title: Upregulated expression of BCL2, MCM7, and CCNE1 indicate cisplatin-resistance in the set of two human bladder cancer cell lines: T24 cisplatin sensitive and T24R2 cisplatin resistant bladder cancer cell lines.
abstract: OBJECTIVE
  The mechanism of resistance to cisplatin during treatment of bladder cancer (BC) has been a subject of intense investigation in clinical research. This study aims to identify candidate genes associated with resistance to cisplatin, in order to understand the resistance mechanism of BC cells to the drug, by combining the use of microarray profiling, quantitative reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses.
  
  
  METHODS
  The cisplatin sensitive human BC cell line (T24) and the cisplatin resistant BC cell line, T24R2, were used for microarray analysis to determine the differential expression of genes that are significant in cisplatin resistance. Candidate upregulated genes belonging to three well-known cancer-related KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways (p53 tumor suppressor, apoptosis, and cell cycle) were selected from the microarray data. These candidate genes, differentially expressed in T24 and T24R2, were then confirmed by quantitative RT-PCR and western blot. A fold change ≥2 with a p-value <0.05 was considered significant.
  
  
  RESULTS
  A total of 18 significantly upregulated genes were detected in the three selected cancer-related pathways in both microarray and RT-PCR analyses. These genes were PRKAR2A, PRKAR2B, CYCS, BCL2, BIRC3, DFFB, CASP6, CDK6, CCNE1, STEAP3, MCM7, ORC2, ORC5, ANAPC1, and ANAPC7, CDC7, CDC27, and SKP1. Western blot analyses also confirmed the upregulation of BCL2, MCM7, and CCNE1 at the protein level, indicating their crucial association with cisplatin resistance.
  
  
  CONCLUSIONS
  The BCL2, MCM7, and CCNE1 genes might play distinctive roles in cisplatin resistance in BC.
authors.affiliation: Department of Urology, National Cancer Center, Goyang, Korea.
authors.forename: Sung Han
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam, Korea.; Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Jin-Nyoung
authors.initials: JN
authors.lastname: Ho
authors.affiliation: Biomedical Research Institute, Seoul National University Bundang Hospital, Seongnam, Korea.; Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Hyunjin
authors.initials: H
authors.lastname: Jin
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sang Chul
authors.initials: SC
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sung-Kyu
authors.initials: SK
authors.lastname: Hong
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jeong Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Eun-Sik
authors.initials: ES
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000494:pharmacology*; D019927:Cyclin E / Q000096:biosynthesis* / Q000235:genetics; D019008:Drug Resistance, Neoplasm / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm; D006801:Humans; D064168:Minichromosome Maintenance Complex Component 7 / Q000096:biosynthesis* / Q000235:genetics; D015513:Oncogene Proteins / Q000096:biosynthesis* / Q000235:genetics; D040081:Protein Array Analysis / Q000379:methods; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015854:Up-Regulation; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism
chemical_list: D000970:Antineoplastic Agents; C000595707:BCL2 protein, human; C475820:CCNE1 protein, human; D019927:Cyclin E; D015513:Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C101624:MCM7 protein, human; D064168:Minichromosome Maintenance Complex Component 7; D002945:Cisplatin
keywords: Cell line; Cisplatin; Drug resistance; Microarray analysis; Urinary bladder neoplasms