Citations

Follicular thyroid carcinoma (FTC) exhibits frequent loss of heterozygosity (LOH) on chromosomes 10q and 3p, suggesting involvement of tumor suppressor genes. We screened 14 FTC (10 Hurthle cell carcinomas and 4 nonoxyphilic FTC), 14 papillary thyroid carcinomas, and 7 follicular adenomas for LOH on chromosome arms 1p, 3p, 3q, 10p, 10q, 11p, 11q, 13q, 17p, and 17q. LOH was more frequent in FTC than in follicular adenoma or papillary thyroid carcinoma. In FTC, rates of LOH on 3p (86%), 17p (72%), and 10q (57%) were higher than the average rate of LOH (33%; P < 0.05). Most frequently involved were 3p21–25 and 17p13.1–13.3, the sites for the VHL (3p25–26) and p53 (17p13.1) tumor suppressors. We, therefore, characterized these genes by dideoxy fingerprinting and DNA sequencing. Two FTC had mutations in p53, but only 1 of these exhibited LOH at 17p. No VHL gene mutations were found. Thus, neither p53 nor VHL genes play a significant role in the pathogenesis of differentiated thyroid cancer. LOH on 17p, but not on 3p or 10q, was correlated with mortality. Accordingly, 3p and 10q LOH may represent early, and 17p LOH late, events in FTC development. The data suggest the presence of novel tumor suppressor genes on chromosomes 3p and 17p that may be important in the pathogenesis of FTC.

Until recently, neuromyelitis optica (NMO) was considered to be a sub-type of multiple sclerosis (MS), which has a strong predilection for Caucasian populations, whereas NMO is more frequent in non-Caucasian individuals. The objective of this study was to compare the HLA-DRB profile in Brazilian Mulatto patients with NMO spectrum disorders (NMOSDs) with that observed for Mulatto MS patients and healthy Mulatto controls. Twenty seven NMOSD patients (20 women), all seropositive for NMO-IgG, 29 MS patients and 28 Mulatto healthy blood donors were evaluated for HLA-DRB allele groups. HLA-DRB1*03 allele group was overrepresented in NMO patients compared with healthy controls (p = 0.0401; OR = 3.23, 95%CI: 1.07—9.82). In contrast, the HLA-DRB1*15 allele group was overrepresented in Brazilian MS patients (OR = 15.89, 95%CI: 3.51—71.85; p < 0.0001). DRB3 was overrepresented in NMO (p = 0.0064), and DRB5 overrepresented in MS patients (p = 0.0001). The low frequency of HLA-DRB1*15 alleles was associated with the presence of long and central cord lesions at magnetic resonance. In addition, DRB1*15 alleles were associated with the fulfillment of the Barkhof criteria. In conclusion, these results indicate that the DRB profile of NMO patients is different from that observed for MS patients, further corroborating the distinction between NMO and MS.