The anticancer efficiency of the xenogeneic vaccine and the indication for its use

Aim: To investigate the anticancer efficiency of the xenogeneic vaccine in different tumor models and to assess the possibility whe­ther level of antibodies (Ab) specific for vaccine’s proteins can be used as an indication for its use. Methods: Mice with Lewis lung carcinoma (LLC), Ehrlich carcinoma (EC) or Sarcoma 37 (S37) were immunized with a xenogeneic anticancer vaccine based on chicken embryo proteins (CEP) and its anticancer activity was examined. The level of specific Ab in the blood serum of non-immunized tumor-bearing mice was studied by ELISA. Results: CEP application statically significantly inhibited the growth of LLC (the index of tumor growth inhibition was 42.10–53.13% depending on the day of tumor growth); vaccinated mice with EC showed significant tumor growth inhibition and life prolongation by 34.48%. Among mice with S37, there was noticed no antitumor effect. The number of tumor-bearing non-immunized mice which have had pre-existing CEP-specific Ab did not differ depending on the tumor model. The level of CEP-specific Ab among mice with LLC and EC increased with the growth of the tumor volume, but it decreased among mice be­aring S37. Probably, the low level of CEP-specific Ab alongside huge tumor burden shows it is futile to apply the CEP-based vaccine. Conclusion: Different tumor strains vary in their susceptibility to CEP-based vaccine. Probably, the low level of CEP-specific Ab when a tumor burden is huge shows it is futile to apply the CEP-based vaccine. Key Words: xenogeneic anticancer vaccine, chicken embryo proteins anticancer activity, Lewis lung carcinoma, Ehrlich carcinoma, Sarcoma 37, CEP-specific antibodies. Key Words: xenogeneic anticancer vaccine, chicken embryo proteins anticancer activity, Lewis lung carcinoma, Ehrlich carcinoma, Sarcoma 37, CEP-specific antibodies

Anticancer effectiveness of vaccination based on xenogeneic embryo proteins applied in different schedules

The aim: To evaluate anticancer activity of vaccination with chicken embryo proteins (CEP) applied in different schedules. Materials and Methods: C57Bl mice were vaccinated with CEP before (prophylactic schedule) or after (different therapeutic schedules with or without preliminary tumor removal) the Lewis lung carcinoma cells transplantation. The latent period of tumor development, tumor volume and metastasis rate were evaluated. Results: Potent antimetastatic effect of CEP-based vaccination was seen in case of therapeutic regimen after primary tumor removal. The metastasis inhibition index (MII) reached 96.9 and 97.8% on 18th and 34th day after tumor removal, respectively. When CEP vaccination was performed in the settings of therapeutic regimen without primary tumor removal the anticancer effect was evident only if vaccinations started as early as 24 h after the cancer cells injections. The highest MII achieved in such condition was 77.6%, tumor volume in the group of vaccinated animals was by 53.1–42.1% lower than in the control tumor-bearing mice. CEP vaccination before tumor challenge (prophylactic immunization) led to a statistically significant prolongation of the latent period of tumor development, a reduction of tumor volume (35.8–48.8% compared to control unvaccinated mice) and a marked inhibition of metastasis (MII was 71.1%). Conclusion: Vaccination based on CEP exhibited both prophylactic and therapeutic anticancer effects. The last one is more pronounced when the vaccination starts shortly after the primary tumor resection. Key Words: chicken embryo proteins, anticancer activity, Lewis lung carcinoma

ANTICANCER EFFECTIVENESS OF VACCINATION BASED ON XENOGENEIC EMBRYO PROTEINS APPLIED IN DIFFERENT SCHEDULES

The aim: To evaluate anticancer activity of vaccination with chicken embryo proteins (CEP) applied in different schedules. Materials and Methods: C57Bl mice were vaccinated with CEP before (prophylactic schedule) or after (different therapeutic schedules with or without preliminary tumor removal) the Lewis lung carcinoma cells transplantation. The latent period of tumor development, tumor volume and metastasis rate were evaluated. Results: Potent antimetastatic effect of CEP-based vaccination was seen in case of therapeutic regimen after primary tumor removal. The metastasis inhibition index (MII) reached 96.9 and 97.8% on 18th and 34th day after tumor removal, respectively. When CEP vaccination was performed in the settings of therapeutic regimen without primary tumor removal the anticancer effect was evident only if vaccinations started as early as 24 h after the cancer cells injections. The highest MII achieved in such condition was 77.6%, tumor volume in the group of vaccinated animals was by 53.1–42.1% lower than in the control tumor-bearing mice. CEP vaccination before tumor challenge (prophylactic immunization) led to a statistically significant prolongation of the latent period of tumor development, a reduction of tumor volume (35.8–48.8% compared to control unvaccinated mice) and a marked inhibition of metastasis (MII was 71.1%). Conclusion: Vaccination based on CEP exhibited both prophylactic and therapeutic anticancer effects. The last one is more pronounced when the vaccination starts shortly after the primary tumor resection. Key Words: chicken embryo proteins, anticancer activity, Lewis lung carcinoma