Related Experiment Videos
Internalization with high targeting potential of mouse monoclonal antibody ONS-M21 recognizing human malignant glioma
K Shimizu1, K C Park, K Tamura
1Department of Neurosurgery, Osaka University Medical School, Suita City, Japan.
Abstract:
In order to evaluate the targeting potential of mouse monoclonal antibody ONS-M21 recognizing a human astrocytoma- and medulloblastoma-associated antigen, the internalization ability of this antibody and the selective cytotoxicity in the toxin-conjugated form were examined. Internalization assay with 125I-labeled ONS-M21 showed that about 20% of the total radioactivities was detected in the cellular fraction of human medulloblastoma cell line ONS-76 cells and that the reaction reached a plateau level in 30 min. To examine the selective delivery capacity of a high molecular substance in place of 125I, an immunotoxin was prepared with ricin A chain and ONS-M21 via disulfide bonds. A cytotoxic effect against ONS-76 cells was found with [3H]thymidine incorporation assay using the immunotoxin, but not against antigen-negative HuH-7 and SW480 cells. These results suggest that ONS-M21 could effectively deliver toxins, chemotherapeutic agents or radionuclei to malignant glioma specifically.
Insights
Mouse monoclonal antibody ONS-M21 effectively targets human astrocytoma and medulloblastoma cells. When conjugated to toxins, ONS-M21 demonstrates selective cytotoxicity against these cancer cells, indicating potential for targeted cancer therapy.
Area of Science:
- Oncology
- Immunology
- Biochemistry
Background:
- Monoclonal antibodies are crucial for targeted cancer therapies.
- Identifying antibodies that specifically bind to tumor-associated antigens is essential for developing effective treatments.
Purpose of the Study:
- To evaluate the targeting potential of the mouse monoclonal antibody ONS-M21.
- To assess the internalization ability and selective cytotoxicity of ONS-M21 when conjugated to toxins.
Main Methods:
- Internalization assay using 125I-labeled ONS-M21 on human medulloblastoma cell line ONS-76.
- Preparation of an immunotoxin by conjugating ricin A chain to ONS-M21 via disulfide bonds.
- Cytotoxicity assay using [3H]thymidine incorporation to evaluate the immunotoxin's effect on ONS-76, HuH-7, and SW480 cells.
Main Results:
- Internalization assay showed approximately 20% of radioactivities detected in ONS-76 cells within 30 minutes.
- The ONS-M21 immunotoxin exhibited significant cytotoxic effects on ONS-76 cells.
- No significant cytotoxicity was observed against antigen-negative cell lines (HuH-7 and SW480), confirming antigen specificity.
Conclusions:
- Mouse monoclonal antibody ONS-M21 demonstrates effective internalization into medulloblastoma cells.
- ONS-M21 can selectively deliver toxins to antigen-positive malignant glioma cells.
- This antibody holds promise for targeted delivery of toxins, chemotherapeutic agents, or radionuclei in cancer therapy.