Surgical management of tongue cancer during pregnancy.

There are ethical dilemmas in managing head and neck cancers during pregnancy. Diagnostic and treatment modalities need to be carefully determined. We herein describe 3 cases of tongue cancer during pregnancy. The details of the management would contribute to the daily practices for head and neck cancers. All three patients were Japanese female patients, two of them were 29 years old and one was 26 years old. All patients were admitted to the Nippon Medical School Hospital during pregnancy, complaining of oral pain and/or discomfort. Case 1 was diagnosed as tongue cancer stage T3N0M0, however, the tumor was superficial and controllable by partial glossectomy. Case 2 was stage T2N0M0 with deep invasion with ulcer, and the hemi-glossectomy with neck dissection and the reconstruction was thought to be the standard modality. However, she underwent partial glossectomy in order to reduce the stress of the fetus. Case 3 could not be diagnosed on admission by biopsy and she underwent partial glossectomy after delivery. In case 3, the pathological diagnosis was pT1 tongue cancer. In case 1 and case 3, the patient and baby were healthy. In case 2, however, the patient died of recurrence at the primary site. In decision making of the strategy, the most important factors are not only oncological evaluation but also ethical and emotional factors.

2-o-phosphorylation of xylose and 6-o-sulfation of galactose in the protein linkage region of glycosaminoglycans influence the glucuronyltransferase-I activity involved in the linkage region synthesis.

Sulfated glycosaminoglycans (GAGs), including heparan sulfate and chondroitin sulfate, are synthesized on the so-called common GAG-protein linkage region (GlcUAbeta1-3Galbeta1-3Galbeta1-4Xylbeta1-O-Ser) of core proteins, which is formed by the stepwise addition of monosaccharide residues by the respective specific glycosyltransferases. Glucuronyltransferase-I (GlcAT-I) is the key enzyme that completes the synthesis of this linkage region, which is a prerequisite for the conversion of core proteins to functional proteoglycans bearing GAGs. The Xyl and Gal residues in the linkage region can be modified by phosphorylation and sulfation, respectively, although the biological significance of these modifications remains to be clarified. Here we present evidence that these modifications can significantly influence the catalytic activity of GlcAT-I. Enzyme assays showed that the synthetic substrates, Gal-Gal-Xyl(2-O-phosphate)-O-Ser and Gal-Gal(6-O-sulfate)-Xyl(2-O-phosphate)-O-Ser, served as better substrates than the unmodified compound, whereas Gal(6-O-sulfate)-Gal-Xyl(2-O-phosphate)-O-Ser exhibited no acceptor activity. The crystal structure of the catalytic domain of GlcAT-I with UDP and Gal-Gal(6-O-sulfate)-Xyl(2-O-phosphate)-O-Ser bound revealed that the Xyl(2-O-phosphate)-O-Ser is disordered and the 6-O-sulfate forms interactions with Gln(318) from the second GlcAT-I monomer in the dimeric enzyme. The results indicate the possible involvement of these modifications in the processing and maturation of the growing linkage region oligosaccharide required for the assembly of GAG chains.