Chronic inflammation is widely considered to predispose individuals to cancer. Microorganisms facilitate recruitment and activation of inflammatory cells and thus allow release of inflammatory mediators. These molecules can then promote accumulation of mutations, leading to tumor development in the host. Porphyromonas gingivalis, a pathogen causing chronic periodontitis, is detected in oral squamous cell carcinoma (OSCC) tissues. Considering a strong link between chronic inflammation and tumor development, functional consequences of P. gingivalis infection may include malignant transformation of the host cells. In this study, we monitored transcriptional changes induced by invasion of P. gingivalis in OSCC cells using microarrays. Our preliminary results suggest changes in a wide range of genes involved in inflammation, apoptosis and autophagy, tumor progression, and carcinogenesis. Further studies on molecular mechanisms underlying these changes will lay a useful foundation to elucidate the role of microorganism-related inflammation and for the development of preventive and therapeutic agents for oral cancer.

Ⅰ. INTRODUCTION
 Ⅱ. MATERIALS AND METHODS
  1. Bacteria and culture conditions
  2. Oral squamous cell carcinoma cell culture
  3. Bacterial infection
  4. RNA isolation
  5. Labeling and purification
  6. Hybridization
  7. Raw data preparation and Microarray DataAnalysis
 Ⅲ. RESULTS
  1. Global Gene Expression Profiles
  2. Ontology analysis
 Ⅳ. DISCUSSION
 Ⅴ. REFERENCES

• 박지은(Department of Oral Pathology) | Ji Eun Park
• 우복희(Department of Oral Pathology) | Vok Hee Woo
• 박대근(Department of Oral Pathology) | Dae Geun Park
• 박봉수(Department of Oral Anatomy, School of Dentistry, Pusan National University) | Bong Soo Park
• 이지혜(Department of Oral Pathology) | Ji Hye Lee
• 박혜련(Department of Oral Pathology) | Hae Ryoun Park correspondence