CD10-positive Cells Research Articles

Diagnostic clues of BCL2-negative, faint, or controversial follicular lymphomas: a study of 103 cases

BCL2 positivity by immunohistochemistry is helpful for the diagnosis of follicular lymphoma (FL); however, a minority of FL cases are BCL2-negative, and the diagnosis is thus challenging. We retrospectively analyzed the incidence, morphology, immunophenotype, and genetic status of BCL21+ (weakly/focally positive by clone 124), BCL20 (negative), and BCL2controversial FLs compared with BCL22+ (strongly positive) FLs to clarify diagnostic clues. In 1068 FL cases, 103 (10%) with BCL21+ (37 cases, 4%), BCL20 (61 cases, 6%), or BCL2controversial (5 cases, 0.5%) were included in the final analysis. BCL21+ and BCL20 FLs tended to have limited stage disease, nodal disease, and grades 3A/3B histology and showed a higher complete response rate than BCL22+ FLs. Among 103 BCL20, BCL21+, or BCL2controversial FL cases, 34 (33%) had a diffuse area composed of CD20-positive small-to medium-sized lymphoid cells, a feature of low-grade B-cell lymphoma. Interfollicular dense CD20-positive cells and interfollicular clusters of CD10-positive cells were observed in 59% and 37% of cases, respectively. In remaining 13/40 cases (33%), BCL2 was converted to BCL22+ by other clones E17/SP66. CD23 and MUM1 were positive in 10/40 (25%) and 1/40 (3%) cases, respectively. IGH/BCL2 fusion and clonality were detected in 6/37 (16%) and 31/34 (91%) cases, respectively. In conclusion, morphological examination of the distribution of CD20-and/or CD10-positive cells and the presence of diffuse area could be used to diagnose FL in most cases. The majority of the remaining FL cases could be diagnosed using other BCL2 clones and clonality analyses.

Expression of BerEP4 and CD10 IHC Markers in Basal Cell Carcinoma, Squamous Cell Carcinoma and Adnexal Tumours of Follicular Differentiation: A Comparative Study.

Basal cell carcinoma (BCC) is the most common cutaneous malignancy. In most cases, BCC can be diagnosed by its characteristic histopathological features. The differential diagnosis includes basaloid squamous cell carcinoma (SqCC) and adnexal tumours of follicular differentiation. Cluster of differentiation 10 (CD10) and name of an immunostain (BerEP4) are reported to be useful in differentiating between them. The primary objective was to compare the expression of BerEP4 and CD10 in BCC with that of SqCC and adnexal tumours of follicular differentiation, and the secondary objective was to evaluate the proportion of different histological subtypes of BCC. Twenty-eight cases of BCCs, 34 cases of SqCCs and 16 adnexal tumours of follicular differentiation received in the institution during the study period January 2017 to June 2018 were included in this descriptive study. Immunostaining with CD10 and BerEP4 was performed, and the staining pattern was studied in all 78 cases. A detailed histopathological evaluation including subtyping was carried out for BCC cases. All BCCs showed positivity with CD10 and BerEP4, but the intensity and pattern varied. Squamous cell carcinomas were completely negative for BerEP4 and CD10 in tumour cells, and 25 of 34 cases showed stromal CD10 positivity. Among adnexal tumours of follicular differentiation, proliferating trichilemmal tumour was completely negative for both markers; other adnexal tumours (n = 11/16) showed peritumoral stromal accentuation for CD10, and nine of 11 cases showed BerEP4 tumour cell positivity (P < 0.001). BerEP4 can reliably detect BCCs of all types and distinguish between BCC and SqCC, but it is unable to do so for adnexal tumours such as trichoepithelioma, trichilemmoma and trichoblastoma. CD10 is a useful adjunct marker in distinguishing both trichoepithelioma (TE) and SqCC from BCC. CD10-positive tumour cells favour a diagnosis of BCC and peritumoral stromal accentuation for trichoblastoma (TB) and trichilemmoma (TL). Tumour cells in SqCC are almost always negative for CD10. A combined immunohistochemistry (IHC) panel of CD10 and BerEP4 can serve as a very reliable adjunctive in the diagnosis of BCC.

Inguinal endometriosis with a disappearing mass preoperatively: A case report.

IntroductionEndometriosis is a common gynecological disease that affects approximately 10% of reproductive-age women. Inguinal endometriosis is uncommon, affecting only 0.6% of all patients with endometriosis. We present a case of inguinal endometriosis with a disappearing mass preoperatively.Presentation of caseA 44-year-old woman presented with a palpable mass and pain in her left inguinal region. Computed tomography showed a 20-mm mass near the pubic tubercle. After 2 months of observation, the mass became impalpable and could not be confirmed by computed tomography; however, the inguinal pain did not improve regardless of menstrual cycles. Resection of the inguinal mass and the entire extraperitoneal portion of the uterine round ligament was performed. Histopathological examination revealed endometrial glands and stroma with CD10-positive cells, which confirmed inguinal endometriosis diagnosis. Erythrophagocytic macrophages indicated endometriosis-related hematoma absorption. Her symptoms disappeared after surgery, and no postoperative complications occurred.DiscussionFor treating inguinal endometriosis, the complete removal of the mass and the entire extraperitoneal portion of the round ligament by an anterior approach is necessary to prevent postoperative residual symptoms and recurrence. However, the preoperative diagnosis of inguinal endometriosis remains a challenge and is frequently discovered incidentally by intraoperative findings and pathological examination.ConclusionClinicians should have a high suspicion of inguinal endometriosis and improved diagnostic precision to select the appropriate surgical approach. Regardless of menstrual variability, the feature of a decreased mass size caused by endometriosis-related hematoma absorption can serve as a preoperative diagnostic clue.

PERK-mediated IL8 secretion can enhance the migration, invasion, and cisplatin resistance of CD10-positive oral cancer cells

BackgroundCancer stem cells (CSCs) drive tumor initiation and progression and participate in tumor chemoresistance. We recently discovered that oral squamous cell carcinoma (OSCC) cells that highly express CD10 (CD10H cells) present cancer stem cells (CSC)-associated characteristics, which, in turn, affect the tumor growth, epithelial-mesenchymal transition (EMT), and resistance to cisplatin. In this study, we further investigated this mechanism in vitro and in vivo. We hypothesized that IL8 might regulate migration, invasion, and cisplatin resistance of CD10-positive oral cancer cells through the ERK pathway.MethodsCD10 MicroBead Kit was used to select HN6 cells with high and low expression of CD10. The target protein IL8 was screened via protein chip assay. Lentiviral transduction and specific inhibitor were applied to investigate the signaling pathway. Real-time PCR, Western blot, and immunohistochemistry were used to analyze the mRNA and protein expression; transwell assay, spheroid formation assay, and cell viability assay were used to study the cell biological behavior in vitro; xenograft animal model was used to evaluate the tumor formation rate in vivo.ResultsOverexpression of CD10 promoted CSC-related genes expression and enhanced migration, invasion, spheroid formation, and chemoresistance in HN6 cells. Moreover, the overexpression of IL8 was detected in OSCC tumor tissue and cell lines (HN6 and CAL27) overexpressing CD10. IL8 secreted by CD10H HN6 promoted migration and invasion and restored tumor chemosensitivity via the p-ERK signaling pathway, while the inhibition of IL8 increased the chemosensitivity to cisplatin.ConclusionsIL8 secretion by CD10 positive cells promotes migration, invasion, and cisplatin resistance of OSCC via the p-ERK signaling pathway.

The expression pattern of CD10 and CD31 identifies fine fibrovascular stroma of grade 1-endometrial endometrioid carcinomas in cytology.

The objective of this study was to assess the diagnostic utility of CD10 in the differential diagnosis of grade 1-endometrial endometrioid carcinoma (G1-EEC) and the metaplastic changes associated with the endometrial glandular and stromal breakdown (EGBD) on liquid-based cytological (LBC) samples. (1) The type and distribution of CD10-positive cells in EGBD and G1-EEC patients were evaluated. (2) Based on the results from (1), histological and cytological specimens were double-immunostained with CD31 and CD10 to confirm whether CD10-positive tubular-canalicular material found in (1) was represented by fine threads of endometrial-type fibrovascular stroma. (3) Based on the results from (2), additional immunostaining of histological specimens was performed for CD146 and αSMA as markers of perivascular cells. (1) CD10 positive cells showed two main patterns of expression: cytoplasmic immunoreactivity in the form of dense brown granules in EGBD and tubular-canalicular branching patterns in G1-EEC. (2) The tubular-canalicular material observed in cytological specimens of G1-EEC samples co-expressed CD10 and CD31, and was interpreted as representing fine threads of endometrial fibrovascular stroma in the corresponding histological samples. Conversely, metaplastic changes in EGBD cases, only a few CD31-positive signals were found inside the condensed stromal clusters with CD10-positive. (3) Cells surrounding the CD31-positive vascular endothelial cells expressed CD146 and αSMA; moreover, some of the thin CD10-positive fibrous stromal strands also co-expressed αSMA. CD10 is a very useful immunomarker for distinguishing between G1-EEC and the metaplastic changes of EGBD in LBC samples.

Featured Cover

Oral DiseasesVolume 27, Issue 6 p. ii-ii FEATURED COVER Featured Cover First published: 12 August 2021 https://doi.org/10.1111/odi.13992AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract The cover image is based on the Original Article Cancer stemness of CD10-positive cells regulated by Hedgehog pathway promotes the resistance to cisplatin in oral squamous cell carcinoma by Yifei Wang et al., https://doi.org/10.1111/odi.13673. Volume27, Issue6September 2021Pages ii-ii RelatedInformation

Cancer stemness of CD10‐positive cells regulated by Hedgehog pathway promotes the resistance to cisplatin in oral squamous cell carcinoma

To explore the role of CD10 in cisplatin resistance of oral squamous cell carcinoma (OSCC) and its association with the Hedgehog (Hh) signaling pathway and cancer stem cells (CSCs). The correlation between cell viability and CD10 expression was analyzed in different OSCC cell lines after the cisplatin treatment. Genes related to chemotherapy resistance, cancer stem cells and the epithelial-mesenchymal transition were detected by quantitative real-time PCR (qPCR) in CD10high and CD10low OSCC cells. Mouse xenograft model and venous metastasis model were used to explore the potential regulatory mechanism of the resistance effect of CD10 on cisplatin. The higher expression of CD10 gene in different cell lines displayed enhanced cisplatin resistance ability. The expression of genes related to chemotherapy resistance, cell stemness, and the epithelial-mesenchymal transition was significantly higher in CD10high cells compared with CD10low cells. Moreover, the combination of cisplatin and Hh pathway inhibitors significantly reduced the resistance of CD10 to cisplatin in the xenograft model and venous metastasis models. CD10-positive cells are implicated in developing cisplatin resistance of OSCC, which could be related to its cancer stem cell characteristics regulated by the Hedgehog pathway.

Stromal Expression of CD10 by Immunohistochemistry in Odontogenic Keratocyst (OKC), Dentigerous and Radicular Cysts and Its Correlation with Local Recurrence and Aggressive Behaviour

Objective:To assess and compare the stromal expression of CD10 in OKC, dentigerous and radicular cysts.Materials and Methods:This comparative, cross sectional study was conducted at Armed Forces Institute of Pathology (AFIP), Rawalpindi, from Jan 2017 to Dec 2017. Total sixty cases comprising 20 of each OKC, Dentigerous and Radicular cysts were included in this study. Hematoxylin and eosin (H and E) sections were performed followed by immunohistochemical staining for CD10 antibody. Expression of CD10 was evaluated and compared. Results were analyzed by using SPSS version 20.0. Chi Square test was performed with P value < 0.05 was considered as significant.Results:A total of 60 cases, 20 of each OKC, dentigerous and radicular cysts were taken. In our study, 38 (63.3%) male and 22 (36.7%) female patients with the mean age of 32 ± 15 (mean ± SD) were included. Percentage of CD10 positive cells were highest in sub-epithelial stroma of OKC (95% cases) as compared to radicular and dentigerous cysts (60 and 70%) with highest number of cases showing intense staining in OKC 13(65%) as compared to other odontogenic cysts i-e 4(20%) and 2 (10%) respectively. There was a statistically significant association between odontogenic cysts and proportional score, intensity score and combined score of stromal CD10 expression (P=0.009, p=0.001 and p=0.000).Conclusion:In this study, we found that highest stromal CD10 expression in OKC as compared to dentigerous and radicular cyst, which might be due to aggressive behaviour and increased risk of recurrence in OKC. Expression of CD10 marker will further aid the clinician to plan appropriate surgical intervention and keep regular follow-ups to identify recurrences.

Composition of the Stroma in the Human Endometrium and Endometriosis.

To analyze whether the endometrial and endometriotic microenvironment is involved in the pathogenesis of endometriosis, we characterized the stromal composition. We used CD90 for fibroblasts, α-smooth muscle actin for myofibroblasts as well as CD10 and CD140b for mesenchymal stromal cells. Quantification of eutopic endometrial stroma of cases without endometriosis showed a high percentage of stromal cells positive for CD140b (80.7%) and CD10 (67.4%), a moderate number of CD90-positive cells (57.9%), and very few α-smooth muscle actin-positive cells (8.5%). These values are highly similar to cases with endometriosis showing only minor changes: CD140b (76.7%), CD10 (63%), CD90 (53.9%), and α-smooth muscle actin (6.9%). There are no significant differences in the composition of CD140b- and CD10-positive stromal cells between the eutopic endometrial stroma and the 3 different endometriotic entities (ovarian, peritoneal, and deep infiltrating endometriosis), except for a significant difference between CD10-positive stromal cells in peritoneal lesions compared to ovarian lesions. However, the percentage of CD90-positive stromal cells was reduced in the 3 different endometriotic entities compared to the endometrium, especially significant in the ovarian lesions. In contrast, the percentage of α-smooth muscle actin-positive cells in the ovary was moderately increased. Taken together, the marker signature of eutopic endometrial and endometriotic stromal cells resembles mostly mesenchymal stromal cells. Our results show clearly that the proportion of the different stromal cell types in the endometrium with or without endometriosis does not differ significantly, thus suggesting that the stromal eutopic endometrial microenvironment does not contribute to the pathogenesis of endometriosis.

Differential diagnostic significance of epithelial and stromal CD10 expression in tumors of trichogenic origin.

The histological differential diagnosis between benign trichogenic skin tumors and basal cell carcinoma may be challenging. We therefore set out to investigate whether expression of CD10, a cell surface protein with neutral endopeptidase activity, might be a suitable marker for the histological differential diagnosis of trichogenic skin tumors. We immunohistochemically analyzed 119 cases of benign trichogenic skin tumors and basal cell carcinoma. These included 28 nodular and 15 sclerosing basal cell carcinomas, 21 Pinkus tumors, 20 trichoblastomas, nine trichofolliculomas, eleven trichoepitheliomas, five desmoplastic trichoepitheliomas, and ten seborrheic keratoses. The majority of nodular basal cell carcinomas expressed CD10 in tumor cells at the peripheral (22/28 [75%]). On the other hand, trichoblastomas revealed peripheral CD10 expression in only 10% (2/20) of cases, whereas 50% showed central expression (10/20). Peripheral epithelial expression of CD10 was also found in Pinkus tumors (9/21 [42.9%]) and trichoepithelioma (4/11 [36.4%]). Desmoplastic trichoepithelioma showed no tumoral CD10 expression at all (0/5 [0%]), while the majority of sclerosing basal cell carcinomas was positive for CD10 (13/15 [86.7%]). Our findings suggest that epithelial expression of CD10 -and not peritumoral stromal CD10 expression, as has been postulated -may well be of differential diagnostic significance. The pattern of distribution of CD10-positive neoplastic cells in particular can be useful in the diagnosis of trichogenic tumors.

CD10-positive mantle cell lymphoma: clinicopathologic and prognostic study of 30 cases.

Mantle cell lymphoma is usually negative for CD10 which is useful in distinguishing MCL from other CD10 + B cell lymphomas. Here we assessed the clinicopathologic features of 30 cases of CD10+ MCL, the largest series to date in the English literature, and compared them with a group of 212 typical MCL cases (CD5+, CD10-negative, CD23-negative, cyclin D1+). The 30 patients with CD10+ MCL included 17 men and 13 women with a median age of 68 years. Compared with CD10-negative MCL, patients with CD10+ MCL showed a lower male predominance (p = 0.01), more often had a diffuse growth pattern (p = 0.04) and blastoid/pleomorphic morphology (p < 0.0001), and more often showed BCL6 expression (p = 0.009). In all MCL patients, CD10 expression was not associated with overall survival (OS) (p = 0.16). However, in more aggressive subsets of MCL patients including those with high Ki67 (> 60%), blastoid/pleomorphic morphology, or high MCL International Prognostic Index (MIPI), CD10 expression was associated with a worse OS (p = 0.003, 0.04, and 0.001, respectively). High Ki67 (> 60%), blastoid/pleomorphic morphology, and high MIPI were also been identified as poor prognostic factors patients with in CD10+ MCL (p = 0.001, 0.0003, and 0.01, respectively). In summary, CD10+ MCL more often has a diffuse growth pattern, blastoid/pleomorphic morphology, and BCL6 expression. In MCL patients with a high Ki-67 (> 60%), blastoid/pleomorphic morphology, or high MIPI, CD10 expression contributes to an even worse prognosis. MCL should be included in the differential diagnosis of CD10 + B cell lymphomas.

CD10-positive myoepithelial cells are usually prominent around in situ lobular neoplasia of the breast and much less prominent or absent in DCIS

AimsTo study the relationship between the neoplastic cells of in situ lobular neoplasia (ILN) and ductal carcinoma in situ (DCIS) and the surrounding CD10-positive myoepithelial cells.Materials and methodsTwenty consecutive cases...

A Unique Composite Follicular Lymphoma and Mantle Cell Lymphoma With a Mixed Cell Pattern and Aggressive Course

There are a limited number of reports of composite follicular lymphoma (FL) and mantle cell lymphoma (MCL) in the literature, and all previous cases report that FL and MCL components are separated, even within a single lymph node. Here we report a case of a patient with a distinctive composite FL and MCL with a mixed cell pattern. A 34-year-old man presented with left supraclavicular lymphadenopathy for one month. The lymph node contained closely packed nodules of lymphocytes. Immunostaining and fluorescence in situ hybridization demonstrated the FL nature of the Bcl-2- and CD10-positive tumor cells, as well as the scattered cyclin D1-positive MCL tumor cells in the nodules. Double immunohistochemical staining showed an unusual mixed pattern of both types of tumor cells. The patient received a regimen of CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemotherapy and achieved partial remission following four cycles of chemotherapy but relapsed 1 month after the last treatment and died of meninges involvement 8 months after the first presentation. To our knowledge, this is the first report of composite FL and MCL with a mixed pattern. A mixture of grade IIIb FL and MCL may explain the poor prognosis of the patient.

Distribution of CD10-positive epithelial and mesenchymal cells in human mid-term fetuses: a comparison with CD34 expression

CD10, a marker of immature B lymphocytes, is expressed in the developing epithelium of mammary glands, hair follicles, and renal tubules of human fetuses. To assess mesenchymal and stromal expression of CD10, we performed immunohistochemical assays in whole body sections from eight fetuses of gestational ages 15-20 weeks. In addition to expression in urinary tract and intestinal epithelium, CD10 was strongly expressed at both gestational ages in fibrous tissues surrounding the airways from the larynx to lung alveoli, in the periosteum and ossification center, and in the glans of external genitalia. CD10 was not expressed, however, in other cavernous tissues. These findings suggest that mesenchymal, in addition to epithelial cells at specific sites, are likely to express CD10. The glomeruli, alveoli, and glans are all end products of budding or outgrowth processes in the epithelium or skin. However, in contrast to the CD34 marker of stromal stem cells, CD10 was not expressed in vascular progenitor cells and in differentiated vascular endothelium. The alternating pattern of CD10 and CD34 expression suggests that these factors play different roles in cellular differentiation and proliferation of the kidneys, airway and external genitalia.

Primary cutaneous follicular helper T‐cell lymphoma: diagnostic pitfalls of this new lymphoma subtype

The recently proposed entity of cutaneous follicular helper T (T(FH)) cell lymphoma (CT(FH)CL) harbors distinct clinical and histopathologic features. Here, diagnostic pitfalls are exemplified in a case report and by review of the literature. A 45-year-old patient developed rapidly growing nodules and plaques on upper arms and buttocks, which were initially misdiagnosed as primary cutaneous follicle center B-cell lymphoma (CFCL). Consequently, systemic therapy with rituximab failed and consecutive skin biopsies revealed CT(FH)CL (CD3+CD4+CD10+PD-1+bcl6+ICOS+CXCL13+). Interestingly, the prima vista PD-1-positive and CD10-positive tumor cells lost PD-1 expression in follow-up biopsies while retaining CD10, ICOS and CXCL13 expression. All biopsy specimens displayed an identical clonal T-cell population. Initially, nodules were controlled by local radiotherapy and oral psoralen combined with ultraviolet A (PUVA) therapy. However, disease recurred and progressed rapidly with disseminated nodules. Treatment with bexarotene, methotrexate and polychemotherapy failed to stop disease progression. Finally, modified total skin electron beam radiation resulted in complete remission. Disease stabilized on maintenance therapy with bexarotene in combination with ultraviolet A (UVA) therapy. The case highlights that because of concomitant B-cell stimulation, CT(FH)CL clinicopathologically is prone to be mistaken for CFCL. Importantly, CT(FH)CL might lose PD-1 while retaining CD10 expression in later stages, which may lead to confusion in distinguishing CT(FH)CL from CFCL.

Abstract 442: CD10 positive head and neck squamous cell carcinoma have chemoresistant and radioresistant properties.

Abstract Background: Despite recent advances in the understanding of head and neck squamous cell carcinoma (HNSCC) and the development of novel therapeutic targets, five-year survival rates for HNSCC have not improved in more than three decades. Prognosis for recurrent or metastatic HNSCC remains poor. Thus, it is important for improvement of HNSCC therapy, to research therapeutic resistant mechanism. We found CD10 positive HNSCC cells have chemoresistant and radioresistant properties. Materials and Methods: In order to investigate HNSCC chemoresistant and radioresistant properties, we used Lyoplate (company:BD).This reagent contains 242 purified monoclonal antibodies to cell surface markers and can be used for screening cells with flow cytometry. First, in three HNSCC cell lines, we compared cell surface antigen expression patterns to normal cultured cells, temporarily cisplatin exprosured cells and irradiated cells. Result: We found four cell surface markers that upragulated in cisplatin exprosured cells and irradiated cells. These are CD10, CD15s, CD146, CD282. Next, we compered these expression pattern to normal cultured cells and cisplatinresistant cells. CD10 and CD282 was upregulated. Focused on CD10, we performed cisplatin MTT assay. CD10 positive cells had more resistant property than CD10 negative cells. Conclusion: CD10 is a cell surface zinc-dependent metalloendopeptidase, which is expressed in a wide variety of normal cells. CD10 is also expressed by several solid tumors such as melanoma and several carcinomas originating from kidney, lung, skin, pancreas, prostate, liver, breast, stomach, cervix, and bladder. Several studies have shown that CD10 might be a good marker for differentiating between primary tumors and derived metastases, and therefore for evaluating tumor progression. In HNSCC, only one report demonstrated role of CD10 in the differentiation and growth of neoplastic cells and concluded that CD10 expression can have an important role in the tumor invasion, metastases. Our date is first report that CD10 positive HNSCC have chemoresisitant and radioresistant properties. This result may correlate with CD10 positive HNSCC has invasive and metastatic character. Learning Objective: We identified CD10 positive HNSCC have chemoresisitant and radioresistant properties. Citation Format: Takahito Fukusumi. CD10 positive head and neck squamous cell carcinoma have chemoresistant and radioresistant properties. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 442. doi:10.1158/1538-7445.AM2013-442

Tetraspanin protein CD9 interacts with metalloprotease CD10 and enhances its release via exosomes

Tetraspanins interact with a wide variety of transmembrane and intracellular proteins called molecular partners, and modulate their function. In this article, we describe a new partner of tetraspanin web, membrane metalloprotease CD10, which is selectively associated with CD9. By constructing chimeras between tetraspanins CD9 and CD82 (the latter does not interact with CD10) or by using site-directed mutagenesis, we determined that a portion of the large extracellular loop from the CCG motif to transmembrane domain 4, as well as the C-terminal tail of CD9, are involved in the interaction with CD10. The stable expression of wild-type CD9 in K562 CD10-positive cells enhanced the level of CD10 released with exosomes five-fold. In contrast, the expression of chimeric CD9, which contained the cytoplasmic C-terminal domain from CD82, had little effect on CD10 release. Short hairpin RNA knockdown of CD9 expression in Nalm-6 pre-B cells resulted in a two-fold reduction in the amount of endogenous CD10 released with microvesicles. The peptidase activity of CD10 measured either on cells or on exosomes correlated with the level of CD10 expression, and was not significantly modulated by CD9 expression as such. Our data suggest that the interaction of CD10 with tetraspanin CD9 can play an important role in the redistribution of peptidase activity from the cell surface to outer microenvironments. In bone marrow, where CD10 presumably contributes to the maturation of pre-B cells and migration of B cells to the blood circulation, release of CD10 peptidase activity with exosomes may effectively regulate extracellular matrix microenvironments.

Synchronous Adenocarcinoma and Follicular Lymphoma of the Stomach

A 73-year-old Japanese man with synchronous follicular lymphoma and adenocarcinoma of the stomach underwent curative surgical resection. The follicular lymphoma lesion was preoperatively diagnosed as extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) according to biopsy samples. However, postoperative pathological evaluations revealed components of CD10-positive and CD10-negative lymphoma cells within the lymphoma lesion. This case highlights the potential difficulty of diagnosing gastric follicular lymphoma. In such cases, conducting repeat pathological examinations of biopsy samples or resected specimens is required to obtain a correct diagnosis of follicular lymphoma.

Use of CD10 as a marker of canine mammary myoepithelial cells

CD10 is an important cell marker in the diagnosis of acute lymphoblastic leukaemia and of breast myoepithelial (ME) cells in humans. The objective of this study was to assess the value of CD10 as a marker of canine ME cells using immunohistochemistry on routinely processed normal, dysplastic and neoplastic mammary tissue. Five different CD10 positive cell types were identified on the basis of cell morphology, pattern of immunoreactivity, and on the co-expression of additional cell lineage-specific markers. Type 1 cells were typical fusiform cells with a ME cell phenotype (calponin- and cytokeratin [CK] 14-positive, CK8/18-negative). Type 2 cells were typical or atypical polyhedral cells with a luminal epithelial (LE) cell phenotype (calponin- and CK14-negative, CK8/18-positive). Type 3 cells had a type 1 phenotype with variable morphology, and type 4 were atypical neoplastic cells with a mixed ME/LE phenotype. Type 5 cells were typical fusiform cells with a stromal phenotype. Type 1 cells were considered normal ME cells and were found in all sample types; type 2 cells were considered normal or neoplastic LE cells and were also found in all sample types; types 3 and 4 cells were restricted to tumour samples and to malignant tumours, respectively, and type 5 cells were found in all sample types, although predominantly in neoplastic tissue. The findings indicate that the CD10 antigen is a sensitive (although not specific) marker of canine ME cells in normal, dysplastic and neoplastic mammary tissue. Differences in the distribution and staining intensity of CD10-positive cells suggest a number of potential roles for this protein in the pathogenesis of canine mammary neoplasia.

Epithelial to mesenchymal transition in cutaneous squamous cell carcinoma is correlated with COX-2 expression but not with the presence of stromal macrophages or CD10-expressing cells

Epithelial to mesenchymal transition (EMT) is an intricate process by which epithelial cells loose epithelial characteristics and acquire a mesenchymal-like phenotype. EMT and cyclooxygenase 2 (COX-2) expression are related to tumor invasion and metastasis. The tumor microenvironment plays a major role in tumor progression and the induction of EMT. Here, we investigated the relationship between EMT and COX-2 expression as well as tumor-associated macrophages (TAM) and CD10-positive stromal cells during the development of cutaneous squamous neoplastic lesion. We performed immunohistochemical staining for vimentin, E-cadherin, β-catenin, COX-2, CD68, and CD10 in 41 cases of squamous cell cancers (SCC), 20 of Bowen's disease, 30 of actinic keratosis, and 30 samples of normal skin. SCC cells showed significantly increased vimentin expression and reduced expression of membranous E-cadherin and β-catenin compared with cells in precursor lesions and in normal skin. COX-2 expression was also markedly increased in SCC cells. E-cadherin expression was positively correlated with β-catenin expression and inversely correlated with COX-2 expression in SCC cells. The number of TAM and CD10-positive stromal cells increased from the normal skin to precursor lesions and SCC cells. The number of TAM and of CD10-positive stromal cells did not correlate with the expression of E-cadherin, β-catenin, COX-2, and vimentin in SCC cells. We suggest that cutaneous SCC cells show EMT, which appears to be correlated with COX-2 expression but not with stromal CD10 expression and TAM.