Toppage >> About Our Therapy – Molecular target irradiation
"Molecular target irradiation" is a new radiation therapy method that is focused on abnormality in transcription function of cancer cells and their nature as stem cells. It works out to reduce tolerance to radioactivity of cancer cells by selectively influencing to these natures. Epigenetics medicines used in the therapy and medicines that have selective effects on markers on surface cancer stem cells have been developed based on the latest tumor molecular biology.
Previous therapies such as carbon-ion radiotherapy and oxygen filling sensitizers enhance effects of radiotherapy but could do damage to normal cells and organs as well, because the methods strengthen kill-a-cell effects of radiation physically and chemically. But "Molecular target irradiation" uses drugs that have effects only on cancer cells and enhance their radiation sensitivity, because the drugs can make out what characterizes cancer cells on a molecular structure level. The therapy has a wide range of application.
We have some drugs that could attach to and modify molecular structure specifically of cancer cells. DNA methylation inhibitor and histone deacetylase inhibitor are effective for abnormality of transcription. CD44V surface marker system inhibitor or CD133 surface marker system inhibitor is effective for stem cell. (Either of them has been found to inhibit NFκB in the HIF1 process) These drugs have turned out to be almost harmless to normal organs.
We have practiced Tomotherapy IGIMRT treatment to patients with multiple lesions, together with these drugs administrated directly to cancer lesions for 3 years. As a result, we have achieved 75% - 80% local control rate even with radiation dose deducted by 60%.
*"Molecular target irradiation" uses drugs in combination with Tomotherapy. Please contact us for schedule and cost of therapy.
Radiation therapy using linac x-ray beam or linac electron beam sometimes could not be effective to large cancer lesions or some kinds of cancer such as malignant melanoma to extent expected. Two thirds of damages to cancer cells by x-ray beam or electron beam are caused by indirect actions of free radicals chemically reacted with water molecules, while one thirds of them are cause by direct action of beam to biopolymers such as that to DNA.
Many of radiation resistant cancers have such nature because they are lack in oxygen and do not keep free radicals required for the above indirect actions.
Carbon-ion radiotherapy or Radiosensitizer is applied to cope with such nature of radiation resistant cancers. Because carbon-ion radiotherapy can cause very strong direct actions to DNA, we can expect therapy effects, regardless of amount of oxygen in cancer.
On the other hand, Radiosensitizer enhances sensitiveness of cancer cells to radiation. Radiosensitizers generally used today fill up cancers with active oxygen and make ordinary radiation therapy be able to exert its indirect actions to cancer sufficiently. Hydrogen peroxide water is an example of radiosensitizers of this type.
Investigations and studies of molecular biology in recent years have found that some particular protein abnormality and stemness of cell cause ineffectiveness of radiation therapy.
Generally case of protein abnormality has been regarded to be abnormality of responsible gene. But recent studies tell us that abnormal protein could be reacted even without any abnormality in responsive gene if there is some problem in transcription processes.
Especially if there exists some abnormality in tumor suppressor gene protein, apoptosis, processes of self-destroy caused by changes in internal environment of cells brought about by exposure to radiation, cannot work well and, as a result, cancer cells could survive.
And it has been found out that cancer cells with stemness character are able to survive by reducing obstacles given by radiation or anti-cancer agents. Not only to survive but also to be source of metastasis.