Browsing by Subject "Microenvironment"

Now showing 1 - 9 of 9
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    The Brain: Is it a Next Frontier to Better Understand the Regulation and Control of Hematopoiesis for Future Modulation and Treatment?
    (Springer, 2021-08) Broxmeyer, Hal E.; Yoder, Karmen K.; Wu, Yu-Chien; Hutchins, Gary D.; Cooper, Scott H.; Farag, Sherif S.; Microbiology and Immunology, School of Medicine
    We wish to suggest the possibility there is a link between the brain and hematopoiesis in the bone marrow and that in the future it may be possible to use such information for better understanding of the regulation of hematopoiesis, and for efficacious treatment of hematopoietic disorders.
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    Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer
    (MDPI, 2023-12-05) Wang, Ji; Ford, James C.; Mitra, Anirban K.; Medical and Molecular Genetics, School of Medicine
    Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.
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    Downregulation of IRF8 in alveolar macrophages by G-CSF promotes metastatic tumor progression
    (Elsevier, 2024-02-10) Tzetzo, Stephanie L.; Kramer, Elliot D.; Mohammadpour, Hemn; Kim, Minhyung; Rosario, Spencer R.; Yu, Han; Dolan, Melissa R.; Oturkar, Chetan C.; Morreale, Brian G.; Bogner, Paul N.; Stablewski, Aimee B.; Benavides, Fernando J.; Brackett, Craig M.; Ebos, John M. L.; Das, Gokul M.; Opyrchal, Mateusz; Nemeth, Michael J.; Evans, Sharon S.; Abrams, Scott I.; Medicine, School of Medicine
    Tissue-resident macrophages (TRMs) are abundant immune cells within pre-metastatic sites, yet their functional contributions to metastasis remain incompletely understood. Here, we show that alveolar macrophages (AMs), the main TRMs of the lung, are susceptible to downregulation of the immune stimulatory transcription factor IRF8, impairing anti-metastatic activity in models of metastatic breast cancer. G-CSF is a key tumor-associated factor (TAF) that acts upon AMs to reduce IRF8 levels and facilitate metastasis. Translational relevance of IRF8 downregulation was observed among macrophage precursors in breast cancer and a CD68hiIRF8loG-CSFhi gene signature suggests poorer prognosis in triple-negative breast cancer (TNBC), a G-CSF-expressing subtype. Our data highlight the underappreciated, pro-metastatic roles of AMs in response to G-CSF and identify the contribution of IRF8-deficient AMs to metastatic burden. AMs are an attractive target of local neoadjuvant G-CSF blockade to recover anti-metastatic activity.
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    ETS1 induction by the microenvironment promotes ovarian cancer metastasis through focal adhesion kinase
    (Elsevier, 2018-02-01) Tomar, Sunil; Plotnik, Joshua P.; Haley, James; Scantland, Joshua; Dasari, Subramanyam; Sheikh, Zahir; Emerson, Robert; Lenz, Dean; Hollenhorst, Peter C.; Mitra, Anirban K.; Pathology and Laboratory Medicine, School of Medicine
    Metastatic colonization involves paracrine/juxtacrine interactions with the microenvironment inducing an adaptive response through transcriptional regulation. However, the identities of transcription factors (TFs) induced by the metastatic microenvironment in ovarian cancer (OC) and their mechanism of action is poorly understood. Using an organotypic 3D culture model recapitulating the early events of metastasis, we identified ETS1 as the most upregulated member of the ETS family of TFs in metastasizing OC cells as they interacted with the microenvironment. ETS1 was regulated by p44/42 MAP kinase signaling activated in the OC cells interacting with mesothelial cells at the metastatic site. Human OC tumors had increased expression of ETS1, which predicted poor prognosis. ETS1 regulated OC metastasis both in vitro and in mouse xenografts. A combination of ChIP-seq and RNA-seq analysis and functional rescue experiments revealed FAK as the key transcriptional target and downstream effector of ETS1. Taken together, our results indicate that ETS1 is an essential transcription factor induced in OC cells by the microenvironment, which promotes metastatic colonization though the transcriptional upregulation of its target FAK.
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    The importance of nerve microenvironment for schwannoma development
    (Springer-Verlag, 2016-08) Schulz, Alexander; Büttner, Robert; Hagel, Christian; Baader, Stephan L.; Kluwe, Lan; Salamon, Johannes; Mautner, Victor-Felix; Mindos, Thomas; Parkinson, David B.; Gehlhausen, Jeffrey R.; Clapp, D. Wade; Morrison, Helen; Department of Pediatrics, IU School of Medicine
    Schwannomas are predominantly benign nerve sheath neoplasms caused by Nf2 gene inactivation. Presently, treatment options are mainly limited to surgical tumor resection due to the lack of effective pharmacological drugs. Although the mechanistic understanding of Nf2 gene function has advanced, it has so far been primarily restricted to Schwann cell-intrinsic events. Extracellular cues determining Schwann cell behavior with regard to schwannoma development remain unknown. Here we show pro-tumourigenic microenvironmental effects on Schwann cells where an altered axonal microenvironment in cooperation with injury signals contribute to a persistent regenerative Schwann cell response promoting schwannoma development. Specifically in genetically engineered mice following crush injuries on sciatic nerves, we found macroscopic nerve swellings in mice with homozygous nf2 gene deletion in Schwann cells and in animals with heterozygous nf2 knockout in both Schwann cells and axons. However, patient-mimicking schwannomas could only be provoked in animals with combined heterozygous nf2 knockout in Schwann cells and axons. We identified a severe re-myelination defect and sustained macrophage presence in the tumor tissue as major abnormalities. Strikingly, treatment of tumor-developing mice after nerve crush injury with medium-dose aspirin significantly decreased schwannoma progression in this disease model. Our results suggest a multifactorial concept for schwannoma formation-emphasizing axonal factors and mechanical nerve irritation as predilection site for schwannoma development. Furthermore, we provide evidence supporting the potential efficacy of anti-inflammatory drugs in the treatment of schwannomas.
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    The Many Faces of Long Noncoding RNAs in Cancer
    (Mary Ann Liebert, 2018-09-20) Wu, Xue; Tudoran, Oana M.; Calin, George A.; Ivan, Mircea; Medicine, School of Medicine
    SIGNIFICANCE: The emerging connections between an increasing number of long noncoding RNAs (lncRNAs) and oncogenic hallmarks provide a new twist to tumor complexity. Recent Advances: In the present review, we highlight specific lncRNAs that have been studied in relation to tumorigenesis, either as participants in the neoplastic process or as markers of pathway activity or drug response. These transcripts are typically deregulated by oncogenic or tumor-suppressing signals or respond to microenvironmental conditions such as hypoxia. CRITICAL ISSUES: Among these transcripts are lncRNAs sufficiently divergent between mouse and human genomes that may contribute to biological differences between species. FUTURE DIRECTIONS: From a translational standpoint, knowledge about primate-specific lncRNAs may help explain the reason behind the failure to reproduce the results from mouse cancer models in human cell-based systems. Antioxid. Redox Signal. 29, 922-935.
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    Musculoskeletal Effects of Oncostatin M in Pancreatic Cancer Cachexia
    (2022-07) Jengelley, Daenique Heather Andrene; Zimmers, Teresa A.; Goebl, Mark G.; Mayo, Lindsey D.; Nakshatri, Harikrishna; Ostrowski, Michael C.
    Pancreatic Ductal Adenocarcinoma (PDAC) is the third leading cause of cancerrelated deaths with a five-year survival rate of 11%. PDAC tumors are characterized by a dense desmoplastic stromal microenvironment, mediated in part through local cytokine production. PDAC tumors also elicit a systemic inflammatory response in the host; this, combined with a loss of body weight due to muscle and fat wasting, is characteristic of cachexia. Understanding the molecular mechanisms that drive malignant inflammation is critical to improve PDAC therapy and increase patient survival. Oncostatin M (OSM) belongs to the IL-6/GP130 family of cytokines, members of which have been shown to promote PDAC tumor development, inflammation, and cachexia. Much less is known of OSM. My central hypothesis was that OSM promotes pancreatic cancer and cachexia by inducing local and systemic inflammation, fibrosis, and wasting via OSM signaling through the receptor, OSM receptor (OSMR). We investigated effects of exogenous OSM administration in wildtype and IL-6 null mice without cancer. OSM induced systemic fibrosis, bone loss, local muscle wasting, and cardiac dysfunction in presence and absence of IL-6. We further defined the roles of OSM/OSMR in the pancreatic cancer microenvironment and macroenvironment. OSM activated genes involved in inflammation, fibrosis, and tumor progression in both tumor cells and fibroblasts and altered the tumor microenvironment, promoting a dense compaction of tumor cells and cancer associated fibroblasts. Loss of systemic OSM signaling altered tumor metabolism and reduced the stromal compartment without affecting tumor size. Loss of OSMR signaling in tumor cells reduced tumor size and promoted survival. However, systemic loss of OSM or OSMR in host cells did not halt effects of cachexia including muscle dysfunction, atrophy, or inflammation/anemia. Overall, OSM/OSMR signaling in the microenvironment is necessary in modulating tumor phenotype and promoting survival in PDAC but may not be necessary for pancreatic cancer cachexia.
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    Productive Cross-Talk with the Microenvironment: A Critical Step in Ovarian Cancer Metastasis
    (MDPI, 2019-10-21) Abd El Aziz, Mohamed A.; Agarwal, Komal; Dasari, Subramanyam; Mitra, Anirban K.; Medical and Molecular Genetics, School of Medicine
    Most ovarian cancer patients present with disseminated disease at the time of their diagnosis, which is one of the main reasons for their poor prognosis. Metastasis is a multi-step process and a clear understanding of the mechanism of regulation of these steps remains elusive. Productive reciprocal interactions between the metastasizing ovarian cancer cells and the microenvironment of the metastatic site or the tumor microenvironment play an important role in the successful establishment of metastasis. Much progress has been made in the recent past in our understanding of such interactions and the role of the cellular and acellular components of the microenvironment in establishing the metastatic tumors. This review will outline the role of the microenvironmental components of the ovarian cancer metastatic niche and their role in helping establish the metastatic tumors. Special emphasis will be given to the mesothelial cells, which are the first cells encountered by the cancer cells at the site of metastasis.
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    Targeting microenvironment in cancer therapeutics
    (Impact Journals, 2016-08-09) Martin, Matthew; Wei, Han; Lu, Tao; Department of Pharmacology and Toxicology, IU School of Medicine
    During development of a novel treatment for cancer patients, the tumor microenvironment and its interaction with the tumor cells must be considered. Aspects such as the extracellular matrix (ECM), the epithelial-mesenchymal transition (EMT), secreted factors, cancer-associated fibroblasts (CAFs), the host immune response, and tumor-associated microphages (TAM) are critical for cancer progression and metastasis. Additionally, signaling pathways such as the nuclear factor κB (NF-κB), transforming growth factor β (TGFβ), and tumor necrosis factor α (TNFα) can promote further cytokine release in the tumor environment, and impact tumor progression greatly. Importantly, cytokine overexpression has been linked to drug resistance in cancers and is therefore an attractive target for combinational therapies. Specific inhibitors of cytokines involved in signaling between tumor cells and the microenvironment have not been studied in depth and have great potential for use in personalized medicines. Together, the interactions between the microenvironment and tumors are critical for tumor growth and promotion and should be taken into serious consideration for future novel therapeutic approaches.