Qiang W A, Liu J R, Wang Y S, Lei Y D
Department of Pharmacology, West China University of Medical Sciences, Chengdu.
Yao Xue Xue Bao. 1994;29(5):340-5.
Polyactin A (PAA) is a home-made immunomodulator, isolated from submerged culture broths of alpha-hemolytic streptococci. The effect of PAA on the metastasis of B16-F10 melanoma cells in the syngeneic C57BL/6J mice and its antimetastatic mechanism have been studied. The results showed that: PAA inhibited the experimental pulmonary metastasis nodules at a dose of 100 mg.kg-1.d-1 for 18 d. The number of pulmonary metastasis nodules were significantly decreased from 137 to 95 as compared with those in the control; The plasma concentration of TXB2 in B16 bearing mice was higher than that in normal mice. After treatment with PAA, a decreased content of TXB2 and 6-keto-PGF1 alpha was found without change of the ratio TXB2 to 6-keto-PGF1 alpha. The cellular immunities were evidently decreased in the B16 bearing mice. The restoration of lymphocyte proliferation response and augmentation of the NK cell activity of the splenocytes were found in vivo in normal mice and B16 bearing mice after treated with PAA. PAA was also shown to antagonize the suppressing effect of cyclophosphamide on murine NK cells; PAA at the concentration of 10-5000 micrograms.ml-1 was found to inhibit the biosynthesis of DNA, RNA and protein in the B16-F10 melanoma cells to different degrees and the effect was dose-dependent. It is evident that PAA is effective in preventing the pulmonary metastasis of B16-F10 melanoma and the antimetastatic action may be related not only to promoting the effect the antitumor immunities, but also to inhibiting the growth of B16-F10 melanoma cells.
聚肌胞苷酸（PAA）是一种自制的免疫调节剂，从α-溶血性链球菌的深层培养液中分离得到。研究了PAA对同基因C57BL/6J小鼠体内B16-F10黑色素瘤细胞转移的影响及其抗转移机制。结果表明：PAA以100mg·kg-1·d-1的剂量连续给药18天可抑制实验性肺转移瘤结节。与对照组相比，肺转移瘤结节数量从137个显著减少至95个；荷B16小鼠血浆TXB2浓度高于正常小鼠。PAA治疗后，TXB2和6-酮-PGF1α含量降低，但TXB2与6-酮-PGF1α的比值无变化。荷B16小鼠的细胞免疫明显降低。在正常小鼠和荷B16小鼠体内，经PAA治疗后，脾细胞的淋巴细胞增殖反应恢复，NK细胞活性增强；PAA还显示出拮抗环磷酰胺对小鼠NK细胞的抑制作用；发现浓度为10-5000μg·ml-1的PAA可不同程度地抑制B16-F10黑色素瘤细胞的DNA、RNA和蛋白质生物合成，且作用呈剂量依赖性。显然，PAA对预防B16-F10黑色素瘤的肺转移有效，其抗转移作用可能不仅与增强抗肿瘤免疫效应有关，还与抑制B16-F10黑色素瘤细胞生长有关。
