Journal of Pathology and Translational Medicine

Original Articles

An Analysis of p53, bcl-2 and Ki-67 Expressions, and Apoptosis in Rectal Cancer: Their Correlation with the Tumor Response after Preoperative Radiochemotherapy.: Jinyoung Yoo, Su Zy Kim, Hyeon Min Cho, Sung Whan Kim, Hyung Min Chin, Jung Yong Lee, Jun Ki Kim, Seok Jin Kang, Chung Soo Chun, Chang Suk Kang; Korean J Pathol. 2005;39(4):222-228.

Abstract PDF: Background
: Preoperative radiochemotherapy (RCT) has been administered for locally advanced rectal cancer to increase the therapeutic benefits, and to preserve the sphincter in low-lying tumors, however, tumor responses after RCT are variable. Methods : Apoptotic index (AI), and expressions of Ki-67, p53 and bcl-2 were analyzed in pretreatment biopsies from 69 patients with rectal cancer by immunohistochemistry. Tumor response was graded in surgically resected specimens by using a three-scale grading system: no response (NR), partial remission (PR) and complete remission (CR). Results : CR was identified in 19 cases (28%), PR in 24 cases (35%), and NR in 26 cases (38%) of 69 cases. p53 protein was expressed in 49 cases (71%), whereas bcl-2 was in 42 cases (61%). The pretreatment Ki-67 labeling index was 65.4+/-3.4%. The tumor response was not associated with any of these markers. Tumors with CR/PR showed a higher AI (0.84+/-.84%/0.66+/-.52%) than that of tumors with NR (0.58+/-0.54%). There was a significant correlation between tumor response and the histologic differentiation (p=0.008) or recurrence (p=0.039). Conclusions : The AI revealed a tendency to increase in tumors with CR/PR, while expressions of p53 and bcl-2, and Ki-67 labeling index had little direct association with tumor response.

Thrombospondin-1 and -2 Expressions in Hepatocellular Carcinomas: an Association with Tumor Angiogenesis and p53 Overexpression.: Jae Sin Chung, Ho Sung Park, Hyun Jin Son, Myoung Jae Kang, Woo Sung Moon; Korean J Pathol. 2005;39(4):215-221.

Abstract PDF: Background
: It has been suggested that thrombospondin (TSP) is a p53-dependent negative regulator of tumor angiogenesis. TSP expression and localization in hepatocellular carcinomas (HCCs) and its association with overexpression of p53 protein were investigated. Methods : TSP-1 and -2 expressions were examined in 40 HCC specimens by immunohistochemical staining and in 4 HCC cell lines by Western blotting. In addition, p53 protein expression and microvessel density (MVD) were correlated with the TSP expression. Results : Strong immu- nopositivity for TSP-1 was observed in fibroblasts, vascular endothelial cells, and some vas- cular smooth muscle cells of the stroma in 18 cases (45%), and in tumor cells in 3 cases (7.5%) of 40 cases of HCC. Immunoreactivity for TSP-2 was observed in only the sinusoidal lining cells of the tumor in 15 cases (46%), and in tumor cells in 2 cases (6%) of 32 cases of HCC. TSP-1 expression was inversely correlated with MVD (p=0.028), but TSP-2 expression did not show any correlation with MVD. Although p53 was overexpressed in 17 cases, there was no significant correlation between TSP and p53 expressions. None of the HCC cell lines expressed TSP-1 or -2. Conclusions : These findings indicate that TSP-1 is mainly derived from nonparenchymal cells, and may decrease tumor angiogenesis in HCC.

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