Giovanna Giannico

Local Renal Autoantibody Production in Lupus Nephritis

Autoantibodies are central to the pathogenesis of several autoimmune diseases including systemic lupus erythematosus. Plasma cells secrete these autoantibodies, but the anatomical sites of these cells are not well defined. Here, we found that although dsDNA-specific plasma cells in NZB/W mice were present in spleen and bone marrow, a large number were in the kidneys and their number correlated with the serum dsDNA-IgG titer. We observed renal plasma cells only in mice with nephritis, where they located mainly to the tubulointerstitium of the cortex and outer medulla. These cells had the phenotypic characteristics of fully differentiated plasma cells and, similar to long-lived bone marrow plasma cells, they were not in cell cycle. In patients with lupus nephritis, plasma cells were often present in the medulla in those with the most severe disease, especially combined proliferative and membranous lupus nephritis. The identification of the kidney as a major site of autoreactive plasma cells has implications for our understanding of the pathogenesis of lupus nephritis and for strategies to deplete autoreactive plasma cells, a long-standing therapeutic aim.

Lupus Nephritis: Is the Kidney Biopsy Currently Necessary in the Management of Lupus Nephritis?

Most patients with SLE develop kidney disease related to this systemic underlying disease process. Lupus nephritis is an important cause of morbidity and even mortality in patients with systemic lupus erythematosus. Lupus nephritis has diverse morphologic manifestations with varying clinical presentations and consequences. The pathogeneses involve immune complexes, which can deposit anywhere in the kidney, and other mechanisms, including endothelial injury, podocytopathy, and tubulointerstitial injury. Treatment and prognosis accordingly range from excellent even with only observation with minimal mesangial deposits, to kidney failure despite aggressive immunosuppression in patients with severe proliferative disease. Renal biopsy plays a crucial role in the diagnosis of the specific form of lupus nephritis in any patient. However, the role of the renal biopsy in prediction of outcome, treatment, and prognosis has been controversial. We will review the current classification of lupus nephritis and the value of renal biopsy in the management of these patients.

Distinct Epitopes for Anti–Glomerular Basement Membrane Alport Alloantibodies and Goodpasture Autoantibodies within the Noncollagenous Domain of α3(IV) Collagen: A Janus-Faced Antigen

Alport posttransplantation anti-glomerular basement membrane (GBM) nephritis is mediated by alloantibodies against the noncollagenous (NC1) domains of the alpha3alpha4alpha5(IV) collagen network, which is present in the GBM of the allograft but absent from Alport kidneys. The specificity of kidney-bound anti-GBM alloantibodies from a patient who had autosomal recessive Alport syndrome (ARAS) and developed posttransplantation nephritis was compared with that of Goodpasture autoantibodies from patients with autoimmune anti-GBM disease. Allograft-eluted alloantibodies reacted specifically with alpha3alpha4alpha5 NC1 hexamers, targeting their alpha3NC1 and alpha4NC1 subunits, and recognized a noncontiguous alloepitope formed jointly by the E(A) and E(B) regions of alpha3NC1 domain. In contrast, human Goodpasture autoantibodies recognized the separate E(A) and E(B) autoepitopes of alpha3NC1 but not the composite alloepitope. Molecular modeling of alpha3NC1 revealed that the alloepitope is more accessible within the NC1 hexamers than the partially sequestered Goodpasture autoepitopes. Overall, the specificity of alloantibodies indicated a selective lack of immune tolerance toward the alpha3 and alpha4(IV) collagen chains not expressed in patients with ARAS. Using COL4A3 knockout mice, a model of ARAS, it was shown further that acid-dissociated rather than native alpha3alpha4alpha5 NC1 hexamers elicited murine anti-GBM antibodies most closely resembling human ARAS alloantibodies. In contrast, alpha3NC1 monomers elicited Goodpasture-like murine antibodies, targeting the E(A) and E(B) autoepitopes. Thus, the identity of alpha3NC1 epitopes targeted by anti-GBM antibodies is strongly influenced by the molecular organization of the immunogen. These findings suggest that different isoforms of alpha3(IV) collagen may be implicated in the pathogenesis of ARAS posttransplantation anti-GBM nephritis and Goodpasture disease.

Integrin-Free Tetraspanin CD151 Can Inhibit Tumor Cell Motility upon Clustering and Is a Clinical Indicator of Prostate Cancer Progression

Normal physiology relies on the organization of transmembrane proteins by molecular scaffolds, such as tetraspanins. Oncogenesis frequently involves changes in their organization or expression. The tetraspanin CD151 is thought to contribute to cancer progression through direct interaction with the laminin-binding integrins α3β1 and α6β1. However, this interaction cannot explain the ability of CD151 to control migration in the absence of these integrins or on non-laminin substrates. We demonstrate that CD151 can regulate tumor cell migration without direct integrin binding and that integrin-free CD151 (CD151(free)) correlates clinically with tumor progression and metastasis. Clustering CD151(free) through its integrin-binding domain promotes accumulation in areas of cell-cell contact, leading to enhanced adhesion and inhibition of tumor cell motility in vitro and in vivo. CD151(free) clustering is a strong regulator of motility even in the absence of α3 expression but requires PKCα, suggesting that CD151 can control migration independent of its integrin associations. The histologic detection of CD151(free) in prostate cancer correlates with poor patient outcome. When CD151(free) is present, patients are more likely to recur after radical prostatectomy and progression to metastatic disease is accelerated. Multivariable analysis identifies CD151(free) as an independent predictor of survival. Moreover, the detection of CD151(free) can stratify survival among patients with elevated prostate-specific antigen levels. Cumulatively, these studies demonstrate that a subpopulation of CD151 exists on the surface of tumor cells that can regulate migration independent of its integrin partner. The clinical correlation of CD151(free) with prostate cancer progression suggests that it may contribute to the disease and predict cancer progression.

Osteoblastoma characterized by a three-way translocation: report of a case and review of the literature

Osteoblastoma, an uncommon primary bone tumor, produces both osteoid and primitive woven bone in a background of fibrovascular connective tissue. Although most osteoblastomas are considered benign, a controversial aggressive variant has been described, which may cause diagnostic confusion with malignant tumors such as osteosarcoma. To date, no specific diagnostic cytogenetic or molecular marker has been identified for osteoblastoma to aid in its distinction. Conventional cytogenetic analysis of an osteoblastoma arising in the femur of a 23-year-old woman revealed a novel three-way translocation involving chromosomes 1, 2 and 14 [t(1;2;14) (q42;q13;q24)]. Rearrangement of 1q42 has been identified in a previously reported case.

Aberrant expression of p63 in adenocarcinoma of the prostate a radical prostatectomy study

Prostatic adenocarcinoma with aberrant diffuse expression of p63 (p63-PCa) is a recently described variant of prostatic adenocarcinoma. The aim of this study was to investigate the clinical and pathologic features of p63-PCa at radical prostatectomy (RP). We reviewed 21 cases of p63-PCa diagnosed on needle biopsy at subsequent RP. Immunohistochemical analysis for PIN4 and Ki-67 was performed in all RP cases. p63-PCa showed a distinctive morphology consisting of atrophic, poorly formed glands, with multilayered and often spindled nuclei. Gleason grading was 3+3=6 in 28.5%, 3+5=8 in 38%, 3+4=7 in 14.3%, and 4+3=7, 5+3=8, and 5+4=9 in 9.5%. Usual-type acinar carcinoma coexisted in 85.7% with only p63-PCa present in the remaining cases. The usual-type carcinoma was Gleason grade 3+2=5 in 4.7%, 3+3=6 in 57%, 3+4=7 in 19%, and 4+3=7 in 4.3%. Overall, p63-PCa represented 65% of the total cancer volume (median 80%). The tumor was organ-confined in 16 cases (76.2%). In the remaining 5 cases, 2 had p63-PCa extending to the margin in areas of intraprostatic incisions, 2 had usual-type acinar adenocarcinoma extending to the margin and extraprostatic tissue, respectively, and 1 had p63-PCa with an unusual cribriform morphology involving the bladder neck. Ki-67 was low, <5% in all cases of p63-PCa, with similar expression in the coexisting acinar-type carcinoma. In summary, it is recommended that these tumors not be assigned a Gleason score and their favorable findings at RP be noted.

Prostate Adenocarcinomas Aberrantly Expressing p63 Are Molecularly Distinct from Usual-Type Prostatic Adenocarcinomas

We have described a rare group of prostate adenocarcinomas that show aberrant expression of p63, a protein strongly expressed in prostatic basal cells and absent from usual-type acinar prostate cancers. The partial basal-like immunophenotype of these tumors is intriguing in light of the persistent debate surrounding the cell-of-origin for prostate cancer; however, their molecular phenotype is unknown. We collected 37 of these tumors on radical prostatectomy and biopsy and assessed subsets for a diverse panel of molecular markers. The majority of p63-expressing tumors were positive for the ΔNp63 isoform (6/7) by immunofluorescence and p63 mRNA (7/8) by chromogenic in situ hybridization. Despite p63 positivity, these tumors uniformly expressed luminal-type cytokeratin proteins such as CK18 (13/13), CK8 (8/8), and markers of androgen axis signaling commonly seen in luminal cells, including androgen receptor (10/11), NKX3.1 (8/8), and prostein (12/13). Conversely, basal cytokeratins such as CK14 and CK15 were negative in all cases (0/8) and CK5/6 was weakly and focally positive in 36% (4/11) of cases. Pluripotency markers including β-catenin, Oct4, and c-kit were negative in p63-expressing tumors (0/11). Despite nearly universal expression of androgen receptor and downstream androgen signaling targets, p63-expressing tumors lacked ERG rearrangements by fluorescence in situ hybridization (0/14) and ERG protein expression (0/37). No tumors expressed SPINK1 or showed PTEN protein loss (0/19). Surprisingly, 74% (14/19) of p63-expressing tumors expressed GSTP1 protein at least focally, and 33% (2/6) entirely lacked GSTP1 CpG island hypermethylation by bisulfite sequencing. In contrast to usual prostatic adenocarcinomas, prostate tumors with p63 expression show a mixed luminal/basal immunophenotype, uniformly lack ERG gene rearrangement, and frequently express GSTP1. These data strongly suggest that p63-expressing prostate tumors represent a molecularly distinct subclass and further study of this rare tumor type may yield important insights into the role of p63 in prostatic biology and the prostate cancer cell-of-origin.

Biallelic Alteration and Dysregulation of the Hippo Pathway in Mucinous Tubular and Spindle Cell Carcinoma of the Kidney

Mucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare subtype of renal cell carcinoma (RCC) with distinctive morphologic and cytogenetic features. Here, we carry out whole-exome and transcriptome sequencing of a multi-institutional cohort of MTSCC (n = 22). We demonstrate the presence of either biallelic loss of Hippo pathway tumor suppressor genes (TSG) and/or evidence of alteration of Hippo pathway genes in 85% of samples. PTPN14 (31%) and NF2 (22%) were the most commonly implicated Hippo pathway genes, whereas other genes such as SAV1 and HIPK2 were also involved in a mutually exclusive fashion. Mutations in the context of recurrent chromosomal losses amounted to biallelic alterations in these TSGs. As a readout of Hippo pathway inactivation, a majority of cases (90%) exhibited increased nuclear YAP1 protein expression. Taken together, nearly all cases of MTSCC exhibit some evidence of Hippo pathway dysregulation. SIGNIFICANCE MTSCC is a rare and relatively recently described subtype of RCC. Next-generation sequencing of a multi-institutional MTSCC cohort revealed recurrent chromosomal losses and somatic mutations in the Hippo signaling pathway genes leading to potential YAP1 activation. In virtually all cases of MTSCC, there was evidence of Hippo pathway dysregulation, suggesting a common mechanistic basis for this disease. Cancer Discov; 6(11); 1258-66. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1197.

Lack of P16ink4a Over Expression in Penile Squamous Cell Carcinoma is Associated with Recurrence after Lymph Node Dissection

PURPOSE There have been conflicting data in studies on the prognostic role of high risk human papillomavirus in penile squamous cell carcinoma. Using P16(ink4a) over expression as a surrogate marker for high risk human papillomavirus, we evaluated high risk human papillomavirus status with respect to various clinical features, including recurrence and overall survival, among others. MATERIALS AND METHODS P16(ink4a) over expression was evaluated by immunohistochemistry for 119 consecutive patients with penile squamous cell carcinoma. Several variables were recorded including age, stage, histological grade, lymph node status, lymphovascular invasion, metastasis and recurrence. Median followup was 30 months. RESULTS P16(ink4a) over expression was detected in 49.5% (59 of 119) of samples. There was no significant difference between P16(ink4a) negative and P16(ink4a) positive tumors in terms of stage (p = 0.518), histological grade (p = 0.225), lymphovascular invasion (p = 0.388), overall survival (p = 0.156) or lymph node metastasis (p = 0.748). P16(ink4a) negative tumors were more likely to recur overall (p = 0.04), especially if patients had positive lymph nodes at diagnosis (p = 0.002). CONCLUSIONS These data suggest that P16(ink4a)/high risk human papillomavirus status is associated with recurrence, especially in patients with positive lymph nodes at diagnosis. Thus, patients with P16(ink4a) negative penile cancer, particularly those with lymph node metastases, may warrant closer observation after surgery.

MAGI-2 in prostate cancer: an immunohistochemical study ☆

Membrane-associated guanylate kinase, WW and PDZ domain-containing protein 2 (MAGI-2) is a scaffolding protein that links cell adhesion molecules, receptors, and signaling molecules to the cytoskeleton and maintains the architecture of cell junctions. MAGI-2 gene rearrangements have recently been described in prostate cancer. We studied the immunohistochemical expression of MAGI-2 protein in prostate tissue. Seventy-eight radical prostatectomies were used to construct 3 tissue microarrays consisting of 512 cores, including benign tissue, benign prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia (HGPIN), and adenocarcinoma, Gleason patterns 3 to 5. Immunohistochemistry for phosphatase and tensin homologue (PTEN) and double-stain MAGI-2/p63 was performed and analyzed by visual and image analysis, the latter as percent of analyzed area (%AREA), and mean optical density multiplied by %AREA (STAIN). By visual and image analysis, MAGI-2 was significantly higher in adenocarcinoma and HGPIN compared with benign (benign versus HGPIN P < .001; benign versus adenocarcinoma, P < .001). HGPIN and adenocarcinoma did not significantly differ by either modality. Using visual intensity to distinguish benign tissue and adenocarcinoma, a receiver operating curve yielded an area under the curve of 0.902. A STAIN threshold of 1470 yielded a sensitivity of 0.66 and specificity of 0.96. There was a significant correlation between PTEN and MAGI-2 staining for normal and benign prostatic hyperplasia, but this was lost in HGPIN and cancer. We conclude that MAGI-2 immunoreactivity is elevated in prostate cancer and HGPIN compared with normal tissue, and suggest that MAGI-2 may contribute to prostate carcinogenesis. This is the first report of MAGI-2 staining by immunohistochemistry in prostate cancer.