Hiroyuki Maeta

Protein expression of matrix metalloproteinases 2 and 9 and tissue inhibitors of metalloproteinase 1 and 2 in papillary thyroid carcinomas.

Abstract. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play an important role in tumor invasion and metastasis. There have been only a few studies on the protein expression of MMPs and TIMPs in thyroid carcinomas. Therefore, we investigated the protein expression of MMP-2, MMP-9, TIMP-1 and TIMP-2 in 86 papillary thyroid carcinomas using immunohistochemistry, semiquantitative scoring morphometry of immunohistochemistry, gelatin zymography, and western blotting. We also examined the correlations between the immunohistochemical scores and several clinicopathological parameters. The immunoreactivities of MMP-2, MMP-9, TIMP-1, and TIMP-2 were largely located in the tumor cells or non-tumor follicular cells and to a much lesser extent in the fibroblasts and endothelial cells in the tumor and non-tumor regions. Compared with non-tumor regions, these four proteins tended to be overexpressed in the tumor cells; the overexpression was found in 64 of 86 (74%), 80 of 86 (93%), 79 of 86 (92%), and 64 of 86 (74%) cases for MMP-2, MMP-9, TIMP-1, and TIMP-2, respectively. Gelatin zymography showed distinct bands of MMP-2 and MMP-9 in tumor extracts but vague bands in non-tumor extracts. Western blotting revealed the specific bands of MMP-2 and MMP-9 in both tumor and non-tumor extracts. Morphometric scoring revealed that high expression of these proteins significantly correlated with large tumor size, presence of lymph node metastasis, high clinical stage, high intrathyroidal invasion, and high vascular invasion. These data suggest that MMP-2, MMP-9, TIMP-1, and TIMP-2 proteins and activities are increased in tumors cells of papillary thyroid carcinomas and that they play an important role in the invasion and metastasis of papillary thyroid carcinomas.

c-erbB-2 protein is expressed in hepatolithiasis and cholangiocarcinoma.

The c‐erbB‐2 proto‐oncogene encodes a transmembrane protein which is highly homologous to epidermal growth factor receptor. Overexpression of this c‐erbB‐2 protein has been reported in many human carcinomas, including breast carcinoma. However, there have been few studies of the expression of c‐erbB‐2 in cholangiocarcinoma and hepatolithiasis, a condition occasionally associated with cholangiocarcinoma.

Immunohistochemical and In Situ Hybridization Analyses of Midkine Expression in Thyroid Papillary Carcinoma

Midkine (MK) is a novel heparin-binding growth factor whose gene has been identified in embryonal carcinoma cells in early stages of retinoic acid-induced differentiation. We immunohistochemically examined 90 thyroid papillary carcinomas (85 invasive type and five encapsulated type), using a rat IgG2a monoclonal antibody against the carboxyl terminal region of human MK in archival paraffin sections. The thyroid tumors exhibited an intense reaction in the cytoplasm. Most of the papillary carcinomas (77/90), had tumor cells that expressed MK. These were classified into the following two types: invasive type (76/85) and encapsulated type (1/5). Notably, the intensity of MK was stronger at the invading border area of the tumors than in the center. In tissues adjacent to the cancer tissues, normal follicular epithelial cells expressed MK very faintly or not at all. The in situ hybridization analysis revealed that the signals of MK transcripts were found in the cytoplasm of the cancer cells. In the noncancerous follicular epithelial cells adjacent to neoplasm the signals of MK transcripts were detected very weakly or not at all. The distribution and localization of the MK-transcript signals determined by in situ hybridization analysis were similar to those obtained by immunohistochemical analysis. We conclude that thyroid papillary carcinoma strongly expresses MK protein and messenger RNA, and that this overexpression may relate to the development and invasion of these carcinomas.

Overexpression of p53 protein and MDM2 in papillary carcinomas of the thyroid: Correlations with clinicopathologic features

Expression of p53 protein and MDM2 was evaluated in paraffin‐embedded tissue from 78 patients with papillary carcinomas of the thyroid (PCT), in order to elucidate the relationship between them and their correlations with some clinicopathologic features implicated in tumor progression. These proteins were expressed in nuclei of tumor cells, but not in non‐tumor cells. Staining was defined as positive when 10% or more of tumor cells expressed these proteins. The number of cases positive for p53 protein was 21/78 (27%), and that positive for MDM2 was 26/78 (33%). Co‐overexpression of p53 protein and MDM2 was observed in 12/78 cases (15%). A significant positive relationship was found between them (P < 0.01); p53‐positive cases tended to be also positive for MDM2 and vice versa. Statistical analysis revealed that overexpression of p53 protein significantly correlated with large tumor size (P = 0.0271) and the presence of capsular invasion (P = 0.04). There were significant positive correlations between tumor size and intrathyroidal invasion and between tumor size and capsular invasion in PCT, suggesting that p53 protein overexpression is associated only with tumor progression (tumor size). However, we could not find any significant correlations between MDM2 expression and clinicopathologic features. Our findings suggest that overexpression of p53 protein and MDM2 in papillary carcinoma of the thyroid is associated with the progression of the tumors, and that p53 may be a marker of the progression of PCT.

Absence of mutations in the β-catenin and adenomatous polyposis coli genes in papillary and follicular thyroid carcinomas

β‐Catenin has multiple functions both in intercellular adhesion and in signal transduction. As a signaling molecule, mutations in exon 3 of the β‐catenin gene stabilize this protein in the cytoplasm. Subsequently, accumulated β‐catenin protein translocates to nuclei with T‐cell factor‐4, and upregulates transcriptional activity of the target genes involved in carcinogenesis. Mutations in exon 3 of the β‐catenin gene have been detected in various carcinomas. We examined immunolocalization of β‐catenin protein and mutations in the β‐catenin and adenomatous polyposis coli (APC) genes in papillary carcinoma (25 cases), follicular carcinoma (two cases), and benign thyroid tumor (29 cases). We detected no mutation in exon 3 of the β‐catenin gene in both malignant and benign thyroid tumors by polymerase chain reaction (PCR) and direct sequencing. No mutations in the mutation cluster region of APC were found in any tumor samples analyzed. Immunohistochemically, β‐catenin showed membranous localization in most specimens. These results suggest that mutations of the β‐catenin and APC genes are rare and that activation of the Wnt signaling pathway may not contribute to pathogenesis in human papillary and follicular thyroid carcinomas.

Mixed ductal-endocrine carcinoma of the pancreas presenting as gastrinoma with Zollinger-Ellison syndrome: an autopsy case with a 24-year survival period

Abstract We report an autopsy case of mixed ductal-endocrine carcinoma of the pancreas presenting as gastrinoma with Zollinger-Ellison syndrome. A 38-year-old Japanese male was found to have Zollinger-Ellison syndrome and pancreatic gastrinoma, and gastrectomy and resection of the pancreatic tumor were performed. However, hypergastrinemia persisted, and the patient died of disseminated carcinomatosis at 62 years of age, 24 years after the onset of Zollinger-Ellison syndrome. At autopsy, the main tumor was present in the residual pancreas, and metastases were noted in many organs. In the pancreas and other organs, ductal and endocrine carcinoma areas were mixed and there was a gradual transition between the two. No acinar differentiation was noted. The ductal elements were positive for mucins and carcinoembryonic antigen but negative for neuroendocrine markers, while endocrine elements were positive for chromogranin A and synaptophysin and to a lesser extent for gastrin, but negative for mucins and carcinoembryonic antigen. The ductal elements comprised about 30% of the tumor cells, and endocrine elements 70%. According to the revised World Health Organization classification, our case was diagnosed as mixed ductal-endocrine carcinoma. Our case is rare because the tumor manifested as gastrinoma with Zollinger-Ellison syndrome and the patient survived for 24 years. To the best of our knowledge, no such case has been reported. Our case suggests that pancreatic endocrine tumors may evolve into mixed ductal-endocrine carcinomas.

Advanced cancer with situs inversus totalis associated with KIF3 complex deficiency: Report of two cases

Situs inversus totalis (SIT) is a relatively rare congenital anomaly, occurring at an incidence of 1 in 10 000–50 000 live births. Although there are some case reports of SIT with the presence of cancer, there are few reports on the relationship between SIT and cancer. However, the recent phylogenetic investigations of this condition suggest that this may be linked to the development and progression of cancer on the molecular level. The key elements are one of the intracellular motor proteins, the KIF3 complex, and the cell-adhesion factors N-cadherin and β-catenin. We herein present the cases of advanced gastric cancer and lung cancer with SIT, and review the relationship between SIT and the development and progression of cancer.

Epithelioid leiomyosarcoma with osteoclast-like giant cells in the rectum.

We report a rare case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells. A 71-year-old Japanese man was admitted to a hospital with melena. Results of a colonoscopy test revealed a polypoid tumor in the rectum, and a biopsy specimen from the lesion showed a sarcoma; the patient underwent rectosigmoidectomy. At gross inspection, the tumor measured 8 x 7 x 4 cm and was polypoid with ulcerations. Necrotic and hemorrhagic foci were scattered. Microscopically, the tumor consisted of 2 cell types: malignant tumor cells with epithelioid features and benign-appearing osteoclast-like giant cells. The tumor cells were polygonal and epithelioid in shape and had eosinophilic or clear cytoplasms, with scattered giant tumor cells. Immunohistochemical examination revealed that the tumor cells were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin, whereas the osteoclast-like giant cells were positive for CD68, leukocyte common antigen, and lysozymes. We diagnosed this case as epithelioid leiomyosarcoma with osteoclast-like giant cells. To the best of our knowledge, this is the first case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells.

Surgical removal of left atrial myxoma through mini sternotomy and the superior transseptal approach

A 32-year-old man admitted for treatment of a left atrial myxoma showed a 76 x 25 mm tumor in the left atrium originating in the interatrial septum upon echocardiography. The myxoma was surgically removed using a mini sternotomy and the superior transseptal approach. The hospital course was unremarkable. In the 2 years since operation, the patient has remained asymptomatic and tumor-free. The superior transseptal approach is thus useful in surgical removal of left atrial myxoma because it can be excised with minimum manipulation despite the mini sternotomy and small skin incision.

A case of acute arterial thrombosis caused by nephrotic syndrome.

Venous thromboembolic complications are frequently caused by nephrotic syndrome, while arterial thrombosis has rarely been reported. We report the successful treatment of a 53-year-old man who suffered from sudden severe pain of the left lower limb and facial edema. Abdominal computed tomography showed that the left common iliac artery was occluded from its origin. Although he had left peroneal nerve paralysis, thrombectomy and fasciotomy were performed for limb salvage. Renal biopsy revealed minimal change nephrotic syndrome after the operation. No recurrence has been observed. Nephrotic syndrome might be considered as a cause of acute arterial thrombosis.