key: cord-0021852-gwpye0w8 authors: Vemuganti, Geeta K title: Viral etiology in retinoblastoma date: 2021-08-03 journal: Indian J Ophthalmol DOI: 10.4103/ijo.ijo_1801_21 sha: 7eba2989b59141001bee6a0174be97396de28471 doc_id: 21852 cord_uid: gwpye0w8 nan Retinoblastoma can be considered as a great teacher-it provided insights into Knudson's 2 hit hypothesis, was first gene to be cloned, and finally paved way for prescreening evaluation of embryos that resulted in the birth of a successful unaffected fetus. Mutation of RB1, a tumor suppressor gene on chromosome 13, interacts with over 100 cell proteins and regulates cell cycle through binding and inactivation of the transcription factor E2F. Recent evidence also points toward somatic mutations in MYCN can give rise to RB. However with regards to viral etiology in RB, evidence for association of HPV and Retinoblastoma keeps surfacing, both in favour and against. When the data of transforming proteins of adenovirus, papillomavirus, and the polyomaviruses BK and JC binding to the product of the RB gene was emerging, Howard et al. [2] evaluated and negated for the presence of five human DNA in Retinoblastoma tumor viruses. If the argument goes about the techniques used, then Gillison ML [3] used a myriad of tools like genomic DNA sequences by real-time polymerase chain reaction, genetic and epigenetic alterations in all 27 exons of the RB1 gene locus and promoter by exonic copy number detection, sequencing and methylation-specific PCR of the promoter region. Based on all the above, he reported that substantial quantitative evidence indicated that neither HPV nor any other pRB-inactivating human DNA tumor viruses play a role in the development of RB, regardless of RB1 genotype. However other studies report the presence of viral genome and imply a role in its pathogenesis. [4] Interestingly, the evidence of role of vertical transmission and persistence of HPV in newborns is also variable. While one study reports no persistent infection in infants at 6 months suggesting a temporary inoculation rather than true vertical infection, [5] another study reported the proportion of HPV positivity in multiple sites including the conjunctiva. [6] However, as always happens in science, search for evidence should continue as they have the potential of influencing the treatment protocols in future. School of Medical Sciences, University of Hyderabad, Hyderabad, Telangana, India. E-mail: gkvemuganti@gmail.com The environment and disease: Association or causation? Five DNA tumor viruses undetectable in human retinoblastomas Human retinoblastoma is not caused by known pRb-inactivating human DNA tumour viruses Presence of human papilloma virus in tumour tissue from children with retinoblastoma: An alternative mechanism for tumour development Rate of vertical transmission of human papillomavirus from mothers to infants: Relationship between infection rate and mode of delivery Human papillomavirus (HPV) perinatal transmission and risk of HPV persistence among children: Design, methods and preliminary results of the HERITAGE study Cite this article as: Vemuganti GK. Viral etiology in retinoblastoma Dr Geeta K Vemuganti joined School of Medical Sciences, University of Hyderabad as a Professor and Founder Dean, after leading Ophthalmic Pathology Laboratory and Sudhakar and Sreekant Ravi Stem Cell Biology Laboratory at the renowned L V Prasad Eye Institute, Hyderabad. Her experience and expertise is in the area of ocular tumors and stem cell biology, where she has contributed to the cutting edge research that led to bench-to-bedside applications. Her current research includes cancer stem cells in retinoblastoma, new animal models, and human lacrimal gland regeneration. She has published widely, authoring more than 200 papers with an H Index of 46. She is also a recipient of several national and international awards including the recent Senior Achievement award by American Academy of Ophthalmology and Fellow, ARVO. Dr Vemuganti has received many prestigious academic as well as research grants from national and international agencies and has guided many doctoral students in both basic and applied research projects. This is an open access journal, and articles are distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given and the new creations are licensed under the identical terms.