Lenalidomide augments the efficacy of bacillus Calmette-Guerin (BCG) immunotherapy in vivo

Abstract

Objective Intravesical bacillus Calmette-Guerin (BCG) is the gold standard for high-grade non-muscle-invasive bladder cancer (NMIBC); however, some patients do not respond to initial therapy while others relapse and/or progress. Therefore, combination strategies that can enhance the efficacy and sustainability of BCG are needed. Herein, we explore the efficacy of lenalidomide, a thalidomide derivative with immunomodulatory effects, in combination with BCG, both in vitro and in vivo. Materials and methods We explored the outcomes of lenalidomide in combination with BCG in vivo using the MBT-2 cell line implanted in C3H immunocompetent mice. Apoptosis, cell proliferation, and microvessel density were measured by immunohistochemistry. In vitro, we performed Western blotting for cell cycle and apoptosis regulatory proteins and a chromatin condensation assay to evaluate TNF-α and FasL in combination with lenalidomide. Results In the mouse model, combination therapy with BCG and lenalidomide resulted in a statistically significant decrease in tumor size compared with the control group. IHC demonstrated a nonsignificant increase in apoptosis in the combination condition and no effect on cellular proliferation. Microvessel density was decreased in all treated conditions. In vitro, caspase-3 activation and chromatin condensation studies demonstrated increased cell death in the combinations of lenalidomide and TNF-α. Conclusions The immunomodulatory molecule lenalidomide augments the response to BCG in an in vivo mouse model. This provides the rationale for studying the combination in patients with high grade NMIBC.

Surface PD-L1, E-cadherin, CD24, and VEGFR2 as markers of epithelial cancer stem cells associated with rapid tumorigenesis

“…For tumorigenicity assays, 200,000 cells in 100 μl of HBSS with or without matrigel (1:1) were injected subcutaneously in the flanks of male, athymic nude mice (NCr-nu/nu: NCI) (n = 5/group; was able to give statistically significant differences). Tumor formation dates were recorded; tumor growth was measured and tumor volume was calculated as described previously 42 ; and overall survival was noted. See the statistical analysis section for more details.…”

Current clinical trials in non–muscle invasive bladder cancer

“…[41] It has been shown to enhance the response to BCG in a murine model of bladder cancer. [41] The ongoing phase II trial is evaluating the efficacy of oral Lenalidomide with BCG instillation in BCG failure NMIBC patients by assessing the 1-year progression-free survival.…”

Novel PKC-ζ to p47phox interaction is necessary for transformation from blebbishields

“…Approximately 80% of patients with bladder cancer have non-muscle invasive bladder cancer at the time of diagnosis 2 . Non-muscle invasive bladder cancer is treated primarily with BCG immunotherapy 3 , which works predominantly by recruiting neutrophils into the bladder 1 . Neutrophils in turn secrete cytotoxic cytokines such as TNF-α upon BCG stimulation 4 5 .…”