Gene Therapy for Prostate Cancer by Controlling Adenovirus E1a and E4 Gene Expression with PSES Enhancer

Abstract

PSES is a chimeric enhancer containing enhancer elements from prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA) genes that are prevalently expressed in androgen-independent prostate cancers. PSES shows strong activity equivalent to cytomegalovirus (CMV) promoter, specifically in PSA/PSMA-positive prostate cancer cells, the major cell types in prostate cancer in the absence of androgen. We developed a recombinant adenovirus (AdE4P-SESE1a) by placing adenoviral E1a and E4 genes under the control of the bidirectional enhancer PSES and enhanced green fluorescent protein gene for the purpose of intratumoral virus tracking under the control of CMV promoter. Because of PSES being very weak in nonprostatic cells, including HEK293 and HER911 that are frequently used to produce recombinant adenovirus, AdE4PSESE1a can only be produced in the HER911E4 cell line which expresses both E1 and E4 genes. AdE4PSESE1a showed similar viral replication and tumor cell killing activities to wild-type adenovirus in PSA/PSMApositive prostate cancer cells. The viral replication and tumor cell killing activities were dramatically attenuated in PSA/ PSMA-negative cells. To test whether AdE4PSESE1a could be used to target prostate tumors in vivo, CWR22rv s.c. tumors were induced in nude mice and treated with AdE4PSESE1a via intratumoral and tail vein injection. Compared to tumors treated with control virus, the growth of CWR22rv tumors was dramatically inhibited by AdE4PSESE1a via tail vein injection or intratumoral injection. These data show that adenoviral replication can be tightly controlled in a novel fashion by controlling adenoviral E1a and E4 genes simultaneously with a single enhancer. (Cancer Res 2005; 65(5): 1941-51)

Prostate Cancer-Specific and Potent Antitumor Effect of a DD3-Controlled Oncolytic Virus Harboring the PTEN Gene

“…PSA is a well-known biomarker of prostate cancer and its promoter has been widely used to study biotherapies for prostate cancer, including gene therapy with different vectors [22], [23], [24], [25]. Different recombinant promoters have been generated based on the Prostate Cancer-specific activity of a promoter or enhancer to increase the Prostate Cancer-specific activity of the promoter controlling the replication of the oncolytic virus [26], [27], [28], [29]. Cell killing efficacy could be improved by many methods, such as combining the oncolytic adenovirus with radiotherapy or chemotherapy.…”

Efficacy of CD46-targeting chimeric Ad5/35 adenoviral gene therapy for colorectal cancers

“…To construct Ad5/35CMV-GFP, pAd1020sfidA-CMV-GFP, which was described previously [43], was digested with the restriction enzyme Sfi I to release CMV-GFP-pA and the ψ packaging signal. The fragment encompassing the CMV-GFP-pA and the ψ packaging signal was recombined with RightZap1.3 (OD260, Boise, ID, USA) in HEK293 cells.…”

Development of replication-competent adenovirus for bladder cancer by controlling adenovirus E1a and E4 gene expression with the survivin promoter

“…Briefly, adenovirus Ad5/35E1apsurvivinE4 was composed of following three cloning segments: 1) a shuttle vector, pAd1020 sfi dA, which harbors a left-end inverted terminal repeat (ITR) and packaging signal (1-358 bp); 2) a modified adenovirus serotype 5 genome backbone vector termed E1bF5/35E4, which contains most of the Ad5 genome from the E1bTATA box to the E4TATA box but with the deletion of E4orf1-4; and 3) a shuttle vector termed p304 sfi that contains the right-end ITR from 35,819 to 35,935 bp of the wild-type Ad5 genome. The left-sided CMV promoter-driven GFP expression cassette that was used to make pAd1020sfidA.CMV.GFP was described in a previous report [40]. pAd1020 Sfi dA.CMV.GFP was then digested with the restriction enzyme Sfi I to remove CMV.GFP and the λ packaging signal.…”