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Updated: Oct 1, 2026
Laser-capture Microdissection of Human Prostatic Epithelium for RNA Analysis
Published on: November 26, 2015
Differential regulation of the human gene DAB2IP in normal and malignant prostatic epithelia: cloning and
Hong Chen1, Rey-Chen Pong, Zhi Wang
1Department of Urology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9110, USA.
Abstract:
Human DAB2IP (for DAB2 interaction protein) is a novel member of the RasGTPase-activating protein family. It interacts directly with DAB2, which suppresses growth of many cancer types. We demonstrated that DAB2IP is often downregulated in human prostate cancer cell lines. The predicted DAB2IP protein (967 amino acids) shares 94.2% homology with the rat DIP1/2 protein. We mapped the promoter of DAB2IP and studied its regulation in normal and malignant prostate cancer cells. This gene is located at 9q33.1-q33.3 and spans approximately 96 kb with 15 exons and 14 introns. The DAB2IP promoter does not contain any typical TATA box-evidenced by the presence of various RNAs with differential transcription starting sites. We further demonstrated that normal prostatic epithelial cells have elevated DAB2IP mRNA compared with cancer cells, which correlates with increased DAB2IP promoter activity. These data indicate that transcriptional regulation of DAB2IP is responsible for the downregulation of DAB2IP expression in prostate cancer cells.
Insights
Human DAB2IP, a novel Ras GTPase-activating protein, is downregulated in prostate cancer. Its expression is regulated transcriptionally, with lower mRNA and promoter activity observed in cancer cells compared to normal cells.
Area of Science:
- Molecular Biology
- Genetics
- Cancer Research
Background:
- DAB2IP (DAB2 interacting protein) is a novel Ras GTPase-activating protein.
- DAB2IP interacts with DAB2, a known tumor suppressor.
- DAB2IP is frequently downregulated in human prostate cancer cell lines.
Purpose of the Study:
- To investigate the regulation of DAB2IP expression in prostate cancer.
- To map and characterize the promoter region of the human DAB2IP gene.
- To compare DAB2IP expression and promoter activity in normal versus malignant prostate cells.
Main Methods:
- Gene expression analysis (mRNA levels).
- Promoter mapping and activity assays.
- Bioinformatic analysis of gene structure and homology.
Main Results:
- DAB2IP gene located at 9q33.1-q33.3, spanning ~96 kb with 15 exons.
- DAB2IP promoter lacks a TATA box, indicating alternative transcription initiation.
- Normal prostate cells exhibit higher DAB2IP mRNA and promoter activity than cancer cells.
Conclusions:
- Transcriptional regulation is responsible for DAB2IP downregulation in prostate cancer.
- Altered DAB2IP expression may contribute to prostate cancer development.
- DAB2IP represents a potential therapeutic target in prostate cancer.
