High mobility group box 1 promotes tumor cell migration through epigenetic silencing of semaphorin 3A.

High mobility group box 1 (HMGB1) is a 25-kDa chromatin-associated protein that aids in transcription and DNA repair by directly binding to DNA and altering its conformation. Additionally, HMGB1 can act as an extracellular ligand. When released from dying or stressed cells, HMGB1 binds to the RAGE receptor and activates the p42/44 MAP kinase (MAPK) cascade. HMGB1 is overexpressed in many types of cancer and frequently associated with tumor stage and metastasis. This has predominantly been attributed to an autocrine function that drives MAPK pathway activity. However, by using tumor cells with activating MAPK pathway mutations, we have identified a role for HMGB1 in promoting metastasis and tumor growth that is independent of this pathway. In the absence of HMGB1, these tumor cells show defective in vitro migration as well as reduced metastasis and tumor growth in vivo despite high p42/44 phosphorylation. We found that semaphorin 3A (SEMA3A), previously shown to act as a suppressor of angiogenesis and migration, was highly increased during expression in the absence of HMGB1. SEMA3A/HMGB1 double knockdown rescued the migration defect in HMGB1 single knockdown cells. HMGB1 bound at the semaphorin 3A genomic locus, promoted hetrochromatin formation, and decreased occupancy of acetylated histones. Based on human tumor gene expression databases, HMGB1 was significantly inversely correlated with SEMA3A, suggesting that this mechanism may be more widely relevant in different cancer types.

Mutations of carnitine palmitoyltransferase II (CPT II) in Japanese patients with CPT II deficiency.

Carnitine palmitoyltransferase II (CPT II) deficiency is an inherited disorder involving beta-oxidation of long-chain fatty acids. CPT II deficiency is a wide-spectrum disorder that includes a lethal neonatal form, an infantile form, and an adult-onset form. However, the ethnic characteristics and the relationship between genotype and clinical manifestation are not well understood. We investigated three non-consanguineous Japanese patients with CPT II deficiency and examined cell lines from 4 unrelated patients and 50 healthy donors. The CPT 2 gene was typed by direct DNA sequencing of polymerase chain reaction-amplified gene products. Case 1 (infantile form) was heterozygous for a phenylalanine to tyrosine substitution at position 383 (p.F383Y) and a novel valine to leucine substitution at 605 (p.V605L). Cases 2, 4, and 5 (infantile form) and case 3 (adult-onset form) were heterozygous for a single mutation at F383Y. Case 6 (adult-onset form) was compound heterozygous at the CPT 2 locus, with deletion of cytosine and thymine at residue 408, resulting in a stop signal at 420 (p.Y408fsX420), and an arginine to cysteine substitution at position 631 (p.R631C). Case 7 (adult-onset form) was homozygous for the p.F383Y mutation. In conclusion, we identified p.F383Y mutations in six of seven patients with CPT II deficiency and two novel variants of the coding gene: p.Y408fsX420 and p.V605L. These mutations differ from those in Caucasian patients, who commonly harbor p.S113L, p.P50H, and p.Q413fsX449 mutations; therefore, our data and those of other Japanese groups suggest that the p.F383Y mutation is significant in Japanese patients with CPT II deficiency.

Halonium ion-mediated reaction of unsaturated hydroperoxy acetals. Competition between the formation of cyclic peroxides and the migration of the methoxy (or hydroxy) group.

Monoozonolyses of dienes 2 in methanol gave in each case the corresponding unsaturated alpha-methoxy hydroperoxides 3. Capture of 2-alkyl-substituted cyclohexanone oxides by methanol was highly diastereoselective, thereby providing exclusively the hydroperoxides derived from attack by methanol from the less hindered face of the carbonyl oxide intermediates. Halonium ion-mediated reactions of the hydroperoxides 3 gave the novel methoxy- or hydroxy-migrated products, together with the expected halogen-substituted 1, 2-dioxanes and/or 1,2-dioxepanes, the composition of the product mixture being a function of the halogenating agent utilized and the structure of 3.

[Immunocytochemical localization of carcinoembryonic antigen (CEA) and transport of CEA into the blood vessels in gastric cancer].

CEA was localized in the luminal border, cytoplasm, but not in mucus, in Signet ring cell carcinoma (sig) and mucinous carcinoma (muc). Electronmicroscopically, CEA was localized in the glycocalyx of the microvilli and microvesicles of the cytoplasm. The histologically different cancer types showed no difference in the localization of T-CEA. We also studied P-CEA elevating factors in 38 CEA-positive (++) patients manifesting subserosal (ss) or deeper invasion. No remarkable findings were obtained. When P-CEA elevating factors were studied in 20 patients with (+) CEA reaction and ss or deeper invasion, we found that the incidence of por was high in P-CEA negative cases. In particular, the por incidence was significantly low (p less than 0.01) in patients with scirrhous type. High P-CEA levels were detected in blood adjacent to the cancer. Among 6 cases with negative P-CEA in the vessels adjacent to the cancer whose T-CEA reactions were (++) or (+), and who manifested ss or deeper invasion, there was a high incidence of por (5 cases) and scirrhous type (4 cases), histologically.

An improved method for the preparation of chondroitin by solvolytic desulfation of chondroitin sulfates.

By heating the pyridinium salts of chondroitin 4- and 6-sulfates in dimethyl sulfoxide containing 10% of water or methanol at 80 degrees C for 1--5 h, several chondroitin preparations with sulfur contents of 0.02--1.05% were prepared in 83--96% yields, respectively. Chemical properties of the preparations, such as degrees of desulfation and of depolymerization, were compared with those of the products obtained by the previously described methods.