Related Experiment Videos
Src activation regulates anoikis in human colon tumor cell lines
T Christopher Windham1, Nila U Parikh, Doris R Siwak
1Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, Texas, TX 77030, USA.
Oncogene
|November 7, 2002
Summary
Src tyrosine kinase activation enhances colon cancer cell survival by preventing anoikis, a form of apoptosis triggered by cell detachment. This pathway involves Akt signaling, suggesting a target for anti-cancer therapies.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- Src is a non-receptor protein tyrosine kinase frequently overexpressed and hyperactivated in human colon cancers.
- Src activity is implicated in the tumorigenicity and survival of colon adenocarcinoma cells.
- Src plays a role in regulating signal transduction pathways crucial for cellular survival.
Purpose of the Study:
- To investigate the role of Src activation in anoikis (detachment-induced apoptosis) in colon tumor cells.
- To determine if Src modulates resistance to anoikis through Akt-mediated survival pathways.
Main Methods:
- Utilized five colon tumor cell lines with varying properties.
- Manipulated Src expression and activity using transfections and a Src-specific inhibitor (PD173955).
- Assessed apoptosis using staurosporine and anoikis assays; measured Akt phosphorylation and utilized a PI3K inhibitor (LY 294002).
Main Results:
- Src expression and activity correlated with resistance to anoikis across different colon tumor cell lines.
- Enforced Src activation increased anoikis resistance, while Src inhibition increased anoikis susceptibility.
- Src modulation affected Akt phosphorylation, indicating a role in Akt-mediated survival pathways.
- Src inhibition sensitized cells to anoikis, but not to staurosporine-induced apoptosis in attached cells.
Conclusions:
- Src activation contributes to colon tumor cell survival by inhibiting anoikis.
- The Src-mediated resistance to anoikis is, in part, dependent on the activation of Akt-mediated survival pathways.
- Targeting Src activity may represent a therapeutic strategy to overcome anoikis resistance in colon cancer progression and metastasis.