Expression Of Cancer Susceptibility Candidate 2 Research Articles

The expression of lncRNAs CASC2, NEAT1, LINC00299 in breast cancer tissues and their relationship with the XBP1 splicing rate in Iranian patients during 2014-2019: A cross-sectional study.

Breast cancer is a leading cause of incidence and mortality in women globally. Identifying new molecular markers can aid in cancer diagnosis, targeted therapy, and treatment monitoring. This study aimed to measure the expression of the X-box binding protein 1 (XBP1) gene, an index of the unfolded protein response (UPR), and long noncoding RNAs (lncRNAs), including Nuclear Enriched Abundant Transcript 1 (NEAT1), Cancer Susceptibility Candidate 2 (CASC2), and Long Intergenic Nonprotein Coding RNA 299 (LINC00299), as possible regulators of the UPR pathway. Total RNA was extracted from 40 samples of breast tumor tissues and their respective controls. The expression level of lncRNAs CASC2, NEAT1, and LINC00299 was quantified using reverse transcription-polymerase chain reaction (RT-PCR). The ratio of the spliced form of XBP1 to its unspliced form (XBP1u) was determined by PCR and electrophoresis. The results showed a 2.8-fold increase in the ratio of XBP1s/u in breast cancer tissues compared to adjacent nonmalignant samples (p < 0.05). Additionally, the level of lncRNAs NEAT1, CASC2, and LINC00299 in breast tumor tissues increased significantly by twofold, 1.5-fold, and 2.3-fold, respectively, compared to adjacent nonmalignant samples (p < 0.05). Based on the association between the expression of lncRNAs CASC2, LINC00299, and NEAT1 and the XBP1s/u ratio, these lncRNAs could be potential regulators of the UPR pathway. Also, CASC2 and NEAT1 genes could be suggested as suitable biomarkers to distinguish cancerous tissue from noncancerous breast tissue due to their significant increase in expression in cancerous samples compared to adjacent noncancerous.

The lncRNA CASC2 Modulates Hepatocellular Carcinoma Cell Sensitivity and Resistance to TRAIL Through Apoptotic and Non-Apoptotic Signaling.

The immune cytokine tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been widely concerned as a tumor therapy because of its ability of selective triggering cancer cell apoptosis; nevertheless, hepatocellular carcinoma (HCC) exhibits acquired resistance to TRAIL-induced apoptosis. In the present study, tumor-suppressive lncRNA cancer susceptibility candidate 2 (CASC2) was downregulated in HCC tissues and cell lines; HCC patients with lower CASC2 expression predicted a shorter overall survival rate. In vitro, CASC2 overexpression dramatically repressed HCC cell proliferation and inhibited cell apoptosis; in vivo, CASC2 overexpression inhibited subcutaneous xenotransplant tumor growth. CASC2 affected the caspase cascades and NF-κB signaling in TRAIL-sensitive [Huh-7 (S) and HCCLM3 (S)] or TRAIL-resistant cell lines [Huh-7 (R) and HCCLM3 (R)] in different ways. In Huh-7 (S) and HCCLM3 (S) cells, CASC2 affected cell apoptosis through the miR-24/caspase-8 and miR-221/caspase-3 axes and the caspase cascades. miR-18a directly targeted CASC2 and RIPK1. In Huh-7 (R) and HCCLM3 (R) cells, CASC2 affected cell proliferation through the miR-18a/RIPK1 axis and the NF-κB signaling. RELA bound to CASC2 promoter region and inhibited CASC2 transcription. In conclusion, CASC2 affects cell growth mainly via the miR-24/caspase-8 and miR-221/caspase-3 axes in TRAIL-sensitive HCC cells; while in TRAIL-resistant HCC cells, CASC2 affects cell growth mainly via miR-18a/RIPK1 axis and the NF-κB signaling. These outcomes foreboded that CASC2 could be a novel therapeutic target for further study of HCC-related diseases.

Transcription factor NFIC functions as a tumor suppressor in lung squamous cell carcinoma progression by modulating lncRNA CASC2

ABSTRACT Nuclear factor I (NFI) family is emerging found playing oncogenic or tumor-suppressive potential in cancers. However, the function and underlying mechanisms of NFIC, in the progression of Lung Squamous Cell Carcinoma (LUSC) remain unclear. Therefore, this study aims to probe into the function of NFIC in the development of LUSC. In the present study, we reported that NFIC was low expressed in human LUSC tissues and cell lines. NFIC inhibited LUSC cell proliferation and promoted cell apoptosis in vitro and in vivo. Moreover, NFIC also inhibited LUSC cell migration and invasion. Furthermore, we found that there were binding sites between lncRNA cancer susceptibility candidate 2 (CASC2) and NFIC, whose relationship was confirmed by the luciferase reporter assay. The expression of CASC2 and the expression of NFIC were positively correlated, and the function of CASC2 overexpression is similar to that of NFIC overexpression, which suggested that CASC2 may play a key role in LUSC development. Our study provided a new perspective for NFIC acting as an antioncogene in LUSC tumorigenesis, and NFIC and CASC2 may serve as novel potential targets for the treatment of LUSC.

Propofol suppresses proliferation, migration, invasion, and tumor growth of liver cancer cells via suppressing cancer susceptibility candidate 9/phosphatase and tensin homolog/AKT serine/threonine kinase/mechanistic target of rapamycin kinase axis.

Propofol is a commonly used drug for sedation and general anesthesia during cancer surgery. Previous studies indicate that propofol exerts anti-tumor effect in various cancers. The aim of this study was to investigate the underlying molecular mechanism of propofol in liver cancer. The effects of propofol on liver cancer cells were evaluated by cell viability assay, colony formation assay, and tumor xenograft model. Dysregulated lncRNAs of propofol-treated liver cancer cells were evaluated by transcriptome RNA sequencing. The underlying molecular mechanisms of lncRNA cancer susceptibility candidate 9 (CASC9) in propofol-induced anti-tumor effects were evaluated by western blot, quantitative real-time polymerase chain reaction (qRT-PCR), wound scratch healing assay, transwell cell migration and invasion assay, TUNEL staining, fluorescence in situ hybridization, RNA immunoprecipitation (RIP), and chromatin immunoprecipitation (ChIP). We found that propofol suppressed proliferation, migration, invasion, and tumor xenograft growth of liver cancer cells in a dose-dependent manner. Exosomes transfer from propofol-treated cells inhibited proliferation, migration, and invasion and promoted apoptosis of liver cancer cells. Transcriptional profiling of propofol-treated liver cancer cells identified CASC9 as significantly downregulated lncRNA in cells and exosomes. Enforced CASC9 expression partially rescued the inhibitory effects of propofol on liver cancer cells. Furthermore, CASC9 was found to interact directly with EZH2 and epigenetically regulated PTEN expression. Restoration of CASC9 partially abrogated the inhibition of propofol on Akt/mTOR signaling. Our results indicated that propofol exerted anti-tumor effects by downregulating CASC9, and subsequently suppressed Akt/mTOR signaling. Our findings provided a novel insight into propofol-induced anti-tumor effects in liver cancer.

Long non-coding RNA CASC2 restrains high glucose-induced proliferation, inflammation and fibrosis in human glomerular mesangial cells through mediating miR-135a-5p/TIMP3 axis and JNK signaling

BackgroundDiabetic nephropathy (DN) is a common complication of diabetes. Long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) is reported to exert a protective role in DN by a previous study. The working mechanism underlying the protective role of CASC2 in DN progression was further explored in this study.MethodsThe expression of CASC2 and microRNA-135a-5p (miR-135a-5p) was determined by real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation ability was assessed by Cell Counting Kit-8 (CCK8) assay and 5-ethynyl-29-deoxyuridine (EDU) assay. Enzyme-linked immunosorbent assay (ELISA) was conducted to analyze the production of inflammatory cytokines in the supernatant. Western blot assay was performed to analyze protein expression. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were performed to verify the target relationship between miR-135a-5p and CASC2 or tissue inhibitors of metalloproteinase 3 (TIMP3).ResultsHigh glucose (HG) treatment reduced the expression of CASC2 in human glomerular mesangial cells (HMCs) in a time-dependent manner. CASC2 overexpression suppressed HG-induced proliferation, inflammation and fibrosis in HMCs. miR-135a-5p was validated as a target of CASC2, and CASC2 restrained HG-induced influences in HMCs partly by down-regulating miR-135a-5p. miR-135a-5p bound to the 3ʹ untranslated region (3ʹUTR) of TIMP3, and CASC2 positively regulated TIMP3 expression by sponging miR-135a-5p in HMCs. miR-135a-5p silencing inhibited HG-induced effects in HMCs partly by up-regulating its target TIMP3. CASC2 overexpression suppressed HG-induced activation of Jun N-terminal Kinase (JNK) signaling partly through mediating miR-135a-5p/TIMP3 signaling.ConclusionsIn conclusion, CASC2 alleviated proliferation, inflammation and fibrosis in DN cell model by sponging miR-135a-5p to induce TIMP3 expression.

Cancer Susceptibility Candidate 9 (CASC9) Promotes Colorectal Cancer Carcinogenesis via mTOR-Dependent Autophagy and Epithelial-Mesenchymal Transition Pathways.

BackgroundColorectal cancer (CRC) is the third most common cancer worldwide. Many recent studies have demonstrated that different long non-coding RNAs (lncRNAs) are involved in the initiation, advancement, and metastasis of many cancers including CRC. Cancer susceptibility candidate 9 (CASC9) is an lncRNA that has been reported in many cancers, but its role in CRC is poorly understood. In this study, we aimed to examine the expression of CASC9 in CRC cell lines and to determine the mechanism of action of CASC9 in CRC carcinogenesis.MethodsThe expression of CASC9 in CRC tissues was compared with normal samples from publicly available datasets in The Cancer Genome Atlas (TCGA) and The Encyclopedia of RNA Interactomes (ENCORI). CASC9 expression was further verified in four CRC cell lines (DLD1, HT-29, SW480, and HCT-116) and normal colorectal cell line (CCD-112CoN) by real-time quantitative polymerase chain reaction (RT-qPCR). After gene silencing in HCT-116 and SW480, Cell Counting Kit-8 assay, clonogenic assay, and wound healing assay were performed to evaluate cell proliferation, viability, and migration index of cells. Western blotting was used to explore the key pathways involved.ResultsCASC9 was significantly upregulated as analyzed from both public datasets TCGA and ENCORI where its overexpression was associated with poor survival of CRC patients. Similarly, CASC9 was significantly overexpressed in the CRC cell lines compared with normal cells studied. The silencing of CASC9 in HCT-116 and SW480 attenuated cell proliferation and migration significantly. Furthermore, pathways investigations showed that silencing of CASC9 significantly induced autophagy, promoted AMP-activated protein kinase (AMPK) phosphorylation, inhibited mTOR and AKT signaling pathways, and altered epithelial–mesenchymal transition (EMT) marker protein expression.ConclusionWe demonstrated that silencing of CASC9 contributes to the reduced CRC cell proliferation and migration by regulating autophagy and AKT/mTOR/EMT signaling. Therefore, CASC9 plays an important role in carcinogenesis, and its expression may act as a prognostic biomarker and a potential therapeutic target of CRC management.

Long Non-Coding RNA CASC2 Overexpression Ameliorates Sepsis-Associated Acute Kidney Injury by Regulating MiR-545-3p/PPARA Axis

Long non-coding RNAs (lncRNAs) have been demonstrated to be involved in the progression of sepsis-induced acute kidney injury (AKI). In this study, we aimed to explore the functions of lncRNA cancer susceptibility candidate 2 (CASC2) in sepsis-induced AKI. The sepsis cell models were established by exposing HK2 and HEK293 cells into lipopolysaccharide (LPS). Quantitative real-time polymerase chain reaction (qRT-PCR) assay was conducted to determine the expression of CASC2, miR-545-3p and peroxisome proliferator-activated receptor-α (PPARA) mRNA. Cell Counting Kit-8 (CCK-8) assay, flow cytometry analysis and wound healing assay were employed for cell viability, apoptosis and migration, respectively. Western blot assay was conducted for the protein levels of E-cadherin, α-SMA and PPARA. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were measured by specific kits. The relationship between miR-545-3p and CASC2 or PPARA was verified by dual-luciferase reporter assay. CASC2 level was decreased in sepsis patients' serums and LPS-treated HK2 and HEK293 cells. CASC2 overexpression facilitated cell viability and restrained cell apoptosis, migration, epithelial-mesenchymal transition (EMT) and oxidative stress in LPS-triggered HK2 and HEK293 cells. CASC2 was identified as a sponge for miR-545-3p to regulate PPARA expression. MiR-545-3p overexpression restored the impact of CASC2 on LPS-induced injury in HK2 and HEK293 cells. Moreover, miR-545-3p overexpression aggravated LPS-induced cell injury in HK2 and HEK293 cells by targeting PPARA. CASC2 overexpression relieved the damage of HK2 and HEK293 cells mediated by LPS treatment through regulating miR-545-3p/PPARA axis.

LncRNA CASC9 sponges miR‑758‑3p to promote proliferation and EMT in bladder cancer by upregulating TGF‑β2.

The long noncoding RNA cancer susceptibility candidate 9 (CASC9) has been revealed to be an oncogenic gene in several types of cancer, and high CASC9 expression is related to tumorigenesis and cancer progression. However, the role of CASC9 in bladder cancer (BC), particularly during epithelial-mesenchymal transition (EMT), has not been characterized. RT-qPCR, EdU, CCK-8, wound scratch, Transwell and flow cytometric assays were performed to detect CASC9 expression, miR-758-3p expression and their functions in BC. RNA FISH was used to detect CASC9 subcellular localization. Luciferase reporter assay, RT-qPCR assay and western blotting were used to explore the relationship of CASC9, miR-758-3p and TGF-β2. In the present study, it was revealed that CASC9 regulated EMT in BC. CASC9 expression was significantly upregulated in BC cell lines and specimens compared to that in adjacent normal bladder tissues. Upregulated CASC9 was associated with increased invasion ability and poor prognosis of BC. CASC9 knockdown inhibited BC cell proliferation, migration and invasion. Furthermore, a bioinformatics study and luciferase reporter assays revealed that CASC9 functioned as a ceRNA for miR-758-3p. CASC9 inhibited microRNA (miR)-758-3p activity and resulted in the de-suppression of its target transforming growth factor (TGF)-β2. TGF-β signaling driven by TGF-β2 was crucial for CASC9 to promote EMT in BC. Collectively, these results indicated that CASC9 sponged miR-758-3p to regulate the expression of TGF-β2, which activated the TGF-β signaling pathway and promoted proliferation and EMT in BC.

The Role of CASC2 and miR-21 Interplay in Glioma Malignancy and Patient Outcome.

Recently long non-coding RNAs (lncRNAs) were highlighted for their regulatory role in tumor biology. The novel human lncRNA cancer susceptibility candidate 2 (CASC2) has been characterized as a potential tumor suppressor in several tumor types. However, the roles of CASC2 and its interplay with miR-21 in different malignancy grade patient gliomas remain unexplored. Here we screened 99 different malignancy grade astrocytomas for CASC2, and miR-21 gene expression by real-time quantitative polymerase chain reaction (RT-qPCR) in isocitrate dehydrogenase 1 (IDH1) and O-6-methylguanine methyltransferase (MGMT) assessed gliomas. CASC2 expression was significantly downregulated in glioblastomas (p = 0.0003). Gliomas with low CASC2 expression exhibited a high level of miR-21, which was highly associated with the higher glioma grade (p = 0.0001), IDH1 wild type gliomas (p < 0.0001), and poor patient survival (p < 0.001). Taken together, these observations suggest that CASC2 acts as a tumor suppressor and potentially as a competing endogenous RNA (ceRNA) for miR-21, plays important role in IDH1 wild type glioma pathogenesis and patients’ outcomes.

LncRNA CASC2 Enhances 131I Sensitivity in Papillary Thyroid Cancer by Sponging miR-155.

Long noncoding RNA cancer susceptibility candidate 2 (CASC2) has been reported to play an anticancer role in papillary thyroid cancer (PTC). Radioiodine (131I) is a common option for the treatment of PTC. However, the role and mechanism of CASC2 in 131I sensitivity remain unclear. In this study, 131I-resistant cells were constructed through continuous treatment of 131I. The expression levels of CASC2 and miR-155 were measured by qRT-PCR. The IC50 of 131I was analyzed by cell viability using MTT assay. Flow cytometry was conducted to determine cell apoptosis induced by 131I. The association between CASC2 and miR-155 was evaluated by luciferase assay and RNA immunoprecipitation. A mouse xenograft model was built to explore the effect of CASC2 on the growth of 131I-resistant PTC cells in vivo. Results showed that CASC2 expression was decreased in PTC tissues and cells, and low expression of CASC2 was associated with poor outcome of patients. CASC2 level was reduced in 131I-resistant cells. Knockdown of CASC2 inhibited 131I sensitivity in thyroid cancer cells. Overexpression of CASC2 enhanced 131I sensitivity in constructed resistant PTC cells. CASC2 was a decoy of miR-155, and CASC2-mediated promotion of 131I sensitivity was weakened by decreasing miR-155. Abundance of CASC2 inhibited the growth of 131I-resistant cells in vivo. As a conclusion, CASC2 increases 131I sensitivity in PTC by sponging miR-155, providing a novel target for the treatment of thyroid cancer patients with 131I resistance.

LncRNA CASC2 inhibits lipopolysaccharide‑induced acute lung injury via miR‑27b/TAB2 axis.

Long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) has been reported to exert an important role in acute lung injury (ALI). The present study aimed to investigate the potential underlying mechanism of CASC2 in ALI progression. Reverse transcription-quantitative PCR was conducted to examine the expression of CASC2, microRNA (miR/miRNA)-27b and TGF-β activated kinase 1 and MAP3K7-binding protein 2 (TAB2) in A549 cells. Cell viability and apoptosis were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and flow cytometry. Enzyme-linked immunosorbent assay was used to measure the levels of inflammatory-related cytokines to assess the inflammatory response, including interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α). The binding sites of miR-27b in CASC2 or TAB2 were predicted using LncBase or microT-CDS software, following which dual-luciferase reporter and RNA binding protein immunoprecipitation assays were performed to confirm the target relationship between miR-27b and CASC2 or TAB2. The protein expression of TAB2 was detected by western blotting. The decreased viability, and increased apoptosis and inflammatory responses were attenuated by the accumulation of CASC2 in lipopolysaccharide (LPS)-stimulated A549 cells. CASC2 could directly bind to miR-27b in A549 cells. CASC2 protected A549 cells from LPS-triggered injury by downregulating miR-27b. TAB2 was a target of miR-27b in A549 cells. The influence of miR-27b depletion was reversed by the silencing of TAB2 in an ALI cell model. CASC2 could increase the expression of TAB2 by serving as a competing endogenous RNA of miR-27b in A549 cells. Collectively, the results suggested that CASC2 attenuated LPS-induced injury in the ALI cell model by modulating the miR-27b/TAB2 axis.

Oncogenic LncRNA CASC9 in Cancer Progression.

Long non-coding RNAs (LncRNAs), with the length of over 200 nucleotides, that originate from intergenic, antisense, or promoter-proximal regions, are a large family of RNAs that lack coding capacity. Emerging evidences illustrated that LncRNAs played significant roles in a variety of cellular functions and biological processes in profuse human diseases, especially in cancers. Cancer susceptibility candidate 9 (CASC9), as a member of the LncRNAs group, firstly found its oncogenic function in esophageal cancer. In the following recent studies, a growing amount of human malignancies are verified to be correlated with CASC9, most of which are derived from the squamous epithelium tissue. This present review attempts to highlight the latest insights into the expression, functional roles, and molecular mechanisms of CASC9 in different human malignancies. In this review, the latest findings related to the pathophysiological processes of CASC9 in human cancers were summarized and analyzed, and the associated studies collected in systematic retrieval of PubMed used lncRNA and CASA9 as keywords. CASC9 expression is identified to be aberrantly elevated in a variety of malignancies. The over-expression of CASC9 has been suggested to accelerate cell proliferation, migration, cell growth and drug resistance of cancer cells, while depressing cell apoptosis, revealing its role as an oncogene. Moreover, the current review demonstrated CASC9 as closely related to the neoplastic transformation of squamous epithelial cells and squamous metaplasia in non-squamous epithelial tissues. Finally, we discuss the limitations and tremendous diagnostic/ therapeutic potential of CASC9 in various human cancers. Long non-coding RNA CASC9 likely serve as useful disease biomarkers or therapeutic targets which be effectively applied in the treatment of different kinds of cancers.

Long non-coding RNA CASC2 targeting miR-18a suppresses glioblastoma cell growth, metastasis and EMT in vitro and in vivo

Long non-coding RNAs (lncRNAs) cancer susceptibility candidate 2 (CASC2) has been characterized as a tumor suppressor in glioma. Although CASC2 may predict the prognosis of glioma patients, the role and mechanism of CASC2 in human glioblastoma remain to be fully illuminated. Expression of CASC2 and miR- 18a was detected using RT-qPCR. Cell growth was evaluated by MTT assay, colony formation assay, and flow cytometry; metastasis and epithelial-mesenchymal transition (EMT) were determined with transwell assay and Western blot, respectively. The target binding between CASC2 and miR-18a was predicted on Starbase software, and confirmed by luciferase reporter assay and RNA immunoprecipitation. Xenograft experiment measured tumor growth. As a result, CASC2 was downregulated and miR-18a was upregulated in glioblastoma tumor tissues and cells (T98 and A172). Overexpression of CASC2 promoted apoptosis rate and E-cadherin expression, but suppressed cell viability, colony-forming ability, migration, invasion, and expression of N-cadherin and Vimentin in T98 and A172 cells, accompanied with tumor growth inhibition in vivo; whereas, silencing of CASC2 exerted the opposite effect on cell growth, metastasis and EMT of T98 and A172 cells in vitro. However, reintroduction of miR-18a could reverse CASC2 upregulation-mediated suppression on above cell behaviors in vitro. More importantly, miR-18a was a downstream target for CASC2, and was negatively regulated by CASC2. Collectively, this study demonstrated that CASC2 served as tumor suppressor in glioblastoma by inhibiting cell growth, metastasis and EMT both in vitro and in vivo partially via CASC2- miR-18a axis.

Long non-coding RNA CASC9 promotes the progression of retinoblastoma via interacting with miR-145-5p

ABSTRACT Abnormal expression of long non-coding RNA cancer susceptibility candidate 9 (CASC9) has been found to play vital roles in many human tumors. However, the role and the regulatory mechanism of CASC9 have not yet been demonstrated in retinoblastoma (RB). Hence, we performed this study to explore the function and mechanism of CASC9 in RB. CASC9 expression was firstly detected in human RB tissues and cells. The influence of CASC9 on the malignant phenotypes of RB cells, including cell proliferation, invasion, epithelial–mesenchymal transition (EMT) and apoptosis, was analyzed by overexpressing or silencing CASC9. The association between CASC9, miR-145-5p and E2F transcription factor 3 (E2F3) was determined by dual-luciferase reporter assay and RNA immunoprecipitation. We found that CASC9 expression was elevated in RB tissues and cells. Overexpression of CASC9 significantly facilitated the proliferation, invasion and EMT of RB cells. On the contrary, knockdown of CASC9 inhibited the proliferation, invasion and EMT, while enhanced the apoptosis of RB cells. CASC9 acted as a competing endogenous RNA (ceRNA) for miR-145-5p to regulate E2F3. Additionally, miR-145-5p inhibitor and E2F3 overexpression both partly reversed the malignant phenotypes of RB cells affected by CASC9 knockdown. However, miR-145-5p overexpression further strengthened these features induced by CASC9 downregulation. These findings suggested that CASC9 contributed to RB development by regulating E2F3 via sponging miR-145-5p. CASC9 might be a possible therapeutic target for RB.

Long non-coding RNA CASC9 promotes tumor growth and metastasis via modulating FZD6/Wnt/\u03b2-catenin signaling pathway in bladder cancer

BackgroundAccumulating evidence have highlighted the importance of long noncoding RNAs (lncRNAs) in multiple cancers development and progression. Cancer susceptibility candidate 9 (CASC9) is a novel long non-coding RNA and plays important regulatory role in diverse biological processes of cancers. However, the clinical significance and molecular mechanism of CASC9 in bladder cancer is still unknown.MethodsComprehensive lncRNAs profiling analysis were conducted to identify lncRNAs profile alterations and uncover valuable lncRNA candidates for bladder cancer. The expression level of CASC9 was determined in a total of 106 patients with bladder cancer. Loss-of-function experiments were performed to identify the functions of CASC9 in tumor growth and metastasis of bladder cancer in vitro and in vivo. Bioinformatics analysis and further experiments were performed to explore the molecular mechanisms underlying the functions of CASC9.ResultsThis study found that CASC9 expression was markedly upregulated in bladder cancer and related to histological grade, TNM stage and prognosis. Knockdown of CASC9 inhibited tumor growth and metastasis of bladder cancer in vitro and in vivo. Mechanistically, we found that CASC9 functions as a miRNA sponge to positively regulate FZD6 expression and subsequently activates Wnt/β-catenin signaling pathway, thus playing an oncogenic role in bladder cancer pathogenesis.ConclusionIn summary, lncRNA CASC9 plays a critical regulatory role in bladder cancer. The CASC9/miR-497-5p/ FZD6 axis provides insights for regulatory mechanism of bladder cancer, and new strategies for clinical practice.

Upregulated lncRNA CASC9 Contributes to Progression of Non-Small Cell Lung Cancer Through Inhibition of miR-335-3p and Activation S100A14 Expression.

IntroductionNon-small cell lung cancer (NSCLC) is a deadly cancer type worldwide and the main sub-type of lung cancer. Cancer susceptibility candidate-9 (CASC9) was reported to be a key player in cancer progression. However, its function and underlying mechanism in NSCLC remain unclear.Materials and MethodsExpression level of CASC9 in NSCLC tissues and cells was measured with RT-qPCR. Biological roles of CASC9 in NSCLC were analyzed with a series of in vitro experiments. Potential mechanisms of CASC9 in NSCLC were analyzed by predicting and validating the possible targets of CASC9 in NSCLC.ResultsIn this study, we found CASC9 expression was upregulated in NSCLC tissues and cell lines. High CASC9 expression was identified as a predictor for poorer overall survival of NSCLC patients. Furthermore, functional assays showed CASC9 knockdown suppressed NSCLC cell proliferation, migration, and invasion, while CASC9 overexpression caused opposite effects. We also found microRNA-335-3p (miR-335-3p) could act as a target of CASC9 in NSCLC and the inhibition effect of CASC9 knockdown on NSCLC progression required the activity of miR-335-3p. In addition, we identified S100 calcium-binding protein A14 (S100A14) acts as a target of miR-335-3p.DiscussionTaken together, our study suggested CASC9 could promote NSCLC progression via miR-335-3p/S100A14 axis. The CASC9/miR-335-3p/S100A14 regulatory triplets identified in this work might provide new therapeutic strategies for NSCLC treatment.

LncRNA CASC2 downregulation participates in rheumatoid arthritis, and CASC2 overexpression promotes the apoptosis of fibroblast‑like synoviocytes by downregulating IL‑17.

lncRNA cancer susceptibility candidate 2 (CASC2) is a recently identified oncogenic lncRNA in different types of cancers. Our preliminary microarray data showed that lncRNA CASC2 was downregulated in the plasma of patients with rheumatoid arthritis (RA), indicating the involvement of this lncRNA in RA. In the present study, lncRNA CASC2 and IL-17 in plasma were detected by reverse transcription--quantitative PCR and ELISA, respectively. Diagnostic analyses were performed using receiver operating characteristic curves. Flow cytometry was performed to evaluate cell apoptosis. The effects of lncRNA CASC2 on IL-17 expression were determined via western blotting. lncRNA CASC2 was found to be downregulated, while IL-17 was upregulated in the plasma of RA patients when compared with these levels in the plasma of healthy controls. Plasma levels of lncRNA CASC2 and IL-17 were significantly and inversely correlated in both RA patients and healthy controls. Altered plasma levels of lncRNA CASC2 and IL-17 were able to differentiate RA patients from healthy controls. Overexpression of lncRNA CASC2 promoted, while treatment with IL-17 inhibited the apoptosis of human fibroblast-like synoviocytes (HFLSs) isolated from RA patients. Overexpression of lncRNA CASC2 inhibited IL-17 expression in HFLS, while treatment with IL-17 did not significantly affect the expression of lncRNA CASC2. Therefore, downregulation of lncRNA CASC2 is involved in RA and lncRNA CASC2 overexpression may promote the apoptosis of HFLS by downregulating IL-17.

ELF1 activated long non-coding RNA CASC2 inhibits cisplatin resistance of non-small cell lung cancer via the miR-18a/IRF-2 signaling pathway.

Chemoresistance is the leading cause of recurrence in non-small cell lung cancer (NSCLC). The long non-coding RNA (lncRNA) cancer susceptibility candidate 2 (CASC2) inhibits the tumorigenesis of various cancers. However, the regulatory function of CASC2 on the chemoresistance of NSCLC remains unclear. The levels of CASC2 and miR-18a in cisplatin (DDP)-resistant NSCLC tissues and cell lines were evaluated by quantitative Polymerase Chain Reaction (qPCR). The role of low CASC2 levels on overall survival in patients with NSCLC was tested using the log-rank test. The Chi-squared test was used to assess the relation between CASC2 expression and clinicopathological features of NSCLC patients. Cell Counting Kit-8 (CCK-8) assays tested the cell proliferation of cisplatin-resistant NSCLC cells (H226/DDP and A549/DDP). The underlying regulatory mechanism between CASC2 and miR-18a or miR-18a and interferon regulatory factor 2 (IRF-2) was predicted by bioinformatics and verified by a Dual-Luciferase reporter assay, RNA transfection, qPCR, and Western blotting. Chromatin immunoprecipitation (ChIP) assay was done to exam the relation between E74 like factor 1 (ELF1) and CASC2 gene. Mice xenografts were applied to exam the function of CASC2 on chemosensitivity of cisplatin of NSCLC cells in vivo. Low CASC2 expression is more likely to present in patients with advanced TNM stage (IV), cisplatin-resistance, and poor overall survival. The expression of CASC2 sharply decreased in cisplatin-resistant NSCLC tissues and cell lines (H226/DDP and A549/DDP). CASC2 overexpression strongly inhibited proliferation, migration, and invasion of cisplatin-resistant NSCLC cells (H226/DDP and A549/DDP) in vitro and inhibited tumor growth in vivo. Besides, CASC2 repressed miR-18a function by binding to the complementary sites of miR-18a as competing endogenous RNAs (ceRNAs). MiR-18a released by the declining expression of CASC2 reduced the protein concentration of IRF-2 in NSCLC cells. Furthermore, the transcription factor ELF1 was found to be promotor of CASC2 and increased its levels in cisplatin-resistant NSCLC cells. IRF-2 expression mediated by the ELF1/CASC2/miR-18a axis is markedly associated with the proliferation, migration, and invasion of cisplatin-resistant NSCLC, resulting in inferior survival. These findings suggest that this regulatory axis may serve as a novel therapeutic target in NSCLC.

Long non‑coding RNA CASC2 ameliorates sepsis‑induced acute kidney injury by regulating the miR‑155 and NF‑κB pathway.

Sepsis is a systemic inflammatory response syndrome that can cause multiple‑organ damage, including acute kidney injury (AKI). Studies have shown that the long non‑coding RNA cancer susceptibility candidate2 (CASC2) is involved in the occurrence and development of multiple human diseases, although its expression and role in AKI has not yet been reported. The present study demonstrated that the expression of CASC2 was significantly decreased in the serum of patients with sepsis compared with healthy subjects. In addition, the CASC2 level was negatively associated with the severity of AKI. Further experiments revealed that CASC2 promoted cell viability and inhibited inflammatory factor secretion, apoptosis and oxidative stress in lipopolysaccharide‑stimulated human renal tubular epithelial HK‑2 cells. Importantly, the current study observed that CASC2 was negatively associated with a pro‑inflammatory microRNA (miR)‑155. In addition, the upregulation of CASC2 significantly suppressed the nuclear factorκB (NF‑κB) signaling pathway. In conclusion, the results of the present study suggested that CASC2 may serve as a potential target for treating sepsis‑induced AKI by inhibiting the miR‑155 and NF‑κB pathway‑mediated inflammation.

LncRNA CASC2 suppresses the growth of hemangioma cells by regulating miR-18a-5p/FBXL3 axis.

Dysregulation of lncRNA cancer susceptibility candidate 2 (CASC2) is involved in the pathogenesis of multiple malignancies. However, the underlying mechanisms by which lncRNA CASC2 regulates the proliferation of hemangiomas (HAs) remain undocumented. Herein, the expression levels of lncRNA CASC2 and VEGF in proliferating or involuting phase HAs were assessed by qRT-PCR analysis, and the effects of lncRNA CASC2 on HAs cell growth were evaluated by MTT, colony formation assays and Western blot analysis. lncRNA CASC2 specific binding with miR-18a-5p was confirmed by luciferase report assay. Consequently, we found that the expression of lncRNA CASC2 was reduced in proliferating phase HAs as compared with the involuting phase HAs or normal tissues, and possessed a negative correlation with VEGF expression in proliferating phase HAs. Restored expression of lncRNA CASC2 repressed cell viability and colony formation and downregulated VEGF expression, while silencing lncRNA CASC2 showed the opposite effects. Moreover, lncRNA CASC2 was confirmed to bind with miR-18a-5p, which could reverse lncRNA CASC2-induced anti-proliferative effects by targeting FBXL3 in HAs cells. Altogether, our findings demonstrated that lncRNA CASC2 suppressed the growth of HAs cells by regulating miR-18a-5p/FBXL3 axis.