EFFECT OF BOTULINUM NEUROTOXINS FROM MENDOZA OF Clostridium botulinum STRAINS ON CYTOSKELETAL PROTEINS OF MAMMARY TUMOR CELLS

CHAPANA A; GUARNIOLO D; CARVELLI L; SOSA MA; RA FERNANDEZ; PATRICIA CABALLERO

Congreso; IV JOINT MEETING OF THE BIOLOGY SOCIETIES OF ARGENTINA; 2020

Sociedad de Biología de Cuyo

The botulinum neurotoxin serotype A (BoNT A) produced by Clostridium botulinum, which causes botulism, is used for the treatment of multipleneurological diseases and its therapeutic action against cancer is currently being evaluated. In previous studies, we have shown that BoNT A fromautochthonous soil strains (Su) have different properties than the reference A Hall strain. Among these, its molecular structure, its enzymatic activityagainst brain SNARE proteins and its greater specific toxic activity (AE) stands out. In cells from human mammary carcinoma (MCF-7) treated withBoNTs for 45 min, we found a marked effect on the expression of cytoskeletal proteins. Therefore, in this work, we delve into the study of the actionof autochthonous BoNTs A and prototype A Hall on the distribution of actin and tubulin in these cells. Native forms of autochthonous BoNT (Sustrains 1935 and 1891, Tupungato) and prototype A Hall were purified by saline precipitation. Their AE values (LD50/mg protein) were established,and their electrophoretic characteristics were evaluated under non-denaturing conditions. 250 LD50 of the BoNTs were incubated to MCF-7 cellcultures for 10 or 25 min. Later, the cells were fixed and processed for indirect immunofluorescence with the use of specific antibodies that recognizetubulin or actin. The samples were visualized by fluorescence microscopy. At the two times evaluated, the three types of BoNTs produced a markedredistribution of the actin cytoskeleton, patch form, on areas coinciding with the plasma membrane. Tubulin was redistributed to multiple areas withhigh signal density at 10 min of incubation only in the presence of BoNT 1891. At 25 min of incubation, the cells treated with BoNTs 1891 and 1935showed this effect, while in those incubated with A Hall, the distribution of these proteins was not modified. The notable alterations in thedistribution of components of the tumor cell cytoskeleton by BoNT from native strains of Mendoza soils open new perspectives for therapy againstsolid tumors.