Critical role and regulation of transcription factor FoxM1 in human gastric cancer angiogenesis and progression.
The mammalian forkhead box (Fox) transcription factor FoxM1b is implicated in tumorigenesis. However, the presence of expression and role of FoxM1b in gastric cancer remain unknown. Therefore, we investigated FoxM1b expression in 86 cases of primary gastric cancer and 57 normal gastric tissue specimens. We further investigated the underlying mechanisms of altered FoxM1b expression in and the effect of this altered expression on gastric cancer growth and metastasis using in vitro and animal models of gastric cancer. We found weak expression of FoxM1b protein in the mucous neck region of gastric mucosa, whereas we observed strong staining for FoxM1b in tumor cell nuclei in various gastric tumors and lymph node metastases. A Cox proportional hazards model revealed that FoxM1b expression was an independent prognostic factor in multivariate analysis (P < 0.001). Experimentally, overexpression of FoxM1b by gene transfer significantly promoted the growth and metastasis of gastric cancer cells in orthotopic mouse models, whereas knockdown of FoxM1b expression by small interfering RNA did the opposite. Promotion of gastric tumorigenesis by FoxM1b directly and significantly correlated with transactivation of vascular endothelial growth factor expression and elevation of angiogenesis. Given the importance of FoxM1b to regulation of the expression of genes key to cancer biology overall, dysregulated expression and activation of FoxM1b may play important roles in gastric cancer development and progression.
Li
Qiang
Q
Department of Gastrointestinal Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
Zhang
Nu
N
Jia
Zhiliang
Z
Le
Xiangdong
X
Dai
Bingbing
B
Wei
Daoyan
D
Huang
Suyun
S
Tan
Dongfeng
D
Xie
Keping
K
D000818:Animals; D048708:Cell Growth Processes / Q000502:physiology; D018450:Disease Progression; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009362:Neoplasm Metastasis; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D013274:Stomach Neoplasms / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015533:Transcriptional Activation; D014162:Transfection; D014183:Transplantation, Heterologous; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
C107585:FOXM1 protein, human; D000072278:Forkhead Box Protein M1; D051858:Forkhead Transcription Factors; D034741:RNA, Small Interfering; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A