Gc-MAF in treatment of prostate cancer

In a post earlier today, we promised to provide follow-up on the research of Dr. Nobutu Yamamoto and colleagues into the use of a biologic agent known as Gc-MAF in the treatment of prostate cancer.

We have now been able to identify one paper published by Dr. Yamamoto and his colleagues that is specific to prostate cancer and was published earlier this year in an somewhat obscure journal known as Translational Oncology. This paper appears to address, in greater detail, information about the same 16 patients who are referred to in slide 16 of the slide presentation previously referenced.

According to the abstract of this 2008 paper:

  • A biologic molecule known as serum Gc protein or vitamin D3-binding protein is a key precursor to the principal macrophage-activating factor (MAF).
  • In prostate cancer patients, the MAF precursor activity of serum Gc protein is lost or reduced because Gc protein is deglycosylated* by an enzyme found in serum and called alpha-N-acetylgalactosaminidase (also known as “Nagalase”).
  • Nagalase is made in cancerous cells and transferred from the cancer cells into serum.
  • The result is that macrophages of prostate cancer patients having deglycosylated Gc protein cannot be activated, and are therefore immunosuppressed.
  • Yamamoto et al. treated 16 ” non-anemic” prostate cancer patients with once-weekly doses of 100 ng of Gc-MAF for periods ranging from 14 to 25 weeks. (It is not clear from the abstract what the clinical stage of any of these patients was at the time of treatment.)
  • As the Gc-MAF activity increased, their serum Nagalase activity decreased.
  • After the 14-25 weekly administrations of Gc-MAF, all 16 patients had very low serum Nagalase levels comparable to those of healthy control values, “indicating that these patients are tumor-free.”
  • “No recurrence” was apparent for 7 years.

Now there is a whole series of questions that needs answers, and we will attempt to get these answers by obtaining a full copy of the paper, and talking to Dr. Yamamoto directly if necessary. They include the following:

  • What was the clinical stage, grade, etc., for these 16 patients at the time of their treatment with Gc-MAF?
  • What other treatments (if any) did they have before or after treatment with Gc-MAF?
  • When were they actually treated and have other patients been treated subsequently? (Our best guess, based on the data available in the abstract and in slide 16 of the above-mentioned presentation, is that these patients must have been treated in 2000 or earlier.)
  • How were they followed up?
  • What is meant by the phrase “no recurrence” in the abstract? No biochemical recurrence evident from a rising PSA? No recurrence evident from a rising Nagalase level? No recurrence evident from a bone scan or an MRI? What?
  • Is a Nagalase level comparable to that of a healthy control in a patient previously diagnosed with prostate cancer actually sufficient evidence that that patient is “tumor-free”?

If any reader has additional and specific information about any of these 16 patients that they are in a position to share, please let us know.

*”Deglycolization” is a process in which an enzyme strips one or more glycol molecules (complex alcohol-like units) from a complex biologic molecule.

2 Responses

  1. You may find more success researching DBP-MAF, which appears to be the name given by other researchers performing similar work.

  2. We are told that there is a degree of distress among some members of the HIV community about the lack of media attention to an article by Yamamoto et al. that appeared last January, and which suggested that GcMAF also has activity in elimination of HIV expression in non-anemic HIV patients.

    While we have not got into the details of the actions of the HIV community to gain publicity for these data, there does appear to be a surprising disinterest in the data being published by Yamamoto and his colleagues, and one wonders why there is this level of disinterest.

    We thank “Visonetto” in Italy for bringing this matter to our attention.

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