Sagawa T, Yamashita K, Kawamura M, Hayashi H, Mure K, Shimizu T
Nihon Sanka Fujinka Gakkai Zasshi. 1985 Jan;37(1):61-5.
Changes in cell growth and hormone production of the choriocarcinoma cell line BeWo were studied to determine the manner in which the change in the cell cycle due to antimetabolite MTX affects heat sensitivity. First of all, BeWo was treated with 10(-7)M-MTX for 48 hrs. on day 4. And heat (43 degrees C for 1 h.) was applied at various stages after MTX removal on day 6. At the same time, the change in the cell cycle induced by MTX was studied by autoradiography. The labeling index (L.I.), which was increasing until 90% by MTX exposure, still remained more than 80% up to 5 hrs. after MTX removal and then decreased to about 43% at 9 hrs. after MTX removal. The greatest effect on cell growth and HCG production was seen when heat was applied within 5 hrs. after MTX removal. And these 5 hrs. corresponded to the time when the L.I. was as high as 80 to 90%. When heat was applied more than 6 hrs. after MTX removal, the heat sensitivity was reduced in proportion to the degree of decrease in the L.I. These findings suggest that the change in the cell cycle induced by MTX has the greatest effect on the heat sensitivity of BeWo. It is therefore possible to conclude that synchronization of BeWo with S phase by using MTX or possibly other antimetabolites is very important in the application of hyperthermia.
为了确定抗代谢物甲氨蝶呤（MTX）引起的细胞周期变化如何影响热敏感性，研究了绒毛膜癌细胞系BeWo的细胞生长和激素产生的变化。首先，在第4天用10（-7）M - MTX处理BeWo 48小时。然后在第6天去除MTX后的不同阶段施加热（43℃，1小时）。同时，通过放射自显影研究MTX诱导的细胞周期变化。标记指数（L.I.）在MTX暴露下直至90％一直增加，在去除MTX后5小时内仍保持超过80％，然后在去除MTX后9小时降至约43％。在去除MTX后5小时内施加热时，对细胞生长和人绒毛膜促性腺激素（HCG）产生的影响最大。这5小时对应于L.I.高达80％至90％的时间。当在去除MTX后6小时以上施加热时，热敏感性与L.I.的降低程度成比例降低。这些发现表明，MTX诱导的细胞周期变化对BeWo的热敏感性影响最大。因此可以得出结论，在热疗应用中，使用MTX或可能的其他抗代谢物使BeWo与S期同步非常重要。
