@article {232, title = {HZE Radiation Non-Targeted Effects on the Microenvironment That Mediate Mammary Carcinogenesis.}, journal = {Front Oncol}, volume = {6}, year = {2016}, month = {2016}, pages = {57}, abstract = {

Clear mechanistic understanding of the biological processes elicited by radiation that increase cancer risk can be used to inform prediction of health consequences of medical uses, such as radiotherapy, or occupational exposures, such as those of astronauts during deep space travel. Here, we review the current concepts of carcinogenesis as a multicellular process during which transformed cells escape normal tissue controls, including the immune system, and establish a tumor microenvironment. We discuss the contribution of two broad classes of radiation effects that may increase cancer: radiation targeted effects that occur as a result of direct energy deposition, e.g., DNA damage, and non-targeted effects (NTE) that result from changes in cell signaling, e.g., genomic instability. It is unknown whether the potentially greater carcinogenic effect of high Z and energy (HZE) particle radiation is a function of the relative contribution or extent of NTE or due to unique NTE. We addressed this problem using a radiation/genetic mammary chimera mouse model of breast cancer. Our experiments suggest that NTE promote more aggressive cancers, as evidenced by increased growth rate, transcriptomic signatures, and metastasis, and that HZE particle NTE are more effective than reference γ-radiation. Emerging evidence suggest that HZE irradiation dampens antitumor immunity. These studies raise concern that HZE radiation exposure not only increases the likelihood of developing cancer but also could promote progression to more aggressive cancer with a greater risk of mortality.

}, issn = {2234-943X}, doi = {10.3389/fonc.2016.00057}, author = {Barcellos-Hoff, Mary Helen and Jiang-Hua Mao} } @article {219, title = {Identification of genetic loci that control mammary tumor susceptibility through the host microenvironment.}, journal = {Sci Rep}, volume = {5}, year = {2015}, month = {2015}, pages = {8919}, abstract = {

The interplay between host genetics, tumor microenvironment and environmental exposure in cancer susceptibility remains poorly understood. Here we assessed the genetic control of stromal mediation of mammary tumor susceptibility to low dose ionizing radiation (LDIR) using backcrossed F1 into BALB/c (F1Bx) between cancer susceptible (BALB/c) and resistant (SPRET/EiJ) mouse strains. Tumor formation was evaluated after transplantation of non-irradiated Trp53-/- BALB/c mammary gland fragments into cleared fat pads of F1Bx hosts. Genome-wide linkage analysis revealed 2 genetic loci that constitute the baseline susceptibility via host microenvironment. However, once challenged with LDIR, we discovered 13 additional loci that were enriched for genes involved in cytokines, including TGFβ1 signaling. Surprisingly, LDIR-treated F1Bx cohort significantly reduced incidence of mammary tumors from Trp53-/- fragments as well as prolonged tumor latency, compared to sham-treated controls. We demonstrated further that plasma levels of specific cytokines were significantly correlated with tumor latency. Using an ex vivo 3-D assay, we confirmed TGFβ1 as a strong candidate for reduced mammary invasion in SPRET/EiJ, which could explain resistance of this strain to mammary cancer risk following LDIR. Our results open possible new avenues to understand mechanisms of genes operating via the stroma that affect cancer risk from external environmental exposures.

}, keywords = {Animals, Breast Neoplasms, Cell Line, Tumor, Cytokines, Female, Genetic Predisposition to Disease, Mice, Mice, Inbred BALB C, Neoplasms, Radiation-Induced, Quantitative Trait Loci, Risk Factors, Transforming Growth Factor beta1, Tumor Microenvironment}, issn = {2045-2322}, doi = {10.1038/srep08919}, author = {Zhang, Pengju and Lo, Alvin and Huang, Yurong and Huang, Ge and Liang, Guozhou and Mott, Joni and Karpen, Gary H and Blakely, Eleanor A and Bissell, Mina J and Barcellos-Hoff, Mary Helen and A Snijders and Jiang-Hua Mao} } @article {212, title = {Densely ionizing radiation acts via the microenvironment to promote aggressive Trp53-null mammary carcinomas.}, journal = {Cancer Res}, volume = {74}, year = {2014}, month = {2014 Dec 1}, pages = {7137-48}, abstract = {

Densely ionizing radiation, which is present in the space radiation environment and used in radiation oncology, has potentially greater carcinogenic effect compared with sparsely ionizing radiation that is prevalent on earth. Here, we used a radiation chimera in which mice were exposed to densely ionizing 350 MeV/amu Si-particles, γ-radiation, or sham-irradiated and transplanted 3 days later with syngeneic Trp53-null mammary fragments. Trp53-null tumors arising in mice irradiated with Si-particles had a shorter median time to appearance and grew faster once detected compared with those in sham-irradiated or γ-irradiated mice. Tumors were further classified by markers keratin 8/18 (K18, KRT18), keratin 14 (K14, KRT14) and estrogen receptor (ER, ESR1), and expression profiling. Most tumors arising in sham-irradiated hosts were comprised of both K18- and K14-positive cells (K14/18) while those tumors arising in irradiated hosts were mostly K18. Keratin staining was significantly associated with ER status: K14/18 tumors were predominantly ER-positive, whereas K18 tumors were predominantly ER-negative. Genes differentially expressed in K18 tumors compared with K14/18 tumor were associated with ERBB2 and KRAS, metastasis, and loss of E-cadherin. Consistent with this, K18 tumors tended to grow faster and be more metastatic than K14/18 tumors, however, K18 tumors in particle-irradiated mice grew significantly larger and were more metastatic compared with sham-irradiated mice. An expression profile that distinguished K18 tumors arising in particle-irradiated mice compared with sham-irradiated mice was enriched in mammary stem cell, stroma, and Notch signaling genes. These data suggest that carcinogenic effects of densely ionizing radiation are mediated by the microenvironment, which elicits more aggressive tumors compared with similar tumors arising in sham-irradiated hosts.

}, keywords = {Animals, Biomarkers, Tumor, Cadherins, Female, Gene Expression Profiling, Keratins, Mammary Neoplasms, Experimental, Mice, Mice, Inbred BALB C, Proto-Oncogene Proteins p21(ras), Radiation, Ionizing, Receptor, ErbB-2, Receptors, Estrogen, Receptors, Notch, Stem Cells, Tumor Microenvironment, Tumor Suppressor Protein p53}, issn = {1538-7445}, doi = {10.1158/0008-5472.CAN-14-1212}, author = {Illa-Bochaca, Irineu and Ouyang, Haoxu and Tang, Jonathan and Sebastiano, Christopher and Jiang-Hua Mao and Costes, Sylvain V and Demaria, Sandra and Barcellos-Hoff, Mary Helen} } @article {213, title = {Distinct luminal-type mammary carcinomas arise from orthotopic Trp53-null mammary transplantation of juvenile versus adult mice.}, journal = {Cancer Res}, volume = {74}, year = {2014}, month = {2014 Dec 1}, pages = {7149-58}, abstract = {

Age and physiologic status, such as menopause, are risk factors for breast cancer. Less clear is what factors influence the diversity of breast cancer. In this study, we investigated the effect of host age on the distribution of tumor subtypes in mouse mammary chimera consisting of wild-type hosts and Trp53 nullizygous epithelium, which undergoes a high rate of neoplastic transformation. Wild-type mammary glands cleared of endogenous epithelium at 3 weeks of age were subsequently transplanted during puberty (5 weeks) or at maturation (10 weeks) with syngeneic Trp53-null mammary tissue fragments and monitored for one year. Tumors arose sooner from adult hosts (AH) compared with juvenile hosts (JH). However, compared with AH tumors, JH tumors grew several times faster, were more perfused, exhibited a two-fold higher mitotic index, and were more highly positive for insulin-like growth factor receptor phosphorylation. Most tumors in each setting were estrogen receptor (ER)-positive (80\% JH vs. 70\% AH), but JH tumors were significantly more ER-immunoreactive (P = 0.0001) than AH tumors. A differential expression signature (JvA) of juvenile versus adult tumors revealed a luminal transcriptional program. Centroids of the human homologs of JvA genes showed that JH tumors were more like luminal A tumors and AH tumors were more like luminal B tumors. Hierarchical clustering with the JvA human ortholog gene list segregated luminal A and luminal B breast cancers across datasets. These data support the notion that age-associated host physiology greatly influences the intrinsic subtype of breast cancer.

}, keywords = {Animals, Breast Neoplasms, Cell Transformation, Neoplastic, Cluster Analysis, Epithelium, Female, Gene Expression Regulation, Neoplastic, Humans, Mammary Glands, Human, Mammary Neoplasms, Experimental, Mice, Mice, Inbred BALB C, Phosphorylation, Receptors, Estrogen, Receptors, Somatomedin, Tumor Suppressor Protein p53}, issn = {1538-7445}, doi = {10.1158/0008-5472.CAN-14-1440}, author = {Nguyen, David H and Ouyang, Haoxu and Jiang-Hua Mao and Hlatky, Lynn and Barcellos-Hoff, Mary Helen} } @article {207, title = {Irradiation of juvenile, but not adult, mammary gland increases stem cell self-renewal and estrogen receptor negative tumors.}, journal = {Stem Cells}, volume = {32}, year = {2014}, month = {2014 Mar}, pages = {649-61}, abstract = {

Children exposed to ionizing radiation have a substantially greater breast cancer risk than adults; the mechanism for this strong age dependence is not known. Here we show that pubertal murine mammary glands exposed to sparsely or densely ionizing radiation exhibit enrichment of mammary stem cell and Notch pathways, increased mammary repopulating activity indicative of more stem cells, and propensity to develop estrogen receptor (ER) negative tumors thought to arise from stem cells. We developed a mammary lineage agent-based model (ABM) to evaluate cell inactivation, self-renewal, or dedifferentiation via epithelial-mesenchymal transition (EMT) as mechanisms by which radiation could increase stem cells. ABM rejected cell inactivation and predicted increased self-renewal would only affect juveniles while dedifferentiation could act in both juveniles and adults. To further test self-renewal versus dedifferentiation, we used the MCF10A human mammary epithelial cell line, which recapitulates ductal morphogenesis in humanized fat pads, undergoes EMT in response to radiation and transforming growth factor β (TGFβ) and contains rare stem-like cells that are Let-7c negative or express both basal and luminal cytokeratins. ABM simulation of population dynamics of double cytokeratin cells supported increased self-renewal in irradiated MCF10A treated with TGFβ. Radiation-induced Notch concomitant with TGFβ was necessary for increased self-renewal of Let-7c negative MCF10A cells but not for EMT, indicating that these are independent processes. Consistent with these data, irradiating adult mice did not increase mammary repopulating activity or ER-negative tumors. These studies suggest that irradiation during puberty transiently increases stem cell self-renewal, which increases susceptibility to developing ER-negative breast cancer.

}, keywords = {Aging, Animals, Biomarkers, Cell Line, Cell Lineage, Cell Proliferation, Computer Simulation, Dose-Response Relationship, Radiation, Epithelial Cells, Female, Humans, Mammary Glands, Animal, Mammary Neoplasms, Animal, Mice, Morphogenesis, Radiation, Ionizing, Receptors, Estrogen, Receptors, Notch, Stem Cells, Transforming Growth Factor beta}, issn = {1549-4918}, doi = {10.1002/stem.1533}, author = {Tang, Jonathan and Fernandez-Garcia, Ignacio and Vijayakumar, Sangeetha and Martinez-Ruis, Haydeliz and Illa-Bochaca, Irineu and Nguyen, David H and Jiang-Hua Mao and Costes, Sylvain V and Barcellos-Hoff, Mary Helen} } @article {199, title = {Murine microenvironment metaprofiles associate with human cancer etiology and intrinsic subtypes.}, journal = {Clin Cancer Res}, volume = {19}, year = {2013}, month = {2013 Mar 15}, pages = {1353-62}, abstract = {

PURPOSE: Ionizing radiation is a well-established carcinogen in rodent models and a risk factor associated with human cancer. We developed a mouse model that captures radiation effects on host biology by transplanting unirradiated Trp53-null mammary tissue to sham or irradiated hosts. Gene expression profiles of tumors that arose in irradiated mice are distinct from those that arose in na{\"\i}ve hosts. We asked whether expression metaprofiles could discern radiation-preceded human cancer or be informative in sporadic breast cancers.

EXPERIMENTAL DESIGN: Affymetrix microarray gene expression data from 56 Trp53-null mammary tumors were used to define gene profiles and a centroid that discriminates tumors arising in irradiated hosts. These were applied to publicly available human cancer datasets.

RESULTS: Host irradiation induces a metaprofile consisting of gene modules representing stem cells, cell motility, macrophages, and autophagy. Human orthologs of the host irradiation metaprofile discriminated between radiation-preceded and sporadic human thyroid cancers. An irradiated host centroid was strongly associated with estrogen receptor-negative breast cancer. When applied to sporadic human breast cancers, the irradiated host metaprofile strongly associated with basal-like and claudin-low breast cancer intrinsic subtypes. Comparing host irradiation in the context of TGF-β levels showed that inflammation was robustly associated with claudin-low tumors.

CONCLUSIONS: Detection of radiation-preceded human cancer by the irradiated host metaprofile raises possibilities of assessing human cancer etiology. Moreover, the association of the irradiated host metaprofiles with estrogen receptor-negative status and claudin-low subtype suggests that host processes similar to those induced by radiation underlie sporadic cancers.

}, keywords = {Animals, Breast Neoplasms, Female, Gene Expression Regulation, Neoplastic, Humans, Mammary Neoplasms, Animal, Mice, Radiation, Ionizing, Transcriptome, Tumor Microenvironment, Tumor Suppressor Protein p53}, issn = {1078-0432}, doi = {10.1158/1078-0432.CCR-12-3554}, author = {Nguyen, David H and Fredlund, Erik and Zhao, Wei and Perou, Charles M and Balmain, Allan and Jiang-Hua Mao and Barcellos-Hoff, Mary Helen} } @article {177, title = {Radiation acts on the microenvironment to affect breast carcinogenesis by distinct mechanisms that decrease cancer latency and affect tumor type.}, journal = {Cancer Cell}, volume = {19}, year = {2011}, month = {2011 May 17}, pages = {640-51}, abstract = {

Tissue microenvironment is an important determinant of carcinogenesis. We demonstrate that ionizing radiation, a known carcinogen, affects cancer frequency and characteristics by acting on the microenvironment. Using a mammary chimera model in which an irradiated host is transplanted with oncogenic Trp53 null epithelium, we show accelerated development of aggressive tumors whose molecular signatures were distinct from tumors arising in nonirradiated hosts. Molecular and genetic approaches show that TGFβ mediated tumor acceleration. Tumor molecular signatures implicated TGFβ, and genetically reducing TGFβ abrogated the effect on latency. Surprisingly, tumors from irradiated hosts were predominantly estrogen receptor negative. This effect was TGFβ independent and linked to mammary stem cell activity. Thus, the irradiated microenvironment affects latency and clinically relevant features of cancer through distinct and unexpected mechanisms.

}, keywords = {Animals, Breast Neoplasms, Cell Transformation, Neoplastic, Dose-Response Relationship, Radiation, Epithelial Cells, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Gene Regulatory Networks, Mammary Glands, Animal, Mice, Mice, Inbred BALB C, Mice, Knockout, Neoplasms, Radiation-Induced, Radiation Chimera, Reaction Time, Receptors, Estrogen, Time Factors, Transforming Growth Factor beta1, Tumor Burden, Tumor Microenvironment, Tumor Suppressor Protein p53, Whole-Body Irradiation}, issn = {1878-3686}, doi = {10.1016/j.ccr.2011.03.011}, author = {Nguyen, David H and Oketch-Rabah, Hellen A and Illa-Bochaca, Irineu and Geyer, Felipe C and Reis-Filho, Jorge S and Jiang-Hua Mao and Ravani, Shraddha A and Zavadil, Jiri and Borowsky, Alexander D and Jerry, D Joseph and Dunphy, Karen A and Seo, Jae Hong and Haslam, Sandra and Medina, Daniel and Barcellos-Hoff, Mary Helen} } @article {88, title = {Multidimensional profiling of cell surface proteins and nuclear markers}, journal = {IEEE/ACM Trans Comput Biol Bioinform}, volume = {7}, year = {2010}, month = {2010 Jan-Mar}, pages = {80-90}, abstract = {

Cell membrane proteins play an important role in tissue architecture and cell-cell communication. We hypothesize that segmentation and multidimensional characterization of the distribution of cell membrane proteins, on a cell-by-cell basis, enable improved classification of treatment groups and identify important characteristics that can otherwise be hidden. We have developed a series of computational steps to 1) delineate cell membrane protein signals and associate them with a specific nucleus; 2) compute a coupled representation of the multiplexed DNA content with membrane proteins; 3) rank computed features associated with such a multidimensional representation; 4) visualize selected features for comparative evaluation through heatmaps; and 5) discriminate between treatment groups in an optimal fashion. The novelty of our method is in the segmentation of the membrane signal and the multidimensional representation of phenotypic signature on a cell-by-cell basis. To test the utility of this method, the proposed computational steps were applied to images of cells that have been irradiated with different radiation qualities in the presence and absence of other small molecules. These samples are labeled for their DNA content and E-cadherin membrane proteins. We demonstrate that multidimensional representations of cell-by-cell phenotypes improve predictive and visualization capabilities among different treatment groups, and identify hidden variables.

}, keywords = {Cadherins, Cell Membrane, Cell Nucleus, Computer Simulation, DNA, Gene Expression Profiling, Membrane Proteins, Models, Biological}, issn = {1557-9964}, doi = {10.1109/TCBB.2008.134}, author = {Ju Han and Hang Chang and Andarawewa, Kumari and Yaswen, Paul and Barcellos-Hoff, Mary Helen and Parvin, Bahram} }