[Bacterial phagelysates and malignant tumor growth].

Anti-tumor preventive efficacy of E.coli phagelysate has been studied. Investigations were conducted on 2-3 months 48 male mice. Regimen of preventive vaccinations were: single - 0,25 ml phagelysate intraperitoneal injection, 3 days before Ehrlich carcinoma inoculation (1x10(6) tumor cells); 3 times vaccinations (0,25 ml, with 3 day intervals) 3, 6, and 9 days before inoculation of carcinoma; and 10 times (during 10 days, before inoculation of carcinoma). Treatment efficacy was evaluated according to the indices of cancer growth (development of cancer tissue, cancer growth inhibition percent, lifespan and survival percent). Experiments have shown that single and 3 times preventive vaccinations inhibited tumor development and delayed malignant growth, while, 10 times permanent vaccinations had no effects on cancer growth. Cancer growth inhibition percent in single and 3 times vaccinated animals were 58% on the average. Maximal lifespan in control group mice consisted 59 days. By the 125th day of cancer growth, at single vaccination 17% of mice were alive, while in 3 times vaccinated mice the survival percent was 25%. Anti-tumor potential of E.coli pagelysate supposedly could be explained by immunoregulatory properties of the preparation.

Antitumor and adjuvant effects of phagelysates of E.coli in mice with Ehrlich carcinoma.

AIM: To augment anti-tumor host response and overcome the tumor-induced immunosuppression is of paramount importance especially when patient is subjected to radio-/chemotherapy and immune system suffers significantly. Various immunological methods have been employed as supplemental antitumor therapies. We were aimed to investigate the antitumor potential of phagelysates of gram-negative bacteria and their adjuvant effects for conventional chemotherapy in experiment. METHODS: Bacterial phagelysates of E.coli and purified suspensions of corresponding Un bacteriophage were obtained by standard methods of phage research. Experiments were carried out on BL57C/6J mice bearing transplanted Ehrlich carcinoma. Different regimens of phagelysate administration (0,5 ml E. coli phagelysate, 3/8 times with 5 day intervals) and conventional chemotherapy (combination of Doxorubicin 60 mg/m2, Cyclophosphan 800 mg/m(2), Ftoruracil 600 mg/m(2), 3 times with 21 day intervals) were tested. Treatment efficacy was evaluated by tumor growth inhibition percent, index of malignant growth, lifespan and survival percent. RESULTS: Experiments have shown that application of optimal doses of E. coli phagelysate can be well tolerated in mice. No stimulation or support of malignant growth was observed. E. coli phagelysate exhibited significant anticancer effect and adjuvant efficacy. Cancer development was delayed in 65% of inoculated animals in the test group. E. coli phagelysate inhibited tumor growth by 80-90% without apparent side effects. The mice survival was prolonged twice and more. On 65th-69th days of tumor growth in 13% animals complete regression of neoplasms was registered. Application of phagelysates in combination with chemotherapy significantly increased antitumor efficacy of conventional chemotherapeutic drugs. CONCLUSION: Application of bacterial phagelysates can be considered as promising novel strategy in cancer therapeutics.

[Application of bacterial thermo-and phagelysates for suppression of malignant tumor growth in experimental studies: 1. Anticancer efficacy of thermo- and phagelysates of E.coli].

Immunotherapy is considered as one of the promising treatment strategies for patients with malignant tumors. In the presented work antitumor effects of E.coli thermo- and phagelysates on Ehrlich carcinoma growth in mice have been studied. The treatment efficacy was evaluated by estimation of dynamic changes in volume of cancer tissue and by the percentage of cancer growth inhibition. Semi-empirical mathematical model, describing cancer volume variations in relation to time, passed after Ehrlich carcinoma inoculation was elaborated. It was shown that at the early stage of cancer growth both tested bacterial preparations significantly inhibit cancer growth. Antitumor treatment effects were better expressed in animal studies using bacterial phagelysates in comparison to that of thermolysates. After cessation of administration of bacterial preparations a prolonged antitumor activity in animals treated with E. coli phagelysates was demonstrated.