Engineering conditionally replication-competent adenoviral vectors carrying the cytosine deaminase gene increases the infectivity and therapeutic effect for breast cancer gene therapy.
We constructed a conditionally replication-competent adenoviral vector Ad.Lp-CD-IRES-E1A(control) in which the expression of both the prodrug-activating cytosine deaminase gene and the viral replication E1A gene were driven by the L-plastin tumor-specific promoter. In order to overcome the low infectivity of the adenoviral vectors for breast cancer cells, and to increase the safety and efficacy for cancer gene therapy, this vector was further modified on a transductional level by simultaneously ablating the native tropism of the vector to the primary CAR receptor and inserting a RGD-4C peptide into the HI loop of the fiber, which allows the vector to use the alphavbeta3 and alphavbeta5 receptors as alternative receptors. The resulting vector was named Ad.Lp-CD-IRES-E1A(MRGD). The transduction efficiency of the vector for breast cancer cell lines which have low expression level of CAR was increased both in vitro and in vivo. The Ad.Lp-CD-IRES-E1A(MRGD) vector produces a higher vector particle yield and a greater cytotoxic effect in tumor cells which have a low expression level of CAR, than did the Ad.Lp-CD-IRES-E1A(control) vector. Intratumoral injection of the Ad.Lp-CD-IRES-E1A(MRGD) vector following the intraperitoneal injection of 5FC into xenotransplanted human breast cancer cell lines which have low expression level of CAR led to greater degree of tumor regression in vivo than did the intratumoral injection of control adenoviral vectors not so modified.
Liu
Y
Y
Sidney Kimmel Cancer Center, San Diego, CA 92121, USA.
Ye
T
T
Maynard
J
J
Akbulut
H
H
Deisseroth
A
A
D000256:Adenoviridae / Q000502:physiology*; D017500:Adenovirus E1A Proteins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000378:metabolism / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D043525:Cytosine Deaminase / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005437:Flucytosine / Q000378:metabolism / Q000494:pharmacology; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D039302:Integrin alphaVbeta3 / Q000378:metabolism; D016023:Integrins / Q000378:metabolism; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D019030:Receptors, Vitronectin / Q000378:metabolism; D014161:Transduction, Genetic
D017500:Adenovirus E1A Proteins; D000964:Antimetabolites, Antineoplastic; D039302:Integrin alphaVbeta3; D016023:Integrins; D008562:Membrane Glycoproteins; D008840:Microfilament Proteins; D009842:Oligopeptides; D010750:Phosphoproteins; D019030:Receptors, Vitronectin; C064660:integrin alphaVbeta5; C026742:plastin; C047981:arginyl-glycyl-aspartic acid; D005437:Flucytosine; D043525:Cytosine Deaminase