ABSTRACT
@#Breast cancer and cervical cancer are among the leading causes of death among women in the world. Even though chemotherapy is available as cancer treatment, the development of drug resistance in both cancer cells has reduced the efficacy of chemotherapeutic drugs in such treatment. The current study was aimed to evaluate the cell viability of human breast cancer cells, MCF-7, and cervical cancer cells, HeLa upon the combination treatment of ascorbic acid and tamoxifen. The cell viability was measured using the MTT assay, with an incubation period of 72 hours in a humidified CO2 incubator. The concentrations of tamoxifen and ascorbic acid that reduced 50% of the cell population (IC50) were determined from the dose-response curve. The IC50 concentration was used to determine the cell viability in the treated cells. CompuSyn software was used to evaluate the combined effects towards both cells upon treatment and the results were calculated as combination index (CI). The data were analyzed using GraphPad Prism (version 7). Statistical analysis was performed using an independent t-test. The IC50 values of tamoxifen and ascorbic acid on MCF-7 cells were 14.53 µg/ml and 15.8 µg/ml respectively, while the IC50 values of tamoxifen and ascorbic acid on HeLa cells were 11.09 µg/ml and 202.3 µg/ml respectively. The combination of tamoxifen and ascorbic acid exerted a greater growth reduction percentage in both cells compared to tamoxifen alone. The results indicated that ascorbic acid synergizes the cytotoxic effect of tamoxifen at lower concentrations towards MCF-7 cells with a CI less than 1. However, the combination of tamoxifen and ascorbic acid exerted an antagonistic effect in HeLa cells, with a CI more than 1.
ABSTRACT
Objective: To determine the effects of toll-like receptor 2 (TLR-2) agonist, Pam3CSK4, on cellular and humoral immune response against recombinant Mycobacterium bovis bacille Calmette-Guérin (rBCG) expressing the C-terminus of merozoite surface protein-1 of Plasmodium falciparum. Methods: Six groups of mice (n=6 per group) received intraperitoneal phosphate buffered saline T80 (PBS-T80), BCG or rBCG in the presence or absence of Pam3CSK4. Enzyme-linked immunosorbent assay was carried out to measure serum total IgG, IgG1, IgG2a, and IgG2b production. Spleens were also harvested and splenocytes were co-cultured with rBCG antigen for in vitro determination of IL-4 and IFN-γ via enzyme-linked immunosorbent assay. Results: The production of total IgG and the isotype IgG1, IgG2a and IgG2b was significantly higher in rBCG-immunised mice than in the BCG and PBS-T80-immunised mice, and Pam3CSK4 further enhanced their productions. A similar pattern was also observed in IFN-γ production. Moreover, there was no significant difference in IL-4 production in all groups either in the presence or absence of Pam3CSK4. Conclusions: We present evidence of the adjuvant effects of TLR-2 agonist in enhancing the production of total IgG, IgG1, IgG2a, IgG2b, as well as IFN-γ in response to rBCG. However, the presence or absence of Pam3CSK4 had no effect on IL-4 production.
ABSTRACT
Objective: To investigate the role of toll-like receptor 2 (TLR2) in inflammatory activity of macrophage infected with the recombinant Mycobacterium bovis bacillus Calmette-Guerin (rBCG). Methods: Mouse macrophage cell line J774A.1 was infected with Mycobacterium bovis bacillus Calmette-Guerin (BCG) and rBCG cultures for 48 h in the presence or absence of 10 μg/mL of TLR2 inhibitor. Untreated macrophages were used as a negative control while lipopolysaccharide-stimulated macrophages were used as a positive control. The ability of the macrophage to engulf the BCG and rBCG in the absence or presence of TLR2 inhibitor was assessed using a phagocytic assay, while the production of inflammatory cytokines and nitric oxide by the infected macrophages was evaluated using ELISA and Griess reagent method, while the expression of the inducible nitric oxide synthase was determined using Western blot analysis. Results: The results showed that blocking TLR2 function reduced the phagocytic activity, nitric oxide production and proinflammatory cytokine secretion such as TNF- α, IL-1 β and IL-12p40 as well as inducible nitric oxide synthase expression in the infected macrophages. These data showed the importance of TLR2 in the activation of macrophages following BCG and rBCG infections. Conclusions: Through exploring the immunological mechanism which underlies the protection conferred by the candidate vaccine, this study will improve our understanding of the vaccine candidate's mechanism to protect the host from malaria infection.