Eosinophilic esophagitis and duodenal food challenge - evaluation through endoscopic confocal laser endomicroscopy.

BACKGROUND: Endoscopic confocal laser endomicroscopy (eCLE) is an established technique that allows clinical evaluation of mucosal integrity by fluorescein leaking through the mucosa upon duodenal food challenge (DFC). Analysis of eCLE with DFC in eosinophilic esophagitis (EoE) would be interesting to evaluate epithelial barrier dysfunction also in other regions of the gastrointestinal tract and to characterize potential individual food allergens that trigger the esophageal inflammation. METHODS: In an observational and proof of concept study we evaluated 9 patients with histologically proven EoE by eCLE and DFC. Severity of symptoms were graduated according to the validated symptom-based EoE activity index. The endoscopic appearance of the esophagus was described according to the Endoscopic Reference Score System (ERERS). Spontaneous and food induced transfer of fluorescein into duodenal lumen were detected 10 minutes following intravenously application of fluorescein and 10 minutes after DFC. Food allergens were yeast, egg, soy, milk, and wheat, respectively. Local application of sodium chloride solution 10 % to the duodenal mucosa before DFC served as a control. Patients responding to DFC received a dietary exclusion therapy according to the results of DFC. RESULTS: We investigated 9 patients with EoE (8 men, 49.7±13.8, 36-76 years). Symptom-based EoE activity index was 79±27.4, 33-100. In all patients EoE was confirmed by histology with number of esophageal mucosal eosinophilic granulocytes > 15/HPF, (91.4±77.4, 42-263). Mean ERERS score was 4.5±1.3, 3-7. None of the patients was aware of any food intolerance. eCLE revealed one patient with spontaneous transfer of i. v. fluorescein into duodenal lumen before DFC ("leaky gut"). 40 DFC were performed in the remaining 8 patients of whom 5 patients (61 %) responded to DFC. Rank order of fluorescein leakage upon DFC was wheat and milk in 37.5 % each, soy in 25 %, and egg in 12.5 %. The patients were treated by PPI (n=9), esophageal bouginage (n=5) and/or local corticoid therapy (n=3). The 5 patients responding to DFC received an additional food exclusion dietary advice focussed on the results of DFC. All patients reported a reduction of their symptoms. EoE activity indexes of patients with positive DFC were 73.7+28.6, 33-100 before and 22.7+37.9, 0-79 four weeks after food exclusion. CONCLUSION: The findings of our proof of concept study suggest that eCLE with DFC may be an interesting tool to further evaluate patients with EoE. This technique has the potential to identify patients who may benefit from an additional individual dietary therapy.

Gastrointestinal adverse reaction to food (GARF) and endoscopic confocal laser endomicroscopy (eCLE).

BACKGROUND AND STUDY AIMS: Gastrointestinal adverse reaction to food (GARF) is reported frequently in the general population and even more in patients with disorders of the gut brain axis. However, there is a significant difference between self-reported and objective proven GARF. The aim of the study was to characterize a mucosal correlate of GARF by endoscopic confocal laser endomicroscopy (eCLE) with duodenal food challenge (DFC). PATIENTS AND METHODS: In an observational and proof of concept study we evaluated 71 patients with disorders of the gut brain axis without (group I, n=19) and with (group II, n=52) GARF by eCLE and DFC. Spontaneous and food induced transfer of fluorescein into duodenal lumen was detected 10 minutes following intravenously application of fluorescein and 10 minutes after DFC. RESULTS: According to Rom IV, the patients (group I/II) could be classified as irritable bowel syndrome (IBS) 32%/31%, functional abdominal pain without changes in bowel movement 47 %/48 %, functional abdominal bloating/distension 0 %/10 %, functional diarrhea 5 %/ 2 %, and unspecified functional bowel disorder 16 %/10 %, respectively. 21 %/27 % of the patients responded with a fluorescein leakage into the duodenal lumen before and 74 %/69 % following to DFC. Frequency rank order of food components that induced a response were soy (55.5 %/60 %), wheat (60 %/45.5 %), egg (35.7 %/8.3), milk (30 %/18.2 %) and yeast (10 %/6.6 %), respectively. Histology of duodenal biopsies, number, form and distribution of intraepithelial lymphocytes and mucosal mast cells as well as mast cell function were normal. Overall, 14 %/79 % reported main symptom benefit following a food exclusion therapy according to eCLE and DFC that was significant different between the groups. CONCLUSION: The results of our study indicate that eCLE with DFC is a technique to clinically evaluate patients with disorders of the gut brain axis and GARF resulting in a high proportion of patients reporting symptom benefit upon food exclusion dietary advice focussed on the results of eCLE.

Endoscopic laser endomicroscopy and "leaky gut" in patients with functional gastrointestinal symptoms and food intolerance.

BACKGROUND: Intestinal epithelial barrier dysfunction ("leaky gut syndrome", LGS) is thought to play a major role in the pathogenesis of disorders of the gut brain axis. Endoscopic confocal laser endomicroscopy (eCLE) is an objective measure to test duodenal permeability. We applied this technique in patients with functional gastrointestinal symptoms and food intolerance to characterize the proportion of patients with LGS. MATERIAL AND METHODS: In an observational study, we evaluated 85 patients with functional gastrointestinal symptoms and food intolerance. Gastrointestinal symptoms were classified according to Rom IV into functional abdominal pain (FAP), irritable bowel syndrome (IBS), irritable bowel syndrome diarrhea dominant (IBS-D), irritable bowel syndrome constipation dominant (IBS-C), irritable bowel syndrome with mixed stool (IBS-M), functional abdominal bloating (FAB), functional diarrhea (FD) and unclassified (NC). During eCLE, spontaneous transfer of intravenously applied fluorescein into duodenal lumen (LGS) and following duodenal food challenge (DFC) were analyzed. Blood analysis comprised parameters of mast cell function, histology of duodenal mucosal biopsies analysis of mucosal inflammation, intraepithelial lymphocytes (IELs) as well as number, distribution and morphology of mast cells. RESULTS: 24 patients (9 IBS, 9 FAP, 3 FAB, 1 FD, 2 NC), showed LGS, 50 patients (14 IBS-D, 4 IBS-C, 3 IBS-M, 23 FAP, 3 FAB, 3 NC) had no LGS but responded to DFC and 11 patients (6 NC, 3 FAP, 1 FAB, 1 FD) had no LGS and no response to DFC. The proportion of subgroups with/or without spontaneous leakage of fluorescein (+LGS/-LGS) were IBS-LGS/IBS+LGS 67%/33%, FAP-LGS/FAP+LGS 72%/28%,FAB-LGS/FAB+LGS 50%/50%, NC-LGS/NC+LGS 60%/40%. Subgroup analysis revealed no significant differences for all parameters tested. CONCLUSION: As a proof of concept, the results of our study indicate that eCLE is a clinical useful tool to evaluate patients with disorders of the gut brain axis and those suspicious of LGS. However, the clinical significance of LGS remains unclear. The study should be an incentive to perform a randomized study including healthy controls.

Is CCL2 an Important Mediator of Mast Cell-Tumor Cell Interactions in Oral Squamous Cell Carcinoma?

In this study, we aimed to evaluate the influence of interactions between mast cells (MCs) and oral squamous cell carcinoma (OSCC) tumor cells on tumor proliferation and invasion rates and identify soluble factors mediating this crosstalk. To this end, MC/OSCC interactions were characterized using the human MC cell line LUVA and the human OSCC cell line PCI-13. The influence of an MC-conditioned (MCM) medium and MC/OSCC co-cultures on the proliferative and invasive properties of the tumor cells was investigated, and the most interesting soluble factors were identified by multiplex ELISA analysis. LUVA/PCI-13 co-cultures increased tumor cell proliferation significantly (p = 0.0164). MCM reduced PCI-13 cell invasion significantly (p = 0.0010). CC chemokine ligand 2 (CCL2) secretion could be detected in PCI-13 monocultures and be significantly (p = 0.0161) increased by LUVA/PCI-13 co-cultures. In summary, the MC/OSCC interaction influences tumor cell characteristics, and CCL2 could be identified as a possible mediator.

Verrucous carcinoma of the esophagus - a case report and literature review.

BACKGROUND: Verrucous carcinoma of the esophagus is a rare disease leading to dysphagia, chest pain, and weight loss. The diagnosis is difficult because even repeated biopsies are often without tumor evidence. We present a patient with verrucous carcinoma of the esophagus and a literature review. CASE REPORT: A 64-year-old patient with dysphagia and sore throat received esophagogastroduodenoscopy illustrating segmental circumferential verrucous inflammation and Candida esophagitis in the middle part of the esophagus. Repeated mucosal biopsies revealed reactive hyperkeratosis of the squamous epithelium with minimal atypia but without ulcera, eosinophilic esophagitis, or suspicion of cancer. Mucosal infection with adenovirus, herpes simplex virus 1, human papilloma virus types, and cytomegaly virus was ruled out. Veruccous carcinoma was detected finally by endoscopic mucosal resection. The patient was successfully treated by esophageal resection. Tumor stage was G1, pT1b, pN0, L0, V0, Pn0, R0. CONCLUSION: The results suggest that macroscopic suspicion of verrucous esophageal carcinoma should lead to resections of larger tissue specimens by EMR to confirm the diagnosis.

Eosinophilic esophagitis and achalasia - just a coincidence?

BACKGROUND: Eosinophilic esophagitis (EoE) is detected frequently in dysphagia and noncardiac chest pain. Management of patients with EoE may be complicated because EoE is associated frequently with esophageal motility disorders. We present the rare case of esophageal achalasia (EA) associated with eosinophilic infiltration and a literature review. MATERIAL AND METHODS: A patient with dysphagia and eosinophilic infiltration referred to our clinic underwent standardized diagnostic work-up including symptom questionnaire, esophagogastroduodenoscopy (EGD) with esophageal biopsies, barium swallow, high-resolution esophageal manometry, and combined intraluminal 24-hour pH-impedance testing (pH/MII). RESULTS: The patient had an Eckardt score of 8. EGD and mucosal biopsies showed typical EoE with > 15 eosinophil leucocytes per high-power field. Barium swallow revealed typical sign of achalasia. HREM indicated EA type 2 according to the Chicago classification. PH/MII was normal. Oral and systemic corticoid therapy were without effect. After successful treatment by pneumatic dilation of the cardia, symptoms relieved and eosinophilic infiltration returned to normal. CONCLUSION: The results suggest that the patient had primary EA associated with eosinophilic infiltration and that the combined occurrence of these rare diseases is not just a coincidence.

Food intolerance in patients with functional abdominal pain: Evaluation through endoscopic confocal laser endomicroscopy.

Background and study aims Gastrointestinal symptoms assumed to be caused by food intolerance are reported frequently in the general population. There is a significant difference between self-reported and objective proven food intolerance, as shown by placebo-controlled, double-blind, randomized trials. This discrepancy may be overcome by endoscopic confocal laser endomicroscopy (eCLE). Patients and methods In an observational study we evaluated 34 patients with functional abdominal pain and adverse reaction to food by eCLE and local duodenal food challenge for the first time. Spontaneous and food-induced transfer of fluorescein into the duodenal lumen was detected 10 minutes after intravenously application of fluorescein and 10 minutes after duodenal food challenge (DFC). Results Of the patients, 67.6 % responded with a fluorescein leakage into the duodenal lumen. Frequency rank order of food antigens that induced a response were soy (50 %), wheat (46.1 %), milk (20 %), egg (12 %), and yeast (11.5 %), respectively. Of the patients, 23.5 % showed spontaneous leakage of fluorescein, suggesting leaky gut syndrome. Histology of duodenal biopsies and mast cell function were normal. Overall, 69.5 % of patients improved with food exclusion therapy and 13 % were symptom-free according to eCLE. Conclusions The results of our study indicate that eCLE is a clinically useful tool to evaluate patients with functional abdominal pain and adverse reaction to food and to create individualized dietary therapy with clinical benefit for patients.

N-cadherin expression in malignant germ cell tumours of the testis.

BACKGROUND: Testicular germ cell tumours (TGCTs) are the most common malignancy in young men aged 18-35 years. They are clinically and histologically subdivided into seminomas and non-seminomas. Cadherins are calcium-dependent transmembrane proteins of the group of adhesion proteins. They play a role in the stabilization of cell-cell contacts, the embryonic morphogenesis, in the maintenance of cell polarity and signal transduction. N-cadherin (CDH2), the neuronal cadherin, stimulates cell-cell contacts during migration and invasion of cells and is able to suppress tumour cell growth. METHODS: Tumour tissues were acquired from 113 male patients and investigated by immunohistochemistry, as were the three TGCT cell lines NCCIT, NTERA-2 and Tcam2. A monoclonal antibody against N-cadherin was used. RESULTS: Tumour-free testis and intratubular germ cell neoplasias (unclassified) (IGCNU) strongly expressed N-cadherin within the cytoplasm. In all seminomas investigated, N-cadherin expression displayed a membrane-bound location. In addition, the teratomas and yolk sac tumours investigated also differentially expressed N-cadherin. In contrast, no N-cadherin could be detected in any of the embryonal carcinomas and chorionic carcinomas examined. This expression pattern was also seen in the investigated mixed tumours consisting of seminomas, teratomas, and embryonal carcinoma. CONCLUSIONS: N-cadherin expression can be used to differentiate embryonal carcinomas and chorionic carcinomas from other histological subtypes of TGCT.

Loss of inducible nitric oxide synthase expression in the mouse renal cell carcinoma cell line RENCA is mediated by microRNA miR-146a.

Tumor-associated macrophages can potentially kill tumor cells via the high concentrations of nitric oxide (NO) produced by inducible nitric oxide synthase (iNOS); however, tumor-associated macrophages actually support tumor growth, as they are skewed toward M2 activation, which is characterized by low amounts of NO production and is proangiogenic. We show that the mouse renal cell carcinoma cell line, RENCA, which, on stimulation, expresses high levels of iNOS mRNA, loses its ability to express the iNOS protein. This effect is mediated by the microRNA miR-146a, as inhibition of RENCA cells with anti-miR- 146a restores iNOS expression and NO production (4.8 ± 0.4 versus 0.3 ± 0.1 µmol/L in uninhibited cells, P < 0.001). In vivo, RENCA tumor cells do not stain for iNOS, while infiltrating tumor-associated macrophages showed intense staining, and both cell types expressed iNOS mRNA. Restoring iNOS protein expression in RENCA cells using anti-miR-146a increases macrophage-induced death of RENCA cells by 73% (P < 0.01) in vitro and prevents tumor growth in vivo. These results suggest that, in addition to NO production by macrophages, tumor cells must produce NO to induce their own deaths, and some tumor cells may use miR-146a to reduce or abolish endogenous NO production to escape macrophage-mediated cell death. Thus, inhibiting miR-146a may render these tumor cells susceptible to therapeutic strategies, such as adoptive transfer of M1-activated macrophages.

Contralateral metastasis of parotid gland in advanced breast cancer with peripheral facial paralysis.

PURPOSE: Malignant tumors of the parotid gland are very rare. Until now there have only been a few reported cases of patients with distant metastasis of breast cancer in the parotid gland. This case shows the rarity of the disease. METHODS: This case is about a 74-year-old woman with an invasive lobular carcinoma of the left breast. The initial diagnosis was made four years ago. The operation which was done was a quadrantectomy and axillary lymph node dissection. It was followed by radiotherapy of the breast. The recommended chemotherapy was declined by the patient. RESULTS: Three years after the initial diagnosis of lobular invasive breast cancer a nodular change in the cicatrice of the mastectomy occurred. The patient also had a contralateral peripheral facial paralysis, caused by a distant metastasis in the right parotid gland. CONCLUSIONS: When there is a tumor in the parotid gland and a histological classified adenocarcinoma is found, the differential diagnosis of breast cancer metastasis should be considered.

Molecular pathology as a diagnostic aid in difficult-to-classify melanocytic tumours with spitzoid morphology.

Accurate classification of melanocytic proliferations has important implications for prognostic prediction, treatment and follow-up. Although most melanocytic proliferations can be accurately classified using clinical and pathological criteria, classification (specifically distinction between nevus and melanoma) can be challenging in a subset of cases, including those with spitzoid morphology. Genetic studies have shown that mutation profiles differ between primary melanoma subtypes and Spitz nevi. These differences may aid in distinguishing benign from malignant in some melanocytic tumours. Here, we present a selection of melanocytic proliferations with equivocal histopathological criteria, wherein genetic analysis was requested to help guide classification. In two of four cases, the genetic results offered valuable insights, allowing a definitive diagnosis, indicating the diagnostic value of mutation profiling in a real-world routine clinical setting. Although histopathological assessment remains decisive in melanocytic proliferation classification, we recommend including genetic profiling in cases of borderline or atypical lesion to support accurate classification.

Tumor-associated macrophages in clear cell renal cell carcinoma express both gastrin-releasing peptide and its receptor: a possible modulatory role of immune effectors cells.

PURPOSE: Renal cell carcinomas (RCC) frequently express the gastrin-releasing peptide receptor (GRP-R). Gastrin-releasing peptide (GRP) stimulates tumor cell proliferation and neoangiogenesis. Tumor-associated macrophages (TAM) comprise an important cellular component of these tumors. We analyzed the GRP/GRP-R network in clear cell RCC (ccRCC) and non-clear cell RCC (non-ccRCC) with special regard to its expression by macrophages, tumor cells and microvessels. METHODS: Gastrin-releasing peptide and GRP-R expression in 17 ccRCC and 9 non-ccRCC were analyzed by RT-PCR, immunohistochemistry and double immunofluorescence staining. RESULTS: Tumor-associated macrophages expressed GRP and GRP receptor in ccRCC. Tumor cells and microvessels showed low to intermediate GRP-R expression in nearly all cases. In 12 ccRCC tumor epithelia also expressed low levels of GRP. Microvascular GRP expression was found in nine cases of ccRCC. For non-RCC, the expression of GRP and GRP receptor expression pattern was similar. CONCLUSIONS: Tumor-associated macrophages are the main source of GRP in RCC. GRP receptor on TAM, tumor epithelia and microvessels might be a molecular base of a GRP/GRP receptor network, potentially acting as a paracrine/autocrine modulator of TAM recruitment, tumor growth and neoangiogenesis.

Generation of functional cardiomyocytes from adult mouse spermatogonial stem cells.

Stem cell-based therapy is a promising approach for the treatment of heart failure. Adult stem cells with the pluripotency of embryonic stem cells (ESCs) would be an ideal cell source. Recently, we reported the successful establishment of multipotent adult germline stem cells (maGSCs) from mouse testis. These cultured maGSCs show phenotypic characteristics similar to ESCs and can spontaneously differentiate into cells from all 3 germ layers. In the present study, we used the hanging drop method to differentiate maGSCs into cardiomyocytes and analyzed their functional properties. Differentiation efficiency of beating cardiomyocytes from maGSCs was similar to that from ESCs. The maGSC-derived cardiomyocytes expressed cardiac-specific L-type Ca(2+) channels and responded to Ca(2+) channel-modulating drugs. Cx43 was expressed at cell-to-cell contacts in cardiac clusters, and fluorescence recovery after photobleaching assay showed the presence of functional gap junctions among cardiomyocytes. Action potential analyses demonstrated the presence of pacemaker-, ventricle-, atrial-, and Purkinje-like cardiomyocytes. Stimulation with isoproterenol resulted in a significant increase in beating frequency, whereas the addition of cadmium chloride abolished spontaneous electrical activity. Confocal microscopy analysis of intracellular Ca(2+) in maGSC-derived cardiomyocytes showed that calcium increased periodically throughout the cell in a homogenous fashion, pointing to a fine regulated Ca(2+) release from intracellular Ca(2+) stores. By using line-scan mode, we found rhythmic Ca(2+) transients. Furthermore, we transplanted maGSCs into normal hearts of mice and found that maGSCs were able to proliferate and differentiate. No tumor formation was found up to 1 month after cell transplantation. Taken together, we believe that maGSCs provide a new source of distinct types of cardiomyocytes for basic research and potential therapeutic application.

Leupaxin, a novel coactivator of the androgen receptor, is expressed in prostate cancer and plays a role in adhesion and invasion of prostate carcinoma cells.

In the present study, we demonstrate that leupaxin mRNA is overexpressed in prostate cancer (PCa) as compared with normal prostate tissue by using cDNA arrays and quantitative RT-PCR analyses. Moderate to strong expression of leupaxin protein was detected in approximately 22% of the PCa tissue sections analyzed, and leupaxin expression intensities were found to be significantly correlated with Gleason patterns/scores. In addition, different leupaxin expression levels were observed in PCa cell lines, and at the subcellular level, leupaxin was usually localized in focal adhesion sites. Furthermore, mutational analysis and transfection experiments of LNCaP cells using different green fluorescent protein-leupaxin constructs demonstrated that leupaxin contains functional nuclear export signals in its LD3 and LD4 motifs, thus shuttling between the cytoplasm and the nucleus. We could also demonstrate for the first time that leupaxin interacts with the androgen receptor in a ligand-dependent manner and serves as a transcriptional activator of this hormone receptor in PCa cells. Down-regulation of leupaxin expression using RNA interference in LNCaP cells resulted in a high rate of morphological changes, detachment, spontaneous apoptosis, and a reduction of prostate-specific antigen secretion. In contrast, knockdown of leupaxin expression in androgen-independent PC-3 and DU 145 cells induced a significant decrease of both the invasive capacity and motility. Our results therefore indicate that leupaxin could serve as a potential progression marker for a subset of PCa and may represent a novel coactivator of the androgen receptor. Leupaxin could function as a putative target for therapeutic interventions of a subset of advanced PCa.

Generation of highly differentiated BHY oral squamous cell carcinoma multicellular spheroids.

Three-dimensional (3D) multicellular spheroids (MCS) are considered suitable models in cancer research and anticancer drug development. Although studying the complex tumour characteristics from all different degrees of malignancy is vital, MCS generation has only been described in a few moderately- and poorly differentiated oral squamous cell carcinoma (OSCC) cell lines. No previous study has demonstrated the MCS formation in a highly differentiated OSCC cell line. For the first time, the present study aimed to generate MCS from the highly differentiated OSCC cell line BHY. BHY spheroids were grown in three independent experiments in 96-well plates through the use of the liquid overlay technique. Although BHY cells are grow slowly and are difficult to culture, they formed compact MCS within 24 h. After 3 days of incubation, no further increase in spheroid size was observed. MCS were harvested, paraffin-embedded and 2 µm tissue sections were prepared for further analysis. The diameter and volume of each spheroid were determined. BHY MCS diameter ranged between 46.76 and 233.26 µm, with a volume range from 5.35×104-6.65×106 µm3. In conclusion, using the liquid overlay technique, the highly differentiated OSCC cell line BHY forms different sized spheroids, which may be used for further investigations.

High mast cell density indicates a longer overall survival in oral squamous cell carcinoma.

This study evaluates the effects of tumour-associated mast cells on the prognosis of patients suffering from oral squamous cell carcinoma (OSCC). Tryptase-positive (MCT+) and CD117-positive (CD117+) mast cells were immunohistochemically evaluated in tissue samples of 118 OSCC patients. Besides, various clinicopathological parameters, the influence of the MCT+ and CD117+ mast cell density on overall survival and the incidence of first local recurrence was analysed by Cox regression and competing risk regression. Among all investigated parameters, multiple Cox regression revealed a significant influence of the MCT+ (cut-off at 14.87 mast cells/mm2 stroma; p = 0.0027) and CD117+ mast cell density (cut-off at 33.19 mast cells/mm2 stroma; p = 0.004), the age at primary diagnosis, and the T and N stage (all p-values < 0.05) on overall survival. Patients with a low mast cell density showed a significantly poorer overall survival rate compared to those with a high mast cell density in the tumour-associated stroma. Competing risk regression revealed a significant influence of the resection status (R) on the incidence of first local recurrence (p = 0.0023). A high mast cell density in the tumour-associated stroma of oral squamous cell carcinoma indicates a longer patient survival.

Overexpression of Eag1 potassium channels in clinical tumours.

BACKGROUND: Certain types of potassium channels (known as Eag1, KCNH1, Kv10.1) are associated with the production of tumours in patients and in animals. We have now studied the expression pattern of the Eag1 channel in a large range of normal and tumour tissues from different collections utilising molecular biological and immunohistochemical techniques. RESULTS: The use of reverse transcription real-time PCR and specifically generated monoclonal anti-Eag1 antibodies showed that expression of the channel is normally limited to specific areas of the brain and to restricted cell populations throughout the body. Tumour samples, however, showed a significant overexpression of the channel with high frequency (up to 80% depending on the tissue source) regardless of the detection method (staining with either one of the antibodies, or detection of Eag1 RNA). CONCLUSION: Inhibition of Eag1 expression in tumour cell lines reduced cell proliferation. Eag1 may therefore represent a promising target for the tailored treatment of human tumours. Furthermore, as normal cells expressing Eag1 are either protected by the blood-brain barrier or represent the terminal stage of normal differentiation, Eag1 based therapies could produce only minor side effects.

CD45 monoclonal antibody-mediated cytolysis of human NK and T lymphoma cells.

BACKGROUND AND OBJECTIVES: The CD45 rat monoclonal IgG2b antibodies YTH24.5 and YTH54.12 act synergistically to produce cytolysis of normal lymphocytes and have been safely given to patients in conditioning regimens for allogeneic stem cell transplantation. The antibodies are not lytic for hematopoietic stem cells, but the depletion of the lymphoid lineage cells is profound and sustained. DESIGN AND METHODS: We evaluated the YTH24.5 and YTH54.12 pair for complement-dependent cytotoxicity (CDC), antibody-dependent cell-mediated cytotoxicity (ADCC), and apoptotic and antiproliferative effects against a panel of non-Hodgkin's lymphoma (NHL) cell lines and against primary specimens. RESULTS: Significant CDC activity was observed against two of two NK and one of four T lymphoma cell lines; moderate activity was seen against two of four T, and four of eight B lymphoma cell lines. In the responding cell lines, the lytic activity of YTH24.5 and YTH54.12 was as least as strong as that of alemtuzumab or antithymocyte globulin. The combination of YTH24.5 and YTH54.12 also induced ADCC in one of two NK and two of four T lymphoma cell lines, as well as three primary specimens, but was ineffective in B-NHL. The antibodies decreased viability in two of two NK and one lymphoma cell line, measurable as apoptosis or direct cell death in the cell lines NK92 and CEM, respectively. In a tumor model of Jurkat lymphoma in SCID mice, administration of YTH24.5 and YTH54.12 impaired local tumor growth and delayed systemic disease progression. INTERPRETATION AND CONCLUSIONS: CD45 antibodies YTH24.5 and YTH54.12 have lytic activity against NK and T lymphoma cells via CDC and ADCC, are effective in a preclinical tumor model, and may be candidates for immunotherapeutic approaches to the treatment of human NK and T cell lymphoma.

Models of monocytic invasion into glioma cell aggregates.

BACKGROUND: In order to investigate why human gliomas are abundantly infiltrated by monocytic cells without signs of antitumor activity, experimental models were established in vitro and in vivo. MATERIALS AND METHODS: Peripheral human blood monocytes were added to A172 or U118 glioma cell spheroids and probes analyzed after 72 h by immunohistochemistry. Fluorescence-labelled peritoneal macrophages were administered to syngeneic RG2-glioma-bearing Fischer rats by intravenous or intracarotid injection. RESULTS: Spheroids of both cell lines were infiltrated by monocytes, which took on a chronic inflammatory phenotype with co-expression of MRP8 and MAC 387/MRP14 and positivity to 25F9, but not to 27E10. After both intra-arterial and intravenous injection, labelled monocytes accumulated within the tumor parenchyma of the rat gliomas, while the surrounding brain was only sparsely infiltrated. CONCLUSION: The experimental models described here allow for further investigation of the interactions between monocytes and glioma cells, both in vitro and in vivo. Moreover, monocytes that infiltrate from the peripheral blood into brain tumors may serve as carriers for targeted therapies.