Hi rla,
My findings led me to no clear evidence that CMT's are being used to
treat bone cancer in veterinary Oncology, however I did find evidence
of it used in clinical testing with animals. Because of no clear cut
yes or no, I have placed this as a comment. If you feel my comment
answers your question I'll be happy to answer.
NIDCR Research Digest - April 1997
http://www.nidr.nih.gov/news/digest/archives/april97/bonedest.asp
More Evidence Shows Tetracyclines Inhibit Tissue and Bone Destruction
Many Uses for CMTs
"Findings from studies supported by the NIDR are providing further
evidence that tetracyclines, independent of their antibiotic
abilities, can inhibit the activity of enzymes that degrade connective
tissue and bone. The scientists say their findings, and other studies
based on their work, suggest tetracyclines might have a place in
treating arthritis, osteoporosis, and cancer, conditions that are
characterized by the excessive production of tissue-degrading
enzymes."
[edit]
"In a separate group of studies, Dr. Golub and his colleagues found
that chemically modified tetracyclines (CMTs), stripped of their
antibiotic abilities, showed promise in preventing bone loss and
speeding wound healing in animals, and also in blocking the movement
of cancer cells in laboratory and animal models of metastasis."
[edit]
"The researchers also investigated a possible role for CMTs in
preventing the spread of cancer. For cancer cells to spread beyond
their original site, they must attach to and degrade basement
membrane, sheets of protein that surround all organs and blood
vessels. In their laboratory studies of metastasis, the scientists
placed cancer cells on a synthetic basement membrane material in the
presence of various CMTs to determine whether the drugs could inhibit
the metastatic process. Of the several tetracycline-like drugs tested,
the scientists found that CMT-3, also called COL-3, was the most
effective in preventing cells from degrading and crossing the basement
membrane.
In a rat model of prostate cancer, COL-3 inhibited the spread of
cancer. The analogue also reduced tumor size in some animals and
caused tumor remission in others. Scientists at the National Cancer
Institute, are now conducting safety and efficacy studies of COL-3 in
animals, a necessary step in moving toward clinical testing of this
drug."
===========================================================================
http://www.parkpub.com/oncology/discourse-fall02-pg6.html
note: See Image - Figure 2
"The left panel shows the femur of a control animal in which no tumour
cells were injected and no drug was given. The femur in the middle
panel is from an animal which received breast cancer cells. There is
widespread destruction of the bone with metastatic tumour shown by the
red outline. The right panel shows a femur from an animal injected
with tumour cells and treated with doxycycline. There is a dramatic
decrease in tumour burden compared with the untreated animal."
Studies with doxycycline (one of the derivatives of Tetracycline)
"Preclinical studies are very encouraging. We have evaluated the
effects of tetracyclines in vivo in a mouse model in which
intracardiac injection of human breast cancer cells leads to the
development of bone metastases. Animals treated with doxycycline, a
synthetic antimicrobial tetracycline, showed a 70% decrease in tumour
burden compared to untreated animals. Figure 2 demonstrates the
dramatic protection from metastasis seen in the femurs of sacrificed
doxycycline-treated animals. This beneficial effect on bone tumour
burden was greater than that achieved with a bisphosphonate used in a
similar model. Bone resorption parameters and numbers of osteoclasts
were also lower in the treatment group. The treated animals showed
increased bone formation, indicating that tetracycline alleviated the
uncoupling of the rates of bone resorption and formation usually seen
in metastasis.
Experiments currently underway include combining and comparing
doxycycline with bisphosphonates and using models of prostate cancer
bone metastasis. Promising preclinical data, combined with the ease
of administration, low cost and low toxicity of tetracyclines, point
to hope of successful use in patients. Testing on humans is
anticipated in the near future."
Google search:
chemically modified tetracycline bone cancer animals
CMT's research animals
Best regards,
tlspiegel |
