No abstract

For the detection of chromosome translocations/chimeric genes and specific genetic abnormalities in soft tissue tumors, we conducted fluorescence in situ hybridization (FISH) analysis on 280 cases of soft tissue and other tumors using formalin-fixed paraffin-embedded tissue sections. The detection rate of the FISH split-signal was 84% (129/154 cases) for the translocation-associated soft tissue tumors, such as Ewing's sarcoma/primitive neuroectodermal tumor, synovial sarcoma, alveolar rhabdomyosarcoma, myxoid liposarcoma, clear cell sarcoma and so forth. Positive split-signals from EWSR1, SS18 and FOXO1A probes were detected in 3% (2/64) of various histological types of carcinoma, lymphoma, melanoma, meningioma and soft tissue tumors. In FISH using the INI1/CEP22 probe, the INI1 deletion signal was detected in 100% (9/9) of epithelioid sarcoma. In well-differentiated and dedifferentiated liposarcomas, detection of MDM2 amplification signals in FISH using the MDM2/CEP12 probe were both as high as 85% (11/13) and 100% (13/13), respectively. In other adipocytic and non-adipocytic tumors requiring differentiation from these types, detection was only 13% (5/39), and CEP12 polysomy was frequently detected. As these results demonstrate the high sensitivity and specificity of FISH, we concluded FISH to be a useful pathological diagnostic adjunct for definite and differential diagnosis of soft tissue tumors.

Background: The pterygium is a growth onto the cornea of fibrovascular tissue that is continuous with the conjunctiva, whereas the mechanisms of cell proliferation in pterygium epithelium are unknown. Aim: To analyse the histopathology and the expression of cell cycle-related molecules in pterygium tissues. Methods: Seven pterygia were surgically removed using the bare-sclera procedure, and three normal bulbar conjunctivas were also obtained. Formalin-fixed, paraffin-wax-embedded tissues were analysed by immunohistochemistry with antip27(KIP1), cyclin D1 and Ki-67 antibodies. Results: Conjunctival epithelium consisted of several layers of round cells with a few goblet cells. Nuclear immunoreactivity for p27(KIP1) was noted in many normal epithelial cells, where cyclin D1 and Ki-67-positive nuclei were intermingled. A variety of goblet cells were located in the superficial layer of the pterygium head as well as those of the body epithelia. Several pterygium epithelial cells were p27(KIP1) positive, whereas nuclear immunoreactivity for cyclin D1 and Ki-67 was detected in many epithelial cells. By contrast, immunoreactivity for p27(KIP1), cyclin D1 and Ki-67 was hardly detected in the pterygium stroma. Conclusion: It is suggested that pterygium growth and development are associated with the proliferation of epithelium, which is possibly involved in the expression of cell cycle-related molecules.

Caspase-associated recruitment domains (CARD) are proteinprotein interaction modules found extensively in proteins that play important roles in apoptosis. One of the CARD-containing proteins, TUCAN (CARD8), was reported previously as an antiapoptotic protein with a molecular weight of 48 kDa, which was up-regulated in colon cancer cells. We identified a novel isoform of TUCAN with a molecular weight of 54 kDa. The new variant of TUCAN, termed TUCAN-54, was expressed in gastric, colon, and breast cancer tissues but was barely detected in normal noncancerous tissues, whereas 48-kDa TUCAN was detected in tumor tissues and noncancerous tissues. To know the function of TUCAN-54 in the apoptosis of cancer cells, TUCAN-54 was overexpressed in tumor cells by gene transfection. Its overexpression inhibited pro-caspase-9 activation, leading to the suppression of the cell death induced by a protein kinase inhibitor, staurosporine, or a chemotherapeutic reagent, etoposide (VP-16). In contrast, specific small interfering RNA-mediated suppression of TUCAN-54 expression in tumor cells increased the VP-16-induced cell death rate, indicating that expression of TUCAN-54 might be associated with chemoresistance of tumor cells. In addition, it inhibited caspase-8 activation as well, thereby suppressing Fas-induced cell death. It was revealed that Fas-associated death domain was physically associated with TUCAN-54 but not with 48-kDa TUCAN. Thus, TUCAN-54 might be a novel tumor-specific antiapoptotic molecule expressed in a variety of human cancer tissues, which might aggravate malignant potential of cancer cells, such as chemoresistance and immunoresistance.

Heat shock protein 40 (Hsp40) family proteins are known to bind to Hsp70 through their J-domain and regulate the function of Hsp70 by stimulating its adenosine triphosphatase activity. In the endoplasmic reticulum (ER), there are 5 Hsp40 family proteins known so far, 3 of which were recently identified. In this report, one of the novel Hsp40 cochaperones, ERdj3, was characterized in terms of its subcellular localization, stress response, and stress tolerance of cells. By using ERdj3-specific polyclonal antibody, endogenous ERdj3 protein was shown to reside in the ER as gene transfer-mediated exogenous ERdj3. Analysis of the expression level of endogenous ERdj3 protein revealed its moderate induction in response to various ER stressors, indicating its possible action as a stress protein in the ER. Subsequently, we analyzed whether this molecule was involved in ER stress tolerance of cells, as was the case with the ER-resident Hsp70 family protein BiP. Although overexpression of ERdj3 by gene transfection could not strengthen ER stress tolerance of neuroblastoma cells, reduction of ERdj3 expression by small interfering ribonucleic acid decreased the tolerance of cells, indicating that ERdj3 might have just a marginal role in the ER stress resistance of neuroblastoma cells. In contrast, overexpression of ERdj3 notably suppressed vero toxin-induced cell death. These data suggest that ERdj3 might have diverse roles in the ER, including that of the molecular cochaperone of BiP and an as yet unknown protective action against vero toxin.