Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture.
Expression of the biochemical defect of methionine dependence in fresh patient tumors in primary histoculture.
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发表时间：
1993-06
期刊：
影响因子：
11.2
通讯作者：
H. Guo;H. Herrera;Alex Groce;R. Hoffman
中科院分区：
文献类型：
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作者：
H. Guo;H. Herrera;Alex Groce;R. Hoffman
蛋氨酸依赖性是一种代谢缺陷，发生在许多人类肿瘤细胞系中，但在未建立的细胞株中并不正常。当培养基（MET-HCY+ 培养基）中的蛋氨酸被其直接前体同型半胱氨酸取代时，蛋氨酸依赖性肿瘤细胞系无法增殖并停滞在细胞周期的晚期 S/G2 期。然而，尚不清楚新鲜患者肿瘤中是否会像细胞系中那样发生甲硫氨酸依赖性。为了确定新鲜患者肿瘤中是否发生甲硫氨酸依赖性以及新鲜患者肿瘤和细胞系中是否发生甲硫氨酸依赖性，我们利用海绵凝胶支持的组织培养技术直接在手术中培养肿瘤。然后，我们通过图像分析测量了核 DNA 含量，以确定 21 名人类患者肿瘤中 MET-HCY+ 与 MET+HCY- 培养基中细胞周期的位置。通过细胞计数发现蛋氨酸依赖性的人肿瘤细胞系用作阳性对照，并且发现与 MET-HCY+ 培养基中细胞周期中的总细胞相比，相对于 MET+HCY-培养基中的 G1: 总细胞比率，G1 期细胞显着减少。因此，晚期细胞周期停滞被用作组织培养的患者肿瘤的蛋氨酸依赖的标志。根据细胞周期分析，我们发现 21 种人类肿瘤中有 5 种依赖于蛋氨酸，其中包括结肠癌、乳腺癌、卵巢癌、前列腺癌和黑色素瘤。这些关于新鲜人类肿瘤的数据表明，甲硫氨酸依赖可能经常发生在癌症患者群体中。讨论了基于蛋氨酸依赖性的潜在治疗的意义。
Methionine dependence is a metabolic defect that occurs in many human tumor cell lines but not normal in unestablished cell strains. Methionine-dependent tumor cell lines are unable to proliferate and arrest in the late S/G2 phase of the cell cycle when methionine is replaced by its immediate precursor homocysteine in the culture medium (MET-HCY+ medium). However, it is not known whether methionine dependence occurs in fresh patient tumors as it does in cell lines. In order to determine whether methionine dependence occurs in fresh patient tumors as well as whether methionine dependence occurs in fresh patient tumors as well as in cell lines we took advantage of the technique of sponge-gel-supported histoculture to grow tumors directly from surgery. We then measured nuclear DNA content by image analysis to determine the cell cycle position in MET-HCY+ compared to MET+HCY- medium in 21 human patient tumors. Human tumor cell lines found to be methionine dependent by cell count were used as positive controls and were found to have marked reduction of cells in G1 compared to total cells in the cell cycle in MET-HCY+ medium with respect to the G1: total cell ratio in MET+HCY- medium. Therefore late cell cycle arrest was used as a marker of methionine dependence for histocultured patient tumors. We found that 5 human tumors of 21, including tumors of the colon, breast, ovary, prostate, and a melanoma, were methionine dependent based on cell cycle analysis. These data on fresh human tumors indicate that methionine dependence may frequently occur in the cancer patient population. Implications for potential therapy based on methionine dependence are discussed.