Differential Expression of Vascular Endothelial Growth Factor (VEGF) and VEGF Receptors in the Sequence of Hyperplastic Polyp, Serrated Adenoma and Adenocarcinoma of Colorectum

AIM: The aim of this study was to investigate the role for vascular endothelial growth factor (VEGF) and its receptors, VEGFR-1 and -2, in the hyperplastic polyp (HP)- serrated adenoma (SA)-adenocarcinoma (AC) sequence of the colorectum.Methods: Thirty-six HPs, 33 SAs and 7 ACs (which contained HP and/or SA) were immunohistochemically examined for the expression of VEGF, VEGFR-1, and VEGFR-2.Results: VEGF protein was expressed in the cytoplasm of SA and AC tumor cells, and VEGFR-1 and VEGFR-2 were expressed both in the cytoplasm and on the membrane of these tumors, while there was faint or no expression of VEGF, VEGFR-1 and VEGFR-2 in HPs. Immunohistochemical staining revealed that 8.3% (3 of 36) HPs, 87.9% (29 of 33) SAs and 100% (7 of 7) ACs were positive for VEGF; 2.8% (1 of 36) HPs, 97.0% (32 of 33) SAs and 100% (7 of 7) ACs were positive for VEGFR-1; 16.7% (6 of 36) HPs, 100% (33 of 33) SAs and 100% (7 of 7) ACs were positive for VEGFR-2. The expression of VEGF, VEGFR-1 or VEGFR-2 was statistically correlated with the sequence of HP, SA and AC (P < 0.0001, respectively) Conclusion: Our results suggest that the VEGF pathway may play an important role in the HP-SA-AC sequence

Immunohistochemical analyses of beta-catenin and cyclin D1 expression in giant cell tumor of bone (GCTB): A possible role of Wnt pathway in GCTB tumorigenesis.

Giant cell tumor of bone (GCTB) is a benign neoplasm but occasionally shows local recurrence, and histologically consists of osteoclast-like giant cells (GC) and stromal mononuclear cells (SC), which are capable of proliferation and osteoblastic differentiation. Activation of Wnt signaling can induce osteoblast differentiation and osteoclastgenesis during bone resorption process. This study analyzed the profiles of beta-catenin and cyclin D1 expression in GCTB to elucidate an involvement of Wnt pathway in tumorigenesis. We performed immunohistochemistry for beta-catenin, cyclin D1, and Ki-67 in 16 GCTB tumors, including 5 recurrent cases that were surgically resected. All 16 cases of GCTB displayed beta-catenin, cyclin D1, and Ki-67 expression. Immunoreactivity for beta-catenin was observed in nuclei of SC and GC. Cyclin D1 immunoreactivity was found mainly in nuclei of GC, while Ki-67 immunoreactivity was restricted to nuclei of SC. The nuclear beta-catenin labeling index (LI) in both SC (60.6 vs. 41.8%, p=0.074) and GC (41.7 vs. 20.1%, p=0.095) was higher in recurrent tumors than in primary tumors in all the 4 cases. However, Ki-67 LI in SC (18.8 vs. 19.9%, p=0.851) and cyclin D1 LI in GC (55.4 vs. 70.1%, p=0.225) were not higher in recurrent tumors than in primary tumors. Our results suggested activation of Wnt/ beta-catenin pathway in GCTB tumorigenesis. Since cyclin D1 in GC was never associated with the expression of the well-known proliferative marker Ki-67, cyclin D1 expression might play a role in GC formation instead of promoting cell proliferation during GCTB tumorigenesis. Importantly, it was suggested that the nuclear beta-catenin staining level might be associated with tumor recurrence in GCTB

Expression and Significance of Angiopoietin-1, 2 and Tie-2 Receptor in Human Extrahepatic Bile Duct Carcinoma: Correlation with Clinicopathological Factors

Extrahepatic bile duct cancer is a high mortal malignancy. Angiopoietin (Ang) and its receptor Tie, which are known to contribute to angiogenesis, have recently been reported to participate in the proliferation and differentiation of malignant tumor cells. The aim of this study is to investigate the expression and the significance of Ang-1, 2 and Tie-2 in extrahepatic bile duct carcinoma cells. We used immunohistochemistry to study 119 cases of surgically resected human extrahepatic bile duct carcinoma, and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) to confirm the expression of Ang-1, 2 and Tie-2 mRNA. Among these 119 cases, 52 (43.7%), 50 (42.0%) and 89 (74.8%) cases showed positive staining for Ang-1, 2 and Tie-2, respectively, in bile duct carcinoma cells. In 38 cases of normal mucosa, 6 (15.8%), 10 (26.3%) and 9 (23.7%) cases were positive for Ang-1, 2 and Tie-2, respectively. The positivity for Ang-1 and Tie-2 in normal mucosa was significantly different from all carcinomas (p<0.01 and p<0.001, respectively). We found no significant correlation between Ang-1 and Ang-2 expression and other clinicopathological factors such as histological differentiation, grade of tumor invasion or survival rate after surgery. In contrast, Tie-2 expression correlated significantly with degree of desmoplasia, cancer stage and survival of patients. RT-PCR analyses of five surgically resected tumor samples and three human bile duct cancer cell lines all showed positive expression of Ang-1, 2 and Tie-2 mRNAs. High expressions of Ang-1, 2 and Tie-2 in human extrahepatic bile duct carcinoma cells suggested that Ang-Tie system may be involved in the progression of human bile duct cancer

Differential Expression of Vascular Endothelial Growth Factor (VEGF) and VEGF Receptors in the Sequence of Hyperplastic Polyp, Serrated Adenoma and Adenocarcinoma of Colorectum

AIM: The aim of this study was to investigate the role for vascular endothelial growth factor (VEGF) and its receptors, VEGFR-1 and -2, in the hyperplastic polyp (HP)- serrated adenoma (SA)-adenocarcinoma (AC) sequence of the colorectum.Methods: Thirty-six HPs, 33 SAs and 7 ACs (which contained HP and/or SA) were immunohistochemically examined for the expression of VEGF, VEGFR-1, and VEGFR-2.Results: VEGF protein was expressed in the cytoplasm of SA and AC tumor cells, and VEGFR-1 and VEGFR-2 were expressed both in the cytoplasm and on the membrane of these tumors, while there was faint or no expression of VEGF, VEGFR-1 and VEGFR-2 in HPs. Immunohistochemical staining revealed that 8.3% (3 of 36) HPs, 87.9% (29 of 33) SAs and 100% (7 of 7) ACs were positive for VEGF; 2.8% (1 of 36) HPs, 97.0% (32 of 33) SAs and 100% (7 of 7) ACs were positive for VEGFR-1; 16.7% (6 of 36) HPs, 100% (33 of 33) SAs and 100% (7 of 7) ACs were positive for VEGFR-2. The expression of VEGF, VEGFR-1 or VEGFR-2 was statistically correlated with the sequence of HP, SA and AC (P < 0.0001, respectively) Conclusion: Our results suggest that the VEGF pathway may play an important role in the HP-SA-AC sequence

An Acquired Form of Dandy-Walker Malformation with Enveloping Hemosiderin Deposits

Dandy-Walker malformation (DWM) is a posterior fossa anomaly characterized by hypoplasia and upward rotation of the cerebellar vermis and cystic dilation of the fourth ventricle. The cyst of DWM rarely extends posteriorly to almost completely fill the entire posterior fossa, which mimics primary cerebellar agenesis, a cerebellar porencephalic cyst, and an arachnoid cyst due to the lack of clarity of the thin cystic wall. A 10-month-old female born at 23 weeks’ gestation with cerebellar hemorrhage in the neonatal period was admitted to our hospital with dysphagia and side-to-side head bobbing. The detection of hemosiderin deposits enveloping the cyst wall by T2 star-weighted angiography (SWAN) was useful for the differential diagnosis of an acquired form of DWM from primary cerebellar agenesis. Cyst fenestration successfully improved dysphagia and head bobbing. A pathological specimen of the perforated cyst consisted of collagen fibers with hemosiderin deposits but lacked congenital cyst components. In infants with posterior fossa cysts, SWAN will be useful for a differential diagnosis between DWM and primary cerebellar agenesis