deep-sequencing, that were genotyped in 2051 cancer-free subjects. Next, we conducted an MR analysis of lung (16 396 cases, 13 013 controls) and head and neck cancer (4415 cases, 5013 controls) using eight genetic instruments for TL. Lastly, the 5p15.33 instrument and distinct 5p15.33 lung cancer risk loci were evaluated using two-sample mediation analysis, to quantify their direct and indirect, telomere-mediated, effects.

RESULTS

The multi-allelic 5p15.33 instrument explained 1.49-2.00% of TL variation in our data (p = 2.6 × 10-9). The MR analysis estimated that a 1000 base-pair increase in TL increases risk of lung cancer [odds ratio (OR) = 1.41, 95% confidence interval (CI): 1.20-1.65] and lung adenocarcinoma (OR = 1.92, 95% CI: 1.51-2.22), but not squamous lung carcinoma (OR = 1.04, 95% CI: 0.83-1.29) or head and neck cancers (OR = 0.90, 95% CI: 0.70-1.05). Mediation analysis of the 5p15.33 instrument indicated an absence of direct effects on lung cancer risk (OR = 1.00, 95% CI: 0.95-1.04). Analysis of distinct 5p15.33 susceptibility variants estimated that TL mediates up to 40% of the observed associations with lung cancer risk.

CONCLUSIONS

Our findings support a causal role for long telomeres in lung cancer aetiology, particularly for adenocarcinoma, and demonstrate that telomere maintenance partially mediates the lung cancer susceptibility conferred by 5p15.33 loci.

LncRNA TP73-AS1 is upregulated in non-small cell lung cancer and predicts poor survival

The present study was carried out to investigate the role of lncRNA TP73-AS1 in non-small cell lung cancer (NSCLC). We found that TP73-AS1 was upregulated in tumor tissues than in non-tumor tissues of NSCLC patients, and high expression levels of TP73-AS1 predicted poor survival. MiR-21 was also upregulated in tumor tissues and positively correlated with TP73-AS1. TP73-AS1 overexpression led to miR-21 upregulation, while miR-21 overexpression failed to affect TP73-AS1. TP73-AS1 and miR-21 overexpression caused the accelerated invasion and migration of NSCLC cells. However, TP73-AS1 overexpression failed to affect cell proliferation. Therefore, TP73-AS1 may upregulate miR-21 to promote NSCLC cell migration and invasion.

Identification of a novel lncRNA GABPB1-IT1 that is downregulated and predicts a poor prognosis in non-small cell lung cancer

Lung cancer is the leading cause of cancer-associated mortality worldwide. Previous studies have demonstrated that long non-coding RNAs (lncRNAs) serve important roles in diverse biological processes. However, the molecular function and prognostic value of the majority of lncRNAs in non-small cell lung cancer (NSCLC) remain unknown. The present study investigated the expression of the lncRNA GABPB1 intronic transcript (GABPB1-IT1) in NSCLC tissues using publicly available databases. Subsequently, protein-protein interaction (PPI) and co-expression networks were constructed to identify key targets of lncRNA GABPB1-IT1. Furthermore, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to investigate the potential roles of lncRNA GABPB1-IT1. The current study identified that the expression of GABPB1-IT1 was significantly downregulated in NSCLC samples compared with normal samples. Furthermore, the expression levels of GABPB1-IT1 were lower in high grade NSCLC samples compared with low grade NSCLC samples. Additionally, overexpression of GABPB1-IT1 in cancer samples was associated with improved survival of patients with NSCLC. GABPB1-IT1 was revealed to be involved in the regulation of cell cycle-associated biological processes, including sister chromatid cohesion, mitotic nuclear division, DNA replication, chromosome segregation, G1/S transition of mitotic cell cycle, mitotic cytokinesis and cell division. Finally, a GABPB1-IT1-associated protein-protein interaction network was constructed for NSCLC. To the best of our knowledge, the present study was the first to demonstrate that GABPB1-IT1 is associated with the prognosis of NSCLC. The current study provides useful information to assist with the investigation of potential candidate biomarkers for diagnosis, prognosis and drug targets for NSCLC.

SNPs in LncRNA genes are associated with non-small cell lung cancer in a Chinese population

Background

It has indicated that single nuclear polymorphisms (SNPs) in the regions encoding non‐coding transcripts are associated with lung cancer susceptibility. In a previous microarray study, we identified 13 differentially expressed long non‐coding RNAs (lncRNAs) in non‐small cell lung cancer (NSCLC) and associations of SNPs in these lncRNA genes with lung cancer were unknown. We conducted a case‐control study to address this issue.

Methods

Using the TaqMan method, we genotyped 17 SNPs located in the 13 lncRNA genes in 1294 cases with NSCLC and 1729 healthy controls. Unconditional logistic regression and Cox proportional hazards regression were used to analyze the associations of these SNPs with NSCLC risk and patient survival, respectively. These analyses were also repeated in subgroups of cases and controls stratified by gender, age group, smoking status, disease stage, and histological type.

Results

We identified three SNPs associated with NSCLC risk. For SNP rs498238, CC genotype was associated with lower risk compared to TT genotype (adjusted OR = 0.33, 95%CI: 0.11‐0.97, P = 0.043). For rs16901995, CT/TT genotypes were associated with lower risk compared to CC genotype in non‐smokers (adjusted OR = 0.78, 95%CI: 0.62‐0.98, P = 0.035). Variant genotypes in rs219741 were associated with NSCLC risk in young patients, and the adjusted OR was 1.47 (95%CI: 1.03‐2.10, P = 0.033) when compared to the wild genotype. No SNPs were found to be associated with patient overall survival in the study.

Conclusion

The study suggests that some genetic polymorphisms in the lncRNA genes may influence the risk of NSCLC among Chinese.

The Role of HOX Transcription Factors in Cancer Predisposition and Progression

Homeobox (HOX) transcription factors, encoded by a subset of homeodomain superfamily genes, play pivotal roles in many aspects of cellular physiology, embryonic development, and tissue homeostasis. Findings over the past decade have revealed that mutations in HOX genes can lead to increased cancer predisposition, and HOX genes might mediate the effect of many other cancer susceptibility factors by recognizing or executing altered genetic information. Remarkably, several lines of evidence highlight the interplays between HOX transcription factors and cancer risk loci discovered by genome-wide association studies, thereby gaining molecular and biological insight into cancer etiology. In addition, deregulated HOX gene expression impacts various aspects of cancer progression, including tumor angiogenesis, cell autophagy, proliferation, apoptosis, tumor cell migration, and metabolism. In this review, we will discuss the fundamental roles of HOX genes in cancer susceptibility and progression, highlighting multiple molecular mechanisms of HOX involved gene misregulation, as well as their potential implications in clinical practice.

Association between Family History of Cancer and Lung Cancer Risk among Japanese Men and Women

Although cigarette smoking is a major risk factor for lung cancer, genetic susceptibility may also affect lung cancer risk. To explore the role of genetic risk, this case-control study investigated the association between family history of cancer at several sites and lung cancer risk. A total of 1,733 lung cancer cases and 6,643 controls were selected from patients aged 30 years and over admitted to a single hospital in Japan between 1997 and 2009. Information on family history of cancer was collected using a self-administered questionnaire and odds ratios (ORs) were estimated by unconditional logistic regression. Family history of lung cancer in first-degree relatives was associated with an increased risk of lung cancer among both sexes. According to histology and type of relatives, a parental history of lung cancer was significantly associated with an increased risk of female adenocarcinoma (OR = 1.72). Stratification by smoking status revealed that this significant positive association in women was limited to ever-smokers (OR = 4.13). In men, a history of lung cancer in siblings was significantly associated with an increased risk of small cell carcinoma (OR = 2.28) and adenocarcinoma (OR = 2.25). Otherwise, positive associations between history of breast (OR = 1.99) and total (OR = 1.71) cancers in siblings and the risk of male adenocarcinoma were observed. These results suggest that inherited genetic susceptibility may contribute to the development of lung cancer. In men, shared exposure to environmental factors among siblings may also be responsible for the increase in lung cancer risk.

DNA repair as an emerging target for COPD-lung cancer overlap

Cigarette smoking is the leading cause of lung cancer and chronic obstructive pulmonary disease (COPD). Many of the detrimental effects of cigarette smoke have been attributed to the development of DNA damage, either directly from chemicals contained in cigarette smoke or as a product of cigarette smoke-induced inflammation and oxidative stress. In this review, we discuss the environmental, epidemiological, and physiological links between COPD and lung cancer and the likely role of DNA damage and repair in COPD and lung cancer development. We explore alterations in DNA damage repair by DNA repair proteins and pathways. We discuss emerging data supporting a key role for the DNA repair protein, xeroderma pigmentosum group C (XPC), in cigarette smoke-induced COPD and early lung cancer development. Understanding the interplay between cigarette smoke, DNA damage repair, COPD, and lung cancer may lead to prognostic tools and new, potentially targetable, pathways for lung cancer prevention and treatment.

A prospective study of dietary polyunsaturated fatty acids intake and lung cancer risk

Animal studies have shown that polyunsaturated fatty acids (PUFAs) have antineoplastic and anti-inflammatory properties. Results from epidemiologic studies on specific types of PUFAs for lung cancer risk, however, are inconclusive. We prospectively evaluated the association of specific types of dietary PUFA intakes and lung cancer risk in two population-based cohort studies, the Shanghai Women's Health Study (SWHS) and Shanghai Men's Health Study (SMHS) with a total of 121,970 study participants (i.e., 65,076 women and 56,894 men). Dietary fatty acid intakes were derived from data collected at the baseline using validated food frequency questionnaires (FFQs). Cox proportional hazards model was performed to assess the association between PUFAs and lung cancer risk. Total, saturated and monounsaturated fatty acid intakes were not significantly associated with lung cancer risk. Total PUFAs intake was inversely associated with lung cancer risk [HRs and respective 95% CIs for quintiles 2-5 vs quintile 1: 0.84 (0.71-0.98), 0.97 (0.83-1.13), 0.86 (0.74-1.01) and 0.85 (0.73-1.00), ptrend  = 0.11]. However, DHA intake was positively associated with lung cancer risk [HRs and 95% CIs: 1.01 (0.86-1.19), 1.20 (1.03-1.41), 1.21 (1.03-1.42) and 1.24 (1.05-1.47), ptrend  = 0.001]. The ratio of n-6 PUFAs to n-3 PUFAs (i.e., 7:1) was inversely associated with lung cancer risk, particularly among never-smokers and adenocarcinoma patients. Total PUFAs and the ratio between n-6 PUFAs and n-3 PUFAs were inversely associated with lung cancer risk. This study highlights an important public health impact of PUFA intakes toward intervention/prevention programs of lung cancer.

Genetic modifiers of radon-induced lung cancer risk: a genome-wide interaction study in former uranium miners

PURPOSE

Radon is a risk factor for lung cancer and uranium miners are more exposed than the general population. A genome-wide interaction analysis was carried out to identify genomic loci, genes or gene sets that modify the susceptibility to lung cancer given occupational exposure to the radioactive gas radon.

METHODS

Samples from 28 studies provided by the International Lung Cancer Consortium were pooled with samples of former uranium miners collected by the German Federal Office of Radiation Protection. In total, 15,077 cases and 13,522 controls, all of European ancestries, comprising 463 uranium miners were compared. The DNA of all participants was genotyped with the OncoArray. We fitted single-marker and in multi-marker models and performed an exploratory gene-set analysis to detect cumulative enrichment of significance in sets of genes.

RESULTS

We discovered a genome-wide significant interaction of the marker rs12440014 within the gene CHRNB4 (OR = 0.26, 95% CI 0.11-0.60, p = 0.0386 corrected for multiple testing). At least suggestive significant interaction of linkage disequilibrium blocks was observed at the chromosomal regions 18q21.23 (p = 1.2 × 10-6), 5q23.2 (p = 2.5 × 10-6), 1q21.3 (p = 3.2 × 10-6), 10p13 (p = 1.3 × 10-5) and 12p12.1 (p = 7.1 × 10-5). Genes belonging to the Gene Ontology term "DNA dealkylation involved in DNA repair" (GO:0006307; p = 0.0139) or the gene family HGNC:476 "microRNAs" (p = 0.0159) were enriched with LD-blockwise significance.

CONCLUSION

The well-established association of the genomic region 15q25 to lung cancer might be influenced by exposure to radon among uranium miners. Furthermore, lung cancer susceptibility is related to the functional capability of DNA damage signaling via ubiquitination processes and repair of radiation-induced double-strand breaks by the single-strand annealing mechanism.

Fine mapping of MHC region in lung cancer highlights independent susceptibility loci by ethnicity

The basis for associations between lung cancer and major histocompatibility complex genes is not completely understood. Here the authors further consider genetic variation within the MHC region in lung cancer patients and identify independent associations within HLA genes that explain MHC lung cancer associations in Europeans and Asian populations.

Lung cancer has several genetic associations identified within the major histocompatibility complex (MHC); although the basis for these associations remains elusive. Here, we analyze MHC genetic variation among 26,044 lung cancer patients and 20,836 controls densely genotyped across the MHC, using the Illumina Illumina OncoArray or Illumina 660W SNP microarray. We impute sequence variation in classical HLA genes, fine-map MHC associations for lung cancer risk with major histologies and compare results between ethnicities. Independent and novel associations within HLA genes are identified in Europeans including amino acids in the HLA-B*0801 peptide binding groove and an independent HLA-DQB1*06 loci group. In Asians, associations are driven by two independent HLA allele sets that both increase risk in HLA-DQB1*0401 and HLA-DRB1*0701; the latter better represented by the amino acid Ala-104. These results implicate several HLA–tumor peptide interactions as the major MHC factor modulating lung cancer susceptibility.