HMGB1 expression in urothelial carcinoma of the bladder.

PURPOSE: HMGB1, the most important member of the high mobility group box protein family, is a nuclear protein with different functions in the cell; it has a role in cancer progression, angiogenesis, invasion, and metastasis development. We studied the expression of HMGB1 and whether it is a prognostic factor in urothelial carcinoma of bladder (UCB) or not. METHODS: The study included 90 cases that were histopathologically diagnosed with UCB in the tissue samples obtained by transurethral resection (TUR). HMGB1 expression was investigated by immunohistochemistry. RESULTS: A total of 90 patients, 80 (88.9%) male and 10 (11.1%) female, were enrolled in the study. The histopathological diagnosis was infiltrating urothelial carcinoma (IUC) in 63 (70.0%) and non-invasive papillary urothelial carcinoma (NIPUC) in 27 (30.0%). When the NIPUC cases were grouped according to grade, 24 (88.9%) of the cases were low grade and 3 (11.1%) were high grade. HMGB1 expression was found positive in 51 (56.7%) and negative in 39 (43.3%) of the patients. HMGB1 expression was significantly higher in IUCs (p=0.046). CONCLUSION: The results of our study demonstrate that HMGB1 overexpression has a significant role in UCB progression and it corroborates the idea that it might be an important prognostic factor.

Expression of claudin 1, 4 and 7 in thyroid neoplasms.

The distinction of thyroid carcinoma from benign thyroid neoplasm, as well as the subtyping of papillary carcinoma (PC) and follicular carcinoma (FC), may be performed histopathologically in the majority of cases. However, in certain cases, it is difficult to histopathologically distinguish between PC and FC, as well as follicular adenoma (FA), FC and the dominant nodule of multinodular goiter (MNG-DN). The present study aimed to determine the roles of the expression levels of the tight junction proteins claudin 1, 4 and 7 in the differential diagnosis of PC, FC, FA, MNG-DN, medullary carcinoma (MC) and anaplastic carcinoma (AC). The current study included 114 cases of histopathologically diagnosed thyroid neoplasia, which were distributed as follows: 29 FA, 18 MNG-DN, 47 PC, 10 FC, 5 MC and 5 AC. The expression levels of claudin 1, 4 and 7 were examined using immunohistochemical methods. The results revealed a significant difference in claudin 1 expression between malignant and benign thyroid neoplasms (P<0.001). Claudin 1 expression was not detected in any of the MNG-DN cases, and no significant difference in claudin 1 expression levels was identified between FA and FC (P=0.653). However, a statistically significant difference was observed between FC and PC (P<0.001). Claudin 4 expression did not differ between malignant and benign thyroid neoplasms, neither between MNG-DN, FA and FC, nor between FC and PC (P=0.068, P=0.502 and P=0.481, respectively). Claudin 7 exhibited positive immunohistochemical staining in 107 patients (94%); however, no significant difference in claudin 7 expression §levels was identified between malignant and benign thyroid neoplasms among MNG-DN, FA and FC (malignant, P=0.135; benign, P=0.470). Claudin 7 exhibited positive staining in all PC and FC cases. Therefore, claudin 1 expression levels may be useful in distinguishing cases of FC and PC with overlapping histopathological features, and provide a novel immunohistochemical marker for the subtyping of thyroid carcinoma.