Abstract
Background & Aims: Lgr5 overexpression has been detected in colorectal cancers (CRCs), including some cases of colitis-associated CRCs. In colitis-associated CRCs, chronic inflammation is a contributing factor in carcinogenesis. We recently reported that intestinal Na+/H+ exchanger isoform 8 (NHE8) plays an important role in intestinal mucosal protection and that loss of NHE8 expression results in an ulcerative colitis–like condition. Therefore, we hypothesized that NHE8 may be involved in the development of intestinal tumors. Methods: We assessed NHE8 expression in human CRCs by immunohistochemistry and studied tumor burden in NHE8 knockout (KO) mice using an azoxymethane/dextran sodium sulfate colon cancer model. We also evaluated cell proliferation in HT29NHE8KO cells and assessed tumor growth in NOD scid gamma (NSG) mice xenografted with HT29NHE8KO cells. To verify if a relationship exists between Lgr5 and NHE8 expression, we analyzed Lgr5 expression in NHE8KO mice by polymerase chain reaction and in situ hybridization. Lgr5 expression and cell proliferation in the absence of NHE8 were confirmed in colonic organoid cultures. The expression of β-catenin and c-Myc also were analyzed to evaluate Wnt/β-catenin activation. Results: NHE8 was undetectable in human CRC tissues. Although only 9% of NHE8 wild-type mice showed tumorigenesis in the azoxymethane/dextran sodium sulfate colon cancer model, almost 10 times more NHE8KO mice (89%) developed tumors. In the absence of NHE8, a higher colony formation unit was discovered in HT29NHE8KO cells. In NSG mice, larger tumors developed at the site where HT29NHE8KO cells were injected compared with HT29NHE8 wild type cells. Furthermore, NHE8 deficiency resulted in increased Lgr5 expression in the colon, in HT29-derived tumors, and in colonoids. The absence of NHE8 also increased Wnt/β-catenin activation. Conclusions: NHE8 might be an intrinsic factor that regulates Wnt/β-catenin in the intestine.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 19-31 |
| Number of pages | 13 |
| Journal | CMGH |
| Volume | 7 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2019 |
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Keywords
- Colorectal Tumor
- Lgr5
- NHE8
ASJC Scopus subject areas
- Hepatology
- Gastroenterology
Cite this
NHE8 Deficiency Promotes Colitis-Associated Cancer in Mice via Expansion of Lgr5-Expressing Cells. / Xu, Hua; Li, Jing; Chen, Hao; Ghishan, Fayez K.
In: CMGH, Vol. 7, No. 1, 01.01.2019, p. 19-31.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - NHE8 Deficiency Promotes Colitis-Associated Cancer in Mice via Expansion of Lgr5-Expressing Cells
AU - Xu, Hua
AU - Li, Jing
AU - Chen, Hao
AU - Ghishan, Fayez K
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Background & Aims: Lgr5 overexpression has been detected in colorectal cancers (CRCs), including some cases of colitis-associated CRCs. In colitis-associated CRCs, chronic inflammation is a contributing factor in carcinogenesis. We recently reported that intestinal Na+/H+ exchanger isoform 8 (NHE8) plays an important role in intestinal mucosal protection and that loss of NHE8 expression results in an ulcerative colitis–like condition. Therefore, we hypothesized that NHE8 may be involved in the development of intestinal tumors. Methods: We assessed NHE8 expression in human CRCs by immunohistochemistry and studied tumor burden in NHE8 knockout (KO) mice using an azoxymethane/dextran sodium sulfate colon cancer model. We also evaluated cell proliferation in HT29NHE8KO cells and assessed tumor growth in NOD scid gamma (NSG) mice xenografted with HT29NHE8KO cells. To verify if a relationship exists between Lgr5 and NHE8 expression, we analyzed Lgr5 expression in NHE8KO mice by polymerase chain reaction and in situ hybridization. Lgr5 expression and cell proliferation in the absence of NHE8 were confirmed in colonic organoid cultures. The expression of β-catenin and c-Myc also were analyzed to evaluate Wnt/β-catenin activation. Results: NHE8 was undetectable in human CRC tissues. Although only 9% of NHE8 wild-type mice showed tumorigenesis in the azoxymethane/dextran sodium sulfate colon cancer model, almost 10 times more NHE8KO mice (89%) developed tumors. In the absence of NHE8, a higher colony formation unit was discovered in HT29NHE8KO cells. In NSG mice, larger tumors developed at the site where HT29NHE8KO cells were injected compared with HT29NHE8 wild type cells. Furthermore, NHE8 deficiency resulted in increased Lgr5 expression in the colon, in HT29-derived tumors, and in colonoids. The absence of NHE8 also increased Wnt/β-catenin activation. Conclusions: NHE8 might be an intrinsic factor that regulates Wnt/β-catenin in the intestine.
AB - Background & Aims: Lgr5 overexpression has been detected in colorectal cancers (CRCs), including some cases of colitis-associated CRCs. In colitis-associated CRCs, chronic inflammation is a contributing factor in carcinogenesis. We recently reported that intestinal Na+/H+ exchanger isoform 8 (NHE8) plays an important role in intestinal mucosal protection and that loss of NHE8 expression results in an ulcerative colitis–like condition. Therefore, we hypothesized that NHE8 may be involved in the development of intestinal tumors. Methods: We assessed NHE8 expression in human CRCs by immunohistochemistry and studied tumor burden in NHE8 knockout (KO) mice using an azoxymethane/dextran sodium sulfate colon cancer model. We also evaluated cell proliferation in HT29NHE8KO cells and assessed tumor growth in NOD scid gamma (NSG) mice xenografted with HT29NHE8KO cells. To verify if a relationship exists between Lgr5 and NHE8 expression, we analyzed Lgr5 expression in NHE8KO mice by polymerase chain reaction and in situ hybridization. Lgr5 expression and cell proliferation in the absence of NHE8 were confirmed in colonic organoid cultures. The expression of β-catenin and c-Myc also were analyzed to evaluate Wnt/β-catenin activation. Results: NHE8 was undetectable in human CRC tissues. Although only 9% of NHE8 wild-type mice showed tumorigenesis in the azoxymethane/dextran sodium sulfate colon cancer model, almost 10 times more NHE8KO mice (89%) developed tumors. In the absence of NHE8, a higher colony formation unit was discovered in HT29NHE8KO cells. In NSG mice, larger tumors developed at the site where HT29NHE8KO cells were injected compared with HT29NHE8 wild type cells. Furthermore, NHE8 deficiency resulted in increased Lgr5 expression in the colon, in HT29-derived tumors, and in colonoids. The absence of NHE8 also increased Wnt/β-catenin activation. Conclusions: NHE8 might be an intrinsic factor that regulates Wnt/β-catenin in the intestine.
KW - Colorectal Tumor
KW - Lgr5
KW - NHE8
UR - http://www.scopus.com/inward/record.url?scp=85056620074&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85056620074&partnerID=8YFLogxK
U2 - 10.1016/j.jcmgh.2018.08.005
DO - 10.1016/j.jcmgh.2018.08.005
M3 - Article
C2 - 30465020
AN - SCOPUS:85056620074
VL - 7
SP - 19
EP - 31
JO - Cellular and Molecular Gastroenterology and Hepatology
JF - Cellular and Molecular Gastroenterology and Hepatology
SN - 2352-345X
IS - 1
ER -