lncRNA-PCAT1 rs2632159 polymorphism could be a biomarker for colorectal cancer susceptibility

Long non-coding RNAs in pancreatic cancer

This article reviews the recent advances in pathogenesis, diagnosis and treatment of pancreatic cancer, as well as the relationship between long non-coding RNA (lncRNA) in disease progression. Unfortunately, pancreatic cancer has no early symptoms and quickly invades surrounding tissue and organs, making it one of the deadliest. Accordingly, we urgently need to identify high-risk individuals with precancerous lesions through screening methods to identify early disease, provide better prevention strategies and improve overall survival. LncRNAs have a variety of biological functions in both physiologic and pathophysiologic states including tumor growth, differentiation and proliferation. Herein we review the biological functions, expression patterns, clinical significance and targeted therapy potential of lncRNAs to provide new approaches for diagnosis and treatment in pancreatic cancer.

Upregulation of Long Noncoding RNA PCAT1 in Iranian Patients with Colorectal Cancer and Its Performance as a Potential Diagnostic Biomarker

Background: Long noncoding RNAs (lncRNAs) as critical molecules play an essential role in the development of cancers. In colorectal cancer (CRC), various lncRNAs are related to cell proliferation, apoptosis, migration, and invasion. LncRNA prostate cancer-associated transcript 1 (PCAT-1), as an oncogenic factor, is a diagnostic biomarker that regulates cell proliferation, migration, invasion, and apoptosis. Methods: This study evaluated the relationship between PCAT-1, CRC occurrence, and pathological features of Iranian patients. The studied samples included 100 colorectal tumor tissues and 100 adjacent healthy tissues of Iranian CRC patients. RNAs were extracted from cancerous and noncancerous tissues to synthesize complementary DNA. The expression level of PCAT-1 was assessed using the real-time PCR method, and the data analysis was assessed using SPSS software. Results: In this study, expression level of PCAT-1 in tumor tissue was significantly increased in Iranian patients, and pathological studies of the patients had no significant relationship with the PCAT-1 expression profile. Conclusion: Our results suggested that the high expression of PCAT-1 resulted in the occurrence of colorectal tumor tissues in Iranian patients, which can be considered a diagnostic biomarker in CRC.

FTO plays a crucial role in gastrointestinal cancer and may be a target for immunotherapy: an updated review

Gastrointestinal cancer is a common malignancy with high mortality and poor prognosis. Therefore, developing novel effective markers and therapeutic targets for gastrointestinal cancer is currently a challenging and popular topic in oncology research. Accumulating studies have reported that N6-methyladenosine is the most abundant epigenetic modification in eukaryotes. N6-methyladenosine plays an essential role in regulating RNA expression and metabolism, including splicing, translation, stability, decay, and transport. FTO, the earliest demethylase discovered to maintain the balance of N6-adenosine methylation, is abnormally expressed in many tumors. In this review, we discuss the molecular structure and substrate selectivity of FTO. we focus on the role of FTO in gastrointestinal tumor proliferation, migration, invasion, apoptosis, autophagy, immune microenvironment, and its molecular mechanisms. We also discuss its potential in the treatment of gastrointestinal cancers.

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.

CCAT 1- A Pivotal Oncogenic Long Non-Coding RNA in Colorectal Cancer

Colorectal cancer (CRC) is ranked as the third most common cancer and second deadliest cancer in both men and women in the world. Currently, the cure rate and 5-year survival rate of CRC patients remain relatively low. Therefore, discovering a novel molecular biomarker that can be used to improve CRC screening, diagnosis, prognosis, and treatment would be beneficial. Long non-coding RNA colon cancer-associated transcript 1 (CCAT 1) has been found overexpressed in CRC and is associated with CRC tumorigenesis and treatment outcome. CCAT 1 has a high degree of specificity and sensitivity, it is readily detected in CRC tissues and is significantly overexpressed in both premalignant and malignant CRC tissues. Besides, CCAT 1 is associated with clinical manifestation and advanced features of CRC, such as lymph node metastasis, high tumor node metastasis stage, differentiation, invasion, and distant metastasis. In addition, they can upregulate oncogenic c-MYC and negatively modulate microRNAs via different mechanisms of action. Furthermore, dysregulated CCAT 1 also enhances the chemoresistance in CRC cells while downregulation of them reverses the malignant phenotypes of cancer cells. In brief, CCAT 1 serves as a potential screening, diagnostic and prognostic biomarker in CRC, it also serves as a potential therapeutic marker to treat CRC patients.

LNC-ZNF33B-2:1 gene rs579501 polymorphism is associated with organ dysfunction and death risk in pediatric sepsis

Background: Sepsis is a severe systemic reaction disease induced by bacteria and virus invading the bloodstream and subsequently causing multiple systemic organ dysfunctions. For example, the kidney may stop producing urine, or the lungs may stop taking in oxygen. Recent studies have shown that long non-coding RNAs (lncRNAs) are related to the dysfunction of organs in sepsis. This study aims to screen and validate the sepsis-associated lncRNAs and their functional single nucleotide polymorphisms (SNPs).

Result: Unconditional multiple logistic regression based on the recessive model (adjusted odds ratio = 2.026, 95% CI = 1.156–3.551, p = 0.0136) showed that patients with the CC genotype of rs579501 had increased risk of sepsis. Stratification analysis by age and gender indicated that patients with the rs579501 CC genotype had higher risk of sepsis among children aged <12 months (adjusted odds ratio = 2.638, 95% CI = 1.167–5.960, p = 0.0197) and in male patients (adjusted odds ratio = 2.232, 95% CI = 1.127–4.421, p = 0.0213). We also found a significant relationship between rs579501 and severe sepsis risk (CC versus AA/AC: adjusted odds ratio = 2.466, 95% CI = 1.346–4.517, p = 0.0035). Stratification analysis for prognosis and number of organ dysfunctions demonstrated that the rs579501 CC genotype increased non-survivors’ risk (adjusted odds ratio = 2.827, 95% CI = 1.159–6.898, p = 0.0224) and one to two organs with dysfunction risk (adjusted odds ratio = 2.253, 95% CI = 1.011–5.926, p = 0.0472).

Conclusion: Our findings showed that the lnc-ZNF33B-2:1 rs579501 CC genotype increases the susceptibility to sepsis. From the medical perspective, the lnc-ZNF33B-2:1 rs579501 CC genotype could be serving as a biochemical marker for sepsis.

Exosomal lncRNA PCAT1 Promotes Tumor Circulating Cell-Mediated Colorectal Cancer Liver Metastasis by Regulating the Activity of the miR-329-3p/Netrin-1-CD146 Complex

Objective

This study explored the colorectal cancer exosome lncRNA prostate cancer associated transcript 1– (PCAT1) mediated circulating tumors and the mechanism of cell colorectal cancer liver metastasis.

Methods

Exosomes were extracted from the primary colorectal cancer (CRC) cell lines HCT116 and SW480 and cultured with T84 and human umbilical vein endothelial (HUVE) cells. The expression of PCAT1 and miR-329-3p was detected by real-time quantitative polymerase chain reaction (RT-qPCR), the expression of Netrin-1, CD146, and epithelial mesenchymal transition (EMT) related proteins was detected by Western blot, the proliferation activity of T84 cells was detected by cell counting kit 8 (CCK-8), and cell migration was detected by Transwell. The expression of the F-actin signal was detected by immunofluorescence after coculture of exosomes with human umbilical vein endothelial cells (HUVECs). Changes in subcutaneous tumor and liver nodule size after PCAT1 deletion were observed in a mouse model of liver metastasis from rectal cancer.

Results

PCAT1 expression was upregulated in primary cell lines and their exosomes. After exosomes were cocultured with colorectal cancer tumor circulating T84 cells, the expression of Netrin-1 and CD146 was upregulated, the expression of miR-329-3p was downregulated, the proliferation and migration ability of T84 cells were enhanced, and EMT occurred. After knocking down PCAT1, the above phenomenon was reversed. Similarly, after exosomes were cocultured with HUVECs, the expression of the F-actin signal increased, and after PCAT1 was knocked down, the F-actin signal also decreased. PCAT1 regulates miR-329-3p/Netrin-1 and affects the biological behavior of T84 and F-actin signal expression in HUVECs. In a mouse model of colorectal cancer liver metastasis, knocking down PCAT1 significantly reduced the nodules formed by liver metastasis in mice.

Conclusions

LncRNA PCAT1 derived from colorectal cancer exosomes regulates the activity of the Netrin-1-CD146 complex in circulating tumor cells (CTCs) to promote the occurrence of colorectal cancer EMT and liver metastasis and provides new molecular targets for the treatment of colorectal cancer liver metastasis.

Impact of Long Noncoding RNA LINC00673 Genetic Variants on Susceptibility to Diabetic Retinopathy

Long noncoding RNAs (lncRNAs) have been proven to play critical roles in diabetic retinopathy (DR). This study investigated whether the single nucleotide polymorphism (SNP) of long intergenic noncoding RNA 00673 (LINC00673) affects the clinical characteristics of diabetic retinopathy (DR). A total of three loci of LINC00673 SNPs (rs6501551, rs9914618, and rs11655237) were genotyped using TaqMan allelic discrimination in 276 and 454 individuals with and without DR, respectively. Our results revealed that LINC00673 SNP rs11655237 CT genotype (AOR: 1.592, 95% CI: 1.059–2.395, p = 0.026), CT + TT genotype (AOR: 1.255, 95% CI: 1.029–1.531, p = 0.025), and allele T (AOR: 1.185, 95% CI: 1.004–1.397, p = 0.044) yielded higher ratios in the non-proliferative diabetic retinopathy (NPDR) subgroup than in the non-DR group. Furthermore, the interval of diabetes mellitus (DM) was significantly shorter in the LINC00673 SNP rs11655237 CT + TT variant than that in the LINC00673 SNP rs11655237 wild type (10.44 ± 7.10 vs. 12.98 ± 8.34, p = 0.009). In conclusion, the LINC00673 SNP rs11655237 T allele is associated with a higher probability of NPDR development. Patients with the LINC00673 SNP rs11655237 CT + TT variant exhibited a short DM interval.

Prognostic Value of LINC-ROR (rs1942347) Variant in Patients with Colon Cancer Harboring BRAF Mutation: A Propensity Score-Matched Analysis

Emerging studies show that long intergenic non-protein coding RNA, regulator of reprogramming (LINC-ROR) is aberrantly expressed in several types of cancer, including colon cancer (CC). LINC-ROR intronic variant rs1942347 may impact gene regulation and disease phenotype. We aimed to explore the potential association of LINC-ROR (rs1942347) with the clinicopathological features and outcome of CC cases. Archived FFPE (n = 180) CC samples were enrolled. Taq-Man allelic discrimination PCR was used for genotyping in propensity-matched cohorts with/without positive staining for mutant BRAF protein after eliminating confounders bias. The rs1942347*A allele variant was associated with high pathological grade, larger tumor size, distant metastasis, and mortality. Multiple logistic regression analysis adjusted by sex and BRAF mutation showed A/A genotype carriers to have 3 times more risk of early onset of cancer (OR = 3.13, 95%CI = 1.28–7.69, p = 0.034) than T/T genotype carriers. Overall analysis showed that rs1942347*A allele carriers had higher risk of mortality under heterozygote (OR = 2.13, 95%CI = 1.08–4.35, p = 0.003), homozygote (OR = 5.0, 95%CI = 1.69–14.29, p = 0.003), dominant (OR = 3.33, 95%CI = 1.20–9.09, p = 0.003), and recessive (OR = 2.63, 95%CI = 1.37–5.0, p = 0.011) models compared to T/T allele carriers. Stratified analysis by BRAF status revealed that the ancestor T/T allele conferred protection in BRAF mutant CC patients and was associated with a 73–93% reduced risk of mortality under heterozygote/homozygote comparison models. Using Kaplan–Meier curves, carriers of the A/A genotype had shorter survival times than T/T cohorts. The univariate Cox regression model revealed that the A/A genotype was associated with a 3.5 times greater mortality risk than the T/T genotype. However, after adjustment by multiple Cox regression analysis, the risk was insignificant. In conclusion, this is the first study identifying the potential association of the LINC-ROR (rs1942347) variant with CC prognosis.

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.

Association between long noncoding RNA rs944289 and rs7990916 polymorphisms and the risk of colorectal cancer in a Chinese population

Long non-coding RNAs (LncRNAs) play vital roles in the tumorigenesis of many cancers. Single nucleotide polymorphisms (SNPs) of the lncRNA also play vital roles in tumorigenesis. We explored lncRNA rs944289 and rs7990916 polymorphisms and analyzed the relationship between these lncRNA polymorphisms with the colorectal cancer (CRC) risk in a Chinese population. We recruited 1003 CRC patients from the Affiliated People’s Hospital of Jiangsu University and the Fujian Medical University Union Hospital from October 2014 to August 2017. Genomic DNA was extracted using a DNA Kit from lymphocytes of peripheral blood and the genotyping was performed with a SNPscan method. We found that the rs944289 TT homozygote was associated with the decreased CRC risk in the overall population. LncRNA rs944289 TT decreased the CRC risk in the subgroup of female, male, age ≥ 61, without alcohol intake, smoking and BMI ≥ 24 by logistic regression. The subgroup analysis revealed that lncRNA rs7990916 was not associated with CRC risk except for age < 61. Logistic regression analysis revealed that lncRNA rs944289 TT homozygote was associated with the increased risk of rectum cancer (TT vs. CC + CT: adjusted OR = 1.29, 95% CI 1.10–1.66, P = 0.041) or colon cancer. In summary, we proved that lncRNA rs944289 might be significantly related to the decreased CRC risk in the Chinese Han populations and lncRNA rs7990916 was not associated with the CRC risk except for patients of age < 61. In the future, studies with larger samples should be conducted to validate our results.

VPS9D1-AS1 gene rs7206570 polymorphism associated with the clinical stage of colorectal cancer and binding with hsa-miR-361-3p

VPS9D1-AS1 is a long non-coding RNA that can operate as a competitive endogenous RNA and plays an essential role in the occurrence and development of malignancies, including colorectal cancer (CRC). In this study, we investigated whether a putative functional polymorphism (rs7206570) in the VPS9D1-AS1 gene is linked to the risk and clinical stage of CRC. Sanger sequencing method was used to detect the rs7206570 polymorphism in 500 CRC patients and 500 healthy individuals. Quantitative real-time PCR technology was used to detect the expression of VPS9D1-AS1 and hsa-miR-361-3p in colorectal tissues with different rs7206570 genotypes. The dual-luciferase reporter assay was used to examine whether the rs7206570 polymorphism affects hsa-miR-361-3p binding. The rs7206570 polymorphism was not associated with CRC risk, but was associated with the clinical stage of CRC. CRC patients with rs7206570 A allele were less likely to have high-stage CRC. Furthermore, there was a significant negative correlation between the expression of VPS9D1-AS1 and hsa-miR-361-3p in CRC tissues with rs7206570 GG genotype. Dual-luciferase reporter assay showed that the rs7206570 A allele presumably hinders the binding of VPS9D1-AS1 to hsa-miR-361-3p. In conclusion, VPS9D1-AS1 gene rs7206570 polymorphism affecting hsa-miR-361-3p binding was associated with the clinical stage of CRC, which might be able to assist in the preoperative staging of CRC.

Construction and characterization of rectal cancer-related lncRNA-mRNA ceRNA network reveals prognostic biomarkers in rectal cancer

Rectal cancer is an important cause of cancer‐related deaths worldwide. In this study, the differentially expressed (DE) lncRNAs/mRNAs were first identified and the correlation level between DE lncRNAs and mRNAs were calculated. The results showed that genes of highly correlated lncRNA‐mRNA pairs presented strong prognosis effects, such as GPM6A, METTL24, SCN7A, HAND2‐AS1 and PDZRN4. Then, the rectal cancer‐related lncRNA‐mRNA network was constructed based on the ceRNA theory. Topological analysis of the network revealed that the network was maintained by hub nodes and a hub subnetwork was constructed, including the hub lncRNA MIR143HG and MBNL1‐SA1. Further analysis indicated that the hub subnetwork was highly related to cancer pathways, such as ‘Focal adhesion’ and ‘Wnt signalling pathway’. Hub subnetwork also had significant prognosis capability. A closed lncRNA‐mRNA module was identified by bilateral network clustering. Genes in modules also showed high prognosis effects. Finally, a core lncRNA‐TF crosstalk network was identified to uncover the crosstalk and regulatory mechanisms of lncRNAs and TFs by integrating ceRNA crosstalks and TF binding affinities. Some core genes, such as MEIS1, GLI3 and HAND2‐AS1 were considered as the key regulators in tumourigenesis. Based on the authors’ comprehensive analysis, all these lncRNA‐mRNA crosstalks provided promising clues for biological prognosis of rectal cancer.

GWAS Links New Variant in Long Non-Coding RNA LINC02006 with Colorectal Cancer Susceptibility

Simple Summary

Identifying risk factors for cancer development can allow for appropriate stratification and surveillance of individuals at risk, increasing their chances of benefiting from early disease detection; however, most of the genetic factors contributing to the risk of colorectal cancer (CRC) remain undetermined. Here, we adopted a new approach for selecting index polymorphism for further validation in combination with a genome-wide association study of pooled DNA samples for CRC susceptibility variants in the Polish population. This study, including 2013 patients and controls, uncovered five susceptibility loci not previously reported for CRC. Four of identified variants were located within genes likely involved in tumor invasiveness and metastasis, suggesting that they could be markers of poor prognosis in CRC patients. Our results provide evidence that conducting association studies on small but homogenous populations can help us discover new common risk variants specific to the studied population.

Abstract

Despite great efforts, most of the genetic factors contributing to the risk of colorectal cancer (CRC) remain undetermined. Including small but homogenous populations in genome-wide association studies (GWAS) can help us discover new common risk variants specific to the studied population. In this study, including 465 CRC patients and 1548 controls, a pooled DNA samples-based GWAS was conducted in search of genetic variants associated with CRC in a Polish population. Combined with a new method of selecting single-nucleotide polymorphisms (SNPs) for verification in individual DNA samples, this approach allowed the detection of five new susceptibility loci not previously reported for CRC. The discovered loci were found to explain 10% of the overall risk of developing CRC. The strongest association was observed for rs10935945 in long non-coding RNA LINC02006 (3q25.2). Three other SNPs were also located within genes (rs17575184 in NEGR1, rs11060839 in PIWIL1, rs12935896 in BCAS3), while one was intergenic (rs9927668 at 16p13.2). An expression quantitative trait locus (eQTL) bioinformatic analysis suggested that these polymorphisms may affect transcription factor binding sites. In conclusion, four of the identified variants were located within genes likely involved in tumor invasiveness and metastasis. Therefore, they could possibly be markers of poor prognosis in CRC patients.

LncRNA signature in colorectal cancer

Colorectal cancer (CRC) is among the most frequent cancers and is associated with high mortality particularly when being diagnosed in advanced stages. Although several environmental and intrinsic risk factors have been identified, the underlying cause of CRC is not clear in the majority of cases. Several studies especially in the recent decade have pointed to the role of epigenetic factors in this kind of cancer. Long non-coding RNAs (lncRNAs) as important contributors in the epigenetic mechanisms are involved in the initiation, progression and metastasis of CRC. Tens of oncogenic lncRNAs and a lower number of tumor suppressor lncRNAs have been recently identified to be dysregulated in CRC cells and tissues. Notably, expressions of a number of these transcripts have been dysregulated in serum samples of CRC patients, providing a non-invasive route for detection of this kind of cancer. The involvement of lncRNAs in the regulation of autophagy has provided them the ability to modulate response of CRC cells to chemotherapeutic modalities. In the current manuscript, we review the studies which evaluated the role of lncRNAs in the pathogenesis and progression of CRC to appraise their application as diagnostic/ prognostic markers.

LncRNA PCAT1 Interacts with DKC1 to Regulate Proliferation, Invasion and Apoptosis in NSCLC Cells via the VEGF/AKT/Bcl2/Caspase9 Pathway

Long noncoding RNAs (lncRNAs) are increasingly recognized as indispensable components of the regulatory network in the progression of various cancers, including nonsmall cell lung cancer (NSCLC). The lncRNA prostate cancer associated transcript 1 (PCAT1) has been involved in tumorigenesis of multiple malignant solid tumors, but it is largely unknown that what is the role of lncRNA-PCAT1 and how it functions in the progression of lung cancer. Herein, we observed that lncRNA PCAT1 expression was upregulated in both human NSCLC tissues and cell lines, which was determined by qualitative polymerase chain reaction analysis. Then, gain-and loss-of-function manipulations were performed in A549 cells by transfection with a specific short interfering RNA against PCAT1 or a pcDNA-PCAT1 expression vector. The results showed that PCAT1 not only promoted NSCLC cell proliferation and invasion but also inhibited cell apoptosis. Bioinformatics and expression correlation analyses revealed that there was a potential interaction between PCAT1 and the dyskerin pseudouridine synthase 1 (DKC1) protein, an RNA-binding protein. Then, RNA pull-down assays with biotinylated probes and transcripts both confirmed that PCAT1 directly bounds with DKC1 that could also promote NSCLC cell proliferation and invasion and inhibit cell apoptosis. Moreover, the effects of PCAT1 and DKC1 on NSCLC functions are synergistic. Furthermore, PCAT1 and DKC1 activated the vascular endothelial growth factor (VEGF)/protein kinase B (AKT)/Bcl-2/caspase9 pathway in NSCLC cells, and inhibition of epidermal growth factor receptor, AKT, or Bcl-2 could eliminate the effect of PCAT1/DKC1 co-overexpression on NSCLC cell behaviors. In conclusion, lncRNA PCAT1 interacts with DKC1 to regulate proliferation, invasion, and apoptosis in NSCLC cells via the VEGF/AKT/Bcl-2/caspase9 pathway.

MAGI2-AS3 rs7783388 polymorphism contributes to colorectal cancer risk through altering the binding affinity of the transcription factor GR to the MAGI2-AS3 promoter

Background

It has been indicated that the single nuclear polymorphisms (SNPs) in the long noncoding RNA (lncRNA) have association with colorectal cancer (CRC) susceptibility.

Methods

We enrolled 1078 cases with CRC and 1175 age‐ and gender‐matched cancer‐free controls to explore whether the polymorphisms in MAGI2‐AS3 have associations with CRC risk. qRT‐PCR, expression quantitative trait loci (eQTL) analyses, dual‐luciferase reporter assay, chromatin immunoprecipitation (ChIP), flow cytometry, and transwell assays were performed to explore the specific mechanisms in which MAGI2‐AS3 rs7783388 variation influenced the tumorigenesis of CRC.

Results

Subjects carrying rs7783388 GG genotype presented a higher risk of CRC compared with the AG/AA genotypes. Mechanistically, we found that the functional genetic variant of rs7783388 A > G decreased binding affinity of transcription factor glucocorticoid receptor (GR) to the MAGI2‐AS3 promoter, resulting in decreased transcriptional activity that subsequently downregulated MAGI2‐AS3 expression. Furthermore, functional experiments elucidated that MAGI2‐AS3 overexpression suppressed CRC cell proliferation, migration, and invasion capacities, arrested cell cycle at G0/G1 phase, and promoted cell apoptosis.

Conclusion

Taken together, our study demonstrated that the potential function of MAGI2‐AS3 as a tumor suppressor for CRC, and the MAGI2‐AS3 rs7783388 polymorphism is associated with the increased susceptibility to CRC by altering the binding ability of GR to the MAGI2‐AS3 promoter.

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.

Long non-coding RNA polymorphisms on 8q24 are associated with the prognosis of gastric cancer in a Chinese population

Background

Gastric cancer (GC) remains the third leading cause of cancer death in China. Although genome-wide association studies have identified the association between several single nucleotide polymorphisms (SNPs) on 8q24 and the risk of GC, the role of these SNPs in the prognosis of GC in Chinese populations has not yet been fully evaluated. Therefore, this study was conducted to explore the association between long non-coding RNA (lncRNA) polymorphisms on 8q24 and the prognosis of GC.

Methods

We genotyped 726 surgically resected GC patients to explore the association between eight SNPs in the lncRNAs CCAT1 (rs10087719, rs7816475), PCAT1 (rs1026411), PRNCR1 (rs12682421, rs13252298), and CASC8 (rs1562430, rs4871789, rs6983267) transcribed from the 8q24 locus and the prognosis of GC in a Chinese population.

Results

We found that the patients carrying rs12682421 AA genotypes survived for a shorter time than those with the GG/GA genotype (HR = 1.39, 95% confidence interval (CI) [1.09-1.78]). Compared with the CC/CT genotype, the TT genotype of rs1562430 was associated with an increased risk of death (HR = 1.38, 95% CI [1.06-1.80]). Furthermore, the results also identified the rs1026411 SNP as an independent prognostic factor for poor survival in GC patients. Patients carrying AA/AG variant genotypes had a 36% increased risk of death compared to those carrying the GG genotype (HR = 1.36, 95% CI [1.06-1.74]). These findings suggested that the rs12682421, rs1026411 and rs1562430 SNPs may contribute to the survival of GC and be prognostic markers for GC.

Assessment of biochemical recurrence of prostate cancer (Review)

The assessment of the risk of biochemical recurrence (BCR) is critical in the management of males with prostate cancer (PC). Over the past decades, a comprehensive effort has been focusing on improving risk stratification; a variety of models have been constructed using PC-associated pathological features and molecular alterations occurring at the genome, protein and RNA level. Alterations in RNA expression (lncRNA, miRNA and mRNA) constitute the largest proportion of the biomarkers of BCR. In this article, we systemically review RNA-based BCR biomarkers reported in PubMed according to the PRISMA guidelines. Individual miRNAs, mRNAs, lncRNAs and multi-gene panels, including the commercially available signatures, Oncotype DX and Prolaris, will be discussed; details related to cohort size, hazard ratio and 95% confidence intervals will be provided. Mechanistically, these individual biomarkers affect multiple pathways critical to tumorigenesis and progression, including epithelial-mesenchymal transition (EMT), phosphatase and tensin homolog (PTEN), Wnt, growth factor receptor, cell proliferation, immune checkpoints and others. This variety in the mechanisms involved not only validates their associations with BCR, but also highlights the need for the coverage of multiple pathways in order to effectively stratify the risk of BCR. Updates of novel biomarkers and their mechanistic insights are considered, which suggests new avenues to pursue in the prediction of BCR. Additionally, the management of patients with BCR and the potential utility of the stratification of the risk of BCR in salvage treatment decision making for these patients are briefly covered. Limitations will also be discussed.