A Novel Hybrid Promoter ARE-hTERT for Cancer Gene Therapy

Abstract

describe a novel hybrid tumor-specific promoter, ARE-hTERT, composed of the human TERT gene promoter (hTERT) and the antioxidant response element (ARE) from the human GCLM gene promoter. The hybrid promoter retains the tumor specificity of the basal hTERT promoter but is characterized by an enhanced transcriptional activity in cancer cells with abnormal activation of the Nrf2 transcription factor and upon induction of oxidative stress. In the in vitro enzyme-prodrug cancer gene therapy scheme, ARE-hTERT promoter-driven expression of CD : UPRT (yeast cytosine deaminase : uracil phosphoribosyltransferase) chimeric protein induced a more pronounced death of cancer cells either upon treatment with 5-fluorouracil (5FC) alone or when 5FC was combined with chemotherapeutic drugs as compared to the hTERT promoter. The developed hybrid promoter can be considered a better alternative to the hTERT promoter in cancer gene therapy schemes.

Redirecting anti-Vaccinia virus T cell immunity for cancer treatment by AAV-mediated delivery of the VV B8R gene

“…In order to express the B8R protein only in tumor cells, we synthesized a new telomerase-based, tumor-cell-specific promoter, termed ATM, based on literature regarding sequence alterations that enhance promoter activity. 22 , 23 The ATM promoter was composed of an antioxidant response element (ARE), a human telomerase reverse transcriptase (hTERT) promoter with C to T mutation at nucleotide −124 site and a c-Myc binding sequence ( Figure 3 B). We constructed a rAAV vector containing the ATM promoter ( Figure 3 C) and compared its expression intensity with the broad-spectrum CB (chicken β-actin promoter plus cytomegalovirus enhancer) promoter in immortalized 293T cells, the human esophageal squamous carcinoma cell line SBRC-EC01, and the mouse melanoma cell line B16 through plasmid transfection.…”

“…19 , 20 Many factors were reported that can influence the activity of TERT promoter, such as a c-Myc binding site, 21 point mutation in TERT promoter, 22 and presence of an antioxidative response element (ARE). 23 We combined all these features to create a potent promoter that is tumor-cell-specific (termed the ATM promoter). We constructed a rAAV with the ATM promoter to express the VV B8R gene specifically in tumor cells and activate VV-specific memory T cells to antagonize cancer growth and eliminate tumors.…”