Lars Christian Horn

Fate of extrahepatic human stem and precursor cells after transplantation into mouse livers

In recent years, a large number of groups studied the fate of human stem cells in livers of immunodeficient animals. However, the interpretation of the results is quite controversial. We transplanted 4 different types of human extrahepatic precursor cells (derived from cord blood, monocytes, bone marrow, and pancreas) into livers of nonobese diabetic/severe combined immunodeficiency mice. Human hepatocytes were used as positive controls. Tracking of the transplanted human cells could be achieved by in situ hybridization with alu probes. Cells with alu‐positive nuclei stained positive for human albumin and glycogen. Both markers were negative before transplantation. However, cells with alu‐positive nuclei did not show a hepatocyte‐like morphology and did not express cytochrome P450 3A4, and this suggests that these cells represent a mixed cell type possibly resulting from partial transdifferentiation. Using antibodies specific for human albumin, we also observed a second human albumin–positive cell type that could be clearly distinguished from the previously described cells by its hepatocyte‐like morphology. Surprisingly, these cells had a mouse and not a human nucleus which is explained by transdifferentiation of human cells. Although it has not yet been formally proven, we suggest horizontal gene transfer as a likely mechanism, especially because we observed small fragments of human nuclei in mouse cells that originated from deteriorating transplanted cells. Qualitatively similar results were obtained with all 4 human precursor cell types through different routes of administration with and without the induction of liver damage. Conclusion: We observed evidence not for transdifferentiation but instead for a complex situation including partial differentiation and possibly horizontal gene transfer. (HEPATOLOGY 2007.)

A Comparison of Outcomes for Interfascial and Intrafascial Nerve-sparing Radical Prostatectomy

OBJECTIVE To compare the outcome of intrafascial nerve-sparing endoscopic extraperitoneal radical prostatectomy (nsEERPE) with interfascial (standard) nsEERPE. METHODS Four-hundred patients underwent nsEERPE; 200 patients underwent bilateral intrafascial nsEERPE (group A) and 200 bilateral standard nsEERPE (group B). Tumor stages of T1 and T2a, prostate-specific antigen level <10 ng/mL, maximal Gleason score 3+4 (not 4+3) and preoperative potency were considered as candidates for nsEERPE. Patients were randomized to the aforementioned groups. Perioperative data, and functional and oncological outcome were reviewed. Patients not requiring any pads or requiring 1 pad for safety were defined as continent. Patients responding positively to sexual encounter profile diary question numbers 2, 3, and 5 were considered as potent. RESULTS Perioperative data were similar between groups. At 3 months, 74% of group A and and 63% of group B were continent. At 6 months, the respective figures were 87.9% and 76.2%, respectively (A, B). At 12 months, 93.2% of group A and 90.7% of group B were continent. Potency rates of group A were 93.5% (<55 years), 83.3% (55-65 years), and 60% (>65 years) at 12 months. The respective figures for Group B were 77.1%, 50%, and 40%. Positive surgical margins were detected in 9% and 9.5% of groups A and B, respectively. CONCLUSIONS Intrafascial nsEERPE provides significantly better potency in patients <55 years of age at 12 months and in patients 55-65 years of age at 6 and 12 months, with probably limited effect on the oncological outcome. Significantly improved continence was observed at 3 and 6 months in favor of intrafascial nsEEPRE.

MR-guided percutaneous core biopsy of small breast lesions: first experience with a vertically open 0.5T scanner.

The growing use of highly sensitive but only moderate specific breast MRI requires the development of both minimal‐invasive as well as precise biopsy systems. The aim of the study was to prove the accuracy and feasibility of a biopsy procedure carried out in prone position in a vertically opened MR imager.

Combined serial section-based 3D reconstruction of cervical carcinoma invasion using H&E/p16INK4a/CD3 alternate staining†

Malignant growth and invasiveness of cancers is a function of both intratumoral and stromal factors. The accessibility to nutrients, oxygen and growth factors, the stromal composition, and the interference with the immune system all shape the tumor invasion front. A recent study has shown a prognostic difference with respect to different invasion patterns analyzed on histological specimens of cervical cancers. The present study analyzes the spatial organization of a cervical cancer and the relation of the tumor invasion front and the infiltration with CD3+ T‐cells.

STAT3/IRF1 Pathway Activation Sensitizes Cervical Cancer Cells to Chemotherapeutic Drugs.

Neoadjuvant radio/chemotherapy regimens can markedly improve cervical cancer outcome in a subset of patients, while other patients show poor responses, but may encounter severe adverse effects. Thus, there is a strong need for predictive biomarkers to improve clinical management of cervical cancer patients. STAT3 is considered as a critical antiapoptotic factor in various malignancies. We therefore investigated STAT3 activation during cervical carcinogenesis and its impact on the response of cervical cancer cells to chemotherapeutic drugs. Tyr705-phosphorylated STAT3 increased from low-grade cervical intraepithelial neoplasia (CIN1) to precancerous CIN3 lesions. Notably, pTyr705-STAT3 activation significantly declined from CIN3 to invasive cancer, also when compared in the same clinical biopsy. pTyr705-STAT3 was also low or absent in cultured human cervical cancer cell lines, consistent with the in vivo expression data. Unexpectedly, IL6-type cytokine signaling inducing STAT3 activation rendered cervical cancer cells significantly more susceptible to chemotherapeutic drugs, that is, cisplatin or etoposide. This chemosensitization was STAT3-dependent and we identified IFN regulatory factor-1 (IRF1) as the STAT3-inducible mediator required for cell death enhancement. In line with these data, pTyr705-STAT3 significantly correlated with nuclear IRF1 expression in cervical cancer in vivo Importantly, high IRF1 expression in pretreatment cervical cancer biopsy cells was associated with a significantly better response to neoadjuvant radio/chemotherapy of the patients. In summary, our study has identified a key role of the STAT3/IRF1 pathway for chemosensitization in cervical cancer. Our results suggest that pretherapeutic IRF1 expression should be evaluated as a novel predictive biomarker for neoadjuvant radio/chemotherapy responses. Cancer Res; 76(13); 3872-83. ©2016 AACR.

Clinicopathologic profile of gestational trophoblastic disease

ZusammenfassungHintergrundNach Therapie einer gestationsbedingten trophoblastären Neoplasie (GTN) kann es in 20% zu einer persistierenden Form (pGTN) kommen. Die Aussagekraft prädiktiver Faktoren wie DNA-Ploidie, Karyotypisierung oder c-erbB-2 Amplifikationsrate und Expression ist nach wie vor umstritten. Diese Studie untersucht das klinisch-pathologische Profil gestationsbedingter Trophoblastentumoren hinsichtlich einer möglichen Bedeutung des Onkogens c-erbB-2. Zusätzlich wurden die DNA-Ploidie und der Karyotyp bestimmt. Die erhaltenen Daten wurden mit den histopathologischen Charakteristika der trophoblastären Tumoren korreliert.MethodenPatientendaten sowie Tumormaterial wurden von der Universität Leipzig, Abt. für Gynäkologie und Geburtshilfe, zur Verfügung gestellt. Die Bestimmung der c-erbB-2 Amplifikationsrate wurde mit der differentiellen Polymerase-Kettenreaktion (DPCR), die Karyotypisierung mittels FluoreszensIn-situ-Hybridisierungs- (FISH)-Technik an 4′, 6-Diamidin-2-Phenylindoldihydrochlorid (DAPI) gefärbten Kernsuspensionen und die Proteinexpression immunohistochemisch durchgeführt. DNA-Ploidie erfolgte an Feulgen gefärbten Paraffinschnittpräparaten.ErgebnisseVon den 36 gestationsbedingten Trophoblastentumoren konnten 27 (75%) Patientinnen mittels Curettage erfolgreich behandelt werden, davon erhielten 2 Patientinnen eine einmalige Chemotherapie. Die durchschnittliche Zeitspanne zwischen vorangegangener Schwangerschaft und der GTN betrug 45,4 Monate. In 9 Fällen (5 komplette Blasenmolen, 3 invasive Molen und ein Chorionkarzinom) entwickelte sich eine persistierende Form. Eine komplette Remission konnte in allen 9 Fällen einer pGTN erzielt werden. Aggressives Verhalten bzw. Persistenz korrelierte mit einer c-erbB-2 Amplifikation und Überexpression, sowie einer DNA-Hyperploidie und XY-Karyotyp.SchlussfolgerungDie c-erbB-2 Amplifikations- und Überexpressionsrate, sowie der DNA-Ploidiegehalt dürften somit als prädiktive Parameter der invasiven Potenz einer gestationsbedingten Trophoblastneoplasie interpretiert werden. Weiters ließen sich eine Korrelation mit aggressivem Verhalten und XY als Karyotyp erkennen.SummaryMuch debate exists on factors predicting the development of persistent gestational trophoblastic disease (pGTD). Diagnosis is still limited by following persistently elevated or rising postevacutation β-human chorionic gonadotropin (β-hCG) titers. The aim of the present work was to evaluate the hypothesis that the presence of c-erbB-2 oncogene amplification and expression, in combination with parameters such as DNA-content and karyotype of the sex chromosomes, confer an increased risk of developing pGTD. Clinicopathological characteristics were evaluated in 36 cases of gestational trophoblastic diseases (GTD) and analyzed for c-erbB-2 amplification and protein p185 expression using differential polymerase chain reaction (DPCR) and immunohistochemical (IHC) techniques. The DNA-content was determined by image analysis on Feulgen stained nuclear cell preparations and karyotyping for XY chromosomes was performed by fluorescencein situ hybridization (FISH). The data was correlated with histopathological characteristics of GTD. Seventy-five percent (n=27) of the examined cases showed spontaneous regression after evacuation, including 2 patients who received additional chemotherapy. Twenty-five percent (n=9) resulted in a persistent or metastatic disease. The median time between antecedent pregnancy and GTD was 45.4 months. Complete remission was achieved in all patients with pGTD after administration of chemotherapeutic agents or adjuvant surgical procedures. Cases with c-erbB-2 amplification and expression in combination with DNA hyperploidy showed higher proliferation and more aggressive behavior (2 complete hydatidiform moles with lung and liver metastases, 2 invasive moles and 1 choriocarcinoma). XY karyotype was evident in the choriocarcinoma and in 2 complete hydatidiform moles with advanced stage and DNA hyperploidy. From these results we conclude that c-erbB-2 amplification and/or protein expression in combination with DNA-content show a significant correlation with the proliferative and aggressive potential of GTD, suggesting their combined use as a possible marker for pGTD.