Antonia Wenners

Neutrophil Gelatinase-Associated Lipocalin (NGAL) Predicts Response to Neoadjuvant Chemotherapy and Clinical Outcome in Primary Human Breast Cancer

In our previous work we showed that NGAL, a protein involved in the regulation of proliferation and differentiation, is overexpressed in human breast cancer (BC) and predicts poor prognosis. In neoadjuvant chemotherapy (NACT) pathological complete response (pCR) is a predictor for outcome. The aim of this study was to evaluate NGAL as a predictor of response to NACT and to validate NGAL as a prognostic factor for clinical outcome in patients with primary BC. Immunohistochemistry was performed on tissue microarrays from 652 core biopsies from BC patients, who underwent NACT in the GeparTrio trial. NGAL expression and intensity was evaluated separately. NGAL was detected in 42.2% of the breast carcinomas in the cytoplasm. NGAL expression correlated with negative hormone receptor (HR) status, but not with other baseline parameters. NGAL expression did not correlate with pCR in the full population, however, NGAL expression and staining intensity were significantly associated with higher pCR rates in patients with positive HR status. In addition, strong NGAL expression correlated with higher pCR rates in node negative patients, patients with histological grade 1 or 2 tumors and a tumor size <40 mm. In univariate survival analysis, positive NGAL expression and strong staining intensity correlated with decreased disease-free survival (DFS) in the entire cohort and different subgroups, including HR positive patients. Similar correlations were found for intense staining and decreased overall survival (OS). In multivariate analysis, NGAL expression remained an independent prognostic factor for DFS. The results show that in low-risk subgroups, NGAL was found to be a predictive marker for pCR after NACT. Furthermore, NGAL could be validated as an independent prognostic factor for decreased DFS in primary human BC.

Role of Cannabinoid Receptor CB2 in HER2 Pro-oncogenic Signaling in Breast Cancer

BACKGROUND Pharmacological activation of cannabinoid receptors elicits antitumoral responses in different cancer models. However, the biological role of these receptors in tumor physio-pathology is still unknown. METHODS We analyzed CB2 cannabinoid receptor protein expression in two series of 166 and 483 breast tumor samples operated in the University Hospitals of Kiel, Tübingen, and Freiburg between 1997 and 2010 and CB2 mRNA expression in previously published DNA microarray datasets. The role of CB2 in oncogenesis was studied by generating a mouse line that expresses the human V-Erb-B2 Avian Erythroblastic Leukemia Viral Oncogene Homolog 2 (HER2) rat ortholog (neu) and lacks CB2 and by a variety of biochemical and cell biology approaches in human breast cancer cells in culture and in vivo, upon modulation of CB2 expression by si/shRNAs and overexpression plasmids. CB2-HER2 molecular interaction was studied by colocalization, coimmunoprecipitation, and proximity ligation assays. Statistical tests were two-sided. RESULTS We show an association between elevated CB2 expression in HER2+ breast tumors and poor patient prognosis (decreased overall survival, hazard ratio [HR] = 0.29, 95% confidence interval [CI] = 0.09 to 0.71, P = .009) and higher probability to suffer local recurrence (HR = 0.09, 95% CI = 0.049 to 0.54, P = .003) and to develop distant metastases (HR = 0.33, 95% CI = 0.13 to 0.75, P = .009). We also demonstrate that genetic inactivation of CB2 impairs tumor generation and progression in MMTV-neu mice. Moreover, we show that HER2 upregulates CB2 expression by activating the transcription factor ELK1 via the ERK cascade and that an increased CB2 expression activates the HER2 pro-oncogenic signaling at the level of the tyrosine kinase c-SRC. Finally, we show HER2 and CB2 form heteromers in cancer cells. CONCLUSIONS Our findings reveal an unprecedented role of CB2 as a pivotal regulator of HER2 pro-oncogenic signaling in breast cancer, and they suggest that CB2 may be a biomarker with prognostic value in these tumors.

Transcription factors associated with epithelial–mesenchymal transition and cancer stem cells in the tumor centre and margin of invasive breast cancer

Although tumor surgery aims for a complete resection respecting tumor-specific safety distance, in many cases the most peripheral part, the invasion front, remains in situ. Tumor cells at the tumor margin lose epithelial properties and acquire features of mesenchymal cells. The process of epithelial-to-mesenchymal transition (EMT) has been suggested to be of prime importance for tissue and vessel invasion. Recently, features of EMT were shown to be linked to cells with tumor-founding capability, so- called cancer stem cells (CSC). In this study we show that transcription factors associated with EMT markers Snail, Slug, Twist and Zeb1 are differentially expressed between normal breast epithelium, ductal carcinoma in situ and invasive breast cancer. Both invasive and in situ carcinoma expressed less Slug and Twist and more Zeb1 compared to normal epithelium. Using fluorescence multi-staining the number of potential CSC among invasive cancer cells varied dramatically depending on the staining combination used (18.5% for CD44(+)/CD24(-) and 2.4% for CD49f(+)/CD24(+)). Interestingly, neither transcription factors associated with EMT nor potential CSC counts varied between tumor centre and invasion front. No association of these features with clinical outcome was detected. Our results suggest that reliable in situ markers for EMT are missing for invasive breast cancer. Alternatively, the process of EMT might be activated in tumor cells at the margin as well as the centre. Furthermore, our data show that the bio-markers of CSC detect very variable cell populations within breast cancer, challenging the assumption of a hierarchical organization of CSC in these tumors.

Differential expression of MMP-2, MMP-9 and PCNA in endometriosis and endometrial carcinoma

OBJECTIVES Endometriosis is a common gynaecological disease with clinical symptoms such as chronic pain, infertility and intra-abdominal adhesions. Different theories on the pathogenesis of endometriosis and especially its aggressive subtype with infiltrative growth have been discussed. The objective of this study is to evaluate differences in proliferation and invasive properties of invasive colorectal endometriosis, superficial peritoneal endometriosis and endometrial carcinoma (G1 and G2). STUDY DESIGN Paraffin embedded tissues of peritoneal endometriosis, endometriosis of the intestine and endometrial carcinoma from 97 patients were stained immunohistochemically to assess differences in expression patterns of matrix metalloproteinases (MMP-2, MMP-9) as markers of invasion and the marker of proliferation PCNA. MMP expression was evaluated using the Immuno Reactive Score (IRS) (combining positive cell ratio and staining intensity) and PCNA expression was assessed as the percentage of positively stained cells in representative areas. RESULTS MMP-2, MMP-9 and PCNA showed differential expression patterns in the different tissues examined. MMP-2 and PCNA expression was stronger in invasive colorectal endometriosis than in superficial peritoneal endometriosis (p=0.0394). MMP-9, however, was more frequently expressed in peritoneal endometriosis (59.1%) than in colorectal endometriosis (44.4%). This result did not reach statistical significance. When colorectal endometriosis was compared to low grade endometrial carcinoma, proliferation detected by PCNA was significantly higher in endometriosis (p=0.0008). MMP-2 and MMP-9 showed higher expression in endometrial carcinoma than in endometriosis. CONCLUSIONS There are obvious differences in expression patterns of MMP-2, MMP-9 and PCNA in different stages of endometriosis and in endometrial cancer. These markers can be helpful to evaluate aggressiveness and invasiveness of endometriosis in different localizations. The results obtained could be of relevance for a better understanding of the pathogenesis of endometriosis and the development of an individual therapy concept.

Activation of the orphan receptor GPR55 by lysophosphatidylinositol promotes metastasis in triple-negative breast cancer.

The orphan G protein-coupled receptor GPR55 has been directly or indirectly related to basic alterations that drive malignant growth: uncontrolled cancer cell proliferation, sustained angiogenesis, and cancer cell adhesion and migration. However, little is known about the involvement of this receptor in metastasis. Here, we show that elevated GPR55 expression in human tumors is associated with the aggressive basal/triple-negative breast cancer population, higher probability to develop metastases, and therefore poor patient prognosis. Activation of GPR55 by its proposed endogenous ligand lysophosphatidylinositol confers pro-invasive features on breast cancer cells both in vitro and in vivo. Specifically, this effect is elicited by coupling to Gq/11 heterotrimeric proteins and the subsequent activation, through ERK, of the transcription factor ETV4/PEA3. Together, these data show that GPR55 promotes breast cancer metastasis, and supports the notion that this orphan receptor may constitute a new therapeutic target and potential biomarker in the highly aggressive triple-negative subtype.

Nilotinib in Combination with Carboplatin and Paclitaxel Is a Candidate for Ovarian Cancer Treatment

Purpose: Nilotinib is a selective tyrosine kinase inhibitor of c-Kit, Abl and platelet-derived growth factor receptor-α/β. To evaluate nilotinibs potential use as a treatment of human ovarian cancer, we tested nilotinibs preclinical activity in ovarian cancer cell lines with different tyrosine kinase expression patterns. Methods: The effects of nilotinib on ovarian cancer cell growth were studied alone and in combination with carboplatin and paclitaxel. Proapoptotic and antimigratory effects were examined using TUNEL and migration assays. Results: Nilotinib alone and in combination with carboplatin and paclitaxel significantly inhibited cell growth in PDGFR-α-positive ovarian cancer cell lines. The combination of nilotinib with carboplatin and paclitaxel showed synergistic effects on cell proliferation. Nilotinib treatment led to the inhibition of cell migration alone and in combination with carboplatin and paclitaxel. Apoptosis induction occurred in response to nilotinib that increased in combination with carboplatin. Conclusions: Nilotinib may be a feasible targeted therapy option for the treatment of ovarian cancer.

Stromal markers AKR1C1 and AKR1C2 are prognostic factors in primary human breast cancer

BackgroundStromal fibroblasts influence tumor growth and progression. We evaluated two aldo–keto reductases, AKR1C1 and AKR1C2, in stromal fibroblasts and carcinoma cells as prognostic factors in primary human breast cancer. They are involved in intratumoral progesterone metabolism.MethodsImmunohistochemistry was performed on tissue microarrays from 504 core biopsies from breast cancer patients. Primary endpoints were disease-free (DFS) and overall (OS) survival.ResultsAKR1C1 and AKR1C2 expression in fibroblasts and tumor cells correlated with favorable tumor characteristics, such as small tumor size and negative nodal status. In univariate analysis, AKR1C1 expression in carcinoma cells correlated positively with DFS und OS; AKR1C2 expression in both fibroblasts and tumor cells also showed a positive correlation with DFS and OS. In multivariate analysis, AKR1C1 expression in carcinoma cells was an independent prognostic marker.ConclusionIt can be assumed that our observations are due to the independent regulatory function of AKR1C1/2 in progesterone metabolism and therefore provide a basis for new hormone-based therapy options for breast cancer patients, independent of classic hormone receptor status.

2D Versus 3D in Laparoscopic Surgery by Beginners and Experts: A Randomized Controlled Trial on a Pelvitrainer in Objectively Graded Surgical Steps

BACKGROUND AND OBJECTIVE Progress in endoscopic surgery in the past few decades has led to the application of 3-dimensional (3D) procedures in operating rooms. This permits patient- and surgeon-friendly operations and also maximizes the superiority of laparoscopy over laparotomy. In this study, we compare 2-dimensional (2D) and 3D endoscopy techniques with regard to time, efficiency, optics, and handling by users with different degrees of experience at 4 difficulty levels. DESIGN A randomized controlled trial on a pelvitrainer in objectively graded surgical steps for students and postgraduates. SETTING The trials took place at the Kiel School of Gynaecological Endoscopy, a training unit of the Kiel University Department of Obstetrics and Gynecology, a tertiary academic medical center. PARTICIPANTS The 277 study participants, divided into students, residents, and specialists, worked on pelvitrainers with 2 different optical systems, the 2D full HD and the 3D mode. The following 4 exercises were performed with each optical system: (1) grasping and transferring of pins, (2) cutting predetermined marks, (3) vaginal closure with prevention of prolapse, and (4) sacrocolpopexy. The duration and success of the tasks were measured and compared. A self-assessment questionnaire was completed by the participants. RESULTS Overall, the 3D-system permitted a greater improvement in working speed, superior optical visualization, and better endoscopic handling in all groups, independent of surgical experience. All students improved in speed (exercises: 1-3) and made significantly fewer mistakes (exercise 2) on 3D compared with 2D. Residents made progress in time (exercises: 1-4) and task performance (exercise 3). Specialists improved significantly in the more challenging tasks 3 and 4. Subjectively, 68.8% of participants preferred 3D for performing laparoscopy. CONCLUSION Systematic training programs on pelvitrainers can improve endoscopic skills not only in beginners but also in experienced surgeons. The 3D system offered distinct advantages over 2D imaging and was well accepted by surgeons.

In situ localization of tumor cells associated with the epithelial-mesenchymal transition marker Snail and the prognostic impact of lymphocytes in the tumor microenvironment in invasive ductal breast cancer

PURPOSE Tumor surgery is aimed at complete resection of the lesion while ensuring a sufficient tumor-specific safety distance. Nevertheless, in many cases the most peripheral part - the invasion front - remains in situ. Tumor cells at the tumor margin have been reported to lose their epithelial properties and acquire features of mesenchymal cells. The process of epithelial-to-mesenchymal transition (EMT) is believed to be of prime importance for tissue and vessel invasion. Furthermore, the detection of tumor-infiltrating lymphocytes in the microenvironment of breast cancer might serve as a reliable prognostic marker. METHODS We investigated tissue microarrays of 352 breast cancer patients with regard to the presence and distribution of the EMT factor Snail, and the presence of FoxP3, CD3 and CD8 in the immune microenvironment. RESULTS The expression of the transcription factor Snail is strongly associated with longer disease-free and overall survival. The presence of CD3, CD8 or FoxP3 is associated with a better outcome, although statistically significant results were noted only for FoxP3. The prognostic significance of FoxP3 and Snail were also proven in multivariate analysis. CONCLUSIONS Based on previous studies concerning the intratumoral heterogeneity of EMT, our results suggest that Snail and FoxP3 are possible prognostic markers for breast cancer. The diverse presence of lymphocytes in the tumor microenvironment (CD3 and CD8) was confirmed. Although the importance of these markers is known, their specific role in tumor invasion and metastasis as well as their hierarchical organization in these tumors remain unclear.

Frequent translocations of 11q13.2 and 19p13.2 in ovarian cancer.

Aberrations of chromosome arm 19p in ovarian cancer were first described decades ago and have been confirmed in recent publications, which have focused on chromosome 11 as a translocation partner. Recently, genetic analysis of the ovarian cancer cell line SKOV3 revealed a rearrangement described as der(19)t(11;19)(q13.2;p13.2), which lead to a fusion protein containing parts of HOOK2 and frame shifted ACTN3 that had unknown functionality. To evaluate the frequency of these breakpoints, we used fluorescence in situ hybridization (FISH) probes flanking these genes for interphase analysis of ovarian cancer cells. We analyzed 49 primary cell cultures of ovarian cancers using FISH probes next to these breakpoints on chromosomes 11 and 19 defined in SKOV3. Co‐localizations of the signals in interphase nuclei were considered to be positive fusions when the frequency was over the experimentally calculated cutoff of 24.3% (mean average value for normal ovary cells plus three times the standard deviation). Fusions between 11q13.2 and 19p13.2 were confirmed in 22 (45%) primary cell cultures of ovarian cancers. However, by PCR, the fusion originally described in SKOV3 was not detected in any of the primary cell cultures. Our results confirm other reports and show that these regions are very frequently involved in chromosomal rearrangements in ovarian cancer. Furthermore, they reveal a significant correlation (P = 0.023) of co‐localized signals of 11q13.2 and 19p13.2 with low and intermediate grades in ovarian cancer.