Cytotoxicity and apoptosis induction of Bacillus vallismortis BIT-33 metabolites on colon cancer carcinoma cells.
OBJECTIVE
The objective of this research was to isolate and identify a cytotoxic marine bacterium, BIT-33, and to investigate the apoptosis effects of its metabolite on colon cancer cells.


RESULTS
We isolated 93 marine bacteria from seawater samples. Of these, strain BIT-33 exhibited the strongest cytotoxic activity on three colon cancer cells (HT-29, SW480 and HCT116). Biochemical tests and 16S rDNA sequencing of this strain allowed us to identify BIT-33 as a strain of Bacillus vallismortis. The cytotoxic compound from B. vallismortis BIT-33 was purified by reverse-phase high-performance liquid chromatography. Direct cytotoxic effect of the compound was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazoliumbromide assay. The compound induced apoptosis of colon cancer cells, as indicated by DNA fragmentation of agarose gel electrophoresis, flow cytometric analysis (sub-G(1) method) and annexin V staining.


CONCLUSIONS
The cytotoxic compound from B. vallismortis BIT-33 was purified, and the compound showed direct cytotoxic and apoptotic effects on colon cancer cells in a dose- and time-dependent manner.


CONCLUSIONS
Taken together, our results suggest that the compound from B. vallismortis BIT-33 could be a candidate for the development of apoptosis-specific anti-tumour agents. This study indicated that marine bacteria could be an important source of cytotoxic metabolites.
Jeong
S-Y
SY
Korea Bio-IT Foundry Center, Pusan National University, Busan, Republic of Korea.
Park
S-Y
SY
Kim
Y-H
YH
Kim
M
M
Lee
S-J
SJ
D017209:Apoptosis / Q000187:drug effects; D001407:Bacillus / Q000737:chemistry*; D045744:Cell Line, Tumor; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D003603:Cytotoxins / Q000302:isolation & purification* / Q000627:therapeutic use; D053938:DNA Fragmentation; D004305:Dose-Response Relationship, Drug; D004587:Electrophoresis, Agar Gel; D005434:Flow Cytometry; D006801:Humans; D012623:Seawater; D013194:Staining and Labeling; D013997:Time Factors
D003603:Cytotoxins