Related Experiment Video
Updated: Sep 21, 2026
Ex vivo Expansion of Tumor-reactive T Cells by Means of Bryostatin 1/Ionomycin and the Common Gamma Chain Cytokines Formulation
Published on: January 15, 2011
The immune stimulatory protein 90K increases major histocompatibility complex class I expression in a human breast
C Natoli1, S Iacobelli, L Kohn
1Department of Medical Oncology, University G. D'Annunzio Medical School, Chieti, Italy.
Insights
The human serum protein 90K, also known as tumor protein 53 (TP53)-induced glycolysis regulator (TIG3), enhances immune responses and may suppress tumor formation. This study shows 90K increases MHC class I expression on breast cancer cells.
Area of Science:
- Immunology
- Molecular Biology
- Oncology
Background:
- 90K is a secreted human protein found in serum, with elevated levels in cancer patients.
- 90K has known stimulatory effects on natural killer and lymphokine-activated killer cell activity.
- Tumor cell line studies suggest 90K expression inversely correlates with tumor formation.
Purpose of the Study:
- To investigate the mechanism behind 90K's potential tumor suppressive effects.
- To evaluate 90K's impact on MHC class I molecule expression in human breast cancer cells.
Main Methods:
- Human breast cancer cell line EVSA-T was treated with varying concentrations of 90K (1-50 µg/ml).
- MHC class I expression levels were measured using flow cytometry.
- Interferon-gamma (IFN-γ) was used as a positive control.
Main Results:
- Treatment with 90K significantly increased MHC class I expression by approximately sixfold compared to control levels.
- IFN-γ, used as a positive control, increased MHC class I expression approximately eightfold.
- These findings indicate a direct effect of 90K on MHC class I expression.
Conclusions:
- 90K directly influences the expression of MHC class I molecules.
- This modulation of MHC class I expression by 90K may contribute to protective anti-tumor responses.
- Further research is warranted to elucidate the precise mechanisms of 90K's tumor suppressive activity.
Abstract:
90K is a widely expressed, secreted 90 kDa human serum protein found both in normal individuals and at elevated levels in the serum of cancer patients. Functional characterization revealed stimulatory effects of 90K on immune defense systems, such as natural killer and lymphokine-activated killer cell activity. Recently, experiments have shown that 90K expression in several tumor cell lines inversely correlates with tumor formation in athymic mice. The mechanism of this tumor suppressive effect is unknown. In the present study, we evaluated the ability of 90K to affect the expression of MHC class I molecules in the human breast cancer cell line EVSA-T. Treatment with 90K (1-50 micrograms/ml) caused the levels of MHC class I expression to increase approximately sixfold above control levels, as measured by flow cytometry. IFN-gamma was used as a positive control and yielded increased expression of MHC class I molecules approximately 8 times over control levels. These data demonstrate that 90K can directly affect the expression of molecules that are engaged in protective antitumor response.
