Role of heat shock proteins in oral squamous cell carcinoma: A systematic review.

BACKGROUND: Environmental and patho-physiologic stresses stimulate synthesis of heat shock proteins (HSPs) which enable the cell to survive and recover from stressful conditions, by as yet incompletely understood mechanisms. Heat shock proteins show an increased expression in a wide range of human cancers and have been associated with tumor cell proliferation, differentiation, invasion, metastasis, death, and recognition by the immune system. Yet the role of heat shock proteins in oral cancer is ambiguous. The objective of this review was to systematically assess the data available on the role of HSP expression in oral cancer with special reference to its role in diagnosis, prognosis and treatment. METHODS AND RESULTS: A systematic review of studies that investigated the HSP expression in oral squamous cell carcinoma using Scopus, Medline, Embase and Google scholar databases from their inceptions to 2013, without language restrictions was conducted. We selected 24 studies from which data extraction and validations were performed. CONCLUSION: The literature search revealed differential expression of HSPs during oral tumorigenesis with implications for the specific role of HSPs in the pathogenesis of oral cancer. HSP expression has been regarded as an independent prognostic factor for oral squamous cell carcinoma patients and HSPs are being explored as potent vehicles for delivery of preventive and treatment vaccines in cancer and other diseases.