Prediction of Response to Paclitaxel by ChemoFx assay Correlates with Estrogen Receptor Status and Changes in Apoptosis Pathway in Human Breast Cancers

Background: Paclitaxel belongs to the taxane family of therapeutics, which have emerged as critically important drugs for breast cancer treatment. In addition to inhibiting cell growth by interfering with microtubule disassembly, its mechanism of action also includes induction of apoptosis. Recent studies suggest that besides being a key predictor for endocrine therapy response, Estrogen Receptor (ER) status also influences sensitivity of breast cancer to paclitaxel, with ER negative tumors being more responsive to the drug.Methods: The ChemoFx live cell chemoresponse assay was performed on 25 breast cancer cell lines (10 ER+ and 15 ER-). These cells were treated with a range of 10 doses of paclitaxel for 72 hours before DAPI staining of nuclei and counting. AUC (Area Under Curve) values were calculated and additional statistical analysis was performed on the resulting dose-response curves. Differential gene expression analysis was conducted to compare ER+ (n=82) and ER- (n=51) breast cancer patients using a public Microarray database. In addition, 2 of the 25 breast cancer cell lines, T47D (ER+) and SKBR3 (ER-), were treated with paclitaxel, lysed, and analyzed with Western blotting to detect cleaved caspase-3 and cleaved PARP expression, with beta-actin employed as a normal control.Results: The ChemoFx assay results revealed that none of the ER+ cells were categorized as R (responsive) to paclitaxel, with seven NR (non-responsive) and one IR (intermediate responsive). On the contrary, of the 15 ER- cell lines, three were categorized as R, only four were categorized as NR, and eight were categorized as IR. Statistical analysis suggested that paclitaxel responsiveness based on ChemoFx assay correlates with ER status (Chi-square test, p<0.05), with ER- breast tumors being more responsive to paclitaxel. Microarray analysis revealed differential expressions of genes implicated in the apoptosis pathway (q< 0.05) in ER+ and ER- breast cancers. Western blot analysis showed that paclitaxel induced cleaved caspase-3 and cleaved PARP expressions, both of which are indicators of activation of apoptosis, in SKBR3 cells (ER-), but not in T47D cells (ER+).Conclusions: ER status appears to predict in part, the response of breast cancer cells to paclitaxel as determined by the ChemoFx assay. ER-negative breast cancer cells are more likely to be responsive, which is consistent with established clinical findings. Our assay also distinguishes between NR/IR and R to paclitaxel within the ER- population. Similar ChemoFx assays are being performed on primary cultures from ER+ and ER- breast cancer patient specimens. Results from RNA microarray and Western blot analyses indicate that differences in gene expression in the apoptosis pathway, and in activation of apoptosis pathway, namely changes in expressions of cleaved PARP and cleaved caspase-3 in response to paclitaxel, may explain differences in the responsiveness of ER+ and ER- breast cancers to paclitaxel. This also suggests a potential role of cleaved PARP and cleaved caspase-3 as biomarkers in addition to ER for prediction of paclitaxel responsiveness in breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2028.

Medical treatment of craniosynostosis: recombinant Noggin inhibits coronal suture closure in the rat craniosynostosis model

INTRODUCTION - The mechanisms underlying craniosynostosis remains unknown. However, mutations in FGFR2 are associated with craniosynostotic syndromes. We previously compared gene expression patterns of patent and synostosing coronal sutures in the nude rat and demonstrated down regulation of Noggin in synostosing sutures. Noggin expression is also suppressed by FGF2 and constitutive FGFR2 signaling [Warren et al. (2003) Nature, vol. 422, pp. 625-9; McMahon et al. (1998) Genes Dev, vol. 12, pp. 1438-52]. Thus, we therefore hypothesized that the addition of rhNoggin to prematurely fusing sutures should prevent synostosis. MATERIALS AND METHODS - Cohorts of nude rats were subjected to: 1) surgical elevation of the coronal suture (shams); 2) surgical elevation and placement of normal or FGFR2 mutant human osteoblasts onto the underlying dura (xenotransplants); or 3) xenotransplantation with co-application of heparin acrylic beads soaked with recombinant human (rh) Noggin. Eleven days post-surgery the sutures were harvested, stained, and histologically examined. RESULTS - Animals that received control osteoblasts, sham surgery, or no surgery demonstrated normal skull growth and coronal suture histology, whereas animals transplanted only with FGFR2 mutant osteoblasts showed evidence of bridging synostosis on the calvarial dural surface. Sutures treated with FGFR2 mutant osteoblasts and rhNoggin remained patent. CONCLUSION - The chimeric nude rate model is a viable model of craniosynostosis. FGFR2 mutations in osteoblasts induce bridging osteosynthesis demonstrating one of the mechanisms for premature suture fusion. Topical application of rhNoggin protein prevents craniosynostosis in the weanling nude rat xenotransplantation model of syndromic craniosynostosis.

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

e22234

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.

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

e22204

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.

Luminal group may give more benefit for invasive micropapillary carcinoma component breast cancer patients: experience from Cancer Hospital Fudan University

Abstract #6152

Objective: Comparative studies on clinical features and outcomes of very rare invasive micropapillary carcinoma of breast cancer of 4 subtypes by immunohistochemistry staining.&#x2028; Methods: From Aug 2005 to Mar 2008, a total of 52 breast cancer patients(BCPs) with an invasive micropapillary component (IMPC) among 1951 Chinese BCPs with complete of clinicopathologic data in our institution were enrolled into a retrospective analysis. We characterized all these 52 patients and analyzed using various parameters.&#x2028; Results: The 52 cases of breast carcinoma with an IMPC all occurred in women. Mean age was 51 years (range from 26-82). All of these patients had breast masses; one also had metastasis to the supraclavicular lymph node at the time of diagnosis., mean tumor size was 2.83cm(T2), 23.08%(12/52) was pure invasive micropapillary carcinoma, and lymph node positive percentage was 75.59 %( 36/51).Fifty one patients received surgery, while one of them lost the chance of surgery. Forty of them received the modified mastectomy while one was performed lumpectomy due to old age. One was performed LAND alone and four were performed lumpectomy and sentinel lymph node biopsy.&#x2028; By using IHC staining, when we regard HER2/neu 0 and +as negative. The Luminal A group, Luminal B, trip-negative, HER2+ /ER- were 76.92% (40/52), 11.54 %( 6/52), 7.69 %( 4/52), 3.85 %( 2/52), respectively. Compared to the database of 2005 breast cancer carcinoma in our institution, there was more Luminal A group patients than the whole group (P=0.01, chi-square test.), more Luminal B (P=0.028, Fisher exact possibility test), less trip-negative group (P=0.001, chi-square test). The positive lymph node among the Luminal A group, Luminal B, trip-negative, HER2+ /ER- were 65%,80%, 100%, 100%, respectively, while the lymphvascular invasion were 55%,33.33%,50%,50%,respectively, Mulifocality in Luminal A was 25% , 16.67% in Luminal B , while 50% in both trip-negative and HER2+/ER-.&#x2028; Twenty-one of them received both anthracyclines and Taxane, while 27 only received anthracyclines, Four patients only were received only AIs due to old age. All the luminal group patients received endrocine therapy after chemo. After nearly 14 months (2∼34 months) follow up, thirty-six women were disease free, one had local recurrence, and 1 had lung metastasis, while 1 had ovary carcinoma when the diagnosis of breast malignant, one patient lost following up due to mental disorder. Among the luminal B, one had metastasis when diagnosis, others were disease free. One woman of the trip-negative died of non-breast cancer disease,the HER2+/ER- group was no recurrence or metastasis.&#x2028; Discussion: The prelimary results showed that more luminal group in the IMPC may get benefit from the endocrine therapy. However the number of these cases is small and follow-up time is not very long, further studies are necessary to explain these rare and unique pattern of invasive carcinoma.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6152.

Time distributions and prognosis factors of breast cancer recurrence in different sites after operation

Abstract #2080

Objective Our study aims to analyze the breast caner patients with different sites of recurrence, and to have knowledge of the regular patterns and influence factors of metastastic breast cancer.&#x2028; Methods We performed a retrospective study of 210 female breast cancer patients who were continuously followed up in our hospital from January 2005 to May 2007 and had complete data of metastasis. The clinical and biological characteristics were compared between the patients with organ metastases (lung, liver, brain) and non-viscera metastases (lymph node, bone).&#x2028; Results Cox regression analysis-hazard function showed that patients with elder age (RR=0.927 95%CI 0.877∼0.981, P=0.008) and HER-2 negative(RR=0.253 95%CI 0.076∼0.836, P=0.024)tended to develop non-viscera metastases, while patients with larger tumors (RR=3.832 95%CI 1.073∼13.687, P=0.039) tended to develop organ metastasesp.&#x2028; &#x2028; When stratified by the prognostic factors, the annual risk hazard curve of the patients with high risk of recurrence had double peaks at the second year and the ninth years after mastectomy respectively, and it was significantly higher than those of the patients with middle and low risk.[figure1]Annual risk hazard curves of both local relapse and metastasis also showed a double-peaked pattern. The curves for lymph node, bone, lung and liver metastasis showed a similar pattern, but all the peaks of curve emerged later than that of the local relapse.&#x2028; &#x2028; Conclusion Patients with different clinical and biological characteristics may develop recurrence in different sites. There are certain regular patterns of time distribution for different metastasis sites after mastectomy. The local recurrence may be the foreboding for the metastasis and we should pay attention to the local relapse signs especially in the patients with high risk.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2080.

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A comparison of tumor characteristics between ER+/PR+ and ER+/PR- breast tumors in Chinese women

21097

Background: Although breast caner patients with any one of the two sex hormone receptors positive can be treated with endocrine therapy, many clinical data showed that there was different response to endocrine therapy for patients with ER+/PR+ and with ER+/PR- tumors. The aim of this study was to find out the factors related to PR expression by comparing the ER+/PR+ tumors and ER+/PR- tumors clinically and biologically. Methods: Between January 1990 to August 2006, 5,191 female breast cancer patients with known ER/PR expression status who received operation in our hospital were enrolled onto this retrospective study. Clinical and biological features of 2,227 patients with ER+/PR+ tumors were compared with those of 909 patients with ER+/PR- tumors. χ2 test was used for univariate analysis and logistic regression for multivariate analysis. Disease-free survival (DFS) and overall survival (OS) was calculated using Kaplan-Meier analyses, and all statistical tests were two-sided. Results: The peak onset age of patients with ER+/PR+ tumors and ER+/PR- tumors was 50, and it was significantly higher than that of patients with ER- tumors, which is 48(P=0.001). Univariate analysis showed that ER+/PR- tumors were larger in size, had more lymph nodes of metastasis, were higher in tumor grade than ER+/PR+ tumors. Furthermore, the expression of ER and CathepsinD was significantly lower, and CerbB-2 expression was higher in ER+/PR- tumors than in ER+/PR+ tumors. Multivariate analysis indicated that positive PR expression was associated with the level of ER(OR=1.792, P=0.000), CathepsinD(OR=1.380, P=0.035)and CerbB-2(OR=0.639, P=0.007). DFS(P=0.004) and OS(P=0.009) were higher among patients with PR-expressing tumors than with PR- negative tumors. Conclusions: ER+/PR+ tumors and ER+/PR- tumors may have the same etiology which is different from that of ER- tumors. Because of low ER level and changes of the expression of CerbB-2 and CathepsinD, the tumors that lacked PR expression display more aggressive features and have worse prognosis. According to these differences, new target of therapy and endocrine regimen may provide the possibility of improving the response and prognosis of endocrine therapy for patients with ER+/PR- tumors.

No significant financial relationships to disclose.

The rule of mortality risk in young women (≤35 years) with primary breast cancer

21098

Background: The prognosis of young women (=35 years) is poorer than that of women over 35 years, which may indicate that they bear different biologic characteristics. However, such data is still not available at home and abroad as the rule of mortality risk in young women and its distinction from that in women over 35 years. We sought to investigate the clinical characteristics, prognosis and the rule of mortality risk in young women (=35 years) with primary breast cancer. Methods: We performed a retrospective study of 2331 female unilateral breast cancer patients undergoing surgery in our hospital from January 1990 to October 2005.They were divided into two groups with the cut-off of 35 years. Selection criteria included complete data on the following: age, tumor size, axillary nodal status, estrogen receptor (ER) status, menopausal status.Overall survival curve was estimated by Kaplan-Meier method and annual mortality hazard by hazard function. Their clinicopathologic indices, overall survival curve and annual mortality hazard were analyzed. Results: There was statistical significance between =35 years and >35 years group in terms of tumor size( P =0.0231), axillary nodal status( P <0.001) and estrogen receptor status( P =0.064). 10-year overall survival was 72% and 79% ( P = 0.0081), respectively, for =35 years and >35 years group. Although annual mortality hazard curve for both groups showed double-peaked pattern, there also exist some differences. Mortality surges for =35 years patients appeared earlier than those for >35 years counterparts. Moreover, =35 years group showed a minor increase between double peaks, which cannot be found in >35 years group. Conclusions: Between the two groups, different tumor biology leads to the discrepancy of overall survival and mortality pattern, which might indicate distinct principles and measures in the follow-up and treatment for young patients to provide the possibility of improving the therapeutic effect and reducing the mortality hazard.

No significant financial relationships to disclose.

Genetic variability of group A and B human respiratory syncytial viruses isolated from 3 provinces in China

The genetic variability of HRSV in China was studied using nucleotide sequencing of the hypervariable C-terminal region of the G protein gene and phylogenetic analysis on 80 isolates obtained from three children's hospitals over a period of three epidemic seasons, 1990/1991, 2000/2001, and 2003/2004. The results showed that 76/80 of these isolates belonged to group A and 4/80 belonged to group B. Phylogenetic analysis revealed that most of the group A isolates were genotype GA2 (74/76 isolates), and the other two isolates were GA3 and GA5. All group B isolates clustered into genotype GB3. There was substantial variation among the GA2 isolates, with nucleotide sequence and amino acid homologies ranging from 88.1-100% and 78.4-100%, respectively, in the hypervariable C-terminal region of the G protein gene. One group B virus, HRSV/Beijing/B/04/11, contained a 60-nucleotide duplication in the C-terminal region of the G protein, which was similar to what has been reported previously for isolates in several countries. This is the first report on the genetic diversity of human respiratory syncytial virus isolated during epidemic periods from children in China. These data provided a preliminary evaluation of patterns of circulation and the genetic diversity of isolates associated with HRSV epidemics within China.

Key Feature Extraction for Fatigue Identification using Random Forests

Electroencephalogram (EEG) might be the most predictive and reliable physiological indicator of mental fatigue. However, the extraction of key features from massive EEG data for mental fatigue identification remains a challenge. The objective of this study is to identify the key EEG features in relationship to mental fatigue, from a broad pool of EEG features generated by quantitative EEG (qEEG) techniques, using Random Forests (RF), which is a recently developed machine learning algorithm. The method is applied to key EEG feature extraction for 5-level mental fatigue identification using the five subjects' EEG data recorded in 25-hour fatigue experiments. RF produces significant feature reduction with little compromise of the classification performance. The identified key EEG features also indicate that electrode locations in frontal and occipital regions of the brain are most important for adequate representation of the deactivation of functional lobes of the brain, which is consistent with the anatomical areas known to be involved in mental fatigue. It is also interesting to discover that the four frequency bands are all important for the mental fatigue identification.

Phenotypic characterization of Streptococcus pneumoniae biofilm development

Streptococcus pneumoniae is among the most common pathogens associated with chronic otitis media with effusion, which has been hypothesized to be a biofilm disease. S. pneumoniae has been shown to form biofilms, however, little is known about the developmental process, the architecture, and the changes that occur upon biofilm development. In the current study we made use of a continuous-culture biofilm system to characterize biofilm development of 14 different S. pneumoniae strains representing at least 10 unique serotypes. The biofilm development process was found to occur in three distinct stages, including initial attachment, cluster formation, and biofilm maturation. While all 14 pneumococcal strains displayed similar developmental stages, the mature biofilm architecture differed significantly among the serotypes tested. Overall, three biofilm architectural groups were detected based on biomass, biofilm thickness, and cluster size. The biofilm viable cell counts and total protein concentration increased steadily over the course of biofilm development, reaching approximately 8 x 10(8) cells and approximately 15 mg of protein per biofilm after 9 days of biofilm growth. Proteomic analysis confirmed the presence of distinct biofilm developmental stages by the detection of multiple phenotypes over the course of biofilm development. The biofilm development process was found to correlate not only with differential production of proteins but also with a dramatic increase in the number of detectable proteins, indicating that biofilm formation by S. pneumoniae may be a far more complex process than previously anticipated. Protein identification revealed that proteins involved in virulence, adhesion, and resistance were more abundant under biofilm growth conditions. A possible role of the identified proteins in biofilm formation is discussed.

NMR spectroscopy of hydrogen adsorption on single-walled carbon nanotubes after exposure to high pressure

Hydrogen storage properties of single-walled carbon nanotubes (CNTs) after exposure to a pressure of 14.3 MPa are studied by (1)H nuclear magnetic resonance spectroscopy. The nanotubes were carefully pre-characterized using inductively coupled plasma mass spectrometry (ICP-MS), transmission electron microscopy (TEM), and Raman spectroscopy. We have shown previously that at ambient temperature in the pressure range from 0 to 1.5 MPa, hydrogen adsorption is fast and reversible and must be described as physisorption. However, exposure to a much higher pressure (14.3 MPa) of hydrogen leads to slower desorption kinetics where longer exposure causes greater hydrogen uptake. Our data suggest that interstitial sites and the tube interior may be identified as these strong adsorption sites.

Media remodeling – the result of stent induced media necrosis and repair

Background: Stents have been introduced clinically to help maintaining the patency of the vascular lumen after balloon angioplasty. To ensure a sufficient lumen of the stented vessel, oversized stents are frequently used. However especially deployment of oversized stents may lead to mechanical injury of the intima and media of the vessel wall. The aim of the study was to characterize the vascular lesions and repair processes within the first 4 weeks after implantation of oversized stents in the rabbit carotid artery and thereby contribute to the understanding of vascular remodeling during stent implantation. Methods: Oversized stents were implanted in the carotid artery of Chinchilla rabbits. Rabbits were sacrificed 3, 7, 14, and 28 days after stent implantation and a detailed histologic and immunohistochemical analysis was performed. Results: The carotid artery was expanded by a factor of 1.3–1.5, leading to a constant dilatation of the vessel. The struts were deeply impressed in the vessel wall, resulting in a disruption of the intima, thrombus formation, media compression and segmental media necrosis. The necrotic media was repopulated by smooth muscle cells by day 7. In contrast to the intima lesions, necrotic areas of the media were not invaded by an inflammatory infiltrate. Formation of neointima, characterized by a confluent layer of endothelial cells and deposition collagen fibers started in close vicinity of the struts. Conclusions: Being part of a high-pressure system, the arterial vessel apparently adapts to constant dilatation. Deployment of oversized stents caused intima disruption, media necrosis of varying degree and constant dilatation of the vessel wall. Necrosis and repopulation of smooth muscle cells of the media took place within the first 4 weeks, leading to the speculation whether the repopulating SMC are more resistant to the constant pressure.

Adoptive transfer of donor-derived immunity by liver transplantation: a potential avenue to prevent hepatitis B virus reinfection

Immunity to hepatitis B has been successfully transferred by bone marrow transplantation, but has also occurred after liver transplantation (LTx). This study was designed to analyse the influence of alloreactivity and immunosuppression, on the efficacy of adoptive immune transfer to hepatitis B by liver transplantation. Orthotopic LTx (n = 34) were performed in three rat strain combinations representing different genetic constellations. Donors had been vaccinated twice with recombinant hepatitis B surface antigen while recipients were unimmunized. Half of the allogeneic recipients were immunosuppressed with cyclosporin A. All animals were monitored weekly for the presence of anti-hepatitis B surface antibodies (anti-HBs). Effective anti-HBs titres were detected in 85% (29/34) of liver recipients and lasted from 2 to 10 weeks. Donor titre above >15 000 mIU/mL ensured a 100% seroconversion rate in the recipients. The maximal anti-HBs titre in recipients represented 0.06% approximately 0.76% of the donor titre. Rejection reduced the adoptive immune transfer, which was protected by immunosuppression. These observations suggest that transfer of functionally active donor lymphocytes, deriving from the graft, contributed to the donor-derived immune response in the recipient. Further studies to augment the donor-derived immune response are warranted to ensure a therapeutic effect for the recipient at risk of reinfection.