MicroRNA-194 promotes the growth, migration, and invasion of ovarian carcinoma cells by targeting protein tyrosine phosphatase nonreceptor type 12

PTPN12 down-regulated by miR-146b-3p gene affects the malignant progression of laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a common malignancy among men in the anatomical position of head and neck. Hoarseness, pharyngalgia, and dyspnea are common symptoms. LSCC is a complex polygenic carcinoma that is caused by many factors involving polygenic alteration, environmental pollution, tobacco, and human papillomavirus. Classical protein tyrosine phosphatase nonreceptor type 12 (PTPN12) has been extensively studied to decipher its mechanism as a tumor suppressor gene in various human carcinomas; however, there is no comprehensive elucidation of the PTPN12 expression and its regulatory mechanisms in LSCC. As such, we expect to provide new insights for finding new biomarkers and effective therapeutic targets in LSCC. Immunohistochemical staining, western blot (WB), and quantitative real-time RT-PCR (qRT-PCR) were used for the messenger RNA (mRNA) and protein expression analyses of PTPN12, respectively. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, clone formation, transwell migration, and transwell invasion assays were used to assess the proliferation, migration, and invasion ability of LSCC cells. Online prediction and design software tools (http://www.targetscan.org/ and http://www.microRNA.org) were used to predict associated miRNA. Studying the targeted regulatory relationship between miR-146b-3p and PTPN12 was based on dual luciferase reporter gene analysis. qRT-PCR was used to assess miR-146b-3p expression in LSCC. miR-146b-3p inhibitor and mimic were transfected, followed by qRT-PCR and WB assays to detect the expression of PTPN12. The gain and loss functional experiments were used to investigate the effects of miR-146b-3p transfection on the proliferation, migration, and invasion of tumor cells. Online bioinformatics prediction software (https://cn.string-db.org/ and https://www.genecards.org/) was used to determine potential downstream target genes of PTPN12. qRT-PCR and WB analyses were used to assess the mRNA and protein expression levels of target genes. Our study showed significantly decreased mRNA and protein expression levels of PTPN12 in LSCC compared with the adjacent normal tissues. The lower PTPN12 mRNA expression was correlated with pathological differentiation, and lower PTPN12 protein expression was correlated with the TNM stage in LSCC tissues. The subsequent in vitro functional analyses showed the inhibitory effect of PTPN12 over-expression on the proliferation, migration, and invasiveness abilities of LSCC cell line. Using online prediction and design software, miR-146b-3p was searched to target PTPN12. The miR-146b-3p was expressed at a high level in LSCC tissues and cell lines. Luciferase reporter assay exhibited that miR-146b-3p inhibited the luciferase activity of PTPN12 markedly. The functional analyses showed the tumor-promoting role of miR-146b-3p on the proliferation, migration, and invasiveness abilities of LSCC cell. Furthermore, co-transfection of cells with miR-146b-3p and PTPN12 significantly restored the inhibitory effect of PTPN12 on LSCC cell growth, migration, and invasiveness. This phenomenon unveiled that miR-146b-3p regulated the proliferation, migration, and invasion of LSCC cells by targeting PTPN12. EGFR and ERBB2 were selected as the downstream-regulation target genes. Up-regulation of PTPN12 significantly suppressed EGFR expression. Accordingly, the miR-146b-3p mimic significantly up-regulated the EGFR expression. However, up-regulation of PTPN12 and miR-146b-3p mimic suppressed ERBB2 protein expression but induced its gene expression. Down-regulation of PTPN12 is associated with up-regulation of miR-146b-3p in LSCC. Moreover, PTPN12 serves as a tumor suppressor gene through regulating the proliferation, migration, and invasion of LSCC cells. miR-146b-3p/PTPN12 axis is expected to be a novel therapeutic target in LSCC.

The interplay of signaling pathways with miRNAs in cholangiocarcinoma pathogenicity and targeted therapy

Cholangiocarcinoma (CCA), the second most frequent liver cancer after hepatocellular carcinoma, has been rising worldwide in recent epidemiological research. This neoplasia's pathogenesis is poorly understood. Yet, recent advances have illuminated the molecular processes of cholangiocyte malignancy and growth. Late diagnosis, ineffective therapy, and resistance to standard treatments contribute to this malignancy's poor prognosis. So, to develop efficient preventative and therapy methods, the molecular pathways that cause this cancer must be better understood. MicroRNAs (miRNAs) are non-coding ribonucleic acids (ncRNAs) that influence gene expression. Biliary carcinogenesis involves abnormally expressed miRNAs that act as oncogenes or tumor suppressors (TSs). The miRNAs regulate multiple gene networks and are involved in cancer hallmarks like reprogramming of cellular metabolism, sustained proliferative signaling, evasion of growth suppressors, replicative immortality, induction/access to the vasculature, activation of invasion and metastasis, and avoidance of immune destruction. In addition, numerous ongoing clinical trials are demonstrating the efficacy of therapeutic strategies based on miRNAs as powerful anticancer agents. Here, we will update the research on CCA-related miRNAs and explain their regulation involved in the molecular pathophysiology of this malignancy. Eventually, we will disclose their potential as clinical biomarkers and therapeutic tools in CCA.

Effects of an inhibitor of the SHH signaling pathway on endometrial cells of patients with endometriosis

BACKGROUND

Endometriosis is one of the most common gynecological diseases, and seriously reduces the quality of life of patients. However, the pathogenesis of this disease is unclear. Therefore, more studies are needed to elucidate its pathogenesis. Our previous publication found that the Sonic Hedgehog (SHH) signaling pathway was activated in endometriosis. This study tested whether SHH signaling in endometrial stromal cells (ESCs) was critical for the pathogenesis of endometriosis.

METHODS

To examine the effect of inhibiting the SHH signaling pathway on endometriosis, we first isolated ESCs from eutopic endometrial tissues of patients with or without endometriosis and identified the extracted cells by morphological observation and immunofluorescence. Then, we treated ESCs with the GLI inhibitor GANT61 and used CCK-8, wound healing and invasion assays to detect cell activities, such as proliferation, invasion and metastasis. Furthermore, we detected the expression of key proteins and proliferation markers of the SHH signaling pathway in the lesions of nude mice using immunochemistry.

RESULTS

We demonstrated that higher concentrations of GANT61 decreased the proliferation rate and migration distance of ESCs. We observed that GANT61 inhibited the invasion of ESCs. In addition, blockage of the SHH signaling pathway significantly reduced cell proliferation in vitro.

CONCLUSIONS

Our study suggested that inhibition of the SHH pathway is involved in cell proliferation and invasive growth in the pathogenesis of endometriosis.

Critical roles of PTPN family members regulated by non-coding RNAs in tumorigenesis and immunotherapy

Since tyrosine phosphorylation is reversible and dynamic in vivo, the phosphorylation state of proteins is controlled by the opposing roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatase (PTPs), both of which perform critical roles in signal transduction. Of these, intracellular non-receptor PTPs (PTPNs), which belong to the largest class I cysteine PTP family, are essential for the regulation of a variety of biological processes, including but not limited to hematopoiesis, inflammatory response, immune system, and glucose homeostasis. Additionally, a substantial amount of PTPNs have been identified to hold crucial roles in tumorigenesis, progression, metastasis, and drug resistance, and inhibitors of PTPNs have promising applications due to striking efficacy in antitumor therapy. Hence, the aim of this review is to summarize the role played by PTPNs, including PTPN1/PTP1B, PTPN2/TC-PTP, PTPN3/PTP-H1, PTPN4/PTPMEG, PTPN6/SHP-1, PTPN9/PTPMEG2, PTPN11/SHP-2, PTPN12/PTP-PEST, PTPN13/PTPL1, PTPN14/PEZ, PTPN18/PTP-HSCF, PTPN22/LYP, and PTPN23/HD-PTP, in human cancer and immunotherapy and to comprehensively describe the molecular pathways in which they are implicated. Given the specific roles of PTPNs, identifying potential regulators of PTPNs is significant for understanding the mechanisms of antitumor therapy. Consequently, this work also provides a review on the role of non-coding RNAs (ncRNAs) in regulating PTPNs in tumorigenesis and progression, which may help us to find effective therapeutic agents for tumor therapy.

Protein tyrosine phosphatase non-receptor type 12 (PTPN12), negatively regulated by miR-106a-5p, suppresses the progression of hepatocellular carcinoma

Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is abnormally expressed in many human cancers. However, its role in hepatocellular carcinoma (HCC) is indeterminate. In this study, immunohistochemistry and Western blot were adopted to detect PTPN12 protein expression in HCC tissues and cell lines. MiR-106a-5p and PTPN12 mRNA expressions were determined by quantitative real-time polymerase chain reaction (qRT-PCR). siRNA was used to knockdown PTPN12 expression in HCC cells, and the multiplication, migration, and invasion of HCC cells were determined by cell counting kit 8 (CCK-8) and Transwell assays. The interaction between PTPN12 and miR-106a-5p was verified by dual-luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay. In the present study, we demonstrated that PTPN12 expression in HCC tissues and cells was significantly decreased, which was associated with the tumor size, TNM stage, and lymph node metastasis of HCC patients. Functionally, knocking down PTPN12 significantly promoted the multiplication, migration, invasion, and epithelial-mesenchymal transition (EMT) of HCC cells. PTPN12 was identified as the direct target of miR-106a-5p, and its expression was negatively modulated by miR-106a-5p. Besides, PTPN12 counteracted the promoting effects of miR-106a-5p on the viability, migration, invasion, and EMT of HCC cells. In conclusion, this study substantiates that PTPN12 inhibits the growth, migration, invasion, and EMT of HCC cells, and miR-106a-5p contributes to its dysregulation in HCC.

Oleuropin controls miR-194/XIST/PD-L1 loop in triple negative breast cancer: New role of nutri-epigenetics in immune-oncology

Oleuropein, the main secoiridoid glucoside found in Olea europaea L., has attracted scientific community as a potential anticancer agent. Immunotherapy and RNA interference revolutionized cancer treatment. Success of PD-L1/PD-1 antibodies encouraged the investigation of PD-1/PD-L1 regulation by non-coding RNAs. This study aimed to verify the cytotoxic effect of oleuropein on MDA-MB-231 cell line and to unravel novel ceRNA interaction between miR-194-5p and XIST in breast cancer and their immunomodulatory effect on PD-L1 expression to propose a promising prophylactic and preventive role of Oleuropin in diet. For the first time, miR-194/Lnc-RNA XIST/PD-L1 triad was investigated in breast cancer, where miR-194 and PD-L1 levels were significantly upregulated in 21 BC-biopsies, yet XIST was downregulated. Ectopic expression of miR-194 enhanced cell function and viability with concomitant increase in PD-L1 expression yet XIST expression decreased, in contrast to miR-194 antagomirs that yielded opposite results. XIST knock-out elevated miR194-5p and PD-L1 levels. miR-194-5p mimics and XIST siRNAs co-transfection induced PD-L1 expression, while miR-194-5p mimics and TSIX siRNAs co-transfection showed opposite effect. Oleuropein showed anti-carcinogenic impact by decreasing miR-194 and PD-L1 levels while increasing XIST level. In conclusion, our study highlighted novel ceRNA interaction controlling PD-L1 expression in BC. Oleuropein is a promising nutraceutical for cancer therapy. Therefore, oleuropin represents a new nutri-epigenetic in immune-oncology that controls miR-194/XIST/PD-L1 loop in triple negative breast cancer.

Expression and clinical significance of PTPN12 in clear cell renal cell carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is a common urological disease. Expression of the protein tyrosine phosphatase 12 gene (PTPN12) is decreased in many cancers; however, the relationship between PTPN12 gene function and renal cancer remains unclear.

Methods

We detected PTPN12 protein expression in ccRCC and corresponding normal tissues from 64 patients with ccRCC by immunohistochemistry, and relative PTPN12 mRNA levels by real-time quantitative polymerase chain reaction. The relationships between the relative expression levels of PTPN12 mRNA and the patients’ clinical data were analyzed.

Results

PTPN12 protein and mRNA expression levels were significantly lower in ccRCC compared with the corresponding normal tissues. The mRNA expression levels in the ccRCC and corresponding normal tissues from the 64 patients with ccRCC were 0.459±0.445 and 1.001±0.128, respectively, compared with the control (glyceraldehyde 3-phosphate dehydrogenase). There was a significant correlation between relative expression of PTPN12 mRNA in ccRCC tissues and tumor diameter and clinical stage.

Conclusion

The expression levels of PTPN12 protein and mRNA were significantly lower in ccRCC tissues compared with normal tissues. The role of PTPN12 may provide new insights and evidence to aid the diagnosis and targeted therapy of ccRCC.

The Role of microRNAs in Epithelial Ovarian Cancer Metastasis

Epithelial ovarian cancer (EOC) is the deadliest gynecological cancer, and the major cause of death is mainly attributed to metastasis. MicroRNAs (miRNAs) are a group of small non-coding RNAs that exert important regulatory functions in many biological processes through their effects on regulating gene expression. In most cases, miRNAs interact with the 3′ UTRs of target mRNAs to induce their degradation and suppress their translation. Aberrant expression of miRNAs has been detected in EOC tumors and/or the biological fluids of EOC patients. Such dysregulation occurs as the result of alterations in DNA copy numbers, epigenetic regulation, and miRNA biogenesis. Many studies have demonstrated that miRNAs can promote or suppress events related to EOC metastasis, such as cell migration, invasion, epithelial-to-mesenchymal transition, and interaction with the tumor microenvironment. In this review, we provide a brief overview of miRNA biogenesis and highlight some key events and regulations related to EOC metastasis. We summarize current knowledge on how miRNAs are dysregulated, focusing on those that have been reported to regulate metastasis. Furthermore, we discuss the role of miRNAs in promoting and inhibiting EOC metastasis. Finally, we point out some limitations of current findings and suggest future research directions in the field.

MiR-342-3p inhibits cell migration and invasion through suppressing forkhead box protein Q1 in ovarian carcinoma

Previous studies have shown that microRNAs are involved in the pathogenesis of ovarian carcinoma (OC). However, the abnormal expression and function of miR-342-3p have not been reported in OC. Therefore, this research was designed to explore its role in OC. In this study, qRT-PCR assay showed that the expression level of miR-342-3p was reduced in OC tissues and cell lines. Functionally, Transwell assay suggested that overexpression of miR-342-3p suppressed cell migration and invasion in OC. In addition, forkhead box protein Q1 (FOXQ1) was confirmed to be a direct target gene by luciferase activity assay. Furthermore, FOXQ1 was found to be upregulated and function as an oncogene in OC. More importantly, miR-342-3p was negatively correlated with FOXQ1 expression in OC tissues. Furthermore, overexpression of FOXQ1 could partially rescue inhibitory effect of miR-342-3p on cell migration and invasion in OC. In brief, we concluded that miR-342-3p inhibited migration and invasion of OC cells through suppressing FOXQ1 expression.

Progress in the correlation between PTPN12 gene expression and human tumors

BACKGROUND

The global morbidity of cancer is rising rapidly. Despite advances in molecular biology, immunology, and cytotoxic and immune-anticancer therapies, cancer remains a major cause of death worldwide. Protein tyrosine phosphatase non-receptor type 12 (PTPN12) is a new member of the cytoplasmic protein tyrosine phosphatase family, isolated from a cDNA library of adult colon tissue. Thus far, no studies have reviewed the correlation between PTPN12 gene expression and human tumors.

METHODS

This article summarizes the latest domestic and international research developments on how the expression of PTPN12 relates to human tumors. The extensive search in Web of Science and PubMed with the keywords including PTPN12, tumor, renal cell carcinoma, proto-oncogenes, tumor suppressor genes was undertaken.

RESULTS

More and more studies have shown that a tumor is essentially a genetic disease, arising from a broken antagonistic function between proto-oncogenes and tumor suppressor genes. When their antagonistic effect is out of balance, it may cause uncontrolled growth of cells and lead to the occurrence of tumors. PTPN12 is a tumor suppressor gene, so inhibiting its activity will lead directly or indirectly to the occurrence of tumors.

CONCLUSION

The etiology, prevention, and treatment of tumors have become the focus of research around the world. PTPN12 is a tumor suppressor gene. In the future, PTPN12 might serve as a novel molecular marker to benefit patients, and even the development of tumor suppressor gene activation agents can form a practical research direction.

Downregulation of serum miR-194 predicts poor prognosis in osteosarcoma patients

BACKGROUND

Circulating microRNAs (miRNAs) have promising potential as diagnostic and prognostic biomarkers for osteosarcoma. This study aimed to explore the expression pattern of serum miR-194 and its potential clinical value in patients with osteosarcoma.

METHODS

Messenger RNA was isolated from serum sample from 124 osteosarcoma patients, 60 periostitis patients and 60 healthy volunteers. The serum miR-194 level was then examined by quantitative real-time polymerase chain reaction (qRT-PCR). The bioinformatic analysis of the downstream targets of miR-194 was also performed.

RESULTS

The results showed serum miR-194 levels were significantly decreased in osteosarcoma patients compared to those in periostitis patients or healthy controls. Receiver-operating characteristic (ROC) analysis demonstrated that serum miR-194 had a good diagnostic value for identifying osteosarcoma subjects from periostitis patients and normal controls. In addition, serum miR-194 levels were dramatically increased following surgery in osteosarcoma cases. Moreover, low serum miR-194 expression was strongly correlated with positive metastasis and advanced clinical stage, as well as worse survival. Furthermore, serum miR-194 was confirmed to be an independent prognostic biomarker for osteosarcoma. Bioinformatic analysis showed that the downstream targeted genes of miR-194 were closely associated with cancer initiation and development.

CONCLUSION

In conclusion, our results have demonstrated that serum miR-194 might serve as a novel and promising biomarker for the detection and prognosis of osteosarcoma.

MicroRNAs and Metastasis

Metastasis, the development of secondary malignant growths at a distance from the primary site of a cancer, is associated with almost 90% of all cancer deaths, and half of all cancer patients present with some form of metastasis at the time of diagnosis. Consequently, there is a clear clinical need for a better understanding of metastasis. The role of miRNAs in the metastatic process is beginning to be explored. However, much is still to be understood. In this review, we present the accumulating evidence for the importance of miRNAs in metastasis as key regulators of this hallmark of cancer.

MicroRNA-503 serves an oncogenic role in retinoblastoma progression by directly targeting PTPN12

Numerous studies have demonstrated that microRNAs (miRNAs or miRs) are abnormally expressed in retinoblastoma (RB). miRNAs may serve a role in oncogene or tumor-suppressor activity in RB genesis and development by modulating various biological processes. miRNAs therefore, may be effective therapeutic targets for miRNA-based therapy in patients with RB. Recently it has been revealed that miR-503 may serve a role in various types of human cancer. However, the expression and functional roles of miR-503 are rarely reported in RB. In the current study, the expression of miR-503 was significantly upregulated in RB tissues and cell lines. In addition, Cell Counting Kit-8 and in vitro invasion assays were performed to assess cell proliferation and invasion, respectively. The results of the present study revealed that miR-503 inhibition impeded RB in vitro cell proliferation and invasion. Furthermore, protein tyrosine phosphatase nonreceptor type 12 (PTPN12) was demonstrated to be a direct target gene of miR-503 in RB cells. PTPN12 overexpression also led to the downregulation of miR-503 in RB cell proliferation and invasion. PTPN12 knockdown could therefore abrogate the effects of miR-503 downregulation in RB cells. In conclusion, the results demonstrated that miR-503 may serve a role in RB oncogenic activity progression by directly targeting PTPN12. Therefore, miR-503 may be a target for effective therapy in patients with RB.

Downregulation of miR-194-5p induces paclitaxel resistance in ovarian cancer cells by altering MDM2 expression

Paclitaxel is a first-line drug for treating epithelial ovarian cancer (EOC). However, prognosis for patients with advanced stage cancer remains poor due to primary or acquired drug resistance. Therefore, overcoming chemoresistance is one of the greatest challenges in treating EOC. In this study, we identified microRNAs (miRNA) that regulate paclitaxel resistance and tested their potential utility as therapeutic targets. Paclitaxel-resistant cell lines were established using two EOC cell lines: SKVO3ip1 and HeyA8. miRNA PCR arrays showed that miR-194-5p was downregulated in paclitaxel-resistant cells. Forced expression of miR-194-5p resensitized resistant cells to paclitaxel. Conversely, miR-194-5p inhibition induced paclitaxel resistance in parental cells. In silico analysis and luciferase reporter assay revealed that MDM2 is a direct target of miR-194-5p. MDM2 was upregulated in paclitaxel resistant cells compared with parental cells. MDM2 inhibition also resensitized resistant cells to paclitaxel and forced MDM2 induced paclitaxel resistance in parental cells. miR-194-5p induced p21 upregulation and G1 phase arrest in resistant cells by downregulating MDM2. Furthermore, a public database showed that high MDM2 expression was associated with a shorter progression-free survival in EOC patients treated with paclitaxel. Collectively, our results show that restoring miR-194-5p expression resensitizes EOCs to paclitaxel, and this may be exploited as a therapeutic option.

MiR-194 regulates nasopharyngeal carcinoma progression by modulating MAP3K3 expression

Despite the recent development of treatment strategies for nasopharyngeal carcinoma, the effective management of this disease remains a challenging clinical problem. A better understanding of the regulatory roles of miR‐194 and mitogen‐activated protein kinase kinase kinase 3 (MAP3K3) in the nasopharyngeal‐carcinoma‐related gene network is required to address this issue. Here, we measured relative expression of miR‐194 in human nasopharyngeal carcinoma tissues and normal epithelial tissues by quantitative real time PCR. We transfected cultured CNE‐1 and C666‐1 cells with miR‐194 mimics, and then examined the effects on cell proliferation, cell migration and invasion. Luciferase reporter assay was used to validate the putative binding between miR‐194 and MAP3K3. We then examined the effect of knockdown and overexpression of MAP3K3 on cell tumorigenesis. Expression of miR‐194 is significantly down‐regulated in nasopharyngeal carcinoma specimens and tumor cell lines when compared with normal controls. In addition, miR‐194 suppressed tumor cell proliferation and viability, as well as migration and invasion of carcinoma cells. We found that miR‐194 binds the 3′ untranslated region of MAP3K3, and knockdown of miR‐194 inhibited nasopharyngeal carcinoma cell proliferation, migration and invasion. In accordance, overexpression of MAP3K3 reversed the inhibitory effects of miR‐194 in carcinoma cells. This study suggests that expression of miR‐194 is down‐regulated in nasopharyngeal carcinoma, and that miR‐194 can directly target MAP3K3 to regulate tumor progression. Given the pivotal involvement of MAP3K3 in nasopharyngeal carcinoma development, targeting miR‐194 may be a novel strategy for the treatment of nasopharyngeal carcinoma.

miR-205 regulates the proliferation and invasion of ovarian cancer cells via suppressing PTEN/SMAD4 expression

MicroRNAs (miRNAs/miRs) are non-coding RNAs that post-transcriptionally control target genes, and are involved in tumorigenesis, apoptosis, proliferation, invasion, metastasis and chemoresistance. However, data concerning miRNAs in ovarian cancer remain incomplete. The present study aimed to identify miRNAs that affected the malignant phenotype of ovarian cancer, and to analyze their potential mechanisms. The data demonstrated that miR-205 promoted cell proliferation and invasion of ovarian cancer cells via suppressing Phosphatase and tensin homolog (PTEN)/mothers against decapentaplegic homolog 4 (SMAD4) expression. Based on the Cancer Genome Atlas database analysis results, it was identified that miR-205 was significantly upregulated in ovarian cancer tissues and markedly correlated with poor prognosis in patients with ovarian cancer; its abnormal expression was also confirmed in tissues from patients with ovarian cancer by reverse transcription quantitative polymerase chain reaction. Additional Gene Ontology analysis revealed that the target genes of miR-205 were associated with cell proliferation and invasion. Consistent with the database analysis, miR-205 overexpression significantly promoted ovarian cancer cell proliferation and invasion in vitro. To additionally explore the mechanism by which miR-205 was associated with proliferation and invasion of ovarian cancer cells, a protein-protein interaction network was constructed based on miR-205 target genes associated with proliferation and invasion, and it was revealed that PTEN and SMAD4 were key target genes of miR-205. In ovarian cancer tissues, the expression levels of PTEN and SMAD4 were significantly downregulated, suggesting that miR-205 may suppress the expression of PTEN and SMAD4 in vivo. In vitro, miR-205 overexpression markedly suppressed the expression of SMAD4 and PTEN, additionally verifying that PTEN and SMAD4 were the target genes of miR-205 in ovarian cancer cells. These results elucidated the tumor-promoting role of miR-205 and established miR-205 as a potential treatment target for ovarian cancer.

Application values of miR-194 and miR-29 in the diagnosis and prognosis of gastric cancer

The object of this study was to analyze the expression of miR-194 and miR-29 in gastric cancer and their roles in the regulation of malignant phenotype of gastric cancer cells, and to explore the application value of miR-194 and miR-29 in diagnosis and prognosis of gastric cancer. Tumor tissue and adjacent healthy tissue of 165 gastric cancer patients diagnosed by pathologic examinations were collected. Expression of miR-194 and miR-29 in the tissues was detected by RT-PCR. The relationship between miR-194 and miR-29 expression and clinical data was analyzed. SGC7901 cells were treated with miR-194 and miR-29 mimics, respectively. Effects of miR-194 and miR-29 on proliferation and invasion of SGC7901 cells were investigated. Expression levels of miR-194 and miR-29 in tumor tissue were lower than those in adjacent tissues (P<0.001). There was no significant difference in expression level of miR-194 and miR-29 in cancer tissues derived from gastric cancer patients in different age and gender groups (P>0.05). Expression of miR-194 and miR-29 in tumor tissue was closely related to TNM stage, differentiation degree of cancer cells and lymph node metastasis (P<0.05). Proliferation and migration of SGC7901 cells were significantly inhibited by miR-194 mimic and miR-29 mimic transfection (P<0.05). miR-194 and miR-29 are downregulated in gastric cancer, and the expression levels of miR-194 and miR-29 were closely related to tumor differentiation and metastasis. Overexpression of miR-194 and miR-29 significantly inhibited the proliferation and migration of gastric cancer. The detection of the expression of miR-194 and miR-29 can provide basis for the diagnosis and prognosis of gastric cancer.

Potential microRNA-related Targets for Therapeutic Intervention with Ovarian Cancer Metastasis

Treatment of disseminated epithelial ovarian cancer (EOC) is an unmet medical need. Therefore, the identification along with preclinical and clinical validation of new targets is an issue of high importance. In this review we focus on microRNAs that mediate metastasis of EOC. We summarize up-regulated metastasis-promoting and down-regulated metastasis-suppressing microRNAs. We focus on preclinical in vitro and in vivo functions as well as their metastasis-related clinical correlations. Finally, we outline modalities for therapeutic intervention and critical issues of microRNA-based therapeutics in the context of metastatic EOC.

MicroRNAs in gynecological cancers: Small molecules with big implications

Gynecological cancers (GCs) are often diagnosed at advanced stages, limiting the efficacy of available therapeutic options. Thus, there remains an urgent and unmet need for innovative research for the efficient clinical management of GC patients. Research over past several years has revealed the enormous promise of miRNAs. These small non-coding RNAs can aid in the diagnosis, prognosis and therapy of all major GCs, viz., ovarian cancers, cervical cancers and endometrial cancers. Mechanistic details of the miRNAs-mediated regulation of multiple biological functions are under constant investigation, and a number of miRNAs are now believed to influence growth, proliferation, invasion, metastasis, chemoresistance and the relapse of different GCs. Modulation of tumor microenvironment by miRNAs can possibly explain some of their reported biological effects. miRNA signatures have been proposed as biomarkers for the early detection of GCs, even the various subtypes of individual GCs. miRNA signatures are also being pursued as predictors of response to therapies. This review catalogs the knowledge gained from collective studies, so as to assess the progress made so far. It is time to ponder over the knowledge gained, so that more meaningful pre-clinical and translational studies can be designed to better realize the potential that miRNAs have to offer.

MicroRNA-125a-5p plays a role as a tumor suppressor in lung carcinoma cells by directly targeting STAT3

Increasing evidence supports that the dysregulation of microRNA expression plays an important role in the process of tumor occurrence and development. Studies have found that mir-125a-5p expression was downregulated in a variety of tumors, but the effects and mechanism of mir-125a-5p in lung cancer are still unclear. The aim of this study is to detect the expression of mir-125a-5p in lung cancer tissues and lung cancer cell lines and to explore the effects of mir-125a-5p on the biological characteristics of lung cancer cells; thus, this study aims to provide new methods and new strategies for the treatment of lung cancer. The result from quantitative reverse transcription polymerase chain reaction showed that the expression of miR-125a-5p was significantly lower in lung cancer tissues and lung cancer cell lines (95-D, A549, HCC827, and NCI-H1299) than that in normal tissue adjacent to lung cancer or normal human bronchial epithelial cells. In order to explore the function and mechanism of mir-125a-5p in lung cancer cells, miR-125a-5p mimic or mir-125a-5p inhibitor was transfected into A549 cells. Mir-125a-5p displayed an obvious upregulation in A549 cells transfected with miR-125a-5p and an obvious downregulation in A549 cells transfected with mir-125a-5p inhibitor compared to that in A549 cells transfected with control miRNA. 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, BrdU staining, flow cytometry, and Transwell assay showed that the upregulation of miR-125a-5p could significantly decrease the cell viability, proliferation, and invasion of lung cancer cells and increase apoptosis of lung cancer cells. The downregulation of miR-125a-5p provided very contrasting results. Computational algorithms predicted that the STAT3 is a target of miR-125a-5p. Here, we validated that miR-125a-5p could directly bind to the 3'-untranslated region of STAT3, and miR-125a-5p overexpression could significantly inhibit the protein expression of STAT3. These results suggested that mir-125a-5p can regulate the expression of STAT3 in lung cancer cells. To further verify whether mir-125a-5p can play a biological role through regulating STAT3, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, flow cytometry, and Transwell analysis demonstrated that overexpression of STAT3 can reverse the cells' biological effects induced by mir-125a-5p overexpression. Mir-125a-5p downregulated in lung cancer tissue and cell lines can negatively regulate STAT3 protein expression. Taken together, mir-125a-5p inhibited the proliferation and invasion of lung cancer cells and facilitated lung cancer cell apoptosis through suppressing STAT3. Enhancing the expression of miR-125a-5p is expected to benefit the therapy for the patients with lung cancer.

Molecular Mechanisms of Ovarian Carcinoma Metastasis: Key Genes and Regulatory MicroRNAs

Metastasis of primary tumors progresses stepwise - from change in biochemistry, morphology, and migratory patterns of tumor cells to the emergence of receptors on their surface that facilitate directional migration to target organs followed by the formation of a specific microenvironment in a target organ that helps attachment and survival of metastatic cells. A set of specific genes and signaling pathways mediate this process under control of microRNA. The molecular mechanisms underlying biological processes associated with tumor metastasis are reviewed in this publication using ovarian cancer, which exhibits high metastatic potential, as an example. Information and data on the genes and regulatory microRNAs involved in the formation of cancer stem cells, epithelial-mesenchymal transition, reducing focal adhesion, degradation of extracellular matrix, increasing migration activity of cancer cells, formation of spheroids, apoptosis, autophagy, angiogenesis, formation of metastases, and development of ascites are presented. Clusters of microRNAs (miR-145, miR-31, miR-506, miR-101) most essential for metastasis of ovarian cancer including the families of microRNAs (miR-200, miR-214, miR-25) with dual role, which is different in different histological types of ovarian cancer, are discussed in detail in a section of the review.

Downregulation of miR-493 promoted melanoma proliferation by suppressing IRS4 expression

Accumulating evidence indicated that aberrantly expressed microRNAs play critical roles in the initiation and progression of human cancers. However, the underlying functions of miR-493 in human melanoma remains unknown. Here, our study found that miR-493 expression was downregulated in human melanoma tissues and cells. Overexpression of miR-493 suppressed cell proliferation and cell cycle in human melanoma cell line A375. IRS4 was defined as a target for downregulation by miR-493 and was confirmed by luciferase assay. We also found that knockdown of IRS4 counteracted the proliferation promotion by miR-493 inhibitor. In summary, these results demonstrated that miR-493 acts as a tumor suppressor and inhibits cell proliferation and cell cycle in human melanoma by directly targeting IRS4.

MicroRNA-194 modulates epithelial-mesenchymal transition in human colorectal cancer metastasis

MicroRNAs (miRNAs), as key regulators of gene expression, are closely related to tumor occurrence and progression. MiR-194 has been proved as a tumor regulatory factor in various cancers; however, the biological function and mechanism of action in colorectal cancer (CRC) have not been well explored. In the present study, we found that miR-194 expression is upregulated in CRC clinical specimens, while overexpression of miR-194 promotes cell migration and invasion in CRC cell lines. Besides, miR-194 significantly influenced the epithelial–mesenchymal transition (EMT) markers by downregulating E-cadherin expression (P<0.01) and upregulating vimentin and MMP-2 expression (P<0.001, P<0.05). Cell migration is the cell movement related to actin cytoskeleton. In this study, we found miR-194 increased cell polarization in SW480 cells. Moreover, zymography assay showed that miR-194 significantly upregulated the gelatin-degrading activity of MMP-2 (P<0.01). Collectively, our findings suggest that miR-194 functions as a tumor promoter in CRC, which may provide new insights for the study of CRC development and metastasis.

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-194 regulates keratinocyte proliferation and differentiation by targeting Grainyhead-like 2 in psoriasis

MicroRNAs (miRNAs) are currently emerged as important regulators in psoriasis. Psoriasis is characterized by hyperproliferation and impaired differentiation of keratinocytes in skin lesions. miR-194 is a well-known regulator of cell proliferation and differentiation. However, the role of miR-194 in psoriasis pathogenesis remains unclear. In this study we aimed to investigate the role of miR-194 in keratinocyte hyperproliferation and differentiation. We found that miR-194 was significantly downregulated in psoriasis lesional skin. Overexpression of miR-194 inhibited the proliferation and promoted the differentiation of primary human keratinocytes, whereas miR-194 suppression promoted the proliferation and inhibited their differentiation. Bioinformatic analysis predicted that the Grainyhead-like 2 (GRHL2) was a target gene of miR-194, which we further validated with a dual-luciferase reporter assay, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blot analysis. The effect of miR-194 on cell proliferation and differentiation was significantly reversed by overexpression of GRHL2. Moreover, the expression of miR-194 and GRHL2 was inversely correlated in psoriasis lesional skin. Taken together, our results suggest that miR-194 inhibits the proliferation and promotes the differentiation of keratinocytes through targeting GRHL2. The downregulation of miR-194 expression may contribute to the pathogenesis of psoriasis and targeting miR-194 may represent a novel and potential therapeutic strategy for psoriasis.

MicroRNA and Long Non-Coding RNA in Ovarian Carcinoma: Translational Insights and Potential Clinical Applications

Reliable biomarkers for the detection of early ovarian carcinoma are currently unavailable. MicroRNA and long non-coding RNA may be important in cancer initiation and progression by regulating gene expression through post-transcriptional mechanisms. MicroRNAs, such as miR-26a and miR-132, have been investigated as novel biomarkers for diagnosis, prognosis, monitoring of therapeutic response, and therapeutic targets in ovarian carcinomas. Some long non-coding RNAs, such as H19 and UCA1, may be involved in the pathogenesis of ovarian carcinomas. MicroRNA and long non-coding RNA have potential clinical utility in the diagnosis of ovarian cancer and predicting prognosis, metastasis, recurrence, and response to therapy.