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Updated: Jul 11, 2026
An Orthotopic Bladder Cancer Model for Gene Delivery Studies
Published on: December 1, 2013
Midkine promoter-based conditionally replicative adenovirus for targeting midkine-expressing human bladder cancer
Shuji Terao1, Toshiro Shirakawa, Shuji Kubo
1Laboratory of Cell and Gene Therapy Institute for Advanced Medical Sciences, Hyogo College of Medicine, Nishinomiya-shi, Hyogo, Japan.
Objectives:
To develop a novel therapeutic strategy against human bladder cancer using Ad-MK-E1a-a midkine (MK) promoter-regulated, conditionally replicating, adenovirus.
Methods:
We tested several human cancer cell lines in vitro, including those of bladder cancer (KK47, 5637, and T24), lung cancer (A549), and head and neck cancer (H891). In each cell line, we examined MK mRNA expression by TaqMan real-time quantitative polymerase chain reaction, MK promoter activity, after plasmid transfection, using a luciferase assay, and the transduction efficiency by co-transfection with the cytomegalovirus-beta-gal plasmid. In these cells, we assessed the cell type-specific replication of Ad-MK-E1a virus by measuring the E1a DNA copy number by real-time polymerase chain reaction and the cell growth inhibition due to this virus using the Alamar blue assay. In animal studies, nude mice were subcutaneously inoculated with KK47 cells and later intratumorally injected with phosphate-buffered saline or Ad5-CMV-LacZ or Ad-MK-E1a.
Results:
The MK mRNA expression level and MK promoter-driven luciferase activity were relatively greater and markedly increased, respectively, in the 5637, A549, and KK47 cells than in the T24 and H891 cells. After Ad-MK-E1a infection, the E1a DNA copy number increased more significantly in the KK47, 5637, and A549 cells than in the T24 and H891 cells. At a multiplicity of infection of 0.01, Ad-MK-E1a significantly inhibited KK47 and 5637 cell growth. In vivo, Ad-MK-E1a injection markedly inhibited KK47 tumor growth.
Conclusions:
We have demonstrated the antitumor effect of Ad-MK-E1a in a human bladder cancer model overexpressing MK mRNA.
Insights
A novel oncolytic adenovirus, Ad-MK-E1a, shows promise for treating human bladder cancer. This therapy targets midkine (MK) overexpression, effectively inhibiting tumor growth in preclinical models.
Area of Science:
- Oncolytic virotherapy
- Gene therapy
- Cancer research
Background:
- Human bladder cancer remains a significant health concern.
- Targeted therapeutic strategies are crucial for improving treatment outcomes.
- Midkine (MK) is implicated in various cancers, including bladder cancer.
Purpose of the Study:
- To develop and evaluate a novel conditionally replicating adenovirus, Ad-MK-E1a.
- To utilize the midkine (MK) promoter for cell-specific viral replication and oncolysis.
- To assess the therapeutic potential of Ad-MK-E1a against human bladder cancer models.
Main Methods:
- In vitro analysis of MK expression and promoter activity in human cancer cell lines.
- Assessment of Ad-MK-E1a replication and transduction efficiency.
- Evaluation of Ad-MK-E1a-induced cell growth inhibition using cell viability assays.
- In vivo efficacy study of Ad-MK-E1a in a human bladder cancer xenograft mouse model.
Main Results:
- Ad-MK-E1a demonstrated enhanced replication and activity in cancer cell lines with higher MK expression (KK47, 5637, A549).
- Significant inhibition of bladder cancer cell growth (KK47, 5637) was observed in vitro.
- Intratumoral injection of Ad-MK-E1a markedly suppressed tumor growth in a preclinical bladder cancer model.
Conclusions:
- Ad-MK-E1a exhibits potent antitumor effects in human bladder cancer models.
- The MK promoter effectively directs oncolytic adenovirus activity in MK-overexpressing tumors.
- Ad-MK-E1a represents a promising novel therapeutic strategy for bladder cancer.
