Anticancer effect and immunologic response to xenogeneic embryonic proteins in mice bearing ehrlich solid carcinoma

Aim: To investigate anticancer and immunologic effects of chicken embryonic proteins (CEP) in mice bearing Ehrlich solid carcinoma. Materials and Methods: The study was carried out on male Balb/c mice bearing Ehrlich solid carcinoma. The immunizations were performed after the tumor transplantation. The immune status was assessed on days 7, 14, 21 and 28 after the tumor challenge. Cytotoxic activity (CAT) of macrophages (Mph), natural killer cells (NK), cytotoxic T-lymphocytes (CTL) and blood serum, as well as the influence of the blood serum on immune cells activity was checked in MTT-assay; Mph’s cytochemical activity was tested in NBT-assay; Ehrlich antigen-specific or CEP-specific antibodies were detected in ELISA-assay; medium size circulating immune complexes (CIC) were detected in reaction of 4.5% polyethylene glycol precipitation. Results: The immunization resulted in tumor growth suppression and significant 25.64% prolongation of the survival time. In both control and immunized mice with transplanted tumors antibodies specific to Ehrlich carcinoma antigens and to CEP were detected, but antibody response was more balanced in the treatment group. In the treatment group both cytochemical and CAT of Mph was moderately activated and well preserved until late stages of tumor development; CAT of NK and CTL remained in the range of the intact mice until day 28 after the tumor transplantation. The immunized mice were well protected from accumulation of CIC and suppressive activity of autologous blood serum. Conclusion: Collectively, our data indicate that CEP can elicit immunomodulating and immunoprotecting effects sufficient to provide tumor growth inhibition. The further elaboration of a xenogeneic anticancer vaccine based on CEP is warranted

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

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

Cytotoxic activity of immune cells following administration of xenogeneic cancer vaccine in mice with melanoma B-16

Aim: To study the effects of xenogeneic cancer vaccine (XCV) developed on the basis of nervous tissue antigen from rat embryo of late gestation period and protein-containing metabolite of Bacillus subtilis with molecular weight of 70 kDa, on specific and unspecific antitumor reactions of cellular and humoral chains of immune system, and to analyze possible mechanisms of its antimetastatic action. Materials and Methods: XCV was administered triply with 3-day intervals after surgical removal of experimental melanoma В-16 in C57Bl/6 mice. Cytotoxic activity (CTA) of splenocytes against target cells К-562 as well as CTA of splenocytes, peritoneal macrophages (PM) and blood serum against melanoma В-16 target cells were determined using МТТ test. The content of circulating immune complexes (CIC) in blood serum was evaluated by precipitation reaction. Results: Immunologic effects of XCV vaccination in experimental animals with surgically removed melanoma B-16 in comparison with similarly treated unvaccinated mice were as follows: prevention of medium molecular weight CIC accumulation in blood serum during all observation period, significant increase (р < 0.05) of CTA of effectors of unspecific antitumor immunity (natural killer cells — NK — by 25.5 ± 1.7 vs 12.5 ± 5.4%, and PM — by 37.3 ± 0.6 vs 32.0 ± 0.9%, respectively) at 37th day after the surgery, and also preservation of functional activity of specific cytotoxic lymphocytes at the level of intact control. Conclusion: The results of the study allow propose that antimetastatic effect of XCV vaccination could be based on increased CTA of NK and PM, and preservation of CTL functional activity at late terms after surgical removal of B-16 primary tumors. Key Words: xenogeneic cancer vaccine, melanoma В-16, natural killer cells, macrophages, cytotoxic lymphocytes, cytotoxic activity, antimetastatic activity

Effect of enterosorption on paraneoplastic syndrome manifestations in mice with highly angiogenic variant of lewis lung carcinoma

Aim: To study the correcting effects of microgranulated HSGD enterosorbent on hematological, morphological and biochemical indices of paraneoplastic syndrome in mice with highly angiogenic variant of Lewis lung carcinoma LLC/R9. Methods: The study was performed on male С57/ВL6 mice with transplanted LLC/R9. Enterosorbent HSGD was administered daily at a dose of 0.625 g/kg for 2 weeks starting from 7th day after tumor cell transplantation. When enterosorption was completed, an analysis of peripheral blood, biochemical indices and morphological structure of tumor, lung, liver, spleen and thymus was carried out by standard methods. Results: It has been shown that administration of enterosorbent did not affect LLC/R9 growth but resulted in nearly two fold decrease of the volume of lung metastases (p < 0.05). Erythrocyte number and hemoglobin level were higher by 30.0% (p < 0.05) and 23.3% (p < 0.05), respectively, in mice treated with enterosorbents as compared to untreated animals. In addition sorbent treatment completely normalized the thrombocyte index resulting in elevation of platelet number by 54.5% (p < 0.01) up to their level in intact mice. The morphological examination of liver and biochemical analysis of peripheral blood evidenced on significant positive correcting effect of enterosorption on histological structure of this organ and its functional acti­vity. Normalization of total proteins and serum albumin level as well as significant decrease of total lipid concentration by 29% (p < 0.01) in blood of treated mice were observed. Conclusion: Positive influence of microgranulated carbon sorbent on some hematological, morphological and biochemical indices of tumor associated symptoms in LLC/R9-bearing mice denotes that enterosorption-based therapy can be considered as a prospective treatment for correction of some paraneoplastic syndrome signs in cancer patients. Key Words: paraneoplastic syndrome, Lewis lung carcinoma LLC/R9, enterosorption

ANTICANCER EFFECT AND IMMUNOLOGIC RESPONSE TO XENOGENEIC EMBRYONIC PROTEINS IN MICE BEARING EHRLICH SOLID CARCINOMA

Aim: To investigate anticancer and immunologic effects of chicken embryonic proteins (CEP) in mice bearing Ehrlich solid carcinoma. Materials and Methods: The study was carried out on male Balb/c mice bearing Ehrlich solid carcinoma. The immunizations were performed after the tumor transplantation. The immune status was assessed on days 7, 14, 21 and 28 after the tumor challenge. Cytotoxic activity (CAT) of macrophages (Mph), natural killer cells (NK), cytotoxic T-lymphocytes (CTL) and blood serum, as well as the influence of the blood serum on immune cells activity was checked in MTT-assay; Mph’s cytochemical activity was tested in NBT-assay; Ehrlich antigen-specific or CEP-specific antibodies were detected in ELISA-assay; medium size circulating immune complexes (CIC) were detected in reaction of 4.5% polyethylene glycol precipitation. Results: The immunization resulted in tumor growth suppression and significant 25.64% prolongation of the survival time. In both control and immunized mice with transplanted tumors antibodies specific to Ehrlich carcinoma antigens and to CEP were detected, but antibody response was more balanced in the treatment group. In the treatment group both cytochemical and CAT of Mph was moderately activated and well preserved until late stages of tumor development; CAT of NK and CTL remained in the range of the intact mice until day 28 after the tumor transplantation. The immunized mice were well protected from accumulation of CIC and suppressive activity of autologous blood serum. Conclusion: Collectively, our data indicate that CEP can elicit immunomodulating and immunoprotecting effects sufficient to provide tumor growth inhibition. The further elaboration of a xenogeneic anticancer vaccine based on CEP is warranted

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

CYTOTOXIC ACTIVITY OF IMMUNE CELLS FOLLOWING ADMINISTRATION OF XENOGENEIC CANCER VACCINE IN MICE WITH MELANOMA B-16

Aim: To study the effects of xenogeneic cancer vaccine (XCV) developed on the basis of nervous tissue antigen from rat embryo of late gestation period and protein-containing metabolite of Bacillus subtilis with molecular weight of 70 kDa, on specific and unspecific antitumor reactions of cellular and humoral chains of immune system, and to analyze possible mechanisms of its antimetastatic action. Materials and Methods: XCV was administered triply with 3-day intervals after surgical removal of experimental melanoma В-16 in C57Bl/6 mice. Cytotoxic activity (CTA) of splenocytes against target cells К-562 as well as CTA of splenocytes, peritoneal macrophages (PM) and blood serum against melanoma В-16 target cells were determined using МТТ test. The content of circulating immune complexes (CIC) in blood serum was evaluated by precipitation reaction. Results: Immunologic effects of XCV vaccination in experimental animals with surgically removed melanoma B-16 in comparison with similarly treated unvaccinated mice were as follows: prevention of medium molecular weight CIC accumulation in blood serum during all observation period, significant increase (р < 0.05) of CTA of effectors of unspecific antitumor immunity (natural killer cells — NK — by 25.5 ± 1.7 vs 12.5 ± 5.4%, and PM — by 37.3 ± 0.6 vs 32.0 ± 0.9%, respectively) at 37th day after the surgery, and also preservation of functional activity of specific cytotoxic lymphocytes at the level of intact control. Conclusion: The results of the study allow propose that antimetastatic effect of XCV vaccination could be based on increased CTA of NK and PM, and preservation of CTL functional activity at late terms after surgical removal of B-16 primary tumors. Key Words: xenogeneic cancer vaccine, melanoma В-16, natural killer cells, macrophages, cytotoxic lymphocytes, cytotoxic activity, antimetastatic activity