FOXQ1 is overexpressed in colorectal cancer and enhances tumorigenicity and tumor growth.
Forkhead box Q1 (FOXQ1) is a member of the forkhead transcription factor family, and it has recently been proposed to participate in gastric acid secretion and mucin gene expression in mice. However, the role of FOXQ1 in humans and especially in cancer cells remains unknown. We found that FOXQ1 mRNA is overexpressed in clinical specimens of colorectal cancer (CRC; 28-fold/colonic mucosa). A microarray analysis revealed that the knockdown of FOXQ1 using small interfering RNA resulted in a decrease in p21(CIP1/WAF1) expression, and a reporter assay and a chromatin immunoprecipitation assay showed that p21 was one of the target genes of FOXQ1. Stable FOXQ1-overexpressing cells (H1299/FOXQ1) exhibited elevated levels of p21 expression and inhibition of apoptosis induced by doxorubicin or camptothecin. Although cellular proliferation was decreased in H1299/FOXQ1 cells in vitro, H1299/FOXQ1 cells significantly increased tumorigenicity [enhanced green fluorescent protein (EGFP): 2/15, FOXQ1: 7/15] and enhanced tumor growth (437 +/- 301 versus 1735 +/- 769 mm3, P < 0.001) in vivo. Meanwhile, stable p21 knockdown of H1299/FOXQ1 cells increased tumor growth, suggesting that FOXQ1 promotes tumor growth independent of p21. Microarray analysis of H1299/EGFP and H1299/FOXQ1 revealed that FOXQ1 overexpression upregulated several genes that have positive roles for tumor growth, including VEGFA, WNT3A, RSPO2, and BCL11A. CD31 and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining of the tumor specimens showed that FOXQ1 overexpression mediated the angiogenic and antiapoptotic effect in vivo. In conclusion, FOXQ1 is overexpressed in CRC and enhances tumorigenicity and tumor growth presumably through its angiogenic and antiapoptotic effects. Our findings show that FOXQ1 is a new member of the cancer-related FOX family.
Kaneda
Hiroyasu
H
Department of Genome Biology, Kinki University School of Medicine, Osaka-Sayama, Osaka, Japan.
Arao
Tokuzo
T
Tanaka
Kaoru
K
Tamura
Daisuke
D
Aomatsu
Keiichi
K
Kudo
Kanae
K
Sakai
Kazuko
K
De Velasco
Marco A
MA
Matsumoto
Kazuko
K
Fujita
Yoshihiko
Y
Yamada
Yasuhide
Y
Tsurutani
Junji
J
Okamoto
Isamu
I
Nakagawa
Kazuhiko
K
Nishio
Kazuto
K
D000818:Animals; D017209:Apoptosis / Q000235:genetics; D048708:Cell Growth Processes / Q000502:physiology; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000098:blood supply / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D051858:Forkhead Transcription Factors / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D015533:Transcriptional Activation; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C484579:FOXQ1 protein, human; D051858:Forkhead Transcription Factors; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53