Microenvironment-induced restoration of cohesive growth associated with focal activation of P-cadherin expression in lobular breast carcinoma metastatic to the colon.

Invasive lobular carcinoma (ILC) is a special breast cancer type characterized by noncohesive growth and E-cadherin loss. Focal activation of P-cadherin expression in tumor cells that are deficient for E-cadherin occurs in a subset of ILCs. Switching from an E-cadherin deficient to P-cadherin proficient status (EPS) partially restores cell-cell adhesion leading to the formation of cohesive tubular elements. It is unknown what conditions control EPS. Here, we report on EPS in ILC metastases in the large bowel. We reviewed endoscopic colon biopsies and colectomy specimens from a 52-year-old female (index patient) and of 18 additional patients (reference series) diagnosed with metastatic ILC in the colon. EPS was assessed by immunohistochemistry for E-cadherin and P-cadherin. CDH1/E-cadherin mutations were determined by next-generation sequencing. The index patient's colectomy showed transmural metastatic ILC harboring a CDH1/E-cadherin p.Q610* mutation. ILC cells displayed different growth patterns in different anatomic layers of the colon wall. In the tunica muscularis propria and the tela submucosa, ILC cells featured noncohesive growth and were E-cadherin-negative and P-cadherin-negative. However, ILC cells invading the mucosa formed cohesive tubular elements in the intercryptal stroma of the lamina propria mucosae. Inter-cryptal ILC cells switched to a P-cadherin-positive phenotype in this microenvironmental niche. In the reference series, colon mucosa infiltration was evident in 13 of 18 patients, one of which showed intercryptal EPS and conversion to cohesive growth as described in the index patient. The large bowel is a common metastatic site in ILC. In endoscopic colon biopsies, the typical noncohesive growth of ILC may be concealed by microenvironment-induced EPS and conversion to cohesive growth.

Noninferiority of Artificial Intelligence-Assisted Analysis of Ki-67 and Estrogen/Progesterone Receptor in Breast Cancer Routine Diagnostics.

Image analysis assistance with artificial intelligence (AI) has become one of the great promises over recent years in pathology, with many scientific studies being published each year. Nonetheless, and perhaps surprisingly, only few image AI systems are already in routine clinical use. A major reason for this is the missing validation of the robustness of many AI systems: beyond a narrow context, the large variability in digital images due to differences in preanalytical laboratory procedures, staining procedures, and scanners can be challenging for the subsequent image analysis. Resulting faulty AI analysis may bias the pathologist and contribute to incorrect diagnoses and, therefore, may lead to inappropriate therapy or prognosis. In this study, a pretrained AI assistance tool for the quantification of Ki-67, estrogen receptor (ER), and progesterone receptor (PR) in breast cancer was evaluated within a realistic study set representative of clinical routine on a total of 204 slides (72 Ki-67, 66 ER, and 66 PR slides). This represents the cohort with the largest image variance for AI tool evaluation to date, including 3 staining systems, 5 whole-slide scanners, and 1 microscope camera. These routine cases were collected without manual preselection and analyzed by 10 participant pathologists from 8 sites. Agreement rates for individual pathologists were found to be 87.6% for Ki-67 and 89.4% for ER/PR, respectively, between scoring with and without the assistance of the AI tool regarding clinical categories. Individual AI analysis results were confirmed by the majority of pathologists in 95.8% of Ki-67 cases and 93.2% of ER/PR cases. The statistical analysis provides evidence for high interobserver variance between pathologists (Krippendorff's α, 0.69) in conventional immunohistochemical quantification. Pathologist agreement increased slightly when using AI support (Krippendorff α, 0.72). Agreement rates of pathologist scores with and without AI assistance provide evidence for the reliability of immunohistochemical scoring with the support of the investigated AI tool under a large number of environmental variables that influence the quality of the diagnosed tissue images.

Classification of Pancreatic Ductal Adenocarcinoma Using MALDI Mass Spectrometry Imaging Combined with Neural Networks.

Despite numerous diagnostic and therapeutic advances, pancreatic ductal adenocarcinoma (PDAC) has a high mortality rate, and is the fourth leading cause of cancer death in developing countries. Besides its increasing prevalence, pancreatic malignancies are characterized by poor prognosis. Omics technologies have potential relevance for PDAC assessment but are time-intensive and relatively cost-intensive and limited by tissue heterogeneity. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can obtain spatially distinct peptide-signatures and enables tumor classification within a feasible time with relatively low cost. While MALDI-MSI data sets are inherently large, machine learning methods have the potential to greatly decrease processing time. We present a pilot study investigating the potential of MALDI-MSI in combination with neural networks, for classification of pancreatic ductal adenocarcinoma. Neural-network models were trained to distinguish between pancreatic ductal adenocarcinoma and other pancreatic cancer types. The proposed methods are able to correctly classify the PDAC types with an accuracy of up to 86% and a sensitivity of 82%. This study demonstrates that machine learning tools are able to identify different pancreatic carcinoma from complex MALDI data, enabling fast prediction of large data sets. Our results encourage a more frequent use of MALDI-MSI and machine learning in histopathological studies in the future.

Inter-observer agreement for the histological diagnosis of invasive lobular breast carcinoma.

Invasive lobular breast carcinoma (ILC) is the second most common breast carcinoma (BC) subtype and is mainly driven by loss of E-cadherin expression. Correct classification of BC as ILC is important for patient treatment. This study assessed the degree of agreement among pathologists for the diagnosis of ILC. Two sets of hormone receptor (HR)-positive/HER2-negative BCs were independently reviewed by participating pathologists. In set A (61 cases), participants were provided with hematoxylin/eosin (HE)-stained sections. In set B (62 cases), participants were provided with HE-stained sections and E-cadherin immunohistochemistry (IHC). Tumor characteristics were balanced. Participants classified specimens as non-lobular BC versus mixed BC versus ILC. Pairwise inter-observer agreement and agreement with a pre-defined reference diagnosis were determined with Cohen's kappa statistics. Subtype calls were correlated with molecular features, including CDH1/E-cadherin mutation status. Thirty-five pathologists completed both sets, providing 4,305 subtype calls. Pairwise inter-observer agreement was moderate in set A (median κ = 0.58, interquartile range [IQR]: 0.48-0.66) and substantial in set B (median κ = 0.75, IQR: 0.56-0.86, p < 0.001). Agreement with the reference diagnosis was substantial in set A (median κ = 0.67, IQR: 0.57-0.75) and almost perfect in set B (median κ = 0.86, IQR: 0.73-0.93, p < 0.001). The median frequency of CDH1/E-cadherin mutations in specimens classified as ILC was 65% in set A (IQR: 56-72%) and 73% in set B (IQR: 65-75%, p < 0.001). Cases with variable subtype calls included E-cadherin-positive ILCs harboring CDH1 missense mutations, and E-cadherin-negative ILCs with tubular elements and focal P-cadherin expression. ILCs with trabecular growth pattern were often misclassified as non-lobular BC in set A but not in set B. In conclusion, subtyping of BC as ILC achieves almost perfect agreement with a pre-defined reference standard, if assessment is supported by E-cadherin IHC. CDH1 missense mutations associated with preserved E-cadherin protein expression, E- to P-cadherin switching in ILC with tubular elements, and trabecular ILC were identified as potential sources of discordant classification.

Classification of Inflammatory Bowel Disease from Formalin-Fixed, Paraffin-Embedded Tissue Biopsies via Imaging Mass Spectrometry.

PURPOSE: Discrimination between ulcerative colitis (UC) and Crohn's disease (CD) by histologic features alone can be challenging and often leads to inaccurate initial diagnoses in inflammatory bowel disease (IBD) patients. This is mostly due to an overlap of clinical and histologic features. However, exact diagnosis is not only important for patient treatment but it also has a socioeconomic impact. It is therefore important to develop and improve diagnostic tools complementing traditional histomorphological approaches. EXPERIMENTAL DESIGN: In this retrospective proof-of-concept study, the utilization of MALDI imaging is explored in combination with multi-variate data analysis methods to classify formalin-fixed, paraffin-embedded (FFPE) colon biopsies from UC (87 biopsies, 14 patients), CD (71 biopsies, 14 patients), and normal colonic (21 biopsies, 14 patients) tissues. RESULTS: The proposed method results in an overall balanced accuracy of 85.7% on patient and of 80.4% on sample level, thus demonstrating that the assessment of IBD from FFPE tissue specimens via MALDI imaging is feasible. CONCLUSIONS AND CLINICAL RELEVANCE: The results emphasize the high potential of this method to distinguish IBD subtypes in FFPE tissue sections, which is a prerequisite for further investigations in retrospective multicenter studies, as well as for a future implementation into clinical routine.

Isolated Intraocular Rosai-Dorfman Disease.

BACKGROUND/AIMS: To report a case of Rosai-Dorfman disease (RDD) presenting as a solitary, choroidal mass, initially suspicious for uveal melanoma, in a 72-year-old woman. METHODS: Retrospective case report of a single patient. RESULTS: A 72-year-old woman presented with sudden vision loss in the right eye. A month prior, visual acuity was 20/40, but she was noted to have a choroidal mass confirmed with B-scan ultrasonography. Patient's vision deteriorated significantly a month later and a shallow retinal detachment was newly noted. Magnetic resonance imaging was obtained, demonstrating a hyperintense intraocular tumor on TI imaging. Patient underwent enucleation of the right eye for suspicion of a uveal melanoma. Pathology revealed a mixed cellular infiltrate with histiocytes, some exhibiting emperipolesis. Macrophage immunohistochemical stains were positive, while melanocytic markers were negative. A diagnosis of RDD was made. Subsequently, the patient had a negative workup for systemic involvement. A final diagnosis of intraocular RDD without extraocular and systemic involvement was determined. CONCLUSION: We describe a rare presentation of RDD as a solitary choroidal mass in an elderly patient with overlapping features of uveal melanoma. Definitive diagnosis could only be made on histology. RDD should be considered in the differential diagnosis of a choroidal lesion in the elderly.

The EndoRotor(®): endoscopic mucosal resection system for non-thermal and rapid removal of esophageal, gastric, and colonic lesions: initial experience in live animals.

BACKGROUND AND STUDY AIMS: The EndoRotor(®) is a novel, non-thermal, automated mechanical endoscopic resection system designed to remove benign mucosal neoplastic tissue throughout the gastrointestinal tract. It uses suction pressure to pull in mucosa and rapidly and precisely cut it while automatically transporting the samples to a collection trap for later histologic evaluation. PATIENTS AND METHODS: To study the technical properties and therapeutic potential of this new tool, we performed multiple upper and lower gastrointestinal endoscopic mucosal resections in three healthy live pigs. Animals were anesthetized and kept artificially ventilated while two physicians performed multiple qualitative mucosal resections on various sites of the pigs' esophagus, stomach, duodenum, and colon. RESULTS: Rapid resection of flat and slightly elevated mucosa up to several centimeters in size/diameter was performed. No major bleeding occurred during and after resections. When used properly, no gastrointestinal wall perforations occurred during superficial resections. Perforations in the colon were only observed when the device was deliberately pushed against deeper sub-mucosal layers or when exceptional force was applied to penetrate the gastrointestinal wall. Histologic specimens showed complete mucosal removal at resection sites. The flexible catheter could be moved and directed towards most of the areas of interest in the gastrointestinal tract. CONCLUSION: The EndoRotor rapidly and easily resects flat and slightly elevated gastrointestinal mucosa with a short learning curve. Future studies in humans should be performed to prove its ability for large-area mucosal resections in benign conditions such as laterally spreading adenomas in the colon, or Barrett's mucosa in the distal esophagus.

Multicenter randomized controlled trial comparing the performance of 22 gauge versus 25 gauge EUS-FNA needles in solid masses.

BACKGROUND AND AIMS: Few randomized studies have assessed the clinical performance of 25-gauge (25G) needles compared with 22-gauge (22G) needles during endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) biopsy of intra-abdominal lesions. We aimed to compare the diagnostic yield, as well as performance characteristics of 22G versus 25G EUS biopsy needles by determining their diagnostic capabilities, the number of needle passes as well as cellularity of aspirated tissue specimen. METHODS: The study is a prospective, randomized, multicenter study. Patients were referred between January 2009 and January 2010 for diagnostic EUS including EUS-guided FNA of different lesions adjacent to the upper GI tract. All patients were randomized to EUS-FNA performed with either a 22G or 25G aspiration needle. RESULTS: EUS-FNA was performed in 135 patients (62 patients with a 22G needle). Sensitivity and specificity of the 22G needle was 94.1% and 95.8%, respectively, and for the 25G needle 94.1% and 100%, respectively. Investigators reported better visualization and performance for the 22G needle compared to the 25G (p < 0.0001). The number of tissue slides obtained was higher for the 22G needle during the second and third needle passes (p < 0.05). We did not observe significant differences between the number and preservation status of obtained cells (p > 0.05). CONCLUSIONS: A significant difference was found between the two types of needles in terms of reduced visualization of the 25G needle and suboptimal performance rating. However, this did not impact on overall results since both needles were equally successful in terms of a high diagnostic yield and overall accuracy.

Impact of single-dose application of TGF-ß, copper peptide, stanozolol and ascorbic acid in hydrogel on midline laparatomy wound healing in a diabetic mouse model.

Despite numerous advances and improvements in surgical techniques the incidence of incisional hernias after laparotomy remains high. The aim of this study was to investigate possible effects of single application of ascorbic acid, stanozolol, a synthetic anabolic steroid, copper peptide and transforming growth factor-ß (TGF-ß) on laparotomy wound healing in an incisional wound model in diabetic mice. After diabetes induction with streptozotozin in Balb-c mice, midline laparatomies were carried out. Closure of the linea alba was followed by single-dose application of the agents dissolved in a hydrogel before skin closure. The functional outcome was assessed in terms of maximum tensile strength. In addition, vessel densities, collagen contents and proliferation, were measured. The breaking strength of the skin 14 days after surgery was significantly higher in ascorbic acid (ΑΑ)-treated incisional wounds, whereas the other agents did not show a significantly better functional outcome. No significant differences were seen in vessel densities. Collagen type III contents was higher in the ΑΑ-treated animals, whereas the percentage of Ki67-positive nuclei was lower compared to the other groups. These data underline the positive effect of topically applied ascorbic acid in wound healing.

Priming with a combination of proangiogenic growth factors enhances wound healing in streptozotocin-induced diabetes in mice.

BACKGROUND: Numerous proangiogenic growth factors have been shown to improve impaired wound healing. This study evaluated the effects of subcutaneous pretreatment with a combination of proangiogenic growth factors on wound closure, mechanical properties, vessel density, and morphology. METHODS: Thirty-six Balb/c mice with streptozotocin-induced diabetes were divided into 3 groups. A mixture of VEGF (35.0 µg), bFGF (2.5 µg), and PDGF (3.5 µg) was administered subcutaneously 3, 5, and 7 days prior to wounding in the first group, whereas the second group received three doses of 3.5 µg PDGF. Wound sizes were assessed daily and the repaired tissues were harvested 7 days after wound closure. RESULTS: Complete closure (≥95% healing of initial wound area) was reached in all proangiogenic pretreated animals by day 17, whereas the PDGF monotherapy group needed up to 20 days for complete closure. By the time of tissue harvesting on day 24, complete closure was not reached in all control animals. Punch biopsy material revealed 1.6-fold higher vessel densities in the proangiogenic combination-pretreated group than in the controls. CONCLUSIONS: Proangiogenic priming revealed several significant effects on diabetic wound healing: faster time to closure, a higher vessel density, and improved functional outcome.

Priming with a combination of proangiogenic growth factors improves wound healing in normoglycemic mice.

Growth factors and/or angiogenic factors are supposed to improve wound healing. The aim of our study was to evaluate the effects of subcutaneous pretreatment with combinatory proangiogenic factors on wound closure, mechanical properties, vessel density and morphology. Twenty-eight Balb/c mice were divided equally into two groups. A mixture of VEGF (35.0 µg), bFGF (2.5 µg) and PDGF (3.5 µg) was administered subcutaneously 3, 5 and 7 days to 14 mice before full thickness skin punch biopsy wounding, whereas 14 control animals received three injections of 0.2 ml saline solution. Wound sizes were assessed daily and the repaired tissues were harvested 7 days after complete wound closure. Complete closure (≥ 95% healing of initial wound area) was reached in all proangiogenic pretreated animals on day 10, whereas controls needed 13 days for complete closure. Tensile strengths were nearly twofold higher compared to the controls (p ≤ 0.01). The punch biopsy material revealed 4.2-fold higher vessel densities in the proangiogenic pretreated group. On day 17, the vessel densities in the proangiogenic pretreated wounds were also 3.2-fold higher compared to the untreated controls. No significant differences were seen in the collagen ratio. Pretreatment with proangiogenic factors revealed several significant effects on wound healing: faster time to closure, a higher vessel density and a better functional outcome. These results suggest a beneficial effect of pretreatment with combinatory growth factors in mouse skin wounds without impaired wound healing. This might be exploited in further investigations in diabetic healing as a therapeutic approach for elective surgery.

MALDI imaging as a specific diagnostic tool for routine cervical cytology specimens.

Cervical squamous cell carcinoma (SCC) is among the most common malignancies in women worldwide. In developed countries routine cytology screening has dramatically reduced SCC mortality within the last three decades. High risk (HR) human papilloma virus (HPV) infection is the main causal factor in nearly 100% of invasive SCCs, in most cases of low grade squamous intraepithelial lesion (LSIL) and in nearly all cases of high grade squamous intraepithelial lesion (HSIL). Detection of HR-HPV DNA has been extensively evaluated for the triage of patients with low grade cytological abnormalities in order to identify those at greatest risk for underlying or developing HSIL or SCC. However, the vast majority of HR-HPV-positive precursor lesions will not progress to invasive cancer. A variety of other screening tools are available which aim to stratify clinically significant HPV infections and cytological alterations. Matrix assisted laser desorption/ionization (MALDI) imaging mass spectrometry is a promising technology to assist in this endeavor. It delivers accurate mass spectrometric information of the sample's proteins and enables the visualization of the spatial distribution of protein expression profiles in correlation with histological features. In this study, 18 samples with Pap IIID or higher (>LSIL) and 14 samples with Pap I-II (WNL) were analyzed by MALDI imaging mass spectrometry (IMS). A genetic algorithm was applied to classify spectra resulting in an overall cross validation, sensitivity for Pap IIID and Pap I-II of 83.7%, 88.9% and 78.6%, respectively. As this IMS based approach allows for unbiased and automated classifiction of cytological samples it appears to be a promising tool for stratification of cervical Pap smears.

Application of MALDI imaging for the diagnosis of classical Hodgkin lymphoma.

Hodgkin lymphoma (HL) is a distinctive lymphoma subtype characterized by rareness of tumor cells [Hodgkin's and Reed-Sternberg (HRS) cells in classical HL and lymphocytic and histiocytic cells in lymphocyte predominant HL] as well as the vast majority of the surrounding inflammatory-like cellular infiltrate. Still the onset of this highly variable disease is not completely understood. Proteome analysis can lead to the identification of potential proteins capable of elucidating malignant growth and survival in HL. Especially MALDI imaging could result in pinpointing differentially expressed proteins, which might represent potential marker molecules. In this study, we were able to distinguish between classical Hodgkin lymphoma and lymphadenitis with a sensitivity and specificity of 83.92 and 89.37%, respectively.

Impact of combinatory growth factor application on rabbit Achilles tendon injury with operative versus conservative treatment: a pilot study.

Acute Achilles tendon (AT) rupture is a common injury with a comparatively high complication rate. Presently, surgical treatments compete with nonoperative treatment modalities. The aim of this study was to elucidate the possible beneficial effects of short-term combinatory application of growth factors on tendon healing during operative or conservative treatment. In this controlled laboratory study, the left ATs of 40 adult New Zealand White rabbits were transected and either sutured or treated conservatively. Half of the animals from each treatment modality group repetitively received a mixture of VEGF165, bFGF, and rPDGF which was administered peritendineally. The left legs were immobilized with external fixateurs for 6 weeks. The ATs were harvested 3 months after intervention. Tensile strength tests revealed no significant differences between operative and conservative treatments. Compared to the normal right ATs, 60% of the average breaking strength was reached 3 months after surgery. Growth factor application did not result in significant improvements. Only a tendency towards higher blood vessel densities was noted in the groups treated with the factors. Collagen type I/III ratios also displayed no significant differences. This study indicates that there is no difference in the biomechanical outcome of conservative versus operative AT rupture treatment and only a marginal impact of short-term combinatory growth and angiogenesis factor application.

Polymorphisms of the apoptosis-associated gene DP1L1 (deleted in polyposis 1-like 1) in colon cancer and inflammatory bowel disease.

PURPOSE: The deleted-in-polyposis1-like1 (DP1L1) gene displays pro-apoptotic activity and was proposed to be a tumor suppressor. It locates on chromosome 19p13.3, which harbors the locus for Peutz-Jeghers-Syndrome and is deleted in various tumors. We analyzed the association of DP1L1 polymorphisms with colon cancer, and cancer-associated Ulcerative colitis and Crohn's disease. EXPERIMENTAL DESIGN: Fifty-eight patients with colon cancer, 18 with Ulcerative colitis, 18 with Crohn's disease, and 70 control individuals were genotyped for SNPs at positions 992 and 996 of DP1L1 cDNA. RESULTS: Homozygous carriers of 992A alleles comprised 16% of the control group but were significantly increased in colon cancer with a frequency of 36% (P = 0.013 cancer vs control). Homozygous 991-A was also elevated in Ulcerative colitis (N = 18) with a frequency of 33%. In contrast, 18 patients with Crohn's disease showed no difference in frequency of 992AA (22%) compared to control. The A-allele of the adjacent C996A polymorphism has a low frequency (3.5%) in the control population, but significantly increased frequency of 13% in colon cancer (P = 0.0149 for allele frequency, Fisher's exact). 996-A allele frequency is also increased in inflammatory bowel disease (IBD): 22% of Ulcerative colitis- and 50% of Crohn's disease-patients were heterozygous carriers of 996-A (P = 0.052 for CU and P < 0.0001 for MC vs controls). CONCLUSIONS: DP1L1 polymorphisms are associated with colon cancer and IBD. This indicates that DP1L1 plays a functional role in these conditions. Thus DP1L1 may be a diagnostic and therapeutic target for colon cancer and IBD.

Mutational analysis of the BRAF, RAS and EGFR genes in human adrenocortical carcinomas.

The serine/threonine kinase B-Raf plays a key role in the Ras/Raf/MEK/ERK pathway that relays extracellular signals for cell proliferation and survival. Several types of human malignancies harbor activating BRAF mutations, most frequently a V600E substitution. The epidermal growth factor receptor (EGFR), a transmembrane tyrosine kinase (TK) receptor that mediates proliferation and survival signaling, is expressed in a wide variety of normal and neoplastic tissues. EGFR inhibitors have produced objective responses in patients with non-small cell lung carcinomas harboring activating EGFR TK domain somatic mutations. We evaluated the presence of mutations in BRAF (exons 11 and 15), KRAS (exons 1 and 2), NRAS (exons 1 and 2), and EGFR (exons 18-21) in adrenal carcinomas (35 tumor specimens and two cell lines) by DNA sequencing. BRAF mutations were found in two carcinomas (5.7%). Four carcinomas (11.4%) carried EGFR TK domain mutations. One specimen carried a KRAS mutation, and another carried two NRAS mutations. No mutations were found in the two adrenocortical cell lines. BRAF- and EGFR-mutant tumor specimens exhibited stronger immunostaining for the phosphorylated forms of the MEK and ERK kinases than their wild-type counterparts. EGFR-mutant carcinomas exhibited increased phosphorylation of EGFR (Tyr 992) compared with wild-type carcinomas. We conclude that BRAF, RAS, and EGFR mutations occur in a subset of human adrenocortical carcinomas. Inhibitors of the Ras/Raf/MEK/ERK and EGFR pathways represent candidate targeted therapies for future clinical trials in carefully selected patients with adrenocortical carcinomas harboring respective activating mutations.

The human trithorax protein hASH2 functions as an oncoprotein.

Regulation of chromatin is an important aspect of controlling promoter activity and gene expression. Posttranslational modifications of core histones allow proteins associated with gene transcription to access chromatin. Closely associated with promoters of actively transcribed genes, trimethylation of histone H3 at lysine 4 (H3K4me3) is a core histone mark set by several protein complexes. Some of these protein complexes contain the trithorax protein ASH2 combined with the MLL oncoproteins. We identified human ASH2 in a complex with the oncoprotein MYC. This finding, together with the observation that hASH2 interacts with MLL, led us to test whether hASH2 itself is involved in transformation. We observed that hASH2 cooperates with Ha-RAS to transform primary rat embryo fibroblasts (REF). Furthermore, transformation of REFs by MYC and Ha-RAS required the presence of rAsh2. In an animal model, the hASH2/Ha-RAS-transformed REFs formed rapidly growing tumors characteristic of fibrosarcomas that, compared with tumors derived from MYC/Ha-RAS transformed cells, were poorly differentiated. This finding suggests that ASH2 functions as an oncoprotein. Although hASH2 expression at the mRNA level was generally not deregulated, hASH2 protein expression was increased in most human tumors and tumor cell lines. In addition, knockdown of hASH2 inhibited tumor cell proliferation. Taken together, these observations define hASH2 as a novel oncoprotein.

Activation of Wnt signalling in stroma from pancreatic cancer identified by gene expression profiling.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an abundant desmoplastic stroma. Interactions between cancer and stromal cells play a critical role in tumour invasion, metastasis and chemoresistance. Therefore, we hypothesized that gene expression profile of the stromal components of pancreatic carcinoma is different from chronic pancreatitis and reflects the interaction with the tumour. We investigated the gene expression of eleven stromal tissues from PDAC, nine from chronic pancreatitis and cell lines of stromal origin using the Affymetrix U133 GeneChip set. The tissue samples were microdissected, the RNA was extracted, amplified and labelled using a repetitive in vitro transcription protocol. Differentially expressed genes were identified and validated using quantitative RT-PCR and immuno-histochemistry. We found 255 genes to be overexpressed and 61 genes to be underexpressed within the stroma of pancreatic carcinoma compared to the stroma of chronic pancreatitis. Analysis of the involved signal transduction pathways revealed a number of genes associated with the Wnt pathway of which the differential expression of SFRP1 and WNT5a was confirmed using immunohistochemistry. Moreover, we could demonstrate that WNT5a expression was induced in fibroblasts during cocultivation with a pancreatic carcinoma cell line. The identified differences in the expression profile of stroma cells derived from tumour compared to cells of inflammatory origin suggest a specific response of the tissue surrounding malignant cells. The overexpression of WNT5a, a gene involved in the non canonical Wnt signalling and chondrocyte development might contribute to the strong desmoplastic reaction seen in pancreatic cancer.

Proteomic analysis of mucosal preparations from patients with ulcerative colitis.

Proteomic profiling with the identification of molecular signatures is a powerful tool in the study of pathogenesis, and may allow us to predict the prognosis of disease states. In this study, mucosa/submucosa from the colonic resections of five patients with ulcerative colitis (UC) who had undergone colonic resection were microdisected. Proteins were separated by two-dimensional (2D) polyacrylamide gel electrophoresis. Proteins of interest were further extracted and identified by tryptic in-gel digestion and mass spectrometry. Among the proteins found were ones associated with inflammation and tissue repair, namely protocadherin, α-1 antitrypsin, tetratricopeptide repeat domains and caldesmon. Surprisingly, in all five cases specific spots were identified that represented mutated forms of desmin expressed in UC mucosa/submucosa (two spots were sequenced) and were verified with Western blotting. In summary, proteomic signature profiles of UC represent proteins associated with inflammation and repair. Mutated desmin may represent a specific protein associated with UC and may be used in the differential diagnosis of forms of inflammatory bowel disease (IBD).

Lessons from a patient with an unusual hepatic overlap syndrome.

BACKGROUND: A 24-year-old white male was diagnosed as having Crohn's disease by clinical, endoscopic and histological assessments, and long-term remission was successfully induced with short-course prednisolone. While the Crohn's disease was still in remission, the patient presented with cholestasis and hyperbilirubinemia but normal alanine aminotransferase levels, negative results for serological tests for infectious causes of hepatopathy and normal gamma-globulin levels. INVESTIGATIONS: Repeated laboratory and serological tests, ultrasonography, endoscopic retrograde cholangiopancreatographies, CT scan, magnetic resonance cholangiopancreatography and liver biopsies. DIAGNOSIS: Autoimmune hepatitis-primary sclerosing cholangitis (AIH-PSC) overlap syndrome on the background of PSC with a rare course of sequential manifestations of the different disease components. MANAGEMENT: Combined immunosuppression with prednisolone and treatment with ursodeoxycholic acid (UDCA), endoscopic treatment of dominant stenoses, bile duct stent implantation, and close follow-up.