Expression In Breast Cancer Patients Research Articles

Prognostic significance of MAGE-A10 and NY-ESO-1 cancer-testis antigen in breast cancer.

e21126 Background: Cancer testis antigens (CTAs) are expressed in a variety of malignant tumors. In normal adult tissues CTA expression is restricted predominantly to germs cells of the adult testis and placenta. Based on their tumor-restricted expression pattern, CTAs are regarded as valuable targets for cancer immunotherapy. The prognostic significance of CTAs in breast cancer has not been analyzed previously. Methods: To evaluate the potential prognostic significance of two member of this family, MAGE-A10 and NY-ESO-1 antigens, we examined their expression in breast cancer patients who underwent curative surgery at our hospital between 2002 and 2003. Paraffin embedded tumor sections were collected retrospectively from 165 breast cancer patients and immunohistochemical staining for MAGE-A10 and NY-ESO-1 was performed. Impact of MAGE-A10 and NY-ESO-1 expression on disease free survival (DFS) and overall survival (OS) was analyzed by the Kaplan-Meier method using 8-year follow up data. Results: MAGE-A10 expression (score ≥2+) was detected in 105/164 (64%) and NY-ESO-1 expression (score ≥2+) was observed in 14/164 (8.5%) patients. 8-year DFS for MAGE-A10 positive patients was 69% and 73% for MAGE-A10 negative (p=0.452). 8-year OS for MAGE-A10 positive patients was 80% and 90% for MAGE-A10 negative (p=0.134). For NY-ESO-1 positive patients 8-year DFS was 67% and 70% for NY-ESO-1 negative patients (p=0.837). 8-year OS for NY-ESO-1 positive patients was 83% and 84% for NY-ESO-1 negative patients. (p=0.991) Conclusions: To our knowledge this is the first study analyzing prognostic significance CTAs in breast cancer. In this retrospective study we did not show statistically significant correlation between MAGE-A10 and NY-ESO-1 expression and clinical outcome. Additional studies are warranted to determine weather this antigens might have prognostic value in breast cancer patients.

Topoisomerase II alpha gene status, HER2, and microtubule-associated protein tau as predictors of pathologic complete response after neoadjuvant chemotherapy.

10555 Background: There is growing evidence that topoisomerase II-alpha (TOPOIIα) is a marker for anthracycline-, and microtubule-associated protein tau (MAPT) for taxane sensitivity. HER2 has been described as a marker of both anthracycline and taxane sensitivity.The goal of our study was to examine the predictive and prognostic value of TOPOIIα, MAPT and HER2 expression in breast cancer patients (pts) who received neoadjuvant chemotherapy (NAC) based on anthracycline-taxane regimens. We analyzed the relationship between these biomarkers and pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Methods: Between November 1993-2009, 140 pts (mean age 52 years) with locally advanced breast cancer (T1-4, N0-3, M0) were retrospectively studied. The study contained 2 groups: group A included 85 pts who received NAC with an anthracycline-taxane regimen and group B included the last 55 pts who received NAC with only an anthracycline-based regimen. HER2 was tested by immunohistochemistry (IH) or FISH, TOPOIIα by CISH and MAPT by IH. Expression of these proteins was evaluated in core needle breast biopsy. Results: Overall, 12 pts (8.5%) had a pCR. TOPOIIα was amplified in 6 (4%) of the tumors. Among pts without amplification, 6 (4%) had deletion of the TOPOIIα, and 10 (7%) polysomia of chromosome 17. TOPOIIα gene aberrations (amplification, deletion, polysomia), which was present in 22 (25%) of the tumors, was a strong predictive factor for pCR (p=0.018) but showed no direct association with prognostic outcome in multivariate analysis. HER2 amplification, which was present in 16% (21) of the tumors, show no direct association with pCR, DFS or OS. Finally, differences by treatment arm or pCR in low versus high MAPT expression groups were not observed, indicating that MAPT is not a useful predictive marker for taxane-based chemotherapy. In multivariate analysis high MAPT expression was associated with longer DFS (p=0.002). Conclusions: TOPOIIα gene aberrations but not HER2 are highly predictive of pCR for anthracycline-based regimen. MAPT is not associated with response to taxanes but has a prognostic value.

8O_PR MUCIN-1 Protein and Mrna Expression in Breast Cancer Patients Treated with Neoadjuvant Chemotherapy

ABSTRACT Mucin-1 (MUC1) is expressed in normal breast epithelium and invasive breast cancer. It has pleiotropic effects on tumour biology, e.g. regulation of cell polarity, crosstalk with cellular signalling and regulation of immune response. Tumor vaccines targeting MUC1 are currently tested in clinical trials. The aim of this study was to evaluate the frequency of MUC1 expression and its predictive value for response and survival after neoadjuvant anhracycline/taxane-based chemotherapy. We investigated MUC1 protein (n = 691) and mRNA (n = 268) expression in pre-treatment core biopsies from participants of the GeparTrio trial by immunohistochemistry and quantitative RT-PCR from formalin-fixed paraffin-embedded (FFPE) samples. MUC1 protein expression was detectable in 656 (95%) cases; mRNA levels covered a range of 103 copy numbers. Protein and mRNA expression were correlated (p High MUC1 protein and mRNA expression were more frequently in HR+ (hormone-receptor positive) tumors (p Low MUC1 protein and mRNA expression were predictive for pCR (pathologic complete response) in the overall population (p MUC1 protein expression was a positive prognostic marker for survival in the overall population (p = 0.03) and in HER2- (p = 0.005) tumors. MUC1 mRNA was prognostic in the overall population (p MUC1 is frequently expressed in a large cohort of breast cancer, especially in HR+ tumors. Evaluation is feasible by immunohistochemistry and quantitative RT-PCR from FFPE tissue and provides information on therapy response and survival following neoadjuvant chemotherapy. MUC1 expression may serve as a predictive marker in clinical immunotherapy trials. Disclosure All authors have declared no conflicts of interest.

Abstract 4895: Caveolin-1 modulates docetaxel activity by inducing p53 expression in breast cancer.

Abstract Caveolin-1 is reported to be down-regulated in breast cancers compared with normal mammary tissue. More recent data showed that high caveolin-1 expression is more associated with basaloid cancers than ER and/or PR or HER-2 expressing cancers. Investigatirs have reported that Caveolin-1 promoted resistance to chemotherapy-induced apoptosis in Ewing's sarcoma cells. However, the biologic relevance of caveolin-1 in breast cancer remains unclear. Thus, the aim of this study is to investigate its potential biologic relevance of Caveolin-1 to cell survival after docetaxel chemotherapy, one of the most important drug in breast cancer treatment. In this current study, we first showed that Caveolin-1 protein expression was suppressed in the ER(+) human breast cancer cell lines (MCF-7, T47D, and ZR75-1), but not in triple negative cancer cells (MDA-MB-231 and HS578T) and one of the HER-2 type cell (HCC1954) using Western blot analysis. Better cytotoxic effect of docetaxel was observed in the caveolin-1-expressing triple negative cells and HER-2 type cell than the other caveolin-1-deficient HER-2 type and luminal type of cancer cells. Next, caveolin-1 gene was reintroduced into caveolin-1 deficient luminal type breast cancer cells (MCF-7 and ZR75-1) to investigate its potential modulatory effect on docetaxel-induced cytotoxicity. The cell proliferation and MTT assay showed that the overexpressed caveolin-1 had further modulated docetaxel-induced anti-proliferative and cytotoxic effect in the luminal type cells. The anti-proliferative effect of docetaxel in the caveolin-1 gene over-expressed breast cancer cell lines was accompanied by decreasing cyclin D1 expression and inducing cyclin B1 accumulation, then resulting in cell cycle arrest at G2/M phase in the FACS analysis. In addition, re-introduction of caveolin-1 further increased docetaxel-induced cell death by synergistically inducing p53 expression and subsequent induction of p21, then finally apoptosis of breast cancer cells. These results were verified in the mouse model using SCID mice implated with either Caveolin-1-MCF-7 cells or control MCF-7 cells. When each group of tumor-bearing mice were treated by docetacel, mice with Caveolin-1-MCF-7 tumors showed a signiflcantly smaller tumors than those of control group. These results suggest that caveolin-1 may have a modulating factor for docetaxel activity by inducing p53 expression in breast cancer patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4895. doi:1538-7445.AM2012-4895

LMW-E/CDK2 Deregulates Acinar Morphogenesis, Induces Tumorigenesis, and Associates with the Activated b-Raf-ERK1/2-mTOR Pathway in Breast Cancer Patients

Elastase-mediated cleavage of cyclin E generates low molecular weight cyclin E (LMW-E) isoforms exhibiting enhanced CDK2–associated kinase activity and resistance to inhibition by CDK inhibitors p21 and p27. Approximately 27% of breast cancers express high LMW-E protein levels, which significantly correlates with poor survival. The objective of this study was to identify the signaling pathway(s) deregulated by LMW-E expression in breast cancer patients and to identify pharmaceutical agents to effectively target this pathway. Ectopic LMW-E expression in nontumorigenic human mammary epithelial cells (hMECs) was sufficient to generate xenografts with greater tumorigenic potential than full-length cyclin E, and the tumorigenicity was augmented by in vivo passaging. However, cyclin E mutants unable to interact with CDK2 protected hMECs from tumor development. When hMECs were cultured on Matrigel, LMW-E mediated aberrant acinar morphogenesis, including enlargement of acinar structures and formation of multi-acinar complexes, as denoted by reduced BIM and elevated Ki67 expression. Similarly, inducible expression of LMW-E in transgenic mice generated hyper-proliferative terminal end buds resulting in enhanced mammary tumor development. Reverse-phase protein array assay of 276 breast tumor patient samples and cells cultured on monolayer and in three-dimensional Matrigel demonstrated that, in terms of protein expression profile, hMECs cultured in Matrigel more closely resembled patient tissues than did cells cultured on monolayer. Additionally, the b-Raf-ERK1/2-mTOR pathway was activated in LMW-E–expressing patient samples, and activation of this pathway was associated with poor disease-specific survival. Combination treatment using roscovitine (CDK inhibitor) plus either rapamycin (mTOR inhibitor) or sorafenib (a pan kinase inhibitor targeting b-Raf) effectively prevented aberrant acinar formation in LMW-E–expressing cells by inducing G1/S cell cycle arrest. LMW-E requires CDK2–associated kinase activity to induce mammary tumor formation by disrupting acinar development. The b-Raf-ERK1/2-mTOR signaling pathway is aberrantly activated in breast cancer and can be suppressed by combination treatment with roscovitine plus either rapamycin or sorafenib.

Adiponectin Can Affect ER Signaling in Obese Breast Cancer Patients

Background: While the various antitumororal activities of adiponectin as an adipocyte-derived hormone well studied, it is speculated that there is a crosstalk between adiponectin and esterogen receptor (ER) signaling. To test this hypothesis we evaluate the possible correlation between serum level of adiponectin with two estrogen receptors (ERα and ERβ) gene expression in breast cancer patients. Methods: In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI 2 and 34 obese, BMI ≥ 25 kg/m2).The mean age of Participants was 44.53 yr ± 1.79 yr (21 yr - 70 yr) .Serum level of adiponectin determined by ELISA. Following quantitative expression of estrogen receptors mRNA in tumor tissues was evaluated by Real-time PCR. Results: We find a significant reverse correlation between serum level of Adiponectin and ERα mRNA (r = –0.229, n = 64, p = 0.035) but no correlation was between adiponectin and ERβ in samples (p = 0.228). The lower adiponectin multiplied the odds of having higher ERα mRNA level by a factor of OR = 4.33, 1.28 - 14.6, 95% confidence interval (CI) as compared with those that displayed a moderate or higher serum level of adiponectin (>7.02 ng/ml). The same odds for next estrogen receptor, ERβ, was not greater than unity (OR = 0.31, 0.06 - 1.56, 95% CI). Conclusion: According to the obtained results, it is speculated that as adiponectin can affect ERs gene expression, so affecting the steroid receptor signaling can be proposed as a new underling mechanism of action for this adipokine in breast cancer pathogenesis especially in obese ones.

Fascin is a key regulator of breast cancer invasion that acts via the modification of metastasis-associated molecules.

The actin-bundling protein, fascin, is a member of the cytoskeletal protein family that has restricted expression in specialized normal cells. However, many studies have reported the induction of this protein in various transformed cells including breast cancer cells. While the role of fascin in the regulation of breast cancer cell migration has been previously shown, the underlying molecular mechanism remained poorly defined. We have used variety of immunological and functional assays to study whether fascin regulates breast cancer metastasis-associated molecules. In this report we found a direct relationship between fascin expression in breast cancer patients and; metastasis and shorter disease-free survival. Most importantly, in vitro interference with fascin expression by loss or gain of function demonstrates a central role for this protein in regulating the cell morphology, migration and invasion potential. Our results show that fascin regulation of invasion is mediated via modulating several metastasis-associated genes. We show for the first time that fascin down-regulates the expression and nuclear translocation of a key metastasis suppressor protein known as breast cancer metastasis suppressor-1 (BRMS1). In addition, fascin up-regulates NF-kappa B activity, which is essential for metastasis. Importantly, fascin up-regulates other proteins that are known to be critical for the execution of metastasis such as urokinase-type plasminogen activator (uPA) and the matrix metalloproteases (MMP)-2 and MMP-9. This study demonstrates that fascin expression in breast cancer cells establishes a gene expression profile consistent with metastatic tumors and offers a potential therapeutic intervention in metastatic breast cancer treatment through fascin targeting.

Prognostic significance of tumor/stromal caveolin‐1 expression in breast cancer patients

Caveolin-1 (Cav-1) has been extensively characterized in cancer biological research. However, the role of Cav-1 in the interaction between tumor and stromal cells remains unclear. In the present study, we examined Cav-1 expression in tumor cells and stromal cells in breast cancer tissue by immunohistochemical analysis and evaluated its prognostic value in a training cohort. Immunohistochemical analysis of Cav-1 expression was scored as (++), (+) or (-) according to the proportion of positively stained tumor cells (T) and stromal cells (S). Correlation analysis between tumor/stromal Cav-1 expression and clinicopathological parameters revealed that only T(++) Cav-1 status was positively associated with tumor size and histological nodal status (P = 0.019 and 0.021, respectively). Univariate analysis revealed that combined T(++)/S(-) status was significantly correlated with unfavorable prognostic outcomes (P < 0.001). Multivariate analysis demonstrated that this combined status is an independent prognostic factor for primary breast cancer (P = 0.002). Clinical outcomes in different subgroups of breast cancer patients were also strictly dependent on this combined status (P < 0.05). The prognostic value of T(++)/S(-) Cav-1 status was also validated in the testing cohort. Collectively, our data indicate that high Cav-1 expression in tumor cells and lack of this expression in stromal cells could help identify a particular subgroup of breast cancer patients with potentially poor survival. Further studies are required to understand the regulatory mechanism of Cav-1 in the tumor microenvironment.

Prognostic role of c-met expression in breast cancer patients

Background Hepatocyte growth factor plays an important role in tumor growth, metastasis and angiogenesis. C-met is HGF's high affinity receptor. Aim The aim of the study was to assess the correlations between c-met expression and clinic-pathological factors in breast cancer tissues. Furthermore, the purpose of the study was to evaluate the prognostic value of the hepatocyte growth factor receptor (HGFR, c-met) expressions in homogenous group of breast cancer patients. Materials and methods Tumor samples were collected from 302 patients with breast carcinoma treated with primary surgery. We have assessed the percentage of tumor cells with c-met expression, the intensity of reaction and the ratio of these two factors—immunoreactivity according to the Remmele score. Results We have observed no correlations between HGFR immunoreactivities and clinical parameters (tumor size, grade, axillary lymph node status, age). In 5-year observation we have found prognostic value of assessing c-met immunoreactivity in primary tumor. Conclusion Our study has revealed prognostic value of c-met. Unlike in other authors’ studies, our patients’ group is very homogenous which might contribute to obtained results.

Down-regulation of kallikrein-related peptidase 5 (KLK5) expression in breast cancer patients: a biomarker for the differential diagnosis of breast lesions

BackgroundKallikrein-related peptidase 5 (KLK5) is a secreted trypsin-like protease of the KLK family, encoded by the KLK5 gene. KLK5 has been found to cleave various extracellular matrix components, as well as to activate several other KLK proteases, triggering the stimulation of tissue microenvironment proteolytic cascades.Material and MethodsKLK5 expression levels were quantified in 102 cancerous and benign breast tissue specimens, obtained by randomly chosen patients, using RT-qPCR assay. Subsequently, advanced biostatistics were applied in order to analyze the KLK5 expression profile in the two patients' cohorts and also to evaluate its clinical significance for the discrimination of breast tumors.ResultsA statistically significant (p < 0.001) down-regulation of the KLK5 expression levels were observed in the malignant specimens compared to the benign ones. Logistic regression and ROC curve analysis revealed the significant (p < 0.001) and the independent (p < 0.001) value of the KLK5 expression quantification, for the discrimination of the malignant from the benign mammary gland biopsies. Moreover, KLK5 expression levels correlate with the pre-menopausal status (p < 0.005) as well as the ER-negative staining (p = 0.028) of women with breast cancer.ConclusionsThe quantification of KLK5 expression in breast tissue biopsies may be considered as a novel and independent biomarker for the differential diagnosis between malignant and benign tumors of the mammary gland.

Abstract 716: O6-Methylguanine DNA methyl transferase (MGMT) and tamoxifen resistance in patients with breast cancer

Abstract Tamoxifen is an estrogen receptor antagonist in breast tissue. It has been used as a hormonal therapy for early and advanced breast cancer both in premenopausal and postmenopausal patients with estrogen receptor positive breast cancer. Acquired resistance to tamoxifen therapy is a common therapeutic encounter. Different mechanisms for Tamoxifen resistance have been postulated. In the present study we investigated if over expression of MGMT causes tamoxifen resistance in breast cancer patients. Purpose: We sought to determine MGMT expression levels in various breast cancer cell lines as well as in breast cancer patient's samples before and after treatment with tamoxifen. Experimental Design: MGMT expression levels were compared in breast cancer tissue samples obtained from patients before starting treatment with Tamoxifen and after tumor progression due to development of Tamoxifen resistance. MGMT expression level was evaluated using western blot and immunohistochemical assays. Several commercial breast cell lines were evaluated for expression of MGMT. Results: We found that MGMT is over expressed in the majority of breast cancer cell lines compared to normal breast epithelial cells. Compared to pre Tamoxifen treatment, post Tamoxifen treated breast cancer patient samples have significantly higher levels of MGMT expression. Conclusion: Collectively, our results demonstrate that breast cancer cells showed significantly higher levels of MGMT expression and furthermore, Tamoxifen treatment induces further MGMT over expression in breast cancer patients. According to our results over expression of MGMT is a possible cause for Tamoxifen resistance. Inhibition of MGMT might overcome Tamoxifen resistance and restore breast cancer sensitivity to Tamoxifen treatment. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 716. doi:10.1158/1538-7445.AM2011-716

Correlation of interleukin 6 (IL-6) with estrogen and progesterone receptor expression in breast cancer patients

Background: Multifunctional cytokines play important and only partially defined roles in mammary tumor development and progression. Normal human mammary epithelial cells constitutively produce interleukin 6(IL-6) and a non-secreted form of tumor necrosis factor. Transformation of mammary epithelial cells by different oncogenesis is frequently associated with alterations of cytokine/ growth factor production and responsiveness.Methods: We measured levels of 1L-6 in 84 females with breast cancer and examined their correlation with clinicopathological variables including stages of the disease and estrogen andprogesterone receptor expression on tumor cell.Results: Our results revealed significantly higher serum IL-6 in breast cancer patients (12.98 pg/ml) compared to a healthy group (2.05pg/ml) (P&lt;0.05) and a direct association with different clinical stages. And we found that expression of this cytokine was inversely associated with estrogen and progesterone receptor cells.Conclusion: Serum levels of IL-6 are highly elevated in breast cancer patients and correlate with tumor progression. Assay for serum levels IL-6 can be used as predictive non-invasive tests for tumor progression in breast cancer patients; also our data suggest that cytokine could be involved in the aggressiveness of ER-PR negative breast tumors. Expression of interleukin 6(IL-6) correlates with estrogen and progesterone receptor in breast cancer patients.

Quantification of Steroid Receptors Gene Expression in Breast Cancer Patients: Possible Correlation with Serum Level of Adipocytokines

Background: While the role of adipocyte-derived hormones in breast cancer pathogenesis well studied, it is speculated that there is a crosstalk between adipocytokines and Esterogen receptor(ER) signaling. To test this hypothesis we evaluate the possible correlation between serum levels of adipocytokins with steroid hormone receptors gene expression in breast cancer patients. Methods: In this case-control study, 70 women with breast cancer participated with different grades of obesity (36 none obese, BMI 0.05). In case of leptin, we observed a positive correlation between leptin and ERα and PR mRNA. (r = 0.553, n = 64, p < 0.001, r = 0.359, n = 64, p = 0.002 and a reverse significant correlation between leptin and ERβ (r= –0.506, n = 64 and p < 0.001). We also observed a significant correlation between TNFα and IL6 with steroid receptors gene expression in samples (P < 0.05). Conclusion: As the presence of steroid receptors are used as the most common prognostic markers in breast cancer patients, so targeting adipocytokines as potential regulators of steroid receptorsgene expression can be a new approach in treatment of obese breast cancer subjects.

Significance of Bax Expression in Breast Cancer Patients

Bax protein, the proapoptotic member of Bcl-2 protein family, plays the key role in apoptosis pathway. THE AIM OF THE STUDY was to assess the expression of Bax protein in breast cancer cells. Sixty-two breast cancer patients were included in the study. The control group encompassed 11 fibroadenoma patients. Single cells were isolated from defrosted samples and prepared for flow cytometry measurement. Median expression of Bax protein in study group was 7.9% (range: 0-49.4%) and was significantly lower than in control (median expression 15.8%; range 4.9-30.9%; p=0.034). Expression of Bax correlated with expression of p53 and caspase-3 proteins (p<0.01, rank Spearman test). In patients under 70 years old and with positive estrogen receptors status the expression of Bax protein was significantly higher (p=0.03 and p=0.01 respectively). Lower expression of Bax protein in breast cancer cells may suggest the potential way of apoptosis avoidance of tumor cells. Correlations among Bax protein, p53 and caspase-3 are likely associated with active apoptotic mechanism in breast cancer cells expressing Bax protein. Further investigation with long time follow-up should be performed to establish the prognostic role of Bax protein expression in breast cancer patients.

Androgen receptor expression in breast cancer patients tested for BRCA1 and BRCA2 mutations

To assess the expression of receptors for androgen (AR), oestrogen (ER) and progesterone (PR) as well as human epidermal growth factor receptor type 2 (Her-2/neu) status of breast carcinomas in breast cancer susceptibility gene (BRCA) BRCA1/2 mutation carriers and BRCA1/2 negative tested women. One hundred and thirty-five breast cancers in women tested for BRCA1/2 mutations. Screening for BRCA1 and BRCA2 mutations was performed by direct sequencing of all BRCA1 and BRCA2 exons as well as the surrounding intronic sequences. Additionally, BRCA genes were analysed with multiplex ligation-dependent probe amplification. Consecutive paraffin sections were examined immunohistochemically for AR, ER, PR and Her-2/neu. Of the 135 tumours, 43 (32%) were BRCA1-related, 18 (13%) were BRCA2-related and 74 (55%) were BRCA1/2-negative. Seventy-two per cent of the BRCA1-related, 22% of the BRCA2-related and 12% of the BRCA1/2-negative tumours were triple (ER, PR, Her2neu)-negative. Eighty-four per cent of BRCA1 mutated cancers were high-grade (G3) tumours. ARs were expressed in 30% (13 of 43) of BRCA1-related, in 78% (14 of 18) in BRCA2-related tumours and in 76% (56 of 74) in BRCA1/2 negative tumours. Twenty-one per cent of ER-negative BRCA1-related tumours expressed androgen receptors. Approximately one in five BRCA1 mutated breast cancers negative for ER and PR express androgen receptors. Modulation of AR might open a new avenue for treating these high-risk cancers.

Topoisomerase II-α as a predictive factor of response to therapy with anthracyclines in locally advanced breast cancer

BackgroundTopoisomerase II-α is a molecular target of anthracyclines; several studies have suggested that topoisomerase II-α expression is related to response to anthracycline treatment. The objective of this study was to evaluate if topoisomerase II-α overexpression predicts response to anthracycline treatment in locally advanced breast cancer patients. Material and methodsTopoisomerase II-α, HER2, estrogen receptor (ER) and progesterone receptor (PR) expression were evaluated by immunohistochemistry in formalin-fixed, paraffin-embedded breast tumors from 111 patients presenting with locally advanced breast cancer between 1995 and 2002. The prognostic value of these markers was analyzed using a multivariate proportional hazards regression model and an interaction analysis between topoisomerase II-α status and dose intensity. ResultsTumors from 40 patients (36%) showed topoisomerase II-α overexpression, 62 patients (56%) for ER, 39 (35%) for PR and 26 (23%) for HER2. There were no significant correlations between topoisomerase II-α expression and response to therapy, progression-free survival (PFS) or overall survival (OS). Anthracycline dose intensity had a significant impact on PFS and OS in patients overexpressing topoisomerase II-α (P=0.010 and 0.027, respectively). Negative PR (P=0.041), positive HER2 (P=0.013) were identified as risk factors in the multivariate model. The multivariate analysis in patients topoisomerase II-α negative shown no significance (HR=0.92, IC 95% 0.39–2.15, P=0.839) while the multivariate analysis in topoisomerase II-α positive, dose intensity shown to be statistically significant (HR=2.725, IC 95% 1.07–6.95, P=0.036). ConclusionsOur data do not support a correlation between topoisomerase II-α expression in breast cancer patients and improved clinical benefit with anthracycline therapy. However, they do suggest that tumors overexpressing topoisomerase II-α may experience better clinical benefit with higher anthracycline dose intensity.

Anti-angiogenic effect of tamoxifen combined with epirubicin in breast cancer patients

Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) are the key factors mediating neo-vascularization. They are often coexpressed in breast cancer. Sex steroids may stimulate angiogenesis via the estrogen receptor (ER) pathway. We investigated to compare the effects of the addition of tamoxifen to epirubicin versus epirubicin alone on VEGF and VEGFR2 expression in breast cancer patients. The expression of VEGF and VEGFR2 was assessed on tissue microarray by immunohistochemistry at baseline conditions and after treatments in the case of 191 patients with T2-4 N0-1 breast cancer enrolled in a randomized trial comparing four cycles of single agent epirubicin versus epirubicin plus tamoxifen as primary systemic treatment. Epirubicin alone failed to induce changes in VEGF expression (P = 0.54), while the addition of tamoxifen to epirubicin resulted in a significant reduction in VEGF expression (P < 0.001). As a consequence, baseline VEGF had a negative prognostic role in patients who received epirubicin alone but not in patients receiving epirubicin plus tamoxifen (interaction test P < 0.05). VEGFR2 expression increased at residual tumor histology in both treatment arms, with a lesser extent in patients receiving tamoxifen plus epirubicin. Decrease in VEGFR2 expression was significantly associated with response rate (P = 0.02). The addition of tamoxifen to epirubicin resulted in a suppression of a key angiogenic pathway. These data suggest a potential synergism of these two drugs.

450 Leptin and estrogen receptor expression in breast cancer patients with different clinical characteristics

MDM2 expression is down-regulated upon E2F1 over-expression, but the mechanism is not well defined. In the current study, we found that E2F1 inhibits MDM2 expression by suppressing its promoter activity. Although E2F1 binds to the MDM2 promoter, the inhibitory effect of E2F1 on the MDM2 promoter does not require the direct binding. We demonstrate that E2F1 inhibits MDM2 promoter activity in a p53-dependent manner. Knockdown of p53 in U2OS cells impairs the inhibitory effect of E2F1 on the MDM2 promoter. Consistent with this observation, E2F1 does not inhibit MDM2 promoter activity in p53-deficient H1299 cells, and the inhibition is restored when p53 is expressed exogenously. Both E2F1 and p53 are up-regulated after DNA damage stimulation. We show that such stimulation induces E2F1 to inhibit MDM2 promoter activity and promote p53 accumulation. Furthermore, inhibition of MDM2 by E2F1 promotes E2F1 induced apoptosis. These data suggest that E2F1 regulates the MDM2-p53 pathway by inhibiting p53 induced up-regulation of MDM2.

Abstract 1057: BRMS1 restoration of gap junctional intercellular communication involves modulation of KATP channels and downregulation of phosphoinositide 3-kinase (PI3K)

Abstract Metastatic disease remains the most lethal aspect of cancer, accounting for over 90% of cancer related mortality. Breast Cancer Metastasis Suppressor 1 (BRMS1) specifically inhibits the ability of tumor cells to metastasize to secondary sites while having little or no affect on primary tumor growth. Clinically, a loss of BRMS1 mRNA expression in breast cancer patients is correlated with poor prognosis and a decrease in BRMS1 protein levels predicts reduced disease free survival. The mechanisms of BRMS1 remain unclear; however expression of BRMS1 significantly decreases the PI3K signaling pathway, a pathway that is often over activated in cancer cells. PI3K is a lipid kinase that phosphorylates phosphatidylinositol (4,5)-bisphosphate (PtdIns(4,5)P2) to PtdIns(3,4,5)P3, leading to downstream signaling. BRMS1 acts to reduce the substrate of PI3K, PtdIns(4,5)P2, by &amp;gt;90% when expressed in metastatic cells. Re-expression of BRMS1 in cancer cell lines also restores gap junctional intercellular communication (GJIC), a process that mediates cellular homeostasis and is often lost during neoplastic progression. GJIC has been shown to be affected by PI3K; thus we hypothesized that inhibition of PI3K signaling by BRMS1 might be responsible for the restoration of GJIC. In support of this, treatment with the PI3K inhibitor LY294002 (10µM) in vector control and parental cell lines from multiple cancer cell types, mimicked the effects of BRMS1 on GJIC. Interestingly, inhibition of signaling molecules further downstream of PI3K (AKT, mTOR) did not produce the same effect, suggesting the mechanism of action may directly involve the ratio of PtdIns(4,5)P2/PtdIns(3,4,5)P3. We show that alterations in an ATP dependent potassium channel, KATP, regulated by phosphoinositides, is responsible for the changes in GJIC observed by BRMS1 expression. Delineation of this mechanism will allow for in vivo analysis to determine if changes in GJIC are causative for the BRMS1 mediated suppression of metastasis. Taken together, our data suggest an inhibitory mechanism on gap junctional communication mediated by PI3K, that is relieved by restoration of BRMS1 expression. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1057.

Prognostic value of NDRG1 and SPARC protein expression in breast cancer patients

An increasing number of studies have shown altered expression of secreted protein acidic and rich in cysteine (SPARC) and N-myc down-regulated gene (NDRG1) in several malignancies, including breast carcinoma; however, the role of these potential biomarkers in tumor development and progression is controversial. In this study, NDRG1 and SPARC protein expression was evaluated by immunohistochemistry on tissue microarrays containing breast tumor specimens from patients with 10 years of follow-up. NDRG1 and SPARC protein expression was determined in 596 patients along with other prognostic markers, such as ER, PR, and HER2. The status of NDRG1 and SPARC protein expression was correlated with prognostic variables and patient clinical outcome. Immunostaining revealed that 272 of the 596 cases (45.6%) were positive for NDRG1 and 431 (72.3%) were positive for SPARC. Statistically significant differences were found between the presence of SPARC and NDRG1 protein expression and standard clinicopathological variables. Kaplan-Meier analysis showed that NDRG1 positivity was directly associated with shorter disease-free survival (DFS, P < 0.001) and overall survival (OS, P < 0.001). In contrast, patients expressing low levels of SPARC protein had worse DFS (P = 0.001) and OS (P = 0.001) compared to those expressing high levels. Combined analysis of the two markers indicated that DFS (P < 0.001) and OS rates (P < 0.001) were lowest for patients with NDRG1-positive and SPARC-negative tumors. Furthermore, NDRG1 over-expression and SPARC down-regulation correlated with poor prognosis in patients with luminal A or triple-negative subtype breast cancer. On multivariate analysis using a Cox proportional hazards model, NDRG1 and SPARC protein expression were independent prognostic factors for both DFS and OS of breast cancer patients. These data indicate that NDRG1 over-expression and SPARC down-regulation could play important roles in breast cancer progression and serve as useful biomarkers to better define breast cancer prognosis.