Selective ETAR antagonist atrasentan inhibits hypoxia-induced breast cancer cell invasion.

Tumour hypoxia, being widespread in solid tumours, is related to an increased risk of invasion and metastasis as well as to resistance to chemotherapy and radiotherapy. Hypoxia-inducible factor-1alpha (HIF-1alpha) has emerged as the key regulator of the cellular response to hypoxia. In primary breast cancers, HIF-1alpha is overexpressed, and high levels of HIF-1alpha predict for early relapse and increased metastasis. The endothelin (ET) axis, comprising the peptides ET-1, -2, -3 and their receptors A (ETAR) and B (ETBR), is another regulatory system of major relevance in human breast cancer. However, little is known about the interaction of HIF-1alpha and the ET axis in breast carcinomas. Therefore, we analysed expression of HIF-1alpha and the ET axis in 600 breast cancer tissue samples by immunohistochemistry, observing a significant correlation between expression of HIF-1alpha and ET-1 (P<0.001). In vitro, hypoxia was found to double ET-1 secretion of MCF-7 breast cancer cells (203.5% of controls; P<0.001), thereby promoting an invasive phenotype. Of note, real-time PCR analysis revealed that the increase of ET-1 was not due to enhanced transcription of the ET-1 gene. In invasion assays, breast cancer cell invasiveness was strongly increased by hypoxia (150.0% of controls; P=0.007). Most important, this increase was completely inhibited by the selective ETAR antagonist atrasentan. In conclusion, we provide evidence for a relevant interaction between hypoxia and the ET axis in breast cancer cells. Our data suggest that tumour hypoxia induces breast carcinoma invasiveness by releasing intracellularly stored ET-1. However, induction of invasiveness may be inhibited by selective ETAR antagonism, thus emphasising the promising status of the ET axis as a therapeutic target in breast cancer.

Expression of aromatase and estrogen sulfotransferase in preinvasive and invasive breast cancer.

PURPOSE: Intratumoral estradiol levels in postmenopausal women with breast cancer are thought to be mainly regulated by the aromatase-mediated conversion from androgens and estrogen sulfotransferase (EST)-mediated reduction of bioavailability. While in invasive breast cancer (IBC) the role of both enzymes has been extensively studied and has led to the use of aromatase inhibitors as a key therapeutic strategy, comparably little is still known about their role in the local regulation of estradiol in ductal carcinoma in situ (DCIS). METHODS: We have performed immunohistochemistry to investigate the expression of aromatase and sulfotransferase in custom-made breast cancer tissue arrays containing 96 samples of pure DCIS and in 104 tumor biopsies which contain both, DCIS and invasive components. RESULTS: We found that aromatase was equally detectable in epithelial components of both, DCIS and IBC (P = 0.884, Chi square test). However, stromal aromatase expression was significantly higher in IBC compared to adjacent DCIS components (P = 0.034, Chi square test). Whereas no significant difference was observed for epithelial aromatase expression in high versus non-high grade DCIS (P = 0.735 Chi square test), epithelial EST levels were found to be significantly down-regulated in high-grade DCIS compared to non-high grade cases (P = 0.042). CONCLUSION: We have demonstrated the presence of both aromatase and EST in malignant epithelium and adjacent stromal fibroblasts in DCIS. Lower stromal aromatase expression in preinvasive breast cancer and lower EST levels in high-grade DCIS suggest that the net effect of intratumoral estradiol (E2)-modulating enzymes results in lower local E2 levels in earlier stages of breast tumorigenesis.

Expression and prognostic impact of the protein tyrosine phosphatases PRL-1, PRL-2, and PRL-3 in breast cancer.

The aim of this study was to investigate the expression of the protein tyrosine phosphatases (PTP) PRL-1, PRL-2, and PRL-3 in human breast cancer and to evaluate its clinical and prognostic significance. PRL-PTP mRNA expression was examined in malignant (n = 7) and nonmalignant (n = 7) cryoconserved breast tissue samples as well as in eight breast cancer cell lines by RT-PCR. Furthermore, protein expression of PRL-3 was analysed semiquantitatively by immunohistochemistry in ductal breast carcinoma in situ (n = 135) and invasive breast cancer (n = 147) by use of tissue microarray technology (TMA). In 24 lymph node-positive patients we selected the corresponding lymph node metastases for analysis of PRL-3 expression, and a validation set (n = 99) of invasive breast cancer samples was examined. Staining results were correlated with clinicopathological parameters and long-term follow-up. PRL-3 mRNA expression was significantly higher in malignant compared to benign breast tissue. For PRL-1 and PRL-2 expression no significant differences were observed. Staining of TMAs showed PRL-3 expression in 85.9% ductal carcinoma in situ and 75.5% invasive breast carcinomas. Analysis of survival parameters revealed a shorter disease-free survival (DFS) in patients with PRL-3-positive carcinomas, and in particular a significantly shorter DFS in nodal-positive patients with PRL-3 overexpressing tumours as compared to PRL-3-negative breast carcinomas (66+/-7 months (95% CI, 52-80) vs 97+/-9 months (95% CI, 79-115); P = 0.032). Moreover, we found a more frequent expression of PRL-3 in lymph node metastases as compared to the primary tumours (91.7 vs 66.7%; P = 0.033). Our results suggest that PRL-3 might serve as a novel prognostic factor in breast cancer, which may help to predict an adverse disease outcome.

Expression patterns of angiogenic and lymphangiogenic factors in ductal breast carcinoma in situ.

The objective of this study was to investigate expression of various growth factors associated with angiogenesis and lymphangiogenesis and of their receptors in ductal carcinomas in situ of the breast (DCIS). We studied protein expression of basic fibroblast growth factor (bFGF), vascular endothelial growth factor (VEGF)-A, endothelin (ET)-1, and VEGF-C, and their receptors bFGF-R1, Flt-1, KDR, ET(A)R, ET(B)R, and Flt-4 immunohistochemically in 200 DCIS (pure DCIS: n=96; DCIS adjacent to an invasive component: n=104) using self-constructed tissue microarrays. Basic fibroblast growth factor-R1, VEGF-C, Flt-4, and ET(A)R were expressed in the tumour cells in the majority of cases, whereas bFGF and Flt-1 expression was rarely observed. VEGF-A, KDR, ET-1, and ET(B)R were variably expressed. The findings of VEGF-C and its receptor Flt-4 as lymphangiogenic factors being expressed in tumour cells of nearly all DCIS lesions and the observed expression of various angiogenic growth factors in most DCIS suggest that in situ carcinomas are capable of inducing angiogenesis and lymphangiogenesis. Moreover, we found a higher angiogenic activity in pure DCIS as compared to DCIS with concomitant invasive carcinoma. This association of angiogenic factors with pure DCIS was considerably more pronounced in the subgroup of non-high-grade DCIS (n=103) as compared with high-grade DCIS (n=94). Determination of these angiogenic markers may therefore facilitate discrimination between biologically different subgroups of DCIS and could help to identify a particularly angiogenic subset with a potentially higher probability of recurrence or of progression to invasiveness. For these DCIS, targeting angiogenesis may represent a feasible therapeutic approach for prevention of progression of DCIS to invasion.

A prospective randomized trial of closing laparoscopic trocar wounds by transcutaneous versus subcuticular suture or adhesive papertape.

BACKGROUND: Several methods for closure of trocar wounds are known in laparoscopic surgery. The choice of technique (mostly transcutaneous or subcuticular suture or adhesive papertape) is often based on the surgeon's personal experience. Thus, the objective of this trial was to assess the impact of these closure methods on potential complications of wound healing, cosmetic outcome, and patient satisfaction. METHODS: Sixty patients undergoing operative laparoscopic surgery for gynecologic indications were enrolled in this prospective randomized trial. Five-millimeter port-site incisions were closed either with subcuticular or transcutaneous absorbable sutures (4-0 polyglactin 910) or with adhesive papertape. Postoperative complications, pain, and patient satisfaction with scars were evaluated at 3-month follow-up after operation using a questionnaire. RESULTS: Data from 52 patients who returned the questionnaire were analyzed. Dissatisfying cosmetic results were reported significantly more frequently after subcuticular sutures (p < 0.05). Assessment of patient satisfaction with cosmetic outcome on a visual-analogue scale revealed significantly better results after transcutaneous skin closure than with other approaches (p < 0.05). Adverse wound healing (e.g., infections and dehiscence) was observed most frequently in the subcuticular suture group. Also, the rate of painful scars was highest with this technique. CONCLUSIONS: Transcutaneous closure with absorbable suture material seems to be the most suitable technique for closure of laparoscopic port-site incisions.

[Cyclooxygenase-2-expression in bladder cancer: tumor-biological and clinical implications]. / Cyclooxygenase-2-Expression beim Harnblasenkarzinom: Tumorbiologische und klinische Bedeutung.

PURPOSE: Cyclooxygenase-2 (Cox-2) contributes to the carcinogenesis of human tumors by various mechanisms. As Cox-2-expression has been found in most human neoplasms, selective Cox-2-inhibitors could be used as a molecular targeted therapy, and first clinical trials have already been initiated. Moreover, Cox-2-inhibitors have been shown to add to the activity of conventional cytotoxic therapies in experimental and clinical studies. We analyzed Cox-2-expression in bladder cancer and its implications on clinical parameters. MATERIALS AND METHODS: Cox-2-expression was evaluated immunohistochemically in 157 patients undergoing radical cystectomy. Sixty-two patients had received cisplatin-based treatment during follow-up, either as adjuvant therapy or for metastatic disease. Cox-2-expression was correlated with clinical and pathological parameters, survival data and outcome of chemotherapy. RESULTS: Cox-2 was expressed in 83.4 % of tumors. No association was found with TNM-staging and histological grading, but a significant relation to the histologic subtype (transitional vs. squamous cell carcinoma, p = 0.038) was present. Survival analysis showed no impact of Cox-2-expression on overall or disease-free survival. However, a subgroup of chemotherapy patients demonstrated a significant correlation of strong Cox-2-expression with worse overall survival time (p = 0.01). CONCLUSIONS: Cox-2-expression was found in the majority of invasive bladder tumors. For patients who underwent chemotherapy, a significant relation of Cox-2-expression and worse overall survival was demonstrated. Cox-2 seems to be an interesting molecular target for the diagnosis and therapy of bladder cancer. Further experimental and clinical studies are warranted to elucidate whether Cox-2-inhibition can serve as an additive therapy to chemotherapy of bladder cancer.

Expression of endothelin-A-receptor predicts unfavourable response to neoadjuvant chemotherapy in locally advanced breast cancer.

Endothelin-1 (ET-1) and its receptors (ETAR and ETBR), referred to as the endothelin (ET) axis, are overexpressed in breast carcinomas and appear to influence tumour growth and progression. The objective of this study was to determine the effect of expression of the ET axis in breast carcinomas on response to cytotoxic chemotherapy. The study included 44 patients with locally advanced breast cancer participating in a prospective phase III study evaluating high-dose neoadjuvant chemotherapy of epirubicin and cyclophosphamide. Expression of ET-1, ETAR and ETBR was determined by semiquantitative immunohistochemical analysis of breast cancer tissue from prechemotherapy tru-cut biopsies. Immunohistochemical staining was positive for ET-1 in 61.5%, for ETAR in 35% and for ETBR in 35.9% of breast carcinomas. Pathological response to chemotherapy was significantly decreased in ETAR-positive patients (P=0.002). In total, 50% of ETAR-positive patients as compared to 7.7% of ETAR-negative patients attained pathologically 'no change'. Logistic regression confirmed ETAR as an independent predictive marker for pathological response (P=0.009). These data indicate that increased expression of ETAR in breast carcinomas is associated with resistance to chemotherapy. Determination of ETAR status may serve as a predictive marker for identifying patients less likely to be responsive to conventional chemotherapy.