Hilke Zander

Notch signaling activated by replication stress-induced expression of Midkine drives Epithelial-Mesenchymal Transition and Chemoresistance in Pancreatic Cancer

The incidence of pancreatic ductal adenocarcinoma (PDAC) nearly equals its mortality rate, partly because most PDACs are intrinsically chemoresistant and thus largely untreatable. It was found recently that chemoresistant PDAC cells overexpress the Notch-2 receptor and have undergone epithelial-mesenchymal transition (EMT). In this study, we show that these two phenotypes are interrelated by expression of Midkine (MK), a heparin-binding growth factor that is widely overexpressed in chemoresistant PDAC. Gemcitabine, the front-line chemotherapy used in PDAC treatment, induced MK expression in a dose-dependent manner, and its RNAi-mediated depletion was associated with sensitization to gemcitabine treatment. We identified an interaction between the Notch-2 receptor and MK in PDAC cells. MK-Notch-2 interaction activated Notch signaling, induced EMT, upregulated NF-κB, and increased chemoresistance. Taken together, our findings define an important pathway of chemoresistance in PDAC and suggest novel strategies for its clinical attack.

Prognostic impact of CXCR4 and CXCR7 expression in pancreatic adenocarcinoma.

Chemokines and their receptors are known to play important roles in the tumorigenesis of many malignancies. The aim of this study was to evaluate the prognostic impact of the expression of the chemokine receptors CXCR4 and CXCR7 in patients with pancreatic adenocarcinoma (PAC).

Activated leukocyte cell adhesion molecule (CD166)--its prognostic power for colorectal cancer patients.

BACKGROUND The activated leukocyte cell adhesion molecule (ALCAM, CD166) has been reported to be involved in tumorigenesis of colorectal cancer (CRC) and to function as a cancer stem cell marker. Controversial data exist regarding the prognostic power of ALCAM expression in CRC. Here, we evaluate the expression of ALCAM in a cohort of CRC patients and its usage as a prognostic marker for survival. MATERIALS AND METHODS Tissue specimens from 299 patients with CRC treated between 1993 and 2006 were analyzed via ALCAM immunohistochemistry (clone MOG/07) using a tissue microarray. Results were correlated with clinical, histopathological, and patient survival data (Chi-square test, Kaplan-Meier analysis, and log-rank test, respectively). Multivariate analysis also was performed (Cox regression). RESULTS ALCAM is expressed in most primary (76%) and secondary (62%) CRC lesions (P = 0.014). Immunohistochemistry revealed an inverse association with tumor grading (P = 0.002) but not with any other clinical or histopathological data. Kaplan-Meier survival analysis revealed a significant overall survival benefit in the group of ALCAM-positive patients (P = 0.019). Multivariate analysis showed that ALCAM is an independent positive prognostic marker for overall survival (P = 0.023). CONCLUSIONS ALCAM expression is a positive prognostic marker for overall survival of CRC patients, and its detection might help to optimize the existing prognostic staging system. Elevated expression in higher differentiated tumors might indicate a potential role in the early steps of tumorigenesis, and its loss might be associated with reduced cellular adhesion, resulting in a higher metastatic potential of the tumor. Further studies must be conducted investigating these hypotheses.

ALCAM (CD166) expression and serum levels are markers for poor survival of esophageal cancer patients

The expression of the activated leukocyte cell adhesion molecule (ALCAM and CD166) is increased in various types of cancer. We aimed to evaluate its role as a prognostic marker for esophageal cancer (EC). We retrospectively analyzed ALCAM expression in 299 primary lesions, 147 lymph node and 46 distant metastases from EC patients, on a tissue microarray using immunohistochemistry. Bone marrow samples from representative cancer patients (n = 16), taken before primary surgery, were stained by double‐immunofluorescence for ALCAM and cytokeratins (CK). Blood serum samples from 236 cancer patients and 127 controls were analyzed for serum ALCAM (s‐ALCAM) by ELISA. The immunohistochemical analysis showed increased ALCAM expression in the majority of lesions (primary tumor 71%, lymph node 76% and distant metastases 80%). ALCAM expression was not associated with histopathological parameters except for tumor grading (p = 0.015). ALCAM‐positive patients had significantly worse recurrence‐free and overall survival (OS; p = 0.002). Disseminated tumor cells (DTC) in bone marrow showed two phenotypes, ALCAM+/CK+ (36%) and ALCAM‐/CK+ (64%). Multivariate analysis revealed that ALCAM expression and elevated s‐ALCAM serum values are powerful prognostic variables for OS in patients with EC (hazard ratio [HR] 3.987, 95% confidence interval [95%CI] 1.906–8.340, p < 0.001 and HR 1.915, 95%CI 1.021–3.592, p = 0.043). The results of our study provide preliminary evidence for the potential clinical utility of ALCAM as a prognostic biomarker for EC, which might be a basis for future clinical application. In addition, ALCAM expression in a subset of DTC of the bone marrow indicates a potential function in the metastatic cascade of EC.

Activated Leukocyte Cell Adhesion Molecule (CD166): An “Inert” Cancer Stem Cell Marker for Non-Small Cell Lung Cancer?

Recently, the activated leukocyte cell adhesion molecule (CD166) was identified as an “inert” cancer stem cell (CSC) marker for non‐small cell lung cancer (NSCLC). Few data exist regarding the clinical relevance of CD166 expression in NSCLC. We evaluated the expression of CD166 using immunohistochemistry in a large cohort of NSCLC patients (n = 1,910) on a tissue microarray basis. Expression was inversely associated with tumor size and lymph node status. Grading slightly failed to be significantly inversely associated, and survival analysis revealed no significant survival benefit of CD166‐positive patients. Due to the results of this study, the theory of CD166 as a CSC marker for NSCLC must be questioned. The association of CD166 with smaller tumors and no nodal metastases does not make it a typical CSC marker. Further studies are required to investigate the functional role of CD166 in NSCLC. Stem Cells 2014;32:1429–1436

L1 is Highly Expressed in Tumors of the Nervous System: A Study of Over 8000 Human Tissues

BACKGROUND L1 cell adhesion molecule (CD171) has been detected in different malignant tumors and is associated with unfavorable outcome. It thus represents a target for tumor diagnosis and therapy. In this study, we assessed L1 expression in more than 8000 normal human tissues and different types of tumors, both malignant and non-malignant, and neural and non-neural. MATERIALS AND METHODS Tissue micro-arrays, including a multi-tumor-array of 128 different tumor types, up to 50 samples of each type (approximately 5500 different samples), arrays with approximately 3000 different prostate and 600 mesenchymal tumor samples, and a normal human tissue-array were analyzed by immunohistochemistry with a monoclonal antibody using immunoperoxidase staining. RESULTS L1 expression was detected in tumors of neural and neural crest origin and other types of non-neural tumors, but not in those of epithelial origin. In normal human tissues, L1 was detected in skin basal cells and small blood vessels, most notably in the mature placenta and peripheral nerves. CONCLUSION This first comprehensive study of the importance of L1 expression in human demonstrates strong L1 overexpression in tumors of neuroectodermal and neural crest origin and an expression in only very few normal human tissues. L1 thus is a potentially important therapeutic target, particularly with respect to malignant melanoma, gastrointestinal stromal tumor, neuroblastoma, and certain subtypes of non-neural tumors.

CXCR7 expression in esophageal cancer

BackgroundThe chemokine CXCL12 and its receptor CXCR4 play a major role in tumor invasion, proliferation and metastasis in different malignant diseases, including esophageal carcinoma, amongst others. CXCR7 was recently identified as a novel alternate receptor for CXCL12. The aim of this study was to evaluate the prognostic impact of expression of chemokine receptor CXCR7 in patients with esophageal carcinoma (EC).MethodsExpression of CXCR7 in primary tumors, lymph nodes and distant metastases of 299 patients with EC was evaluated by immunohistochemistry on a tissue microarray and compared with clinical and histopathological data.ResultsIn esophageal cancer sections, CXCR7-specific reactivity was apparent in 45% of the squamous cell carcinomas (ESCC), but only occasionally in adenocarcinomas. No correlation between CXCR4 and CXCR7 expression was evident. We correlated expression with clinical and histopathological characteristics, but could not find any association.ConclusionsContrary to the other known CXCL12 receptor, CXCR4, CXCR7 is expressed in ESCC only, underlining the divergent mechanisms and backgrounds of EAC and ESCC. The results of the study do not indicate a significant functional role for CXCR7 in EAC or ESCC of the esophagus. However, its variable expression in the main two main types of EC needs to be further investigated.

Circulating levels of cell adhesion molecule L1 as a prognostic marker in gastrointestinal stromal tumor patients

BackgroundL1 cell adhesion molecule (CD171) is expressed in many malignant tumors and its expression correlates with unfavourable outcome. It thus represents a target for tumor diagnosis and therapy. An earlier study conducted by our group identified L1 expression levels in primary gastrointestinal stromal tumors (GIST) as a prognostic marker. The aim of the current study was to compare L1 serum levels of GIST patients with those of healthy controls and to determine whether levels of soluble L1 in sera could serve as a prognostic marker.MethodsUsing a sensitive enzyme-linked immunosorbent assay (ELISA), soluble L1 was measured in sera of 93 GIST patients und 151 healthy controls. Soluble L1 levels were then correlated with clinicopathological data.ResultsMedian levels of soluble L1 were significantly higher (p < 0.001; Mann-Whitney U test) in sera of GIST patients compared to healthy individuals. Median soluble L1 levels were particularly elevated in patients with recurrence and relapse (p < 0.05; Mann Whitney U test).ConclusionThese results suggest that high soluble L1 levels predict poor prognosis and may thus be a promising tumor marker that can contribute to individualise therapy.

Relevance of activated leukocyte cell adhesion molecule (ALCAM) in tumor tissue and sera of cervical cancer patients

BackgroundAn altered expression of the activated leukocyte cell adhesion molecule (ALCAM) is associated with cancer progression in various cancer types. In some cancers ALCAM has a prognostic value or is predictive for the benefit of therapeutic interventions. To date there are no data on the role of ALCAM in cervical cancer available.MethodsIn this study, ALCAM expression was analysed by immunohistochemistry (IHC) in tissue samples of 233 patients with cervical cancer, among them 178 with complete follow-up information. In addition, soluble (s-)ALCAM was measured in sera of a subset of the included patients (n = 55) by enzyme-linked immunosorbent assay (ELISA).ResultsALCAM overexpression was detected (immunoreactive score (IRS) 2-12) in 58.4% of the cervical cancer samples. The normal ectocervical or endocervical epithelium showed no ALCAM reactivity. In untreated patients, ALCAM overexpression in tumor tissue tended to be associated with shorter cancer-specific survival (CSS) and disease-free survival (DFS). Patients, whose tumor samples showed ALCAM overexpression receiving a cytotoxic therapy like radiotherapy or chemoradiation, however, had a favourable prognosis compared to those patients, whose cancers showed no or minimal ALCAM staining. This effect was particularly apparent in patients receiving chemoradiation where the CSS was significantly longer in patients with ALCAM-positive tumors (p = 0.038; cumulative incidence rates at 96 months 8%, 95% CI 0%-23%, and 26%, CI 3%-43% in ALCAM-positive and ALCAM-negative cases, respectively).Median preoperative s-ALCAM concentration in sera from tumor patients was 27.6 ng/ml (range 17.5-55.1 ng/ml, mean 28.9 ng/ml), serum levels did not correlate with intratumoral ALCAM expression.ConclusionsThe data of our retrospective study suggest that the prognostic value of ALCAM expression in cervical carcinoma might be therapy-dependent, and that ALCAM might function as a predictive marker for the response to chemoradiation. This should be confirmed in further, prospective studies.

Detection of activated leukocyte cell adhesion molecule in the serum of breast cancer patients and implications for prognosis.

Objective: Conflicting results have been reported about activated leukocyte cell adhesion molecule (ALCAM) expression in breast cancer and its prognostic value. Little is known about the role of ALCAM levels in the serum of breast cancer patients. Methods: We analyzed soluble ALCAM (sALCAM) levels in the serum of 157 primary breast cancer patients and 48 healthy women by ELISA. In addition, we determined ALCAM protein expression by Western blot analysis (n = 120) and mRNA expression by cDNA microarray analysis (n = 115) in the tumor tissue of corresponding patients. Results: sALCAM levels differed between patients and healthy controls (median 24.2 vs. 18.9 ng/ml, p < 0.001). We observed no correlation between serum levels and protein or mRNA expression in corresponding tumors (r < 0.1, p = n.s.). sALCAM levels were not correlated with histological type, grading, tumor stage, or patient age, but elevated sALCAM levels were associated with shorter disease-free survival (HR = 1.97, 95% CI 1.01–3.2, p = 0.043). Conclusions: Our results indicate that sALCAM can be detected in the serum of patients with primary breast cancer. Elevated serum levels might indicate more aggressive tumor behavior as they might be an independent factor for a worse prognosis in breast cancer patients.