Hsp70 Promotes SUMO of HIF-1α and Promotes Lung Cancer Invasion and Metastasis

Objective. This study aims to investigate the effect of heat shock protein-70 (Hsp70) on epithelial-mesenchymal transition (EMT) of lung cancer cells under heat stimulation and to explore its possible molecular mechanism. Methods. qRT-PCR and immunohistochemistry assay were used to detect the expression of Hsp70 in lung cancer tissues and adjacent tissues. EdU assay was used to detect the cell activity. The effect of Hsp70 on the migration and invasion of A549 and NCI-H446 cells was detected by the wound-healing assay and Transwell assay. A tumor transplantation animal model was established to detect the effect of overexpression of Hsp70 on proliferation and metastasis of lung cancer cells. Western blot assay was used to detect the effect of thermal stimulation and overexpression of Hsp70 on SUMO modification of HIF-1α. Results. The wound-healing rate of A549 and NCI-H446 cells under Hsp70 stimulation was significantly higher than blank control group. At the same time, the number of cells passing through the membrane increased significantly. Hypodermic tumor transplantation in nude mice proved that knockout Hsp70 can inhibit proliferation and metastasis of lung cancer cells. Thermal stimulation upregulated the expression of Hsp70 and promoted SUMO modification of HIF-1α, ultimately promoting the proliferation and metastasis of lung cancer. Inhibition of Hsp70 reverses the effect of thermal stimulation on lung cancer by reducing the SUMO modification of HIF-1α. Conclusion. Thermal stimulation can promote EMT in A549 and NCI-H446 cells and promote cell migration and invasion in vitro and in vivo by upregulation of Hsp70. This process is associated with the promotion of SUMO modification of HIF-1α.

Evaluation of the antitumor activity of 2-[3-(2-chloroethyl)-3-nitrosoureido]-1,3-propanediol (chlonisol) in C57BL/6 mice with intracranially transplanted B16 melanoma

Background. The arsenal of antitumor drug therapy for melanoma brain metastases is limited. The search and study of new agents capable to penetrate the blood-brain barrier and provide a therapeutic effect against intracranial tumors remains an unmet clinical need. The aim is to evaluate the antitumor activity of the domestic derivative of nitrosoalkylureas, chlonisol, in mice with intracranially transplanted syngeneic B16 melanoma. Methods. The experiment was carried out in 18 female inbred C57BL/6 mice. After intracranial tumor transplantation, performed according to modified technique, the animals were randomized into two groups: I. Control (n = 10) – the animals were injected with normal saline 10 ml/kg intraperitoneally; II. Chlonisol (n = 8) – the animals were treated with the test compound at a dose of 15 mg/kg in normal saline intraperitoneally. The single administration of normal saline and chlonisol was performed 24 hours after tumor transplantation. The end point of the study was overall survival (OS) of the animals. Results. Compared with the control group, administration of chlonisol significantly increased the median OS of mice from 13 to 18 days (log rank test, p = 0.0005). Chlonisol significantly decreased the risk of death by 71 % compared with the control group (HR = 0.29; 95 %CI 0.10–0.82). By the 15th day after intracranial transplantation of B16 melanoma, all 10 mice in the control group died from intracerebral tumors (100 %), whereas in the chlonisol group only 2 out of 8 (25 %) mice died (Fisher's exact test, p = 0.0015). Conclusion. Despite the exploratory nature of the present study, it provides a good starting point for further research of chlonisol in brain tumors.

Application of Ginkgo biloba L. extract at early stage of tumor development helps cyclophosphamide inhibit the growth of tumor cells

Background: There is inconsistency in the application of antioxidants in tumor treatment. This study explored whether the application of an antioxidant at the early stage of tumor transplantation enhances efficacy of a chemotherapeutic agent in inhibiting tumor cell growth. Methods: EMT-6 cells were injected into 48 ICR mice. 24h later, cyclophosphamide (CTX) and Ginkgo biloba L. extract (GBE) were administered to mice separately and in combination. Apoptotic markers and related signaling pathways were measured. Tumor weights were compared and survival analysis was used to investigate latency periods in the three treatment groups compared to a PBS control group. Results: The mice administered GBE and CTX had significantly lower tumor weights compared with those administered PBS (p=0.01), however, the mice administered CTX did not have significantly lower tumor weight compared with those administered PBS (p=0.19). The expression of NF-κB, IκB-ɑ,, and the phosphorylation of NF-κB, IκB-ɑ, were all significantly decreased in the tumors from GBE+CTX (p<0.05). Moreover, the ratio of Bax/Bcl-2 was significantly higher for the tumors of mice administered GBE+CTX than that of mice administered GBE, CTX, or PBS (p<0.05), the expression of FADD, Caspase-8, and Cyto-C was significantly increased in the tumors of mice administered GBE+CTX compared with those administered PBS or GBE (p<0.05). Conclusions: Application of an antioxidant at an early stage of tumor transplantation could help chemotherapeutic agents inhibit the growth of tumor cells. GBE+CTX treated mice showed a longer latency period to tumor development and markers that consistently indicated greater apoptotic activity and reduced tumor promotion.

Application of Ginkgo Biloba L. Extract at Early Stage of Tumor Development Helps Cyclophosphamide Inhibit the Growth of Tumor Cells

Background There is inconsistency in the application of antioxidants in tumor treament, the study is to explore whether the application of an antioxidant at the early stage of tumor transplantation enhances efficacy of a chemotherapeutic agent in inhibiting tumor cell growth.Methods EMT-6 cells were injected into the 48 ICR mice. 24h later, cyclophosphamide (CTX) and Ginkgo biloba L. extract (GBE) were administered to mice separately and in combination. Apoptotic markers and related signaling pathways were measured. Tumor weights were compared and survival analysis was used to investigate latency periods in the three treatment groups compared to a PBS control group. Results The mice administered GBE and CTX had significantly lower tumor weights compared with those administered PBS (p=0.01), however, the mice administered CTX did not have significantly lower tumor weight compared with those administered PBS (p=0.19). The expression of NF-κB, IκB-ɑ, and the phosphorylation of NF-κB and IκB-ɑ were all significantly decreased in the tumor from GBE+CTX (p<0.05). Moreover, the ratio of Bax/Bcl-2 was significantly higher for the tumor of mice administered GBE+CTX than that of mice administered GBE, CTX, or PBS (p<0.05), the expression of FADD, Caspase-8, and Cyto-C was significantly increased in the tumors of mice administered GBE+CTX than those administered PBS or GBE (p<0.05). Conclusions Application of an antioxidant at an early stage of tumor transplantation could help chemotherapeutic agent inhibit the growth of tumor cells. GBE+CTX treated mice showed a longer latency period to tumor development and markers that consistently indicated greater apoptotic activity and reduced tumor promotion.

Biological Features of Tumors Results of Experimental Studies

Tumor anaplasia can be of varying degrees, being especially marked in fast-growing malignant tumors. Blastomatose tissue is characterized by morphological, chemical, physico-chemical and energetic anaplasia. Structural changes of the tissue specific to blastomatose growth often provide the opportunity to differentiate this tissue from a normal or any other growing tissue. Out of various factors that may influence the external environment of tumors, we should mention food, profession, living and working conditions. Tumors and especially malignant tumors are accompanied by changes in the entire body. These are not just a consequence of the blastomatose growth but also play a role in its subsequent development. Experimental tumors are one of the methods of studying the issue of blastomatose growth. The tumor transplantation method is widespread and extensively applied in laboratory practice. It uses standard strains of tumors (rats, mice, etc.). The simplicity of the tumor transplantation method, which consists of the inoculation under the skin of animals of tumor fragments using a trocar or of the injection of a tumor emulsion under aseptic conditions, enables researchers to maintain the purity of the strain for a long time. Various views have been formulated at different times on the origin of tumor growth in accordance with the level of knowledge on this issue.

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.