Yamamoto N, Naraparaju V R
Laboratory of Cancer Immunology and Molecular Biology, Albert Einstein Cancer Center, Philadelphia, Pennsylvania 19141, USA.
Cancer Res. 1997 Jun 1;57(11):2187-92.
Vitamin D3-binding protein (DBP; human DBP is known as Gc protein) is the precursor of macrophage activating factor (MAF). Treatment of mouse DBP with immobilized beta-galactosidase or treatment of human Gc protein with immobilized beta-galactosidase and sialidase generated a remarkably potent MAF, termed DBPMAF or GcMAF, respectively. The domain of Gc protein responsible for macrophage activation was cloned and enzymatically converted to the cloned MAF, designated CdMAF. In Ehrlich ascites tumor-bearing mice, tumor-specific serum alpha-N-acetylgalactosaminidase (NaGalase) activity increased linearly with time as the transplanted tumor cells grew in the peritoneal cavity. Therapeutic effects of DBPMAF, GcMAF, and CdMAF on mice bearing Ehrlich ascites tumor were assessed by survival time, the total tumor cell count in the peritoneal cavity, and serum NaGalase activity. Mice that received a single administration of DBPMAF or GcMAF (100 pg/mouse) on the same day after transplantation of tumor (1 x 10(5) cells) showed a mean survival time of 35 +/- 4 days, whereas tumor-bearing controls had a mean survival time of 16 +/- 2 days. When mice received the second DBPMAF or GcMAF administration at day 4, they survived more than 50 days. Mice that received two DBPMAF administrations, at days 4 and 8 after transplantation of 1 x 10(5) tumor cells, survived up to 32 +/- 4 days. At day 4 posttransplantation, the total tumor cell count in the peritoneal cavity was approximately 5 x 10(5) cells. Mice that received two DBPMAF administrations, at days 0 and 4 after transplantation of 5 x 10(5) tumor cells, also survived up to 32 +/- 4 days, while control mice that received the 5 x 10(5) ascites tumor cells only survived for 14 +/- 2 days. Four DBPMAF, GcMAF, or CdMAF administrations to mice transplanted with 5 x 10(5) Ehrlich ascites tumor cells with 4-day intervals showed an extended survival of at least 90 days and an insignificantly low serum NaGalase level between days 30 and 90.
维生素D3结合蛋白（DBP；人类DBP被称为Gc蛋白）是巨噬细胞活化因子（MAF）的前体。用固定化β-半乳糖苷酶处理小鼠DBP或用固定化β-半乳糖苷酶和唾液酸酶处理人类Gc蛋白可产生一种极具活性的MAF，分别称为DBPMAF或GcMAF。负责巨噬细胞活化的Gc蛋白结构域被克隆，并通过酶促转化为克隆的MAF，命名为CdMAF。在荷艾氏腹水瘤小鼠中，随着移植的肿瘤细胞在腹腔内生长，肿瘤特异性血清α-N-乙酰半乳糖苷酶（NaGalase）活性随时间呈线性增加。通过生存时间、腹腔内肿瘤细胞总数和血清NaGalase活性评估DBPMAF、GcMAF和CdMAF对荷艾氏腹水瘤小鼠的治疗效果。在肿瘤（1×10⁵个细胞）移植后的同一天接受单次DBPMAF或GcMAF（100 pg/小鼠）给药的小鼠，平均生存时间为35±4天，而荷瘤对照小鼠的平均生存时间为16±2天。当小鼠在第4天接受第二次DBPMAF或GcMAF给药时，它们存活超过50天。在移植1×10⁵个肿瘤细胞后的第4天和第8天接受两次DBPMAF给药的小鼠，存活长达32±4天。在移植后第4天，腹腔内肿瘤细胞总数约为5×10⁵个细胞。在移植5×10⁵个肿瘤细胞后的第0天和第4天接受两次DBPMAF给药的小鼠，也存活长达32±4天，而仅接受5×10⁵个腹水瘤细胞的对照小鼠仅存活14±2天。对移植5×10⁵个艾氏腹水瘤细胞的小鼠每隔4天进行四次DBPMAF、GcMAF或CdMAF给药，显示生存时间延长至少90天，且在第30天至90天期间血清NaGalase水平极低且无显著差异。
