Downregulation of microRNA-206 suppresses clear cell renal carcinoma proliferation and invasion by targeting vascular endothelial growth factor A

MicroRNA-206 in human cancer: Mechanistic and clinical perspectives

MicroRNAs (miRNAs), small non-coding RNAs approximately 20-25 nt in length, play important roles via directly binding to the corresponding 3' UTR of target mRNAs. Recent research has shown that miRNAs cover a wide range of diseases, including several types of cancer. It is interesting to note that miR-206 operates as a tumor suppressor and is downregulated in abundant cancer types, such as breast cancer, lung cancer, colorectal cancer, and so forth. Interestingly, a growing number of studies have also reported that miR-206 could function as an oncogene and promote tumor cell proliferation. Thereby, miR-206 may act as either oncogenes or tumor suppressors under certain conditions. In addition, it was widely acknowledged that restoring tumor-suppressor miR-206 has emerged as an unconventional cancer therapy strategy. Therefore, miR-206 might be a newfangled procedure for achieving a more significant treatment outcome for cancer patients. This review summarizes the role of miR-206 in several cancer types and the contributions made between miR-206 and the diagnosis, treatment, and drug resistance of solid tumors.

The Significance of MicroRNAs in the Molecular Pathology of Brain Metastases

Brain metastases are the most frequent intracranial tumors in adults and the cause of death in almost one-fourth of cases. The incidence of brain metastases is steadily increasing. The main reason for this increase could be the introduction of new and more efficient therapeutic strategies that lead to longer survival but, at the same time, cause a higher risk of brain parenchyma infiltration. In addition, the advances in imaging methodology, which provide earlier identification of brain metastases, may also be a reason for the higher recorded number of patients with these tumors. Metastasis is a complex biological process that is still largely unexplored, influenced by many factors and involving many molecules. A deeper understanding of the process will allow the discovery of more effective diagnostic and therapeutic approaches that could improve the quality and length of patient survival. Recent studies have shown that microRNAs (miRNAs) are essential molecules that are involved in specific steps of the metastatic cascade. MiRNAs are endogenously expressed small non-coding RNAs that act as post-transcriptional regulators of gene expression and thus regulate most cellular processes. The dysregulation of these molecules has been implicated in many cancers, including brain metastases. Therefore, miRNAs represent promising diagnostic molecules and therapeutic targets in brain metastases. This review summarizes the current knowledge on the importance of miRNAs in brain metastasis, focusing on their involvement in the metastatic cascade and their potential clinical implications.

MicroRNA-206 has a bright application prospect in the diagnosis of cases with oral cancer

Previous studies have shown that microRNA‐206 (miR‐206) exhibits anti‐tumour properties in various tumours. Nevertheless, diagnostic significance of miR‐206 in oral cancer is still poorly known. Our research was carried out to explore the performance of miR‐206 in the diagnosis of oral cancer. Quantitative real‐time polymerase chain reaction (qRT‐PCR) method was adopted to measure the level of miR‐206 in serum specimens from oral cancer cases and control individuals. Chi‐square test was performed to analyse the correlation between miR‐206 level and clinicopathological parameters of the cases. Receiver operating characteristic (ROC) curve was constituted to assess diagnostic accuracy of miR‐206 in oral cancer. Serum miR‐206 level in oral cancer patients was significantly lower than that in control individuals (P < .001). miR‐206 expression was obviously related to T classification (P = .033), TNM stage (P = .008) and lymph node metastasis (P = .028). The area under the curve (AUC) of the ROC curve was 0.846 (95% CI = 0.797‐0.896, P < .001) with a specificity of 72.7% and a sensitivity of 81.2%. It revealed that miR‐206 might be a non‐invasive indicator in differentiating oral cancer cases from control individuals. Down‐regulation of miR‐206 is related to the development of oral cancer. Serum miR‐206 might be an effective indicator for early detection of oral cancer.

MiR-206 promotes extracellular matrix accumulation and relieves infantile hemangioma through targeted inhibition of DNMT3A

MiR-206 is abnormally expressed in infant hemangioma endothelial cells (HemECs), but the mechanism is not clear. We explored the intervention of miR-206 in HemECs in relation to extracellular matrix (ECM) metabolism. We selected 48 cases of infantile hemangioma (IH) from volunteer organizations. After the isolated and extracted HemECs were interfered with overexpressed or silenced miR-206, the effects of miR-206 on the proliferation, migration and invasion of HemECs were examined through basic cell function experiments. The expression differences of miR-206, DNA Methyltransferase 3A (DNMT3A) and ECM-related genes were analyzed as needed by qRT-PCR or Western blot. TargetScan and dual-luciferase experiments were applied to predict and confirm the binding relationship between miR-206 and DNMT3A. The correlation between miR-206 and DNMT3A was analyzed in IH tissues by Pearson correlation coefficient, and further confirmed in HemECs by conducting rescue experiments. A nude mouse model of xenograft tumor was constructed to verify the results of in vitro experiments. MiR-206, which was downregulated in proliferative hemangioma, suppressed the malignant development of HemECs by regulating ECM-related genes. As the target gene of miR-206, DNMT3A was high-expressed in IH tissues and was negatively correlated with miR-206. Overexpressed DNMT3A counteracted the inhibitory effect of miR-206 mimic on HemECs and its regulatory effect on ECM. The results of in vivo experiments were consistent with those from cell experiments. Thus, miR-206 could promote ECM accumulation through targeted inhibition of DNMT3A, further inhibiting the malignant development of HemECs and relieving IH.

miR-206 regulates non-small-cell lung cancer cell aerobic glycolysis by targeting hexokinase 2

Aerobic glycolysis was closely associated with the malignant transformation and prognosis of tumours. miR-206 was found to be downregulated in several cancers. However, whether miR-206 functions in non-small-cell lung cancers (NSCLCs) via the process of aerobic glycolysis remains poorly characterized. Quantitative real-time PCR was performed to detect miR-206 level in NSCLC cells and tissues. The effect of miR-206 on hexokinase 2 (HK2) expression was examined through miR-206 overexpression or miR-206 knockdown. CCK-8 assay and colony formation assay were carried out to explore the role of miR-206 on cell proliferation and colony formation, respectively. The relationship between miR-206 and HK2 was measured by dual-luciferase reporter assay. Glucose consumption, lactate production assay and ATP generation were performed in NSCLC cells following miR-206 and HK2 overexpression. We found that miR-206 was downregulated in NSCLC tissues and cells. miR-206 overexpression downregulated the expression of HK2 via targeting HK2 3'UTR in NSCLC cells. In addition, miR-206 decreased the cell viability and colony formation in NSCLC cells. Furthermore, miR-206 reduced glucose uptake, lactate production and ATP generation in NSCLC cells via HK2 repression. In conclusion, these findings suggested that miR-206 regulated NSCLC cell aerobic glycolysis by targeting HK2.

hsa_circ_0041795 contributes to human retinal pigment epithelial cells (ARPE 19) injury induced by high glucose via sponging miR-646 and activating VEGFC

Diabetic retinopathy (DR)is a common diabetes complication, resulting in the loss of vision. circRNAshave been reported to serve as ceRNA via targeting corresponding miRNAs and modulating mRNA expression in various diseases. Recently, increasing reports has indicated circRNAs can exert a significant role inDR progression. However, the expression and mechanism of hsa_circ_0041795 in human retinal pigment epithelial cells ARPE-19 treated by high glucose remains poorly known. Hence, we aimed to work figure out the effect of hsa_circ_0041795 in high glucose (HG)-induced ARPE-19 cell damage and study its molecular mechanisms. In our current research, we found that hsa_circ_0041795 was obviously up-regulated in HG-treated ARPE-19 cells. High dose of glucose greatly depressed ARPE-19 cell survival and contributed to cell apoptosis. In addition, we observed that loss of hsa_circ_0041795 enhanced cell proliferation and inhibit ARPE-19 cell apoptosis, after HG incubation. Furthermore, data of ELISA indicated that hsa_circ_0041795 siRNA significantly restrained inflammatory factors expression, such as TNF-α, IL-1β and IL-6 in ARPE-19 cells treated with HG. miR-646 has been recognized in multiple diseases and currently, we predicted that miR-646 acted as a target of hsa_circ_0041795. Moreover, we found that miR-646 inhibitors dramatically reversed the effect of hsa_circ_0041795 siRNA on ARPE-19 cells. Additionally, a dual-luciferase reporter assay proved that VEGFC was a direct target of miR-646. Our results demonstrated that hsa_circ_0041795 might exhibit a novel therapeutic potential in the treatment of DR.

miR-206 Promotes Cancer Progression by Targeting Full-Length Neurokinin-1 Receptor in Breast Cancer

Substance P plays a pivotal role in human cancer development and progression by binding to its receptor, neurokinin-1. Neurokinin-1 has 2 isoforms: full-length neurokinin-1 and truncated neurokinin-1, the latter lacking the cytoplasmic terminal 96-amino acid residues of the full-length protein. We have identified 3 candidate miR-206 target sites within the 3′-untranslated region of the full-length neurokinin-1 gene from bioinformatics database searches. In the present study, real-time quantitative polymerase chain reaction was performed to quantify the expression of miR-206, and the expression of neurokinin-1 and full-length neurokinin-1 was detected by immunohistochemistry in 82 clinical cases of breast cancer and paired adjacent normal tissues. The miR-206 target gene was demonstrated by using a dual-luciferase reporter assay, quantitative real-time polymerase chain reaction, and Western blotting. Transwell migration and invasion, colony formation, and proliferation assays were performed to evaluate the effects of miR-206 expression on various aspects of breast cancer cell behavior in vitro. We showed that miR-206 expression is upregulated in breast cancer cell lines and breast cancer tissues when compared to that in adjacent normal tissues, and full-length neurokinin-1 expression inversely correlates with Tumor Lymph Node Metastasis (TNM) stage and lymph node metastasis. Western blotting, quantitative real-time polymerase chain reaction, and dual-luciferase reporter assays demonstrated that miR-206 binds the 3′-untranslated region of full-length neurokinin-1 messenger RNA, regulating protein expression. We showed that the overexpression of miR-206 promotes breast cancer cell invasion, migration, proliferation, and colony formation in vitro. The present study furthers the current understanding of the mechanisms underlying breast cancer pathogenesis and may be useful for the development of novel targeted therapies.

Downregulation of MicroRNA-206 Alleviates the Sublethal Oxidative Stress-Induced Premature Senescence and Dysfunction in Mesenchymal Stem Cells via Targeting Alpl

Bone marrow-derived mesenchymal stem cells (MSCs) have shown great promise in tissue engineering and regenerative medicine; however, the regenerative capacity of senescent MSCs is greatly reduced, thus exhibiting limited therapy potential. Previous studies uncovered that microRNA-206 (miR-206) could largely regulate cell functions, including cell proliferation, survival, and apoptosis, but whether miR-206 is involved in the senescent process of MSCs remains unknown. In this study, we mainly elucidated the effects of miR-206 on MSC senescence and the underlying mechanism. We discovered that miR-206 was upregulated in the senescent MSCs induced by H₂O₂, and abrogation of miR-206 could alleviate this tendency. Besides, we determined that by targeting Alpl, miR-206 could ameliorate the impaired migration and paracrine function in MSCs reduced by H₂O₂. In vivo study, we revealed that inhibition of miR-206 in senescent MSCs could effectively protect their potential for myocardial infarction treatment in a rat MI model. In summary, we examined that inhibition of miR-206 in MSCs can alleviate H₂O₂-induced senescence and dysfunction, thus protecting its therapeutic potential.

Silencing circZFR inhibits the proliferation, migration and invasion of human renal carcinoma cells by regulating miR-206

Background

Renal cell carcinoma (RCC) is the most prevalent kind of kidney cancer. At present, the most efficient treatment mean is surgery. 40% patients with clear cell RCC (ccRCC) relapse after surgery. Identifying novel therapeutic markers and spots for early detection and treatment of RCC is necessary.

Methods

qRT-PCR was utilized to quantify circZFR and miR-206 expression in CAKI-1 and ACHN cells. Cell viability was detected by CCK-8 assay. Colony formation capacity was measured by colony formation assay. Transwell assay was utilized to investigate migration and invasion capacity. Expression of migration and apoptosis-associated proteins was quantified by Western blot.

Results

As a result, circZFR was highly expressed in RCC tissues and cells. Si-circZFR suppressed cell growth, migration and invasion of experimental cells. In addition, knockdown of circZFR upregulated miR-206 expression. Moreover, the antigrowth, antimigrating and anti-invasive effects of si-circZFR were attenuated when downregulating miR-206. Furthermore, Met is the target gene of miR-206 in experimental cells. The suppression on these signaling pathways was acted by targeting miR-206/Met axis.

Conclusion

The results demonstrated si-circZFR inhibited cell growth, migration and invasion in experimental cells by up-regulating of miR-206. Furthermore, si-circZFR suppressed Wnt/β-catenin and PI3K/AKT pathways via targeting miR-206/Met axis.

miRNA-206 regulates human pulmonary microvascular endothelial cell apoptosis via targeting in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a leading cause of death due to tis high morbidity and mortality. microRNAs have emerged as new biomarkers for the prognosis and diagnosis of patients with COPD. In this study, we aimed to investigate the expression of microRNA-206 (miR-206) in lung tissues from COPD patients and to explore the regulatory role of miR-206 in the human pulmonary microvascular endothelial cells (HPMECs). Our results showed that cigarette smoke extract (CSE) promoted cell apoptosis, increased caspase-3 activity, and upregulated the expression of miR-206 in HPMECs, which was significantly reversed by the miR-206 knockdown. Transfection with miR-206 mimics led to cell apoptosis and was closely related to changes in the protein expression levels of caspase-3, caspase-9, and Bcl-2 in HPMECs. Further bioinformatics prediction analysis revealed that the 3'-untranslated region (3'UTR) of Notch3 and vascular endothelial growth factor-A (VEGFA) harbored miR-206-binding sites, and overexpression of miR-206 repressed the luciferase activity of the vectors containing Notch3 and VEGFA 3'UTR. Overexpression of either Notch3 or VEGFA attenuated miR-206-induced cell apoptosis in HPMECs. More importantly, miR-206 expression was upregulated in the lung tissues from COPD patients and was positively corrected with forced expiratory volume 1% predicted in COPD patients, while Notch3 and VEGFA mRNA levels were downregulated and were negatively correlated with the expression level of miR-206 in the lung tissues from COPD patients. In conclusion, our results showed that miR-206 was upregulated in COPD patients and CSE-treated HPMECs, promoted cell apoptosis via directly targeting Notch3 and VEGFA in HPMECs.

Effects of thymoquinone on liver miRNAs and oxidative stress in Ehrlich acid mouse solid tumor model

We investigated the effects of thymoquinone (TQ) on the expression of liver microRNAs (miRNAs), liver histopathology and oxidative stress in Ehrlich acid solid tumor model induced mice. We used 24 male BALB/c mice divided randomly into three groups. Control (C) group mice were injected intraperitoneally (i.p.) with 0.5 ml saline for four weeks. Tumor (T) group mice were injected i.p. with 0.5 ml saline for four weeks, then Ehrlich acid tumor cells were injected subcutaneously into the neck to induce solid tumor formation. TQ (T + Tq) group mice injected i.p. with 10 mg/kg TQ for four weeks, then Ehrlich acid tumor cells were injected subcutaneously into the neck of the mice in this group to induce solid tumor formation. At the end of the study, liver from all groups were removed for histopathological and miRNAs analysis, and oxidative stress measurement. We found that the expression of miR-206b-3p was up-regulated and the oxidative stress and necrosis increased in the liver tissue of mice with Ehrlich acid solid tumor. TQ application decreased the oxidative stress, prevented necrosis, increased regeneration and down-regulated the expression of miR-206b-3p in the liver tissue.

WISP-3 inhibition of miR-452 promotes VEGF-A expression in chondrosarcoma cells and induces endothelial progenitor cells angiogenesis

Chondrosarcoma is the second most prevalent general primary tumor of bone following osteosarcoma. Chondrosarcoma development may be linked to angiogenesis, which is principally elicited by vascular endothelial growth factor-A (VEGF-A). VEGF-A level has been recognized as a prognostic marker in angiogenesis. WNT1-inducible signaling pathway protein-3 (WISP)-3/CCN6 belongs to the CCN family and is involved in regulating several cellular functions, including cell proliferation, differentiation, and migration. Nevertheless, the effect of WISP-3 on VEGF-A production and angiogenesis in human chondrosarcoma remains largely unknown. This current study shows that WISP-3 promoted VEGF-A production and induced angiogenesis of human endothelial progenitor cells. Moreover, WISP-3-enhanced VEGF-A expression and angiogenesis involved the c-Src and p38 signaling pathways, while miR-452 expression was negatively affected by WISP-3 via the c-Src and p38 pathways. Our results illustrate the clinical significance of WISP-3, VEGF-A and miR-452 in human chondrosarcoma patients. WISP-3 may illustrate a novel therapeutic target in the metastasis and angiogenesis of chondrosarcoma.

miR-514a-3p functions as a tumor suppressor in renal cell carcinoma

Renal cell carcinoma (RCC) is the most common type of kidney cancer, and the prognosis of metastatic RCC remains poor with a high rate of recurrence and mortality. A previous study has revealed that microRNA (miRNA), which negatively regulates protein expression, serves a role of oncogene or tumor suppressor. The aim of the present study was to investigate the expression and function of miR-514a-3p in RCC. To detect the expression of miR-514a-3p in 32 paired RCC tissues, quantitative polymerase chain reaction (qPCR) was performed. The function of miR-514a-3p in the proliferation, mobility and apoptosis of RCC cells (786-O and ACHN) was assessed by MTT, CCK-8, cell scratch, Transwell, Hoechst 33342 staining and flow cytometry assay. The results of qPCR revealed that miR-514a-3p was significantly downregulated in RCC tissues compared with adjacent normal tissues. Upregulation of miR-514a-3p by transfection of mimics suppressed RCC cell proliferation, migration and invasion, and induced cell apoptosis. The results revealed that miR-514a-3p was significantly downregulated in RCC and may serve a role as tumor suppressor in RCC. Further studies are required, focusing on the possibility of using miR-514a-3p as a biomarker for RCC as well as the pathway of miR-514a-3p in RCC.

miR-144 inhibits growth and metastasis of cervical cancer cells by targeting VEGFA and VEGFC

MicroRNAs (miRs) are aberrantly expressed in various cancer types and have critical roles in their genesis and progression. miR-144 has been identified to be involved in the development of hepatocellular carcinoma and rectal cancer. However, the roles of miR-144 in cervical cancer and the underlying molecular mechanisms have remained elusive. The present study identified that miR-144 was significantly decreased in cervical cancer tissues compared with that in matched normal cervical tissues as well as in metastatic vs. non-metastatic cervical cancer tissues. miR-144 downregulation was significantly associated with the International Federation of Gynecology and Obstetrics stage and lymph node metastasis. In a gain-of function study, miR-144 mimics were transfected into the Hela and C33A cervical cancer cell lines, which led to suppression of cell growth. In addition, overexpression of miR-144 inhibited the migration and invasion of Hela and C33A cells. Furthermore, a bioinformatics analysis identified vascular endothelial growth factor A (VEGFA) VEGFC as two novel target genes of miR-144. Of note, a dual luciferase reporter assay, reverse-transcription quantitative polymerase chain reaction analysis and western blot analysis demonstrated that miR-144 repressed the expression of VEGFA and VEGFC by directly targeting to their 3'-untranslated region. Taken together, the results suggested that miR-144 acts as a tumor suppressor in the proliferation and metastasis of cervical cancer cells by directly targeting VEGFA and VEGFC, suggesting that miR-144 may be a novel promising diagnostic and therapeutic biomarker for cervical cancer.

Association of Vascular Endothelial Growth Factor Gene Polymorphism With Renal Cell Carcinoma Risk

The conclusion of the relationship between vascular endothelial growth factor gene polymorphism and renal cell carcinoma risk was inconsistent. This study was performed to assess the relationship between vascular endothelial growth factor gene polymorphism and renal cell carcinoma risk using meta-analysis. The association studies were identified from PubMed, Embase, and Web of Science, and eligible studies were included and calculated. Ten studies were included for this meta-analysis. vascular endothelial growth factor (VEGF) +405G > CC allele and GG genotype were associated with renal cell carcinoma risk for overall populations in this meta-analysis (C allele: odds ratio = 1.18, 95% confidence interval: 1.05-1.33, P = .004; CC genotype: odds ratio = 1.20, 95% confidence interval: 0.96-1.50, P = .12; GG genotype: odds ratio = 0.79, 95% confidence interval: 0.67-0.93, P = .004). Furthermore, VEGF +936C>T gene polymorphism and VEGF −2578 C>A gene polymorphism were associated with renal cell carcinoma risk for overall populations (+936C>T: T allele: odds ratio = 1.16, 95% confidence interval: 1.05-1.29, P = .004; TT genotype: odds ratio = 1.25, 95% confidence interval: 1.02-1.52, P = .03; CC genotype: odds ratio = 0.86, 95% confidence interval: 0.75-0.98, P = .03; −2578 C>A: A allele: odds ratio = 1.26, 95% confidence interval: 1.15-1.38, P < .00001; AA genotype: odds ratio = 1.39, 95% confidence interval: 1.16-1.67, P = .0004; CC genotype: odds ratio = 0.75, 95% confidence interval: 0.61-0.92, P = .006). However, VEGF −634G>C, VEGF −460T>C, VEGF −1154 G>A, and VEGF +1612 G>A gene polymorphisms were not associated with renal cell carcinoma risk. In conclusion, VEGF +405G>CC allele and GG genotype, VEGF +936C>T gene polymorphism, and VEGF −2578 C>A gene polymorphism were associated with renal cell carcinoma risk for overall populations. However, more studies should be performed to assess this relationship in the future.

MiR-206 Suppresses the Progression of Coronary Artery Disease by Modulating Vascular Endothelial Growth Factor (VEGF) Expression

Background

We investigated whether microRNA-206 (miR-206) is abnormally expressed in patients with coronary artery disease (CAD). The potential mechanism by which miR-206 may regulate CAD progression was also studied.

Material/Methods

A total of 78 CAD patients in the case group and 65 subjects in the control group were enrolled in this study so that the correlation between miR-206 and CAD could be accurately determined. Serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides were detected using a biochemistry analyzer. MiR-206 and vascular endothelial growth factor (VEGF) expression levels were tested using either reverse transcription polymerase chain reaction or western blot. Associations between miR-206 expression and different clinicopathological features of CAD patients were also analyzed. CAD cells were transfected with miR-206 mimic (miR-206), its negative control (miR-NC), miR-206 inhibitor (anti-miR-206), and its negative control (anti-miR-NC), respectively. Flow cytometry was conducted to explore the function of miR-206 in CAD cell apoptosis after transfection. Moreover, transwell assay was carried out to study the migratory ability of endothelial progenitor cells (EPCs) in CAD patients.

Results

MiR-206 expression was enriched in both diseased EPCs and plasma of CAD patients. No significant correlation was found between decrease in miR-206 expression and different clinicopathological features. In addition, miR-206 significantly suppressed the viability and invasion of EPCs in CAD patients, and it promoted the apoptosis of their EPCs. Moreover, we found that miR-206 is able to inhibit VEGF expression.

Conclusions

As suggested by our study, MiR-206 can be a novel benign biomarker for CAD because it may regulate VEGF expression.

Amphiregulin enhances VEGF-A production in human chondrosarcoma cells and promotes angiogenesis by inhibiting miR-206 via FAK/c-Src/PKCδ pathway

Chondrosarcoma is the second most common primary malignancy of bone after myeloma and osteosarcoma. Chondrosarcoma development may be linked to angiogenesis, which is principally elicited by vascular endothelial growth factor-A (VEGF-A). The expression of VEGF-A has been recognized as a prognostic marker in angiogenesis. Amphiregulin (AR), an epidermal growth factor receptor ligand, promotes tumor proliferation, metastasis and angiogenesis. However, the role of AR in VEGF-A expression and angiogenesis in human chondrosarcoma remains largely unknown. This current study shows that AR promoted VEGF-A production and induced angiogenesis of human endothelial progenitor cells. Moreover, AR-enhanced VEGF-A expression and angiogenesis involved the FAK, c-Src and PKCδ signaling pathways, while miR-206 expression was negatively mediated by AR via the FAK, c-Src and PKCδ pathways. Our results illustrate the clinical significance between AR, VEGF-A and miR-206, as well as tumor stage, in human chondrosarcoma. AR may represent a novel therapeutic target in the metastasis and angiogenesis of chondrosarcoma.