MiR-506 functions as a tumor suppressor in glioma by targeting STAT3

Overexpression of miR-506-3p reversed doxorubicin resistance in drug-resistant osteosarcoma cells

Background and objective: Osteosarcoma is a common primary malignant tumor of bone, and doxorubicin is one of the most widely used therapeutic drugs. While the problem of doxorubicin resistance limits the long-term treatment benefits in osteosarcoma patients. The role of miRNAs and their target genes in osteosarcoma have become increasingly prominent. Currently, there is no report on miR-506-3p reversing doxorubicin resistance by targeting STAT3 in osteosarcoma. The purpose of this study was to investigate the molecular mechanism that overexpression of miR-506-3p reverses doxorubicin resistance in drug-resistant osteosarcoma cells. Methods: Doxorubicin-resistant osteosarcoma cells (U-2OS/Dox) were constructed by intermittent stepwise increasing stoichiometry. The target genes of miR-506-3p were predicted by bioinformatics approach and the targeting relationship between miR-506-3p and STAT3 was detected using dual luciferase reporter assay. U-2OS/Dox cells were treated with miR-506-3p overexpression and STAT3 silencing respectively. Then Western blot and RT-qPCR were used to detect the protein and mRNA expression levels of JAK2/STAT3 signaling pathway, drug-resistant and apoptotic associated molecules. The migration and invasion were assessed by cell scratch assay and transwell assay. The cell proliferative viability and apoptosis were investigated by CCK8 assay and flow cytometry assay. Results: U-2OS/Dox cells were successfully constructed with a 14.4-fold resistance. MiR-506-3p is directly bound to the 3'-UTR of STAT3 mRNA. Compared with U-2OS cells, the mRNA expression of miR-506-3p was reduced in U-2OS/Dox cells. Overexpression of miR-506-3p decreased the mRNA expression levels of JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and decreased the protein expression levels of p-JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and conversely increased Bax expression. It also inhibited the proliferation, migration and invasion of U-2OS/Dox cells and promoted cells apoptosis. The results of STAT3 silencing experiments in the above indicators were consistent with that of miR-506-3p overexpression. Conclusion: Overexpression of miR-506-3p could inhibit the JAK2/STAT3 pathway and the malignant biological behaviors, then further reverse doxorubicin resistance in drug-resistant osteosarcoma cells. The study reported a new molecular mechanism for reversing the resistance of osteosarcoma to doxorubicin chemotherapy and provided theoretical support for solving the clinical problems of doxorubicin resistance in osteosarcoma.

miRNAs role in glioblastoma pathogenesis and targeted therapy: Signaling pathways interplay

High mortality and morbidity rates and variable clinical behavior are hallmarks of glioblastoma (GBM), the most common and aggressive primary malignant brain tumor. Patients with GBM often have a dismal outlook, even after undergoing surgery, postoperative radiation, and chemotherapy, which has fueled the search for specific targets to provide new insights into the development of contemporary therapies. The ability of microRNAs (miRNAs/miRs) to posttranscriptionally regulate the expression of various genes and silence many target genes involved in cell proliferation, cell cycle, apoptosis, invasion, angiogenesis, stem cell behavior and chemo- and radiotherapy resistance makes them promising candidates as prognostic biomarkers and therapeutic targets or factors to advance GBM therapeutics. Hence, this review is like a crash course in GBM and how miRNAs related to GBM. Here, we will outline the miRNAs whose role in the development of GBM has been established by recent in vitro or in vivo research. Moreover, we will provide a summary of the state of knowledge regarding oncomiRs and tumor suppressor (TS) miRNAs in relation to GBM with an emphasis on their potential applications as prognostic biomarkers and therapeutic targets.

MiR-506 targets polypyrimidine tract-binding protein 1 to inhibit airway inflammatory response and remodeling via mediating Wnt/β-catenin signaling pathway

BACKGROUND

Airway remodeling, which contributes to the clinical course of childhood asthma, occurs due to airway inflammation and is featured by anomalous biological behaviors of airway smooth muscle cells (ASMCs). microRNA (miRNA) plays an essential role in the etiopathogenesis of asthma.

OBJECTIVE

This research was aimed to characterize miR-506 in asthma and uncover potential regulatory machinery.

MATERIAL AND METHODS

The asthmatic cell model was established by treating ASMCs with transforming growth factor-beta1 (TGF-β1) and assessed by the levels of interleukin (IL)-1β and interferon gamma (IFN-γ). Using real-time quantitative polymerase chain reaction, mRNA expression of miR-506 and polypyrimidine tract-binding protein 1 (PTBP1) was measured. Cell counting kit-8 and Transwell migration tests were used for estimating the capacity of ASMCs to proliferate and migrate. Luciferase reporter assay was used to corroborate whether miR-506 was directly bound to PTBP1. Expression of PTBP1, collagen I and III, and essential proteins of the wingless-related integration (Wnt)/β-catenin pathway (β-catenin, c-MYC and cyclin D1) was accomplished by Western blot analysis. The involvement of Wnt/β-catenin signaling in asthma was confirmed by Wnt signaling pathway inhibitor (IWR-1).

RESULTS

miR-506 was poorly expressed in asthmatic tissues and cell model. Functionally, overexpression of miR-506 reduced aberrant proliferation, migration, inflammation and collagen deposition of ASMCs triggered by TGF-β1. Mechanically, miR-506 directly targeted the 3' untranslated region (3-UTR) of PTBP1 and had a negative regulation on PTBP1 expression. Moreover, overexpression of miR-506 suppressed the induction of Wnt/β-catenin pathway. The administration of IWR-1 further validated negative correlation between miR-506 and the Wnt/β-catenin pathway in asthma.

CONCLUSION

Our data indicated that targeting miR-506/PTBP1/Wnt/β-catenin axis might point in a helpful direction for treating asthma in children.

BGIG10116_34868: A Newly Discovered Gene Regulating Ejaculation Function

Ejaculation is a complex biphasic process involving a series of neurophysiological activities, such as the contraction of a large number of muscle groups and the ejaculation of semen from the urethra anterior. Due to the complexity of the process, many related factors have not been fully clarified, resulting in ejaculation dysfunction. As a common ejaculation dysfunction, lifelong premature ejaculation (LPE) is a problem for many people. Notably, gene polymorphism might play an important role in the etiology of LPE. However, the quest for identifying the actual genetic loci that contribute to LPE etiology has not been successful. Due to discrepancies in the design and methods of research, the correlation of most reports was not obtained in subjective replication experiments, and the conclusions may be inconsistent. In our study, three groups of ejaculation rats, namely, “rapid, normal, and delayed,” were selected based on the animal model of premature ejaculation (PE) in rats and the theory of ejaculation. Among them, the rats in the “rapid” ejaculation group can be used to stimulate humans with PE. Subsequently, we used the rat brain tissue for whole-transcriptome sequencing to screen the differential genes among the three groups. We tried to identify the actual genetic loci that contribute to PE etiology and provide a theoretical basis for the targeted therapy of PE.

Noncoding RNAs involved in the STAT3 pathway in glioma

Glioma is the most common malignant primary brain tumour in adults. Despite improvements in neurosurgery and radiotherapy, the prognosis of glioma patients remains poor. One of the main limitations is that there are no proper clinical therapeutic targets for glioma. Therefore, it is crucial to find one or more effective targets. Signal transducer and activator of transcription 3 (STAT3) is a member of the STAT family of genes. Abnormal expression of STAT3 is involved in the process of cell proliferation, migration, invasion, immunosuppression, angiogenesis, dryness maintenance, and resistance to radiotherapy and chemotherapy in glioma. Therefore, STAT3 has been considered an ideal therapeutic target in glioma. Noncoding RNAs (ncRNAs) are a group of genes with limited or no protein-coding capacity that can regulate gene expression at the epigenetic, transcriptional and posttranscriptional level. In this review, we summarized the ncRNAs that are correlated with the ectopic expression of STAT3 in glioma.

Plasma microRNA-720 may predict prognosis and diagnosis in glioma patients

We enrolled 122 patients with glioma who received surgery treatment in our hospital from June 2010 to May 2012, and 60 healthy individuals. We found that the plasma miR-720 in the glioma group was significantly higher than that in the healthy control group (3.19 ± 1.26 vs 0.98 ± 0.65, P<0.001). The sensitivity and specificity were 71.3% (95%CI: 62.4–79.1%) and 83.3% (71.5–91.7%), respectively. The results indicated that the plasma miR-720 level was associated with tumor grade (t = 104.418, P<0.001). The advanced tumor tended to have higher miR-720 expression level. No significant association was found between miR-720 and age, sex, tumor size, KPS and tumor position (P=0.438, 0.514, 0.518, 0.058, 0.226). The multivariate cox analysis indicated that the high expression of miR-720 (HR = 1.48, 95%CI: 1.12–2.97, P=0.023) was independently predictors of adverse prognosis in patients with glioma. The high expression of miR-720 was also associated with recurrence or development in patients with glioma (HR = 1.47, 95%CI: 1.18–3.14, P=0.012). Plasma miR-720 has a moderate diagnostic ability in early diagnostic of glioma and may be a potential tumor biomarker. The high plasma miR-720 was related to adverse prognosis in patients with glioma and could be a prognosis predictor of glioma patients.

Effect of hnRNPA2/B1 on the proliferation and apoptosis of glioma U251 cells via the regulation of AKT and STAT3 pathways

Glioma is the most common malignant tumor in the human central nervous system. Although heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNPA2/B1) was previously presumed to be a tumor-promoting gene, the relationship between hnRNPA2/B1 and glioma is unclear. Targeting hnRNPA2/B1 interference in glioma cells can significantly inhibit proliferation and increase apoptosis of human glioma cells in vitro. In a tumor xenograft model, knockdown of hnRNPA2/B1 suppressed tumor growth in glioma cells in vivo. In terms of a mechanism, the knockdown of hnRNPA2/B1 led to inactivation of the AKT and STAT3 signaling pathways, which ultimately reduced the expression of B-cell lymphoma-2 (Bcl-2), CyclinD1 and proliferating cell nuclear antigen (PCNA). Collectively, these data suggest that the inhibition of hnRNPA2/B1 can reduce the growth of gliomas through STAT3 and AKT signaling pathways, and this inhibition is expected to be a therapeutic target for gliomas.

Long non-coding RNA FOXD2-AS1 promotes cell proliferation, metastasis and EMT in glioma by sponging miR-506-5p

Long non-coding RNA forkhead box D2 adjacent opposite strand RNA 1 (FOXD2-AS1) has emerged as a potential oncogene in several tumors. However, its biological function and potential regulatory mechanism in glioma have not been fully investigated to date. In the present study, RT-qPCR was conducted to detect the levels of FOXD2-AS1 and microRNA (miR)-506-5p, and western blot assays were performed to measure the expression of CDK2, cyclinE1, P21, matrix metalloproteinase (MMP)7, MMP9, N-cadherin, E-cadherin and vimentin in glioma cells. A luciferase reporter assay was performed to verify the direct targeting of miR-506-5p by FOXD2-AS1. Subsequently, cell viability was analyzed using the CCK-8 assay. Cell migration and invasion were analyzed using Transwell and wound healing assays, respectively. The results demonstrated that FOXD2-AS1 was significantly overexpressed in glioma cells, particularly in U251 cells. Knockdown of FOXD2-AS1 in glioma cells significantly inhibited cell proliferation, migration, invasion and epithelial–mesenchymal transition (EMT) and regulated the expression of CDK2, cyclinE1, P21, MMP7 and MMP9. Next, a possible mechanism for these results was explored, and it was observed that FOXD2-AS1 binds to and negatively regulates miR-506-5p, which is known to be a tumor-suppressor gene in certain human cancer types. Furthermore, overexpression of miR-506-5p significantly inhibited cell proliferation, migration, invasion and EMT, and these effects could be reversed by transfecting FOXD2-AS1 into the cells. In conclusion, our data suggested that FOXD2-AS1 contributed to glioma proliferation, metastasis and EMT via competitively binding to miR-506-5p. FOXD2-AS1 may be a promising target for therapy in patients with glioma.

Overexpression of MiR-506 in Jurkat (Acute T Cell Leukemia) Cell Line

Background & Objective:

Acute lymphoblastic leukemia (ALL) is a malignant disease that arises from various mutations in B or T-lymphoid progenitors. MicroRNAs (miRNAs) regulate gene expression by binding to the 3' untranslated region of protein-coding genes. Dysregulation of miRNA expression may result in the development of cancerous phenotypes. Therefore, for the first time in this field, the present study aims to investigate the effect of overexpression of miR-506 in Jurkat (acute T cell leukemia) cell line.

Methods:

In this study, Jurkat cell lines were cultured in RPMI-1640 medium. Next, miR-506 was transfected with concentrations of 50 and 100 nM with Lipofectamine 2000. The accuracy of the transfection was confirmed by the transfection of siRNA conjugated with FITC. 48 h after transfection, the cells were prepared for other tests (flow cytometry, MTT assay, and RNA extraction). The expression level of miR-506 in the cells was analyzed using the quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Finally, SPSS 21 software was used for the data analysis.

Results:

According to our results, the viability of cells in concentrations of 50 and 100 nM was significantly higher than the control group. By overexpression of miR-506, the expressions of pro-apoptotic genes (p53, p21) and anti-apoptotic gene B-cell lymphoma-2 (BCL-2) are decreased and increased, respectively.

Conclusion:

This study showed that miR-506 may function as an oncogenic miRNA in the T- ALL cell line. In conclusion, overexpression of miR-506 leads to an increase in viable cancer cells.

Gelsolin inhibits malignant phenotype of glioblastoma and is regulated by miR-654-5p and miR-450b-5p

We have previously shown that gelsolin (GSN) levels are significantly lower in the blood of patients with glioblastoma (GBM) than in healthy controls. Here, we analyzed the function of GSN in GBM and examined its clinical significance. Furthermore, microRNAs involved in GSN expression were also identified. The expression of GSN was determined using western blot analysis and found to be significantly lower in GBM samples than normal ones. Gelsolin was mainly localized in normal astrocytes, shown using immunohistochemistry and immunofluorescence. Higher expression of GSN was correlated with more prolonged progression‐free survival and overall survival. Gelsolin knockdown using siRNA and shRNA markedly accelerated cell proliferation and invasion in GBM in vitro and in vivo. The inactive form of glycogen synthase kinase‐3β was dephosphorylated by GSN knockdown. In GBM tissues, the expression of GSN and microRNA (miR)‐654‐5p and miR‐450b‐5p showed an inverse correlation. The miR‐654‐5p and miR‐450b‐5p inhibitors enhanced GSN expression, resulting in reduced proliferation and invasion. In conclusion, GSN, which inhibits cell proliferation and invasion, is suppressed by miR‐654‐5p and miR‐450b‐5p in GBM, suggesting that these miRNAs can be targets for treating GBM.

LINC00963 Confers Oncogenic Properties in Glioma by Regulating the miR-506/BCAT1 Axis

Background

Glioma is a prevalent disease of the central nervous system with a high incidence and mortality rate. Many long noncoding RNAs (lncRNAs) have been determined to be critical regulators of glioma oncogenesis. However, the function and mechanism of LINC00963 in glioma have not been fully elucidated.

Methods

The expression level of RNA was determined by qRT-PCR, and the protein level was determined by Western blot analysis. A luciferase activity assay was conducted to verify the interaction between miRNA and lncRNA or the target gene. The proliferation, cell cycle distribution, invasion, and migration were evaluated by MTT, EdU, flow cytometry, wound-healing and Transwell invasion assays, respectively. In vivo tumor growth was evaluated in a xenograft nude mouse model.

Results

We found that LINC00963 was upregulated in glioma cells and tissues and associated with the poor prognosis of patients with glioma. Ectopic expression of LINC00963 promoted cell proliferation, cell cycle progression, migration, and invasion in vitro and tumorigenesis in vivo. Mechanistically, the results of luciferase activity and RNA pulldown assays validated that LINC00963 could act as a molecular sponge of miR-506. Reciprocal repression was found between LINC00963 and miR-506. In addition, BCAT1 was identified as a target of miR-506, and both the mRNA and protein levels of BCAT1 were reduced by miR-506. In tumor tissues, the expression of BCAT1 was negatively and positively correlated with miR-506 and LINC00963 expression, respectively. The reintroduction of BCAT1 in glioma cells abolished the tumor suppressive function of miR-506 by promoting cell viability and motility. The upregulated LINC00963 and BCAT1 were associated with the aggressive phenotypes of tumors.

Conclusion

Our data revealed that LINC00963 confers oncogenic function in the progression of glioma and that the LINC00963/miR-506/BCAT1 axis may be a novel mechanism and therapeutic strategy for this disease.

Long Non-Coding RNA: Dual Effects on Breast Cancer Metastasis and Clinical Applications

As a highly heterogeneous malignancy, breast cancer (BC) has become the most significant threat to female health. Distant metastasis and therapy resistance of BC are responsible for most of the cases of mortality and recurrence. Distant metastasis relies on an array of processes, such as cell proliferation, epithelial-to-mesenchymal transition (EMT), mesenchymal-to-epithelial transition (MET), and angiogenesis. Long non-coding RNA (lncRNA) refers to a class of non-coding RNA with a length of over 200 nucleotides. Currently, a rising number of studies have managed to investigate the association between BC and lncRNA. In this study, we summarized how lncRNA has dual effects in BC metastasis by regulating invasion, migration, and distant metastasis of BC cells. We also emphasize that lncRNA has crucial regulatory effects in the stemness and angiogenesis of BC. Clinically, some lncRNAs can regulate chemotherapy sensitivity in BC patients and may function as novel biomarkers to diagnose or predict prognosis for BC patients. The exact impact on clinical relevance deserves further study. This review can be an approach to understanding the dual effects of lncRNAs in BC, thereby linking lncRNAs to quasi-personalized treatment in the future.

MiRNA-506 inhibits rheumatoid arthritis fibroblast-like synoviocytes proliferation and induces apoptosis by targetting TLR4

Fibroblast-like synoviocytes (FLSs) play a crucial role in rheumatoid arthritis (RA) pathogenesis. While miRNA (miR)-506 has been implicated in the progression of multiple diseases, its role in RA remains to be explored. The present study evaluated the function of miR-506 in the regulation of RA-FLSs. FLSs were prepared from RA and healthy synovial tissues. The expression of miR-506 was measured by quantitative real time PCR (qRT-PCR). The effects of miR-506 on RA-FLSs proliferation and apoptosis were detected by cell counting Kit-8 and flow cytometry assays, respectively. The determination of TNF-α, IL-6, and IL-1β concentrations in RA-FLSs supernatant were done by ELISA. The levels of miR-506 were detected to be significantly lower in the synovial tissues and FLSs of RA than in the synovial tissues and FLSs of healthy controls. The miR-506 up-regulation in RA-FLSs significantly inhibited the proliferation and promoted cell cycle arrest at the G₀/G₁ phase. The overexpression of miR-506 induced apoptosis, along with an increase in activities of caspase-3 and -8. A target gene Toll-like receptor 4 (TLR4) under the direct regulation of miR-506 was identified through the luciferase assay, qRT-PCR and western blot analysis. Forced overexpression of TLR4 in the rescue experiments showed that TLR4 effectively reversed the effect on proliferation and apoptosis in miR-506-overexpressing RA-FLSs. Thus, miR-506 may be a potential target for RA prevention and therapy of RA.

Circular RNA HIPK3 promotes glioma progression by binding to miR-124-3p

This study aims to investigate whether circ-HIPK3 could promote the proliferation and invasion of glioma cells by upregulating STAT3 after binding to miR-124-3p, thus participating in the development of glioma. Expression levels of circ-HIPK3, miR-124-3p and STAT3 in glioma cell lines were determined using qRT-PCR. The regulatory effects of circ-HIPK3, miR-124-3p and STAT3 on proliferative and invasive capacities of glioma cells were accessed using EdU assay, CCK-8 assay and invasion assay, respectively. Cell cycle assay and cell apoptosis assay were performed by flow cytometry. Dual-luciferase reporter gene assay was conducted to determine the binding condition among circ-HIPK3, miR-124-3p and STAT3. Rescue experiments were performed in co-transfected glioma cells. QRT-PCR data showed that circ-HIPK3 and STAT3 are highly expressed, whereas miR-124-3p is lowly expressed in glioma cells than those of negative control cell. Knockdown of circ-HIPK3 in U87 and U251 cells inhibited their proliferative and invasive capacities. On the contrary, miR-124-3p knockdown improved proliferative and migratory capacities. Dual-luciferase reporter gene assay exerted that circ-HIPK3 could bind to miR-124-3p and STAT3 is the target gene of miR-124-3p. Western blot results elucidated that circ-HIPK3 stabilizes STAT3 expression, whereas miR-124-3p degrades STAT3 expression. Rescue experiments demonstrated that overexpression of circ-HIPK3 could partially reverse the inhibited proliferative and migratory capacities induced by miR-124-3p in U87 and U251 cells. In summary, we found that overexpression of circ-HIPK3 promotes proliferative and invasive capacities of glioma cells by sponging miR-124-3p to upregulate STAT3 expression.

The emerging role of miR-506 in cancer

MicroRNAs (miRNAs) are small non-coding RNAs that post-transcriptionally regulate gene expression. They are involved in almost all biological processes, and many have been identified as potential oncogenes or tumor suppressor genes. miR-506 was recently discovered to play pivotal roles in regulating cell proliferation, differentiation, migration and invasion. Dysregulation of miR-506 has been demonstrated in multiple types of cancers; however, whether it functions as an oncogene or a tumor suppressor seems to be context-dependent. Altered miR-506 expression in cancer is caused by promoter methylation and changes in upstream transcription factors. In this review, we summarize the current understanding of the diverse roles and underlying mechanisms of miR-506 and its involvement in cancer, and suggest the potential therapeutic strategy based on miR-506.

KIAA0247 suppresses the proliferation, angiogenesis and promote apoptosis of human glioma through inactivation of the AKT and Stat3 signaling pathway

Gliomas are the most common and aggressive type of primary adult brain tumors. Although KIAA0247 previously is a speculated target of the tumor suppressor gene, little is known about the association between KIAA0247 and glioma. In this study, we clearly demonstrate that KIAA0247 expression is decreased in glioma and was negatively correlated with the histologic grade. Overexpression of KIAA0247 in glioma cells inhibits proliferation, angiogenesis and promoted apoptosis of human glioma cells in vitro. In contrast, knockdown of KIAA0247 increases the proliferation, angiogenesis and decreases apoptosis of these cells. In a tumor xenograft model, overexpression of KIAA0247 suppresses tumor growth of glioma cells in vivo, while KIAA0247 knockdown promotes the tumor growth. Mechanistically, overexpression of KIAA0247 is able to inhibit phosphorylation of AKT and Stat3 in glioma cells, resulting in inactivation of the AKT and Stat3 signaling pathways, this ultimately decreases the expression of PCNA, CyclinD1, Bcl2 and VEGF. Collectively, these data indicate that KIAA0247 may work as a tumor suppressor gene in glioma and a promising therapeutic target for gliomas.

MicroRNA-598 Inhibits Cell Proliferation and Invasion of Glioblastoma by Directly Targeting Metastasis Associated in Colon Cancer-1 (MACC1)

The dysregulation of microRNA (miRNA) expression is closely related with tumorigenesis and tumor development in glioblastoma (GBM). In this study, we found that miRNA-598 (miR-598) expression was significantly downregulated in GBM tissues and cell lines. Restoring miR-598 expression inhibited cell proliferation and invasion in GBM. Moreover, we validated that metastasis associated in colon cancer-1 (MACC1) is a novel target of miR-598 in GBM. Restoring MACC1 expression reversed the inhibitory effects of miR-598 overexpression on GBM cells. In addition, miR-598 overexpression suppressed Met/AKT pathway activation in GBM. Our results provided compelling evidence that miR-598 serves tumor-suppressive roles in GBM and that its antioncogenic effects are mediated chiefly through the direct suppression of MACC1 expression and regulation of the Met/AKT signaling pathway. Therefore, miR-598 is a potential target in the treatment of GBM.

Therapeutic Potential of Thymoquinone in Glioblastoma Treatment: Targeting Major Gliomagenesis Signaling Pathways

Glioblastoma multiforme (GBM) is one of the most devastating brain tumors with median survival of one year and presents unique challenges to therapy because of its aggressive behavior. Current treatment strategy involves surgery, radiotherapy, immunotherapy, and adjuvant chemotherapy even though optimal management requires a multidisciplinary approach and knowledge of potential complications from both the disease and its treatment. Thymoquinone (TQ), the main bioactive component of Nigella sativa L., has exhibited anticancer effects in numerous preclinical studies. Due to its multitargeting nature, TQ interferes in a wide range of tumorigenic processes and counteract carcinogenesis, malignant growth, invasion, migration, and angiogenesis. TQ can specifically sensitize tumor cells towards conventional cancer treatments and minimize therapy-associated toxic effects in normal cells. Its potential to enter brain via nasal pathway due to volatile nature of TQ adds another advantage in overcoming blood-brain barrier. In this review, we summarized the potential role of TQ in different signaling pathways in GBM that have undergone treatment with standard therapeutic modalities or with TQ. Altogether, we suggest further comprehensive evaluation of TQ in preclinical and clinical level to delineate its implied utility as novel therapeutics to combat the challenges for the treatment of GBM.

Overexpression of microRNA-506-3p aggravates the injury of vascular endothelial cells in patients with hypertension by downregulating Beclin1 expression

The aim of the present study was to measure the expression of microRNA (miRNA)-506-3p in the peripheral blood of patients with hypertension and to determine the biological functions and mechanisms of action of miR-506-3p. A total of 61 patients with primary hypertension were included in the present study. Peripheral blood was collected from all patients, as well as 31 healthy subjects who were included in a control group. The expression of miR-506-3p in peripheral blood was determined by reverse transcription-quantitative polymerase chain reaction. Human umbilical vein endothelial cells (HUVECs) were transfected with miR-506-3p mimics or miR-506-3p inhibitor. The proliferation and migration of HUVECs were determined using cell-counting kit 8 and Transwell assays, respectively. The cell cycle and apoptosis of HUVECs were detected by flow cytometry. The expression of Beclin1 (BECN1) protein, a potential target of miR-506-3p, was measured using western blotting. A dual-luciferase reporter assay was performed to determine the interaction between BECN1 and miR-506-3p. It was demonstrated that miR-506-3p expression in the peripheral blood of patients with patients was upregulated and dependent on the severity of hypertension. miR-506-3p overexpression inhibited the proliferation and migration of HUVECs. In addition, miR-506-3p inhibited the transition from the G1 phase to the S-phase in HUVECs. Overexpression of miR-506-3p promoted the apoptosis of HUVECs. Notably, miR-506-3p downregulated the expression of BECN1 by directly binding to its 3′-untranslated region. The present study demonstrated that miR-506-3p expression is elevated in the peripheral blood of patients with hypertension and is associated with the severity of hypertension. By downregulating BECN1 expression, miR-506-3p aggravates injury in vascular endothelial cells by inhibiting the proliferation and migration of HUVECs, as well as promoting their apoptosis.

MicroRNA-29a inhibits proliferation and induces apoptosis in rheumatoid arthritis fibroblast-like synoviocytes by repressing STAT3

Rheumatoid arthritis-fibroblast-like synoviocytes (RA-FLS) with aberrant expression of microRNA (miRNA) have been reported to be involved in the initiation, progression, and perpetuation of rheumatoid arthritis (RA). In this study, we explored the biological function and underlying mechanism of microRNA-29a (miR-29a) in cultured RA-FLS from RA patients. The expression of miR-29a in serum, synovial tissues, and FLS from RA patients and health donors was detected by real-time quantitative RT-PCR (qRT-PCR). The effects of miR-29a on cell proliferation, apoptosis, and inflammatory cytokine levels in RA-FLS were also determined using Counting Assay Kit-8 (CCK-8), flow cytometry, and enzyme-linked immunosorbent assay (ELISA) respectively. Luciferase reporter assay was carried out to identify the target genes of miR-29a. We observed that expression of miR-29a was markedly downregulated in serum, synovial tissues and FLS of RA patients. miR-29a overexpression in RA-FLS significantly inhibited proliferation, promoted apoptosis, and suppressed expression of inflammatory cytokines. Signal transducer and activator of transcription 3 (STAT3) was identified to be a direct target of miR-29a in RA-FLS. miR-29a overexpression suppressed the expression of STAT3, as well as phosphorylated STAT3(p-STAT3) and its downstream targets protein (Cyclin D1 and Bcl-2). In addition, the levels of miR-29a were inversely correlated with that of STAT3 in synovial tissues. Rescue experiments showed that overexpression of STAT3 effectively reversed the effect of miR-29a on proliferation and apoptosis in RA-FLS. These data indicate that miR-29a inhibits proliferation and induces apoptosis in RA-FLS by targeting STAT3, suggesting that promoting miR-29a expression may yield therapeutic benefits in the treatment of RA.

miRnalyze: an interactive database linking tool to unlock intuitive microRNA regulation of cell signaling pathways

The various pathophysiological processes occurring in living systems are known to be orchestrated by delicate interplays and cross-talks between different genes and their regulators. Among the various regulators of genes, there is a class of small non-coding RNA molecules known as microRNAs. Although, the relative simplicity of miRNAs and their ability to modulate cellular processes make them attractive therapeutic candidates, their presence in large numbers make it challenging for experimental researchers to interpret the intricacies of the molecular processes they regulate. Most of the existing bioinformatic tools fail to address these challenges. Here, we present a new web resource 'miRnalyze' that has been specifically designed to directly identify the putative regulation of cell signaling pathways by miRNAs. The tool integrates miRNA-target predictions with signaling cascade members by utilizing TargetScanHuman 7.1 miRNA-target prediction tool and the KEGG pathway database, and thus provides researchers with in-depth insights into modulation of signal transduction pathways by miRNAs. miRnalyze is capable of identifying common miRNAs targeting more than one gene in the same signaling pathway-a feature that further increases the probability of modulating the pathway and downstream reactions when using miRNA modulators. Additionally, miRnalyze can sort miRNAs according to the seed-match types and TargetScan Context ++ score, thus providing a hierarchical list of most valuable miRNAs. Furthermore, in order to provide users with comprehensive information regarding miRNAs, genes and pathways, miRnalyze also links to expression data of miRNAs (miRmine) and genes (TiGER) and proteome abundance (PaxDb) data. To validate the capability of the tool, we have documented the correlation of miRnalyze's prediction with experimental confirmation studies.

Database URL

http://www.mirnalyze.in.

MiR-592 functions as a tumor suppressor in glioma by targeting IGFBP2

A growing body of evidence suggests that microRNA-592 is involved in tumor initiation and development in several types of human cancers. However, the biological functions and molecular mechanism of microRNA-592 in glioma remain unclear. In this study, we explored the potential role of microRNA-592 in glioma as well as the possible molecular mechanisms. Our results proved that microRNA-592 expression was significantly downregulated in glioma tissues and cell lines (p < 0.01). Functional assays revealed that overexpression of microRNA-592 dramatically reduced the cell proliferation, migration, and invasion and induced cell arrest at G1/G0 phase in vitro. Mechanistic investigations defined insulin-like growth factor binding protein 2 as a direct and functional downstream target of microRNA-592, which was involved in the microRNA-592-mediated tumor-suppressive effects in glioma cells. Moreover, the in vivo study showed that microRNA-592 overexpression produced the smaller tumor volume and weight in nude mice. In summary, these results elucidated the function of microRNA-592 in glioma progression and suggested a promising application of it in glioma treatment.

MIR506 induces autophagy-related cell death in pancreatic cancer cells by targeting the STAT3 pathway

Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive and lethal cancer. The role of autophagy in the pathobiology of PDAC is intricate, with opposing functions manifested in different cellular contexts. MIR506 functions as a tumor suppressor in many cancer types through the regulation of multiple pathways. In this study, we hypothesized that MIR506 exerted a tumor suppression function in PDAC by inducing autophagy-related cell death. Our results provided evidence that downregulation of MIR506 expression was associated with disease progression in human PDAC. MIR506 triggered autophagic flux in PDAC cells, which led to autophagy-related cell death through direct targeting of the STAT3 (signal transducer and activator of transcription 3)-BCL2-BECN1 axis. Silencing and inhibiting STAT3 recapitulated the effects of MIR506, whereas forced expression of STAT3 abrogated the effects of MIR506. We propose that the apoptosis-inhibitory protein BCL2, which also inhibits induction of autophagy by blocking BECN1, was inhibited by MIR506 through targeting STAT3, thus augmenting BECN1 and promoting autophagy-related cell death. Silencing BECN1 and overexpression of BCL2 abrogated the effects of MIR506. These findings expand the known mechanisms of MIR506-mediated tumor suppression to activation of autophagy-related cell death and suggest a strategy for using MIR506 as an anti-STAT3 approach to PDAC treatment.

MiR-320a effectively suppresses lung adenocarcinoma cell proliferation and metastasis by regulating STAT3 signals

MicroRNAs play important roles in tumorigenesis of various types of cancers. MiR-320a can inhibits cell proliferation of some cancers, but the biologic roles of miR-320a in lung cancer need to be further studied. Here, we investigated the roles of miR-320a in suppressing the proliferation of lung adenocarcinoma cells. MiR-320a treatment was found to effectively suppress LTEP-a-2 and A549 cell proliferation, and induce more apoptotic cells with irradiation treatment compared with control treatment. Our results also showed that miR-320a, as a novel miRNA, directly regulated signal transducer and activator of transcription 3 (STAT3) and its signals, such as Bcl^-2, Bax, and Caspase 3. The siRNA-inhibited STAT3 levels further proved its roles in regulating STAT3 signals. Moreover, miR-320a treatment effectively suppressed cancer cell growth in mice xenografts compared with controls, and significantly inhibited cell migration in vitro and in vivo. Our findings collectively demonstrated that miR-320a, by directly regulating STAT3 signals, not only suppressed cell proliferation and metastasis, but also enhanced irradiation-induced apoptosis of adenocarcinomia cells.

Long non-coding RNA NEAT1 facilitates pancreatic cancer progression through negative modulation of miR-506-3p

Recently, long non-coding RNAs (lncRNAs) have been shown to have critical regulatory roles in tumourigenesis. Increasing evidence has suggested that lncRNA NEAT1 has been implicated in various types of human cancer. However, the potential biological roles and regulatory mechanisms of NEAT1 in pancreatic cancer (PC) remains unclear. Here, we found that the expression level of NEAT1 was higher in PC tissues compared to the corresponding non-tumor tissues. Besides, our findings indicate that high NEAT1 expression level is closely correlated with tumor progression and poor survival in PC patients. Furthermore, we also found that knockdown of NEAT1 remarkably suppressed cell proliferation by inducing cell cycle arrest and apoptosis promotion in PC cells. Moreover, bioinformatics analysis and luciferase reporter assay revealed that NEAT1 directly bound to the miR-506-3p, which has been reported to act as a tumor suppressor in diverse cancers. Additionally, our results confirmed that the tumor-promoting effects of NEAT1 in PC cells is at least partly through negative modulation of miR-506-3p. Overall, our results suggested that NEAT1 functions as an oncogenic lncRNA in PC, which could be a novel diagnostic and therapeutic target for PC.

Demethoxycurcumin was superior to temozolomide in the inhibition of the growth of glioblastoma stem cells in vivo

Temozolomide (TMZ) is widely used in the treatment of glioblastoma multiforme (GBM) as it can effectively inhibit the growth of GBM for some months; however, this cancer type is still incurable. The existence of glioma stem cells (GSCs) is thought to be responsible for the invariable recurrence of GBM after treatment, but GSCs are insensitive to TMZ. Our recent research showed that demethoxycurcumin (DMC), a component of curcumin, was superior to TMZ in its ability to inhibit proliferation and induce apoptosis of GSCs in vitro. In addition, the combined treatment of TMZ + DMC induced more obvious anti-GSC effects. However, in this study, no obvious synergistic anti-GSC effects of TMZ + DMC were found in vivo, while DMC was still superior to TMZ with respect to growth inhibition of GSCs in vivo. Furthermore, immunohistochemistry for proliferating cell nuclear antigen (PCNA) showed that such inhibitory effects were mainly related to the inhibition of cell proliferation rather than to apoptosis. However, a high concentration of DMC (50 mg/kg) alone or combined with TMZ could also induce approximately 10 % of the cells to undergo apoptosis according to a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Finally, an investigation of the underlying mechanism revealed that the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) 3 signaling pathway played an important role in the anti-GSC effects. When the JAK inhibitor AG490 was applied, the anti-GSC effects of DMC were enhanced. Taken together, the present work reveals that DMC is superior to TMZ with respect to its anti-GSC effects in vivo, which are mediated through the inhibition of the activation of the JAK/STAT3 pathway; however, DMC demonstrated no synergistic effects with TMZ.

Role of STAT3 in Genesis and Progression of Human Malignant Gliomas

Signal transducer and activator of transcription 3 (STAT3) is aberrantly activated in glioblastoma and has been identified as a relevant therapeutic target in this disease and many other human cancers. After two decades of intensive research, there is not yet any approved STAT3-based glioma therapy. In addition to the canonical activation by tyrosine 705 phosphorylation, concordant reports described a potential therapeutic relevance of other post-translational modifications including mainly serine 727 phosphorylation. Such reports reinforce the need to refine the strategy of targeting STAT3 in each concerned disease. This review focuses on the role of serine 727 and tyrosine 705 phosphorylation of STAT3 in glioma. It explores their contribution to glial cell transformation and to the mechanisms that make glioma escape to both immune control and standard treatment.

MicroRNA-506 is up-regulated in the development of pancreatic ductal adenocarcinoma and is associated with attenuated disease progression

BACKGROUND

MicroRNA-506 (miR-506) has been reported to function in several tumors as a tumor suppressor gene or oncogene. However, the expression and role of miR-506 in pancreatic ductal adenocarcinoma (PDAC) remains unclear. In this study, we aimed to evaluate the phenotype of miR-506 in PDAC.

METHODS

Using miRNA in situ hybridization, we examined the expression of miR-506 in 113 PDACs and 87 paired normal pancreatic tissues. We evaluated miR-506 expression in PDAC cells, normal pancreatic ducts, and acinus/islands, and we analyzed the associations between miR-506 expression and the clinicopathologic characteristics of PDAC patients.

RESULTS

miR-506 expression was higher in PDAC than in matched normal pancreatic ductal cells (P < 0.001). On the other hand, the combined group of well and moderately differentiated PDACs showed higher levels of miR-506 than the poorly differentiated ones (P = 0.023). Moreover, miR-506 expression was negatively associated with pathologic T category (P = 0.004) and lymph node metastasis (P = 0.033), suggesting that miR-506 might inhibit the progression of PDAC.

CONCLUSIONS

Our results suggest that miR-506 either plays a role as an oncogene in the tumorigenesis and a tumor suppressor in the progression or serves as a house-keeping, tumor-suppressing miRNA, whose expression can be activated by oncogenic signals in early development to hinder the progression of PDAC.