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Scientists Have Silver Bullet To Kill Multiple Cancers, Human Trials Starting
EXCERPT:
Researchers have previously noticed that a specific surface marker, called CD47, was expressed at high levels on cancer cells and cells in the blood. They found that this CD47 molecule signals the immune system to ‘not eat me,’ and protects cells from being killed off. Cancers use this flag to evade the immune system and hide while it grows and eventually spreads through the body, ignored by the immune system.
Recently the lab of Irving Weissman at the Stanford University School of Medicine in Palo Alto, California has treated mice with leukemias and lymphomas with an antibody that blocks and effectively hides this CD47 marker and calls on the immune system to attack and kill the cancerous cells.
Now in the most recent publication, Weissman and his research group has gone a step further and tested multiple types of human cancer cells including breast, ovary, colon, bladder, brain, liver, and prostate tumors in petri dishes and in mice to determine the effectiveness of this ‘Anti-CD47’ antibody treatment.
In vitro, in petri dishes, researchers found that when they blocked this ‘do not eat me’ signal, macrophages, a type of immune cell that eats harmful cells and bacteria, killed and ate the cancer cells. And without the drug, the macrophages ignored the cancer cells completely.
In mice, researchers transferred multiple types of human cancer cells, which would normally grow large, metastasize and eventually kill the mouse. Yet, the mice treated with the drug all had shrinkage of tumors, no evidence of cancer spread to lymph nodes and remained cancer free for four months after researchers stopped the treatment (when the experiment was completed).
From the Science editorial “In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer.”
The editorial continues: Cancer researcher Tyler Jacks of the Massachusetts Institute of Technology in Cambridge says that although the new study is promising, more research is needed to see whether the results hold true in humans. “The microenvironment of a real tumor is quite a bit more complicated than the microenvironment of a transplanted tumor,” he notes, “and it’s possible that a real tumor has additional immune suppressing effects.”
Weissman’s research laboratory has received a $20 million grant from California Institute for Regenerative Medicine to move from mouse trials to safety tests in humans (Phase I trials).
Reports coming in fast...
SEE HERE: http://en.ria.ru/science/20130327/180288463.html
US Scientists Find One Drug to Fight Different Cancers
EXCERPT:
Researchers at the Stanford University School of Medicine in California have discovered a single drug that has killed or shrunk every kind of cancer tumor it has been used against.
The drug blocks a protein called CD47, which cancer cells produce in large amounts and thereby trick the body’s immune system into not destroying the cancer cells. Scientists have created an antibody that blocks CD47, prompting the immune system to attack the cancer cells.
“We showed that even after the tumor had taken hold, the antibody can either cure the tumor or slow its growth and prevent metastasis,” biologist Irving Weissman of the Stanford University School of Medicine was quoted by Science Magazine as saying.
The drug was effective against several kinds of cancer tumors that were transplanted into mice, including human breast, ovary, colon, bladder, brain, liver and prostate tumors. In every case the antibody was able to get the mice’s immune system to kill the cancer cells.
“It is the first antibody treatment shown to be broadly effective against a variety of human solid tumors, and the dramatic response … has the investigators eager to begin phase-1 and -2 human clinical trials within the next two years,” the Stanford School of Medicine reported on its website.
The research was published Tuesday on the website of the Proceedings of the National Academy of Sciences.
A decade ago Weissman discovered that leukemia cells produce higher levels of CD47 than healthy cells, Science Magazine reported. And in the last several years, Weissman and his team of researchers discovered that blocking CD47 with an antibody cured some cases of lymphoma and leukemia in mice by stimulating the immune system to see the cancer cells as invaders.
“What we’ve shown is that CD47 isn’t just important on leukemias and lymphomas,” Weissman said. “It’s on every single human primary tumor that we tested.”