Oral squamous cell carcinoma (SCC) is one of the leading causes of cancer mortality worldwide. It is generally thought that adjuvant chemotherapy provides modest prolongation of survival in various carcinoma. Docetaxel (Taxotere, TXT) play a significant role in the treatment of various solid tumors of epithelial origin. CsA (immunosuppressive drug) was widely used as adjunct for the treatment of cancer. Thus, it is important to pursue the apoptosis of IHOK and oral SCC induced by TXT combined with CsA related to the pathogenesis of oral SCC. But TXT combined CsA effect on IHOK and oral SCC remains unclear. After cultured IHOK and HN 22 oral squamous cell carcinoma cell line treated by 10 nM TXT and 1 μM, and caspase inhobitor, respectively, apoptosis index, cytochrome c and caspase-3 -8, -9 mRNA expression by RT-PCR, and procaspase-3 protein amount by immunoslot blotting was prepared. The purpose of this study were to examine the TXT-induced apoptosis pathway via caspase activation by CsA enhancement, and to apply these results to an effective therapeutic treatment plan for oral SCC by TXT combined CsA . 10 nM TXT showed about 60%, 55% celluar apoptosis of IHOK and HN 22, cell line, respectively, while CsA alone did not induce apoptosis in IHOK and HN 22 cell line. 1 μM CsA combined with 10 nM TXT increased apoptosis in IHOK and HN 22 cell line through caspase-3 and cytochrome c mRNA expression, while could not effect on caspase-8 and -9. Caspase inhibitor suppressed apoptosis of IHOK and HN 22 cell line induced by a combination of 1 μM CsA and 10 nM TXT. Immnoslot blotting showed procaspase-3 activation by a combination 1 μM CsA and 10 nM TXT, while caspase inhibitor inhibited activation. It suggested that a combination of CsA and TXT might induce increased apoptosis of IHOK and HN 22 oral squamous cell carcinoma cell line through caspase-3 activation. This treatment with a combination of TXT and CsA may be an effective therapeutic strategy for oral squamous cell carcinoma

I. INTRODUCTION
 II. MATERIALS and METHODS
  1. Cell Culture Condition
  2. Apoptosis Index
  3. Caspase Inhibitor
  4. Total RNA Extraction and RT-PCR Analysis
  5. R T-PCR reaction for cDNA
  6. Immunoslot Blotting
 III. RESULTS
 IV. DISCUSSIONS
 V. REFERENCES

• 송영성(Department of Oral Pathology, The Oral Aging Research Center, Dental College, Dankook University) | Yeoung Seoung Song
• 박경주(Department of Oral Pathology, The Oral Aging Research Center, Dental College, Dankook University) | Gyeong Ju Park
• 이종헌(Department of Oral Pathology, The Oral Aging Research Center, Dental College, Dankook University) | Chong Heon Lee correspondence