Nalini Venkatesan, Segu Ramya, Deepa Perinkulam Ravi, Khetan Vikas, Vasudevan Madavan, Krishnakumar Subramanian
Larsen and Toubro Department of Ocular Pathology, Vision Research Foundation, Sankara Nethralaya, Chennai, India. ; Birla Institute of Technology and Science (BITS), Pilani, India.
Bioinform Biol Insights. 2013 Sep 18;7:289-306. doi: 10.4137/BBI.S12494. eCollection 2013.
Management of Retinoblastoma (RB), a pediatric ocular cancer is limited by drug-resistance and drug-dosage related side effects during chemotherapy. Molecular de-regulation in post-chemotherapy RB tumors was investigated.
cDNA microarray analysis of two post-chemotherapy and one pre-chemotherapy RB tumor tissues was performed, followed by Principle Component Analysis, Gene ontology, Pathway Enrichment analysis and Biological Analysis Network (BAN) modeling. The drug modulation role of two significantly up-regulated genes (p≤0.05) - Ect2 (Epithelial-cell-transforming-sequence-2), and PRAME (preferentially-expressed-Antigen-in-Melanoma) was assessed by qRT-PCR, immunohistochemistry and cell viability assays.
Differential up-regulation of 1672 genes and down-regulation of 2538 genes was observed in RB tissues (relative to normal adult retina), while 1419 genes were commonly de-regulated between pre-chemotherapy and post- chemotherapy RB. Twenty one key gene ontology categories, pathways, biomarkers and phenotype groups harboring 250 differentially expressed genes were dys-regulated (EZH2, NCoR1, MYBL2, RB1, STAMN1, SYK, JAK1/2, STAT1/2, PLK2/4, BIRC5, LAMN1, Ect2, PRAME and ABCC4). Differential molecular expressions of PRAME and Ect2 in RB tumors with and without chemotherapy were analyzed. There was neither up- regulation of MRP1, nor any significant shift in chemotherapeutic IC50, in PRAME over-expressed versus non-transfected RB cells.
Cell cycle regulatory genes were dys-regulated post-chemotherapy. Ect2 gene was expressed in response to chemotherapy-induced stress. PRAME does not contribute to drug resistance in RB, yet its nuclear localization and BAN information, points to its possible regulatory role in RB.
视网膜母细胞瘤（RB）是一种儿童眼部癌症，其治疗受化疗期间耐药性和药物剂量相关副作用的限制。本研究对化疗后RB肿瘤中的分子失调情况进行了调查。
对两个化疗后和一个化疗前的RB肿瘤组织进行了cDNA微阵列分析，随后进行主成分分析、基因本体论、通路富集分析和生物分析网络（BAN）建模。通过qRT-PCR、免疫组织化学和细胞活力测定评估了两个显著上调基因（p≤0.05）——Ect2（上皮细胞转化序列2）和PRAME（黑色素瘤中优先表达的抗原）的药物调节作用。
在RB组织中（相对于正常成人视网膜）观察到1672个基因上调和2538个基因下调，而在化疗前和化疗后的RB之间共有1419个基因失调。包含250个差异表达基因的21个关键基因本体类别、通路、生物标志物和表型组失调（EZH2、NCoR1、MYBL2、RB1、STAMN1、SYK、JAK1/2、STAT1/2、PLK2/4、BIRC5、LAMN1、Ect2、PRAME和ABCC4）。分析了化疗和未化疗的RB肿瘤中PRAME和Ect2的差异分子表达。在PRAME过表达的RB细胞与未转染的RB细胞中，MRP1既没有上调，化疗IC50也没有任何显著变化。
化疗后细胞周期调控基因失调。Ect2基因在化疗诱导的应激反应中表达。PRAME对RB的耐药性没有影响，但其核定位和BAN信息表明它可能在RB中发挥调节作用。
