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Updated: Jul 3, 2026
In vitro Organoid Culture of Primary Mouse Colon Tumors
Published on: May 17, 2013
Src transformation of colonic epithelial cells: enhanced anchorage-independent growth in an Apc(+/min) background
Sabata S Constancio-Lund1, Jan Brabek, Steven K Hanks
1Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN-37232-8240, USA.
Abstract:
Colon cancer arises through a multistep process involving inactivation of tumor suppressor proteins and activation of oncogene-encoded proteins. Development of colon cancer frequently involves mutation of the adenomatous polyposis coli (APC) tumor suppressor. The activity of the proto-oncogene-encoded Src tyrosine kinase is commonly elevated in colon cancer, with higher activity observed as tumors progress and metastasize. Both APC and Src are multifunctional proteins that have been implicated in the control of cell proliferation, but also as regulators of cytoskeletal changes associated with cell motility and invasion. To investigate the potential for biological cooperativity between APC partial loss-of-function and Src gain-of-function, oncogenic Src was stably expressed in mouse colon epithelial cell lines IMCE (APC(+/min)) and YAMC (APC(+/+)). Under permissive growth conditions, these lines are conditionally immortalized through inactivation of p53. Irrespective of the APC genotype or p53 status, oncogenic Src expression led to morphologic transformation associated with loss of cell-cell junctions, cytoskeletal disorganization, and acquisition of invasive properties. However IMCE cells that carry one copy of the mutant APC(min) allele exhibited increased capacity for Src-mediated anchorage-independent proliferation as compared to the YAMC cells, and this property was enhanced under permissive growth conditions. beta-catenin levels and transcriptional activity were also elevated in the Src-transformed IMCE cells. The selective Src inhibitor, AZD0530, was found to be effective in blocking both cell invasion and anchorage-independent proliferation. These findings suggest that the combined effects of elevated Src activity and APC partial loss-of-function may contribute to the growth of colon tumors.
Insights
Colon cancer progression involves tumor suppressor gene mutations and oncogene activation. This study shows that combined loss of adenomatous polyposis coli (APC) function and gain of Src tyrosine kinase activity promotes colon tumor growth and invasion.
Area of Science:
- Oncology
- Molecular Biology
- Cell Biology
Background:
- Colon cancer development involves complex genetic alterations, including tumor suppressor inactivation and oncogene activation.
- Adenomatous polyposis coli (APC) mutations and elevated Src tyrosine kinase activity are frequently observed in colon tumors.
- Both APC and Src play roles in cell proliferation, motility, and invasion.
Purpose of the Study:
- To investigate the cooperative effects of partial APC loss-of-function and Src gain-of-function on colon epithelial cell transformation.
- To determine the impact of combined APC and Src alterations on cell proliferation, invasion, and anchorage-independent growth.
- To evaluate the efficacy of a Src inhibitor in blocking these oncogenic processes.
Main Methods:
- Stable expression of oncogenic Src in mouse colon epithelial cell lines (IMCE and YAMC) with different APC genotypes.
- Conditional immortalization of cell lines via p53 inactivation under permissive growth conditions.
- Assessment of morphologic changes, cell-cell junction integrity, cytoskeletal organization, invasion, anchorage-independent proliferation, and beta-catenin levels.
- Treatment with the selective Src inhibitor AZD0530.
Main Results:
- Oncogenic Src expression induced morphologic transformation, loss of cell-cell junctions, cytoskeletal disorganization, and invasiveness in both APC genotypes.
- IMCE cells (carrying mutant APC) showed enhanced Src-mediated anchorage-independent proliferation compared to YAMC cells, especially under permissive conditions.
- Elevated beta-catenin levels and transcriptional activity were observed in Src-transformed IMCE cells.
- AZD0530 effectively inhibited both cell invasion and anchorage-independent proliferation.
Conclusions:
- Partial loss of APC function cooperates with Src gain-of-function to promote colon tumor cell proliferation and invasion.
- The combined genetic alterations contribute to the aggressive phenotype of colon tumors.
- Targeting Src activity represents a potential therapeutic strategy for colon cancers with these specific molecular alterations.
