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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. [ABSTRACT FROM AUTHOR]

The article offers information on various procedures regarding the treatment of breast cancer. Procedural elements related to breast cancer treatment (BCT), breast-conserving surgery (BCS), and adjuvant radiation therapy are discussed. An overview of the theory on intratumoral heterogeneity, tumor stem cells (cancer initiating cells), and epithelial-to-mesenchymal transition is presented. Also mentioned are TSC or cancer initiating cells (CIC), snail immunostaining, and slug immunostaning.

Background: The purpose of this single-center study was to determine the practicability of the intra-operative use of one-step nucleic acid amplification (OSNA) as the only method for detection of SLN. The OSNA system has been well described and is supposed to be as accurate as conventional histology., Methods: Three hundred and thirty SLNs from 143 breast cancer patients were analyzed in an intra-operative setting. The CK19-copy number was determined by OSNA and divided into 3 results ("-" no metastasis; "+" micrometastasis; "++" marcometastasis). If OSNA gave a positive result, an axillary lymph node dissection was carried out during the same session. The central 1-mm slice of each node was obtained for permanent histology. Additionally, the results were correlated to clinicopathological factors, and the time for the intra-operative use was evaluated., Results: Thirty-nine of the 143 patients were OSNA positive, 22 with macrometastatic and 17 with micrometastatic spread. The mean time for the OSNA run with one SLN was 34.4 min. We could show a correlation between the tumor size and OSNA positivity as well as between the numbers of OSNA positive SLNs with the tumor load of associated non-SLNs. Furthermore, we found that a cutoff CK19 copy number of 7,900/μL indicates a positive non-SLN result with the highest sensitivity (91 %) and specificity (61 %)., Conclusion: We found OSNA to be very helpful for the intra-operative determination of the tumor load of a SLN as a basis for decision-making concerning further surgical axillary intervention. OSNA allows precise differentiation of micro- from macrometastasis, and the CK19 copy number predicts the probability of tumor load in other axillary lymph nodes and might help to find adequate adjuvant treatment options. This objective method is well suitable for everyday use and may reduce the pathologic workload and the risk of secondary operative interventions with all associated costs and stress for the patients.

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., (Copyright © 2012 Elsevier Inc. All rights reserved.)

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., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)