Decrease expression and clinicopathological significance of miR-148a with poor survival in hepatocellular carcinoma tissues

The court's judgment on the true identity of the author responsible for identity fraud and the consequent batch retraction of Iranian's papers in the journal of diagnostic pathology

This letter concerns retracted papers published in the Journal of Diagnostic Pathology, where my name was misused as the author or corresponding author without my permission or knowledge. Considering that all misconducts were directed by an author during initial manuscripts' submissions, I opened a case in Iran's Cyber Police (FATA) to unravel the true identity of the submitting author. After Cyber Police's report revealed the true identity of the submitting author, the court started a thorough investigation and finally convicted the submitting author for identity fraud and data forgery through creating and using fake email addresses.

Metformin regulates expression of DNA methyltransferases through the miR-148/-152 family in non-small lung cancer cells

BACKGROUND

To understand the molecular mechanisms involved in regulation of DNA methyltransferases (DNMTs) by metformin in non-small cell lung cancer (NSCLC) cells.

METHODS

Expression levels of DNMTs in response to metformin were analyzed in NSCLC cells. MicroRNAs regulating expression of DNMTs at the post-transcriptional level were searched using miRNA-target databases (miRDB and miRTarBase), TCGA RNASeqV2 lung cancer data, and miRNA-seq.

RESULTS

Metformin dose-dependently downregulated expression of DNMT1 and DNMT3a at the post-transcriptional level and expression of DNMT3b at the transcriptional level in A549 lung cancer cells. Activity of DNMTs was reduced by about 2.6-fold in A549 cells treated with 10 mM metformin for 72 h. miR-148/-152 family members (miR-148a, miR-148b, and miR-152) targeting the 3'UTR of DNMTs were associated with post-transcriptional regulation of DNMTs by metformin. Metformin upregulated expression of miR-148a, miR-148b, and miR-152 in A549 and H1650 cells. Transfection with an miR-148b plasmid or a mimic suppressed expression of DNMT1 and DNMT3b in A549 cells. Transfection with the miR-148a mimic in A549 and H1650 cells decreased the luciferase activity of DNMT1 3'UTR. A combination of metformin and cisplatin synergistically increased expression levels of miR-148/-152 family members but decreased expression of DNMTs in A549 cells. Low expression of miR-148b was associated with poor overall survival (HR = 2.56, 95% CI 1.09-6.47; P = 0.04) but not with recurrence-free survival.

CONCLUSIONS

The present study suggests that metformin inhibits expression of DNMTs by upregulating miR-148/-152 family members in NSCLC cells.

Preliminary study on the role of miR‑148a and DNMT1 in the pathogenesis of acute myeloid leukemia

MicroRNA (miR)‑148a is differentially expressed in numerous malignant tumors and it was identified to regulate tumor growth, cell proliferation, apoptosis, angiogenesis and drug resistance via the regulation of the expression levels of its target genes. However, the biological function of miR‑148a in acute myeloid leukemia (AML) and its molecular mechanisms of action remain unclear. In the present study, the expression levels of miR‑148a and DNA methyltransferase 1 (DNMT1) were detected using reverse transcription‑quantitative polymerase chain reaction (PCR) and western blotting. Methylation‑specific PCR was used to detect the methylation levels in the miR‑148a promoter. The effects of miR‑148a on cell proliferation and apoptosis were assessed by Cell Counting kit‑8 or flow cytometry assays, respectively. A dual‑luciferase reporter assay was performed to investigate the association between miR‑148a and DNMT1. Patients with AML exhibited an increased expression level of miR‑148a, whereas the expression level of DNMT1 was identified to be decreased compared with healthy control subjects. In AML cell lines, the methylation state of miR‑148 promoter was significantly increased compared with normal cells. Following knockdown of DNMT1 in U937 cells, the expression level of miR‑148a increased significantly, whereas the methylation level of the miR‑148a promoter decreased. The mRNA and protein expression levels of DNMT1 decreased following transfection with miR‑148a mimics in U937 cells. Conversely, transfection with miR‑148a inhibitor in Kasumi‑1 cells led to an increase in the expression level of DNMT. Dual‑luciferase reporter assays suggested that DNMT1 was one of the direct target genes of miR‑148a. Overexpression of miR‑148a inhibited cell proliferation and promoted apoptosis. Inhibition of DNMT1 led to a decreased methylation level of the 5'‑cytosine‑phosphate‑guanine‑3' islands in the miR‑148a promoter, thus increasing the expression level of miR‑148a. DNMT1 was identified to be a downstream target of miR‑148a, and was negatively regulated by miR‑148a in AML cell lines, suggesting that miR‑148a and DNMT1 form a mutual negative feedback loop.

MYO18B promotes hepatocellular carcinoma progression by activating PI3K/AKT/mTOR signaling pathway

BACKGROUND

MYO18B has been identified as a novel tumor suppressor gene in several cancers. However, its specific roles in the progression of hepatocellular carcinoma (HCC) has not been well defined.

METHODS

We firstly identified the expression and prognostic values of MYO18B in HCC using TCGA cohort and our clinical data. Then, MYO18B knockdown by RNA inference was implemented to investigate the effects of MYO18B on HCC cells. Quantitative RT-PCR and Western blot were used to determine gene and protein expression levels. CCK-8 and colony formation assays were performed to examine cell proliferation capacity. Wound healing and transwell assays were used to evaluate the migration and invasion of HepG2 cells.

RESULTS

MYO18B was overexpressed and correlated with poor prognosis in HCC. MYO18B expression was an independent risk factor for overall survival. Knockdown of MYO18B significantly inhibited the proliferation, migration and invasion of HepG2 cells. Meanwhile, MYO18B knockdown could effectively suppress the phosphorylation of PI3K, AKT, mTOR and P70S6K, suggesting that MYO18B might promote HCC progression by targeting PI3K/AKT/mTOR signaling pathway.

CONCLUSIONS

MYO18B promoted tumor growth and migration via the activation of PI3K/AKT/mTOR signaling pathway. MYO18B might be a promising target for clinical intervention of HCC.

Investigation of clinicopathological parameters in emergency colorectal cancer surgery: a study of 67 patients

INTRODUCTION

The aim of the present study was to establish, having adjusted for case mix, the size of the differences in postoperative mortality and 5-year survival between patients presenting as an emergency with evidence of obstruction and perforation and the association of clinicopathological factors with mortality (bivariate analyses).

MATERIAL AND METHODS

The study included 67 patients who presented with colorectal cancer (CRC) between 2009 and 2013 in Iran. The mean age of the patients was 59.7 years. Of the 67 patients, 37 (55.22%) were male and 30 (44.77%) were female. Certain parameters that correlated with CRC and surgical treatment were investigated.

RESULTS

Our results showed that 46 (68.65%) patients had obstruction, while perforation was observed in 21 (31.34%) cases. Among the patients with obstruction, obstruction of the right colon was observed in 29 (43.28%) cases. There was no significant difference in mortality rate between right and left colonic obstruction. Based on the bivariate analyses, our findings showed that death of patients was significantly related to tumor grade (p = 0.02) and TNM staging (p = 0.026), but no association was found between other parameters and death, including age, sex, and tumor site.

CONCLUSIONS

Compared with patients who undergo elective surgery for colon cancer, those who present as an emergency with evidence of obstruction or perforation have higher postoperative mortality rates and poorer cancer-specific survival. Also, colorectal cancer patients with emergency surgery showed aggressive histopathology and an advanced stage.

MicroRNA-148a suppresses epithelial-mesenchymal transition and invasion of pancreatic cancer cells by targeting Wnt10b and inhibiting the Wnt/β-catenin signaling pathway

Epithelial-mesenchymal transition (EMT) plays a critical role in the process of cancer invasion and metastasis. The Wnt/β-catenin signaling pathway is known as a stimulative factor, which may trigger EMT and metastasis of cancer cells. In addition, several microRNAs (miRNAs) have been proven to regulate the EMT process. Recent research revealed that miR‑148a is downregulated in pancreatic cancer. However, the definite role of miR-148a in EMT and invasion of pancreatic cancer is still unknown. The present study attempted to demonstrate the underlying mechanism of miR-148a in the regulation of EMT and invasion of pancreatic cancer cells. Our data revealed that the expression of miR-148a was markedly downregulated in human pancreatic ductal adenocarcinoma (PDAC) cell lines and tissues. In addition, the downregulation of miR-148a was associated with poor prognosis and EMT phenotype. Furthermore, restoration of miR-148a expression inhibited the EMT process, as well as the migration and invasion of BxPC-3 pancreatic cancer cells. Wnt10b, a promoting molecule of the Wnt/β-catenin signaling pathway, was demonstrated by dual‑luciferase reporter assay to be a direct target of miR‑148a. Subsequently, we found that miR‑148a negatively regulated the protein expression of β-catenin, cyclin D1 and MMP-9, which were important components of the Wnt/β-catenin signaling pathway. In conclusion, these findings revealed that miR-148a suppresses EMT and invasion of pancreatic cancer cells by targeting Wnt10b and inhibiting the Wnt/β-catenin signaling pathway, and thus, miR-148a may serve as a novel therapeutic target for pancreatic cancer.

Upregulation of cyclin-dependent kinase 7 and matrix metalloproteinase-14 expression contribute to metastatic properties of gastric cancer

The aim of this study was to evaluate the protein and mRNA expressions of matrix metalloproteinase-14 (MMP14) and CDK7 in gastric cancer (GC) tissues. Upregulation of MMP14 mRNA level was observed in GC tissues when compared with the matched normal tissues (mean ± SD: 3.92 ± 1.15 vs. 1.35 ± 0.81, P < 0.001). This study indicated that mRNA levels of CDK7 were statistically overexpressed in GC when compared with matched normal tissues (4.12 ± 0.84 vs. 1.43 ± 0.71, P < 0.001). The protein levels of MMP14 were found to be increased in GC (60.41%; P < 0.001). The expression of CDK7 was higher in GC tissues than matched normal tissues (70.83; P < 0.001). We found that high MMP14 expression was related to advanced TNM stage (P = 0.004), tumor grade (P = 0.002), and lymph node metastasis (P = 0.015), but no association with other clinical variables (P > 0.05). In addition, high expression of CDK7 was significantly linked to advanced TNM stage (P = 0.001), pathological grade (P = 0.012), and presence of lymph node metastasis (P = 0.009), while no correlation between CDK7 expression and other clinical variables, such as age and gender, distance metastasis. The patients with high expression of MMP14 and CDK7 exhibited worse survival time than those with higher levels. Cox multivariate regression analysis clearly showed that high expression of MMP14 and CDK7 was independent prognostic factors for overall survival in patients with GC. Taken together, these results indicated the overexpression of above markers in the progression and the tumorigenesis of GC and overall patient survival. © 2016 IUBMB Life, 68(10):799-805, 2016.

Diagnosis of HCC for patients with cirrhosis using miRNA profiles of the tumor-surrounding tissue - A statistical model based on stepwise penalized logistic regression

The presence of hepatocellular carcinoma (HCC) is a significant complication of cirrhosis because it changes the prognosis and the treatment of the patients. By now, contrast-enhanced CT and MR scans are the most reliable tools for the diagnosis of HCC; however, in some cases, a biopsy of the tumor is necessary for the final diagnosis. The aim of the study was to develop a diagnostic tool using the microRNA (miRNA) profiles of the tissue surrounding the HCC tumor combined with clinical parameters in statistical models. At a transplantation setting, 32 patients with HCC and cirrhosis (B) were compared to 22 patients suffering from cirrhosis only (A). The diagnosis and exclusion of HCC was confirmed following the histopathological examination of the explanted liver. The HCC patients were significantly older than the patients with cirrhosis only (B: 60.6 and A: 49.9, p<0.001) and showed higher levels of ALT (A: 0.76μkat/l, B: 1.02μkat/, p=0.006) and AFP (A: 5.8ng/ml, B: 70.3ng/ml, p<0.001), whereas the bilirubin levels were higher in the cirrhosis only group (p=0.002). Using age (cut-off 50.23years) and AFP (cut-off 4.2ng/ml) thresholds, the levels of expression of miR-1285-3p and miR-943 differentiated between the patients with HCC and cirrhosis from those with cirrhosis only with an accuracy of 96.3%. This is the first report about the use of stepwise penalized logistic regression and decision tree analyses of miRNA expressions in the tumor-surrounding tissue combined with clinical parameters for the diagnosis of HCC.

MicroRNA-148a represents an independent prognostic marker in bladder cancer

A previous study has demonstrated the roles of microRNA-148a (miR-148a) on apoptosis of bladder cancer cells. The goal of this study was to investigate whether the miR-148a expression level could serve as a new biomarker for the prognosis of bladder cancer patients. We collected a total of 126 bladder cancer samples. The expression level of miR-148a was determined with quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan-Meier method was used to analyze the overall survival. Cox regression analysis was further used to identify prognostic factors. The expression levels of miR-148a in bladder cancer tissues were identified (1.5 ± 0.3; P < 0.001). The bladder cancer patients in the low-expression group more frequently had a high tumor grade (P = 0.025), increased tumor recurrence (P = 0.002), and advanced lymph node (LN) metastasis (P = 0.001). Patient survival analysis revealed a clear positive correlation between miR-148a expression level and survival time of bladder cancer patients (P = 0.005, log-rank = 7.714). In univariate Cox proportional hazards regression analysis, we found that a low-expression level of miR-148a (P = 0.018), tumor grade (P = 0.006), lymph node metastasis (P = 0.001), and recurrence (P < 0.001) were associated with the prognosis of bladder cancer. In multivariate analysis, we found that miR-148a expression (RR = 0.206, 95 % CI 0.095-0.813, P = 0.029), tumor grade (RR = 0.714, 95 % CI 0.224-0.958, P = 0.714), lymph node metastasis (RR = 6.604, 95 % CI 3.192-12.547, P < 0.001), and recurrence (RR = 15.126, 95 % CI 6.714-22.025, P < 0.001) retained significance as an independent prognostic factor of bladder cancer survival (Table 3). All results have showed that miR-148a expression was decreased in bladder cancer specimens and reduced miR-148a expression was associated with poorer survival time, indicating that miR-148a may become a candidate factor for predicting the prognosis of bladder cancer.

Down-regulation of microRNA-26a and up-regulation of microRNA-27a contributes to aggressive progression of human osteosarcoma

BACKGROUND

Osteosarcoma is the most common primary bone malignancy with high local aggressiveness and rapid metastasizing potential, resulting in poor survival. Increasing reports suggest that deregulated microRNAs (miRNAs) might provide novel therapeutic targets for cancers. However, the expression of miR-26a and miR-27a in osteosarcoma need further investigation in clinical samples. In our study, we evaluate the expression of these miRNAs in osteosarcoma tissues and compared with paired adjacent non-tumor bone tissues using RT-qPCR.

METHODS

Total RNA was purified from patients with osteosarcoma and noncancerous bone tissues. Real-time PCR was applied to quantify the expression level of miR-26a and miR-27a. Moreover, the correlation of these markers with clinicopathological characteristics was also evaluated in osteosarcoma patients. A cox proportional hazards model was performed to assess multivariate analyses of prognostic values.

RESULTS

Our result suggested that miR-26aexpression level in osteosarcoma bone tissue was significantly lower than that in the paired noncancerous bone tissues. MiR-27a expression was higher in osteosarcoma bone tissue in comparison with paired noncancerous bone tissues. The results indicated that low expression level of miR-26a and high expression of miR-27a were associated with high TNM stage (P = 0.001; P = 0.012), tumor grade (P = 0.007; P = 0.016), and distant metastasis (P = 0.004; P = 0.001). Kaplan-Meier analysis and log-rank test indicated that patients with low expression of miR-26a and high expression of miR-27a had shorter overall survival (log-rank test: P < 0.001). Multivariate Cox proportional hazards model analysis showed that low expression of miR-26a and high expression of miR-27a (P = 0.021; P = 0.011), high TNM stage (P = 0.001; P = 0.003), tumor grade (P = 0.005; P = 0.01), and distant metastasis.(P = 0.002; P = 0.005) were independent prognostic factors for overall survival patients with osteosarcoma cancer.

CONCLUSIONS

In conclusion, our findings suggested that expression level of miR-26a and miR-27a contributes to aggressive progression of this malignancy. Therefore, may have clinical potentials as a non-invasive diagnostic/prognostic biomarker for osteosarcoma patients.