Strategy to conquer cancer drug resistance uncovered

Source: info.cancerresearchuk.org Author: staff US scientists have identified a way in which cancer cells can become resistant to the cancer drug cetuximab (Erbitux), and suggest that treatments that are already available might be able to overcome this resistance. Researchers from the Dana-Farber Cancer Institute in Boston, US, have been studying why some patients only experience short-term benefits with cetuximab, or none at all. Cetuximab is an antibody that interferes with cancer cell growth. It can be given in combination with chemotherapy to patients with bowel cancer or head and neck cancer. Until now, scientists didn't know why some cancers failed to respond to the drug, or initially responded but then became resistant. The new study, published in Science Translational Medicine, found that in some of the drug-resistant cells, a protein known as ErbB2 (also known as HER2/neu) was sending 'grow' signals. These were bypassing the 'stop growing' signals caused by the drug. Pasi Janne, the study's co-senior author, said: "ErbB2 activates a critical signalling pathway that is not normally blocked by cetuximab, and in this way subverts cetuximab's function. "Because ErbB2 isn't affected by cetuximab, this is an easy way for cancers to become resistant to the drug." The researchers suggest that combining cetuximab with already available ErbB2 inhibitors such as trastuzumab (Herceptin) could produce an effective therapy to tackle cancers that previously showed resistance to cetuximab. Henry Scowcroft, science information manager at Cancer Research UK, said: "Unfortunately, patients's tumours can become resistant to treatment, and understanding why this happens is a major [...]

2011-09-09T05:32:14-07:00September, 2011|Oral Cancer News|

Monoclonal Antibody Drugs for Cancer Treatment

Source: www.newswise.com Author: staff The strategy of using monoclonal antibodies for cancer treatment was first described in the late 1970s with the promise that they could be developed into therapies that were highly specific to cancer cells, killing them with few or no side effects. For several types of cancer, monoclonal antibodies have already offered this advantage to patients. For other cancer types, they have provided an additional therapeutic weapon, but with smaller benefits and sometimes new side effects. "The first efforts for monoclonal antibody cancer therapy were to find antibodies that would home in on tumors and bind to proteins on the surface of cancer cells," explained physician-scientist David A. Scheinberg. "We looked for unique proteins that were specific only to cancer cells. The idea was that the antibody would be used to stimulate an immune response in the body, which would kill the cancer cell." Dr. Scheinberg, who is Chair of Memorial Sloan-Kettering's Experimental Therapeutics Center and the Molecular Pharmacology and Chemistry Program within the Sloan-Kettering Institute, developed an antibody called M195, which targets a protein on leukemia cells, when working as a research fellow in collaboration with Memorial Sloan-Kettering immunologist Lloyd Old in the 1980s. This approach further evolved when researchers realized they could use the antibody as a carrier to deliver a radioactive isotope or a toxic drug directly to the cancer cell, where it would kill the cell while sparing nearby healthy tissue. Antibodies are proteins that help the immune system to identify foreign substances [...]

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