PT  - JOURNAL ARTICLE
AU  - SRINATH PALAKURTHI
AU  - JOHN WILSON
AU  - STEVE A. McQUARRIE
AU  - MAVANUR R. SURESH
AU  - JOHN R. MERCER
AU  - GERALD G. MILLER
TI  - Target Specificity of <sup>188</sup>Re-labeled B27.1 Monoclonal Antibodies to Ovarian Cancer Cells <em>In Vivo</em>
DP  - 2008 May 01
TA  - In Vivo
PG  - 321--326
VI  - 22
IP  - 3
4099  - http://iv.iiarjournals.org/content/22/3/321.short
4100  - http://iv.iiarjournals.org/content/22/3/321.full
SO  - In Vivo2008 May 01; 22
AB  - Background: Currently we are exploring a new multistep pretargeting approach involving administration of a bispecific antibody (B27.1 x P54) which has an anti-CA-125 (B27.1) and antibiotin (P54) paratope. It is followed by the administration of radiolabeled biotinylated liposomes to target the 188Re to the ovarian cancer cells. As a preliminary step to realize this goal, we determined the target specificity of the monoclonal antibodies (B27.1) to the ovarian cancer cells in vivo. Materials and Methods: B27.1 monoclonal antibodies were photoreduced using UV light and incubated with reduced 188Re for 30 min at 25°C. 188Re-labeled B27.1 antibodies were purified using size exclusion chromatography. A comparative biodistribution of Re-B27.1 and 188Re was performed in nude mice xenografted with NIH:OVCAR-3 cells. Results: While free rhenium distributed preferentially into thyroid and stomach with insignificant accumulation in the cancer cells, about 20% of the injected dose of 188Re-B27.1 was recovered in ascites cells with insignificant localization in other organs four hours after administration. Conclusion: The study validates the affinity of the B27.1 antibodies to the ovarian cancer cells in vivo.