Expression profile of cancer stem cell markers SOX2, OCT4 & NANOG in salivary gland malignancies: A systematic review.

Background & objectives Cancer stem cells influence aggressive biology, metastasis, recurrence, and treatment resistance in various malignancies. The transcription factors SRY-box transcription factor 2 (SOX2), Octamer-binding transcription factor 4 (OCT4), and Homeobox protein NANOG (NANOG) are prime controllers of the signalling circuit required for embryonic stem cell pluripotency. Salivary gland tumours exhibit diverse biological and clinical behaviours ranging from a benign, innocuous nature to highly aggressive tumours, with a great tendency for recurrence, and poor prognosis. Advances in therapeutic modalities have also been limited. This systematic review aims to uncover the differential expression and influence of SOX2, OCT4, and NANOG in salivary gland malignancies. This could help the stratification of high-risk patients and the identification of newer prognostic and predictive remedial targets. Methods PubMed, Scopus, Google Scholar, and Clinical key databases were searched for relevant articles, and studies that met the eligibility criteria were selected. Results Ten articles that fulfilled the eligibility criteria were included. All the studies supported the role of the studied markers as prognosticators and potential therapeutic targets. Interpretation & conclusion The aforementioned transcription factors might have contributed to aggressiveness and poor prognosis. Thus, it has been inferred that a combination of these factors may serve as a marker to determine the behaviour and therapeutic approaches for salivary gland malignancies.