Dominick J. DiMaio

Aberrant Expression of Mucin Core Proteins and O-Linked Glycans Associated with Progression of Pancreatic Cancer

Purpose: Mucin expression is a common feature of most adenocarcinomas and features prominently in current attempts to improve diagnosis and therapy for pancreatic cancer and other adenocarcinomas. We investigated the expression of a number of mucin core proteins and associated O-linked glycans expressed in pancreatic adenocarcinoma—sialyl Tn (STn), Tn, T antigen, sialyl Lewis A (CA19-9), sialyl Lewis C (SLeC), Lewis X (LeX), and sialyl LeX (SLeX)—during the progression of pancreatic cancer from early stages to metastatic disease. Experimental Design: Immunohistochemical analyses of mucin and associated glycan expression on primary tumor and liver metastatic tumor samples were conducted with matched sets of tissues from 40 autopsy patients diagnosed with pancreatic adenocarcinoma, 14 surgically resected tissue samples, and 8 normal pancreata. Results: There were significant changes in mucin expression patterns throughout disease progression. MUC1 and MUC4 were differentially glycosylated as the disease progressed from early pancreatic intraepithelial neoplasias to metastatic disease. De novo expression of several mucins correlated with increased metastasis indicating a potentially more invasive phenotype, and we show the expression of MUC6 in acinar cells undergoing acinar to ductal metaplasia. A “cancer field-effect” that included changes in mucin protein expression and glycosylation in the adjacent normal pancreas was also seen. Conclusions: There are significant alterations in mucin expression and posttranslational processing during progression of pancreatic cancer from early lesions to metastasis. The results are presented in the context of how mucins influence the biology of tumor cells and their microenvironment during progression of pancreatic cancer. Clin Cancer Res; 19(8); 1981–93. ©2013 AACR.

Immunohistochemical staining of CD10 in atypical fibroxanthomas

Background:  The histologic diagnosis of atypical fibroxanthoma (AFX) may be difficult at times with a differential diagnosis including spindle cell/desmoplastic melanoma and a poorly differentiated squamous cell carcinoma (SCC). While there are immunohistochemical stains that may be used to support a diagnosis of either melanoma or carcinoma, the diagnosis of AFX tends to be one of exclusion.

Adenovirus infections in pediatric small bowel transplant recipients.

Background. Adenovirus is commonly isolated from pediatric small bowel transplant recipients, but its clinical consequences remain poorly understood. Methods. The medical records of pediatric small bowel transplant recipients transplanted between January 2003 and December 2007 were reviewed. Thymoglobulin and basiliximab induction and tacrolimus-based immunosuppression were the standard of care. Logistic regression analysis was performed to determine risk factors for infection, descriptive analysis to determine adenovirus incidence, and Kaplan-Meier curve analysis to determine the timing of events after transplantation. Results. Ninety-eight patients were included; 38 were positive for adenovirus (incidence 23.5%), 23 for viral shedding, 23 for infections. Nine infections developed in the first month after transplantation and 8 during the following 5 months. The small bowel was involved in 19 cases. Younger age at transplantation was a risk factor for adenovirus infection (odds ratio=0.81, 95% confidence interval, 0.663–0.994, P=0.04). Treatment of rejection did not increase the risk of adenovirus infection. Cytomegalovirus D+/R− sero-status was a protective factor (odds ratio=0.26, 95% confidence interval, 0.06–1.089, P=0.04). Conclusions. Adenovirus infections affected 24% of recipients and developed mostly during the first 6 months after transplantation. Small bowel is the most frequently involved site. Younger age at transplantation is a risk factor for adenovirus infection; whereas cytomegalovirus D+/R− sero-status seems to be protective.

Differential Expression of Metabolic Genes in Tumor and Stromal Components of Primary and Metastatic Loci in Pancreatic Adenocarcinoma

Background Pancreatic cancer is the fourth leading cause of cancer related deaths in the United States with a five-year survival rate of 6%. It is characterized by extremely aggressive tumor growth rate and high incidence of metastasis. One of the most common and profound biochemical phenotypes of animal and human cancer cells is their ability to metabolize glucose at high rates, even under aerobic conditions. However, the contribution of metabolic interrelationships between tumor cells and cells of the surrounding microenvironment to the progression of cancer is not well understood. We evaluated differential expression of metabolic genes and, hence, metabolic pathways in primary tumor and metastases of patients with pancreatic adenocarcinoma. Methods and Findings We analyzed the metabolic gene (those involved in glycolysis, tri-carboxylic acid pathway, pentose-phosphate pathway and fatty acid metabolism) expression profiles of primary and metastatic lesions from pancreatic cancer patients by gene expression arrays. We observed two principal results: genes that were upregulated in primary and most of the metastatic lesions; and genes that were upregulated only in specific metastatic lesions in a site-specific manner. Immunohistochemical (IHC) analyses of several metabolic gene products confirmed the gene expression patterns at the protein level. The IHC analyses also revealed differential tumor and stromal expression patterns of metabolic enzymes that were correlated with the metastasis sites. Conclusions Here, we present the first comprehensive studies that establish differential metabolic status of tumor and stromal components and elevation of aerobic glycolysis gene expression in pancreatic cancer.

Lack of a common or characteristic cytogenetic anomaly in solitary fibrous tumor.

Solitary fibrous tumor is a mesenchymal tumor that was initially described as a pleural-based lesion, but later was discovered in many other locations. The light-microscopic appearance of solitary fibrous tumor may overlap with other diagnostic entities; however, consistent tumor cell CD34 immunoreactivity is useful in establishing the diagnosis. Limited data suggest that solitary fibrous tumors are karyotypically diverse, and no common or characteristic anomaly has yet emerged for this entity. Cytogenetic analysis of two solitary fibrous tumors, one peritoneal and the other arising in the liver, revealed predominantly structural abnormalities in the former and numerical imbalances in the latter. Clonal karyotypic abnormalities were lacking in three additional solitary fibrous tumors.

Dormant Cancer Cells Contribute to Residual Disease in a Model of Reversible Pancreatic Cancer

The initiation and progression of pancreatic ductal adenocarcinoma (PDAC) is governed by a series of genetic and epigenetic changes, but it is still unknown whether these alterations are required for the maintenance of primary and metastatic PDAC. We show here that the c-Myc oncogene is upregulated throughout the entire process of neoplastic progression in human PDAC and in genetically engineered mice that express mutant Kras. To experimentally address whether c-Myc is essential for the growth and survival of cancer cells, we developed a novel mouse model that allows a temporally and spatially controlled expression of this oncogene in pancreatic progenitors and derived lineages of the exocrine pancreas. Unlike previous reports, upregulation of c-Myc was sufficient to induce the formation of adenocarcinomas after a short latency without additional genetic manipulation of cell survival pathways. Deficiency in Cdkn2a increased the rate of metastasis but had no effect on tumor latency or c-Myc-mediated cancer maintenance. Despite a macroscopically complete regression of primary, metastatic, and transplantable tumors following the ablation of c-Myc, some cancer cells remained dormant. A significant number of these residual neoplastic cells expressed cancer stem cell markers, and re-expression of exogenous c-Myc in these cells led to rapid cancer recurrence. Collectively, the results of this study suggest that c-Myc plays a significant role in the progression and maintenance of PDAC, but besides targeting this oncogene or its downstream effectors, additional therapeutic strategies are necessary to eradicate residual cancer cells to prevent disease recurrence.

Rab11 is a useful tool for the diagnosis of microvillous inclusion disease

Microvillous inclusion disease (MVID) is a congenital condition presenting with intractable diarrhea. Biopsies demonstrate abnormal apical PAS and CD10 staining in surface enterocytes correlating with the presence of characteristic cytoplasmic inclusions. MVID has been linked to mutations in myosin Vb, important in apical membrane recycling. Rab11 associates with myosin Vb in vesicle membranes and is also integral in recycling plasma membrane components. The authors performed Rab11 immunostaining on biopsies from 7 MVID cases, 10 normal small intestines, and 10 with chronic enteritis. In MVID cases, Rab11 showed diffuse apical cytoplasmic staining of surface enterocytes in a pattern similar to PAS and CD10, which was absent in all the 20 control cases. Ultrastructural examination confirmed localization to the external surface of MVID cytoplasmic inclusions. Rab11 staining may be a useful adjunct in MVID diagnosis and the results support that myosin Vb dysfunction is important in the pathogenesis of MVID.

Organoid profiling identifies common responders to chemotherapy in pancreatic cancer

Pancreatic cancer is the most lethal common solid malignancy. Systemic therapies are often ineffective, and predictive biomarkers to guide treatment are urgently needed. We generated a pancreatic cancer patient-derived organoid (PDO) library that recapitulates the mutational spectrum and transcriptional subtypes of primary pancreatic cancer. New driver oncogenes were nominated and transcriptomic analyses revealed unique clusters. PDOs exhibited heterogeneous responses to standard-of-care chemotherapeutics and investigational agents. In a case study manner, we found that PDO therapeutic profiles paralleled patient outcomes and that PDOs enabled longitudinal assessment of chemosensitivity and evaluation of synchronous metastases. We derived organoid-based gene expression signatures of chemosensitivity that predicted improved responses for many patients to chemotherapy in both the adjuvant and advanced disease settings. Finally, we nominated alternative treatment strategies for chemorefractory PDOs using targeted agent therapeutic profiling. We propose that combined molecular and therapeutic profiling of PDOs may predict clinical response and enable prospective therapeutic selection.Significance: New approaches to prioritize treatment strategies are urgently needed to improve survival and quality of life for patients with pancreatic cancer. Combined genomic, transcriptomic, and therapeutic profiling of PDOs can identify molecular and functional subtypes of pancreatic cancer, predict therapeutic responses, and facilitate precision medicine for patients with pancreatic cancer. Cancer Discov; 8(9); 1112-29. ©2018 AACR.See related commentary by Collisson, p. 1062This article is highlighted in the In This Issue feature, p. 1047.

Characterization of epithelial apoptosis in biopsies of small-bowel allografts using cleaved caspase 3 immunostaining

Background. The diagnosis of acute cellular rejection (ACR) in small-bowel allograft biopsies depends in part on quantification of crypt apoptotic bodies (ABs). The definition of ABs varies between authors. Recently, immunoperoxidase stains specific for apoptotic material have been used in paraffin-embedded tissue. The aim was to characterize AB morphology and quantify ABs using immunoperoxidase and hematoxylin and eosin (H&E) staining. Methods. Allograft biopsies with diagnoses of negative for ACR, indeterminate for ACR, and mild ACR were selected. Sections were stained for cleaved caspase 3 (CC3). The number of ABs per 10 crypt epithelial cells was compared by H&E and CC3 staining. Results. A total of 39 cases (15 negative, 12 indeterminate, 12 mild ACR) were obtained. CC3 staining revealed that ABs varied from well-developed “classical” exploding crypt cells to intraepithelial clusters of basophilic material. In 61%, the number detected by CC3 was higher than on H&E stains (mean 4.30 and 3.56; P < .002), with good overall correlation. With the latter definition, AB numbers by H&E were significantly higher in most cases (72%), with the diagnosis of mild ACR being downgraded in 50% if only classical ABs were counted. Conclusions. ABs have a range of morphology in biopsies of intestinal allografts, and H&E identifies the majority. The results suggest that AB counts should include basophilic clusters.

A colonization of basal cell carcinoma by malignant melanoma in situ resembling a malignant basomelanocytic tumor.

We report a case of colonization of basal cell carcinoma (BCC) by malignant melanoma in situ (MIS) simulating a malignant basomelanocytic tumor. A biopsy of a pigmented lesion present on an 83-year-old mans scalp displayed intimate admixing of basaloid and melanocytic cells. This seemingly inseparable combination of BCC and neoplastic melanocytes has been referred to as a malignant basomelanocytic tumor. However, our case also displays an adjacent component of MIS, thus favoring colonization of BCC by MIS as the etiology. To our knowledge, this is the third case report of colonization of BCC by MIS resembling a malignant basomelanocytic tumor.