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

Extensive oral mucosa loss from a variety of conditions is associated with significant functional morbidity and mortality. Although it is known that keratinocytes are a rich source of wound healing promoting factors such as transforming growth factor-β1(TGF-β1), it is not clear whether differentiated keratinocytes in a multi-layer form release this multi-functional growth factor. This study examined the hypothesis that keratinocytes in mono- and multi-layer forms expressed different levels of TGF-β1. When NHOK reached confluency in serum free medium(KBM), in test medium containing 1.2 mM Ca++ KBM NHOK were allowed to form multi-layers and differentiate. The purpose of this study were to investigate the mRNA level of TGF-β1, FGF-2, and TIMP-1 by RT-PCR analysis and also to evaluate the expression of TGF-β1 and involucrin in keratinocytes at different times of the onset of differentiation. The numbers and sizes of these nodules were increased as the process of keratinocyte differentiation proceed. Cultured NHOK in preconfluency under KBM medium expressed a significantly higher level of TGF-β1 relative to those grown in multi-layer forms, while the level of TGF-β1 mRNA gradually reduced to its lowest level at 7 days of growing cells in test medium. Cultured NHOK in preconfluency of KBM medium expressed a lower level of FGF-2 and TIMP-1 relative to those grown in multi-layer forms, while the level of FGF-2 and TIMP-1 mRNA showed the highest level at 3 days at gradually reduced to its lowest level at 7 days of growing cells in test medium. As a differentiation marker for keratinocytes at different time points, the highest level of involucrin mRNA expression was found at the later stage of cell differentiation. It suggested that the expression of TGF-β1 mRNA be consistent with the expression of FGF-2 and TIMP-1 mRNA in NHOK grown in high calcium medium during the terminal differentiation. But differentiated NHOK expressing higher involucrin mRNA could show constant espression of TGF-β1, FGF-2 and TIMP-1.