Kazuyoshi Kajimoto

Vitamin D3 supports osteoclastogenesis via functional vitamin D response element of human RANKL gene promoter

Receptor activator of NF‐κB ligand (RANKL) has been identified as requisite for osteoclastogenesis. To elucidate the molecular mechanism that conducts its catabolic action on bone, the effect of 1α,25 dihydroxyvitamin D3 (1α,25(OH)2D3) on osteoclastogenesis and RANKL mRNA expression was examined by coculture, RT‐PCR and nuclear run‐on studies. By accelerating the transcription rate of the RANKL gene in SaOS2 osteoblastic cells, 1α,25(OH)2D3 enhanced in vitro osteoclast formation from peripheral monocytes. Cloning and characterization of the 5′‐flanking region of the human RANKL gene revealed that the basic promoter comprises inverted TATA‐ and CAAT‐boxes flanked by RUNX2 binding sites. Both electrophoresis mobility shift assay (EMSA) and transfection studies demonstrated that 1α,25(OH)2D3 activated human RANKL promoter through vitamin D responsive elements (VDRE) located at −1584/−1570 by binding VDR and RXRα heterodimers in a ligand‐dependent manner. The results provide direct evidence that 1α,25(OH)2D3 augments osteoclastogenesis by transactivating the human RANKL gene in osteoblastic cells through VDRE. J. Cell. Biochem. 89: 771–777, 2003.

Intravascular large B-cell lymphoma presenting with mass lesions in the central nervous system: A report of five cases

We have encountered five cases of intravascular large B‐cell lymphoma (IVL) presenting with central nervous system (CNS) mass lesions during their clinical course. The age of the patients ranged from 50 to 74 years and three patients were male. All of these cases histopathologically showed typical intravascular localization of the neoplastic cells in the initial biopsy specimens obtained from sites other than the CNS. Despite multiagent chemotherapy, patients suffered from single or multiple CNS mass lesions 5–44 months after the initial diagnosis of IVL, except for one case in which IVL and the CNS mass lesion were diagnosed at the same time. The subsequent biopsy and autopsy specimens obtained from the CNS mass lesions revealed diffuse infiltration of the tumor cells with perivascular spreading, but minimal or no intravascular components. Immunohistochemical analysis of intravascular tumor cells and CNS mass lesions revealed expression of CD20, CD79a, bcl‐2 and negative for CD3e and Epstein–Barr virus encoded RNA. The overall features of the CNS mass lesions were very similar to or indistinguishable from those of the primary CNS lymphomas. This implies that CNS mass lesions in the IVL cases can be correctly diagnosed only by careful attention to clinical and pathological findings. Moreover, there is the possibility that some cases previously diagnosed as primary CNS lymphomas may have include IVL cases. Further investigation is needed to explore this unusual phenomenon.

Levels of soluble FasL and FasL gene expression during the development of graft‐versus‐host disease in DLT‐treated patients

Three patients with different clinical symptoms of graft‐versus‐host disease (GVHD) who had received donor lymphocyte transfusion (DLT) for the treatment of relapsed leukaemia after an allogeneic bone marrow transplantation (BMT) from HLA‐matched sibling donors were analysed for the presence of soluble FasL (sFasL) in the sera and for the expression of the Fas ligand (FasL) gene in the peripheral blood mononuclear cells (PBMNC). Two patients who demonstrated liver damage with increased levels of serum bilirubin showed significantly increased levels of serum sFasL. The increase in the sFasL level was observed prior to the increase in the bilirubin during the clinical courses of both patients. The high dose of methyl predonisolone administered to one of these patients greatly reduced the levels of sFasL in the serum. The bilirubin levels were also reduced thereafter. The third patient (without liver damage) did not show any increase in the serum sFasL level.

Intravascular large T-cell lymphoma: a case report of CD30-positive and ALK-negative anaplastic type with cytotoxic molecule expression

We reported a case of intravascular T-cell lymphoma (T-IVL) with anaplastic large cell morphology, the hemophagocytic syndrome, and an aggressive clinical course. Phenotypic analysis of the tumor cells revealed CD2+, CD3−, CD4+, CD5−, CD8−, CD30+, CD56−, T-cell receptor alpha/beta−, ALK−, TIA1+, granzyme B+, and perforin+. No association with Epstein–Barr virus was found by in situ hybridization. A review revealed that 25 cases of T-IVL have been reported in the available literature, only two of which were of CD30+ anaplastic large cell or cytotoxic T-cell type. The findings in the present case may highlight the unique clinicopathologic aspects of a subset of CD30-positive T-IVLs with an ALK-negative cytotoxic phenotype.

Expression of parathyroid hormone-related protein (PTHrP) in multiple myeloma

Multiple myeloma is a plasma cell neoplasia often associated with multiple skeletal lesions and hypercalcemia. Several cytokines, including interleukin (IL)‐1, IL‐6 and tumor necrosis factor‐β (TNF‐β), derived from myeloma cells are thought to accelerate osteoclastic bone resorption and cause hypercalcemia through a paracrine mechanism. We report on a case of a 69‐year‐old man with multiple myeloma associated with hypercalcemia and advanced osteolytic lesions. After bisphosphonate treatment and MP (melphalan and prednisolone) therapy, the patient’s serum calcium level was successfully but transiently recovered to the normal range. Biochemical analysis showed a remarkable increase in serum parathyroid hormone‐related protein (PTHrP; 3.7 pmol/L) and IL‐6 (22.0 pg/mL). On the other hand, parathyroid hormone and 1α,25(OH)2 vitamin D3 were suppressed. By immunohistochemistry and in situ hybridization on aspiration‐biopsied bone marrow clot sections, PTHrP mRNA and protein were detected in the cytoplasm of myeloma cells. The rate of PTHrP‐positive myeloma cells was estimated to be at least one‐third. Since PTHrP can, as an endocrine factor, systemically act on bone and kidney, hypercalcemia in this case might have been caused through both local osteolytic hypercalcemia and humoral hypercalcemia of malignancy mechanisms.

Immunohistochemical Profiling of ALK Fusion Gene–Positive Adenocarcinomas of the Lung

Our aim was to determine whether or not non-small-cell lung cancer is squamous cell carcinoma (SQCC); even in small samples, it is essential in view of the side effects attendant on new therapeutics. Lung adenocarcinoma (ADC) with the EML4-ALK fusion gene has been described as demonstrating mucinous cribriform/acinar growth and signet-ring cells, sometimes partially simulating SQCC. We investigated the relation among morphology, anaplastic lymphoma kinase (ALK) rearrangement, and immunophenotype in 321 ADCs by tissue microarray using SQCC markers cytokeratin (CK)5/6, CK14, desmocollin-3, desmoglein-3, p40, p63 versus ADC markers thyroid transcription factor (TTF)-1 and napsin A. Unlike 312 ALK-negative ADCs, 9 ALK-positive cases were negative for 4 SQCC markers. Only 1 ALK-positive ADC showing assertive morphology was positive for CK5/6 and p63 as well as for TTF-1 and napsin A. Coexpression of TTF-1/p40 was not observed, unlike that of TTF-1/p63 reported previously. There was no statistically significant difference between ALK-negative and ALK-positive ADC by immunohistochemical profiling.

Significance of microscopic invasion into hilar peribronchovascular soft tissue in resection specimens of primary non-small cell lung cancer

INTRODUCTION The significance and handling of microscopic invasion of non-small cell lung cancer (NSCLC) into hilar peribronchovascular soft tissue (SHEATH+) have not been defined in the TNM classification by AJCC/UICC; nevertheless, SHEATH+ may be equivalent to spread into the mediastinum. Also, assessment of the margin of peribronchial resection is challenging because of the technical difficulty of inking, and intraoperative and postoperative artifacts. METHODS Records of 592 consecutive Asian patients with primary NSCLC (excluding adenocarcinoma in situ) who had, without any preoperative therapy, undergone lobectomy, sleeve lobectomy and pneumonectomy were examined. SHEATH+, simply defined as invasion of hilar peribronchovascular soft tissue, without categorizing any invasive patterns, and its significance were statistically analyzed. RESULTS Forty-four SHEATH+ cases demonstrated significantly advanced TNM stages, and were statistically associated with central occurrence, pN1-3, and vascular invasion, as assessed by logistic regression analysis. No statistically significant differences were observed between TNM stage-adjusted frequency of recurrence and recurrence-free intervals. Kaplan-Meiers estimates of the rate of overall and recurrence-free survival after surgery showed no statistically significant differences between SHEATH+ and SHEATH-. Coxs multivariate analysis suggested SHEATH was not a statistically independent prognostic factor under the TNM classification by AJCC/UICC (7th edition). CONCLUSIONS SHEATH+ in NSCLC was simply associated with central occurrence and advanced TNM stages. To the best of our knowledge, this is the first report on the significance of SHEATH+ in NSCLC.

Pleural malignant mesothelioma with osteoclast‐like giant cells

Reported herein is the first case of malignant mesothelioma with osteoclast‐like giant cells (OGC) in a 55‐year‐old man, a building contractor. Open thoracoscopic biopsy from the left parietal pleura showed a pleomorphic tumor composed of round to spindle cells mixed with numerous OGC; focal hemorrhage and necrosis were observed, but neither bone nor osteoid tissue was seen. The tumor cells had eosinophilic cytoplasm and round to oval nuclei with varying degrees of atypia. OGC had multiple small uniform nuclei without atypia and large eosinophilic cytoplasm, similar to giant cells of the so‐called giant‐cell tumors. On immunohistochemistry the tumor cells stained positive for AE1/AE3 and mesothelial markers, including calretinin, thrombomodulin, D2‐40, and negative for carcinoma markers, including CEA, MOC31, and thyroid transcription factor‐1. Consequently the tumor was diagnosed as malignant mesothelioma with OGC. Because malignant mesothelioma with OGC has not been reported to date, described herein are the histopathology and immunohistochemistry findings of this tumor, and a review of the literature.

CD56-positive diffuse large B-cell lymphoma: possible association with extranodal involvement and bcl-6 expression

Abstract Among B-cell non-Hodgkins lymphomas, neural cell adhesion molecule/CD56 expression is exceptional. In this study, seven cases of CD56-positive diffuse large B-cell lymphoma (DLBCL) are described. The frequency of CD56-positive DLBCL was 7% in our hospital. Four of seven (57·1%) cases expressed both CD10 and bcl-6 suggestive of a germinal center B-cell phenotype. Six of seven (85·7%) cases expressed bcl-6. Two cases expressed aberrant T cell-associated antigens, one each of CD7 and CD8. However, none of these seven cases showed CD5 expression. No significant difference was observed between CD56-positive and CD56-negative DLBCL in terms of the five international prognostic index risk factors. However, all seven cases had at least one extranodal involvement and showed a good response to initial treatment. The predominance of extranodal involvement in our series may be associated with the adhesion-related function of CD56. A high frequency of bcl-6 expression may be associated with a more favorable clinical course and prognosis.

t(14;18)(q32;q21)-bearing pleural MALT lymphoma with IgM paraproteinemia: Value of detection of specific cytogenetic abnormalities in the differential diagnosis of MALT lymphoma and lymphoplasmacytic lymphoma

Abstract A 67-year-old woman presented with a pleural effusion and a tumor in the right pleural wall. Histological examination of thoracoscopic tumor and pleural biopsy specimens showed infiltration by medium sized cells, some of which showed plasmacytoid differentiation. In view of the presence of IgM paraproteinemia and bone marrow involvement by lymphoma cells, the patient was diagnosed tentatively as having lymphoplasmacytic lymphoma (LPL). However, chromosomal analysis of the cells in the pleural fluid detected t(14;18)(q32;q21), while fluorescence in situ hybridization was positive for 11% of the MALT1 split signal. Because of the presence of characteristic genetic abnormalities and notable extranodal involvement, the patient was diagnosed as having MALT lymphoma. She was treated with three courses of cladribine and rituximab, and achieved complete regression of the tumor. In this case the detection of t(14;18)(q32;q21) involving IGH and MALT1 was useful for the differential diagnosis of LPL and MALT lymphoma.