Trypsinization and the radiosensitivity of mitotic and log phase Chinese hamster V79 cells exposed to 250 kVp X-rays.
Trypsinization and the radiosensitivity of mitotic and log phase Chinese hamster V79 cells exposed to 250 kVp X-rays.
复制标题
暴露于 250 kVp X 射线的有丝分裂和对数期中国仓鼠 V79 细胞的胰蛋白酶消化和放射敏感性。
DOI：
10.1080/09553008914550111
复制
发表时间：
1989
影响因子：
2.6
通讯作者：
Lange,CS
中科院分区：
文献类型：
--
作者：
Reddy,NM;Stevenson,AF;Lange,CS
我们研究了胰蛋白酶诱导的形态学变化对细胞辐射敏感性的影响，这些细胞以低密度（4-600/cm 2）或高密度（2 × 104/cm 2）接种，并在处理前生长过夜。胰蛋白酶处理引起铺展细胞收缩和变圆。胰蛋白酶消化和铺板的细胞的放射敏感性：（1）在低密度下细胞D 0 = 1·7戈伊，高密度下细胞D 0 = 1·5戈伊之前，或（2）在（D 0 = 1·6戈伊，高密度细胞）照射高于（3）高密度细胞，照射和延迟平板接种[细胞保持铺展直至潜在致死性损伤修复（PLDR）和胰蛋白酶消化完成，D 0 = 2·2戈伊]，（4）低密度细胞，照射后（D 0 = 2·4戈伊）既不延迟平板接种，也不胰蛋白酶消化（即保持铺展）。这些数据表明，PLDR在胰蛋白酶处理的高密度培养物（比较1b和2与3）和低密度培养物（比较1a与4）的细胞中均降低;后一种比较提供了胰蛋白酶效应的直接测量。由于条件1和2与条件3和4之间的比较是圆形细胞与铺展细胞的比较，因此PLDR似乎受到细胞形态状态的影响。动力学研究表明，当细胞在生长培养基中孵育，以恢复从胰蛋白酶诱导的辐射前的影响，辐射敏感性的蔓延细胞（platedin原位），但不是那些剩余的圆形（在悬浮液中，直到平板和辐射），降低，并成为等于延迟平板高密度细胞。高渗盐水处理的辐照细胞和有丝分裂细胞均未显示胰蛋白酶效应。这些结果提示：（1）胰蛋白酶诱导的细胞收缩影响细胞修复辐射损伤的能力;（2）铺展细胞比圆形细胞更能修复PLD;（3）高密度培养中细胞的立即平板存活可能并不代表其内在的辐射敏感性;（4）对数期细胞修复PLD不需要细胞间的接触。
We studied the influence of trypsin-induced morphological changes on the radiosensitivity of cells plated at either low (4–600/cm2) or high (2 × 104/cm2) density and grown overnight before treatments. Trypsin treatment induced contraction and rounding of spread cells. The radiosensitivity of cells trypsinized and plated either: (1) immediately before [(a) D0= 1·7 Gy for cells at low-, and (b) 1·5 Gy at high-density] or (2) immediately after (D0= 1·6 Gy, high-density cells) irradiation was higher than that of (3) cells at high density, irradiated and delayed plated [cells remained spread until the completion of potentially lethal damage repair (PLDR) and trypsinization, D0= 2·2 Gy], and (4) cells at low density which were neither delayed plated nor trypsinized (i.e. remained spread) after irradiation (D0= 2·4 Gy). These data show that PLDR is reduced in trypsin-treated cells of both high (compare 1b and 2 with 3) and low (compare 1a with 4) density cultures; the latter comparison provides a direct measure of the trypsin effect. Since the comparison between conditions 1 and 2 vs. 3 and 4 is of round vs. spread cells, PLDR appears to be influenced by the cell's morphological state. Kinetic studies showed that when cells were incubated in growth medium to recover from trypsin-induced effects before irradiation, the radiation sensitivity of spread cells (platedin situ), but not of those remaining rounded (in suspension until plating and irradiation), decreased and became equal to that of delayed plated high-density cells. Neither irradiated cells treated with hypertonic saline, nor mitotic cells, showed the trypsin effect. From these results we suggest that: (1) trypsin-induced cell contraction affects the ability of cells to repair radiation damage, (2) spread cells are better able to repair PLD than rounded cells, (3) immediate plating survival of cells in high-density cultures may not represent their intrinsic radiosensitivity and (4) cell-to-cell contact is not necessary for log phase cells to repair PLD.