CLIC4 Function in the Epithelial-Mesenchymal Transition of Epithelial Odontogenic Lesions.

BACKGROUND: Odontogenic lesions constitute a heterogeneous group of lesions. CLIC4 protein regulates different cellular processes, including epithelial-mesenchymal transition and fibroblast-myofibroblast transdifferentiation. This study analyzed CLIC4, E-cadherin, Vimentin, and α-SMA immunoexpression in epithelial odontogenic lesions that exhibit different biological behavior. METHODS: It analyzed the immunoexpression of CLIC4, E-cadherin, and Vimentin in the epithelial cells, as well as CLIC4 and α-SMA in the mesenchymal cells, of ameloblastoma (AM) (n = 16), odontogenic keratocyst (OKC) (n = 20), and adenomatoid odontogenic tumor (AOT) (n = 8). Immunoexpressions were categorized as score 0 (0% positive cells), 1 (< 25%), 2 (≥ 25% - < 50%), 3 (≥ 50% - < 75%), or 4 (≥ 75%). RESULTS: Cytoplasmic CLIC4 immunoexpression was higher in AM and AOT (p < 0.001) epithelial cells. Nuclear-cytoplasmic CLIC4 was higher in OKC's epithelial lining (p < 0.001). Membrane (p = 0.012) and membrane-cytoplasmic (p < 0.001) E-cadherin immunoexpression were higher in OKC, while cytoplasmic E-cadherin expression was higher in AM and AOT (p < 0.001). Vimentin immunoexpression was higher in AM and AOT (p < 0.001). Stromal CLIC4 was higher in AM and OKC (p = 0.008). Similarly, α-SMA immunoexpression was higher in AM and OKC (p = 0.037). Correlations in these proteins' immunoexpression were observed in AM and OKC (p < 0.05). CONCLUSIONS: CLIC4 seems to regulate the epithelial-mesenchymal transition, modifying E-cadherin and Vimentin expression. In mesenchymal cells, CLIC4 may play a role in fibroblast-myofibroblast transdifferentiation. CLIC4 may be associated with epithelial odontogenic lesions with aggressive biological behavior.

Diagnosis of thymic epithelial tumor subtypes by a quantitative proteomic approach.

The histological typing of thymic epithelial tumours (TETs) still remains a challenge for surgical pathologists, especially when encountering borderline cases mainly focused on spindle cell types (including type A, atypical type A (aA), AB, and B3). A systematic proteomics analysis of TETs was performed using isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS). In total, 6479 and 6305 proteins were identified and quantified, respectively. After Gene Ontology (GO) annotation and Ingenuity Pathway Analysis (IPA), six differentially expressed proteins were validated by tissue microarray or multiple reaction monitoring (MRM) quantification. ABCE1 and CLIC2 are promising to be diagnostic candidate biomarkers in thymic carcinomas (TCs). CHD1L was up-regulated in type AB and type B thymomas compared with type A thymoma. Both CLIC2 and MAP7 were negatively detected in type B1 and B2 thymomas. SMAD4 was overexpressed in type aA thymomas and TCs. CDC42 was significantly down-regulated in type B2 thymomas compared with other subtypes. Six novel candidate biomarkers were found to be useful in differentiating subtypes of TETs. SMAD4 may play a specific role in tumorigenesis and the development of aA thymomas and thymic carcinomas.

BSND is a Novel Immunohistochemical Marker for Oncocytic Salivary Gland Tumors.

BSND protein, which is involved in chloride transport, is expressed in normal kidney and the inner ear and is known as an immunohistochemical marker for chromophobe renal cell carcinoma (RCC) and renal oncocytoma; however, other organs and tumor types exhibiting BSND expression have not yet been reported. In this study, we investigated the expression of BSND using data from the Cancer Genome Atlas (TCGA) database and by performing immunohistochemical analyses. As a result, we found that BSND was also expressed in the striated duct cells of normal salivary glands. Next, BSND expression was examined immunohistochemically in 7 types of salivary gland tumors, and BSND positivity was found in Warthin's tumor (25 out of 25 cases; 100%) and oncocytoma (4/4; 100%), both of which are usually classified as oncocytic tumors, whereas BSND negativity was observed for pleomorphic adenoma (0/11), adenoid cystic carcinoma (0/7), acinic cell carcinoma (0/6), mucoepidermoid carcinoma (0/6), and salivary duct carcinoma (0/5). Finally, the expression of BSND mRNA in 30 types of tumors other than chromophobe RCC and salivary gland tumors was examined using data from the TCGA database, but none of these tumors exhibited BSND expression. These results suggest that BSND is expressed only in normal salivary glands and oncocytic salivary gland tumors such as Warthin's tumor and oncocytoma in addition to the two known organs and the two known renal tumor types mentioned above. The selective expression pattern of BSND suggests that BSND is an excellent novel immunohistochemical marker for oncocytic salivary gland tumors.

GIST Manifesting as a Retroperitoneal Tumor: Clinicopathologic Immunohistochemical, and Molecular Genetic Study of 112 Cases.

Most gastrointestinal stromal tumors (GISTs) occur in the tubular gastrointestinal (GI) tract, but some present apparently outside the GI tract. In this study, we analyzed 112 GISTs located in the retroperitoneum. These tumors occurred in 55 women and 57 men with a median age of 65 years (range: 21 to 89 y). On the basis of clinically or histologically detected connections to GI tract, 15 tumors were considered likely of gastric, 9 duodenal, and 13 of small intestinal origin. The remaining cases were categorized by location as peripancreatic (n=25), pelvic (n=11), mesenteric (n=4), and of unspecified/miscellaneous sites (n=35). The tumors varied in size 3 to 35 cm (median, 15 cm) and by mitotic rate per 5 mm, 0 to >100 (median, 10). Histologically the tumors apparently arising outside the GI tract had features of intestinal (n=41) and gastric GISTs (n=25); 9 cases had indeterminate histology. The histologic variants included spindled, epithelioid, vacuolated, nested, and myxoid potentially simulating other tumors such as liposarcoma and solitary fibrous tumor. Most GISTs were KIT-positive (106/112 cases), and the remaining 6 tumors were DOG1/Ano1-positive. Five cases showed focal nuclear positivity for MDM2. KIT mutations were detected in 42/59 cases, and PDGFRA mutations in 4/16 KIT wild-type and 3/5 of the KIT-negative tumors analyzed. One pelvic retroperitoneal GIST was succinate dehydrogenase deficient. All 79 patients were dead at last follow-up with a median survival of 14 months, with few survivals >5 years. Only operable versus inoperable tumor was a statistically favorable factor in univariate analysis (P<0.01). In multivariate analysis, mitotic rate >50/5 mm was significant for a shorter survival (hazard ratio, 5.25; 95% confidence interval, 1.65-16.8; P<0.01). Histologic and clinicopathologic similarity of extragastrointestinal retroperitoneal GISTs with GISTs of GI tract suggests their GI tract origin. Potentially overlapping features between GIST and other retroperitoneal tumors necessitate use of multiple diagnostic markers and molecular genetic studies.

The Diagnostic and Prognostic Utility of DOG1 Expression on Gastrointestinal Stromal Tumors.

OBJECTIVE: We aimed to review our archives in order to evaluate both the diagnostic and prognostic significance of DOG1 on gastrointestinal stromal tumors (GISTs), and add further insight about those issues to the current literature including some conflicting results. MATERIAL AND METHOD: DOG1 was evaluated in 100 cases of GISTs, immunohistochemically. Immunostaining index was counted for each antibody by using both the intensity and extent of staining. The association between immunostaining index of DOG1 and CD117, CD34, SMA desmin, S-100, and Ki-67 index and clinicopathological features were analyzed. RESULTS: Ninety cases were positive for DOG1, and 89 were positive for CD117. All CD117-negative tumors were positive for DOG1. High-risk group was directly correlated with tumor diameter, cellularity, necrosis, nuclear pleomorphism, mitotic count and Ki-67 index, by univariate analysis. The association between high-risk group and tumor diameter, mitotic count, and Ki-67 index was proved by multivariate analysis. Immunostaining index of DOG1, Ki-67 index, mitotic count, ulceration and hemorrhage were inversely correlated with overall survival by univariate analysis. The adverse impact of DOG1 ISI and mitotic count on overall survival were supported by multivariate analysis. CONCLUSION: DOG1 positivity was detected in most of GISTs and all in CD117-negative cases as a result underlining its diagnostic utility. Additionally, DOG1 overexpression was related with adverse prognosis. Thus, we suggest that immunostaining index of DOG1 should routinely be used while diagnosing GIST, and DOG1 might be considered as a potential prognostic tool and a target for novel therapies.

Combined DOG1 and Mammaglobin Immunohistochemistry Is Comparable to ETV6-breakapart Analysis for Differentiating Between Papillary Cystic Variants of Acinic Cell Carcinoma and Mammary Analogue Secretory Carcinoma.

BACKGROUND: We investigated the reliability of combined DOG1 and mammaglobin immunohistochemistry compared with ETV6 fluorescence in situ hybridization (FISH) in the assessment of salivary tumors previously diagnosed as acinic cell carcinoma (ACC). Ultrastructural features of cases reclassified as mammary analogue secretory carcinoma (MASC) were assessed by transmission electron microscopy (TEM). METHODS: Immunohistochemical (IHC) reactivity to DOG1 and mammaglobin was validated against FISH targeting the ETV6 gene in all 14 cases. RESULTS: Three cases with papillary cystic histomorphology previously diagnosed as ACC were revised to MASC. TEM features of the ETV6 rearrangement-positive MASC cases showed large numbers of secretory granules with extrusion into the intercellular spaces, well-developed endoplasmic reticulum, lipid-laden vacuoles, well-formed microvilli, and large lining cystic spaces. CONCLUSIONS: Combined DOG1 and mammaglobin immunohistochemistry is comparable to ETV6 -breakapart analysis for differentiating between papillary cystic variants of ACC and MASC.

Expression of DOG1 (Using SP31) in Poorly Differentiated Carcinoma of the Head and Neck.

BACKGROUND: The calcium-activated chloride channel protein discovered on gastrointestinal stromal tumour 1 (DOG1) is expressed in a variety of normal and neoplastic tissues. DOG1 is a specific marker for gastrointestinal stromal tumour. In the head and neck region, DOG1 is a sensitive discriminator for acinar cell carcinoma. Only a few publications have presented data concerning the expression of DOG1 in head and neck squamous cell carcinoma (HNSCC). The expression of DOG1 in HNSCC appears to be associated with a poor prognosis. The aim of this study was to analyze the expression pattern of DOG1 in poorly differentiated carcinoma of the upper aerodigestive tract. MATERIALS AND METHODS: A total of 84 specimens from 31 patients with carcinomas of the upper aerodigestive tract were immunohistochemically investigated for DOG1 expression. Inclusion criterion was poorly to undifferentiated carcinoma of the head and neck, but samples of the same resection site that exhibited moderate or well-differentiated squamous cell carcinoma were also enrolled. Immunoreactivity in carcinomas was estimated using a visual score (0: negative; 1: basally positive, 2: parabasally positive, 3: completely positive, 4: basally and parabasally positive). RESULTS: Fifteen out of 84 specimens were immunoreactive to antibody to DOG1 (17.8%). DOG1 immunoreactivity was restricted to eight patients (25.8%). However, DOG1 expression was considerably heterogeneous in tumours, with three (9.6%) cases showing a positive reaction in all samples. Basal and parabasal staining patterns (five specimens each) dominated. DISCUSSION: This study demonstrated expression of DOG1 to be restricted to some poorly differentiated carcinomas of the upper aerodigestive tract. Although the proportion of DOG1-positive carcinomas was moderate compared to results of previous studies on head and neck cancer tissues, DOG1 expression possibly indicates a subset of HNSCC. Further studies are necessary to investigate the heterogeneity and clinical relevance of DOG1 expression in HNSCC.

Altered tryptophan hydroxylase 2 expression in enteric serotonergic nerves in Hirschsprung's-associated enterocolitis.

AIM: To determine if expression of colonic tryptophan hydroxylase-2 (TPH2), a surrogate marker of neuronal 5-hydroxytryptamine, is altered in Hirschsprung's-associated enterocolitis. METHODS: Entire resected colonic specimens were collected at the time of pull-through operation in children with Hirschsprung's disease (HSCR, n = 12). Five of these patients had a history of pre-operative Hirschsprung's-associated enterocolitis (HAEC). Controls were collected at colostomy closure in children with anorectal malformation (n = 10). The distribution of expression of TPH2 was evaluated using immunofluorescence and confocal microscopy. Protein expression of TPH2 was quantified using western blot analysis in the deep smooth muscle layers. RESULTS: TPH2 was co-expressed in nitrergic and cholinergic ganglia in the myenteric and submucosal plexuses in ganglionic colon in HSCR and healthy controls. Co-expression was also seen in submucosal interstitial cells of Cajal and PDGFRα(+) cells. The density of TPH2 immuno-positive fibers decreased incrementally from ganglionic bowel to transition zone bowel to aganglionic bowel in the myenteric plexus. Expression of TPH2 was reduced in ganglionic bowel in those affected by pre-operative HAEC compared to those without HAEC and healthy controls. However, expression of TPH2 was similar or high compared to controls in the colons of children who had undergone diverting colostomy for medically refractory HAEC. CONCLUSION: Altered TPH2 expression in colonic serotonergic nerves of patients with HSCR complicated by HAEC may contribute to intestinal secretory and motor disturbances, including recurrent HAEC.

The utility of CDX2, GATA3, and DOG1 in the diagnosis of testicular neoplasms: an immunohistochemical study of 109 cases.

We identified 109 testicular tumors, including pure and mixed germ cell tumors and sex cord-stromal tumors, and conducted immunohistochemical staining for CDX2, DOG1, and GATA3 to address the potential utility of these readily available and commonly used markers in the evaluation of testicular tumors. Their expression has not been previously thoroughly examined in testicular germ cell tumors. The distribution, percentage, and intensity of positivity were assessed. CDX2 was positive in all yolk sac tumors, 25% of choriocarcinomas, 9% of seminomas, and 4% of embryonal carcinomas (sensitivity for yolk sac tumor, 100%; specificity, 89% [teratomas excluded]). CDX2 also stained glandular components within teratomas and identified inconspicuous yolk sac tumor components in 3 cases previously diagnosed as pure embryonal carcinoma. GATA3 was positive in all choriocarcinomas (sensitivity, 100%). Weak GATA3 immunostaining was also seen in 12% of yolk sac tumors and 2 of 2 primitive neuroectodermal tumors. DOG1 was negative in all tumors, but stained spermatocytes and spermatids and the luminal borders of the epididymis and rete testis of nonneoplastic testis. We conclude that CDX2 is a sensitive and relatively specific marker for yolk sac tumor among the nonteratomatous germ cell tumors. It may serve to screen for yolk sac tumor components often overlooked on hematoxylin and eosin-stained slides. GATA3 is helpful in the recognition of trophoblastic cells, especially of intermediate type. DOG1 is a sensitive marker for spermatocytes and needs to be further studied for its significance.

Expression of SOX10 in Salivary Gland Oncocytic Neoplasms: A Review and a Comparative Analysis with Other Immunohistochemical Markers.

OBJECTIVES: We evaluated SOX10 (SRY-related HMG-box 10) in differentiating acinic cell carcinoma (AciCC) from other salivary gland neoplasms with oncocytic features on fine-needle aspiration cell blocks (FNA CB) and compared its performance to DOG1 (discovered on gastrointestinal stromal tumor 1). MATERIAL AND METHODS: 35 FNA CB of oncocytic salivary gland neoplasms, i.e. 13 cases of AciCC, 16 of Warthin tumor (WT), 3 of mucoepidermoid carcinoma (MEC) and 3 of oncocytoma (ONC), and 75 salivary gland resections, i.e. 26 AciCC, 7 WT, 36 MEC, 3 ONC, 2 mammary analog secretory carcinomas (MASC) and 1 papillary cystadenoma were stained for SOX10 and DOG1. RESULTS: None of the benign oncocytic neoplasms were immunoreactive for SOX10 on CB or resection, similar to DOG1. On CB, 61.5 and 77% of AciCC were positive for SOX10 and DOG1, respectively. All surgically resected AciCC cases were positive for SOX10 and DOG1; other malignant oncocytic lesions such as MEC and MASC demonstrated variable SOX10 and DOG1 staining. CONCLUSION: The use of SOX10 may increase the diagnostic accuracy of oncocytic lesions on FNA. In this context, SOX10 is equivalent to DOG1 in ruling out benign lesions such as WT and ONC; however, negative results for SOX10 as well as DOG1 do not favor a benign diagnosis since MEC is often negative for both markers.

Mammary analog secretory carcinoma, low-grade salivary duct carcinoma, and mimickers: a comparative study.

Mammary analog secretory carcinoma (MASC) is a recently recognized low-grade salivary carcinoma characterized by a specific ETV6 rearrangement. We describe 14 new MASCs and examine their immunophenotypic and genetic profiles in the context of look-alikes, namely, low-and high-grade salivary duct carcinoma and acinic cell carcinoma. ETV6 rearrangement, and robust expression of mammaglobin and S100, were demonstrated in 11/11, 14/14, and 12/14 MASCs, respectively. All low-grade salivary duct carcinomas coexpressed S100/mammaglobin (6/6); none harbored ETV6 rearrangements (0/5). Given that S100/mammaglobin coexpression and absence of zymogen granules are features of both MASC and low-grade salivary duct carcinoma, these two are best distinguished histologically. The former is predominantly an extraductal neoplasm with bubbly pink cytoplasm, whereas the latter is a distinct intraductal micropapillary and cribriform process. Querying ETV6 gene status may be necessary for difficult cases. No acinic cell carcinoma expressed mammaglobin (0/13) or harbored an ETV6 rearrangement (0/7); only 1/13 acinic cell carcinomas weakly expressed S100. DOG1 expression was limited or absent among all tumor types, except acinic cell carcinoma which expressed DOG1 diffusely in a canalicular pattern. Therefore, histology and immunohistochemistry (mammaglobin, S100, DOG1) suffices in distinguishing acinic cell carcinoma from both MASC and low-grade salivary duct carcinoma. HER2 (ERBB2) amplification was detected in only 1/10 acinic cell carcinomas, but none of the MASCs or low-grade salivary duct carcinomas tested. High-grade salivary duct carcinomas frequently expressed mammaglobin (11/18) and harbored HER2 amplifications (13/15); none harbored ETV6 rearrangements (0/12). High-grade salivary duct carcinomas can easily be distinguished from these other entities by histology and HER2 amplification.

Relationship of endothelial area with VEGF-A, COX-2, maspin, c-KIT, and DOG-1 immunoreactivity in liposarcomas versus non-lipomatous soft tissue tumors.

Soft tissue tumors are rare tumors that show a heterogeneous structure; thus far, their molecular behavior has not been elucidated. The aim of our study was to define the relationship between microvessel density (MVD), evaluated with CD31, and other immunohistochemical markers, such as vascular endothelial growth factor (VEGF), cyclooxygenase-2 (COX-2), CD34, maspin, DOG-1, and c-KIT. Immunostains were done in 55 cases consisting of benign and malignant tumors, such as liposarcomas, dermatofibrosarcomas, and tumors with histiocytic differentiation. Renal tubes were used as external control for VEGF, maspin, and DOG-1. Although DOG-1 is considered a specific marker for gastrointestinal tumors (GISTs), its positivity, correlated with c-KIT and VEGF immunoexpression, was also shown by dermatofibrosarcomas and tumors with histiocytic and lipomatous differentiation, suggesting its possible pro-angiogenic role. Maspin expression was observed in adipose tissue tumors only. Regarding angiogenesis, 31 of the 55 cases were VEGF-positive, such positivity being directly correlated with COX-2 and CD34 positivity as evaluated in the tumor cells and also with MVD. Although no significant differences in angiogenic activity were found between benign and malignant non-lipomatous tumors, the MVD was directly correlated with the histological type/grade of liposarcomas. Based on these aspects, we conclude that VEGF/COX-2-induced angiogenesis is specific for non-lipomatous tumors, whereas liposarcomas are dependent on the VEGF/maspin angiogenic pathway. The DOG-1/c-KIT/VEGF target may be used for further personalized therapy of soft tissue sarcomas. No data about DOG-1 and maspin positivity in liposarcomas have been published to date.

Establishment of functional acinar-like cultures from human salivary glands.

Disorders of human salivary glands resulting from therapeutic radiation treatment for head and neck cancers or from the autoimmune disease Sjögren syndrome (SS) frequently result in the reduction or complete loss of saliva secretion. Such irreversible dysfunction of the salivary glands is due to the impairment of acinar cells, the major glandular cells of protein, salt secretion, and fluid movement. Availability of primary epithelial cells from human salivary gland tissue is critical for studying the underlying mechanisms of these irreversible disorders. We applied 2 culture system techniques on human minor salivary gland epithelial cells (phmSG) and optimized the growth conditions to achieve the maintenance of phmSG in an acinar-like phenotype. These phmSG cells exhibited progenitor cell markers (keratin 5 and nanog) as well as acinar-specific markers-namely, α-amylase, cystatin C, TMEM16A, and NKCC1. Importantly, with an increase of the calcium concentration in the growth medium, these phmSG cells were further promoted to acinar-like cells in vitro, as indicated by an increase in AQP5 expression. In addition, these phmSG cells also demonstrated functional calcium mobilization, formation of epithelial monolayer with high transepithelial electrical resistance (TER), and polarized secretion of α-amylase secretion after ß-adrenergic receptor stimulation. Taken together, suitable growth conditions have been established to isolate and support culture of acinar-like cells from the human salivary gland. These primary epithelial cells can be useful for study of molecular mechanisms involved in regulating the function of acinar cells and in the loss of salivary gland function in patients.

TMEM16A protein attenuates lipopolysaccharide-mediated inflammatory response of human lung epithelial cell line A549.

OBJECTIVE: To observe the expression of endogenous TMEM16A in rat alveolar type II epithelial cells (AT-II) and A549, and study the effect of TMEM16A on lipopolysaccharide (LPS)-induced proinflammatory cytokine secretion. METHODS: Rat AT-II cells were isolated and TMEM16A protein expression in rat AT-II cells was measured by Western blot. TMEM16A mRNA and protein expressions in A549 were measured by real-time quantitative polymerase chain reaction (PCR) and Western blot, respectively. TMEM16A gene was transfected into A549 using Lipofectamine 2000. Transfected cells were selected in the presence of G418 to create a stable TMEM16A overexpression A549 cell line. The expression of TMEM16A in A549 was knocked down by lentiviral vector-mediated RNA interference. TNF-α and IL-8 levels were determined by enzyme-linked immunosorbent assay (ELISA). A dual-luciferase reporter assay system was used to measure the transcriptional activity of NF-κB. RESULTS: (1) Endogenous TMEM16A was expressed in rat AT-II and A549. (2) TMEM16A expression in A549 significantly increased at 24 hours and 36 hours, and then decreased at 48 hours after LPS treatment. (3) TMEM16A mRNA and protein expressions were increased in the stable TMEM16A overexpression A549 cell line. (4) TMEM16A overexpression decreased the LPS-induced TNF-α and IL-8 secretions. (5) TMEM16A mRNA and protein expressions were knocked down in TMEM16A-siRNA lentivirus transfected A549. (6) TMEM16A knockdown increased the LPS-induced TNF-α and IL-8 secretions. (7) TMEM16A overexpression inhibited LPS-induced NF-κB activation. CONCLUSIONS: TMEM16A is expressed in AT-II. TMEM16A in A549 inhibits LPS-induced NF-κB activation and decreases proinflammatory cytokines release, protecting A549 from acute LPS-mediated damage.

Leiomyoma of the gastrointestinal tract with interstitial cells of Cajal: a mimic of gastrointestinal stromal tumor.

Leiomyomas (LMs) of the gastrointestinal tract arise within the muscularis mucosae (superficial) and muscularis propria (deep). There are isolated reports of KIT-positive cells, presumed interstitial cells of Cajal (ICCs), within gastrointestinal LMs. We have encountered esophageal LMs with a high proportion of KIT-positive and DOG1-positive spindle-shaped cells, an appearance that mimicked gastrointestinal stromal tumor. Our aim was to explore the prevalence of ICCs in LMs of the gastrointestinal tract and the etiopathogenic significance of these cells in this benign neoplasm. We identified 34 esophageal LMs (28 deep, 6 superficial), 8 gastric LMs, and 5 small-bowel LMs (all lesions in muscularis propria). We performed immunohistochemical staining studies for desmin, DOG1, and KIT on these neoplasms. We also evaluated 12 superficial colonic LMs. ICCs were distinguished from mast cells on the basis of morphology (elongated and occasionally branching spindle-shaped cells) and the presence of DOG1 reactivity. Four cases were screened for mutations in PDGFRA exons 12, 14, and 18 and KIT exons 9, 11, 13, and 17. ICCs were identified in all deep esophageal LMs and constituted an average of 20% of the lesional cells; focally, these cells comprised >50% of cells. The density of these cells was significantly higher than the background muscularis propria, and hyperplasia of ICCs was not identified in the adjacent muscle. ICCs were identified in 6 of 8 gastric LMs and 1 of 5 small-bowel LMs and were entirely absent in all superficial esophageal and colonic/rectal LMs. There were no mutations in KIT or PDGFRA. ICCs are universally present in deep esophageal LMs, and thus these neoplasms could be mistaken for gastrointestinal stromal tumors, particularly on biopsy samples, an error associated with adverse clinical consequences. ICCs are also identified in gastric and intestinal LMs, albeit in a smaller proportion of cases. Colonization and hyperplasia by non-neoplastic ICCs likely account for this phenomenon.

Searching for mammary analogue [corrected] secretory carcinoma of salivary gland among its mimics.

Mammary analog secretory carcinoma of salivary gland is a recently described entity with unique morphologic, clinical, and genetic characteristics, including the characteristic t(12;15)(p13;q25) with ETV6-NTRK3 translocation found in secretory carcinomas of the breast. Before their initial description, these salivary gland tumors were generally diagnosed as acinic cell carcinoma or adenocarcinoma. For the purpose of this study, all cases of salivary gland acinic cell carcinoma, cribriform cystadenocarcinoma, and adenocarcinoma, not otherwise specified (NOS), diagnosed over a 10-year period were retrieved from our surgical pathology files. There were a total of 11 cases diagnosed as acinic cell carcinoma, 10 cases of adenocarcinoma, NOS, and 6 cases of cribriform cystadenocarcinoma. All slides were reviewed by two pathologists (AP, CGF) and tumors that show morphologic features of mammary analog secretory carcinoma according to the recent literature were selected. This process narrowed down the initial number to six cases originally diagnosed as acinic cell carcinoma, three cases originally diagnosed as adenocarcinoma, NOS, and one case originally diagnosed as cribriform cystadenocarcinoma. The 10 cases were subjected to immunohistochemistry for S-100, mammaglobin, and ANO1, as well as fluorescence in situ hybridization analysis for t(12;15)(p13;q25) with ETV6-NTRK3 fusion rearrangement. The ETV6-NTRK3 gene rearrangement was detected in three tumors. These three tumors, initially diagnosed as acinic cell carcinomas, stained positive for S-100 and mammaglobin, and negative for ANO1 by immunohistochemistry. Two of the three patients were male (2/3). In summary, mammary analog secretory carcinoma is a newly described diagnostic entity that should be in the differential diagnosis of salivary gland tumors that morphologically mimic other neoplasms, mainly acinic cell carcinomas. They differ from conventional acinic cell tumors immunohistochemically and molecularly. Positivity for mammaglobin and S-100, and negativity for ANO1 are useful screening tools before confirmatory molecular studies.

Diagnostic significance of DOG-1 and PKC-θ expression and c-Kit/PDGFRA mutations in gastrointestinal stromal tumours.

OBJECTIVE: To investigate discovered on gastrointestinal stromal tumor (GIST)-1 (DOG-1) and protein kinase C-θ (PKC-θ) expression in a series of GISTs and determine the sensitivity, specificity, and diagnostic value of these two antigens. METHODS: Immnunohistochemistry (IHC) was used to detect CD117, DOG-1, PKC-θ, CD34, Ki-67, α-smooth muscle actin (SMA), S100, and Desmin expression in 147 GISTs and 51 non-GISTs. c-Kit gene (exons 9, 11, 13, and 17) and platelet-derived growth factor receptor-alpha (PDGFRA) gene (exons 12 and 18) mutations were also detected. RESULTS: About 94.5% GISTs were CD117 positive, 96% were DOG-1 positive, and 90.5% were PKC-θ positive. DOG-1 had a specificity of 100%, while CD117 and PKC-θ had a specificity of 90% and 80%, respectively. There was no significant difference between DOG-1 and PKC-θ expressions when compared to CD117 expression. In 30 out of 42 (71.5%) GISTs, a c-Kit gene mutation was found, and in 3 out of 42 cases (7%), PDGFRA was mutated. Wild-type c-Kit/PDGFRA genes accounted for 21.5% (9/42). Most c-Kit gene mutations were found to be located at exon 11, mainly as in-frame deletions. Mutations in exon 9 were all missense mutations. Most PDGFRA gene mutations were found in exon 18, codon 842. c-Kit gene mutations in exons 13 and 17, and the PDGFRA gene mutation in exon 12 were not detected. CONCLUSIONS: Compared to CD117, DOG-1 is a biomarker with higher sensitivity and specificity. The combination of CD117 and DOG-1 can be used to improve the diagnosis of GIST. Although PKC-θ has a lower specificity than DOG-1, it can be a useful biomarker, especially in CD117(-) and/or DOG-1(-) cases.

Contribution of DOG1 expression to the diagnosis of gastrointestinal stromal tumors.

Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract, and the majority contain KIT or PDGFRA-activating mutations. However, up to 10% of GISTs are c-kit-negative. Antibodies with increased sensitivity and specificity for the detection of c-kit-negative GIST cases may be of value, especially because some of these cases may also benefit from tyrosine kinase inhibitor therapy. Hematoxylin and Eosin sections of 33 GISTs were re-examined in order to define histopathological criteria used in risk assessment of these tumors. Immunohistochemistry with a panel of antibodies [c-kit, DOG1 (discovered on GIST 1), CD34, smooth muscle actin (SMA), Desmin, S100 and Ki67] was performed on 5µm-thick paraffin sections of all tumors. Statistical analysis of immunohistochemical studies showed that DOG1 and CD117 were the most sensitive and specific antibodies in the diagnosis of GISTs. Other antibodies were unhelpful in confirming a diagnosis of GIST, but were particularly useful in the differential diagnosis. Reactivity for DOG1 may aid in the diagnosis of GISTs, which fail to express c-kit antigen, and lead to appropriate treatment with imatinib mesylate, an inhibitor of the KIT tyrosine kinase.

Chloride intracellular channel 1 is overexpression in hepatic tumor and correlates with a poor prognosis.

Chloride intracellular channel 1 (CLIC1) is expressed in many human tissues and has been reported to be involved in the regulation of cell cycle, cell proliferation, and differentiation. Its roles in human hepatic tumor, however, remain unclear. The aim of this study was to investigate the clinicopathological significance and expression pattern of CLIC1 in human primary hepatic tumors. We examined the expression pattern of CLIC1 mRNA and protein in hepatic tumors using real-time quantitative RT-PCR and Western blot, respectively. CLIC1 protein and mRNA levels were significantly higher in cancerous tissues compared with corresponding normal tissue. In 85 hepatic tumor tissues, CLIC1 was significantly higher in 69 cases (81.2%), as determined by immunohistochemical staining. Increased CLIC1 expression was correlated with tumor size (p = 0.021), distant metastasis (p = 0.025), pathological TNM (pTNM) stage (p = 0.023), and poor survival (25.11 ± 2.27 vs 45.29 ± 4.28 months, p = 0.001). Our data show that increased CLIC1 protein expression is associated with clinicopathological factors and a poor prognosis of hepatic tumors, and suggest that CLIC1 might represent a valuable prognostic marker for human hepatic tumors.