Features Of Human Breast Cancer Research Articles

Polypropylene microplastics promote metastatic features in human breast cancer

Microplastics (MPs) are now a global issue due to increased plastic production and use. Recently, various studies have been performed in response to the human health risk assessment. However, these studies have focused on spherical MPs, which have smooth edges and a spherical shape and account for less than 1% of MPs in nature. Unfortunately, studies on fragment-type MPs are very limited and remain in the initial stages. In this study, we studied the effect that 16.4 µm fragment type polypropylene (PP) MPs, which have an irregular shape and sharp edges and form naturally in the environment, had on breast cancer. The detrimental effects of PPMPs on breast cancer metastasis were examined. Here, 1.6 mg/ml of PPMP, which does not induce cytotoxicity in MDA-MB-231, was used, and at this concentration, PPMP did not induce morphological changes or cellular migrating in the MDA-MB-231 and MCF-7 cells. However, PPMP incubation for 24 hours in the MDA-MB-231 cells significantly altered the level of cell cycle-related transcripts in an RNA-seq analysis. When confirmed by qRT-PCR, the gene expression of TMBIM6, AP2M1, and PTP4A2 was increased, while the transcript level of FTH1 was decreased. Further, secretion of the pro-inflammatory cytokine IL-6 from cancer cells was elevated with the incubation of PPMP for 12 hours. These results suggest that PPMP enhances metastasis-related gene expression and cytokines in breast cancer cells, exacerbating breast cancer metastasis.

Retraction: Notch-1 Signaling Promotes the Malignant Features of Human Breast Cancer through NF-κB Activation.

Retraction: Notch-1 Signaling Promotes the Malignant Features of Human Breast Cancer through NF-κB Activation.

Canine as a Comparative and Translational Model for Human Mammary Tumor.

Despite the advances in research and treatment of human breast cancer, its incidence rate continues to increase by 0.5% per year, and the discovery of novel therapeutic strategies for specific subtypes of human breast cancer remains challenging. Traditional laboratory mouse models have contributed tremendously to human breast cancer research. However, mice do not develop tumors spontaneously; consequently, genetically engineered mouse models or patient-derived xenograft models are often relied upon for more sophisticated human breast cancer studies. Since human breast cancer develops spontaneously, there is a need for alternative, yet complementary, models that can better recapitulate the features of human breast cancer to better understand the molecular and clinical complexities of the disease in developing new therapeutic strategies. Canine mammary tumors are one such alternative model that share features with human breast cancer, including prevalence rate, subtype classification, treatment, and mutational profiles, all of which are described in this review.

Abstract 2918: Characterization of a novel transplantable C3TAg breast cancer model in C57BL/6J mice

Abstract Introduction: In women in the United States, breast cancer (BC) is the second leading cause of cancer-related death. BC is a heterogeneous disease, characterized by several subtypes based on molecular markers including several hormone receptors. Transcriptomic analysis further stratifies the disease. The basal-like subtype, often triple-negative for hormone receptors, has the poorest prognosis partially due to the absence of targeted therapies. Obesity, a preventable cause of cancer, is an established risk factor for breast cancer, including basal-like breast cancers. Mouse models to study the interaction of BC and obesity, particularly the more aggressive basal-like BC, are crucial. The C3(1)/SV40 large T-antigen (TAg) transgenic mouse model is an established model of basal-like mammary cancer that recapitulates several key features of human breast cancer. However, this model was generated in FVB mice, which is not an ideal genetic background for studying obesity, immunology and other aspects of cancer research. The goal of this study was to develop and characterize a C3TAg transgenic mouse model on a C57BL/6 background. Therefore, the current study backcrossed C3TAg transgenic FVB mice with C57BL/6 mice, a model most commonly used to study obesity, for 10 generations to create a transplantable C3TAg model in C57BL/6 mice. Methods: Cell Line Generation: C3TAg transgenic FVB mice were backcrossed with C57BL/6 mice for 10 generations. Tumors from 6-month-old heterozygous female mammary tissue were harvested, dissociated, and subcloned by limited dilution. A total of 156 clonal lines were established from which a subset of 12 lines displaying differences in morphology, growth and expression of metabolic and EMT genes (by qPCR). In vivo: 96 female C57BL/6J mice were randomized into 12 groups (n=8/group) and orthotopically injected with three different cell densities (5*104, 1.5*105, 5*105 cells/mouse) from one of the four selected lines. Mice tumor growth was assessed using electronic calipers. In vitro: Proliferation and cellular respiration were assessed and molecular subtyping was conducted using Affymetrix microarray data. Results: All tested cell lines formed tumors in vivo, with macroscopic characteristics of basal-like tumors including central necrosis. In vitro growth and metabolism of tested lines showed modest dissimilarity; in contrast, tumor growth rates and metastatic outgrowth were starkly dissimilar among the tested lines. Transcriptomic data clustered these cell lines with human BC tumors. Conclusions: Here we report for the first time a transplantable C3TAg model in C57BL/6 mice with highly effective tumor engraftment and growth, and with variable phenotypes for tumor growth and metastasis. Thus, this model may serve as an attractive model for the study of the interactions of basal-like breast cancer and obesity. This work was supported by R35CA197627 to SH. Citation Format: Meredith S. Carson, Michael F. Colman, Daniel Roth, Jody Albright, Melissa VerHague, John E. French, Stephen D. Hursting. Characterization of a novel transplantable C3TAg breast cancer model in C57BL/6J mice [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 2918.

Exploration of organoid in breast cancer related research

Breast cancer is the most common cancer in women. At present, the in vivo model and traditional cell culture are mainly used in breast cancer researches. However, as high as 90% clinical trials are failed for drugs explored by the above two methods, due to the inherent species differences between humans and animals, as well as the differences in the tissue structure between organs and cells. Therefore, organoid three-dimensional culture is emerging. As a new tumor research model, organoid, a three-dimensional cell complex with spatial structure, has broad application prospects, such as precision medicine, organ transplantation, establishment of refractory disease model, gene therapy and drug research and development. Therefore, organoid is considered as one of the ideal carriers for life science research in the future. Breast cancer, a heterogeneous disease with complex phenotypes, has a low survival rate. Breast cancer organoid can reproduce many key features of human breast cancer, thus, the construction of organoid biological library of breast cancer will provide a new platform for studying the occurrence, development, metastasis and drug resistance mechanism of breast cancer. In this review, we systematically introduce the culture conditions of organoids and their application in breast cancer related research, and the application prospect of organoids.

Cross-species oncogenic signatures of breast cancer in canine mammary tumors

Genomic and precision medicine research has afforded notable advances in human cancer treatment, yet applicability to other species remains uncertain. Through whole-exome and transcriptome analyses of 191 spontaneous canine mammary tumors (CMTs) that exhibit the archetypal features of human breast cancers, we found a striking resemblance of genomic characteristics including frequent PIK3CA mutations (43.1%), aberrations of the PI3K-Akt pathway (61.7%), and key genes involved in cancer initiation and progression. We also identified three gene expression-based CMT subtypes, one of which segregated with basal-like human breast cancer subtypes with activated epithelial-to-mesenchymal transition, low claudin expression, and unfavorable disease prognosis. A relative lack of ERBB2 amplification and Her2-enrichment subtype in CMT denoted species-specific molecular mechanisms. Taken together, our results elucidate cross-species oncogenic signatures for a better understanding of universal and context-dependent mechanisms in breast cancer development and provide a basis for precision diagnostics and therapeutics for domestic dogs.

Progress in the application of organoids to breast cancer research

Breast cancer is the most common cancer diagnosed in women. Breast cancer research is currently based mainly on animal models and traditional cell culture. However, the inherent species gap between humans and animals, as well as differences in organization between organs and cells, limits research advances. The breast cancer organoid can reproduce many of the key features of human breast cancer, thereby providing a new platform for investigating the mechanisms underlying the development, progression, metastasis and drug resistance of breast cancer. The application of organoid technology can also promote drug discovery and the design of individualized treatment strategies. Here, we discuss the latest advances in the use of organoid technology for breast cancer research.

Estrogen-related receptors are targetable ROS sensors.

Excessive reactive oxygen species (ROS) can cause oxidative stress and consequently cell injury contributing to a wide range of diseases. Addressing the critical gaps in our understanding of the adaptive molecular events downstream ROS provocation holds promise for the identification of druggable metabolic vulnerabilities. Here, we unveil a direct molecular link between the activity of two estrogen-related receptor (ERR) isoforms and the control of glutamine utilization and glutathione antioxidant production. ERRα down-regulation restricts glutamine entry into the TCA cycle, while ERRγ up-regulation promotes glutamine-driven glutathione production. Notably, we identify increased ERRγ expression/activation as a hallmark of oxidative stress triggered by mitochondrial disruption or chemotherapy. Enhanced tumor antioxidant capacity is an underlying feature of human breast cancer (BCa) patients that respond poorly to treatment. We demonstrate that pharmacological inhibition of ERRγ with the selective inverse agonist GSK5182 increases antitumor efficacy of the chemotherapeutic paclitaxel on poor outcome BCa tumor organoids. Our findings thus underscore the ERRs as novel redox sensors and effectors of a ROS defense program and highlight the potential therapeutic advantage of exploiting ERRγ inhibitors for the treatment of BCa and other diseases where oxidative stress plays a central role.

Transcriptional regulation of normal human mammary cell heterogeneity and its perturbation in breast cancer.

The mammary gland in adult women consists of biologically distinct cell types that differ in their surface phenotypes. Isolation and molecular characterization of these subpopulations of mammary cells have provided extensive insights into their different transcriptional programs and regulation. This information is now serving as a baseline for interpreting the heterogeneous features of human breast cancers. Examination of breast cancer mutational profiles further indicates that most have undergone a complex evolutionary process even before being detected. The consequent intra‐tumoral as well as inter‐tumoral heterogeneity of these cancers thus poses major challenges to deriving information from early and hence likely pervasive changes in potential therapeutic interest. Recently described reproducible and efficient methods for generating human breast cancers de novo in immunodeficient mice transplanted with genetically altered primary cells now offer a promising alternative to investigate initial stages of human breast cancer development. In this review, we summarize current knowledge about key transcriptional regulatory processes operative in these partially characterized subpopulations of normal human mammary cells and effects of disrupting these processes in experimentally produced human breast cancers.

Mapping Mammary Tumor Traits in the Rat.

For nearly a century, the rat has served as a key model for studying the pathophysiology and genetic risk modifiers of breast cancer. Rat mammary tumors that initiate after exposure to carcinogens or estrogens closely resemble the etiological, histopathological, and genomic features of human breast cancer. Recent developments in genome-editing techniques in the rat have also enabled the development of sophisticated models for identifying the genetic modifiers of the nonmalignant tumor microenvironment that contribute to the formation, progression, and outcome of breast cancer. In this protocol review, we discuss the current methodologies for the three genetic mapping techniques in the rat that are widely used for identifying and testing the heritable genetic modifiers of breast cancer.

Reprogramming of the estrogen responsive transcriptome contributes to tamoxifen-dependent protection against tumorigenesis in the p53 null mammary epithelial cells.

The tumor suppressor gene p53 is frequently mutated in human breast cancer and is a marker for poor prognosis and resistance to chemotherapy. Transplantation of p53 null mouse mammary epithelium into syngeneic wild-type mice leads to normal mammary gland development followed by spontaneous mammary tumors that recapitulate many of the phenotypic, molecular and genetic features of human breast cancer. Transient exposure of p53 null mice to the anti-estrogen, tamoxifen leads to sustained and robust protection against tumor development. However the mechanism underlying this anti-tumor activity remains poorly understood. Here we demonstrate that transient exposure to tamoxifen leads to a reduction in mammary ductal side-branching and epithelial cell proliferation after tamoxifen withdrawal. Global gene expression analysis showed that transient tamoxifen exposure leads to persistent changes in the expression of a subset of estrogen regulated gene signatures in mammary epithelial cells (MECs). Among these was the protein tyrosine phosphatase, non-receptor type 5 (Ptpn5). We show that Ptpn5 is a novel tamoxifen regulated target gene which is upregulated in MECs after transient tamoxifen exposure and displays tumor suppressor activity in human breast cancer cells. Further, PTPN5 expression is strongly associated with good clinical outcome in tamoxifen treated human breast cancer patients suggesting that PTPN5 may represent a novel biomarker of tamoxifen response in human breast cancer.

Abstract P4-14-02: CSF1/CSF1R axis reprograms epithelial-to-mesenchymal phenotypes in inflammatory breast cancer

Abstract Inflammatory breast cancer (IBC) accounts for 2% of breast cancers but 10% of breast cancer-related deaths in the US. Clinical hallmarks of IBC are tumor cell emboli in lymphatic vessels and overexpression of E-cadherin, which promotes cell clustering. Given these hallmarks, IBC is thought to spread via collective invasion and cell clusters. However, we showed that IBC cells underwent epithelial-to-mesenchymal transition (EMT) and metastasized through EMT. Thus, there are two contradictory theories of IBC metastasis. The objectives of this study were 1) to propose a model that reconciles these two models, and 2) to identify target molecules for inhibition of IBC metastasis. Methods: We previously showed that Matrigel culture induced EMT-like changes in SUM149 IBC cells. To test if this transformation from epithelial (E) to mesenchymal (M) in Matrigel culture is unique to IBC cells, a panel of breast cancer cells was cultured in both monolayer and Matrigel-coated plates. The cells were IBC (SUM149, SUM190, KPL4, IBC3), triple-negative breast cancer (TNBC) (MDA-MB-231, MDA-MB-468), and ER+ (MCF7) cells. Phenotypic changes in morphology and expression of EMT markers (E-cadherin, vimentin) were captured with bright field and immunofluorescent (IF) images, respectively. For genome-wide and targeted transcriptional analysis, SUM149 cells cultured in monolayer and Matrigel were processed using DNA microarrays and Taqman qRT-PCR. To correlate the Matrigel gene signature with M features in human breast cancer, a human breast cancer data set was hierarchically clustered with the Matrigel gene signature. Results: SUM149 cells showed a remarkable phenotypic change from E in monolayer culture to M in Matrigel. IF analysis confirmed induction of vimentin expression in Matrigel but stable expression of E-cadherin (thus, we refer to this state as E/M hybrid). This trend was also observed with SUM190 cells. Using qRT-PCR, we confirmed downregulation of E-cadherin and upregulation of M markers (vimentin, Twist1, Snail1, ZEB2) in Matrigel-cultured SUM149 and SUM190 cells compared to monolayer-cultured cells. DNA microarray transcriptional analysis confirmed this trend in SUM149 cells. TNBC has more M-like features than other breast cancer subtypes. Given this evidence, we clustered human breast cancer data using overexpressed genes in Matrigel-cultured SUM149 cells. We identified a cluster of 20 genes in TNBC samples and, assuming that these genes are drivers of E to E/M transition, chose the inflammation-related gene CSF1 as a candidate. The CSF1/CSF1R axis was inhibited by a CSF1R inhibitor, BLZ945; moreover, treatment with BLZ945 reversed the EMT changes in cells in Matrigel culture. Treatment with 5 μM BLZ945 re-induced E-cadherin expression and suppressed Snail1 and Twist1 expression in Matrigel-cultured SUM149 cells. Conclusion: IBC cells are more prone to undergo transition from E to E/M phenotype in Matrigel culture than are cells of other breast cancer subtypes. The CSF1/CSF1R axis plays a role in this E to E/M transition, thus warranting testing its significance using an in vivo IBC model. Phenotypic transition and reversion between E and E/M phenotypes could be a new paradigm that reconciles two contradictory models of IBC metastasis. Citation Format: Kai K, Iwamoto T, Zhang D, Rao AUK, Thompson A, Sen S, Ueno NT. CSF1/CSF1R axis reprograms epithelial-to-mesenchymal phenotypes in inflammatory breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-14-02.

Regulatory T Cells Exhibit Distinct Features in Human Breast Cancer

Regulatory T (Treg) cells reside in lymphoid organs and barrier tissues where they control different types of inflammatory responses. Treg cells are also found in human cancers, and studies in animal models suggest that they contribute to cancer progression. However, properties of human intratumoral Treg cells and those present in corresponding normal tissue remain largely unknown. Here, we analyzed features of Treg cells in untreated human breast carcinomas, normal mammary gland, and peripheral blood. Tumor-resident Treg cells were potently suppressive and their gene-expression pattern resembled that of normal breast tissue, but not of activated peripheral blood Treg cells. Nevertheless, a number of cytokine and chemokine receptor genes, most notably CCR8, were upregulated in tumor-resident Treg cells in comparison to normal tissue-resident ones. Our studies suggest that targeting CCR8 forthe depletion of tumor-resident Treg cells might represent a promising immunotherapeutic approach for the treatment of breast cancer.

The presence of LC3B puncta and HMGB1 expression in malignant cells correlate with the immune infiltrate in breast cancer

ABSTRACTSeveral cell-intrinsic alterations have poor prognostic features in human breast cancer, as exemplified by the absence of MAP1LC3B/LC3B (microtubule-associated protein 1 light chain 3 β)-positive puncta in the cytoplasm (which indicates reduced autophagic flux) or the loss of nuclear HMGB1 expression by malignant cells. It is well established that breast cancer is under strong immunosurveillance, as reflected by the fact that scarce infiltration of the malignant lesion by CD8+ cytotoxic T lymphocytes or comparatively dense infiltration by immunosuppressive cell types (such as FOXP3+ regulatory T cells or CD68+ tumor-associated macrophages), resulting in low CD8+:FOXP3+ or CD8+:CD68+ ratios, has a negative prognostic impact. Here, we reveal the surprising finding that cell-intrinsic features may influence the composition of the immune infiltrate in human breast cancer. Thus, the absence of LC3B puncta is correlated with intratumoral (but not peritumoral) infiltration by fewer CD8+ cells and more FOXP3+ or CD68+ cells, resulting in a major drop in the CD8+:FOXP3+ or CD8+:CD68+ ratios. Moreover, absence of HMGB1 expression in nuclei correlated with a general drop in all immune effectors, in particular FOXP3+ and CD68+ cells, both within the tumor and close to it. Combined analysis of LC3B puncta and HMGB1 expression allowed for improved stratification of patients with respect to the characteristics of their immune infiltrate as well as overall and metastasis-free survival. It can be speculated that blocked autophagy in, or HMGB1 loss from, cancer cells may favor tumor progression due to their negative impact on anticancer immunosurveillance.

Abstract A07: Spontaneous canine mammary cancers: A much-needed model for human basal-like breast cancer and an ideal system to understand myoepithelial cells

Abstract Spontaneous canine mammary cancer represents an excellent model of human breast cancer but is greatly understudied. To better utilize this valuable resource, we performed the first comprehensive characterization of the genome, transcriptome and epigenome of 12 canine mammary cancer cases, including 7 simple carcinomas and 4 complex carcinomas (1). Simple carcinomas, which histologically match human breast carcinomas, harbor extensive genomic aberrations, many of which faithfully recapitulate key features of human breast cancer. Notably, these tumors closely cluster with human basal-like breast carcinomas from TCGA (2), but not with other intrinsic subtypes, in PAM50 classification with human breast carcinomas. Furthermore, these tumors match the basal-like cancer profile, including MYC amplification, PTEN deletion, BRCA1 mutation, etc. Our results indicate canine simple carcinomas could serve as a much-needed spontaneous cancer model of basal-like breast cancer by effectively bridging the gap between preclinical research and human trials, speeding up drug discovery for the worst subtype of breast cancer. Canine complex carcinomas, characterized by proliferation of both luminal and myoepithelial cells (rare in human breast cancer), appear to lack genomic abnormalities. Instead, these tumors have ~35 chromatin-modification genes downregulated, and are abnormally enriched with active histone modification H4-acetylation while depleted with repressive histone modification H3K9me3. Our findings indicate that these tumors likely originate from epigenomic alterations instead of genomic lesions. Canine complex carcinomas offer an ideal system to study myoepithelial cells, the second major yet significantly understudied cell lineage of the mammary gland.

Lowered circulating aspartate is a metabolic feature of human breast cancer.

Distinct metabolic transformation is essential for cancer cells to sustain a high rate of proliferation and resist cell death signals. Such a metabolic transformation results in unique cellular metabolic phenotypes that are often reflected by distinct metabolite signatures in tumor tissues as well as circulating blood. Using a metabolomics platform, we find that breast cancer is associated with significantly (p = 6.27E-13) lowered plasma aspartate levels in a training group comprising 35 breast cancer patients and 35 controls. The result was validated with 103 plasma samples and 183 serum samples of two groups of primary breast cancer patients. Such a lowered aspartate level is specific to breast cancer as it has shown 0% sensitivity in serum from gastric (n = 114) and colorectal (n = 101) cancer patients. There was a significantly higher level of aspartate in breast cancer tissues (n = 20) than in adjacent non-tumor tissues, and in MCF-7 breast cancer cell line than in MCF-10A cell lines, suggesting that the depleted level of aspartate in blood of breast cancer patients is due to increased tumor aspartate utilization. Together, these findings suggest that lowed circulating aspartate is a key metabolic feature of human breast cancer.

Lowered circulating aspartate is a metabolic feature of human breast cancer

Lowered circulating aspartate is a metabolic feature of human breast cancer

"Omics" and Immunologic Approaches to Optimizing Cure Rates in HER2-Positive Breast Carcinomas.

"Omics" and Immunologic Approaches to Optimizing Cure Rates in HER2-Positive Breast Carcinomas.

Molecular homology and difference between spontaneous canine mammary cancer and human breast cancer.

Spontaneously occurring canine mammary cancer represents an excellent model of human breast cancer, but is greatly understudied. To better use this valuable resource, we performed whole-genome sequencing, whole-exome sequencing, RNA-seq, and/or high-density arrays on twelve canine mammary cancer cases, including seven simple carcinomas and four complex carcinomas. Canine simple carcinomas, which histologically match human breast carcinomas, harbor extensive genomic aberrations, many of which faithfully recapitulate key features of human breast cancer. Canine complex carcinomas, which are characterized by proliferation of both luminal and myoepithelial cells and are rare in human breast cancer, seem to lack genomic abnormalities. Instead, these tumors have about 35 chromatin-modification genes downregulated and are abnormally enriched with active histone modification H4-acetylation, whereas aberrantly depleted with repressive histone modification H3K9me3. Our findings indicate the likelihood that canine simple carcinomas arise from genomic aberrations, whereas complex carcinomas originate from epigenomic alterations, reinforcing their unique value. Canine complex carcinomas offer an ideal system to study myoepithelial cells, the second major cell lineage of the mammary gland. Canine simple carcinomas, which faithfully represent human breast carcinomas at the molecular level, provide indispensable models for basic and translational breast cancer research.

Expression of vimentin filaments in canine malignant mammary gland tumors: A simulation of clinicopathological features of human breast cancer.

Canine malignant mammary gland tumors (CMMGTs) are the most common malignancies observed in females. Several biological similarities have been reported between CMMGTs and human breast cancer (HBC). The present study aimed to assess the correlation of vimentin filaments overexpression, as part of the process of epithelial-mesenchymal transition (EMT) and the clinicopathological characteristics in CMMGTs. The clinicopathological characteristics of 42 CMMGTs were collected. Paraffin-embedded blocks underwent immunohistochemistry staining, which was performed using vimentin (to assess the evolution of the EMT process), Ki-67 (for evaluation of tumor proliferation) and cluster of differentiation 34 (CD34) (for evaluation of angiogenesis) antibodies. The tumor stage, grade, vascular invasion, margin status, rate of expression of the vimentin filaments, microvessel density-CD34 and proliferation rate data were obtained. Finally, the association between the expression of the vimentin filaments and those parameters was resolved statistically. A significant association was shown between the overexpression of the vimentin filaments and tumor size (r=0.71, P=0.03), tumor grade (r=0.80, P=0.021), angiogenesis (r=0.57, P=0.043), proliferation coefficient (r=0.06, P=0.001) and vascular invasion (r=0.76, P=0.043). Vimentin overexpression did not statistically correlate with the tumor stage or the margin status. Similar to the findings of the present study, certain recent studies have indicated that vimentin filament expression in HBC and CMMGTs is associated with the severity of cancer. Thus, spontaneous canine mammary tumor models appear to be an appropriate animal model for breast cancer research, and the results of the present study could aid to reinforce the association.