[Multilingualism and the Reserve Theory]

It has been well recognized that patients with comparable dementia severity may show different levels of brain pathology. This is commonly explained by cognitive or brain reserve theory: patients with more reserve can tolerate more severe brain pathologies because the reserve can compensate for the neuropathological processes. Various life experiences contribute to the reserve, one of which may be multilingualism. Multilinguals need to select the appropriate language for a conversational partner and to keep other languages inactivated. Such experiences reinforce the multilingual executive functions, and change neuroanatomical and neurophysiological features of the brain, which some researchers propose can serve as a reserve and prevent dementia. The earliest such report was Bialystok et al.'s (2007) paper, which demonstrated multilinguals showing signs of dementia approximately four years later than monolinguals. This finding seemed to support the hypothesis of multilingualism as a reserve, and was followed by many other reports testing the same. Notwithstanding the initial excitement, the data obtained so far have been mixed at best in terms of the possibility of multilingualism influencing the neuropathological processes of dementia. This paper summarizes recent findings on multilingualism and the reserve theory, and discusses identified research issues that need to be resolved.

[Multilingualism and child psychiatry: on differential diagnoses of language disorder, specific learning disorder, and selective mutism]

Multilingualism poses unique psychiatric problems, especially in the field of child psychiatry. The author discusses several linguistic and transcultural issues in relation to Language Disorder, Specific Learning Disorder and Selective Mutism. Linguistic characteristics of multiple language development, including so-called profile effects and code-switching, need to be understood for differential diagnosis. It is also emphasized that Language Disorder in a bilingual person is not different or worse than that in a monolingual person. Second language proficiency, cultural background and transfer from the first language all need to be considered in an evaluation for Specific Learning Disorder. Selective Mutism has to be differentiated from the silent period observed in the normal successive bilingual development. The author concludes the review by remarking on some caveats around methods of language evaluation in a multilingual person.

[Two cases of isolated ACTH deficiency suspected as depression with severe appetite loss]

Diagnosing isolated ACTH deficiency can be a challenging task for a clinician due to its non-specific symptoms, such as a decreased appetite, general fatigue, and psychological dysfunction. This report is on two patients with isolated ACTH deficiency who presented with extreme appetite loss and were referred for psychiatric evaluation with a suspected diagnosis of depression.

CASE I

A business executive in his late sixties showed severe appetite loss and vomiting in May of the year X. His business had started to experience difficulty two months earlier. A medical workup of the digestive system and a brain MRI revealed no abnormality. Subsequently, the patient was referred for a psychiatric examination with suspected depression in August. Psychiatric pharmacotherapy improved his appetite only temporarily, and he was admitted as a psychiatric inpatient. A more thorough evaluation led to a diagnosis of isolated ACTH deficiency on the basis of abnormally low levels of ACTH and cortisol. The patient's symptoms improved with hydrocortisone supplementation. CASE II: A factory worker in his late fifties started to experience appetite loss, nausea/ vomiting, and decreased energy in May of the year Y, without any apparent cause. Medical evaluations by a family physician, a digestive system specialist, and a neurologist, including a brain CT, were unremarkable. Depression was suspected and the patient was referred to the authors' psychiatric clinic in July of the same year. Upon examination, the patient presented with depressive symptoms such as a depressed mood, decreased energy, middle insomnia, and loss of interest. Blood tests and a hormonal workup revealed abnormally low ACTH and cortisol levels. The patient was admitted as an inpatient of the endocrinology department, and a diagnosis of isolated ACTH deficiency was made. Hydrocortisone supplementation improved his symptoms. In both cases, anti-pituitary antibody was negative and there were no findings of an empty sella or swelling of the pituitary gland. Therefore, isolated ACTH deficiency was a more likely diagnosis than lymphocytic adenohypophysitis. It is important to diagnose this condition as early as possible since it is treatable with hydrocortisone supplementation with a favorable prognosis. Screening for ACTH and cortisol levels should be considered when symptoms of suspected depression include severe general fatigue and appetite loss with vomiting.

Low-grade fibromyxoid sarcoma versus low-grade myxofibrosarcoma in the extremities and trunk. A comparison of clinicopathological and immunohistochemical features

AIMS

Low-grade fibromyxoid sarcoma (LGFMS) is a distinctive variant of fibrosarcoma and has been reported to have metastatic potential despite its low-grade histological findings. Low-grade myxofibrosarcoma (MFS) is an important differential diagnosis of LGMFS, because it shows different biological behaviour. Of 75 MFSs in the extremities and trunk, we defined 22 grade 1 tumours as low-grade MFS according to the French Federation of Cancer Centres grading system and compared the clinicopathological factors and immunohistochemical expression of cell cycle regulators with those of 11 LGFMSs.

METHODS AND RESULTS

The two entities could be distinguished on histological grounds. Low-grade MFS was characterized by the presence of prominent elongated, curvilinear capillaries and pseudolipoblasts, accompanied by an abundant myxoid matrix. It had no extensive solid areas. LGFMS was composed of bland spindle cells arranged in a whorled pattern with alternating myxoid and fibrous stroma. Curvilinear capillaries were not prominent and cytological atypia was absent. No tumour necrosis was observed in any of the 11 LGFMSs, whereas only one case showed tumour necrosis in less than 50% of the tumour in 22 low-grade MFSs. The patients with low-grade MFS were significantly older than those with LGFMS (low-grade MFS average, 60.1 years; LGFMS average, 31.5 years; P < 0.0001) and low-grade MFS occurred more frequently in a superficial location (low-grade MFS 14/20; LGFMS 2/11; P = 0.0077). As for cell cycle regulator expression, the MIB-1 labelling index (LI) (14.76 on average) and cyclin E LI (11.55 on average) in low-grade MFS were significantly higher than those (MIB-1 LI, 4.68 on average; cyclin E LI, 3.38 on average) of LGFMS, while p21 LI (25.53 on average) and p27 LI (42.68 on average) in low-grade MFS were significantly lower than those (p21 LI, 42.74 on average; p27 LI, 57.28 on average) of LGFMS.

CONCLUSIONS

We conclude that low-grade MFS and LGFMS are distinctly different clinicopathological entities and the assessment of the immunohistochemical expression of MIB-1, cyclin E, p21 and p27 as well as conventional clinicopathological features may be helpful to distinguish low-grade MFS from LGFMS.

Characterisation of TGF-β2 signalling and function in a human lens cell line

There is increasing evidence implicating Transforming growth factor beta (TGF-beta) in pathological states of the lens. However, the underlying signalling mechanisms in human cells have not been fully examined. We have therefore investigated in a human lens cell line, FHL 124, the signalling characteristics of TGF-beta and Smad proteins. Moreover, we have tested the effectiveness of a fully human monoclonal anti-TGF-beta2 antibody, CAT-152, in suppressing TGF-beta2 induced changes in a number of conditions. FHL 124 cells were routinely cultured in Eagle's minimum essential medium (EMEM) supplemented with 10% FCS. Characterisation of the cell line was determined using Affymetrix gene microarrays and compared to native human lens epithelium. Cells were serum starved for 24 hr prior to exposure to TGF-beta2 in the presence and absence of CAT-152. Non-stimulated cells served as controls. Smad 4 localisation was observed by immunocytochemistry. To study Smad-dependent transcriptional activity, cells were transfected with SBE4-luc, an artificial smad-specific reporter, using Fugene-6. Transcriptional activity was determined by luciferase activity. Gene expression was assessed using reverse transcriptase-polymerase chain reaction (RT-PCR). Proliferation was determined by 3H-thymidine DNA incorporation. Growth and contraction were assessed using a scratch and patch assay. Affymettrix gene microarrays identified 99.5% homology between FHL 124 cells and the native lens epithelium with respect to expression pattern of the 22,270 genes on the chip. Moreover, FHL 124 cells expressed phenotypic markers, alphaA-crystallin and pax6 along with lens epithelial cell specific marker FoxE3. Immunocytochemical studies revealed the presence of Smad 4 which following TGF-beta2 exposure accumulated in the cell nucleus. Furthermore, Smad-dependent transcriptional activity was also stimulated. TGF-beta2 enhanced the expression of mRNA levels of alpha smooth muscle actin (alphaSMA) and connective tissue growth factor (CTGF). Exposure to TGF-beta2 resulted in a relatively small inhibition of 3H-thymidine incorporation of FHL 124 cells. However, a more marked contractile effect was also observed. In serum-supplemented medium, growth rates and TGF-beta induced contraction were enhanced. Treatment with 0.1-10 microg ml(-1) CAT-152 dose-dependently inhibited 10 ng ml(-1) TGF-beta2 induced effects in the presence and absence of serum. Exposure of FHL 124 cells to TGF-beta therefore induces Smad translocation, transcription, expression of transdifferentiation markers and induces marked contraction. Treatment with CAT-152 can effectively inhibit these responses. TGF-beta2 induced changes can also persist long after the period of exposure and when in the presence of serum TGF-beta induced contraction is enhanced. The work presented therefore demonstrates a platform technology to study TGF-beta2 signalling in human lens epithelial cells and provides evidence to show TGF-beta2 can be a potent factor in the development of posterior capsule opacification following cataract surgery.

p53 Mutation and MDM2 amplification in inflammatory myofibroblastic tumours

AIMS

The pathogenic mechanism and predictive indicators of biological behaviour of inflammatory myofibroblastic tumour are poorly understood. We investigated molecular abnormalities of p53 and MDM2 in order to assess whether these play an important role in pathogenesis, and whether they also contribute to clinicopathological aggressive phenotype in inflammatory myofibroblastic tumour.

METHODS AND RESULTS

We compared the immunohistochemical expression of calponin, h-caldesmon, ALK, and p53 gene mutation and MDM2 gene amplification with clinicopathological findings in 15 cases of inflammatory myofibroblastic tumour. Histologically, cellular atypia was observed in five (33.3%) out of 15 cases. Local recurrences were observed in two (14.3%) of 14 informative cases, but no distant metastasis was observed. The expression of calponin (9/14; 64%) but not h-caldesmon (0/14; 0%) was seen, which suggested myofibroblastic differentiation. ALK expression was seen in eight (53.3%) out of 15 cases, particularly in patients under 40 years old. Nuclear expression of p53 protein was recognized in only one (6.7%) of 15 cases, and polymerase chain reaction single-strand conformation polymorphism followed by direct sequencing revealed p53 gene missense mutations in two (13.3%) of 15 cases. Nuclear expression of MDM2 was seen in four (26.7%) of 15 cases, and the MDM2 gene amplification was observed in two of the four cases.

CONCLUSION

Inflammatory myofibroblastic tumour shows a wide spectrum of cellular atypia and biological behaviour with p53 and MDM2 expression. However, the alterations in the p53 pathway seem not to play a major role in the pathogenesis of inflammatory myofibroblastic tumour.

Renal cell carcinoma with rhabdoid features: an aggressive neoplasm

AIMS

Only a few reports on renal cell carcinoma with rhabdoid features have been published. This study was performed to investigate the clinicopathological characteristics of renal cell carcinomas with rhabdoid features.

METHODS AND RESULTS

Among 253 cases of renal cell carcinoma in adults, eight cases with rhabdoid features were detected. Rhabdoid areas ranged from 10% to 90% of each of the cases. Seven of the eight cases were TNM stage III or IV, and four of the eight cases died within 8 months of surgery. Immunohistochemically, the rhabdoid areas were positive for CAM 5.2 (4/8), AE1/AE3 (6/8), epithelial membrane antigen (6/8) and vimentin (8/8), and negative for myogenetic markers (0/8). The mean MIB-1 labelling index in the rhabdoid areas was higher than that in the definite carcinomatous areas. Ultrastructurally, perinuclear whorls of intermediate filaments were demonstrated in three of the eight cases using paraffin-embedded blocks.

CONCLUSIONS

The rhabdoid areas in renal cell carcinoma have histological, immunohistochemical and ultrastructural similarities to malignant rhabdoid tumours. Renal cell carcinoma with rhabdoid features is a highly aggressive neoplasm and its malignant behaviour may be due to the high cell-proliferative activity of the rhabdoid areas. Rhabdoid features in renal cell carcinoma may represent the endpoint of clonal evolution of renal cell carcinoma (especially in clear cell type cases).

Calponin and h-caldesmon expression in atypical fibroxanthoma and superficial leiomyosarcoma

To evaluate smooth muscle differentiation, myogenic markers [desmin, alpha-smooth muscle actin (SMA), and muscle-specific actin (HHF35)] have been widely used. Calponin and h-caldesmon, which are cytoskeleton-associated actin-binding proteins, have been reported to be more specific myogenic markers, especially since myofibroblasts express a small amount of h-caldesmon. Atypical fibroxanthoma (AFX) occurs in the sun-exposed skin of the elderly and follows a benign clinical course. Histologically, AFX, which is a pleomorphic spindle cell tumor and considered to be a superficial variant of malignant fibrous histiocytoma, also mimics leiomyosarcoma. AFX has been thought to differentiate along pathways with fibrohistiocytic and myofibroblastic phenotypes. AFX ( n=10), superficial leiomyosarcoma (S-LMS) ( n=17) and benign fibrous histiocytoma (BFH) ( n=17) were analyzed for myofibroblastic and smooth muscle differentiation immunohistochemically from the viewpoint of comparison. AFX and BFH showed immunoreactivities respectively for calponin (3/10, 11/17), desmin (3/10, 1/17), SMA (3/10, 13/17), and HHF35 (1/10, 5/17), but failed to express h-caldesmon (0/10, 0/17). S-LMS had a high immunoreactive rate of calponin (17/17), desmin (13/17), SMA (16/17), and HHF35 (16/17), while also expressing caldesmon (11/17). The results reveal that AFX and BFH have immunoreactivities for several myogenic markers, with myofibroblastic differentiation (calponin: +/-, h-caldesmon: -), but without the smooth muscle differentiation seen in S-LMS (calponin:+, h-caldesmon: +/-). In addition, calponin and h-caldesmon are considered to be useful markers for distinguishing AFX from S-LMS.

Clinicopathological prognostic factors in soft tissue leiomyosarcoma: a multivariate analysis

AIMS

Prognostic factors affecting survival in cases of leiomyosarcoma of soft parts were investigated in this study.

METHODS AND RESULTS

A retrospective study of 267 patients was carried out. This group comprised 142 females (53%) and 125 males (47%), whose ages ranged from 7 to 95 years (median 58 years). One hundred and five cases were superficially situated (arising from the skin or subcutis), while the remaining 162 cases were deeply situated (subfacial). Nineteen were cases of pleomorphic leiomyosarcoma where the diagnosis had been amended from malignant fibrous histiocytoma to leiomyosarcoma whilst under review. Of the 167 patients with follow-up data, 83 died of leiomyosarcoma. In univariate analysis, depth, tumour size (>or=50 mm), mitotic rate of >20 per 10 high-power fields (HPF), tumour necrosis of >50% and a high stage according to the most recent American Joint Committee on Cancer (AJCC) staging for soft tissue sarcoma were found to lessen significantly the rate of survival (log rank test; P < 0.05). However, in multivariate analysis (Cox's proportional hazards model), tumour size and high AJCC stage were the only factors that were correlated independently with decreased survival.

CONCLUSIONS

This study indicates that the most reliable prognostic parameters are tumour size and AJCC stage in leiomyosarcoma.

Matrix metalloproteinase-2 expression correlates with morphological and immunohistochemical epithelial characteristics in synovial sarcoma

AIMS

Synovial sarcoma is a unique mesenchymal tumour characterized by the presence of epithelial differentiation, although the mechanism involved in the epithelial morphology is still unclear. The aim of this study was to evaluate the function of matrix metalloproteinase-2 (MMP-2) in synovial sarcoma, in order to assess whether MMP-2 expression plays an important role in epithelial differentiation, or whether it contributes to a poor clinical outcome.

METHODS AND RESULTS

Immunohistochemical stainings for MMP-2, cytokeratins (CKs) 7, 8, 18 and 19, and E-cadherin were performed for 58 (44 monophasic and 14 biphasic) cases of synovial sarcoma, and we compared the expression of these proteins with the histological and clinical findings. MMP-2 and E-cadherin expression was observed in 43 cases (74.1%) and in 18 cases (31.0%), respectively. Expression of these proteins was preferentially observed in the glandular components of biphasic tumours or the epithelioid areas of monophasic tumours. Statistically significant correlations were recognized between MMP-2 expression and E-cadherin expression of biphasic subtype. Moreover, there were statistically significant correlations between monophasic tumours with epithelioid areas and MMP-2 expression or E-cadherin expression. MMP-2 expression was correlated with epithelial differentiation as assessed by CK immunoreactivity. The expression of MMP-2 did not affect the overall survival rate in synovial sarcoma.

CONCLUSIONS

MMP-2 expression seemed to have an important role to play in the epithelial differentiation of tumour cells in synovial sarcoma, through remodelling of the extracellular matrix and by changing the cytoskeletal interaction between the extracellular matrix and tumour cells.

E-cadherin gene mutations frequently occur in synovial sarcoma as a determinant of histological features

Synovial sarcoma is a mesenchymal tumor that has an epithelial character and two major histological subtypes, the biphasic type and the monophasic fibrous type. However, the mechanisms involved in its epithelial differentiation are unknown, and furthermore, the determinants for histological subtype in synovial sarcoma remain unclear. In this study, we immunohistochemically examined E-cadherin expression and screened for genetic alterations in the E-cadherin gene from exon 4 to exon 9 in 49 cases of synovial sarcoma. In addition, we also examined the mRNA expressions of E-cadherin and Snail, a direct repressor of E-cadherin gene expression, by reverse transcriptase-polymerase chain reaction in 20 samples of frozen material. Immunohistochemical E-cadherin membranous expression was observed in 12 cases (24.5%), and was predominant in biphasic tumors. Single-strand conformation polymorphism analysis followed by DNA direct sequencing revealed 15 missense E-cadherin mutations in 12 cases (24.5%: monophasic, 11 of 42; biphasic, 1 of 6; poorly, 0 of 1) and 7 silent mutations (14.3%) in 7 cases. Ten of the 12 cases with E-cadherin missense mutations did not show E-cadherin membranous expression. Reverse transcriptase-polymerase chain reaction demonstrated E-cadherin and Snail mRNA expressions in 14 cases (70%) and in all cases, respectively. E-cadherin gene expression was inactivated by missense mutations in three of the eight cases (37.5%) of monophasic fibrous tumors that showed E-cadherin mRNA expressions. The E-cadherin gene was potentially inactivated in a significant number of synovial sarcomas. E-cadherin dysfunction because of its mutation in the central region of the molecule was associated with its decreased immunohistochemical expression and histological fibroblastic and spindle-shaped features of monophasic tumors. Thus, E-cadherin gene mutation may be one of the determinants of histological subtype in synovial sarcoma.

Immunoexpression of neurofibromin, S-100 protein, and leu-7 and mutation analysis of the NF1 gene at codon 1423 in osteofibrous dysplasia

The NF1 (neurofibromatosis type 1, or von Recklinghausen disease) gene, is a tumor-suppressor gene, and its product, neurofibromin, down-regulates ras protein by its guanosine triphosphatase-activating protein (GAP)-related domain. Osteofibrous dysplasia (OFD) is characterized by fibroblast-like spindle cells and osseous tissue and is generally seen in the tibia or fibula during childhood. The precise nature of OFD remains controversial. Cosegregations of OFD and NF1 have been reported, and it has been surmised that OFD is associated with the NF1 gene. We studied the expressions of NF1 gene product (neurofibromin) and so-called Schwann cell markers (S-100 protein, Leu-7) in 17 cases of OFD immunohistochemically. Ten cases of fibrous dysplasia (FD) were also used for the purpose of comparison. Five OFD and 7 FD cases were analyzed for NF1 gene mutation at codon 1423, which is a GAP-related domain, by single-strand conformation polymorphism. Fibroblast-like cells of OFD showed the expression of neurofibromin (5 of 17), S-100 protein (9 of 17), and Leu-7 (5 of 17), and those of FD did not show these expressions, with the exception of 1 case that showed Leu-7 expression. Regarding the OFD cases, significant correspondence was found between cases showing expression of neurofibromin and S-100 protein, between cases showing expression of neurofibromin and Leu-7, and between cases showing expression of S-100 protein and Leu-7 (P < .01). NF1 gene mutation at codon 1423 was not detected in either the OFD (0 of 5) or FD (0 of 7) cases. These results seem to suggest the possible involvement of neurofibromin in the development of OFD, which is associated with the expression of Schwann cell markers (S-100 protein and Leu-7). Furthermore, NF1 gene mutation at codon 1423 did not seem to be related to OFD.

H-, K-, and N-ras gene mutation in atypical fibroxanthoma and malignant fibrous histiocytoma

Atypical fibroxanthoma (AFX) which is histologically similar to malignant fibrous histiocytoma (MFH), occurs in the sun-exposed skin. The presence of mutations at codons 12 and 13 of the H- and K-ras genes and in exons 1 and 2, which include codons 12, 13, and 61, of the N-ras gene was studied in 8 cases of AFX and 8 cases of storiform-pleomorphic-type MFH using polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-single-conformation polymorphism. Two of the 8 cases of MFH showed ras mutations in the H-ras gene at codon 12 (GGC-AGC) and in the K-ras gene at codon 13 (GGC-GAC). H- and K-ras gene mutations were not seen in any of the cases of AFX (0 of 8). N-ras gene mutation was not detected in either the AFX (0 of 8) or MFH (0 of 8) cases. In conclusion, although the number of cases in this study was small, H- and K-ras genes were present in some of the MFH cases and accordingly may play an important role in the pathogenesis of MFH. In addition, the finding that H-, K-, and N-ras gene mutations are not present in AFX may indicate why AFX has a more favorable behavior than MFH.

beta-catenin nuclear expression correlates with cyclin D1 overexpression in sporadic desmoid tumours

The immunohistochemical expression of beta-catenin, cyclin D1, Ki-67 and PCNA was Examined in 38 cases of sporadic extra-abdominal or abdominal-wall desmoid tumours without familial adenomatous polyposis (FAP), to evaluate the hypothesis that the accumulated beta-catenin within the nuclei could affect the regulation of the cyclin D1 gene. There was a statistically significant correlation between beta-catenin accumulation and cyclin D1 overexpression (p=0.029). Each group with beta-catenin accumulation or cyclin D1 overexpression showed a higher PCNA-LI than those without, the difference being statistically significant (p=0.007, p=0.004, respectively). Differential PCR was also performed to detect amplification of the cyclin D1 gene and mutational analysis was undertaken for exon 3 of the beta-catenin gene. Amplification of the cyclin D1 gene was observed in 13 out of 22 cases (59.1%). There were nine-point mutations in 7 out of 18 cases (38.9%). The distribution of beta-catenin mutation fell within a wide range, from codon 21 to codon 67. In conclusion, beta-catenin nuclear expression correlated with cyclin D1 overexpression in sporadic desmoid tumours, which could be an in vivo model system for the APC-beta-catenin-Tcf pathway. In addition, beta-catenin mutations in desmoid tumours occurred at an unusually wide range of sites within the gene.

Subcellular distribution of cytokeratin and vimentin in malignant rhabdoid tumor: three-dimensional imaging with confocal laser scanning microscopy and double immunofluorescence

Malignant rhabdoid tumor (MRT) is a highly aggressive neoplasm that mostly occurs in childhood, characterized histologically by rhabdoid cells as shown by eosinophilic intracytoplasmic inclusions. Although it is known that rhabdoid cells co-express cytokeratin (CK) and vimentin, the distribution patterns of these two kinds of intermediate filaments and structural relationship between them are still not known. We investigated the subcellular distribution of CKs 8 and 18 and vimentin in MRT cell lines (Tm87-16, STM91-01, TTC549, and TC289) using confocal laser scanning microscopy and double immunofluorescence, in addition to ultrastructural examination. Vimentin was diffusely expressed in the cytoplasm of MRT cells, focally forming a filamentous network. In contrast, CKs 8 and 18 were partially expressed in the cytoplasm of MRT cells, forming globules or a few vague agglomerates. Three-dimensional images in TC289 cells revealed distinct distribution patterns of cytokeratin and vimentin, showing agglomerates of cytokeratins within the vimentin filament network. We conclude that these globules and agglomerates of CKs 8 and 18 correspond with the characteristic ultrastructural finding, showing cytoplasmic bundles of intermediate filaments concentrated in whorled arrays.

Malignant peripheral nerve sheath tumours: high Ki67 labelling index is the significant prognostic indicator

AIMS

We investigated p53, Ki67, MDM2, and p21WAF1/CIP1 in order to evaluate its relationship with prognosis in malignant peripheral nerve sheath tumours (MPNST).

METHODS AND RESULTS

In 49 cases of MPNSTs, the immunohistochemical studies of Ki67, p53, MDM2, p21WAF1/CIP1 and polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) with direct sequencing of p53 were performed with the formalin-fixed paraffin-embedded tissue. In 43 cases with survival data available, an evaluation of the prognostic significance of clinicopathological factors was also carried out. A high Ki67 labelling index (LI) (>25%) was correlated with a reduced survival rate in the 43 cases of MPNST (P=0.0106, log-rank test). Furthermore, there was a significant correlation between the Ki67 LI and the immunohistochemical expression of p53 or MDM2. In 17 MPNST cases, PCR amplification of exons 5 through 8 of the p53 gene was successful. One case showed a base change of codon 240 (AGT-->AGC), but translated amino acid (Ser) remained unchanged. Multivariate Cox analysis of our series showed that the association of von Recklinghausen's disease, tumour depth, and the presence of rhabdomyoblasts (malignant triton tumour) each had an independent negative impact on overall survival.

CONCLUSION

High Ki67 LI (>25%) was of significant prognostic value in MPNST.

Pleomorphic leiomyosarcoma: clinicopathologic and immunohistochemical study with special emphasis on its distinction from ordinary leiomyosarcoma and malignant fibrous histiocytoma

Pleomorphic leiomyosarcoma (PLMS) was recently described as a morphologic variant of leiomyosarcoma; however, its diagnostic criteria, as shown by morphologic features and biologic behavior, remain controversial. We describe 28 cases of pleomorphic sarcoma with pleomorphic areas in more than two thirds of the tumor and an ordinary leiomyosarcomatous fascicular area covering less than one third as PLMS. PLMS comprised 8.6% of all the leiomyosarcomas (322 cases) registered in our institute. Patients ranged in age from 31 to 89 years (average, 57.9 years). Seventeen patients (60.7%) were male and 11 were female. Tumor location was as follows: the extremities in 17 cases, the retroperitoneum or abdominal cavity in 7 cases, the chest/abdominal wall in 3 cases, and the scalp in 1 case. Histologically, all cases showed at least small foci of fascicles consisting of smooth muscle tumor cells, in addition to pleomorphic areas mimicking storiform-pleomorphic malignant fibrous histiocytoma. The border between pleomorphic and leiomyosarcomatous fascicular areas was sharp in 3 cases, gradual in 2 cases, and blending in 23 cases. Sixteen cases (57.1%) showed a typical storiform pattern, 6 cases revealed extensive stromal hyalinization, 6 cases showed a chronic inflammatory infiltrate, 2 cases had the foci of foamy xanthomatous cells, and 7 cases contained myxoid malignant fibrous histiocytoma-like areas covering less than 50% of the tumor. The tumors had a tendency to be of a morphologically higher grade (10 tumors were French Federation of Cancer Centers grade 2, 18 were grade 3). Five of 28 cases (18%) showed rhabdoid features. Immunohistochemically, all of the 28 tumors examined showed a positive reactivity for at least one smooth muscle marker (desmin, muscle-specific actin, and alpha-smooth muscle actin) in the leiomyosarcomatous fascicular areas. In the pleomorphic areas the expression of smooth muscle markers (desmin 10 of 28, muscle-specific actin 13 of 28, and alpha-smooth muscle actin 14 of 28) was significantly reduced, compared with that in leiomyosarcomatous fascicular area (desmin 18 of 28, muscle-specific actin 26 of 28, and alpha-smooth muscle actin 24 of 28). No significant difference was observed between the MIB-1 labeling index in the leiomyosarcomatous fascicular areas (26.10 on average) and that in the pleomorphic areas (26.17 on average). However, the MIB-1 labeling index in PLMS was significantly higher than that in ordinary leiomyosarcoma (n = 20, 12.86 on average) or storiform-pleomorphic malignant fibrous histiocytoma (n = 16, 16.63 on average). In 23 patients follow-up data were available with a duration of 1-239 months. Eleven patients developed metastases, and lung accounted for the most common site of metastasis (9 cases). Fifteen of 23 patients (65.2%) died of disease. Our results indicate that PLMS should be differentiated from ordinary leiomyosarcoma because of its high proliferative activities and rather aggressive biologic behavior.

Malignant peripheral nerve sheath tumour arising within neurofibroma. An immunohistochemical analysis in the comparison between benign and malignant components

AIMS

To compare the expression of immunohistochemical variables between benign and malignant components of malignant peripheral nerve sheath tumour (MPNST) arising within neurofibroma.

METHODS

Eight cases of MPNST arising within a neurofibroma, associated with neurofibromatosis type 1 (NF1), were studied. The areas of MPNST and neurofibroma were compared immunohistochemically with regard to the expression of proliferative activity (MIB-1), growth factors, p53, bcl-2, neural cell adhesion molecule (N-CAM), and CD34.

RESULTS

The expression of transforming growth factor beta 1 (TGF-beta 1), TGF-beta receptor type II, hepatocyte growth factor alpha (HGF-alpha), c-met, p53, and N-CAM was higher in the areas of MPNST than in the neurofibromatous areas in four, five, five, eight, five, and three of the eight cases, respectively. CD34 expression was lower in the areas of MPNST than in the neurofibroma areas in three of the eight cases.

CONCLUSIONS

On the basis of these findings, TGF-beta 1, HGF-alpha, and p53 might be involved in the malignant transformation of neurofibroma to MPNST.

Mutations of the p53 gene in malignant rhabdoid tumors of soft tissue and the kidney: immunohistochemical and DNA direct sequencing analysis

Malignant rhabdoid tumor (MRT) is characterized by the presence of intracytoplasmic eosinophilic inclusions composed of whorls of intermediate filaments. This tumor was originally described as an entity of the abortive type of Wilms' tumor in childhood. Recently, it has been proved that these rhabdoid cells can be observed in various types of malignant tumors, including soft tissue sarcoma or carcinoma. To investigate the oncogenesis of this tumor, we examined the p53 gene alteration by means of immunohistochemical analysis and DNA direct sequencing in three cases of malignant rhabdoid tumor (MRT) of the soft tissue and three cases of MRT of the kidney. All the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed immunopositivity for p53 protein. Among them, one of the cases of MRT of the soft tissue and two of the cases of MRT of the kidney showed missense mutations of the p53 gene. These results strongly suggest that p53 gene alterations may have an important role to play in the aggressive biological behavior and poor prognosis of this tumor.

Expression of intercellular adhesion molecules in epithelioid sarcoma and malignant rhabdoid tumor

We clinicopathologically evaluated 31 cases of epithelioid sarcoma (ES; 25 'classical' type and six 'proximal variant' type) and six cases of malignant rhabdoid tumor (MRT; three extrarenal and three renal). We also did immunohistochemical studies on 12 classical and three proximal variant cases of ES, and six cases of MRT, to clarify the differences in biological behavior in these tumors. E-cadherin, beta-catenin and CD34 expression was evaluated. We also carried out mutational analysis of exon 3 of the beta-catenin gene by polymerase chain reaction-single-strand conformation polymorphism analysis. In ES, the 5- and 10-year survival rates were 71.1 and 55.3%, respectively. A high mitotic rate (>15/10 high-power fields) was significantly correlated with a poor overall survival rate in ES (P = 0.0248). E-cadherin expression was observed in nine cases (69.2%) of ES and in four cases (66.7%) of MRT. Most of these tumors showed aberrant E-cadherin expression. Seven cases (46.7%) of ES were positive for CD34, although none of the cases of MRT were CD34 positive. Eleven cases (73.3%) of ES were positive for beta-catenin, which was localized to the cellular membrane, whereas all of the cases of MRT were beta-catenin negative. Mutational analysis for the beta-catenin gene was done in nine cases of ES and six cases of MRT, however, genetic alteration was not found. From our results, we conclude that beta-catenin membranous expression could be a useful marker for distinguishing ES, including the proximal variant, from MRT.

Impaired production of naive T lymphocytes in human T-cell leukemia virus type I-infected individuals: its implications in the immunodeficient state

Opportunistic infections frequently occur in patients with adult T-cell leukemia (ATL) and human T-cell leukemia virus type I (HTLV-I) carriers. However, the underlying mechanisms of such infections remain unknown. To clarify the mechanism of immunodeficiency in those infected with HTLV-I, this study analyzed the T-cell subsets in HTLV-I carriers and patients with HTLV-I-associated myelopathy/tropical spastic paraparesis and ATL using 3-color fluorescence with CD62L and CD45RA coexpression either with CD4(+) or CD8(+) T cells. The number of naive T lymphocytes was markedly suppressed in patients with ATL, particularly in those with acute form, compared with uninfected control individuals. The number of naive T cells was low in HTLV-I-infected individuals under 50 years old compared with uninfected individuals, whereas the number of memory T lymphocytes was greater in HTLV-I-infected individuals. Although the increase of memory T lymphocytes correlated with HTLV-I provirus loads, no relationship was found between naive T-cell counts and provirus loads. T-cell receptor rearrangement excision circles (TRECs), which are generated by DNA recombination during early T lymphopoiesis, were quantified to evaluate thymic function in HTLV-I-infected individuals. TREC levels were lower in HTLV-I-infected individuals than in uninfected individuals. In HTLV-I carriers less than 70 years old, an increase of Epstein-Barr virus DNA in peripheral blood mononuclear cells was observed in 6 of 16 (38%) examined, whereas it was detectable in only 1 of 11 uninfected controls. These results suggested that the low number of naive T lymphocytes was due to suppressed production of T lymphocytes in the thymus, which might account for immunodeficiency observed in HTLV-I-infected individuals.

FGF: an autocrine regulator of human lens cell growth independent of added stimuli

PURPOSE

Posterior capsule opacification (PCO) arises because of a persistent growth of lens epithelial cells. Cultured human lens cells residing on their native collagen capsule and maintained in serum-free medium actively grow and thus show an intrinsic capacity for regulation. In the present study, the authors investigated the role of the putative FGF autocrine system in human capsular bags.

METHODS

Capsular bags were prepared from human donor eyes and maintained in a 5% CO(2) atmosphere at 35 degrees C. On-going observations were by phase-contrast microscopy. Cellular architecture was examined by fluorescence cytochemistry. De novo protein synthesis was determined by the incorporation of 35S-methionine. Basic fibroblast growth factor (FGF) and FGF receptor (R)-1 were detected using enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR) techniques. FGFR-1 inhibition was achieved using the specific antagonist SU5402.

RESULTS

Human lens epithelial cells can maintain metabolic activity for more than 1 year in a protein-free medium. Basic FGF was shown to be present in capsular bags throughout culture and also in capsular bags removed from donor eyes that had previously undergone cataract surgery. Furthermore, FGFR-1 was identified. Inhibition of FGFR-1 caused a significant retardation of growth on the posterior capsule. On no occasion did any treated bag reach confluence, whereas all match-paired control samples did.

CONCLUSIONS

The results provide evidence that FGF plays an integral role in the long-term survival and growth of human lens epithelial cells, independent of external stimuli. Inhibition of FGFR-1 by specific synthetic molecules, such as SU5402, could provide a potential therapeutic approach to resolving PCO.

Immunoreactivity of p53, mdm2, and p21WAF1 in dedifferentiated liposarcoma: special emphasis on the distinct immunophenotype of the well-differentiated component

Alteration of the p53/mdm2 pathway has been reported in the well-differentiated liposarcoma (WDLS)/dedifferentiated liposarcoma (DDLS) group. We investigated the immunoreactivity of p53, mdm2, and p21WAF1, along with the MIB-1-labeling index (MIB-1-LI) in 21 WDLS and 21 DDLS cases, to clarify the association of these markers with the morphologic changes and the biological factors responsible for the aggressiveness of DDLS. Within DDLS, p53 and p21WAF1 expression and mdm2 overexpression were significantly more prevalent in the dedifferentiated (DD) components than in the well-differentiated (WD) components. The mdm2 overexpression and p21WAF1 expression was significantly associated with sclerosing liposarcomas in both WDLS and the WD components of DDLS. There was no significant difference in the immunoreactivity of p53, mdm2, or p21WAF1 or MIB-1-LI between WDLS and the WD components of DDLS. An association was found between p53 expression and mdm2 overexpression in the WD group (comprising WDLS and WD components of DDLS) and in the DD group, significantly so in the WD group. Notably, this correlation was found in the subtype of sclerosing liposarcoma but not in that of lipoma-like liposarcoma. Within DDLS, the clinical outcome of the nonaccessible soft tissue (non-AST: comprising retroperitoneum and mediastinum) group was significantly worse than that of the accessible soft tissue (AST: comprising extremities, buttocks, axilla, and scrotum) group; however, the immunophenotypes of p53, mdm2, and p21WAF1 and the MIB-1-LI showed no correlation with survival in the AST group alone, in the non-AST group alone, or in the 2 together. This study suggests that the immunoreactivity of p53, mdm2, and p21WAF1 is associated with the morphologic changes, but not with the biological factors responsible for the aggressiveness of DDLS.

H-ras oncogene mutation in dedifferentiated chondrosarcoma: polymerase chain reaction-restriction fragment length polymorphism analysis

Dedifferentiated chondrosarcomas, which are known for their poor prognosis, are characterized by conventional chondrosarcoma with high-grade anaplastic components. Activating mutations in ras genes are a common genetic abnormality in human malignancies. The presence of point mutations at codons 12 and 13 of the H-ras gene was studied in 20 formalin-fixed paraffin-embedded chondrosarcomas, comprising 11 cases of conventional chondrosarcoma (six Grade 1 cases and five Grade 2 cases) and nine cases of dedifferentiated chondrosarcoma, using polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. H-ras mutations were only seen in two out of the nine cases of dedifferentiated chondrosarcoma (2/9, 22%) and they were not seen in any of the cases of conventional chondrosarcoma (0/11, 0%). Dedifferentiated chondrosarcomas had a worse prognosis than conventional chondrosarcomas (P < .01); among the patients with dedifferentiated chondrosarcomas, those with H-ras mutation (n = 2) tended to have a worse prognosis than those without (n = 7), although the difference was not statistically significant (P = 0.068). Our results would seem to suggest that H-ras mutation may occur during the course of dedifferentiation and may also have some effect on malignant potential.

Relative quantitation of p53 and MDM2 gene expression in leiomyosarcoma; real-time semi-quantitative reverse transcription-polymerase chain reaction

To investigate the etiology of leiomyosarcoma, we examined abnormalities of p53 and its regulation in 13 cases of leiomyosarcoma using fresh tumor specimens. We estimated p53 and MDM2 mRNA level and MDM2 gene amplification using a real-time semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) based on the TaqMan fluorescence method. We also used immunohistochemistry (IHC) for p53 and MDM2 protein overexpression, polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing to detect p53 mutation. Eight of the 13 cases (62%) showed an overexpression of p53 protein on IHC and eight of 13 cases (62%) had p53 gene point mutations. Five of the 13 cases (38%) showed positive staining for MDM2 protein and only one case (7.7%) demonstrated MDM2 gene amplification. The relative p53 mRNA level of the tumors compared with normal tissue ranged from 1.14 to 12.19 arbitrary units (AU), and the MDM2 mRNA level ranged from 1.06 to 17.17 AU. The mRNA level in the p53-positive cases was higher than in the negative cases (positive: 7.70 AU on average; negative: 3.38 AU on average; P=0.0344). However, there was no significant correlation between the MDM2 mRNA level and other factors, such as p53 IHC, p53 mutation status, p53 mRNA level and MDM2 IHC. Our results indicate that p53 abnormalities are major events and that an increasing level of p53 mRNA is associated with an overexpression of p53 protein in leiomyosarcoma and they may play an important role in the tumorigenesis in this tumor.

Glomangiopericytoma causing oncogenic osteomalacia. A case report with immunohistochemical analysis

A 47-year-old woman suffered from gait disturbance due to back pain and muscle weakness. Laboratory data showed serum hypophosphatemia, elevated alkaline phosphatase, and a normal level of ionized calcium. Radiological examinations revealed multiple pathologic fractures in the ribs and pubic rami. She had had no episode of familial or any other notable disorder, and so she was initially treated with medication for adult-onset osteomalacia. However, 19 years later (when she was 66 years old), she noticed a soft-tissue tumor in her buttock. The tumor was excised. The histological features were those of glomangiopericytoma characterized by both glomus tumor-like and hemangiopericytoma-like structures. After removal of the tumor, her symptoms disappeared immediately. Laboratory data normalized 8 months later. To our knowledge, this is the first report of oncogenic osteomalacia caused by glomangiopericytoma.

H-ras oncogene mutation in dedifferentiated liposarcoma. Polymerase chain reaction-restriction fragment length polymorphism analysis

Point mutations of the ras gene family (K-ras, H-ras, and N-ras) are thought to be involved in the development of a variety of human tumors. Dedifferentiated liposarcoma is characterized by the coexistence of well-differentiated (WD) and high-grade anaplastic (HG) components. The presence of point mutations at codons 12 and 13 of the H-ras gene was studied in 34 liposarcomas, comprising 15 well-differentiated liposarcomas and 19 dedifferentiated liposarcomas, and in 8 storiform-pleomorphic type malignant fibrous histiocytomas (MFHs) using polymerase chain reaction-restriction fragment length polymorphism and direct sequencing analysis. The 2 components of dedifferentiated liposarcoma were analyzed independently. H-ras mutations were seen only in dedifferentiated liposarcomas (4/19 [21%]), 1 in WD components and 3 in HG components. The mutation was not seen in any of 15 cases of well-differentiated liposarcoma. MFHs showed an H-ras mutation in 1 (12%) of 8 cases. Our results seem to suggest that the H-ras mutation is a relatively uncommon event in dedifferentiated liposarcoma, which may demonstrate an epiphenomenon of dedifferentiation in dedifferentiated liposarcoma.

Cytokeratin subunits of inclusion bodies in rhabdoid cells: immunohistochemical and clinicopathological study of malignant rhabdoid tumor and epithelioid sarcoma

Extrarenal malignant rhabdoid tumor (MRT), which is recognized as being histologically similar to renal MRT, is characterized by the presence of "rhabdoid cell" (RC) and a highly aggressive biological behavior. Recently it has been proposed that "proximal variant" of epithelioid sarcoma (ES), whose morphology is similar to that of MRT, actually has a more aggressive clinical course than classical type ES. Detailed immunohistochemical analysis of cytokeratin (CK) subunits was performed in 3 cases of extrarenal MRT, 3 cases of renal MRT, and 11 cases of ES comprising 2 "proximal variants" and 9 classical types. Renal and extrarenal MRTs showed positive immunoreactivity for both CK8 and CK18. Classical type ESs were diffusely positive, not only for CK8 and CK18, but also for other cytokeratin subunits including CK4, 6, 10, 13, 16, 17, and "high-molecular-weight" CKs (CK1, 5, 10, and 14). On the other hand, proximal ES revealed limited immunohistochemical reactivity for cytokeratins, compared with classical ES. In conclusion, the inclusion bodies of RCs show immunoreactivity confined to CK8, CK18, and vimentin. Furthermore, ES has additional CK expressions, while proximal ES possesses characteristics intermediate between those of classical ES and those of external MRT.

Establishment and characterization of malignant rhabdoid tumor of the kidney

Malignant rhabdoid tumor of the kidney (MRTK) is a highly aggressive tumor which occurs in childhood and which is histologically characterized by the existence of eosinophilic intracytoplasmic inclusions. We established and characterized a cell line from this tumor with histological, immunohistochemical and cytogenetical analysis. Histologically, the tumor cells demonstrate typical eosinophilic inclusions, while immunohistochemically the cells demonstrate common mesenchymal and epithelial differentiation. Although the conventional karyotyping of this tumor lacked the abnormalities of 22q chromosome, Southern blot analysis and microsatellite analysis verified abnormalities of the BCR gene and of the hSNF5/INI1 gene. Despite the variety of locations, these common genetic abnormalities appear to contribute to distinguish rhabdoid tumor from such other small round cell tumors as primitive neuroectodermal tumor, rhabdomyosarcoma, poorly differentiated synovial sarcoma and desmoplastic small round cell tumor.

Hepatocyte growth factor function and c-Met expression in human lens epithelial cells

PURPOSE

Hepatocyte growth factor (HGF) and its receptor c-met perform a multitude of functions. However, despite the significant degree of study of HGF and c-met in numerous tissues and cell types, relatively few investigations have been performed on the lens. In the current study, therefore, the role of HGF and the receptor c-met in human lens epithelial cells was investigated.

METHODS

Anterior epithelium and capsular bags were prepared from human donor eyes and maintained in Eagle's minimum essential medium (EMEM) in a 5% CO(2) atmosphere at 35 degrees C. In addition, the human lens cell line FHL124, was routinely cultured and seeded onto glass coverslips (c-met immunodetection), 12-well plates (DNA and protein synthesis), and tissue culture dishes (migration). c-Met was detected by immunocytochemistry and fluorescence-activated cell scanning (FACS). HGF was measured using enzyme-linked immunosorbent assay (ELISA) techniques. Proliferation and protein synthesis were determined by [(3)H]thymidine and (35)S-methionine incorporation into DNA and proteins, respectively. Migration was assessed using a scratch-wound assay and time-lapse video microscopy.

RESULTS

HGF was detected at all stages of culture of capsular bags in protein-free medium. Moreover, c-met was present on the native epithelium and after mechanical trauma was seen to be upregulated. Immunolocalization and FACS analysis demonstrated c-met expression on FHL124 cells throughout the whole population. Furthermore, FACS analysis showed that serum-maintained cells sustained a higher level of receptor expression relative to serum-deprived cells. Additionally, HGF was found to stimulate proliferation, protein synthesis, and migratory responses.

CONCLUSIONS

c-Met receptors are expressed in native epithelium, capsular bag cultures, and FHL124 cells. Receptor is distributed across the entire cell population; however, this expression is environmentally and mechanically sensitive. HGF is also present in capsular bags at all stages of culture. In addition, HGF can stimulate migration, proliferation, and protein synthesis. It therefore appears that a multifunctional autocrine loop involving HGF and c-met is in place and could be important in the development of posterior capsule opacification.

Induction of matrix metalloproteinases 2 and 9 following stress to the lens

Matrix metalloproteinase 2 and 9 (MMP-2 and 9, also known as gelatinase A and B) have been implicated in a number of eye diseases, but their possible involvement in lens pathology is yet to be determined. In the present study, we therefore investigated a possible role of matrix metalloproteinases in cataract and posterior capsule opacification. Whole porcine lenses were removed from the eye and cultured in either Eagles Minimum Essential Medium (EMEM) or EMEM supplemented with 1 m M hydrogen peroxide. The medium was sampled and changed every 2 days. On some occasions a sham cataract operation was performed on cultured lenses. The resulting capsular bag was secured to a Petri dish and cultured in EMEM. Culture media from all preparations were analysed for MMP-2 and 9 activity by gelatin zymography. Media samples from lenses which maintained clarity over the 6 day culture period did not display any detectable gelatinolytic activity. However, media from cataractous lenses demonstrated a gelatinolytic band, which had similar molecular weights to the pro-form of MMP-2. In addition to this band, bands with a similar molecular weight to pro-MMP-9 and its dimeric form were also detected in samples obtained from capsular bag preparations within 24 hr. The data presented indicate that normal lenses have undetectable gelatinase activity. However, there is an associated expression of gelatinases with pathological states of the lens, and therefore gelatinase expression could play an important role in cataractogenesis and posterior capsule opacification.

Prognostic value of the preserved expression of the E-cadherin and catenin families of adhesion molecules and of beta-catenin mutations in synovial sarcoma

This study addresses the immunohistochemical expression of the E-cadherin and catenin families and mutations of the beta-catenin gene detected by PCR-SSCP in synovial sarcoma. Immunohistochemical analysis was performed for 72 cases, with follow-up data available on 62. The prognostic value of the expression of these proteins was evaluated. Reduced immunoreactivity for E-cadherin and alpha-catenin was significantly correlated with a poor survival rate (p=0.0040 and 0.0053, respectively). According to multivariate analysis, low AJC stage (stages I and II: p<0.0001), the preservation of alpha-catenin expression (p=0.0001), and a low necrotic rate (<50%: p=0.0139) were independent favourable prognostic factors. Widespread aberrant staining of beta-catenin protein within cytoplasm and/or nuclei was observed in 28 cases (38.9%) and was significantly correlated with poor survival (p=0.0122). In addition, there was a trend towards a correlation between widespread aberrant staining of beta-catenin and the MIB-1 labelling index (p=0.0535). Mutational analysis of exon 3 of the beta-catenin gene was performed for 49 cases. Nucleotide sequencing analysis revealed that four (8.2%) contained point mutations (three in codon 32, GAC to TAC; one in codon 37, TCT to TTT). Survival data were available for three out of four cases with beta-catenin mutations; two of these patients died within 1 year (died of disease at 6 and 11 months, respectively). These results suggest that E-cadherin and alpha-catenin undertake important roles as intercellular adhesion molecules; their preserved expression is associated with a better overall survival rate in synovial sarcoma and may have prognostic value. Abnormal levels of beta-catenin, with or without mutation, could contribute to the development and progression of synovial sarcoma, through increasing the proliferative activity of the tumour cells.

H-ras-1 point mutation in malignant peripheral nerve sheath tumors: polymerase chain reaction restriction fragment length polymorphism analysis and direct sequencing from paraffin-embedded tissues

It has been shown that the NF1 (neurofibromatosis type 1) gene encodes a tumor suppressor which inactivates ras proteins. Among malignant mesenchymal tumors, H-ras-1 mutations have been found in malignant fibrous histiocytoma, leiomyosarcoma and embryonal rhabdomyosarcoma. However, studies on H-ras-1 mutation of many cases of malignant peripheral nerve sheath tumors (MPNST) have not been documented. Therefore, we investigated H-ras-1 mutations of MPNST. In 45 cases of MPNSTs of our files, DNA was extracted from the formalin-fixed paraffin-embedded tissue, and the mutations of the H-ras-1 gene were detected by using PCR-RFLP (polymerase chain reaction- restriction fragment length polymorphisms) method and direct sequencing. We found two cases with H-ras-1 point mutation in MPNST for the first time. Both cases showed the same mutation in codon 13.1 [GGT(Gly) to AGT(Ser) transition]. Interestingly, both cases were associated with NF1. It is possibile that the mutation of the H-ras-1 gene occurred after the mutation of the NF1 gene in the MPNST.

Growth of L929 cells on polymeric films prepared by Langmuir-Blodgett and casting methods

The growth and spreading of fibroblast, L929 cells, on various polymeric films prepared by the Langmuir-Blodgett (LB) and casting methods were investigated. L929 cells, which were cultivated on collagen and synthetic polymeric films prepared by the LB method, adhered and spread much more than those on synthetic films prepared by the casting method. This is explained by the fact that cell growth and cell spreading are suitable for L929 cells on the films having serum proteins that contain a high alpha-helix content, because LB films adsorbed those serum proteins estimated from the circular dichroism measurements of the films immersed in cell culture medium. An exponential relationship was observed from the plot of the cell density vs root mean square of roughness of the films, which is estimated by atomic force microscopy, whereas a linear relationship was observed from the plot of the spreading ratio vs the root mean square of roughness. It is suggested that the correlation between the cell growth or spreading ratio and surface roughness of the films where L929 cells were cultivated is considered to be more important than the correlation between the cell growth or spreading ratio and the contact angle of the films.

Increasing methylation of the CDKN2A gene is associated with the progression of adult T-cell leukemia

In this study, we examined the methylation status of the CDKN2A gene in patients with different forms of adult T-cell leukemia (ATL) using Southern blot analysis, methylation-specific PCR (MSPCR), and nucleotide sequencing. We found that the CDKN2A gene was more frequently methylated in fresh tumor cells isolated from patients with acute ATL (47%) or lymphoma-type ATL (73%) than in those with less malignant chronic (17%) and smoldering (17%) ATL. In addition, deletions of the CDKN2A gene were found in 24% of acute ATL patients; thus, abnormalities of the CDKN2A gene totaled 71% in acute ATL patients. In contrast, no CDKN2A gene methylation was found in asymptomatic carriers or uninfected individuals. Methylation of the p15 gene was not found in any samples from 36 ATL patients. Direct sequencing of the CDKN2A gene after sodium bisulfite treatment of genomic DNA revealed that the methylation of CpG sites had occurred in 24 of 32 ATL cases (75%) including chronic and smoldering ATL, even when MSPCR and the Southern blot had failed to detect CDKN2A gene methylation. Among fresh ATL samples with methylation, methylation was detected in the promoter region and exon in 17 of 24 cases, and methylation in the exon without promoter region was detected in 7 of 24 cases. In one case, the pattern of methylation proved to be different between peripheral blood cells and lymph node cells, suggesting the presence of multiple subclones with regard to methylation patterns, despite the same HTLV-I integration site. Quantitative PCR showed a marked decrease in CDKN2A mRNA expression in the cells with a methylated CDKN2A gene, especially if the promoter region was methylated. These findings suggest that CpG methylation decreases CDKN2A expression and represents a critical factor in the disease progression of ATL.

Evaluation of Epstein-Barr virus infection in sinonasal small round cell tumors

Sinonasal undifferentiated carcinoma, olfactory neuroblastoma and malignant melanoma of the sinonasal regions are included within the category of small round cell tumors of the sinonasal region. It is difficult to diagnose these tumors on the basis of light-microscopic features alone, but, in some instances, immunohistochemical staining evaluating cytokeratin and S-100 protein, for example, is of value. On the other hand, the sinonasal region is a significant site for Epstein-Barr-virus (EBV)-related tumors, including sinonasal undifferentiated carcinoma or malignant lymphoma. Twenty-three sinonasal small round cell tumors (SSRCT) comprising 5 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas and 9 malignant melanomas were evaluated for the presence of EBV infection by in situ hybridization for EBV-encoded RNA, combined with immunostaining for EBV-related proteins (LMP-1 and EBNA2). Furthermore, 55 SSRCT comprising 37 sinonasal undifferentiated carcinomas, 9 olfactory neuroblastomas, and 9 malignant melanomas were examined for the presence of cytokeratins (AE1/ AE3 and CAM5.2), S-100 protein and p53 protein using immunohistochemical staining. According to in situ hybridization for detecting EBV-encoded RNA 1 (EBER1), all of the sinonasal undifferentiated carcinomas showed clear, intense hybridization signals localized over the nuclei of the tumor cells and, in 3 out of 9 (33.3%) malignant melanomas, hybridization signals were also recognized. However, none of the olfactory neuroblastomas revealed hybridization signals. Immunohistochemically, 4 out of 5 (80%) sinonasal undifferentiated carcinomas were positive for LMP-1, whereas only 2 out 9 (22.2%) malignant melanomas and no olfactory neuroblastomas were positive. With regard to EBNA2, sinonasal undifferentiated carcinomas, malignant melanomas and olfactory neuroblastomas were all negative. Out of 37 sinonasal undifferentiated carcinomas 35 (94.6%) showed a diffuse positive immunoreaction for AE1/AE3, whereas neither olfactory neuroblastoma nor malignant melanoma revealed a positive reaction. All 9 malignant melanomas and 6 out of 9 olfactory neuroblastomas (75%) were positive for S-100 protein, whereas only 6 cases of sinonasal undifferentiated carcinomas (19.4%) were positive. As for p53 protein, 16 of 37 sinonasal undifferentiated carcinomas (43.2%) were positive, whereas neither olfactory neuroblastoma nor malignant melanoma revealed any positive reaction. The above results suggest that EBV infection is closely associated with sinonasal undifferentiated carcinomas, and that some malignant melanomas may also have a relationship with its infection. For the differential diagnosis of SSRCT, it is important to evaluate EBV infection along with immunohistochemical staining for cytokeratins and S-100 protein. The overexpression of p53 protein was found to be related to the oncogenesis of sinonasal undifferentiated carcinoma; however, there was no association between its overexpression and malignant melanoma or olfactory neuroblastoma.

Expressions of basic fibroblast growth factor and fibroblast growth factor receptor mRNA in soft tissue tumors by in situ hybridization

Basic fibroblast growth factor (bFGF) is a mitogenic and angiogenic polypeptide produced by diverse cell types, including the cells derived from normal tissue and neoplastic lesions. To evaluate the possible differential expression of bFGF in soft tissue tumors, we examined 17 frozen primary soft tissue tumors including extra-abdominal desmoids, leiomyosarcomas, synovial sarcomas, myxoid liposarcomas, and alveolar soft part sarcomas by nucleic acid in situ hybridization. Three of the four leiomyosarcomas and two of the three synovial sarcomas studied expressed bFGF mRNA, whereas all of the myxoid liposarcomas and alveolar soft part sarcomas were negative. Two of the leiomyosarcomas were also positive for FGF receptor mRNA. These results indicated the possibility of an autocrine or paracrine mechanism in the function of bFGF and also lent support to the opinion that in situ hybridization is useful for examining cell character.

Mutation of CD95 (Fas/Apo-1) gene in adult T-cell leukemia cells

CD95 antigen (also known as Fas or Apo-1) and Fas ligand play key roles in apoptosis of cells of the immune system, function as effector molecules of cytotoxic T lymphocytes, and function in the elimination of activated lymphocytes during the downregulation of the immune response. The critical roles of the Fas-Fas ligand system in apoptosis suggest that its inactivation may be involved in malignant transformation. We analyzed the expression of Fas antigen on adult T-cell leukemia (ATL) cells by flow cytometry and found that Fas antigen expression was absent in a case of ATL and markedly decreased in another case among 47 cases examined. Apoptosis could not be induced in the Fas-negative ATL cells by antibody against Fas antigen. Sequencing of reverse transcription-polymerase chain reaction products of the Fas genes in the Fas negative cells showed two types of aberrant transcripts: one had a 5-bp deletion and a 1-bp insertion in exon 2, and the other transcript lacked exon 4. These mutations caused the premature termination of both alleles, resulting in the loss of expression of surface Fas antigen. These aberrant transcripts were not detected in a nonleukemic B-cell line from the same patient. An RNase protection assay of the Fas gene showed mutations in 2 additional cases with Fas-positive ATL cells of 35 cases examined: 1 case lacked exon 4 and the other was a silent mutation. In the Fas antigen-negative case, leukemic cells were resistant to anticancer drugs in vivo, indicating that the loss of expression of Fas antigen may be associated with a poor response to anticancer drugs. Indeed, Fas-negative ATL cells were resistant to adriamycin-induced apoptosis in vitro, which is consistent with the finding that ATL in this case was resistant to chemotherapy. These findings indicate that mutation of the Fas gene may be associated with the progression of ATL and with resistance to anticancer drugs.

Persistent clonal proliferation of human T-lymphotropic virus type I-infected cells in vivo

Clonal proliferation of human T-lymphotropic virus type I (HTLV-I)-infected cells has been detected by Southern blot analysis and inverse PCR in patients with adult T-cell leukemia, patients with HTLV-I-associated diseases, and even in asymptomatic carriers. Combining inverse PCR with long PCR, we amplified the genomic DNA regions flanking the integration sites of the HTLV-I provirus to detect clones of infected cells. Inverse long PCR revealed that increased virus load was associated with an increase of both the number of cells in each clone and the number of clones. Clonal proliferations were found in both CD4- and CD8-positive cells in a carrier and a patient with HTLV-I-associated neuropathy/tropical spastic paraparesis. These HTLV-I-infected clones persisted over several years in the same carriers, and, moreover, most of the persistent clones were CD4 positive in a HTLV-I carrier. These findings indicate that HTLV-I infection plays an important role in the clonal expansion of lymphocytes and the prolonged survival of CD4-positive cells in vivo. Surviving T-lymphocytes may be susceptible to genetic changes, leading to the onset of leukemia.

HTLV-I provirus in the clinical subtypes of ATL

Adult T cell leukemia (ATL) is an aggressive neoplasm of mature helper T cell, which is etiologically linked with human T-lymphotropic virus type 1 (HTLV-I). We studied HTLV-I provirus in 61 cases of ATL with Southern blot analyses and long PCR. These methods detected defective virus in 34 cases (56%). Furthermore, it found two types of defective virus. The first type (type 1) defective virus had both LTRs, but lacked internal sequences, such as gag and pol. Type 1 defective virus was seen in 50% of all defective virus. The second form (type 2) of defective virus had only one LTR, and 5'-LTR was preferentially deleted. This type of defective virus could be more frequently detected in aggressive types of ATL (16/44 cases) than chronic type (1/17 cases). This defective virus might be associated with clinical subtype.