S20 Poster Session I. Biology/Pathology/Basic Research Thursday, 17 March 2011

P112 FGF-8 stimulates breast cancer cell mitosis by regulating

BMP and ER actions

H. Masuda1, F. Otsuka2, T. Nogami1, T. Shien1, N. Taira1, H. Makino2,H. Doihara1. 1Department of Cancer and Thoracic Surgery, 2Departmentof Medicine and Clinical Science, Okayama University Graduate Schoolof Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan

Goals: Fibroblast growth factor (FGF)-8 is widely expressed during em-bryonic development and has mitogenic and transforming activities. In-creased expression of FGF-8 has been reported in human breast cancertissues, which is possibly linked to the growth and progression of breastcancer. We earlier reported the inhibitory effects of bone morphogeneticproteins (BMPs) in estrogen-induced mitosis of MCF-7 breast cancer cellsby inhibiting MAPK pathways and estrogenic enzyme expression. Theseresults suggest the existence of a novel functional crosstalk between theBMP system and ER actions in breast cancer cells. FGFs and BMPs havebeen shown to regulate cell differentiation cooperatively in a cell/tissue-dependent manner. Here we investigated the underlying mechanism ofER-sensitive breast cancer cell proliferation through the interrelationshipbetween FGF-8 and BMP system.

Methods: The human breast cancer cell line, MCF-7 was utilized in thepresent study.

Results: The expression of ERa, ERb, BMP receptors (BMP-R), Smadsand FGF receptors (FGF-R) was detected in MCF-7 breast cancer cellsby RT-PCR or Western blots. Estradiol stimulated MCF-7 cell proliferationin a concentration-responsive manner, whereas BSA-bound estradiol hada weak effect on MCF-7 cell mitosis compared with the effects of freeestradiol. It was of note that estrogen-induced proliferation was enhancedin the presence of FGF-8 treatments. It was also revealed that FGF-8increased the expression levels of ERa, ERb and aromatase mRNAs,while estradiol reduced that of ERs, aromatase and steroid sulfatase inMCF-7 cells. FGF-8-induced phosphorylation of FGF-R was augmentedby estradiol. In addition, FGF-8-induced activation of MAPKs and AKTsignaling was also upregulated in the presence of estrogen. On theother hand, FGF-8 suppressed BMP-7 actions that are linked to mitoticinhibition by activating cell cycle regulator cdc2. In MCF-7 cells, FGF-8was uncovered to inhibit BMP-R actions shown as Id-1 promoter activityand Smad1/5/8 phosphorylation by suppressing BMP type-II receptorsexpression and by increasing inhibitory Smads expression.

Conclusion: Collectively, FGF-8 acts to facilitate cell proliferation byupregulating endogenous estrogenic actions as well as by suppressingBMP-R signaling in ER-positive breast cancer cells.Disclosure of Interest: None Declared

P113 The biology and prognosis of breast cancer in Japanese

patients under 50 years of age

R. Nishimura1, S. Ohno2, T. Osako1, H. Kawaguchi2, Y. Sagara3,Y. Kamada4, M. Tanaka5, K. Anan6, S. Mitsuyama6. 1Department ofBreast & Endocrine Surgery, Kumamoto City Hospital, Kumamoto City,2Department of Breast Oncology, National Kyushu Cancer Center,Fukuoka City, 3Department of Breast Surgery, Sagara Hospital,Kagoshima City, 4Department of Surgery, Naha Nishi Clinic, Naha City,5Department of Surgery, Social Insurance Kurume Daiichi Hospital,Kurume City, 6Department of Surgery, Kitakyushu Municipal MedicalCenter, Kitakyushu City, Japan

Goals: Early-onset breast cancer is characterized by the presence ofmany poor prognostic factors such as histological malignancy, lymph nodemetastasis, and estrogen receptor (ER)-negative and human epidermalgrowth factor receptor 2 (HER2)-positive phenotypes. Age below 35 yearswas used as an independent risk factor for early-onset breast cancer inthe St. Gallen Consensus Conference (2007).

Methods: We assessed 4,172 female invasive breast cancer patients(<50 years old) from 6 Medical institutions in Kyushu, Japan who hadundergone primary breast cancer surgery between January 2000 andDecember 2009. These patients were divided into young, (356; 8.5%,�34 years old), 35−39 (614; 14.7%), and 40−49 (3,202; 76.7%) year agegroups to retrospectively analyze age-related characteristic differences inthe biology and prognosis of invasive breast cancer. The patients werefurther classified depending on breast cancer morphology (ER+/HER2−,ER+/HER2+, ER−/HER2+, ER−/HER2−), regional lymph node metastases(n: 0, 1−3, and �4), and Ki-67 expression (<30%, and �30%).

Results: The ER/HER2 expression was related to age; the incidencesof theER−/HER2− and ER+/HER2− phenotypes were higher and lower,respectively, in the young group than the other 2 age groups. The incidenceof lymph node metastasis was higher in the young patients, with no signif-icant relationship to age. The expression of Ki67 (>30%) and incidence ofchemotherapy were higher in the young group than the other age groups,showing a relationship with age. The mean tumor diameter was greater inthe young group, with a low incidence of <2 cm-diameter tumors.

Prognosis: The 3.8-year (median) follow-up showed 5-year disease-freesurvival (DFS) and overall survival (OS) of 84.5% and 94.0%, respectively.Young breast cancer patients had a poor prognosis, and age was relatedwith DFS and OS.

Conclusion: Young breast cancer patients (�34 years old) commonlyhave the ER−/HER2− phenotype, large tumor diameter, >30% of Ki67expression, and a poor prognosis.Disclosure of Interest: None Declared

P114 The anti-neoplastic ErbB2-antibody 2C4 produces left

ventricular dysfunction in murine hearts

C.G. Tocchetti1, C. Coppola1, G. Ragone1, A. Barbieri1, D. Rea1,M. Gala1, C. Arra1, C. De Lorenzo2, R.V. Iaffaioli1, N. Maurea1. 1NationalCancer Institute, G Pascale Foundation, 2Federico II University, Naples,Italy

Goals: Anti-ErbB2 therapies have greatly improved the prognosis of pa-tients with breast cancer. Unfortunately, such treatments are associatedwith an increased risk of left ventricular (LV) dysfunction. Trastuzumab,the prototypical ErbB-targeted therapy, increases the frequency of asymp-tomatic decrease in LV ejection fraction (LVEF) by 3−18%, and the riskof heart failure (HF) by 2−4%. The newer ErbB2 antibody rhuMAb 2C4(pertuzumab) seems to affect ligand induced ErbB signaling in a moredirect fashion, affecting EGFR/ErbB2 dimerization; yet, its cardiac sideeffects are only beginning to emerge. Here, we test whether the murine2C4 induces cardiac dysfunction in normal mice.

Methods: In vivo cardiac function was measured with LV fractionalshortening (FS) by M-mode echocardiography in sedated C57BL/6 mice(2−4 mo. old) at day 0, and after 2 and 6 days of daily administrationof 2C4 (2.25mg/g/day) ip, and in a control group. With Speckle Trackingechocardiography (ST) we also evaluated radial myocardial strain (%), avery sensitive parameter which can predict LV dysfunction.

Results: After 2 days of treatment, myocardial strain was alreadyreduced in 2C4-treated mice compared to sham: 40±8% vs 66±0.6%,p = 0.02. Also, FS was significantly decreased: 58±1% vs 60±0.4, p = 0.01.LV dysfunction was exacerbated after 6 days of treatment, with strainfurther decreasing to 31±7%, and FS to 39±5%.

Conclusion: The murine ErbB2 antibody 2C4 induces cardiac dysfunc-tion in normal mice. Still, the clear mechanisms of anti ErbB2-inducedcardiotoxicity are to be elucidated. Further studies will be crucial to es-tablish the cardiotoxic mechanisms of ErbB2-antagonists, and to influencethe design of future anticancer therapies in an attempt to retain anticancereffects, while minimizing cardiac toxicity. We also plan to apply speckletracking echocardiography to clinical studies, in order to evaluate the im-pact of early identification of ErbB2-blockers cardiotoxicity in the treatmentof women with breast cancer.Disclosure of Interest: None Declared

P115 Decreased Hsp90 expression in the continuum of breast

lobular lesions

F. Zagouri1, T. Sergentanis1, A. Nonni1, D. Chrysikos1, G. Bletsa1,I. Flessas1, M. Lymperi1, C. Papadimitriou1, A.-M. Dimopoulos1,G. Zografos1. 1University of Athens, Athens, Greece

Goals: Elevated Hsp90 expression has been documented in breast ductalcarcinomas. This is the first study to focus exclusively on the continuumof breast lobular lesions, going beyond lobular neoplasia and assessingHsp90 expression in infiltrative lobular carcinomas.

Methods: Tissue specimens were taken from 65 patients with lobularneoplasia and 32 patients with infiltrative lobular carcinoma. Immunohis-tochemical assessment of Hsp90 was performed both in the lesion andthe adjacent normal breast ducts and lobules; the latter serving as control.Concerning Hsp90 assessment: (i) the percentage of positive cells and