MicroRNA and its roles in esophageal cancer

MicroRNA-375 in extracellular vesicles - novel marker for esophageal cancer diagnosis

BACKGROUND

MicroRNAs have been confirmed to function as diagnostic biomarkers for esophageal cancer (EC). This study aimed to investigate the diagnostic potential of miR-375 in the plasma or extracellular vesicles (EVs) of esophageal cancers (ECs).

METHODS

miRNAs with diagnostic potential were identified through public database searches and validated through clinical sample testing. The diagnostic value of miR-375 in plasma and EVs was evaluated via receiver operating characteristic analysis and area under the curve. In addition, expression and survival analyses of the top ten target genes of miR-375 were conducted using the cancer genome atlas database.

RESULTS

MiR-375 was identified as a potential biomarker for ECs by searching the gene expression omnibus database. Results of clinical sample measurements showed that miR-375 in plasma or EVs was significantly different between ECs and controls ( P < .01), but did not differ by gender or age. receiver operating characteristic analysis demonstrated that miR-375 in EVs could function as a diagnostic marker for ECs, with a higher area under the curve (0.852) than that in plasma. The expression and survival analysis of the top ten target genes for miR-375 showed that only EIF4G3 was significantly associated with survival ( P < .05).

CONCLUSION

This research shows that miR-375, particularly in EVs, could serve as a biomarker for the diagnosis of ECs.

Circ_0057558 promotes nonalcoholic fatty liver disease by regulating ROCK1/AMPK signaling through targeting miR-206

Nonalcoholic fatty liver disease (NAFLD) is one of the most prevalent chronic liver disorders that is featured by the extensive deposition of fat in the hepatocytes. Current treatments are very limited due to its unclear pathogenesis. Here, we investigated the function of circ_0057558 and miR-206 in NAFLD. High-fat diet (HFD) feeding mouse was used as an in vivo NAFLD model and long-chain-free fatty acid (FFA)-treated liver cells were used as an in vitro NAFLD model. qRT-PCR was used to measure levels of miR-206, ROCK1 mRNA, and circ_0057558, while Western blotting was employed to determine protein levels of ROCK1, p-AMPK, AMPK, and lipogenesis-related proteins. Immunohistochemistry were performed to examine ROCK1 level. Oil-Red O staining was used to assess the lipid deposition in cells. ELISA was performed to examine secreted triglyceride (TG) level. Dual-luciferase assay was used to validate interactions of miR-206/ROCK1 and circ_0057558/miR-206. RNA immunoprecipitation was employed to confirm the binding of circ_0057558 with miR-206. Circ_0057558 was elevated while miR-206 was reduced in both in vivo and in vitro NAFLD models. miR-206 directly bound with ROCK1 3'-UTR and suppressed lipogenesis and TG secretion through targeting ROCK1/AMPK signaling. Circ_0057558 directly interacted with miR-206 to disinhibit ROCK1/AMPK signaling. Knockdown of circ_0057558 or overexpression of miR-206 inhibited lipogenesis, TG secretion and expression of lipogenesis-related proteins. ROCK1 knockdown reversed the effects of circ_0057558 overexpression. Injection of miR-206 mimics significantly ameliorated NAFLD progression in vivo. Circ_0057558 acts as a miR-206 sponge to de-repress the ROCK1/AMPK signaling and facilitates lipogenesis and TG secretion, which greatly contributes to NAFLD development and progression.

Network analysis of miRNA targeting m6A-related genes in patients with esophageal cancer

Background

We investigated the miRNA-m6A related gene network and identified a miRNA-based prognostic signature in patients with esophageal cancer using integrated genomic analysis.

Methods

We obtained expression data for m6A-related genes and miRNAs from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Survival analysis was conducted to identify potential prognostic biomarkers. LASSO Cox regression was performed to construct the overall survival (OS) associated prediction signature. We used the Kaplan-Meier (K-M) curve and receiver operating characteristic (ROC) curves to explore the signature's efficiency and accuracy. Interactions between the m6A-related genes and miRNAs were identified in starBase3.0 and used to construct the miRNA-m6A related gene network.

Results

We found that HNRNPC, YTHDF, ZC3H13, YTHDC2, and METTL14 were dysregulated in esophageal cancer tissues. Multivariate Cox regression analysis revealed that HNRNPC may be an independent risk factor for OS. Five hundred twenty-two potential upstream miRNAs were obtained from starBase3.0. Four miRNAs (miR-186, miR-320c, miR-320d, and miR-320b) were used to construct a prognostic signature, which could serve as a prognostic predictor independent from routine clinicopathological features. Finally, we constructed a key miRNA-m6A related gene network and used one m6A-related gene and four miRNAs associated with the prognosis. The results of our bioinformatics analysis were successfully validated in the human esophageal carcinoma cell lines KYSE30 and TE-1.

Conclusion

Our study identified a 4-miRNA prognostic signature and established a key miRNA-m6A related gene network. These tools may reliably assist with esophageal cancer patient prognosis.

Identification of differentially expressed microRNAs in primary esophageal achalasia by next-generation sequencing

Molecular knowledge regarding the primary esophageal achalasia is essential for the early diagnosis and treatment of this neurodegenerative motility disorder. Therefore, there is a need to find the main microRNAs (miRNAs) contributing to the mechanisms of achalasia. This study was conducted to determine some patterns of deregulated miRNAs in achalasia. This case-control study was performed on 52 patients with achalasia and 50 nonachalasia controls. The miRNA expression profiling was conducted on the esophageal tissue samples using the next-generation sequencing (NGS). Differential expression of miRNAs was analyzed by the edgeR software. The selected dysregulated miRNAs were additionally confirmed using the quantitative reverse transcription polymerase chain reaction (qRT-PCR). Fifteen miRNAs were identified that were significantly altered in the tissues of the patients with achalasia. Among them, three miRNAs including miR-133a-5p, miR-143-3p, and miR-6507-5p were upregulated. Also, six miRNAs including miR-215-5p, miR-216a-5p, miR-216b-5p, miR-217, miR-7641 and miR-194-5p were downregulated significantly. The predicted targets for the dysregulated miRNAs showed significant disease-associated pathways like neuronal cell apoptosis, neuromuscular balance, nerve growth factor signaling, and immune response regulation. Further analysis using qRT-PCR showed significant down-regulation of hsa-miR-217 (p-value = 0.004) in achalasia tissue. Our results may serve as a basis for more future functional studies to investigate the role of candidate miRNAs in the etiology of achalasia and their application in the diagnosis and probably treatment of the disease.

HDAC2 enhances esophageal squamous cell carcinoma development through down-regulating microRNA-503-5p and promoting CXCL10

Objective

Although esophageal squamous cell carcinoma (ESCC)-oriented mechanism has been widely explored, the integrated action of histone deacetylase 2 (HDAC2), microRNA (miR)-503-5p and C-X-C motif chemokine 10 (CXCL10) in ESCC has not been thoroughly explored. Thus, we performed the research to study the role of HDAC2/miR-503-5p/CXCL10 axis in ESCC.

Methods

ESCC tissues and mucosal tissues (5 cm from cancer tissues) were collected, in which HDAC2, miR-503-5p and CXCL10 expression levels were tested. The mechanism of HDAC2, miR-503-5p and CXCL10 was interpreted. The viability, colony formation ability, apoptosis, invasion and migration abilities of ESCC cells were tested after HDAC2, miR-503-5p or CXCL10 expression was altered. Tumorigenesis in mice was observed to further verify the in vitro effects of HDAC2 and miR-503-5p.

Results

HDAC2 and CXCL10 were up-regulated while miR-503-5p was down-regulated in ESCC. HDAC2 bound to miR-503-5p and miR-503-5p targeted CXCL10. Silencing HDAC2 or restoring miR-503-5p depressed viability, colony-forming, invasion and migration abilities and enhanced apoptosis of ESCC cells in vitro, as well as suppressed ESCC tumorigenesis in vivo. Inhibition of miR-503-5p or elevation of CXCL10 negated HDAC2 knockout-induced effects on ESCC cells.

Conclusion

This work elucidates that HDAC2 knockdown retards the process of ESCC by elevating miR-503-5p and inhibiting CXCL10 expression, which may provide a guidance for ESCC management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01068-8.

Potential miRNA biomarkers for the diagnosis and prognosis of esophageal cancer detected by a novel absolute quantitative RT-qPCR method

miRNAs are expected to become potential biomarkers in the diagnosis and prognosis of Esophageal cancer (EC). Through a series of screening, miR-34a-5p, miR-148a-3p and miR-181a-5p were selected as EC-associated miRNAs. Based on AllGlo probe, a novel absolute quantitative RT-qPCR method with high sensitivity, specificity and accuracy was established for detecting miRNAs. Then the clinical significance of these 3 miRNAs was explored with 213 patients (166 cases with EC and 47 cases with benign diseases) and 170 normal controls. Compared with normal controls, the level of miR-34a-5p increased while miR-148a-3p and miR-181a-5p decreased in EC and benign patients (P < 0.001), and the level of miR-181a-5p in early EC patients was significantly lower (P < 0.001). According to logistic regression analysis, combined detection of miR-34a-5p, miR-148a-3p and Cyfra21-1 provided the highest diagnosis efficiency of 85.07% with sensitivity and specificity reaching 85.45% and 84.71%. Compared with preoperative samples, the level of miR-34a-5p decreased while miR-148a-3p and miR-181a-5p increased in postoperative samples (P < 0.001). Collectively, this first developed, novel absolute quantitative RT-qPCR method exhibits high application value in detecting miRNAs, miR-34a-5p, miR-148a-3p and miR-181a-5p may serve as potential biomarkers in the diagnosis and prognosis of EC, and miR-181a-5p probably could serve as a new biomarker for early EC.

Aberrant DNA methylation of synaptophysin is involved in adrenal cortisol-producing adenoma

Cortisol-producing adenoma (CPA) is the main cause of Adrenal Cushing syndrome. However, its molecular mechanism is not fully understood. Previous study revealed Synaptophysin (SYP) is ubiquitously expressed in adrenocortical tumors, but its function in CPA still need to be discovered. In the present study we determine the molecular mechanism involved in SYP dysregulation in CPA and how SYP affects the secretion of cortisol in CPA. Our results showed that aberrant DNA methylation of SYP is involved in CPA progress. Using a miRNA microarray and qRT-PCR, we found decreased expression of miR-27a-5p in CPA compared with normal adrenal tissue. Moreover, the expression of TET3, the target gene of miR-27a-5p, increased in CPA compared with normal adrenal tissue. Knock-down of TET3 resulted in hypermethylation of SYP which reducing the expression level of SYP in H295R cells. The miR-27a-5p-TET3-SYP signalling pathway may regulate proliferation and cortisol secretion in H295R cells and, thus, play a key role in CPA development.

MicroRNA-146a as a Prognostic Biomarker for Esophageal Squamous Cell Carcinoma

Background and Aims

MicroRNAs including miR146a have a regulatory role on the expression of genes and act with binding to 3'-UTR region of the genes. Cyclooxygenase-2 (COX-2) is involved in carcinogenesis as an inflammatory marker, and microRNA-146a (miR-146a) as a negative regulatory factor. We aimed to evaluate miR146a expression as a prognostic or diagnostic biomarker for esophageal squamous cell carcinoma (ESCC) and also an association between miR146a and COX2 expression.

Materials and Methods

We quantified the level of miR-146a and COX-2 expression in cancerous and adjacent normal tissue samples obtained from 34 patients with ESCC, using real-time-PCR. Statistical analyses were conducted using one-sample t-test. Receiver-operating characteristic (ROC) curve and Kaplan-Meier analysis were applied to assay miR146a as a diagnostic and prognostic marker, respectively, during 4 years of the study. Furthermore, the Cox regression model was performed to assay the hazard ratio (HR). The association between miR-146a and COX2 expression level in ESCC patients was evaluated by nonparametric Spearman's rho analysis.

Results

The results revealed a reduction of miR-146a expression in 50% of cancerous tissue when compared with adjacent normal regions (P-value=0.127). COX-2 expression in 80% of ESCC patients was higher than in the controls (P-value=0.001). Overall, in 60% of cases, direct association was seen between microRNA-146a and COX-2 expression level (correlation coefficient= 0.438, P-value=0.011). COX2 can be considered as a diagnostic biomarker (AUC=0.834, sensitivity=72%, specificity =83%, P-value<0.0001) but miR146a cannot be considered as a diagnostic biomarker (AUC=0.553, sensitivity=88%, specificity =28%, P-value=0.453). Survival analysis by Kaplan-Meier method showed miR146a and COX2 expression can be probably considered as prognostic biomarkers for ESCC because patients with high expression of miR146a had 7 months shorter life span and patients with low expression of COX2 had 8 months shorter life span.

Conclusion

COX2 expression is a diagnostic biomarker. MiR-146a and COX2 expression can probably be considered as prognostic biomarkers for survival in ESCC.

MicroRNA‑542‑3p represses OTUB1 expression to inhibit migration and invasion of esophageal cancer cells

Dysregulation of microRNAs (miRNAs) is involved in the pathogenesis of esophageal cancer. miRNA (miR)‑542‑3p is a tumor suppressor in multiple types of cancer. However, whether and how miR‑542‑3p contributes to the progression of esophageal cancer remains unknown, and this is the aim of the present study. In the current study, decreased expression of miR‑542‑3p was detected in tumor tissues compared with normal tissues from patients with esophageal cancer, and miR‑542‑3p expression was negatively correlated with mRNA expression levels of ovarian tumor domain‑containing ubiquitin aldehyde‑binding protein 1 (OTUB1) in tumor tissues from patients with esophageal cancer. In KYSE150 human esophageal squamous cell carcinoma cells, overexpression of miR‑542‑3p significantly decreased OTUB1 at mRNA and protein levels, whereas downregulation of miR‑542‑3p significantly increased OTUB1 expression. Using a dual‑luciferase assay, OTUB1 was validated to be a target gene of miR‑542‑3p in KYSE150 cells. Functionally, miR‑542‑3p significantly inhibited the migration and invasion of KYSE150 cells by repression of OTUB1 expression. These results demonstrated that miR‑542‑3p may promote the metastasis of esophageal cancer cells, and indicated that miR‑542‑3p may be a treatment target for esophageal cancer.

Small non-coding RNA and colorectal cancer

Colorectal cancer (CRC) is the third most common malignance. Although great efforts have been made to understand the pathogenesis of CRC, the underlying mechanisms are still unclear. It is now clear that more than 90% of the total genome is actively transcribed, but lack of protein‐coding potential. The massive amount of RNA can be classified as housekeeping RNAs (such as ribosomal RNAs, transfer RNAs) and regulatory RNAs (such as microRNAs [miRNAs], PIWI‐interacting RNA [piRNAs], tRNA‐derived stress‐induced RNA, tRNA‐derived small RNA [tRFs] and long non‐coding RNAs [lncRNAs]). Small non‐coding RNAs are a group of ncRNAs with the length no more than 200 nt and they have been found to exert important regulatory functions under many pathological conditions. In this review, we summarize the biogenesis and functions of regulatory sncRNAs, such as miRNAs, piRNA and tRFs, and highlight their involvements in cancers, particularly in CRC.

MicroRNA-375 inhibits esophageal squamous cell carcinoma proliferation through direct targeting of SP1

Several studies have shown that microRNA-375 (miR-375) is frequently downregulated in several types of human cancer including gastric cancer, colorectal cancer and oral squamous cell carcinoma. However, the role of miR-375 in human esophageal cancer remains unknown. In the current study, the expression level of miR-375 was analyzed in 43 esophageal squamous cell carcinoma (ESCC) tissue and matched adjacent normal tissue samples from patients with ESCC by reverse transcription-quantitative polymerase chain reaction. In addition, the expression level of miR-375 was analyzed in ESCC cell lines (KYSE450 and KYSE150) and the human esophageal epithelial cell line Het-1A by the same method. The expression level of miR-375 was significantly downregulated in ESCC tissue samples and cell lines compared with adjacent normal tissue samples and the human esophageal epithelial cell line, respectively. The effect of miR-375 on ESCC cell proliferation was detected by cell counting kit-8 (CCK-8) and colony formation assays. miR-375 overexpression significantly decreased ESCC cell proliferation and colony formation. Bioinformatics analysis was used to predict specificity protein 1 (SP1) as a target gene of miR-375 in ESCC, and this was verified by dual-luciferase assay. The present study demonstrated that SP1 regulates ESCC cell proliferation and colony formation through direct interaction with miR-375. In addition, the overall survival of patients with ESCC was analyzed using the Kaplan-Meier method and log-rank test. The results indicated that patients with ESCC with high miR-375 expression had a better survival rate compared with patients with ESCC with low miR-375 expression. Taken together, these results suggest that downregulated miR-375 promotes ESCC cell proliferation and colony formation via direct targeting of SP1, and this association may contribute to ESCC progression.

Functional implications of Rab27 GTPases in Cancer

Background

The Rab27 family of small GTPases promotes the progression of breast cancer, melanoma, and other human cancers. In this review, we discuss the role of Rab27 GTPases in cancer progression and the potential applications of these targets in cancer treatment.

Main body

Elevated expression of Rab27 GTPases is associated with poor prognosis and cancer metastasis. Moreover, these GTPases govern a variety of oncogenic functions, including cell proliferation, cell motility, and chemosensitivity. In addition, small GTPases promote tumor growth and metastasis by enhancing exosome secretion, which alters intracellular microRNA levels, signaling molecule expression, and the tumor microenvironment.

Conclusion

Rab27 GTPases may have applications as prognostic markers and therapeutic targets in cancer treatment.

F-box proteins involved in cancer-associated drug resistance

The ubiquitin proteasome system (UPS) regulated human biological processes through the appropriate and efficient proteolysis of cellular proteins. F-box proteins are the vital components of SKP1-CUL1-FBP (SCF)-type E3 ubiquitin ligases that determine substrate specificity. As F-box proteins have the ability to control the degradation of several crucial protein targets associated with drug resistance, the dysregulation of these proteins may lead to induction of chemoresistance in cancer cells. Chemotherapy is one of the most conventional therapeutic approaches of treatment of patients with cancer. However, its exclusive application in clinical settings is restricted due to the development of chemoresistance, which typically results treatment failure. Therefore, overcoming drug resistance is considered as one of the most critical issues that researchers and clinician associated with oncology face. The present review serves to provide a comprehensive overview of F-box proteins and their possible targets as well as their correlation with the chemoresistance and chemosensitization of cancer cells. The article also presents an integrated representation of the complex regulatory mechanisms responsible for chemoresistance, which may lay the foundation to explore sensible candidate drugs for therapeutic intervention.

LncRNA PCAT-1 promotes tumour growth and chemoresistance of oesophageal cancer to cisplatin

Oesophageal cancer (OC) is one of the most fatal malignancies in the world, and chemoresistance restricts the therapeutic outcome of OC. Long noncoding RNA (lncRNA) was reported to play roles in multiple cancer types. Yet, the function of lncRNA in chemoresistance of OC has not been reported. A lncRNA gene, PCAT-1, showed higher expression in OC tissues, especially higher in secondary OC compared with normal mucosa tissues. Overexpression of PCAT-1 increased the proliferation rate and growth of OC cells. Inhibition of PCAT-1 decreased proliferation and growth of OC cells, and increased cisplatin chemosensitivity. In a mouse OC xenograft model, PCAT-1 inhibition repressed OC growth in vivo. Therefore, PCAT-1 may potentially serve as a therapeutic target for treating OC. PCAT-1 promotes development of OC and represses the chemoresistance of OC to cisplatin, and silencing of PCAT-1 may be a therapeutic strategy for treating OC.

1,25-Dihydroxyvitamin D3 Does Not Affect MicroRNA Expression When Suppressing Human Th17 Differentiation

Background

Vitamin D is an import regulator of T helper 17 (Th17) differentiation, but our understanding of the underlying mechanisms remains limited. In the present study, we aimed to detect the expression levels of microRNAs (miRNAs) during human Th17 differentiation and evaluate the effects of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), the bioactive form of vitamin D, on Th17 differentiation and miRNA expression.

Material/Methods

We cultured human peripheral blood mononuclear cells (PBMC) in vitro and activated them with anti-CD3 and anti-CD28 antibodies in the presence of Th17-promoting cytokines interleukin (IL)-23, IL-1β, TGF-β1, and IL-6 for 72 hours. 1,25(OH)₂D₃ was added to the medium at a final concentration of 100 nM on day 0. The production of IL-17A in culture medium was detected by enzyme-linked immunosorbent assay (ELISA). The expression levels of miRNAs during Th17 differentiation were determined by quantitative polymerase chain reaction (qPCR).

Results

Six miRNAs were found to be dysregulated during human Th17 differentiation. Of these miRNAs, hsa-miR-155 was significantly up-regulated (median fold change: 3.61, P<0.05), whereas hsa-miR-20b, hsa-miR-21, hsa-miR-181a, hsa-miR-210, and hsa-miR-301a were significantly down-regulated (median fold change: 0.44, 0.37, 0.18, 0.15, and 0.26, respectively, P<0.05). 1,25(OH)₂D₃ treatment significantly decreased IL-17A production (median [interquartile range], 745.7 [473.5] pg/mL vs. 2535.4 [2153.3] pg/mL, P<0.05). However, expression of these miRNAs was not changed after 1,25(OH)₂D₃ treatment.

Conclusions

1,25(OH)₂D₃ suppressed human Th17 differentiation without affecting miRNA expression.

MicroRNA-199a-5p inhibits cisplatin-induced drug resistance via inhibition of autophagy in osteosarcoma cells

Osteosarcoma (OS) is the most common cancer of the bone. Chemotherapy is commonly used for the clinical treatment of OS. However, chemoresistance to cisplatin [also known as diamminedichloridoplatinum (II) (DDP)] is a major obstacle for OS therapy, the underlying mechanism of which is not fully understood. The present study aimed to investigate the role of microRNA (miR)-199a-5p in the regulation of chemoresistance to DDP in OS cells. Reverse transcription-quantitative polymerase chain reaction demonstrated that the expression level of miR-199a-5p was significantly reduced in human OS MG63 cells. In addition, DDP treatment also upregulated the protein levels of light chain 3 (LC3)-II and Beclin1 as well as the ratio of LC3-II vs. LC3-I in MG63 cells, indicating that autophagy was activated. Restoration of miR-199a-5p expression promoted DDP-induced inhibition of MG63 cell proliferation and inhibited DDP-induced autophagy, as indicated by the reduced protein levels of LC3-II and Beclin1 and the ratio of LC3-II vs. LC3-I. Finally, luciferase reporter assay data revealed that miR-199a-5p directly targeted Beclin1 and negatively mediated Beclin1 expression at a post-transcriptional level in MG63 cells. In conclusion, our study suggests that miR-199a-5p promotes the cytotoxicity of DDP in OS cells via inhibition of autophagy. Therefore, miR-199a-5p/autophagy signaling is involved in chemoresistance and may become a potential target for the treatment of DDP-resistant OS.

MiR-193b promotes autophagy and non-apoptotic cell death in oesophageal cancer cells

BACKGROUND

Successful treatment of oesophageal cancer is hampered by recurrent drug resistant disease. We have previously demonstrated the importance of apoptosis and autophagy for the recovery of oesophageal cancer cells following drug treatment. When apoptosis (with autophagy) is induced, these cells are chemosensitive and will not recover following chemotherapy treatment. In contrast, when cancer cells exhibit only autophagy and limited Type II cell death, they are chemoresistant and recover following drug withdrawal.

METHODS

MicroRNA (miRNA) expression profiling of an oesophageal cancer cell line panel was used to identify miRNAs that were important in the regulation of apoptosis and autophagy. The effects of miRNA overexpression on cell death mechanisms and recovery were assessed in the chemoresistant (autophagy inducing) KYSE450 oesophageal cancer cells.

RESULTS

MiR-193b was the most differentially expressed miRNA between the chemosensitive and chemoresistant cell lines with higher expression in chemosensitive apoptosis inducing cell lines. Colony formation assays showed that overexpression of miR-193b significantly impedes the ability of KYSE450 cells to recover following 5-fluorouracil (5-FU) treatment. The critical mRNA targets of miR-193b are unknown but target prediction and siRNA data analysis suggest that it may mediate some of its effects through stathmin 1 regulation. Apoptosis was not involved in the enhanced cytotoxicity. Overexpression of miR-193b in these cells induced autophagic flux and non-apoptotic cell death.

CONCLUSION

These results highlight the importance of miR-193b in determining oesophageal cancer cell viability and demonstrate an enhancement of chemotoxicity that is independent of apoptosis induction.

Plasma miR-15b-5p, miR-338-5p, and miR-764 as Biomarkers for Hepatocellular Carcinoma

Background

Recently, increasing research evidence indicates that miRNA plays important roles in oncogenesis of hepatocellular carcinoma (HCC). The objective of this study was to investigate the potential of plasma miRNAs as biomarkers for HCC determination.

Material/Methods

This trial included 4 phases: (i) miRNAs in tumor tissues were screened with a miRNA array for determining candidate miRNAs. (ii) Candidate miRNAs were measured by RT-qPCR in plasma of 10 HCC patients before and after surgery (7–10 days) for target miRNAs that displayed a pattern of postoperative decrease. (iii) Plasma levels of target miRNAs in 37 HCC patients, 29 cirrhosis patients, and 31 healthy controls were measured by RT-qPCR for determining potential biomarkers. (iv) The powers of biomarkers for differentiating HCC were validated and the correlations with clinicopathological variables of HCC patients were analyzed.

Results

miRNA array demonstrated an abnormal expression of 92 miRNAs in tumor tissues compared to adjacent non-tumor tissues. Of those molecules with an over-expressed level in tumor tissues and preoperative plasmas, a decrease in postoperative plasma was observed in miR-15b-5p, miR-338-5p, and miR-764. Plasma levels of these miRNAs in HCC patients were higher than in the other 2 groups (P<0.05). Receiver-operator characteristic (ROC) curve analyses suggested these plasma miRNAs could be useful biomarkers for determining HCC. miR-338-5p yielded an area under the ROC curve (AUC) of 0.799 (74.5% sensitivity and 82.8% specificity) and 0.909 (72.3% sensitivity and 99.68% specificity) to discriminate HCC patients from cirrhosis patients and healthy controls, respectively. The expression level of miR-338-5p was negatively correlated with the level of AFP (r=−0.306, P=0.036), and the expression level of miR-764 was positively correlated with the tumor size (r=0.371, P=0.01).

Conclusions

Circulating miR-15b-5p, miR-338-5p, and miR-764 may be biomarkers for diagnosis of HCC.

Expression and clinical significance of microRNA-1246 in human oral squamous cell carcinoma

BACKGROUND

MicroRNAs (miRNAs) are small, non-coding RNAs that may function as oncogenes or tumor suppressors. Previous studies have shown that the expression level of miR-1246 was enhanced in multiple types of cancers. However, the expression of miR-1246 in human oral squamous cell carcinoma (OSCC) and its prognostic values remain unclear.

MATERIAL AND METHODS

Quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) was used to analyze the expression of miR-1246 in 106 pairs of matched normal and tumor tissue samples. The chi-square test was used to examine the associations between miR-1246 expression and the clinicopathological characters. The survival curves were constructed by the Kaplan-Meier method. The influence of each clinical variable on survival was examined by the Cox multivariate regression analysis.

RESULTS

The expression level of miR-1246 was significantly higher in tumor tissues and oral cancer cell lines than in normal controls (p<0.01). High expression of miR-1246 was found to significantly correlate with nodal status (p=0.015), TNM stage (p=0.005), and tumor grade (p=0.002). Enhanced miR-1246 correlated significantly with patient survival (p<0.01). In multivariate analysis, we found that miR-1246 expression was an independent prognostic factor of poor patient survival (p= 0.036; HR=2.82; 95% CI=1.07-7.43).

CONCLUSIONS

High miR-1246 expression is associated with poor prognosis in OSCC and may serve as a novel prognostic marker in OSCC.

Circulating miR-221 expression level and prognosis of cutaneous malignant melanoma

BACKGROUND

The aim of this study was to investigate the feasibility of using serum miR-221 as a noninvasive prognostic biomarker for cutaneous malignant melanoma (CMM).

MATERIAL/METHODS

We measured the expression levels of miR-221 in serum samples from 72 CMM patients and 54 healthy controls by real-time quantitative polymerase chain reaction (RT-PCR). The overall survival (OS) and disease-free survival (DFS) were calculated using the Kaplan-Meier method. The differences between the survival curves were tested by using the log-rank test. The COX proportional hazards regression model was used to determine the joint effects of several variables on survival.

RESULTS

The serum miR-221 levels were significantly higher in patients with CMM than in healthy controls (p<0.0001). Patients with high serum miR-221 levels had a significantly lower 5-year OS rate (22.1% vs. 54.6%; P=0.018) and RFS rate (12.5% vs. 45.2%; P=0.008) than those with low serum miR-221 level. In a multivariate Cox model, we found that miR-221 expression was an independent predictor of poor 5-year OS (hazards ratio [HR]=3.189, 95% confidence interval [CI]=1.782-6.777, P=0.007) and 5-year DFS (HR=2.119, CI=1.962-8.552, P=0.01) in CMM patients.

CONCLUSIONS

Our data indicate that serum miR-221 expression level has prognostic value in patients with CMM.

Circulating microRNAs: emerging biomarkers for diagnosis and prognosis in patients with gastrointestinal cancers

To identify novel non-invasive biomarkers for improved detection, risk assessment and prognostic evaluation of cancer, expression profiles of circulating microRNAs are currently under evaluation. Circulating microRNAs are highly promising candidates in this context, as they present some key characteristics for cancer biomarkers: they are tissue-specific with reproducible expression and consistency among individuals from the same species, they are potentially derived directly from the tumour and therefore might correlate with tumour progression and recurrence, and they are bound to proteins or contained in subcellular particles, such as microvesicles or exosomes, making them highly stable and resistant to degradation. The present review highlights the origin of circulating microRNAs, their stability in blood samples, and techniques to isolate exosomal microRNAs, and then addresses the current evidence supporting potential clinical applications of circulating miRNAs for diagnostic and prognostic purposes.

MicroRNA signatures in chemotherapy resistant esophageal cancer cell lines

AIM: To investigate expression of microRNA (miRNA) and potential targets in chemotherapy resistant esophageal cancer cell lines.

METHODS: An in-vitro model of acquired chemotherapy resistance in esophageal adeno- (EAC) and squamous cell carcinoma (ESCC) cells was used, and microRNA expression profiles for cisplatin or 5-fluorouracil (5-FU) resistant variants vs chemotherapy sensitive controls were compared using microarray and quantitative real-time polymerase chain reaction (PCR). The expression of chemotherapy-relevant genes potentially targeted by the dysregulated microRNAs in the chemotherapy resistant variants was also evaluated.

RESULTS: Chemotherapy resistant sublines were found to have specific miRNA signatures, and these miRNA signatures were different for the cisplatin vs 5-FU resistant cells from the same tumor cell line, and also for EAC vs ESCC cells with resistance to the same specific chemotherapy agent. Amongst others, miR-27b-3p, miR-193b-3p, miR-192-5p, miR-378 a-3p, miR-125a-5p and miR-18a-3p were dysregulated, consistent with negative posttranscriptional control of KRAS, TYMS, ABCC3, CBL-B and ERBB2 expression via these miRNAs.

CONCLUSION: The current study supports the hypothesis that microRNA expression has an impact on chemotherapy resistance in esophageal cancer.

Talen-mediated girdin knockout downregulates cell proliferation, migration and invasion in human esophageal carcinoma ECA109 cells

Girdin is an actin-binding Akt substrate that is involved in the regulation of cell migration. Accumulating evidence has revealed that girdin has regulatory effects on invasion and metastasis in several types of cancer. However, the role of girdin in esophageal squamous cell carcinomas (ESCCs) is yet to be investigated. In the present study, tissue microarray data revealed that among 95 cases of ESCC, 27 cases (28.7%) exhibited a low expression of girdin, while 67 cases (71.3%) had an enhanced expression of girdin. However, among 78 cases of adjacent tissues, 64 cases (82.1%) did not express girdin and 14 cases (17.9%) exhibited a low expression of girdin. Furthermore, the expression of girdin was significantly associated with the tumor stage, lymph node metastasis stage, and tumor, lymph node and metastasis stage. Of note, the mean survival time of girdin-positive cases was only 30.62±2.99 months, while it was 53.37±5.02 months in girdin-negative cases, indicating that girdin protein expression is an independent prognostic factor of poor survival. Talen-mediated girdin knockout (KO) significantly suppressed cellular proliferation, migration and invasion in ESCC ECA109 cells. In conclusion, the present study suggested that girdin protein expression was significantly correlated with cancer progression and poor prognosis in ESCCs, and that girdin had a positive role in the regulation of cell proliferation, migration and invasion in ESCC cells. Therefore, girdin may be a potential candidate for the development of novel prognostic tools and therapeutic strategies for ESCCs.

The use of imaging and biomarkers in diagnosing Barrett's esophagus and predicting the risk of neoplastic progression

Long-standing gastroesophageal reflux disease can result in transformation of the normal squamous lining of the esophagus into columnar epithelium (with goblet cells). This condition, Barrett's esophagus (BE), is considered a risk factor for esophageal cancer (EAC) and may be the cause of the increased incidence of EAC over the last few decades. Currently, endoscopy with biopsies revealing dysplasia is the best predictor for neoplastic progression in patients with BE. However, the use of more sophisticated imaging techniques and biomarkers with or without histological assessment may be helpful in more accurate prediction of malignant transformation in these patients. New approaches to the evaluation of BE such as epigenetics, miRNA analysis, detection of DNA content abnormalities and loss of heterozygosity have great potential to shed light on the complex gastroesophageal reflux disease -BE-EAC sequence.