22 research outputs found
The role of IFITM1 in promoting breast cancer aggression and aromatase-inhibitor resistance
Breast cancer remains the leading malignancy among women in the United States, affecting an estimated 246,660 women in 2016. Breast cancer can be separated into three groups known as estrogen receptor/ progesterone receptor positive (ER+/PR+), Her2/neu positive (HER2+), and triple negative (ER-/PR-/HER2-) subtypes. The majority of breast cancers rely on estrogen to stimulate their growth and survival. Estrogen is produced from precursor hormones by the aromatase enzyme, whose action can be blocked with aromatase inhibitors (AIs). Unfortunately ~40% of breast cancer patients are resistant to this treatment and their breast tumors either continue to grow or recur despite depletion of circulating estrogen. The precise cause of AI-resistance is not known. Our lab aims to determine the mechanisms that allow breast cancer cells to survive in estrogen-depleted conditions. We have previously reported the generation of an AI-resistant breast cancer cell line, MCF-7:5C, which was isolated under estrogen-free conditions from the estrogen-dependent breast cancer cell line MCF-7. The MCF-7:5C cell line is highly aggressive and overexpresses several interferon stimulated genes including, interferon inducible transmembrane protein 1 (IFITM1). IFITM1 is a type 1 interferon (IFN) stimulated gene (ISG) that is not expressed in normal breast tissue, and is only induced by the type1 IFNs (IFNα and ÎČ) to protect the host from viral infections. IFNα signals through a specific receptor, IFNAR, which uses JAK/STAT signaling to produce the ISGs. ISGs are known to drive the progression of other cancer types, to inhibit apoptosis and promote DNA damage resistance. However, the significance of constitutive overexpression of ISGs in AI-resistant breast cancer is not known. We hypothesize that IFITM1 overexpression contributes the AI-resistant phenotype and promotes breast cancer cell aggression and survival. In this thesis, we demonstrate that IFITM1 is overexpressed in breast tumors and is correlated with poor response to endocrine therapy using in silico analysis of breast tumor expression databases and a human tissue microarray. Gain and loss of function studies in an IFITM1-overexpressing AI-resistant breast cancer cell line, MCF-7:5C, and an IFITM1-null AI-sensitive breast cancer cell line, MCF-7, reveal that IFITM1 promotes the AI-resistant aggressive phenotype and estrogen-independent growth. Additionally, the orthotopic (mammary fat pad) and mouse mammary intraductal (MIND) models of breast cancer evaluate the role of IFITM1 in tumor growth and invasion respectively. We report that loss of IFITM1 induced cell death in AI-resistant MCF-7:5C cells results in marked increases in p21/Waf1/Cip1 transcription, expression and nuclear localization. Notably, p21 transcriptional upregulation was mediated by STAT1 activation. These findings suggest IFITM1 overexpression contributes directly to breast cancer progression and that it may be a therapeutically relevant target in the treatment of endocrine-resistant breast cancer. Mechanistic studies reveal that MCF-7:5C cells produce elevated levels of IFN as compared to MCF-7 cells and that this cytokine binds to the type 1 IFN receptor, IFNAR, and induces JAK/STAT signaling, ultimately resulting in the overexpression of IFITM1. Independently, we also find that mucin 1 (MUC1) associates with STAT1 and stabilizes its phosphorylated form, thereby contributing directly to IFITM1 expression. MUC1 expression is hormonally controlled and is normally enhanced by estrogen stimulation. We find that MUC1 expression is dysregulated in AI-resistant MCF-7:5C cells and is instead reduced by estrogen stimulation. MCF-7:5C cells are sensitive to apoptosis following exposure to estrogen, which can be enhanced by loss of IFITM1 expression. Loss of MUC1 expression similarly enhances estrogen-induced apoptosis, suggesting that the communication between MUC1 and STAT1 also influences estrogen signaling in AI-resistant breast cancer. In this thesis, we conduct investigations into the mechanisms and functional significance of IFITM1 expression in AI-resistant breast cancer and conclude that IFITM1 overexpression may be a targetable marker of AI-resistant disease
A rare case of group A streptococcal toxicâshock syndrome in a postpartum adolescent leading to multiâorgan failure
A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Teenage pregnancy is not uncommon, but given the age of the patient, experience, and competency among medical providers varies. While toxicâshock syndrome from group A streptococcus is rare in teenage pregnancy, observed is a gap in care of bridging.The University of Kansas (KU) One University Open Access Author Fund sponsored jointly by the KU ProvostKU Vice Chancellor for Research & Graduate StudiesKUMC Vice Chancellor for Research and managed jointly by the Libraries at the Medical Center and KU â Lawrenc
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The Evolving Landscape of B Cells in Cancer Metastasis.
Metastasis is the leading cause of cancer mortality. Functional and clinical studies have documented diverse B-cell and antibody responses in cancer metastasis. The presence of B cells in tumor microenvironments and metastatic sites has been associated with diverse effects that can promote or inhibit metastasis. Specifically, B cells can contribute to the spread of cancer cells by enhancing tumor cell motility, invasion, angiogenesis, lymphangiogenesis, and extracellular matrix remodeling. Moreover, they can promote metastatic colonization by triggering pathogenic immunoglobulin responses and recruiting immune suppressive cells. Contrastingly, B cells can also exhibit antimetastatic effects. For example, they aid in enhanced antigen presentation, which helps activate immune responses against cancer cells. In addition, B cells play a crucial role in preventing the dissemination of metastatic cells from the primary tumor and secrete antibodies that can aid in tumor recognition. Here, we review the complex roles of B cells in metastasis, delineating the heterogeneity of B-cell activity and subtypes by metastatic site, antibody class, antigen (if known), and molecular phenotype. These important attributes of B cells emphasize the need for a deeper understanding and characterization of B-cell phenotypes to define their effects in metastasis
HER2 and HER3 as Therapeutic Targets in Head and Neck Cancer.
Work over the past several decades has identified that aberrations in the ErbB signaling pathways are key drivers of oncogenesis, and concurrent efforts to discover targetable vulnerabilities to counter this aberrant oncogenic signaling offer tremendous promise in treating a host of human cancers. These efforts have been centered primarily on EGFR (also known as HER1), leading to the discovery of the first targeted therapies approved for head and neck cancer. More recently, HER2 and HER3 signaling pathways have been identified as highly dysregulated in head and neck cancer. This review highlights the HER2 and HER3 signaling pathways and clinical efforts to target these receptors and their aberrant signaling to treat head and neck squamous cell carcinomas and other head and neck malignancies, including salivary gland carcinomas. This includes the use of small molecule inhibitors and blocking antibodies, both as single agents or as part of multimodal precision targeted and immunotherapies
Utilization of mediation in the resolution of conflict within the framework of art schools in Prague in the school year 2012/2013
STAT1 and STAT2 knockdown in SUM149 using three different siRNAs. (PPT 185 kb
Additional file 2: Figure S2. of Everolimus downregulates estrogen receptor and induces autophagy in aromatase inhibitor-resistant breast cancer cells
Everolimus targets the phosphorylation of the PI3K/mTOR/Akt pathway at 48 and 72ĂÂ h. MCF-7, MCF-7:5C and MCF-7:2A cells were seeded in 6-well plates and treated with 25, 50 or 100 nM everolimus or vehicle. Cells were harvested at 48 and 72ĂÂ h and protein expression analyzed by western blot. Image represents three independent experiments. (PPT 674 kb
Additional file 1: Figure S1. of Everolimus downregulates estrogen receptor and induces autophagy in aromatase inhibitor-resistant breast cancer cells
Everolimus does not impact the proliferation or cycling of normal breast cells. (a) MCF10A cells were seeded in 24-well plates and treated with a range of everolimus doses in triplicate. The percentage of viable cells was determined after 72ĂÂ h of everolimus treatment. (b) MCF10A cells were seeded in 6-well plates in single cell suspension and treated with 20 nM everolimus for 9ĂÂ days. The number and size of clones was quantified and represents means from two independent experiments conducted in triplicate. (c) After 24, 48 and 72ĂÂ h of 20 nM everolimus treatment in 6-well plates, MCF10A cells were subjected to cell cycle analysis. The percent of cells in G1 phase is highlighted. (PPT 507 kb
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Use of focal radiotherapy boost for prostate cancer: radiation oncologistsâ perspectives and perceived barriers to implementation
BackgroundIn a recent phase III randomized control trial, delivering a focal radiotherapy (RT) boost to tumors visible on MRI was shown to improve disease-free survival and regional/distant metastasis-free survival for patients with prostate cancer-without increasing toxicity. The aim of this study was to assess how widely this technique is being applied in current practice, as well as physicians' perceived barriers toward its implementation.MethodsWe invited radiation oncologists to complete an online questionnaire assessing their use of intraprostatic focal boost in December 2022 and February 2023. To include perspectives from a broad range of practice settings, the invitation was distributed to radiation oncologists worldwide via email list, group text platform, and social media.Results263 radiation oncologist participants responded. The highest-represented countries were the United States (42%), Mexico (13%), and the United Kingdom (8%). The majority of participants worked at an academic medical center (52%) and considered their practice to be at least partially genitourinary (GU)-subspecialized (74%). Overall, 43% of participants reported routinely using intraprostatic focal boost. Complete GU-subspecialists were more likely to implement focal boost, with 61% reporting routine use. In both high-income and low-to-middle-income countries, less than half of participants routinely use focal boost. The most cited barriers were concerns about registration accuracy between MRI and CT (37%), concerns about risk of additional toxicity (35%), and challenges to accessing high-quality MRI (29%).ConclusionsTwo years following publication of a randomized trial of patient benefit without increased toxicity, almost half of the radiation oncologists surveyed are now routinely offering focal RT boost. Further adoption of this technique might be aided by increased access to high-quality MRI, better registration algorithms of MRI to CT simulation images, physician education on benefit-to-harm ratio, and training on contouring prostate lesions on MRI
Performance of African-ancestry-specific polygenic hazard score varies according to local ancestry in 8q24
BACKGROUND: We previously developed an African-ancestry-specific polygenic hazard score (PHS46+African) that substantially improved prostate cancer risk stratification in men with African ancestry. The model consists of 46 SNPs identified in Europeans and 3 SNPs from 8q24 shown to improve model performance in Africans. Herein, we used principal component (PC) analysis to uncover subpopulations of men with African ancestry for whom the utility of PHS46+African may differ. MATERIALS AND METHODS: Genotypic data were obtained from the PRACTICAL consortium for 6253 men with African genetic ancestry. Genetic variation in a window spanning 3 African-specific 8q24 SNPs was estimated using 93 PCs. A Cox proportional hazards framework was used to identify the pair of PCs most strongly associated with the performance of PHS46+African. A calibration factor (CF) was formulated using Cox coefficients to quantify the extent to which the performance of PHS46+African varies with PC. RESULTS: CF of PHS46+African was strongly associated with the first and twentieth PCs. Predicted CF ranged from 0.41 to 2.94, suggesting that PHS46+African may be up to 7 times more beneficial to some African men than others. The explained relative risk for PHS46+African varied from 3.6% to 9.9% for individuals with low and high CF values, respectively. By cross-referencing our data set with 1000 Genomes, we identified significant associations between continental and calibration groupings. CONCLUSION: We identified PCs within 8q24 that were strongly associated with the performance of PHS46+African. Further research to improve the clinical utility of polygenic risk scores (or models) is needed to improve health outcomes for men of African ancestry
Correcting B0 inhomogeneity-induced distortions in whole-body diffusion MRI of bone.
Diffusion-weighted magnetic resonance imaging (DWI) of the musculoskeletal system has various applications, including visualization of bone tumors. However, DWI acquired with echo-planar imaging is susceptible to distortions due to static magnetic field inhomogeneities. This study aimed to estimate spatial displacements of bone and to examine whether distortion corrected DWI images more accurately reflect underlying anatomy. Whole-body MRI data from 127 prostate cancer patients were analyzed. The reverse polarity gradient (RPG) technique was applied to DWI data to estimate voxel-level distortions and to produce a distortion corrected DWI dataset. First, an anatomic landmark analysis was conducted, in which corresponding vertebral landmarks on DWI and anatomic T2-weighted images were annotated. Changes in distance between DWI- and T2-defined landmarks (i.e., changes in error) after distortion correction were calculated. In secondary analyses, distortion estimates from RPG were used to assess spatial displacements of bone metastases. Lastly, changes in mutual information between DWI and T2-weighted images of bone metastases after distortion correction were calculated. Distortion correction reduced anatomic error of vertebral DWI up to 29 mm. Error reductions were consistent across subjects (Wilcoxon signed-rank pâ<â10-20). On average (± SD), participants' largest error reduction was 11.8 mm (± 3.6). Mean (95% CI) displacement of bone lesions was 6.0 mm (95% CI 5.0-7.2); maximum displacement was 17.1 mm. Corrected diffusion images were more similar to structural MRI, as evidenced by consistent increases in mutual information (Wilcoxon signed-rank pâ<â10-12). These findings support the use of distortion correction techniques to improve localization of bone on DWI