Smoking is a risk factor for oral leukoplakia and oral cancer, as well as lung cancer, cardiovascular diseases and many other systemic diseases. Smoking is considered increasing factor of some oral diseases involved indigenous bacteria. In addition, a relationship between smoking and infection of Human papillomavirus (HPV), which is associated with oropharyngeal cancer, remains unclear. The aim of this study is to assess whether smoking has an impact on increase of bacteria inducing oral disease such as dental caries and periodontitis, and HPV infection. DNA of saliva gathered from smokers and non-smokers, consisted of men and women, was analyzed using PCR. Oral disease-causing bacteria were more detected in men smokers than men non-smokers and HPV was most found in women non-smokers. Taken together, this study suggests smoking is related with variation of oral microorganism existence in some way.

Inflammation functions as a double-edged sword against external stimulus. For instance, inflammation can have anti-cancer effect and simultaneously can play cancer-promoting factors. Recent studies have shown that cytokine plays an important role in tumor biology by influencing tumor growth, invasion and metastasis. We classify these cytokines by cancer type and review current knowledge of cytokines in terms of carcinogenesis. Here, we also focus on whether cytokines can act as biomarkers for early detection of oral squamous cell carcinoma (OSCC). This review will provide basis for further approach to study the role of cytokines in carcinogenesis and evaluating the possibilities of cytokines as biomarkers for cancer detection

Cellular microenvironment is an essential issue for regulating epithelial characteristics through the alteration of intricate signaling pathways and intercellular communications in different cell types. Thus, microenvironment influences tumor initiation, progression, and metastasis. This study aimed to investigate the relationship between microenvironment and epithelial property in HPV16 E6/E7-immortalized human oral keratinocytes (IHOKs). To investigate characteristics of IHOK cultured in different media, two media were used, which included keratinocyte growth media (KGM), F-medium composed of 3:1 ratio of DMEM and F-12 (P media) supplemented with 10% FBS and 1% penicillin/streptomycin. Proliferative property and invasive and migratory activity were observed. As results, proliferating activities of IHOK in different culture condition were changed. Likewise, migratory and invasive activities were also different depending on media types. These results suggest that cellular microenvironment can affect modification of biological properties of epithelial cells.