Nonpathogenic Mycobacterium brumae Inhibits Bladder Cancer Growth In Vitro, Ex Vivo, and In Vivo

Mycobacteria-Derived Agents for the Treatment of Urological and Renal Cancers

“…In vitro experiments have demonstrated that M. brumae cells did not persist alive inside both macrophages and BC cells after 72-96 h after infection [76,77]. Besides in vivo experiments in the murine BC model showed that M. brumae do not persist neither in the spleen of mice treated intravesically with M. brumae, contrary to BCG, which is found in splenocytes after finishing the intravesical treatment [76,77].…”

“…Besides in vivo experiments in the murine BC model showed that M. brumae do not persist neither in the spleen of mice treated intravesically with M. brumae, contrary to BCG, which is found in splenocytes after finishing the intravesical treatment [76,77]. Nevertheless further security studies are needed to confirm the safety of this mycobacterium when it is used in its live form.…”

“…In a recent work of our research group [76] brumae triggered the expression of activation markers on macrophages at higher degree than M. phlei or M. vaccae did. Moreover, M. brumae was able to activate human PBMC ex vivo to kill BC cells by both direct contact and using only the soluble factors released by the activated PBMC.…”

“…According to our results [76], Baran and collaborators show that any of the three different strains of M. vaccae they studied was able to inhibit BC proliferation in vitro in a better way than BCG [78]. Regarding M. smegmatis, a recombinant strain expressing human TNF-α was studied.…”

“…Moreover, M. brumae was able to activate human PBMC ex vivo to kill BC cells by both direct contact and using only the soluble factors released by the activated PBMC. M. brumae also was able to activate a murine macrophage cell line [66,76]. Using the murine orthotopic model of BC, a high percentage of live M. brumae-treated mice survived compared to BCG-treated and non-treated tumor-bearing mice, being the differences significant only in comparison to non-treated-bearing mice [76,77].…”