J Oral Maxillofac Surg xx:xxx, 2011 Streptococci–Human Papilloma Virus Interaction With Ethanol Exposure Leads to Keratinocyte Damage Joel Schwartz, DMD, DMedSc,* Sylvia Pavlova, PhD,† Antonia Kolokythas, DDS, MS,‡ Mulokozi Lugakingira, DDS, DMD, MS,§ Lin Tao, DDS, PhD, and Michael Miloro, DMD, MD¶ Purpose: Ethanol, human papilloma virus (HPV), and poor oral hygiene are risk factors that have been attributed to oral carcinogenesis. Streptococci sp and HPV infections are common in the head and neck, often associated with sexual activity. Although HPV is linked to head and neck squamous cell carcinoma, it is unclear whether there is a similar role for Streptococci sp. This cell study examines whether Streptococci sp and HPV-16 with exposure to ethyl alcohol (ETOH) can act as cofactors in the malignant transformation of oral keratinocytes. Materials and Methods: ETOH (0.1%-20% vol/vol) was used to investigate Streptococci sp attachment with immortalized E6-expressing HPV/HOK-16B cells, human oral buccal keratinocytes, and foreskin kera- tinocytes. Streptococci sp (Streptococci mutans [LT11]) and various strains of acetaldehyde (AA) producer and nonproducer Streptococcus salivarius (110-1, 109-2, 101-7, and 107-1) and a lactic acid producer bacterium, Lactobacillus rhamnosus (24-1 and 25-2), were examined for interactions with keratinocytes by use of a green dye (percent of cells with colonies after 24 hours). Carcinogens, AA, malondialdehyde, DNA damage, and proliferation (5=-bromo-2-deoxyuridine) among keratinocytes were also quantified. Results: AA and malondialdehyde production from permissible Streptococci sp significantly increased with attachment to keratinocytes, whereas L rhamnosus did not significantly attach to keratinocytes. This attachment was associated with enhanced levels of AA adduct formation, proliferation (5=-bromo- 2-deoxyuridine incorporation), and enhanced migration through integrin-coated basement membrane by HPV oral keratinocytes, which are characteristics of a malignant phenotype. Conclusions: These cell studies suggest that oral Streptococci sp and HPV (HPV-16) cooperate to transform oral keratinocytes after low-level ETOH (1%) exposure. These results appear to suggest a significant clinical interaction, but further validation is warranted. © 2011 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg xx:xxx, 2011 Poor oral hygiene is a direct or indirect risk factor for oral and oropharyngeal carcinomas, including oral squamous cell carcinoma (OSCC) and head and neck squamous cell carcinoma (HNSCC). 1-8 One possible explanation for this relationship is that Streptococci sp (eg, group B or group A -hemolytic Streptococci sp) infection can be sexually transmitted at a persis- tently low frequency, and this is accompanied by Received from the College of Dentistry, University of Illinois at Chicago, Chicago, IL. *Professor, Department of Oral Medicine and Diagnostic Sci- ences, and Member, University of Illinois Cancer Center. †Research Assistant Professor, Department of Oral Biology. ‡Assistant Professor, Department of Oral and Maxillofacial Sur- gery, and Member, University of Illinois Cancer Center. §Professor, Department of Oral Biology. Chief Resident, Department of Oral Maxillofacial Surgery. ¶Professor and Head, Department of Oral and Maxillofacial Surgery. This study received the American Association of Oral and Max- illofacial Surgeons Poster Award at the 92nd Annual Meeting and Scientific Sessions of the American Association of Oral and Maxill- ofacial Surgeons, Chicago, IL, October 2010. Address correspondence and reprint requests to Dr Schwartz: Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, University of Illinois at Chicago, 801 S Paulina St, Chi- cago, IL 60612; e-mail: joschwar@uic.edu © 2011 American Association of Oral and Maxillofacial Surgeons 0278-2391/11/xx0x-0$36.00/0 doi:10.1016/j.joms.2011.08.005 1