Analysis of housekeeping genes in the peripheral blood of retinoblastoma patients

Retinoblastoma is a pediatric neoplasia with a high incidence in non-developed countries. Nowadays the diagnosis is clinical and unfortunately in advanced stages of the diseases, which puts the childs life risk. The search for molecular diagnosis on retinoblastoma is necessary. Due to their location and tendency to migrate, biopsies of retinoblastoma are not recommended then, peripheral blood samples can be a good source for the search of biomarker. RT qPCR is a sensitive method for gene expression quantification; in order to achieve optimal results, a crucial step is the reference gene choice that cannot be neglected under any circumstance. Six of the most commonly used housekeeping genes; GAPDH, HPRT1, B2M, TBP, RPL13a and 18S, were tested in the blood samples of patients diagnosed with retinoblastoma and healthy controls. The HPRT and TBP were found the most reliable genes whereas GAPDH, that is one of the most commonly used genes for normalisation, together with B2M, RPL13a and 18S have to be avoided. Using the selected reference genes, the Rb mRNA showed significant differences between patients and healthy children whereas no differences were found using to control groups. In the present study, we validate blood samples of patients with retinoblastoma.