Intravenous but not intrathecal central nervous system-directed chemotherapy improves survival in patients with testicular diffuse large B-cell lymphoma.

BACKGROUND: Testicular lymphoma is a rare malignancy affecting mainly elderly men, the majority representing diffuse large B-cell lymphoma (DLBCL). Its relapse rate is higher than that of nodal DLBCL, often affecting the central nervous system (CNS) with dismal prognosis. PATIENTS AND METHODS: We searched for patients with testicular DLBCL (T-DLBCL) involvement from the pathology databases of Southern Finland University Hospitals and the Danish Lymphoma Registry. Clinical information was collected, and outcomes between treatment modalities were evaluated. Progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OS) were assessed using Kaplan-Meier and Cox proportional hazards methods. RESULTS: We identified 235 patients; of whom, 192 were treated with curative anthracycline-based chemotherapy. Full survival data were available for 189 patients. In univariate analysis, intravenous CNS-directed chemotherapy, and irradiation or orchiectomy of the contralateral testis translated into favourable PFS, DSS and OS, particularly among the elderly patients (each p ≤ 0.023). Intrathecal chemotherapy had no impact outcome. In multivariate analyses, the advantage of intravenous CNS-directed chemotherapy (hazard ration [HR] for OS, 0.419; 95% confidence interval [CI], 0.256-0.686; p = 0.001) and prophylactic treatment of contralateral testis (HR for OS, 0.514; 95% CI, 0.338-0.782; p = 0.002) was maintained. Rituximab improved survival only among high-risk patients (International Prognostic Index≥3, p = 0.019). The cumulative risk of CNS progression was 8.4% and did not differ between treatment modalities. CONCLUSION: The results support the use of CNS-directed chemotherapy and prophylactic treatment of the contralateral testis in patients with T-DLBCL involvement. Survival benefit appears resulting from better control of systemic disease rather than prevention of CNS progression.

Alternative splicing discriminates molecular subtypes and has prognostic impact in diffuse large B-cell lymphoma.

Effect of alternative splicing (AS) on diffuse large B-cell lymphoma (DLBCL) pathogenesis and survival has not been systematically addressed. Here, we compared differentially expressed genes and exons in association with survival after chemoimmunotherapy, and between germinal center B-cell like (GCB) and activated B-cell like (ABC) DLBCLs. Genome-wide exon array-based screen was performed from samples of 38 clinically high-risk patients who were treated in a Nordic phase II study with dose-dense chemoimmunotherapy and central nervous system prophylaxis. The exon expression profile separated the patients according to molecular subgroups and survival better than the gene expression profile. Pathway analyses revealed enrichment of AS genes in inflammation and adhesion-related processes, and in signal transduction, such as phosphatidylinositol signaling system and adenosine triphosphate binding cassette transporters. Altogether, 49% of AS-related exons were protein coding, and domain prediction showed 28% of such exons to include a functional domain, such as transmembrane helix domain or phosphorylation sites. Validation in an independent cohort of 92 DLBCL samples subjected to RNA-sequencing confirmed differential exon usage of selected genes and association of AS with molecular subtypes and survival. The results indicate that AS events are able to discriminate GCB and ABC DLBCLs and have prognostic impact in DLBCL.

Breast implant-associated anaplastic large cell lymphoma - From diagnosis to treatment.

Breast lymphomas comprise a rare group of malignant breast tumors. Among these, a new entity has emerged as a potentially under-diagnosed disease. Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) most often manifests as a late periprosthetic effusion between 1 and 10 years after the implantation of silicone or saline-filled breast prostheses. BI-ALCL is an anaplastic lymphoma kinase-negative T-cell lymphoma that has a distinctively different clinical course than other breast lymphomas or ALCLs. Diagnosis is based on aspiration of the effusion around the implant and CD30 positivity of the sample. Every periprosthetic effusion after breast augmentation or reconstruction using implants should be considered as potential BI-ALCL until proven otherwise. The majority of cases at diagnosis are in the in situ stage, i.e., confined to the lumen around the prosthesis. Most patients have an excellent prognosis when complete removal of the capsule and prosthesis with negative margins is achieved surgically. Some patients, however, develop infiltrative disease with a potentially life-threatening clinical course. Treatment planning regarding the extent of surgery and role of adjuvant therapy, especially in advanced cases, requires further investigation.

MicroRNA profiling in chemoresistant and chemosensitive acute myeloid leukemia.

MicroRNA (miRNA) deregulation is associated with progression and treatment outcome in various types of cancers. To identify miRNAs related to therapeutic response, we applied an miRNA microarray followed by PCR verification of 33 available diagnostic bone marrow core biopsies from 33 acute myeloid leukemia patients including 15 chemoresistant and 18 chemosensitive patients. We found 3 significantly upregulated miRNAs, miR-363, miR-532-5p and miR-342-3p, related to therapeutic response (q < 0.05). Further validation of miR-532-5p and miR-363 expression by quantitative RT-PCR confirmed microarray analysis results. Genes targeted by miR-363 include RGS17 and HIPK3, both reported to be associated with drug response.

Dose-densified chemoimmunotherapy followed by systemic central nervous system prophylaxis for younger high-risk diffuse large B-cell/follicular grade 3 lymphoma patients: results of a phase II Nordic Lymphoma Group study.

BACKGROUND: Many patients with aggressive B-cell lymphomas and high clinical risk score still die of lymphoma after conventional R-CHOP chemoimmunotherapy. We hypothesized that intensified chemoimmunotherapy including systemic central nervous system (CNS) prophylaxis improves outcome and reduces the incidence of CNS-related events. PATIENTS AND METHODS: Inclusion criteria were age 18-65 years, primary diffuse large B-cell lymphoma or grade III follicular lymphoma without clinical signs of CNS disease and negative cerebrospinal fluid cytology, age-adjusted International Prognostic Index 2-3 and WHO performance score 0-3. Treatment consisted of six courses of R-CHOEP-14 followed by a course of high-dose cytarabine and a course of high-dose methotrexate. Primary end point was failure-free survival (FFS) at 3 years. RESULTS: A total of 156 eligible patients with a median age of 54 years (range 20-64) were included. Three toxic deaths were observed. Three-year overall survival (OS) and FFS rates (median observation time 52 months for survivors) were 81% and 65%, respectively. Seven patients experienced CNS relapse, all within 6 months. CONCLUSIONS: The results are promising with favorable 3-year OS and FFS rates, a low toxic death rate and a lower than expected number of CNS events. CNS progression might be further reduced by earlier CNS prophylaxis. CinicalTrials.gov. identifier NCT01502982.

Colonic involvement in a patient with chronic lymphocytic leukaemia.

Various gastrointestinal infiltrations have been described in patients with chronic lymphocytic leukaemia (CLL). Here, we report a 69-year-old man with CLL and anaemia in whom the macroscopic finding of colonoscopy was normal, but the histological specimens revealed lymphocytic leukemia in ileum and in colon. If a CLL patient has any symptoms suggesting a possible GI manifestation of the haematologic disease or anaemia not explained by bone marrow infiltration or hemolysis, the diagnostic evaluation should include endoscopies with adequate biopsies.

USAXS and SAXS from cancer-bearing breast tissue samples.

USAXS and SAXS patterns from cancer-bearing human breast tissue samples were recorded at beamline ID02 of the ESRF using a Bonse-Hart camera and a pinhole camera. The samples were classified as being ductal carcinoma, grade II, and ductal carcinoma in situ, partly invasive. The samples included areas of healthy collagen, invaded collagen, necrotic ducts with calcifications, and adipose tissue. The scattering patterns were analyzed in different ways to separate the scattering contribution and the direct beam from the observed rocking curve (RC) of the analyzer. It was found that USAXS from all tissues was weak, and the effects on the analyzer RC were observed only in the low-intensity tails of the patterns. The intrinsic RC was convolved with different model functions for the impulse response of the sample, and the best fit with experiment was obtained by the Pearson VII function. Significantly different distributions for the Pearson exponent m were obtained in benign and malignant regions of the samples. For a comparison with analyzer-based imaging (ABI) or diffraction enhanced imaging (DEI) a "long-slit" integration of the patterns was performed, and this emphasized the scattering contribution in the tails of the rocking curve.

Impact of germinal center and non-germinal center phenotypes on overall and failure-free survival after high-dose chemotherapy and auto-SCT in primary diffuse large B-cell lymphoma.

Non-germinal center (non-GC) phenotype is an adverse prognostic factor in chemotherapy (CT)-treated diffuse large B-cell lymphoma (DLBCL) patients. To determine how high-dose therapy (HDT) supported with auto-SCT as first line therapy influences GC-associated outcome in young high-risk DLBCL patients GC and non-GC phenotypes were determined immunohistochemically from 63 patients. Of these, 29 primary high-risk DLBCL patients were treated with auto-SCT, whereas 34 CT-treated patients served as a control group. Consistent with previous studies, non-GC phenotype was associated with adverse outcome in CT-treated high-risk patients. In contrast, immunohistochemical classification by cell of origin did not associate with survival after auto-SCT. When the impact of treatment on the predictive value of cell of origin was analyzed, the non-GC patients, who received HDT, had a better failure-free survival (FFS) and overall survival (OS) than the patients treated with CT alone. In multivariate analyses, both age-adjusted International Prognostic Index (aaIPI) and treatment were independent prognostic factors for FFS and OS. For the patients with GC phenotype, the influence of auto-SCT on survival was not significant. The data imply that auto-SCT can overcome the adverse prognostic impact of the non-GC phenotype in patients with high-risk DLBCL and warrant additional prospective studies.

Vascular adhesion protein-1 in human ischaemic stroke.

AIMS: Leukocyte extravasation exacerbates tissue injury after ischaemic stroke. Vascular adhesion protein-1 (VAP-1) is an endothelial adhesion molecule with the potential capacity to guide transmigration of inflammatory cells into ischaemic brain. Moreover, VAP-1 could worsen ischaemic brain injury due to its function as a semicarbazide-sensitive amine oxidase (SSAO) producing toxic metabolites from primary amines. The purpose of this study was to elucidate these aspects of VAP-1-function in the pathogenesis of human ischaemic stroke. METHODS: We studied VAP-1 expression in infarcted and control brains post mortem using immunohistochemistry. Levels of soluble VAP-1 (sVAP-1) in the serum of patients with acute stroke and in control sera were determined using enzyme-linked immunosorbent assay. RESULTS: In the acute phase of ischaemic stroke, the frequency of VAP-1-stained vessels was strongly diminished in the ipsilateral hemisphere but in the contralateral hemisphere it was comparable with the expression in the control brains. In the serum of acute stroke patients with a symptom duration <6 h the level of sVAP-1 was significantly increased (652 +/- 224 ng/ml; mean +/- SD) when compared with an age- and sex-matched control group (542 +/- 104 ng/ml; P < 0.05). CONCLUSIONS: As both cell surface and sVAP-1 possess vasculopathy-promoting SSAO enzymatic activity, our results imply that by inducing SSAO-derived toxic metabolites, VAP-1 might aggravate ischaemic vascular changes. The subsequent release of sVAP-1 into circulation could be further examined as a potential marker of early ischaemic vasculopathy.

Collagenase-1 (MMP-1), matrilysin-1 (MMP-7), and stromelysin-2 (MMP-10) are expressed by migrating enterocytes during intestinal wound healing.

BACKGROUND: Matrix metalloproteinases (MMPs) play a crucial role in wound healing of the skin, airways, and cornea, but data on MMPs in normal intestinal wound healing is limited. The aim of this study was to clarify the role of collagenase-1 (MMP-1), matrilysin-1 (MMP-7), and stromelysin-2 (MMP-10) in intestinal wound repair and to determine the effect of cytokines on the expression of these MMPs in intestinal epithelial cell lines. METHODS: Surgical specimens from patients with ischemic colitis (n = 5) were used as an in vivo model of intestinal re-epithelialization. Fetal ileal explants were used as an ex vivo model. In situ hybridization for MMPs -1, -3, -7, and -10 was performed and immunohistochemical stainings were used to localize MMP-7 and -9 expressing cells. Stainings for cytokeratin and laminin-5 were performed to identify epithelial cells and migrating enterocytes, respectively. Caco-2, HT-29, and WiDr cell lines were treated for 6-48 h with different cytokines (e.g. EGF, KGF, IL-1 beta, TGF-alpha, TNF-alpha, and TGF-beta1) and Taqman real-time quantitative RT-PCR was used to investigate their effect on the expression of MMPs-1, -7, and -10. RESULTS: MMP-7, MMP-10, and MMP-1 were expressed by migrating enterocytes bordering intestinal ulcers in 5/5, 3/5, and 3/5 samples, respectively. In the fetal gut model, MMP-1 and MMP-10 were expressed by migrating enterocytes, but matrilysin-1 expression was not detected. Matrilysin-1 was up-regulated by TNF-alpha and IL-1 beta, and stromelysin-2 by TNF-alpha and EGF in Caco-2 and WiDr cell cultures. MMP-1 was up-regulated in Caco-2 cells by TGF-beta, EGF, and IL-1 beta, but only by EGF in WiDR cells. CONCLUSIONS: It is concluded that collagenase-1, stromelysin-2, and matrilysin-1 are involved in intestinal re-epithelialization in vivo and that they are up-regulated by cytokines relevant in wound repair.

Differential expression of three matrix metalloproteinases, MMP-19, MMP-26, and MMP-28, in normal and inflamed intestine and colon cancer.

Several matrix metalloproteinases (MMPs) have been implicated in intestinal inflammation, mucosal wound healing, and cancer progression. The purpose of this study was to examine the cellular location and putative function of MMP-19, MMP-26 (matrilysin-2), and MMP-28 (epilysin), in normal, inflammatory, and malignant conditions of the intestine. Peroperative tissue specimens from patients with ulcerative colitis (UC) (n = 16) and archival tissue samples of ischemic colitis (n = 9), Crohn's disease (n = 7), UC (n = 8), colon cancer (n = 20), and healthy intestine (n = 5) were examined using immunohistochemical analyses with polyclonal antibodies. Unlike many classical MMPs, MMP-19, MMP-26, and MMP-28 were all expressed in normal intestine. In inflammatory bowel disease (IBD), MMP- 19 was expressed in nonmigrating enterocytes and shedding epithelium. MMP-26 was detected in migrating enterocytes, unlike MMP-28. In colon carcinomas, MMP-19 and MMP-28 expression was downregulated in tumor epithelium. Staining for MMP-26 revealed a meshwork-like pattern between cancer islets, which was absent from most dedifferentiated areas. Our results suggest that MMP-19 is involved in epithelial proliferation and MMP-26 in enterocyte migration, while MMP-28 expression is not associated with inflammatory and destructive changes seen in IBD. In contrast to many previously characterized MMPs, MMP-19 and MMP-28 are downregulated during malignant transformation of the colon and may play a prominent role in tissue homeostasis.

Follicular lymphoma cell lines, an in vitro model for antigenic selection and cytokine-mediated growth regulation of germinal centre B cells.

In the periphery, B cells differentiate in germinal centres (GCs) of secondary lymphoid organs. Isolated GC cells die quickly in vitro by apoptosis. Therefore, cell lines originating from follicular lymphomas, which are the malignant counterparts of GC B cells, would provide a stable in vitro model to study the immunobiology of GC B cells. We have established three novel human follicular lymphoma cell lines that were characterized with special reference to immunophenotypic features, response to B-cell receptor (BCR) triggering, response to cytokines and cytokine mRNA expression. One of the cell lines, HF-1A3, has a phenotype of a centrocyte. It expresses surface immunoglobulin G (sIgG) and dies by apoptosis following BCR cross-linking. Co-stimulation with interleukin-6 (IL-6), IL-15 or interferon-gamma (IFN-gamma) rescues HF-1A3 cells from BCR-induced apoptosis. The second cell line, HF-28, also represents phenotypically an IgG+ centrocyte. Ligation of its BCR leads to the cell-cycle arrest at G1 instead of apoptosis. HF-28 cells express both CD45RA and RO isoforms, which is unusual in B lymphocytes apart from plasma cells, thus suggesting a transition to plasma cell phenotype. The third cell line, HF-4.9, which phenotypically represents an sIgM+ centroblast, responds by proliferation to BCR cross-linking. These cell lines offer a unique in vitro model to study antigenic selection and cytokine-mediated growth regulation of human GC B cells.

Overexpression of tissue inhibitor of metalloproteinases-3 in intestinal and cutaneous lesions of graft-versus-host disease.

Matrix metalloproteinases (MMPs) have been implicated in the pathobiology of various T-cell-mediated inflammatory disorders of the intestine and skin. Their synthetic inhibitor has been shown to prevent lethal acute graft-versus-host disease in animal models. We intended to determine the expression of MMPs 1, 3, 7, 9, 10, 12, and 19 and tissue inhibitors of metalloproteinases (TIMPs) 1 and 3 in intestinal and cutaneous lesions of patients suffering from graft-versus-host disease after bone marrow transplantation. In situ hybridizations for MMPs 1, 3, 7, 10, and 12 as well as TIMPs 1 and 3 were performed using (35)S-labeled cRNA probes on intestinal (n = 13) and cutaneous specimens (n = 9) from patients with graft-versus-host disease. Immunohistochemical stainings were carried out to localize MMP-9, MMP-19, TIMP-3, and TGF-beta1 proteins, and TUNEL staining, to detect apoptotic cells. TIMP-3 mRNA and protein were detected in cutaneous lesions in areas with vacuolar degeneration of the basal epidermal layer in all skin samples, and they colocalized with apoptotic keratinocytes and partly with staining for TGF-beta. None of the MMPs examined were overexpressed in skin lesions. Signals for MMP-1 and MMP-3 mRNA was found in 10/13 and 5/13 intestinal biopsies, respectively. In the gut, MMP-19-positive epithelial cells, particularly in the crypts, were found in 10/13 samples. Expression of MMPs 7, 9, 10, and 12 was absent or very low. TIMPs 1 and 3 were expressed by stromal cells in 12/13 and 10/13 gut samples, respectively. Whereas TIMP-1 was expressed particularly by subepithelial cells where epithelium had shed away, TIMP-3 was detected in deeper areas. We conclude that MMPs are differentially regulated in the skin and gut lesions of graft-versus-host disease. In agreement with previous data on cancer cells, TIMP-3, induced by TGF-beta1, may contribute to the apoptosis of keratinocytes in cutaneous graft-versus-host disease lesions, leading to typical histopathological changes. We also conclude that MMPs play a less important role as effector molecules in intestinal graft-versus-host disease than in celiac or inflammatory bowel disease.

Upregulation of CFTR expression but not SLC26A3 and SLC9A3 in ulcerative colitis.

In inflamed colonic mucosa, the equilibrium between absorptive and secretory functions for electrolyte and salt transport is disturbed. We compared the expression of three major mediators of the intestinal salt transport between healthy and inflamed colonic mucosa to understand the pathophysiology of diarrhea in inflammatory bowel disease. Expression levels of the cystic fibrosis transmembrane regulator (CFTR) (Cl- channel), SLC26A3 (Cl-/HCO exchanger) and SLC9A3 (Na+/H+ exchanger) mRNAs were measured by real-time quantitative RT-PCR in peroperative colonic samples from controls (n = 4) and patients with ulcerative colitis (n = 10). Several samples were obtained from each individual. Tissue samples were divided into three subgroups according to their histological degree of inflammation. Expression of CFTR and SLC26A3 proteins were determined by immunohistochemistry and Western blotting from the same samples, respectively. Increased expression of CFTR mRNA was observed in all three groups of affected tissue samples, most pronounced in mildly inflamed colonic mucosa (5-fold increase in expression; P < 0.001). The expression of the CFTR protein was detected from health and inflamed colon tissue. Although the expression of the SLC26A3 mRNA was significantly decreased in severe ulcerative colitis (P < 0.05), the SLC26A3 protein levels remained unchanged in all groups. The expression of SLC9A3 mRNA was significantly changed between the mild and severe groups. Intestinal inflammation modulates the expression of three major mediators of intestinal salt transport and may contribute to diarrhea in ulcerative colitis both by increasing transepithelial Cl- secretion and by inhibiting the epithelial NaCl absorption.

Small-angle x-ray scattering studies of human breast tissue samples.

Small-angle x-ray scattering (SAXS) patterns are recorded from thin breast tissue samples containing healthy and cancerous regions. The SAXS patterns are compared with histo-pathological observations. The information available from SAXS is reviewed, and a model for scattering from collagen is presented. Scattering patterns of collagen at regions far from the tumours are essentially different from those at tumours. The axial period of collagen fibrils is 65.0 +/- 0.1 nm in healthy regions, and 0.3 nm larger in cancer-invaded regions. The average intensity of scattering from cancerous regions is an order of magnitude higher than the intensity from healthy regions. This is interpreted to arise from an increase of the specific surface area of the scatterers, which is due to a disruption of the molecular and supra-molecular structures in cancerous regions and invasion of new types of cells. The differences of the SAXS patterns are large and distinctive enough to suggest that these phenomena may be utilized in mammography.

Evolution of cerebral tumor necrosis factor-alpha production during human ischemic stroke.

BACKGROUND AND PURPOSE: Tumor necrosis factor-alpha (TNF-alpha) is detected in ischemic brain cells in experimental animal models and is believed to play an important role in apoptosis. However, the natural expression of TNF-alpha during human stroke is not known. METHODS: We examined TNF-alpha immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) in brain samples of stroke victims (n=16) after variable survival (15 hours to 18 days). Systemic TNF-alpha content from a separate cohort including severe or lethal stroke cases (n=26) was also assayed. RESULTS: Neuronal TNF-alpha was demonstrated from 0.6 to 5.4 days after the onset of stroke symptoms, peaking bilaterally during days 2 and 3. Bilateral glial TNF-alpha immunoreactivity was detected during the acute phase, with the astrocytic TNF-alpha expression dominating in later phases and persisting contralaterally to the infarct in more matured phases (17 to 18 days). Invading inflammatory cells were TNF-alpha immunopositive beginning on the third day. Besides, vascular wall structures showed immunoreactivity sporadically. TNF-alpha levels were mostly nondetectable in peripheral blood. TUNEL labeling and TNF-alpha staining overlapped, although not completely, during the first days. CONCLUSIONS: The data support the hypothesis that TNF-alpha may be involved both in the acute propagation of inflammatory processes and cell death and possibly in the more delayed reconstitutive processes of human ischemic stroke.

Upregulation and differential expression of matrilysin (MMP-7) and metalloelastase (MMP-12) and their inhibitors TIMP-1 and TIMP-3 in Barrett's oesophageal adenocarcinoma.

Oesophageal adenocarcinoma is believed to arise from metaplastic mucosa in the distal oesophagus, a condition also known as Barrett's oesophagus (BE). BE develops as a result of injury caused by refluxing gastric and duodenal contents and is associated with increased risk of malignant transformation. Matrix metalloproteinases (MMPs) have been implicated in all aspects of tumour progression; tumour growth, basement membrane degradation, invasion and metastatic spread. Using in situ hybridization, we investigated the expression patterns of collagenases-1 and -3, stromelysin-2, matrilysin, metalloelastase and TIMPs-1 and -3 in BE, adenocarcinoma and lymph-node metastases. Matrilysin was expressed abundantly in 12/15 tumours and in 4/6 lymph-node metastases and its expression correlated with the histological aggressiveness of tumour. Matrilysin and metalloelastase were upregulated already in BE. Stromelysin-2 and collagenase-3 expression was detected only in a few tumours. Collagenase-1 was expressed by cancer and stromal cells in 9/15 tumours. Tumour-infiltrating macrophages expressed metalloelastase in 13/15 cancers. TIMPs-1 and -3 were expressed in 12/15 and 11/15 tumours, respectively. Laminin-5 and tenascin were abundantly expressed at the invasive front of poorly differentiated tumours, but not in BE. Our results indicate that matrilysin is the principal MMP expressed by tumour cells in oesophageal adenocarcinoma, and further studies are needed to investigate whether matrilysin or tenascin-C could be used as a predictive marker for progression of BE to cancer.

SLC26A2 (diastrophic dysplasia sulfate transporter) is expressed in developing and mature cartilage but also in other tissues and cell types.

Mutated alleles of the SLC26A2 (diastrophic dysplasia sulfate transporter or DTDST) gene cause each of the four recessive chondrodysplasias, i.e., diastrophic dysplasia (DTD), multiple epiphyseal dysplasia (MED), atelosteogenesis Type II (AO2), and achondrogenesis Type IB (ACG1B). SLC26A2 acts as an Na(+)-independent sulfate/chloride antiporter and belongs to the SLC26 anion transporter gene family, currently consisting of six homologous human members. Although Northern analysis has indicated some expression in all tissues studied, the only tissue known to be affected by SLC26A2 mutations is cartilage. Abundant SLC26A2 expression has previously been detected in normal human colon by in situ hybridization. We have used in situ hybridization and immunohistochemistry to examine multiple normal tissues for the expression of human SLC26A2. As expected, a strong signal for SLC26A2 mRNA and protein immunostaining were detected in developing fetal hyaline cartilage, while bronchial cartilage showed mRNA expression in adult tissues. SLC26A2 expression could also be detected in eccrine sweat glands, in bronchial glands, and in placental villi. In addition, immunoreactivity for the SLC26A2 protein was observed in exocrine pancreas. Our results suggest a more limited expression pattern for SLC26A2 than that found by Northern analysis. However, SLC26A2 expression is also detected in tissues not affected in chondrodysplasias caused by SLC26A2 mutations.

The congenital chloride diarrhea gene is expressed in seminal vesicle, sweat gland, inflammatory colon epithelium, and in some dysplastic colon cells.

Congenital chloride diarrhea (CLD) is an autosomal recessive disorder of intestinal electrolyte transportation caused by mutations in the anion transporter protein encoded by the down-regulated in adenoma (DRA), or CLD, gene. In this study, in situ hybridization and immunohistochemistry were performed to investigate the expression of CLD in extraintestinal normal epithelia and in intestinal inflammatory and neoplastic epithelia. The expression of the closely related anion transporter diastrophic dysplasia sulfate transporter, DTDST, was also examined and compared with that of CLD in colon. The only extraintestinal tissues showing CLD expression were eccrine sweat glands and seminal vesicles. In inflammatory bowel disease and ischemic colitis, expression of CLD mRNA in colon epithelium was similar to histologically normal colon epithelium, but the protein was found deeper in crypts, including proliferative epithelial cells. In intestinal tumors, the expression pattern of CLD was dependent on the differentiation status of the tissue studied: epithelial polyps with no or minor dysplasia showed abundant expression, whereas adenocarcinomas were negative. The DTDST gene was abundantly expressed in the upper crypt epithelium of colonic mucosa.

Expression of the anhidrotic ectodermal dysplasia gene is reduced in skin cancer coinciding with reduced E-cadherin.

X-linked anhidrotic ectodermal dysplasia (EDA) is characterized by defects in the development of hair, teeth, and sweat glands. We have recently cloned the gene for EDA by positional cloning. The EDA gene encodes a transmembrane protein with a putative role in epithelial mesenchymal interactions. Since EDA could play a role in cell-cell or cell-matrix adhesion, acantholytic skin diseases and several types of non-invasive and invasive skin cancers were studied using in situ hybridization. Because of the observation that the promoter region of the EDA gene contains a binding site for LEF-1, which is involved in the signaling through E-cadherin/beta catenin complex, we compared the expression of EDA with immunolocalization for E-cadherin (E-CD). EDA expression during hair growth cycle, in benign adnexal tumors, and neuroectoderm-derived nevus cells was also examined. Our findings indicate that EDA expression is less abundant in malignant tumors, including basal and squamous cell carcinomas and melanoma, and in acantholytic keratinocytes compared to normal epidermis. The reduction in expression also coincides with diminished E-CD staining in all malignant cell types and in acantholytic cells. Our results suggest that EDA protein functions in the regulation of epithelial cell contacts and that it may be associated with the E-CD signaling pathway.