Association between Long Non-coding RNA POLR2E rs3787016 Polymorphism and Cancer Susceptibility: A Meta-analysis of 8725 Cancer Cases and 10710 Controls

authors:

avatar Saeid Ghavami ORCID 1 , * , avatar Mohsen Taheri ORCID 2 , avatar Mohammad Hashemi ORCID 3

Human Anatomy and Cell Science, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
Genetics of Non-communicable Disease Research Canter, Zahedan University of Medical Sciences, Zahedan, Iran
Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
Shiraz E-Medical Journal: Vol.22, issue 4; e102065
published online: November 28, 2020
article type: Systematic Review
received: February 25, 2020
revised: September 2, 2020
accepted: September 4, 2020
DOI: https://doi.org/10.5812/semj.102065

how to cite: Ghavami S, Taheri M, Hashemi M. Association between Long Non-coding RNA POLR2E rs3787016 Polymorphism and Cancer Susceptibility: A Meta-analysis of 8725 Cancer Cases and 10710 Controls. Shiraz E-Med J. 2021;22(4):e102065. https://doi.org/10.5812/semj.102065.

Abstract

Objectives:

Several studies have reported a correlation between the POLR2E rs3787016 polymorphism and cancer development, but findings are inconsistent. Therefore, we designed the current study to understand how rs3787016 polymorphism impacts cancer susceptibility.

Methods:

We searched the Scopus, Web of Science, and PubMed databases for studies related to the topic of interest published up to March 2019. A total of 11 relevant studies, encompassing 8,761 cancer cases and 10,534 controls, were retrieved and subject to quantitative analysis. The strength of the relationship was evaluated using the pooled odds ratios (ORs) with 95% confidence intervals (CIs).

Results:

Overall, the findings proposed a positive association between rs189037 polymorphism and susceptibility to cancer in homozygous (OR = 1.32, 95% CI = 1.11 - 1.57, P = 0.002, TT vs. CC), recessive (OR = 1.21, 95% CI = 1.06-1.39, P = 0.005, TT vs. CT + CC), and allele (OR = 1.12, 95% CI = 1.02-1.22, P = 0.021, T vs. C) genetic models. Stratified analysis showed that rs3787016 increased the risk of prostate and breast cancer. In addition, we found a significant association between the variant and increased cancer risk in Asian and Caucasian populations.

Conclusions:

In summary, the findings of the current meta-analysis suggest that the POLR2E rs3787016 polymorphism is an indicator of cancer susceptibility.

1. Context

Cancer constitutes one of the most important global health concerns (1). The precise mechanisms of carcinogenesis remain largely elusive, but both genomic and environmental factors have been recognized to contribute to cancer development (2-7). Over the years, it has become evident that certain specific single nucleotide polymorphisms (SNPs) are related to cancer predisposition (6, 8-11).

Long non-coding RNAs (lncRNAs), mainly the transcripts of RNA polymerase II, are a class of specific non-coding RNA molecules with a length of more than 200 nucleotides (nt) (12, 13). Accumulating evidence reveals that lncRNA plays an imperative role in numerous biological processes and signaling pathways, such as cell cycle progression, apoptosis, transcription, splicing, translation, epigenetics, and regulation of gene expression (12-15). It has been proposed that alterations in the expression of lncRNAs are involved in cancer development and progression (16-19).

The POLR2E LncRNA gene is mapped to chromosome 19 (19p13). Several investigations have focused on identifying a relationship between the POLR2E rs3787016 polymorphism and the risk of cancer in various populations (20-28), but, overall, the findings have been inconsistent and conflicting. To comprehensively assess the correlation between the POLR2E rs3787016 polymorphism and cancer susceptibility, we designed and performed the current meta-analysis. Three recent meta-analyses have focused on POLR2E rs3787016 polymorphism and cancer. Chu et al. covered only four studies about POLR2E rs3787016 polymorphism, while in the current meta-analysis, we covered 11 manuscripts; therefore, our study is much more comprehensive and conclusive. Chen et al. investigated POLR2E rs3787016 polymorphism in liver and lung cancer and used five articles in their meta-analysis (25); therefore, our meta-analysis with 11 articles is more conclusive and covers more types of cancers. Huang et al. investigated POLR2E rs3787016 polymorphism in prostate cancer, while our meta-analysis covered all types of cancers and investigated POLR2E rs3787016 polymorphism in these cancers. Therefore, the current meta-analysis on POLR2E rs3787016 polymorphism in cancer would be the most comprehensive investigation on the evaluation of POLR2E rs3787016 polymorphism and the risk of cancer.

2. Methods

2.1. Literature Search

Our team performed an extensive literature review using the Scopus, Web of Science, and PubMed electronic databases to retrieve papers of interest published up to March 2019. The search keywords were “POLR2E” and “rs3787016 or variation or mutation or polymorphism” and “cancer or tumor or carcinoma or neoplasms”. We considered studies eligible if they examined the relationship between POLR2E rs3787016 and cancer risk.

2.2. Inclusion and Exclusion Criteria

We applied similar methods as used in our previous investigations to identify the relevant literature for the current meta-analysis (29). Briefly, eligible articles were incorporated in this meta-analysis if they met the following criteria: a) Evaluation of the relationship between POLR2E rs3787016 polymorphism and susceptibility to cancer, b) Appropriate data for estimating the odds ratios (ORs) and 95% confidence intervals (CIs), and c) Sufficient data representing the genotype and allele frequency of cases and controls. Accordingly, studies with the following criteria were excluded: a) Duplicate publications and overlapping data, b) Reviews, conference papers, case reports, letters, and case-only studies, and c) Inadequate information for data extraction.

2.3. Data Extraction

Two of our investigators independently and blindly extracted the following information from each eligible study: The first author’s name, publication year, country of origin, the ethnicity of the study population, genotyping methods, total number of cases and controls, distributions of genotypes and alleles in cases and controls, and p-value of the Hardy-Weinberg Equilibrium (HWE) (Table 1).

2.4. Statistical Analysis

The χ2 test was performed to assess whether the genotype distribution in the controls was in the HWE. The strength of the association between the presence of POLR2E rs3787016 polymorphism and cancer risk was evaluated by calculating pooled ORs and corresponding 95% CIs in six genetic models. The significance of the pooled ORs was assessed by the Z-test. The results with a P value < 0.05 were considered statistically significant.

The heterogeneity among studies was determined by the χ2 test-based Q statistics. A PQ value less than 0.10 indicated the presence of inter-study heterogeneity, in which the random-effects model was used to determine the ORs. Otherwise, the fixed-effects model was applied.

Publication bias was evaluated using Begg’s funnel plots and Egger’s tests. Sensitivity analysis was performed by sequentially eliminating one single study at a time to examine its effect on the pooled ORs. All statistical analyses were conducted using STATA 14.1 software.

3. Results

A flow diagram of the literature selection procedure is illustrated in Figure 1. Ultimately, a total of 11 case-control studies from nine articles (20-28), comprising 8,761 cancer cases and 10,534 controls, were subject to the pooled analysis. The main characteristics of eligible studies are presented in Table 1.

Flowchart of the study selection procedure
Flowchart of the study selection procedure
Figure 1.

Flowchart of the study selection procedure

Table 1.

Characteristics of All Studies Included in the Meta-analysis (POLR2E 3787016)

AuthorYearCountryEthnicityCancer TypeSource of ControlGenotyping MethodCase / ControlCasesControlsHWE (P)
CCCTTTCTCCCTTTCT
Cao DL (21)2014ChinaAsianProstate cancerPBPCR-RFLP1015/1032313513189113989135752415112388260.064
Chen B (25)2018ChinaAsianLiver cancerHBPCR-RFLP480/800922001883845761503642866649360.075
Chen B (25)2018ChinaAsianLung cancerHBPCR-RFLP550/8001192501814886121503642866649360.075
Chen B (26)2018ChinaAsianThyroid cancerHBPCR-RFLP409/800511831752855331503642866649360.075
Chen B (28)2019ChinaAsianBreast CancerHBPCR-RFLP480/58860218202338622902321784125880.287
Chen B (28)2019ChinaAsianCervical cancerHBPCR-RFLP348/58846167171259509902321784125880.287
Jin G (20)2011USACaucasianProstate cancerPBTaqMan assay4196/5007226116382976160223229301800277766023540.997
Kang M (23) 2015ChinaAsianEsophageal cancerHBPCR-RFLP369/37013014990409329105194714043360.268
Nikolic ZZ (22)2013SerbiaCaucasianProstate cancerHBTaqMan assay261/1061401002138014255447154580.544
Sattarifard H (24)2018IranAsianProstate cancerHBPCR-RFLP178/18065112163293333144393210.468
Xu T (27)2017ChinaAsianBreast cancerPBMassARRAy439/43913720993483395149226645243540.144

3.1. Quantitative Data Analysis

We examined the association between the POLR2E rs3787016 polymorphism and the risk of cancer through a meta-analysis of the overall population (Table 2). Our findings revealed that the rs3787016 polymorphism significantly increased the risk of cancer in homozygous (OR = 1.32, 95% CI = 1.11-1.57, P = 0.002, TT vs. CC), recessive (OR = 1.21, 95% CI = 1.06-1.39, P = 0.005, TT vs. CT + CC), and allele (OR = 1.12, 95% CI = 1.02-1.22, P = 0.021, T vs. C) genetic models (Figure 2).

Table 2.

The Pooled Odds Ratios and 95% Confidence Intervals for the Association Between POLR2E Polymorphism and Cancer Susceptibility

Genetic ModelTest Of AssociationHeterogeneity (I2 (%), P)Publication Bias Tests
OR (95%CI)ZPχ 2I2 (%)PEgger’s Test PBegg’s Test P
CT vs. CC1.05 (0.92 - 1.21)0.720.47424.8959.80.0060.2910.697
TT vs. CC1.32 (1.11 - 1.57)3.090.00224.9960.00.0050.6400.938
CT + TT vs. CC1.12 (0.98 - 1.29)1.630.10427.9664.20.0020.4380.935
TT vs. CT + CC1.21 (1.06 - 1.39)2.820.00525.3660.60.0050.5700.938
T vs. C1.12 (1.02 - 1.22)2.300.02133.5370.20.0000.2650.586
Forest plot representing the association between the rs3787016 polymorphism and overall cancer risk in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Forest plot representing the association between the rs3787016 polymorphism and overall cancer risk in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Figure 2.

Forest plot representing the association between the rs3787016 polymorphism and overall cancer risk in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.

Subgroup analysis based on cancer type showed that the polymorphism was associated with the risk of PCa (OR = 1.16, 95% CI = 1.07-1.25, P = 0.000, CT vs. CC; OR = 1.38, 95% CI = 1.20 - 1.59, P = 0.000, TT vs. CC; OR = 1.19, 95% CI = 1.11-1.28, CT + TT vs. CC), and breast cancer (OR = 1.64, 95% CI = 1.25-2.16, P = 0.000, TT vs. CC; OR = 1.40, 95% CI = 1.14 - 1.72, P = 0.001, TT vs. CT + CC; OR = 1.25, 95% CI = 1.10 - 1.43, P = 0.001, T vs. C) (Table 3). In addition, stratified analysis by ethnicity (Table 3) revealed that rs3787016 was associated with increased cancer risk particularly in Asian (OR = 1.31, 95% CI = 1.05-1.63, P = 0.019, TT vs. CC; OR = 1.20, 95% CI = 1.02-1.41, P = 0.031, TT vs. CT + CC) and Caucasian (OR = 1.38, 95% CI = 1.17-1.64, P = 0.000, TT vs. CC; OR = 1.30, 95% CI = 1.10-1.53, P = 0.002, TT vs. CT + CC; OR = 1.25, 95% CI = 1.10 - 1.43, P = 0.001, T vs. C) populations.

Table 3.

Stratified Analysis of Variants on Susceptibility to Cancer

Genetic ModelNo.Test of AssociationHeterogeneity Test
OR (95%CI)ZPχ2I2(%)P
Cancer Type
Prostate cancer4
CT vs. CC1.16 (1.07 - 1.25)3.710.0001.770.00.622
TT vs. CC1.38 (1.20 - 1.59)4.440.0002.930.00.402
CT+TT vs. CC1.19 (1.11 - 1.28)4.640.0002.810.00.423
TT vs. CT + CC1.07 (0.77 - 1.51)0.410.67812.5676.10.006
T vs. C1.05 (0.89 - 1.25)0.580.56211.7574.50.008
Breast cancer2
CT vs. CC1.17 (0.84 - 1.62)0.920.3561.9047.40.168
TT vs. CC1.64 (1.25 - 2.16)3.530.0000.070.00.791
CT + TT vs. CC1.29 (0.96 - 1.74)1.700.0891.7442.70.187
TT vs. CT + CC1.40 (1.14 - 1.72)3.180.0010.660.00.415
T vs. C1.25 (1.10 - 1.43)3.330.0010.220.00.638
Ethnicity
Asian9
CT vs. CC1.04 (0.87 - 1.25)0.430.67020.5661.10.008
TT vs. CC1.31 (1.05 - 1.63)2.350.01924.5167.40.002
CT + TT vs. CC1.12 (0.93 - 1.36)1.190.23425.5168.60.001
TT vs. CT + CC1.20 (1.02 - 1.41)2.160.03124.8167.80.002
T vs. C1.11 (0.98 - 1.25)1.620.10631.8774.90.000
Caucasian2
CT vs. CC1.13 (0.94 - 1.37)1.320.1861.2922.50.256
TT vs. CC1.38 (1.17 - 1.64)3.730.0000.120.00.728
CT + TT vs. CC1.17 (1.00 - 1.38)1.910.0561.2217.90.270
TT vs. CT + CC1.30 (1.10 - 1.53)3.080.0020.010.00.914
T vs. C1.25 (1.10 - 1.43)3.330.0010.220.00.638

3.2. Heterogeneity and Publication Bias

As shown in Table 2, inter-study heterogeneity was detected in all genetic models; therefore, the random-effects model was applied for pooled analysis. In the meta-analysis of the overall population, the Begg’s funnel plot and Egger’s tests did not indicate the presence of publication bias (Figure 3 and Table 2).

Begg’s funnel plot testing publication bias for the association between the rs3787016 polymorphism and overall cancer risk assessed in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Begg’s funnel plot testing publication bias for the association between the rs3787016 polymorphism and overall cancer risk assessed in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Figure 3.

Begg’s funnel plot testing publication bias for the association between the rs3787016 polymorphism and overall cancer risk assessed in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.

3.3. Sensitivity Analysis

We did not find any significant changes in the pooled OR and corresponding 95% CI in the homozygous and recessive genetic models (Figure 4) when individual study results were sequentially omitted, verifying the stability and reliability of the pooled results.

Sensitivity analyses for studies on the association of rs3787016 polymorphism with cancer risk determined in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Sensitivity analyses for studies on the association of rs3787016 polymorphism with cancer risk determined in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.
Figure 4.

Sensitivity analyses for studies on the association of rs3787016 polymorphism with cancer risk determined in heterozygous (A), homozygous (B), dominant (C), recessive (D), and allele (E) genetic models.

4. Discussion

LncRNAs, a novel class of RNAs, have recently become a hot topic of attention due to their fundamental functions, which might be related to their oncogenic and/or tumor-suppressive activities (30, 31) in cellular and molecular mechanisms that drive cancer (18). LncRNAs interact with biological macromolecules (DNA, RNA, and protein) to partake in diverse regulatory activities, such as chromatin remodeling, RNA splicing, and editing (32, 33), as well as the regulation of gene expression at the epigenetic and post-transcription levels (34-36). Genome-wide Association Studies (GWAS) have revealed that lncRNAs have an important role in cancer initiation and progression (37, 38). The expression and function of lncRNAs could be affected by genetic variations in the lncRNAs gene. In this regard, numerous investigations have examined the relationship between the POLR2E rs3787016 polymorphism and various cancers, including squamous cell carcinoma (ESCC) (23), prostate (20-22, 24), thyroid (26), breast (27, 28), cervical (28), liver, and lung cancer (25). In the current study, we conducted a meta-analysis to address the precise role of POLR2E rs3787016 in overall cancer susceptibility. The pooled analysis of 11 eligible studies encompassing 8,761 cancer cases and 10,534 controls revealed that the rs3787016 polymorphism of the POLR2E gene significantly increased the risk of overall cancer in homozygous, recessive, and allele genetic models. Further stratified analyses indicated that this variant was particularly associated with the risk of prostate and breast cancer and increased overall cancer susceptibility in Asian and Caucasian populations. In line with our findings, a previous meta-analysis of four studies (comprising 5,841 cases and 6,702 controls) proposed an association between rs3787016 polymorphism and cancer susceptibility (39), whereas another seven studies (including 7,310 cases 8,554 controls) revealed a correlation with overall cancer risk (25). The statistical power of our meta-analysis is higher than that of previously published meta-analyses due to the inclusion of a larger sample size.

Our current investigation has several weaknesses that should be considered: 1) Heterogeneity existed between studies, which may be the result of differences in cancer type and/or ethnic background, 2) The number of studies used for stratified analyses was relatively small (four studies for prostate cancer, two studies for breast cancer, and two studies for Caucasian population), rendering limited statistical power, and 3) Only one SNP in the POLR2E gene was analyzed. Due to these limitations, the findings should be interpreted with caution.

In conclusion, our meta-analysis suggests that the rs3787016 polymorphism of POLR2E is associated with increased cancer susceptibility. Well-designed, large-scale, case-control studies are warranted to further verify and validate our results.

References

  • 1.

    Hashemi M, Karami S, Sarabandi S, Moazeni-Roodi A, Malecki A, Ghavami S, et al. Association between PD-1 and PD-L1 Polymorphisms and the Risk of Cancer: A Meta-Analysis of Case-Control Studies. Cancers (Basel). 2019;11(8). [PubMed ID: 31405171]. [PubMed Central ID: PMC6721817]. https://doi.org/10.3390/cancers11081150.

  • 2.

    Ntais C, Polycarpou A, Tsatsoulis A. Molecular epidemiology of prostate cancer: androgens and polymorphisms in androgen-related genes. Eur J Endocrinol. 2003;149(6):469-77. [PubMed ID: 14640986]. https://doi.org/10.1530/eje.0.1490469.

  • 3.

    Chokkalingam AP, Stanczyk FZ, Reichardt JK, Hsing AW. Molecular epidemiology of prostate cancer: hormone-related genetic loci. Front Biosci. 2007;12:3436-60. [PubMed ID: 17485312]. https://doi.org/10.2741/2325.

  • 4.

    Zhou X, Wei L, Jiao G, Gao W, Ying M, Wang N, et al. The association between the APE1 Asp148Glu polymorphism and prostate cancer susceptibility: a meta-analysis based on case-control studies. Mol Genet Genomics. 2015;290(1):281-8. [PubMed ID: 25234162]. https://doi.org/10.1007/s00438-014-0916-3.

  • 5.

    Hashemi M, Moazeni-Roodi A, Taheri M. Association of APOBEC3 deletion with cancer risk: A meta-analysis of 26 225 cases and 37 201 controls. Asia Pac J Clin Oncol. 2019;15(6):275-87. [PubMed ID: 30693645]. https://doi.org/10.1111/ajco.13107.

  • 6.

    Moazeni-Roodi A, Hashemi M. Association between miR-124-1 rs531564 polymorphism and risk of cancer: An updated meta-analysis of case-control studies. EXCLI J. 2018;17:608-19. [PubMed ID: 30108465]. [PubMed Central ID: PMC6088220]. https://doi.org/10.17179/excli2018-1419.

  • 7.

    Moazeni-Roodi A, Aftabi S, Sarabandi S, Karami S, Hashemi M, Ghavami S. Genetic association between HOTAIR gene and the risk of cancer: an updated meta-analysis. J Genet. 2020;99. [PubMed ID: 32661201].

  • 8.

    Hashemi M, Moazeni-Roodi A, Ghavami S. Association between CASP3 polymorphisms and overall cancer risk: A meta-analysis of case-control studies. J Cell Biochem. 2018. [PubMed ID: 30368918]. https://doi.org/10.1002/jcb.27994.

  • 9.

    Moazeni-Roodi A, Ghavami S, Ansari H, Hashemi M. Association between the flap endonuclease 1 gene polymorphisms and cancer susceptibility: An updated meta-analysis. J Cell Biochem. 2019;120(8):13583-97. [PubMed ID: 30937972]. https://doi.org/10.1002/jcb.28633.

  • 10.

    Nikseresht M, Shahverdi M, Dehghani M, Abidi H, Mahmoudi R, Ghalamfarsa G, et al. Association of single nucleotide autophagy-related protein 5 gene polymorphism rs2245214 with susceptibility to non-small cell lung cancer. J Cell Biochem. 2018. [PubMed ID: 30242869]. https://doi.org/10.1002/jcb.27467.

  • 11.

    Hashemi M, Aftabi S, Moazeni-Roodi A, Sarani H, Wiechec E, Ghavami S. Association of CASP8 polymorphisms and cancer susceptibility: A meta-analysis. Eur J Pharmacol. 2020;881:173201. [PubMed ID: 32442541]. https://doi.org/10.1016/j.ejphar.2020.173201.

  • 12.

    Kung JT, Colognori D, Lee JT. Long noncoding RNAs: past, present, and future. Genetics. 2013;193(3):651-69. [PubMed ID: 23463798]. [PubMed Central ID: PMC3583990]. https://doi.org/10.1534/genetics.112.146704.

  • 13.

    Orom UA, Derrien T, Beringer M, Gumireddy K, Gardini A, Bussotti G, et al. Long noncoding RNAs with enhancer-like function in human cells. Cell. 2010;143(1):46-58. [PubMed ID: 20887892]. [PubMed Central ID: PMC4108080]. https://doi.org/10.1016/j.cell.2010.09.001.

  • 14.

    Bhan A, Soleimani M, Mandal SS. Long Noncoding RNA and Cancer: A New Paradigm. Cancer Res. 2017;77(15):3965-81. [PubMed ID: 28701486]. https://doi.org/10.1158/0008-5472.CAN-16-2634.

  • 15.

    Huarte M. The emerging role of lncRNAs in cancer. Nat Med. 2015;21(11):1253-61. [PubMed ID: 26540387]. https://doi.org/10.1038/nm.3981.

  • 16.

    Feng LL, Shen FR, Zhou JH, Chen YG. Expression of the lncRNA ZFAS1 in cervical cancer and its correlation with prognosis and chemosensitivity. Gene. 2019;696:105-12. [PubMed ID: 30738960]. https://doi.org/10.1016/j.gene.2019.01.025.

  • 17.

    Shan S, Li HF, Yang XY, Guo S, Guo Y, Chu L, et al. Higher lncRNA CASC15 expression predicts poor prognosis and associates with tumor growth in cervical cancer. Eur Rev Med Pharmacol Sci. 2019;23(2):507-12. [PubMed ID: 30720157]. https://doi.org/10.26355/eurrev_201901_16862.

  • 18.

    Cui N, Liu J, Xia H, Xu D. LncRNA SNHG20 contributes to cell proliferation and invasion by upregulating ZFX expression sponging miR-495-3p in gastric cancer. J Cell Biochem. 2019;120(3):3114-23. [PubMed ID: 30520073]. https://doi.org/10.1002/jcb.27539.

  • 19.

    Chen JB, Zhu YW, Guo X, Yu C, Liu PH, Li C, et al. Microarray expression profiles analysis revealed lncRNA OXCT1-AS1 promoted bladder cancer cell aggressiveness via miR-455-5p/JAK1 signaling. J Cell Physiol. 2019;234(8):13592-601. [PubMed ID: 30609030]. https://doi.org/10.1002/jcp.28037.

  • 20.

    Jin G, Sun J, Isaacs SD, Wiley KE, Kim ST, Chu LW, et al. Human polymorphisms at long non-coding RNAs (lncRNAs) and association with prostate cancer risk. Carcinogenesis. 2011;32(11):1655-9. [PubMed ID: 21856995]. [PubMed Central ID: PMC3204347]. https://doi.org/10.1093/carcin/bgr187.

  • 21.

    Cao DL, Gu CY, Zhu Y, Dai B, Zhang HL, Shi GH, et al. Polymorphisms at long non-coding RNAs and prostate cancer risk in an eastern Chinese population. Prostate Cancer Prostatic Dis. 2014;17(4):315-9. [PubMed ID: 25224557]. https://doi.org/10.1038/pcan.2014.34.

  • 22.

    Nikolic ZZ, Brajuskovic GN, Pavicevic D, Kojic AS, Vukotic VD, Tomovic SM, et al. Assessment of possible association between rs3787016 and prostate cancer risk in Serbian population. Int J Clin Exp Med. 2013;6(1):57-66. [PubMed ID: 23236559]. [PubMed Central ID: PMC3515979].

  • 23.

    Kang M, Sang Y, Gu H, Zheng L, Wang L, Liu C, et al. Long noncoding RNAs POLR2E rs3787016 C/T and HULC rs7763881 A/C polymorphisms are associated with decreased risk of esophageal cancer. Tumour Biol. 2015;36(8):6401-8. [PubMed ID: 25874495]. https://doi.org/10.1007/s13277-015-3328-z.

  • 24.

    Sattarifard H, Hashemi M, Hassanzarei S, Basiri A, Narouie B, Ghavami S. Long non-coding RNA POLR2E gene polymorphisms increased the risk of prostate cancer in a sample of the Iranian population. Nucleosides Nucleotides Nucleic Acids. 2019;38(1):1-11. [PubMed ID: 30587086]. https://doi.org/10.1080/15257770.2017.1391394.

  • 25.

    Chen B, Wang S, Ma G, Han J, Zhang J, Gu X, et al. The association of POLR2E rs3787016 polymorphism and cancer risk: a Chinese case-control study and meta-analysis. Biosci Rep. 2018;38(6). [PubMed ID: 30291213]. [PubMed Central ID: PMC6239260]. https://doi.org/10.1042/BSR20180853.

  • 26.

    Chen B, Li J, Yi C, Jiao Y, Gu X, Feng X. Long non-coding RNA POLR2E rs3787016 is associated with the risk of papillary thyroid carcinoma in Chinese population. Pathol Res Pract. 2018;214(7):1040-4. [PubMed ID: 29724531]. https://doi.org/10.1016/j.prp.2018.04.008.

  • 27.

    Xu T, Hu XX, Liu XX, Wang HJ, Lin K, Pan YQ, et al. Association between SNPs in Long Non-coding RNAs and the Risk of Female Breast Cancer in a Chinese Population. J Cancer. 2017;8(7):1162-9. [PubMed ID: 28607590]. [PubMed Central ID: PMC5463430]. https://doi.org/10.7150/jca.18055.

  • 28.

    Chen B, Jiao Y, Yaolong F, Li T, Liu Y, Wang M, et al. The POLR2E rs3787016 polymorphism is strongly associated with the risk of female breast and cervical cancer. Pathol Res Pract. 2019;215(5):1061-5. [PubMed ID: 30846411]. https://doi.org/10.1016/j.prp.2019.02.015.

  • 29.

    Moazeni-Roodi A, Ghavami S, Hashemi M. The 40bp indel polymorphism of MDM2 increase the risk of cancer: An updated meta-analysis. Mol Biol Res Commun. 2019;8(1):1-8. [PubMed ID: 31528638]. [PubMed Central ID: PMC6510210]. https://doi.org/10.22099/mbrc.2019.31527.1364.

  • 30.

    Liu Q, Huang J, Zhou N, Zhang Z, Zhang A, Lu Z, et al. LncRNA loc285194 is a p53-regulated tumor suppressor. Nucleic Acids Res. 2013;41(9):4976-87. [PubMed ID: 23558749]. [PubMed Central ID: PMC3643595]. https://doi.org/10.1093/nar/gkt182.

  • 31.

    Spizzo R, Almeida MI, Colombatti A, Calin GA. Long non-coding RNAs and cancer: a new frontier of translational research? Oncogene. 2012;31(43):4577-87. [PubMed ID: 22266873]. [PubMed Central ID: PMC3433647]. https://doi.org/10.1038/onc.2011.621.

  • 32.

    Keller C, Buhler M. Chromatin-associated ncRNA activities. Chromosome Res. 2013;21(6-7):627-41. [PubMed ID: 24249576]. [PubMed Central ID: PMC3855497]. https://doi.org/10.1007/s10577-013-9390-8.

  • 33.

    Luco RF, Misteli T. More than a splicing code: integrating the role of RNA, chromatin and non-coding RNA in alternative splicing regulation. Curr Opin Genet Dev. 2011;21(4):366-72. [PubMed ID: 21497503]. [PubMed Central ID: PMC6317717]. https://doi.org/10.1016/j.gde.2011.03.004.

  • 34.

    Pircher A, Gebetsberger J, Polacek N. Ribosome-associated ncRNAs: an emerging class of translation regulators. RNA Biol. 2014;11(11):1335-9. [PubMed ID: 25692232]. [PubMed Central ID: PMC4615380]. https://doi.org/10.1080/15476286.2014.996459.

  • 35.

    Hannon GJ. RNA interference. Nature. 2002;418(6894):244-51. [PubMed ID: 12110901]. https://doi.org/10.1038/418244a.

  • 36.

    Lee JT. Epigenetic regulation by long noncoding RNAs. Science. 2012;338(6113):1435-9. [PubMed ID: 23239728]. https://doi.org/10.1126/science.1231776.

  • 37.

    Gioia R, Drouin S, Ouimet M, Caron M, St-Onge P, Richer C, et al. LncRNAs downregulated in childhood acute lymphoblastic leukemia modulate apoptosis, cell migration, and DNA damage response. Oncotarget. 2017;8(46):80645-50. [PubMed ID: 29113332]. [PubMed Central ID: PMC5655227]. https://doi.org/10.18632/oncotarget.20817.

  • 38.

    Gong J, Liu W, Zhang J, Miao X, Guo AY. lncRNASNP: a database of SNPs in lncRNAs and their potential functions in human and mouse. Nucleic Acids Res. 2015;43(Database issue):D181-6. [PubMed ID: 25332392]. [PubMed Central ID: PMC4383871]. https://doi.org/10.1093/nar/gku1000.

  • 39.

    Chu H, Chen Y, Yuan Q, Hua Q, Zhang X, Wang M, et al. The HOTAIR, PRNCR1 and POLR2E polymorphisms are associated with cancer risk: a meta-analysis. Oncotarget. 2017;8(26):43271-83. [PubMed ID: 28159929]. [PubMed Central ID: PMC5522144]. https://doi.org/10.18632/oncotarget.14920.