Reassessment and clinicopathological prognostic factors of malignant fibrous histiocytoma of soft parts

Recently, the category of malignant fibrous histiocytoma (MFH) has been under discussion and new entities resembling MFH have appeared. To clarify the recent situation regarding MFH, we reassessed previously diagnosed MFH cases in accordance with the most up-to-date diagnostic criteria, which included allied tumors. We carefully reassessed 428 cases that had been diagnosed in our institute during the past 28 years. Moreover, we searched for clinicopathological prognostic factors among the cases that were finally diagnosed as MFH. Among the 428 cases, 138 cases had their diagnoses changed. The revised cases included 78 leiomyosarcomas (57%; ordinary leiomyosarcoma, 45 cases; pleomorphic leiomyosarcoma, 23 cases; myxoid leiomyosarcoma, 10 cases), 12 liposarcomas (9%; pleomorphic liposarcoma, 11 cases; dedifferentiated liposarcoma, one case), seven dermatofibrosarcoma protuberans (5%), six unclassified sarcomas (4%), five primary or metastatic carcinomas (4%), four low-grade fibromyxoid sarcomas (3%), four inflammatory myofibroblastic tumors (3%), three rhabdomyosarcomas (2%), three malignant peripheral nerve sheath tumors (2%), three acral myxoinflammatory fibroblastic sarcomas (2%) and two atypical fibroxanthomas (1.5%). Among the 1974 soft tissue sarcomas registered in our institute, MFH (428 cases) had been the most common sarcoma, followed by liposarcoma, leiomyosarcoma and rhabdomyosarcoma. However, after reassessment, leiomyosarcoma proved to be the most common soft tissue sarcoma (322 cases), followed by 290 MFH, 273 liposarcomas and 202 rhabdomyosarcomas. Among these 290 cases finally diagnosed as MFH, survival data were available in 189 cases. Tumor location in the abdominal cavity, the retroperitoneum or the head and neck (P = 0.0024), tumor size of 5 cm or more (P < 0.0001), deep tumor location (P < 0.0001), high histological grade (grade 3) based on the French Federation of Cancer Centers' grading system (P = 0.0007), and high stage (stage III or IV) based on the American Joint Committee on Cancer (AJCC) staging system (P < 0.0001) were significantly worse prognostic factors by univariate analysis. In multivariate analysis, deep tumor location and high AJCC stage were independent adverse prognostic factors. We conclude that leiomyosarcoma is the most important differential diagnosis for MFH, especially pleomorphic leiomyosarcoma from storiform-pleomorphic type and myxoid leiomyosarcoma from myxoid type. Tumor depth and AJCC stage are the most important predictive prognostic factors in MFH.     

The absence of DNA polymerase kappa does not affect somatic hypermutation of the mouse immunoglobulin heavy chain gene

During the immune response to T cell-dependent antigen, somatic hypermutation (SHM) is introduced into immunoglobulin (Ig) genes. The variable region is the target for SHM and it is here that DNA lesions are introduced and mutations are generated. It has been suggested that error-prone DNA polymerase(s) may play an important role in this mutagenesis phase. Recently, DNA polymerase kappa (Polkappa), which belongs to the Y-family of DNA polymerases, was identified. Since a hot spot of SHMs (RGYW motif) is also a hot spot of mutations by human Polkappa, this enzyme was suggested to be an SHM instigator. In order to address the question whether Polkappa is involved in SHM, we immunized Polkappa-deficient mice and analyzed the SHM of the Ig heavy chain gene. We found that the SHM frequency and spectrum were indistinguishable between the Polkappa knockout mice and control mice. These results suggested that Polkappa is not essential for this process.     

Culturing of skin fibroblasts in a thin PLGA-collagen hybrid mesh

A thin biodegradable hybrid mesh of synthetic poly(DL-lactic-co-glycolic acid) (PLGA) and naturally derived collagen was used for three-dimensional culture of human skin fibroblasts. The hybrid mesh was constructed by forming web-like collagen microsponges in the openings of a PLGA knitted mesh. The behaviors of the fibroblasts on the hybrid mesh and PLGA knitted mesh were compared. The efficiency of cell seeding was much higher and the cells grew more quickly in the hybrid mesh than in the PLGA mesh. The fibroblasts in the PLGA mesh grew from the peripheral PLGA fibers toward the centers of the openings, while those in the hybrid mesh also grew from the collagen microsponges in the openings of the mesh resulting in a more homogenous growth. The proliferated cells and secreted extracellular matrices were more uniformly distributed in the hybrid mesh than in the PLGA mesh. Histological staining of in vitro cultured fibroblast/mesh implants indicated that the fibroblasts were distributed throughout the hybrid mesh and formed a uniform layer of dermal tissue having almost the same thickness as that of the hybrid mesh. However, the tissue formed in the PLGA mesh was thick adjacent to the PLGA fibers and thin in the center of the openings. Fibroblasts cultured in the hybrid mesh were implanted in the back of nude mouse. Dermal tissues were formed after 2 weeks and became epithelialized after 4 weeks. The results indicate that the web-like collagen microsponges formed in the openings of the PLGA knitted mesh increased the efficiency of cell seeding, improved cell distribution, and therefore facilitated rapid formation of dermal tissue having a uniform thickness. PLGA-collagen hybrid mesh may be useful for skin tissue engineering.     

Expression of cyclin D1, retinoblastoma gene protein, and p16 MTS1 protein in atypical adenomatous hyperplasia and adenocarcinoma of the lung

 To clarify the events leading to the disruption of cell growth control that occurs during the development of pulmonary adenocarcinoma (AC), we used immunohistochemistry to evaluate the expression of G1 cycle regulators, cyclin D1, Rb protein (pRb), and p16 MTS1 protein and the tumour proliferation marker, Ki 67, both in AC of the lung and in its precursor lesion, atypical adenomatous hyperplasia (AAH). The frequency of lesions with cyclin D1 overexpression was relatively high in AAH (47–89%), but was decreased in early AC (28%) and overt AC (35%). The loss of pRb expression was rare in both AAH (0–18%) and early AC (0%), and was infrequent even in overt AC (13%). The loss of p16 expression was also relatively infrequent in both the premalignant and the malignant lesions (11–25%). Our results suggest that overexpression of cyclin D1 is an early event and plays an important part in tumorigenesis in the case of lung AC. However, cyclin D1 overexpression is not required for the development and maintenance of a malignant phenotype. It is likely that some cyclin D1-independent pathways other than Rb and p16 abnormalities have an important role in the malignant transformation from AAH to early AC. Received: 8 July 1997 / 26 September 1997     

Viability and osteogenic potential of cryopreserved human bone marrow-derived mesenchymal cells

Human bone marrow-derived mesenchymal cells contain mesenchymal stem cells (MSCs), which are well known for their osteo/chondrogenic potential and can be used for bone reconstruction. This article reports the viability of cryopreserved human mesenchymal cells and a comparison of the osteogenic potential between noncryopreserved and cryopreserved human mesenchymal cells with MSC-like characteristics, derived from the bone marrow of 28 subjects. The viability of cryopreserved mesenchymal cells was approximately 90% regardless of the storage term (0.3 to 37 months). It is clear by fluorescence-activated cell sorter analysis that the cell surface antigens of both noncryopreserved and cryopreserved mesenchymal cells were negative for hematopoietic cell markers such as CD14, CD34, CD45, and HLA-DR but positive for mesenchymal characteristics such as CD29 and CD105. To monitor the osteogenic potential of the cells, such as alkaline phosphatase (ALP) activity and in vitro mineralization, a subculture was conducted in the presence of dexamethasone, ascorbic acid, and glycerophosphate. No difference in osteogenic potential was found between cells with or without cryopreservation treatment. In addition, cells undergoing long-term cryopreservation (about 3 years) maintained high osteogenic potential. In conclusion, cryopreserved as well as noncryopreserved human mesenchymal cells could be applied for bone regeneration in orthopedics.     

PROGRESSIVE MULTIFOCAL LEUKOENCEPHALOPATHY

Clinical, light- and electron microscopic, and immunohistochemical findings of a 44-year-old woman with progressive multifocal leukoencephalopathy were presented. Autopsy revealed a wide distribution of the demyelinating lesion in the cerebrum, cerebellum, brain stem and spinal cord, and intranuclear inclusion bodies and papova-like virions in transmission electron microscopy in the nuclei of oligodendrocytes. SV40 antigen was immunohistochemically detected in these inclusion bodies. The widespread extension of the lesions seemed to correlate with the duration of the patient's illness. The prolongation of the clinical course in this case may be dependent upon the lack of serious underlying diseases except for a small nodule of thyroid carcinoma, SV40 infection rather than JC virus infection and/or improved care of that kind of patient.     

The proliferating cell nuclear antigen (PCNA) index correlates with the grade of cytologic atypia in well-differentiated early adenocarcinomas of the large intestine

Well-differentiated colorectal adenocarcinomas are subclassified into carcinoma with high-grade atypia (CAH) and carcinoma with low-grade atypia (CAL) based on their cellular atypia. It is proposed that CAH and CAL are different in histologic prognostic factors and that the former should be regarded as carcinoma with high-grade malignancy and the latter as low-grade malignancy. In this study, the differences in cell-proliferative activity between CAH and CAL were examined using a monoclonal antibody to the proliferating cell nuclear antigen (PCNA). The PCNA index and mitotic index of 27 early colorectal carcinomas (9 CAL, 5 CAH, and 13 carcinomas with mixed low- and highgrade atypia) was evaluated in relation to their depth of invasion. In intra-mucosal lesions, both indices were higher in CAH (78%, 0.89%) than in CAL (68%, 0.47%; P <0.01). In lesions invading into the submucosa, the PCNA and mitotic indices were also higher in CAH (7596, 0.65%) than in CAL (35%, 0.19%; P <0.01). A significant correlation was observed between the PCNA index and the mitotic index in the mucosal lesions (P<0.05). These results indicate that CAH has a higher proliferative activity than CAL, and support the current authors' proposal that CAH is a high-grade malignancy and CAL a low-grade malignancy.     

p53 protein overexpression and K-rascodon 12 mutation in pancreatic ductal carcinoma: Correlation with histologic factors

The correlation of p53 protein overexpression and the K-ras codon 12 mutatlon wlth histologlc type, grade of cytologic atypla, depth of lnvasion and other histologlc prognostic factors was studied In paraffin sectlons from 43 ductectatic-and 70 solid-type pancreatic ductal carcinomas. Overexpression of p53 was found in 23.3% (10143) of ductectatic carcinomas (17.2% of intraductal and 35.7% of lnvaslve carclnomas) and in 61.4% (43/70) of solid carcinomas. In ductectatic cancers, p53 overexpression was detected In 14.8% (4/27) of carcinomas wlth lowgrade atypla (CAL), 50.0% (5110) of carcinomas wlth high-grade atypla (CAH) and in 16.7% (In) of mixed low- and hlgh-grade cancers. In the last group, expression was restricted to an area of CAH. In solld cancers, p53 overexpression did not dlffer by histologic type or grade. Overexpresslon of p53 and K-ras mutatlons did not correlate with histologlc prognostic factors (lymphatic, venous and perineural Invasion, and lymph node metastasls) in ductectatlc and solld cancers or depth of invasion of solld carclnomas. Our data suggest that p53 alteratlon occurs at an early intraductal stage of solld carcinoma, irrespectlve of cellular atypla, but Is low in ductectatic CAL and becomes hlgher In ductectatlc CAH. K-ras mutatlon, present In a high percentage of tumors of all groups and not correlating with the factors above, showed no changes In frequency with tumor progression.     

Immunoexpression of the α subunit of a guanine nucleotide-binding protein (Go) in pulmonary neuroendocrine cells and neoplasms

The α subunit of a GTP-blndlng protein, Go, was investigated in pulmonary neuroendocrine neoplasms and fetal tissues of the lung by an immunohistochemlcal method. Positive immunostaining for the α subunit of Go (Goα) was found predominantly on the cell membrane and found occasionally in the cytoplasm. Typical carcinoids were all positively stained (9/9), and small cell carcinoma showed weaker and less frequent staining (5 positive cases in 10). Atypical carcinoids were variously stained (3/4). The tendency for obvious neuroendocrine differentiation to be immunohistochemically determined in typical carcinoids and not in small cell carcinoma is also true of staining for neuron specific enolase (NSE), chromogranin A (CG-A) and synaptophysin. In the lung, Goα-immunostaining was positive not only in nerve tissues but also in the airway epithelium. In the fetal lung, serial sections immunostained for NSE, CG-A and Goα confirmed that Goα-immunoreactive cells belong to the neuroendocrine cell population. The biological significance of Goα is unclear in normal and neoplastic lung tissues, but Goα is a useful marker of neuroendocrine cells and neoplasms of the lung.     

The roles of soluble osteopontin using osteopontin-transgenic mice in vivo: proliferation of CD4+ T lymphocytes and the enhancement of cell-mediated immune responses.

We generated transgenic mice expressing osteopontin (OPN) under the control of the alpha(1)-antitrypsin promoter. These mice (OPN-T mice) expressed OPN mRNA in liver and kidney, and released a large amount of plasma OPN, which increased after stimulation with turpentine oil. Before sensitization, the number of CD4+ T cells in lymph nodes was significantly higher in OPN-T than nontransgenic mice, and that in spleen was slightly higher, whereas that of CD8+ T cells was no different between OPN-T and nontransgenic mice. After sensitization, the CD4+ T cell numbers in spleen increased significantly, while there were almost no changes in the CD8+ T cells in lymph nodes and spleen. The intensity of contact hypersensitivity responses to 2,4-dinitrofluorobenzene (DNFB) was obviously enhanced in OPN-T mice. In the delayed-type hypersensitivity (DTH) model elicited by DNFB, the number of CD8+ T cells among DNFB-2,4,6-trinitrobenzenesulfonic acid (TNBS)-peritoneal exudate cells was significantly higher in OPN-T than nontransgenic mice, while there was almost no difference in that of CD4+ T cells. Adoptive transfer experiments revealed that the enhanced reactivity is carried by CD4+ and CD8+ T cells, respectively, although the ability of transferring DTH was significantly lower in CD8+ than in CD4+ T cells. The enhancement of CD8+ T cell migration was observed in OPN-T mice. These results suggest that OPN induces a proliferation of effector CD4+ and CD8+ cells in cell-mediated reactions and plays a role in the migration of CD8+ T cells.