Toxoplasma gondii triggers phosphorylation and nuclear translocation of dendritic cell STAT1 while simultaneously blocking IFNγ-induced STAT1 transcriptional activity.

The protozoan Toxoplasma gondii actively modulates cytokine-induced JAK/STAT signaling pathways to facilitate survival within the host, including blocking IFNγ-mediated STAT1-dependent proinflammatory gene expression. We sought to further characterize inhibition of STAT1 signaling in infected murine dendritic cells (DC) because this cell type has not previously been examined, yet is known to serve as an early target of in vivo infection. Unexpectedly, we discovered that T. gondii infection alone induced sustained STAT1 phosphorylation and nuclear translocation in DC in a parasite strain-independent manner. Maintenance of STAT1 phosphorylation required active invasion but intracellular parasite replication was dispensable. The parasite rhoptry protein ROP16, recently shown to mediate STAT3 and STAT6 phosphorylation, was not required for STAT1 phosphorylation. In combination with IFNγ, T. gondii induced synergistic STAT1 phosphorylation and binding of aberrant STAT1-containing complexes to IFNγ consensus sequence oligonucleotides. Despite these findings, parasite infection blocked STAT1 binding to the native promoters of the IFNγ-inducible genes Irf-1 and Lrg47, along with subsequent gene expression. These results reinforce the importance of parasite-mediated blockade of IFNγ responses in dendritic cells, while simultaneously showing that T. gondii alone induces STAT1 phosphorylation.

Invasive urothelial carcinoma with chordoid features: a report of 12 distinct cases characterized by prominent myxoid stroma and cordlike epithelial architecture.

Urothelial carcinoma is morphologically heterogeneous and many variant forms have been described. We have encountered several invasive urothelial carcinomas with a unique chordoid morphology characterized by prominent cellular cording and associated myxoid stromal matrix, a pattern closely resembling extraskeletal myxoid chondrosarcoma. This morphologic appearance, to our knowledge, has not been formally described in urothelial carcinoma. A series of 166 consecutive invasive urothelial carcinomas were reviewed to identify cases with cellular cording and myxoid stroma. The patient age, sex, tumor stage, morphologic features, association with typical urothelial carcinoma, and clinical outcome were recorded. Immunostains for p63, cytokeratin (CK) 34BE12, CK20, calponin, glial fibrillary acidic protein, S-100 protein, oncofetal protein glypican-3, and brachyury were performed on 7 cases. Mucin histochemistry was performed on 8 cases to evaluate the extracellular myxoid material. Eleven of the 166 (7%) consecutive invasive urothelial carcinomas had areas with a chordoid appearance. A total of 12 cases were analyzed including the addition of a consult case. The patients' ages ranged from 50 to 85 years (mean: 68 y); there were 8 males and 4 females. The specimens consisted of 5 cystectomies, 6 transurethral resections, and 1 anterior exenteration with right nephroureterectomy. Morphologically, each case had at least focal areas in which acellular myxoid stroma was associated with the carcinoma cells. When well developed, the neoplastic cells had scant eosinophilic cytoplasm and were arranged into cords closely mimicking extraskeletal myxoid chondrosarcoma, chordoma, mixed tumor/myoepithelioma of soft tissue, and yolk sac tumor. The percentage of tumor with a chordoid appearance ranged from 5% to 95% (mean: 39%; median: 25%). No conventional sarcomatous differentiation, no intracytoplasmic mucin, and no glandular formation were present in any case. All 12 cases had foci of typical urothelial carcinoma present at least focally and a gradual transition to the chordoid pattern was commonly seen. Immunophenotypically, all 7 cases evaluated showed strong immunoreactivity for p63 (nuclear) and CK34BE12 (cytoplasmic). Immunostains for CK20, calponin, glial fibrillary acidic protein, oncofetal protein glypican-3, and brachyury and were negative in the 7 cases studied (0 out of 7), whereas S-100 protein had focal staining (<5%) in 1 case. The myxoid stromal component was diffusely colloidal iron and Alcian blue positive in all 8 cases examined; periodic acid Schiff was negative in all 8 cases, whereas mucicarmine was only focally positive in 2 of 8 cases. Most cases were high stage (pT4: 5, pT3: 4, pT2: 2, and pT1: 1), and 6 of 8 cases (75%) with nodal sampling had metastatic disease. In 1 case, the lymph node metastasis had areas with chordoid morphology. Nine of 12 patients had available follow-up: 2 were dead of disease (1 and 10 mo), 4 were alive with disease (5 to 8 mo) with distant metastasis in 3, and 3 had no evidence of disease at last follow-up (2 to 120 mo). In summary, we describe a morphologic pattern of urothelial carcinoma with a distinct chordoid appearance that may potentially mimic a spectrum of primary vesical and nonvesical neoplasms with myxoid or mucinous components. These carcinomas maintain an immunophenotype characteristic of urothelial carcinoma and usually present with high stage disease.

Immunohistochemical comparison of MUC1, CA125, and Her2Neu in invasive micropapillary carcinoma of the urinary tract and typical invasive urothelial carcinoma with retraction artifact.

On the basis of recent clinical studies, some urologic oncologists do not offer bladder-sparing therapy for patients diagnosed with micropapillary carcinoma of the urinary bladder, even in the setting superficially invasive disease. Unfortunately, the distinction of invasive micropapillary carcinoma from typical invasive urothelial carcinoma with prominent retraction artifact may be difficult in some cases. In this study, we compared the immunophenotype of invasive micropapillary carcinoma to invasive urothelial carcinoma with retraction artifact using antibodies previously reported as specific for micropapillary carcinoma. Immunohistochemical staining was performed on 24 invasive micropapillary carcinomas of the urinary tract and 24 case controls of invasive urothelial carcinoma with retraction artifact using monoclonal antibodies MUC1, CA125, and Her2Neu. The staining extent and intensity for MUC1 and CA125 were scored on one representative section per case. Immunostaining for Her2Neu was scored based on the 2007 CAP/ASCO guidelines for breast carcinoma. Basal ('reverse-apical') MUC1 staining was identified in 23 of the 24 (96%) invasive micropapillary carcinomas and in 15 of the 24 (63%) invasive urothelial carcinomas with retraction artifact (P=0.0102). Membranous reactivity with CA125 was seen in 8 of the 24 (33%) invasive micropapillary carcinomas and in 3 of the 24 (13%) invasive urothelial carcinomas with retraction artifact (P=0.1681). Positive (3+) membranous Her2Neu staining was present in 6 of 24 (25%) invasive micropapillary carcinomas and in 2 of the 24 (8%) invasive urothelial carcinomas with retraction artifact (P=0.2448). The specificity for invasive micropapillary carcinoma vs invasive urothelial carcinoma with retraction artifact using antibodies MUC1, CA125, and Her2Neu was 37, 87, and 92%, respectively. Invasive micropapillary carcinoma more commonly showed immunoreactivity for MUC1, CA125, and Her2Neu compared to invasive urothelial carcinoma with retraction artifact, but only MUC1 reached statistical significance. The lack of specificity of these evaluated markers for invasive micropapillary carcinoma limits their utility in the distinction from invasive urothelial carcinoma with retraction artifact, especially given the potentially significant therapeutic implications.