Use of 111In-bleomycin for combining radiotherapy and chemotherapy on glioma-bearing mice

Kinetics of 111In-labeled bleomycin in patients with brain tumors: compartmental vs. non-compartmental models

The kinetics of an indium-111 labeled bleomycin complex (111In-BLMC) after rapid intravenous injection in patients with brain tumors was quantified by using compartmental and non-compartmental models. The models were applied to data obtained from 10 glioma, one meningioma, and one adenocarcinoma brain metastasis patients. Blood and urine samples from all the patients and tumor samples from three patients were collected. The mean transit time of 111In-BLMC in the plasma pool was 14 +/- 7 min without and 1.8 +/- 0.6 h when accounting for recirculation, and 13 +/- 4 h in the total body pool. The mean plasma clearance of 111In-BLMC was 0.3 +/- 0.1 m/blood/min and the mean half-life in urine was 3.5 +/- 0.6 h. The mean transfer coefficients for the open three-compartmental model were: excretion from plasma = 0.02 +/- 0.01, from depot to plasma = (12 +/- 9)*10(-4), from plasma to depot = 0.01 +/- 0.01, from tumor to plasma = 0.39 +/- 0.19 and from plasma to tumor = 1.11 +/- 0.57, all in units minute-1. The mean turnover time from the tumor was 4.5 +/- 2.7 min and from the depot 20 +/- 8 h. It is concluded that both compartmental and non-compartmental models are sufficient to describe the kinetics of indium-111 labeled bleomycin complex. The non-compartmental model is more practical and to some extent more efficient in describing the in vivo behaviors of 111In-BLMC than the compartmental model. The compartmental model used provides estimates of both extraction and excretion from the plasma and tumor.

Distribution of111 in-bleomycin complex in small cell lung cancer cells by autoradiography

The distribution of 111In-bleomycin Complex (111In-BLMC) in small cell lung cancer (SCLC) cells was studied by autoradiography. SCLC cells were exposed to 111In-BLMC and 111Indium chloride (111InCl3) for 1 hour, 3 hours, and 4 hours; washed with fresh medium; and spread on slides. The slides were smeared with NTB2 (NTB3) emulsion by wet or dry-mount technique and exposed 3 to 15 days. 111In-BLMC was found to localize in the cell nucleus and nuclear membrane (78.3%); 111InCl3 located mainly in the cytoplasm (52.3%). This distribution of labeled BLM may explain the mechanism of killing SCLC cells by 111In-BLMC.

Killing of human lung cancer cells using a new [111In]bleomycin complex [111In]BLMC

The ability of a [111In]bleomycin complex [( 111In]BLMC) to kill five cell lines of human lung cancer (small cell lung cancer) was investigated. Cells were exposed to either 0.9% NaCl, [111In]Cl3, BLM, [111In]BLMC, nonradioactive InCl3, or In-BLMC for 60 minutes, plated in soft agarose, and assessed for colony formation. [111In]BLMC (40-200 microCi carried by 15-25 micrograms BLM/ml) was more cytotoxic than BLM (15-25 micrograms BLM/ml) by a factor of 1.6-5.3 for five cell lines. The percent survival of N417 cells was 28.4 for [111In]BLMC (40 microCi/15 micrograms BLM/ml) and 54.3 for BLM (15 micrograms/ml); 1.9 for [111In]BLMC (200 microCi/25 micrograms BLM/ml), and 10.0 for BLM (25 micrograms/ml). 111InCl3 (200 microCi/ml) and nonradioactive InCl3 failed to inhibit colony formation. The new [111In]BLMC may be useful for therapy of some lung cancer patients.