Distinct morphological and immunohistochemical features and different growth rates among four human neuroblastomas heterotransplanted into nude mice.

To elucidate more precisely the biological characteristics of neuroblastomas, we examined four human neuroblastomas heterotransplanted into athymic nude mice NB-39 (undifferentiated type), NB-45 (poorly differentiated type with undifferentiated component), NB-52 (poorly differentiated type), and NB-726 (differentiating type) by electron microscopy, immunohistochemistry, and radioimmunoassay for the peptides in tumors. Ultrastructurally, NB-45, NB-52, and NB-726 contained more numerous and variously sized neurosecretory granules than did NB-39. Immunohistochemistry revealed neurofilament proteins, tyrosine hydroxylase, neuropeptide Y (NPY), and chromogranin A-positive cells in the four tumors in the following order of frequency: NB-726, NB-45, NB-52, and NB-39. NB-726, NB-45, and NB-52, but not NB-39, contained galanin-positive tumor cells. NB-45 and NB-726 harbored a few positive cells for calcitonin gene-related peptide. Furthermore, NB-726 exhibited positivity to leu-enkephalin, met-enkephalin, vasoactive intestinal peptide (VIP), and serotonin. Radioimmunoassay substantiated the results of immunohistochemistry, showing NPY in all tumors and either galanin or VIP in three tumors, excepting NB-39. Average doubling time of the tumor was as follows: 2 days in NB-39, 10 days in NB-45, 22 days in NB-52, and 45 days in NB-726. These results indicate that human neuroblastoma cells have different biological characteristics and reduced growth rate with differentiation in terms of ultrastructure and of peptide production abilities.

Immunohistochemistry of gliosarcoma with liposarcomatous differentiation.

A case of gliosarcoma composed of glioblastoma and liposarcoma is presented. A 70-year-old Japanese man was admitted to hospital because of dysarthria and aphasia. Magnetic resonance imaging indicated a brain tumor located in the temporal-parietal area of the left hemisphere. He rejected any therapy and died of respiratory failure. At autopsy the tumor was well-demarcated with firm consistency and myxoid appearance, accompanied by necrosis and hemorrhage. Microscopically the tumor consisted of both glial and sarcomatous components, compatible with a gliosarcoma. Lipoblast-like tumor cells were identified in the sarcomatous area. Glial component was observed in the periphery and was diffusely positive for CD56 and S100 protein and focally for glial fibrillary acidic protein. Only a small number of tumor cells in the sarcomatous area expressed neurogenic markers. Lipoblast-like tumor cells were positive for S100 protein but negative for any other neurogenic markers. A significant number of tumor cells were positive for retinoblastoma protein (pRB) in the glial area, whereas only a few of them were positive in the sarcomatous area, indicating alteration of pRB in sarcomatous component. The present tumor is a rare gliosarcoma with liposarcomatous differentiation; alteration of pRB may play a role in sarcomatous transformation of glial component.

Distribution and variable expression of secretory pathway protein reticulocalbin in normal human organs and non-neoplastic pathological conditions.

Reticulocalbin (RCN) is one member of the Ca(2+)-binding proteins in the secretory pathway and is localized in the endoplasmic reticulum. RCN may play a role in the normal behavior and life of cells, although its detailed role remains unknown. Overexpression of RCN may also play a role in tumorigenesis, tumor invasion, and drug resistance. The new antibody for human RCN is used in the distribution of RCN in normal human organs of fetuses and adults with or without inflammation. Immunohistochemical examination demonstrated a broad distribution of RCN in various organs of fetuses and adults, predominantly in the endocrine and exocrine organs. However, RCN expression was heterogeneous in each constituent cell of some organs. Among non-epithelial organs, vascular endothelial cells, testicular germ cells, neurons, and follicular dendritic cells showed strong staining. Plasma cells were the only RCN-positive cells among hematopoietic and lymphoid cells. In inflammatory conditions, RCN expression was enhanced in both epithelial and non-epithelial cells. Heterogeneous expression of RCN indicates that the amount of RCN needed for cell behavior and life may be variable, depending on each cell type and, therefore, RCN may be helpful in establishing the cell origin of neoplasms in some organs. However, further study is needed to establish the significance of RCN in tumorigenesis and in some peculiar features of neoplasms.

A gene homologous to human endogenous retrovirus overexpressed in childhood acute lymphoblastic leukemia.

To clarify the mechanism of progression and acquired drug resistance of leukemia, we searched for an overexpressed gene in drug-resistant leukemia cells and identified an approximately 5-kb transcript by using the subtraction method. The nucleotide sequence of the gene was highly homologous to those of human endogenous retrovirus (HERV) transcripts. Reverse transcriptase-polymerase chain reaction (RT-PCR) revealed that the gene was overexpressed in cells from 6 childhood acute lymphoblastic leukemia patients (60%) but not in bone marrow cells at remission. Peripheral blood mononuclear cells from normal controls (n=11) and bone marrow cells from non-leukemia patients (n=13) did not express the gene. These findings indicate that the gene may play a role in leukemogenesis and may be a novel leukemia marker. Further studies on the functional role of the gene are needed.

Expression of heart-type fatty acid-binding protein in human gastric carcinoma and its association with tumor aggressiveness, metastasis and poor prognosis.

OBJECTIVE: Fatty acid-binding proteins (FABPs) are involved in lipid metabolism by intracellular transport of long-chain fatty acids. Heart-type (H-) FABP has been reported to inhibit cell growth and induce cell differentiation, but to our knowledge the significance of H-FABP expression in human gastric carcinoma has not been elucidated. The aim of the current study was to examine the expression of H-FABP and its relation to clinicopathologic parameters and fatty acid synthase (FAS) status of gastric carcinoma, since gastric cancer shows increased expression of FAS. METHODS: Immunohistochemistry with anti-H-FABP antibody was performed in 669 gastric carcinomas and 60 tubular adenomas of the stomach. H-FABP-positive and H-FABP-negative carcinomas were analyzed for their clinicopathologic characteristics and FAS status. RESULTS: None of the adenomas expressed H-FABP, whereas 127 of 669 carcinomas (19.0%) were positive for the protein. H-FABP positivity was associated with the depth of invasion (p <0.0001), vascular invasion (p <0.0001), lymph node metastasis (p <0.0001), hepatic metastasis (p=0.0011), stage of the carcinoma (p <0.0001) and FAS status of the carcinoma (p=0.0476). A higher survival rate was noted in H-FABP-negative cases compared with H-FABP-positive cases (p=0.0004). CONCLUSIONS: A subset of human gastric carcinoma expresses H-FABP and its expression is associated with FAS status, disease progression, tumor aggressiveness and poor patient survival.

Multiple epithelial cysts of the spleen and on the splenic capsule, and high serum levels of CA19-9, CA125 and soluble IL-2 receptor.

An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts.

Liver-type fatty acid-binding protein is highly expressed in intestinal metaplasia and in a subset of carcinomas of the stomach without association with the fatty acid synthase status in the carcinoma.

OBJECTIVE: To investigate the relation of liver-type fatty-acid-binding protein (L-FABP) expression to the clinicopathological characteristics or the fatty acid synthase status of gastric cancers. METHODS: L-FABP expression was examined immunohistochemically in 667 gastric cancers, 60 gastric adenomas, and non-neoplastic epithelium contiguous with cancer tissue including normal foveolae, intestinal metaplasia, regenerative epithelium, and gastric glands. RESULTS: L-FABP was positive in 38% (high in 9% and low in 29%) of gastric cancers. It occurred preferentially in papillary carcinomas, female cases, and in patients under 50 years. In gastric cancers, L-FABP expression had no intimate correlation with the FAS status, and it showed no relationship with prognosis and cancer progression as indicated by venous and lymphatic permeation, and nodal or hepatic metastasis. Gastric tubular adenomas mainly revealed low (22%) expression of L-FABP while intestinal metaplasia showed the most frequent (>95%) and intense L-FABP expression. Normal foveolae and gastric glands showed no or less L-FABP expression. CONCLUSIONS: L-FABP is highly and intensely expressed in metaplasia and in a subset of gastric adenocarcinomas, without association with progression, prognosis and fatty acid synthase status of the carcinoma.

Molecular cytogenetic characterization of drug-resistant leukemia cell lines by comparative genomic hybridization and fluorescence in situ hybridization.

Resistance to chemotherapeutic drugs is one of the major difficulties encountered during cancer chemotherapy. To detect genomic aberrations underlying the acquired drug resistance, we examined three cultured human myelomonocytic leukemia cell sublines each resistant to adriamycin (ADR), 1-beta-1-D-arabinofuranosylcytosine (ara-C), or vincristine (VCR), using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), RT-PCR, and western blot techniques. Chromosomes 7, 10 and 16 most conspicuously showed frequent aberrations among the resistant sublines as compared to the parental KY-821 cell line. In ADR-resistant cells, gains at 7q21, 16p12, 16p13.1-13.3, 16q11.1-q12.1, and losses at 7p22-pter, 7q36-qter, 10p12, 10p11.2-pter, 10q21-q25, 10q26-qter were notable. In ara-C-resistant cells, no remarkable gain or loss on chromosome 7, but losses at 10p14-pter, 10q26-qter and 16p11.2-p11.3 were observed. In VCR-resistant cells, gain at 7q21 and losses at 10p11-p13, 10p15 and 16p11.2-p13.3 were found. FISH identified amplified signals for the MDR-1 gene located at 7q21.1 in ADR- and VCR- but not ara-C-resistant cells, and for the MRP-1 gene located at 16p13.1 in ADR-resistant cells. These findings were validated at the mRNA and protein levels. Overlapping of the amplified MRP-1 gene with MDR-1 gene may play a critical part in the acquisition of resistance to ADR. Resistance to ara-C excluded MDR-1 gene involvement and highlighted other key genes such as MXR gene. Several other genes putatively involved in the development of drug resistance might lie in other aberrated chromosomal regions.