bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multicenter phase I clinical trial of daily and weekly RAD001 (everolimus) in combination with vinorelbine and trastuzumab in patients with HER-2-overexpressing metastatic breast cancer with prior resistance to trastuzumab.
Authors: Fasolo A , Gianni L , Rorive A , Bergh J , Dieras V , Cardoso F , Vittori L , Pylvaenaeinen I , Sahmoud T , Jerusalem G 
Published: December 2010

Abstract
Abstract #406
Background: Resistance to trastuzumab (H) is associated with loss of PTEN and AKT/mTOR activation. Preclinically, RAD001, an oral inhibitor of mTOR, enhances the efficacy of H suggesting that RAD001 could reverse resistance to H.&#x2028; Methods: Vinorelbine (V) was administered at a dose of 25 mg/m2, IV over 10-15 min on days 1 and 8 q3w. H 4 mg/kg loading dose administered IV over 90 min on Day 1 (if pt was not already receiving H), followed by weekly H 2 mg/kg IV over 30 min. In the daily RAD001 arm, 3 cohorts were planned (2.5, 5 and 10mg) and in the weekly RAD001 arm, 4 cohorts were planned (20, 30, 50 and 70mg). Treatment continued until progression or unacceptable toxicity.&#x2028; Results: As of June 10 2008, 28 heavily pretreated pts were enrolled: 15 to 5mg/d, 6 to 20mg/w and 7 to 30mg/w cohorts. All pts received prior taxanes. Median number of prior CT regimens was 3 (range: 1-5). The main safety events were grade 2 and 3 stomatitis which led to dose reduction of RAD001 in 3 pts and dose interruption in 3. Grade 4 and 3 Neutropenia were seen in 24 pts (leading to dose reduction of V in 11 pts). Twenty two pts have been evaluated for efficacy (table 1). 1 pt had a CR (45+ weeks), 2 pts had PR (35+, 38 weeks), 15 pts SD (Median 26+, range 8+ to 58 weeks) and 4 pts PD. Clinical benefit rate (CR+PR+SD &gt; 24 wks) is 55%+.&#x2028; Conclusions: Initial findings show that RAD001 is generally well tolerated in combination with V and H and shows promising anticancer activity and clinical benefit in heavily pretreated patients with HER2+ advanced breast cancer. Updated results will be presented.&#x2028; &#x2028;
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 406.
Novel egg white based 3D cell culture system for breast cancer research.
Authors: Kaipparettu BA , Kuiatse I , Tak-Yee Chan B , Kaipparettu MB , Lee AV , Oesterreich S 
Published: December 2010

Abstract
Abstract #4060
Introduction: Over the last few years, much attention has been paid to the development and utilization of three-dimensional (3D) cell culture to replace classical two-dimensional (2D) monolayer cell culture systems grown as a flat layer on plastic. Not completely surprisingly, there are tremendous differences between cells in 2D and 3D culture. However, currently available 3D cell culture media are expensive for regular use by the majority of research laboratories and thus large scale use of 3D cell culture system is presently cost prohibited. In our search for a reliable and economically viable replacement for the expensive commercial 3D media, we hypothesized that avian egg white could be a potential alternative.&#x2028; Methods: Egg white-based chamber slide: Separated egg white from the chicken eggs and coated each wells of an eight well culture chamber with 80μl of egg white by careful heating at 600C on a heating block. After 30-60 minutes, the egg white becomes a semi-solid that adheres to the bottom of the well. The unstuck egg white is washed out by adding 500µl of growth medium and removing it slowly using a Pasteur pipette.&#x2028; Cell culture and analysis: To each well 2x103 immortalized human breast epithelial cells (MCF10A), were added in 0.5ml of appropriate culture medium. We have analyzed the growth curve of the acini, lumen formation, apoptosis and cell proliferation at different days post-culture. Apico/basal polarization of the acini was analyzed using appropriate antibodies. We have also cultured IGFR1-transformed MCF10A cells, different established human cell lines (MCF7, HEK293, HeLa, LNCaP, and Saos-2), and MMTV-PyMT transformed mouse mammary epithelial cells in their appropriate growth media. For comparative studies, we used a well-established reconstituted basement membrane matrix preparation (BM).&#x2028; Results: Our analysis shows that this simple avian egg white based system supports growth of cells in 3D, with significantly decreased cost. Specifically, the growth of MCF10A in egg white-based medium results in formation of acini with hollow lumens, apoptotic clearance of the cells in the lumen, and apico/basal polarization comparable to what has been described using established 3D culture media. There was no significant difference in MCF10A proliferation and acini size between egg white and BM. We have also observed similar morphology for different established cell lines, oncogene-transformed MCF10A, and mouse mammary epithelial cells between egg white and BM.&#x2028; Conclusion: Our data convincingly argue that egg white can be used as a suitable alternative model for 3D cell culture studies. We strongly believe that this simple and inexpensive method should allow researchers to perform 3D cell culture on a regular basis, and thus result in a dramatic increase of utilization of the 3D cell culture in research.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4060.
Biological significance of allele specific loss of the p53 gene in breast carcinomas.
Authors: Wegman P , Paulmalakkaran B , Wingren S 
Published: December 2010

Abstract
Abstract #4064
Background: The p53 tumour suppressor gene has a central role in the defence against cancer, including breast cancer, and contains a polymorphic variant (Arg/Pro) at codon 72 that has been shown to have different biological properties regarding apoptosis and cell cycle arrest. Earlier studies have shown allele specific loss of heterozygosity (LOH) at this particular site and we aimed to investigate its biological relevance in codon 72 heterozygous breast cancer patients (i.e. survival and age of disease onset).&#x2028; Method: 199 postmenopausal cases were analyzed for LOH using MegaBACE1000 and statistics was performed using Statistical Package for Social Sciences. As reference for loss/retention of heterozygosity at the Arg or Pro allele DNA from 30 heterozygous blood donors included in a population based DNA bank was used.&#x2028; Results: LOH was found in totally 124 (62.3%) patients and the Pro allele (n = 103) was significantly more often deleted compared to the Arg allele (n = 21) (p = 0.001). Patients with LOH of the Arg allele were diagnosed at an earlier age (mean age 62.5 years) than those with loss of the Pro allele (mean age 69.2 years) (p = 0.011). LOH of the Arg allele was also associated with worse survival (p = 0.05). Tumour size or number of positive lymph nodes was not associated with LOH.&#x2028; Conclusion: We found a non-random loss of the codon 72 Pro allele, implying the existence of a selective pressure during carcinogenesis that confers a growth advantage to cells lacking the Pro allele. We also found that earlier age of onset was associated with loss of the Arg allele. These results were achieved from primary tumors without any influence of adjuvant treatment, possibly showing a picture of the natural history of carcinogenesis. The worsen prognosis associated with loss of the Arg allele is somewhat more complex to interpret since recurrence free survival could be influenced by genotype, mutational status and adjuvant treatment.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4064.
p53 transcriptional activity is selectively suppressed by estrogen in SNP309 mdm2 overexpressing breast cancer cells.
Authors: Brekman A , Talbott K , Bargonetti J 
Published: December 2010

Abstract
Abstract #4065
p53 is a tumor suppressor frequently inactivated in cancers. Mdm2 targets p53 for proteasomal degradation via E3 ubiquitin ligase activity and represses p53 transcriptional activity by co-localization with p53 on the chromatin. Mdm2 overexpression is associated with estrogen signaling in breast cancer. To investigate estrogen-associated tumorigenesis and p53 pathway suppression, we examined estrogen receptor positive and p53 wild-type breast cancer cell lines, MCF-7 and ZR-75-1. MCF-7 cells are heterozygous for the mdm2 gene single nucleotide polymorphism from T to G at position 309 (SNP309 T/G) and ZR-75-1 are SNP309 homozygous T/T. Cells that carry the G-allele overexpress Mdm2. We found that in the presence of estrogen, the transcriptional activity of p53 in MCF-7, but not in ZR-75-1 cells, was selectively compromised. When MCF-7 cells were treated with the DNA-damaging drug etoposide or the Mdm2 antagonist Nutlin-3, transcription of p53 target genes p21, mdm2, puma and gadd45 was upregulated. However in the presence of estrogen, transcription of puma and gadd45, and not of mdm2 or p21, was downregulated. In ZR-75-1 cells, we did not observe selective inhibition of p53 transcriptional activity in the presence of estrogen. Importantly, we could potentiate p53 transcriptional activity by adding mdm2 siRNA in the presence of estrogen. The coordination between suppression of p53 transcriptional activity and mdm2 SNP309 genotype suggests that estrogen downregulates the p53 response in breast cancer cells by selecting for cells that overexpress Mdm2. This suggests that downregulating Mdm2 in ER+ breast cancer cells could be a beneficial therapeutic approach.&#x2028; This work was supported by The Breast Cancer Research Foundation and was facilitated by grant number RR-03037 from the National Center for Research Resources (NCRR), a component of the National Institutes of Health (NIH).
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4065.
Estrogen regulation of p53 isoforms in the human breast cancer cell line MCF7.
Authors: Vendrell JA , Bourdon J , Cohen PA , Thompson AM 
Published: December 2010

Abstract
Abstract #4067
Background: p53, a transcription factor activated in response to different cellular stresses, is involved in the majority of cancers. Recently, we have shown that the p53 gene, due to alternative splicing, encodes for 9 different p53 proteins (isoforms) expressed in a tissue-dependent manner. Moreover, p53 isoforms bind preferentially some p53 target gene promoters, increasing the complexity of the p53 pathway. Preliminary results indicate that p53 isoforms are differentially expressed in breast tumours and are associated with survival.&#x2028; Methods and Results: As some p53 isoform expression is also associated with ERa status in breast cancer, we aimed to investigate the effect of 17b-estradiol (E2) on the expression of p53 isoforms in MCF7 cells. We observed that E2 regulated the expression of the p53b isoforms at the protein level but not at the mRNA level. To investigate whether E2 confers resistance to genotoxic stress, we treated cells with doxorubicin, a commonly used chemotherapeutic agent. E2 sensitises MCF7 cells to doxorubicin treatment after a long exposure (3 days). However, we observed that E2 protects MCF7 cells from cell death following short exposure (1 hour) to doxorubicin in a p53-dependent manner. p53 isoforms are differentially expressed after 1h or 3 days treatment with doxorubicin, suggesting their involvement in the response to doxorubicin. These data are consistent with our findings in primary breast cancer, linking p53 isoforms to prognosis.&#x2028; Conclusion: Our data demonstrated that E2 may influence p53 isoforms and response to doxorubicin in breast cancer.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4067.
Tumor suppressor PTEN signaling is up-regulated in mammary epithelial cells by soy isoflavone genistein: implications for breast cancer protection.
Authors: Rahal OM , Simmen RC 
Published: December 2010

Abstract
Abstract #4069
Breast cancer is the second leading cause of death in the Western hemisphere affecting one of eight women in their lifetime. In addition to chromosomal and genetic alterations, nutrition is considered a risk determinant for breast cancer. Prevailing evidence suggests a negative correlation between intake of soy-rich foods and breast cancer incidence. Epidemiological and case control studies have shown a two-to eight fold lower occurrence of the disease in Asian women whose early intake of soy products is 20-25 times higher than their American counterparts. Previous work from our group has shown diet-induced protection against DMBA- and NMU-induced mammary tumors in vivo, with decreased tumor incidence and increased tumor latency in rats exposed to dietary soy protein isolate (SPI) or casein (CAS) supplemented with the major soy isoflavone genistein (GEN) when compared to those fed the control casein (CAS) diet. We also have shown that GEN enhanced apoptosis in mammary epithelial cells in vivo and in vitro (MCF-7 cells), attendant with increased expression of the tumor suppressor PTEN and several pro-apoptotic genes Bax, Bok, and p21. Here, we test the hypothesis that GEN induction of PTEN expression and nuclear localization in mammary epithelial cells result in decreased cellular proliferation and enhanced cellular differentiation, to confer protection from mammary tumorigenesis. Using the non-tumor human mammary epithelial cell line MCF-10A, we show that GEN at physiologically relevant concentrations (40 nM, 2 µM) increased PTEN mRNA and protein levels and enhanced nuclear accumulation of active (non-phosphorylated) PTEN. GEN induction of PTEN transcript levels was lost with the inclusion of the transcription inhibitor actinomycin D, suggesting PTEN is a direct GEN target. Further, cells treated with GEN for 6 days had lower cell viability when compared to control cells, concomitant with decreased expression of cyclin D1 and of the PTEN regulated gene pleiotrophin. Interestingly, GEN up-regulation of PTEN expression was accompanied by similar effects on another tumor suppressor p53, which co-localized with PTEN in the nuclei of GEN-treated cells. PTEN siRNA targeting, which decreased basal PTEN expression by 60%, significantly increased cyclin D1 but not p53 expression. Our findings provide support to the hypothesis that the protective effects of GEN in the mammary epithelium may be mediated by PTEN to enhance differentiation and inhibit cellular proliferation, and suggest the participation of another key tumor suppressor p53. Funding by USDA-CRIS 6251-5100002-06S.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4069.
Krupple-like factor 5 promotes breast cancer proliferation through activating fibroblast growth factor-binding protein transcription.
Authors: Zheng H , Zhou Z , Chen C 
Published: December 2010

Abstract
Abstract #4071
Breast cancer is the second leading cause of cancer death in U.S. women. The estrogen receptor negative basal breast cancer is usually invasive and the prognosis is poor. Kruppel-like Factor 5 (KLF5) is a zinc-finger transcription factor promoting cell proliferation, survival, cell cycle, and angiogenesis. High expression level of KLF5 has been shown to be associated with shorter breast cancer patient survival time. In our previous microarray studies, fibroblast growth factor binding protein (FGF-BP) is suggested to be one of the KLF5's downstream target genes in the TSU-Pr1 bladder cancer cell line. FGF-BP has been appreciated to be overexpressed in breast tumors and promotes tumorigenesis. To test whether KLF5 promotes cell proliferation through inducing FGF-BP gene transcription in breast cells, we first examined the KLF5 and FGF-BP protein levels in a panel of breast cell lines and found that KLF5 and FGF-BP are co-expressed in ER-negative basal breast cell lines. Over-expression of KLF5 by adenovirus dramatically increased the FGF-BP mRNA and protein expression in MCF7 and BT474. In contrast, KLF5 knockdown decreased the FGF-BP mRNA and protein expression in HCC1937, BT20, and SW527. Importantly, we found that FGF-BP, like KLF5, promotes cell proliferation in MCF10A, SW527 and TSU-Pr1 cells by H3-thymidine incorporation assay. Furthermore, we demonstrated that KLF5 activates the FGF-BP promoter through a putative KLF5 binding site by luciferase reporter assays. We further showed that KLF5 binds to the FGF-BP promoter in vitro by oligo pull down assays and in vivo by chromatin immunoprecipetation (CHIP) assays. These findings suggest that KLF5 may promote breast cancer cell proliferation through directly activating the FGF-BP mRNA transcription. This study will yield valuable insights into the mechanism of KLF5 induced cancer pathogenesis, and will result in useful diagnostic and therapeutic targets.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4071.
Characterization of PTEN allelic status in a series of sporadic breast carcinomas demonstrating loss of 10q23.3 region by array-CGH.
Authors: Bonnet F , Lafitte M , MacGrogan G , Longy M , Sevenet N 
Published: December 2010

Abstract
Abstract #4072
Background: Since its characterization, PTEN gene seems to play an increasing major role in the breast tumor development. Recently, various studies demonstrated that inactivation of PTEN is more and more detected in sporadic breast carcinomas and that the way of inactivation seems to be gross gene rearrangement rather than deleterious point mutation. Furthermore, because PTEN is an essential component of the PI3K signal transduction pathway, its complete molecular exploration should be done, since it has been demonstrated that PTEN loss-of-function is associated with herceptin resistance in HER2+-breast tumours.&#x2028; Material and methods: A series of 135 sporadic invasive ductal carcinomas resected between 1989 and 1992 in Institut Bergonie, has been extensively studied for genomic profiling using array-CGH. A subgroup of 27 tumours demonstrated allelic imbalance at the locus 10q23.3, targeting the BAC containing the genomic sequence of PTEN was characterized. Genomic DNA and total RNA from those 27 tumours, and 11 other tumours demonstrating IHC PTEN intensity decreased or absent, were used for PTEN point mutation (dHPLC following by sequence of the variants) and gross gene rearrangement (QMP-SF) screening. Total RNA was used for qRT-PCR with specific assays for PTEN, and/or confirmation of the impact of point mutation at the transcript level.&#x2028; Results: 6 PTEN gene point mutations for 5 tumours, 15 biallelic and 10 monoallelic gross PTEN gene rearrangements were detected. All but one of the 27 tumours demonstrating deletion of 10q23.3 by array-CGH were confirmed with other molecular techniques. Some of the tumours with IHC PTEN decreased or absent demonstrated decreased quantity of transcript regarding to a tumour control. All the results of the extensive molecular PTEN exploration will be presented.&#x2028; Discussion : We clearly characterized a subgroup of sporadic breast carcinomas demonstrating biallelic inactivation of PTEN gene either by gross gene rearrangement alone or by the combination of gross gene rearrangement and point mutation. All these molecular events are deleterious leading to a loss-of-function of PTEN protein. In our study, a high percentage of sporadic breast carcinomas demonstrated PTEN inactivation (80% of the subgroup; 15% of the 135 breast carcinomas). Those results demonstrated that inactivation of PTEN is a key step in overall breast carcinogenesis and not only restricted to BRCA1-mutated tumours.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4072.
Disparity between serum and nipple aspirate fluid (NAF) estradiol concentrations during the menstrual cycle.
Authors: Chatterton RT , Heinz RE , Habe-Evans M , Khan SA 
Published: December 2010

Abstract
Abstract #4077
Background: NAF, elicited from healthy women, may provide information about the hormonal environment of the breast and the potential risk for breast cancer. We have studied NAF sex hormone changes across the menstrual cycle and after menopause to determine the relationship to serum concentrations.&#x2028; Methods: Subjects were women attending the Lynn Sage Breast Center at Northwestern Memorial Hospital. Samples of NAF from 20 premenopausal and 23 postmenopausal women were evaluated. Premenopausal women were divided into groups 1 through 4, backdating from the day of menstruation, -28 through -19, -18 through -13, -12 through -6 and -5 through 0, respectively. NAF and venous blood were collected using standard methods. Total protein was measured by a fluorometric procedure. Unconjugated steroids, estradiol (E2), estrone, progesterone (P), and testosterone (T), were extracted into ethyl acetate-hexane (3:2) and were separated by HPLC on a C-18 column with gradient elution before assay. DHEA sulfate, estrone sulfate, and cathepsin D were measured in the aqueous fraction. All analytes were measured by immunoassays. Transformation of the data of all analytes to their natural logarithms normalized the data. Data were analyzed by ANOVA.&#x2028; Results: The protein concentration in the samples was similar among all groups, mean = 128 mg/ml (P=0.904). In NAF only E2 and P differed during the menstrual cycle, P = 0.064 and 0.007, respectively, but the pattern of NAF E2 followed that of NAF P and not serum E2. The figure shows the geometric mean values at each phase of the menstrual cycle. Ovulation should occur in group 2 (-18 through -13 days from menstruation). With the exception of P and DHEA sulfate, which were lower, analytes in samples from postmenopausal women were not significantly different from those from premenopausal women.&#x2028; &#x2028; Comment: The most significant finding is that NAF E2 does not parallel serum levels but follows closely NAF P levels. NAF E2 was actually lowest when serum E2 was highest. Changes in other analytes during the menstrual cycle were minimal. Estradiol, its direct precursors, and the E2-related protein, cathepsin D, were not decreased in NAF after menopause. (Supported by NIH R01 CA 120555-01).
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4077.