A Systematic Review of Potential Immunotherapies Targeting PRAME in Retinoid Resistant Oral Potentially Malignant Disorders and Oral Cancer

Backgound and objective: Early chemoprevention in Oral Potentially Malignant Disorders (OPMDs) and Oral Cancer (OC) has been extensively researched in order to mitigate the malignant transformation and progression of the lesion. Many agents have been attempted, but their cost inefficacy and inadequate outcomes posed a major hindrance in their successful adoption. Retinoid Based Therapy (RBT) though a cheap and effective treatment option, could not achieve much clinical usage because of variable responsiveness in clinical outcomes. Such clinical response variability may be attributed to the repression of retinoid receptors by Preferentially Expressed Antigen of Melanoma (PRAME) protein molecule. Therefore, in order to make RBT successful, targeting PRAME by various immunotherapies is an exciting area of research investigation. This review provides an insight into the various immunotherapeutic strategies targeting PRAME and their usefulness in retinoid-resistant OPMD and OC. Method of data collection: An exhaustive internet-based literature search following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines was carried out in PUBMED and Google SCHOLAR database using terms 'Anti-PRAME' OR 'PRAME Immunotherapy' OR 'PRAME Vaccines' AND 'Cancer' AND 'Retinoid resistance'. Only articles in the English language with at least 1 citation, published in a journal with impact factor >= 1, having relevance to the context and availability of full text were considered. Results: After an initial search, 342 articles were yielded on the basis of inclusion criteria and, by reading the abstract and availability of full text, a total of 124 articles were selected. Further reading the full texts and considering articles from the references of the selected articles, a total of 65 articles were finally included in the review. Conclusion: Our analysis of the literature suggests that PRAME screening in OC and OPMDs prior to RBT should be done. In PRAME positive cases, approaches like PRAME based immunotherapy in the form of Cancer vaccine therapy [Acellular PRAME vaccine, PRAME pulsed Dendritic Cells (DC)]; Adoptive T Cell therapy/T Cell Receptor-T Cell therapy, Antibody therapy/Chimeric Antigen Receptor-T Cell therapy along with Presented antigen modulation Therapies employing histone deacetylase inhibitors and demethylation agents seem plausible. In the future, a combination therapy employing either PRAME vaccines or antibodies or Adoptive T cell Therapy and ATRA could be used in retinoid resistant OC and OPMDs.