Conservation of miR-15a/16-1 and miR-15b/16-2 clusters

MiR-15a/16-1 and miR-15b/16-2 clusters have been shown to play very important roles in regulating cell proliferation and apoptosis by targeting cell cycle proteins and the antiapoptotic Bcl-2 gene. However, the physiological implications of those two clusters are largely elusive. By aligning the primary miR-15a/16-1 sequence among 44 vertebrates, we found that there was a gap in the homologous region of the rat genome. To verify that there was a similar miR-15a/16-1 cluster in rats, we amplified this region from rat genomic DNA using PCR and found that a 697-bp sequence was missing in the current rat genome database, which covers the miR-15a/16-1 cluster. Subsequently, we also investigated the expression pattern of individual miRNAs spliced from miR-15a/16-1 and miR-15b/16-2 clusters, including miR-15a, miR-15a*, miR-15b, miR-15b*, miR-16-1/2, and miR-16-1/2* from various rat tissues, and found that all of those miRNAs were expressed in the investigated tissues. MiR-16 was most expressed in the heart, followed by the brain, lung, kidney, and small intestine, which indicates tissue specificity for individual miRNA expression from both clusters. Our results demonstrated that both miR-15a/16-1 and miR-15b/16-2 clusters are highly conserved among mammalian species. The investigation of the biological functions of those two clusters using transgenic or knockout/knockdown models will provide new clues to understanding their implications in human diseases and finding a new approach for miRNA-based therapy.     

RNPC1 inhibits non-small cell lung cancer progression via regulating miR-181a/CASC2 axis

Objectives

To study the roles and mechanisms of RNA binding protein RNPC1 in non-small cell lung cancer progression.

Results

RNPC1 and long non-coding RNA CASC2 expression levels were significantly downregulated in lung cancer tissues compared with normal adjacent tissues, and their expression levels were positively correlated. Functionally, overexpression of RNPC1 or CASC2 inhibited non-small cell lung cancer cells proliferation, migration and invasion, and promoted cells apoptosis. Mechanistically, RNPC1 was found to harbor binding sites on CASC2 and directly bound to CASC2, and increased CASC2 mRNA stability and expression. Notably, the promotive effects of RNPC1 on CASC2 expression were attenuated by miR-181a overexpression. Moreover, CASC2 3′UTR with mutated miR-181a binding sites did not respond to RNPC1 alteration. Finally, the inhibitory effects of RNPC1 overexpression were attenuated or even reversed by CASC2 knockdown or miR-181a overexpression.

Conclusions

RNA bind protein RNPC1 could inhibit non-small cell lung cancer progression by competitively binding to CASC2 with miR-181a.

     

Vector-based miR-15a/16-1 plasmid inhibits colon cancer growth in vivo

miR-15 (microRNA 15) and miR-16 are frequently deleted or down-regulated in many cancer cell lines and various tumour tissues, suggesting that miR-15a/16-1 plays important roles in tumour progression and might be a method for cancer treatment. We have developed a vector-based plasmid to explore the anti-tumour efficacy of miR-15a/16-1 in colon cancer in vivo. It is proposed that miR-15a and miR-16-1 target cyclin B1 (CCNB1), which associates with several tumorigenic features such as survival and proliferation. The levels of miR-15a and miR-16-1 in colon cancer cells were inversely correlated with CCNB1 expression, and there was consensus between miR-15a/16-1 and CCNB1 mRNA sequences by analysing homology. Vector-based miR-15a/16-1 expression plasmid was constructed and transfected into HCT 116 and SW620 colon cancer cells in vitro. The effects produced on cell viability and angiogenesis were analysed using flow cytometric analysis, colony formation analysis and tube formation analysis. CCNB1 expression down-regulation was checked by Western blotting. Systemic delivery of miR-15a/16-1 plasmids encapsulated in cationic liposome led to a significant inhibition of subcutaneous tumour growth and angiogenesis in tumour tissues, whereas no effects were observed with liposome carrying the non-specific plasmid. In summary, miR-15a/16-1 has been applied in colon cancer treatment in vivo, and resulted in effective colon tumour xenografts growth arrest and angiogenesis decrease. These findings suggest that systemic delivery of vector-based miR-15a/16-1 expression plasmid can be an approach to colon cancer therapy.     

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.     

miR-15a and miR-16-1 down-regulation in pituitary adenomas

Micro RNAs (miRs) are small noncoding RNAs, functioning as antisense regulators of other RNAs. miR-15a and miR-16-1 genes are located at chromosome 13q14, a region which is frequently deleted in pituitary tumors. An inverse correlation has been shown in B cell chronic lymphocytic leukemia (B-CLL) between miR-15a and miR-16-1 expression and the expression levels of arginyl-tRNA synthetase (RARS), an enzyme which associates with the cofactor p43 in the aminoacyl-tRNA synthetase complex. When secreted, p43 regulates local inflammatory response and macrophage chemotaxis, and seems to have anti-neoplastic properties in mice. We explored miR-15a and miR-16-1 expression in 10 GH-secreting and in 10 PRL-secreting pituitary macroadenomas by Northern blot, and investigated the possible correlation with in vivo and in vitro characteristics. We found that miR-15a and miR-16-1 are expressed at lower levels in pituitary adenomas as compared to normal pituitary tissue. Moreover, their expression inversely correlates with tumor diameter and with RARS expression (P < 0.05), but directly correlates with p43 secretion (P < 0.02). Therefore, miR15 and miR16 down-regulation in pituitary adenomas correlates with a greater tumor diameter and a lower p43 secretion, suggesting that these genes may, at least in part, influence tumor growth.     

LINC00184 plays an oncogenic role in non-small cell lung cancer via regulation of the miR-524-5p/HMGB2 axis

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. We aimed to investigate the role of LINC00184 in NSCLC. Migration, proliferation and invasion of NSCLC cells were analysed using the wound healing assay, cell counting kit-8 assay and transwell assay, respectively. Apoptosis and cell cycle were assessed using flow cytometry. Online bioinformatics tools were utilized to predict downstream microRNAs (miRNA) or genes related to LINC00184 expression. The RNA pull-down experiment and luciferase reporter assay were performed to verify the predictions thereof. LINC00184, miR-524-5p, and high mobility group 2 protein (HMGB2) expression levels in NSCLC tissues and cell lines were detected using quantitative real-time polymerase chain reaction. An NSCLC mouse model was constructed for in vivo experiments. LINC00184 overexpression was observed in NSCLC tissues and cell lines and was found to be correlated with poor prognosis. LINC00184 knockdown inhibited cell proliferation, migration and invasion, induced cell cycle arrest and accelerated apoptosis in NSCLC cell lines. LINC00184 suppressed tumour growth and proliferation in NSCLC mouse models and directly targeted the miR-524-5p/HMGB2 axis. Moreover, the expression levels of LINC00184 and HMGB2 were negatively correlated with miR-524-5p expression, whereas LINC00184 expression was positively correlated with HMGB2 expression. LINC00184 affected the cell cycle, proliferation, apoptosis, migration and invasion in NSCLC via regulation of the miR-524-5p/HMGB2 axis.     

Histone deacetylases inhibitor MS-275 suppresses human esophageal squamous cell carcinoma cell growth and progression via the PI3K/Akt/mTOR pathway

Esophageal squamous cell carcinoma (ESCC) is a malignant tumor with low survival rate, so new therapies are urgently needed. Histone deacetylases (HDACs) play a critical role in tumorigenesis, and HDACs inhibition is a potential therapeutic target in ESSC. In our study, we evaluated the effect and molecular mechanism of MS-275 (an inhibitor of HDACs) on ESCC cells. We found that HDAC1 and HDAC2 were overexpressed in ESCC tissues and related with clinical pathological features of patients with ESCC. MS-275 markedly reduced HDAC1 and HDAC2 expression, whereas increased the level of AcH3 and AcH2B. MS-275 suppressed proliferation and clonogenicity of ESCC cells in a concentration-dependent manner. In addition, MS-275 induced apoptosis, arrested cell cycle, and inhibited migration, epithelial–mesenchymal transition, and sphere-forming ability of ESCC cells in vitro. Moreover, p-Akt1 and p-mTOR were downregulated by MS-275. Finally, MS-275 significantly inhibited tumor growth in vivo. Taken together, HDAC1 and HDAC2 are associated with the progression of ESCC, and MS-275 hinders the progression and stemness of ESCC cells by suppressing the PI3K/Akt/mTOR pathway. Our findings show that MS-275 inhibits ESCC cells growth in vitro and in vivo, which is a potential drug for the ESCC therapy.     

Circular RNA circFBXO7 attenuates non-small cell lung cancer tumorigenesis by sponging miR-296-3p to facilitate KLF15-mediated transcriptional activation of CDKN1A

BackgroundAccumulating evidence indicates that circular RNAs (circRNAs) play important roles in various cancers. Hsa_circ_0008832 (circFBXO7) is a circRNA generated from the second exon of the human F-box only protein 7 (FBXO7). Mouse circFbxo7 is a circRNA generated from the second exon of mouse F-box only protein 7 (Fbxo7). The role of human circFBXO7 and mouse circFbxo7 in non-small cell lung cancer (NSCLC) has not been reported.MethodsThe expression of circFBXO7 was measured by quantitative real-time PCR. Survival analysis was performed to explore the association between the expression of circFBXO7 and the prognosis of patients with NSCLC. Lung cancer cell lines were transfected with plasmids. Cell proliferation, cell cycle, and tumorigenesis were evaluated to assess the effects of circFBXO7. Fluorescence in situ hybridization assay was used to identify the location of circFBXO7 and circFbxo7 in human and mouse lung cancer cells. Luciferase reporter assay was conducted to confirm the relationship between circFBXO7 and microRNA.ResultsIn this study, we found that circFBXO7 was downregulated in NSCLC tissues and cell lines. NSCLC patients with high circFBXO7 expression had prolonged overall survival. Overexpression of circFBXO7 inhibited cell proliferation both in vitro and in vivo. Mechanistically, we demonstrated that circFBXO7 upregulated the expression of miR-296-3p target gene Krüppel-like factor 15 (KLF15) and KLF15 transactivated the expression of CDKN1A.ConclusionsCircFBXO7 acts as a tumor suppressor by a novel circFBXO7/miR-296-3p/KLF15/CDKN1A axis, which may serve as a potential biomarker and therapeutic target for NSCLC.     

miR-596-3p suppresses brain metastasis of non-small cell lung cancer by modulating YAP1 and IL-8

Brain metastasis (BM) frequently occurs in advanced non-small cell lung cancer (NSCLC) and is associated with poor clinical prognosis. Due to the location of metastatic lesions, the surgical resection is limited and the chemotherapy is ineffective because of the existence of the blood brain barrier (BBB). Therefore, it is essential to enhance our understanding about the underlying mechanisms associated with brain metastasis in NSCLC. In the present study, we explored the RNA-Seq data of brain metastasis cells from the GEO database, and extracted RNA collected from primary NSCLC tumors as well as paired brain metastatic lesions followed by microRNA PCR array. Meanwhile, we improved the in vivo model and constructed a cancer stem cell-derived transplantation model of brain metastasis in mice. Our data indicated that the level of miR-596-3p is high in primary NSCLC tumors, but significantly downregulated in the brain metastatic lesion. The prediction target of microRNA suggested that miR-596-3p was considered to modulate two genes essential in the brain invasion process, YAP1 and IL-8 that restrain the invasion of cancer cells and permeability of BBB, respectively. Moreover, in vivo experiments suggested that our model mimics the clinical aspect of NSCLC and improves the success ratio of brain metastasis model. The results demonstrated that miR-596-3p significantly inhibited the capacity of NSCLC cells to metastasize to the brain. Furthermore, these finding elucidated that miR-596-3p exerts a critical role in brain metastasis of NSCLC by modulating the YAP1-IL8 network, and this miRNA axis may provide a potential therapeutic strategy for brain metastasis.Subject terms: CNS cancer, miRNAs     

Inhibition of RAC1-GEF DOCK3 by miR-512-3p contributes to suppression of metastasis in non-small cell lung cancer

MicroRNAs are a class of small non-coding RNAs regulating gene expression. In this study, we demonstrated that retinoic acid (RA) treatment increases the expression of miR-512-3p. Overexpression of miR-512-3p inhibited cell adhesion, migration, and invasion in non-small cell lung cancer (NSCLC) cell lines A549 and H1299. miR-512-3p inhibitor partially reversed these effects in H1299 cells stably expressing miR-512. We identified DOCK3, a RAC1-GEF (guanine nucleotide exchange factor), as a target gene of miR-512-3p. Overexpression of miR-512-3p led to the decrease of DOCK3 protein but not its mRNA. Knockdown of DOCK3 resulted in similar effects on adhesion, migration, and invasion as observed of miR-512-3p overexpression. Active RAC1 pull-down assay indicated that overexpression of miR-512-3p could decrease the activity of RAC1 with a higher efficiency than that of DOCK3 knockdown. Furthermore, expression of miR-512-3p was suppressed in most NSCLC patient tumor samples compared to its paired normal controls, suggesting that miR-512-3p might play a crucial role in lung cancer development. In conclusion, our results supported that miR-512-3p could inhibit tumor cell adhesion, migration, and invasion by regulating the RAC1 activity via DOCK3 in NSCLC A549 and H1299 cell lines.     

Anwulignan is a novel JAK1 inhibitor that suppresses non-small cell lung cancer growth

Anwulignan is a monomer compound derived from Schisandra sphenanthera lignans. It has been reported to possess a spectrum of pharmacological activities, including anti-bacterial, anti-inflammatory, anticancer and hepatoprotective properties. However, its anticancer capacity and molecular mechanism(s) against non-small cell lung cancer (NSCLC) have not been fully elucidated. Anwulignan significantly inhibited cell growth and increased G1-phase cell cycle arrest in NSCLC cells. Anwulignan strongly attenuates the JAK1/STAT3 signalling pathway by directly targeting JAK1 protein kinase activity in vitro. The anticancer activity by Anwulignan is dependent upon the JAK1 protein expression. Remarkably, Anwulignan strongly inhibited tumour growth in vivo. In conclusion, Anwulignan is a novel JAK1 inhibitor that may have therapeutic implications for NSCLC management.     

Prognostic significance of TBX2 expression in non-small cell lung cancer

T-box2 (TBX2) expression has been reported to be related to aggressive tumor features. However, the role of TBX2 in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. So we aimed at investigating the potential role of TBX2 in NSCLC. TBX2 expression was evaluated by qRT-PCR and Western blotting in 50 paired fresh lung cancer tissues as well as immunohistochemistry on 212 paraffin-embedded sections. We showed that the expression level of TBX2 was significantly increased in NSCLC as compared with the adjacent noncancerous tissue. Positive expression level of TBX2 was associated with histological type, lymph node metastasis and distant metastasis. Kaplan–Meier survival curves showed that positive expression level of TBX2 was associated with poor overall survival (OS) and progression-free survival of NSCLC patients. Results showed that TBX2 positivity was an independent prognostic factor for OS (HR 1.87, 95 % CI 1.004–3.153, p = 0.012). On the basis of these results, we suggested that TBX2 protein expression may be an unfavorable independent prognostic parameter for NSCLC.