Related Experiment Video
Updated: Jul 31, 2026
Induction of Invasive Transitional Cell Bladder Carcinoma in Immune Intact Human MUC1 Transgenic Mice: A Model for Immunotherapy Development
Published on: October 31, 2013
Antitumor effect of a peptide-glucan preparation extracted from Agaricus blazei in a double-grafted tumor system in
1Division of Immunology, Miyagi Cancer Center Research Institute, Natori, Miyagi, Japan.
Abstract:
The antitumor effect of extracts obtained from the fruit body of Agaricus blazei Murill was examined in a double-grafted tumor system, in which BALB/c mice received simultaneous intradermal injections of Meth-A tumor cells in both the right (10(6) cells) and left flank (2 x 10(5) cells), and were then injected with 5 mg of extracts of A. blazei in the right tumor on days 3, 4 and 5. Intratumoral administration of ethanol-soluble (Fraction 1), water-ethanol-soluble (Fraction 2), ammonium oxalate-soluble (Fraction 3) and ammonium oxalate-insoluble (Fraction 4) fractions resulted in inhibition of tumor growth, with Fraction 3 showing the most tumoricidal activity, producing regression of the right tumor and inhibition of growth of the left, non-injected tumor. The maximum effect was obtained using 0.5 mg of Fraction 3 and this amount was used in subsequent experiments. The antitumor effect of intratumorally administered Fraction 3 was enhanced by oral ad lib administration of feed containing 0.083% of Fraction 3. When immunized spleen cells from mice that had been cured by intratumoral administration of 0.5 mg of Fraction 3 were directly injected (2 x 10(7) cells/mouse) into the Meth-A tumor, tumor growth was inhibited. The tumor cells on day 7 from the Fraction 3-treated right tumor and from the left tumor were cultured for 24 h and their culture supernatants were assayed for neutrophil or macrophage chemotactic activity. Significant macrophage chemotactic factor activity was detected in the culture media from the left tumor tissue. Serum levels of immunosuppressive acidic protein (IAP), produced by activated macrophages and neutrophils, increased transiently soon after intradermal injection of 0.5 mg of Fraction 3. These results suggest that regression of the left non-injected tumor was due to an immune reaction, involving induction of cytotoxic cells in the spleen, and the release of chemotactic factors in the distant tumor.
Insights
Agaricus blazei extracts demonstrated significant antitumor effects, particularly Fraction 3, which induced tumor regression and inhibited distant tumor growth. This suggests a potent immune response mediated by cytotoxic cells and chemotactic factors.
Area of Science:
- Mycology
- Immunology
- Cancer Research
Background:
- The fruit body of Agaricus blazei Murill is known for its potential medicinal properties.
- Investigating natural compounds for cancer treatment is a growing area of research.
Purpose of the Study:
- To evaluate the antitumor efficacy of different Agaricus blazei fruit body extract fractions.
- To elucidate the mechanisms underlying the observed antitumor activity.
Main Methods:
- A double-grafted tumor model in BALB/c mice using Meth-A tumor cells.
- Intratumoral and oral administration of various Agaricus blazei extract fractions.
- Assay of spleen cell activity, chemotactic factors, and serum immunosuppressive acidic protein (IAP) levels.
Main Results:
- Intratumoral administration of Agaricus blazei extracts inhibited tumor growth, with Fraction 3 showing the most potent activity.
- Fraction 3 induced regression of the injected tumor and inhibited growth of a non-injected tumor.
- Oral administration of Fraction 3 enhanced the intratumoral effect, and immunized spleen cells inhibited tumor growth.
Conclusions:
- Agaricus blazei extract, particularly Fraction 3, exhibits significant antitumor properties.
- The antitumor effect appears to be mediated by an immune response, including the induction of cytotoxic spleen cells and chemotactic factors.
- Fraction 3 holds promise as a potential therapeutic agent for cancer treatment.
