A functional genetic variant in GAS5 lncRNA (rs145204276) modulates p27Kip1 expression and confers risk for gastric cancer

Growth arrest-specific 5 (GAS5) insertion/deletion polymorphism and cancer susceptibility in Asian populations: A meta-analysis

BACKGROUND

Previous studies have reported the association of an insertion/deletion (Ins/Del) polymorphism (rs145204276 AGGCA/-) in the promoter region of growth arrest-specific 5 (GAS5) with the risk of cancer, such as breast cancer, gastric cancer, and hepatocellular carcinoma. However, the results are still controversial. We aimed to clarify the association of GAS5 rs145204276 polymorphism with cancer risk by meta-analysis.

METHODS

PubMed, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang, and Cochrane Library were searched for studies concerning GAS5 and cancer published up to November 25, 2019. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate cancer risk.

RESULTS

A total of 12 case-control studies with 8729 cases and 10,807 controls were included in this meta-analysis. We found that the GAS5 rs145204276 polymorphism was not significantly associated with cancer risk (Del vs Ins: OR = 0.96, 95% CI: 0.81-1.13; Del/Del vs Ins/Ins: OR = 1.00, 95% CI: 0.70-1.43; Ins/Del vs Ins/Ins: OR = 0.92, 95% CI: 0.78-1.08; Ins/Del and Del/Del vs Ins/Ins: OR = 0.93, 95% CI: 0.76-1.13; Del/Del vs Ins/Del and Ins/Ins: OR = 1.04, 95% CI: 0.78-1.38). In the stratified analyses, significant effects on gastric cancer were found (Del vs Ins: OR = 0.79, 95% CI: 0.72-0.86; Del/Del vs Ins/Ins: OR = 0.65, 95% CI: 0.52-0.82; Ins/Del vs Ins/Ins: OR = 0.76, 95% CI: 0.68-0.86; Ins/Del + Del/Del vs Ins/Ins: OR = 0.74, 95% CI: 0.66-0.83; Del/Del vs Ins/Ins + Ins/Del: OR = 0.74, 95% CI: 0.59-0.91).

CONCLUSION

Our meta-analysis showed that GAS5 rs145204276 polymorphisms were not related to overall cancer risk. However, the GAS5 rs145204276 polymorphism may be a protective factor for gastric cancer in the stratification analyses.

The effect of mitochondria-targeted antioxidant MitoQ10 on redox signaling pathway components in PCOS mouse model

PURPOSE

Considerable evidence suggests that mitochondrial dysfunction and oxidative stress contribute to the pathogenesis of Polycystic ovary syndrome (PCOS). We aimed to evaluate the effectiveness of mitochondria-targeted antioxidant, MitoQ10, on the redox signaling pathway's component in PCOS.

METHOD

We assessed TXNIP, TRX, and ASK1 expression in granulosa cells (GCs) of the DHEA-induced PCOS mouse model. Female BALB/c mice in five groups of Control, DHEA, and DHEA + MitoQ10 in three doses of 250, 500, and 750 μmol/L MitoQ10 were treated for 21 days.

RESULTS

Histological investigation showed a probable improvement in folliculogenesis; besides, ASK1 and TXNIP expression were significantly increased in GCs of the PCOS mouse F4Fmodel as compared to the control groups and decreased steadily in groups treated by MitoQ10. However, TRX expression showed a drop that was restored by MitoQ10 meaningfully (P ≤ 0.05).

CONCLUSION

The work presented herein suggests mitochondria-targeted antioxidant, MitoQ10, have modulating effects on folliculogenesis in the ovary and also on the redox signaling pathway in GCs of PCOS mouse model which may have potential to attenuate oxidative stress and its relative damages.

Association between long non-coding RNA (lncRNA) GAS5 polymorphism rs145204276 and cancer risk

OBJECTIVE

The long non-coding RNA (lncRNA) growth arrest‑specific transcript 5 (GAS5) plays an important role in various tumors, and an increasing number of studies have explored the association of the GAS5 rs145204276 polymorphism with cancer risk with inconclusive results.

METHODS

PubMed, Medline, EMBASE, Cochrane databases, and Web of Science were searched, and nine studies involving 6107 cases and 7909 controls were deemed eligible. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to evaluate the relationship between rs145204276 and cancer risk in six genetic models.

RESULTS

The pooled results suggest that the variant allele del was not associated with overall cancer risk. However, the subgroup analysis showed that allele del was significantly associated with a 22% decreased risk of gastrointestinal cancer (OR = 0.78, 95% CI: 0.72-0.85). Both sensitivity analyses and trial sequential analyses (TSA) demonstrated that the subgroup results were reliable and robust. Moreover, False-Positive Report Probability (FPRP) analysis indicated that the results had true significant correlations.

CONCLUSION

These findings provide evidence that the GAS5 rs145204276 polymorphism is associated with the susceptibility to gastrointestinal cancer. Further studies with different ethnicities and larger sample sizes are warranted to confirm these results.

The potential of long noncoding RNAs for precision medicine in human cancer

Precision medicine promises to better classify patients by individual clinical and biological biomarkers, which may provide an accurate assessment of disease risk, diagnosis, prognosis and treatment response. Cancer frequently displays substantial inter-tumor and intra-tumor heterogeneity and hence oncology is well suited for application of precision approaches. Recent studies have demonstrated that dysregulated lncRNAs play pivotal roles in tumor heterogeneity. In this review, attention is focused on the potential applications of lncRNAs as biomarker candidates for cancer risk evaluation, detection, surveillance and prognosis. LncRNAs are often stable in clinical samples and easily detected. The functional implications and therapeutic potential of targeting lncRNAs in human cancer are further discussed. Finally, existing deficiencies and future perspectives in translating fundamental lncRNA knowledge into clinical practice are highlighted.

The Non-Coding RNA GAS5 and Its Role in Tumor Therapy-Induced Resistance

The growth arrest-specific transcript 5 (GAS5) is a >200-nt lncRNA molecule that regulates several cellular functions, including proliferation, apoptosis, invasion and metastasis, across different types of human cancers. Here, we reviewed the current literature on the expression of GAS5 in leukemia, cervical, breast, ovarian, prostate, urinary bladder, lung, gastric, colorectal, liver, osteosarcoma and brain cancers, as well as its interaction with various miRNAs and its effect on therapy-related resistance in these malignancies. The general consensus is that GAS5 acts as a tumor suppressor across different tumor types and that its up-regulation results in tumor sensitization to chemotherapy or radiotherapy. GAS5 seems to play a previously unappreciated, but significant role in tumor therapy-induced resistance.

Circulating Long Non-Coding RNA GAS5 Is Overexpressed in Serum from Osteoporotic Patients and Is Associated with Increased Risk of Bone Fragility

Osteoporosis (OP) is a multifactorial disorder in which environmental factors along with genetic variants and epigenetic mechanisms have been implicated. Long non-coding RNAs (lncRNAs) have recently emerged as important regulators of bone metabolism and OP aetiology. In this study, we analyzed the expression level and the genetic association of lncRNA GAS5 in OP patients compared to controls. Quantitative RT-PCR analysis of GAS5 was performed on the serum of 56 OP patients and 28 healthy individuals. OP subjects were divided into three groups of analysis: 29 with fragility fractures of lumbar spine (OP_VF), 14 with fragility fractures of femoral neck (OP_FF) and 13 without fractures (OP_WF). Genotyping of the rs145204276 insertion/deletion polymorphism has also been performed by Restriction fragment length polymorphism (RFLP) and direct sequencing analyses. Expression of circulating GAS5 is significantly increased in OP patients compared to controls (p < 0.01), with a statistically higher significance in fractured OP individuals vs. healthy subjects (p < 0.001). No statistically significant change was found in female OP patients; conversely, GAS5 is upregulated in the subgroup of fractured OP women sera (p < 0.01) and in all OP males (p < 0.05). Furthermore, a direct correlation between GAS5 expression level and parathyroid hormone (PTH) concentration was found in OP patients (r = 0.2930; p = 0.0389). Genetic analysis of rs145204276 revealed that the deletion allele was correlated with a higher expression of GAS5 in OP patients (0.22 ± 0.02 vs. 0.15 ± 0.01, ** p < 0.01). Our results suggest circulating GAS5 as a putative biomarker for the diagnosis and prognosis of OP and OP-related fractures.

GAS5‑mediated regulation of cell signaling (Review)

In recent years, an increasing number of long non-coding RNAs (lncRNAs) have been discovered using microarrays and nucleic acid sequencing technology. LncRNAs exert crucial biological functions by regulating signaling pathways. In particular, the lncRNA growth arrest-specific transcript 5 (GAS5) has been documented to serve a crucial role in numerous signaling pathways. This article discusses the latest developments in the association between GAS5 and microRNA (miRNA), p53, mTOR, glucocorticoid response element (GRE) and AKT in order to investigate the roles served by GAS5. miRNAs can activate related signaling pathways and GAS5 can combine with miRNA to regulate related signaling pathways. GAS5 may regulate p53 expression via derivation of snoRNA, but the underlying mechanism requires further investigation. GAS5 overxpresion reduces the expression level of mTOR, which is induced by inhibiting miR-106a-5p expression. GAS5 is a sponge of GR, and serves a role in controlling and maintaining glucocorticoid sensitivity and drug resistance via competitive combination with GR. GAS5 can interact with miRNAs, such as miR-21 and miR-532-5p, to regulate the expression of AKT signaling pathway, affecting cell survival and apoptosis. Collectively, the data indicate that GAS5 serves a key role in the miRNA, p53, mTOR, GRE, and AKT signaling pathways. GAS5 regulates complex intracellular signaling pathways primarily through three modes of action, all of which are interrelated: Signal, decoy and guide. In the present article, latest developments in the association between GAS5 and a number of cellular signaling pathways are discussed to examine the tumor suppressive role of GAS5.

Impact of Gene Polymorphisms in GAS5 on Urothelial Cell Carcinoma Development and Clinical Characteristics

Urothelial cell carcinoma (UCC) is the commonest malignant tumor of the urinary tract and the second most common kidney cancer malignancy. Growth arrest-specific 5 (GAS5), a long noncoding RNA, is encoded by the GAS5 gene and plays a critical role in cellular growth arrest and apoptosis. In the current study, two single nucleotide polymorphisms (SNPs) in the GAS5 gene, rs145204276 and rs55829688, were selected to investigate correlations between these single SNPs and susceptibility to UCC. A total of 430 UCC cases and 860 ethnically matched healthy controls were included. SNP rs145204276 and SNP rs55829688 were determined using a TaqMan genotyping assay. Logistic regression models demonstrated that female patients with UCC carrying the rs145204276 GAS5 Ins/Del or Del/Del genotype had a 3.037-fold higher risk of larger tumor status (95% confidence interval 1.259–7.324) than did rs145204276 wild type (Ins/Ins) carriers (p  =  0.011). The Cancer Genome Atlas validation cohort analysis demonstrated that the expression of GAS5 in female patients with bladder urothelial carcinoma (BLCA) with larger tumor size was much lower than that in patients with a smaller tumor size (p = 0.041). Kaplan-Meier curve analysis and the log–rank test revealed that female patients with BLCA and lower GAS5 expression had poorer overall survival than those with higher GAS5 expression. In conclusion, genetic variations in GAS5 rs145204276 may serve as a critical predictor of the clinical status of female patients with UCC.

Non-coding RNAs - A primer for the laboratory scientist

Advances in molecular genetics have identified several species of RNA that fail to translate - hence the non-coding RNAs. The two major groups within this class of nucleic acids are microRNAs (miRNA) and long non-coding RNAs (lncRNA). There is growing body of evidence supporting the view that these molecules have regulatory effect on both DNA and RNA. The objective of this brief review is to explain the molecular genetic of these molecules, to summarize their potential as mediators of disease, and to highlight their value as diagnostic markers and as tools in disease management.

Association between lncRNA GAS5, MEG3, and PCAT-1 Polymorphisms and Cancer Risk: A Meta-Analysis

Purpose

Long noncoding RNAs (lncRNAs) have been widely studied, and single nucleotide polymorphisms (SNPs) in lncRNAs are considered to be genetic factors that influence cancer susceptibility. The lncRNA GAS5, MEG3, and PCAT-1 polymorphisms are shown to be possibly associated with cancer risk. The aim of this meta-analysis was to systematically evaluate this association.

Methods

Studies were selected from PubMed, Web of Science, Embase, Google Scholar, Cochrane Library, the Chinese National Knowledge Infrastructure (CNKI), and the Chinese Biomedical Literature Database (CBM) through inclusion and exclusion criteria. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using the random-effects model or fixed-effects model to assess the association between lncRNA polymorphisms and cancer susceptibility. Metaregression and publication bias analyses were also conducted. All analyses were performed using the Stata 12.0 software.

Results

Sixteen articles (covering 13750 cases and 17194 controls) were included in this meta-analysis. A significant association between SNP rs145204276 and gastric cancer risk was observed (del vs. ins: OR = 0.79, 95%CI = 0.72-0.86; del/del vs. ins/ins+del/ins: OR = 0.74, 95%CI = 0.59-0.91; del/ins vs. ins/ins: OR = 0.84, 95%CI = 0.67-1.05). For rs16901904, a decreased cancer risk was observed in three genetic models (C vs. T: OR = 0.79, 95%CI = 0.70-0.90; CC vs. CT+TT: OR = 0.49, 95%CI = 0.37-0.65; CC vs. TT: OR = 0.49, 95%CI = 0.37-0.66). No statistical significance was found in the metaregression analysis. For all of the included SNPs, no publication bias was found in all genotype models.

Conclusions

The rs145204276 SNP in lncRNA GAS5 is likely to be associated with gastric cancer risk, whereas the rs16901904 SNP in lncRNA PCAT-1 bears association with a decreased cancer risk.

Long non-coding RNAs as the critical factors during tumor progressions among Iranian population: an overview

BACKGROUND

Cancer is associated with various genetic and environmental risk factors. Beside the mutations or aberrant expression of protein-coding genes, the genetic deregulation of non-coding RNAs has also an important role during tumor progression and metastasis. Long non-coding RNAs (lncRNAs) are a class of ncRNAs larger than 200 nucleotides that may function as tumor-suppressor or oncogene.

MAIN BODY

There is a raising trend of cancer incidence among Iranian population during the last decades. Therefore, it is required to prepare a general population specific panel of genetic markers for the early detection of cancer in this population. The tissue-specific expression characteristics and high stability in body fluids highlight the lncRNAs as efficient diagnostic and prognostic noninvasive biomarkers in cancer. In present review we summarized all of the lncRNAs which have been reported until now in different tumors among Iranian patients.

CONCLUSIONS

This review paves the way of introducing a population based noninvasive diagnostic panel of lncRNAs for the early detection of tumor cells among Iranian population.

British Journal of Biomedical Science in 2019. What have we learned?

In 2019 the British Journal of Biomedical Science published 40 articles in the various disciplines that comprise biomedical science. These were one review, 22 original articles and 17 'In Brief' short reports. Of those citing original data, the majority were in cellular pathology (14 papers), clinical chemistry (9 papers), and microbiology (6 papers: 4 in bacteriology and 2 in virology). There were 3 papers in haematology and 2 in andrology, whilst 5 papers crossed traditional discipline boundaries (such as the molecular genetics of IL6, liver function tests, and hepatocellular carcinoma). Over two-thirds of papers used techniques in molecular genetics. The present report will summarise key aspects of these publications that are of greatest relevance to laboratory scientists.

Novel Tumor Suppressor lncRNA Growth Arrest-Specific 5 (GAS5) In Human Cancer

Long noncoding RNAs (lncRNAs) play crucial regulatory roles in fundamental biological processes, and deregulations of lncRNAs have been linked to numerous human diseases, especially cancers. Of particular interest in this regard is lncRNA GAS5, which is mainly identified as a tumor suppressor in several cancers. GAS5 was significantly low expressed in multiple cancers and was associated with clinic-pathological characteristics and patient survival, indicating a novel potential diagnostic and prognostic biomarker, and a therapeutic target for cancer. Functionally, GAS5 is involved in cell proliferation, metastasis, invasion, apoptosis, epithelial-mesenchymal transition (EMT), and drug resistance, among others, via multiple molecular mechanisms, such as binding to DNA sequences, forming RNA-DNA triplex complex, triggering or suppressing the expression of genes, binding proteins to form chromatin-modifying complex, which activates or represses gene expression, and acting as miRNA sponge to suppress miRNA expression, leading to regulation of miRNA target genes. This review provides an overview of the current state of knowledge and role of GAS5 in clinical relevance, biological functions and molecular mechanisms underlying the dysregulation of expression and function of GAS5 in cancer. Finally, the potential prospective role as diagnostic and prognostic biomarker and therapeutic target in cancer is discussed.

Functional variants of lncRNA LINC00673 and gastric cancer susceptibility: a case-control study in a Chinese population

Background: Two genome-wide association studies (GWASs) identified LINC00673 rs11655237 was associated with susceptibility to pancreatic cancer. Methods: To investigate the association between LINC00673 polymorphisms and gastric cancer (GC) risk, and the impact of gene-environmental interaction on GC risk, we conducted this case-control study in a Chinese population. Results: We found rs11655237 significantly increased susceptibility of GC in the Chinese population (OR=1.29; 95% CI=1.12-1.48; P=4.1×10-4), and a significant interaction was found between rs11655237 and Helicobacter pylori infection (P=0.006). Expression of LINC00673 was significantly higher in adjacent normal tissues than in paired cancer tissues (P<0.001) and significantly lower in the cancer or paired adjacent normal tissues of GC patients with rs11655237 allele A than in those with rs11655237 allele G (P<0.001). Mechanism exploration found that, the construct with the rs11655237[A] allele had significantly reduced luciferase activity in the presence of miR-1231, and this effect could be completely rescued when miR-1231 inhibitor was present. Conclusion: Our results indicate that LINC00673 rs11655237 is associated with an increased GC risk, possibly by down-regulating LINC00673 expression through creating a miR-1231 binding site.

Association between polymorphism in the promoter region of lncRNA GAS5 and the risk of colorectal cancer

The growth arrest special 5 (GAS5), as a research hotspot of long noncoding RNAs (lncRNAs), has been reported to be associated with colorectal cancer (CRC). However, the association between polymorphisms in GAS5 and the risk of CRC was not clear. In the present study, a case–control study in 1078 CRC patients and 1175 matched healthy controls was performed to evaluate the association between the potential functional genetic variants in GAS5 and the risk of CRC. PCR-TaqMan, qPCR, dual-luciferase assay, electrophoretic mobility shift assay (EMSA), flow cytometry, migration and invasion assays were performed to evaluate the function of polymorphism. Results showed that subjects carrying the rs55829688 CT/TT genotypes had a significantly higher risk of CRC when compared with the CC genotype. Further qPCR assay confirmed that the CRC tissues with rs55829688 CT/TT genotypes had a higher GAS5 mRNA expression level. The dual-luciferase assay, qPCR and EMSA assay revealed that rs55829688 T>C polymorphism could decrease the expression level of GAS5 by impacting the binding ability of the transcription factor Yin Yang-1 (YY1) to the GAS5 promoter region. The expression of apoptosis-related proteins were detected by Western blot. Further, flow cytometry, migration, and invasion experiments showed that GAS5 repressed apoptosis and increased invasion and migration capability of CRC cells. Taken together, our findings provided evidence that the rs55829688 variant in the GAS5 promoter was associated with the risk of CRC and decreased expression of GAS5 by affecting the binding affinity of the transcription factors YY1 to GAS5.