CASC2 Expression Research Articles

CASC15 Promotes Lens Epithelial Cell Apoptosis in Age-Related Cataracts by Regulating MiR-139-5p/caspase-3

Objective: The aim of this study was to reveal the role of CASC15 and miR-139-5p function in regulating agerelated cataracts (ARC). Methods: The expression of CASC15, miR-139-5p and caspase-3 were detected by qRT-PCR. Western blot was used to analyze the level of apoptosis-related proteins. Flow cytometry was used to measure the apoptosis of SAR01/04l cells treated with UV irradiation. Results: The expression of CASC15 and caspase-3 in the lens of ARC was higher than that in normal lens, but the expression of miR-139-5p had opposite trend. The level of caspase-3 and Bax were increased and Bcl-2 was decreased in ARC group. In addition, CASC15 negatively regulated miR-139-5p expression and promoted SAR01/04l cell apoptosis. CASC15 could combine with miR-139-5p, and miR-139-5p could combine with caspase-3 3’-UTR. Furthermore, pcDNA-caspase-3 could reverse the inhibitory effect of si-CASC15 and miR139-5p mimic on SRA01/04 cell apoptosis. Conclusion: CASC15 promoted lens epithelial cell apoptosis by regulating miR-139-5p/caspase-3. Keywords: ARC; CASC15; LECs apoptosis; miR-139-5p

Long non-coding RNA CASC2 serves as a ceRNA of microRNA-21 to promote PDCD4 expression in oral squamous cell carcinoma.

Background: Oral squamous cell carcinoma (OSCC) is a common oral disease with high morbidity and mortality. Recently, long non-coding RNAs (lncRNAs) were identified as critical regulators in OSCC tumorigenesis. The present study aimed to work out the functions and the possible molecular mechanisms of lncRNA CASC2 in human OSCC.Methods: The expression levels of CASC2 in clinical OSCC tissue samples and cultured OSCC cell lines were detected by RT-qPCR analysis. MTT assay was performed to detect the proliferation ability of OSCC cells, whereas the apoptosis rate and cell cycle distribution of OSCC cells were determined by flow cytometric analysis. The expression levels of relevant proteins were detected by Western blot assay. Dual-luciferase reporter assay was performed to validate the predicted relationship between CASC2, miR-21 amd PDCD4. The role of CASC2 in OSCC tumorigenesis in vivo was evaluated using a nude mouse tumor model.Results: The results demonstrated that CASC2 was significantly downregulated in clinical OSCC tissue samples and cultured OSCC cell lines. Low CASC2 expression was closely correlated with adverse clinicopathological characteristics of OSCC patients. Functionally, overexpression of CASC2 remarkably inhibited cell proliferation partly through inducing cell cycle arrest and cell apoptosis. Furthermore, bioinformatics analysis and dual-luciferase reporter assay showed that CASC2 might act as a competing endogenous RNA of miR-21 to promote the expression of PDCD4. Rescue experiments also showed that miR-21 blocked the tumor-suppressive role that CASC2 exerted in OSCC cells. Finally, in vivo study indicated that overexpression of CASC2 restrained OSCC tumor growth in volume and weight.Conclusion: In conclusion, these findings indicate that CASC2/miR-21/PDCD4 axis might be a potential regulator of OSCC tumorigenesis, and shed new light on lncRNA-directed diagnostics and therapeutics in OSCC.

Identification of oncogenic long noncoding RNAs CASC9 and LINC00152 in oral carcinoma through genome-wide comprehensive analysis.

Oral carcinoma (OC) is the major cancer type in the head and neck region; however, the molecular mechanisms of its pathogenesis and progression remain poorly understood. In recent years, the long noncoding RNAs (lncRNAs) have been uncovered as critical regulators in the development and progression of multiple human cancers, but most of the lncRNAs expression patterns, clinical relevance, and biological functions in OC are still unclear. To better understand the significance of lncRNAs in OC carcinogenesis, we analyzed the expression levels of lncRNAs between OC and healthy oral mucosa using The Cancer Genome Atlas Cancer Genome RNA sequencing data and another three independent microarray datasets from Gene Expression Omnibus. As a result, we found that thousands of lncRNAs expression are dysregulated in OC, and further somatic copy number variation analyses showed that some of these lncRNAs alterations are associated with copy number amplification or loss in OC. Moreover, lots of lncRNAs expression levels are associated with OC patients' overall survival and recurrence-free survival; for example, higher CASC9, LINC01232, and MIR4435-1HG expression levels are related to shorter overall survival and recurrence-free survival in OC patients. Finally, the potential function of two lncRNAs (CASC9 and LINC00152) that were upregulated in OC tissues and associated with patients' survival time was verified by loss-of-function assays in OC cells. Our findings indicate that these altered lncRNAs might play important roles in the development of OC, and our data can provide a valuable list of lncRNAs candidates for further investigation of their function and mechanisms in OC.

Increased expression of lncRNA CASC9 promotes tumor progression by suppressing autophagy-mediated cell apoptosis via the AKT/mTOR pathway in oral squamous cell carcinoma

Recent studies showed that lncRNA CASC9 was upregulated and acted as an oncogene in a variety of tumors. However, the expression and biological functions of CASC9 in oral squamous cell carcinoma (OSCC) remain unknown. In this study, we found for the first time that CASC9 was remarkably upregulated in OSCC tissues and cell lines compared with paired noncancerous tissues and normal oral epithelial cells. Highly expressed CASC9 is strongly associated with tumor size, clinical stage, regional lymph node metastasis and overall survival time in OSCC patients. In vitro, CASC9 knockdown in OSCC cells SCC15 and CAL27 significantly promotes autophagy and apoptosis, while inhibiting proliferation. Moreover, the expression levels of p-AKT, p-mTOR, P62 and BCL-2 were significantly decreased, while the expression levels of BAX and the LC3BII/LC3BI ratio were increased in CASC9-knockdown SCC15 and CAL27 cells. After the addition of the AKT activator SC79 in CASC9-knockdown SCC15 and CAL27 cells, we found that the increased autophagy and apoptosis were remarkably rescued. Furthermore, the increased apoptosis was remarkably rescued in CASC9-knockdown OSCC cells treated with the autophagy inhibitor Autophinib. In addition, CASC9 depletion suppressed tumor growth in vivo. In conclusion, our findings demonstrate that lncRNA CASC9 promotes OSCC progression through enhancing cell proliferation and suppressing autophagy-mediated cell apoptosis via the AKT/mTOR pathway. CASC9 could potentially be used as a valuable biomarker for OSCC diagnosis and prognosis.

LncRNA CASC9 regulates cell migration and invasion in hemangioma endothelial cells by targeting miR-125a-3p/Nrg1.

BackgroundDespite being one of the most common benign tumors, the prevalence and pathogenesis of hemangiomas (HAs) are poorly understood. We aimed to identify the biological role of the long non-coding RNA (lncRNA) CASC9 in the HA-derived endothelial cell (HDECs) phenotype as well as elucidate the mechanism involved.MethodsThe expression of CASC9 was identified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). the effect of CASC9 on cell proliferation, migration and invasion of HDECs were examined by CCK8, wound healing, and transwell assay, respectively. Bioinformatics analysis and a luciferase reporter assay were utilized to investigated the mechanisms involved. The in vivo tumorigenesis capability of CASC9 on HA was also evaluated.ResultsThe expression of CASC9 was significantly elevated in HA tissue compared to normal tissue. Down-regulation of CASC9 inhibited proliferation, migration, and invasion of HDECs. The translation of cyclinD1, N-cadherin, Twist, and MMP2 was also decreased by CASC9 knockdown treatment. Furthermore, CASC9 over-expression exerted the opposite effect of proliferation, migration, and invasion of HDECs. We also found that CASC9 interacts with miR-125a-3p/Nrg1 to regulate cellular functions. Interestingly, miR-125a-3p can reverse the effect of CASC9 on proliferation, migration, and invasion of HDECs. Together, the clinical data showed that CASC9 expression is negatively correlated with miR-125a-3p expression and positively correlated with Nrg1 expression. CASC9 also exerted anti-tumorigenesis capability in vivo.ConclusionOur study indicates that CASC9 accelerates cell growth and invasion of HDECs and provides new insights for the diagnosis and molecular therapy of HA.

HNF1A/CASC2 regulates pancreatic cancer cell proliferation through PTEN/Akt signaling.

Pancreatic cancer (PC) has a high mortality rate in all cancers worldwide. According to recent studies, long noncoding RNA-CASC2 is involved in the development and progression of many malignant tumors; in the present study, we demonstrated that lncRNA-CASC2 was specifically downregulated in PC tissues and cell lines, and a lower CASC2 expression in PC was related with a poorer prognosis. CASC2 suppressed PC cell proliferation. Hepatocyte nuclear factor 1 alpha (HNF1A) is a transcription factor known to regulate pancreatic differentiation and maintain the homeostasis of the endocrine pancreas. Recently, HNF1A is considered to be a possible tumor suppressor in PC. In the present study, we observed that HNF1A positively regulated CASC2 expression. Through luciferase assays, we demonstrated that CASC2 gene possessed an HNF1A-responsive element (CASC2-HNF1A RE); HNF1A could promote CASC2 expression through direct binding to CASC2-HNF1A RE. Further, PTEN/Akt signaling was involved in HNF1A regulation of CASC2. Finally, we evaluated the expression level of HNF1A in PC tissues; lower HNF1A expression was correlated with shorter overall survival in patients with PC. Taken together, these findings will shed light on the role and mechanism of HNF1A/CASC2 in regulating PC cells proliferation through PTEN/Akt signaling. CASC2 may serve as a potential therapeutic target in PC in the future.

Long Intergenic Non-Coding RNAs Unambiguously Classify AML Subgroups

Long intergenic non-coding RNAs (lincRNAs) are endogenous RNAs with a transcript length of more than 200nt that lack a long open reading frame. The functional impact of lincRNAs is not well known yet but lincRNAs have been associated with chromatin remodelling, histone modification and DNA methylation, and have been found to impact tumorigenesis. The expression levels of lincRNAs are often significantly altered in various malignancies and can be used as diagnostic markers and potential drug targets. Recent studies have shown that lincRNAs also contribute to the initiation and development of acute myeloid leukemia (AML)(Mer et al. 2018). Today, AML is defined by morphological, genetic, and clinical features but the underlying molecular mechanisms are still not completely understood.Hence, we analysed the transcriptome of 190 AML patients with different cytogenetic aberrations (normal karyotype, n = 50; PML-RARA, n= 49; RUNX1-RUNX1T1, n = 45; CBFB-MYH11, n = 46) to identify and quantify lincRNAs to further expand the knowledge of the contribution of different regulatory levels to the pathogenesis in AML.Total RNA was used for 150bp paired-end RNA sequencing (RNA-Seq) with a median read depth of 50 million. UClncR pipeline (Sun et al. 2017) with a gamma model for stranded RNA-Seq was used for the identification and quantification of novel and known lincRNA. The pipeline automatically performs the novel transcript assembly, predicts lncRNA candidates by filtering based on length, expression, repetitive regions, and coding potential, and quantifies both, known and novel lincRNAs. The resulting count matrix was filtered and only lincRNAs with a minimal count of 5 in at least 66% of the samples were kept. Subsequently, we performed a combined normalization and differential expression (DE) analysis of the lincRNA counts by integration of trimmed mean of M-values normalization factors into the statistical model used to test for DE. lincRNAs with an FDR < 0.05 and an absolute logFC > 1.5 were considered DE.354 unique lincRNAs were identified to be DE between the different AML subtypes. Among those lincRNAs we found MEG3 to be specifically up-regulated in AML with PML-RARA fusion (p < 0.001), whereas the lincRNA was comparably lower expressed in all the other subtypes (Figure 1). MEG3 is a known tumor suppressor that is usually found to be down-regulated in AML. Recent studies indicated that MEG3 expression is regulated by miRNA-22. miRNA-22 is located on the short arm of chromosome 17 and carries a predicted PML-RARA binding site in its promoter region. Binding of the PML-RARA fusion protein to the miRNA-22 promoter might result in its up-regulation which subsequently modulates MEG3 expression levels. Hence, MEG3 might contribute to the pathogenesis in AML with PML-RARA fusion and can be used as a molecular marker.The lincRNA CRNDE showed an expression profile similar to MEG3 in our cohort. CRNDE has already been linked with the PML-RARA fusion in acute promyelocytic leukemia. In addition we found a significantly higher expression of CASC15 in AML RUNX1-RUNX1T1 compared to the other subtypes (p < 0.01). It has been recently reported that CASC15 regulates SOX4 expression in RUNX1-rearranged acute leukemia. As expected we found a high expression of SOX4 in AML RUNX1-RUNX1T1.Using the identified 354 DE lincRNAs a neural network was built to classify the various AML subtypes. The dataset was randomly split into training (90%) and test (10%) data which was used to train the neural network. The procedure was repeated 1000 times to ensure that every sample was seen by the classifier multiple times. The neural network was composed of 424 units, 2 hidden layers with 50 and 20 units, respectively, and the Rectified Linear Unit activation function. The trained neural network with 10-fold cross-validation was able to unambiguously classify the four AML subtypes with an accuracy of 98%.Conclusions: 1) We demonstrated that lincRNAs can be used to reliably classify AML subgroups and the identified subgroup-specific lincRNAs might play a role in therapeutic strategies for these pts. 2) MEG3 can be used as a new molecular marker for AML with PML-RARA fusion. 3) LincRNAs are an additional regulatory level that can further improve diagnosis but might also be taken into account for treatment decisions. DisclosuresWalter:MLL Munich Leukemia Laboratory: Employment. Hernández:MLL Munich Leukemia Laboratory: Employment. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Kern:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Haferlach:MLL Munich Leukemia Laboratory: Employment, Equity Ownership. Meggendorfer:MLL Munich Leukemia Laboratory: Employment.

Downregulation of lncRNA CASC2 promotes the postoperative local recurrence of early oral squamous cell carcinoma.

LncRNA CASC2 plays a role as tumor suppressor gene in different types of human malignancies, while its involvement in oral squamous cell carcinoma (OSCC) is unknown. The present study aimed to investigate the involvement of lncRNA CASC2 in OSCC. In this study, the expression of lncRNA CASC2 in tumor tissues, adjacent healthy tissues, and plasma of 122 OSCC patients as well as in plasma of 52 healthy controls was detected by RT-qPCR. Diagnostic value of lncRNA CASC2 for OSCC was evaluated by ROC curve analysis. Patients were followed up for 5years to record recurrence. LncRNA CASC2 expression vectors were transfected into cells of human OSCC cell lines, and the effects on cancer cell proliferation and miRNA-21 expression were analyzed by CCK-8 assay and RT-qPCR, respectively. We found that CASC2 was significantly downregulated in OSCC patients than in healthy controls. Downregulation of CASC2 distinguished OSCC patients from healthy controls. Local recurrence was observed in 26 out of 122 patients and no distant recurrence was observed during follow-up. Compared with pretreatment levels, plasma levels of CASC2 were significantly increased in patients with local recurrence than in patients without recurrence. Transfection of CASC2 expression vectors led to significantly inhibited tumor cell proliferation and reduced miRNA-21 expression levels. We, therefore, conclude that downregulation of lncRNA CASC2 may participate in the postoperative local recurrence of early OSCC through miRNA-21.

LncRNA cancer susceptibility candidate 15 accelerates the breast cancer cells progression via miR-153–3p/KLF5 positive feedback loop

Emerging literature have illustrated the vital regulatory roles of long noncoding RNAs (lncRNAs) on the breast cancer tumorigenesis. Although series of researches have been proceeded on the pathogenesis, there are still much of unsolved mysteries worth investigating. This study uncovered that CASC15 expression level was aberrantly high-expressed in breast cancer tissue specimens and cells. Functionally, the loss-of-functional experiments showed that knockdown of CASC15 suppressed the malignant behaviors of breast cancer cells, such as proliferation, invasion and tumor growth in vitro and vivo. Mechanically, we confirmed that CASC15 functioned as a competing endogenous RNA (ceRNA) of miR-153–3p, besides, miR-153–3p targeted the 3‘-UTR of KLF5 mRNA utilizing the bioinformatics online tools, luciferase reporter assay and RNA immunoprecipitation. Interestingly, we confirmed that the transcription factor KLF5 binds with the promoter region of CASC15 and activates the transcription. In conclusion, we validated the positive feedback loop of KLF5/CASC15/miR-153–3p/KLF5 in the acceleration of breast cancer malignant behaviors and tumorigenesis, suggesting the important biologic roles of CASC15 on the breast cancer tumorigenesis.

Upregulation of lncRNA VDR/CASC15 induced by facilitates cardiac hypertrophy through modulating miR-432-5p/TLR4 axis

Sustained cardiac hypertrophy has threatened human health. With the development of human genome project, non-coding RNAs (ncRNAs) have attracted more and more attentions of researchers. As a subgroup of ncRNAs, long non-coding RNAs (lncRNAs) has been widely studied in human diseases, including cardiac hypertrophy. According to search results of bioinformatics website, lncRNA CASC15 potentially participates in the course of cardiac hypertrophy. According to the result of qRT-PCR, CASC15 expression was upregulated when cardiomyocytes were treated with Ang-II. Moreover, CASC15 was highly expressed in cardiac hypertrophic model. Upregulation of CASC15 was accompanied with some hypertrophic responses. To explore the specific biological function of CASC15 in cardiac hypertrophy, loss-of-function experiments were conducted in Ang-II-induced cardiomyocytes. Results of immunofluorence staining revealed that cell surface area enlarged by Ang-II was decreased when CASC15 was silenced. The expression levels of hypertrophic factors were attenuated by knockdown of CASC15. To detect the molecular mechanism by which CASC15 regulates the progression of cardiac hypertrophy, mechanism experiments were designed and carried out. It was found that CASC15 was activated by the transcription factor VDR. Furthermore, CASC15 can upregulate TLR4 by competitively binding miR-432-5p. In conclusion, Upregulation of lncRNA CASC15 induced by VDR facilitates cardiac hypertrophy via miR-432-5p/TLR4 axis.

Long Non-Coding RNA CASC2 Improves Diabetic Nephropathy by Inhibiting JNK Pathway.

It's known that long non-coding RNA CASC2 overexpression inhibit the JNK pathway in some disease models, while JNK pathway activation exacerbates diabetic nephropathy. Therefore we speculate that long non-coding RNA CASC2 can improve diabetic nephropathy by inhibiting JNK pathway. Thus, our study was carried out to investigate the involvement of CASC2 in diabetic nephropathy. We found that serum level of CASC2 was significantly lower in diabetic nephropathy patients than in normal people, and serum level of CASC2 showed no significant correlations with age, gender, alcohol consumption and smoking habits, but was correlated with course of disease. ROC curve analysis showed that serum level of CASC2 could be used to accurately predict diabetic nephropathy. Diabetes mellitus has many complications. This study also included a series of complications of diabetes, such as diabetic retinopathy, diabetic ketoacidosis, diabetic foot infections and diabetic cardiopathy, while serum level of CASC2 was specifically reduced in diabetic nephropathy. CASC2 expression level decreased, while JNK1 phosphorylation level increased in mouse podocyte cells treated with high glucose. CASC2 overexpression inhibited apoptosis of podocyte cells and reduced phosphorylation level of JNK1. We conclude that long non-coding RNA CASC2 may improve diabetic nephropathy by inhibiting JNK pathway.

Sanguinarine inhibits epithelial ovarian cancer development via regulating long non-coding RNA CASC2-EIF4A3 axis and/or inhibiting NF-κB signaling or PI3K/AKT/mTOR pathway

ObjectiveThis study aimed to investigate the antitumor effects and possible regulatory mechanisms of sanguinarine in epithelial ovarian cancer. Material and methodsThe effects of sanguinarine on the malignant behaviors of epithelial ovarian cancer SKOV3 cells and the expression of long non-coding RNA CASC2 were investigated. The expression of CASC2 and EIF4A3 in epithelial ovarian cancer tissues and cells were detected, and the potential mechanisms of sanguinarine were explored by investigating the interactions between CASC2 and EIF4A3. Furthermore, the regulatory relationship between sanguinarine and nuclear factor-κB (NF-κB) signaling or PI3K/AKT/mTOR pathway was explored. ResultsSanguinarine exhibited antitumor effects in SKOV3 cells by significantly inhibiting cell viability, migration and invasion and promoting cell apoptosis. Moreover, sanguinarine induced CASC2 expression and silencing of CASC2 reversed the effects of sanguinarine in epithelial ovarian cancer cells. CASC2 was significantly lowly expressed in ovarian cancer tissues and cells, while EIF4A3 was highly expressed. EIF4A3 was identified as a CASC2 binding protein. Knockdown of EIF4A3 reversed the effects of sanguinarine plus CASC2 silencing. Besides, sanguinarine markedly inhibited the activation of NF-κB signaling or PI3K/AKT/mTOR pathway, which was reversed by CASC2 silencing. And the effects of sanguinarine plus CASC2 silencing on the activation of these pathways were further reversed after knockdown of EIF4A3 at the same time. ConclusionsOur findings reveal that sanguinarine exhibits antitumor effects in epithelial ovarian cancer cells possible via regulating CASC2-EIF4A3 axis and/or inhibiting NF-κB signaling or PI3K/AKT/mTOR pathway. Sanguinarine may serve as a potential therapeutic reagent for epithelial ovarian cancer.

LncRNA CASC9 promotes esophageal squamous cell carcinoma metastasis through upregulating LAMC2 expression by interacting with the CREB-binding protein

Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer. Long noncoding RNAs (lncRNAs) are thought to play a critical role in cancer development. Recently, lncRNA CASC9 was shown to be dysregulated in many cancer types, but the mechanisms whereby this occurs remain largely unknown. In this study, we found that CASC9 was significantly upregulated in ESCC tissues, with further analysis revealing that elevated CASC9 expression was associated with ESCC prognosis and metastasis. Furthermore, we found that CASC9 knockdown significantly repressed ESCC migration and invasion in vitro and metastasis in nude mice in vivo. A microarray analysis and mechanical experiments indicated that CASC9 preferentially affected gene expression linked to ECM–integrin interactions, including LAMC2, an upstream inducer of the integrin pathway. We demonstrated that LAMC2 was consistently upregulated in ESCC and promoted ESCC metastasis. LAMC2 overexpression partially compromised the decrease of cell migration and invasion capacity in CASC9 knockdowns. In addition, we found that both CASC9 and LAMC2 depletion reduced the phosphorylation of FAK, PI3K, and Akt, which are downstream effectors of the integrin pathway. Moreover, the reduction in phosphorylation caused by CASC9 depletion was rescued by LAMC2 overexpression, further confirming that CASC9 exerts a pro-metastatic role through LAMC2. Mechanistically, RNA pull-down and RNA-binding protein immunoprecipitation (RIP) assay indicated that CASC9 could bind with the transcriptional coactivator CREB-binding protein (CBP) in the nucleus. Chromatin immunoprecipitation (ChIP) assay additionally illustrated that CASC9 increased the enrichment of CBP and H3K27 acetylation in the LAMC2 promoter, thereby upregulating LAMC2 expression. In conclusion, we demonstrate that CASC9 upregulates LAMC2 expression by binding with CBP and modifying histone acetylation. Our research reveals the prognostic and pro-metastatic roles for CASC9 in ESCC, suggesting that CASC9 could serve as a biomarker for prognosis and a target for metastasis treatment.

Long non-coding RNA CASC2 inhibits tumorigenesis via the miR-181a/PLXNC1 axis in melanoma.

Melanoma is the most malignant and aggressive form of skin carcinoma originating in the pigment-producing melanocytes. In this study, to further investigate the molecular mechanisms of the development and progression of melanoma, we explored the impacts of long non-coding RNA (lncRNA) CASC2 on melanoma cell functions. Microarray analysis was carried out to identify the expression of lncRNA CASC2 in melanoma cells. MiR-181a was predicted as a sponging target of CASC2 by miRcode, while the 3'-UTR of Plexin C1 (PLXNC1) was a potential target of miR-181a according to the TargetScan database. The correlation among CASC2, miR-181a, and PLXNC1 was verified by dual luciferase reporter assay and qRT-PCR. After manipulation of CASC2, miR-181a and PLXNC1 expression with transfection in A375 and M14 cells, cell viability, apoptosis, and invasive ability were evaluated using CCK-8, flow cytometry and Transwell assays, respectively. A low expression of CASC2 was detected in melanoma tissues and cells. Dual luciferase reporting assay confirmed that miR-181a targeted the 3'-UTR of PLXNC1. Furthermore, CASC2 could efficiently sponge miR-181a, thereby facilitating the expression of PLXNC1. Up-regulation of CASC2 suppressed the cell proliferation and invasion, but induced the apoptosis of melanoma cells. Our results demonstrated that lncRNA CASC2 can promote PLXNC1 expression by sponging miR-181a, thereby inhibiting the proliferation and invasion of melanoma cells, indicating that lncRNA CASC2 functions via the miR-181a/PLXNC1 axis in melanoma.

Long Non-Coding RNA Cancer Susceptibility Candidate 2a (CASC2a) Is a Marker of Early Recurrence After Radical Cystectomy in Patients with Urothelial Carcinoma of the Bladder.

BackgroundThe aim of this study was to investigate the expression of long non-coding RNAs (lncRNA) cancer susceptibility candidate 2a (CASC2a) in patients with urothelial carcinoma of the bladder (UCB) and its predictive value in the recurrence of UCB after radical cystectomy (RC).Material/MethodsTumor and paired adjacent normal tissues were obtained from 112 patients with UCB who underwent RC in our hospital from March 2010 to March 2012. The expression of CASC2a was evaluated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH).ResultsCASC2a was down-regulated in UCB tissues, and was highly negatively correlated with the pT, pN, tumor size, and lymphovascular invasion (LVI). The sensitivities of CASC2a for diagnosing UCB and its recurrence after RC were 89.30% and 81.55%, respectively, and the specificities were 71.43% and 58.21%, respectively. Patients with a high expression of CASC2a had a higher 5-year recurrence-free survival rate than those with low expression of CASC2a. Kaplan-Meier survival analysis demonstrated that the pT, pN, tumor grade, tumor size, concomitant carcinoma in situ (CIS), LVI, soft tissue surgical margin (STSM), and CASC2a expression were related to the recurrence in patients undergoing RC for UCB. Cox proportional hazard model analysis showed that CASC2 expression, pT4, lymph node metastasis, and CIS were independent risk factors.ConclusionsCASC2a was down-regulated in patients with UCB, and was associated with the risk of recurrence among patients undergoing RC, indicating that lncRNAs could act as predictive biomarkers and potential therapeutic targets in bladder cancer, including CASC2a.

LncRNA CASC9 promotes tumorigenesis by affecting EMT and predicts poor prognosis in esophageal squamous cell cancer.

The purpose of this study was to explore the clinical significance and biological function of long noncoding RNA CASC9 (CASC9) in esophageal squamous cell carcinoma (ESCC). Quantitative Real-time PCR (qRT-PCR) was used to determine the expression of CASC9 in ESCC tissues and cell lines. Receiver operating characteristic curves were used to evaluate the sensitivity and specificity of CASC9. The correlation between the CASC9 levels and the clinicopathological factors of the patients was also analyzed. Then, the survival was assessed by the Kaplan-Meier method and proportional hazards model. The effects of CASC9 on ESCC cells were evaluated by Cell Counting Kit-8 (CCK-8), migration and invasion. Finally, several EMT markers expression was detected by Western blot. We found that CASC9 was significantly upregulated in ESCC cell lines and clinical tissues. The CASC9 levels discriminated ESCC tissues from normal tissues with an area under the ROC curve (AUC) of 0.813. In addition, there is statistical significance between CASC9 expression level and tumor stage, lymph nodes metastasis, and clinical stage. Kaplan-Meier analysis indicated that high CASC9 expression had a significant impact on overall survival (p = 0.014) and disease-free survival (p = 0.0025). Moreover, CASC9 expression was an independent prognostic marker of overall survival and disease-free survival in a multivariate analysis. In vitro assay indicated that inhibition of CASC9 could suppress proliferation, migration, and invasion in ESCC. Further mechanistic studies found that aberrant CASC9 expression could modulate the expression levels of markers of EMT. Our data highlight the pivotal role of CASC9 as a novel diagnostic, prognostic biomarker and a potential therapeutic target of ESCC.

Down-Regulation of Long Non-Coding RNA CASC9 Suppresses the Migration and Invasion of Esophageal Cancer Cells

The objective of the study was to investigate the role of CASC9 in esophageal cancer cells migration and invasion. Expression of long noncoding RNA (lncRNA) CASC9 was found high in esophageal cancer cells by qRT-PCR. The CASC9 knockdown effects on cell migration and invasion were analyzed in vitro. Expression of lncRNA CASC9 was found markedly high in KYSE-450 cell line as compared to other esophageal cancer cell lines. After the knockdown of CASC9, migration and invasion were significantly decreased as compared to negative control. Increased expression of CASC9 before knockdown and decreased expression after knockdown in esophageal cancer cells, showed that CASC9 may act as a biomarker for esophageal cancer and may help to understand the mechanisms of this lethal disease.

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

To study the roles and mechanisms of RNA binding protein RNPC1 in non-small cell lung cancer progression. 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. RNA bind protein RNPC1 could inhibit non-small cell lung cancer progression by competitively binding to CASC2 with miR-181a.

High expression of LncRNA CASC15 is a risk factor for gastric cancer prognosis and promote the proliferation of gastric cancer.

To investigate the expression of long non-coding RNA CASC15 in gastric cancer tissue and its effect on the proliferation of gastric cancer cell line MKN28. We found that expression of lncRNA CASC15 in gastric cancer tissue was higher than normal gastric epithelium through the TCGA and Gene Expression Omnibus (GEO) database. Then, we detect the RNA level of CASC15 from clinical samples of 42 normal gastric epithelial tissues and 60 gastric cancer tissues. In order to explore the function of CASC15 in gastric cancer, we perform gain-function and loss-function assay in gastric cancer cell lines. We found that expression of lncRNA CASC15 in gastric cancer tissue was higher than normal gastric epithelium through the TCGA database and the related microarray data set was searched from Gene Expression Omnibus (GEO) database. Then, we extracted total RNA from clinical samples of 42 normal gastric epithelial tissues and 60 gastric cancer tissues. The results of quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) were consistent with those of TCGA analysis. Clinical data analysis showed that the expression of LncRNA CASC15 was correlated with the total survival, tumor size and TMN staging in clinical patients. Clinical data analysis showed that the expression level of CASC15 was correlated with tumor size and TNM stage in clinical patients. Compared with the negative control group, the proliferation and cell cloning ability of MKN28 cells overexpressing LncRNA CASC15 significantly increased (p<0.001), indicating that overexpression of LncRNA CASC15 promoted the proliferation of MKN28 cells. The expression of LncRNA CASC15 was significantly higher in gastric cancer tissues and its expression was negatively correlated with the overall survival of clinical patients. It was positively correlated with the tumor size and TMN stage. LncRNA CASC15 could promote the proliferation of gastric cancer cells and was expected to become the molecular marker for prediction and prognosis of gastric cancer, as well as a potential therapeutic target.

Upregulation of CASC2 sensitized glioma to temozolomide cytotoxicity through autophagy inhibition by sponging miR-193a-5p and regulating mTOR expression

ObjectiveNumerous studies suggested autophagy was involved in temozolomide (TMZ) resistance in glioma. Long non-coding RNA (lncRNA) CASC2 was shown to be downregulated in glioma tissues and cell lines, and was related to the TMZ resistance. However, whether CASC2 affects TMZ resistance through regulating autophagy is unknown. The aim of this study was to assess the role and mechanism of CASC2 in TMZ-induced drug resistance in glioma cells. MethodsGlioma and the adjacent non-cancerous tissues from 32 patients were collected. The expressions of CASC2 and miR-193a-5p were determined by PCR, and their correlation was analyzed. The correlation between CASC2 expression and the clinical characteristics of patients was also studied. Glioma cells were treated with TMZ to acquire the TMZ-resistant cell lines in which the expressions of CASC2, miR-193a-5p, and mTOR were measured. The regulatory roles of CASC2, miR-193a-5p, and mTOR were defined through the loss of function and luciferase reporter assays. Autophagy was inhibited by autophagy inhibitor 3-MA, CASC2 and mTOR overexpression, or miR-193a-5p inhibitor, and the effect of which on cell viability, apoptosis, and migration of TMZ-resistant glioma cells was evaluated. ResultsCASC2 downregulation and miR-193a-5p upregulation was found to be associated with advanced clinical stage and TMZ response in patients with glioma. CASC2 negatively regulates miR-193a-5p expression by direct interaction in glioma cells. Overexpression of CASC2 or inhibition of miR-193a-5p reduced TMZ-induced autophagy via mTOR upregulation, which makes the glioma cells become sensitive to TMZ cytotoxicity. ConclusionCASC2 is downregulated in gliomas, resulting in increased miR-193a-5p level and a decrease in mTOR expression, which further induces protective autophagy, leading to TMZ resistance. Inhibition of autophagy helps to increase the efficacy of TMZ.