Kumar S, Shukla Y, Prasad A K, Verma A S, Dwivedi P D, Mehrotra N K, Ray P K
Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow, India.
Cancer Lett. 1992 Jan 10;61(2):105-10. doi: 10.1016/0304-3835(92)90167-t.
Protein A is an immunostimulating glycoprotein obtained from Staphylococcus aureus Cowan I. Its antitumour activity is proven in various tumour models. Its ability to provide protection against tumour initiation by the chemical carcinogen 7,12-dimethylbenzanthracene (DMBA) has been investigated in the present study using a mouse skin model of two-stage carcinogenesis. Protein A was administered intraperitoneally (1 microgram/animal 20 g body wt.) twice a week for 2 weeks, prior to initiation by DMBA. The promotion was performed by twice weekly applications of 12-O-tetradecanoyl phorbol-13-acetate (TPA) (3 or 5 micrograms/animal in 100 microliters acetone). Protein A provided significant protection to animals from DMBA-induced tumour initiation as was observed by the decrease in cumulative number of tumours, percent of animals developing tumours, number of tumours per animal and rate of tumour growth. Our data indicate that protein A has anticarcinogenic properties.
蛋白A是一种从金黄色葡萄球菌考恩I型中获得的具有免疫刺激作用的糖蛋白。其抗肿瘤活性在多种肿瘤模型中得到证实。在本研究中，使用两阶段致癌的小鼠皮肤模型，研究了其对化学致癌物7,12 - 二甲基苯并蒽（DMBA）引发肿瘤的保护能力。在DMBA引发肿瘤之前，每周两次腹腔注射蛋白A（1微克/20克体重动物），持续2周。促癌阶段通过每周两次涂抹12 - O - 十四酰佛波醇 - 13 - 乙酸酯（TPA）（3或5微克/动物，溶于100微升丙酮）来进行。通过观察肿瘤累积数量减少、发生肿瘤的动物百分比、每只动物的肿瘤数量以及肿瘤生长速率，发现蛋白A为动物提供了显著的保护，使其免受DMBA诱导的肿瘤引发。我们的数据表明蛋白A具有抗癌特性。
