ESTABLISHMENT OF CELL LINES DERIVED FROM PATIENTS WITH METASTATIC RETINOBLASTOMA AND THEIR IN VITRO SENSITIVITY TO MAINSTAY CHEMOTHERAPY

ZUGBI SANTIAGO; ANA VANESA TORBIDONI; CHANTADA GUILLERMO; ASCHERO ROSARIO; CAFFERATA EDUARDO; SCHAIQUEVICH PAULA; WINTER URSULA; PODHAJCER OSVALDO

Congreso; XLVIII REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE FARMACOLOGÍA EXPERIMENTAL (SAFE); 2016

Retinoblastoma is a solid tumor that arises during the development of theretina. Despite that intraocular retinoblastoma is a highly curable, patients withmetastatic disease need aggressive treatments and if the tumor spreads into theCNS the disease is usually fatal. We aimed to establish in vitro models ofmetastatic retinoblastoma and evaluate the sensitivity of the tumor cells.Lymph node tumor samples were obtained from a metastatic patient heavilypretreated at the time of tumor progression (LNP) and during the autopsy (LNA)at Hospital Garrahan under an approved protocol. Patient samples were injected s.c.in athymic nude mice and after the tumors grew, were removed and processed toobtain a cell suspension. Once established in neural stem cell medium, 20.000 cells/wellwere cultured and exposed to increasing concentrations of melphalan 0.01 to 327.5.Cell viability was assessed using MTT. The concentration of melphalan thatcaused a 50% cell decrease (IC50%) was calculated and compared to thosepreviously obtained from commercial cells (WERI-Rb1) and from cells derivedfrom non-metastatic patients, naive of treatment (007) or multi-treated (008).Primary retinoblastoma cell lines were establishedboth from LNP and LNA both grew as typical neurospheres and marked positive tocone-rod homeobox (CRX) transcription factor.The median (range) IC50% of melphalan for LNP and LNAwas 78.7uM (105.7-53.8) and 89.6uM (95.7-69.6), respectively (p≥0.05). These IC50are clearly high compared to values (median) previously observed in commercialcells (WERI-Rb1:11.9uM) and a cell line derived from a non-metastatic patient (007:0.3uM;008: 4.9uM) cell lines (p≤0.05). We were able to obtain primary cell lines frommetastatic tumors that were characterized for their pharmacological sensitivityas evidenced by their higher IC50 compared to commercial and non-metastaticderived cell lines.These models have a direct impact in translationalresearch of retinoblastoma.