MicroRNA-524-5p suppresses the progression of papillary thyroid carcinoma cells via targeting on FOXE1 and ITGA3 in cell autophagy and cycling pathways

MicroRNAs are beneficial for cancer therapy as they can simultaneously downregulate multiple targets involved in diverse biological pathways related to tumor development. In papillary thyroid cancer, many microRNAs were identified as differentially expressed factors in tumor tissues. In another way, recent studies revealed cell proliferation, cell cycling, apoptosis, and autophagy are critical pathways controlling papillary thyroid cancer development and progression. As miR-524-5p was approved as a cancer suppressor targeting multiple genes in several types of cancer cells, this study aims to characterize the role of miR-524-5p in the thyroid cancer cell. The expression of miR-524-5p was decreased in the papillary thyroid cancer tissues and cell lines, while forkhead box E1 (FOXE1) and ITGA3 were increased. In the clinical case, expression of miR-524-5p, FOXE1, and ITGA3 were significantly correlated with papillary thyroid cancer development and progression. FOXE1 and ITGA3 were approved as direct targets of miR-524-5p. miR-524-5p could inhibit papillary thyroid cancer cell viability, migration, invasion, and apoptosis through targeting FOXE1 and ITGA3. Cell cycling and autophagy pathways were disturbed by downregulation of FOXE1 and ITGA3, respectively. Collectively, miR-524-5p targeting on FOXE1 and ITGA3 prevents thyroid cancer progression through different pathways including cell cycling and autophagy.     

MicroRNA-30e-5p suppresses non-small cell lung cancer tumorigenesis by regulating USP22-mediated Sirt1/JAK/STAT3 signaling

MicroRNA-30e-5p (miR-30e-5p) is a tumor suppressor that is known to be downregulated in non-small cell lung cancer (NSCLC). However, how miR-30e-5p inhibits NSCLC tumorigenesis is not known. Ubiquitin-specific peptidase 22 (USP22) is upregulated in NSCLC and promotes tumorigenesis via a Sirt1-JAK-STAT3 pathway. In this study, we investigated whether miR-30e-5p inhibits tumor growth by targeting USP22 in NSCLC. Our results reveal that miR-30e-5p expression was correlated negatively with USP22 in NSCLC tissues. Luciferase reporter assays showed that miR-30e-5p negatively regulated USP22 expression by binding to a specific sequence in the 3?UTR. MiR-30e-5p overexpression and USP22 knockdown significantly inhibited tumor growth in vivo and induced cell cycle arrest and apoptosis in NSCLC cells in vitro. The effects of miR-30e-5p inhibition were prevented by USP22 knockdown. MiR-30e-5p inhibited SIRT1 expression and increased expression of p53 and the phosphorylated form of STAT3 (pSTAT3). Furthermore, miR-30e-5p prevented USP22-mediated regulation of SIRT1, pSTAT3, and p53 expression. Taken together, these findings suggest that miR-30e-5p suppresses NSCLC tumorigenesis by downregulatingUSP22-mediated Sirt1/JAK/STAT3 signaling. Our study has identified miR-30e-5p as a potential therapeutic target for the treatment of NSCLC.     

miR-188-5p对肾间质纤维化过程中MMP-13表达的影响

目的:探讨miR-188-5p对肾间质纤维化过程中基质金属蛋白酶(matrixmetalloproteinases,MMPs)表达的影响。方法:采用TGF-β1诱导肾小球系膜细胞(Mesangial cells,MC)纤维化,观察纤维化过程中miR-188-5p和MMP-13的表达变化;通过报告基因实验研究miR-188-5p对MMP-13的调控作用;通过脂质体转染的方法将人工合成的miR-188-5p mimics/inhibitor转入细胞内增加或减少miR-188-5p的表达,进一步观察miR-188-5p对MMP-13表达的影响。结果:TGF-β1诱导肾小球系膜细胞纤维化后miR-188-5p的表达明显升高,而MMP-13表达下调;报告基因实验表明miR-188-5p对MMP-13的表达有明显的调控作用,减少miR-188-5p的表达后MMP-13的表达上调,而增加miR-188-5p的表达后MMP-13的表达下调,呈明显负性调控。结论:在肾间质纤维化过程中,miR-188-5p可能通过抑制MMP-13的表达而发挥促纤维化的作用,本研究为肾间质纤维化的治疗提供了新的靶点。     

Long non-coding RNA OIP5-AS1 promotes pancreatic cancer cell growth through sponging miR-342-3p via AKT/ERK signaling pathway

Opa-interacting protein 5 antisense RNA 1 (OIP5-AS1), a long non-coding RNA (lncRNA), has been reported to link with the progression of some cancers. However, its biological functions and underlying molecular mechanisms in pancreatic cancer are largely unknown. The aim of this study was to investigate the role of lncRNA OIP5-AS1 in pancreatic cancer. Quantitative real-time PCR analysis revealed that OIP5-AS1 is highly expressed in pancreatic cancer tissues versus adjacent non-tumor tissues. In vitro functional assays showed that downregulation of OIP5-AS1 or overexpression of miR-342-3p inhibited the proliferation, decreased Ki67 expression, and induced cell cycle arrest in pancreatic cancer cells. The expression of cyclinD1, CDK4, and CDK6 was decreased by knockdown of OIP5-AS1. Moreover, we found that OIP5-AS1 acted as a miR-342-3p sponge to suppress its expression and function. Dual-luciferase assay confirmed the interaction of OIP5-AS1 and miR-342-3p and verified anterior gradient 2 (AGR2) as a direct target of miR-342-3p. Results showed that depletion of miR-342-3p abolished the inhibitory effects of OIP5-AS1 knockdown on pancreatic cancer cell growth. The expression of Ki67, AGR2, cyclinD1, CDK4, CDK6, p-AKT, and p-ERK1/2 was reversed by silencing of miR-342-3p in pancreatic cancer cells with OIP5-AS1 knockdown. Further, knockdown of OIP5-AS1 suppressed tumor growth in a xenograft mouse model of pancreatic cancer. OIP5-AS1 induced pancreatic cancer progression via activation of AKT and ERK signaling pathways. Therefore, we demonstrate that OIP5-AS1 functions as oncogene in pancreatic cancer and its downregulation inhibits pancreatic cancer growth by sponging miR-342-3p via targeting AGR2 through inhibiting AKT/ERK signaling pathway.

     

Lentiviral delivery of a shRNA sequence analogous to miR-4319/miR-125-5p induces apoptosis in NSCLC cells by arresting G2/M phase

In this study, we explored the therapeutic potential of microRNA (miR) analogs against non–small-cell lung cancer (NSCLC) using lentiviral delivery of short hairpin RNA (shRNA). By using A549 as a model cell line, we used analogs and mimics of miR-4319/miR-125-5p to target the tumorigenic RAF1 gene. Lentiviral vectors carrying shRNA of a highly efficient miRNA analog of miR-4319/miR-125-5p, Analog2, were constructed to infect A549 cells. Our results showed that, compared with the noncancerous bronchial epithelial cell line 16HBE, lentivirus delivering Analog2 shRNA induced significant G2/M arrest and subsequent apoptosis in A549 cells, but not in 16HBE cells. Western blot analysis revealed that key factors regulating cell cycle were downregulated following RAF1 inhibition. In vivo xenograft experiments showed that lentivirus carrying Analog2 shRNA markedly decreased tumor size. Therefore, lentiviral delivery of Analog2 shRNA is a valid RNA interference-based treatment against NSCLC with high potency and specificity.     

MiR-371-5p Facilitates Pancreatic Cancer Cell Proliferation and Decreases Patient Survival

Background

microRNAs (miRNAs) play a critical role in tumorigenesis, either as a tumor suppressor or as an oncogenic miRNA, depending on different tumor types. To date, scientists have obtained a substantial amount of knowledge with regard to miRNAs in pancreatic cancer. However, the expression and function of miR-371-5p in pancreatic cancer has not been clearly elucidated. The aim of this study was to investigate the roles of miR-371-5p in pancreatic cancer and its association with the survival of patients with pancreatic cancer.

Methods

The expression of miR-371-5p was examined in pancreatic duct adenocarcinoma (PDAC) and their adjacent normal pancreatic tissues (ANPT) or in pancreatic cancer cell lines by qRT-PCR. The association of miR-371-5p expression with overall survival was determined. The proliferation and apoptosis of SW-1990 and Panc-1 cells, transfected with miR-371-5p mimics or inhibitor, were assessed using MTT assay and flow cytometry, respectively. The tumorigenicity was evaluated via mice xenograft experiments. miR-371-5p promoter interactions were analyzed by chromatin immunoprecipitation assays (ChIP). Protein expression was analyzed by Western blot.

Results

The expression level of miR-371-5p was dramatically upregulated in clinical PDAC tissues compared with ANPT. Patients with high miR-371-5p expression had a significantly shorter survival than those with low miR-371-5p expression. The in vitro and in vivo assays showed that overexpression of miR-371-5p resulted in cell proliferation and increased tumor growth, which was associated with inhibitor of growth 1 (ING1) downregulation. Interestingly, we also found that ING1, in turn, inhibited expression of miR-371-5p in the promoter region.

Conclusions

our study demonstrates a novel ING1-miR-371-5p regulatory feedback loop, which may have a critical role in PDAC. Thus miR-371-5p can prove to be a novel prognostic factor and therapeutic target for pancreatic cancer treatment.     

Ginsenoside Rg1 and Acori Graminei Rhizoma Attenuates Neuron Cell Apoptosis by Promoting the Expression of miR-873-5p in Alzheimer’s Disease

Alzheimer’s disease (AD) severely threatens human health in their old age, however the potential etiology underlying it is still unclear. Both Ginsenoside Rg1 (GRg1) and Acori graminei Rhizoma (AGR) are the traditional Chinese herbal drug, while their potential role in AD remains need further identification. Both SAMP1 and SAMP8 mice were employed as the control and AD mice. Morris water maze method was used to detect the cognitive function of the mice, TUNEL assay was performed to determine cell apoptosis. Real-time PCR and western blot were carried out to measure gene expression. The relationship between miR-873-5p and HMOX1 was determined using luciferase reporter assay. Comparing with SAMP1, the cognitive function was impaired and cell apoptosis was increased in SAMP8 mice. GRg1?+?AGR treatment significantly attenuated the symptom of AD. The expression of miR-873-5p was decreased, while HMOX1 was increased in SAMP8 mice. GRg1?+?AGR treatment significantly promoted the expression of miR-873-5p, but decreased HMOX1. MiR-873-5p targets HMOX1 to regulate its expression. Aβ1–42 stimulation decreased the expression of miR-873-5p, but increased HMOX1 in PC12 cells. GRg1?+?AGR treatment reversed the effect of Aβ1–42, while miR-873-5p inhibitor abolished the effect of GRg1?+?AGR. In vivo experiments confirmed the protect role of GRg1?+?AGR in AD. GRg1?+?AGR suppressed neuron cell apoptosis by regulating the expression of miR-873-5p in AD.     

miR-3940-5p Functions as a Tumor Suppressor in Non–Small Cell Lung Cancer Cells by Targeting Cyclin D1 and Ubiquitin Specific Peptidase-28

miR-3940-5p level was lower in non–small cell lung cancer (NSCLC) tumor tissues than that in the matched tumor-adjacent tissues and correlated with clinicopathological features. Cyclin D1 (CCND1), a key driver of malignant transformation in NSCLC, was overexpressed in many cancers, including NSCLC. The ubiquitin specific peptidase-28 (USP28) was also overexpressed in NSCLC and associated with poor prognosis of NSCLC patients. We searched for miR-3940-5p targets by using TargetScan and miRanda online tools and found that CCND1 and USP28 were potential targets of miR-3940-5p. Based on these findings, we speculated that miR-3940-5p might target CCND1 and USP28 to inhibit NSCLC growth. We determined the expression of miR-3940-5p, CCND1, and USP28 by quantitative real-time polymerase chain reaction and Western blot assays, respectively, and found downregulation of miR-3940-5p and upregulation of CCND1 and USP28 in NSCLC tissues and cell lines. Cell proliferation and apoptosis assays showed that miR-3940-5p suppressed proliferation and promoted apoptosis in NSCLC cells, and silencing CCND1 and USP28 both recapitulated the effects of miR-3940-5p on NSCLC cells. Furthermore, we verified that CCND1 and USP28 were direct targets of miR-3940-5p and also found that the effects of NSCLC cell proliferation and apoptosis by miR-3940-5p were attenuated by overexpression of CCND1 or USP28. The animal experiments also showed that overexpression of miR-3940-5p inhibited the growth of NSCLC tumors in vivo. These results confirmed our speculation that miR-3940-5p inhibits proliferation and induces apoptosis in NSCLC cells by targeting CCND1 and USP28. These findings facilitate a better understanding of the molecular mechanisms underlying NSCLC initiation and progression and provide promising diagnostic markers and therapeutic targets for NSCLC.     

血清外泌体lncRNA PCGEM1、miR-129-5p与非小细胞肺癌患者临床病理特征及预后的关系

摘要 目的：研究血清外泌体长链非编码核糖核酸（lncRNA）前列腺癌基因表达标记1（PCGEM1）、微小核糖核酸（miR）-129-5p与非小细胞肺癌（NSCLC）患者临床病理特征及预后的关系。方法：选取2016年2月-2018年1月南京脑科医院收治的125例NSCLC患者作为NSCLC组,同期选取体检的70例健康人群作为健康组。采集两组静脉血,提取血清外泌体;采用实时定量聚合酶链式反应（qRT-PCR）检测血清外泌体lncRNA PCGEM1、miR-129-5p表达情况;采用Pearson相关性分析lncRNA PCGEM1与miR-129-5p的关系。并分析血清外泌体lncRNA PCGEM1、miR-129-5p与NSCLC患者临床病理特征的关系。对NSCLC患者行5年随访,绘制Kaplan-Meier曲线分析预后情况,多因素Cox比例风险回归模型分析预后不良危险因素,受试者工作特征（ROC）曲线分析lncRNA PCGEM1、miR-129-5p对NSCLC预后的预测价值。结果：：NSCLC组lncRNA PCGEM1相对表达量高于健康组,miR-129-5p相对表达量低于健康组（P＜0.05）。血清外泌体lncRNA PCGEM1相对表达量与miR-129-5p表达呈负相关（r= -0.420,P＜0.05）。血清外泌体lncRNA PCGEM1、miR-129-5p表达与患者TNM分期、分化程度、淋巴结转移有关（P＜0.05）。Kplan-Meier生存曲线显示,lncRNA PCGEM1低表达组5年生存率69.05%高于lncRNA PCGEM1高表达组35.53%,miR-129-5p高表达组5年生存率68.09%高于miR-129-5p低表达组33.80%。多因素Cox比例风险回归显示,TNM分期III期、有淋巴结转移、lncRNA PCGEM1高表达、miR-129-5p低表达为NSCLC患者预后不良的独立危险因素（P＜0.05）。ROC曲线显示,lncRNA PCGEM1、miR-129-5p联合检测对NSCLC预后的预测曲线下面积（AUC）为0.865,预测价值高于两者单独预测。结论：NSCLC患者血清外泌体lncRNA PCGEM1表达上调、miR-129-5p表达下调,二者表达与NSCLC患者TNM分期、分化程度、淋巴结转移有关,且与患者预后密切相关,对NSCLC预后不良具有较好预测价值。     

microRNA-16-5p-containing exosomes derived from bone marrow-derived mesenchymal stem cells inhibit proliferation,migration, and invasion,while promoting apoptosis of colorectal cancer cells by downregulating ITGA2

Colorectal cancer (CRC) is a form of cancer developing from either the colon or rectum. Nowadays, research supports the functionality of exosome expressing microRNAs (miRNAs) as potential biomarker for various cancers including CRC. This study was performed with the intent of investigating the roles of both bone marrow-derived mesenchymal stem cells (BMSCs) and exosomal miR-16-5p in CRC by regulating integrin α2 (ITGA2). A microarray-based analysis was conducted to screen the CRC-associated differentially expressed genes (DEGs) as well as potential regulatory miRNAs. Next, the role of miR-16-5p in terms of its progression in association with CRC was determined. Subsequently, CRC cells were exposed to exosomes secreted by BMSCs transfected with miR-16-5p, isolated and cocultured with CRC cells in an attempt to identify the role of exosomes. Effects of BMSCs-derived exosomes overexpressing miR-16-5p on biological functions of CRC cells and tumorigenicity were all subsequently detected. Effects of miR-16-5p treated with CRC cells in regard to CRC in vivo were also measured. ITGA2 was overexpressed, while miR-16-5p was poorly expressed in CRC cells and miR-16-5p targeted ITGA2. The in vitro experiments revealed that the BMSCs-derived exosomes overexpressing miR-16-5p inhibited proliferation, migration, and invasion, while simultaneously stimulating the apoptosis of the CRC cells via downregulation of ITGA2. Furthermore, the results of in vivo experiments confirmed that the BMSCs-derived exosomes overexpressing miR-16-5p repressed the tumor growth of CRC. Collectively, BMSCs-derived exosomes overexpressing miR-16-5p restricted the progression of CRC by downregulating ITGA2.     

Exosome-mediated miR-7-5p delivery enhances the anticancer effect of Everolimus via blocking MNK/eIF4E axis in non-small cell lung cancer

Everolimus is a kind of mammalian target of rapamycin (mTOR) inhibitors. Activated mitogen-activated protein kinase interacting kinases/eukaryotic translation initiation factor 4E (MNK/eIF4E) axis plays a crucial role in resistance to Everolimus in non-small cell lung cancer (NSCLC). The eIF4E phosphorylation increased by mTOR inhibitors is mainly mediated by MNKs. However, the mechanisms are poorly understood. Recently, extensive reprogramming of miRNA profiles has also been found after long-term mTOR inhibitor exposure. Our previous studies have confirmed that tumor suppressor miR-7-5p is decreased in A549 cells after treatment with Everolimus. Exactly, MNK1 is the target of miR-7-5p. In this study, we investigated the biological functions and potential molecular mechanisms of miR-7-5p in the NSCLC undergoing treatment with Everolimus. We confirmed that Everolimus targeted mTORC1 inducing NSCLC cells to secrete miR-7-5p-loaded exosomes in Rab27A and Rab27B-dependent manners. Loss of intracellular miR-7-5p induced phosphorylation of MNK/eIF4E axis, but a supplement of extra exosomal miR-7-5p could reverse it. Of note, both low expression of miR-7-5p and elevated MNK1 protein were associated with a poor prognosis of NSCLC. Both endogenous miR-7-5p and exo-miR-7-5p enhanced the therapeutic efficacy of Everolimus by inhibiting the proliferation, migration, and metastasis of NSCLC in vitro and in vivo. The combination of miR-7-5p with Everolimus induced apoptosis to exhibit a synergistic anticancer therapeutic efficacy through dual abrogation of MNK/eIF4E and mTOR in NSCLC. In conclusion, Everolimus decreases the intracellular miR-7-5p by releasing of miR-7-5p loaded exosomes from NSCLC cells in Rab27A and Rab27B dependent manners. Either endogenous miR-7-5p or exo-miR-7-5p combined with Everolimus can enhance the anticancer efficacy by targeting MNK/eIF4E axis and mTOR. Besides, both low levels of miR-7-5p and positive expression of MNK1 act as independent poor prognostic biomarkers for NSCLC. Therefore, restoring miR-7-5p carried by exosome may be a promising novel combined therapeutic strategy with Everolimus for NSCLC.Subject terms: Drug development, Growth factor signalling, Oncogenesis     

miR-199a-3p/5p regulate tumorgenesis via targeting Rheb in non-small cell lung cancer

Lung cancer is one of the deadliest cancers, in which non-small cell lung cancer (NSCLC) accounting for 85% and has a low survival rate of 5 years. Dysregulation of microRNAs (miRNAs) can participate in tumor regulation and many major diseases. In this study, we found that miR-199a-3p/5p were down-expressed in NSCLC tissue samples, cell lines, and the patient sample database. MiR-199a-3p/5p overexpression could significantly suppress cell proliferation, migration ability and promote apoptosis. Through software prediction, ras homolog enriched in brain (Rheb) was identified as a common target of miR-199a-3p and miR-199a-5p, which participated in regulating mTOR signaling pathway. The same effect of inhibiting NSCLC appeared after down-regulating the expression of Rheb. Furthermore, our findings revealed that miR-199a can significantly inhibit tumor growth and metastasis in vivo, which fully demonstrates that miR-199a plays a tumor suppressive role in NSCLC. In addition, miR-199a-3p/5p has been shown to enhance the sensitivity of gefitinib to EGFR-T790M in NSCLC. Collectively, these results prove that miR-199a-3p/5p can act as cancer suppressor genes to inhibit the mTOR signaling pathway by targeting Rheb, which in turn inhibits the regulatory process of NSCLC. Thus, to investigate the anti-cancer effect of pre-miR-199a/Rheb/mTOR axis in NSCLC, miR-199a-3p and miR-199a-5p have the potential to become an early diagnostic marker or therapeutic target for NSCLC.     

Relative expressions of miR-205-5p, miR-205-3p, and miR-21 in tissues and serum of non-small cell lung cancer patients

Objective was to assess and compare the relative expressions of miR-205-5p, miR-205-3p, and miR-21-3p in tissues and serum among non-small cell lung carcinoma (NSCLC) patients, benign pulmonary conditions patients, and healthy volunteers. Serum samples were obtained between October 2011 and September 2012 from 20 NSCLC patients undergoing surgical treatment, 20 patients diagnosed with a benign lung disease (pulmonary tuberculosis, pneumonia, chronic obstructive pulmonary disease, or interstitial pneumonia) (lesion group), and 20 healthy volunteers (control group). NSCLC patients provided cancer tissues and cancer-adjacent normal tissues during surgery (paired specimens). Quantitative RT-PCR was used to assess miR-205-5p, miR-205-3p, and miR-21-3p expressions in serum and tissue samples. The relative expressions of miR-205-5p and miR-205-3p were significantly higher in NSCLC tissues compared with cancer-adjacent paired specimens (both P < 0.001). In the serum, significantly higher miR-205-5p, miR-205-3p, and miR-21-3p relative expressions were observed in the NSCLC group compared with the two other groups (all P < 0.001). The relative expressions of miR-205-5p and miR-21-3p in NSCLC tissues and serum were significantly correlated (r = 0.553, P = 0.011; and r = ?0.541, P = 0.014, respectively), while no significant correlation was observed for miR-205-3P (P = 0.120). Expressions of miR-205-5p and miR-205-3P in squamous cell carcinoma specimens were significantly higher than in lung adenocarcinoma specimens (both P = 0.001). Similarly, higher serum miR-205-5p and miR-205-3p levels were observed in squamous cell carcinoma patients (P = 0.033 and P = 0.002, respectively). In this preliminary and novel study, miR-205-5p was more useful as a marker for NSCLC than miR-205-3p or miR-21, indicating a potential for future applications in NSCLC diagnosis and prognosis.     

miR-140-5p is negatively correlated with proliferation,invasion, and tumorigenesis in malignant melanoma by targeting SOX4 via the Wnt/β-catenin and NF-κB cascades

MicroRNAs (miRNAs) have been validated as critical regulators in the development of melanoma. miR-140 was abnormally downregulated in uveal melanoma samples. However, the expression level and roles of miR-140-5p remain unclear in melanoma for now. We speculate that miR-140-5p is abnormally expressed and may play an important role in melanoma. The expressions of miR-140-5p and SOX4 messenger RNA were determined by quantitative real-time polymerase chain reaction assays. Western blot assays were employed to detect the expression levels of SOX4, Ki67, MMP-2, MMP-7, p-β-catenin, c-Myc, cyclin D1, p65, and IκBα. Luciferase reporter assays were employed to elucidate the interaction between SOX4 and miR-140-5p. MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) and transwell invasion assays were applied to evaluate capabilities of cell proliferation and invasion, respectively. Xenograft models of melanoma were established to verify the role and molecular basis of miR-140-5p. Immunohistochemical (IHC) assays were employed to measure the Ki67 and SOX4 at the protein level in xenografted melanoma tissues. Herein, these observations showed that, miR-140-5p was abnormally downregulated in melanoma tissues and cells, while SOX4 was upregulated. miR-140-5p directly targeted SOX4 and inhibited its expression in melanoma cells. miR-140-5p overexpression repressed melanoma cell proliferation and invasion and its effects were partially restored SOX4 overexpression. Moreover, miR-140-5p hindered melanoma growth in vivo by downregulating SOX4. Mechanistically, miR-140-5p suppressed activation of the Wnt/β-catenin and NF-κB pathways by targeting SOX4. Our study concluded that miR-140-5p hindered cell proliferation, invasion, and tumorigenesis by targeting SOX4 via inactivation of the Wnt/β-catenin and NF-κB signaling pathways in malignant melanoma, which provides an underlying molecular mechanism for the treatment for melanoma with miRNAs.