PT  - JOURNAL ARTICLE
AU  - Iyer, Arun
AU  - Lan, Xiaoli
AU  - Feng, Jinjin
AU  - Zhu, Xiaodong
AU  - Su, Yang
AU  - Liu, Yue
AU  - VanBrocklin, Henry
AU  - Liu, Bin
AU  - He, Jiang
TI  - <sup>111</sup>In-labeled immunoliposomes targeting both epithelioid and sarcomatoid mesothelioma
DP  - 2010 May 01
TA  - Journal of Nuclear Medicine
PG  - 396--396
VI  - 51
IP  - supplement 2
4099  - http://jnm.snmjournals.org/content/51/supplement_2/396.short
4100  - http://jnm.snmjournals.org/content/51/supplement_2/396.full
SO  - J Nucl Med2010 May 01; 51
AB  - 396 Objectives The objectives of the study was to evaluate the in vitro and in vivo tumor targeting of novel human ScFv (M1) anchored immunoliposmes (ILs) on both epithelioid(M-28) and sarcomatoid (VAMT-1) mesothelioma. Methods Immunoliposomes (ILs) were prepared by a thin-film extrusion method followed by insertion of M1 & radiolabeled with 111In via DTPA conjugated to the liposome (111In-IL). For in vitro cell studies, 111In-IL was incubated at 37oC for 24h with M-28, VAMT-1 & a control cell-line (BPH). For animal studies, the 111In-IL or control liposome was injected i.v. to athymic mice bearing M-28 & VAMT-1 tumors on the right & left shoulders respectively. Mice were imaged with μ-SPECT/CT at 24h & 48h, & sacrificed at 24h or 48h post-injection to assess biodistribution. Results The labeling efficiency of the IL was >95% after purification. 111In-IL was stable during the time course of study. 111In-IL efficiently internalized into both subtypes of mesothelioma tumor cells but not in the non-target BPH cells; 81-94% of the total cell accumulation at 37oC accounted to internalization at 24h incubation for the mesothelioma cells whereas only 37-55% of the total was accounted for internalization in control (BPH) cell line. In animal studies, at 24h the accumulation of 111In-IL in mesothelioma tumors was next only to liver and spleen while the tumor uptake at 48h was next only to liver. The tumor uptake was 4.7 %ID/g & 4%ID/g for VAMT-1 & M-28 tumors respectively at 48h. In contrast, at 48h the control liposome exhibited tumor uptake of only 0.5%ID/g & 0.6 %ID/g for VAMT-1 & M-28 tumors respectively. Conclusions The M1 immunoliposomes showed selective tumor targeting to both epithelioid (M-28) & sarcomatoid (VAMT-1) human mesothelioma cancer cells, demonstrating its potentials as a promising vector for radioimmunotherapy, when labeled with therapeutic radionuclides. Research Support NIH/NCI R01CA 135358-01, IRG-97-150-10/ACS