Effect of MALAT1 Polymorphisms on Papillary Thyroid Cancer in a Chinese Population

MALAT1: A Long Non-Coding RNA with Multiple Functions and Its Role in Processes Associated with Fat Deposition

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) belongs to the lncRNA molecules, which are involved in transcriptional and epigenetic regulation and the control of gene expression, including the mechanism of chromatin remodeling. MALAT1 was first discovered during carcinogenesis in lung adenocarcinoma, hence its name. In humans, 66 of its isoforms have been identified, and in pigs, only 2 are predicted, for which information is available in Ensembl databases (Ensembl Release 111). MALAT1 is expressed in numerous tissues, including adipose, adrenal gland, heart, kidney, liver, ovary, pancreas, sigmoid colon, small intestine, spleen, and testis. MALAT1, as an lncRNA, shows a wide range of functions. It is involved in the regulation of the cell cycle, where it has pro-proliferative effects and high cellular levels during the G1/S and mitotic (M) phases. Moreover, it is involved in invasion, metastasis, and angiogenesis, and it has a crucial function in alternative splicing during carcinogenesis. In addition, MALAT1 plays a significant role in the processes of fat deposition and adipogenesis. The human adipose tissue stem cells, during differentiation into adipocytes, secrete MALAT1 as one the most abundant lncRNAs in the exosomes. MALAT1 expression in fat tissue is positively correlated with adipogenic FABP4 and LPL. This lncRNA is involved in the regulation of PPARγ at the transcription stage, fatty acid metabolism, and insulin signaling. The wide range of MALAT1 functions makes it an interesting target in studies searching for drugs to prevent obesity development in humans. In turn, in farm animals, it can be a source of selection markers to control the fat tissue content.

The Role of Genetic Polymorphisms in Differentiated Thyroid Cancer: A 2023 Update

Thyroid cancer is the most common endocrine malignancy, with an increasing trend in the past decades. It has a variety of different histological subtypes, the most frequent one being differentiated thyroid cancer, which refers to papillary carcinoma, the most common histological type, followed by follicular carcinoma. Associations between genetic polymorphisms and thyroid cancer have been investigated over the years and are an intriguing topic for the scientific world. To date, the results of associations of single nucleotide polymorphisms, the most common genetic variations in the genome, with thyroid cancer have been inconsistent, but many promising results could potentially influence future research toward developing new targeted therapies and new prognostic biomarkers, thus consolidating a more personalized management for these patients. This review focuses on emphasizing the existing literature data regarding genetic polymorphisms investigated for their potential association with differentiated thyroid cancer and highlights the opportunity of using genetic variations as biomarkers of diagnosis and prognosis for thyroid cancer patients.

Associations of MALAT1 and its functional single nucleotide polymorphisms with cancer

BACKGROUND

Systematic research on the associations between vital single nucleotide polymorphisms (SNPs) in MALAT1 and cancer risk was still lacking. Thus, we performed this study.

MATERIALS AND METHODS

The literature searches were until April 1, 2022. The pooled association-analysis results were assessed by odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) in three genetic models. In addition, we explored the potential functions of MALAT1 and its vital SNPs based on several public websites.

RESULTS

Eighteen articles about four SNPs (rs619586, rs664589, rs1194338, and rs3200401) involving 11,843 cancer cases and 14,682 controls were collected. Rs619586, rs664589, and rs1194338 were associated with cancer risk (all P-value < 0.05). Each SNP of the three was significantly related to the risk of colorectal cancer (CRC), and rs619586 correlated with hepatocellular carcinoma (HCC) risk (all P-value < 0.05). The three SNPs might affect the transcription factor, promoter, or enhancer functions. MALAT1 expressed significantly higher in CRC and HCC than in normal tissues. The respective area under the receiver operating characteristic curve of MALAT1 for CRC and HCC patients was 0.783 and 0.864. Moreover, survival analysis indicated that MALAT1 might be a potential prognostic marker of CRC and HCC (all relevant P-value < 0.05).

CONCLUSIONS

The functional SNPs in MALAT1 correlated with cancer risk. MALAT1 and its vital functional SNPs might be potential biomarkers for predicting the risk and prognosis of two types of cancer, especially CRC. Further investigations are needed to confirm our present findings.

The Relationship between MALAT1 Polymorphism rs3200401 C > T and the Risk of Overall Cancer: A Meta-Analysis

Background and Objectives: At present, the association between the long non-coding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) polymorphism rs3200401 C > T and cancer risk remain controversial. The aim of this meta-analysis was to assess the association between rs3200401 C > T and cancer susceptibility. Materials and Methods: The databases of PubMed, EMBASE and Web of Science were searched for literature published in English until 1 September 2021. The odd ratios (ORs) and 95% confidence intervals (CIs) were applied to evaluate the strength of association in five genetic models. Heterogeneity was assessed using the Q-test and I² test. Begg’s funnel plot and Egger’s linear regression test were conducted to assess publication bias. Meta-regression analysis was used to explore potential sources of heterogeneity. Trial sequential analysis (TSA) was performed to validate the reliability of the results. Results: A total of 10 case–control studies involving 6630 cases and 7457 controls were included in this study. The pooled ORs showed no significant association between MALAT1 rs3200401 C > T and cancer risk in five genetic models. Similarly, the association was not found in the subgroups of control source, ethnicity and study quality. In the cancer type subgroup, the results demonstrated that the T allele increased the risk of colorectal cancer (CRC) compared with the C allele. (C vs. T: OR, 1.16; 95% CI, 1.01–1.33). Conclusion: In the current meta-analysis, we found no significant association between MALAT1 polymorphism rs3200401 C > T and overall cancer risk. However, the rs3200401 C > T may be linked to a higher risk of CRC, which needs more studies to be further confirmed.

Significance of the lncRNAs MALAT1 and ANRIL in occurrence and development of glaucoma

Background

Primary open‐angle glaucoma (POAG) is the commonest form of glaucoma which is estimated to cause bilaterally blind within 11.1 million people by 2020. Therefore, the primary objectives of this study were to investigate the clinical significance of single‐nucleotide polymorphisms (SNPs) in the lncRNAs MALAT1 and ANRIL in a Chinese Han POAG cohort.

Methods

Three hundred and forty‐six glaucoma patients and 263 healthy controls were recruited, and totally 14 SNPs in MALAT1 and ANRIL were genotyped between the two populations.

Results

The MALAT1 SNPs rs619586 (A>G), rs3200401 (C>T), and rs664589 (C>G) were associated with POAG risk, and the ANRIL SNPs rs2383207 (A>G), rs564398 (A>G), rs2157719 (A>G), rs7865618 (G>A), and rs4977574 (A>G) were associated with POAG (p < 0.05). The MALAT1 haplotypes ACG and ATC, comprised rs619586, rs3200401, and rs664589, increased POAG risk, and the ANRIL haplotype AAGAA, made up of rs2383207, rs7865618, rs4977574, rs564398, and rs2157719, show a significantly increased risk of POAG. In addition, rs619586 (A>G) of MALAT1 and rs564398/rs2157719 of ANRIL were associated with a smaller vertical cup‐to‐disc ratio, while rs619586 of MALAT1 and rs2383207/rs4977574 of ANRIL were associated with higher intraocular pressure in the POAG population.

Conclusion

Single‐nucleotide polymorphisms and haplotypes in ANRIL and MALAT1 were associated with POAG onset in our study population, which provide more possibilities to POAG diagnosis and treatment.

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.

Associations between LncRNA MALAT1 Polymorphisms and Lymph Node Metastasis in Prostate Cancer

Current evidence elucidates that long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) could regulate genetic expression and play a crucial role in both the diagnosis and prognosis of prostate cancer. Single-nucleotide polymorphisms (SNPs) of MALAT1 could alter the oncogenesis in various cancers. However, the associations between MALAT1 SNPs and prostate cancer have barely been investigated to date. This study included 579 patients with prostate cancer who received robotic-assisted radical prostatectomy at Taichung Veterans General Hospital from 2012 to 2017. Three SNPs of MALAT1 were analyzed to identify the impacts of SNPs on the clinicopathologic features in Taiwanese prostate cancer. Our results show that patients with a polymorphic G allele at rs619586 had a significantly higher risk of being in an advanced Gleason grade group (AOR: 1.764; 95% CI: 1.011–3.077; p = 0.046). Moreover, individuals with at least one polymorphic A allele at MALAT1 rs1194338 in the PSA >10 ng/mL group were positively associated with node-positive prostate cancer. In conclusion, MALAT1 SNPs are significantly associated with the susceptibility to both advanced Gleason grade and nodal metastasis in prostate cancer. The presence of MALAT1 SNPs rs619586 and rs1194338 seems to enhance oncogenesis in prostate cancer.

Combined Impacts of Genetic Variants of Long Non-Coding RNA MALAT1 and the Environmental Carcinogen on the Susceptibility to and Progression of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignant tumor of the oral cavity, and long non-coding (lnc)RNA of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was recently reported to play a crucial role in OSCC development and progression. However, potential effects of genetic variants of MALAT1 on the development of OSCC are still unclear. Herein, we performed a case-control study in 1350 patients with OSCC and 1199 healthy controls to evaluate the association between functional single-nucleotide polymorphisms (SNPs) of MALAT1 and OSCC susceptibility, as well as its clinicopathologic characteristics. A TaqMan allelic discrimination assay was used to genotype four tagging SNPs, viz., rs3200401 C>T, rs619586 A>G, rs1194338 C>A, and rs7927113 G>A, and results showed that the MALAT1 rs3200401 T allele had a lower risk of OSCC (adjusted odds ratio (AOR): 0.779, 95% confidence interval (CI): 0.632~0.960, p=0.019) and a higher risk of developing moderately (grade II)/poorly (grade III) differentiated OSCC (AOR: 1.508-fold, 95% CI: 1.049~2.169, p=0.027) under a dominant model. According to environmental carcinogen exposure, patients with a betel quid-chewing habit who carried the T allele of rs3200401 more easily developed high-grade (II/III) OSCC (AOR: 1.588, 95% CI: 1.055~2.390, p=0.027), and patients with the same genotype but who did not chew betel quid had a lower risk of developing lymph node metastasis (AOR: 0.437, 95% CI: 0.255~0.749, p=0.003). In addition to rs3200401, the rs619586 AG/GG genotype was associated with increased risks of developing advanced stages (III+IV) and larger tumor sizes (>T2) compared to the AA genotype, especially in the subgroup of betel quid chewers. Furthermore, analyses of clinical datasets revealed that the MALAT1 expression level was upregulated in OSCC compared to normal tissues, especially in the betel quid-chewing population. These results indicated involvement of MALAT1 SNPs rs3200401 and rs619586 in the development of OSCC and support the interaction between MALAT1 gene polymorphisms and the environmental carcinogen as a predisposing factor for OSCC progression.

Long noncoding RNA LINC00284 facilitates cell proliferation in papillary thyroid cancer via impairing miR-3127-5p targeted E2F7 suppression

Accumulating evidence has suggested that long noncoding RNAs (lncRNAs) exert crucial modulation roles in the biological behaviors of multiple malignancies. Nonetheless, the specific function of lncRNA LINC00284 in papillary thyroid cancer (PTC) remains not fully understood. The objective of this research was to explore the influence of LINC00284 in PTC and elucidate its potential mechanism. The Cancer Genome Atlas (TCGA), gene expression omnibus (GEO) datasets were used to analyze LINC00284 expression differences in thyroid cancer and normal samples, followed by the verification of qRT-PCR in our own PTC and adjacent non-tumor tissues. The impacts of LINC00284 on PTC cell growth were detected in vitro via CCK-8, colony formation, EdU assays, and in vivo via a xenograft tumor model. Bioinformatics analyses and biological experiments were conducted to illuminate the molecular mechanism. We found that LINC00284 expression was remarkably increased in PTC tissues and its overexpression was closely correlated with larger tumor size. In addition, silencing LINC00284 could effectively attenuate PTC cell proliferation, induce apoptosis and G1 arrest in vitro, as well as suppress tumorigenesis in mouse xenografts. Mechanistic investigations showed that LINC00284 acted as a competing endogenous RNA (ceRNA) for miR-3127-5p, thus resulting in the disinhibition of its endogenous target E2F7. In short, our findings indicated that LINC00284–miR-3127-5p–E2F7 axis exerted oncogenic properties in PTC and may offer a new promising target for the diagnosis and therapy of PTC.

Meta-analysis of the association between MALAT1 rs619586 A>G polymorphism and cancer risk

Objective

This study aimed to systematically assess the effect of the metastasis associated lung adenocarcinoma transcript 1 (MALAT1) long noncoding RNA rs619586 polymorphism on cancer risk.

Methods

We conducted a literature search of the PubMed, Embase, and China National Knowledge Internet databases to identify relevant studies, and calculated the pooled odds ratios (ORs) and 95% confidence intervals (CIs) for the retrieved studies using RevMan software.

Results

Nine eligible studies including 5968 cases and 7439 controls were included in the meta-analysis. The pooled results showed that MALAT1 rs619586 polymorphism was significantly associated with cancer risk [(AG + GG) vs. AA: OR = 0.88; GG vs. (AG + AA): OR = 0.64; GG vs. AA: OR = 0.63; AG vs. AA: OR = 0.91; G vs. A: OR = 0.87]. However, subgroup analyses based on ethnicity and cancer type showed significant associations between MALAT1 rs619586 polymorphism and cancer risk in Asians and for cancers other than hepatocellular carcinoma, but not for Caucasians and hepatocellular carcinoma.

Conclusions

MALAT1 rs619586 polymorphism may play a role in cancer risk. However, further studies are needed to confirm these findings.

Antitumor activity via apoptotic cell death pathway of water soluble copper(II) complexes: effect of the diamino unit on selectivity against lung cancer NCI-H460 cell line

The cytotoxicity against five human tumor cell lines (THP-1, U937, Molt-4, Colo-205 and NCI-H460) of three water soluble copper(II) coordination compounds containing the ligands 3,3'-(ethane-1,2-diylbis(azanediyl))dipropanamide (BCEN), 3,3'-(piperazine-1,4-diyl)dipropanamide (BPAP) or 3,3'-and (1,4-diazepane-1,4-diyl)dipropanamide (BPAH) are reported in this work. The ligands contain different diamine units (ethylenediamine, piperazine or homopiperazine) and two propanamide units attached to the diamine centers, resulting in N₂O₂ donor sets. The complex containing homopiperazine unit presented the best antiproliferative effect and selectivity against lung cancer cell line NCI-H460, showing inhibitory concentration (IC₅₀) of 58 μmol dm^-3 and Selectivity Index (SI) > 3.4. The mechanism of cell death promoted by the complex was investigated by Sub-G1 cell population analysis and annexin V and propidium iodide (PI) labeling techniques, suggesting that the complex promotes death by apoptosis. Transmission electron microscopy investigations are in agreement with the results presented by mitochondrial membrane potential analysis and also show the impairment of other organelles, including endoplasmic reticulum.

Diagnostic, prognostic, and therapeutic significance of long non-coding RNA MALAT1 in cancer

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1) is a widely studied lncRNA in cancer. Although dispensable for normal physiology, MALAT1 is important for cancer-related pathways regulation. It is localized in the nuclear speckles periphery along with centrally located pre-RNA splicing factors. MALAT1 associated cancer signaling pathways include MAPK/ERK, PI3K/AKT, β-catenin/Wnt, Hippo, VEGF, YAP, etc. Molecular tools such as immunoprecipitation, RNA pull-down, reporter assay, Northern blotting, microarray, and q-RT-PCR has been used to elucidate MALAT1's function in cancer pathogenesis. MALAT1 can regulate multiple steps in the development of tumours. The diagnostic and prognostic significance of MALAT1 has been demonstrated in cancers of the breast, cervix, colorectum, gallbladder, lung, ovary, pancreas, prostate, glioma, hepatocellular carcinoma, and multiple myeloma. MALAT1 has also emerged as a novel therapeutic target for solid as well as hematological malignancies. In experimental models, siRNA and antisense oligonucleotide (ASO) based strategy has been used for targeting MALAT1. The lncRNA has also been targeted for the chemosensitization and radiosensitization of cancer cells. However, most studies have been performed in preclinical models. How the cross-talk of MALAT1 with other signaling pathways affect cancer pathogenesis is the focus of this article. The diagnostic, prognostic, and therapeutic significance of MALAT1 in multiple cancer types are discussed.

Oral Contraceptive Steroids Promote Papillary Thyroid Cancer Metastasis by Targeting Angiogenesis and Epithelial-Mesenchymal Transition

Thyroid cancer is the most prevalent type of endocrine malignancy with the highest incidence rate among women under 45 years old. Ethinylestradiol (EE) and levonorgestrel (LNG) are two steroid components of low-dose oral contraceptives used all over the world. In this study, we aimed to examine the possible effects of the combination of these two steroids on metastasis and angiogenic factors in BCPAP papillary thyroid cancer (PTC) cell line. After treatment of BCPAP cells with the combination of 20 nM EE and 90 nM LNG, mRNA expression levels of long noncoding RNAs HOTAIR and MALAT1, angiogenic and antiangiogenic gene markers VEGFA and THBS1, and epithelial-mesenchymal transition (EMT) biomarkers CDH1, CDH2, FN1, and VIM were analyzed by real-time PCR. Additionally, the protein expression of VEGFA was semiquantified by Western blotting. Results showed that the combination of LNG and EE significantly elevated the level of VEGFA protein and mRNA expression of VEGFA, MALAT1, HOTAIR, CDH2, FN1, and VIM genes while decreased CDH1 gene expression but had no marked effect on the expression of THBS1 gene in comparison with the control group. Also, our results suggest that LNG and EE may increase the metastatic and migratory properties of BCPAP cells via modulating angiogenic and EMT biomarkers. These data may highlight the potential of exogenous steroids in the advancement of PTC tumors.

Association of long noncoding RNA MALAT1 polymorphisms with gastric cancer risk in Korean individuals

Background

Metastasis‐associated lung adenocarcinoma transcript 1 (MALAT1) drives tumorigenesis of various human cancers. However, the association between MALAT1 variants and gastric cancer (GC) risk is unknown. We performed a case‐control study to evaluate the possible association between rs619586 and rs3200401 SNPs in MALAT and GC risk.

Methods

Samples from 458 patients with GC and 381 controls were genotyped using the TaqMan genotyping assay.

Results

In stratified analyses, we observed that rs3200401 CT in the codominant model and CT+TT in the dominant model were associated with increased GC risk in male patients (CT: odds ratio [OR] = 1.81, 95% confidence interval [CI] = 1.09–3.01, p = 0.022; CT+TT: OR = 1.74, 95% CI = 1.07–2.83, p = 0.026), and the differentiated (CT: OR =1.79, 95% CI = 1.18–2.73, p = 0.007; CT+TT: OR = 1.76, 95% CI = 1.17–2.64, p = 0.007), and intestinal (CT: OR = 1.67, 95% CI = 1.11–2.49, p = 0.013; CT+TT: OR = 1.68, 95% CI = 1.14–2.47, p = 0.009) GC subgroups.

Conclusion

MALAT1 rs3200401 increases GC susceptibility and might affect GC development. Further studies are needed to validate our results in large populations and different ethnic groups.

The crosstalk between lncRNAs and the Hippo signalling pathway in cancer progression

LncRNAs play a pivotal role in the regulation of epigenetic modification, cell cycle, differentiation, proliferation, migration and other physiological activities. In particular, considerable studies have shown that the aberrant expression and dysregulation of lncRNAs are widely implicated in cancer initiation and progression by acting as tumour promoters or suppressors. Hippo signalling pathway has attracted researchers’ attention as one of the critical cancer‐related pathways in recent years. Increasing evidences have demonstrated that lncRNAs could interact with Hippo cascade and thereby contribute to acquisition of multiple malignant hallmarks, including proliferation, metastasis, relapse and resistance to anti‐cancer treatment. Specifically, Hippo signalling pathway is reported to modulate or be regulated by widespread lncRNAs. Intriguingly, certain lncRNAs could form a reciprocal feedback loop with Hippo signalling. More speculatively, lncRNAs related to Hippo pathway have been poised to become important putative biomarkers and therapeutic targets in human cancers. Herein, this review focuses on the crosstalk between lncRNAs and Hippo pathway in carcinogenesis, summarizes the comprehensive role of Hippo‐related lncRNAs in tumour progression and depicts their clinical diagnostic, prognostic or therapeutic potentials in tumours.

The Role of Long Non-Coding RNAs in Thyroid Cancer

Thyroid cancer, the most common endocrine malignancy, has become the most commonly diagnosed malignant solid tumor. Moreover, some cases have poor prognosis, and the survival period is only 3-5 months. Long noncoding RNAs (lncRNAs) are a group of functional RNA molecules more than 200 nucleotides in length that lack the ability to encode protein but participate in all aspects of gene regulation. Functionally, many lncRNAs play essential roles in epigenetic regulation at transcriptional and post-transcriptional levels via various molecular mechanisms. Recent studies have discovered important roles for lncRNAs during the complex process of carcinogenesis in thyroid cancer. In this review, we focus on lncRNAs dysregulated in thyroid cancer and summarize recently reported associations between lncRNAs and thyroid cancer in order to demonstrate the significant value of lncRNAs in diagnosis and treatment.