MicroRNA-599 suppresses glioma progression by targeting RAB27B

Silencing of long non-coding RNA SNHG15 suppresses proliferation, migration and invasion of pancreatic cancer cells by regulating the microRNA-345-5p/RAB27B axis

Pancreatic cancer (PC) is the seventh most common cause of cancer-associated mortality worldwide. The current study aimed to investigate the function and molecular mechanism underlying long non-coding (lnc)RNA SNHG15 in PC tissues and cells. Relative expression levels of lncRNA SNHG15, miR-345-5p and RAB27B in PC cells and tissues were examined by performing reverse transcription-quantitative PCR. The association between SNHG15, miR-345-5p and RAB27B was validated using a Dual-luciferase reporter assay. Proliferation, invasion and migration of PC cells were analysed by conducting MTT, wound healing and Transwell assays. Western blotting was performed to detect the relative expression of the RAB27B protein. The relative expression level of lncRNA SNHG15 and RAB27B was elevated, but that of miR-345-5p was decreased in PC. Silencing of SNHG15 suppressed the proliferation, invasion and migration of PC cells in vitro and suppressed tumour growth in xenograft mice in vivo. miR-345-5p was the target gene of SNHG15 and suppressed cell proliferation, migration and invasion in PC. Furthermore, miR-345-5p targeted RAB27B. The use of miR-345-5p inhibitor or overexpression of RAB27B reversed the suppressive effect of the small interfering RNA si-SNHG15-1 exerted on the proliferation, invasion and migration of PC cells. Silencing of SNHG15 inhibited the proliferation, invasion and migration of PC cells by mediating the miR-345-5p/RAB27B axis, thereby implying its potential as a prognostic marker and target for PC therapy.

Altered Expression of miR-575 in Glioma is Related to Tumor Cell Proliferation, Migration, and Invasion

Glioma is a kind of brain tumor with low overall survival and treatment success rates in the advanced stage. Evidence has shown microRNA-575 (miR-575) plays an important role in the generation and development of various cancers. This study aimed to explore the function of miR-575 in the prognosis and cell biological behavior of glioma. qRT-PCR was used to evaluate the expression of miR-575 in glioma tissues and cells, Kaplan-Meier survival analysis and Cox regression analysis were used to evaluate the prognostic value. The proliferation ability of glioma cells was determined by MTT assay; the invasion and migration abilities were determined by transwell assays. Compared with normal brain tissues, the expression of miR-575 in glioma tissue cells was significantly up-regulated (P < 0.001). The survival rate of patients in the miR-575 high expression group was significantly lower than that in the low expression group (P = 0.020). In addition, the overexpression of miR-575 promoted the proliferation, migration, and invasion of glioma cells. The results of this study suggested that miR-575 may be a new biomarker for the prognosis of glioma.

EIF4A3-induced circ_0084615 contributes to the progression of colorectal cancer via miR-599/ONECUT2 pathway

BACKGROUND

Colorectal cancer (CRC) is a common malignant tumor. Circular RNAs (circRNAs) have been reported to take part in the progression of CRC. However, the functions of circ_0084615 in CRC development are still undefined. In this study, we aimed to explore the functions and underlying mechanisms of circ_0084615 in CRC.

METHODS

qRT-PCR, western blot assay and IHC assay were utilized for the levels of circ_0084615, miR-599, ONECUT2 or EIF4A3. 5-ethynyl-2'-deoxyuridine (EdU) assay and colony formation assay were conducted for cell proliferation ability. Wound-healing assay and transwell assay were applied to evaluate cell migration and invasion. Tube formation assay was used to analyze angiogenesis ability. RNA immunoprecipitation (RIP) assay, RNA pull down assay and dual-luciferase reporter assay were used to analyze the relationships of circ_0084615, miR-599, ONECUT2 and EIF4A3. Murine xenograft model assay was employed for the role of circ_0084615 in vivo.

RESULTS

Circ_0084615 was elevated in CRC tissues and was linked to TNM stages, lymph node metastasis, differentiation and overall survival rate. Circ_0084615 knockdown inhibited CRC cell proliferation, migration, invasion and angiogenesis in vitro and hampered tumorigenesis in vivo. Circ_0084615 sponged miR-599 and miR-599 inhibition reversed circ_0084615 knockdown-mediated effects on CRC cell growth, motility and angiogenesis. ONECUT2 was identified as the target gene of miR-599. ONECUT2 overexpression recovered the effects of miR-599 on CRC malignant behaviors. Additionally, EIF4A3 induced circ_0084615 expression.

CONCLUSIONS

EIF4A3-induced circ_0084615 played an oncogenic role in CRC development via miR-599/ONECUT2 axis.

Upregulation of circ-ASPH contributes to glioma cell proliferation and aggressiveness by targeting the miR-599/AR/SOCS2-AS1 signaling pathway

Glioma (GM) is the most common type of malignant brain tumor with a high recurrence rate. Circular RNAs (circRNAs) play a key role in mediating tumorigenesis. However, the functions and mechanisms of circRNAs in GM are still not fully understood. A circRNA microarray was performed to identify differentially expressed circRNAs in GM and non-cancerous specimens. Reverse transcription-quantitative PCR was used to detect circ-aspartyl/asparaginyl β-hydroxylase (ASPH) expression in GM tissues and cells. The clinical importance of circ-ASPH was investigated using Kaplan-Meier analysis. The functions of circ-ASPH were investigated in LN229 and U87MG cells. Bioinformatics, RNA immunoprecipitation, RNA pull-down and luciferase reporter assays were used to explore the mechanisms of circ-ASPH in GM. circ-ASPH levels were upregulated in GM specimens and cells. The prognostic role of circ-ASPH was identified in patients with GM. Loss/gain of function assays demonstrated that circ-ASPH increased cell proliferation, migration and invasion in GM cells. Mechanistically, circ-ASPH counteracted microRNA (miR)-599-mediated androgen receptor (AR) suppression by acting as a sponge for miR-599. Rescue assays indicated that circ-ASPH facilitated cell progression by regulating AR expression. Moreover, AR activated long non-coding RNA suppressor of cytokine signaling 2-antisense RNA 1 (SOCS2-AS1) expression in GM cells. Taken together, circ-ASPH/miR-599/AR/SOCS2-AS1 signaling may be a promising biomarker/therapeutic target for GM.

LncRNA XIST Promotes Atherosclerosis by Regulating miR-599/TLR4 Axis

Long noncoding RNAs (lncRNAs) have been reported to be implicated in various biological and pathological processes. However, the function and mechanism of XIST in vascular smooth muscle cells (VSMCs) remains unknown. The levels of XIST, miR-599, and TLR4 were tested by RT-qPCR. VSMCs and human mononuclear cells (U937) treated with ox-LDL were used as atherosclerosis (AS) cell models. The CCK-8 assay was adopted to detect cell viability. Cell apoptosis was examined by the TUNEL assay. A dual-luciferase reporter assay was employed to investigate the interaction between miR-599 and XIST or TLR4. In this research, we uncovered that the XIST level was elevated in the serum of AS patients and ox-LDL-treated AS cell models. Functional analysis revealed that XIST depletion restrained cell proliferation, while induced the apoptosis in AS cell models. Besides, miR-599 was verified to be a direct downstream target of XIST and miR-599 inhibitor reversed the effects of XIST knockdown on AS progression. Finally, we demonstrated that XIST increased TLR4 expression by serving as a ceRNA of miR-599. All these findings manifested the role of the XIST/miR-599/TLR4 axis in AS development.

Long non-coding RNA MCM3AP-AS1 facilitates colorectal cancer progression by regulating the microRNA-599/ARPP19 axis

Colorectal cancer (CRC) is one of the most aggressive malignancies worldwide. Increasing evidence has indicated that microRNA (miR)-599 is involved in the occurrence and development of different types of tumors, such as breast cancer and glioma. However, the role of miR-599 in CRC remains unclear. Thus, the present study aimed to identify the regulatory mechanism of miR-599 in CRC progression. Reverse transcription-quantitative PCR was used to analyze the expression levels of MCM3AP-AS1, miR-599 and ARPP19, and Cell Counting Kit-8 and Transwell assays were used to determine the cell proliferation and migration of CRC cells. In addition, a Dual-luciferase reporter assay was used to analyze the direct interaction between miR-599 and MCM3AP-AS1 or ARPP19. Reverse transcription-quantitative PCR analysis demonstrated that miR-599 expression decreased in patients with CRC and in CRC cell lines, while miR-599 overexpression inhibited cell proliferation and migration abilities in vitro. MCM3AP-AS1 was identified as a molecular sponge of miR-599, and further investigation indicated that MCM3AP-AS1 silencing inhibited cell proliferation and migration of the CRC cell lines. In addition, ARPP19 was identified as a target gene of miR-599, and MCM3AP-AS1-knockdown decreased ARPP19 mRNA expression and increased miR-599 expression. Furthermore, silencing ARPP19 inhibited the proliferation and migration of the CRC cell lines. The results also demonstrated that MCM3AP-AS1 promoted CRC cell progression by regulating the miR-599/ARPP19 axis. Taken together, the results of the present study suggest that MCM3AP-AS1 may be a novel therapeutic target for patients with CRC.

Rab27b contributes to radioresistance and exerts a paracrine effect via epiregulin in glioblastoma

Background

Radiotherapy is the standard treatment for glioblastoma (GBM). However, radioresistance of GBM cells leads to recurrence and poor patient prognosis. Recent studies suggest that secretion factors have important roles in radioresistance of tumor cells. This study aims to determine whether Rab27b, a small GTPase involved in secretory vesicle trafficking, plays a role in radioresistance of GBM.

Methods

Microarray analysis, cell viability analysis, apoptosis assay, immunostaining, and in vivo experiments were performed to assess the effect of Rab27b on radioresistance of GBM. We further investigated paracrine effects mediated by Rab27b after X-ray irradiation using coculture systems of glioma cell lines.

Results

Rab27b was specifically upregulated in irradiated U87MG cells. Furthermore, Rab27b knockdown decreased the proliferation of GBM cells after irradiation. Knockdown of Rab27b in U87MG cells combined with radiation treatment suppressed orthotopic tumor growth in the mouse brain and prolonged the survival of recipient mice. Interestingly, the co-upregulation of Rab27b and epiregulin (EREG), a member of the epidermal growth factor (EGF) family, correlated with radioresistance in glioma cell lines. Additionally, EREG, which was secreted from U87MG cells via Rab27b-mediated mechanism, activated EGF receptor and contributed to H4 cell proliferation in a paracrine manner.

Conclusions

Our results show that Rab27b mediates the radioresistance of highly malignant GBM cells. Rab27b promotes the proliferation of adjacent cells through EREG-mediated paracrine signaling after irradiation. Thus, the Rab27b-EREG pathway is a novel potential target to improve the efficacy of radiotherapy in GBM.

Amalgamation of PI3K and EZH2 blockade synergistically regulates invasion and angiogenesis: combination therapy for glioblastoma multiforme

Glioblastoma multiforme is known as the primary malignant and most devastating form of tumor in central nervous system of adult population. Amongst all CNS cancers, Glioblastoma multiforme GBM is a rare grade IV astrocytoma and it has the worst prognosis initiated by metastasis to supra-tentorial region of the brain. Current options for the treatment include surgery, radiation therapy and chemotherapy. Substantial information of its pathology and molecular signaling exposed new avenues for generating innovative therapies. In our study, we have undertaken a novel combination approach for GBM treatment. PI3K signaling participates in cancer progression and plays a significant role in metastasis. Here, we are targeting PI3K signaling pathways in glioblastoma along with EZH2, a known transcriptional regulator. We found that targeting transcriptional regulator EZH2 and PI3K affect cellular migration and morphological changes. These changes in signatory activities of cancerous cells led to inhibit its progression in vitro. With further analysis we confirmed the angiogenic inhibition and reduction in stem-ness potential of GBM. Later, cytokine proteome array analysis revealed several participants of metastasis and tumor induced angiogenesis using combination regime. This study provides a significant reduction in GBM progression investigated using Glioblastoma Multiforme U-87 cells with effective combination of pharmacological inhibitors PI-103 and EPZ-6438. This strategy will be further used to combat GBM more innovatively along with the existing therapies.

Hsa_circ_0006916 Knockdown Represses the Development of Hepatocellular Carcinoma via Modulating miR-599/SRSF2 Axis

Background

The aberrantly expressed circular RNAs (circRNAs) are implicated in the progression of hepatocellular carcinoma (HCC). CircRNA hsa_circ_0006916 (circ_0006916) is dysregulated in HCC, but the function and mechanism of this circRNA in HCC development remain uncertain.

Methods

Thirty paired HCC and normal tissues were collected. circ_0006916, microRNA (miR)-599 and serine/arginine rich splicing factor 2 (SRSF2) abundances were examined via quantitative reverse transcription polymerase chain reaction or Western blot. Cell viability, colony ability, migration, invasion, cell cycle and apoptosis were tested via cell counting kit-8, colony formation, wound healing analysis, transwell analysis, and flow cytometry. The interaction between miR-599 and circ_0006916 or SRSF2 was analyzed via dual-luciferase reporter and RNA immunoprecipitation analyses. The function of circ_0006916 on cell growth in vivo was analyzed via xenograft model.

Results

circ_0006916 expression was increased in HCC tissues and cell lines. circ_0006916 knockdown reduced cell viability, colony formation, migration and invasion and caused cell cycle arrest and apoptosis. miR-599 was targeted via circ_0006916, and miR-599 knockdown reversed the influence of circ_0006916 silence on HCC progression. SRSF2 was targeted via miR-599, and miR-599 overexpression suppressed cell viability, colony formation, migration and invasion and promoted cell cycle arrest and apoptosis via decreasing SRSF2. circ_0006916 could regulate SRSF2 expression via miR-599. circ_0006916 knockdown decreased HCC cell growth in the xenograft model.

Conclusion

circ_0006916 knockdown represses the progression of HCC via regulating miR-599 and SRSF2.

MicroRNA-505-3p inhibits development of glioma by targeting HMGB1 and regulating AKT expression

Previous studies have reported that microRNA (miR)-505 exhibits important effect in human cancers. However, the regulatory mechanism of miR-505-3p/high-mobility group box 1 (HMGB1) axis is still unclear in glioma. Therefore, the regulatory mechanism of miR-505-3p/HMGB1 axis in glioma was illuminated. Expression of miR-505-3p and HMGB1 was observed by RT-qPCR. Protein expression was measured by western blot analysis. Dual luciferase assay was performed to confirm the relationship between miR-505-3p and HMGB1. The function of miR-505-3p was investigated by MTT and Transwell assays. Expression of miR-505-3p was reduced in glioma, which was related to poor clinical outcomes and prognosis in glioma patients. Moreover, overexpression of miR-505-3p suppressed proliferation, migration and invasion of glioma cells. In addition, HMGB1 was confirmed as a direct target of miR-505-3p, and miR-505-3p inhibited the development of glioma by targeting HMGB1. Furthermore, miR-505-3p blocked EMT suppressing p-AKT expression in glioma cells. In conclusion, miR-505-3p inhibited the development of glioma by targeting HMGB1 and regulating AKT expression.

MiR-489-3p inhibits cell proliferation, migration, and invasion, and induces apoptosis, by targeting the BDNF-mediated PI3K/AKT pathway in glioblastoma

Among astrocyte tumors, glioblastoma (GBM) is the most malignant glioma, highly aggressive and invasive, with extremely poor prognosis. Previous research has reported that microRNAs (miRNAs) participate in the progression of many cancers. Thus, this study aimed to explore the role and the underlying mechanisms of microRNA (miR)-489-3p in GBM progression. The expression of miR-489-3p and brain-derived neurotrophic factor (BDNF) mRNA was measured by quantitative real-time polymerase chain reaction. Western blot analysis was used to detect BDNF protein and the PI3K/AKT pathway-related protein. Cell proliferation, apoptosis, migration, and invasion were analyzed using CKK-8 assay, flow cytometry, and transwell assay, respectively. The interaction between BDNF and miR-489-3p was explored by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. MiR-489-3p was down-regulated and BDNF was up-regulated in GBM tissues and cells. MiR-489-3p re-expression or BDNF knockdown inhibited GBM cell proliferation, migration, and invasion, and promoted apoptosis. BDNF was a target of miR-489-3p, and BDNF up-regulation reversed the effects of miR-489-3p on GBM cells. The protein levels of p-AKT and p-PI3K were notably reduced in GBM cells by overexpression of miR-489-3p, but were rescued following BDNF up-regulation. Therefore, miR-489-3p inhibited proliferation, migration, and invasion, and induced apoptosis, by targeting the BDNF-mediated PI3K/AKT pathway in GBM, providing new strategies for clinical treatment of GBM.

Diagnostic and prognostic value of microRNA-193b in patients with glioma and its effect on tumor progression

Emerging evidence has indicated the important roles of microRNAs (miRs) in the pathogenesis of cancer in humans. The present study sought to assess the expression patterns of miR-193b in patients with glioma, and investigated its clinical significance and biological function in this disease. The expression of miR-193b in the serum, tissues and cells of patients with glioma was analyzed using reverse transcription-quantitative PCR. Its diagnostic value was evaluated using the receiver operating characteristic (ROC) curve analysis, and its prognostic value was analyzed using Kaplan-Meier survival and Cox regression analyses. Experiments on glioma cells were conducted to explore the influence of miR-193b on proliferation, migration and invasion. Increased expression of miR-193b was observed in serum, tissues and cells of patients with glioma compared with the corresponding controls (all P<0.05). miR-193b expression was associated with the World Health Organization grading and the Karnofsky Performance Scale of the patients (all P<0.05). The area under the curve of the ROC analysis of miR-193b was 0.903, indicating its high diagnostic accuracy for glioma. High expression of miR-193b was associated with poor overall survival rate in patients (P=0.002). Therefore, miR-193b is a potential independent prognostic factor in glioma. Furthermore, the overexpression of this miR in glioma cells led to increased proliferation, migration and invasion, whereas its inhibition resulted in the opposite effects on these cell behaviors (all P<0.05). Thus, the findings from the present study indicate that the overexpression of miR-193b serves as a useful biomarker for the diagnosis and prediction of prognosis in glioma. The upregulation of miR-193b expression may enhance glioma progression, and may therefore be a potential target for glioma therapy.

Combination therapy to checkmate Glioblastoma: clinical challenges and advances

Combination therapy is increasingly becoming the cornerstone of current day antitumor therapy. Glioblastoma multiforme is an aggressive brain tumor with a dismal median survival post diagnosis and a high rate of disease recurrence. The poor prognosis can be attributed to unique treatment limitations, which include the infiltrative nature of tumor cells, failure of anti-glioma drugs to cross the blood-brain barrier, tumor heterogeneity and the highly metastatic and angiogenic nature of the tumor making cells resistant to chemotherapy. Combination therapy approach is being developed against glioblastoma with new innovative combination drug regimens being tested in preclinical and clinical trials. In this review, we discuss the pathophysiology of glioblastoma, diagnostic markers, therapeutic targeting strategies, current treatment limitations, novel combination therapies in the context of current treatment options and the ongoing clinical trials for glioblastoma therapy.

Extracellular Vesicles in Bladder Cancer: Biomarkers and Beyond

Tumor-derived extracellular vesicles (TEVs) are membrane-bound, nanosized vesicles released by cancer cells and taken up by cells in the tumor microenvironment to modulate the molecular makeup and behavior of recipient cells. In this report, we summarize the pivotal roles of TEVs involved in bladder cancer (BC) development, progression and treatment resistance through transferring their bioactive cargos, including proteins and nucleic acids. We also report on the molecular profiling of TEV cargos derived from urine and blood of BC patients as non-invasive disease biomarkers. The current hurdles in EV research and plausible solutions are discussed.