Polymorphisms in Long Noncoding RNA-Prostate Cancer-Associated Transcript 1 Are Associated with Lung Cancer Susceptibility in a Northeastern Chinese Population

Associations of long non-coding RNAs HOTAIR, LINC00951, POLR2E and HULC polymorphisms with the risk of esophageal and esophagogastric junction cancer in a western population: a case-control study

BACKGROUND

The incidence of single-nucleotide-polymorphisms with malignant potential in esophageal cancer tissues has only been sparsely investigated in the west. Hence, we explored the contribution of four long non-coding RNAs' polymorphisms HOTAIR rs920778, LINC00951 rs11752942, POLR2E rs3787016 and HULC rs7763881 in esophageal cancer susceptibility.

METHODS AND RESULTS

Formalin-fixed paraffin-embedded tissue specimens from 95 consecutive patients operated for esophageal/esophagogastric junction carcinoma during 25/03/2014-25/09/2018 were processed. Demographic data, histopathological parameters, surgical and oncological outcomes were collected. DNA findings of the abovementioned population were compared with 121 healthy community controls. Both populations were of European/Greek ancestry. Sixty-seven patients underwent Ivor Lewis/McKeown esophagectomy for either squamous cell esophageal carcinoma (N = 6) or esophageal/esophagogastric junction Siewert I or II adenocarcinoma (N = 61). Twenty-eight patients were subjected to extended total gastrectomy for esophagogastric junction Siewert III adenocarcinoma. Neither LINC00951 rs11752942 nor HULC rs7763881 polymorphisms were detected more frequently in esophageal cancer patients compared with healthy community subjects. A significantly higher presence of HOTAIR rs920778 TT genotype in esophagogastric junction Siewert I/II adenocarcinoma was identified. POLR2E rs3787016 C allele and CC genotypes were overrepresented in the control group, and when found in esophageal cancer carriers were associated with earlier disease stages, as well as with minor lymph node involvement and lesser metastatic potential.

CONCLUSIONS

HOTAIR rs920778 may serve as a potential therapeutic suppression target, while POLR2E rs3787016 may represent a valuable biomarker to evaluate esophageal cancer predisposition and predict treatment response and prognosis. Clinical implications of these findings need to be verified with further prospective studies with larger sample-size.

LncRNA polymorphisms and lung cancer risk

Lung cancer (LC) imposes a significant burden, and is associated with high mortality and morbidity among malignant tumors. Aberrant expression of particular lncRNAs is closely linked to LC. LncRNA polymorphisms cause abnormal expression levels and/or structural dysfunction. They can affect the progression of cancer, survival, response to chemotherapy and recurrence rates in cancer patients. The present article provides a comprehensive overview of the effect of lncRNA genetic polymorphisms on LC. It is proposed that lncRNA-related variants can be used to predict cancer risk and therapeutic outcomes. More large-scale trials on diverse ethnic groups are required to validate the results, thus personalizing LC therapy based on lncRNA genotypes.

MALAT1 Polymorphisms and Lung Cancer Susceptibility in a Chinese Northeast Han Population

Background: LncRNA MALAT1 (metastasis-associated lung adenocarcinoma transcript 1) was competitive endogenous RNA (ceRNA) involved in various molecular processes for metastasis development in lung cancer. Single nucleotide polymorphisms (SNPs) in MALAT1 gene might be predictive markers for lung cancer. In our study, we selected rs619586 and rs3200401 in MALAT1 gene to explore their effects on lung cancer susceptibility. Methods: The case-control study included 444 lung cancer cases and 460 healthy controls. Genotyping was performed by Taqman allelic discrimination method. Logistic regression, Student t-test, and Chi-square test (χ² ) were used to analyze the data. Results: The findings of the study showed that rs3200401 was significantly associated with the risk of non-small cell lung cancer (NSCLC) and lung squamous cell carcinoma (LUSC). Compared with homozygous CC genotype, CT heterozygous genotype decreased risk of NSCLC (P^a = 0.034) and LUSC (P^a = 0.025). In addition, no statistical association was detected between rs619586 and lung cancer susceptibility. The interactions between genes and cigarette smoking were discovered via crossover analysis. However, there were no remarkable gene-environment interactions in additive and multiplicative model. Conclusion: Rs3200401 in lncRNA MALAT1 was associated with the susceptibility of non-small-cell lung cancer and lung squamous cell carcinoma. The gene-environmental (cigarette smoking) interactions were not notable.

LncRNA PRNCR1 rs1456315 and CCAT2 rs6983267 Polymorphisms on 8q24 Associated with Lung Cancer

Background

Long noncoding RNA single nucleotide polymorphisms (lncRNA-SNPs) PCAT1 rs710886, PRNCR1 rs1456315 and CCAT2 rs6983267 on 8q24 region present generalizability in the susceptibility to multiple cancers, however, the influence of rs710886, rs1456315 and rs6983267 on lung cancer has not been assessed. The aim of this study was to investigate associations between three lncRNA-SNPs and lung cancer.

Methods

A case–control study was performed on 438 patients with lung cancer and 456 healthy controls in the Han population from southern China. The collected samples were genotyped by the TaqMan genotyping, and the association with clinical characteristics, including age, gender, drinking status, smoking status, pathological types and clinical stages were analyzed. And the SNP function prediction was based on lncRNASNP2, RNAfold and GTEx.

Results

The rs1456315 T allele increased the risk of lung cancer [OR=1.95, 95% CI (1.58–2.43), P=0.003] compared to the rs1456315 C allele, and rs1456315 significantly increased the risk of lung cancer in the dominant model [OR=1.86, 95% CI (1.16–3.00), P=0.002]. The rs6983267 G allele, compared with the T allele, increased the risk of lung cancer [OR=1.29, 95% CI (1.07–1.57), P=0.007], and rs6983267 was identified as a risk factor for lung cancer [OR=1.28, 95% CI (1.06–1.55), P=0.003] in the additive model. Both rs1456315 and rs6983267 demonstrated significance after adjusting for the smoking status, drinking status and age. The structure prediction found rs6983267 and rs1456315 influence the secondary structure of its lncRNA. The results from lncRNASNP2 indicated that rs6983267 and rs1456315 change gain/loss target of miRNAs.

Conclusion

PRNCR1 rs1456315 and CCAT2 rs6983267 on 8q24 region are significantly associated with lung cancer in the Han population of southern China and alter the potential biological function in bioinformatic analysis, and the results further extended generalism of the susceptibility of cancer-associated lncRNA-SNPs to lung cancer and underlying mechanism involved in lung cancer.

The potential of long noncoding RNAs for precision medicine in human cancer

Precision medicine promises to better classify patients by individual clinical and biological biomarkers, which may provide an accurate assessment of disease risk, diagnosis, prognosis and treatment response. Cancer frequently displays substantial inter-tumor and intra-tumor heterogeneity and hence oncology is well suited for application of precision approaches. Recent studies have demonstrated that dysregulated lncRNAs play pivotal roles in tumor heterogeneity. In this review, attention is focused on the potential applications of lncRNAs as biomarker candidates for cancer risk evaluation, detection, surveillance and prognosis. LncRNAs are often stable in clinical samples and easily detected. The functional implications and therapeutic potential of targeting lncRNAs in human cancer are further discussed. Finally, existing deficiencies and future perspectives in translating fundamental lncRNA knowledge into clinical practice are highlighted.

PCAT1: An oncogenic lncRNA in diverse cancers and a putative therapeutic target

The critical roles of long non-coding RNAs (lncRNAs) in the regulation of diverse biological functions has potentiated them as cancer biomarkers. Among these transcripts is the prostate cancer associated transcript 1 (PCAT1) which has been initially shown to exert oncogenic roles in prostate cancer. Further studies revealed its similar roles in various kinds of human malignancies including both solid tumors and hematological malignancies. Animal studies have shown that down-regulation of this lncRNA can attenuate tumor growth in a wide array of cancers including prostate cancer, colorectal cancer, squamous cell carcinoma lung cancer and hepatocellular carcinoma. Studies aimed at identification of diagnostic value of this lncRNA in human cancers reported various values ranging from 0.66 to 0.89 in diverse cancers with the best value reported in multiple myeloma. This lncRNA has a number of putative functional genomic variants such as rs1902432, rs2632159, rs1026411, rs710886, rs16901904 and rs710886 which can modify expression or function of PCAT1 thus altering the risk of human cancers. Based on aberrant expression of PCAT1 in malignancies of diverse origins, this lncRNA can be regarded as a therapeutic target in a vast array of cancers. Thus, modalities for efficient reduction of its expression would be beneficial for several patients.