MicroRNA-153 is a prognostic marker and inhibits cell migration and invasion by targeting SNAI1 in human pancreatic ductal adenocarcinoma

microRNAs Associated with Gemcitabine Resistance via EMT, TME, and Drug Metabolism in Pancreatic Cancer

Despite extensive research, pancreatic cancer remains a lethal disease with an extremely poor prognosis. The difficulty in early detection and chemoresistance to therapeutic agents are major clinical concerns. To improve prognosis, novel biomarkers, and therapeutic strategies for chemoresistance are urgently needed. microRNAs (miRNAs) play important roles in the development, progression, and metastasis of several cancers. During the last few decades, the association between pancreatic cancer and miRNAs has been extensively elucidated, with several miRNAs found to be correlated with patient prognosis. Moreover, recent evidence has revealed that miRNAs are intimately involved in gemcitabine sensitivity and resistance through epithelial-to-mesenchymal transition, the tumor microenvironment, and drug metabolism. Gemcitabine is the gold standard drug for pancreatic cancer treatment, but gemcitabine resistance develops easily after chemotherapy initiation. Therefore, in this review, we summarize the gemcitabine resistance mechanisms associated with aberrantly expressed miRNAs in pancreatic cancer, especially focusing on the mechanisms associated with epithelial-to-mesenchymal transition, the tumor microenvironment, and metabolism. This novel evidence of gemcitabine resistance will drive further research to elucidate the mechanisms of chemoresistance and improve patient outcomes.

A comprehensive review on miR-153: Mechanistic and controversial roles of miR-153 in tumorigenicity of cancer cells

miRNAs play a crucial role in regulating genes involved in cancer progression. Recently, miR-153 has been mainly well-known as a tumor suppressive miRNA modulating genes in proliferation, metastasis, EMT, angiogenesis and drug resistance ability of a variety types of cancer. Mechanistic activity of miR-153 in tumorigenicity has not been fully reviewed. This manuscript presents a comprehensive review on the tumor suppressive activity of miR-153 as well as introducing the controversial role of miR-153 as an oncogenic miRNA in cancer. Furthermore, it summarizes all potential non-coding RNAs such as long non-coding RNAs (LncRNAs), transcribed ultra-conserved regions (T-UCRs) and circular RNAs (CircRNAs) targeting and sponging miR-153. Understanding the critical role of miR-153 in cell growth, metastasis, angiogenesis and drug resistance ability of cancer cells, suggests miR-153 as a potential prognostic biomarker for detecting cancer as well as providing a novel treatment strategy to combat with several types of cancer.

The Roles of MicroRNA in Pancreatic Cancer Progression

Pancreatic Ductal Adenocarcinoma (PDAC) has a poor patient survival rate in comparison with other cancer types, even after targeted therapy, chemotherapy, and immunotherapy. Therefore, a great deal needs to be done to gain a better understanding of the biology and identification of prognostic and predictive markers for the development of superior therapies. The microRNAs (miRNAs) belong to small non-coding RNAs that regulate post-transcriptional gene expression. Several shreds of evidence indicate that miRNAs play an important role in the pathogenesis of pancreatic cancer. Here we review the recent developments in miRNAs and their target role in the development, metastasis, migration, and invasion.

The Impact of Epithelial-Mesenchymal Transition and Metformin on Pancreatic Cancer Chemoresistance: A Pathway towards Individualized Therapy

Globally, pancreatic ductal adenocarcinoma remains among the most aggressive forms of neoplastic diseases, having a dismal prognostic outcome. Recent findings elucidated that epithelial-mesenchymal transition (EMT) can play an important role in pancreatic tumorigenic processes, as it contributes to the manifestation of malignant proliferative masses, which impede adequate drug delivery. An organized literature search with PubMed, Scopus, Microsoft Academic and the Cochrane library was performed for articles published in English from 2011 to 2021 to review and summarize the latest updates and knowledge on the current understanding of EMT and its implications for tumorigenesis and chemoresistance. Furthermore, in the present paper, we investigate the recent findings on metformin as a possible neoadjuvant chemotherapy agent, which affects EMT progression and potentially provides superior oncological outcomes for PDAC patients. Our main conclusions indicate that selectively suppressing EMT in pancreatic cancer cells has a promising therapeutic utility by selectively targeting the chemotherapy-resistant sub-population of cancer stem cells, inhibiting tumor growth via EMT pathways and thereby improving remission in PDAC patients. Moreover, given that TGF-β1-driven EMT generates the migration of tumor-initiating cells by directly linking the acquisition of abnormal cellular motility with the maintenance of tumor initiating potency, the chemoprevention of TGF-β1-induced EMT may have promising clinical applications in the therapeutic management of PDAC outcomes.

Butyrate promotes oral squamous cell carcinoma cells migration, invasion and epithelial-mesenchymal transition

BACKGROUND

Oral squamous cell carcinoma (OSCC), the most common type of primary malignant tumor in the oral cavity, is a lethal disease with high recurrence and mortality rates. Butyrate, a metabolite produced by periodontal pathogens, has been linked to oral diseases. The purpose of this study was to evaluate the effect of sodium butyrate (NaB) on the proliferation, migration, and invasion of OSCC cells in vitro and to explore the potential mechanism.

METHODS

Two OSCC cell lines (HSC-4 and SCC-9) were treated with NaB at different concentrations. The cell proliferation was assayed by CCK-8, ethylene deoxyuridine (EdU), and flow cytometry. Wound healing and transwell assay were performed to detect cell migration and invasion. Changes in epithelial-mesenchymal transition (EMT) markers, including E-cadherin, Vimentin, and SNAI1, were evaluated by quantitative real-time PCR (qRT-PCR), western blot, and immunofluorescent staining. The expression levels of matrix metalloproteinases (MMPs) were analyzed by qRT-PCR and gelatin zymography.

RESULTS

Our results showed that NaB inhibited the proliferation of OSCC cells and induced cell cycle arrest at G1 phase, but NaB significantly enhanced cell migration and invasion compared with the control group. Further mechanistic investigation demonstrated that NaB induced EMT by increasing the expression of Vimentin and SNAI1, decreasing the expression of membrane-bound E-cadherin, and correspondingly promoting E-cadherin translocation from the membrane to the cytoplasm. In addition, the overexpression of MMP1/2/9/13 was closely related to NaB treatment.

CONCLUSIONS

Our study conclude that butyrate may promote the migration and invasion of OSCC cells by inducing EMT. These findings indicate that butyrate may contribute to OSCC metastasis.

MicroRNAs in Medullary Thyroid Carcinoma: A State of the Art Review of the Regulatory Mechanisms and Future Perspectives

Medullary thyroid carcinoma (MTC) is a rare malignant neoplasia with a variable clinical course, with complete remission often difficult to achieve. Genetic alterations lead to fundamental changes not only in hereditary MTC but also in the sporadic form, with close correlations between mutational status and prognosis. In recent years, microRNAs (miRNAs) have become highly relevant as crucial players in MTC etiology. Current research has focused on their roles in disease carcinogenesis and development, but recent studies have expounded their potential as biomarkers and response predictors to novel biological drugs for advanced MTC. One such element which requires greater investigation is their mechanism of action and the molecular pathways involved in the regulation of gene expression. A more thorough understanding of these mechanisms will help realize the promising potential of miRNAs for MTC therapy and management.

How metformin affects various malignancies by means of microRNAs: a brief review

Metformin known as the first-line orally prescribed drug for lowering blood glucose in type II diabetes (T2DM) has recently found various therapeutic applications including in cancer. Metformin has been studied for its influences in prevention and treatment of cancer through multiple mechanisms such as microRNA (miR) regulation. Alteration in the expression of miRs by metformin may play an important role in the treatment of various cancers. MiRs are single-stranded RNAs that are involved in gene regulation. By binding to the 3'UTR of target mRNAs, miRs influence protein levels. Irregularities in the expression of miRs that control the expression of oncogenes and tumor suppressor genes are associated with the onset and progression of cancer. Metformin may possess an effect on tumor prevention and progression by modifying miR expression and downstream pathways. Here, we summarize the effect of metformin on different types of cancer by regulating the expression of various miRs and the associated downstream molecules.

Noncoding RNAs Associated with Therapeutic Resistance in Pancreatic Cancer

Therapeutic resistance is an inevitable impediment towards effective cancer therapies. Evidence accumulated has shown that the signaling pathways and related factors are fundamentally responsible for therapeutic resistance via regulating diverse cellular events, such as epithelial-to-mesenchymal transition (EMT), stemness, cell survival/apoptosis, autophagy, etcetera. Noncoding RNAs (ncRNAs) have been identified as essential cellular components in gene regulation. The expression of ncRNAs is altered in cancer, and dysregulated ncRNAs participate in gene regulatory networks in pathological contexts. An in-depth understanding of molecular mechanisms underlying the modulation of therapeutic resistance is required to refine therapeutic benefits. This review presents an overview of the recent evidence concerning the role of human ncRNAs in therapeutic resistance, together with the feasibility of ncRNAs as therapeutic targets in pancreatic cancer.

miR-153 enhances the therapeutic effect of radiotherapy by targeting JAG1 in pancreatic cancer cells

Pancreatic cancer is one of the deadliest diseases, due to the lack of early symptoms and resistance to current therapies, including radiotherapy. However, the mechanisms of radioresistance in pancreatic cancer remain unknown. The present study explored the role of microRNA-153 (miR-153) in radioresistance of pancreatic cancer. It was observed that miR-153 was downregulated in pancreatic cancer and positively correlated with patient survival time. Using stably-infected pancreatic cancer cells that overexpressed miR-153 or miR-153 inhibitor, it was found that miR-153 overexpression sensitized pancreatic cancer cells to radiotherapy by inducing increased cell death and decreased colony formation, while cells transfected with the miR-153 inhibitor promoted radioresistance. Further investigation demonstrated that miR-153 promoted radiosensitivity by directly targeting jagged canonical Notch ligand 1 (JAG1). The addition of recombinant JAG1 protein in the cell cultures reversed the therapeutic effect of miR-153. The present study revealed a novel mechanism of radioresistance in pancreatic cancer and indicated that miR-153 may serve as a potential therapeutic target for radioresistance.

Dysregulated SREBP1c/miR-153 signaling induced by hypertriglyceridemia worsens acute pancreatitis and delays tissue repair

Severe acute pancreatitis (AP) is a life-threatening disease with up to 30% mortality. Therefore, prevention of AP aggravation and promotion of pancreatic regeneration are critical during the course and treatment of AP. Hypertriglyceridemia (HTG) is an established aggravating factor for AP that hinders pancreatic regeneration; however, its exact mechanism remains unclear. Using miRNA sequencing and further verification, we found that miRNA-153 (miR-153) was upregulated in the pancreas of HTG animal models and in the plasma of patients with HTG-AP. Increased miR-153 aggravated HTG-AP and delayed pancreatic repair via targeting TRAF3. Furthermore, miR-153 was transcriptionally suppressed by sterol regulatory element-binding transcription factor 1c (SREBP1c), which was suppressed by lipoprotein lipase malfunction-induced HTG. Overexpressing SREBP1c suppressed miR-153 expression, alleviated the severity of AP, and facilitated tissue regeneration in vivo. Finally, therapeutic administration of insulin also protected against HTG-AP via upregulating SREBP1c. Collectively, our results not only provide evidence that HTG leads to the development of more severe AP and hinders pancreatic regeneration via inducing persistent dysregulation of SREBP1c/miR-153 signaling, but also demonstrate that SREBP1c activators, including insulin, might be used to treat HTG-AP in patients.

Prognostic and clinicopathological significance of MicroRNA-153 in human cancers: A meta-analysis

BACKGROUND

Several studies have explored the prognostic value of MicroRNA-153 (miR-153) in various cancers, but obtained inconsistent results. Thus, we conducted a meta-analysis to assess the prognostic significance of miR-153 for patients with cancer.

METHODS

Eligible studies were identified by searching the online databases Pubmed, Embase, Web of Science, Medline,and the China National Knowledge Infrastructure (CNKI) up to March 2020. Hazard ratios (HRs) with 95% CIs and were calculated to clarify the correlation between miR-153 expression and prognosis of different cancers. Odds ratios (ORs) with 95% CI were selected to appraise the correlation between miR-153 with clinicopathological characteristics of cancer patients.

RESULTS

In total, 933 patients from 11 articles were enrolled in our meta-analysis. The results revealed that low miR-153 expression was significantly correlated with poor overall survival (OS) (HR = 2.45, 95% CI = 1.66-3.63, P < .001), but not with disease-free survival (DFS) (HR = 1.67, 95% CI = 0.45-6.19, P = .442). Subgroup analysis found that low miR-153 expression was associated with worse OS in the reported directly from articles group (HR = 2.67, 95% CI: 1.32-5.37, P = .006), survival curves group (HR = 2.10, 95% CI: 1.56-2.84, P < .001), digestive system tumor (HR = 2.76, 95% CI: 1.73-4.41, P < .001), and breast cancer (HR = 4.01, 95% CI: 1.46-11.04, P = .007).Moreover, cancer patients with low miR-153 expression were prone to poor tumor differentiation(poor vs well+moderate, OR = 2.41, 95% CI = 1.52-3.82, P < .001), earlier lymph node metastasis (present vs absent, OR = 2.19, 95% CI = 1.12-4.25, P = .021) and earlier distant metastasis (present vs absent,OR = 8.24, 95% CI = 2.93-23.21, P < .001), but not associated with age,gender and TNM stage.

CONCLUSIONS

This meta-analysis indicated that low miR-153 expression is associated with poor prognosis. miR-153 may serve as an effective predictive biomarker for tumor prognosis, especially for digestive system tumor and breast cancer.

MicroRNAs in Lung Cancer Oncogenesis and Tumor Suppression: How it Can Improve the Clinical Practice?

BACKGROUND

Lung cancer (LC) development is a process that depends on genetic mutations. The DNA methylation, an important epigenetic modification, is associated with the expression of non-coding RNAs, such as microRNAs. MicroRNAs are particularly essential for cell physiology, since they play a critical role in tumor suppressor gene activity. Furthermore, epigenetic disruptions are the primary event in cell modification, being related to tumorigenesis. In this context, microRNAs can be a useful tool in the LC suppression, consequently improving prognosis and predicting treatment.

CONCLUSION

This manuscript reviews the main microRNAs involved in LC and its potential clinical applications to improve outcomes, such as survival and better quality of life.

miR‑539 suppresses the proliferation, migration, invasion and epithelial mesenchymal transition of pancreatic cancer cells through targeting SP1

MicroRNA (miR)‑539 has inhibitory effects on certain types of cancer, but its role in pancreatic cancer (PCa) remains unclear. The present study investigated the effects of miR‑539 on PCa, and aimed to determine possible therapeutic targets for the treatment of PCa. The expression of miR‑539 in PCa tissues, paired normal adjacent tissues and PCa cell lines (CAPAN‑2, BxPC3, CFPAC1, SW1990 and PANC1), and human non‑cancerous pancreatic cells (hTRET‑HPNE) was determined and compared. The effects of upregulation and downregulation of miR‑539 on proliferation, apoptosis, cell cycle, invasion, migration and epithelial‑mesenchymal transition (EMT) of PCa cells were investigated. Additionally, the target gene of miR‑539 was predicted and its effects on PCa cells were further investigated. The results revealed low expression of miR‑539 in PCa tissues and cell lines. Additionally, increasing miR‑539 expression inhibited the proliferation, migration, invasion and EMT of PCa cells and induced apoptosis by blocking G1 phase of the cell cycle, while reducing miR‑539 expression had the opposite results. Furthermore, specificity protein 1 (SP1) was found to be the target gene of miR‑539. SP1 promoted the proliferation, migration, invasion and EMT transformation of PCa cells, but these effects were reversed by high expression of miR‑539. Additionally, miR‑539 suppressed the proliferation, metastasis, invasion and EMT transformation of PCa cells through targeting SP1. Therefore, miR‑539 overexpression may contribute toward development of novel therapeutic strategies for PCa in the future.

Prognostic value of microRNAs in pancreatic cancer: a meta-analysis

BACKGROUND

The prognostic impact of microRNA (miRNA) expression levels in pancreatic cancer (PC) has been estimated for years, but the outcomes are controversial and heterogeneous. Therefore, we comprehensively reviewed the evidence collected on miRNA expression in PC to determine this effect.

RESULTS

PC patients with high miR-21 (HR=2.61, 95%CI=1.68-4.04), miR-451a (HR=2.23, 95%CI=1.23-4.04) or miR-1290 (HR=1.43, 95%CI=1.04-1.95) levels in blood had significantly poorer OS (P<0.05). Furthermore, PC patients with high miR-10b (HR=1.73, 95%CI=1.09-2.76), miR-17-5p (HR=1.91, 95%CI=1.30-2.80), miR-21 (HR=1.90, 95%CI=1.61-2.25), miR-23a (HR=2.18, 95%CI=1.52-3.13), miR-155 (HR=2.22, 95%CI=1.27-3.88), miR-203 (HR=1.65, 95%CI=1.14-2.40), miR-221 (HR=1.72, 95%CI=1.08-2.74), miR-222 levels (HR=1.72, 95%CI=1.02-2.91) or low miR-29c (HR=1.39, 95%CI=1.08-1.79), miR-126 (HR=1.55, 95%CI=1.23-1.95), miR-218 (HR=2.62, 95%CI=1.41-4.88) levels in tissues had significantly shorter OS (P<0.05).

CONCLUSIONS

In summary, blood miR-21, miR-451a, miR-1290 and tissue miR-10b, miR-17-5p, miR-21, miR-23a, miR-29c, miR-126, miR-155, miR-203, miR-218, miR-221, miR-222 had significant prognostic value.

METHODS

We searched PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews to recognize eligible studies, and 57 studies comprising 5445 PC patients and 15 miRNAs were included to evaluate the associations between miRNA expression levels and overall survival (OS) up to June 1, 2019. Summary hazard ratios (HR) with 95% confidence intervals (CI) were calculated to assess the effect.

Interplay among SNAIL Transcription Factor, MicroRNAs, Long Non-Coding RNAs, and Circular RNAs in the Regulation of Tumor Growth and Metastasis

SNAIL (SNAI1) is a zinc finger transcription factor that binds to E-box sequences and regulates the expression of genes. It usually acts as a gene repressor, but it may also activate the expression of genes. SNAIL plays a key role in the regulation of epithelial to mesenchymal transition, which is the main mechanism responsible for the progression and metastasis of epithelial tumors. Nevertheless, it also regulates different processes that are responsible for tumor growth, such as the activity of cancer stem cells, the control of cell metabolism, and the regulation of differentiation. Different proteins and microRNAs may regulate the SNAIL level, and SNAIL may be an important regulator of microRNA expression as well. The interplay among SNAIL, microRNAs, long non-coding RNAs, and circular RNAs is a key event in the regulation of tumor growth and metastasis. This review for the first time discusses different types of regulation between SNAIL and non-coding RNAs with a focus on feedback loops and the role of competitive RNA. Understanding these mechanisms may help develop novel therapeutic strategies against cancer based on microRNAs.

RET Kinase-Regulated MicroRNA-153-3p Improves Therapeutic Efficacy in Medullary Thyroid Carcinoma

Background: Medullary thyroid carcinoma (MTC) presents a disproportionate number of thyroid cancer deaths due to limited treatment options beyond surgery. Gain-of-function mutations of the human REarranged during Transfection (RET) proto-oncogene have been well-established as the key driver of MTC tumorigenesis. RET has been targeted by tyrosine kinase inhibitors (TKIs), such as cabozantinib and vandetanib. However, clinical results have been disappointing, with regular dose reductions and inevitable progression. This study aimed to identify RET-regulated microRNAs (miRNAs) and explore their potential as novel therapeutic targets. Methods: Small RNA sequencing was performed in MTC TT cells before and after RET inhibition to identify RET-regulated miRNAs of significance. In vitro gain-of-function studies were performed to investigate cellular and molecular effects of potential miRNAs on cell phenotypes. Systemic delivery of miRNA in MTC xenografts using EDV™ nanocells, targeted to epidermal growth factor receptor on tumor cells, was employed to assess the therapeutic potential and possible modulation of TKI responses. Results: The study demonstrates the tumor suppressive role of a specific RET-regulated miRNA, microRNA-153-3p (miR-153-3p), in MTC. Targeted intravenous delivery of miR-153-3p impeded the tumor growth in MTC xenografts. Furthermore, combined treatment with miR-153-3p plus cabozantinib caused greater growth inhibition and appeared to reverse cabozantinib resistance. Mechanistically, miR-153-3p targets ribosomal protein S6 kinase B1 (RPS6KB1) of mTOR signaling and reduced downstream phosphorylation of Bcl-2 associated death promoter. Conclusion: This study provides evidence to establish systemic miRNA replacement plus TKIs as a novel therapeutic for patients with metastatic, progressive MTC.

MicroRNA-200b and -301 are associated with gemcitabine response as biomarkers in pancreatic carcinoma cells

Chemotherapy resistance (congenital or acquired) is one of the principal challenges for the treatment of pancreatic carcinoma. Recent evidence has demonstrated that epithelial to mesenchymal transition (EMT) is associated with chemoresistance in pancreatic carcinoma cells. However, the molecular mechanism underlying the development of chemoresistance remains unknown, and limited therapeutic options are available. Therefore, to anticipate individual chemosensitivity or acquired chemoresistance for patients with pancreatic carcinoma, predictive biomarkers are urgently required. Extensive evidence suggests that microRNAs (miRNAs) serve a crucial role in regulating EMT. The aim of this study was to examine the potential role of miRNA (miR)‑200b and miR‑301 in predicting the chemo‑responses to treatment for pancreatic carcinoma. The present results demonstrate that miR‑200b expression predicted chemo‑sensitivity and may have potential as a biomarker. In six different pancreatic carcinoma cell lines (Capan‑1, Capan‑2, Panc‑1, MIAPaCa‑2, BxPC‑3 and PL45 cells), the expression of miR‑200b correlated positively with chemosensitivity. Moreover, the enhanced expression of miR‑200b increased chemosensitivity and induced mesenchymal to epithelial transition. Conversely, miR‑301 modulated gemcitabine resistance and induced EMT through the downregulation of cadherin 1 expression. In addition, gemcitabine‑resistant cells (Capan‑2 and Panc‑1) exhibited upregulated miR‑301 expression and downregulated gemcitabine‑induced apoptosis. In summary, these two miRNAs may serve roles as biomarkers in pancreatic carcinoma, miR‑200b expression may predict chemosensitivity, and elevated miR‑301 expression may have potential applications in the prediction of acquired gemcitabine resistance.

MicroRNA-153 suppresses cell invasion by targeting SNAI1 and predicts patient prognosis in glioma

Glioma is the most common and rapidly progressive type of malignant primary brain tumor in adults. miR-153 plays a major role in many malignancies; nevertheless, few studies have been conducted on glioma. The aim of the present study was to explore the role of miR-153 and SNAI1 on invasion in glioma. Reverse transcription-quantitative PCR was employed to measure the expression levels of miR-153 and SNAI1 mRNA. Transwell assay was utilized to calculate the capacity of invasion. Luciferase report assay was applied to detect whether SNAI1 was a target of miR-153. miR-153 was downregulated in glioma tissues and cells versus paracancerous tissues and normal immortalized gliocyte HEB cells. Transwell assay was used to measure whether a low expression of miR-153 in glioma indicated inhibition of cell invasion. We verified that SNAI1 was a target of miR-153 and had a negative association with miR-153 detected by luciferase reporter assay. Additionally, miR-153 suppressed cell invasive ability by regulating SNAI1 expression, whose partial function was reversed by SNAI1. miR-153 suppressed cell invasion of glioma by directly targeting SNAI1. Thus, miR-153/SNAI1 axis may be a novel target for cervical cancer treatment.

miR-30a regulates the proliferation and invasion of breast cancer cells by targeting Snail

The present study aims to investigate the effect of miR-30a on the proliferative and invasive abilities of breast cancer cells, and to observe the role of miR-30a in the pathogenesis of breast cancer. With the increase of pathological grade and malignant degree of breast cancer cells, the miR-30a expression level gradually decreased (P<0.01). Transfection with miR-30a mimic significantly inhibited the proliferative and invasive ability of SK-BR-3 cells (P<0.01), while transfection with anti-miR-30a significantly improved the proliferative and invasive ability of these cells (P<0.01). It was revealed using bioinformatic methods that Snail was the functional target gene of miR-30a, and this was verified by the results of a luciferase reporter gene assay. The results of analysis of Snail expression in breast cancer tissues and breast cancer cells revealed that with the increase in pathological grade and malignant degree of breast cancer cells, Snail expression levels gradually increased (P<0.01). Western blotting revealed that miR-30a significantly inhibited Snail expression in SK-BR-3 cells, upregulated the expression of EMT-associated E-cadherin, and downregulated the expression of EMT-associated N-cadherin and Vimentin. MiR-30a was able to affect the proliferation and invasion of breast cancer cells by regulating Snail expression, and therefore has a regulatory effect on the occurrence and development of breast cancer.

miR-153 inhibits the migration and the tube formation of endothelial cells by blocking the paracrine of angiopoietin 1 in breast cancer cells

The sprouting of endothelial cells is the first step of tumor angiogenesis. Our previous study suggests that miR-153 suppresses breast tumor angiogenesis partially through targeting hypoxia-induced factor (HIF1α). In this study, we demonstrated that miR-153 also suppresses the migration and the tube formation of endothelial cells through directly targeting angiopoietin 1 (ANG1) in breast cancer cells. There was a negative correlation between miR-153 and ANG1 levels in breast cancer. miR-153 blocked the expression and secretion of ANG1 in breast cancer cells through binding to ANG1 mRNA. Conditioned medium from the breast cancer cell, MCF7, treated with miR-153 had no effect on the proliferation of HUVECs, but significantly inhibited the migration and tube formation of HUVECs, which could be rescued by overexpression of ANG1. In addition, miR-153 also directly inhibited the proliferation and migration of MCF7 through downregulation of ANG1. These findings suggest that miR-153 suppresses the activity of tumor cells and the migration and tube formation of endothelial cells by silencing ANG1.

Targeting IGF1R pathway in cancer with microRNAs: How close are we?

Cancer of the head and neck are the most common cancers in India and account for 30% of all cancers. At molecular level, it could be attributed to the overexpression of growth factors like IGF1-R, EGFR, VEGF-R and deregulation of cell cycle regulators and tumor suppressors. IGF1-R is an emerging target in head and neck cancer treatment, because of its reported role in tumor development, progression and metastasis. IGF1R targeted agents are in advanced stages of clinical development. Nevertheless, these agents suffer from several disadvantages including acquired resistance and toxic side effects. Hence there is a need for developing newer agents targeting not only the receptor but also its downstream signaling. miRNAs are considered as master regulators of gene expression of multiple genes and has been widely reported to be a promising therapeutic strategy. This review discusses the present status of research in both these arenas and emphasizes the role of miRNA as a promising agent for biologic therapy.

Prognostic microRNAs and their potential molecular mechanism in pancreatic cancer: A study based on The Cancer Genome Atlas and bioinformatics investigation

Although certain biomarkers that are directly associated with the overall survival (OS) of patients with pancreatic adenocarcinoma (PAAD) have been identified, the efficacy of a single factor is limited to predicting the prognosis. The aim of the present study was to identify a combination micro (mi)RNA signature that enhanced the prognostic prediction for PAAD. Following analysis of the data available from The Cancer Genome Atlas (TCGA), 175 PAAD samples were selected for the present study, and the associations between 494 miRNAs and OS were investigated. The prognostic value of all miRNAs was analyzed by multivariate Cox regression, and the miRNAs were ranked according to the hazard ratio (HR) and P-values. The top 5 miRNAs (miR-1301, miR-125a, miR-376c, miR-328 and miR-376b) were significantly associated with OS (HR=0.139; 95% confidence interval, 0.043–0.443; P<0.001), thus demonstrating that this panel was able to serve as an independent prognostic factor for PAAD. In addition, the present study also predicted the target genes of the top 10 miRNAs with the highest prognostic values using 12 different prediction software, and enrichment signaling pathway analyses elucidated that several pathways may be markedly associated with these miRNAs, including ‘Pathways in cancer’, ‘Chronic myeloid leukemia’, ‘Glioma’ and ‘MicroRNAs in cancer’. Lastly, ubiquitin C, epidermal growth factor receptor, estrogen receptor 1, mitogen-activated protein kinase 1, mothers against decapentaplegic homolog 4 and androgen receptor may be the hub genes revealed by STRING analysis. The present study identified several miRNAs, particularly a five-miRNA-pool, that may be reliable, independent factors for predicting survival in patients with PAAD. However, the underlying molecular mechanisms require further investigation in the future.

MicroRNAs in lung cancer

Lung cancer (LC) is a serious public health problem responsible for the majority of cancer deaths and comorbidities in developed countries. Tobacco smoking is considered the main risk factor for LC; however, only a few smokers will be affected by this cancer. Current screening methods are focused on identifying the early stages of this malignancy. Thus, new data concerning the roles of microRNA alterations in inflammation, epithelial-mesenchymal transition and lung disease have increased hope about LC pathogenesis, diagnosis, treatment and prognosis. MicroRNA mechanisms include angiogenesis promotion, cell cycle regulation by modulating cellular proliferation and apoptosis, and migration and invasion inhibition. In this context, this manuscript reviews the current information about many important microRNAs as they relate to the initiation and progression of LC.

miR-153 enhances the therapeutic effect of gemcitabine by targeting Snail in pancreatic cancer

Pancreatic cancer (PC) is one of the most lethal cancers, with an overall 5 years survival rate of <5%. The clinical benefit of gemcitabine based chemotherapeutic strategy on PC was limited by its high drug resistance rate. Snail, one of the master regulators of epithelial-mesenchymal transition, has been implicated in the progression of various cancers. However, whether it is also linked to the development of chemosensitivity to gemcitabine in PC is unknown, and the regulatory pathways controlling Snail also need to be explored. Cell apoptosis analysis was performed using flow cytometry assay. Quantitative real-time PCR was used to investigate the level of microRNA and the mRNA expression of its target, Snail. Snail expression was measured by immunoblotting and immunohistochemistry. A xenografted tumor model was used to test the in vivo effects of miR-153 on chemosensitivity to gemcitabine. The results of this study demonstrated the decrease of miR-153 expression in PC tumor tissue, which is correlated with a poor prognosis. miR-153 mimic transfection enhanced gemcitabine sensitivity in gemcitabine-resistant PC cells, while downregulation of miR-153 decreased gemcitabine sensitivity. In addition, miR-153 was found to target the 3'-UTR of Snail mRNA. Furthermore, we found that the increase of apoptosis in gemcitabine-resistant PC cells resulted from miR-153 mimic transfection was reversed by overexpression of Snail. miR-153 reverses the resistance of PC cells to gemcitabine by directly targeting Snail, and it may be a potential novel therapeutic target for overcoming gemcitabine resistance in human PC.

MicroRNA‑296 targets AKT2 in pancreatic cancer and functions as a potential tumor suppressor

Although microRNA-296 (miR-296) has been studied in various types of human cancer, its expression, biological role and mechanism of action in pancreatic cancer remains to be elucidated. The aim of the current study was to investigate the expression level, possible roles and underlying molecular mechanisms of miR‑296 in pancreatic cancer. The present study revealed that miR‑296 is significantly downregulated in tissue from patients with pancreatic cancer and in human pancreatic carcinoma cell lines, when compared with matched healthy tissue and normal human pancreatic cell lines, respectively. In addition, restoration of miR‑296 expression was revealed to inhibit the proliferation, migration and invasive activity of pancreatic cancer cells. Furthermore, bioinformatics analysis and a luciferase reporter assay validated the AKT2 gene as a direct target of miR‑296 in pancreatic cancer. Reverse transcription‑quantitative polymerase chain reaction and western blot analysis revealed that miR‑296 was able to decrease AKT2 expression at the post‑transcriptional level. Notably, the effects of AKT2 knockdown were similar to miR‑296 overexpression in pancreatic cancer. In conclusion, the present findings indicate a role for miR‑296 as a tumor suppressor in pancreatic cancer through directly targeting AKT2, thus suggesting that miR‑296 may serve as a potential therapeutic target for the treatment of pancreatic cancer.

MicroRNA-153-3p suppress cell proliferation and invasion by targeting SNAI1 in melanoma

Malignant melanoma is one of the most common malignancies of the skin cancer and increasing evidences revealed that microRNAs (miRNAs) exert significant effects in melanoma. In the present study, the underlying function of microRNA-153-3p (miR-153-3p) in melanoma was investigated from different levels, including cell level, protein level and gene level. Our results showed that expression of miR-153-3p was lower in melanoma tissues and melanoma cells compared with the para-tumor tissue and normal melanocytes. The overexpression of miR-153-3p inhibited the cell proliferation and invasion, at the same time promoted cell apoptosis. Moreover, we identified that snail family transcriptional repressor 1 (SNAI1) is the direct target of miR-153-3p, and there is a negative correlation between miR-153-3p level and SNAI1 expression. In summary, we presented the evidences that miR-153-3p may act as a tumor suppressor by down-regulating the expression of SNAI1 in melanoma and miR-153-3p might be a potential biomarker in the diagnosis and treatment of malignant melanoma.

MiR-143 Targeting TAK1 Attenuates Pancreatic Ductal Adenocarcinoma Progression via MAPK and NF-κB Pathway In Vitro

BACKGROUND

Transforming growth factor (TGF)-β-activated kinase 1 (TAK1) is one of the major regulators of inflammation-induced cancer cell growth and progression. MiR-143 dysregulation is a common event in a variety of human diseases including pancreatic ductal adenocarcinoma (PDA).

AIMS

To identify the interaction between TAK1 and miR-143 in PDA.

METHODS

Data mining of TAK1 expression in PDA patient gene profiling was conducted. QRT-PCR and western blot were performed to detect the expression of TAK1 in PDA tissues and cell lines. Ectopic miR-143 and TAK1 were introduced to PDA cells. Cell growth, apoptosis and migration were examined. Xenograft models were used to examine the function of TAK1 in vivo. Western blot and luciferase assay were carried out to investigate the direct target of miR-143.

RESULTS

PDA patient gene profiling data (GSE15471 and GSE16515) showed that TAK1 mRNA was aberrantly up-regulated in PDA tissues. TAK1 protein levels were overexpressed in PDA tissues and cell lines. Overexpression of TAK1 was strongly associated with positive lymph node metastasis. Inhibition of TAK1 suppressed cell growth, migration, and induced cell apoptosis in vitro and in vivo. Further studies demonstrated that TAK1 was a direct target gene of miR-143. MiR-143 also inhibited PDA cells proliferation and migration, induced apoptosis and G₁/S arrest. Moreover, TAK1 depletion inactivated MAPK and NF-κB pathway, mimicking the function of miR-143.

CONCLUSIONS

The study highlights that miR-143 acts as a tumor suppressor in PDA through directly targeting TAK1, and their functional regulation may provide potential therapeutic strategies in clinics.

miR-211-5p Suppresses Metastatic Behavior by Targeting SNAI1 in Renal Cancer

The Snail family transcriptional repressor 1 (SNAI1) is known to promote metastatic phenotypes in renal cell carcinoma (RCC). However, the mechanism by which SNAI1 promotes RCC metastasis remains largely unexplored. Here, bioinformatics and quantitative validation revealed that miR-211-5p was downregulated in metastatic RCC clinical specimens compared with nonmetastatic RCC tissues. Overexpression of miR-211-5p suppressed RCC cell migration and invasion via downregulation of SNAI1 expression. Luciferase reporter assays demonstrated that miR-211-5p directly targeted 3'-UTR of SNAI1. Furthermore, miR-211-5p decreased xenograft tumor weight and reduced in vivo tumor metastasis in mice. These findings indicate that miR-211-5p-mediated inhibition of SNAIL1 expression contributes to the suppression of RCC progression.Implications: Targeting the miR-211-5p/SNAI1 signaling pathway may be a novel therapeutic approach for the treatment of RCC metastasis. Mol Cancer Res; 15(4); 448-56. ©2017 AACR.

MiR-137 and miR-34a directly target Snail and inhibit EMT, invasion and sphere-forming ability of ovarian cancer cells

Background

In ovarian cancer (OC) cells, Snail was reported to induce the epithelial-to-mesenchymal transition (EMT), which is a critical step in OC metastasis. At present little is known about controlling Snail expression in OC cells by using specific microRNAs (miRNAs).

Methods

We first used a computational target prediction analysis to identify 6 candidate miRNAs that bind to the 3′-untranslated region (3′-UTR) region of the Snail mRNA. Among these miRNAs, two miRNAs (miR-137 and miR-34a) with a potential to regulate Snail were validated by quantitative real-time PCR, Western blot analysis, and Snail 3′-UTR reporter assays. We assessed the effects of miR-137 and miR-34a on EMT, invasion and sphere formation in OC cells. We also evaluated the expression of miR-137 and miR-34a in OC tissues and adjacent normal tissues and analyzed the relationship between their expression and patient survival.

Results

We report that OC tissues possess significantly decreased levels of miR-137 and miR-34a and increased expression of Snail when compared to their adjacent normal tissues, and lower miR-137 and miR-34a expression correlates with worse patient survival. Using luciferase constructs containing the 3′-UTR region of Snail mRNA combined with miRNA overexpression and mutagenesis, we identified miR-137 and miR-34a as direct suppressors of Snail in OC cells. The introduction of miR-137 and miR-34a resulted in the suppression of Snail at both the transcript and protein levels, and effectively suppressed the EMT phenotype and sphere formation of OC cells. However, the inhibition of miR-137 and miR-34a with antisense oligonucleotides promoted EMT and OC cell invasion. Moreover, ectopic expression of Snail significantly reversed the inhibitory effects of miR-137 and miR-34a on OC cell invasion and sphere formation.

Conclusions

These findings suggest that both miR-137 and miR-34a act as Snail suppressors to negatively regulate EMT, invasive and sphere-forming properties of OC cells.

MicroRNA-30b Suppresses Epithelial-Mesenchymal Transition and Metastasis of Hepatoma Cells

Epithelial-mesenchymal transition (EMT) is critical for induction of invasiveness and metastasis in HCC. Growing evidence indicates that upregulation of Snail, the major EMT inducer, significantly correlates with the metastasis and poor prognosis of HCC. Here, we investigate the underlying mechanism of miR-30b in suppressing metastasis of hepatoma cells by targeting Snail. In this study, we found that miR-30b was significantly downregulated and negatively associated with Snail production in HCC cell lines with higher metastatic potentials. Gain- and loss-of-function studies revealed that miR-30b could dramatically inhibit in vitro HCC cell migration and invasion. In vivo orthotopic liver xenograft model further demonstrated that stable over-expression of miR-30b significantly repressed the local invasion and lung metastasis of hepatoma cells. Meanwhile, the restoration of miR-30b expression suppressed the distant colonization of hepatoma cells. Both gain- and loss-of-function studies showed that miR-30b suppressed the EMT of hepatoma cells as indicated by the morphology changes and deregulation of epithelial and mesenchymal markers. Using RNAi, we further investigated the role of Snail in HCC cell EMT and demonstrated that knockdown of Snail significantly inhibited the EMT and cancer cell metastasis. Additionally, miR-30b exhibited inhibitory effects on HCC cell proliferation in vitro and in vivo. In conclusion, our findings highlight the significance of miR-30b downregulation in HCC tumor metastasis and invasiveness, and implicate a new potential therapeutic target for HCC metastasis. J. Cell. Physiol. 232: 625-634, 2017. © 2016 Wiley Periodicals, Inc.

Surgical and molecular pathology of pancreatic neoplasms

BACKGROUND

Histologic characteristics have proven to be very useful for classifying different types of tumors of the pancreas. As a result, the major tumor types in the pancreas have long been classified based on their microscopic appearance.

MAIN BODY

Recent advances in whole exome sequencing, gene expression profiling, and knowledge of tumorigenic pathways have deepened our understanding of the underlying biology of pancreatic neoplasia. These advances have not only confirmed the traditional histologic classification system, but also opened new doors to early diagnosis and targeted treatment.

CONCLUSION

This review discusses the histopathology, genetic and epigenetic alterations and potential treatment targets of the five major malignant pancreatic tumors - pancreatic ductal adenocarcinoma, pancreatic neuroendocrine tumor, solid-pseudopapillary neoplasm, acinar cell carcinoma and pancreatoblastoma.

miR-153 regulates apoptosis and autophagy of cardiomyocytes by targeting Mcl-1

MicroRNAs (miRs) are a class of important regulators, which are involved in the regulation of apoptosis. Oxidative stress‑induced apoptosis is the predominant factor accounting for cardiac ischemia‑reperfusion injury. miR‑153 has been previously shown to have an antitumor effect in cancer. However, whether miR‑153 is involved in oxidative stress‑induced apoptosis in the heart remains to be elucidated. To this end, the present study used reverse transcription‑quantitative polymerase chain reaction to detect miR-153 levels upon oxidative stress, and evaluated apoptosis, autophagy and expression of critical genes by western blotting. A luciferase assay was also used to confirm the potential target gene. In the present study, it was found that the expression of miR‑153 was significantly increased upon H2O2 stimulation, and the inhibition of endogenous miR‑153 decreased apoptosis. To further identify the mechanism underlying the pro‑apoptotic effect of miR‑153, the present study analyzed the 3'untranslated region of myeloid cell leukemia‑1 (Mcl‑1), and found that Mcl‑1 was potentially targeted by miR‑153. The forced expression of miR‑153 inhibited the expression of Mcl‑1 and luciferase activity, which was reversed by its antisense inhibitor. Furthermore, it was shown that the inhibition of miR‑153 induced autophagy during oxidative stress, and that its effects of autophagy induction and apoptosis inhibition were efficiently abrogated by Mcl‑1 small interfering RNA. In conclusion, the results of the present study elucidated a novel mechanism by which miR‑153 regulates the survival of cardimyocytes during oxidative stress through the modulation of apoptosis and autophagy. These effects may be mediated directly by targeting Mcl‑1. These finding revealed the potential clinical value of miR‑153 in the treatment of cardiovascular disease.

MicroRNA Regulation of Epithelial to Mesenchymal Transition

Epithelial to mesenchymal transition (EMT) is a central regulatory program that is similar in many aspects to several steps of embryonic morphogenesis. In addition to its physiological role in tissue repair and wound healing, EMT contributes to chemo resistance, metastatic dissemination and fibrosis, amongst others. Classically, the morphological change from epithelial to mesenchymal phenotype is characterized by the appearance or loss of a group of proteins which have come to be recognized as markers of the EMT process. As with all proteins, these molecules are controlled at the transcriptional and translational level by transcription factors and microRNAs, respectively. A group of developmental transcription factors form the backbone of the EMT cascade and a large body of evidence shows that microRNAs are heavily involved in the successful coordination of mesenchymal transformation and vice versa, either by suppressing the expression of different groups of transcription factors, or otherwise acting as their functional mediators in orchestrating EMT. This article dissects the contribution of microRNAs to EMT and analyzes the molecular basis for their roles in this cellular process. Here, we emphasize their interaction with core transcription factors like the zinc finger enhancer (E)-box binding homeobox (ZEB), Snail and Twist families as well as some pluripotency transcription factors.

Detection of gene communities in multi-networks reveals cancer drivers

We propose a new multi-network-based strategy to integrate different layers of genomic information and use them in a coordinate way to identify driving cancer genes. The multi-networks that we consider combine transcription factor co-targeting, microRNA co-targeting, protein-protein interaction and gene co-expression networks. The rationale behind this choice is that gene co-expression and protein-protein interactions require a tight coregulation of the partners and that such a fine tuned regulation can be obtained only combining both the transcriptional and post-transcriptional layers of regulation. To extract the relevant biological information from the multi-network we studied its partition into communities. To this end we applied a consensus clustering algorithm based on state of art community detection methods. Even if our procedure is valid in principle for any pathology in this work we concentrate on gastric, lung, pancreas and colorectal cancer and identified from the enrichment analysis of the multi-network communities a set of candidate driver cancer genes. Some of them were already known oncogenes while a few are new. The combination of the different layers of information allowed us to extract from the multi-network indications on the regulatory pattern and functional role of both the already known and the new candidate driver genes.

Clinical potential of miR-3651 as a novel prognostic biomarker for esophageal squamous cell cancer

Accumulating evidence indicates that dysregulated microRNA-3651(miR-3651) is involved in tumorigenesis and cancer progression. In this study, we investigated the expression of miR-3651 in esophageal squamous cell cancer(ESCC) and its relationship with tumor progression and clinical prognosis. The expression level of miR-3651 was examined by quantitative Real-time PCR (qRT-PCR) in fresh ESCC tissues and FFPE tissues. The correlation between miR-3651 expression and clinical features and prognosis were statistically analyzed. The results showed that the miR-3651 expression was significantly down-regulated in tumor tissues compared with the paracancerous tissues. Moreover, miR-3651 expression was negatively correlated with T stage of ESCC (P = 0.022) and tumor length (P = 0.015). Kaplan-Meier analysis demonstrated that low miR-3651 expression level was associated with poorer overall survival (OS) (P = 0.004) and disease-free survival (DFS) (P = 0.001). Multivariate analysis identified miR-3651 expression as independent prognostic factor for OS and DFS (P = 0.001 and P = 0.001, resp.). Further stratified analysis revealed the significant association between low miR-3651 expression and worse survival in early patients, but not in the advanced patients. Taken together, miR-3651 was down-regulated in cancerous tissues of ESCC. It may play an important role in cancer progression and could be used as an independent prognostic biomarker for ESCC patients.