Downregulation and tumor-suppressive role of XPO5 in hepatocellular carcinoma

Prognostic significance of exportin-5 in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. As liver cancer often presents no noticeable symptoms in its early stages, most patients are diagnosed at an advanced stage, complicating treatment. Therefore, the identification of new biomarkers is crucial for the early detection and treatment of HCC. Research on exportin-5 (XPO5) could offer new avenues for early diagnosis and improve treatment strategies.

AIM

To explore the role of XPO5 in HCC progression and its potential as a prognostic biomarker.

METHODS

This study assessed XPO5 mRNA expression in HCC using The Cancer Genome Atlas, TIMER, and International Cancer Genome Consortium databases, correlating it with clinical profiles and disease progression. We performed in vitro experiments to examine the effect of XPO5 on liver cell growth. Gene Set Enrichment Analysis, Kyoto Encyclopedia of Genes and Genomes, and Gene Ontology were used to elucidate the biological roles and signaling pathways. We also evaluated XPO5's impact on immune cell infiltration and validated its prognostic potential using machine learning.

RESULTS

XPO5 was significantly upregulated in HCC tissues, correlating with tumor grade, T-stage, and overall survival, indicating poor prognosis. Enrichment analyses linked high XPO5 expression with tumor immunity, particularly CD4 T cell memory activation and macrophage M0 infiltration. Drug sensitivity tests identified potential therapeutic agents such as MG-132, paclitaxel, and WH-4-023. Overexpression of XPO5 in HCC cells, compared to normal liver cells, was confirmed by western blotting and quantitative real-time polymerase chain reaction. The lentiviral transduction-mediated knockdown of XPO5 significantly reduced cell proliferation and metastasis. Among the various machine learning algorithms, the C5.0 decision tree algorithm achieved accuracy rates of 95.5% in the training set and 92.0% in the validation set.

CONCLUSION

Our analysis shows that XPO5 expression is a reliable prognostic indicator for patients with HCC and is significantly associated with immune cell infiltration.

Identification of crucial genes involved in thyroid cancer development

BACKGROUND

A malignancy of the endocrine system, one of the most common types, is thyroid cancer. It is proven that children who receive radiation treatment for leukemia or lymphoma are at a heightened risk of thyroid cancer due to low-dose radiation exposure throughout childhood. Several factors can increase the risk of thyroid cancer (ThyCa), such as chromosomal and genetic mutations, iodine intake, TSH levels, autoimmune thyroid disorders, estrogen, obesity, lifestyle changes, and environmental contaminants.

OBJECTIVES

The study aimed to identify a specific gene as an essential candidate for thyroid cancer progression. We might be able to focus on developing a better understanding of how thyroid cancer is inherited.

METHODS

The review article uses electronic databases such as PubMed, Google Scholar, Ovid MEDLINE, Embase, and Cochrane Central. The most frequently associated genes with thyroid cancer found on PubMed were BAX, XRCC1, XRCC3, XPO5, IL-10, BRAF, RET, and K-RAS. To perform an electronic literature search, genes derived from DisGeNET: a database of gene-disease associations, including PRKAR1A, BRAF, RET, NRAS, and KRAS, are used.

CONCLUSION

Examining the genetics of thyroid cancer explicitly emphasizes the primary genes associated with the pathophysiology of young and older people with thyroid cancer. Developing such gene investigations at the beginning of the thyroid cancer development process can identify better outcomes and the most aggressive thyroid cancers.

Genetic polymorphisms of miRNA machinery genes in bicuspid aortic valve and associated aortopathy

Aim: SNPs in miRNA machinery genes may affect miRNA function by impacting their biogenesis. Here, we investigated the association between three SNPs in miRNA machinery genes (DICER rs1057035, DROSHA rs10719 and XPO5 rs11077) and bicuspid aortic valve (BAV). Materials & methods: Three polymorphisms were analyzed in 177 BAV patients and 414 healthy subjects by using a TaqMan^®SNP assay. Results: The frequencies of XPO5 rs11077 genotype were significantly different between BAV patients and controls (p = 0.022). On multivariate logistic regression analysis, the XPO5 rs11077 C allele resulted a significant predictor of BAV (odds ratio_adjusted = 0.65; CI: 0.42-0.98; p = 0.047). Conclusion: The XPO5 rs11077 SNP was associated with a decreased BAV risk supporting the causative role of miRNAs in aortic valve development.

Exportin-5 SUMOylation promotes hepatocellular carcinoma progression

Increasing evidence has shown that abnormal expression of XPO5 is found in many human cancers and acts as an oncoprotein in certain cancers. However, its functional role in hepatocellular carcinoma (HCC) remains unexplored. In our study, we found that XPO5 was highly expressed in HCC, which was associated with SUMO modification. Moreover, we found that XPO5 was SUMOylated by SUMO2 at K125. Functional experiments revealed that XPO5 SUMOylation could promote MHCC97H cell proliferation, migration and invasion. In addition, we found that the nuclear export of pre-miR-3184 was suppressed by SUMOylated XPO5. Moreover, PLCB1 was identified as the common target of miR-3184-5p and miR-3184-3p. The suppressed phenotype induced by miR-3184-5p and miR-3184-3p could be rescued by overexpression of PLCB1. Bioinformatics analysis showed that PLCB1 expression had a negative relationship with HCC patient survival. The inhibitory effects of MHCC97H cells resulted from abnormal XPO5 SUMO modification could be blocked by miR-3184 inhibitor or PLCB1 overexpression. In conclusion, our findings demonstrate a novel mechanism of XPO5 in HCC, that is, the SUMOylated XPO5 acts as an "oncogenic" role in MHCC97H cells proliferation, migration and invasion by controlling the nuclear-cytoplasm transportation of miR-3184, thus up-regulating PLCB1 expression.

A Key mRNA-miRNA-lncRNA Competing Endogenous RNA Triple Sub-network Linked to Diagnosis and Prognosis of Hepatocellular Carcinoma

Growing evidence has illustrated critical roles of competing endogenous RNA (ceRNA) regulatory network in human cancers including hepatocellular carcinoma. In this study, we aimed to find promising diagnostic and prognostic biomarkers for patients with hepatocellular carcinoma. Three novel unfavorable prognosis-associated genes (CELSR3, GPSM2, and CHEK1) was first identified. We also demonstrated that these genes were significantly upregulated in hepatocellular carcinoma cell lines and tissues. Next, 154 potential miRNAs of CELSR3, GPSM2, and CHEK1 were predicted. CHEK1-hsa-mir-195-5p/hsa-mir-497-5p and GPSM2-hsa-mir-122-5p axes were defined as two key pathways in carcinogenesis of hepatocellular carcinoma by combination of in silico analysis and experimental validation. Subsequently, lncRNAs binding to hsa-mir-195-5p, hsa-mir-497-5p, and hsa-mir-122-5p were predicted via starBase and miRNet databases. After performing expression analysis and survival analysis for these predicted lncRNAs, we showed that nine lncRNAs (SNHG1, SNHG12, LINC00511, HCG18, FGD5-AS1, CERS6-AS1, NUTM2A-AS1, SNHG16, and ASB16-AS1) were markedly increased in hepatocellular carcinoma and their upregulation indicated poor prognosis. Moreover, a similar mRNA-miRNA-lncRNA analysis for six “known” genes (CLEC3B, DNASE1L3, PTTG1, KIF2C, XPO5, and UBE2S) was performed. Subsequently, a comprehensive mRNA-miRNA-lncRNA triple ceRNA network linked to prognosis of patients with hepatocellular carcinoma was established. Moreover, all RNAs in this network exhibited significantly diagnostic values for patients with hepatocellular carcinoma. In summary, the current study constructed a mRNA-miRNA-lncRNA ceRNA network associated with diagnosis and prognosis of hepatocellular carcinoma.

Single-Nucleotide Polymorphisms in XPO5 are Associated with Noise-Induced Hearing Loss in a Chinese Population

Objectives

The purpose of this study was to investigate the correlation between single-nucleotide polymorphism (SNP) in 3′UTR of XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on

Methods

We conducted a case-control study involving 1040 cases and 1060 controls. The effects of SNPs on XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on

Results

We genotyped four SNPs (rs2257082, rs11077, rs7755135, and rs1106841) in the XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on XPO5. Conclusion. The genetic polymorphism, rs11077, within XPO5 is associated with the risk of noise-induced hearing loss in a Chinese population.XPO5 gene and the occurrence of noise-induced hearing loss (NIHL), and to further explore the regulatory mechanism of miRNAs in NIHL on

Prognostic roles of the transcriptional expression of exportins in hepatocellular carcinoma

Aims: A large number of studies have suggested that exportins (XPOs) play a pivotal role in human cancers. In the present study, we analyzed XPO mRNA expression in cancer tissues and explored their prognostic value in hepatocellular carcinoma (HCC).Methods: Transcriptional and survival data related to XPO expression in HCC patients were obtained through the ONCOMINE and UALCAN databases. Survival analysis plots were drawn with Gene Expression Profiling Interactive Analysis (GEPIA). Sequence alteration data for XPOs were obtained from The Cancer Genome Atlas (TCGA) database and c-BioPortal. Gene functional enrichment analyses were performed with Database for Annotation, Visualization and Integrated Discovery (DAVID).Results: Compared with normal liver tissues, significant XPO mRNA overexpression was observed in HCC cancer tissues. There was a trend of higher XPO expression in more advanced clinical stages and lower differentiated pathological grades of HCC. In HCC patients, high expression of XPO1, CSE1L, XPOT, XPO4/5/6 was related to poor overall survival (OS), and XPO1, CSE1L and XPO5/6 were correlated with poor disease-free survival (DFS). The main genetic alterations in XPOs involved mRNA up-regulation, DNA amplification and deletion. General XPO mutations were remarkably associated with worse OS and mostly affected the pathways of RNA transport and oocyte meiosis.Conclusion: High expression of XPOs was associated with a poor prognosis in HCC patients. XPOs may be exploited as good prognostic biomarkers for survival in HCC patients.

MicroRNA (miR)-433 and miR-22 dysregulations induce histone-deacetylase-6 overexpression and ciliary loss in cholangiocarcinoma

Cholangiocytes normally express primary cilia, a multisensory organelle that detects signals from the cellular environment. Cilia are significantly reduced in cholangiocarcinoma (CCA) by a mechanism involving overexpression of histone deacetylase 6 (HDAC6). Despite HDAC6 overexpression in CCA, we found no differences in its mRNA level, suggesting a posttranscriptional regulation, possibly involving microRNAs (miRNAs). Here, we describe that at least two HDAC6-targeting miRNAs, miR-433 and miR-22, are down-regulated in CCA both in vitro and in vivo. Experimental restoration of these miRNAs in CCA cells reduced HDAC6 expression, induced ciliary restoration, and decreased the malignant phenotype. Furthermore, in contrast to the mature forms, levels of precursor forms of these miRNAs were higher in CCA compared to normal cholangiocytes and accumulated in the nuclei, suggesting a defective nuclear export. We assessed the expression of Exportin-5, the protein responsible for transporting miRNA precursors out of the nucleus, and found it to be reduced by 50% in CCA compared to normal cholangiocytes. Experimental overexpression of Exportin-5 in CCA cells restored precursor and mature forms of these miRNAs to normal levels, inducing a decrease in the expression of HDAC6 and a decrease in the malignant phenotype. Conversely, short hairpin RNA (shRNA) depletion of Exportin-5 in normal cholangiocytes resulted in increased nuclear retention of precursor miRNAs, decreased mature miRNAs, increased cell proliferation, and shorter cilia.

CONCLUSION

These data suggest that down-regulated Exportin-5 impairs the nuclear export of miR-433 and miR-22 precursor forms, causing a decrease in levels of mature miR-433 and miR-22 forms, and leading to overexpression of HDAC6 and ciliary loss in CCA. (Hepatology 2018).

XPO5 genetic polymorphisms in cancer risk and prognosis

miRNAs are small noncoding RNA molecules that have a very important role in gene expression regulation and, therefore, in cell homeostasis. SNPs in certain miRNA-related genes have been shown to influence cancer risk and prognosis. miRNA cellular processing is complex and involves multiple proteins. XPO5 is a key factor in this process as it is responsible for the nuclear export of the precursor pre-miRNA to the cytoplasm, where it will be further processed to its final miRNA conformation in order to be loaded to RNA inducing silencing complex to exert its regulatory effect. SNPs in miRNA machinery related genes have previously been shown to influence carcinogenesis, but the role of XPO5 SNPs in its expression and function is not yet fully understood. In our review, we elaborate comprehensively on the role of XPO5 and how polymorphisms have been shown to influence cancer risk and prognosis to date.

Evaluating the Oncogenic and Tumor Suppressor Role of XPO5 in Different Tissue Tumor Types

The miRNAs nuclear export protein XPO5 has been previously studied in several individual malignancies. In our recent study we have demonstrated that excess levels of XPO5 enhanced the proliferation of prostate cancer cells. Similarly, there are studies to support the inhibitory role of XPO5 in cancers. In order to evaluate discrepancies in the expression levels of XPO5 in differential tumor types, we quantified the expression of XPO5 using gene expression RNA-seq data for several tumor types which were independently confirmed by immunohistochemistry in multiple organs cancer tissue microarray (TMAs) experiment. We found that while some tumors (Breast, Bladder, Lymph-node, Lung, Esophagus and Ovary) showed higher differences between normal and malignant tumors in XPO5 expression, there were tissues (Kidney and Brain) that have a significantly lower XPO5 expression in malignant tumors. We further studies these observations of overexpression and down-regulation of XPO5 in breast and kidney cancer cell lines and found that XPO5 might have a dual role in promoting or inhibiting tumor growth in different cancer tissue types.

MicroRNA-Based Drugs for Brain Tumors

MicroRNAs (miRNAs) are key regulatory elements encoded by the genome. A single miRNA can downregulate the expression of multiple genes involved in diverse functions. Because cancer is a disease with multiple gene aberrations, developing novel approaches to identify and modulate miRNA pathways may result in a breakthrough for cancer treatment. With a special focus on glioblastoma (GBM), this review provides an up-to-date summary of miRNA biogenesis, the role of miRNA in cancer resistance, and essential tools for modulating miRNA expression, as well as of clinically promising RNAi delivery systems and how they can be adapted for therapy.

Association of microRNA-related gene XPO5 rs11077 polymorphism with susceptibility to thyroid cancer

Exportin 5 (XPO5) is a microRNA (miRNA)-related nuclear export protein, and its disorder may lead to the dysregulation of miRNAs. Recent studies have demonstrated that the aberrant expression of XPO5 might participate in carcinogenesis in certain cancers. However, there is only limited information of XPO5 in thyroid cancer (TC) development. In our study, we quantified the expression level of XPO5 by real-time polymerase chain reaction (PCR) in 64 TC patients' cancer tissues and adjacent normal tissues. After confirming the XPO5 expression, we evaluated the association between XPO5 potential functional single-nucleotide polymorphisms (SNPs) and risk of TC in a Chinese population (1140 cases vs 1230 controls). Finally, luciferase assays were performed to investigate the function of the SNP in XPO5 3' untranslation region. The message ribonucleic acid (RNA) levels of XPO5 were significantly lower in cancer tissues than normal tissues (P = 0.004). In SNPs screening, only 1 noble SNP rs11077 was identified in XPO5 functional region. The results in our case-control study also confirmed that XPO5 rs11077 was significantly associated with onset of TC (GT/GG vs TT P = 0.035, adjusted odds ratio = 1.25, 95% confidence interval = 1.02-1.54). The adverse influence of this polymorphism was mainly observed in age >45 years (P = 0.028), female (P = 0.020), T1 staging (P = 0.026), N1 (P = 0.038), metastasis (P = 0.031 M0, and P = 0.035 for M1), and early stage (I + II) (P = 0.021). A following luciferase test revealed the critical role of rs11077 for triggering the XPO5 expression. Furthermore, patients with G allele of rs11077 showed lower XPO5 expression level. XPO5 SNP rs11077 influences the expression of XPO5, and this SNP could also be a potential biomarker for the diagnosis of TC in clinical, especially in Chinese population.