BIPOC experiences of (anti-)racist patient engagement in adolescent and young adult oncology research: an electronic Delphi study.

Aims: To characterize Black, Indigenous and People of Color (BIPOC) adolescent and young adult (AYA) cancer patients' experiences of patient engagement in AYA oncology and derive best practices that are co-developed by BIPOC AYAs and oncology professionals. Materials & methods: Following a previous call to action from AYA oncology professionals, a panel of experts composed exclusively of BIPOC AYA cancer patients (n = 32) participated in an electronic Delphi study. Results: Emergent themes described BIPOC AYA cancer patients' direct experiences and consensus opinion on recommendations to advance antiracist patient engagement from BIPOC AYA cancer patients and oncology professionals. Conclusion: The findings reveal high-priority practices across all phases of research and are instructional for advancing health equity.

Perspectives on Benefits and Challenges to Developing a Co-Teaching and Co-Learning Exchange between Community and Academic Partners.

BACKGROUND: To train future professionals in health disparities and social determinants of health, academic health centers often use curricula exclusively developed and instructed by faculty. OBJECTIVE: To examine the perceptions and attitudes of faculty and community stakeholders towards the benefits of and challenges to developing co-teaching/co-learning exchange programs. METHODS: Faculty from six academic professional schools at a single institution and community members participated in focus groups. Interviews were video-recorded and reviewed for themes. RESULTS: Both faculty and community participants felt that partnering in the design and implementation of lectures addressing the social determinants of health could enhance curriculum and provide real-world context for the learning experience. CONCLUSIONS: Our findings add to the literature examining the benefits and challenges of engagement between faculty and community and offer new insights on the value of co-teaching/co-learning experiences.

Inbred Strain Characteristics Impact the NKT Cell Repertoire.

NKT cells are primed lymphocytes that rapidly secrete cytokines and can directly kill cancerous cells. Given the critical role NKT cells play in cancer immune surveillance, we sought to investigate the effect of mutations in Brca1, specifically a conditional deletion of exon 11, on type I invariant NKT cell development. We observed a significant reduction in invariant NKT cells in both primary lymphoid and peripheral organs in Brca1 mutant mice compared with wild-type C57BL/6. However, the original Brca1 mutant strain was on a mixed background containing FVB/N. We determined that strain differences, rather than mutations in Brca1, led to the observed loss in NKT cells. Importantly, we found that whereas FVB/N mice lack Vß8, there was a striking increase in the total number of thymic type I CD1d-α-galactosylceramide tetramer positive NKT cells and skewing of the NKT cell population to NKT2 compared with C57BL/6 mice. Collectively, our data demonstrate the profound effect genetics can have on NKT cell subset differentiation.

Planning for Community Scale-Up of Project HEAL: Insights From the SPRINT Initiative.

Project HEAL (Health through Early Awareness and Learning) is an evidence-based intervention rooted in health behavior change theory and aims to increase cancer awareness and early detection through African American faith-based organizations. This study explored the potential for broader scale-up and dissemination of Project HEAL with the team's participation in a training program called Speeding Research-Tested INTerventions (SPRINT). The SPRINT training was framed using tools from the Business Model Canvas and the Value Proposition Canvas to guide trainees in designing (1) compelling value propositions, (2) a minimal viable product, and (3) questions to gain critical insight from various stakeholders during a process called Customer Discovery. We report on our experiences and insights on intervention scale-up that we gained from the training, including key findings from 41 discovery interviews conducted with various stakeholders of the church. We learned several valuable lessons from the discovery interviews such as scale-up will likely be more incremental than immediate. Additional refinement is needed to scale up the intervention for "real-world" application, such as making our technology more user-friendly and including additional health topics beyond cancer. We discuss how insights from the training refined our plans for future scale-up and dissemination in a constituent-informed way.

RANKL/RANK: from bone loss to the prevention of breast cancer.

RANK and RANKL, a receptor ligand pair belonging to the tumour necrosis factor family, are the critical regulators of osteoclast development and bone metabolism. Besides their essential function in bone, RANK and RANKL have also been identified as the key factors for the formation of a lactating mammary gland in pregnancy. Mechanistically, RANK and RANKL link the sex hormone progesterone with stem cell expansion and proliferation of mammary epithelial cells. Based on their normal physiology, RANKL/RANK control the onset of hormone-induced breast cancer through the expansion of mammary progenitor cells. Recently, we and others were able to show that RANK and RANKL are also critical regulators of BRCA1-mutation-driven breast cancer. Currently, the preventive strategy for BRCA1-mutation carriers includes preventive mastectomy, associated with wide-ranging risks and psychosocial effects. The search for an alternative non-invasive prevention strategy is therefore of paramount importance. As our work strongly implicates RANK and RANKL as key molecules involved in the initiation of BRCA1-associated breast cancer, we propose that anti-RANKL therapy could be a feasible preventive strategy for women carrying BRCA1 mutations, and by extension to other women with high risk of breast cancer.

RANKL/RANK control Brca1 mutation- .

Breast cancer is the most common female cancer, affecting approximately one in eight women during their life-time. Besides environmental triggers and hormones, inherited mutations in the breast cancer 1 (BRCA1) or BRCA2 genes markedly increase the risk for the development of breast cancer. Here, using two different mouse models, we show that genetic inactivation of the key osteoclast differentiation factor RANK in the mammary epithelium markedly delayed onset, reduced incidence, and attenuated progression of Brca1;p53 mutation-driven mammary cancer. Long-term pharmacological inhibition of the RANK ligand RANKL in mice abolished the occurrence of Brca1 mutation-driven pre-neoplastic lesions. Mechanistically, genetic inactivation of Rank or RANKL/RANK blockade impaired proliferation and expansion of both murine Brca1;p53 mutant mammary stem cells and mammary progenitors from human BRCA1 mutation carriers. In addition, genome variations within the RANK locus were significantly associated with risk of developing breast cancer in women with BRCA1 mutations. Thus, RANKL/RANK control progenitor cell expansion and tumorigenesis in inherited breast cancer. These results present a viable strategy for the possible prevention of breast cancer in BRCA1 mutant patients.

Comparison of radioimmuno and carbon nanotube field-effect transistor assays for measuring insulin-like growth factor-1 in a preclinical model of human breast cancer.

BACKGROUND: To realize the promise of personalized medicine, diagnostic instruments used for detecting and measuring biomarkers must become smaller, faster and less expensive. Although most techniques used currently to detect biomarkers are sensitive and specific, many suffer from several disadvantages including their complexity, high cost and long turnaround time. One strategy to overcome these problems is to exploit carbon nanotube (CNT) based biosensors, which are sensitive, use inexpensive disposable components and can be easily adapted to current assay protocols. In this study we investigated the applicability of using a CNT field-effect transistor (CNT-FET) as a diagnostic instrument for measuring cancer biomarkers in serum using a mouse model of Breast Cancer Susceptibility 1-related breast cancer. Insulin like growth factor-1 (IGF-1) was chosen because it is highly relevant in breast cancer and because measuring serum IGF-1 levels by conventional methods is complicated due to specific IGF-1 serum binding proteins. FINDINGS: Our results show that there is good correlation between the two platforms with respect to detecting serum IGF-1. In fact, the CNT-FETs required only one antibody, gave real-time results and required approximately 100-fold less mouse serum than the radioimmunoassay. CONCLUSIONS: Both IGF-1 radioimmuno and CNT-FET assays gave comparable results. Indeed, the CNT-FET assay was simpler and faster than the radioimmunoassay. Additionally, the low serum sample required by CNT-FETs can be especially advantageous for studies constricted by limited amount of human clinical samples and for mouse studies, since animals often need to be sacrificed to obtain enough serum for biomarker evaluation.

Abnormal Mammary Adipose Tissue Environment of Brca1 Mutant Mice Show a Persistent Deposition of Highly Vascularized Multilocular Adipocytes.

A major challenge to breast cancer research is the identification of alterations in the architecture and composition of the breast that are associated with breast cancer progression. The aim of the present investigation was to characterize the mammary adipose phenotype from Brca1 mutant mice in the expectation that this would shed light on the role of the mammary tissue environment in the early stages of breast tumorigenesis. We observed that histological sections of mammary tissue from adult Brca1 mutant mice abnormally display small, multilocular adipocytes that are reminiscent of brown adipose tissue (BAT) as compared to wildtype mice. Using a marker for BAT, the uncoupling protein 1 (UCP1), we demonstrated that these multilocular adipose regions in Brca1 mutant mice stain positive for UCP1. Transcriptionally, UCP1 mRNA levels in the Brca1 mutant mice were elevated greater than 50-fold compared to age-matched mammary glands from wildtype mice. Indeed, BAT has characteristics that are favorable for tumor growth, including high vascularity. Therefore, we also demonstrated that the multilocular brown adipose phenotype in the mammary fat pad of Brca1 mutant mice displayed regions of increased vascularity as evidenced by a significant increase in the protein expression of CD31, a marker for angiogenesis. This Brca1 mutant mouse model should provide a physiologically relevant context to determine whether brown adipose tissue can play a role in breast cancer development.

Loss of BRCA1 leads to an increased sensitivity to Bisphenol A.

Humans are chronically exposed to the plasticizer, Bisphenol A (BPA), that can adversely affect the normal hormonal regulation of cellular functions by mimicking the actions of estrogen. This biological response to BPA may vary according to an individual's genetic characteristics (e.g., BRCA1 mutations or deletion). In this study, both cell culture and mouse models were used to elucidate whether the loss of BRCA1 function could affect BPA-mediated cell proliferation. In studies using BPA levels comparable to human exposures, we found that loss of BRCA1 enhances BPA-induced cell proliferation in both systems. In vitro, we found that loss of BRCA1 enhances BPA-induced ERα signaling. In vivo, we found that BPA administration stimulates mammary gland epithelial tissue/cell proliferation leading to hyperplasia in Brca1 mutant mice compared to wild-type control mice. These results suggest that the biological responses in BRCA1-deficient cells may depend on environmental exposures, specifically BPA.

Comparison of mouse mammary gland imaging techniques and applications: reflectance confocal microscopy, GFP imaging, and ultrasound.

BACKGROUND: Genetically engineered mouse models of mammary gland cancer enable the in vivo study of molecular mechanisms and signaling during development and cancer pathophysiology. However, traditional whole mount and histological imaging modalities are only applicable to non-viable tissue. METHODS: We evaluated three techniques that can be quickly applied to living tissue for imaging normal and cancerous mammary gland: reflectance confocal microscopy, green fluorescent protein imaging, and ultrasound imaging. RESULTS: In the current study, reflectance confocal imaging offered the highest resolution and was used to optically section mammary ductal structures in the whole mammary gland. Glands remained viable in mammary gland whole organ culture when 1% acetic acid was used as a contrast agent. Our application of using green fluorescent protein expressing transgenic mice in our study allowed for whole mammary gland ductal structures imaging and enabled straightforward serial imaging of mammary gland ducts in whole organ culture to visualize the growth and differentiation process. Ultrasound imaging showed the lowest resolution. However, ultrasound was able to detect mammary preneoplastic lesions 0.2 mm in size and was used to follow cancer growth with serial imaging in living mice. CONCLUSION: In conclusion, each technique enabled serial imaging of living mammary tissue and visualization of growth and development, quickly and with minimal tissue preparation. The use of the higher resolution reflectance confocal and green fluorescent protein imaging techniques and lower resolution ultrasound were complementary.

Identification of conserved gene expression features between murine mammary carcinoma models and human breast tumors.

BACKGROUND: Although numerous mouse models of breast carcinomas have been developed, we do not know the extent to which any faithfully represent clinically significant human phenotypes. To address this need, we characterized mammary tumor gene expression profiles from 13 different murine models using DNA microarrays and compared the resulting data to those from human breast tumors. RESULTS: Unsupervised hierarchical clustering analysis showed that six models (TgWAP-Myc, TgMMTV-Neu, TgMMTV-PyMT, TgWAP-Int3, TgWAP-Tag, and TgC3(1)-Tag) yielded tumors with distinctive and homogeneous expression patterns within each strain. However, in each of four other models (TgWAP-T121, TgMMTV-Wnt1, Brca1Co/Co;TgMMTV-Cre;p53+/- and DMBA-induced), tumors with a variety of histologies and expression profiles developed. In many models, similarities to human breast tumors were recognized, including proliferation and human breast tumor subtype signatures. Significantly, tumors of several models displayed characteristics of human basal-like breast tumors, including two models with induced Brca1 deficiencies. Tumors of other murine models shared features and trended towards significance of gene enrichment with human luminal tumors; however, these murine tumors lacked expression of estrogen receptor (ER) and ER-regulated genes. TgMMTV-Neu tumors did not have a significant gene overlap with the human HER2+/ER- subtype and were more similar to human luminal tumors. CONCLUSION: Many of the defining characteristics of human subtypes were conserved among the mouse models. Although no single mouse model recapitulated all the expression features of a given human subtype, these shared expression features provide a common framework for an improved integration of murine mammary tumor models with human breast tumors.

The breast cancer susceptibility gene BRCA1 regulates progesterone receptor signaling in mammary epithelial cells.

The progesterone receptor (PR) plays roles in normal mammary development and breast cancer formation, where it may exert both stimulatory and inhibitory actions. Previously, the breast cancer susceptibility gene product BRCA1 was found to interact with and inhibit the transcriptional activity of estrogen receptor-alpha. In this study, we found that exogenous wild-type BRCA1 inhibited the activity of the PR in transient transfection assays utilizing a mouse mammary tumor virus-Luc reporter. Wild-type BRCA1 inhibited the activity of endogenous PR in human breast cancer cells (T47D and MCF-7) and inhibited the activity of exogenous PR-A, PR-B, and [PR-A plus PR-B] isoforms. On the other hand, knockdown of endogenous BRCA1 using small interfering RNA enhanced the progesterone-stimulated activity of the PR by about 4-fold. We documented an in vivo association of the endogenous BRCA1 with PR isoforms A and B and a direct in vitro interaction between BRCA1 and PR, which was partially mapped. Whereas down-regulation of the coactivator p300 contributes to the BRCA1-mediated repression of estrogen receptor-alpha, this mechanism does not contribute to inhibition of PR activity, because exogenous p300 did not rescue the BRCA1 repression of PR activity. The BRCA1-PR interaction has functional consequences. Thus, we showed that BRCA1 inhibits the expression of various endogenous progesterone-responsive genes and inhibits progesterone-stimulated proliferation of T47D cells. Finally, exogenous progesterone caused an exaggerated proliferative response in the mammary glands of mice harboring a mammary-targeted conditional deletion of the full-length isoform of Brca1. These findings suggest that BRCA1 regulates the activity of progesterone, a major hormone of pregnancy that may also participate in mammary carcinogenesis.

Promotion of mammary cancer development by tamoxifen in a mouse model of Brca1-mutation-related breast cancer.

Loss of full-length Brca1 in mammary epithelial cells of the mouse mammary tumor virus (MMTV)-Cre Brca1 conditional exon 11 deletion mouse model results in the development of mammary adenocarcinomas with similar genetic changes to those found in human BRCA1-mutation-related breast cancers. We used this experimental model to evaluate the chemopreventive effect of tamoxifen on the development of mammary preneoplasia and adenocarcinoma. No protective effects of tamoxifen administration on mammary cancer development were found. Instead, tamoxifen treatment significantly increased rates of mammary epithelial cell proliferation and the prevalence of mammary hyperplasia at 6 months of age. Tamoxifen-exposed mice developed adenocarcinomas at younger ages than control mice and a higher percentage of mice developed adenocarcinomas by 12 months of age. Both whole mouse and tissue culture cell models were used to test if loss of full-length Brca1 was associated with a relative increase in the agonist activity of tamoxifen. Tamoxifen induced increased ductal growth in MMTV-Cre Brca1 conditional mice compared to wild type. Estrogen receptor alpha (ERalpha) expression was downregulated in the tamoxifen-induced hyperplasias. Reducing BRCA1 levels in MCF-7 cells using siRNA resulted in a relative increase in the agonist activity of tamoxifen. Results suggest a model of mammary cancer progression in which loss of full-length Brca1 altered the agonist/antagonist activity of tamoxifen, resulting in tamoxifen-induced mammary epithelial cell proliferation with subsequent loss of ERalpha expression and development of ERalpha-negative hyperplasias and adenocarcinomas.

Mutagenesis and DNA adduct formation in the mouse mammary gland exposed to 2-hydroxyamino-1-methyl-6-phenylimidazo-[4,5-b]pyridine in whole organ culture.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagen and rodent mammary gland carcinogen found in the human diet. 2-Hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine (N-hydroxy-PhIP) is the proximate reactive metabolite of PhIP associated with PhIP-DNA adduct formation and mutagenesis. In the current study, whole mammary glands obtained from transgenic C57Bl/6 mice carrying the plasmid-lacZ mutational reporter gene were cultured in defined medium and exposed to various concentrations of N-hydroxy-PhIP for 24 h. At various times after N-hydroxy-PhIP exposure, PhIP-DNA adduct levels were determined by the (32)P-post-labeling assay and the lacZ(-) mutant frequency determined by the positive selection system. Glands were cultured in either medium containing insulin (I medium), necessary for maintenance of the gland, or I medium containing prolactin, aldosterone and hydrocortisone (IPAH medium) to induce lobuloalveolar development. At 3 and 7 days after exposure to 10 micro M N-hydroxy-PhIP, mutant frequency was upwards of 9-fold higher in glands incubated in IPAH medium than in I medium (15.2 +/- 1.9 and 1.6 +/- 0.7 x 10(-3), respectively, 3 day time point). PhIP-DNA adduct levels were 1.7-fold higher in glands cultivated in IPAH medium than in I medium immediately after exposure to 10 micro M N-hydroxy-PhIP. A statistically significant reduction in PhIP-DNA adduct levels occurred with time in glands cultivated in IPAH medium but not I medium (one-way analysis of variance, P < 0.05). By 7 days after exposure, PhIP-DNA adduct levels were similar in glands cultured in I and IPAH medium (3.2 +/- 0.2 and 2.8 +/- 0.29 adducts/10(7) nucleotides, respectively). DNA synthesis as measured by [(3)H]thymidine labeling was approximately 2-fold higher in glands cultured in IPAH medium than in I medium. The higher mutant frequency in glands cultivated in IPAH medium versus I medium appeared to be due to a combination of higher initial PhIP-DNA adduct levels and a greater fixation of mutations that occurred at higher proliferation rates. The findings indicate that mammotrophic hormones influence the mutagenicity of PhIP in the mammary gland in vitro and emphasize the importance of hormonal milieu on carcinogen-DNA adduct-induced mutations in this organ.