Decreased tumorigenicity of a human colon adenocarcinoma cell line by an antisense expression vector specific for c-Src.
Decreased tumorigenicity of a human colon adenocarcinoma cell line by an antisense expression vector specific for c-Src.
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发表时间：
1997-03
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通讯作者：
Charles A. Staley;N. Parikh;G. Gallick
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作者：
Charles A. Staley;N. Parikh;G. Gallick
在超过80%的结肠肿瘤和已建立的细胞系中，蛋白酪氨酸激酶pp 60（c-src）和pp 62（c-yes）的比活性相对于正常结肠上皮细胞增加。然而，在结肠肿瘤中没有发现任何基因突变。因此，这些蛋白酪氨酸激酶在结肠肿瘤中激活的可能生物学后果尚不清楚。为了确定pp 60（c-src）活化是否影响已建立的结肠肿瘤细胞系的生长和致瘤性，构建了特异性降低pp 60（c-src）表达的反义表达载体。将载体转染到HT 29细胞中，HT 29细胞是一种已建立的结肠肿瘤细胞系，其中pp 60（c-src）和pp 62（c-yes）都被激活。分离出两个稳定的亚克隆，其中pp 60（c-src）而不是pp 62（c-yes）表达和活性降低。这些建立的细胞系比亲本细胞增殖更慢，与pp 60（c-src）表达的减少成比例。当注射到裸鼠体内时，反义转染的细胞形成缓慢生长的肿瘤;然而，肿瘤生长速率的降低远远大于组织培养中增殖速率降低所预测的。与此相反，稳定的亚克隆转染了一个相当的“正义”表达载体在组织培养和裸鼠的生长速度不变，相对于亲本HT 29细胞。这些数据表明，单独的pp 60（c-src）的活化有助于HT 29细胞的致瘤性，HT 29细胞是广泛用作结肠癌生物学特性模型的细胞系。此外，由于pp 60（c-src）和pp 62（c-yes）对正常结肠上皮细胞的生长调节似乎是多余的，数据表明src特异性抑制剂可能对结肠癌有治疗价值。
In greater than 80% of colon tumors and established cell lines, the specific activities of the protein tyrosine kinases pp60(c-src) and pp62(c-yes) are increased with respect to normal colonic epithelial cells. However, no mutations in either gene have been identified in colon tumors. Therefore, the possible biological consequences of activations of these protein tyrosine kinases in colon tumors have been unclear. To determine if pp60(c-src) activation affects growth and tumorigenicity of established colon tumor cell lines, an antisense expression vector that specifically reduces pp60(c-src) expression was constructed. The vector was transfected into HT 29 cells, an established colon tumor cell line in which both pp60(c-src) and pp62(c-yes) are activated. Two stable subclones were isolated in which pp60(c-src) but not pp62(c-yes) expression and activity were reduced. These established cell lines proliferated more slowly than parental cells proportionately to reduction in pp60(c-src) expression. When injected into nude mice, antisense transfected cells formed slow-growing tumors; however, the rate of tumor growth was reduced far greater than would be predicted from decreased proliferation rates in tissue culture. In contrast, stable subclones transfected with a comparable "sense" expression vector were unaltered in growth rates in tissue culture and in nude mice with respect to parental HT 29 cells. These data demonstrate that the activation of pp60(c-src) alone contributes to the tumorigenicity of HT 29 cells, a cell line widely used as a model for biological properties of colon carcinoma. Furthermore, because pp60(c-src) and pp62(c-yes) appear redundant to the growth regulation of normal colonic epithelial cells, the data suggest that src-specific inhibitors might be of therapeutic value for colon cancer.