Overexpression or Lack of beta 2-Adrenergic Receptor Correlate with Progression of Breast Cancer

Background: Recent studies showed that stress can modulate biological behavior of ovarian carcinoma through adrenergic receptors. Since both nonselective beta-adrenergic receptor antagonist propranolol and selective beta 2-adrenergic receptor (b2AR) antagonist ICI 118,551 instead of b1AR antagonist atenolol could eliminate most of the effects, b2AR is accordingly regarded as the key molecule. In this study, we investigated the role of b2AR in breast cancer. Material and Methods: Gene expression of b2AR was analyzed by RT-PCR in human breast cancer cell lines MDA-MB-231, MDA-MB-435, MDA-MB-468, MCF-7, T47D, BT-549, HCC1937, BCaP-37 and normal mammary epithelial-like cell line HBL-100. b2AR cDNA was transfected into MDA-MB-435 cells. Protein level of b2AR was analyzed by immunohistochemistry in clinical samples, including 25 normal human breast or benign disease breast tissues and 202 breast cancer tissues. Results: b2AR was detected in majority of breast cancer cell lines, except for MDA-MB-435, MCF-7 and T47D, and all of normal or benign disease breast tissues. Both nonselective beta-adrenergic receptor agonist norepinephrine (NE) and selective b2AR agonist terbutaline promoted proliferation and invasion of spontaneous b2AR-positive MDA-MB-231 cells and transfectant MDA-MB-435-b2AR cells, these effects were completely inhibited by selective b2AR antagonist ICI 118,551. In the breast cancer patients, 125 samples (61.9%) expressed b2AR weakly or moderately just as normal breast or benign diseases tissue, and 43 (21.3%) presented significantly stronger b2AR expression, while no b2AR staining was found in other 34 samples (16.8%). Higher expression or lack of b2AR were associated with axillary lymph nodes metastasis and poor disease free survival (DFS). Discussion: Based on our preliminary results, the breast cancer patients could be classified into three subgroups: b2AR “normal”, high expression and negative groups. Overexpression or lack of b2AR associated with metastasis and clinical prognosis in breast cancer. Obviously, abnormal expression of b2AR may influence the outcome of breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4165.

Changing Patterns and Present Status of Female Breast Cancer in China over 30 Years

Introduction: As a metropolis with rapid social and economic development over the past three decades, Shanghai has a breast cancer incidence that surpasses all other cancer registries in China.Methods: In order to estimate the regular changing patterns of female breast cancer in urban Shanghai, population-based incidence data from 1975 to 2004 were studied. In addition, a one-hospital-based in-patient database of 9709 female breast cancer patients treated surgically between Jan-1990 and Dec-2008 were reviewed, retrospectively.Results: We observed that breast cancer incidence increased dramatically over the past 30 years and documented a peak incidence represented by the middle-age group (45-59 yrs), which emerged in the last 20 years. The incidence peak moved from the 40-44 year group in the previous two decades to the 50-54 year group in the most recent decade. Median age at diagnosis was earlier in Shanghai than in the western countries, although it increased from 47.5-yr in 1990 to 51-yr in 2008. Considerably higher exposure to reproductive risk factors and relatively fewer hormone-dependent cases were observed- only 49.2% of breast cancers were estrogen receptor(ER) positive, 46.1% were progesterone receptor positive. The proportion of asymptomatic cases detected by screening gradually increased, as well as that of early-stage cases (from 78.6% in 1990 to 87.9% in 2008 and carcinoma in situ (14.9% in 2008). Analysis of surgical treatment patterns suggested a trend of less-invasive options.Conclusions: Rapid socioeconomic growth and birth-control policies have revealed some unique risk factors, which pushed the pattern of breast cancer in Shanghai towards that of the western countries. Age of peak incidence as well as median age at diagnosis increase with time, which suggests that increased incidence trending along with increasing age will be observed in the future. The middle-age group born after 1950s would be involved in current birth-control policies and they are also the cohorts related to the incidence boom. Thus specific screening protocols should be refined for the Chinese population, considering not only increasing age but also birth cohorts. Improvements in breast cancer detection provide patients with more opportunities for less invasive treatment options.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2058.

Epidemiology of Triple Negative Breast Cancer in China

Background:The classification of tumors based on the gene expression may define intrinsic breast cancer subtypes in which the effect of risk factors could be more obvious. We sought to assess the risk factors for triple negative breast cancer on Chinese population.Methods: A retrospective study of 5761 patients was carried out from a large database of breast cancer patients undergoing surgery between January 1, 1991 and June 31, 2008 in Cancer Hospital, Fudan University, Shanghai, China. Univariate analyses were performed by chi-square test of Student's t test and multivariate analyses by logistic regression.Results: A total of 1108 women were identified as having triple negative breast cancer and were compared with the 4653 women with non-triple negative. Regardless the pathological discrepancy, women with triple negative breast cancers were significantly more likely to be younger age(P=0.001; OR=1.615, 95%CI=1.207-2.160), premenopausal (P = 0.003; OR = 1.570, 95% CI = 1.171-2.106) and parous women (P = 0.001; OR = 1.741, 95% CI = 1.269-2.387).There seems no associations with increasing risk of triple negative breast cancer for breastfeeding (P=0.126), younger age at menarche (P=0.129), first degree family history (P=0.111) and oral contraceptive usage (P=0.251).Conclusion:Based on this large population study in Chinese breast cancer patients, the risk factors for triple negative phenotype may be somewhat different from those for Western women. Therefore, a better knowledge of this issue is warranted due to it may have impact on clinical outcomes and may offer some insight into the process of carcinogenesis and therapeutic efficacy.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2065.

VRQ397 (CRAVKY): a novel noncompetitive V2 receptor antagonist

Vasopressin type 2 receptor (V2R) exhibits mostly important properties for hydroosmotic equilibrium and, to a lesser extent, on vasomotricity. Drugs currently acting on this receptor are analogs of the natural neuropeptide, arginine vasopressin (AVP), and hence are competitive ligands. Peptides that reproduce specific sequences of a given receptor have lately been reported to interfere with its action, and if such molecules arise from regions remote from the binding site they would be anticipated to exhibit noncompetitive antagonism, but this has yet to be shown for V2R. Six peptides reproducing juxtamembranous regions of V2R were designed and screened; the most effective peptide, cravky (labeled VRQ397), was characterized. VRQ397 was potent (IC(50) = 0.69 +/- 0.25 nM) and fully effective in inhibiting V2R-dependent physiological function, specifically desmopressin-L-desamino-8-arginine-vasopressin (DDAVP)-induced cremasteric vasorelaxation; this physiological functional assay was utilized to avoid overlooking interference of specific signaling events. A dose-response profile revealed a noncompetitive property of VRQ397; correspondingly, VRQ397 bound specifically to V2R-expressing cells could not displace its natural ligand, AVP, but modulated AVP binding kinetics (dissociation rate). Specificity of VRQ397 was further confirmed by its inability to bind to homologous V1 and oxytocin receptors and its inefficacy to alter responses to stimulation of these receptors. VRQ397 exhibited pharmacological permissiveness on V2R-induced signals, as it inhibited DDAVP-induced PGI(2) generation but not that of cAMP or recruitment of beta-arrestin2. Consistent with in vitro and ex vivo effects as a V2R antagonist, VRQ397 displayed anticipated in vivo aquaretic efficacy. We hereby describe the discovery of a first potent noncompetitive antagonist of V2R, which exhibits functional selectivity, in line with properties of a negative allosteric modulator.

Postsurgical drainage and the risk of breast cancer recurrence in Chinese breast cancer patients

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Background: Clinical investigations suggest that while primary breast cancer surgical removal favorably modifiers the natural history of breast cancer. Postoperative drainage, a surgery-derived discharge after breast cancer surgery, reflecting some biological features of surgical stimulation, was assessed and explored its relationship with breast cancer recurrence in this study. Methods: A total of 1445 women undergoing surgery between Jan 1, 2000 and Dec31, 2002 in Cancer Hospital of Fudan University, Shanghai, China was retrospectively studied. Survival curves were performed with Kaplan-Meier method and the predictive value of postsurgical drainage was estimated using proportional Cox regression model. Conclusions: The larger drainage volume POD 1 is a useful marker, suggesting a greater stimulation to surgical treatment compared to the lower ones. Awareness of the relationship between early surgery-stimulated effects and harmful wound healing response might help to explore new strategies to block or deplete these harmful effects, resulting in improving patients' survival.

No significant financial relationships to disclose.

Expression and epigenetic silencing of ECRG4gene in breast cancer

11046

Previous whole-genome expression array studies in our laboratory had shown the expression of ECRG4 (esophageal cancer related gene 4) was significantly down-regulated in primary breast cancer. The present study was undertaken to investigate the expression and epigenetic regulation ofECRG4in human breast cancer cell lines and primary carcinomas. Here we showed that the expression ofECRG4, as measured by quantitative reverse transcription-PCR, was noticeably increased in 3 methylated breast cancer cell lines (MDA-MB-435, Bcap-37, MCF-7), after treated with 5-aza-2’-deoxycytidine - a demethylation agent. Analysis from 16 paired tissue samples revealed expression of ECRG4 was significantly reverse-correlated with methylation (Spearman correlation coefficient r=-0.419, P=0.017). Analysis of 67 additional samples showed that the ECRG4 CpGs island was in high methylation level in 59.7% of cancer tissues compared with 14.9% in tumor adjacent tissues,with an odds ratio of 3.393 (95% CI, 1.912–6.021,P=8.39E-8). And patients with high methylation level had a higher tumor grade. 90% samples were high methylation levels in grade III vs. 50% in grade I-II (95% CI, 1.063–76.213, P=0.033). In conclusion, the inactivation of ECRG4 gene by hypermethylation appears to be a frequent molecular event in development of primary breast cancer and may be involved in the carcinogenesis of this cancer.

No significant financial relationships to disclose.

Effect of metronomic use of zoledronic acid (ZOL) on antitumor and antiosteoclastic effects in breast cancer patients with bone metastasis

e14603

Background: Zoledronic acid (ZOL) can reduce the risk of skeletal-related events (SREs) and may have direct and indirect antitumor effects, which have been shown in animal models, pilot clinical studies as well as in recent phase III randomized trials. However, the pharmacokinetics of the drug in breast cancer patients remains to be elucidated and optimized. The purpose of this randomized study was to compare the effects of ZOL on osteoclasts and angiogenesis between a weekly low-dose versus a conventional dosage. Methods: Sixty breast cancer patients with bone metastases were recruited in this randomized phase II clinical study. The participants either received ZOL 1mg IV weekly for 4 doses or a single dose of ZOL 4mg IV. No other antitumor treatments were administered. During the first month after initial infusion of ZOL, serial blood samples were collected on day 1, 15 and 29 measuring markers for bone resorption (NTx), angiogenesis (VEGF), and tumor burden (CEA and CA15–3). Results: Compared to a single-dose administration, weekly low dose of ZOL resulted in a greater reduction in serum levels of VEGF and NTx, with a significant trend over time during one month observation. There were no statistically significant differences in circulating levels of CEA and CA15–3 between the two dosing regimens. Patients who received metronomic ZOL had a longer median time to disease progression (TTP) (7.0 months, 95%CI, 6.1–7.9 months) than those who had a single dose of ZOL (2.8 months, 95%CI, 0–5.7 months; p=0.076). Conclusions: The metronomic use of low-dose ZOL 1 mg appeared to be more effective than the conventional regimen in the long-lasting reduction of VEGF and NTx, and in prolonging TTP. This dosing schedule should be further assessed in phase III trials as we demonstrated that ZOL 1mg has greater antitumor properties in our study.

No significant financial relationships to disclose.

Demographic features and prognostic profiles of breast cancer patients presenting with nipple discharge in Chinese population

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Background: Breast cancer patients with nipple discharge (ND) may constitute a distinct clinical entity compared to those without ND, which has not been well elucidated in previous reports. We sought to analyze the demographic features and prognostic profiles of breast cancer patients presenting with nipple discharge in Chinese population. Methods: A total of 3234 patients, categorized as ND (2.47%) and non-nipple discharge (NND; 97.53%) according to different initial signs, were retrospectively analyzed. Survival curves were performed with Kaplan-Meier method and annual recurrence hazard was estimated by hazard function. Results: ND group tended to have smaller tumors and less axillary lymph node (ALN) involvement than NND group (P < 0.05). In the univariate analysis, we found significantly different recurrence-free survivals (RFS) between subgroups (P = 0.0182), with the rate of 77.78% for ND group and 72.46% for the other at the 11th year respectively. In Cox proportional hazards regression analysis, we found that tumor size (P < 0.001), ALN status (P < 0.001) were independent prognostic factors for RFS. To further evaluate whether prognostic effect of ND status remained unabated over time, the test for lack of proportionality was performed. However, it was statistically significant (global test, P = 0.039), which hinted at a demand for the employment of Cox non-proportional hazards regression in this analysis. In time dependent Cox model, ND status (P = 0.0495) as well as ERBB2 status (P = 0.017), tumor size (P < 0.001), ALN status (P < 0.001) were independent prognostic factors when ND and ERBB2 status were taken as time-varying covariates. Annual hazard rates for recurrence remained lower on ND group until approximately 4.5 years after surgery, while the situation was just the opposite thereafter. Conclusions: Our findings suggested that demographic features and prognostic profiles were quite different between breast cancers presenting with and without ND in Chinese population, which may indirectly uncover distinct biological behaviors and potentially enlighten novel therapeutic approaches for patients with different initial signs.

No significant financial relationships to disclose.

Two GABAergic intraglomerular circuits differentially regulate tonic and phasic presynaptic inhibition of olfactory nerve terminals

Olfactory nerve axons terminate in olfactory bulb glomeruli forming excitatory synapses onto the dendrites of mitral/tufted (M/T) and juxtaglomerular cells, including external tufted (ET) and periglomerular (PG) cells. PG cells are heterogeneous in neurochemical expression and synaptic organization. We used a line of mice expressing green fluorescent protein under the control of the glutamic acid decarboxylase 65-kDa gene (GAD65+) promoter to characterize a neurochemically identified subpopulation of PG cells by whole cell recording and subsequent morphological reconstruction. GAD65+ GABAergic PG cells form two functionally distinct populations: 33% are driven by monosynaptic olfactory nerve (ON) input (ON-driven PG cells), the remaining 67% receive their strongest drive from an ON-->ET-->PG circuit with no or weak monosynaptic ON input (ET-driven PG cells). In response to ON stimulation, ON-driven PG cells exhibit paired-pulse depression (PPD), which is partially reversed by GABA(B) receptor antagonists. The ON-->ET-->PG circuit exhibits phasic GABA(B)-R-independent PPD. ON input to both circuits is under tonic GABA(B)-R-dependent inhibition. We hypothesize that this tonic GABA(B)R-dependent presynaptic inhibition of olfactory nerve terminals is due to autonomous bursting of ET cells in the ON-->ET-->PG circuit, which drives tonic spontaneous GABA release from ET-driven PG cells. Both circuits likely produce tonic and phasic postsynaptic inhibition of other intraglomerular targets. Thus olfactory bulb glomeruli contain at least two functionally distinct GABAergic circuits that may play different roles in olfactory coding.