Transcriptional targeting of tumors with a novel tumor-specific survivin promoter

Abstract

It has been demonstrated that survivin, a novel member of the inhibitor of apoptosis (IAP) protein family, is expressed in human cancers but is undetectable in normal differentiated tissues. We employed a recombinant adenoviral vector (reAdGL3BSurvivin) in which a tumor-specific survivin promoter and a luciferase reporter gene were inserted into the E1-deleted region of adenovirus vector. Luciferase activity was measured in both multiple tumor cell lines and two primary melanoma cells infected with reAdGL3BSurvivin. Human fibroblast and mammary epithelial cell lines were used as negative controls. A reAdGL3CMV, containing the CMV promoter and luciferase gene, was used as a positive control to normalize the luciferase activity generated by the survivin promoter. Our data revealed that the survivin promoter showed high activity in both established tumor cell lines and the primary melanoma cells. In contrast, the in vivo studies indicated that the activities of survivin promoter were extremely low in the major mouse organs. The survivin promoter appears to be a promising tumor-specific promoter exhibiting a ''tumor on'' and ''liver off'' profile, and therefore, it may prove to be a good candidate for transcriptional targeting of cancer gene therapy in a wide variety of tumors.

Oncolytic adenoviral vectors which employ the survivin promoter induce glioma oncolysis via a process of beclin-dependent autophagy

“…To date, however, few glioma-relevant promoter elements have been suggested and well characterized for employment in CRAds. We have previously shown that the survivin promoter is upregulated in brain tumors (2,3) and that the human survivin promoter represents a novel transcriptional targeting strategy in malignant glioma (1). Consequently, in the present investigation, we utilized the survivin promoter to drive the expression of an oncolytic adenovirus and analyzed the mechanism of viral induced cell killing in the setting of malignant glioma.…”

“…Our group has shown that the survivin promoter appears to be a promising tumor-specific promoter in in vivo gene therapy of human melanoma, breast cancer, cholangiocarcinoma, and malignant glioma (1)(2)(3)(4). We have also shown the selectivity of survivin-modified adenovectors for malignant glial cells rather than normal human astrocytes (5).…”

The carcinoma-specific epithelial glycoprotein-2 promoter controls efficient and selective gene expression in an adenoviral context

“…In EGP-2-positive colon carcinoma cell lines as well as in an ovarian cancer cell line, the promoter showed efficient transcriptional activity to levels comparable with other tumor type specific promoters. 27,28,31 The 3.4 kb EGP-2 promoter fragment also maintained outstanding selectivity in EGP-2-negative cell lines, with an expression profile comparable with or even more specific than other evaluated tsp. 27,29,32,31 These results demonstrate that the 3.4 kb EGP-2 promoter remained active and specific in an adenoviral context.…”

“…27,28,31 The 3.4 kb EGP-2 promoter fragment also maintained outstanding selectivity in EGP-2-negative cell lines, with an expression profile comparable with or even more specific than other evaluated tsp. 27,29,32,31 These results demonstrate that the 3.4 kb EGP-2 promoter remained active and specific in an adenoviral context. The specificity of 3.4 kb EGP-2 promoter fragment was subsequently determined in vivo.…”

“…In EGP-2-negative cell lines, the activity of the truncated EGP-2 promoter in both forward and reverse orientation in the adenoviral genome was up to 3-log less when compared with CMV activity, which is similar or even superior to other evaluated tsp. 27,29,32,31 It is still largely unclear why some tsp do not lose their tumor specificity in an adenoviral context, while others do. A deletion analysis of the EGP-2 promoter showed that epithelial specificity is maintained within 687 bp of the 5 0 flanking region.…”