Molecular Biomarkers Detected Using Fluorescence in situ Hybridization in a Filipino with Retinoblastoma.

Background And Objective: Retinoblastoma is one of the most common intraocular cancers among children usually caused by the loss of retinoblastoma protein function. Despite being a highly heritable disease, conventional diagnostic and prognostic methods depend on clinical examination, with limited consideration of cancer genetics in the standard of care. , and are commonly explored genes for their utility in liquid biopsies of cancer including lung adenocarcinoma. To date, there are few extensive molecular studies on retinoblastoma in Filipino patients. To this end, the study aimed to describe the copy number of , and in retinoblastoma samples from a Filipino patient and quantitate the respective expression level of these genes.

Methods: Hematoxylin & Eosin (H&E) staining was utilized to characterize the retinoblastoma tissue while fluorescence in situ hybridization (FISH) using probes specific to , and was performed to determine the copy number of genes in retinoblastoma samples from a Filipino patient (n = 1). The gene expression of , and was quantitated using RT-qPCR.

Results: The H&E staining in the retinoblastoma tissue shows poorly differentiated cells with prominent basophilic nuclei. was approximately 1.5-fold overexpressed in the retinoblastoma tissue with respect to the normal tissue, while MUC1 and KRT19 are only slightly expressed. Multiple intense signals of each probe were localized in the same nuclear areas throughout the retinoblastoma tissue, with high background noise.

Conclusion: These findings suggest that is a potential biomarker for the staging and diagnosis of retinoblastoma in Filipino cancer patients. However, further optimization of the hybridization procedures is recommended.