The objective of our study was to construct recombinant adenovirus (rAd) AdHTVP2G5-rev-casp3, which expresses autocatalytic
caspase-3 driven by human
telomerase reverse transcriptase promoter (hTERTp) with a two-step transcription amplification (
TSTA) system and investigate its antitumor effects on
ovarian cancer in vitro and in vivo. Fluorescent detection was used to detect EGFP expression in various cells. Cell viabilities were determined using the Cell Counting Kit-8 and flow cytometry. RT-PCR and immunoblotting assays were used to detect cellular apoptotic activities.
Tumor growth and survival of
tumor-bearing mice were studied. The hTERTp-
TSTA system showed the strongest activity in hTERT-positive
cancer cells when compared with hTERTp and cytomeglovirus promoter (CMVp). In contrast, it showed no activity in hTERT‑negative HUVECs. AdHTVP2G5‑rev-casp3 markedly suppressed the survival of AO cells in a dose-dependent modality with a viability rate of 17.8 ± 3.5% at an MOI of 70, which was significantly lower than that by AdHT-rev-casp3 and Ad-rev-casp3 (rAds which express rev-
caspase-3 driven by hTERTp and CMVp, respectively). In contrast, AdHTVP2G5‑rev-casp3 induced little HUVEC death with a viability rate of 92.7 ± 5.2% at the same MOI. Additionally, AdHTVP2G5-rev-casp3 (MOI=70) caused significant apoptosis in AO cells with an apoptotic rate of 42%. The
tumor growth suppression rate of AdHTVP2G5-rev-casp3 was 81.52%, significantly higher than that of AdHT-rev-casp3 (54.94%) or Ad-rev-casp3 (21.35%). AdHTVP2G5-rev-casp3 significantly improved the survival of
tumor-bearing mice with little liver damage, with a mean survival of 258 ± 28 days. These results showed that AdHTVP2G5-rev-casp3 caused effective apoptosis with significant
tumor selectivity, strongly suppressed
tumor growth and improved mouse survival with little liver toxicity. It can be a potent therapeutic agent for
tumor targeted treatment of
ovarian cancer.