Abstract Oral cancer, and associated HPV-16 infection, and tobacco smoking is a major public health concern in the Kamrup district of India. To facilitate research on oral cancer chemoprevention, we have set up a collaborative research team between Forsyth Institute, an oral medicine specialized center affiliated to Harvard School of Dental Medicine, and KaviKrishna Laboratory, a non-for profit private laboratory set up located in Guwahati, the major city of Kamrup district, India. To study the cellular and molecular mechanism of HPV-16 mediated carcinogenesis, we have developed an in vitro model of HPV-16 mediated carcinogenesis of oral squamous stem cells. In this model (Bhuyan et al. The potential role of oral mucosa stem cell altruistic behavior as the initiating event of malignant transformation. AACR abstract Control # 16-A-6618-AACR), the treatment of oral mucosa cells derived from healthy volunteer with HPV-16 derived E6 protein led to expansion of a p53 deficient CD271+ expressing oral mucosa stem cells (OMSC). Noted that CD271 cell surface marker was recently identified as a putative marker for OMSCs. Using this in vitro carcinogenesis model, we evaluated the potential chemopreventive role of dietary whey protein. The E6 treated p53 deficient CD271+ cells were treated with DMEM/F12 media containing 0.2% of Immunocal, an undenatured whey protein (Tsai WY et al. Nutr Cancer 2000. PMID: 11525598). The p53 status as well as in vitro self-renewal activity of the CD271+ cells were examined by ELISA, transcriptional activity assay, and methylcellulose based clonogenic assay. We also fed Immunocal 20 gm/daily for 6 months to 5 individual with oral leukoplakia lesion with HPV-16 positivity. The CD271+ cells obtained from the leukoplakia lesion of clinical subjects were subjected to p53 status, and clonogenic assay. The data was compared with CD271+ cells obtained from leukoplakia lesion of subjects taking regular diet without whey protein supplements. We found that addition of Immunocal whey protein led to 8-fold decrease in the expansion of CD271+ cells following E6 treatment in the in vitro model of OMSC culture. Importantly, Immunocal treatment prevented the suppression of p53 in OMSCs. In the preliminary clinical study, the dietary intake of Immunocal led to complete loss of leukoplakia lesion in the 4/5 individual. In contrast, the control subjects exhibited the presence of CD271+ cells in the leukoplakia lesion having low p53 status, and high clonogenic activity. We are incorporating a larger number of subjects to study the potential chemopreventive activity of whey protein, using the locally available affordable whey protein extracts. Conclusion: This study indicate that whey protein extract, which is available in the local villages of Kamrup district could serve as a chemopreventive agent against oral cancer. Citation Format: Sora Sandhya, Rika Tsuchida, Sukanya Gayan, Rashmi Bhuyan, Joyeeta Talukdar, Bidisha Pal, Seema Bhuyan, Jugal Ch Das, Amal Ch Kataki, Debabrata Baishya, Bikul Das. Undenatured whey protein isolate exhibit chemopreventive activity against HPV-16 induced carcinogenesis of CD271+ oral mucosa stem cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4324.