Racial Differences in Expression Levels of miRNA Machinery-Related Genes, Dicer, Drosha, DGCR8, and AGO2, in Asian Korean Papillary Thyroid Carcinoma and Comparative Validation Using the Cancer Genome Atlas

DGCR8 Microprocessor Subunit Mutation and Expression Deregulation in Thyroid Lesions

DGCR8 emerged recently as miRNAs biogenesis pathway protein with a highlighted role in thyroid disease. This study aimed to characterize this miRNA biogenesis component, in particular the p.(E518K) mutation and DGCR8 expression in a series of thyroid lesions. The series of thyroid lesions was genotyped for the c.1552G>A p.(E518K) mutation. When frozen tissue was available, DGCR8 mRNA expression was analysed by qPCR. Formalin-fixed paraffin-embedded tissues were studied for DGCR8 immunoexpression. We present for the first time the p.(E518K) mutation in a case of poorly differentiated thyroid carcinoma and present the deregulation of DGCR8 expression at mRNA level in follicular-patterned tumours. The obtained data solidify DGCR8 as another important player of miRNA-related gene mutations in thyroid tumorigenesis, particularly in follicular-patterned thyroid tumours.

STAT5A induced LINC01198 promotes proliferation of glioma cells through stabilizing DGCR8

Background: LINC01198 has been suggested to be able to predict overall prognosis for glioma; however, it has been little described in glioma.

Results: It was shown that LINC01198 was markedly enriched in neoplasmic tissues relative to normal controls; and that elevated LINC01198 significantly correlated with unfavorable overall prognosis. Moreover, activation of STAT5A, identified as transcription factor (TF), can induce the expression of LINC01198. DGCR8, a kind of RNA-binding proteins (RBPs), was identified to be able to bind with LINC01198 that can stabilize the DGCR8. Five differential miRNAs with most significant difference, including miR-21-5p, miR-34-5p, miR-1246, miR-4488 and miR-494, were obtainable after silencing of DGCR8.

Conclusions: Together, the data we presented here suggested that STAT5 induced LINC01198 promotes proliferation and motility of glioma cells through stabilizing DGCR8 in glioma cells.

Methods: Expression of LINC01198 was appraised by quantitative PCR (qPCR) and in situ hybridization (ISH) in glioma clinical specimens, totaling 100 cases. Post hoc statistical analysis was conducted. In vitro, LINC01198 was stably silenced or re-expressed by transfection with lentiviral-based vectors. Chromatin-immunoprecipitation (CHIP) was applied to identify the relevant TFs that can bind with LINC01198, which was corroborated with electrophoretic mobility shift (EMSA) assay. RNA-immunoprecipitation (RIP) was used to identify the RNA-binding protein that can bind with LINC01198. Moreover, miRNA microarray was used to screen out differential miRNAs after silencing of DGCR8.

Exosome mediated miR-155 delivery confers cisplatin chemoresistance in oral cancer cells via epithelial-mesenchymal transition

Cisplatin is used as chemotherapeutic drug for oral squamous cell carcinoma (OSCC). However, OSCC cells develop resistance following long-term cisplatin exposure. Resistance against cisplatin chemo-therapy is accredited to the process of epithelial-to-mesenchymal transition, which in-turn has been linked to tumor-recurrence. miRNA deregulation, a common event in cancer, plays contributory role in chemo-resistance. Exosomes acts as the natural cargo for miRNA and facilitates inter-cell communication in the tumor micro-environment. Hence, exosomal-mediated miRNA transference may play essential role in drug resistance and serve as a target for cancer-therapy. miR-155 upregulation in OSCC has been described, however, its relevance in the observed chemo-resistance is unclear and also, if exosomes have any role in miR-155 regulation remain elusive. In the present study, we document for the first time the critical role of exosomes in mediating increments in miR-155 expression in OSCC cells that have acquired cisplatin resistance (cisRes cells). Importantly, exosomal transfer from cisRes to the cisplatin sensitive (cisSens) cells was found to confer significant miR-155 induction in the recipient cisSens cells. Restoration of miR-155 expression in cisSens cells following miR-155 mimics treatment led to epithelial to mesenchymal transition, enhancements in their migratory potential as well as acquisition of resistant phenotype. Notably, similar augmentations in the migratory and chemo-resistant traits were seen upon delivery of exosomes from cisRes to the recipient cisSens cells. Overall, our findings establish the significance of exosomal-mediated miR-155 shuttling in the cisplatin-chemoresistance, commonly observed in OSCC cells, thereby providing rationale for targeting miR-155 signalling for oral cancer therapy.

Dysregulation of the miRNA biogenesis components DICER1, DROSHA, DGCR8 and AGO2 in clear cell renal cell carcinoma in both a Korean cohort and the cancer genome atlas kidney clear cell carcinoma cohort

Impairment of microRNA (miRNA) biogenesis may be involved in clear cell renal cell carcinoma (ccRCC). The objective of the present study was to investigate the mRNA levels of important miRNA machinery components, DICER1, DROSHA, DiGeroge syndrome critical region gene 8 (DGCR8), and Argonaute 2 (AGO2), and their correlations with clinicopathological characteristics of ccRCC using mRNA expression data from The Cancer Genome Atlas kidney clear cell carcinoma (TCGA KIRC) cohort and a Korean ccRCC cohort. mRNA levels of DICER1, DROSHA, and DGCR8 were significantly decreased in both cohorts. However, AGO2 was significantly downregulated only in the Korean ccRCC cohort. Additionally, positive correlations were observed between the altered mRNA levels of DICER1 and DROSHA as well as DROSHA and DGCR8 in both cohorts. In the TCGA KIRC cohort, alterations in the mRNA levels of DICER1 were significantly correlated with histological grade. Furthermore, the altered mRNA levels of DGCR8 showed significant associations with sex and histologic grades. However, in the Korean ccRCC cohort, no factors were significantly associated with any clinicopathological parameters, including sex, age, T stage, Fuhrman grade/The International Society of Urological Pathology grade, lymphovascular invasion, and peri-renal fat invasion. Taken together, these findings indicate that DICER1, DROSHA, DGCR8 and AGO2 are significantly dysregulated in ccRCC, suggesting that they are important in the pathophysiology of this malignancy.

How hsa-miR-495 performed in the tumorigenesis of pancreatic adenocarcinoma by bioinformatics analysis

INTRODUCTION

Pancreatic adenocarcinoma (PAAD) is one of the most fatal cancers in the world for early metastasis, extensive invasion, and poor prognosis with a 5-year survival rate less than 5%. However, the underlying mechanisms are poorly understood. Therefore, it is urgent to explore molecular markers for early diagnosis or therapy target to improve the outcome of PAAD.

METHODS

We retrieved transcriptome data as well as clinical information from patients with PAAD in The Cancer Genome Altas (TCGA) database. Survival time associated microRNAs (miRNAs) and messenger RNAs (mRNAs) were initially identified, followed by enrichment analysis (Gene Ontology [GO] and pathway). The relationship between survival time associated miRNAs-mRNAs was also investigated to discover putative transcriptional control mechanisms of PAAD. Finally, by consulting the literature and retrieving the database, we found that hsa-miR-495 might have played an important role in PAAD.

RESULTS

In total, 146 miRNAs from 378 miRNAs and 580 mRNA from 17 100 mRNA, including 328 risk mRNA and 252 protective mRNA, were found to be associated with the survival time of PAAD. Eight hundred eighty-eight mRNA-miRNA pairs were related to the survival time of PAAD, involving in 755 mRNAs and 35 miRNAs. We chose 13 miRNAs predicted by target gene in the miRanda database for further research. Among these 13 miRNAs, hsa-miR-495 was identified as a good biomarker. Through GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the significantly enriched pathways involved in focal adhesion, Staphylococcus aureus infection, and Intestinal immune network for immunoglobulin A production. And four target genes and 87 pathways of the hsa-miR-495 were enriched in PAAD. Interestingly, we found hsa-miR-495 with a low expression having a poor overall survival and significantly different recurrence rate within 5 years.

CONCLUSION

Hsa-miR-495 and its target genes may serve as a prognostic and predictive marker in PAAD. Further research on the function of the hsa-miR-495 and its target genes in the KEGG pathway may provide references for treatment of PAAD.

Deregulation of MicroRNA-375 Inhibits Proliferation and Migration in Gastric Cancer in Association With Autophagy-Mediated AKT/mTOR Signaling Pathways

Gastric cancer is a deadly disease. Some microRNAs are involved in tumor invasion and metastasis. Underexpression of miR-375 has been correlated with tumorigenesis, treatment resistance, and poor prognosis. In this study, we first analyzed the profiles and prognostic values of miR-375 expression in gastric cancer tissues from a public database, and the expression level of miR-375 in gastric cancer samples and gastric cancer cell lines was then analyzed by quantitative real- time polymerase chain reaction. Significant underexpression of miR-375 was seen in all the gastric cancer samples compared to paired paracarcinoma tissues, and the expression level of miR-375 in the gastric cancer cell lines was negatively associated with the cell migration ability. A Cell proliferation (CCK-8) assay was performed to examine cell viability. Overexpression of miR-375 suppressed the proliferation of gastric cancer cells. A Western blot analysis was carried out to test protein expression. Overexpression of miR-375 inhibited autophagy through the AKT/ mammalian target of rapamycin signaling pathway. MiR-375 regulated invasion and migration via AKT/ mammalian target of rapamycin pathway-mediated epithelial-to-mesenchymal transition. Wound healing and migration assays were used to determine the motility of gastric cancer cells. A gastric cancer xenograft nude mouse model was used for an in vivo efficacy evaluation. Overexpression of miR-375 significantly suppressed cell proliferation in the established gastric cancer xenograft nude mouse model. Our results demonstrate that increasing the expression level of miR-375 suppresses proliferation in vitro and in vivo, and they provide a mechanistic and applicable rationale for the future clinical evaluation of miR-375 in gastric cancer treatment. Our findings provide not only new information about the molecular mechanism of microRNAs in regulating invasion and migration in gastric cancer but also a theoretical principle for a potential targeted therapy for gastric cancer.

miR-93-5p may be an important oncogene in prostate cancer by bioinformatics analysis

INTRODUCTION

Prostate adenocarcinoma is one of the most prevalent causes of cancer-related deaths in males worldwide. However, the underlying mechanisms remain poorly understood. Hence, it is important to identify specific and effective therapeutic targets, to be able to determine appropriate therapy and management. So, this study aimed to predict that miR-93-5p is an important oncogene in prostate cancer by bioinformatics analysis.

METHODS

In this study, initially we identified differentially expressed genes (DEGs) and differently expressed miRNAs (DEMs) in the The Cancer Genome Atlas (TCGA) database, performed Gene Ontology (GO) and pathway enrichment analysis, then investigated the relationship between DEGs and DEMs, and finally through consulting the literature and retrieving the database, we found that miR-93-5p may play a major role in prostate cancer, so we predicted the expression and survival of miR-93-5p and its isomers by bioinformatics analysis, meanwhile, evaluated the function of miR-93-5p in vitro.

RESULTS

In total, 104 DEMs were differently expressed between prostate cancer and normal samples, including 56 downregulated ones and 48 upregulated ones; miR-93-5p (upregulated) was identified as a good biomarker. And 1904 DEGs were retrieved, including 794 downregulated ones and 1110 upregulated ones. We also obtained 1254 DEGs of the DEMs. In GO and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, the significantly enriched pathways involved pathway in focal adhesion, vascular smooth muscle contraction, and regulation of actin cytoskeleton. By the KEGG pathway, we got 16 target genes and 92 pathways of the miR-93-5p in prostate cancer. We also found that the miR-93-5p and its isomers can express in prostate cancer, and which with a high expression had a poor overall survival and a significant difference recurrence rate within 5 years. Further in vitro verification results demonstrated that the low expression of miR-93-5p can inhibit cell proliferation, migration, invasion, change cell cycle, and promote early apoptosis of PC-3 cells.

CONCLUSION

The miR-93-5p and its target genes were used to define important molecular targets that could serve as a prognostic and predictive marker in the treatment of prostate cancer. Further research on the function of the miR-93-5p and its target genes in the KEGG pathway could provide references for the treatment of prostate cancer.

Clinicopathological characteristics and prognosis of thyroid cancer in northwest China: A population-based retrospective study of 2490 patients

Background

The specific clinical features of thyroid cancer patients in northwest China are unclear; therefore, we analyzed the clinicopathological characteristics and prognosis of this population.

Methods

Clinical characteristics including age, gender, blood type, histological type, and BRAF^V600E gene mutation; and incidence; risk factors; surgical treatment; and prognosis were recorded.

Results

A total of 2490 thyroid cancer patients were included; 98% were diagnosed with papillary thyroid cancer (PTC). Weight, blood type, histological type, and BRAF^V600E gene mutation rates were significantly different. Pediatric thyroid cancer patients had higher lymph node metastasis, lower BRAF^V600E mutation, and 6.2–9.2% greater recurrence rates than adult patients. PTC and papillary thyroid microcarcinoma displayed similar features, while in other types, such as follicular and medullary thyroid cancer, there were variations. Multiple logistic analyses showed that age (odds ratio [OR] 0.957, 95% confidence interval [CI] 0.944–0.970; P < 0.001), focal status (OR 16.174, 95% CI 9.257–28.262; P < 0.001), pathology (OR 0.642, 95% CI 0.473–0.871; P = 0.004) and lymph node metastasis (OR 0.059, 95% CI 0.033–0.107; P < 0.001) were independent factors for BRAF^V600E mutation.

Conclusion

Most real world clinicopathological features, treatment, and prognosis of thyroid cancer are similar to reported data, such as the higher incidence of disease in women and the larger proportion of PTC. However, the results in pediatric patients and those with BRAF gene mutations are controversial and require more clinical incidence.