Human Breast Invasive Ductal Carcinoma Research Articles

Abstract LB365: Generation of a novel severely immunodeficient Sprague Dawley rat model for xenograft studies

Abstract The recombinant-activating gene 2 (Rag2) plays a critical role in the recombination of the immunoglobulin and T cell receptor genes during the maturation of T and B cells. Loss of Rag2 protein leads to a lack of functional T and B cells, which eliminates the adaptive immune response. However, Rag2 deficiency alone may not guarantee the success of xenograft implantation, due to NK cells and other innate cells remaining. Il2rg is a key component of several cytokine receptors involved in differentiation and/or function of numerous adaptive and innate immune cells, including NK cells, mast cells, basophils, and dendritic cells. To generate a more severely immunodeficient rat model, both the Rag2 and Il2rg genes were knocked out in Sprague Dawley (SD) rats; this model was termed B-SDG rats. The immune profile and organ weights of thymus and spleen were investigated in B-SDG rats in comparison with Rag2-/- and wild-type SD rats. The spleen weights of both Rag2-/- and B-SDG rats were similar, but significantly reduced compared to wild-type SD rats. Notably, the thymus weights of B-SDG male rats were significantly smaller than those of Rag2-/- males. The immune cell profiles in thymus, spleen and blood were next evaluated by flow cytometry. A complete lack of B and T cells was observed in both Rag2-/- and B-SDG rats. B-SDG rats lacked CD161+ NK cells in the spleen and blood, which were maintained in Rag2-/- rats. Dendritic cells, monocytes, macrophages, and neutrophils were detected in all strains. In vivo xenograft implantation with human lung, bladder, breast, pancreas, acute monocytic and myelomonocytic leukemia tumor cell lines was next evaluated in B-SDG rats, which demonstrated successful engraftment. Furthermore, several efficacy studies were performed in B-SDG rats, including cisplatin chemotherapy on human breast invasive ductal carcinoma cell (HCC1954) and human large cell lung cancer cell (NCI-H460) xenografts, and a HER2-targeting ADC therapy was tested in B-SDG rats harboring human non-small cell lung cancer tumors (NCI-H1975). Taken together, these data confirm that B-SDG rats provide a powerful immunodeficient model for preclinical in vivo evaluation of novel drug candidates. Citation Format: Yanhui Nie, Meiqi Zhang, Wanling Zhong, Jia Feng, Bahetiyaer Huwatibieke, Zhaoxue Yu. Generation of a novel severely immunodeficient Sprague Dawley rat model for xenograft studies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB365.

Human Breast Extracellular Matrix Microstructures and Protein Hydrogel 3D Cultures of Mammary Epithelial Cells.

Simple SummaryHuman breast tissue extracellular matrix (ECM) is a microenvironment essential for the survival and biological activities of mammary epithelial cells. The ECM structural features of human breast tissues remain poorly defined. In this study, we identified the structural and mechanical properties of human normal breast and invasive ductal carcinoma tissue ECM using histological methods and atomic force microscopy. Additionally, a protein hydrogel was generated using human breast tissue ECM and defined for its microstructural features using immunofluorescence imaging and machine learning. Furthermore, we examined the three-dimensional growth of normal mammary epithelial cells or breast cancer cells cultured on the ECM protein hydrogel, where the cells exhibited biological phenotypes like those seen in native breast tissues. Our data provide novel insights into cancer cell biology, tissue microenvironment mimicry and engineering, and native tissue ECM-based biomedical and pharmaceutical applications.Tissue extracellular matrix (ECM) is a structurally and compositionally unique microenvironment within which native cells can perform their natural biological activities. Cells grown on artificial substrata differ biologically and phenotypically from those grown within their native tissue microenvironment. Studies examining human tissue ECM structures and the biology of human tissue cells in their corresponding tissue ECM are lacking. Such investigations will improve our understanding about human pathophysiological conditions for better clinical care. We report here human normal breast tissue and invasive ductal carcinoma tissue ECM structural features. For the first time, a hydrogel was successfully fabricated using whole protein extracts of human normal breast ECM. Using immunofluorescence staining of type I collagen (Col I) and machine learning of its fibrous patterns in the polymerized human breast ECM hydrogel, we have defined the microstructural characteristics of the hydrogel and compared the microstructures with those of other native ECM hydrogels. Importantly, the ECM hydrogel supported 3D growth and cell-ECM interaction of both normal and cancerous mammary epithelial cells. This work represents further advancement toward full reconstitution of the human breast tissue microenvironment, an accomplishment that will accelerate the use of human pathophysiological tissue-derived matrices for individualized biomedical research and therapeutic development.

MiR-22-3p Suppresses Cell Migration and Invasion by Targeting PLAGL2 in Breast Cancer.

To investigate the expression of miR-22-3p in breast cancer and the mechanism of targeting PLAGL2 to inhibit the invasion and migration in human breast cancer. An experimental study. Department of Oncology and Department of General Surgery, The People's Hospital of China Three Gorges University, China, from March 2019 to December 2020. The miR-22-3p expression level in 41 paired human primary breast invasive ductal carcinoma tissues and para-cancer tissues was obtained by real-time fluorescence quantitative reverse transcriptase PCR (qRT-PCR). The effect of miR-22-3p on the proliferation of breast cancer cells was detected by growth curve method. Online software TargetScan was used to predict the target genes of miR-22-3p. The prediction results were verified by luciferase reporter gene assay and qRT⁃PCR. MiR-22-3p expression was significantly decreased in the breast cancer tissues than in para⁃carcinoma normal breast tissues (p<0.05). Over-expression of miR-22-3p can inhibit the proliferation of MCF-7 cells significantly. Pleomorphic adenoma gene-like protein 2(PLAGL2)is the predicted target gene of miR-22-3p. MiR-22-3p binds to its predicted target gene PLAGL2-3'UTR. The expression of miR-22-3p was negatively correlated with PLAGL2 in MCF-7 cells. MiR-22-3p could suppress the proliferation of breast cancer by targeting PLAGL2. This suggests that miR-22-3p may be a strategy of choice for targeted therapy of breast cancer. Key Words: Breast cancer, MiR-22-3p, PLAGL2, Cell proliferation.

Similarities and Differences in Gene Expression Networks Between the Breast Cancer Cell Line Michigan Cancer Foundation-7 and Invasive Human Breast Cancer Tissues.

Failure to adequately characterize cell lines, and understand the differences between in vitro and in vivo biology, can have serious consequences on the translatability of in vitro scientific studies to human clinical trials. This project focuses on the Michigan Cancer Foundation-7 (MCF-7) cells, a human breast adenocarcinoma cell line that is commonly used for in vitro cancer research, with over 42,000 publications in PubMed. In this study, we explore the key similarities and differences in gene expression networks of MCF-7 cell lines compared to human breast cancer tissues. We used two MCF-7 data sets, one data set collected by ARCHS4 including 1032 samples and one data set from Gene Expression Omnibus GSE50705 with 88 estradiol-treated MCF-7 samples. The human breast invasive ductal carcinoma (BRCA) data set came from The Cancer Genome Atlas, including 1212 breast tissue samples. Weighted Gene Correlation Network Analysis (WGCNA) and functional annotations of the data showed that MCF-7 cells and human breast tissues have only minimal similarity in biological processes, although some fundamental functions, such as cell cycle, are conserved. Scaled connectivity—a network topology metric—also showed drastic differences in the behavior of genes between MCF-7 and BRCA data sets. Finally, we used canSAR to compute ligand-based druggability scores of genes in the data sets, and our results suggested that using MCF-7 to study breast cancer may lead to missing important gene targets. Our comparison of the networks of MCF-7 and human breast cancer highlights the nuances of using MCF-7 to study human breast cancer and can contribute to better experimental design and result interpretation of study involving this cell line.

Abstract P2-04-03: The roles of fucosylation in promoting tumorigenic signaling in breast cancer

Abstract Fucosylation is an important form of protein glycosylation involved in the progression of cancer. Aberrant fucose and fucosylated serum protein/oligosaccharide levels have been previously described in breast cancer (BC). Fucosylation has been reported impact proliferation and key signaling pathways (e.g., ERK1/2, p38 MAPK, and E-selectin) in human breast invasive ductal carcinoma. However, precise roles and functions of fucosylated proteins function in BC remain largely unclear. In our preliminary analyses, we performed immunofluorescent lectin staining of BC tissue microarrays and cell lines grown in vitro and found that fucosylation is increased in BC vs. normal breast tissues. To study the functional contributions of fucosylation to BC biology, we either pharmacologically or genetically suppressed fucosylation in BC cell lines. The treated or modified cell lines were characterized for their ability to grow/proliferate in 2D or 3D, as well as on adhesion to extracellular matrix (ECM). We observed that inhibiting fucosylation blunted BC cell proliferation, particularly in 3D, and attenuated adhesive capacity. To determine the mechanism(s) underlying the biological functions of fucosylation in BC cells, we performed parallel fucosylated and phosphoproteomic mass spectrometric analyses on BC cells that were either pharmacologically or genetically inhibited for fucosylation to identify: (i) all fucosylated proteins in BC cells and (ii) signaling pathways that comprise directly fucosylated proteins and that are significantly altered in activity (phosphorylation). All filtered hits were subject to Ingenuity Pathway Analysis. Thirteen signaling pathways were identified in common amongst both pharmacologically or genetically modulated BC groups. These pathways clustered into the following 3 major functional groups: cell-cell/cell-matrix contact, RNA processing, and endosomal/phagosomal dynamics. The most fucosylated proteins included integrins. We validated the direct fucosylation of integrins and further dissected the molecular and functional contributions of fucosylation to integrin signaling in vitro and in vivo in mouse models of breast cancer. Our data identify new roles for fucosylation in regulating key signal transduction pathways in BC. How integrin signaling and BC cell biology is regulated by fucosylation, as well as potential clinical utility of fucosylated integrins for BC, will be discussed. Citation Format: Kara Snyder, Hui Ren, Daniel Lester, Bin Fang, John Koomen, Eric Lau. H. The roles of fucosylation in promoting tumorigenic signaling in breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P2-04-03.

Spatially Resolved Genetic Analysis of Tissue Sections Enabled by Microscale Flow Confinement Retrieval and Isotachophoretic Purification.

We have developed a method for spatially resolved genetic analysis of formalin-fixed paraffin-embedded (FFPE) cell block and tissue sections. This method involves local sampling using hydrodynamic flow confinement of a lysis buffer, followed by electrokinetic purification of nucleic acids from the sampled lysate. We characterized the method by locally sampling an array of points with a circa 200 μm diameter footprint, enabling the detection of single KRAS and BRAF point mutations in small populations of RKO and MCF-7 FFPE cell blocks. To illustrate the utility of this approach for genetic analysis, we demonstrate spatially resolved genotyping of FFPE sections of human breast invasive ductal carcinoma.

Spatially Resolved Genetic Analysis of Tissue Sections Enabled by Microscale Flow Confinement Retrieval and Isotachophoretic Purification

AbstractWe have developed a method for spatially resolved genetic analysis of formalin‐fixed paraffin‐embedded (FFPE) cell block and tissue sections. This method involves local sampling using hydrodynamic flow confinement of a lysis buffer, followed by electrokinetic purification of nucleic acids from the sampled lysate. We characterized the method by locally sampling an array of points with a circa 200 μm diameter footprint, enabling the detection of single KRAS and BRAF point mutations in small populations of RKO and MCF‐7 FFPE cell blocks. To illustrate the utility of this approach for genetic analysis, we demonstrate spatially resolved genotyping of FFPE sections of human breast invasive ductal carcinoma.

Pyridoxine 5'-phosphate oxidase is correlated with human breast invasive ductal carcinoma development.

Pyridoxine 5′-phosphate oxidase (PNPO) is a converting enzyme for an active form of vitamin B6. This study aims to evaluate the biological function and the regulatory mechanism of PNPO in human breast invasive ductal carcinoma (IDC). We unveiled for the first time that PNPO was upregulated in patients with IDC and was correlated with the overall survival of patients with metastasis at the later stages. Suppression of PNPO inhibited breast cancer cell proliferation, migration, invasion and colony formation, arrested cell cycle at the G2/M phase and induced cell apoptosis. PNPO was positively correlated with lncRNA MALAT1 which was negatively correlated with miR-216b-5p. PNPO was down-regulated and up-regulated by miR-216b-5p mimics and inhibitors, respectively, in breast cancer cells. A microRNA response element was found in both PNPO and MALAT1 transcripts for miR-216b-5p and the dual-luciferase reporter assay confirmed the binding of these transcripts. Knockdown of MALAT1 resulted in an increase of miR-216b-5p and a decrease of PNPO mRNA, indicating a regulatory mechanism of competing endogenous RNAs. Taken together, these results reveal the biological function and a regulatory mechanism of PNPO, in which the MALAT1/miR-216b-5p/PNPO axis may be important in IDC development. Targeting this axis may have therapeutic potential for breast cancer.

The Nogo-B receptor promotes human hepatocellular carcinoma cell growth via the Akt signal pathway.

Nogo-B receptor (NgBR) is a type I receptor with a single transmembrane domain and specifically binds to ligand Nogo-B. A previous study demonstrated that NgBR was highly expressed in human breast invasive ductal carcinoma and promoted epithelial-mesenchymal transition in breast tumor cells. Our recent work found that NgBR expression was associated with a poor prognosis in human patients with hepatocellular carcinoma (HCC). Here, we elucidate that the increased expression of NgBR contributes toward the increased cell growth of human HCC cells both in vitro and in vivo. Cell viability and clonogenic survival analysis results demonstrated that knockdown of NgBR inhibits the cell growth in human HCC cells, which correlates with a reduction in the phosphorylation of Akt levels. Furthermore, overexpression of NgBR by the cotransfected pIRES-NgBR plasmid together with NgBR siRNA in human HCC cells can rescue impaired phosphorylation of Akt levels in NgBR knockdown human HCC cells. In addition, cell viability analyses showed that NgBR overexpression can rescue the cell growth inhibition presented in human HCC NgBR knockdown cells. Taken together, our results suggest that NgBR potentially acts as an oncogene in HCC by increasing Akt activity. Thus, NgBR may represent a new potential diagnostic and therapeutic target for the treatment of HCC.

Overexpression of collagen type V α1 chain in human breast invasive ductal carcinoma is mediated by TGF-β1

Collagen typeVα1 chain (COL5A1) is a minor fibrillar collagen in mammals that co-polymerizes with typeI collagen to adjust the diameter of collagen molecules. However, the function of COL5A1 in invasive ductal carcinoma (IDC) of the human breast remains unknown. In the present study, our group examined the expression of COL5A1 in IDC compared with its adjacent normal tissue and fibroadenoma of the breast. COL5A1 was revealed to be overexpressed in IDC compared with benign tumor and adjacent normal control tissues, and was associated with the expression of estrogen receptor and progesterone receptor. No association between COL5A1 expression and tumor size, lymph node metastasis, clinical stage, age, or Her2 expression was identified. High expression of COL5A1 mRNA was associated with distant metastasis free survival in patients with breast cancer. Knockdown of COL5A1 led to a decrease of cell viability, as detected by the WST-1 assay, and an inhibition of migration and invasion, as detected by wound healing and Transwell assays, respectively, in the breast cancer cell line MCF-7. The expression of COL5A1 in MCF-7 cells was downregulated by transforming growth factor(TGF)‑β1, which was abolished in the presence of SB-431542, an inhibitor of TGF-β typeI receptor. In conclusion, these data indicated that COL5A1 is overexpressed in IDC and regulated by TGF-β1, suggesting that an increase of COL5A1 reflects tumor progression and may serve as a novel biomarker and therapeutic target for the treatment of breast IDC.

C-C motif chemokine receptor 1 (CCR1) is a target of the EGF-AKT-mTOR-STAT3 signaling axis in breast cancer cells.

The CC motif chemokine receptor 1 (CCR1) has been implicated in tumor invasion and metastasis in numerous cancers. However, the detailed mechanism of CCR1 upregulation in metastatic tumor cells is poorly understood. The aim of this study was to clarify the regulatory mechanism underlying transcriptional activation of the CCR1 gene in response to epidermal growth factor (EGF) stimulation in breast cancer cells. CCR1 was highly expressed in human breast invasive ductal carcinoma (IDC) compared to adjacent normal tissues. Upon EGF stimulation, CCR1 expression was upregulated at the transcriptional level. Promoter analysis showed that signal transducer and activator of transcription 3 (STAT3) is necessary for EGF-induced CCR1 promoter activation, and STAT3 silencing abrogated EGF-induced CCR1 transcription. Pharmacological inhibition and short hairpin RNA-mediated knockdown experiments showed that AKT-dependent mammalian target of rapamycin (mTOR) activation was involved in the phosphorylation of serine-727 of STAT3, which in turn stimulated the transcription of the CCR1 gene. In conclusion, the AKT-mTOR-STAT3 signaling axis contributes to EGF-induced CCR1 expression, which promotes invasion and metastasis in breast cancer cells. We propose that the AKT-mTOR-STAT3 axis is a potential therapeutic target for blocking the invasion and metastasis of breast cancers.

Biomarker discovery to improve prediction of breast cancer survival: using gene expression profiling, meta-analysis, and tissue validation.

PurposeBreast cancer is the leading cause of cancer death worldwide in women. The molecular mechanism for human breast cancer is unknown. Gene microarray has been widely used in breast cancer research to identify clinically relevant molecular subtypes as well as to predict prognosis survival. So far, the valuable multigene signatures in clinical practice are unclear, and the biological importance of individual genes is difficult to detect, as the described signatures virtually do not overlap. Early prognosis of this disease, breast invasive ductal carcinoma (IDC) and breast ductal carcinoma in situ (DCIS), is vital in breast surgery.MethodsThus, this study reports gene expression profiling in large breast cancer cohorts from Gene Expression Omnibus, including GSE29044 (N=138) and GSE10780 (N=185) test series and four independent validation series GSE21653 (N=266), GSE20685 (N=327), GSE26971 (N=276), and GSE12776 (N=204). Significantly differentially expressed genes in human breast IDC and breast DCIS were detected by transcriptome microarray analysis.ResultsWe created a set of three genes (MAMDC2, TSHZ2, and CLDN11) that were significantly correlated with disease-free survival of breast cancer patients using a univariate Cox regression model (significance level P<0.01) in a meta-analysis. Based on the risk score of the three genes, the test series patients could be separated into low-risk and high-risk groups with significantly different survival times. This signature was validated in the other three cohorts. The prognostic value of this three-gene signature was confirmed in the internal validation series and another four independent breast cancer data sets. The prognostic impact of one of the three genes, CLDN11, was confirmed by immunohistochemistry. CLDN11 was significantly overexpressed in human breast IDC as compared with normal breast tissues and breast DCIS.ConclusionUsing novel gene expression profiling together with a meta-analysis validation approach, we have identified a three-gene signature with independent prognostic impact. Furthermore, CLDN11 may offer a biomarker to predict prognosis as well as a new target for prognostic and therapeutic intervention for human breast IDC.

Abstract 2141: Rab25 and Rab-coupling protein (RCP) coordinate H-Ras and EGFR post-Golgi vesicle trafficking, plasma membrane targeting, and function in mammary epithelial cells

Abstract In this study we investigated cellular and molecular mechanisms for breast cancer signaling by EGFR and Ras proteins, independent of activating mutations. Epidermal Growth Factor (EGF) ligation to its receptor, EGFR, at the plasma membrane (PM) activates Ras small GTPases, propagating Ras mitogenic signaling. However, activating Ras mutations are not associated with breast cancers. EGFR and palmitoylated (Pa-) Ras localize to lipid rafts at the PM. Pa-Ras isotypes (H- and N-Ras, but not K-Ras) cycle through vesicle trafficking pathways between the Golgi and PM. We have found that anterograde H-Ras vesicles are sorted in the endocytic recycling compartment (ERC) into vesicles which contain the epithelial-specific transport mediator Rab25 (Rab11c), and Rab11/FIP1C (Rab-coupling protein, RCP). RCP couples Rab25 to vesicles to mediate vesicle anterograde transport. Rab25 and RCP expression are highly correlated with breast cancer progression, aggressiveness, and invasion and metastasis. Rab25, unique among the large family of human Rab genes, has been identified as a major marker and potential stimulator of breast cancers. RCP was recently shown to be a breast cancer driver oncogene, supporting the suggestion that RCP and Rab25 status may be significant clinical markers. Moreover, RCP stimulates H-Ras activation. Meta-analysis of human breast cancer cell line panels shows that while most do not harbor H- or N-Ras mutations, both RCP and Rab25 are highly over-expressed and levels correlate with resistance to EGF and Ras signaling inhibitors. We demonstrate that Rab25, RCP, H-Ras and EGFR co-localized in the ERC and in transport vesicles in MCF10A mammary epithelial cells, and that dominant negative (DN) Rab25 sequestered H-Ras and EGFR from the plasma membrane. DN Rab25 or Rab25 knockdown by shRNA inhibited EGF-induced EGFR phosphorylation, H-Ras activation, and ERK phosphorylation (ppERK), demonstrating a functional link between Rab25 activity and EGFR and H-Ras signaling. Both ER/PR-positive and -negative human breast invasive ductal carcinoma tissues showed elevated ppERK correlated with elevated Rab25 expression over normal breast tissue, whereas HER2+ tumor tissues had elevated ppERK even with low Rab25 expression. Thus, Rab25 and RCP regulate EGFR and Ras trafficking to the plasma membrane, required for mitogenic signaling and associated with tumorigenic effects, even in Ras (WT) cells. Citation Format: Allison B. Herman, Jeremy G.T. Wurtzel, Lawrence E. Goldfinger. Rab25 and Rab-coupling protein (RCP) coordinate H-Ras and EGFR post-Golgi vesicle trafficking, plasma membrane targeting, and function in mammary epithelial cells. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2141. doi:10.1158/1538-7445.AM2015-2141

Host response to human breast Invasive Ductal Carcinoma (IDC) as observed by changes in the stromal proteome.

Following initial transformation, tumorigenesis, growth, invasion, and metastasis involves a complex interaction between the transformed tissue and the host, particularly in the microenvironment adjacent to the developing tumor. The tumor microenvironment itself is a unique outcome of the host reacting to the tumor and perhaps the tumor reacting to the host and in turn the tumor altering the host's response to give rise to an environment that ultimately promotes tumor progression. The tumor-adjacent stromal, sometimes referred to as "reactive stromal" or the desmoplastic stroma, has received some investigative studies, but it is incomplete, and likely different tumors promote a varied response and hence different reactive stroma. In this study, we have investigated the proteomics of the host response, both in vitro and in vivo, to breast epithelial cancer, in the former using tissue culture and in the latter laser microdissection of stromal tissue both adjacent and distal to breast invasive ductal cancer (IDC). From proteomic analysis of in vitro tissue culture studies, we observed that the stroma produced is related to the invasiveness of the stimulating breast cancer cell lines but different from that observed from the stromal proteome of archival tissue. In vivo we have identified several potential markers of a reactive stroma. Furthermore, we observed that the proteome of tumor-adjacent stroma differs from that of tumor-distal stroma. The proteomic description of human breast IDC stroma may serve to enhance our understanding of the role of stroma in the progression of cancer and may suggest potential mechanisms of therapeutic interdiction.

Comprehensive proteome quantification reveals NgBR as a new regulator for epithelial-mesenchymal transition of breast tumor cells.

Our previous publication showed that NgBR is highly expressed in human breast invasive ductal carcinoma. However, the roles of NgBR and NgBR-mediated signaling pathway in breast tumor cells are still unclear. Here, we not only demonstrated that the quantitative proteomics analysis is a powerful tool to investigate the global biological function of NgBR, but also revealed that NgBR is involved in the transition of breast epithelial cells to mesenchymal stem cells, which is one of the major mechanisms involved in breast cancer metastasis. These findings provide new insights for understanding the roles of NgBR in regulating breast epithelial cell transform during the pathogenesis of breast cancer.

Serum Soluble CD14 Is a Potential Prognostic Indicator of Recurrence of Human Breast Invasive Ductal Carcinoma with Her2-Enriched Subtype

In clinical practice, breast cancers with lymph node positive, ER/PR-negative and overexpressed human epidermal growth factor receptor 2 (LN+ER/PR-Her2+) have high risk of recurrence, but the effective biomarkers of prognostic for this type tumor are still lacking. Since breast cancers with LN+ER/PR-Her2+ is at higher risk of recurrence than those with LN-ER/PR+Her2-. The differential proteins between those two groups could be related to the risk of recurrence. Herein, we report that serum soluble CD14 (sCD14) was revealed as the stable differential protein between LN+ER/PR-Her2+ (n=50) and LN-ER/PR+Her2- (n=50) breast cancer patients by proteomics analysis. To validate sCD14 as a biomarker for predicting recurrence of breast cancer, 90 breast cancer patients with LN+ER/PR-Her2+ and 93 patients with LN-ER/PR+Her2- were recruited. The patients with higher level of serum sCD14 at primary surgery showed to be at significantly lower risk of relapse in 3 years follow-up than those with lower level of serum sCD14 at primary surgery. The levels of serum sCD14 at primary surgery were significantly correlated to the risk of 3-year recurrence of LN+ER/PR-Her2+ breast cancer and the corresponding AUC of the ROC curve was 0.833 (95% CI, and 0.742 to 0.920). Therefore, we surmise that serum sCD14 could be a potential biomarker for predicting the prognosis of breast invasive ductal carcinoma with LN+ER/PR-Her2+.

MO‐D‐141‐08: Multi‐Scale Analysis of Collagen Architecture for Classifying Tumor and Healthy Breast Tissue Images

Purpose: To quantify differences in collagen microarchitecture between healthy human breast tissue and breast cancer images using extended field of view second harmonic generation (EFOV SHG) microscopy coupled with analysis by the curvelet transform. Methods: Two frozen samples of normal associated human breast tissue (NAT) and invasive ductal carcinoma (IDC) were obtained through the University of Wisconsin BioBank. Samples were thawed, fixed, embedded in agar, cut into 300 micron thick sections using a vibratome and imaged using a custom inverted SHG microscope designed to allow for EFOV imaging. Individual SHG Images were captured at 0.79 micron resolution and a FOV of approximately 200 microns. The FOV was extended by stage scanning and image stitching to produce submicron resolution fields of view up to 2 cm2. NAT and IDC tissues were imaged, stitched using the Grid/Collection Stitching ImageJ plugin, and analyzed using features derived from the curvelet transform including variance in orientation and prevalence at various scales. These novel features were tested using support vector machine (SVM) cross validation. Results: IDC tissue contained linearly aligned, crisscrossing collagen while NAT tissue contained wavy, dense collagen. The mean curvelet alignment value for the normal images was approximately 2X higher than that for IDC. In addition, normal images had approximately 20% fewer closely correlated curvelets compared to IDC. Three‐fold cross validation of a linear SVM classifier revealed average sensitivity and specificity of 0.994 and 0.969 respectively. Conclusion: These results demonstrate the excellent potential for collagen architecture quantification based on features derived from the curvelet transform. We have also shown the value of EFOV SHG imaging to capture both large and small scale features necessary for quantifying collagen morphology. Future work will improve EFOV SHG imaging throughput and test classification capabilities of the curvelet based feature set on a large sample population. NIH R01 grants CA114462 and CA136590 to P.J.K. and K.W.E., T32 CA009206 to J.S.B and the Morgridge Institute for Research

Abstract 4972: Phosphorylation of caspase-3 and caspase-7 by p21-activated protein kinase (PAK)2 inhibits chemotherapeutic drug-induced apoptosis of breast cancer cell lines

Abstract P21-activated kinase (PAK)2, a member of PAK family of serine/threonine protein kinases, plays an important role in physiological processes such as motility, survival, mitosis, and apoptosis. However, the role of PAK2 in chemotherapy resistance remains unclear. Here we report that PAK2 is highly expressed in human breast cancer cell lines and human breast invasive carcinoma tissue compared with human non-tumorigenic mammary epithelial cell lines and adjacent normal breast tissue respectively. Interestingly, we found that PAK2 can phosphorylate caspase-3 at Thr77, Thr152 and Thr245. Moreover, PAK2 can bind with caspase-7 and phosphorylate caspase-7 at Ser30, Thr173 and Ser239. Functionally, the phosphorylation of caspase-3 and caspase-7 decreases their activity, thereby inhibiting staurosporine and doxorubicin HCl-induced cellular apoptosis. Our data indicate that highly expressed PAK2 mediates chemotherapy resistance in human breast invasive ductal carcinoma by negatively regulating caspase-3 and caspase-7 activity. 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 4972. doi:1538-7445.AM2012-4972

Phosphorylation of Caspase-7 by p21-activated Protein Kinase (PAK) 2 Inhibits Chemotherapeutic Drug-induced Apoptosis of Breast Cancer Cell Lines

p21-activated kinase (PAK) 2, a member of the PAK family of serine/threonine protein kinases, plays an important role in physiological processes such as motility, survival, mitosis, and apoptosis. However, the role of PAK2 in resistance to chemotherapy is unclear. Here we report that PAK2 is highly expressed in human breast cancer cell lines and human breast invasive carcinoma tissue compared with a human non-tumorigenic mammary epithelial cell line and adjacent normal breast tissue, respectively. Interestingly, we found that PAK2 can bind with caspase-7 and phosphorylate caspase-7 at the Ser-30, Thr-173, and Ser-239 sites. Functionally, the phosphorylation of caspase-7 decreases its activity, thereby inhibiting cellular apoptosis. Our data indicate that highly expressed PAK2 mediates chemotherapeutic resistance in human breast invasive ductal carcinoma by negatively regulating caspase-7 activity.

Detection and clinical significance of Notch1 methylation in breast cancer and intraductal proliferative breast lesions

To explore the relevance between the promoter methylation status of Notch1 gene and the invasive ductal carcinoma and ductal hyperplastic lesions of the breast. Methylation status of Notch1 gene in human breast invasive ductal carcinoma (IDC, n = 89), ductal carcinoma in situ (DCIS, n = 20), atypical ductal hyperplasia (ADH, n = 11) and usual ductal hyperplasia (UDH, n = 20) were quantitatively evaluated by MALDI-TOF MS. The expression of Notch1 protein was detected by immunohistochemical stain (SP method). Positive expression rates of Notch1 protein in IDC and DCIS were 91.0% (81/89) and 75.0% (15/20), respectively, which were significantly higher than those of ADH (4/11) and UDH (30.0%, 6/20;P < 0.05). Notch1 protein expression was correlated significantly with lymph node metastasis, pathological grades and TNM stages of IDC. The mean methylation levels of Notch1 gene at CpG_3, CpG_4.5 and CpG_8 significantly decreased in IDC group compared with those of DCIS, ADH and UDH groups (P < 0.0083). In breast carcinomas, the mean methylation rates of Notch1 gene at CpG_4.5, CpG_10.11, and CpG_14.15.16 loci in cases with axillary node metastasis were significantly lower than those without axillary node metastasis (P < 0.05); and the methylation rates at CpG_14.15.16 and CpG_18 loci in stage Iwere lower than that in stage II, further lower than that in stage III (P < 0.05); and that in CpG_1.2, CpG_12.13 loci in grade I (highly-differentiated group) were higher than that in grade II (moderate-differentiated group) and grade III (poorly-differentiated group) (P < 0.05); and the methylation rates at CpG_3, CpG_8 and CpG_14.15.16 loci in ER(+) PR(+) HER2(-) group were lower than that in ER(-) PR(-) HER2(+) group (P < 0.05). There is an overall hypomethylation of Notch1 gene in breast invasive ductal carcinomas with corresponding over-expression of Notch1 protein. This inverse correlation show that the alteration of protein expression result from hypomethylation oncogene Notch1, and this change may have important significance in breast tumorigenesis and the development. Specific hypomethylation at CpG_3, CpG_ 4.5 and CpG_8 loci of Notch1 gene may play a role in the pathogenesis of breast carcinoma, suggesting the progression and/or malignant transformation from benign glandular lesions of the breast.