抄録
Hypoxia in solid tumors is known to confer treatment resistance and lead to rapid progression and poor prognosis. As a novel cancer drug-delivery candidate, Lactobacillus casei KJ686 (L.casei KJ686) is a mutant strain of the facultatively anaerobic L.casei ATCC393 that was transformed into an obligate anaerobe to suit the hypoxic conditions within solid tumors. In the present study, we intravenously administered L.casei KJ686 to treat tumor-bearing mice and investigated the in vitro cytotoxicity of L.casei KJ686 and its culture medium containing bacterial excretion products. We discovered that L.casei KJ686 localized exclusively in tumor tissues and suppressed tumor growth in our animal experiments. Furthermore, the culture supernatant of L.casei KJ686 exhibited a strong cytotoxic effect in vitro. The specific cytotoxic substances presented in its culture supernatant may have a pivotal role in direct anti-tumor effect in solid tumors.
