McCully K S
Cancer Res. 1976 Sep;36(9 pt.1):3198-202.
Since abnormal homocysteine metabolism is associated with several disorders of growth, including neoplasia, the metabolic fate of homocysteine thiolactone was studied in cell cultures from several malignant tumors, established cell lines, cell lines transformed by oncogenic viruses, and normal skin cells. In all of the cultures of malignant cells homocysteine thiolactone becaome incorporated in peptide linkage with cellular proteins (thiolation). Normal cells incorporated homocysteine thiolactone in peptide linkage, but homocysteine thiolactone was released by acid hydrolysis. The findings suggest the speculative possibility that malignant cells are deficient in a homocysteine thiolactone derivative that prevents thiolation of proteins by homocysteine thiolactone. This hypothetical substance may also catalyze the synthesis of methionine and release acrolein, a growth-regulatory substance, in normal cells. The growth characteristics and tumorigenicity of cultured cells may be related to depletion of the hypothetical substance, and its identification, synthesis, and administration to animals would be expected to affect growth of malignant neoplasms.
由于同型半胱氨酸代谢异常与包括肿瘤形成在内的多种生长紊乱有关，因此在几种恶性肿瘤的细胞培养物、已建立的细胞系、致癌病毒转化的细胞系以及正常皮肤细胞中研究了同型半胱氨酸硫内酯的代谢命运。在所有恶性细胞培养物中，同型半胱氨酸硫内酯都与细胞蛋白质形成肽键结合（硫醇化）。正常细胞将同型半胱氨酸硫内酯结合到肽键中，但同型半胱氨酸硫内酯可通过酸水解释放出来。这些发现提示了一种推测性的可能性，即恶性细胞缺乏一种同型半胱氨酸硫内酯衍生物，该衍生物可防止同型半胱氨酸硫内酯对蛋白质进行硫醇化。这种假设的物质在正常细胞中还可能催化蛋氨酸的合成并释放出一种生长调节物质丙烯醛。培养细胞的生长特性和致瘤性可能与这种假设物质的消耗有关，预期对其进行鉴定、合成并给予动物将影响恶性肿瘤的生长。
