ABSTRACT
BACKGROUND: Circular RNAs have been widely explored as potential biomarkers and therapeutic targets in bladder cancer; however, few have been functionally characterized. RESULTS: ciRs-6 is expressed at low levels in cancer tissues and advanced tumor grades and stages, and its expression correlates with better outcomes for bladder cancer patients. In vitro and in vivo, ciRs-6 was shown to suppress bladder cancer growth by sponging miR-653 to elevate March1 levels. March1 is an E3 ubiquitin ligase that has been proven to suppress bladder cancer growth; knocking down March1 in ciRs-6 overexpressed bladder cancer cells reversed the tumor suppressive effect of ciRs-6. CONCLUSIONS: Our study identifies an oncogenic role of ciRs-6 and suggests its usefulness as a novel biomarker for bladder cancer diagnosis and prognosis and as a therapeutic target for bladder cancer. METHODS: ciRs-6 was identified by RNA-seq and qPCR; CCK8 assays, clone forming assays and cell cycle analyses were performed to evaluate the in vitro effect of ciRs-6 in bladder cancer; further, a mouse subcutaneous tumor model was designed for in vivo analysis. RNA pulldown assays, miRNA capture experiments and dual luciferase assessments were applied for mechanistic studies.
Subject(s)
Gene Expression Regulation, Neoplastic/physiology , MicroRNAs/metabolism , RNA, Circular/metabolism , Ubiquitin-Protein Ligases/metabolism , Urinary Bladder Neoplasms/metabolism , Animals , Cell Line, Tumor , Down-Regulation , Female , Humans , Mice , Mice, Nude , MicroRNAs/genetics , Neoplasms, Experimental , RNA, Circular/genetics , Ubiquitin-Protein Ligases/genetics , Up-RegulationABSTRACT
BACKGROUND: Increasing evidence suggests that circular RNAs play a key role in regulating bladder cancer progression. However, this remains to be fully elucidated. RESULTS: In this study, we reanalyzed our previous RNA sequence, and circ5912 was found to downregulate significantly in bladder cancer tissues compared with normal control. Expression of circ5912 inversely correlates with bladder cancer grade, stage, metastasis, and better patient outcomes. In vitro and in vivo, circ5912 has been shown to repress transforming growth factor ß signaling, which suppresses proliferation, invasion and migration of bladder cancer induced by mesenchymal-to epithelial transition. CONCLUSIONS: Our study firstly demonstrate that circ5912 regulates mesenchymal-to epithelial transition pathway to suppress bladder cancer progression and propose new therapeutic targets and biomarkers for bladder cancer. MATERIALS AND METHODS: Clinical values of circ5912 in human bladder cancer were examined in a cohort of 58 patients by qPCR. 2 bladder cancer cell lines, T24 and SW780, were used for biological evaluation of circ5912. CCK8, clone formation, wound healing and trans-well assays were performed to determine the in vivo effect of circ5912; a mouse subcutaneous model was designed for in vivo analysis. Western blotting, RNA pulldown assays and florescent in situ hybridization were applied for mechanistic analysis.
Subject(s)
Gene Expression Regulation, Neoplastic/drug effects , Gene Expression Regulation, Neoplastic/physiology , RNA, Circular , Urinary Bladder Neoplasms/metabolism , Animals , Apoptosis , Cell Line, Tumor , Cell Movement , Cell Survival/drug effects , Cell Survival/physiology , Female , Humans , Male , Mice , Mice, Nude , Middle Aged , Proto-Oncogene Proteins c-met , Sincalide/genetics , Sincalide/metabolism , Transforming Growth Factor beta2/genetics , Transforming Growth Factor beta2/metabolism , Transforming Growth Factor beta2/pharmacology , Urinary Bladder Neoplasms/pathologyABSTRACT
Papillary thyroid carcinoma (PTC) is a type of cancer with one of the fastest increasing incidences worldwide. However, the therapeutic choices for PTC patients are limited and it is critical to further understand the molecular pathology underlying this disease. Squamous cell carcinoma antigens (SCCAs) are overexpressed in many tumors and participate in tumorigenesis. However, their roles in PTC are incompletely understood. Therefore, this study investigated the role of SCCA in PTC, evaluating its expression, its clinical implications and prognostic significance in PTC patient samples, as well as its function in vitro and in vivo, using a thyroid cancer cell line in which SCCA levels have been knocked down or overexpressed. In this study, SCCA expression levels were measured by immunohistochemistry (IHC) in noncancerous and tumor tissues. KaplanMeier analyses assessed the survival in PTC patients. MTT assay, western blot analysis, invasion assay and xenograft tumor assay were used to calculate cell proliferation, migration, invasion and tumor growth. Our results showed that SCCA was overexpressed in PTC tissues and was correlated with the clinical stage of PTC. Patients with high SCCA expression had lower overall survival (OS), diseasefree survival (DFS), lymph node recurrencefree survival (LNRFS), and distant recurrencefree survival (DRFS), compared to patients expressing low level of the SCCA protein. SCCA knockdown suppressed thyroid cancer cell proliferation, invasion and reduced xenograft tumor growth, whereas SCCA overexpression increased cell proliferation, invasion and xenograft tumor growth. Mechanistically, the activation of Ras increased SCCA expression, and SCCA expression was positively correlated with Ras levels in the PTC tissues. In conclusion, SCCA protein is overexpressed in PTC and may represent a predictive prognostic factor for PTC patients. Furthermore, activation of the Ras/SCCA pathway plays an important role in promoting tumor growth, invasion and metastasis in PTC.
