title: EpCAM knockdown alters microRNA expression in retinoblastoma--functional implication of EpCAM regulated miRNA in tumor progression.
abstract: The co-ordinated regulation of oncogenes along with miRNAs play crucial role in carcinogenesis. In retinoblastoma (RB), several miRNAs are known to be differentially expressed. Epithelial cell adhesion molecule (EpCAM) gene is involved in many epithelial cancers including, retinoblastoma (RB) tumorigenesis. EpCAM silencing effectively reduces the oncogenic miR-17-92 cluster. In order to investigate whether EpCAM has wider effect as an inducer or silencer of miRNAs, we performed a global microRNA expression profile in EpCAM siRNA knockdown Y79 cells. MicroRNA profiling in EpCAM silenced Y79 cells showed seventy-three significantly up regulated and thirty-six down regulated miRNAs. A subset of these miRNAs was also validated in tumors. Functional studies on Y79 and WERI-Rb-1 cells transfected with antagomirs against two miRNAs of miR-181c and miR-130b showed striking changes in tumor cell properties in RB cells. Treatment with anti-miR-181c and miR-130b showed significant decrease in cell viability and cell invasion. Increase in caspase-3 level was noticed in antagomir transfected cell lines indicating the induction of apoptosis. Possible genes altered by EpCAM influenced microRNAs were predicted by bioinformatic tools. Many of these belong to pathways implicated in cancer. The study shows significant influence of EpCAM on global microRNA expression. EpCAM regulated miR-181c and miR-130b may play significant roles in RB progression. EpCAM based targeted therapies may reduce carcinogenesis through several miRNAs and target genes.
authors.affiliation: L & T Ocular Pathology Department, Kamalanayan Bajaj Research Institute, Vision Research Foundation, No 18/41, College Road, Chennai- 600006, Tamil Nadu; CeNTAB, SASTRA   (Shanmugha Arts, Science,Technology & Research Academy) University, Thanjavur,India.
authors.forename: Madhu
authors.initials: M
authors.lastname: Beta
authors.affiliation: Shri Bhagwan Mahavir Vitreoretinal Services and Ocular Oncology Services, Medical Research Foundation, No 18/41, College Road, Chennai-600 006, Tamil Nadu, India.
authors.forename: Vikas
authors.initials: V
authors.lastname: Khetan
authors.affiliation: L & T Ocular Pathology Department, Kamalanayan Bajaj Research Institute, Vision Research Foundation, No 18/41, College Road, Chennai- 600006, Tamil Nadu, India.
authors.forename: Nivedita
authors.initials: N
authors.lastname: Chatterjee
authors.affiliation: Shri Bhagwan Mahavir Vitreoretinal Services and Ocular Oncology Services, Medical Research Foundation, No 18/41, College Road, Chennai-600 006, Tamil Nadu, India.
authors.forename: Ganesan
authors.initials: G
authors.lastname: Suganeswari
authors.affiliation: Shri Bhagwan Mahavir Vitreoretinal Services and Ocular Oncology Services, Medical Research Foundation, No 18/41, College Road, Chennai-600 006, Tamil Nadu, India.
authors.forename: Pukhraj
authors.initials: P
authors.lastname: Rishi
authors.affiliation: L & T Ocular Pathology Department, Kamalanayan Bajaj Research Institute, Vision Research Foundation, No 18/41, College Road, Chennai- 600006, Tamil Nadu, India.
authors.forename: Jyotirmay
authors.initials: J
authors.lastname: Biswas
authors.affiliation: L & T Ocular Pathology Department, Kamalanayan Bajaj Research Institute, Vision Research Foundation, No 18/41, College Road, Chennai- 600006, Tamil Nadu, India.
authors.forename: Subramanian
authors.initials: S
authors.lastname: Krishnakumar
mesh_terms: D000951:Antigens, Neoplasm / Q000235:genetics*; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000235:genetics*; D045744:Cell Line, Tumor; D003094:Collagen; D019295:Computational Biology; D018450:Disease Progression; D004338:Drug Combinations; D000071858:Epithelial Cell Adhesion Molecule; D005470:Fluorometry; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D055785:Gene Knockdown Techniques; D006801:Humans; D007797:Laminin; D035683:MicroRNAs / Q000378:metabolism*; D046228:Microarray Analysis; D011509:Proteoglycans; D060888:Real-Time Polymerase Chain Reaction; D012175:Retinoblastoma / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D000951:Antigens, Neoplasm; D015815:Cell Adhesion Molecules; D004338:Drug Combinations; C499379:EPCAM protein, human; D000071858:Epithelial Cell Adhesion Molecule; D007797:Laminin; D035683:MicroRNAs; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen