Angiotensin-converting enzyme 2 (ACE2) expression has been shown to be altered in renal tubules from diabetic mice. This study examined the localization of ACE and ACE2 within the glomerulus of kidneys from control (db/m) and diabetic (db/db) mice and the effect of chronic pharmacologic ACE2 inhibition. ACE2 co-localized with glomerular epithelial cell (podocyte) markers, and its localization within the podocyte was confirmed by immunogold labeling. ACE, by contrast, was seen only in glomerular endothelial cells. By immunohistochemistry, in glomeruli from db/db mice, strong ACE staining was found more frequently than in control mice (db/db 64.6 ؎ 6.3 versus db/m 17.8 ؎ 3.4%; P < 0.005). By contrast, strong ACE2 staining in glomeruli from diabetic mice was less frequently seen than in controls (db/db 4.3 ؎ 2.4 versus db/m 30.6 ؎ 13.6%; P < 0.05). For investigation of the significance of reduced glomerular ACE2 expression, db/db mice were treated for 16 wk with a specific ACE2 inhibitor (MLN-4760) alone or combined with telmisartan, a specific angiotensin II type 1 receptor blocker. At the end of the study, glomerular staining for fibronectin, an extracellular matrix protein, was increased in both db/db and db/m mice that were treated with MLN-4760. Urinary albumin excretion (UAE) increased significantly in MLN-4760 -treated as compared with vehicle-treated db/db mice (743 ؎ 200 versus 247 ؎ 53.9 g albumin/mg creatinine, respectively; P < 0.05), and the concomitant administration of telmisartan completely prevented the increase in UAE associated with the ACE2 inhibitor (161 ؎ 56; P < 0.05). It is concluded that ACE2 is localized in the podocyte and that in db/db mice glomerular expression of ACE2 is reduced whereas glomerular ACE expression is increased. The finding that chronic ACE2 inhibition increases UAE suggests that ACE2, likely by modulating the levels of glomerular angiotensin II via its degradation, may be a target for therapeutic interventions that aim to reduce albuminuria and glomerular injury.

converting enzyme (ACE)2 is a carboxypeptidase that degrades angiotensin II and other peptides. In the kidney, ACE2 localization within the glomerulus and tubules is cell specific. This study was aimed to investigate the localization of ACE2 within the renal vasculature. We also studied the effect of the administration of a specific angiotensin II type 1 receptor blocker, telmisartan, on ACE2 expression in the renal vasculature. ACE2 and ACE were localized in renal arterioles using confocal microscopy and specific cell markers. Quantitative measurements of ACE2 and ACE mRNA were estimated in kidney arterioles isolated by laser capture microdissection using real-time PCR. In kidney arterioles, ACE was localized in the endothelial layer, whereas ACE2 was localized in the tunica media. In mice treated with telmisartan (2 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ) for 2 wk, ACE2 expression was increased by immunostaining, whereas ACE expression was decreased. This was reflected in a decrease in the ACE/ ACE2 ratio compared with vehicle-treated controls (0.53 Ϯ 0.14 vs. 7.59 Ϯ 2.72, P ϭ 0.027, respectively). In kidney arterioles isolated by laser capture microdissection, the ACE/ACE2 mRNA ratio was also decreased compared with control mice (1.21 Ϯ 0.31 vs. 4.63 Ϯ 0.86, P ϭ 0.044, respectively). In conclusion, in kidney arterioles ACE2 is preferentially localized in the tunica media, and its expression is increased after administration of the angiotensin II type 1 receptor blocker, telmisartan. Amplification of ACE2 in the renal vasculature may contribute to the therapeutic action of telmisartan by increasing angiotensin II degradation. kidney vessels; angiotensin-converting enzyme; laser microcapture THE RENIN-ANGIOTENSIN SYSTEM (RAS) plays a key role in the control of cardiovascular and renal function (8,13,30). Activation of the RAS has been widely incriminated in the pathophysiology of renal and cardiovascular diseases such as hypertension, myocardial infarction, and heart failure (21, 25). The RAS system primarily involves two enzymes: renin, which cleaves angiotensinogen to the inactive decapeptide angiotensin (ANG) I, and angiotensin-converting enzyme (ACE), a dipeptidyl carboxypeptidase that hydrolyzes ANG I to the octapeptide ANG II (7, 26). The discovery of angiotensinconverting enzyme (ACE)2, the only known enzymatically active homolog of ACE, has added a new level of complexity to the RAS (6, 9). ACE2 degrades ANG II to ANG-(1-7) and ANG I to ANG-(1-9) (10, 17). The impact of these actions of ACE2 and ACE on ANG II as well as the factors that directly or indirectly influence the activity of these enzymes need to be better defined. An understanding of the regulation of these enzymes is clinically relevant in view of recent studies showing that ACE2 expression is altered in pathological conditions such as diabetes, hypertension, and cardiovascular diseases (5,27,28,31,32,34). The potential therapeutic effect of increased ACE2 activity has been recently recognized (2,15,22,33).ANG II type 1 receptor blockers are widely used as an...

Context.-Diagnosis and classification of lymphomas are based on the morphologic, immunologic, and genetic features that the lesional cells share with their normal B and T lymphocyte counterparts. Primary pulmonary lymphomas account for 0.3% of primary lung neoplasms and less than 0.5% of all lymphomas.Objective.-To describe and summarize the clinical and histopathologic features of the primary pulmonary lymphoma and secondary involvement of the lung by lymphoma.Data Sources.-Peer-reviewed published literature and personal experience.Conclusions.-Diagnosis of clonal lymphoid proliferations in the lung has evolved owing to the greater utility of molecular and flow cytometric analysis of tissue. Further studies are needed to best define the clinical and prognostic features, as well as search for targeted therapy for these patients with rare neoplasms.(Arch Pathol Lab Med. 2013;137:382-391; doi: 10.5858/ arpa.2012-0202-RA) P rimary pulmonary lymphoma is defined as clonal lymphoid proliferation affecting one or both lungs (parenchyma and/or bronchi) in a patient with no previous extrapulmonary involvement at the time of diagnosis or during the subsequent 3 months. Primary lymphoma of the lung is a rare disorder and represents only 0.3% of all primary pulmonary malignancies, less than 1% of all the cases of non-Hodgkin lymphoma, and 3% to 4% of all the extranodal manifestations of non-Hodgkin lymphoma.

Summary Endometriosis is a chronic disease that affects millions of reproductive-age women. Despite the destructive and invasive nature of endometrioses, most cases are perpetually benign or eventually regress; however, atypical endometriosis is a precursor lesion and can lead to certain types of ovarian cancer. Endometriosis induced inflammation and auto- and paracrine production of sex steroid hormones contribute to ovarian tumorigenesis. These changes provide microenvironment necessary to accumulate enough genetic alterations for endometriosis associated malignant transformation. It takes years for endometriosis to undergo the pathophysiological progression that begins with atypical epithelial proliferation (atypical endometriosis and metaplasia), and then is followed by the formation of well-defined borderline tumors, and finally culminates in fully malignant ovarian cancer. This study is a review of the natural history of endometriosis and the role of microenvironments that favor the accumulation of genetic alterations and endometriosis-associated ovarian cancer progression.

Nivolumab is a monoclonal antibody that blocks the interaction between programmed cell death 1 (PD1) and programmed cell death 1-ligand 1 (PD-L1), resulting in enhanced antitumor activity by the immune system. Nivolumab is currently approved by the US Food and Drug Administration (FDA) for melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma, classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, and urothelial carcinoma. PD-L1 IHC 28-8 pharmDx is FDA-approved as a complementary diagnostic for immunohistochemical (IHC) detection of PD-L1 in non-squamous NSCLC and melanoma. We report validation of PD-L1 IHC 28-8 pharmDx for PD-L1 detection on formalin-fixed, paraffin-embedded human melanoma specimens using Autostainer Link 48. A prevalence assessment of 104 melanoma specimens indicated that PD-L1 was detected across the full expression level range (0% to 100% of tumor cells). Assay robustness and precision studies were conducted at Agilent Technologies, with additional reproducibility studies performed at 3 external laboratories. Precision studies evaluated at ≥1% and ≥5% expression levels revealed a range of average negative agreement from 89.5%, 95% CI (83.2, 93.6) to 100%, 95% CI (97.3, 100), and average positive agreement from 85.5%, 95% CI (77.6, 90.9) to 100%, 95% CI (97.9, 100). For external reproducibility, precise results were obtained. These results demonstrate PD-L1 IHC 28-8 pharmDx is a precise, robust, and reproducible assay for determining PD-L1 expression in melanoma. This is the first PD-L1 IHC test to receive FDA approval as a complementary diagnostic in melanoma patients whereby positive PD-L1 expression is correlated with the magnitude of nivolumab treatment effect.

No abstract

Oncogenic osteomalacia (OO) is a rare paraneoplastic condition in which a bone or soft tissue tumor induces biochemical and clinical signs and symptoms of osteomalacia (or rickets) most often by the production of the phosphaturic protein, fibroblast growth factor-23. Phosphaturic mesenchymal tumor, mixed connective tissue type (PMTMCT) is a rare, histologically distinct tumor that represents the most common cause of OO. As the clinical diagnosis of OO is typically suspected on the basis of clinical and biochemical features and the presence of a bone or soft tissue tumor, cytologic examination might potentially provide the necessary pathologic confirmation of OO. In this case of a 46-year-old female with clinical stigmata of OO and a right distal humeral mass, we report that the fine-needle aspiration findings of short, cytologically bland spindled cells embedded in a fine, fibrillary stromal-rich matrix and the presence of osteoclast-type giant cells associated with the stromal matrix provide strong pathological evidence for PMTMCT and assist in pathologically confirming the clinical impression of OO, thus alleviating the need for a more invasive diagnostic surgical procedure.

Background: Head and neck squamous cell carcinoma (HNSCC) is a cancer with the ability to modulate the immune system to evade detection. It is the sixth most frequently diagnosed cancer with 550,000 new cases and 300,000 lives lost worldwide per year. New treatments for HNSCC are urgently needed as patients continue to experience a high mortality rate and low response to surgery and chemotherapeutic treatments. Part of the reason why HNSCC is difficult to treat is it upregulates the expression of immune-checkpoint signaling molecule TIGIT (T cell immunoreceptor with Ig and ITIM domains) to inhibit T cell activation in vivo. Emerging evidence shows TIGIT overexpression in the CD8+ and CD4+ T cells that infiltrate the tumor cells of HNSCC patients. TIGIT expression is also associated with up-regulation of immune-checkpoint ligands PD-1 (programmed cell death protein 1) and LAG-3 (lymphocyte-activation gene 3 aka CD223), markers of T-cell exhaustion. Altogether, activation of the TIGIT/PD-1/LAG-3 axis correlates with an immunosuppressive microenvironment as well as cancer development and progression. Although there is ample evidence that the upregulation of TIGIT decreases the immune response in HNSCC, only limited studies have been published that address the location, expression and co-expression of TIGIT, LAG-3 and PD-1 in the HNSCC microenvironment. Methods: In this study, we sought to establish a robust report of immune cells in the tissue of patients with HNSCC. Using Vectra Polaris multiplex immunofluorescence (IF) assays, we studied T-cell exhaustion and T-cell expression in HNSCC patient tissue using a total of 9 markers essential in cancer immunology. Sequential tissue sections were stained in two panels of 6, an exhausted T cell panel comprised of TIGIT, PD-1, LAG-3, panCK, CD4 and CD8 and a T cell panel including CD3, FOXP3, CD45RO, panCK, CD4 and CD8. Results: Multiplexing IF staining revealed a HNSCC histologic landscape characteristic of immune suppression in this study. The data demonstrated abundant T cells with TIGIT overexpression in the tissue microenvironment of HNSCC samples. Using Indica Halo algorithms, we quantified exhausted T cells (TIGIT+PD1+LAG3+CD4+CD3+, TIGIT+PD1+LAG3+CD8+CD3+), T helper cells (CD3+CD4+), T cytotoxic cells (CD3+CD8+), T regulatory cells (CD3+CD4+FoxP3), memory T-cells (CD3+CD4+CD45RO) and anergic T-cells (PD1+CD8+) within the tumor and the stromal regions. Conclusion: Currently AB154, a fully humanized immunoglobulin G1 monoclonal antibody targeting human TIGIT is in phase I clinical trials in HNSCC patients and BGB-A1217, an anti-TIGIT monoclonal antibody in combination with anti-PD-1 monoclonal antibody Tislelizumab is in a Phase 1/1b clinical trial in patients with advanced solid tumors. The Vectra Polaris imaging reported in this study identifies T cell composition in the tumor microenvironment of patients facing high mortality. Citation Format: Sara Pollan, Arezoo Hanifi, Mate Nagy, Nicholas Stavrou, Erinn Parnell, Maricel Gozo, Nickolas Attanasio, Josette William, Qingyan Au. Profiling exhausted T cells using Vectra® Polaris™multiplex immunofluorescence assay in HNSCC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2143.