Beclin 1 gene inhibits tumor growth in colon cancer cell lines.
BACKGROUND
The Beclin 1 gene binds to the apoptosis-inhibiting protein Bcl-2. The expression and function of the Beclin 1 gene in four colorectal cancer cell lines (HT29, DLD-1, SW480, SW620) was investigated.


METHODS
The expression of Beclin 1 mRNA was examined by reverse transcription-polymerase chain reaction (RT-PCR), the cell growth rate of a stable cell line established after transfection of the Beclin 1 gene into low Beclin 1-expressing HT29 colon cancer cells. In addition, changes in cell cycle were investigated by flow cytometry, and the expression levels of cell cycle related proteins in the Beclin 1 transfected colon cancer cell line were assessed.


RESULTS
The expression level of Beclin 1 mRNA in the colon cancer cell lines was variable. Transfection of the low Beclin 1 gene-expressing colon cancer cell line with the Beclin 1 gene resulted in cell growth inhibition. The cell cycle analysis showed that the percentage of GJ-phase cells was significantly higher in Beclin 1 transfectants than in mock transfected cells. The expression levels of cyclin E and phosphorylated Rb were decreased.


CONCLUSIONS
These results indicate that Beclin 1 can inhibit the growth of colorectal cancer cells.
Koneri
Kenji
K
Department of Gastroenterological Surgery, Faculty of Medicine, University of Fukui, Yoshida-gun, Fukui 910-1193, Japan.
Goi
Takanori
T
Hirono
Yasuo
Y
Katayama
Kanji
K
Yamaguchi
Akio
A
D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D000071186:Beclin-1; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D003110:Colonic Neoplasms / Q000235:genetics*; D019927:Cyclin E / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D052138:Genes, Neoplasm / Q000502:physiology*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D012333:RNA, Messenger / Q000032:analysis; D016160:Retinoblastoma Protein / Q000235:genetics / Q000378:metabolism; D014162:Transfection
D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D018797:Cell Cycle Proteins; D019927:Cyclin E; D008565:Membrane Proteins; D012333:RNA, Messenger; D016160:Retinoblastoma Protein