Downregulated miR-495 [Corrected] Inhibits the G1-S Phase Transition by Targeting Bmi-1 in Breast Cancer

MicroRNA-495: a therapeutic and diagnostic tumor marker

Therapeutic and diagnostic progresses have significantly reduced the mortality rate among cancer patients during the last decade. However, there is still a high rate of mortality among cancer patients. One of the important reasons involved in the high mortality rate is the late diagnosis in advanced tumor stages that causes the failure of therapeutic strategies in these patients. Therefore, investigating the molecular mechanisms involved in tumor progression has an important role in introducing the efficient early detection markers. MicroRNAs (miRNAs) as stable factors in body fluids are always considered as non-invasive diagnostic and prognostic markers. In the present review, we investigated the role of miR-495 in tumor progression. It has been reported that miR-495 has mainly a tumor suppressor function through the regulation of transcription factors and tyrosine kinases as well as cellular processes such as multidrug resistance, chromatin remodeling, and signaling pathways. This review can be an effective step towards introducing the miR-495 as a non-invasive diagnostic/prognostic marker as well as a suitable target in tumor therapy.

Downregulated miR-495-3p in colorectal cancer targets TGFβR1, TGFβR2, SMAD4 and BUB1 genes and induces cell cycle arrest

BACKGROUND

Hsa-miR-495 (miR-495) has been extensively investigated in cancer initiation and progression. On the other hand, our bioinformatics analysis suggested that miR-495 exerts its effects through targeting of TGFβ signaling components.

METHODS & RESULTS

In order to investigate such an effect, miR-495 precursor was overexpressed in HEK293T, SW480, and HCT116 cells, which was followed by downregulation of TGFβR1, TGFβR2, SMAD4, and BUB1 putative target genes, detected by RT-qPCR. Also, luciferase assay supported the direct interaction of miR-495 with 3'UTR sequences of TGFβR1, TGFβR2, SMAD4, and BUB1 genes. Furthermore, a negative correlation of expression between miR-495-3p and some of these target genes was deduced in a set of colorectal and breast cancer cell lines. Then, flow cytometry analysis showed that the overexpression of miR-495 in HCT116 and HEK293T resulted in an arrest at the G1 phase. Consistently, western blotting analysis showed a significant reduction of the Cyclin D1 protein in the cells overexpressing miR-495, pointing to downregulation of the TGFβ signaling pathway and cell cycle arrest. Finally, microarray data analysis showed that miR-495-3p is significantly downregulated in colorectal tumors, compared to the normal pairs.

CONCLUSIONS

Overall, the results of the current study introduced miR-495-3p as a cell cycle progression suppressor, which may negatively regulate TGFβR1, TGFβR2, SMAD4, and BUB1 genes. This finding suggests miR-495-3p as a tumor suppressor candidate for further evaluation.

The Crucial Roles of Bmi-1 in Cancer: Implications in Pathogenesis, Metastasis, Drug Resistance, and Targeted Therapies

B-cell-specific Moloney murine leukemia virus integration region 1 (Bmi-1, also known as RNF51 or PCGF4) is one of the important members of the PcG gene family, and is involved in regulating cell proliferation, differentiation and senescence, and maintaining the self-renewal of stem cells. Many studies in recent years have emphasized the role of Bmi-1 in the occurrence and development of tumors. In fact, Bmi-1 has multiple functions in cancer biology and is closely related to many classical molecules, including Akt, c-MYC, Pten, etc. This review summarizes the regulatory mechanisms of Bmi-1 in multiple pathways, and the interaction of Bmi-1 with noncoding RNAs. In particular, we focus on the pathological processes of Bmi-1 in cancer, and explore the clinical relevance of Bmi-1 in cancer biomarkers and prognosis, as well as its implications for chemoresistance and radioresistance. In conclusion, we summarize the role of Bmi-1 in tumor progression, reveal the pathophysiological process and molecular mechanism of Bmi-1 in tumors, and provide useful information for tumor diagnosis, treatment, and prognosis.

Role of miRNA-495 and NRXN-1 and CNTN-1 mRNA Expression and Its Prognostic Importance in Breast Cancer Patients

Breast cancer is a heterogeneous disease in which genetic factors are involved in disease worsening and higher mortality. Epidemiological and clinical research revealed that breast cancer incidence continues to rise. 100 histopathologically confirmed untreated newly diagnosed cases of invasive ductal carcinoma (IDC) of breast and 100 healthy subjects were involved and blood samples were collected in non-EDTA plain vials. Serum was separated by centrifugation, total RNA was extracted from serum, and cDNA synthesis was done to study the miRNA-495 and neurexin-1 (NRXN-1) and contactin 1 (CNTN-1) mRNA expression by QRT-PCR. The expression levels of miRNA-495, NRXN-1, and CNTN-1 were expressed in fold change. The present study observed decreased relative miRNA-495 expression (0.07-fold) while an increase in NRXN-1 (11.61-fold) and CNTN-1 (4.92-fold) was observed among breast cancer patients compared to healthy controls. A significant difference was observed in miRNA-495 expression with menopausal status (p=0.0001) and TNM stages (p=0.02). It was observed that NRXN-1 expression was significantly associated with menopausal status (p=0.03), lymph node involvement (p < 0.0001), estrogen receptor (ER) status (p=0.03), progesterone receptor (PR) status (p=0.005), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). CNTN-1 expression was also found to be associated with lymph node involvement (p=0.01), PR status (p=0.03), HER2 status (p=0.04), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). ROC suggested that NRXN-1 and CNTN-1 could be the important predictive marker for disease advancement and distant organ metastases. The study concluded that the decreased expression of miR-495 observed in breast cancer patients showed a negative correlation with NRXN-1 while the increased expression of NRXN-1 and CNTN-1 was linked with disease advancement and distant metastases and could be the important predictive marker for breast cancer patients.

Diagnostic and Prognostic Potential of MiR-379/656 MicroRNA Cluster in Molecular Subtypes of Breast Cancer

Introduction: Breast cancer is the most frequently diagnosed cancer globally and is one of the most important contributors to cancer-related deaths. Earlier diagnosis is known to reduce mortality, and better biomarkers are needed. MiRNA clusters often co-express and target mRNAs in a coordinated fashion, perturbing entire pathways; they thus merit further exploration for diagnostic or prognostic use. MiR-379/656, at chromosome 14q32, is the second largest miRNA cluster in the human genome and implicated in various malignancies including glioblastoma, melanoma, gastrointestinal tumors and ovarian cancer highlighting its potential importance. In this study, we focus on the diagnostic and prognostic potentials of MiR-379/656 in breast cancer and its molecular subtypes. Materials and Methods: We analyzed miRNA and mRNA next generation sequencing data from 903 primary tumors and 90 normal controls (source: The Cancer Genome Atlas). The differential expression profile between tumor and normal was analyzed using DeSEQ2. Penalized logistic regression modelling (lasso regression) was used to assess the predictive potential of MiR-379/656 expression for tumor and normal samples. The association between MiR-379/656 expression and overall patient survival was studied using Cox Proportional-Hazard Model. The target mRNAs (validated) of MiR-379/656 were annotated via pathway enrichment analysis to understand the biological significance of the cluster in breast cancer. Results: The differential expression analysis for 1390 miRNAs (miRnome) revealed 310 upregulated (22.3%) and 176 downregulated (12.66%) miRNAs in breast cancer patients compared with controls. For MiR-379/656, 32 miRNAs (32/42; 76%) were downregulated. The MiR-379/656 cluster was found to be the most differentially expressed cluster in the human genome (p < 10⁻³⁰). The Basal and Luminal B subtypes showed at least 83% (35/42) of the miRNAs to be downregulated. The binomial model prioritized 15 miRNAs, which distinguished breast cancer patients from controls with 99.15 ± 0.58% sensitivity and 77.78 ± 5.24% specificity. Overall, the Basal and Luminal B showed the most effective predictive power with respect to the 15 prioritized miRNAs at MiR-379/656 cluster. The decreased expression of MiR-379/656 was found to be associated with poorer clinical outcome in Basal and Luminal B subtypes, increasing tumor stage and tumor size/extent, and overall patient survival. Pathway enrichment for the validated targets of MiR-379/656 was significant for cancer-related pathways, especially DNA repair, transcriptional regulation by p53 and cell cycle checkpoints (adjusted p-value < 0.05). Conclusions: Genome informatics analysis of high throughput data for MiR-379/656 cluster has shown that a subset of 15 miRNAs from MiR-379/656 cluster can be used for the diagnostic and prognostic purpose of breast cancer and its subtypes—especially in Basal and Luminal B.

MicroRNA Regulation of Breast Cancer Stemness

Recent advances in our understanding of breast cancer have demonstrated that cancer stem-like cells (CSCs, also known as tumor-initiating cell (TICs)) are central for progression and recurrence. CSCs are a small subpopulation of cells present in breast tumors that contribute to growth, metastasis, therapy resistance, and recurrence, leading to poor clinical outcome. Data have shown that cancer cells can gain characteristics of CSCs, or stemness, through alterations in key signaling pathways. The dysregulation of miRNA expression and signaling have been well-documented in cancer, and recent studies have shown that miRNAs are associated with breast cancer initiation, progression, and recurrence through regulating CSC characteristics. More specifically, miRNAs directly target central signaling nodes within pathways that can drive the formation, maintenance, and even inhibition of the CSC population. This review aims to summarize these research findings specifically in the context of breast cancer. This review also discusses miRNAs as biomarkers and promising clinical therapeutics, and presents a comprehensive summary of currently validated targets involved in CSC-specific signaling pathways in breast cancer.

Enhancer RNAs: transcriptional regulators and workmates of NamiRNAs in myogenesis

miRNAs are well known to be gene repressors. A newly identified class of miRNAs termed nuclear activating miRNAs (NamiRNAs), transcribed from miRNA loci that exhibit enhancer features, promote gene expression via binding to the promoter and enhancer marker regions of the target genes. Meanwhile, activated enhancers produce endogenous non-coding RNAs (named enhancer RNAs, eRNAs) to activate gene expression. During chromatin looping, transcribed eRNAs interact with NamiRNAs through enhancer-promoter interaction to perform similar functions. Here, we review the functional differences and similarities between eRNAs and NamiRNAs in myogenesis and disease. We also propose models demonstrating their mutual mechanism and function. We conclude that eRNAs are active molecules, transcriptional regulators, and partners of NamiRNAs, rather than mere RNAs produced during enhancer activation.

miR-495 and miR-5688 are down-regulated in non-small cell lung cancer under hypoxia to maintain interleukin-11 expression

Background

Hypoxia is a hallmark of cancer and is associated with poor prognosis. However, the molecular mechanism by which hypoxia promotes tumor progression remains unclear. MicroRNAs dysregulation has been shown to play a critical role in the tumor and tumor microenvironment. Here, we investigated the roles of miR‐495 and miR‐5688 in human non‐small cell lung cancer (NSCLC) and their underlying mechanism.

Methods

The expression levels of miR‐495 and miR‐5688 in human NSCLC tissue specimens were measured by quantitative real‐time polymerase chain reaction (qRT‐PCR). Deferoxamine (DFO) was used to determine whether the regulation of miR‐495 and miR‐5688 under hypoxia was dependent on hypoxia‐inducible factor 1‐alpha (HIF‐1α). Furthermore, the functions of miR‐495 and miR‐5688 in tumor progression were evaluated using colony formation, 3‐(4,5‐dimethylthiazol‐2‐yl)‐5‐(3‐carboxymethoxyphenyl)‐2‐(4‐sulfophenyl)‐2H‐tetrazolium (MTS), wound healing, transwell assays, and xenograft model. Two algorithms, PicTAR and Targetscan, were used to predict the target gene of these two miRNAs, and dual‐luciferase reporter assay was conducted to confirm the target. The unpaired two‐tailed t test, Pearson correlation analysis, and Fisher's exact probability test were performed for statistical analyses.

Results

Two miRNAs, miR‐495 and miR‐5688, were found to participate in NSCLC progression under hypoxia. They were down‐regulated in NSCLC tissues compared with normal tissues. We determined that hypoxia led to the down‐regulation of miR‐495 and miR‐5688 in NSCLC cells, which was independent of HIF‐1α and cellular metabolic energy. In addition, miR‐495 and miR‐5688 suppressed cell proliferation, migration, and invasion in vitro. The NSCLC xenograft model showed that miR‐495 and miR‐5688 inhibited tumor formation in vivo. Interestingly, we found that miR‐495 and miR‐5688 had the same target, interleukin‐11 (IL‐11). Recombinant human IL‐11 counteracted the effects of miR‐495 and miR‐5688 on NSCLC cells, suggesting that miR‐495 and miR‐5688 executed their tumor suppressive role by repressing IL‐11 expression.

Conclusion

We found that hypoxia down‐regulated the expression levels of miR‐495 and miR‐5688 in NSCLC to enhance IL‐11 expression and tumor progression, indicating that the miR‐495/miR‐5688/IL‐11 axis may serve as a therapeutic target and potential biomarker for NSCLC.

B lymphoma Moloney murine leukemia virus insertion region 1: An oncogenic mediator in prostate cancer

B lymphoma Moloney murine leukemia virus insertion region 1 (BMI1), a core member of polycomb repressive complex 1 (PRC1), has been intensely investigated in the field of cancer epigenetics for decades. Widely known as a critical regulator in cellular physiology, BMI1 is essential in self-renewal and differentiation in different lineages of stem cells. BMI1 also plays a significant role in cancer etiology for its involvement in pathological progress such as epithelial–mesenchymal transition (EMT) and cancer stem cell maintenance, propagation, and differentiation. Importantly, overexpression of BMI1 is predictive for drug resistance, tumor recurrence, and eventual therapy failure of various cancer subtypes, which renders the pharmacological targeting at BMI1 as a novel and promising therapeutic approach. The study on prostate cancer, a prevalent hormone-related cancer among men, has promoted enormous research advancements in cancer genetics and epigenetics. This review summarizes the role of BMI1 as an oncogenic and epigenetic regulator in tumor initiation, progression, and relapse of prostate cancer.

Cell-free miRNAs as non-invasive biomarkers in breast cancer: Significance in early diagnosis and metastasis prediction

Breast cancer is one of the genetic diseases causing a high mortality among women around the world. Despite the availability of advanced diagnostic tools and treatment strategies, the incidence of breast cancer is increasing every year. This is due to the lack of accurate and reliable biomarkers whose deficiency creates difficulty in early breast cancer recognition, subtypes determination, and metastasis prophecy. Although biomarkers such as ER, PR, Her2, Ki-67, and other genetic platforms e.g. MammaPrint®, Oncotype DX®, Prosigna® or EndoPredict® are available for determination of breast cancer diagnosis and prognosis. However, pertaining to heterogeneous nature, lack of sensitivity, and specificity of these markers, it is still incessant to overcome breast cancer burden. Therefore, a novel biomarker is urgently needed for therapeutic diagnosis and improving prognosis. Lately, it has become more evident that cell-free miRNAs might be useful as good non-invasive biomarkers that are associated with different events in carcinogenesis. For example, some known biomarkers such as miR-21, miR-23a, miR-34a are associated with molecular subtyping and different biomolecular aspects i.e. apoptosis, angiogenesis, metastasis, and miR-1, miR-10b, miR-16 are associated with drug response. Cell-free miRNAs present in human body fluids have proven to be potential biomarkers with significant prognostic and predictive values. Numerous studies have found a distinct expression profile of circulating miRNAs in breast tumour versus non-tumour and in early and advanced-stage, thus implicating its clinical relevance. This review article will highlight the importance of different cell-free miRNAs as a biomarker for early breast cancer detection, subtype classification, and metastasis forecast.

Association between RNF2+P-AKT expression in pretreatment biopsy specimens, and poor survival following radiotherapy in patients with esophageal squamous cell carcinoma

The protein expression levels of Ring finger protein 2 (RNF2) and phosphor-protein kinase B (P-AKT) were determined in esophageal squamous cell carcinoma (ESCC) tissues, and the association between patient clinicopathological characteristics and survival time following definitive intensity-modulated radiotherapy was assessed. Cancerous biopsy tissues were collected from patients with ESCC at The Fourth Affiliated Hospital of Hebei Medical University between January 2010 and December 2013. Of these 99 cases, 83 were used to analyze the protein expression level of RNF2 (89.2% positive), 85 for P-AKT (65.9% positive) and 80 for RNF2+P-AKT protein expression levels (62.5% both positive). The expression levels of RNF2 protein in ESCC were associated with tumor volume (P=0.024), whilst those of P-AKT and RNF2+PAKT were associated with sex (P=0.041 and P=0.003, respectively). There were no significant differences in overall survival (OS) or progression-free survival (PFS) rate between the RNF2^- and the RNF2^+-+++ groups (P=0.134 and P=0.366, respectively), or between the P-AKT^- group and P-AKT^+-+++ group (P=0.468; P=0.580, respectively). The 1-, 3- and 5-year OS rates were 68.0, 28.0, and 20.0%, and 86.7, 53.3, and 31.1%, in the RNF2/P-AKT⁺ group and Other group, respectively (χ²=4.205; P=0.040). Multivariate analysis revealed that age, T stage and RNF2+P-AKT expression were independent prognostic factors for ESCC (P=0.010, P=0.008 and P=0.010, respectively). The expression of RNF2+P-AKT combined was an independent prognostic factor affecting survival rate, and therefore presents a potential prognostic indicator for patients with ESCC, treated with definitive radiotherapy.

miR-496, miR-1185, miR-654, miR-3183 and miR-495 are downregulated in colorectal cancer cells and have putative roles in the mTOR pathway

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by suppressing the target mRNA and inhibiting translation in order to regulate multiple biological processes. miRNAs play important roles as oncogenes or tumor suppressors in the development of various types of human cancer. The regulation of mammalian target of rapamycin (mTOR) by miRNAs has been studied in several types of cancer, including colorectal cancer (CRC). However, to the best of our knowledge, only limited information regarding the function of miRNAs in human CRC is available. In the present study, the expression of 22 miRNAs in CRC cell lines were investigated in regard to key genes in the mTOR pathway. Initially, it was revealed that mTOR, regulatory-associated protein of mTOR complex I and rapamycin-intensive companion of mTOR were overexpressed in CRC cell lines when compared with a normal colorectal cell line. Subsequently, putative miRNA-mRNA associations were identified via multiple miRNA target prediction programs. The expression levels for the candidate miRNAs were validated using quantitative real-time polymerase chain reaction. Expression analysis revealed that, among 20 miRNAs, five miRNAs (miR-496, miR-1185, miR-654, miR-3183 and miR-495) exhibited significant downregulation in association with the mTOR signaling pathway. Taken together, the results from the present study suggest that several miRNAs that are associated with CRC, with possible roles in mTOR signaling, may have potential therapeutic or diagnostic benefits in CRC treatment.

Effective Delivery of a Microtubule Polymerization Inhibitor Synergizes with Standard Regimens in Models of Pancreatic Ductal Adenocarcinoma

PURPOSE

Pancreatic ductal adenocarcinoma (PDA) is a deadly cancer that is broadly chemoresistant, due in part to biophysical properties of tumor stroma, which serves as a barrier to drug delivery for most classical chemotherapeutic drugs. The goal of this work is to evaluate the preclinical efficacy and mechanisms of PTC596, a novel agent with potent anticancer properties in vitro and desirable pharmacologic properties in vivo.Experimental Design: We assessed the pharmacology, mechanism, and preclinical efficacy of PTC596 in combination with standards of care, using multiple preclinical models of PDA.

RESULTS

We found that PTC596 has pharmacologic properties that overcome the barrier to drug delivery in PDA, including a long circulating half-life, lack of P-glycoprotein substrate activity, and high systemic tolerability. We also found that PTC596 combined synergistically with standard clinical regimens to improve efficacy in multiple model systems, including the chemoresistant genetically engineered "KPC" model of PDA. Through mechanistic studies, we learned that PTC596 functions as a direct microtubule polymerization inhibitor, yet a prior clinical trial found that it lacks peripheral neurotoxicity, in contrast to other such agents. Strikingly, we found that PTC596 synergized with the standard clinical backbone regimen gemcitabine/nab-paclitaxel, yielding potent, durable regressions in a PDX model. Moreover, similar efficacy was achieved in combination with nab-paclitaxel alone, highlighting a specific synergistic interaction between two different microtubule-targeted agents in the setting of pancreatic ductal adenocarcinoma.

CONCLUSIONS

These data demonstrate clear rationale for the development of PTC596 in combination with standard-of-care chemotherapy for PDA.

Wnt pathway targeting reduces triple-negative breast cancer aggressiveness through miRNA regulation in vitro and in vivo

Triple-negative breast cancer, devoid of estrogen (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER-2) expression, is deprived of commonly used targeted therapies. MicroRNAs (miRNAs) are undergoing a revolution in terms of potentially diagnostic or therapeutic elements. Combining computational approaches, we enriched miRNA binding motifs of Wnt pathway-associated upregulated genes. Our in-depth bioinformatics, in vitro and in vivo analyses indicated that miR-381 targets main genes of the Wnt signaling pathway including CTNNB1, RhoA, ROCK1, and c-MYC genes. The expression level of miR-381 and target genes was assessed by quantitative real-time polymerase chain reaction (RT-qPCR) in MCF-7, MDA-MB-231, and MCF-10A as well as 20 breast cancer samples and normal tissues. Luciferase reporter assay was performed. Lentiviral particles containing miR-381 were used to evaluate the effect of miR-381 restoration on cell proliferation, migration, and invasion of the invasive triple-negative MDA-MB-231 cell line and also in a mouse model of breast cancer. The expression of miR-381 was lower than that of normal cells, especially in TNBC cell line and breast tissues. Luciferase assay results confirmed that miR-381 targets all the predicted 3'-untranslated regions (3'-UTRs). Upon miR-381 overexpression, the expression of target genes declined, and the migration and invasion potential of miR-381-receiving MDA-MB-231 cells decreased. In a mouse model of triple-negative breast cancer, miR-381 re-expression inhibited the invasion of cancer cells to lung and liver and prolonged the survival time of cancer cell-bearing mice. Therefore, miR-381 is a regulator of Wnt signaling and its re-expression provides a potentially effective strategy for inhibition of TNBC.

Interplay between epigenetic abnormalities and deregulated expression of microRNAs in cancer

Epigenetic abnormalities and aberrant expression of non-coding RNAs are two emerging features of cancer cells, both of which are responsible for deregulated gene expression. In this review, we describe the interplay between the two. Specific themes include epigenetic silencing of tumor suppressor miRNAs, epigenetic activation of oncogenic miRNAs, epigenetic aberrations caused by miRNAs, and naturally occurring compounds which modulate miRNA expression through epigenetic mechanisms.

Association of Elevated Peripheral Blood Micronucleus Frequency and Bmi-1 mRNA Expression with Metastasis in Iranian Breast Cancer Patients

Background:

In order to find cytogenetic and molecular metastasis biomarkers detectable in peripheral blood the spontaneous genomic instability expressed as micronuclei and Bmi-1 expression in peripheral blood of breast cancer (BC) patients were studied in different stages of the disease compared with unaffected first-degree relatives (FDRs) and normal control.

Methods:

The Cytokinesis Block Micronuclei Cytome (CBMN cyt) and nested real-time Reverse Transcription-Polymerase Chain Reaction (RT-PCR) assays, were respectively used to measure genomic instability and Bmi-1 gene expression in 160 Iranian individuals comprised of BC patients in different stages of the disease, unaffected FDRs and normal control groups.

Result:

The frequency of micronuclei and Bmi-1 expression were dramatically higher in distant metastasis compared with non-metastatic BC. In spite of micronucleus frequency with no association with lymph node (LN) involvement and hormone receptor status, the Bmi-1 expression level was higher in LN positive and triple negative patients.

Conclusion:

Our results indicate that increased genomic instability expressed as micronuclei and higher Bmi-1 expression in peripheral blood are associated with metastasis in breast cancer. Therefore implementation of micronucleus assay and Bmi-1 expression analysis in blood as possible cytogenetic and molecular biomarkers in clinical level may potentially enhance the quality of management of patients with breast cancer.

MicroRNA-495 suppresses cell proliferation and invasion of hepatocellular carcinoma by directly targeting insulin-like growth factor receptor-1

Hepatocellular carcinoma (HCC) is the fifth most common malignancy and second-most frequent cause of cancer-associated deaths worldwide. Previously, increasing studies report that microRNAs (miRNAs/miRs) are abnormally expressed in various types of human cancers and may participate in the tumourigenesis and tumour development of HCC. miRNA-based targeted therapy is effective against different molecular targets and may increase the sensitisation of cancer cells to therapy by several folds. Therefore, further validation of potentially important miRNAs involved in HCC initiation and progression may provide valuable insights into the treatment of patients with HCC. miR-495 is abnormally expressed in multiple types of human cancers. However, the expression level and roles of miR-495 in HCC have yet to be completely elucidated. In the present study, miR-495 expression was frequently downregulated in HCC tissues and cell lines, and miR-495 expression levels were significantly correlated with tumour size, tumor-node-metastasis (TNM) stage and lymph node metastasis in patients with HCC. Functional assays revealed that miR-495 overexpression inhibited cell proliferation and invasion in HCC. Insulin-like growth factor receptor-1 (IGF1R) was identified as a direct target gene of miR-495 in HCC. IGF1R was upregulated in HCC tissues and negatively correlated with miR-495 expression level. The upregulation of IGF1R rescued the miR-495-induced tumour-suppressive roles in HCC cell proliferation and invasion, and the restored miR-495 expression inactivated the protein kinase B and extracellular regulated protein kinase signalling pathways in HCC. These results provide novel insights into the molecular mechanism underlying HCC progression, and suggest that miR-495 may be investigated as a novel therapeutic target for patients with this disease.

MiRNA-target network analysis identifies potential biomarkers for Traditional Chinese Medicine (TCM) syndrome development evaluation in hepatitis B caused liver cirrhosis

Hepatitis B is one of most etiologies of Liver cirrhosis in China, and clinically lacks the effective strategy for Hepatitis B caused cirrhosis (HBC) therapy. As a complementary and alternative medicine, Chinese Traditional Medicine (TCM) has special therapeutic effects for HBC. Here, we focus on the evolution process of HBC TCM syndromes, which was from Excessive (Liver-Gallbladder Dampness-Heat Syndrome, LGDHS) to Deficient (Liver-Kidney Deficiency Syndrome, LKYDS) via Excessive-Deficient syndrome (Liver-Depression and Spleen-Deficiency Syndrome, LDSDS). Using R package, 16 miRNAs in LGDHS/Normal, 48 miRNAs in LDSDS/LGDHS, and 16 miRNAs in LKYDS/LDSDS were identified, respectively. The miRNA-target networks show that the LDSDS was most stability and complicated. Subsequently, 4 kernel miRNAs with LGDHS-LDSDS process, and 5 kernel miRNAs with LDSDS-LKYDS process were screened. Using RT-qPCR data, p1 (hsa-miR-17-3p, -377-3p, -410-3p and -495) and p2 miRNA panel (hsa-miR-377-3p, -410-3p, -27a-3p, 149-5p and 940) were identified by Logistic Regression Model, which clearly improve the accuracy of TCM syndrome classification. The rebuilt miRNA-target network shows that the LDSDS is a critical point and might determine the evolution directions of HBC TCM syndrome. This study suggests that the identified kernel miRNAs act as potential biomarkers and benefit to evaluate the evolution tendency of HBC TCM syndromes.

Targeting MicroRNAs in Cancer Gene Therapy

MicroRNAs (miRNAs) are a kind of conserved small non-coding RNAs that participate in regulating gene expression by targeting multiple molecules. Early studies have shown that the expression of miRNAs changes significantly in different tumor tissues and cancer cell lines. It is well acknowledged that such variation is involved in almost all biological processes, including cell proliferation, mobility, survival and differentiation. Increasing experimental data indicate that miRNA dysregulation is a biomarker of several pathological conditions including cancer, and that miRNA can exert a causal role, as oncogenes or tumor suppressor genes, in different steps of the tumorigenic process. Anticancer therapies based on miRNAs are currently being developed with a goal to improve outcomes of cancer treatment. In our present study, we review the function of miRNAs in tumorigenesis and development, and discuss the latest clinical applications and strategies of therapy targeting miRNAs in cancer.

BMI1: A Biomarker of Hematologic Malignancies

BMI1 oncogene is a catalytic member of epigenetic repressor polycomb group proteins. It plays a critical role in the regulation of gene expression pattern and consequently several cellular processes during development, including cell cycle progression, senescence, aging, apoptosis, angiogenesis, and importantly self-renewal of adult stem cells of several lineages. Preponderance of evidences indicates that deregulated expression of PcG protein BMI1 is associated with several human malignancies, cancer stem cell maintenance, and propagation. Importantly, overexpression of BMI1 correlates with therapy failure in cancer patients and tumor relapse. This review discusses the diverse mode of BMI1 regulation at transcriptional, posttranscriptional, and posttranslational levels as well as at various critical signaling pathways regulated by BMI1 activity. Furthermore, this review highlights the role of BMI1 as a biomarker and therapeutic target for several subtypes of hematologic malignancies and the importance to target this biomarker for therapeutic applications.

MicroRNA-495 regulates starvation-induced autophagy by targeting ATG3

The functions of some essential autophagy genes are regulated by microRNAs. However, an ATG3-modulating microRNA has never been reported. Here we show that the transcription of miR-495 negatively correlates with the translation of ATG3 under nutrient-deprived or rapamycin-treated conditions. miR-495 targets ATG3 and regulates its protein levels under starvation conditions. miR-495 also inhibits starvation-induced autophagy by decreasing the number of autophagosomes and by preventing LC3-I-to-LC3-II transition and P62 degradation. These processes are reversed by the overexpression of an endogenous miR-495 inhibitor. Re-expression of Atg3 without miR-495 response elements restores miR-495-inhibited autophagy. miR-495 sustains cell viability under starvation conditions but has no effect under hypoxia. Moreover, miR-495 inhibits etoposide-induced cell death. In conclusion, miR-495 is involved in starvation-induced autophagy by regulating Atg3.