Caspase 9b Drives Cellular Transformation, Lung Inflammation, and Lung Tumorigenesis.

Caspase 9 undergoes alternative splicing to produce two opposing isoforms: proapoptotic Caspase 9a and pro-survival Caspase 9b (C9b). Previously, our laboratory reported that C9b is expressed in majority of non-small cell lung cancer tumors and directly activates the NF-κB pathway. In this study, the role of C9b in activation of the NF-κB pathway in vivo, lung inflammation and immune responses, and lung tumorigenesis were examined. Specifically, a transgenic mouse model expressing human C9b in the lung pneumocytes developed inflammatory lung lesions, which correlated with enhanced activation of the NF-κB pathway and increased influx of immunosuppressive myeloid-derived suppressor cells in contrast to wild-type mice. C9b mice presented with facial dermatitis, a thickened and disorganized dermis, enhanced collagen depth, and increased serum levels of IL6. C9b mice also developed spontaneous lung tumors, and C9b cooperated with oncogenic KRAS in lung tumorigenesis. C9b expression also cooperated with oncogenic KRAS and p53 downregulation to drive the full cell transformation of human bronchial epithelial cells (e.g., tumor formation). IMPLICATIONS: Our findings show that C9b can directly activate NF-κB pathway in vivo to modulate lung inflammation, immune cell influx, and peripheral immune responses, which demonstrates that C9b is key factor in driving cell transformation and lung tumorigenesis.

A Regulatory Role of Apoptosis Antagonizing Transcription Factor in the Pathogenesis of Nonalcoholic Fatty Liver Disease and Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is increasing as a cause of liver-related mortality largely because of the growing burden of nonalcoholic steatohepatitis (NASH). The mechanisms of HCC development in nonalcoholic fatty liver disease (NAFLD) are incompletely understood. We initially identified apoptosis antagonizing transcription factor (AATF) to be associated with HCC in a mouse model of NASH that develops HCC without the addition of specific carcinogens. AATF, also called che-1, is a transcriptional factor that is highly conserved among eukaryotes. AATF is known to be a central mediator of the cellular responses as it promotes cell proliferation and survival by inducing cell cycle arrest, autophagy, DNA repair, and inhibition of apoptosis. However, the role of AATF in NASH and HCC remains unknown. Here, we provide evidence for AATF as a contributory factor for HCC in NAFLD. AATF overexpression was further verified in human NASH and HCC and multiple human HCC cell lines. Tumor necrosis factor-α (TNFα), known to be increased in NASH, induced AATF expression. Promoter analysis of AATF revealed a sterol regulatory element binding transcription factor 1-c (SREBP-1c) binding site; inhibition of SREBP-1 by using specific inhibitors as well as small interfering RNA decreased TNFα-induced AATF expression. AATF interacted with signal transducer and activator of transcription 3 to increase monocyte chemoattractant protein-1 expression. AATF knockdown decreased cell proliferation, migration, invasion, colony formation, and anchorage-dependent growth in HCC cell lines. Xenograft of QGY-7703 HCC cells with AATF stably knocked down into nonobese diabetic scid gamma mice demonstrated reduced tumorigenesis and metastases. Conclusion: AATF drives NAFLD and hepatocarcinogenesis, offering a potential target for therapeutic intervention.

Criteria for Risk Stratification of Vulvar and Vaginal Smooth Muscle Tumors: An Evaluation of 71 Cases Comparing Proposed Classification Systems.

Accurate risk stratification of smooth muscle tumors (SMTs) is essential for appropriate patient management. Yet, the rarity of SMTs of the vagina and vulva makes development of a prognostically meaningful classification system challenging. While 2 classification methods for vulvar SMTs and 1 for vaginal SMTs have been proposed, it is our experience that many pathologists tend to apply criteria for uterine SMTs when evaluating vulvovaginal tumors. We retrospectively reviewed a large cohort of vulvovaginal SMTs with clinical follow-up and evaluated which method most accurately classified tumors according to patient outcome. A total of 71 tumors, 53 vaginal (75%) and 18 vulvar (25%), from 71 patients were identified. All tumors were centrally examined for degree of cytologic atypia, morphology (spindled, epithelioid, myxoid), mitotic index per 10 high power fields, atypical mitotic figures, tumor cell necrosis, ischemic necrosis, tumor interface (circumscribed or infiltrative) and margin status. Clinical features were recorded for each patient. Follow-up was available for 63 patients (89%), and ranged from 1 to 234 months (median: 64 mo). While site-specific and uterine criteria showed equally excellent sensitivity in classifying smooth muscle neoplasms as leiomyosarcoma according to patient outcome, uterine criteria showed improved specificity relatively to site-specific methods in classifying tumors as nonsarcoma according to patient outcome. We recommend that uterine SMT criteria and nomenclature be adopted for evaluation and classification of vulvovaginal SMTs.

Solitary Fibrous Tumors of the Head and Neck: A Multi-Institutional Clinicopathologic Study.

Solitary fibrous tumors (SFTs) of the head and neck are uncommon. Lesions previously diagnosed in the head and neck as hemangiopericytomas (HPCs), giant cell angiofibromas (GCAs), and orbital fibrous histiocytomas (OFHs) are now recognized as within the expanded spectrum of SFTs. To better understand the clinicopathologic profile of head and neck SFTs, we performed a multi-institutional study of 88 examples. There was no sex predilection (F:M ratio 1.2), and the median patient age was 52 years (range: 15 to above 89 y). The sinonasal tract and orbit were the most common sites involved (30% and 25%), followed by the oral cavity and salivary glands (15% and 14%). Original diagnoses included HPC (25%), SFT (67%), and OFH (6%), with 1 SFT and 1 OFH noted as showing GCA-like morphology. On review, the predominant histologic pattern was classic SFT-like in 53% and cellular (former HPC-like) in 47%; lipomatous differentiation (8%) and GCA-like pattern (7%) were less prevalent. Subsets demonstrated nuclear atypia (23%), epithelioid morphology (15%), or coagulative necrosis (6%). Infiltrative growth (49%) and osseous invasion (82%) were prevalent among evaluable cases. Of the 48 SFTs with follow-up (median: 43 mo), 19 showed recurrence (40%). Of these, 4 patients were alive with disease and 4 dead of disease. Size and mitotic rate were negative prognosticators using a joint prognostic proportional hazards regression model. Three patients experienced metastasis, to lungs, parotid, bone, and skull base, including one case showing overtly sarcomatous "dedifferentiation." As a group, SFTs present in a wide anatomic and morphologic spectrum in the head and neck. Only rare examples metastasize or cause death from disease. However, the fairly high local recurrence rate underscores their aggressive potential and highlights the importance of prospective recognition.

Cytopathologic features of clear cell papillary renal cell carcinoma: A recently described variant to be considered in the differential diagnosis of clear cell renal epithelial neoplasms.

BACKGROUND: Clear cell papillary renal cell carcinoma (CCPRCC) is a distinctive variant of renal cell carcinoma that has been formally adopted by the new Word Health Organization classification. An emerging consensus has documented its particularly indolent course and emphasized its separation from conventional clear cell renal cell carcinoma (CCRCC) for treatment planning. CCPRCC features in cytologic preparations have not been studied. METHODS: This study retrospectively identified a series of CCPRCCs that had cytology samples before the histopathologic diagnosis and reviewed corresponding cytologic materials, including aspirate smears, cell block materials, touch preparations, and core biopsy samples. The identified clinicopathologic and cytologic features were tabulated. RESULTS: Five cases of CCPRCC with cytopathologic materials were identified from 4 women and 1 man aged 34 to 70 years (2 with end-stage renal disease), and the sampled lesions were 1.8 to 11.0 cm. The original cytopathologic diagnostic considerations ranged from atypical cyst-lining cells to angiomyolipoma to CCRCC and CCPRCC. The aspirate and touch preparation samples showed scant cellularity with scattered sheets and clusters of small, bland epithelial cells (much smaller than admixed renal tubular cells) with optically clear cytoplasm (lacking conspicuous cytoplasmic vacuolization) and small, grade 1 nuclei. The cell block materials and the core biopsy samples showed cyst walls with prominent myomatous stroma lined by low-grade epithelium with optically clear cytoplasm, inverse nuclear polarization, and a characteristic cytokeratin 7-positive/carbonic anhydrase IX-positive phenotype. Three cases were treated with resection, 1 case was treated with ablation, and 1 case was under surveillance. CONCLUSIONS: CCPRCC demonstrates recognizable cytomorphologic features and merits consideration in the cytologic differential diagnosis for kidney lesions. With increasing experience, more conservative management may be contemplated. Cancer Cytopathol 2016;124:565-72. © 2016 American Cancer Society.

Increased B Cell ADAM10 in Allergic Patients and Th2 Prone Mice.

ADAM10, as the sheddase of the low affinity IgE receptor (CD23), promotes IgE production and thus is a unique target for attenuating allergic disease. Herein, we describe that B cell levels of ADAM10, specifically, are increased in allergic patients and Th2 prone WT mouse strains (Balb/c and A/J). While T cell help augments ADAM10 expression, Balb WT B cells exhibit increased ADAM10 in the naïve state and even more dramatically increased ADAM10 after anti-CD40/IL4 stimulation compared C57 (Th1 prone) WT B cells. Furthermore, ADAM17 and TNF are reduced in allergic patients and Th2 prone mouse strains (Balb/c and A/J) compared to Th1 prone controls. To further understand this regulation, ADAM17 and TNF were studied in C57Bl/6 and Balb/c mice deficient in ADAM10. C57-ADAM10B-/- were more adept at increasing ADAM17 levels and thus TNF cleavage resulting in excess follicular TNF levels and abnormal secondary lymphoid tissue architecture not noted in Balb-ADAM10B-/-. Moreover, the level of B cell ADAM10 as well as Th context is critical for determining IgE production potential. Using a murine house dust mite airway hypersensitivity model, we describe that high B cell ADAM10 level in a Th2 context (Balb/c WT) is optimal for disease induction including bronchoconstriction, goblet cell metaplasia, mucus, inflammatory cellular infiltration, and IgE production. Balb/c mice deficient in B cell ADAM10 have attenuated lung and airway symptoms compared to Balb WT and are actually most similar to C57 WT (Th1 prone). C57-ADAM10B-/- have even further reduced symptomology. Taken together, it is critical to consider both innate B cell levels of ADAM10 and ADAM17 as well as Th context when determining host susceptibility to allergic disease. High B cell ADAM10 and low ADAM17 levels would help diagnostically in predicting Th2 disease susceptibility; and, we provide support for the use ADAM10 inhibitors in treating Th2 disease.