Thin-layer hydroxyapatite deposition on a nanofiber surface stimulates mesenchymal stem cell proliferation and their differentiation into osteoblasts.

Pulsed laser deposition was proved as a suitable method for hydroxyapatite (HA) coating of coaxial poly-ɛ-caprolactone/polyvinylalcohol (PCL/PVA) nanofibers. The fibrous morphology of PCL/PVA nanofibers was preserved, if the nanofiber scaffold was coated with thin layers of HA (200 nm and 400 nm). Increasing thickness of HA, however, resulted in a gradual loss of fibrous character. In addition, biomechanical properties were improved after HA deposition on PCL/PVA nanofibers as the value of Young's moduli of elasticity significantly increased. Clearly, thin-layer hydroxyapatite deposition on a nanofiber surface stimulated mesenchymal stem cell viability and their differentiation into osteoblasts. The optimal depth of HA was 800 nm.

Apoptosis - associated genes and their role in predicting responses to neoadjuvant breast cancer treatment.

BACKGROUND: Neoadjuvant chemotherapy is used in the treatment of breast carcinoma because it substantially reduces the size of the primary tumor and lymph node metastases. The present study investigated biomarkers that can predict a pathologic response to the therapy. MATERIAL/METHODS: The role of apoptosis in regression of the tumors after neoadjuvant chemotherapy was determined by TUNEL and anti-active caspase 3 assay. The transcriptional profile of 84 key apoptosis genes was evaluated in both pre-therapeutically obtained tumor tissue by core needle biopsy and in specimens removed by final surgery, using a pathway-specific real-time PCR assay. Obtained data were analyzed by hierarchical cluster analysis and correlation analysis. The immunohistochemical profile of each tumor was determined using the standard ABC method. RESULTS: On the basis of a hierarchical cluster analysis of 13 significantly changed genes, we divided patients into good and poor prognosis groups, which correlate well with progression-free survival. In the good prognosis group, we found a statistically significant down-regulation of the expression of MCL1 and IGF1R genes after neoadjuvant treatment. We also found a statistically significant overexpression of BCL2L10, BCL2AF1, CASP8, CASP10, CASP14, CIDEB, FADD, HRK, TNFRSF25, TNFSF8 and CD70 genes. In contrast, we found up-regulation of IGF1R after the treatment in the group with poor prognosis. CONCLUSIONS: Gene expression profiling using real-time PCR assay is a valuable research tool for the investigation of molecular markers, which reflect tumor biology and treatment response.

Primary synovial sarcoma of the uterus.

We report a case of a 52-year-old female with synovial sarcoma of the uterine corpus. Grossly, the partly polypoid tumor involved the endometrium with invasion into the inner half of the myometrium. Histologically, the tumor showed biphasic structure with the predominance of poorly differentiated small to medium sized round to oval cells. These cells showed high nuclear to cytoplasmic ratio and were arranged in diffuse sheets. Other component consisted of larger epitheloid cells with ample eosinophilic cytoplasm arranged in irregular nests. These cells were only present in a small amount. Immunohistochemically, the tumor cells in both components showed the expression of EMA, S-100 protein, CD99, and NSE. RT-PCR analysis showed the presence of SYT-SSX1 fusion transcript. At present, the patient shows no signs of tumor relapse 56 months after the diagnosis. To the best of our knowledge, this is the first report of synovial sarcoma arising in uterus.

[KRAS mutation testing in therapeutic algorithm for treatment of metastatic colorectal carcinoma]. / Vysetrení mutacního statutu genu KRAS jako soucást algoritmu lécby metastatického kolorektálního karcinomu.

Targeted therapy has become an integral part of treatment procedures of malignant tumors. Colorectal carcinomas are frequently targeted with monoclonal anti-EGFR antibodies (cetuximab and panitumumab). Activating somatic mutations in codons 12 and 13 of the exon 2 of KRAS gene are considered negative predictive factors of response to anti-EGFR therapy in patients with metastatic colorectal cancer. In the Czech Republic, evaluation of mutational status of KRAS gene is performed in several referral laboratories. In 2009, these laboratories performed 2580 tests of the KRAS mutational status--out of these, 60.2% cases reported non-mutated, wild-type KRAS. In one of the referral laboratories, we demonstrate the logistics of KRAS testing procedure. Stratification of patients with metastatic colorectal tumors based on their KRAS mutational status has evolved to a standard procedure. Laboratories performing these methods shall therefore adhere to the recommendations of the professional and accredited societies.

Actin expression in neural crest cell-derived tumors including schwannomas, malignant peripheral nerve sheath tumors, neurofibromas and melanocytic tumors.

Tumors that originate from neural crest-derived cells represent a heterogeneous group of neoplasms including benign and malignant tumors with melanocytic and schwannian differentiation. The immunophenotype of these tumors is well known but little is known about the expression of smooth muscle/myofibroblastic markers in these tumors. A total of 590 neural crest-derived tumors (50 benign schwannomas, five malignant peripheral nerve sheath tumors, 80 neurofibromas, 240 nevocytic nevi, 115 primary melanomas, and 100 melanoma metastases) were studied with respect to alpha-smooth muscle actin and muscle-specific actin expression. alpha-Smooth muscle actin and muscle-specific actin-positive tumor cells with a co-expression of S-100 protein were found in one benign schwannoma, one primary cutaneous melanoma, and four melanoma metastases. Four of these cases were examined ultrastructurally, but typical actin filaments with focal densities were not found in any of the four. Other immunohistochemical markers examined including desmin, h-caldesmon and smooth muscle myosin heavy chain were negative in the tumor cells. The present results suggest that neural crest-derived tumors could show expression of alpha-smooth muscle actin on rare occasion.

Distribution of chondrocytes containing alpha-smooth muscle actin in human normal, osteoarthrotic, and transplanted articular cartilage.

The aim of our study was to evaluate the occurrence of chondrocytes containing alpha-smooth muscle actin in human normal and diseased cartilage. Immunohistochemistry using monoclonal antibodies for alpha-smooth actin, muscle-specific actin, S-100 protein, CD 34, and desmin was performed on samples of human articular cartilage obtained at autopsy following sudden death, during total hip and knee replacement for osteoarthritis, or after femoral neck fracture in patients without symptoms of osteoarthritis. Moreover, the layers of residual cartilage from chondral posttraumatic defects obtained during preoperative arthroscopy and of newly formed cartilage after autologous-chondrocyte transplantation (Hyalograft C) obtained during second-look arthroscopy were also examined by immunohistochemistry and RT PCR. Our study showed that a significant percentage of articular chondrocytes express alpha-smooth muscle actin in healthy, diseased, and regenerated articular cartilage. Alpha-actin positive chondrocytes (18%) were observed predominantly in the upper zone of normal articular cartilage. By contrast, only approximately 10% of cartilage cells in the deep region stained for this contractile actin isoform. Actin-positive chondrocytes (myochondrocytes) are formed predominantly in response to injury to the osteoarthrotic cartilage, at sites of defective healing, and in newly formed cartilage after autologous chondrocyte transplantation. Fibrocartilage is present in some of these conditions, and it is known that this tissue contains chondrocytes with actin. The presence of myochondrocytes in the surface layer of normal articular cartilage indicates that this region probably plays an important role in maintaining cartilage integrity. Myochondrocytes may utilize the contractile actin isoform in manipulating the extracellular matrix of articular cartilage. It is also possible that actin-containing chondrocytes have a higher potential for regeneration in contrast to chondrocytes that do not contain this contractile material in their cytoplasm.

Pigmented microcystic chromophobe renal cell carcinoma.

We report a case of a 60-year-old female with a pigmented microcystic chromophobe renal cell carcinoma (PMCRCC). The tumor was 4.5 cm in diameter, and was located in the right kidney. Grossly, on cross section, the tumor was light gray with multiple small brown to black pigmented foci up to 0.2 cm in diameter. Histologically, the tumor showed a microcystic arrangement with cribriform areas and formation of adenomatous structures. The microcystic and cribriform areas were composed of larger pale cells and smaller eosinophilic cells, with cytological features of conventional chromophobe renal cell carcinoma (CRCC). The cytological features of the cells within the adenomatous structures were different. These cells were mostly columnar with nuclei at the base, and had a variable amount of pale to eosinophilic cytoplasm. There were foci of ample brown pigmentation located in the cytoplasm of the tumor cells and extracellularly. In addition, microscopic calcifications were present. Immunohistochemically, the tumor cells were positive for EMA, E-cadherin, cytokeratin CAM5.2, and cytokeratin AE1/AE3. Cytokeratin 7 was positive only focally. S-100 protein, melan A, HMB 45, vimentin, and CD117 were negative. PMCRCC is a rare tumor. To the best of our knowledge, only one series containing 20 cases of this variant of CRCC has been described to date. The important feature is that PMCRCC seems to have a relatively benign biological behavior, and distant metastases and sarcomatoid transformation are absent.

Uterine leiomyomas with inclusion bodies: an immunohistochemical and ultrastructural analysis of 12 cases.

We describe 12 cases of leiomyoma with intracytoplasmic inclusion bodies, which were detected in a group of 447 leiomyomas examined at our institution between December 2005 and March 2006. Ten of these tumors were typical leiomyomas, and two cases represented atypical (bizarre) leiomyoma. In some cases, the presence of intracytoplasmic inclusion bodies resulted in a rhabdoid or skeletal muscle-like appearance of the tumor cells. Ultrastructurally, there were two types of inclusions. One of them consisted of an abnormal aggregation of intermediate and actin filaments. Another type of inclusions was composed of dense granular material without an apparent fibrillar structure. The ultrastructure of the inclusions correlates with immunohistochemical and histochemical stainings. The inclusions with apparent fibrillar arrangements were PAS negative, stained red by trichrome, and were, at least at the periphery, actin-, desmin-, and h-caldesmon-positive. The dense granular inclusions were at least focally PAS-positive, stained red by trichrome, and were negative immunohistochemically. The intracytoplasmic inclusions were found in atypical (bizarre) leiomyomas of the uterus and occasionally in epithelioid leiomyomas and leiomyosarcomas. However, to the best of our knowledge, these inclusions have not been found in typical uterine leiomyomas to date.

Intraneural perineurioma of the oral mucosa.

A 16-year-old boy presented with an intraneural perineurioma arising from a small nerve in the buccal mucosa. Histologically, the tumour comprised a tortuous proliferation of spindle cells arranged like an onion bulb. To our knowledge this is the third example of an intraneural perineurioma that did not present in a major nerve.

Pathological findings of uterine leiomyomas and adenomyosis following uterine artery embolization.

Uterine artery embolization (UAE) is an effective and accepted treatment option for symptomatic uterine leiomyoma. Between 2000 and 2005, 91 women were treated using this method, and were prospectively followed at our institution. Twenty of them subsequently underwent surgery. One of these patients was subjected to four surgical procedures. We describe the pathological findings of 23 surgical specimens obtained from these 20 patients. The embolic material used consisted of tris-acryl gelatin microspheres (TGMS) in 15 patients (18 surgical specimens), polyvinyl alcohol particles (PVA) in three patients, and a combination of PVA and TGMS in two patients. Histologically, of the 23 specimens examined, 20 were diagnosed as leiomyomas, and three as adenomyosis. Particles used for embolization were found in all but three specimens. Necrosis was present in 15 of 20 leiomyoma specimens. Hyaline necrosis was found in 12 specimens, coagulative necrosis in one case, and a combination of hyaline and coagulative or suppurative necrosis in two cases. The foci of adenomyosis remained unaltered.

Up-regulation of p21WAF1 expression is mediated by Sp1/Sp3 transcription factors in TGFbeta1-arrested malignant B cells.

BACKGROUND: TGFbeta1 has a profound effect on the growth of various mammalian cell types, including B lymphocytes. The inhibitory action of TGFbeta1 is mediated by deactivation of the cell cycle machinery. Several feedback-sensitive pathways determine whether the cells are stopped in G1 phase or allowed to leave G1 phase and enter S phase. Cell cycle-associated molecules, e.g. cyclin-dependent kinase inhibitors (CKIs), may become targets for the inhibitory signaling pathways induced by TGFbeta1. MATERIAL/METHODS: Our experimental DoHH2 cell line model was derived from a patient with malignant non-Hodgkin's lymphoma of follicular origin. The effect of TGFbeta1 on cell cycle progression was studied by flow cytometry. We examined the effect of TGFbeta1 on the expression of p21WAF1 by immunoblotting and RT-PCR. The binding activity of transcription factors to the p21 gene promoter was determined by gel mobility shift assay (GMSA). RESULTS: Our results showed that TGFbeta1 treatment increased the number of cells arrested in G0/G1 phase compared with untreated control cells. Moreover, we found that p21WAF1 expression was significantly up-regulated on the protein level after TGFbeta1 treatment. Similarly to the protein level, the expression of p21 mRNA was increased in TGFbeta1-treated cells. We further examined the binding activity of the Sp family of transcription factors to examine their role in p21WAF1 up-regulation. CONCLUSIONS: The results indicated that p21WAF1 over-expression in TGFbeta1-arrested malignant B cells is mediated by binding of Sp1/Sp3 transcription factors to the (-92/-71), (-77/-58), and (-65/-45) elements of the promoter region of the p21 gene.

Adrenocortical adenoma with rhabdoid features.

We report a case of an aldosterone producing adrenocortical adenoma with rhabdoid features in a 16-year-old girl. Grossly, the tumor measured 30 mm in diameter and weighed 24 g. Histologically, the tumor was composed of approximately equal parts of tumor cells with rhabdoid features arranged in a solid and trabecular pattern and cells characterized by compact eosinophilic cytoplasm, solid growth with focal necroses, and increased mitotic activity. The lipid-rich tumor cells with ample clear vacuolized cytoplasm represent a minor component. Immunohistochemically, all the tumor cells showed the same results and were positive for vimentin, synaptophysin, Melan A, and alpha-inhibin. Cytokeratin CAM 5.2 was positive only focally. Chromogranin A, actin, alpha-actin, S100 protein, EMA, and cytokeratin AE1/AE3 were negative. Rhabdoid features have been described in many tumors of variable histogenesis; however, to the best of our knowledge, the presence of rhabdoid phenotype has never been described in either adrenocortical adenoma or carcinoma.

Molecular diagnosis of synovial sarcoma: RT-PCR detection of SYT-SSX1/2 fusion transcripts in paraffin-embedded tissue.

BACKGROUND: Synovial sarcomas comprise up to 10 percent of malignant soft tissue tumors, and most are characterized by the chromosomal translocation t(X;18) (pl 1.2;q11.2), which results in the expression of SYT-SSX fusion transcripts. These tumors include two major histological subtypes, biphasic and monophasic. Diagnosing biphasic synovial sarcomas does not usually pose a problem, whereas the monophasic spindle-cell form can be difficult to distinguish from other spindle-cell neoplasms using histological and immunohistochemical profiles only. MATERIAL/METHODS: We investigated the presence of SYT-SSX1/2 chimeric RNA in tumors from 7 patients. We applied amplification of the specific fusion transcripts by reverse transcriptase-polymerase chain reaction (RT-PCR) in fresh, frozen tumors. We also developed a method useful for RT-PCR SYT-SSX fusion transcript detection in formalin-fixed, paraffin-embedded tissue. RESULTS: We found that both histological subtypes of synovial sarcoma were SYT-SSX positive. Moreover, we observed a correlation between histological subtype and type of SYT-SSX fusion transcript. Biphasic synovial sarcoma expressed the SYT-SSX1 fusion transcript, whereas the monophasic subtype expressed the SYT-SSX2 fusion transcript. CONCLUSIONS: The detection of SYT-SSX1/2 fusion transcripts by RT-PCR is a valuable diagnostic marker of synovial sarcoma which can be used for the reclassification of cases whose diagnosis is difficult by routine methods.

The effect of TGFbeta1 on the expression and phosphorylation of key cell-cycle regulators in malignant B cells.

BACKGROUND: Transforming growth factor beta1 (TGFbeta1) induces growth arrest in many cell types, including B lymphocytes. The inhibitory action of TGFbeta1 is mediated by the deactivation of kinase complexes. The cell-cycle engine is tightly controlled by cyclin-dependent kinase (cdk) inhibitors, which mediate extracellular negative signals, resulting in cell-cycle arrest at different G1 points. MATERIAL/METHODS: Our experimental DoHH2 cell line model was derived from a patient with malignant non-Hodgkin's lymphoma (NHL) of follicular origin. We examined the effect of TGFbeta1 on the expression and phosphorylation of key cell-cycle regulators by immunoprecipitation and immunoblotting. RESULTS: After 48 hours of TGFbeta1 (10 ng/ml) treatment, a significantly increased number of DoHH2 cells was retained in G0/G1 phase. Our results showed the inhibitory action was associated with hypophosphorylation of pRb on serine 795 (S795) and threonine 373 (T373). We examined the composition of the cdk complexes and the level of cdk inhibitors to explain the inhibitory action of TGFbeta1 on cdk activity. Western blotting showed that the total level of the kinase inhibitor p21 (WAF1) increased after TGFbetal treatment. Our results indicate that a notably high level of p21(WAF1) was bound to cdk4/6 due to the treatment and that the binding of p21(WAF1) was associated with cyclin D-cdk4/6 complex decomposition. CONCLUSIONS: Our investigation of the effect of TGFbetal on cell-cycle progression of a non-Hodgkin's lymphoma cell line of follicular lymphoma subtype showed that the TGFbeta1-induced growth arrest of malignant B cells was associated with the activation of CIP/KIP family members of cdk inhibitors.