MicroRNA Binding Site Polymorphisms of the Long-Chain Noncoding RNA MALAT1 are Associated with Risk and Prognosis of Colorectal Cancer in Chinese Han Population

MALAT1 in Liquid Biopsy: The Diagnostic and Prognostic Promise for Colorectal Cancer and Adenomas?

Introduction

The development of colorectal cancer (CRC) is a multistep process accompanied by the accumulation of mutations that start from specific precancerous lesion - colorectal adenomas (CA). CRC incidence and mortality can be reduced by the early identification of these neoplasm. Colonoscopy is the most widely used screening method for CRC identification. Nowadays, clinical research interest is shifting to the use of liquid biopsy that may help with the early diagnosis of CA and CRC. In our previous study, we identified long non-coding RNA MALAT1 gene amplification associated with the development of CA.

Methods

This study aimed to describe the potential of MALAT1 expression levels in the adenoma tissue of patients used in the previous study by real-time qPCR. Furthermore, we analysed the plasma samples of an independent group of patients with CA (n=97), CRC (n=101), and cancer-free individuals (CFI, n=48).

Results

There was no difference in the MALAT1 expression level between CA patients with or without MALAT1 amplification. However, the plasma MALAT1 expression levels were significantly upregulated in patients with CRC and CA compared to CFI (for both p<0.001). Moreover, a correlation between MALAT1 expression and histological types of adenomas was identified- high-CRC-risk adenomas also displayed the highest MALAT1 expression levels. Furthermore, in CRC patients, MALAT1 levels were associated with a response to therapy.

Conclusion

MALAT1 expression levels could serve as a promising circulating biomarker for early CA and CRC diagnosis, and even as a predictor of therapy response in CRC patients.

MALAT1 in colorectal cancer: Its implication as a diagnostic, prognostic, and predictive biomarker

Metastasis Associated Lung Adenocarcinoma Transcript 1 (MALAT1), originally described as a prognostic biomarker remarkably linked with metastasis potential in lung cancer, has been identified as contributing to many diseases, including colorectal cancer (CRC). This long non-coding RNA (lncRNA) has come to the forefront of lncRNA research for its implications in cancer-related processes, such as cell proliferation and migration. In general, lncRNAs are recognized as enhancers, scaffolds, or decoys for a variety of oncogenes and tumor suppressors, although our understanding of lncRNA functions and mechanisms of action is still limited. Nowadays, cancer research is attracted to lncRNAs' ability to improve the early diagnosis of cancer, determine patients' prognosis, or predict therapy outcomes. In this review, we aimed to evaluate recent publications trying to uncover the cellular mechanisms of MALAT1-mediated regulation, and its potential exploitation in the management of CRC. The conclusions of this review provide robust support for the essential role of MALAT1 in CRC development and future personalized therapy.

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.

Potentials of long non-coding RNAs as biomarkers of colorectal cancer

Colorectal cancer (CRC) is the third most common malignant tumor worldwide and the fourth major cause of cancer-related death, with high morbidity and increased mortality year by year. Although significant progress has been made in the therapy strategies for CRC, the great difficulty in early diagnosis, feeble susceptibility to radiotherapy and chemotherapy, and high recurrence rates have reduced therapeutic efficacy resulting in poor prognosis. Therefore, it is urgent to understand the pathogenesis of CRC and unravel novel biomarkers to improve the early diagnosis, treatment and prediction of CRC recurrence. Long non-coding RNAs (lncRNAs) are non-coding RNAs with a length of more than 200 nucleotides, which are abnormally expressed in tumor tissues and cell lines, activating or inhibiting specific genes through multiple mechanisms including transcription and translation. A growing number of studies have shown that lncRNAs are important regulators of microRNAs (miRNAs, miRs) expression in CRC and may be promising biomarkers and potential therapeutic targets in the research field of CRC. This review mainly summarizes the potential application value of lncRNAs as novel biomarkers in CRC diagnosis, radiotherapy, chemotherapy and prognosis. Additionally, the significance of lncRNA SNHGs family and lncRNA-miRNA networks in regulating the occurrence and development of CRC is mentioned, aiming to provide some insights for understanding the pathogenesis of CRC and developing new diagnostic and therapeutic strategies.

MALAT1-related signaling pathways in colorectal cancer

Colorectal cancer (CRC) is one of the most lethal and prevalent solid malignancies worldwide. There is a great need of accelerating the development and diagnosis of CRC. Long noncoding RNAs (lncRNA) as transcribed RNA molecules play an important role in every level of gene expression. Metastasis‐associated lung adenocarcinoma transcript‐1 (MALAT1) is a highly conserved nucleus-restricted lncRNA that regulates genes at the transcriptional and post-transcriptional levels. High expression of MALAT1 is closely related to numerous human cancers. It is generally believed that MALAT1 expression is associated with CRC cell proliferation, tumorigenicity, and metastasis. MALAT1 by targeting multiple signaling pathways and microRNAs (miRNAs) plays a pivotal role in CRC pathogenesis. Therefore, MALAT1 can be a potent gene for cancer prediction and diagnosis. In this review, we will demonstrate signaling pathways associated with MALAT1 in CRC.

C5orf66 rs4976270/rs639933 Are Associated with Colorectal Cancer Risk in Southern Chinese Han Population: A Case-Control Study

BACKGROUND

Colorectal cancer (CRC) is one of the common malignant tumors, with high mortality and poor prognosis. Our study aimed to determine the association between the long noncoding RNA (LncRNA) C5orf66 polymorphism and CRC risk in southern Chinese Han population.

METHOD

Using the experimental design of "case-control" study (512 cases and 513 controls), we selected 4 candidate single-nucleotide polymorphisms (SNPs) of C5orf66. All candidate SNPs were genotyped by Agena MassARRAY. Logistic regression was used to analyze the association between SNPs and CRC risk. Then, we used false-positive report probability analysis to detect whether the significant result is just a chance or noteworthy observation. Multi-factor dimensionality reduction was used to analyze the interaction of "SNP-SNP" in CRC risk.

RESULTS

Our results showed that C5orf66 SNPs rs4976270 (odds ratio [OR] = 1.69, p = 0.021) and rs639933 (OR = 1.67, p = 0.024) were, respectively, associated with increasing CRC risk in the southern Chinese Han population. Stratified analysis showed that rs4976270 and rs639933 were significantly associated with an increased risk of CRC in subgroups (>60 years, body mass index ≤24 and drinking) under multiple genetic models. In addition, rs254563 and rs647161 also had potential association with CRC risk in subgroups (BMI ≤24 and drinking). Finally, haplotype analysis results showed that haplotype "TA" was significantly associated with increased CRC risk (OR = 1.21, confidence interval = 1.47-2.02, p = 0.043).

CONCLUSION

Our study provides a new idea for the risk assessment of CRC. LncRNA C5orf66 SNPs have a certain association with CRC risk in the southern Chinese Han population.

Long noncoding RNA polymorphisms and colorectal cancer risk: Progression and future perspectives

Colorectal cancer (CRC) is one of the most common cancers causing death worldwide. Many long noncoding RNAs (lncRNAs) have possible carcinogenic or tumor suppressor functions. Some lncRNA polymorphisms are useful for predicting cancer risk, and may help advance personalized therapy management. While the use of lncRNAs as biomarkers is promising, there are still drawbacks, and further studies are needed to verify the consistency of current outcomes in large-scale populations and different ethnicities. Single nucleotide polymorphisms (SNPs) can disrupt a lncRNAs' function, thus enhancing or hindering disease occurrence. SNPs can directly influence the lncRNA expression by interfering with transcription factor binding or affecting indirectly a regulatory factors' expression. Moreover, the association between lncRNAs and other RNAs or proteins may be disrupted by SNPs. This research sought to assess the association between lncRNA polymorphisms and CRC risk, as well as clinical and therapeutic consequences in certain cases.

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.

MicroRNAs as important contributors in the pathogenesis of colorectal cancer

Colorectal cancer (CRC) is the third most fatal and fourth most frequently diagnosed neoplasm in the world. Numerous non-coding RNAs have been shown to contribute in the development of CRC. MicroRNAs (miRNAs) are among the mostly assessed non-coding RNAs in CRC. These transcripts influence expression and activity of TGF-β, Wnt/β-catenin, MAPK, PI3K/AKT and other CRC-related pathways. In the context of CRC, miRNAs interact with long non-coding RNAs to influence CRC course. Stool and serum levels of miRNAs have been used to distinguish CRC patients from healthy controls, indicating diagnostic roles of these transcripts in CRC. Therapeutic application of miRNAs in CRC has been assessed in animal models, yet has not been verified in clinical settings. In the current review, we have provided a recent update on the role of miRNAs in CRC development as well as diagnostic and prognostic approaches.

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.