Characterization of NCC-RbC-51, an RB cell line isolated from a metastatic site

Identification of dysregulation of sphingolipids in retinoblastoma using liquid chromatography-mass spectrometry

Retinoblastoma (RB) is a rare ocular cancer seen in children that counts for approximately 3% of all childhood cancers. It is found that mutation in RB1, a tumour Suppressor Gene on chromosome 13 as the cause of malignancy. Retinoblastoma protein is the target for ceramide to cause apoptosis. We studied lipidomics of two RB cell lines, one aggressive cell line (NCC-RbC-51) derived from a metastatic site and one non aggressive cell line (WERI-Rb1) in comparison with a control cell line (MIO-M1). Lipid profiles of all the cell lines were studied using high resolution mass spectrometer coupled to high performance liquid chromatography. Data acquired from all the three cell lines in positive mode were analyzed to identify differentially expressed metabolites. Several phospholipids and lysophospholipids were found to be dysregulated. We observed upregulation of hexosyl ceramides, and down regulation of dihydroceramides and higher order sphingoglycolipids hinting at a hindered sphingolipid biosynthesis. The results obtained from liquid chromatography-mass spectrometry are validated by using qPCR and it was observed that genes involved in ceramide biosynthesis pathway are getting down regulated.

Treatment of Retinoblastoma: What Is the Latest and What Is the Future

The management of retinoblastoma, the most common intraocular malignancy in children, has changed drastically over the last decade. Landmark developments in local drug delivery, namely, safer techniques for intravitreal chemotherapy injection and ophthalmic artery chemosurgery, have resulted in eye globe salvages that were not previously attainable using systemic chemotherapy or external beam irradiation. Novel drugs, oncolytic viruses, and immunotherapy are promising approaches in the treatment of intraocular retinoblastoma. Importantly, emerging studies of the pattern of tumor dissemination and local drug delivery may provide the first steps toward new treatments for metastatic disease. Here, we review recent advances in retinoblastoma treatment, especially with regard to local drug delivery, that have enabled successful conservative management of intraocular retinoblastoma. We also review emerging data from preclinical and clinical studies on innovative approaches that promise to lead to further improvement in outcomes, namely, the mechanisms and potential uses of new and repurposed drugs and non-chemotherapy treatments, and discuss future directions for therapeutic development.

Serum exosomal miRNA as biomarkers for Retinoblastoma

Retinoblastoma (RB) is a childhood eye tumor, caused by RB1 mutation. Though diagnosing RB is easier, prognosticating RB is limited to examining the patient under anesthesia and imaging technique. The aim of the study is to find exosomal miRNA biomarkers to prognosticate RB. Exosomes were isolated from one control - MIO-M1 and two RB cell lines - WERI-Rb-1 and NCC-RbC-51. Small RNA sequencing was performed on exosomal miRNA isolated from the three cell lines. miRNAs specific to each cell line were shortlisted. A total of 243, 606 and 400 miRNAs were identified in MIO-M1, WERI-Rb-1 and NCC-RbC-51 cell lines respectively. Nine miRNAs were shortlisted based on adjusted p value and literature, MIO-M1 specific (n = 1), WERI-RB-1 specific (n = 2), NCC-RbC-51 specific (n = 2) and miRNAs common to both RB cell lines (n = 4) were chosen. Validation was done using specific Taqman miRNA assays.miRNA validation was carried out on cell lines, cell line derived exosomes, primary RB tissues and exosomes isolated from serum of the RB patients. Validation of the miRNAs in cell lines and exosomes derived from the cell lines, confirmed the sequencing data. However, only 2 miRNAs - hsa-miR-301b-3p and hsa-miR-216b-5p were upregulated in the primary RB tissues. None of the miRNAs had significant expression in the serum exosomes of RB patients. Therefore, serum exosomal miRNA may not be ideal for prognosticating RB.Further research on other body fluids like CSF and vitreous could serve as potential source for biomarkers for prognosticating RB.