Molecular detection of metastatic retinoblastoma cells by reverse transcription polymerase reaction for interphotoreceptor retinoid-binding protein mRNA - A case report

BACKGROUND. In the current study, the authors report a 4 year old girl with disseminated retinoblastoma. To find sensitive and specific molecular mark ers for detection of retinoblastoma cells in blood and marrow the authors e valuated three photoreceptor-associated gene transcripts by using reverse t ranscription polymerase chain reaction (RT-PCR). METHOD. Samples of bone marrow and blood were obtained from healthy donors and the patient. RT-PCR was performed to detect the cone alpha'-subunit of cGMP phosphodiesterase (cone alpha'-PDE), the rod beta -subunit of cGMP (ro d beta -PDE), and the interphotoreceptor retinoid-binding protein (IRBP) ge ne transcript in RNA extracted from the samples. RESULTS, While no expression of rod beta -PDE or IRBP was detected in any o f the normal samples, expression of cone alpha'-PDE was detected in two out of seven normal marrow samples. Expression of rod beta -PDE was not detect ed in the patient samples. Expression of IRBP was detected in the patient s amples obtained from iliac bone marrow before intensive chemotherapy but no t thereafter. CONCLUSION, RT-PCR for IRBP was a useful method for detecting metastatic re tinoblastoma cells as well as for evaluating the therapeutic effects of tre atment in this particular case. Cancer 2001;91:1568-73. (C) 2001 American C ancer Society.