Biomedical subjects

Anna Kanerva

Publications and source records attributed to Anna Kanerva.

22 records · Page 2Linked to original sources

PubMed2002

The flt-1 promoter for transcriptional targeting of teratocarcinoma.

Flt-1, a receptor for vascular endothelial growth factor, is known to display dysregulated expression in both tumor vasculature and tumor cells per se, suggesting that the flt-1 promoter might be a useful candidate to achieve tumor-specific transgene expression. In addition, adenoviral vectors containing transgenes under the control of the flt-1 promoter achieve very low levels of expression in the normal liver, the major organ responsible for blood clearance of adenoviruses and inadvertent transgene-related toxicity. Thus, we assessed the ability of adenoviral vectors containing the flt-1 promoter to achieve transgene expression in a range of gynecological and breast tumor lines. High transgene expression levels were detected in teratocarcinoma lines, correlating with levels of flt-1 mRNA. These results suggest that the flt-1 promoter could be useful for transcriptionally targeted gene expression to teratocarcinoma, and that evaluation in other flt-1-positive tumors is warranted.

Animals↗

PubMed2002

Gene transfer to ovarian cancer versus normal tissues with fiber-modified adenoviruses.

Adenovirus serotype 5 (Ad5) displays unparalleled gene transfer efficacy to cells with high coxsackie-adenovirus receptor (CAR) expression. Unfortunately, cells isolated from clinical human cancers, both ovarian and other types, express highly variable and often low levels of CAR. Fortunately, native Ad5 tropism can be modified to circumvent CAR deficiency and to enhance infectivity. Ad5/3luc1 incorporates the serotype 3 fiber knob and binds to a receptor distinct from CAR, while the fiber of Ad5lucRGD is modified with an RGD-4C motif, allowing CAR-independent binding to integrins. We studied the liver tropism and blood clearance of these viruses after intravenous (i.v.) injection, and biodistribution after intraperitoneal (i.p.) injection to tumor-bearing mice. To estimate efficacy, we assessed gene transfer to purified human primary ovarian cancer cells, and in a mouse model of ovarian cancer. Ad5/3luc1 achieved improved gene transfer over Ad5lucRGD, and both infectivity-enhanced viruses were superior to the isogenic control with an unmodified Ad5 capsid. In the presence of malignant ascites, gene transfer was improved with both Ad5/3luc1 and Ad5lucRGD. Thus, retargeting to the Ad3 receptor enhances gene transfer to clinically relevant ovarian cancer substrates, while the mouse toxicity and biodistribution profile of both fiber-modified Ad vectors is comparable to Ad5.

Adenoviridae↗

PubMed2002

Targeting adenovirus to the serotype 3 receptor increases gene transfer efficiency to ovarian cancer cells.

Gene delivery efficiency in clinical cancer gene therapy trials with recombinant adenoviruses (Ads) based on serotype 5 (Ad5) has been limited partly because of variable expression of the primary Ad5 receptor, the coxsackie and adenovirus receptor (CAR), on human primary cancer cells. As a means of circumventing CAR deficiency, Ad vectors have been retargeted by creating chimeric fibers possessing knob domains of alternate Ad serotypes. In this study, we have constructed an Ad5-based vector, Ad5/3luc1, with a chimeric fiber protein featuring a knob domain derived from Ad3. This virus is retargeted to the Ad3 receptor and, therefore, has different tissue tropism. A novel knob binding assay was used to measure expression of CAR and the Ad3 receptor. Further, to evaluate the correlation of receptor expression and infectivity by Ad, a panel of ovarian cancer cell lines and purified primary cancer cells were infected with Ad5luc1 and Ad5/3luc1 at 50, 200, and 1000 viral particles/cell. Our results confirm that Ad5/3luc1 is retargeted to the Ad3 receptor. Furthermore, the Ad3 receptor is present at higher levels than CAR on ovarian adenocarcinoma cells. Also, the amount of binding to primary receptor appears to be the major factor determining the efficiency of transgene expression. The Ad5/3 chimera displays enhanced infectivity for ovarian cancer cell lines and purified primary tumor cells, which could translate into increased efficacy in clinical trials.

Adenocarcinoma↗

PubMedDate not supplied

Enhanced adenovirus infection of melanoma cells by fiber-modification: incorporation of RGD peptide or Ad5/3 chimerism.

The incidence of malignant melanoma has been increasing. Unfortunately, advanced melanomas are rarely curable with standard therapy; therefore, new forms of treatment such as gene therapy are needed. The success of gene delivery or oncolysis depends on the nature of the vector. Adenoviral vectors are advantageous for several reasons; however, they are dependent on CAR (coxsackie and adenovirus receptor) which is deficient or heterogeneously expressed on melanoma cells in situ. Correspondingly, transduction of freshly purified melanoma cells has been shown to be minimal or variable. In order to overcome this shortcoming, it is necessary to construct tropism modified adenoviral vectors. With this goal in mind, we generated two tropism modified vectors, Ad5lucRGD which has an RGD motif incorporated into the HI loop of the fiber knob and Ad5/3luc1 which contains the tail and shaft domain of the Ad5 fiber and the knob domain of the Ad3 fiber. Herein we demonstrate that Ad5/3luc1 infects CAR-negative primary melanoma cells 1128 times better than Ad5luc1 and 34 times better than Ad5lucRGD. Furthermore we show that Ad5/3luc1 and Ad5lucRGD infect via a CAR independent route by blocking the CAR receptor. In addition, we show that the infectivity of the cells correlates with the expression of CAR and Ad3 receptors determined by FACS analysis. Therefore, Ad5/3 is very attractive as a potential therapeutic vector for malignant melanoma.

Adenoviruses, Human↗