Genistein-induced changes in gene expression in Panc 1 cells at physiological concentrations of genistein.
OBJECTIVE
To investigate the effect of genistein on gene expression in Panc 1 cells using microarray technology.


METHODS
Panc 1 cells were treated with 10 micromol/L genistein or DMSO (vehicle control) for 0, 1, 3, 6, or 12 hours. Total RNA from each sample was isolated, and biotin-labeled probes were hybridized to the human genome U133A chip, after which the chip was washed and scanned. Data were analyzed using DMT software (Affymetrix). For genes that showed large changes in expression due to genistein, these changes were confirmed using real-time PCR assays.


RESULTS
Two independent microarray experiments showed that genistein significantly changed the expression of 47 genes: up-regulating of egr-1 and IL-8 and down-regulating of EGF-R AKT2, CYP1B1, NELL2, SCD, DNA ligase III, Rad as well as 18s and 28s rRNA and others. These alterations in expression were confirmed using real-time PCR, although the increase in change was not exactly the same in the 2 assays.


CONCLUSIONS
Our data suggest the reported apparent ability of genistein to inhibit carcinogenesis may involve a number of pathways. The most obvious target is the EGF-R signaling pathway since the expression of 5 genes related to this pathway was reduced (EGFR, egr-1, AKT2, CYP1B1, and NELL2). Genistein may also act by disabling cancer cell self-protection by inhibiting expression of AKT2, CYP1B1, and DNA ligase III. Furthermore, genistein may inhibit car-cinogenesis by inhibiting expression of SCD. Finally, our data support findings indicating that genistein inhibits rRNA formation, which is an important mechanism by which genistein regulates tumor cell growth.
Bai
Jianfeng
J
Department of Surgery, Jichi Medical School, Tochigi, Japan.
Sata
Naohiro
N
Nagai
Hideo
H
Wada
Tomoaki
T
Yoshida
Koji
K
Mano
Hiroyuki
H
Sata
Fumihiro
F
Kishi
Reiko
R
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D002471:Cell Transformation, Neoplastic / Q000187:drug effects; D004260:DNA Repair / Q000187:drug effects; D066246:ErbB Receptors / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D019833:Genistein / Q000494:pharmacology*; D006801:Humans; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D012334:RNA, Neoplasm / Q000096:biosynthesis / Q000235:genetics; D012335:RNA, Ribosomal / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects
D009363:Neoplasm Proteins; D012334:RNA, Neoplasm; D012335:RNA, Ribosomal; D019833:Genistein; D066246:ErbB Receptors