Effect of Different Bacillus Calmette-Guerin Substrains on Growth Inhibition of T24 Bladder Cancer Cells and Cytokines Secretion by BCG Activated Peripheral Blood Mononuclear Cells of PBMCs

Abstract

Background. Bladder carcinoma is the most common malignancy of the urinary tract. Approximately 75-85% of patients present non-muscle invasive bladder cancer (NMIBC). Standard primary treatment for NIMBC is transurethral resection (TUR) followed by intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. BCG has been accepted as the most effective agent in clinical use against NMIBC. Various BCG substrains are used worldwide for bladder cancer immunotherapy although the impact of used BCG substrain on BCG antitumor capacity is a little investigated. Objectives. The aim of this study was to compare the antitumor capacity and the ability to trigger cytokines production of three BCG substrains by stimulation of the local innate immunity in vitro. Material and Methods. The human bladder cancer cell line T24 was co-cultured with each of the BCG substrains: Moreau, Tice and RIVM alone or with BCG pretreated DCs (dendric cells) and allogenic PBMCs derived from the same donor. The inhibition of T24 cell growth was evaluated by 3 H-thymidine incorporation. Production of Th1 cytokines (IFN-γ, TNF-α, IL-12) and Th2 cytokines (IL-10, IL-4) was measured in cultures of BCG-activated PBMCs by ELISA test.Results. An approximately two-fold inhibition of T24 cell proliferation was observed as a direct cytotoxic effect of tested BCG substrains on T24 cells. However, BCG inhibited the growth of tumor cells mainly by activating the effector cells of innate immunity. About a 10-fold inhibition of T24 cell proliferation was observed when T24 cells were co-cultured with allogenic BCG pretreated DC s and PBMCs derived from the same donor. The PBMCs activated by compared live BCG substrains secreted large amounts of TNF-α and IFN-γ cytokines. Conclusions. Tested BCG substrains had little direct inhibitory effect on T24 cell proliferation. Moreau evolutionarily early BCG substrain showed similar strong, indirect antitumor effects as evolutionarily late BCG substrains Tice and RIVM (Adv Clin Exp Med 2014, 23, 6, 877-884).

Early vaccination protects against childhood leukemia: A systematic review and meta-analysis

“…The mechanism in which BCG vaccine ameliorates effectively cancer was not well-explored. Several studies investigated the alteration of different types of cytokines by BCG vaccine 59 – 62 , such as Th1’s cytokines (IFN-γ, TNF-α, IL-12) and Th2’s cytokines (IL-10, IL-4). These substances play roles in regulation of natural killer cells, macrophages or cytotoxic T lymphocytes cells 61 , which have antitumor effects.…”

High baseline levels of interleukin-8 in leukocytes and urine predict tumor recurrence in non-muscle invasive bladder cancer patients receiving bacillus Calmette–Guerin therapy: A long-term survival analysis

“…Abbreviations: PBL, peripheral blood leukocyte; BCG, bacillus Calmette-Guerin; MST, median recurrence-free survival time. secreted from activated PBLs, 30 could also predict BCG therapy effectiveness. We therefore conducted the analysis in 112 urine samples from NMIBC patients receiving BCG therapy.…”

Non-Muscular Invasive Bladder Cancer: Re-envisioning Therapeutic Journey from Traditional to Regenerative Interventions

“…While in-vitro testing, the BCG sub-strains i.e. Moreau, Tice and RIVM, have also shown inhibitory effect on human bladder cancer cell line, T24, which has been attributed to presence of cytotoxic mycolic acids on cell surface of these strains [83]. Moreover, presence of Th1 cytokines such as TNF-α and IFN-γ enhance tumor cell proliferation by inhibiting activity of BCG strains.…”

“…In a systemic meta-analysis, it was concluded that compared to BCG alone, the synergistic effect of intravesical BCG and chemotherapy improved recurrence free survival, overall survival and disease specific survival with significantly decreased rate of fever, irritative symptoms and hematuria therapy among NMIBC patients [93]. Nonetheless, the therapeutic efficacy of BCG is undermined owing to its associated local and systemic side effects such as dysuria, haematuria, cystitis, sepsis, malaise and fever [83,90]. Moreover, in case of observed severe side effect such as sepsis, the BCG therapy is withdrawn and followed by tuberculosis treatment [94].…”