miR-1236-3p represses the cell migration and invasion abilities by targeting ZEB1 in high-grade serous ovarian carcinoma

Expression Profile and Gene Regulation Network of NUSAP1 in Pan Cancers Based on Integrated Bioinformatics Analysis

Background

Nucleolar and spindle-associated protein 1 (NUSAP1) plays key roles in microtubules and chromosomes in normal cells both structurally and functionally. In malignancies, NUSAP1 is frequently dysregulated and mutated. However, the expression profiles and biological functions of NUSAP1 in tumors remain unclear.

Methods

NUSAP1 expression in BALB/c mice and human normal or tumor tissues was examined using immunohistochemistry. Kaplan-Meier survival analysis was utilized to assess the prognostic significance of NUSAP1 in tumors, and principal component analysis and co-expression analysis were performed to explore the unique roles of NUSAP1. Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed with DAVID. The relevance between NUSAP1 and tumor-infiltrating immune cells was investigated using TIMER. A transcriptional regulation network was constructed using data from The Cancer Genome Atlas.

Results

NUSAP1 expression levels in various mice tissues were different. Compared with normal tissues, NUSAP1 was strongly expressed in several human tumor tissues. We believe that NUSAP1 distinctly impacts the prognosis of several cancers and plays various roles in thymoma and testicular germ cell tumors. Further, NUSAP1 expression levels were significantly positively associated with diverse infiltrating levels of immune cells, including B cells, CD4+ and CD8+ T cells, dendritic cells, and macrophages, in thymoma. The expression level of NUSAP1 demonstrated strong relevance with various immune markers in thymoma. Finally, the miR-1236-5p-NUSAP1 and TCF3-NUSAP1 network revealed the tumor-promoting role of NUSAP1 and pertinent underlying mechanisms in human liver hepatocellular carcinoma.

Conclusion

NUSAP1 may be regarded as a therapeutic target or potential prognostic biomarker for various cancer types.

MiR-1236: Key controller of tumor development and progression: Focus on the biological functions and molecular mechanisms

Combating with the cancer, as one of the leading causes of morbidity and mortality worldwide, scientific community extensively evidenced microRNA 1236 (miR-1236) roles in the pathogenesis of malignant tumors. It has been mentioned that miR-1236 target genes and signal pathways that are key controller of tumor development and progression. Consistently, increasing evidence reports that miR-1236 participates in cancer cell growth, migration, invasion, apoptosis, and drug resistance, as well as tumor diagnosis, and prognosis. MiR-1236 is also implicated in epithelial-mesenchymal transition (EMT), which is a significant indicator of the metastatic process. Moreover, miR-1236 itself is regulated by several newly discovered long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs). Current review aimed to summarize and discuss different dimensions of miR-1236 involvement in the fundamental cellular and molecular mechanisms of tumor progressions. We believe that miR-1236 may serve as a non-invasive diagnostic marker and potential therapeutic target for cancer.

VEGFR3 suppression through miR-1236 inhibits proliferation and induces apoptosis in ovarian cancer via ERK1/2 and AKT signaling pathways

Vascular endothelial growth factor receptor 3 (VEGFR3) is expressed in cancer cell lines and exerts a critical role in cancer progression. However, the signaling pathways of VEGFR3 in ovarian cancer cell proliferation remain unclear. This study aimed to demonstrate the signaling pathways of VEGFR3 through the upregulated expression of miR-1236 in ovarian cancer cells. We found that the messenger RNA and protein of VEGFR3 were expressed in the ovarian cancer cell lines, but downregulated after microRNA-1236 (miR-1236) transfection. The inhibition of VEGFR3, using miR-1236, significantly reduced cell proliferation, clonogenic survival, migration, and invasion ability in SKOV3 and OVCAR3 cells (p < 0.01). The flow cytometry results indicated that the rate of apoptotic cells in SKOV3 (38.65%) and OVCAR3 (41.95%) cells increased following VEGFR3 inhibition. Moreover, VEGFR3 stimulation (using a specific ligand, VEGF-CS) significantly increased extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (AKT) phosphorylation (p < 0.01), whereas VEGFR3 suppression reduced p-ERK1/2 (67.94% in SKOV3 and 93.52% in OVCAR3) and p-AKT (59.56% in SKOV3 and 78.73% in OVCAR3) compared to the VEGF-CS treated group. This finding demonstrated that miR-1236 may act as an endogenous regulator of ERK1/2 and AKT signaling by blocking the upstream regulator of VEGFR3. Overall, we demonstrated the important role of the miR-1236/VEGFR3 axis in ovarian cancer cell proliferation by regulating the ERK1/2 and AKT signaling that might be an effective strategy against ovarian cancer.

Molecular mechanisms of miR-1236 in the assessment of tumor lymphangiogenesis in human ovarian cancer patients

BACKGROUND

Tumor lymphangiogenesis is a critical component in the progression of cancers and specific microRNAs have been reported to be implicated in this process. Recent studies revealed the involvement of miR-1236 in lymphangiogenic signaling by targeting vascular endothelial growth factor receptor 3 (VEGFR3). However, the prognostic importance of miR-1236 and its clinical relevance for lymphangiogenesis in ovarian cancer (OC) remains unclear.

METHODS

The study included 52 ovarian tumors and 28 normal ovarian tissues. Quantitative real-time PCR was utilized to analyze the VEGFR3, VEGF-C, LYVE-1 and PROX1 mRNA expression as well as miR-1236. VEGFR3 protein expression was measured by immunohistochemistry staining. Immunohistochemistry for the podoplanin marker (D2-40) was performed to measure lymphatic vessel density (LVD). In addition, diagnostic evaluation based on the receiver-operating characteristic (ROC) curve was performed. The influence of miR-1236 on overall survival was evaluated by Kaplan-Meier method.

RESULTS

Here, we show that miR-1236 expression was significantly decreased in ovarian tumors compared with control tissues (p < 0.001) and correlated with advanced clinical stage, lymph node metastasis, distant metastasis and patient survival (All P < 0.05). Moreover, in ovarian tumors, LVD as well as the gene expression of VEGFR3, VEGF-C and LYVE-1, but not PROX1, were found to be remarkably higher compared with control tissues. We also detected a more robust positive staining for VEGFR3 in OC tissues than in control tissues. Furthermore, our results demonstrated an inverse association of miR-1236 expression with LVD, VEGFR3, LYVE-1 and PROX1 expression in OC tissues. The ROC curve analysis indicated that miR-1236 expression has the potential to be used as a diagnostic and prognostic biomarker in OC. Survival analysis further verified a lowered overall survival rate in patients with low miR-1236 expression than in those with high expression.

CONCLUSIONS

Our results provide evidence for the translational involvement of miR-1236 in the lymphangiogenesis of OC by regulating lymphangiogenesis-related factors and support the clinical importance of miR-1236 as a new diagnostic and prognostic biomarker for OC.

CircRNA circ_0000554 promotes ovarian cancer invasion and proliferation by regulating miR-567

Circular RNAs (circRNAs) indicated potential modulating effects in tumor development. However, the specific role of circ_0000554 in ovarian tumor remains unknown. We found that circ_0000554 was overexpressed in ovarian tumor specimens and cells. Forced expression of circ_0000554 promoted cell growth, invasion, and epithelial to mesenchymal transition (EMT). We illustrated that miR-567 was downregulated in ovarian tumor specimens and cells. circ_0000554 was negatively correlated with miR-567 in ovarian tumor specimens. circ_0000554 sponged miR-567 expression in ovarian tumor. RIP assay showed that elevated expression of miR-567 could be enriched with circ_0000554. Luciferase reporter assay indicated that luciferase intensity was inhibited after treated with miR-567 mimic; however, the luciferase value of mut type was not decreased. Elevated expression of circ_0000554 suppressed miR-567 expression in HO8910 cell. circ_0000554 promoted ovarian tumor cell growth, invasion, and EMT via sponging miR-567. It suggested that circ_0000554 represent a potential therapy target for ovarian tumor.

Splice and Dice: Intronic microRNAs, Splicing and Cancer

Introns span only a quarter of the human genome, yet they host around 60% of all known microRNAs. Emerging evidence indicates the adaptive advantage of microRNAs residing within introns is attributed to their complex co-regulation with transcription and alternative splicing of their host genes. Intronic microRNAs are often co-expressed with their host genes, thereby providing functional synergism or antagonism that is exploited or decoupled in cancer. Additionally, intronic microRNA biogenesis and the alternative splicing of host transcript are co-regulated and intertwined. The importance of intronic microRNAs is under-recognized in relation to the pathogenesis of cancer.

MiR-1236-3p Inhibits the Proliferation, Invasion, and Migration of Colon Cancer Cells and Hinders Epithelial-Mesenchymal Transition by Targeting DCLK3

BACKGROUND

Dysregulated microRNAs (miRNAs) are common in human cancer and are involved in the proliferation, promotion, and metastasis of tumor cells. Therefore, this study aimed to evaluate the expression and biological function of miR-1236-3p in colon cancer.

METHODS

This study screened the miRNA in normal and colon cancer tissues through array analysis. In addition, quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) analysis was performed to validate the expression of miR-1236-3p in normal and tumor tissues from colon cancer patients and cancer cell lines. Online predicting algorithms and luciferase reporter assays were also employed to confirm Doublecortin Like Kinase 3 (DCLK3) was the target for miR-1236-3p. Moreover, the impact of miR-1236-3p on the progression of colon cancer was evaluated in vitro and in vivo. Western blotting and qRT-PCR were also performed to investigate the interactions between miR-1236-3p and DCLK3.

RESULTS

MiR-1236-3p was significantly downregulated in colon cancer tissues and its expression was associated with the TNM stage and metastasis of colon. In addition, the in vitro and in vivo experiments showed that miR-1236-3p significantly promoted cancer cell apoptosis and inhibited the proliferation, invasion, and migration of cancer cells. The results also showed that miR-1236-3p hindered Epithelial-mesenchymal Transition (EMT) by targeting DCLK3. Moreover, the expression of DCLK3 mediated the effects of miR-1236-3p on the progression of cancer.

CONCLUSIONS

MiR-1236-3p functions as a tumor suppressor in colon cancer by targeting DCLK3 and is therefore a promising therapeutic target for colon cancer.

Knockdown of circ_0006528 Suppresses Cell Proliferation, Migration, Invasion, and Adriamycin Chemoresistance via Regulating the miR-1236-3p/CHD4 Axis in Breast Cancer

BACKGROUND

Adriamycin (ADM) is one of the postoperative chemotherapy drugs for breast cancer (BCa) patients. Circular RNAs have been shown to modulate ADM resistance in many cancers. However, it is unclear whether circ_0006528 can modulate the ADM chemoresistance in BCa.

METHODS

Levels of circ_0006528, microRNA-1236-3p (miR-1236-3p), and chromodomain helicase DNA-binding protein 4 (CHD4) were detected by quantitative real-time polymerase chain reaction or western blot. Cell proliferation, the half maximal inhibitory concentration (IC50) value of ADM, and cell migration and invasion were evaluated by cell counting kit-8 and transwell assays, respectively. The interaction among circ_0006528, miR-1236-3p, and CHD4 was confirmed using dual-luciferase reporter assays. Tumor formation in nude mice was performed to explore the effect of circ_0006528 in vivo.

RESULTS

Higher levels of circ_0006528 and CHD4 and lower level of miR-1236-3p were found in ADM-resistant BCa tissues and cells, and patients with high circ_0006528 had a shorter overall survival. Circ_0006528 could directly bind to miR-1236-3p, and circ_0006528 knockdown or miR-1236-3p overexpression could suppress cell proliferation, migration, invasion, and ADM resistance in ADM-resistant BCa cells. Moreover, circ_0006528-regulated CHD4 expression by sponging miR-1236-3p, and CHD4 elevation reversed the inhibitory effect of circ_0006528 knockdown on ADM-resistant BCa cells. Consistently, circ_0006528 inhibition retarded ADM-resistant BCa tumor growth in vivo by decreasing CHD4 and increasing miR-1236-3p.

CONCLUSIONS

Downregulation of circ_0006528 restrained cell proliferation, migration, invasion, and drug resistance of ADM-resistant BCa cells through inhibiting CHD4 and inducing miR-1236-3p.

Circular RNA circRNA_101996 promoted cervical cancer development by regulating miR-1236-3p/TRIM37 axis

Circular RNAs (circRNAs) appear to be significant modulators in various physiological processes. Recently, it is found that circRNA_101996 exerts important roles in various cancers. Our previous studies showed that circRNA_101996 promoted cervical cancer growth and metastasis by regulating miR-8075/TPX2. However, the potential regulatory role of circRNA_101996 in cervical cancer still needs further investigation. Our results in this study suggested that circRNA_101996 was over-expressed in cervical cancer patients. circRNA_101996 up-regulation remarkably assisted cell proliferation, cell cycle progression, and cell migration in cervical cancer, while circRNA_101996 knockdown exerted the inverse effects. The molecular investigations indicated that circRNA_101996 could increase the expression level of miR-1236-3p, tripartite motif-containing 37 (TRIM37), through binding to miR-1236-3p and reducing its expression. Moreover, in vivo results demonstrated that circRNA_101996 shRNA can function as a tumor suppressor through down-regulating TRIM37 in cervical cancer. In conclusion, our data indicated that circRNA_101996/miR-1236-3p/TRIM37 axis accelerated cervical cancer development, providing novel insights into cervical cancer diagnosis and treatment.

An alternative miRISC targets a cancer-associated coding sequence mutation in FOXL2

Recent evidence suggests that animal microRNAs (miRNAs) can target coding sequences (CDSs); however, the pathophysiological importance of such targeting remains unknown. Here, we show that a somatic heterozygous missense mutation (c.402C>G; p.C134W) in FOXL2, a feature shared by virtually all adult-type granulosa cell tumors (AGCTs), introduces a target site for miR-1236, which causes haploinsufficiency of the tumor-suppressor FOXL2. This miR-1236-mediated selective degradation of the variant FOXL2 mRNA is preferentially conducted by a distinct miRNA-loaded RNA-induced silencing complex (miRISC) directed by the Argonaute3 (AGO3) and DHX9 proteins. In both patients and a mouse model of AGCT, abundance of the inversely regulated variant FOXL2 with miR-1236 levels is highly correlated with malignant features of AGCT. Our study provides a molecular basis for understanding the conserved FOXL2 CDS mutation-mediated etiology of AGCT, revealing the existence of a previously unidentified mechanism of miRNA-targeting disease-associated mutations in the CDS by forming a non-canonical miRISC.

MicroRNA-1236-3p inhibits human osteosarcoma growth

Osteosarcoma (OS) is a common bone tumor with high mortality worldwide. The long-term survival rate of patients with metastatic or recurrent disease is <20%. The present study explored the biological role of microRNA (miRNA/miR)-1236-3p in OS. miRNA and mRNA expression levels were measured via reverse transcription-quantitative PCR. Fluorescence in situ hybridization was performed to determine miR-1236-3p expression levels in clinical specimens. Protein expression was measured via western blotting. Immunohistochemical analysis was used to detect Wnt target gene expression in tumor tissues. The interaction between the Wnt3a 3′untranslated region and miR-1236-3p was assessed via dual-luciferase reporter assays. Cell cycle, Transwell, Cell Counting Kit-8 and wound healing assays were conducted to evaluate the function of the miR-1236-3p/Wnt3a axis. Human OS (HOS) cells stably transfected with vector or miR-1236-3p sponge were injected subcutaneously into nude mice to assess the role of miR-1236-3p in vivo. miR-1236-3p expression was downregulated in OS tissues compared with chondroma tissues, and miR-1236-3p overexpression inhibited OS cell migration and proliferation compared with the negative control group. Furthermore, in vivo xenograft assays displayed enhanced tumour growth rates in the miR-1236-3p sponge group compared with the vector control group. In the present study, the results indicated that miR-1236-3p inhibited OS progression and Wnt3a was identified as a target of miR-1236-3p.

Circ_0032821 Facilitates Gastric Cancer Cell Proliferation, Migration, Invasion and Glycolysis by Regulating MiR-1236-3p/HMGB1 Axis

Background

Circular RNAs (circRNAs) play an essential role in the pathogenesis of malignant tumors, including gastric cancer (GC). However, the effect of circ_0032821 on GC remains largely unknown.

Methods

QRT-PCR assay was employed to examine the levels of circ_0032821, CEP128 mRNA and miR-1236-3p. RNase R digestion assay was utilized to verify the feature of circ_0032821. Cell Counting Kit-8 (CCK-8) assay and transwell assay were adopted to evaluate cell proliferation and metastasis. The level of glycolysis was evaluated through detecting ECAR, OCR, lactate production, glucose uptake and ATP synthesis. Dual-luciferase reporter assay and RIP assay were conducted to analyze the relationship between miR-1236-3p and circ_0032821 or HMGB1. Western blot assay was adopted for high mobility group box 1 (HMGB1) level. Murine xenograft model assay was utilized for the effect of circ_0032821 in vivo.

Results

High level of circ_0032821 was observed in GC tissues and cells. Silencing of circ_0032821 markedly repressed cell proliferation, metastasis and glycolysis in GC cells in vitro and blocked tumorigenesis of GC in vivo. For mechanism analysis, circ_0032821 was identified as the sponge of miR-1236-3p and HMGB1 was the target gene of miR-1236-3p. Moreover, miR-1236-3p suppression restored the influences of circ_0032821 deficiency on GC cell proliferation, metastasis and glycolysis. Overexpression of miR-1236-3p relieved the malignant behaviors of GC cells by targeting HMGB1.

Conclusion

Circ_0032821 accelerated GC development through elevating HMGB1 expression via sponging miR-1236-3p.

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.

lncRNA FEZF1‑AS1 promotes migration, invasion and epithelial‑mesenchymal transition of retinoblastoma cells by targeting miR‑1236‑3p

Long non-coding RNAs (lncRNAs) and microRNAs (miRs) have been reported to regulate disease progression in numerous types of disease, including retinoblastoma (Rb). Therefore, the present study aimed to investigate the effects of the lncRNA FEZ family zinc finger 1 antisense RNA 1 (FEZF1-AS1) on Rb and to determine its possible mechanism of action. Reverse transcription-quantitative PCR and western blot analysis were conducted to detect the gene or protein expression. Cell Counting Kit-8, wound healing and transwell invasion assays were performed to estimate the capabilities of cell viability, invasion and migration. The potential association between FEZF1-AS1 and miR-1236-3p in Y79 cells was measured via dual-luciferase reporter assay. The results of the present study revealed that the levels of FEZF1-AS1 were significantly upregulated in different Rb cell lines, with the most prominent upregulation observed in Y79 cells. In addition, the cell viability, invasive and migratory abilities, and the ability to undergo epithelial-mesenchymal transition (EMT), were significantly inhibited following the transfection of short hairpin RNA (shRNA)-FEZF1-AS1 into Y79 cells. Further experimental validation confirmed that miR-1236-3p may be a direct target of FEZF1-AS1. Notably, the miR-1236-3p inhibitor was discovered to reverse the inhibitory effects of shRNA-FEZF1-AS1 on cell viability, invasion, migration and EMT. In conclusion, the findings of the present study suggested that lncRNA-FEZF1-AS1 may promote the viability, migration, invasion and EMT of Rb cells by modulating miR-1236-3p.

MicroRNAs and Their Influence on the ZEB Family: Mechanistic Aspects and Therapeutic Applications in Cancer Therapy

Molecular signaling pathways involved in cancer have been intensively studied due to their crucial role in cancer cell growth and dissemination. Among them, zinc finger E-box binding homeobox-1 (ZEB1) and -2 (ZEB2) are molecules that play vital roles in signaling pathways to ensure the survival of tumor cells, particularly through enhancing cell proliferation, promoting cell migration and invasion, and triggering drug resistance. Importantly, ZEB proteins are regulated by microRNAs (miRs). In this review, we demonstrate the impact that miRs have on cancer therapy, through their targeting of ZEB proteins. MiRs are able to act as onco-suppressor factors and inhibit the malignancy of tumor cells through ZEB1/2 down-regulation. This can lead to an inhibition of epithelial-mesenchymal transition (EMT) mechanism, therefore reducing metastasis. Additionally, miRs are able to inhibit ZEB1/2-mediated drug resistance and immunosuppression. Additionally, we explore the upstream modulators of miRs such as long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), as these regulators can influence the inhibitory effect of miRs on ZEB proteins and cancer progression.

The emerging roles of circular RNAs in ovarian cancer

Circular RNA (circRNA) is a novel class of regulatory noncoding RNA (ncRNA) molecules with a unique covalently closed loop structure. Next-generation sequencing shows that thousands of circRNAs are widely and stably expressed in multiple eukaryotes. As novel regulatory ncRNAs, circRNAs possess several specific molecular functions, including regulating gene transcription and translation, acting as miRNA sponges, and interacting with functional proteins. Ovarian cancer (OvCa) is one of the most aggressive malignant diseases affecting the lives of thousands of women worldwide, and the majority of OvCa cases are diagnosed at advanced stages. Accumulating evidence has revealed the significant roles of circRNAs in the occurrence and progression of OvCa, indicating the function of circRNAs as promising biomarkers and their therapeutic relevance in this disease. This review aims to summarize the mechanisms by which circRNAs mediate OvCa progression as well as their diagnostic and prognostic values in OvCa.

CircRNA hsa_circ_0070934 functions as a competitive endogenous RNA to regulate HOXB7 expression by sponging miR‑1236‑3p in cutaneous squamous cell carcinoma

Circular ribonucleic acids (circRNAs) serve a vital role in the pathological processes of a number of diseases. Previous microarray results of circRNA expression revealed that hsa_circ_0070933 and hsa_circ_0070934, two circRNAs associated with the La ribonucleoprotein 1B gene, were highly expressed in cutaneous squamous cell carcinoma (CSCC). The present study aimed to explore the specific role of these circRNAs in CSCC. Through reverse transcription-quantitative PCR, hsa_circ_0070933 and hsa_circ_0070934 expression levels in CSCC cell lines and a human keratino-cyte cell line were detected. Additionally, direct interactions between miR-1236-3p and HOXB7 or circ-0070934 were identified using RNA binding protein immunoprecipitation assays and dual-luciferase reporter assays. Cell Counting Kit-8, 5-ethynyl-2′-deoxyuridine, Transwell invasion and flow cytometry assays were used to assess the roles of miR-1236-3p or circ-0070934 in cell invasion, proliferation and apoptosis. Subsequently, in vivo tumor formation assays were used to verify the role of circ-0070934 in CSCC. The results demonstrated that the expression of circ-0070934 was stably upregulated in a number of CSCC cell lines compared with that in normal human keratinocytes. Knockdown of circ-0070934 inhibited the invasive and proliferative potential of CSCC cells and promoted apoptosis both in vivo and in vitro. In addition, circ-0070934 modulated HOXB7 expression through competitive binding with miR-1236-3p. In conclusion, the results of the present study demonstrated the effects of the circ-0070934/miR-1236-3p/HOXB7 regulatory axis on CSCC and provided a novel insight for the pathogenesis of CSCC.

MiR-1236-3p serves as a new diagnostic and prognostic biomarker for gastric cancer

BACKGROUND

The microRNA plays an important role in tumor progression. MiR-1236-3p acts as a tumor suppressor in various malignancies.

OBJECTIVE

The aim of present study was to explore the expression of miR-1236-3p in gastric cancer (GC) and its correlation with clinicopathological features, and evaluate the feasibility of using it as a prognostic biomarker in GC.

METHODS

Seventy-six pairs of tissue specimens were collected from GC patients. MiR-1236-3p expression level was detected by using qRT-PCR. The diagnostic value of miR-1236-3p was evaluated by receiver operating characteristic curve, and Kaplan-Meier method was used to analyze the overall survival. Prognosis analysis was performed using multivariate cox proportional hazards regression analysis.

RESULTS

The expression of miR-1236-3p was significantly reduced in tumor tissues (P< 0.001). In addition, miR-1236-3p expression was correlated with TNM stage (P= 0.001), lymph node metastasis (P= 0.005) and differentiated degree (P= 0.001). The area under the curve was 0.7016, and its specificity and sensitivity were 60.53% and 73.68%. Kaplan-Meier survival curves showed that patients with high miR-1236-3p expression had better overall survival than those with low expression (P= 0.0190). Multivariate Cox regression analysis showed that the miR-1236-3p expression (P= 0.033) was an independent prognostic factor for overall survival of GC prognosis.

CONCLUSIONS

The study showed that miR-1236-3p is downregulated in GC tissues, and low expression of miR-1236-3p is associated with a poor prognosis in GC. It may be a new diagnostic and prognostic biomarker for GC.

CircMYC Regulates Glycolysis and Cell Proliferation in Melanoma

Circular RNAs (cicRNAs) have been identified to play pivotal roles in several cancer types. However, functions of circRNA in malignant melanoma are poor defined. Our current study demonstrated that human circMYC was obviously upregulated in human melanoma tissue. Furthermore, circMYC promoted the proliferation of human melanoma cells and Mel-CV cells. The expression of circMYC can repress Mel-CV cell glycolysis and LDHA activities in the in vitro glycolysis and lactate production evaluations. circMYC directly bound to miR-1236 as a molecular sponge that targeting miR-1236 in Mel-CV cells via bioinformatics analysis, pull-down assay, and luciferase reporter assays. Our present study revealed that 3' UTR of LDHA acted as a target of miR-1236 using Mel-CV cells. Based on our findings, c-MYC-SRSF1 axis may regulate the production of circMYC. Overall, these results elucidate potential effects of circMYC in melanoma development and provide a promising biomarker for melanoma diagnosis.

MicroRNA-1236-3p/translationally controlled tumor protein (TPT1) axis participates in congenital hypothyroidism progression by regulating neuronal apoptosis

Congenital hypothyroidism (CH) is an endocrine disease caused by congenital thyroid hormone (TH) deficiency. MicroRNAs (miRNAs or miRs) have been reported to inhibit the progression of congenital hypothyroidism. However, the expression and role of miR-1236-3p in CH remains unclear. To address this, 12 day old Sprague-Dawley rats were divided into five groups: Control; Congenital hypothyroidism (CH), miR-1236-3p inhibitor control (inhibitor control); miR-1236-3p inhibitor (inhibitor); and miR-1236-3p inhibitor + translationally-controlled tumor protein 1 (TPT1)-small interfering (si)RNA (inhibitor + siRNA). Propylthiouracil (50 mg/day) was injected intraperitoneally into pregnant rats to generate pups with CH. The levels of miR-1236-3p and TPT1 were detected via reverse transcription-quantitative PCR and western blot analysis. Bioinformatics analysis was performed to predict the targets of miR-1236-3p, which was confirmed using dual luciferase reporter assay. Flow cytometry and MTT assay were used to measure neuronal cell apoptosis and cell viability, whereas western blotting was applied to detect the expression of Pim-3, p-Bad (Ser112), Bad and Bcl-xL, proteins associated with apoptosis. The results revealed that miR-1236-3p expression was significantly upregulated, whilst TPT1 expression was significantly downregulated in the hippocampus tissues of CH rats compared with the control group. TPT1 was confirmed as a target of miR-1236-3p. MiR-1236-3p inhibitor prevented hippocampal neuron apoptosis induced by CH induction, which was reversed by TPT1-siRNA transfection. In addition, following miR-1236-3p inhibitor transfection, neuronal cell apoptosis significantly reduced compared with the control group, which was accompanied by significantly increased expressions of Pim-3, p-Bad (Ser112) and Bcl-xL expression. These effects were reversed by TPT1-siRNA co-transfection. These results indicated that inhibition of miR-1236-3p expression inhibited neuron apoptosis in vivo and in vitro by targeting TPT1, serving a protective role in CH.

Circular RNAs in cancer: new insights into functions and implications in ovarian cancer

Circular RNAs (circRNAs) are a class of long non-coding RNAs (lncRNAs) which have a circular and closed loop structure. They are ubiquitous, stable, conserved and diverse RNA molecules with a range of activities such as translation and splicing regulation, which are able to interacting with RNA-binding proteins and specially miRNA sponge. The expression patterns of the circRNAs exhibited tissue specificity and also, step and stage specificity. Accumulating evidences approved the critical role of circular RNAs in many cancers such as ovarian cancer. Given that these molecules exert their effects through multiple cellular and molecular mechanisms (i.e., angiogenesis, apoptosis, growth, and metastasis) which are involved in cancer pathogenesis, circular RNAs, in particular, act by controlling cell proliferation in ovarian cancer, so that, it has been shown that the deregulation of these molecules is associated with initiation and progression of ovarian cancer. Therefore, they are attractive molecules which have introduced them as cancer biomarkers. Moreover, they could be used as new therapeutic candidates for developing novel treatment strategies. Here, for first time, we have provided a comprehensive review on the recent knowledge of circular RNAs and their pathological roles in the ovarian cancer.

An RNA Metabolism and Surveillance Quartet in the Major Histocompatibility Complex

At the central region of the mammalian major histocompatibility complex (MHC) is a complement gene cluster that codes for constituents of complement C3 convertases (C2, factor B and C4). Complement activation drives the humoral effector functions for immune response. Sandwiched between the genes for serine proteinase factor B and anchor protein C4 are four less known but critically important genes coding for essential functions related to metabolism and surveillance of RNA during the transcriptional and translational processes of gene expression. These four genes are NELF-E (RD), SKIV2L (SKI2W), DXO (DOM3Z) and STK19 (RP1 or G11) and dubbed as NSDK. NELF-E is the subunit E of negative elongation factor responsible for promoter proximal pause of transcription. SKIV2L is the RNA helicase for cytoplasmic exosomes responsible for degradation of de-polyadenylated mRNA and viral RNA. DXO is a powerful enzyme with pyro-phosphohydrolase activity towards 5' triphosphorylated RNA, decapping and exoribonuclease activities of faulty nuclear RNA molecules. STK19 is a nuclear kinase that phosphorylates RNA-binding proteins during transcription. STK19 is also involved in DNA repair during active transcription and in nuclear signal transduction. The genetic, biochemical and functional properties for NSDK in the MHC largely stay as a secret for many immunologists. Here we briefly review the roles of (a) NELF-E on transcriptional pausing; (b) SKIV2L on turnover of deadenylated or expired RNA 3'→5' through the Ski-exosome complex, and modulation of inflammatory response initiated by retinoic acid-inducible gene 1-like receptor (RLR) sensing of viral infections; (c) DXO on quality control of RNA integrity through recognition of 5' caps and destruction of faulty adducts in 5'→3' fashion; and (d) STK19 on nuclear protein phosphorylations. There is compelling evidence that a dysregulation or a deficiency of a NSDK gene would cause a malignant, immunologic or digestive disease.

circ-CSPP1 promotes proliferation, invasion and migration of ovarian cancer cells by acting as a miR-1236-3p sponge

Circular RNAs are known to participate in tumorigenesis through a variety of pathways, and as such, have potential to serve as molecular markers in tumor diagnosis and treatment. Here, using quantitative reverse transcription (qRT)-PCR, we showed that circ-CSPP1 is highly expressed in ovarian cancer (OC) tissues. Particularly, we detected circ-CSPP1 expression in three OC cell lines; of which, OVCAR3 and A2780 demonstrated higher levels of circ-CSPP1 expression, and CAOV3 showed lower circ-CSPP1 expression level. Subsequent silencing of circ-CSPP1 in OVCAR3 and A2780 cell lines revealed decreased cell growth, migration and invasion, while overexpression of circ-CSPP1 caused opposite results We also found that miR-1236-3p is a target of circ-CSPP1. Circ-CSPP1 silencing increased the expression of miR-1236-3p, and circ-CSPP1 overexpression decreased miR-1236-3p expression. MiR-1236-3p reportedly plays a tumor-suppressor role in OC by targeting zinc finger E-box binding homeobox 1 (ZEB1). In agreement with this, we showed that silencing circ-CSPP1 significantly decreased ZEB1 expression at both RNA and protein levels, and epithelial-mesenchymal transition (EMT) related markers (E-cadherin and N-cadherin) varied with ZEB1 expression. Circ-CSPP1 silencing also caused decreased expression of matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor A (VEGFA), both of which are related to tumorigenesis. Overexpression of circ-CSPP1 had opposite effects. In addition, we indicated that the tumor-promoting effect was inhibited after we transfected miR-1236-3p into circ-CSPP1 overexpressing OC cells. Altogether, our findings suggest that by acting as a miR-1236-3p sponge, circ-CSPP1 impairs the inhibitory effect of miR-1236-3p on ZEB1, which subsequently promotes EMT and OC development.

ZNF671 DNA methylation as a molecular predictor for the early recurrence of serous ovarian cancer

Serous ovarian cancer is the most frequent type of epithelial ovarian cancer. Despite the use of surgery and platinum‐based chemotherapy, many patients suffer from recurrence within 6 months, termed platinum resistance. Currently, the lack of relevant molecular biomarkers for the prediction of the early recurrence of serous ovarian cancers is linked to the poor prognosis. To identify an effective biomarker for early recurrence, we analyzed the genome‐wide DNA methylation status characteristic of early recurrence after treatment. The patients in The Cancer Genome Atlas (TCGA) dataset who showed a complete response after the first therapy were categorized into 2 groups: early recurrence serous ovarian cancer (ERS, recurrence ≤12 months, n = 51) and late recurrence serous ovarian cancer (LRS, recurrence >12 months, n = 158). Among the 12 differently methylated probes identified between the 2 groups, we found that ZNF671 was the most significantly methylated gene in the early recurrence group. A validation cohort of 78 serous ovarian cancers showed that patients with ZNF671 DNA methylation had a worse prognosis (P < .05). The multivariate analysis revealed that the methylation status of ZNF671 was an independent factor for predicting the recurrence of serous ovarian cancer patients both in the TCGA dataset and our cohort (P = .049 and P = .021, respectively). Functional analysis revealed that the depletion of ZNF671 expression conferred a more migratory and invasive phenotype to the ovarian cancer cells. Our data indicate that ZNF671 functions as a tumor suppressor in ovarian cancer and that the DNA methylation status of ZNF671 might be an effective biomarker for the recurrence of serous ovarian cancer after platinum‐based adjuvant chemotherapy.

microRNA-1236-3p Regulates DDP Resistance in Lung Cancer Cells

Lung cancer is a malignant tumor leading to the most cancer-related deaths worldwide. The treatment efficiency of lung cancer remains poor mainly due to chemotherapy drug resistance, including cisplatin. MicroRNAs (miRNAs) are closely related to chemotherapy resistance of tumor cells. Here, we illustrated the underlying mechanism of miR-1236-3p on the DDP resistance in lung cancer cells. In this study, we found that the expression level of miR-1236-3p was significantly decreased in lung cancer tissues and A549 cell line. In addition, the half maximal inhibitory concentration (IC50) of DDP in A549 cells was significantly lower than that in A549/DDP cells, while the expression level of miR-1236-3p was prominently down-regulated in A549/DDP cells. Combining the online tool TargetScan and a dual-luciferase reporter assay, tumor protein, translationally-controlled 1 (TPT1) was proved to be the direct target gene of miR-1236-3p. The MTT and flow cytometry assays demonstrated that up-regulation of miR-1236-3p could markedly inhibit A549/DDP cell proliferation but promote apoptosis, which could be significantly reversed by pcDNA3.1-TPT1 plasmids. Finally, we further demonstrated that miR-1235-3p could restrain the expression levels of TPT1, Pim-3, phosphate-Bcl-2-associated death promoter (p-BAD) and B-cell lymphoma-extra large (Bcl-XL) in A549/DDP cells, while the inhibition could be reversed by pcDNA3.1-TPT1 as well. In a word, our study demonstrated that miR-1236-3p could reverse DDP resistance by modulation of TPT1 gene and inhibition of Pim-3 signaling pathway in lung cancer cells.

miR-205-5p inhibits cell migration and invasion in prostatic carcinoma by targeting ZEB1

Many studies have demonstrated that miRNAs have influence on tumorigenesis and progression of human cancers, including invasion and migration. Thus, the role of miR-205/ZEB1 axis for the migration and invasion of prostate cancer cells was explored in the present study. The miR-205-5p and zinc finger E-box binding homeobox 1 (ZEB1) mRNA expression levels were observed in prostate cancer tissues or cell lines via reverse transcription-quantitative PCR (RT-qPCR), and the protein level of ZEB1 was measured by western blotting. Dual-Luciferase Reporter Assay was used to verify the relationship between miR-205-5p and ZEB1. In addition, cell migration and invasion was measured by Transwell assay. The results revealed that, compared with the control, downregulation of miR-205-5p was detected in prostate cancer tissues and cell lines, and miR-205-5p overexpression was found to inhibit cell migration and invasion. Moreover, miR-205-5p was confirmed to directly target ZEB1 in prostate cancer. Importantly, ZEB1 was identified to weaken the inhibitory effect of miR-205-5p in prostate cancer. In conclusion, miR-205-5p inhibited cell migration and invasion in prostatic carcinoma by targeting ZEB1 and miR-205-5p/ZEB1 axis shows potential to be developed in therapeutic strategies for prostate cancer.

miR-1236-3p inhibits invasion and metastasis in gastric cancer by targeting MTA2

Background

MicroRNAs deregulation are common in human tumor progression. miR-1236-3p has been reported to function as tumor suppressor microRNA in various malignancies. The aim of this study was to demonstrate the downregulated expression of miR-1236-3p in gastric cancer (GC) tissues and cell lines, and clarify its biological function in GC.

Methods

Real-time polymerase chain reaction was used to measure the mRNA level of miR-1236-3p in GC. Dual luciferase assay was used to demonstrate that MTA2 was one of the candidate target genes of miR-1236-3p. Western blots were utilized to detect the protein levels. Cell function assays were also performed to determine the function of miR-1236-3p in GC.

Results

miR-1236-3p expression, which was associated with lymph node metastasis, differentiation and clinical stage, was significantly reduced in GC tissues and cell lines. miR-1236-3p over-expression could inhibit GC cell proliferation, migration and invasion, and inhibition of miR-1236-3p expression had opposite effects. Furthermore, we demonstrated that MTA2 was a candidate target of miR-1236-3p, and miR-1236-3p over-expression significantly inhibited the process of epithelial-mesenchymal transition. We also found that miR-1236-3p could suppress the PI3K/Akt signaling pathway in GC cells.

Conclusions

Our results suggest that miR-1236-3p functions as a tumor suppressor in GC and could be a promising therapeutic target for GC.

MicroRNA-595 sensitizes ovarian cancer cells to cisplatin by targeting ABCB1

Ovarian cancer is among the leading cause of cancer-related deaths in females. In this study, we demonstrated that miR-595 expression was downregulated in the ovarian cancer tissues and cell lines. miR-595 expression was lower in the lymph node metastases tissues than in the primary ovarian cancer tissues and normal tissues. Furthermore, miR-595 overexpression suppressed the ovarian cancer cell proliferation, colony formation and invasion and promoted the sensitivity of ovarian cancer cell to cisplatin. We identified ABCB1 as a direct target gene of miR-595 in the ovarian cancer cell. ABCB1 expression was upregulated in the ovarian cancer tissues and cell lines. Morevoer, the expression level of ABCB1 was inversely correlated with miR-595 in the ovarian cancer tissues. In addition, overexpression of ABCB1 decreased the miR-595-overexpressing HO8910PM and SKOV-3 cell sensitivity to cisplatin. Ectopic expression of ABCB1 promoted the miR-595-overexpressing HO8910PM and SKOV-3 cell proliferation, colony formation and invasion. These data suggested that miR-595 acted a tumor suppressor role in ovarian cancer development and increased the sensitivity of ovarian cancer to cisplatin.

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.

MicroRNA-150 functions as an antioncogenic regulator in osteosarcoma

Numerous studies have demonstrated that microRNAs (miRs) are involved in several physiological and pathological processes, and participate in cancer initiation and progression. The abnormal expression of miR-150 has been reported in numerous types of human cancer. However, at present there are no studies of miR-150 in osteosarcoma (OS). Reverse transcription-quantitative polymerase chain reaction was performed to measure miR-150 expression levels in OS tissues and cell lines. Subsequent to transfection with miR-150 mimics or zinc finger E-box binding homeobox 1 (ZEB1) small interfering RNA, an MTT assay, Transwell migration and invasion assays, western blotting and a Dual-Luciferase reporter assay were performed in human OS cell lines. The present study revealed that miR-150 was downregulated in OS tissues and cell lines. In addition, the expression levels of miR-150 were correlated with the clinical stage and degree of distant metastasis of patients with OS. In addition, ZEB1 was identified as a direct target of miR-150 in vitro. In conclusion, miR-150 targeted ZEB1 to function as an antioncogenic regulator in OS. These findings elucidated a novel underlying mechanism for the pathogenic process in OS carcinogenesis and progression, and may provide novel targeted therapeutic regimens for patients with OS.

MicroRNAs driving invasion and metastasis in ovarian cancer: Opportunities for translational medicine (Review)

Epithelial ovarian cancer is the fifth most frequent cause of cancer death in women. In spite of the advantages in early detection and treatment options, overall survival rates have improved only slightly in the last decades. Therefore, alternative therapeutic approaches need to overcome resistance and improve the patient survival and outcome. MicroRNAs are evolutionary conserved small non-coding RNAs that function as negative regulators of gene expression by inhibiting translation or inducing degradation of messenger RNAs. In cancer, microRNAs are aberrantly expressed thus representing potential prognostic biomarkers and novel therapeutic targets. The knowledge of novel and unexpected functions of microRNAs is rapidly evolving and the advance in the elucidation of potential clinical applications deserves attention. Recently, a specific set of microRNAs dubbed as metastamiRs have been shown to initiate invasion and metastasis in diverse types of cancer. We reviewed the current status of microRNAs in development and progression of ovarian cancer with a special emphasis on tumor cells invasion and metastasis. Also, we show an update of microRNA functions in oncogenic pathways and discuss the current scenario for potential applications in clinical and translational research in ovarian cancer.

MicroRNA miR-204 and miR-1236 inhibit hepatitis B virus replication via two different mechanisms

Hepatitis B virus (HBV) is a major human pathogen. In this study, we found that miR-204 and miR-1236 were down-regulated in HBV-producing cells, and each could suppress HBV replication. Using a bioinformatic approach and a reporter assay, we identified miR-1236, which can reduce HBV replication and protein production by directly targeting at HBV specific mRNA. In contrast, miR-204 was identified by a microarray approach, and had no effect on HBV RNA and protein production. Surprisingly, miR-204 could inhibit HBV pregenomic RNA encapsidation and capsid assembly. We further demonstrated that HBV suppressed miR-204 expression via activating a host transcription factor STAT3. We established a positive feed-forward loop between HBV, miR-204 and STAT3. Interestingly, miR-204 has been considered as a tumor suppressor in some literature. Since the risk for hepatocellular carcinoma (HCC) is significantly increased in chronic HBV patients, it is possible that chronic suppression of miR-204 by HBV contributes to HCC incidence. Both miR-204 and miR-1236 might be useful for developing new therapeutics against HBV.

The expression of microRNA 574-3p as a predictor of postoperative outcome in patients with esophageal squamous cell carcinoma

BACKGROUND

Despite advances in radical esophagectomies and adjuvant therapy, the postoperative prognosis in esophageal squamous cell carcinoma (ESCC) patients remains poor. The aim of this study was to identify a molecular signature to predict postoperative favorable outcomes in patients with ESCC.

METHODS

As a training data set, total RNA was extracted from formalin-fixed paraffin-embedded samples of surgically removed specimens from 19 ESCC patients who underwent curative esophagectomy. The expression of microRNA (miRNA) was detected using a miRNA oligo chip on which 885 genes were mounted. As a validation data set, we obtained frozen samples of surgically resected tumors from 12 independent ESCC patients and the expression of miR-574-3p was detected by quantitative real-time PCR.

RESULTS

Our microarray analysis in the training set patients identified three miRNAs (miR-574-3p, miR-106b, and miR-1303) and five miRNAs (miR-1203, miR-1909, miR-204, miR-371-3p, miR-886-3p) which were differentially expressed between the patients with (n = 14) and without (n = 5) postoperative tumor relapse (p < 0.01 and p < 0.05, respectively). Higher expression of miR-574-3p, which showed the most significant association with non-relapse (p = 0.001), was associated with favorable overall survival (p = 0.016). Real-time PCR experiments on the validation set patients confirmed that higher expression of miR-574-3p was associated with non-tumor relapse (p = 0.029) and better overall survival (p = 0.004).

CONCLUSIONS

Our results suggest that the aberrant expression of the miRNAs identified in this study plays key roles in the progression of ESCC. miR-574-3p was suggested to have a tumor suppressor effect, and thus, to be a predictor of postoperative outcome in patients with ESCC.

miR-1236 regulates hypoxia-induced epithelial-mesenchymal transition and cell migration/invasion through repressing SENP1 and HDAC3

Intratumoral hypoxia induces epithelial-mesenchymal transition and promotes cancer metastasis. MicroRNAs (miRNAs) are endogenous, single-strand RNA molecules that regulate gene expression. MiRNAs control cell growth, proliferation, differentiation and cell death and may function as oncogenes or tumor suppressors. HDAC3 and SENP1 are two molecules involved in hypoxia-induced EMT and HIF-1α stability, respectively. In this report, we show that miR-1236 plays a critical role in hypoxia-induced EMT and metastasis. MiRNA prediction programs TargetScan and miRanda show that miR-1236 may target HDAC3 and SENP1. MiR-1236 represses the luciferase activity of reporter constructs containing 3'UTR of HDAC3 and SENP1 as well as the expression levels of HDAC3 and SENP1. MiR-1236 abolishes hypoxia-induced EMT and inhibits migration and invasion activity of tumor cells. Hypoxia represses miR-1236 expression. The promoter region of miR-1236 is identified as the NELFE promoter. Twist1, an EMT regulator activated by hypoxia/HIF-1α, is shown to repress the reporter construct driven by the NELFE promoter. The binding site of Twist1 in the NELFE promoter is identified and chromatin immunoprecipitation assays show the direct binding of Twist1 to this site. Overexpression or knockdown of Twist1 in stable cell lines shows the inverse correlation between Twist1 and miR-1236 expression. These results identify a miRNA that regulates hypoxia-induced EMT and metastasis through repressing HDAC3 and SENP1 expression and present a regulatory network that involves many key players in hypoxia-induced EMT.

miR-128 modulates chemosensitivity and invasion of prostate cancer cells through targeting ZEB1

OBJECTIVE

Recent reports strongly suggest the profound role of miRNAs in cancer therapeutic response and progression, including invasion and metastasis. The sensitivity to therapy and invasion is the major obstacle for successful treatment in prostate cancer. We aimed to investigate the regulative effect of miR-128/zinc-finger E-box-binding homeobox 1 axis on prostate cancer cell chemosensitivity and invasion.

METHODS

The miR-128 expression pattern of prostate cancer cell lines and tissues was detected by real-time reverse transcriptase-polymerase chain reaction, while the mRNA and protein expression levels of zinc-finger E-box-binding homeobox 1 were measured by real-time reverse transcriptase-polymerase chain reaction and western blot assay, respectively. Dual-luciferase reporter gene assay was used to find the direct target of miR-128. Furthermore, prostate cancer cells were treated with miR-128 mimic or zinc-finger E-box-binding homeobox 1-siRNA, and then the cells' chemosensitivity and invasion were detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and transwell assay, respectively.

RESULTS

We found miR-128 expression obviously decreased in prostate cancer tissues compared with paired normal tissues. Restored miR-128 expression sensitized prostate cancer cells to cisplatin and inhibited the invasion. Furthermore, there was an inverse expression pattern between miR-128 and zinc-finger E-box-binding homeobox 1 in prostate cancer cells and tissues, and zinc-finger E-box-binding homeobox 1 was identified as a direct target of miR-128 in prostate cancer. Knockdown of zinc-finger E-box-binding homeobox 1 expression efficiently sensitized prostate cancer cells to cisplatin and inhibited the invasion. However, ectopic zinc-finger E-box-binding homeobox 1 expression impaired the effects of miR-128 on chemosensitivity and invasion in prostate cancer cells.

CONCLUSIONS

miR-128 functions as a potential cancer suppressor in prostate cancer progression and rational therapeutic strategies for prostate cancer would be developed based on miR-128/zinc-finger E-box-binding homeobox 1 axis.