In this study, we aimed to evaluate the effect of all-trans-retinoic acid (PLGA-COOH nanoparticles) on the induction of dedifferentiation of thyroid cancer and the enhancement of iodine uptake. Patients (32 cases) with pathologically confirmed thyroid cancer (24 differentiated and 8
undifferentiated) received all trans-retinoic acid (1.0–1.5 mg/kg) for six weeks. Whole-body imaging was performed after 72 h. Using the American phogamma camera, the radioactivity counts of each pixel in the metastasis was measured by the semi-quantitative method of region of interest
(ROI). Changes in uptake radioactivity of the metastases were compared before and after PLGA-COOH nanoparticle induction. The size of the metastasis was determined by ultrasound, X-ray, or computed tomography (CT), and the serum thyroglobulin (TG) was determined by radioimmunoassay. After
radioiodine treatment, the average measurable iodine uptake of different sites of metastasis was significantly lower than that before treatment. After 32 patients were treated with PLGA-COOH nanoparticles, the uptake of a single lesion was increased in 14 cases (43.8%), no significant change
was found in 7 cases (20.8%), and the uptake of one lesion was decreased in 6 cases (25%). In 827 cases, the metastasis decreased, 12 cases remained unchanged, and 7 cases increased. There was no correlation between the pathological type and the change of a lesion. After induction, serum TG
decreased in 12 cases (40%), increased in 11 cases (36.7%), and remained unchanged in 7 cases (23.3%). Serum TG level was not related to a change in iodine uptake ability. In 12 cases (37.5%), two indexes were changed (e.g., increased iodine uptake, reduced ROI, or decreased serum TG). Thyroid-stimulating
hormone nano interventional therapy breaks through the single and limitation of traditional treatment of thyroid diseases. PLGA-COOH nanoparticles can play an important role in the differentiation of differentiated thyroid cancer cells and the transformation of undifferentiated thyroid cancer
cells. PLGA-COOH nanoparticles provide an effective method to induce the treatment of undifferentiated thyroid cancer.
Aberrant Thyroid-Stimulating Hormone Receptor Signaling Increases VEGF-A and CXCL8 Secretion of Thyroid Cancer Cells, Contributing to Angiogenesis and Tumor Growth
