Dorai T, Perlman H, Walsh K, Shabsigh A, Goluboff E T, Olsson C A, Buttyan R
Molecular Urology Laboratory, Columbia University College of Physicians and Surgeons, New York, NY, USA.
Int J Cancer. 1999 Sep 9;82(6):846-52. doi: 10.1002/(sici)1097-0215(19990909)82:6<846::aid-ijc13>3.0.co;2-c.
Over-expression of bcl-2, a potent anti-apoptosis protein, is likely to be one of the genetic mechanisms through which human prostate cancer cells develop resistance to hormonal and other forms of therapy. To develop a therapeutic agent for hormone-resistant prostate cancer based on suppression of bcl-2 expression, we had previously designed and synthesized a dual-hammerhead ribozyme capable of recognizing and specifically cleaving human bcl-2 mRNA in vitro as well as in vivo. To increase the efficiency by which the anti-bcl-2 ribozyme can be delivered to target cells, we have created a recombinant replication-deficient (defective) adenoviral agent capable of expressing the anti-bcl-2 ribozyme upon infection. This viral agent effectively reduces intracellular levels of bcl-2 mRNA and protein in cultured LNCaP prostate cancer cells following standard infection procedures. Likewise, the defective adenovirus-anti-bcl-2 ribozyme induces extensive apoptosis in several androgen-sensitive (LNCaP) and androgen-insensitive (LNCaP/bcl-2 and PC-3) human prostate cancer cell lines that express differing amounts of bcl-2 protein. One androgen-insensitive prostate cancer cell line, DU-145, lacking in bcl-2 expression, was found to be completely refractory to the effects of the virus ribozyme, supporting the concept that the cytotoxic effects of the ribozyme are based solely on its effects on bcl-2 expression. Our results support further development of this adenovirus/anti-bcl-2 ribozyme for potential gene therapeutic purposes in certain forms of hormone-resistant prostate cancer where over-expression of bcl-2 proto-oncogene is indicated.
bcl-2是一种强效抗凋亡蛋白，其过度表达可能是人类前列腺癌细胞对激素及其他形式治疗产生耐药性的遗传机制之一。为了基于抑制bcl-2表达开发一种针对激素抵抗性前列腺癌的治疗药物，我们之前设计并合成了一种双锤头核酶，它能够在体外及体内识别并特异性切割人类bcl-2 mRNA。为了提高抗bcl-2核酶传递至靶细胞的效率，我们构建了一种重组复制缺陷型腺病毒载体，它在感染后能够表达抗bcl-2核酶。按照标准感染程序，这种病毒载体可有效降低培养的LNCaP前列腺癌细胞内bcl-2 mRNA和蛋白的水平。同样，缺陷型腺病毒-抗bcl-2核酶可诱导几种表达不同量bcl-2蛋白的雄激素敏感型（LNCaP）和雄激素不敏感型（LNCaP/bcl-2和PC-3）人类前列腺癌细胞系发生广泛凋亡。发现一种缺乏bcl-2表达的雄激素不敏感型前列腺癌细胞系DU-145对病毒核酶的作用完全不敏感，这支持了核酶的细胞毒性作用仅基于其对bcl-2表达的影响这一概念。我们的结果支持进一步开发这种腺病毒/抗bcl-2核酶，用于某些显示bcl-2原癌基因过度表达的激素抵抗性前列腺癌的潜在基因治疗目的。
