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

Effect of single nucleotide polymorphisms on the structure of long noncoding RNAs and their interaction with RNA binding proteins

Long non-coding RNAs (lncRNA) are emerging as a new class of regulatory RNAs with remarkable potential to be utilized as therapeutic targets against many human diseases. Several genome-wide association studies (GWAS) have catalogued Single Nucleotide Polymorphisms (SNPs) present in the noncoding regions of the genome from where lncRNAs originate. In this study, we have selected 67 lncRNAs with GWAS-tagged SNPs and have also investigated their role in affecting the local secondary structures. Majority of the SNPs lead to changes in the secondary structure of lncRNAs to a different extent by altering the base pairing patterns. These structural changes in lncRNA are also manifested in form of alteration in the binding site for RNA binding proteins (RBPs) along with affecting their binding efficacies. Ultimately, these structural modifications may influence the transcriptional and post-transcriptional pathways of these RNAs, leading to the causation of diseases. Hence, it is important to understand the possible underlying mechanism of RBPs in association with GWAS-tagged SNPs in human diseases.

The Intergenic Type LncRNA (LINC RNA) Faces in Cancer with In Silico Scope and a Directed Lens to LINC00511: A Step toward ncRNA Precision

BACKGROUND

Long intergenic non-coding RNA, is one type of lncRNA, exerting various cellular activities, as does ncRNA, including the regulation of gene expression and chromatin remodeling. The abnormal expression of lincRNAs can induce or suppress carcinogenesis.

MAIN BODY

LincRNAs can regulate cancer progression through different mechanisms and are considered as potential drug targets. Genetic variations such as single nucleotide polymorphisms (SNPs) in lincRNAs may affect gene expression and messenger ribonucleic acid (mRNA) stability. SNPs in lincRNAs have been found to be associated with different types of cancer, as well. Specifically, LINC00511 has been known to promote the progression of multiple malignancies such as breast cancer, colorectal cancer, lung cancer, hepatocellular carcinoma, and others, making it a promising cancer prognostic molecular marker.

CONCLUSION

LincRNAs have been proved to be associated with different cancer types through various pathways. Herein, we performed a comprehensive literature and in silico databases search listing lncRNAs, lincRNAs including LINC00511, lncRNAs' SNPs, as well as LINC00511 SNPs in different cancer types, focusing on their role in various cancer types and mechanism(s) of action.

Risk SNP-mediated LINC01614 upregulation drives head and neck squamous cell carcinoma progression via PI3K/AKT signaling pathway

As potential biomarkers and therapeutic targets, long noncoding RNAs (lncRNAs) are involved in the tumorigenesis of various tumors. Genetic variation in long noncoding regions can lead to lncRNA dysfunction and even cancer. Nevertheless, studies on the association between lncRNA-associated single-nucleotide polymorphisms (SNPs) and the risk of head and neck squamous cell carcinoma (HNSCC) remain inadequate. Here, we aimed to explore the association between SNPs in LINC01614 and HNSCC risk, and the potential role of LINC01614 in tumorigenesis. In this study, we found that rs16854802 A > G (odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.22-1.77, p < 0.001) and rs3113503 G > C (OR = 1.38, 95% CI: 1.15-1.64, p < 0.001) in LINC01614 increased the risk of HNSCC in the Chinese population. Functional bioinformatic analysis and luciferase reporter assay revealed that rs3113503 G > C variant disrupted the binding of miRNA-616-3p to LINC01614, which resulted in the increased expression of LINC01614. Further analysis of the TCGA database demonstrated that the upregulated LINC01614 in HNSCC cancer tissues was associated with poor prognostic in HNSCC patients. In vitro experiments showed that knockdown of LINC01614 inhibited the proliferation, invasion, and migration ability of HNSCC cells. Mechanistically, allele C of rs3113503 in LINC01614 was more effective than allele G in activating the PI3K/AKT signaling pathway. Moreover, the reduced expression of LINC01614 also inhibited the activation of the PI3K/AKT signaling pathway. In summary, our findings revealed that the risk SNP rs3113503 G > C in LINC01614 altered the binding to miR-616-3p, which led to increased LINC01614 expression and promoted HNSCC progression by activating the PI3K/AKT signaling pathway.

Assessing Long Non-coding RNAs in Tobacco-associated Oral Cancer

Cancer is one of the compelling and pegged diseases battled by clinicians and researchers worldwide. Among different types of cancer, oral cancer holds the sixth position globally. With an escalating prevalence in Asian countries, India, China, and Pakistan constitute a large proportion of total incidents of oral cancer patients in terms of new cases or deaths. This mounting prevalence is ascribed to poor oral hygiene and rampant use of substances earmarked as potential risk factors for the disease. Risk factors (dietary/lifestyle habits/occupational/environmental) trigger the activation of oncogenes, dysregulation of lncRNA and miRNA, and silence the tumor suppressor genes, which robustly contributes to the onset and progression of tumorigenesis in oral squamous cell carcinoma. Evidence suggests that specific carcinogens identified in tobacco and related products alter many cellular pathways predisposing to advanced stages of oral cancer. Long non-coding RNAs represent a broad group of heterogenous transcripts longer than 200 nucleotides which do not translate to form functional proteins. They regulate various cellular pathways by specifically interacting with other RNAs, DNA, and proteins. Their role in the pathogenesis of OSCC and other cancer is still being debated. In this review, we discuss the molecular insights of significant lncRNAs involved in some crucial deregulated pathways of tobacco-associated OSCC. The implications and challenges to harnessing the potential of lncRNAs as biomarkers in early diagnosis and targeted treatment have also been analyzed.

LncRNA GAS5 expression in non-small cell lung cancer tissues and its correlation with Ki67 and EGFR

OBJECTIVE

This research explored and analyzed LncRNA GAS5 expression in non-small cell lung cancer (NSCLC) tissues and its correlation with Ki67 and EGFR.

METHODS

A total of 130 samples of paraffin-embedded NSCLC tissues and para-cancerous normal tissues that were collected in the Department of Pathology from January 2014 to April 2016 were selected. The relative expression of LncRNA GAS5 and Ki67/EGFR in both NSCLC tissues and para-cancerous normal tissues were detected via RT-PCR and immunohistochemistry respectively. Subsequently, we analyzed the relative expression of LncRNA GAS5, the expression of Ki67/EGFR and its correlation with clinicopathological features and prognosis of patients, and studied the correlation between LncRNA GAS5 and Ki67/EGFR.

RESULTS

The relative expression of LncRNA GAS5 in NSCLC tissues was substantially less than that of the para-cancerous normal tissues (P<0.05). The positive expression rate of Ki67/EGFR in NSCLC tissues remarkably exceeded that in para-cancerous normal tissues (P<0.05). The relative expression of LncRNA GAS5 was correlated with the degree of tumor differentiation, TNM staging and lymph node metastasis (P<0.05). The positive expression rate of Ki67 and EGFR in NSCLC tissues was related to TNM stage and metastasis of lymph node (P<0.05). In addition, the survival of patients with high LncRNA GAS5 expression was obviously superior to those with low LncRNA GAS5 expression (P<0.05), patients with negative Ki67 had superior survival than those with positive Ki67 (P<0.05), and patients with negative EGFR had increased survival over those with positive EGFR (P<0.05). Moreover, the positive rates of Ki67 and EGFR in patients with low LncRNA GAS5 expressions were obviously higher than those with high LncRNA GAS5 expressions (P<0.05). The relative expression level of LncRNA GAS5 in NSCLC patients had a remarkably negative correlation with Ki67 and EGFR (P<0.05).

CONCLUSION

The decrease in LncRNA GAS5 expression and the over-express of Ki67/EGFR occur in NSCLC tissues, the expressions of LncRNA GAS5, Ki67 and EGFR are connected with the progression, metastasis and prognosis of tumor; and LncRNA GAS5 is related to the expression of Ki67 and EGFR. These three factors are involved in the tumorigenesis and growth of the NSCLC process.

Association between sex hormones regulation-related SNP rs12233719 and lung cancer risk among never-smoking Chinese women

BACKGROUND

The mechanism of rapidly increased non-small cell lung cancer (NSCLC) among never-smoking Chinese women has not been elucidated. Ovarian sex steroid hormones have been suggested to counteract lung cancer development, and sex hormone-binding globulin (SHBG) is essential in sex hormones regulation. This study aims to exploring single nucleotide polymorphisms (SNPs) in genomic regions associated with SHBG concentrations that contributed to never-smoking female NSCLC.

METHODS

Candidate genes were selected by a genome-wide association (GWAS) meta-analysis and gene expression profiles of never-smoking NSCLC of Chinese women. The candidate SNPs limited to common minor allele frequency (MAF), missense variant, ethnic heterogeneous distribution, and SNPs were genotyped using the TaqMan method. A two-stage case-control design was adopted for exploration and validation of associations between candidate SNPs and risk of NSCLC. All participants were never-smoking Chinese women. Chi-square test and multivariate logistic regression were applied.

RESULTS

Beginning with 12 genomic regions associated with circulating SHBG concentrations and gene expression profiles from never-smoking NSCLC in Chinese women, candidate SNP rs12233719 and rs7439366 both located in candidate gene UGT₂ B_7, which may be related to circulating SHBG concentrations and cancer risk, were identified. A two-stage case-control study was conducted in Shenyang and Tianjin represented as the training stage and validation stage, respectively. Under the dominant model, compared to individuals with the wild G/G genotype, the adjusted OR of those with the T allele was 1.58 (95% CI: 1.15-2.16) in Chinese Shenyang training set, and was 1.49 (95% CI: 1.02-2.18) in Chinese Tianjin validation set, both accompanied with a significant trend relationship consistently. UGT2B7 was upregulated in female NSCLC patients' tumor tissues and was associated with a poor prognosis in NSCLC.

CONCLUSION

Our findings indicated that a sex hormones regulation-related SNP rs12233719 was associated with never-smoking female lung cancer risk, which might partially explain NSCLC-susceptibility in Chinese women.

The Effects of Single Nucleotide Polymorphisms in Cancer RNAi Therapies

Tremendous progress in RNAi delivery methods and design has allowed for the effective development of siRNA-based therapeutics that are currently under clinical investigation for various cancer treatments. This approach has the potential to revolutionize cancer therapy by providing the ability to specifically downregulate or upregulate the mRNA of any protein of interest. This exquisite specificity, unfortunately, also has a downside. Genetic variations in the human population are common because of the presence of single nucleotide polymorphisms (SNPs). SNPs lead to synonymous and non-synonymous changes and they occur once in every 300 base pairs in both coding and non-coding regions in the human genome. Much less common are the somatic mosaicism variations associated with genetically distinct populations of cells within an individual that is derived from postzygotic mutations. These heterogeneities in the population can affect the RNAi's efficacy or more problematically, which can lead to unpredictable and sometimes adverse side effects. From a more positive viewpoint, both SNPs and somatic mosaicisms have also been implicated in human diseases, including cancer, and these specific changes could offer the ability to effectively and, more importantly, selectively target the cancer cells. In this review, we discuss how SNPs in the human population can influence the development and success of novel anticancer RNAi therapies and the importance of why SNPs should be carefully considered.

LINC00152 promotes pancreatic cancer cell proliferation, migration and invasion via targeting miR-150

Pancreatic cancer (PC) is one of the top deaths causing cancers with low 5-year survival rate. Long non-coding RNAs (lncRNAs) are recognized as a crucial type of nonprotein-coding transcripts implicated in tumorigenesis. Emerging evidence has implied that LINC00152 exerts the potential oncogenic functions in various cancers. Nevertheless, the role of LINC00152 in PC remains elusive. In the present study, we found that LINC00152 was significantly up-regulated while miR-150 was down-regulated both in tissues and cell lines of PC, indicating their negative correlation in PC progression. Functionally, overexpression of LINC00152 promoted cell proliferation, migration and invasion, while LINC00152 knockdown reversed these effects. Mechanistic experiments reveal that miR-150 acted as a target of LINC00152 confirmed by luciferase reporter assay. Moreover, inhibition of miR-150 could markedly attenuate the suppression of cell proliferation, migration and invasion by knocking down LINC00152. Altogether, our findings concluded that LINC00152 facilitated PC progression through inhibiting miR-150 expression, indicating an innovative therapeutic target for PC.

CircRNA_103762 promotes multidrug resistance in NSCLC by targeting DNA damage inducible transcript 3 (CHOP)

BACKGROUND

CircRNAs have been found to play crucial roles in multiple tumor including non-small cell lung cancer (NSCLC). Here, we researched the correlation between circRNA_103762 and chemotherapy resistance.

METHODS

RT-PCR assay was performed to detect circRNA_103762 and DNA damage inducible transcript 3 (CHOP) expression. CCK8 assay was performed to examine cell proliferation and IC₅₀ of different drug. Migration and invasion assay was used to detect cell migration and invasion.

RESULTS

In our study, circRNA_103762 expression was upregulated in NSCLC tissues and cell. Knockdown of circRNA_103762 can inhibited cell proliferation, migration and invasion in NSCLC. In addition, downregulation of circRNA_103762 promoted CHOP expression and inhibited multidrug resistance (MDR) in NSCLC.

CONCLUSION

Together, we demonstrated that circRNA_103762 is upregulated in NSCLC and functions as an oncogene in NSCLC, and circRNA_103762 enhanced MDR by inhibited CHOP expression in NSCLC cells. These results will help us understand the MDR of NSCLC, providing better effective therapy strategies for patients.

Circular RNA SMARCA5 may serve as a tumor suppressor in non-small cell lung cancer

BACKGROUND

This study aimed to investigate the correlation of circular RNA SMARCA5 (circ-SMARCA5) expression with clinicopathological characteristics and survival profiles, furthermore, to explore the function of circ-SMARCA5 on regulating cell proliferation and chemotherapy sensitivity in non-small cell lung cancer (NSCLC).

METHODS

A total of 460 NSCLC patients were retrospectively reviewed, and circ-SMARCA5 expressions in tumor tissue and adjacent tissue were detected by RT-qPCR. Clinical characteristics were collected. Disease-free survival (DFS) and overall survival (OS) were calculated. In vitro, circ-SMARCA5 overexpression and control overexpression plasmids were transfected into NCI-H1437 as well as NCI-H1299 cells, which were further treated with different concentrations of cisplatin and gemcitabine.

RESULTS

Circ-SMARCA5 expression was decreased in tumor tissues compared to adjacent tissues. Moreover, circ-SMARCA5 expression negatively correlated with tumor size, lymph node metastasis, and TNM stage, but positively correlated with DFS and OS. Subsequent analysis displayed that circ-SMARCA5 high expression independently predicted prolonged DFS and OS. In vitro, circ-SMARCA5 expression was reduced in NSCLC cell lines (NCI-H650, NCI-H1299, NCI-H1437, and A549) compared to human normal lung bronchus epithelial cell line (BEAS-2B). In NCI-H1437 and NCI-H1299 cells, cell proliferation was decreased by circ-SMARCA5 overexpression, furthermore, chemosensitivity to cisplatin and gemcitabine were enhanced in circ-SMARCA5 overexpression treated cells compared to the control cells.

CONCLUSION

Circ-SMARCA5 may serve as a tumor suppressor in NSCLC, which provides insight to the exploration of novel strategies in NSCLC management.

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.