Most deaths from cancer diseases are not associated with the tumor and its spread in the body. Most often the cause of death is a secondary tumor or metastases.
At a late stage breast cancer , about 70% of patients have bone metastasis. Once cancer cells spread to the bone of the patient, to fight the disease it becomes much more difficult. Current treatments do not work well enough, and the therapy takes place with a number of side effects. In addition, cancer cells can not respond to medications.
Investigation of bone metastases
much time was spent on the study of how cancer spreads and how it can be stopped or slowed down. Yibin Kang and his team of researchers at Princeton University in New Jersey have put a lot of effort to study this issue.
Results of the work were published this month in the journal Cancer Cell.
Lead researcher Hanchzhu Zheng explains the work of the team, "Kahn lab mainly studies the metastasis of breast cancer - how cancer cells spread from the breast to other organs because lethal for the majority of cancer patients is not the original tumor and metastasis."
A recent study has focused specifically on bone metastases and cancer cells interact with bone.
Rebecca Tan Kang's team: "We have learned that Jagged1 molecule is an important part of tumor spread and help the spread of metastasis of breast cancer cells."
"The challenge was to understand how to reduce metastasis or even prevent them from using 15D11 antibody blocking Jagged1», - she adds.
Studying the interaction of cancer cells and bone cells
In healthy bones seen constant change: the bone cells are removed by osteoclasts and osteoblasts is restored. This regeneration means that the bone tissue is healthy and fully functioning.
But with bone cancer the normal process does not work. Osteoclasts can destroy too many healthy cells, or osteoblasts may hide tumor cells and protect them from chemotherapy.
"Cancer cells can not be seen due to the osteoblast", - says Kahn.
They found that when the antibody 15D11 combined with chemistry, the treatment took place better than if the patient was receiving only chemotherapy. In addition antibody unexpectedly began to operate not only against cancer cells with high expression of Jagged1, but also against those who are less pronounced Jagged1.
Standard chemotherapy stops working when Jagged1 begins to create osteoblasts, thus cancer leverages Jagged1 as a shield. Specifically targeting Jagged1, 15D11 destroys this shield, and chemotherapy can continue to work.
Kang and his team worked with genetically modified mouse model, with Jagged1 in bone cells.
The first results were confirmed: in the mice which received 15D11 and chemotherapy, cancer cells disappeared better than the treatment of one way. In one experiment, bone cancer has decreased in more than a hundred times after chemotherapy and 15D11.
"This is the result, which we have never seen in any of our previous therapeutic tests against bone metastasis in mice," - Yibin Kang.
Although this study only investigated the breast cancer and its metastases in the bones, scientists believe that this method may not work for other types of cancer that metastasize to bones, such as prostate cancer .
The next step would be human trials. Kahn hopes that this will be a relatively quick process, because 15D11 «fully human" created "humanized mouse".