Monika Pilichowska

Primary hepatic carcinoid and neuroendocrine carcinoma: Clinicopathological and immunohistochemical study of five cases

Primary hepatic carcinoid and neuroendocrine carcinoma (NEC) are rare tumors. We experienced three carcinoids and two NEC originating in the liver during the past 25 years and attempted to elucidate the clinicopathological and immunohistochemical features of these tumors. The patients had no endocrine symptoms despite two of them having elevated plasma serotonin. Three of the five patients died of the tumor after operation with an average survival time of 20.6 months. All tumors were large (up to 26 cm in diameter), four of them solitary and one multinodular, and were not associated with liver cirrhosis. The carcinoid tumors showed insular, trabecular or glandular arrangement of argyrophilic cells, whereas in the NEC this histological pattern was distorted. Immunohistochemically the tumors showed expression of chromogranin A (all cases), chromogranin B (three cases), pancreastatin and chromostatin (four cases, respectively), prohormone convertase PC3 (three cases), carcinoembryonic antigen (CEA) and CA19‐9 (two cases), cytokeratin 56 kDa (three cases), 160 kDa neurofilament (two cases) and neuron‐specific enolase (two cases). Serotonin and glucagon were sporadically detected in two tumors. The most useful marker to confirm the diagnosis was chromogranin A, which was cleaved to pancreastatin and chromostatin in the tumor tissue, and was more reliable than other markers of neuroendocrine differentiation.

Resistance Training Increases Muscle Mitochondrial Biogenesis in Patients with Chronic Kidney Disease

BACKGROUND AND OBJECTIVES Muscle wasting, a common complication in chronic kidney disease (CKD), contributes to poor outcomes. Mitochondrial biogenesis is critical for the maintenance of skeletal muscle function and structural integrity. The present study--a secondary analysis from a published randomized controlled trial--examined the effect of resistance exercise training on skeletal muscle mitochondrial (mt)DNA copy number and determined its association with skeletal muscle phenotype (muscle mass and strength). DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Twenty-three patients with moderate-to-severe CKD were randomized to resistance training (n = 13) or an attention-control (n = 10) group for 12 weeks. After a run-in period of a low-protein diet that continued during the intervention, mtDNA copy number in the vastus lateralis muscle was estimated by quantitative real-time PCR at baseline and 12 weeks. RESULTS Participants mean age was 64 +/- 10 (SD) years and median (interquartile range, IQR) GFR 27.5 (37.0) ml/min. There were no differences between groups at baseline. Median (IQR) mtDNA copy number was 13,713 (10,618). There was a significant increase in muscle mtDNA with exercise compared with controls (1306 [13306] versus -3747 [15467], P = 0.01). The change in muscle mtDNA copy number was positively correlated with previously reported changes in types I and II muscle fiber cross-sectional area. CONCLUSIONS In this pilot study, resistance training was highly effective in enhancing mitochondrial content in patients with moderate-to-severe CKD. This finding suggests that the mitochondrial dysfunction observed with chronic disease could potentially be restored with this exercise modality and should be investigated further.

AG-221, a First-in-Class Therapy Targeting Acute Myeloid Leukemia Harboring Oncogenic IDH2 Mutations.

Somatic gain-of-function mutations in isocitrate dehydrogenases (IDH) 1 and 2 are found in multiple hematologic and solid tumors, leading to accumulation of the oncometabolite (R)-2-hydroxyglutarate (2HG). 2HG competitively inhibits α-ketoglutarate-dependent dioxygenases, including histone demethylases and methylcytosine dioxygenases of the TET family, causing epigenetic dysregulation and a block in cellular differentiation. In vitro studies have provided proof of concept for mutant IDH inhibition as a therapeutic approach. We report the discovery and characterization of AG-221, an orally available, selective, potent inhibitor of the mutant IDH2 enzyme. AG-221 suppressed 2HG production and induced cellular differentiation in primary human IDH2 mutation-positive acute myeloid leukemia (AML) cells ex vivo and in xenograft mouse models. AG-221 also provided a statistically significant survival benefit in an aggressive IDH2R140Q-mutant AML xenograft mouse model. These findings supported initiation of the ongoing clinical trials of AG-221 in patients with IDH2 mutation-positive advanced hematologic malignancies.Significance: Mutations in IDH1/2 are identified in approximately 20% of patients with AML and contribute to leukemia via a block in hematopoietic cell differentiation. We have shown that the targeted inhibitor AG-221 suppresses the mutant IDH2 enzyme in multiple preclinical models and induces differentiation of malignant blasts, supporting its clinical development. Cancer Discov; 7(5); 478-93. ©2017 AACR.See related commentary by Thomas and Majeti, p. 459See related article by Shih et al., p. 494This article is highlighted in the In This Issue feature, p. 443.

Immunohistochemical Expression of Chromogranins A and B, Prohormone Convertases 2 and 3, and Amidating Enzyme in Carcinoid Tumors and Pancreatic Endocrine Tumors

Although chromogranin A (CgA) is widely distributed in neuroendocrine tumors, the distribution of chromogranin B (CgB) has not been elucidated. Hormones produced by tumors are sometimes prohormones and not necessarily bioactive hormones. Prohormones have to be processed into bioactive peptides by prohormone convertases (PCs), and some of them have to be amidated by peptidylglycine α-amidating monooxygenase (PGM). Whether PCs and PGM are present or not in tumors may explain why some tumors are functioning and some are nonfunctioning. We investigated 45 carcinoids and 16 pancreatic endocrine tumors. Of the carcinoids, CgA was expressed in most of the tumors, except for the rectal and ovarian carcinoids, which expressed CgB strongly. The expressions of PC2, PC3, and PGM were 31%, 100%, and 87%, respectively. In the pancreatic tumors, CgA was expressed in all tumors, whereas CgB was not expressed in any tumor. The expressions of PC2, PC3, and PGM were 63%, 88%, and 63%, respectively. PC3 was expressed in all of the functioning tumors but not in two of the four nonfunctioning tumors. PC2 and PGM were not expressed in three of the four nonfunctioning tumors. In conclusion, expression of CgA and CgB was different depending on the tumor location. High frequency of PCs and PGM may explain why even nonfunctioning tumors produce some inconspicuous peptides.

Genetic and Functional Drivers of Diffuse Large B Cell Lymphoma

Diffuse large B cell lymphoma (DLBCL) is the most common form of blood cancer and is characterized by a striking degree of genetic and clinical heterogeneity. This heterogeneity poses a major barrier to understanding the genetic basis of the disease and its response to therapy. Here, we performed an integrative analysis of whole-exome sequencing and transcriptome sequencing in a cohort of 1,001 DLBCL patients to comprehensively define the landscape of 150 genetic drivers of the disease. We characterized the functional impact of these genes using an unbiased CRISPR screen of DLBCL cell lines to define oncogenes that promote cell growth. A prognostic model comprising these genetic alterations outperformed current established methods: cell of origin, the International Prognostic Index comprising clinical variables, and dual MYC and BCL2 expression. These results comprehensively define the genetic drivers and their functional roles in DLBCL to identify new therapeutic opportunities in the disease.

Histiocytic Necrotizing Lymphadenitis (Kikuchi-Fujimoto Disease) Lesional Cells Exhibit an Immature Dendritic Cell Phenotype

Histiocytic necrotizing lymphadenitis (HNL) is a rare benign disorder characterized histologically by nodal lesions composed of histiocytes, lymphoid cells, and so-called plasmacytoid T cells/plasmacytoid monocytes, with associated karyorrhexis. It has been proposed that plasmacytoid monocytes represent immature myeloid and lymphoid (plasmacytoid) early-committed dendritic cells (DCs). Monoclonal antibodies are now available for the detection of myeloid (CD1c [BDCA-1]+) and plasmacytoid (CD303 [BDCA-2]+) dendritic cells. With an extensive panel of antibodies to immature and mature DCs and interferon-alpha (IFN-alpha), cryostat section studies of 6 cases of HNL revealed that the morphologically distinctive mononuclear cells in lesional areas consisted of 2 populations of immature DCs: myeloid DCs immunoreactive for CD1c with coexpression of myeloid antigens CD13 and CD33 and plasmacytoid DCs immunoreactive for CD303 and CD123. These cells were CD68+, strongly expressed the IFN-alpha inducible protein MxA, and were nonreactive for fascin, a mature DC marker.

Central nervous system lymphoproliferative disorder in pediatric kidney transplant recipients

Abstract:  Post‐transplant lymphoproliferative disorder (PTLD) is a complication of transplantation resulting from impaired immune surveillance because of pharmacologic immunosuppression. We present two cases of central nervous system (CNS) PTLD in children on calcineurin‐inhibitor free immunosuppression with dramatically different presentations and outcomes. One patient had brain and spinal cord lymphoma with a rapid and fatal course. The other patient had brain and ocular PTLD that responded to multimodal therapy with reduction of immunosuppression, high‐dose steroids, and rituximab given in a dose‐escalation protocol. This protocol may have enhanced the penetration of rituximab into the CNS. We review the literature on CNS and ocular PTLD and elaborate on the treatments available for both diseases.

Dosage of X‐linked Toll‐like receptor 8 determines gender differences in the development of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease with a high incidence in females and a complex phenotype. Using 564Igi mice, a model of SLE with knock‐in genes encoding an autoreactive anti‐RNA Ab, we investigated how expression of Toll‐like receptors (TLRs) in B cells and neutrophils affects pathogenesis. We established that TLR signaling through MyD88 is necessary for disease. Autoantibody was produced in mice with single deletions of Tlr7, Tlr8, or Tlr9 or combined deletions of Tlr7 and Tlr9. Autoantibody was not produced in the combined absence of Tlr7 and Tlr8, indicating that TLR8 contributes to the break in tolerance. Furthermore, TLR8 was sufficient for the loss of B‐cell tolerance, the production of class‐switched autoantibody, heightened granulopoiesis, and increased production of type I IFN by neutrophils as well as glomerulonephritis and death. We show that dosage of X‐linked Tlr8 plays a major role in the high incidence of disease in females. In addition, we show that the negative regulation of disease by TLR9 is exerted primarily on granulopoiesis and type I IFN production by neutrophils. Collectively, we suggest that individual TLRs play unique roles in the pathogenesis of systemic lupus erythematosus, suggesting new targets for treatment.

Surgery combined with controlled-release doxorubicin silk films as a treatment strategy in an orthotopic neuroblastoma mouse model

Background:Neuroblastoma tumour resection goal is maximal tumour removal. We hypothesise that combining surgery with sustained, local doxorubicin application can control tumour growth.Methods:We injected human neuroblastoma cells into immunocompromised mouse adrenal gland. When KELLY cell-induced tumour volume was >300 mm3, 80–90% of tumour was resected and treated as follows: instantaneous-release silk film with 100 μg doxorubicin (100IR), controlled-release film with 200 μg (200CR) over residual tumour bed; and 100 and 200 μg intravenous doxorubicin (100IV and 200IV). Tumour volume was measured and histology analysed.Results:Orthotopic tumours formed with KELLY, SK-N-AS, IMR-32, SH-SY5Y cells. Tumours reached 1800±180 mm3 after 28 days, 2200±290 mm3 after 35 days, 1280±260 mm3 after 63 days, and 1700±360 mm3 after 84 days, respectively. At 3 days post KELLY tumour resection, tumour volumes were similar across all groups (P=0.6210). Tumour growth rate was similar in untreated vs control film, 100IV vs 100IR, and 100IV vs 200IV. There was significant difference in 100IR vs 200CR (P=0.0004) and 200IV vs 200CR (P=0.0003). Tumour growth with all doxorubicin groups was slower than that of control (P: <0.0001–0.0069). At the interface of the 200CR film and tumour, there was cellular necrosis, surrounded by apoptotic cells before reaching viable tumour cells.Conclusions:Combining surgical resection and sustained local doxorubicin treatment is effective in tumour control. Administering doxorubicin in a local, controlled manner is superior to giving an equivalent intravenous dose in tumour control.

The genetic basis of hepatosplenic T-cell lymphoma

Hepatosplenic T-cell lymphoma (HSTL) is a rare and lethal lymphoma; the genetic drivers of this disease are unknown. Through whole-exome sequencing of 68 HSTLs, we define recurrently mutated driver genes and copy-number alterations in the disease. Chromatin-modifying genes, including SETD2, INO80, and ARID1B, were commonly mutated in HSTL, affecting 62% of cases. HSTLs manifest frequent mutations in STAT5B (31%), STAT3 (9%), and PIK3CD (9%), for which there currently exist potential targeted therapies. In addition, we noted less frequent events in EZH2, KRAS, and TP53SETD2 was the most frequently silenced gene in HSTL. We experimentally demonstrated that SETD2 acts as a tumor suppressor gene. In addition, we found that mutations in STAT5B and PIK3CD activate critical signaling pathways important to cell survival in HSTL. Our work thus defines the genetic landscape of HSTL and implicates gene mutations linked to HSTL pathogenesis and potential treatment targets.Significance: We report the first systematic application of whole-exome sequencing to define the genetic basis of HSTL, a rare but lethal disease. Our work defines SETD2 as a tumor suppressor gene in HSTL and implicates genes including INO80 and PIK3CD in the disease. Cancer Discov; 7(4); 369-79. ©2017 AACR.See related commentary by Yoshida and Weinstock, p. 352This article is highlighted in the In This Issue feature, p. 339.