Study on differentiation and apoptosis-inducing therapy for head and neck cancer by vesnarinone

1. 当人口腔鳞状细胞癌细胞（BHY、HN: p53野生型（exon4-9））和人唾液癌细胞（HSG、HSG- aza1、HSG- aza3: p53野生型；TYS: p53密码子281^<Asp→Hls>）经vesnarinone处理后，细胞均出现生长抑制和G1阻滞，其中p21^<Waf1>、p27^<Kip1>和TSC-22基因上调，p53基因下调。2 .当向携带TYS肿瘤的裸鼠体内注射vesnarinone时，肿瘤生长受到明显抑制，细胞分化为角化细胞和腺泡细胞。Vesnarinone对人口腔鳞状细胞癌和人唾液腺样囊性癌有很好的治疗效果。我们从经vesnarinone处理的TYS细胞中分离并鉴定了人TSC-22基因。(1)体外培养和裸鼠培养的人唾液癌细胞中，TSC-22基因下调可显著加速肿瘤生长，上调可显著抑制非锚定生长。(2) TYS细胞中TSC-22蛋白的过度表达导致抗癌药物（5-FU和CDDP）或放疗对细胞凋亡的诱导增强。(3) TSC-22基因由3个外显子组成。转录起始位点分别位于TATA box - like序列下游7bp和29bp处。TSC-22启动子区包含NF-kB、MyoD、AP-1、PU、C/EBP、p53、C- myb、Sp1、NF1或Smad.5等转录因子的推定结合位点。在TYS细胞中，p21Waf1启动子中存在Sp1和Sp3转录因子与vesnarin -responsive element （Sp1-1和Sp1-2位点）结合。Vesnarinone诱导TYS细胞组蛋白超乙酰化。

1. When human oral squamous cell carcinoma cell lines (BHY, HN: p53 wild type (exon4-9)) and human salivary cancer cell lines (HSG, HSG-AZA1, HSG-AZA3: p53 wild type; TYS : p53 codon 281^<Asp→Hls>) were treated with vesnarinone, inhibition of cell growth and induction of G1 arrest occurred in all of the treated cells, where up-regulation of p21^<Waf1>, p27^<Kip1> and TSC-22 genes as well as down-regulation of p53 gene were detected.2. When vesnarinone was administered per os into the nude mice bearing TYS tumors, significant inhibition of the tumor growth as well as cellular differentiation into keratinocyte and acinar cells occurred.3. Vesnarinone was very therapeutically effective for human oral squamous cell carcinoma or for human salivary adenoid cystic carcinoma.4. We isolated and characterized human TSC-22 gene from the TYS cells treated with vesnarinone.(1) Down-regulation of TSC-22 gene in human salivary cancer cells, grown in vitro and in nude mice, caused the marked acceleration of tumor growth and up-regulation of the gene inhibited significantly anchorage-independent growth.(2) Overexpression of TSC-22 protein in TYS cells resulted in the augmented induction of apotosis by anti-cancer drugs (5-FU and CDDP) or radiation.(3) TSC-22 gene was comprised of 3 exons. Transcription initiatin sites were located at 7bp and 29bp downstream from TATA box like sequence. TSC-22 promoter region contained putative binding sites for transcription factor such as NF-kB, MyoD, AP-1, PU, C/EBP, p53, c-Myb, Sp1, NF1 or Smad.5. Sp1 and Sp3 transcription factors bound to the vesnarinone-responsive element (Sp1-1 and Sp1-2 sites) present in p21Waf1 promoter in TYS cells.6. Vesnarinone induced the histone hyperacetylation in TYS cells.