Comparison of Biological Effects Produced by Radioactively Labeled Antibodies
Date
2024-09-13
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
ORCID
0009-0003-4473-0304
Type
Thesis
Degree Level
Masters
Abstract
Acute myeloid leukemia (AML) is one of the most common and deadliest forms of leukemia. AML patients often become immunocompromised as a result of their treatment making them susceptible to opportunistic fungal infections. Radioimmunotherapy (RIT) has been investigated clinically and pre-clinically as a treatment for AML and for opportunistic fungal infections, respectively. Here we compare the radiobiological effects of antibodies radiolabeled with an alpha-emitter Actinium-225 (225Ac) and a beta-emitter Lutetium-177 (177Lu) on AML cells and on opportunistic fungal pathogen Cryptococcus neoformans. C. neoformans Cap-67 strain and human acute myeloid leukemia (OCI-AML3) cells were used in all experiments. Cap-67 cells were treated with an anti-(1-3)-beta-glucan antibody 400-2, while OCI-AML3 cancer cells were treated with anti-CD33 antibody HuM-195. Both antibodies were conjugated to bifunctional chelator DOTA, radiolabeled with the similar activities of 225Ac and 177Lu and cells were treated for 24 hr followed by clonogenic survival, γH2A/X immunofluorescent staining, and micronuclei assays. In addition, the internalization of 400-2 and HuM-195 antibodies into cells was measured via flow cytometry. Treatment of fungal and leukemia cells with radiolabeled antibodies resulted in similar decreases in clonogenic survival, development of DNA double-strand breaks as measured by γH2A/X, and formation of micronuclei. The antibody HuM-195 was internalized into OCI-AML3 cells while 400-2 did not internalize into Cap-67 cells. Similarity of radiobiological effects in leukemic and fungal cells can be explained by their eukaryotic nature. The results demonstrate promising and similar mechanistic effects of RIT which could benefit immunocompromised leukemia patients in the future.
Description
Keywords
AML Acute myeloid leukemia
BBB Blood-brain barrier
BFCA Bifunctional chelating agent
CFS Cerebrospinal fluid
CFU Colony forming units
CNS Central nervous system
DOTA Dodecane tetraacetic acid
DSBs Double-strand breaks
DTPA Diethylenetriaminepentaacetic acid (DTPA)
EDTA Ethylenediaminetetraacetic acid
ELISA Enzyme-linked immunosorbent assay
ESMO European Society of Medical Oncology
HCT Hematocrit
LA Latex agglutination
LFA Lateral flow assays
LSCs Leukemic stem cells
MRD Minimal residual disease
mAb Monoclonal antibody
NCCN National Comprehensive Cancer Network
PCR Polymerase chain reaction
RIT Radioimmunotherapy
ROS Reactive oxygen species
RPMI Roswell Park Memorial Institute
TI Therapeutic index
Citation
Degree
Master of Science (M.Sc.)
Department
Pharmacy and Nutrition
Program
Pharmacy