The Regulatory Role of MicroRNAs in EMT and Cancer. J Oncol. 2015;2015:865816. [PMID: 25883654 PMCID: PMC4389820 DOI: 10.1155/2015/865816]

Downregulation of miR-130a promotes cell growth and epithelial to mesenchymal transition by activating HMGB2 in glioma

Aberrant expression of miR-130a is usually found in cancer studies; however, the role of miR-130a has seldom been reported in glioma. We explored miR-130a's function and the underlying mechanism in glioma. It was found that miR-130a expression was significantly down-regulated in glioma tissues and cell lines. Overexpression of miR-130a decreased glioma cell growth and invasion both in vitro and in vivo. We identified the oncogene HMGB2 as a downstream target of miR-130a by using luciferase and western blot assays. Knockdown of HMGB2 mimicked the effect of miR-130a in glioma cells. Taken together, our study demonstrate that miR-130a may function as a tumor suppressor in glioma and suggest that miR-130a is a potential therapeutic target for glioma patients.

Polyphenolic Nutrients in Cancer Chemoprevention and Metastasis: Role of the Epithelial-to-Mesenchymal (EMT) Pathway

The epithelial-to-mesenchymal transition (EMT) has received significant interest as a novel target in cancer prevention, metastasis, and resistance. The conversion of cells from an epithelial, adhesive state to a mesenchymal, motile state is one of the key events in the development of cancer metastasis. Polyphenols have been reported to be efficacious in the prevention of cancer and reversing cancer progression. Recently, the antimetastatic efficacy of polyphenols has been reported, thereby expanding the potential use of these compounds beyond chemoprevention. Polyphenols may affect EMT pathways, which are involved in cancer metastasis; for example, polyphenols increase the levels of epithelial markers, but downregulate the mesenchymal markers. Polyphenols also alter the level of expression and functionality of important proteins in other signaling pathways that control cellular mesenchymal characteristics. However, the specific proteins that are directly affected by polyphenols in these signaling pathways remain to be elucidated. The aim of this review is to analyze current evidence regarding the role of polyphenols in attenuating EMT-mediated cancer progression and metastasis. We also discuss the role of the most important polyphenol subclasses and members of the polyphenols in reversing metastasis and targeting EMT. Finally, limitations and future directions to improve our understanding in this field are discussed.

Epithelial-to-Mesenchymal Transition and MicroRNAs in Lung Cancer

Despite major advances, non-small cell lung cancer (NSCLC) remains the major cause of cancer-related death in developed countries. Metastasis and drug resistance are the main factors contributing to relapse and death. Epithelial-to-mesenchymal transition (EMT) is a complex molecular and cellular process involved in tissue remodelling that was extensively studied as an actor of tumour progression, metastasis and drug resistance in many cancer types and in lung cancers. Here we described with an emphasis on NSCLC how the changes in signalling pathways, transcription factors expression or microRNAs that occur in cancer promote EMT. Understanding the biology of EMT will help to define reversing process and treatment strategies. We will see that this complex mechanism is related to inflammation, cell mobility and stem cell features and that it is a dynamic process. The existence of intermediate phenotypes and tumour heterogeneity may be debated in the literature concerning EMT markers, EMT signatures and clinical consequences in NSCLC. However, given the role of EMT in metastasis and in drug resistance the development of EMT inhibitors is an interesting approach to counteract tumour progression and drug resistance. This review describes EMT involvement in cancer with an emphasis on NSCLC and microRNA regulation.

MicroRNAs as Therapeutic Targets and Colorectal Cancer Therapeutics

The diagnosis and treatment of colorectal cancer (CRC) have improved greatly over recent years; however, CRC is still one of the most common cancers and a major cause of cancer death worldwide. Several recently developed drugs and treatment strategies are currently in clinical trials; however, there is still a compelling need for novel, highly efficacious therapies. MicroRNAs (miRNAs) are short non-coding RNAs consisting of 20-25 nucleotides that regulate post-transcriptional gene expression by binding to the 3'-untranslated region of mRNAs. miRNAs are known to regulate cancer pathways and to be expressed aberrantly in cancer. Since their initial discovery, a large number of miRNAs have been identified as oncogenes, whereas others function as tumor suppressors. Furthermore, signaling pathways that are important in CRC (e.g. the WNT, MAPK, TGF-β, TP53 and PI3K pathways) are regulated by miRNAs. A single miRNA can simultaneously regulate several target genes and pathways, indicating the therapeutic potential of miRNAs in CRC. However, significant obstacles remain to be overcome, such as an efficient miRNA delivery system, and the assessment of safety and side effects. Thus, miRNA therapy is still developing and possesses great potential for the treatment of CRC. In this chapter, we focus on miRNAs related to CRC and summarize previous studies that emphasize the therapeutic aspects of miRNAs in CRC.

EMT: Present and future in clinical oncology

Epithelial/mesenchymal transition (EMT) has emerged as a key regulator of metastasis by facilitating tumor cell invasion and dissemination to distant organs. Recent evidences support that the reverse mesenchymal/epithelial transition (MET) is required for metastatic outgrowth; moreover, the existence of hybrid epithelial/mesenchymal (E/M) phenotypes is increasingly being reported in different tumor contexts. The accumulated data strongly support that plasticity between epithelial and mesenchymal states underlies the dissemination and metastatic potential of carcinoma cells. However, the translation into the clinics of EMT and epithelial plasticity processes presents enormous challenges and still remains a controversial issue. In this review, we will evaluate current evidences for translational applicability of EMT and depict an overview of the most recent EMT in vivo models, EMT marker analyses in human samples as well as potential EMT therapeutic approaches and ongoing clinical trials. We foresee that standardized analyses of EMT markers in solid and liquid tumor biopsies in addition to innovative tools targeting the E/M states will become promising strategies for future translation to the clinical setting.

Clear Cell Renal Cell Carcinoma is linked to Epithelial-to-Mesenchymal Transition and to Fibrosis

Clear cell renal cell carcinoma (ccRCC) represents the most common type of kidney cancer with high mortality in its advanced stages. Our study aim was to explore the correlation between tumor epithelial-to-mesenchymal transition (EMT) and patient survival. Renal biopsies of tumorous and adjacent nontumorous tissue were taken with a 16 g needle from our patients (n = 26) undergoing partial or radical nephrectomy due to ccRCC RNA sequencing libraries were generated using Illumina TruSeq® Access library preparation protocol and TruSeq Small RNA library preparation kit. Next generation sequencing (NGS) was performed on Illumina HiSeq2500. Comparative analysis of matched sample pairs was done using the Bioconductor Limma/voom R-package. Liquid chromatography-tandem mass spectrometry and immunohistochemistry were applied to measure and visualize protein abundance. We detected an increased generic EMT transcript score in ccRCC Gene expression analysis showed augmented abundance of AXL and MMP14, as well as down-regulated expression of KL (klotho). Moreover, microRNA analyses demonstrated a positive expression correlation of miR-34a and its targets MMP14 and AXL Survival analysis based on a subset of genes from our list EMT-related genes in a publicly available dataset showed that the EMT genes correlated with ccRCC patient survival. Several of these genes also play a known role in fibrosis. Accordingly, recently published classifiers of solid organ fibrosis correctly identified EMT-affected tumor samples and were correlated with patient survival. EMT in ccRCC linked to fibrosis is associated with worse survival and may represent a target for novel therapeutic interventions.

Epithelial-Mesenchymal Transition in Docetaxel-Resistant Prostate Cancer

Castration-resistant prostate cancer (CRPCa) is an advanced stage of prostate cancer in which a tumour progresses even under androgen deprivation. Treatment alternatives for CRPCa remain very limited and mostly rely on docetaxel-based chemotherapy. Despite being shown to increase patients’ overall survival, docetaxel’s clinical efficacy is impaired by development of chemoresistance. Most patients do not respond to docetaxel treatment and even those initially responsive ultimately develop resistance. Recently, chemoresistance was found to be closely related to epithelial-mesenchymal transition (EMT), a process in which epithelial cells transition into a mesenchymal phenotype. In fact, EMT markers are overexpressed in prostate cancer and are correlated to a higher Gleason score. For this reason, new therapeutic strategies are being studied to inhibit this process in several cancers. However, the clinical usefulness of targeting EMT as a way to overcome docetaxel resistance in CRPCa is still questionable and suffers from some significant limitations. This review briefly summarises the most common mechanisms of EMT-induced chemoresistance and evaluates its use as a new approach to overcome docetaxel resistance in CRPCa.

Members of the microRNA-200 family are promising therapeutic targets in cancer

MicroRNAs (miRs) are non-coding, single-stranded RNA molecules that regulate gene expression at the posttranscriptional level. Abnormal expression of miR may result in pathophysiological processes occurring that stimulate the development of various diseases. miRs are commonly dysregulated in cancer and may act as either oncogenes or tumor suppressors. Studies have indicated that members of the miR-200 family are involved in different aspects of cancer biology, including the epithelial-to-mesenchymal transition, tumor angiogenesis and chemoresistance by targeting and repressing the expression of several key messenger RNAs. The present review aims to summarize the role of the miR-200 family and its potential mechanism of action in tumor progression, which may advance the development of novel therapeutic drugs against tumor metastasis in clinical cancer treatment.

ZEB1 Mediates Drug Resistance and EMT in p300-Deficient CRC

We discuss the hypothesis that ZEB1-Wnt-p300 signaling integrates epithelial to mesenchymal transition (EMT) and resistance to histone deacetylase inhibitors (HDACis) in colorectal cancer (CRC) cells. The HDACi butyrate, derived from dietary fiber, has been linked to CRC prevention, and other HDACis have been proposed as therapeutic agents against CRC. We have previously discussed that resistance to butyrate likely contributes to colonic carcinogenesis, and we have demonstrated that butyrate resistance leads to cross-resistance to cancer therapeutic HDACis. Deregulated Wnt signaling is the major initiating event in most CRC cases. One mechanism whereby butyrate and other HDACis exert their anti-CRC effects is via Wnt signaling hyperactivation, which promotes CRC cell apoptosis. The histone acetylases (HATs) CBP and p300 are mediators of Wnt transcriptional activity, and play divergent roles in the downstream consequences of Wnt signaling. CBP-mediated Wnt signaling is associated with cell proliferation and stem cell maintenance; whereas, p300-mediated Wnt activity is associated with differentiation. We have found that CBP and p300 differentially affect the ability of butyrate to influence Wnt signaling, apoptosis, and proliferation. ZEB1 is a Wnt signaling-targeted gene, whose product is a transcription factor expressed at the invasive front of carcinomas where it promotes malignant progression and EMT. ZEB1 is typically a transcriptional repressor; however, when associated with p300, ZEB1 enhances transcription. These changes in ZEB1 activity likely affect the cancer cell phenotype. ZEB1 has been shown to promote resistance to chemotherapeutic agents, and expression of ZEB1 is upregulated in butyrate-resistant CRC cells that lack p300 expression. Since the expression of ZEB1 correlates with poor outcomes in cancer, ZEB represents a relevant therapeutic target. Here we propose that targeting the signaling network established by ZEB1, Wnt signaling, and p300 signaling can reverse HDACi resistance and inhibit EMT.

Specific Gene- and MicroRNA-Expression Pattern Contributes to the Epithelial to Mesenchymal Transition in a Rat Model of Experimental Colitis

The aim of this study was to determine the gene- and microRNA-expression profile contributing to epithelial to mesenchymal transition in a rat model of experimental colitis. For this, inflammation was induced by injecting 2,4,6-trinitrobenzene sulphonic acid to the colon of male Wistar rats. Samples were taken from both inflamed and uninflamed regions of the same colon, total RNA was isolated, and the mRNA and microRNA expressions were monitored. We have determined that the expression of genes responsible for inducing mesenchymal phenotype, such as Egr1, Fgf2, Fgf7, Jak2, Notch2, Hif1α, Zeb2, Mmp9, Lox, and Vim, was all significantly induced in the inflamed regions of the affected colons while the epithelial marker E-cadherin (Cdh1) was downregulated. In contrast, the expression of microRNAs miR-192, miR-143, miR-375, miR-30a, miR-107, and miR-200b responsible for the regulation of the above mentioned genes was significantly downregulated in inflamed colon. Importantly, we detected moderate induction in the expression of five out of six tested microRNAs in the uninflamed regions. In summary, we identified numerous interacting genes and microRNAs with mutually exclusive expression pattern in inflamed regions of colitis-induced rats. These findings suggest that—among others—an important step in the epithelial to mesenchymal transition in experimental colitis is the dysregulated microRNA expression.

microRNA-664 enhances proliferation, migration and invasion of lung cancer cells

Altered microRNA (miR) expression serves an important role in the development and progression of lung cancer. In the present study, the effect of miR-664 on proliferation, migration and invasion of lung cancer cells was assessed. The proliferation of lung cancer cells with an overexpression of miR-664 was examined via MTT assay. The Caspase-Glo3/7 assay was used to examine the effect of miR-664 on cisplatin-induced apoptosis in lung cancer cells. The migration and invasion of lung cancer cells were assessed by Transwell migration and matrigel invasion assays. Western blot analysis was used to examine the protein expression levels. miR-664 improved the proliferation of lung cancer cells and inhibited cisplatin-induced apoptosis of A549 and A427 cells. Furthermore, altered expression of miR-664 affected migration and invasion of lung cancer cells. In addition, a miR-664 mimic decreased E-cadherin expression and increased vementin and Snail expression in lung cancer cells. Notably, the expression level of protein kinase B in A549 cells was changed following altered expression of miR-664. The results of the present study suggest that miR-664 serves an essential role in tumor development and progression in lung cancer.

Long non-coding RNA HOTAIR functions as miRNA sponge to promote the epithelial to mesenchymal transition in esophageal cancer

BACKGROUND

Accumulating evidence indicates dysregulated expression of the long non-coding RNA HOTAIR (lncRNA-HOTAIR) may play a significant role in tumor progression. LncRNA-HOTAIR promotes several processes in esophageal cancer (EC), including cell growth, differentiation, invasion and migration. However, the mechanisms by which lncRNA-HOTAIR promotes invasion and migration EC remain unclear.

METHODS

LncRNA-HOTAIR and miR-148a expression were quantified in 40 paired human EC and tumor-adjacent tissues and EC cell lines by quantitative real-time PCR (qRT-PCR). The CCK8 assay was used to quantify cell proliferation. Transwell invasion and migration assays were performed to assess cell invasion and migration. Western blot analysis was used to quantify E-cadherin, N-cadherin, Vimentin, and Snail2 expression. StarBase V2.0 was used to identify putative miRNA binding sites in lncRNA-HOTAIR; luciferase reporter assays were performed to validate the function of the predicted binding sites.

RESULT

High lncRNA-HOTAIR expression was associated with significantly poorer overall survival in EC. In vitro analysis showed lncRNA-HOTAIR enhanced EC cell proliferation, invasion and migration, and promoted the EMT. Mechanistic investigations revealed lncRNA-HOTAIR promotes the EMT by acting as a miR-148a sponge to positively regulate Snail2 expression.

CONCLUSIONS

LncRNA-HOTAIR acts as a miR-148a sponge to positively regulate Snail2 expression, enhance cell invasion and metastasis, and promote the EMT in EC. LncRNA-HOTAIR may play an important role in tumor development and progression and represent a novel therapeutic target for EC.

Dicer1 dysfunction promotes stemness and aggression in endometrial carcinoma

Endometrial carcinoma is one of the most common gynecological malignancies, but the molecular events involved in the development and progression of endometrial carcinoma remain unclear. Dicer1 and cancer stem cells play important roles in cell motility and survival. This study investigated the role of the let-7 family and Dicer1 in the stemness of endometrial carcinoma cells. We profiled Dicer1 expression in clinical samples and explored its relationship with stem cell-associated markers and clinical parameters. We showed that Dicer1 dysfunction leads to the enrichment of tumor stemness features and tumor aggression both in vitro and in vivo. We also identified the mechanism related to this potential tumor-predisposing phenotype: loss of Dicer1 induced abnormal expression of the let-7 family, which comprises well-known tumor suppressors, thus regulating stemness in endometrial carcinoma cells.

Re-expression of miR-200c suppresses proliferation, colony formation and in vivo tumor growth of murine claudin-low mammary tumor cells

Claudin-low breast cancer is a relatively rare breast cancer subtype. These cancers are typically ER-/PR-/HER2- and express high levels of mesenchymal genes as well as genes associated with inflammation, angiogenesis and stem cell function. In addition to alterations in gene expression, it was recently demonstrated that claudin-low breast cancers express very low levels of the miR-200 family of miRNAs. Given that each miRNA can regulate tens, hundreds or even thousands of genes, miRNAs are being evaluated as therapeutic targets. In this study we show that mammary tumors from MTB-IGFIR transgenic mice and cell lines derived from these tumors represent a model of human claudin-low breast cancer and murine claudin-low mammary tumors and cell lines express only very low levels of all five members of the miR-200 family. Reduced miR-200 family expression appears to be regulated via methylation as cells and tumors expressing low levels of miR-200 family members had higher levels of CpG methylation in a putative promoter region than tumors and cells expressing high levels of miR-200 family members. Re-expression of miR-200c in murine claudin-low mammary tumor cells inhibited tumor cell proliferation and colony formation in vitro and tumor growth in vivo. With respect to tumor growth in vivo, re-expression of miR-200c was associated with a reduction in tumor vasculature and expression of Flt1 and Vegfc. Therefore, miR-200c is an important regulator of mesenchymal tumor cell growth.

MicroRNA-590-3p promotes cell proliferation and invasion by targeting inositol polyphosphate 4-phosphatase type II in human prostate cancer cells

Inositol polyphosphate 4-phosphatase type II emerges as a tumor suppressor in prostate cancer, and its loss of expression is associated with poor prognosis for prostate cancer. However, the mechanism of downregulation of inositol polyphosphate 4-phosphatase type II in prostate cancer development has not yet been fully clarified. In this study, microRNA-590-3p was found to be upregulated in both prostate cancer tissues and cell lines. Overexpression of microRNA-590-3p by microRNA-590-3p mimics promoted prostate cancer cell proliferation and invasion and accelerated the growth of xenografted tumors, while microRNA-590-3p inhibitors contributed to inhibition of cellular proliferation and invasion as well as tumor growth. A dual-luciferase reporter assay and expression analysis further confirmed that inositol polyphosphate 4-phosphatase type II was a direct target of microRNA-590-3p. Enforced expression of microRNA-590-3p led to repression of inositol polyphosphate 4-phosphatase type II messenger RNA and protein expression, as well as upregulation of p-Akt, p-FoxO3a, and cyclin D1 and downregulation of p21 expression in prostate cancer cell lines. Overexpression of inositol polyphosphate 4-phosphatase type II could reduce microRNA-590-3p-induced cell proliferation and invasion as well as tumor growth, and decrease microRNA-590-3p-mediated upregulation of cyclin D1 and downregulation of p21 expression in prostate cancer cells. Taken together, our findings reveal that microRNA-590-3p is a potential onco-microRNA that participates in carcinogenesis of human prostate cancer by suppressing inositol polyphosphate 4-phosphatase type II expression and involving the Akt/FoxO3a pathway. MicroRNA-590-3p may represent a potential therapeutic target for prostate cancer patients.

Overexpressions of miR-212 are associated with poor prognosis of patients with pancreatic ductal adenocarcinoma

BACKGROUND

The miR-212 was among the top differentially expressed miRNAs in pancreatic ductal adenocarcinoma (PDAC).

OBJECTIVE

The aim of this study was to investigate the expression of miR-212 in PDAC and evaluate its correlation with major clinicopathologic features and patients' survival.

METHODS

Fluorescence in situ hybridization (FISH) was adopted to examine miRNA expression in 45 pancreatic cancer and 20 normal pancreatic tissues. The relationship of miR-212 expression with clinicopathologic parameters and clinical outcome was evaluated.

RESULTS

miR-212 was confirmed to have significantly higher expression in PDAC compared with normal pancreatic tissues (51.1% vs 10%, p< 0.01). High expression of miR-212 was significantly associated with tumor size (p = 0.048) and tumor stage (p = 0.023). Moreover, in univariant analysis, patients with high expression of miR-212 demonstrate significantly poorer overall survival (p= 0.02).

CONCLUSIONS

High expression of miR-212 in PDAC is associated with shorter overall survival. It may be not only a potential prognostic marker, but also a possible therapeutic target in PDAC.

MiR-139-5p as a novel serum biomarker for recurrence and metastasis in colorectal cancer

Approximately 30-50% of colorectal cancer (CRC) patients who undergo curative resection subsequently experience tumor recurrence or metastasis. Although microRNAs (miRNAs) are a class of small noncoding RNAs frequently deregulated in various human malignancies, it remains unknown if these can help predict recurrence and metastasis in CRC patients. MiRNAs were initially screened using miRNA-microarray and miRNA-seq datasets with or without recurrence. Candidate miRNAs were then tested in two independent cohorts of 111 stage II/III and 139 stage I-III CRC patients, as well as serum samples and matched primary and metastatic liver tissues. An animal model of peritoneal dissemination was used to assess the oncogenic role of the target miRNA. Four candidate miRNAs were identified during the initial screening, and we subsequently validated upregulation of miR-139-5p in two independent clinical cohorts, wherein it associated with poor recurrence-free survival. Moreover, miR-139-5p were also upregulated in the serum of recurrence-positive CRC patients and yielded significantly shorter recurrence-free survival. Intriguingly, miR-139-5p was upregulated in metastatic liver tissues and negatively correlated with genes associated with epithelial-mesenchymal transition. Lastly, we showed that miR-139-5p overexpression enhanced peritoneal dissemination in a mouse model. In conclusion, we identified miR-139-5p as a novel biomarker for tumor recurrence and metastasis in CRC.

The Epithelial-to-Mesenchymal Transition-Like Process in Glioblastoma: An Updated Systematic Review and In Silico Investigation

Glioblastoma multiforme (GBM) is the most aggressive form of brain cancer due to its highly invasive nature that impedes the surgical removal of all tumor cells, making relapse inevitable. However, the mechanisms used by glioma cells to invade the surrounding tissue are still unclear. In this context, epithelial-to-mesenchymal transition (EMT) has emerged as a key regulator of this invasive state and although the real relevance of this program in malignant glioma is still controversial, it has been strongly associated with GBM malignancy. EMT is a very complex process regulated by several families of transcriptional factors through many signaling pathways that form a network that allows cancer cells to acquire invasive properties and penetrate the neighboring stroma, resulting in the formation of an advantageous microenvironment for cancer progression and metastasis. In this systematic review, we focus on the molecular mechanisms of EMT including EMT-factors, drug resistance, miRNA, and new therapeutic strategies. In addition, we address controversial questions about mesenchymal shift in GBMs with a bioinformatics analysis to show that in terms of epithelial and mesenchymal phenotype, the majority of GBMs samples analyzed have a profile more mesenchymal than epithelial. If induced, this phenotype can be shifted toward an even more mesenchymal phenotype in an EMT-like process in glioma cells. A better understanding of the molecular regulation of the EMT during tumor spreading will help to provide potential therapeutic interventions to target this program when treating GBM.

Role of miRNAs in human cancer metastasis: Implications for therapeutic intervention

Metastasis is the spread and growth of localized cancer to new locations in the body and is considered the main cause of cancer-related deaths. Metastatic cancer cells display distinct genomic and epigenomic profiles and almost universally an aggressive pathophysiology. A better understanding of the molecular mechanisms and regulation of metastasis, including how metastatic tumors grow and survive in the nascent niche and the interactions of the emergent metastatic cancer cells within the local microenvironment may provide tools to design strategies to restrict metastatic dissemination. Aberrant microRNAs (miRNA) expression has been reported in metastatic cancer cells. MicroRNAs are known to regulate divergent and/or convergent metastatic gene pathways including activation of reprogramming switches during metastasis. An in-depth understanding of role of miRNAs in the metastatic cascade may lead to the identification of novel targets for anti-metastatic therapeutics as well as potential candidate miRNAs for cancer treatment. This review primarily focuses on the role of miRNAs in the mechanisms of cancer metastasis as well as implications for metastatic cancer treatment.

MicroRNA-196a as a Potential Diagnostic Biomarker for Esophageal Squamous Cell Carcinoma

We observed significant up-regulation of miR-196a in esophageal squamous cell carcinoma (ESCC) as compared with their adjacent normal tissue (p = .002). Receiver operating characteristics curve analysis confirmed the suitability of miR-196a as a potential tumor marker for diagnosis of ESCC. Furthermore, analysis of miR-196a levels in saliva samples determined an average of 27-fold up-regulations in ESCC patients compared with healthy group. Our results suggest that salivary miR-196a may be a suitable noninvasive biomarker for diagnosis of ESCC. In addition, molecular pathway enrichment analysis of microRNA (miR)-196a determined focal adhesion, spliceosome and p53 signaling pathways as the most relevant pathways with miR-196a targetome.

Tumor Microenvironment Modulation via Gold Nanoparticles Targeting Malicious Exosomes: Implications for Cancer Diagnostics and Therapy

Exosomes are nanovesicles formed in the endosomal pathway with an important role in paracrine and autocrine cell communication. Exosomes secreted by cancer cells, malicious exosomes, have important roles in tumor microenvironment maturation and cancer progression. The knowledge of the role of exosomes in tumorigenesis prompted a new era in cancer diagnostics and therapy, taking advantage of the use of circulating exosomes as tumor biomarkers due to their stability in body fluids and targeting malignant exosomes’ release and/or uptake to inhibit or delay tumor development. In recent years, nanotechnology has paved the way for the development of a plethora of new diagnostic and therapeutic platforms, fostering theranostics. The unique physical and chemical properties of gold nanoparticles (AuNPs) make them suitable vehicles to pursuit this goal. AuNPs’ properties such as ease of synthesis with the desired shape and size, high surface:volume ratio, and the possibility of engineering their surface as desired, potentiate AuNPs’ role in nanotheranostics, allowing the use of the same formulation for exosome detection and restraining the effect of malicious exosomes in cancer progression.

ΔNp63α and microRNAs: leveraging the epithelial-mesenchymal transition

The epithelial-mesenchymal transition (EMT) is a cellular reprogramming mechanism that is an underlying cause of cancer metastasis. Recent investigations have uncovered an intricate network of regulation involving the TGFβ, Wnt, and Notch signaling pathways and small regulatory RNA species called microRNAs (miRNAs). The activity of a transcription factor vital to the maintenance of epithelial stemness, ΔNp63α, has been shown to modulate the activity of these EMT pathways to either repress or promote EMT. Furthermore, ΔNp63α is a known regulator of miRNA, including those directly involved in EMT. This review discusses the evidence of ΔNp63α as a master regulator of EMT components and miRNA, highlighting the need for a deeper understanding of its role in EMT. This expanded knowledge may provide a basis for new developments in the diagnosis and treatment of metastatic cancer.

MicroRNAs in Oncogenesis and Tumor Suppression

MicroRNAs (MiRNAs) have emerged in the last 15 years as central players in the biology of cancer. Increasing lines of evidence have supported their regulatory role in the expression of both oncogenes and tumor-suppressor genes, progressively clarifying which genes are modulated by specific MiRNAs dysregulated in cancer. Intriguingly, a "target-specific" understanding of MiRNA function in oncology has been replaced by a more "pathway-specific" vision of their involvement in cancer biology. This work provides a state-of-the-art knowledge of the role of MiRNAs in the most frequently altered signaling pathways in cancer cells and provides an updated overview on some of the most relevant findings trying to decode the complex molecular mechanisms of cancer.

Upregulation of MiR-205 under hypoxia promotes epithelial-mesenchymal transition by targeting ASPP2

The epithelial–mesenchymal transition (EMT) is one of the crucial procedures for cancer invasion and distal metastasis. Despite undergoing intensive studies, the mechanisms underlying EMT remain to be completely elucidated. Here, we identified that apoptosis-stimulating protein of p53-2 (ASPP2) is a novel target of MiR-205 in various cancers. Interestingly, the binding site of MiR-205 at the 3′-untranslated region of ASPP2 was highly conserved among different species. An inverse correlation between MiR-205 and ASPP2 was further observed in vivo in cervical cancers, suggesting MiR-205 may be an important physiological inhibitor of ASPP2. Hypoxia is a hallmark of solid tumor microenvironment and one of such conditions to induce EMT. Notably, MiR-205 was remarkably induced by hypoxia in cervical and lung cancer cells. A marked suppression of ASPP2 was observed simultaneously. Further studies confirmed that hypoxia-induced ASPP2 suppression was mainly attributed to the elevated MiR-205. Interestingly, the alteration of MiR-205/ASPP2 under hypoxia was accompanied with the decreased epithelial marker E-cadherin and increased mesenchymal marker Vimentin, as well as a morphological transition from the typical cobblestone-like appearance to the mesenchymal-like structure. More importantly, MiR-205 mimics or ASPP2 silencing similarly promoted EMT process. By contrast, ASPP2 recovery or MiR-205 inhibitor reversed MiR-205-dependent EMT. Further studies demonstrated that the newly revealed MiR-205/ASPP2 axis promoted cell migration and also increased cell proliferation both in vivo and in vitro. These data together implicated a critical impact of MiR-205/ASPP2 on promoting EMT. MiR-205/ASPP2 may be potential diagnostic and therapeutic biomarkers in cervical and lung cancers.

Roles and epigenetic regulation of epithelial-mesenchymal transition and its transcription factors in cancer initiation and progression

The epithelial-mesenchymal transition (EMT) is a crucial developmental process by which epithelial cells undergo a mesenchymal phenotypic change. During EMT, epigenetic mechanisms including DNA methylation and histone modifications are involved in the regulation of EMT-related genes. The epigenetic gene silencing of the epithelial marker E-cadherin has been well characterized. In particular, three major transcriptional repressors of E-cadherin, Snail, ZEB, and Twist families, also known as EMT-inducing transcription factors (EMT-TFs), play a crucial role in this process by cooperating with multiple epigenetic modifiers. Furthermore, recent studies have identified the novel epigenetic modifiers that control the expression of EMT-TFs, and these modifiers have emerged as critical regulators of cancer development and as novel therapeutic targets for human cancer. In this review, the diverse functions of EMT-TFs in cancer progression, the cooperative mechanisms of EMT-TFs with epigenetic modifiers, and epigenetic regulatory roles for the expression of EMT-TFs will be discussed.

MicroRNA-132/212 Upregulation Inhibits TGF-β-Mediated Epithelial-Mesenchymal Transition of Prostate Cancer Cells by Targeting SOX4

BACKGROUND

MicroRNAs (miRNAs) are noncoding RNAs that are important for embryonic stem cell development and epithelial to mesenchymal transition (EMT). Accumulating evidence indicates that miRNAs play critical roles in prostate cancer (PCa) metastasis and have potential use as therapeutic targets. Although dysregulated miR-132/212 have been suggested to be directly involved in the proliferation and invasion of multiple malignancies, the exact role of miR-132/212 in PCa has not yet been fully understood.

METHODS

Real-time quantitative PCR (RT-qPCR) and bioinformatics analysis were used to validate the expression levels of miR-132/212 in PCa cell lines as well as in prostatic tissues. The biological function of miR-132/212 was evaluated by MTS, transwell, and wound healing assays, respectively. RT-qPCR and Western blot were used to study the transcript and protein expression levels. Bioinformatics tools and luciferase reporter assay were utilized to identify the molecular target of miR-132/212. Immunohistochemistry (IHC) was used to detect the expression of SOX4.

RESULTS

miR-132 and miR-212 from the same gene cluster are downregulated in human PCa tissues when compared with benign prostatic hyperplasia tissues (both P < 0.05). Functionally, upregulation of miR-132/212 inhibits the migration and invasive capacity of Vcap and Lncap cells by wound-healing and transwell assays, respectively. Notably, overexpression of miR-132/212 could inhibit TGF-β (transforming growth factor-β)-induced EMT in Vcap and Lncap cells at both the mRNA and protein expression levels. SOX4 gene, an important EMT regulator of PCa, was identified as the target of miR-132/212 by bioinformatics tools and luciferase reporter assay. Clinically, miR-132/212 expression levels were adversely correlated with Gleason score (P < 0.001) and SOX4 expression by IHC and RT-qPCR in PCa tissues.

CONCLUSION

Our data suggested that miR-132/212 may act as tumor suppressors in PCa progression through disrupting EMT process by directly targeting SOX4. Prostate 76:1560-1570, 2016. © 2016 Wiley Periodicals, Inc.

Cathepsin L upregulation-induced EMT phenotype is associated with the acquisition of cisplatin or paclitaxel resistance in A549 cells

AIM

Cathepsin L (CTSL), a lysosomal acid cysteine protease, is known to play important roles in tumor metastasis and chemotherapy resistance. In this study we investigated the molecular mechanisms underlying the regulation of chemoresistance by CTSL in human lung cancer cells.

METHODS

Human lung cancer A549 cells, A549/PTX (paclitaxel-resistant) cells and A549/DDP (cisplatin-resistant) cells were tested. The resistance to cisplatin or paclitaxel was detected using MTT and the colony-formation assays. Actin remodeling was observed with FITC-Phalloidin fluorescent staining or immunofluorescence. A wound-healing assay or Transwell assay was used to assess the migration or invasion ability. The expression of CTSL and epithelial and mesenchymal markers was analyzed with Western blotting and immunofluorescence. The expression of EMT-associated transcription factors was measured with Western blotting or q-PCR. BALB/c nude mice were implanted subcutaneously with A549 cells overexpressing CTSL, and the mice were administered paclitaxel (10, 15 mg/kg, ip) every 3 d for 5 times.

RESULTS

Cisplatin or paclitaxel treatment (10-80 ng/mL) induced CTSL expression in A549 cells. CTSL levels were much higher in A549/PTX and A549/DDP cells than in A549 cells. Silencing of CTSL reversed the chemoresistance in A549/DDP and A549/TAX cells, whereas overexpression of CTSL attenuated the sensitivity of A549 cells to cisplatin or paclitaxel. Furthermore, A549/DDP and A549/TAX cells underwent morphological and cytoskeletal changes with increased cell invasion and migration abilities, accompanied by decreased expression of epithelial markers (E-cadherin and cytokeratin-18) and increased expression of mesenchymal markers (N-cadherin and vimentin), as well as upregulation of EMT-associated transcription factors Snail, Slug, ZEB1 and ZEB2. Silencing of CTSL reversed EMT in A549/DDP and A549/TAX cells; In contrast, overexpression of CTSL induced EMT in A549 cells. In xenograft nude mouse model, the mice implanted with A549 cells overexpressing CTSL exhibited significantly reduced sensitivity to paclitaxel treatment, and increased expression of EMT-associated proteins and transcription factors in tumor tissues.

CONCLUSION

Cisplatin and paclitaxel resistance is associated with CTSL upregulation-induced EMT in A549 cells. Thus, CTSL-mediated EMT may be exploited as a target to enhance the efficacy of cisplatin or paclitaxel against lung cancer and other types of malignancies.

Pathologically decreased expression of miR-193a contributes to metastasis by targeting WT1-E-cadherin axis in non-small cell lung cancers

Background

The metastatic cascade is a complex and multistep process with many potential barriers. Recently, miR-193a has been reported to be a suppressive miRNA in multiple types of cancers, but its underlying anti-oncogenic activity in non-small cell lung cancers (NSCLC) is not fully elucidated.

Methods

The expressions of miR-193a (miR-193a-5p) in human lung cancer tissues and cell lines were detected by real-time PCR. Dual-luciferase reporter assay was used to identify the direct target of miR-193a. Cell proliferation, apoptosis, and metastasis were assessed by CCK-8, flow cytometry, and Transwell assay, respectively.

Results

The expression of miR-193a in lung cancer tissues was decreased comparing to adjacent non-tumor tissues due to DNA hypermethylation in lung cancer tissues. Ectopic expression of miR-193a inhibited cell proliferation, colony formation, migration, and invasion in A549 and H1299 cells. Moreover, overexpression of miR-193a partially reversed tumor growth factor-β1 (TGF-β1)-induced epithelial-to-mesenchymal transition (EMT) in NSCLC cells. Mechanistically, miR-193a reduced the expression of WT1, which negatively regulated the protein level of E-cadherin, suggesting that miR-193a might prevent EMT via modulating WT1-E-cadherin axis. Importantly, knockdown of WT1 resembled the anti-cancer activity by miR-193a and overexpression of WT1 partially reversed miR-193a-induced anti-cancer activity, indicating that WT1 plays an important role in miR-193a-induced anti-cancer activity. Finally, overexpression of miR-193a decreased the growth of tumor xenografts in mice.

Conclusion

Collectively, our results have revealed an important role of miR-193a-WT1-E-cadherin axis in metastasis, demonstrated an important molecular cue for EMT, and suggested a therapeutic strategy of restoring miR-193a expression in NSCLC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0450-8) contains supplementary material, which is available to authorized users.

Molecular Mechanism of MicroRNA-200c Regulating Transforming Growth Factor-β (TGF-β)/SMAD Family Member 3 (SMAD3) Pathway by Targeting Zinc Finger E-Box Binding Homeobox 1 (ZEB1) in Hypospadias in Rats

Background

The aim of this study was to explore effects of microRNA-200c regulating TGF-β/Smad3 pathway by targeting Zeb1 on the occurrence and development of hypospadias and to evaluate the relationship between microRNA-200c and occurrence of hypospadias.

Material/Methods

Pregnant rats with a gestational age of 12 days were allocated into 2 groups; one received gavage of DEHP-contained soybean oil (1 ml/day, 8 days; Group A) and the other had gavage of normal soybean oil (1 ml/day, 8 days; Group B). Baby rats with hypospadias from Group A were assigned to the model group (n=20) and healthy baby rats from Group B were assigned to the control group (n=20). Real-time quantitative polymerase chain reaction (qRT-PCR), immunohistochemistry and Western blot analysis were performed to detect microRNA-200c, Zeb1, TGF-β, and Smad3 mRNA and protein expressions in the model group (n=20) and the control group (n=20). The relationship between microRNA-200c and Zeb1 was detected using a dual-luciferase reporter gene experiment. After the in vitro intervention experiment in fetal rat penises, Western blot was used to detect the expression of Zeb1, TGF-β, and Smad3.

Results

In the model group, microRNA-200c was expressed at a low level, and microRNA-200c expression in control group was 2.1 times higher than in the model group (P<0.05). When compared with the control group, mRNA expressions, protein expressions, and positive rates of Zeb1, TGF-β, and Smad3 were higher in the model group (all P<0.01). Luciferase gene report determined that Zeb1 is a target gene of microRNA-200c. The in vitro intervention experiment in fetal rat penises found that a high concentration of microRNA-200c inhibited hypospadias occurrence by suppressing the expression of Zeb1, TGF-β, and Smad3.

Conclusions

MicroRNA-200c was expressed in hypospadias penis tissues at low levels and was negatively correlated with Zeb1 expression. MicroRNA-200c up-regulated Zeb1 expression to regulate the TGF-β/Smad3 pathway, which led to the occurrence of hypospadias.

Role of epigenetics in lung cancer heterogeneity and clinical implication

Lung cancer, as a highly heterogeneous disease, can be initiated and progressed through the interaction between permanent genetic mutations and dynamic epigenetic alterations. However, the mediating mechanisms of epigenetics in cancer heterogeneity remain unclear. The evolution of cancer, the existence of cancer stem cells (CSCs) and the phenomenon of epithelial-mesenchymal transition (EMT) have been reported to be involved in lung cancer heterogeneity. In this review, we briefly recap the definition of heterogeneity and concept of epigenetics, highlight the potential roles and mechanisms of epigenetic regulation in heterogeneity of lung cancer, and summarize the diagnostic and therapeutic implications of epigenetic alterations in lung cancer, especially the role of DNA methylation and histone acetylation. Deep understanding of epigenetic regulation in cancer heterogeneity is instrumental to the design of novel therapeutic approaches that target lung cancer.

Diagnostic and prognostic value of plasma microRNA-195 in patients with non-small cell lung cancer

BACKGROUND

Recently, circulating microRNAs (miRNAs) have been reported to be stably detectable in plasma/serum and to function as potent biomarkers in various cancers. The aim of this study was to evaluate the expression level of plasma miRNA-195 in patients with non-small cell lung cancer (NSCLC) and investigate its diagnostic and prognostic value.

METHODS

Quantitative real-time PCR was performed to evaluate plasma miRNA-195 levels in 100 NSCLC patients and 100 healthy volunteers. The association between miRNA-195 expression and clinicopathological factors as well as the overall survival was analyzed. Receiver-operating characteristic (ROC) curve analysis was carried out to assess the potential value of plasma miRNA-195 for NSCLC diagnosis.

RESULTS

Plasma miRNA-195 was downregulated in NSCLC patients compared with healthy controls (P < 0.001). Decreased plasma miRNA-195 expression was significantly associated with lymph node metastasis and advanced clinical stage. ROC curve analysis showed that plasma miRNA-195 was a useful marker for NSCLC diagnosis. Multivariate Cox regression analysis confirmed low plasma miRNA-195 expression as an independent unfavorable prognostic factor for NSCLC patients.

CONCLUSIONS

These findings indicate that plasma miRNA-195 might serve as a promising biomarker for the early detection and prognosis evaluation of NSCLC.

Pancreatic cancer stem cell markers and exosomes - the incentive push

Pancreatic cancer (PaCa) has the highest death rate and incidence is increasing. Poor prognosis is due to late diagnosis and early metastatic spread, which is ascribed to a minor population of so called cancer stem cells (CSC) within the mass of the primary tumor. CSC are defined by biological features, which they share with adult stem cells like longevity, rare cell division, the capacity for self renewal, differentiation, drug resistance and the requirement for a niche. CSC can also be identified by sets of markers, which for pancreatic CSC (Pa-CSC) include CD44v6, c-Met, Tspan8, alpha6beta4, CXCR4, CD133, EpCAM and claudin7. The functional relevance of CSC markers is still disputed. We hypothesize that Pa-CSC markers play a decisive role in tumor progression. This is fostered by the location in glycolipid-enriched membrane domains, which function as signaling platform and support connectivity of the individual Pa-CSC markers. Outside-in signaling supports apoptosis resistance, stem cell gene expression and tumor suppressor gene repression as well as miRNA transcription and silencing. Pa-CSC markers also contribute to motility and invasiveness. By ligand binding host cells are triggered towards creating a milieu supporting Pa-CSC maintenance. Furthermore, CSC markers contribute to the generation, loading and delivery of exosomes, whereby CSC gain the capacity for a cell-cell contact independent crosstalk with the host and neighboring non-CSC. This allows Pa-CSC exosomes (TEX) to reprogram neighboring non-CSC towards epithelial mesenchymal transition and to stimulate host cells towards preparing a niche for metastasizing tumor cells. Finally, TEX communicate with the matrix to support tumor cell motility, invasion and homing. We will discuss the possibility that CSC markers are the initial trigger for these processes and what is the special contribution of CSC-TEX.

MicroRNA-21 activation of Akt via PTEN is involved in the epithelial-mesenchymal transition and malignant transformation of human keratinocytes induced by arsenite

MicroRNAs are involved in the epithelial-mesenchymal transition (EMT) and malignant transformation of cells. However, the molecular mechanisms remain unclear. In seeking new biomarkers of chemical exposure in the risk assessment of arsenite-induced skin cancer, the function of microRNA-21 (miR-21) in the regulation of serine/threonine kinase (Akt) activation was investigated. Akt suppresses phosphatase and tensin homolog (PTEN) and is involved in neoplastic and metastatic properties of arsenite-transformed human keratinocyte (T-HaCaT) cells. In HaCaT cells, arsenite caused an increase of miR-21 levels and a decrease of PTEN, which activated Akt signaling and induced the EMT. On inhibiting miR-21, the levels of PTEN were increased, and activation of Akt was blocked. Knock-down of PTEN by siRNA enhanced the activation of Akt. The effects of an miR-21 inhibitor on Akt activation were antagonized by PTEN siRNA. In T-HaCaT cells, blocking the activation of Akt by LY294002 inhibited the EMT. Moreover, the effects of an miR-21 mimic on the EMT and the neoplastic capacity, invasion, and metastasis of T-HaCaT cells were antagonized by LY294002. T-HaCaT transfected with PTEN plasmids showed decreased Akt activation and E-cadherin expression and increased vimentin levels. Thus, activation of Akt, controlled by miR-21/PTEN, is involved in the EMT, and thereby affects the neoplastic, invasion, and migratory capacities of T-HaCaT cells. The results point to the potential use of miR-21 as a biomarker for skin cancer and as a target for cancer prevention and treatment.

New Concepts in Cancer Biomarkers: Circulating miRNAs in Liquid Biopsies

The effective and efficient management of cancer patients relies upon early diagnosis and/or the monitoring of treatment, something that is often difficult to achieve using standard tissue biopsy techniques. Biological fluids such as blood hold great possibilities as a source of non-invasive cancer biomarkers that can act as surrogate markers to biopsy-based sampling. The non-invasive nature of these “liquid biopsies” ultimately means that cancer detection may be earlier and that the ability to monitor disease progression and/or treatment response represents a paradigm shift in the treatment of cancer patients. Below, we review one of the most promising classes of circulating cancer biomarkers: microRNAs (miRNAs). In particular, we will consider their history, the controversy surrounding their origin and biology, and, most importantly, the hurdles that remain to be overcome if they are really to become part of future clinical practice.

Notch in fibrosis and as a target of anti-fibrotic therapy

The Notch pathway represents a highly conserved signaling network with essential roles in regulation of key cellular processes and functions, many of which are critical for development. Accumulating evidence indicates that it is also essential for fibrosis and thus the pathogenesis of chronic fibroproliferative diseases in diverse organs and tissues. Different effects of Notch activation are observed depending on cellular and tissue context as well as in both physiologic and pathologic states. Close interactions of Notch signaling pathway with other signaling pathways have been identified. In this review, current knowledge on the role of the Notch signaling with special focus on fibrosis and its potential as a therapeutic target is summarized.

The relationship between vasculogenic mimicry and epithelial-mesenchymal transitions

Vasculogenic mimicry (VM) is a vascular‐like structure which can mimic the embryonic vascular network pattern to nourish the tumour tissue. As a unique perfusion way, VM is correlated with tumour progression, invasion, metastasis and lower 5‐year survival rate. Notably, epithelial‐mesenchymal transition (EMT) regulators and EMT‐related transcription factors are highly up‐regulated in VM‐forming tumour cells, which demonstrated that EMT may play a crucial role in VM formation. Therefore, the up‐regulation of EMT‐associated adhesion molecules and other factors can also make a contribution in VM‐forming process. Depending on these discoveries, VM and EMT can be utilized as therapeutic target strategies for anticancer therapy. The purpose of this article is to explore the advance research in the relationship of EMT and VM and their corresponding mechanisms in tumorigenesis effect.

A novel uPAg-KPI fusion protein inhibits the growth and invasion of human ovarian cancer cells in vitro

Urokinase-type plasminogen activator (uPA) acts by breaking down the basement membrane and is involved in cell proliferation, migration and invasion. These actions are mediated by binding to the uPA receptor (uPAR) via its growth factor domain (GFD). The present study evaluated the effects of uPAg-KPI, a fusion protein of uPA-GFD and a kunitz protease inhibitor (KPI) domain that is present in the amyloid β-protein precursor. Using SKOV-3 cells, an ovarian cancer cell line, we examined cell viability, migration, invasion and also protein expression. Furthermore, we examined wound healing, and migration and invasion using a Transwell assay. Our data showed that uPAg-KPI treatment reduced the viability of ovarian cancer SKOV-3 cells in both a concentration and time-dependent manner by arresting tumor cells at G1/G0 phase of the cell cycle. The IC₅₀ of uPAg-KPI was 0.5 µg/µl after 48 h treatment. At this concentration, uPAg-KPI also inhibited tumor cell colony formation, wound closure, as well as cell migration and invasion capacity. At the protein level, western blot analysis demonstrated that uPAg-KPI exerted no significant effect on the expression of total extracellular signal-regulated kinase (ERK)1/ERK2 and AKT, whereas it suppressed levels of phosphorylated ERK1/ERK2 and AKT. Thus, we suggest that this novel uPAg-KPI fusion protein reduced cell viability, colony formation, wound healing and the invasive ability of human ovarian cancer SKOV-3 cells in vitro by regulating ERK and AKT signaling. Further studies using other cell lines will confirm these findings.

Regulation of epithelial-mesenchymal transition in endometrial cancer: connecting PI3K, estrogen signaling, and microRNAs

Endometrial cancer (EC) prognosis is dependent on many factors such as time of diagnosis, histological type, and degree of invasion. Type I EC has a more favorable prognosis as it is less prone to myometrial invasion, which is believed to be the first step in the metastatic cascade. Type II EC displays a more aggressive and motile phenotype, and therefore has a poorer prognosis. Recent work suggests that despite the epithelial nature of Type I and Type II endometrial tumors, both are capable of undergoing an epithelial-mesenchymal transition (EMT), which may facilitate myometrial invasion and metastasis. Activation of the PI3K/Akt pathway has been shown to contribute to EMT through the upregulation of EMT-associated factors. Recent research has also linked estrogen signaling and microRNAs to the regulatory mechanisms that drive EMT in EC. Understanding the intricate relationships between these pathways will provide a better understanding of metastatic progression in EC.

MicroRNA aberrations: An emerging field for gallbladder cancer management

Gallbladder cancer (GBC) is infrequent but most lethal biliary tract malignancy characterized by an advanced stage diagnosis and poor survival rates attributed to absence of specific symptoms and effective treatment options. These necessitate development of early prognostic/predictive markers and novel therapeutic interventions. MicroRNAs (miRNAs) are small, non-coding RNA molecules that play a key role in tumor biology by functioning like tumor suppressor- or onco- genes and their aberrant expression are associated with the pathogenesis of several neoplasms with overwhelming clinical implications. Since miRNA signature is tissue specific, here, we focused on current data concerning the miRNAs abberations in GBC pathogenesis. In GBC, miRNAs with tumor suppressor activity (miR-135-5p, miR-335, miR-34a, miR-26a, miR-146b-5p, Mir-218-5p, miR-1, miR-145, mir-130a) were found downregulated, while those with oncogenic property (miR-20a, miR-182, mir-155) were upregulated. The expression profile of miRNAs was significantly associated with GBC prognosis and prediction, and forced over-expression/ inhibition of these miRNAs was shown to affect tumor growth and development. Further, differential expression of miRNAs in the blood samples of GBC patients suggest miRNAs as promising noninvasive biomarker. Thus, miRNAs represent potential candidate for GBC management, though many hurdles need to be overcome before miRNAs therapy can be clinically applied to GBC prevention and treatment.

Caffeic acid phenethyl ester activates pro-apoptotic and epithelial-mesenchymal transition-related genes in ovarian cancer cells A2780 and A2780cis

Ovarian cancer is a highly aggressive pathology, displaying a poor prognosis and chemoresistance to classical therapy. The present study was conducted to evaluate the effect of caffeic acid phenethyl ester (CAPE) on survival of ovarian cancer cell lines, A2780 (sensitive to cisplatin) and A2780cis (resistant to cisplatin). MTT assay was used to evaluate cell viability, while the apoptotic processes were examined by flow cytometry and qRT-PCR. A reduction of cell proliferation and activation of the apoptosis was observed in both cell lines. qRT-PCR evaluation demonstrated the activation of the pro-apoptotic genes (BAD, CASP8, FAS, FADD, p53) in both cell lines. The limited therapeutic effect in A2780 cells is explained by the activation of epithelial-mesenchymal transition-related genes (ZEB1, ZEB2, or TGFBB1) as displayed by Ingenuity Network analysis. Overall data suggest that CAPE can be used as an alternative in sensitizing cells to chemotherapy.