The Study On Relationship Between ～(131)Ⅰ Irradiation And Dedifferentiated Of Thyroid Cancer And Screening Of Differentially Expressed Genes In Dedifferential Thyroid Cancer

The highly selective uptake of iodineion is one of characteristic feature of thyroid tissue and most differentiated thyroid cancer (DTC) still retain this capability to concentrate the iodine. So the radioiodine (131I) is applied in the treatment of DTC and the accumulated 131I will then ablate the malignant tumor tissue as a consequence. The cancer cells of about 30% of patient with DTC, however, has dedifferentiation to some extent, showing the degenerative change in morphology and making them lose their ability to express the TSH receptor and to accumulate the iodine. The dedifferentiation is a poor prognosis factor for DTC patients, since the dedifferentiation of the DTC cells enables them to be uncontrol by the 131I and TSH suppression treatment, making them more aggressive and having a faster metastasis. Some DTC cells become dedifferentiated after repeated exposure to the 131I and fail to uptake and accumulate the 131I, making the 131I treatment less effective than its' first time application. It has not been known clearly about how the 131I irradiation leads to the dedifferentiation of DTC cells and how these cells lose their ability to uptake iodine.