MicroRNA-1270 is associated with poor prognosis and its inhibition yielded anticancer mechanisms in human osteosarcoma

Hsa_circ_0000069 Accelerates Cervical Cancer Progression by Sponging miR-1270 to Facilitate CPEB4 Expression

The critical importance of circular RNAs (circRNAs) in human cancers, including cervical cancer (CC), has been discovered in recent years. However, the function and mechanism of hsa_circ_0000069 (circ_0000069) in CC have been fully understood. The expression levels of circ_0000069, microRNAs (miR-1270, miR-1276 and miR-620) and cytoplasmic polyadenylation element binding protein 4 (CPEB4) mRNA were detected by quantitative real time polymerase chain reaction (qRT-PCR). Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, wound healing, transwell and tube formation assays were used to clarify the effects of circ_0000069 on the functional behaviors of CC cells. The binding relationships among miR-1270, circ_0000069 and CPEB4 were detected by dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. A xenograft tumor model was established to explore the effect of circ_0000069 on tumor growth in vivo. Circ_0000069 was upregulated in CC clinical samples and cell lines, and its expression was associated with the clinical stage of CC patients. Circ_0000069 knockdown significantly decreased cell proliferation, invasion, migration, and tube formation and increased cell apoptosis in vitro. Moreover, miR-1270 was a direct target of circ_0000069, and CPEB4 was the downstream target of miR-1270. Knockdown of miR-1270 reversed the inhibitory effect of circ_0000069 knockdown on CC progression, and CPEB4 overexpression overturned the effect of miR-1270 on CC progression. In xenograft experiments, the oncogenic effect of circ_0000069 on tumor growth was verified. Altogether, circ_0000069 adsorbed miR-1270 to upregulate CPEB4 expression, thereby promoting the malignant phenotypes of CC cells. Circ_0000069 might be a potential target for treatment of CC.

The homologous tumor-derived-exosomes loaded with miR-1270 selectively enhanced the suppression effect for colorectal cancer cells

BACKGROUND

Colorectal cancer (CRC), known as prevalent cancer, has risen to be the leading cause of cancer-related death. Engineered exosomes had attracted much attention since they acted as carriers to deliver small molecule drugs, therapeutic nucleic acids, and polypeptides to treat a series of cancers.

METHODS AND RESULTS

Here, we found that the PKH-26 labeled exosomes, which were derived from the CRC cells, could be efficiently absorbed by SW1116 cells and had an abundant fluorescence distribution in tumors, compared with the exosomes derived from mesenchymal stem cells (MSC) and HepG2 cells. This Research demonstrated that engineered CRC-exosomes loaded with functional miR-1270 (Exo-miR-1270) enriched in miR-1270 strongly inhibited the proliferation by CCK-8 and EdU assays, migration by wound-healing and transwell assays, and promoted the apoptosis for CRC cells through flow cytometry. MiR-1270 overexpression delivered by CRC exosomes contributed to inhibiting the tumor growth potential of CRC in vivo and increasing the overall survival of the mice. Moreover, the safety evaluation results showed that CRC-exosomes loaded with functional miR-1270-mimics had no toxicity for other organs by histopathological analysis and no influence on the vital chemistry and hematology parameters for mice in vivo safety evaluation.

CONCLUSION

These results indicate that Exo-miR-1270 can effectively treat CRC tumors by intravenous administration. Our work provided a foundation that the homologous tumor-derived exosomes mediated miRNA delivery for the treatment of CRC.

MicroRNAs, long non-coding RNAs, and circular RNAs and gynecological cancers: focus on metastasis

Gynecologic cancer is a significant cause of death in women worldwide, with cervical cancer, ovarian cancer, and endometrial cancer being among the most well-known types. The initiation and progression of gynecologic cancers involve a variety of biological functions, including angiogenesis and metastasis-given that death mostly occurs from metastatic tumors that have invaded the surrounding tissues. Therefore, understanding the molecular pathways underlying gynecologic cancer metastasis is critical for enhancing patient survival and outcomes. Recent research has revealed the contribution of numerous non-coding RNAs (ncRNAs) to metastasis and invasion of gynecologic cancer by affecting specific cellular pathways. This review focuses on three types of gynecologic cancer (ovarian, endometrial, and cervical) and three kinds of ncRNAs (long non-coding RNAs, microRNAs, and circular RNAs). We summarize the detailed role of non-coding RNAs in the different pathways and molecular interactions involved in the invasion and metastasis of these cancers.

Hsa_circ_0128846 knockdown attenuates the progression of pancreatic cancer by targeting miR-1270/NR3C1 axis

The considerable role of circular RNAs (circRNAs) make them prospective biomarkers in cancer therapy. Our study aimed to unveil the function of circ_0128846 in pancreatic cancer (PC). The expressions of circ_0128846, miR-1270 and NR3C1 mRNA were measured via RT-qPCR. The expressions of NR3C1 protein and apoptosis-related markers (Bax and Bcl-2) were measured via western blotting. CCK-8, colony-forming, or wound healing assay was respectively utilized to identify cell proliferation, growth and migration. Xenograft model was developed to evaluate tumor growth affected by circ_0128846 in vivo. The putative binding between miR-1270 and circ_0128846 or NR3C1 was testified by dual-luciferase reporter, RIP or pull-down assay. Circ_0128846 showed elevated expression in PC. Circ_0128846 deficiency restrained cancer cell proliferation, colony formation and migratory ability, enhanced cell apoptotic rate, and also impeded tumor development in vivo. Circ_0128846 directly targeted miR-1270 whose expression was declined in PC. The suppressive effects of silencing circ_0128846 on PC cell malignant phenotypes were largely reversed by miR-1270 inhibition. NR3C1 was targeted by miR-1270 and was highly regulated in PC. The repressive effects of NR3C1 knockdown on PC cell malignant phenotypes were partly abolished by miR-1270 inhibition. Circ_0128846 deficiency blocked PC progression via mediating the miR-1270/NR3C1 pathway, which partly illustrated PC pathogenesis.

Nectin-4 promotes osteosarcoma progression and metastasis through activating PI3K/AKT/NF-κB signaling by down-regulation of miR-520c-3p

PURPOSE

Nectin-4 is specifically up-regulated in various tumors, exert crucial effects on tumor occurrence and development. Nevertheless, the role and molecular mechanism of Nectin-4 in osteosarcoma (OS) are rarely studied.

METHODS

The expression of Nectin-4 and its relationship with clinical characteristics of OS were investigated using OS clinical tissues, tissue microarrays, TCGA, and GEO databases. Moreover, the effect of Nectin-4 on cell growth and mobility was detected by CCK-8, colony formation, transwell, and wound-healing assays. The RT-qPCR, Western blotting, and luciferase reporter assays were performed to explore molecular mechanisms through which Nectin-4 mediates the expression of miR-520c-3p, thus modulating PI3K/AKT/NF-κB signaling. In vivo mice models constructed by subcutaneous transplantation and tail vein injection were used to validate the functional roles of Nectin-4 and miR-520c-3p.

RESULTS

Nectin-4 displayed a higher expression in OS tumor tissues compared with normal tissues, and its overexpression was positively associated with tumor stage and metastasis in OS patients. Functionally, Nectin-4 enhanced OS cells growth and mobility in vitro. Mechanistically, Nectin-4 down-regulated the levels of miR-520c-3p that directly targeted AKT-1 and P65, thus leading to the stimulation of PI3K/AKT/NF-κB signaling. In addition, the expression of miR-520c-3p was apparently lower in OS tissues than in normal tissues, and its low expression was significantly related to tumor metastasis. Furthermore, ectopic expression of miR-520c-3p markedly blocked the effect of Nectin-4 on OS cell growth and mobility. Knockdown of Nectin-4 could suppress the tumorigenesis and metastasis in vivo, which could be remarkably reversed by miR-520c-3p silencing.

CONCLUSIONS

Nectin-4 as an oncogene can promote OS progression and metastasis by activating PI3K/AKT/NF-κB signaling via down-regulation of miR-520c-3p, which could represent a novel avenue for identifying a potential therapeutic target for improving patient outcomes.

Downregulation of miR-1270 mediates endothelial progenitor cell function in preeclampsia: Role for ATM in the Src/VE-cadherin axis

Preeclampsia, a pregnancy-related hypertensive disorder, is associated with endothelial dysfunction and increased cardiovascular risk of the offspring in adulthood. In preeclampsia, endothelial colony-forming cells (ECFC) are reduced in number and function. Recently, we have shown that miR-1270, which is involved in cancer in vitro proliferation, migration, and tumor progression, is downregulated in fetal ECFC from preeclamptic pregnancies. We now hypothesize that miR-1270 dysregulation contributes to vascular endothelial dysfunction occurring after preeclampsia via ATM (ataxia telangiectasia mutated) overexpression, the key kinase of DNA damage repair. Here, we show that miR-1270 silencing in normal ECFC and downregulation in preeclamptic ECFC are accompanied by an increase in the expression levels of ATM. Furthermore, ATM activation correlates with upregulated tyrosine kinase Src leading to phosphorylation and internalization of VE-cadherin (vascular endothelial-cadherin) which subsequently compromises endothelial barrier permeability and morphodynamic cell parameters. Treatment with specific ATM inhibitors reveals a novel role of ATM upstream of tyrosine kinase Src activation. Subsequently, Src phosphorylation and internalization of VE-cadherin compromise endothelial barrier permeability. Our findings suggest that downregulation of miR-1270 contributes to impaired ECFC function via the associated ATM overexpression, which further identifies ATM as a novel and critical factor for ECFC defects in preeclampsia. Our study provides new insights into the understanding of ECFC impairment associated with cardiovascular risk in preeclamptic offspring and identifies potential novel therapeutic targets.

LncRNA HCG11 represses ovarian cancer cell growth via AKT signaling pathway

AIM

Ovarian cancer is a main contributor of cancer-relevant deaths among women worldwide due to high incidence and mortality. Mounting evidence has unveiled that lncRNAs play critical roles in malignancies, including ovarian cancer. Although the tumor suppressor function of HCG11 in prostate cancer and glioma has been proved, investigations on HCG11 role in ovarian cancer are still scarce.

METHODS

Gene or protein expression was quantified by RT-qPCR or western blot. HCG11 effects on ovarian cancer were assessed by functional assays. Bioinformatics analysis and mechanism experiments were implemented to identify the association among HCG11, miR-1270, and PTEN.

RESULTS

HCG11 was weakly expressed in ovarian cancer and functioned as a tumor suppressor in ovarian cancer by retarding cell proliferation, migration, and EMT. Besides, HCG11 could bind to miR-1270 and PTEN was a target gene of miR-1270. Mechanically, HCG11 competitively bound with miR-1270 to upregulate PTEN. From rescue experiments, HCG11 impeded AKT/mTOR pathway to retard ovarian cancer cell growth by miR-1270/PTEN.

CONCLUSIONS

HCG11 was a tumor suppressor in ovarian cancer cells and additionally, HCG11 regulated AKT/mTOR pathway to hinder ovarian cancer cell growth via modulating miR-1270/PTEN, indicating that HCG11 may represent a promising target for effective treatment of ovarian cancer patients.

LncRNA ASMTL-AS1/microRNA-1270 differentiate prognostic groups in gastric cancer and influence cell proliferation, migration and invasion

The objective of this study was to determine the expression levels of ASMTL-AS1 and miR-1270 in gastric cancer, and to explore whether ASMTL-AS1 and miR-1270 is associated with cancer prognosis and progression or not. ASMTL-AS1 and miR-1270 expression were quantified in gastric cancer tissues and adjacent normal tissues (n = 167) and cell lines. The potential of ASMTL-AS1 and miR-1270 as prognostic biomarkers was evaluated by the receiver operating characteristic (ROC) curve, Kaplan-Meier, and multivariate Cox regression analyses. The binding between ASMTL-AS1 and miR-1270 was verified by the Luciferase reporter assay and RNA pull-down assay. Functional roles of ASMTL-AS1/miR-1270 on cells were investigated in HGC-27 and NCI-N87 cells by MTS viability, Transwell migration, and Matrigel invasion assay. ASMTL-AS1 was significantly downregulated while miR-1270 was upregulated in gastric cancer tissues as compared with normal tissue and cell lines. According to the studies, ASMTL-AS1 and miR-1270 were related to unfavorable clinical parameters, such as the advanced TNM stage. Downregulated ASMTL-AS1 and upregulated miR-1270 were associated with reduced 5-year overall survival. Functional studies suggested that ASMTL-AS1 inhibits proliferation, migration, and invasion of HGC-27 and NCI-N87 cells by regulation of miR-1270. In summary, ASMTL-AS1 and miR-1270 are associated with poor prognosis of patients with gastric cancer. ASMTL-AS1 inhibited gastric cancer progression by regulating miR-1270. Therefore, ASMTL-AS1/miR-1270 may be a potential prognostic biomarker and novel strategy for gastric cancer targeted therapy.

Osteosarcoma and Metastasis

Osteosarcoma is the most common primary bone malignancy in adolescents. Its high propensity to metastasize is the leading cause for treatment failure and poor prognosis. Although the research of osteosarcoma has greatly expanded in the past decades, the knowledge and new therapy strategies targeting metastatic progression remain sparse. The prognosis of patients with metastasis is still unsatisfactory. There is resonating urgency for a thorough and deeper understanding of molecular mechanisms underlying osteosarcoma to develop innovative therapies targeting metastasis. Toward the goal of elaborating the characteristics and biological behavior of metastatic osteosarcoma, it is essential to combine the diverse investigations that are performed at molecular, cellular, and animal levels from basic research to clinical translation spanning chemical, physical sciences, and biology. This review focuses on the metastatic process, regulatory networks involving key molecules and signaling pathways, the role of microenvironment, osteoclast, angiogenesis, metabolism, immunity, and noncoding RNAs in osteosarcoma metastasis. The aim of this review is to provide an overview of current research advances, with the hope to discovery druggable targets and promising therapy strategies for osteosarcoma metastasis and thus to overcome this clinical impasse.

MicroRNAs as prognostic biomarkers for survival outcome in osteosarcoma: A meta-analysis

BACKGROUND

Osteosarcoma was considered to be one of the most prevalent malignant bone tumors in adolescents.

AIM

To explore the prognostic significance of microRNA (miRNA) in osteosarcoma.

METHODS

The literature was selected by searching online in PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Database until July 1, 2021. The pooled hazard ratio (HR) with corresponding 95% confidence interval (CI) for the outcomes of overall survival (OS), disease-free survival (DFS), progression-free survival (PFS) and recurrence-free survival were calculated. Subgroup analyses were carried out to identify potential sources of heterogeneity. Publication bias was assessed by Egger’s bias indicator test.

RESULTS

A total of 60 studies from 54 articles with 5824 osteosarcoma patients were included for this meta-analysis. The pooled HR for OS, DFS, PFS were 2.92 (95%CI: 2.43-3.41, P = 0.000), 3.70 (95%CI: 2.80-4.61, P = 0.000), and 3.57 (95%CI: 1.60-5.54, P = 0.000), respectively. The high miR-21 expression levels were related to poor OS in osteosarcoma (HR = 2.86, 95%CI: 1.20-4.53, P = 0.001). Subgroup analysis demonstrated that a high expression level of miRNA correlated with worse OS (HR: 3.56, 95%CI: 2.59-4.54, P = 0.000). In addition, miRNA from tissue (HR: 3.20, 95%CI: 2.16-4.23, P = 0.000) may be a stronger prognostic biomarker in comparison with that from serum and plasma.

CONCLUSION

miRNA (especially miR-21) could be served as a potential prognostic biomarker for osteosarcoma. A high expression level of miRNA in tumor tissue correlated with worse OS of osteosarcoma.

miR-1270 enhances the proliferation, migration, and invasion of osteosarcoma <em>via</em> targeting cingulin

Osteosarcoma (OS), characterized by high morbidity and mortality, is the most common bone malignancy worldwide. MicroRNAs (miRNAs) play a crucial role in the initiation and development of OS. The purpose of this study was to investigate the roles of miR-1270 in OS. RT-qPCR and Western blot were applied to detect the mRNA and protein level, respectively. CCK-8, colony formation, and TUNEL assays were conducted to determine the cell viability, proliferation, and apoptosis of OS cells. Wound healing and transwell assay were performed to detect the migration and invasion ability of OS cells. Bioinformatics analysis and dual-luciferase reporter assay were used to predict the target genes of miR-1270. Tumor xenograft in vivo assay was carried out to determine miR-1270 effect on the tumor size, volume, and weight. In this study, miR-1270 was overexpressed in OS tissues and cells. However, miR-1270 knockdown inhibited the proliferation, migration and invasion, and promoted the OS cells’ apoptosis. Mechanistically, cingulin (CGN) was predicted and proved to be a target of miR-1270 and partially alleviated the effects of miR-1270 on the proliferation, migration and invasion ability of OS cells. Taken together, knockdown of miR-1270 may inhibit the development of OS via targeting CGN. This finding may provide a novel therapeutic strategy for OS.

Hsa-circRNA-103809 Promotes Hepatocellular Carcinoma Development via MicroRNA-1270/PLAG1 Like Zinc Finger 2 Axis

BACKGROUND

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death in the worldwide. A great number of reports manifested that circular RNA hsa-circRNA-103809 (circRNA-103809) could work in several cancers.

AIMS

This study aimed to explore the function and mechanism of circRNA-103809 in HCC.

METHODS

Gene expressions were detected by quantitative real-time polymerase chain reaction. Colony formation, cell counting kit-8, transwell and wound healing assays were implemented to check the role of circRNA-103809 in HCC. Subcellular fractionation analysis was designed to figure out the cellular location of circRNA-103809. Luciferase reporter assay and RNA pull down assay were employed to verify the relationships among RNAs.

RESULTS

CircRNA-103809 was highly expressed in HCC cell lines. After interfering circRNA-103809, the proliferation, migration, invasion and epithelial-to-mesenchymal transition process were all hindered in HCC cells. Significantly, circRNA-103809 competed with PLAG1 like zinc finger 2 (PLAGL2) for binding with microRNA-1270 (miR-1270), which formulated a competing endogenous RNA network in HCC. Thereafter, we verified the tumor-facilitating effect of circRNA-103809/miR-1270/PLAGL2 axis on biological behaviors of HCC cells.

CONCLUSION

Hsa-circRNA-103809 promoted development of HCC via sequestering miR-1270 and up-regulating PLAGL2.

Circ_0001247 functions as a miR-1270 sponge to accelerate cervical cancer progression by up-regulating ZEB2 expression level

BACKGROUND

There is increasing evidence that circular RNA (circRNA) disorders have an impact on the progression of various malignancies. The expression characteristics, function and underlying mechanism of circ_0001247 in cervical cancer (CC) have not been confirmed.

METHODS

GSE147483 datasets of circRNAs expression in CC cell line and normal cervical cell line were retrieved from GEO database, and the circRNA with significant difference was selected; circ_0001247, miR-1270, and Zinc finger E-box binding homeobox 2 (ZEB2) expressions in CC tissues and cell lines were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) assay; cell counting kit-8 (CCK-8) assay and BrdU assay were applied to monitor the proliferative ability of CC cells; Transwell assay was conducted to examine the migration and invasion of CC cells, and flow cytometry was used to evaluate the apoptosis; Western blot assay was adopted to detect ZEB2 protein expressions; dual-luciferase report gene assay was used to verify the targeting relationship between circ_0001247 and miR-1270, and miR-1270 and the 3'UTR of ZEB2.

RESULTS

Analysis of GSE147483 suggested that circ_0001247 could probably be an oncogenic circRNA in CC. Compared with that in adjacent tissues and normal cervical epithelial cells, circ_0001247 expression in CC tissues and cell lines was significantly increased; knocking down circ_0001247 expression could inhibit the proliferation and metastasis of CC cells, and promote apoptosis, while circ_0001247 overexpression worked oppositely; circ_0001247 sponged miR-1270 in CC cells; miR-1270 diminished the promoting effect of circ_0001247 by inactivating the ZEB2.

CONCLUSION

Circ_0001247 promotes progression of CC by sponging miR-1270 to upregulate ZEB2 expression level.

Circ-IGF1R inhibits cell invasion and migration in non-small cell lung cancer

BACKGROUND

Circular RNA (circRNA) is a novel molecular marker and target candidate that is closely associated with tumor invasion and migration. The mechanism of action of hsa_circ_0005035 (circ-IGF1R) in non-small cell lung cancer remains unclear. In this study, we aimed to study the mechanism of action of circ-IGF1R in lung cancer.

METHODS

We screened circ-IGF1R, one of the most notable differential expressions, from the Gene Expression Omnibus database, GSE104854, for further research. The expression level of circ-IGF1R was examined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in five different lung cancer cell lines and 50 pairs of lung cancer and adjacent tissues. Wound-healing and Transwell assays were used for verifying the biological function of circ-IGF1R. The effect of overexpressing circ-IGF1R on the transcriptome of whole lung cancer cells was explored in lung cancer cell lines using RNA-seq.

RESULTS

The expression level of circ-IGF1R was notably lower in lung cancer tissues and lung cancer cell lines than in the adjacent normal tissues and cells (P < 0.0001). In addition, the expression level of circ-IGF1R was associated with larger tumors (T2/T3/T4) and lymph node metastasis (N1/ N2/N3) (P < 0.05). The overexpression of circ-IGF1R significantly inhibited the invasion and migration of the lung cancer cells. The potential network of circ-IGF1R-miR-1270-VANGL2 was preliminarily determined, and the expression patterns of miR-1270 and VANGL2 were verified in lung cancer cell lines.

CONCLUSION

Circ-IGF1R may inhibit lung cancer invasion and migration through a potential network of circ-IGF1R-miR-1270-VANGL2.

Circ-SOX4 drives the tumorigenesis and development of lung adenocarcinoma via sponging miR-1270 and modulating PLAGL2 to activate WNT signaling pathway

Background

Lung adenocarcinoma (LUAD), a widespread histopathological subtype of lung cancer, is deemed as a malignant tumor with a peak risk of mortality. Emerged as RNA with a loop structure that depleted protein coding ability, circular RNA (circRNA) has been identified as a regulator in cancer progression. Circ-SOX4, identified as a novel circRNA, has not been studied in any cancer yet. Thus, the regulatory function that circ-SOX4 exerts on LUAD development remains obscure.

Aim of the study

This study aimed to investigate the biological function and molecular mechanism of circ-SOX4 in LUAD.

Methods

The expression of circ-SOX4 was detected by qRT-PCR. CCK-8, colony formation, transwell and wound healing assays were performed to explore the biological function of circ-SOX4 in LUAD. The interaction between miR-1270 and circ-SOX41 (or PLAGL2) was confirmed by RNA pull down, luciferase reporter and RIP assays.

Results

Circ-SOX4 was found to be obviously upregulated in LUAD tissues and cells, and knockdown of it inhibited cell proliferation, invasion and migration in LUAD. Furthermore, silenced circ-SOX4 also inhibited LUAD tumor growth. Molecular mechanism assays revealed that circ-SOX4 interacted with miR-1270 in LUAD. Besides, PLAGL2 was confirmed as a downstream gene of miR-1270. Rescue assays validated that miR-1270 suppression or PLAGL2 overexpression countervailed circ-SOX4 depletion-mediated inhibition on cell proliferation, invasion and migration in LUAD. Additionally, it was discovered that circ-SOX4/miR-1270/PLAGL2 axis activated WNT signaling pathway in LUAD.

Conclusions

Circ-SOX4 boosted the development of LUAD and activate WNT signaling pathway through sponging miR-1270 and modulating PLAGL2, which provided a valuable theoretical basis for exploring underlying therapeutic target in LUAD.

The many (sur)faces of B cells

This issue of the Biomedical Journal is dedicated to the latest findings concerning the complex development and functions of B lymphocytes, including their origins during embryogenesis, their meticulous control by the CD22 receptor and different types of T cells, as well as the immunosuppressive abilities of certain B cell subsets. Furthermore, we learn about the complicated genetic background of a rare cardiac disease, the surgical outcomes of pure conus medullaris syndrome and occurrences of tuberculous spondylitis after percutaneous vertebroplasty. Finally, we discover that brain waves could very well be used for biometric authentication and that diffusion imaging displays good reproducibility through a spectrum of spatial resolutions.

Upregulation of microRNA-1270 suppressed human glioblastoma cancer cell proliferation migration and tumorigenesis by acting through WT1

Background

Glioblastoma multiforme (GBM) is one of the most aggressive brain tumors among human beings. In this study, we explored the functions of human microRNA-1270 (hsa-miR-1270) on GBM cancer cell proliferation, migration, and tumorigenesis.

Materials and methods

In GBM cell lines and clinical tissues, hsa-miR-1270 expression was probed by quantitative real-time PCR (qRT-PCR). In LN-18 and A172 cells, hsa-miR-1270 was upregulated by lentiviral transduction. The effects of hsa-miR-1270 upregulation on GBM in vitro and in vivo functions were probed by proliferation, migration, and xenograft assays, respectively. The correlation between hsa-miR-1270 and Wilms’ tumor gene (WT1) was probed by dual-luciferase activity assay, qRT-PCR, and Western blot. WT1 was then secondarily over-expressed in hsa-miR-1270-upregulated LN-18 and A172 cells, to explore its mechanisms in GBM’s association with hsa-miR-1270.

Results

Hsa-miR-1270 was significantly downregulated in both GBM cell lines and clinical tumors. Upregulating hsa-miR-1270 considerably suppressed GBM cell proliferation and migration in vitro and xenograft in vivo. WT1 was inversely correlated with hsa-miR-1270 in GBM. WT1 overexpression in hsa-miR-1270-upregulated GBM cells reversed the anticancer functions of hsa-miR-1270 on cancer proliferation and migration.

Conclusion

Hsa-miR-1270 upregulation may have suppressing effects on GBM cancer cells, likely by functionally acting through WT1.

Circular RNA Cdr1as sensitizes bladder cancer to cisplatin by upregulating APAF1 expression through miR-1270 inhibition

Circular RNAs (circRNAs) have recently emerged as essential regulators in carcinogenesis and cancer progression. Previous studies have shown that Cdr1as functions as a microRNA (miRNA) sponge in various cancer types. However, the role of Cdr1as in cisplatin chemosensitivity in bladder cancer remains unclear. Here, we used real‐time PCR to examine miRNA and gene expression in bladder cancer tissues and cell lines. The abilities of Cdr1as and its downstream regulatory molecules to induce apoptosis and promote cisplatin‐induced chemosensitivity of bladder cancer cells were determined by flow cytometry and cell counting kit. Bioinformatic analysis was utilized to predict potential miRNA target sites, and biotin‐coupled miRNA capture, biotin‐coupled probe pull‐down assay, and RNA fluorescent in situ hybridization were used to study the interaction between Cdr1as and target miRNAs. Dual‐luciferase reporter assay was also used to validate the target genes of miRNAs. The expression level of apoptotic protease‐activating factor 1 (APAF1) in bladder cancer cells was identified via western blot. Finally, the sensitivity of Cdr1as to cisplatin chemotherapy in nude mice xenografts was evaluated in terms of the size, volume of tumors, and the survival of mice. We report that Cdr1as induced the apoptosis and enhanced the cisplatin chemosensitivity of bladder cancer cells both in vitro and in vivo. Silencing of APAF1 reduced the sensitivity of bladder cancer cells to cisplatin chemotherapy. Furthermore, Cdr1as could directly sponge miR‐1270 and abolish its effect on APAF1. Our study verified that Cdr1as exerts a cisplatin‐chemosensitization effect on bladder cancer cells through the Cdr1as/miR‐1270/APAF1 axis. This newly identified axis may be a potential therapeutic target for bladder cancer patients.