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Published on: July 28, 2010
Loss of HLTF function promotes intestinal carcinogenesis
Sumit Sandhu1, Xiaoli Wu, Zinnatun Nabi
1Department of Biochemistry and Medical Genetics, University of Manitoba, 745 Bannatyne Avenue, Winnipeg MB R3E 0J9, Canada.
Molecular Cancer
|March 29, 2012
Summary
Loss of Helicase-like Transcription Factor (HLTF) function alone does not cause colon cancer. However, HLTF deficiency significantly increases intestinal tumor formation and malignancy by inducing genomic instability.
Area of Science:
- Genetics
- Molecular Biology
- Cancer Research
Background:
- Helicase-like Transcription Factor (HLTF) is a DNA helicase crucial for genomic stability and gene regulation.
- HLTF inactivation via promoter hypermethylation is common in human colon cancers.
- The role of HLTF epigenetic silencing in intestinal carcinogenesis remains unclear.
Purpose of the Study:
- To investigate the role of HLTF loss of function in intestinal cancer development.
- To determine if HLTF deficiency contributes to colon tumor progression and malignancy.
Main Methods:
- Generation of Hltf-deficient mice to study its role in intestinal carcinogenesis.
- Analysis of tumor formation and development in Hltf mutant mice, including on an Apcmin/+ background.
- Cytogenetic analysis of tumor cells to assess chromosomal stability.
- In vitro studies using HCT116 human colon cancer cells with reduced HLTF expression.
Main Results:
- Hltf-deficient mice did not develop intestinal tumors independently, indicating loss of HLTF is insufficient for cancer initiation.
- On an Apcmin/+ background, Hltf deficiency significantly increased intestinal adenocarcinoma and colon cancer formation.
- Colon tumor cells from Hltf-/-/Apcmin/+ mice exhibited high rates of chromosomal instability (e.g., aneuploidy, Robertsonian fusions).
- Reduced HLTF expression in HCT116 cells led to increased tumor growth and genomic instability.
Conclusions:
- Loss of HLTF function promotes the malignant transformation of intestinal adenomas to carcinomas by inducing genomic instability.
- Epigenetic inactivation of HLTF, observed in human colon cancers, likely plays a significant role in colon tumor progression to malignancy.
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