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Updated: Aug 26, 2026
Cell-Specific Paired Interrogation of the Mouse Ovarian Epigenome and Transcriptome
Published on: February 24, 2023
Transcriptional targeting in ovarian cancer cells using the human epididymis protein 4 promoter
Nicholas B Berry1, Yong Mee Cho, Maureen A Harrington
1Medical Sciences, Indiana University School of Medicine, Bloomington, IN 47405, USA.
Objective:
Limitations of current ovarian cancer gene therapies include lack of specificity and transduction of normal tissues. One strategy toward overcoming these limitations is to direct gene therapy specifically to ovarian cancer cells by using tissue- and tumor-specific promoters. The whey-acidic protein human epididymis protein 4 (HE4) is frequently overexpressed in ovarian cancer, suggesting that the HE4 promoter is highly transcriptionally active in the disease. The objective of this study was to isolate the HE4 promoter and examine its ability to selectively activate reporter gene expression in an ovarian cancer-specific manner.
Methods:
To investigate transcriptional targeting in ovarian cancer gene therapy, we isolated a region of the HE4 promoter from -530 to +122 (pHE4-652; relative to the ATG start site of HE4) and placed it upstream of a luciferase reporter gene plasmid to generate pHE4-652-luc. The activity of the pHE4-652-luc reporter construct was characterized in transient transfection assays in a panel of epithelial ovarian cancer cell lines (SKOV-3, SKOV-3x, CP70, HeyC2, A2780, A2780CP, OVCAR-3), non-ovarian tumor cell lines, and primary cultures of normal cells. The activity of two other candidate gene therapy promoters, human telomerase reverse transcriptase (hTERT) and OSP1, was also characterized in these cell lines.
Results:
The HE4 promoter was active in 5/7 ovarian cancer cell lines with the range of activity spanning 0.06- to 3-fold that observed for a positive control, cotransfected reporter construct (SV-40-luc). Minimal pHE4-652 promoter activity, defined as < or =5% of the activity detected with the SV-40-luc construct, was observed in the non-ovarian tumor cell lines and normal cells. The hTERT and the OSP1 promoters were active in the ovarian cancer lines. hTERT activity was highest in the CP70 cell line, and OSP1 activity was highest in the SKOV-3x cell line. Modest OSP1 and hTERT promoter activity was observed in normal cell lines and in selected non-ovarian cancer cell lines.
Conclusion:
This is the first report using the pHE4-652 promoter to drive specific reporter gene expression in epithelial ovarian cancer cell lines, and we are continuing to develop this promoter for use in transcriptional targeting in ovarian cancer gene therapy.
Insights
Researchers isolated the human epididymis protein 4 (HE4) promoter to target ovarian cancer gene therapy. This HE4 promoter demonstrated specific activity in ovarian cancer cells, showing promise for improved gene delivery and reduced side effects.
Area of Science:
- Oncology
- Molecular Biology
- Gene Therapy
Background:
- Current ovarian cancer gene therapies suffer from poor specificity and off-target effects on healthy tissues.
- Tissue- and tumor-specific promoters offer a strategy to enhance gene therapy precision.
- Human epididymis protein 4 (HE4) is overexpressed in ovarian cancer, indicating its promoter's potential for targeted gene expression.
Purpose of the Study:
- To isolate and characterize the HE4 promoter for its potential use in ovarian cancer gene therapy.
- To evaluate the HE4 promoter's ability to drive reporter gene expression specifically in ovarian cancer cells.
Main Methods:
- A specific region of the HE4 promoter (pHE4-652) was isolated and cloned upstream of a luciferase reporter gene.
- The activity of the pHE4-652-luc construct was assessed via transient transfection assays in various ovarian cancer cell lines, non-ovarian tumor cell lines, and normal cells.
- The performance of the HE4 promoter was compared with other candidate promoters, hTERT and OSP1.
Main Results:
- The pHE4-652 promoter showed activity in 5 out of 7 ovarian cancer cell lines.
- Minimal promoter activity (<5% of control) was detected in non-ovarian tumor and normal cells, indicating specificity.
- While hTERT and OSP1 promoters were also active in ovarian cancer lines, they exhibited some activity in normal cells.
Conclusions:
- The pHE4-652 promoter is the first reported to drive specific reporter gene expression in epithelial ovarian cancer cell lines.
- This study validates the HE4 promoter as a promising tool for transcriptional targeting in ovarian cancer gene therapy.
- Further development of the pHE4-652 promoter is ongoing for its application in advanced ovarian cancer gene therapy strategies.
