Breast Tumor Tissues Research Articles

Abstract 2341: Metabolomic analysis reveals unique biochemical signatures associated with microbial dysbiosis, inflammation and energy metabolism in breast tissues of obese and nonobese black and white breast cancer patients

Abstract Black women are more likely to be diagnosed with late-stage breast cancer than white women and have the lowest probability of cause-specific survival. Obesity is associated with increased breast cancer risk and deaths in black women. Insulin-resistant obesity features chronic systemic and local inflammation of fat, which has been linked to breast cancer outcomes. The breast also consists of a mucosal immune system that provides a complex mechanical barrier and an inherent defense against pathogens. Growing evidence shows that an imbalance in the microbiome due to inflammation may give rise to cancer development. However, there is a lack of data on the role of the microbiome in breast tumors from black women. Using a global metabolomics approach, we investigated normal (n= 24) and breast cancer (n=27) tissue from black and white women to identify microbial metabolites and metabolomic signatures that differ by breast tumor subtype and obesity status. Principal component analysis and hierarchical clustering of the global metabolite profiling data revealed separation between the metabolic signatures of normal and breast tumor tissue. Random forest analysis also revealed a unique biochemical signature in normal versus breast tumors by obesity status and breast tumor subtype, including triple negative breast tumors. Our data show that obesity associates with a unique set of metabolic pathways that facilitate the handling of inflammation, protein catabolism and tissue remodeling, and energy metabolism, which may be regulated by microbial processing in breast tumor tissue. Citation Format: Athena Starlard-Davenport, Alana Smith, Elizabeth Tolley, Lu Lu. Metabolomic analysis reveals unique biochemical signatures associated with microbial dysbiosis, inflammation and energy metabolism in breast tissues of obese and nonobese black and white breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2341.

Abstract 2486: Pleiotropic anti-cancer effects of STING in estrogen receptor positive breast cancer cells

Abstract Purpose: Stimulator of interferon genes (STING) is an upstream regulator of interferon and NF-κB, the key mediators of immune and inflammatory responses associated with cancer, triggered by cytosolic DNA. Downregulation of STING in breast tumor tissues has been reported. STING elicits caspase-8-dependent cell apoptosis via NF-κB in breast cancer cells. STING agonists are considered as potent anti-cancer agents. The current study aims to assess the biological functions of STING in breast cancer progression. Experimental design: Data of mRNA expression levels and recurrence-free survival in patients with breast cancer from The Cancer Genome Atlas and Kaplan Meier-plotter databases were analyzed. Transwell assays were used to evaluate cell migrated and invaded abilities. Sphere formation was performed in stem cell-selective medium and ultra-low attachment plates. Two STING agonists, ADU-S100 and diABZI STING agonist-1 trihydrochloride, were used for in vitro studies. The molecular events were examined by Western blot analysis. Results: Data from public database showed that lower transcripts levels of STING in Her2 and luminal B breast cancer tissues than normal breast tissues. Luminal-type breast cancer cell lines harbored low STING transcripts compared with other subtypes. Importantly, breast cancer patients with low expression levels of STING was associated with worse recurrence-free survival. Results of immunoblotting indicated that breast cancer cell lines have lower STING protein expressions than normal MCF10A cells. Knockdown of STING led to aggressive phenotypes of MCF10A and BT474 cells. In contrast, overexpression of STING suppressed the abilities of migration, invasion and sphere formation of MCF7 and BT474 cells. The markers of epithelial were increased while the markers of mesenchymal and stemness were decreased by STING overexpression. STING agonist slightly suppressed cell viability of breast cancer cells but not MCF10A cells. Treatment of STING agonists reduced cell migrated ability with upregulation of E-cadherin and γ-catenin. Conclusion: These findings suggest that STING serves tumor-suppressive effects in breast cancer. Citation Format: Chun-Yu Liu, Ji-Lin Chen, Chun-Teng Huang, Pei-Yi Chu, Mei-Fang Tseng, Yu-Hsuan Lee, Wan-Lun Wang, Ling-Ming Tseng. Pleiotropic anti-cancer effects of STING in estrogen receptor positive breast cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2486.

Abstract 2087: Breast tissue-specific DNA methylation levels predicted by genetic variants in association with breast cancer

Abstract Aberrant DNA methylation (DNAm) contributes to the development of breast cancer. Both genetic and environmental factors influence DNAm levels in a tissue-specific fashion. Previously studies have reported that genetically predicted DNAm levels at CpGs were associated with breast cancer risk. However, the prediction models were built based on DNAm measured in blood, which may not be the most relevant tissue for breast cancer. In this study, we aim to build statistical models to predict breast tissue-specific DNAm levels using genetic data and DNAm sequencing data of normal breast tissue from healthy women (N=293). We applied these models to the GWAS data from the Breast Cancer Association Consortium that includes 46,785 breast cancer patients and 42,892 controls. We evaluated the association of genetically predicted breast tissue-specific DNAm levels at CpGs with breast cancer risk using MetaXcan. Due to our small sample size of normal breast tissue samples, we restricted our statistical models to those that were well-validated and highly correlated between predicted and measured DNAm levels (r≥0.6). We thus identified 45 CpGs that were significantly associated with breast cancer risk after correction for multiple testings, and many of these CpGs were also differentially methylation between breast tumor and normal tissue samples. Genes annotated to these CpG sites are enriched in Wnt signaling, cell cycle, and stem cell proliferation pathways, including known genes such as FGFR2, KLF4, CASC8, TERT, and EMBP1. We also identified novel putative DNAm markers for the development of breast cancer. Our study provides insight into tissue-specific genetic regulation of DNAm in normal breast tissue. Citation Format: Chunyan He, James Castle, Nan Lin, Jinpeng Liu, Chi Wang, Yunlong Liu. Breast tissue-specific DNA methylation levels predicted by genetic variants in association with breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2087.

Abstract 3081: Secretory human ribonuclease 1 functions as Eph receptor A4 ligand to promote breast tumor initiation

Abstract The pancreatic human ribonuclease (hRNase) A superfamily is comprised of eight canonical hRNases, including hRNase 1, all of which can be detected in various body fluids, e.g., serum and plasma. Secretory hRNase 1 exerts its ribonucleolytic activity to function in extracellular RNA clearance. Moreover, hRNase 1 regulates hemostasis, inflammation, and innate immunity, indicating that hRNase 1 possesses multiple functions in addition to RNA clearance. Studies on hRNase 1 have been extensively investigated the biochemical properties and post-translational modifications, such as glycosylation. Nonetheless, the biological function of hRNase1 and whether it plays a role in cancer have not yet been completely defined. Recent studies indicated that hRNase 5 serves as a ligand for the receptor tyrosine kinase (RTK) epidermal growth factor receptor and plexin-B2 receptor in solid and hematopoietic cancers. Those findings reveal a role of the hRNase A superfamily in tumor progression and an unconventional ligand-receptor relationship between RNase and RTK families. Here, we demonstrate that hRNase 1, independently its ribonucleolytic activity, enriches the stem-like cell population and enhances the tumor-initiating ability of breast cancer cells. Specifically, secretory hRNase 1 binds to and activates the RTK Eph receptor A4 (EphA4) signaling to promote breast tumor initiation in an autocrine/paracrine manner, which is distinct from the classical ligand-receptor ephrin-EphA4 juxtacrine signaling through contact-dependent cell-cell communication. In addition, analysis of human breast tumor tissue microarrays reveals a positive correlation between hRNase 1, EphA4 activation, and stem cell marker CD133. Notably, high hRNase 1 level in plasma samples is positively associated with EphA4 activation in tumor tissues from the paired breast cancer patients, highlighting the pathological relevance of the hRNase 1-EphA4 axis in breast cancer. The discovery of hRNase 1 as a secretory ligand of EphA4 to enhance breast cancer stemness suggests a potential treatment strategy for breast cancer by inactivating the hRNase 1-EphA4 axis. Citation Format: Ying-Nai Wang, Heng-Huan Lee, Wen-Hao Yang, Gabriel N. Hortobagyi, Dihua Yu, Mien-Chie Hung. Secretory human ribonuclease 1 functions as Eph receptor A4 ligand to promote breast tumor initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3081.

Abnormal Long Non-Coding RNAs Expression Patterns Have the Potential Ability for Predicting Survival and Treatment Response in Breast Cancer.

Abnormal long non-coding RNAs (lncRNAs) expression has been documented to have oncogene or tumor suppressor functions in the development and progression of cancer, emerging as promising independent biomarkers for molecular cancer stratification and patients’ prognosis. Examining the relationship between lncRNAs and the survival rates in malignancies creates new scenarios for precision medicine and targeted therapy. Breast cancer (BRCA) is a heterogeneous malignancy. Despite advances in its molecular classification, there are still gaps to explain in its multifaceted presentations and a substantial lack of biomarkers that can better predict patients’ prognosis in response to different therapeutic strategies. Here, we performed a re-analysis of gene expression data generated using cDNA microarrays in a previous study of our group, aiming to identify differentially expressed lncRNAs (DELncRNAs) with a potential predictive value for response to treatment with taxanes in breast cancer patients. Results revealed 157 DELncRNAs (90 up- and 67 down-regulated). We validated these new biomarkers as having prognostic and predictive value for breast cancer using in silico analysis in public databases. Data from TCGA showed that compared to normal tissue, MIAT was up-regulated, while KCNQ1OT1, LOC100270804, and FLJ10038 were down-regulated in breast tumor tissues. KCNQ1OT1, LOC100270804, and FLJ10038 median levels were found to be significantly higher in the luminal subtype. The ROC plotter platform results showed that reduced expression of these three DElncRNAs was associated with breast cancer patients who did not respond to taxane treatment. Kaplan–Meier survival analysis revealed that a lower expression of the selected lncRNAs was significantly associated with worse relapse-free survival (RFS) in breast cancer patients. Further validation of the expression of these DELncRNAs might be helpful to better tailor breast cancer prognosis and treatment.

Characterization of tree shrew telomeres and telomerase

The use of tree shrews as experimental animals for biomedical research is a new practice. Several recent studies suggest that tree shrews are suitable for studying cancers, including breast cancer, glioblastoma, lung cancer, and hepatocellular carcinoma. However, the telomeres and the telomerase of tree shrews have not been studied to date. Here, we characterize telomeres and telomerase in tree shrews. The telomere length of tree shrews is approximately 23 kb, which is longer than that of primates and shorter than that of mice, and it is extended in breast tumor tissues according to Southern blot and flow-fluorescence in situ hybridization (FISH) analyses. Tree shrew spleen, bone marrow, testis, ovary, and uterus show high telomerase activities, which are increased in breast tumor tissues by telomeric repeat amplification protocol assays. The telomere length becomes shorter, and telomerase activity decreases with age. The tree shrew TERT and TERC are more highly similar to primates than to rodents. These findings lay a solid foundation for using tree shrews to study aging and cancers.

Tumor infiltrating NK cell (TINK) subsets and functional molecules in patients with breast cancer

IntroductionNK cells have been introduced as the main innate arm of immunity against malignancies. Recent advances introduced new subsets of, and new effector molecules on NK cells suggesting new paradigms for NK cell functions in tumor immunity. Considering these new paradigms, in the current research we investigated the frequency of tumor infiltrating NK cell (TINK) subsets and their functional molecules in breast tumor tissues by flowcytometry method. MethodsBreast tumor tissues were obtained from 32 untreated patients with breast cancer. The tissues were then minced mechanically to acquire a single cell suspension and surface-stained with monoclonal antibodies against CD3, CD56, CD11b, CD27, NKG2A, NKG2D and CXCR3. For intracellular staining (ICS), the surface-stained cells were then fixed, permeabilized and stained with anti-Perforin and anti-Granzyme B antibodies. The samples were run and the data were acquired on a four-color flowcytometer. ResultsThe cell suspension derived from tumor tissue encompassed 3.10 ± 0.52 % CD3−CD56+(bright/dim) total NK cells. Based on the conventional classification the percentages of cytotoxic (CD3− CD56dim) and regulatory (CD3− CD56bright) NK cells were respectively 1.74 ± 0.24 % and 1.36 ± 0.48 %. According to the new classification the percentages of cytotoxic (CD3- CD56+ CD11b+ CD27−), regulatory (CD3−CD56+ CD11b+/- CD27+) and tolerant (CD3−CD56+ CD27- CD11b−) NK cells were respectively 0.48 ± 0.07, 1.55 ± 0.34 and 1.15 ± 0.51. A significant higher frequency of total NK cells (CD3−CD56+ (bright/dim)) in the breast tumor tissues of the patients whose tumor draining lymph nodes (TDLNs) has not been yet involved by tumor cells (LN− patients) compared with the ones with lymph nodes involvement (LN+) (5.91 ± 1.79 % Vs. 2.20 ± 0.20 %, P < 0.004). Furthermore, NK cells with overexpressed activating receptor; NKGD2 (CD3- CD56+(bright/dim) NKG2D+ NK cells) was observed to be elevated in LN− patients compared with the LN+ ones (70.01 ± 7.96 Vs. 42.5 ± 4.81, P < 0.011). Correlation analysis revealed the percentages of conventional regulatory NK cells (CD3- CD56bright) in breast tumor tissue to be in positive correlation with the tumor size (R = 0.380, P < 0.04). The mean percentage of this cell subset was also observed to be higher in patients with T3 tumor size compared with smaller T1 tumor size (1.61 ± 0.20 % vs. 0.75 ± 0.15 %, P < 0.023. ConclusionOur observations suggest that accumulation of NK cells as well as the expression of activating NKG2D receptor by TINKs may play roles in breast tumor regression especially in the LN− patients. As the tumor growths and the size of tumor increases the accumulation of regulatory NK cells may facilitate the tumor improvement. These observations may have implications in cancer NK cell-based immunotherapy.

HER2-PI9 and HER2-I12: two novel and functionally active splice variants of the oncogene HER2 in breast cancer

In this study, two novel alternative splice variants of HER2, named HER2-PI9 and HER2-I12, were identified in breast cancer cell lines and breast tumour tissues. Whilst HER2-P19 arises from the inclusion of an 117 bp cassette-exon of intron 9 of HER2, HER2-I12 results from intron 12 inclusion. In silico analyses were performed to predict the amino acid sequences of these two HER2 novel variants. To confirm their protein expression, plasmid vectors were generated and transfected into the HER2 negative breast cancer cell line, MCF-7. Additionally, their functional properties in oncogenic signalling were confirmed. Expression of HER2-PI9 and HER2-I12 was successful and matched the in silico predictions. Importantly, these splice variants can modulate the phosphorylation levels of extracellular signal-related kinase 1/2 (ERK1/2) and Akt/protein kinase B (Akt) signalling in MCF-7 breast cancer cells. Enhanced cellular proliferation, migration and invasion were observed in the case of the HER2-I12 expressing model. In human tissues and breast carcinoma tumours both variants were present. This study reveals two novel splice variants of HER2. Additionally, the potential biological activity for HER2-PI9 and HER2-I12 in breast cancer cells is also reported..

MiR-361-5p as a promising qRT-PCR internal control for tumor and normal breast tissues.

BackgroundOne of the most widely used evaluation methods in miRNA experiments is qRT-PCR. However, selecting suitable internal controls (IC) is crucial for qRT-PCR experiments. Currently, there is no consensus on the ICs for miRNA qRT-PCR experiments in breast cancer. To this end, we tried to identify the most stable (the least expression alteration) and promising miRNAs in normal and tumor breast tissues by employing TCGA miRNA-Seq data and then experimentally validated them on fresh clinical samples.MethodsA multi-component scoring system was used which takes into account multiple expression stability criteria as well as correlation with clinical characteristics. Furthermore, we extended the scoring system for more than two biological sub-groups. TCGA BRCA samples were analyzed based on two grouping criteria: Tumor & Normal samples and Tumor subtypes. The top 10 most stable miRNAs were further investigated by differential expression and survival analysis. Then, we examined the expression level of the top scored miRNA (hsa-miR-361-5p) along with two commonly used ICs hsa-miR-16-5p and U48 on 34 pairs of Primary breast tumor and their adjacent normal tissues using qRT-PCR.ResultsAccording to our multi-component scoring system, hsa-miR-361-5p had the highest stability score in both grouping criteria and hsa-miR-16-5p showed significantly lower scores. Based on our qRT-PCR assay, while U48 was the most abundant IC, hsa-miR-361-5p had lower standard deviation and also was the only IC capable of detecting a significant up-regulation of hsa-miR-21-5p in breast tumor tissue.ConclusionsmiRNA-Seq data is a great source to discover stable ICs. Our results demonstrated that hsa-miR-361-5p is a highly stable miRNA in tumor and non-tumor breast tissue and we recommend it as a suitable reference gene for miRNA expression studies in breast cancer. Additionally, although hsa-miR-16-5p is a commonly used IC, it’s not a suitable one for breast cancer studies.

Disruption of STAT5A and NMI signaling axis leads to ISG20-driven metastatic mammary tumors

Molecular dynamics of developmental processes are repurposed by cancer cells to support cancer initiation and progression. Disruption of the delicate balance between cellular differentiation and plasticity during mammary development leads to breast cancer initiation and metastatic progression. STAT5A is essential for differentiation of secretory mammary alveolar epithelium. Active STAT5A characterizes breast cancer patients for favorable prognosis. N-Myc and STAT Interactor protein (NMI) was initially discovered as a protein that interacts with various STATs; however, the relevance of these interactions to normal mammary development and cancer was not known. We observe that NMI protein is expressed in the mammary ductal epithelium at the onset of puberty and is induced in pregnancy. NMI protein is decreased in 70% of patient specimens with metastatic breast cancer compared to primary tumors. Here we present our finding that NMI and STAT5A cooperatively mediate normal mammary development. Loss of NMI in vivo caused a decrease in STAT5A activity in normal mammary epithelial as well as breast cancer cells. Analysis of STAT5A mammary specific controlled genetic program in the context of NMI knockout revealed ISG20 (interferon stimulated exonuclease gene 20, a protein involved in rRNA biogenesis) as an unfailing negatively regulated target. Role of ISG20 has never been described in metastatic process of mammary tumors. We observed that overexpression of ISG20 is increased in metastases compared to matched primary breast tumor tissues. Our observations reveal that NMI-STAT5A mediated signaling keeps a check on ISG20 expression via miR-17–92 cluster. We show that uncontrolled ISG20 expression drives tumor progression and metastasis.

Protein citrullination as a source of cancer neoantigens

BackgroundCitrulline post-translational modification of proteins is mediated by protein arginine deiminase (PADI) family members and has been associated with autoimmune diseases. The role of PADI-citrullinome in immune response in cancer...

Tissue-Specific Warburg Effect in Breast Cancer and Cancer-Associated Adipose Tissue-Relationship between AMPK and Glycolysis.

Simple SummarySpecific metabolic phenotypes of breast cancer result from local interactions such as cancer-adipocyte cross-talk and systemic metabolic influences such as obesity. Here we examined key regulatory enzymes involved in glucose metabolism in breast cancer tissue and cancer-associated adipose tissue of normal-weight and overweight/obese premenopausal women in comparison to benign breast tumor tissue and adipose tissue of weight-matched women. We show a simultaneous increase in 5′-AMP-activated protein kinase (AMPK) protein expression with glucose utilization favoring glycolysis and pentose phosphate pathway in breast cancer tissue. In parallel, we show an increased AMPK protein expression with glucose utilization favoring the pentose phosphate pathway in cancer-associated adipose tissue. Moreover, specific features of cancer tissue glycolysis and glycogen metabolism differ between normal-weight and overweight/obese women. The results suggest context-dependent induction of tissue-specific Warburg effect in breast cancer and cancer-associated adipose tissue.Typical features of the breast malignant phenotype rely on metabolic reprogramming of cancer cells and their interaction with surrounding adipocytes. Obesity is strongly associated with breast cancer mortality, yet the effects of obesity on metabolic reprogramming of cancer and cancer-associated adipose tissue remain largely unknown. Paired biopsies of breast tumor tissue and adipose tissue from premenopausal women were divided according to pathohistological analyses and body mass index on normal-weight and overweight/obese with benign or malignant tumors. We investigated the protein expression of key regulatory enzymes of glycolysis, pentose phosphate pathway (PPP), and glycogen synthesis. Breast cancer tissue showed a simultaneous increase in 5′-AMP-activated protein kinase (AMPK) protein expression with typical features of the Warburg effect, including hexokinase 2 (HK 2) overexpression and its association with mitochondrial voltage-dependent anion-selective channel protein 1, associated with an overexpression of rate-limiting enzymes of glycolysis (phosphofructokinase 1—PFK-1) and pentose phosphate pathway (glucose-6-phosphate dehydrogenase—G6PDH). In parallel, cancer-associated adipose tissue showed increased AMPK protein expression with overexpression of HK 2 and G6PDH in line with increased PPP activity. Moreover, important obesity-associated differences in glucose metabolism were observed in breast cancer tissue showing prominent glycogen deposition and higher glycogen synthase kinase-3 protein expression in normal-weight women and higher PFK-1 and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) protein expression in overweight/obese women. In conclusion, metabolic reprogramming of glycolysis contributes to tissue-specific Warburg effect in breast cancer and cancer-associated adipose tissue.

MiR-139 Modulates Cancer Stem Cell Function of Human Breast Cancer through Targeting CXCR4.

Simple SummaryThe C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in various cancer stem/progenitor cells via activation of the epithelial-mesenchymal transition (EMT) program to facilitate tumor cell aggressiveness in the premetastatic niche. Through miRNAs microarray and bioinformatics analysis, we confirmed that miR-139 directly interacted with the 3′-untranslated region (3′-UTR) of CXCR4. Overexpression of miR-139 down-modulated CXCR4/p-Akt axis to attenuate invasion and migration of human breast cancer stem cells both in vitro and in vivo. Furthermore, miR-139 expression assessed by quantitative real-time PCR (qRT-PCR) in laser capture microdissected tumor samples significantly correlated with more advanced tumors in patients with breast cancer. Our findings provide support to account for the preferential role of miR-139 in interrupting breast cancer progression, identifying miR-139 as a potential biomarker in prediction of breast cancer invasiveness.Elevated expression of C-X-C motif chemokine receptor 4 (CXCR4) correlates with chemotaxis, invasion, and cancer stem cell (CSC) properties within several solid-tumor malignancies. Recent studies reported that microRNA (miRNA) modulates the stemness of embryonic stem cells. We aimed to investigate the role of miRNA, via CXCR4-modulation, on CSC properties in breast cancer using cell lines and xenotransplantation mouse model and evaluated miR-193 levels in 191 patients with invasive ductal carcinoma. We validated miR-139 directly targets the 3′-untranslated region of CXCR4. Hoechst 33342 fluorescence-activated cell sorting (FACS) and sphere-forming assay were used to identify CSCs. MiR-139 suppressed breast CSCs with mesenchymal traits; led to decreased migration and invasion abilities through down-regulating CXCR4/p-Akt signaling. In lung cancer xenograft model of nude mice transplanted with human miR-139-carrying MDA-MB-231 cells, metastatic lung nodules were suppressed. Clinically, microdissected breast tumor tissues showed miR-139 reduction, compared to adjacent non-tumor tissues, that was significantly associated with worse clinicopathological features, including larger tumor size, advanced tumor stage and lymph node metastasis; moreover, reduced miR-139 level was predominately occurred in late-stage HER2-overexpression tumors. Collectively, our findings highlight miR-139-mediated suppression of CXCR4/p-Akt signaling and thereby affected mesenchymal stem-cell genesis, indicating its potential as a therapeutic target for invasive breast cancer.

Neutrally charged self-assembling peptide hydrogel recapitulates in vitro mechanisms of breast cancer progression

Self-assembling peptide hydrogels (SAPH) are a popular biomaterial due to their biocompatibility with a wide range of cell types, synthetic design, structural properties that provide a more accurate 3D microenvironment, and potential for cell- and/or drug-delivery system. Mimicking solid tumors in vitro using hydrogels is one method of testing anti-cancer drug efficacy and observing cancerous cell-ECM interactions within a 3D system. In this study, a SAPH, PeptiGel®Alpha1, was used to model in vitro the 3D breast tumor microenvironment. PeptiGel®Alpha1 is composed of entangled nanofibers with consistent diameter and mechanical properties similar to breast cancer that more accurately mimic the stiffness of breast tumor tissue than Matrigel® or collagen type I. PeptiGel®Alpha1 supported the viability and growth of the breast cancer cell lines MCF-7 and MDA-MB-231 and recapitulated key features of solid tumors such as hypoxia and invasion. MCF-7 cells in the hydrogels formed large spheroids resembling acini, while MDA-MB-231 remained dispersed. When treated with tamoxifen, PeptiGel®Alpha1 acted as a barrier, providing drug penetration geometry similar to that in vivo, providing better prediction of the drug effect. Finally, it was observed that MCF-7 cells engulfed the peptide matrix after 14 days, highlighting a potential use in drug delivery. PeptiGel®Alpha1 is a suitable platform for in vitro modeling of breast cancer.

Heterogeneity between core needle biopsy and synchronous axillary lymph node metastases in early breast cancer patients: Comparison of HER2, estrogen and progesterone receptor expression profiles during primary treatment regime.

e12565 Background: Therapeutic decisions for the primary treatment of breast cancer is commonly based on the expression profiles of estrogen (ER), progesterone (PR) and the human epidermal growth factor 2 (HER2) receptors. However, breast cancer is a very heterogeneous disease, and receptor changes were manifold reported during progression. Little is known about receptor discordance in the primary setting. Here, we compared receptor expression profiles between core needle biopsy (CNB) of the breast tumor tissue and synchronous axillary lymph node metastases (LNM) not at recurrence, but at the primary treatment. Methods: In a German single center study, we retrospectively analyzed 175 breast cancer patients with axillary synchronous LNM. 69,7% of our patients were without any upfront therapy. Profiles of ER, PR and HER2 were immunohistochemically analyzed using the common cut-off at 10% positive tumor cells vs. the controversially discussed low-positive cut-off at 1%. Receptor status was compared between CNB specimens of the primary tumor tissue and axillary LNM. Further, clinicopathological characteristics were correlated to receptor changes. Results: The discordance rates between CNB and axillary LNM were 12.7% for HER2, 6.9% for ER and 22.6% for PR using the ≥1% cut-off, respective 7.5% for ER and 25.6% for PR when using the ≥10% cut-off-level. The most frequently occurring change was a PR loss. Analysis of clinical parameters revealed a significant association of ER change between CNB and LNM in younger patients (p &lt; 0.01) with increased proliferation marker Ki-67 (p = 0.04). Conclusions: Receptor discordance between CNB and synchronous axillary LNM appears to exist at the primary setting already. Hence, receptor profiles of the tumor tissue and the synchronous axillary LNM should be considered for treatment decision.

SCUBE3 serves as an independent poor prognostic factor in breast cancer

BackgroundAccumulating evidences indicate that the signal peptide-CUB-EGF-like domain-containing protein 3 (SCUBE3) plays a key role in the development and progression of many human cancers. However, the underlying mechanism and prognosis value of SCUBE3 in breast cancer are still unclear.MethodsThe clinical data of 137 patients with breast cancer who underwent surgical resection in Taizhou Hospital of Zhejiang Province were retrospectively analyzed. We first conducted a comprehensive study on the expression pattern of SCUBE3 using the Tumor Immune Estimation Resource (TIMER) and UALCAN databases. In addition, the expression of SCUBE3 in breast tumor tissues was confirmed by immunohistochemistry. The protein–protein interaction analysis and functional enrichment analysis of SCUBE3 were analyzed using the STRING and Enrichr databases. Moreover, tissue microarray (TMA) was used to analyze the relationship between SCUBE3 expression levels and clinical-pathological parameters, such as histological type, grade, the status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor (HER2). We further supplemented and identified the above results using the UALCAN and bc-GenExMiner v4.4 databases from TCGA data. The correlation between the expression of SCUBE3 and survival was calculated by multivariate Cox regression analysis to investigate whether SCUBE3 expression may be an independent prognostic factor of breast cancer.ResultsWe found that the expression level of SCUBE3 was significantly upregulated in breast cancer tissue compared with adjacent normal tissues. The results showed that the distribution of breast cancer patients in the high expression group and the low expression group was significantly different in ER, PR, HER2, E-cadherin, and survival state (p < 0.05), but there was no significant difference in histologic grade, histologic type, tumor size, lymph node metastasis, TMN stage, subtypes, or recurrence (p > 0.05). In addition, the high expression of SCUBE3 was associated with relatively poor prognosis of ER- (p = 0.012), PR- (p = 0.029), HER2 + (p = 0.007). The multivariate Cox regression analysis showed that the hazard ratio (HR) was 2.80 (95% CI 1.20–6.51, p = 0.0168) in individuals with high SCUBE3 expression, and HR was increased by 1.86 (95% CI 1.06–3.25, p = 0.0300) for per 1-point increase of SCUBE3 expression.ConclusionsThese findings demonstrate that the high expression of SCUBE3 indicates poor prognosis in breast cancer. SCUBE3 expression may serve as a potential diagnostic indicator of breast cancer.

Temperature Variation in Breast Tissue Model With and Without Tumor Based on Porous Media

The human body is made by 200 different types of cells, which are separated by voids. Blood supplies the nutrients and minerals to all cells within the tissue through these voids. The breast tissue is treated as a porous media in the study. Tumor includes the vascular (blood) and the extra-vascular (solid) regions. The porosity of a tumor is higher than normal tissue. The present work deals with the temperature variation of normal and tumorous breast tissue based on porous media. The finite element method is used to solve the two-dimensional bio-heat equation. The results show that the temperature profile of normal breast tissue in the porous media model is almost identical with the conventional bio-heat model at correction factor is equal to 0:6. The temperature of tumor region in the porous media model is slightly lower than the conventional bio-heat model. When the porosity is increased, the temperature of normal breast tissue is increased. But in tumorous breast tissue, the temperature is slightly increased in skin surface to anterior part of the tumor and slightly decreased in tumor region. The temperature of normal and tumorous breast tissue is increased when metabolism, blood velocity, and room temperature are increased in the porous media model. The central temperature of the tumor region reaches a steady state faster than anterior and posterior temperature of both normal and tumorous breast tissue in conventional bio-heat model and porous media model.

Human ribonuclease 1 serves as a secretory ligand of ephrin A4 receptor and induces breast tumor initiation

Human ribonuclease 1 (hRNase 1) is critical to extracellular RNA clearance and innate immunity to achieve homeostasis and host defense; however, whether it plays a role in cancer remains elusive. Here, we demonstrate that hRNase 1, independently of its ribonucleolytic activity, enriches the stem-like cell population and enhances the tumor-initiating ability of breast cancer cells. Specifically, secretory hRNase 1 binds to and activates the tyrosine kinase receptor ephrin A4 (EphA4) signaling to promote breast tumor initiation in an autocrine/paracrine manner, which is distinct from the classical EphA4-ephrin juxtacrine signaling through contact-dependent cell-cell communication. In addition, analysis of human breast tumor tissue microarrays reveals a positive correlation between hRNase 1, EphA4 activation, and stem cell marker CD133. Notably, high hRNase 1 level in plasma samples is positively associated with EphA4 activation in tumor tissues from breast cancer patients, highlighting the pathological relevance of the hRNase 1-EphA4 axis in breast cancer. The discovery of hRNase 1 as a secretory ligand of EphA4 that enhances breast cancer stemness suggests a potential treatment strategy by inactivating the hRNase 1-EphA4 axis.

The association between the expression of nuclear Yes-associated protein 1 (YAP1) and p53 protein expression profile in breast cancer patients.

BackgroundYes-associated protein 1 (YAP1) is a key effector molecule regulated by the Hippo pathway and described as a poor prognostic factor in breast cancer. Tumor protein 53 (TP53) mutation is well known as a biomarker related to poor survival outcomes. So far clinical characteristics and survival outcome according to YAP1 and TP53 mutation have been poorly identified in breast cancer.Patients and methodsRetrospectively, 533 breast tumor tissues were collected at the Seoul St Mary’s hospital and Gangnam Severance Hospital from 1992 to 2017. Immunohistochemistry with YAP1 and p53 specific antibodies were performed, and the clinical data were analyzed.ResultsMutant p53 pattern was associated with aggressive tumor features and advanced anatomical stage. Inferior overall survival (OS) and recurrence free survival (RFS) were related with mutant p53 pattern cases with low nuclear YAP1 expression (P = 0.0009 and P = 0.0011, respectively). Multivariate analysis showed that mutant p53 pattern was an independent prognostic marker for OS [hazard ratios (HR): 2.938, 95% confidence intervals (CIs): 1.028–8.395, P = 0.044] and RFS (HR: 1.842, 95% CIs: 1.026–3.304). However, in cases with high nuclear YAP1 expression, there were no significantly difference in OS and RFS according to p53 staining pattern.ConclusionWe found that mutant p53 pattern is a poor prognostic biomarker in breast tumor with low nuclear YAP1 expression. Our findings suggest that interaction between nuclear YAP1 and p53 expression pattern impact survival outcomes.

Mediator of DNA Damage Checkpoint 1 (MDC1) Is a Novel Estrogen Receptor Coregulator in Invasive Lobular Carcinoma of the Breast.

Invasive lobular carcinoma (ILC) is the most common special histologic subtype of breast cancer, and nearly all ILC tumors express estrogen receptor alpha (ER). However, clinical and laboratory data suggest ILC are strongly estrogen-driven but not equally antiestrogen-sensitive. We hypothesized ILC-specific ER coregulators mediate ER functions and antiestrogen resistance in ILC, and profiled ER-associated proteins by mass spectrometry. Three ER+ ILC cell lines (MDA MB 134VI, SUM44PE, and BCK4) were compared with ER+ invasive ductal carcinoma (IDC) line data, and we examined whether siRNA of identified proteins suppressed ER-driven proliferation in ILC cells. This identified mediator of DNA damage checkpoint 1 (MDC1), a tumor suppressor in DNA damage response (DDR), as a novel ER coregulator in ILC. We confirmed ER:MDC1 interaction was specific to ILC versus IDC cells, and found MDC1 knockdown suppressed ILC cell proliferation and tamoxifen resistance. Using RNA-sequencing, we found in ILC cells MDC1 knockdown broadly dysregulates the ER transcriptome, with ER:MDC1 target genes enriched for promoter hormone response elements. Importantly, our data are inconsistent with MDC1 tumor suppressor functions in DDR, but suggest a novel oncogenic role for MDC1 as an ER coregulator. Supporting this, in breast tumor tissue microarrays, MDC1 protein was frequently low or absent in IDC, but MDC1 loss was rare in ER+ ILC. ER:MDC1 interaction and MDC1 coregulator functions may underlie ER function in ILC and serve as targets to overcome antiestrogen resistance in ILC. IMPLICATIONS: MDC1 has novel ER coregulator activity in ILC, which may underlie ILC-specific ER functions, estrogen response, and antiestrogen resistance.