Objective:To evaluate the efficacy of computed tomography (CT)-guided implantation of radioactive ~(125)I seeds in the treatment of residual foci of nasopharyngeal carcinoma after radiotherapy.Methods:Twenty-five nasopharyngeal carcinoma patients who had residual foci after radiotherapy were implanted radioactive ~(125)I seeds from January 2007 to January 2008 in our hospital. Three-dimensional treatment planning system (TPS) was used to calculate the quantity and total dosage of ~(125)I seeds. The radioactive ~(125)I seeds were implanted into residual foci under CT guidance. The dosage distribution of radioactive ~(125)I seeds were verified after surgery. The nasopharyngeal endoscopy CT scans were performed at 3, 6, and 12 months after surgery and the short-term efficacy and adverse reaction were evaluated. Results:Out of the 25 patients, 20 patients had complete response (CR), 2 patients had partial response (PR), 2 patients had no change (NC), and 1 patient had progressive diseases (PD). The overall effective rate (CR+PR) was 88.0%. All patients had no serious postoperative complications. Conclusion:CT-guided implantation of radioactive ~(125)I seed was an effective and safe method in the treatment of the residual foci of nasopharyngeal carcinoma after radiotherapy.

Hedgehog was first described in Drosophila melanogaster by the Nobel laureates Eric Wieschaus and Christiane Nüsslein-Volhard. The hedgehog (Hh) pathway is a major regulator of cell differentiation, proliferation, tissue polarity, stem cell maintenance, and carcinogenesis. The first link of Hh signaling to cancer was established through studies of a rare familial disease, Gorlin syndrome, in 1996. Follow-up studies revealed activation of this pathway in basal cell carcinoma, medulloblastoma and, leukemia as well as in gastrointestinal, lung, ovarian, breast, and prostate cancer. Targeted inhibition of Hh signaling is now believed to be effective in the treatment and prevention of human cancer. The discovery and synthesis of specific inhibitors for this pathway are even more exciting. In this review, we summarize major advances in the understanding of Hh signaling pathway activation in human cancer, mouse models for studying Hh-mediated carcinogenesis, the roles of Hh signaling in tumor development and metastasis, antagonists for Hh signaling and their clinical implications.
Animals ; Antineoplastic Agents ; therapeutic use ; Basal Cell Nevus Syndrome ; drug therapy ; metabolism ; Carcinoma, Basal Cell ; drug therapy ; metabolism ; Cell Differentiation ; Cerebellar Neoplasms ; drug therapy ; metabolism ; Hedgehog Proteins ; antagonists & inhibitors ; metabolism ; Humans ; Medulloblastoma ; drug therapy ; metabolism ; Models, Animal ; Neoplasms ; drug therapy ; metabolism ; Patched Receptors ; Receptors, Cell Surface ; genetics ; metabolism ; Signal Transduction ; drug effects ; Skin Neoplasms ; drug therapy ; metabolism

The link of hedgehog (Hh) signaling activation to human cancer and synthesis of a variety of Hh signaling inhibitors raise great expectation that inhibiting Hh signaling may be effective in human cancer treatment. Cyclopamine (Cyc), an alkaloid from the Veratrum plant, is a specific natural product inhibitor of the Hh pathway that acts by targeting smoothened (SMO) protein. However, its poor solubility, acid sensitivity, and weak potency relative to other Hh antagonists prevent the clinical development of Cyc as a therapeutic agent. Here, we report properties of cyclopamine tartrate salt (CycT) and its activities in Hh signaling-mediated cancer in vitro and in vivo. Unlike Cyc, CycT is water soluble (5-10 mg/mL). The median lethal dose (LD50) of CycT was 62.5 mg/kg body weight compared to 43.5 mg/kg for Cyc, and the plasma half-life (T1/2) of CycT was not significantly different from that of Cyc. We showed that CycT had a higher inhibitory activity for Hh signaling-dependent motor neuron differentiation than did Cyc (IC50 = 50 nmol/L for CycT vs. 300 nmol/L for Cyc). We also tested the antitumor effectiveness of these Hh inhibitors using two mouse models of basal cell carcinomas (K14cre:Ptch1(neo/neo) and K14cre:SmoM2(YFP)). After topical application of CycT or Cyc daily for 21 days, we found that all CycT-treated mice had tumor shrinkage and decreased expression of Hh target genes. Taken together, we found that CycT is an effective inhibitor of Hh signaling-mediated carcinogenesis.
Animals ; Carcinoma, Basal Cell ; pathology ; Cell Differentiation ; drug effects ; Embryonic Stem Cells ; cytology ; Hedgehog Proteins ; antagonists & inhibitors ; metabolism ; Mice ; Motor Neurons ; cytology ; Plants, Medicinal ; chemistry ; Receptors, G-Protein-Coupled ; antagonists & inhibitors ; metabolism ; Signal Transduction ; drug effects ; Skin Neoplasms ; pathology ; Smoothened Receptor ; Solubility ; Tartrates ; blood ; pharmacology ; Tumor Burden ; drug effects ; Veratrum ; chemistry ; Veratrum Alkaloids ; blood ; isolation & purification ; pharmacology