Clinical relevance of circulating tumour cells in the bone marrow of patients with SCCHN

Background: Clinical outcome of patients with head and neck squamous cell carcinoma (SCCHN) depends on several risk factors like the presence of locoregional lymph node or distant metastases, stage, localisation and histologic differentiation of the tumour. Circulating tumour cells in the bone marrow indicate a poor prognosis for patients with various kinds of malignoma. The present study examines the clinical relevance of occult tumour cells in patients suffering from SCCHN. Patients and Methods: Bone marrow aspirates of 176 patients suffering from SCCHN were obtained prior to surgery and stained for the presence of disseminated tumour cells. Antibodies for cytokeratin 19 were used for immunohistochemical detection with APAAP on cytospin slides. Within a clinical follow-up protocol over a period of 60 months, the prognostic relevance of several clinicopathological parameters and occult tumour cells was evaluated. Results: Single CK19-expressing tumour cells could be detected in the bone marrow of 30.7% of the patients. There is a significant correlation between occult tumour cells in the bone marrow and relapse. Uni- and multivariate analysis of all clinical data showed the metastases in the locoregional lymph system and detection of disseminated tumour cells in the bone marrow to be statistically highly significant for clinical prognosis. Conclusion: The detection of minimal residual disease underlines the understanding of SCCHN as a systemic disease. Further examination of such cells will lead to a better understanding of the tumour biology, as well as to improvement of diagnostic and therapeutic strategies

Widespread expression of erythropoietin receptor in brain and its induction by injury

Erythropoietin (EPO) exerts potent neuroprotective, neuroregenerative and procognitive functions. However, unequivocal demonstration of erythropoietin receptor (EPOR) expression in brain cells has remained difficult since previously available anti-EPOR antibodies (EPOR-AB) were unspecific. We report here a new, highly specific, polyclonal rabbit EPOR-AB directed against different epitopes in the cytoplasmic tail of human and murine EPOR and its characterization by mass spectrometric analysis of immuno-precipitated endogenous EPOR, Western blotting, immunostaining and flow cytometry. Among others, we applied genetic strategies including overexpression, Lentivirus-mediated conditional knockout of EpoR and tagged proteins, both on cultured cells and tissue sections, as well as intracortical implantation of EPOR-transduced cells to verify specificity. We show examples of EPOR expression in neurons, oligodendroglia, astrocytes and microglia. Employing this new EPOR-AB with double-labeling strategies, we demonstrate membrane expression of EPOR as well as its localization in intracellular compartments such as the Golgi apparatus. Moreover, we show injury-induced expression of EPOR. In mice, a stereotactically applied stab wound to the motor cortex leads to distinct EpoR expression by reactive GFAP-expressing cells in the lesion vicinity. In a patient suffering from epilepsy, neurons and oligodendrocytes of the hippocampus strongly express EPOR. To conclude, this new analytical tool will allow neuroscientists to pinpoint EPOR expression in cells of the nervous system and to better understand its role in healthy conditions, including brain development, as well as under pathological circumstances, such as upregulation upon distress and injury

Intratumorale Injektion eines bispezifischen Antikörpers führt zu effizienter Steigerung der Immunabwehr

Zu den innovativen Therapieansätzen in der Onkologie zählt der Einsatz bispezifischer Antikörper (bsAk). Der bsAb BIU III redirigiert antitumoral wirksame T-Lymphozyten zu tumorassoziierten Antigenen auf der Tumorzelle und rekrutieren zusätzlich akzessorische Zellen, wie z.B. Makrophagen. Dieser Trizellkomplex führt so zu einer potenten Zerstörung der Tumorzelle und zur Induktion eines immunologischen Gedächtnisses.In Kooperation mit Fresenius Heaemocare wurde deshalb an vier Patienten eine klinische Studie mit intratumoraler Injektion des bsAb in oberflächlich gelegene, gut erreichbare Tumoren der Mundhöhle und des Oropharynx durchgeführt. Im Rahmen des Immune monitoring wurden multiple Parameter des Immunsystems erfasst.Mittels Durchflußzytometrie, Ellispot und Bioplexsystem wurden engmaschig phänotypische und funktionelle Veränderungen aller Immuneffektorzellen gemessen.Die intratumorale Gabe des bsAb führte über eine definierte Zytokinfreisetzung zu einer massiven Aktivierung des Immunsystems. Dies ließ sich sowohl an der Verschiebung der Proportion der Immuneffektorzellen, als auch des Phänotyps und der Funktion zeigen.Bei guter klinischer Verträglichkeit ist somit eine Möglichkeit geschaffen, präoperativ ein verstärktes Priming des Immunsystems gegen den autologen Tumor zu erreichen, welches postoperativ durch z.B. weitere Vakzinierung genutzt werden könnte