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  • American Association for Cancer Research (AACR)  (6)
  • 1
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 28, No. 9 ( 2022-05-02), p. 1979-1990
    Abstract: Proficient DNA repair by homologous recombination (HR) facilitates resistance to chemoradiation in glioma stem cells (GSC). We evaluated whether compromising HR by targeting HSP90, a molecular chaperone required for the function of key HR proteins, using onalespib, a long-acting, brain-penetrant HSP90 inhibitor, would sensitize high-grade gliomas to chemoradiation in vitro and in vivo. Experimental Design: The ability of onalespib to deplete HR client proteins, impair HR repair capacity, and sensitize glioblastoma (GBM) to chemoradiation was evaluated in vitro in GSCs, and in vivo using zebrafish and mouse intracranial glioma xenograft models. The effects of HSP90 inhibition on the transcriptome and cytoplasmic proteins was assessed in GSCs and in ex vivo organotypic human glioma slice cultures. Results: Treatment with onalespib depleted CHK1 and RAD51, two key proteins of the HR pathway, and attenuated HR repair, sensitizing GSCs to the combination of radiation and temozolomide (TMZ). HSP90 inhibition reprogrammed the transcriptome of GSCs and broadly altered expression of cytoplasmic proteins including known and novel client proteins relevant to GSCs. The combination of onalespib with radiation and TMZ extended survival in a zebrafish and a mouse xenograft model of GBM compared with the standard of care (radiation and TMZ) or onalespib with radiation. Conclusions: The results of this study demonstrate that targeting HR by HSP90 inhibition sensitizes GSCs to radiation and chemotherapy and extends survival in zebrafish and mouse intracranial models of GBM. These results provide a preclinical rationale for assessment of HSP90 inhibitors in combination with chemoradiation in patients with GBM.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2022
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  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 70, No. 8_Supplement ( 2010-04-15), p. LB-224-LB-224
    Abstract: Background: Leptin, an adipocytokine secreted by adipose tissue, is responsible for many biological functions including appetite regulation, energy homeostasis, bone formation, and more recently, carcinogenesis. Levels of circulating leptin are typically elevated in obese states and have been associated with increased tumor proliferation, angiogenesis, and increased metastatic behavior. Therefore, obesity has been clearly associated with increased risk of cancer and metastasis. Breast cancer remains as the second leading cause of cancer-related deaths to American women. Many epidemiological studies have shown that obese women are more at risk for developing breast cancer compared to non-obese women. Therefore, it is imperative to understand the contribution of leptin to breast cancer development and progression. Methods and Results: In this study, we used MCF-7 and MDA-MB-231 breast cancer cell lines to examine the relationship between leptin and survivin, a dual-function protein. Survivin has become an interesting target in cancer research because it is highly expressed in cancerous tissues while being nearly undetectable in normal tissues. We observed that leptin increases mRNA and protein expression of survivin in a time-dependent manner. Earlier studies from our lab demonstrated that leptin increases breast cancer cell migration and invasion and underlying mechanisms involved a bidirectional crosstalk between leptin and IGF1 leading to transactivation of EGFR. Examining the underlying mechanisms, we found that blocking EGFR activation decreased leptin-induced survivin expression indicating the involvement of EGFR. To examine the role of survivin in leptin-induced migration of breast cancer cells, we transfected both cell lines with wild-type or p-silencer-survivin and subjected the cells to scratch and electric cell-substrate impedance sensing (ECIS) migration assays. We found that survivin overexpression increased migration potential of breast cancer cells compared to untransfected cells. In addition, leptin treatment further enhanced migration of breast cancer cells with survivin overexpression. Inhibition of survivin inhibited migration of breast cancer cells alone and even in the presence of leptin. These studies showed the importance of survivin in leptin-induced migration of breast cancer cells. For therapeutic purposes, we treated the breast cancer cells with lovastatin, commonly used as an HMG-CoA reducatase inhibitor. Lovastatin has been previously shown to inhibit survivin expression. We treated cells with lovastatin in a dose-dependent manner and observed a complete inhibition of survivin expression. Combination treatment with leptin did not restore survivin protein expression. Importantly, lovastatin treatment efficiently inhibited migration of breast cancer cells even in the presence of leptin. Conclusion: In conclusion, we have established a novel role for survivin in leptin-induced migration of breast cancer cells. Targeting survivin using lovastatin may provide new therapeutic targets for the treatment of metastatic breast carcinogenesis in obese patients. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-224.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2010
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    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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  • 3
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    American Association for Cancer Research (AACR) ; 2010
    In:  Cancer Research Vol. 70, No. 8_Supplement ( 2010-04-15), p. LB-57-LB-57
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 70, No. 8_Supplement ( 2010-04-15), p. LB-57-LB-57
    Abstract: Background: Gene expression studies have identified two biologically distinct estrogen receptor (ER)-positive subtypes of breast cancer: luminal A and luminal B. Some luminal B tumors can be identified by their expression of Her2 but the major biological distinction between luminal A and luminal B is their proliferation signature. Upon treatment with adjuvant tamoxifen, luminal A breast tumors show a good prognosis, however the clinical outcome of luminal B breast tumor is poor. The underlying mechanisms for the differential response to adjuvant tamoxifen therapy between luminal A and luminal B breast tumors are probably multifactorial and remain largely unknown. In this study, we examined the molecular mechanisms contributing to the poor prognosis of the luminal B ER-positive breast cancer subtype in response to tamoxifen. Methods and Results: We developed a physiologically relevant luminal B ER-positive breast cancer (luminal B) model. This cell line model exhibited an elevated growth factor signaling pathway. We showed that tamoxifen treatment inhibited clonogenicity and anchorage-independent growth of luminal A breast cancer cells. Interestingly, acting as a potent agonist, tamoxifen resulted in significantly increased clonogenicity and anchorage-independent growth in luminal B cells. We found that tamoxifen also increased expression of ER-responsive genes in luminal B cells in contrast to luminal A cells where it effectively inhibited ER-transactivation and ER-responsive gene expression. Mediator complex is an essential coactivator complex for the expression of ER-responsive genes. Investigating the underlying mechanisms, we discovered that anchor subunit of mediator coactivator complex, Med1, was overexpressed in luminal B cells. Furthermore, we found hyper-phosphorylation of Med1 and ER in luminal B cells due to persistent activation of ERK. Hyper-phosphorylated Med1 showed increased recruitment to ER-responsive promoters in the presence of tamoxifen in luminal B cells. Stably silencing Med1 in luminal B cells not only inhibited tamoxifen-induced clonogenicity and anchorage-independent growth, it also inhibited tamoxifen-induced ER-transactivation. These data clearly showed the essential role of Med1 in mediating tamoxifen response in luminal B cells. Conclusions: These data demonstrate a novel role of Med1 in promotion of tamoxifen-induced growth of luminal B breast cancer cells and suggest that inhibiting Med1/or its activation may prove to be beneficial to overcome/reduce poor prognosis of basal B breast tumors. This conclusion is supported by in vivo data showing overexpression of Med1 in luminal B estrogen receptor-positive breast tumors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-57.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2010
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  • 4
    In: Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 20, No. 11 ( 2021-11-01), p. 2098-2109
    Abstract: Macrophages can be co-opted to contribute to neoplastic, neurologic, and inflammatory diseases. Colony-stimulating factor 1 receptor (CSF1R)-dependent macrophages and other inflammatory cells can suppress the adaptive immune system in cancer and contribute to angiogenesis, tumor growth, and metastasis. CSF1R-expressing osteoclasts mediate bone degradation in osteolytic cancers and cancers that metastasize to bone. In the rare disease tenosynovial giant cell tumor (TGCT), aberrant CSF1 expression and production driven by a gene translocation leads to the recruitment and growth of tumors formed by CSF1R-dependent inflammatory cells. Small molecules and antibodies targeting the CSF1/CSF1R axis have shown promise in the treatment of TGCT and cancer, with pexidartinib recently receiving FDA approval for treatment of TGCT. Many small-molecule kinase inhibitors of CSF1R also inhibit the closely related kinases KIT, PDGFRA, PDGFRB, and FLT3, thus CSF1R suppression may be limited by off-target activity and associated adverse events. Vimseltinib (DCC-3014) is an oral, switch control tyrosine kinase inhibitor specifically designed to selectively and potently inhibit CSF1R by exploiting unique features of the switch control region that regulates kinase conformational activation. In preclinical studies, vimseltinib durably suppressed CSF1R activity in vitro and in vivo, depleted macrophages and other CSF1R-dependent cells, and resulted in inhibition of tumor growth and bone degradation in mouse cancer models. Translationally, in a phase I clinical study, vimseltinib treatment led to modulation of biomarkers of CSF1R inhibition and reduction in tumor burden in TGCT patients.
    Type of Medium: Online Resource
    ISSN: 1535-7163 , 1538-8514
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2021
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    SSG: 12
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  • 5
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 4_Supplement ( 2021-02-15), p. PS8-03-PS8-03
    Abstract: Background: Physical resilience, the ability to resist decline and maintain functional status despite a stressor such as chemotherapy, is a central aspect of successful aging. Understanding clinical and biological factors associated with resilience in older women receiving chemotherapy for early breast cancer may facilitate the development of targeted interventions to maintain an individual’s robustness.Methods: Women age ≥65 (N=406) with Stage I-III breast cancer who were part of a clinical study of neo/adjuvant chemotherapy in older women were recruited from 16 sites (NCT01472094, R01AG037037). The Deficit Accumulation Index (DAI), a continuous score (0-1) calculated based on 51-items from geriatric assessment data (Cohen et al Cancer 2017), was measured before and after receipt of chemotherapy. DAI was categorized as robust (0.0 & lt;0.2), prefrail (0.2 & lt;0.35) and frail (≥0.35). Baseline blood biomarkers of inflammation (interleukin-6 [IL-6], C-reactive protein [CRP] ) and coagulation (D-dimer) were measured and defined as elevated if values were ≥median values in this cohort. The population of interest was older women who were robust prior to initiation of chemotherapy. The primary outcome was resilience (Yes/No); yes, defined as retaining robustness [DAI 0.0 & lt;0.2] before and ≤1 month after chemotherapy. Demographic, disease, and pretreatment variables associated with resilience in univariate analysis with p & lt;0.1 were further adjusted using multivariable logistic regression to examine the associations between baseline biomarkers and resilience. Results: Before starting chemotherapy, 324 of 406 (80%) older women were robust. The median age was 70 (range 65-86), 61% had stage II or III disease, 29% had HER2+ disease, 22% had TNBC, 37% received an anthracycline-based regimen, 49% had planned duration of treatment & gt; 12 weeks, and 74% received primary prophylaxis with WBC growth factors. Among these 324 robust older women, 253 (78%) remained robust (resilient) at the end of chemotherapy, 63 (19%) became prefrail, and 8 (3%) became frail. In univariate analyses, patients treated with anthracycline (OR=0.63, p=0.09), planned duration of treatment & gt; 12 weeks (OR=0.56, p=0.04), elevated IL-6 ≥2.7 pg/ml (OR=0.59, p=0.05), elevated CRP ≥4.3 μg/ml (OR=0.57, p=0.04), elevated D-dimer ≥0.7 μg/ml (OR=0.61, p=0.07), or at least one elevated biomarker (OR=0.18, p & lt;0.001) at baseline were less likely to be resilient after systemic chemotherapy. Adjusting for anthracyclines and treatment duration, patients who had one or more elevated biomarker were still significantly less likely to be resilient (OR=0.15, 95 CI 0.04-0.49, p=0.002) compared to those with no elevated biomarkers at baseline. Conclusions: In this cohort of older women with early breast cancer who were robust prior to initiation of chemotherapy, 22% became prefrail or frail at end of treatment. Resilience to chemotherapy was related to inflammatory and coagulation biomarkers. Further research is needed to examine the mechanism underlying why some older women are resilient and retain their robustness after receiving treatment, whereas others experience decline, and further explore the role of inflammation/coagulation in this phenomenon. Table 1. Multivariable associations between baseline blood biomarkers and resilienceResilient (n=253) No. %Non-resilient (n=71) No. %Multivariable OR (95%CI)P value# of elevated biomarkers*064 (25)4 (6)1.00190 (36)29 (41)0.16 (0.05-0.55)0.004255 (22)22 (31)0.14 (0.04-0.49)0.002344 (17)16 (23)0.14 (0.04-0.51)0.003No elevated biomarker64 (25)4 (6)1.00At least one elevated189 (75)67 (94)0.15 (0.04-0.49)0.002*Biomarkers were defined as elevated using the entire cohort median value as cut off points (IL-6 ≥2.7 pg/ml, CRP ≥4.3 μg/ml, and D-dimer ≥0.7 μg/ml). Combined effects of biomarkers were examined by creating a four-level categorical combination variable: 0=all three biomarkers are & lt;median; 1=one of the biomarkers ≥median; 2=two of the biomarkers ≥median; and, 3=all three biomarkers ≥median. A dichotomized variable was also created comparing none (all three biomarkers are & lt;median) vs at least one biomarker elevated (≥median). Citation Format: Mina S Sedrak, Canlan Sun, Hyman Muss, Rachel A. Freedman, Allison Magnuson, Cary P. Gross, William P. Tew, Heidi D. Klepin, Tanya M. Wildes, Efrat Dotan, Tracey O'Connor, Mary Ann Fenton, Ruby Sharma, Andrew Chapman, Cynthia Owusu, Selina Chow, Heeyoung Kim, Vani Katheria, Mark LaBarge, William Dale, Saro Armenian, Susan Neuhausen, Harvey J. Cohen. Inflammation and coagulation biomarkers associated with physical resilience in older women receiving chemotherapy for early breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS8-03.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2021
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    detail.hit.zdb_id: 1432-1
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  • 6
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 76, No. 15_Supplement ( 2016-08-01), p. C30-C30
    Abstract: Purpose of Study: Research over the past decade has established a critical role for the tumor microenvironment in facilitating tumor growth and promoting invasiveness. Cells of the myeloid lineage, including macrophages, have been known to be key mediators of tumor progression and facilitate metastasis. Recent work from our lab highlights the Ets transcription factors, PU.1 and ETS2, as important players in tumor associated macrophages (TAMs) during breast cancer progression. Both transcription factors are downstream effectors of the Colony Stimulating Factor 1 (CSF1) signaling pathway, which is not only important for myeloid cell survival, but also has a well-established role within the tumor microenvironment. Here, we investigated the requirement of PU.1 in TAMs in a mouse mammary tumor model and have begun to address the role of PU.1 during metastasis. Research Method: We employed cre-loxP technology to conditionally delete PU.1 in the myeloid cell compartment. Syngeneic mice were orthotopically injected with mammary tumor cells directly into the fat pad. To model breast cancer brain metastasis in the mouse, we employed an intracranial injection model which recapitulates the biology of the human disease. We were able to isolate tumor associated macrophages from either site (mammary or brain tumor) for downstream applications. Novel Findings: Macrophage-specific deletion of PU.1 resulted in a significant reduction in mammary tumor growth as well as tumor angiogenesis. Our results suggest that ETS2 and PU.1, acting downstream of the CSF1 signaling pathway, cooperatively regulate the expression of pro-tumor genes along with ‘oncogenic’ microRNA. Conventional ChIP assays show that both transcription factors occupy enhancer regions adjacent to a set of selected genes and cooperatively regulate expression in tumor infiltrating macrophages. We focused on miR-21 and miR-29a for a more detailed investigation as both are expressed in CSF1R+ myeloid cells within the brain metastatic microenvironment. In our intracranial injection model, macrophages (F4/80 positive cells) are recruited to the growing tumor, and both miR-21 and miR-29a are upregulated in TAMs isolated by FACS from tumor-bearing mice as compared to controls. Conclusions and Implications: Given our present data, we believe that the Ets factors, PU.1 and Ets2, regulate a transcriptional program, including microRNAs, that is critical for CSF1 action in tumor infiltrating macrophages. Currently, clinical trials are underway using CSF1R inhibitors for several solid tumor types [clinicaltrials.gov] . The macrophage-specific microRNA, including miR-21 and miR-29a, may serve as indicators for to the efficacy of CSF1R inhibition. Citation Format: Katie Thies, David A. Taffany, Haritha Mathsyaraja, Sudarshana M. Sharma, Walter Hans Meisen, Tom Liu, Cynthia Timmers, Jose Otero, Balveen Kaur, Michael C. Ostrowski. The CSF1-PU.1 pathway in tumor associated macrophages promotes breast cancer growth and progression. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr C30.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2016
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    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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