Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2007-12-6
pubmed:abstractText
The persistent activation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is oncogenic and involved in colorectal neoplasia. Mutations of both regulatory subunit and catalytic subunit of PI3K have been demonstrated in colon cancers. In the present study, we show that heterozygous disruption of the phosphatase and tensin homolog (PTEN) tumor suppressor gene promoted tumor progression in APC(min/+) mice. Number and size of intestinal tumors were significantly increased in mice bearing both adenomatous polyposis coli (APC) and PTEN mutations. While APC(min/+)PTEN(+/+) mice developed adenomas, invasive carcinomas developed in APC(min/+)PTEN(+/-) mice. Large tumors often resulted in intestinal intussusception and early death of APC(min/+)PTEN(+/-) mice. Targeted array revealed that osteopontin (OPN) was the leading gene whose expression was strongly induced by deficiency of PTEN. In colon cancer cells, gain-of-function mutation of PI3K robustly increased levels of OPN and treatment with OPN reduced growth factor deprivation-induced programmed cell death. Moreover, OPN expression was strongly increased in Ras-induced transformation of intestinal epithelial cells in a PI3K-dependent manner. Inhibition of OPN expression by specific small interfering RNA reduced uncontrolled growth and invasiveness of Ras-transformed intestinal epithelial cells. Thus, our results suggest that the PI3K pathway promotes the transformation of intestinal adenoma to adenocarcinoma. OPN, a downstream effector of PI3K, protects transformed intestinal epithelial cells from programmed cell death and stimulates their anchorage-independent growth.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1460-2180
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2476-83
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:17693663-Adenocarcinoma, pubmed-meshheading:17693663-Adenoma, pubmed-meshheading:17693663-Adenomatous Polyposis Coli, pubmed-meshheading:17693663-Animals, pubmed-meshheading:17693663-Apoptosis, pubmed-meshheading:17693663-Cell Line, Transformed, pubmed-meshheading:17693663-Cell Survival, pubmed-meshheading:17693663-Colonic Neoplasms, pubmed-meshheading:17693663-Crosses, Genetic, pubmed-meshheading:17693663-Genes, ras, pubmed-meshheading:17693663-Heterozygote, pubmed-meshheading:17693663-Intestinal Mucosa, pubmed-meshheading:17693663-Mice, pubmed-meshheading:17693663-Mice, Transgenic, pubmed-meshheading:17693663-Mutation, pubmed-meshheading:17693663-Neoplasm Invasiveness, pubmed-meshheading:17693663-Osteopontin, pubmed-meshheading:17693663-PTEN Phosphohydrolase, pubmed-meshheading:17693663-Phosphatidylinositol 3-Kinases, pubmed-meshheading:17693663-Signal Transduction
pubmed:year
2007
pubmed:articleTitle
Heterozygous disruption of the PTEN promotes intestinal neoplasia in APCmin/+ mouse: roles of osteopontin.
pubmed:affiliation
Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural