Datta K, Sundberg C, Karumanchi S A, Mukhopadhyay D
Departments of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
Cancer Res. 2001 Mar 1;61(5):1768-75.
The von Hippel-Lindau (VHL) tumor suppressor gene is mutated in patients with VHL disease and in the majority of patients with sporadic renal cell carcinomas (RCCs). RCCs are dependent on insulin-like growth factor-1 receptor-mediated signaling for tumor growth and invasion in vivo. Reintroduction of the VHL gene product (pVHL) can inhibit on insulin-like growth factor-I receptor-mediated signaling in RCC cells in vitro through interaction with protein kinase C delta and is mediated by a specific amino acid sequence (104-123) in the beta-domain of the pVHL. In the present study, the amino acid sequence (104-123) of the pVHL was conjugated to the protein transduction domain of HIV-TAT protein (TATFLAGVHL-peptide) to facilitate entry into cells, and we demonstrate that this amino acid region of VHL is sufficient to block proliferation and invasion of 786-O renal cancer cells in vitro. Furthermore, daily i.p. injections with the TATFLAGVHL peptide retarded and, in some cases, caused partial regression of renal tumors that were implanted in the dorsal flank of nude mice. Treatment with this peptide also inhibits the invasiveness of renal tumors. A 56% decrease in the proliferative index in tumors treated with the TATFLAGVHL-peptide versus control-peptide-treated mice was observed. Taken together, these results show the novel importance of a 20-amino acid sequence of the beta-domain of the VHL gene product capable of inhibiting tumor growth and invasion. These results lay the foundation for a unique approach toward treating RCCs using this small-molecular-weight peptide fused to the TAT-sequence, which may, in the future, be used alone or in conjunction with other therapies.
在VHL病患者以及大多数散发性肾细胞癌（RCC）患者中，冯·希佩尔-林道（VHL）肿瘤抑制基因发生了突变。肾细胞癌在体内的肿瘤生长和侵袭依赖于胰岛素样生长因子-1受体介导的信号传导。重新引入VHL基因产物（pVHL）可通过与蛋白激酶Cδ相互作用，在体外抑制肾癌细胞中胰岛素样生长因子-I受体介导的信号传导，且这一过程由pVHLβ结构域中的特定氨基酸序列（104 - 123）介导。在本研究中，将pVHL的氨基酸序列（104 - 123）与HIV-TAT蛋白的蛋白转导结构域偶联（TATFLAGVHL-肽）以促进其进入细胞，并且我们证明VHL的这一氨基酸区域足以在体外阻断786-O肾癌细胞的增殖和侵袭。此外，每天腹腔注射TATFLAGVHL肽可延缓并在某些情况下使植入裸鼠背部侧翼的肾肿瘤部分消退。用该肽治疗还可抑制肾肿瘤的侵袭性。观察到与对照肽处理的小鼠相比，用TATFLAGVHL-肽处理的肿瘤增殖指数降低了56%。综上所述，这些结果表明VHL基因产物β结构域的一个20氨基酸序列在抑制肿瘤生长和侵袭方面具有新的重要性。这些结果为使用与TAT序列融合的这种小分子肽治疗肾细胞癌的独特方法奠定了基础，这种方法未来可能单独使用或与其他疗法联合使用。
