INVESTIGADORES
CASTRO Marisa Silvia
congresos y reuniones científicas
Título:
In vitro characterization of several bacterial strains' properties on human tumor cells
Autor/es:
MOLINA MA; AZPIROZ MB; LOMBARDO T; ÁLVAREZ EMC; CASTRO MS; MANGHI MA
Lugar:
Buenos Aires
Reunión:
Congreso; First French-Argentine Immunology Congress (FAIC 2010); 2010
Institución organizadora:
Soc. Arg. Inmunología; French Society of Immunology
Resumen:
Our laboratory studies the immunomodulatory effects of the probiotic
strain Enterococcus faecalis CECT7121, which shows anti-tumor effects on
several models, either by direct inhibition of tumor cell proliferation as
well as by stimulating the anti-tumor immune response.
The aim of this work was to investigate the in vitro effects of several
E. faecalis strains on 2 tumor cell lines: Raji and PL104. Stimuli employed
included whole cell bacteria, purified cell walls, soluble lysates, and
culture supernatant. Also, on PL104 cells, combinatory assays were performed
with CAPE (anti-tumor drug). The tumor cells? proliferation was determined by
(3)H-thymidine uptake assays, on 48 h cultures.
Our results show that Raji cell proliferation was inhibited in a
dose-dependent manner by both whole cell bacteria and purified cell walls
(ANOVA, ***p<0.001). These observations are shared by the different E.
faecalis strains tested, but not when a Micrococcus luteus strain was
employed as stimulus (different cell wall components). This inhibitory effect
could not be achieved employing culture supernatants, indicating that the
active compounds are not released to the culture media. In these studies, the
strain E. faecalis CECT7121 showed the highest effect, comparing with the
other Enterococcus strains (63%; ANOVA, **p<0.01).
E. faecalis CECT7121, as well as its purified cell wall and soluble
lysate, showed a dose-dependent inhibition on PL104 cell proliferation,
specially when employing bacterial soluble compounds (ANOVA, ***p<0.001).
These components, combined with CAPE, achieved a synergic effect on the
inhibition of PL104 cells, as determined by the construction of an
isobologram.
Our results suggest that several bacterial components have an inhibitory
effect on different hematological tumor cell lines. Further studies should be
performed to identify and isolate the active components involved, and to
characterize its behavior in several combinatory treatments.