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  • 1
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 12, No. 1 ( 2022-03-25)
    Kurzfassung: Representative models are needed to screen new therapies for patients with cancer. Cancer organoids are a leap forward as a culture model that faithfully represents the disease. Mouse-derived cancer organoids (MDCOs) are becoming increasingly popular, however there has yet to be a standardized method to assess therapeutic response and identify subpopulation heterogeneity. There are multiple factors unique to organoid culture that could affect how therapeutic response and MDCO heterogeneity are assessed. Here we describe an analysis of nearly 3500 individual MDCOs where individual organoid morphologic tracking was performed. Change in MDCO diameter was assessed in the presence of control media or targeted therapies. Individual organoid tracking was identified to be more sensitive to treatment response than well-level assessment. The impact of different generations of mice of the same genotype, different regions of the colon, and organoid specific characteristics including baseline size, passage number, plating density, and location within the matrix were examined. Only the starting size of the MDCO altered the subsequent growth. These results were corroborated using ~ 1700 patient-derived cancer organoids (PDCOs) isolated from 19 patients. Here we establish organoid culture parameters for individual organoid morphologic tracking to determine therapeutic response and growth/response heterogeneity for translational studies.
    Materialart: Online-Ressource
    ISSN: 2045-2322
    Sprache: Englisch
    Verlag: Springer Science and Business Media LLC
    Publikationsdatum: 2022
    ZDB Id: 2615211-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 13_Supplement ( 2021-07-01), p. 1944-1944
    Kurzfassung: Background: Mutations in PIK3CA occur in 18% of colorectal cancers (CRC) and result in constitutive activation of the PI3K pathway. Previous work from our lab has determined that MTORC1/2 inhibition, with copanlisib (cop), a PI3K/MTOR inhibitor, is sufficient to induce a treatment response. We hypothesized that the BCL2 family inhibitor navitoclax (nav), a BCL2/BCLxL inhibitor, would enhance the therapeutic response of cop and increase the induction of apoptosis. Methods: Murine derived cancer organoids (MDCOs) were generated from adenocarcinomas arising in Apc and Pik3ca mutant transgenic mice ((FVB x B6) F1 Apcfl/+ Pik3caH1047R/+). MDCOs were plated and matured for 24 hours. MDCOs were treated for 48 hours. Change in diameter was used to assess response. Additionally, human 2D isogenic cell lines SW48 and SW48PIK3CA-H1047R (SW48PK) were plated and treated for 48 hours. WST-1 proliferation assay was used to determine response. In vivo response was assessed as median relative change (MRC) in tumor volume of SW48 and SW48PK xenografts in immunocompromised Rag2-Il2rg-/- (R2G2) mice. Induction of apoptosis was determined with immunoblotting (IB) for PARP cleavage. Results: MDCOs were treated with cop (200nM) or nav (250nM) alone and in combination. Single agent cop resulted in -16% MRC (p & lt;0.001). Nav alone did not have an effect (+95% p & lt;0.07). Enhanced therapeutic response was seen in the combination therapy compared to cop alone (cop -16% vs combo -100%; p & lt;0.001). In SW48 and SW48PK with cop (1nM or 10nM) or nav (250nM) alone and in combination, a greater response was seen in the combination therapy in both cell lines compared to either single agent alone (p & lt;0.005). SW48 and SW48PK xenograft studies demonstrated significant activity of this combination in vivo. SW48 tumor growth was limited with either cop (10mg/kg), nav (80mg/kg), or the combination compared to control (control +5.0 MRC, cop +3.4, nav +2.6, combo +2.6; control vs combo p & lt;0.01; cop vs combo p=0.29). Enhanced activity of this combination was observed in SW48PK tumors compared to SW48. Growth was significantly more limited with the combination (control +5.0 MRC, cop +3.4, nav +4.5, combo +0.7; control vs combo p & lt;0.01; cop vs combo p=0.06). IB of cleaved PARP showed induction of apoptosis was the highest in the combination therapy in all in vitro models and seen as early as 6 hours post treatment. To identify which BCL2 family member nav was primarily targeting, cop was combined with WEHI539 (BCLxL inhibitor; 250nM) or ABT199 (BCL2 inhibitor; 250nM). BCL2 inhibition did not enhance the efficacy of cop in the MDCOs or isogenic lines. However, BCLxL inhibition did enhance the efficacy of cop in both in vitro models. Conclusion: These data indicate that navitoclax, through BCLxL inhibition, enhances the efficacy of copanlisib with a greater induction of apoptosis in several models of PIK3CA mutant CRC. Citation Format: Rebecca Anna DeStefanis, Alyssa DeZeeuw, Gioia Sha, Autumn Olson, Samantha J. Anderson, Christopher P. Babiarz, Cheri A. Pasch, Linda Clipson, Dustin A. Deming. Navitoclax enhances the efficacy of copanlisib predominantly through inhibition of BCLxL in PIK3CA mutant colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1944.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
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    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2021
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 3
    Online-Ressource
    Online-Ressource
    American Association for Cancer Research (AACR) ; 2020
    In:  Cancer Research Vol. 80, No. 16_Supplement ( 2020-08-15), p. 3048-3048
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 16_Supplement ( 2020-08-15), p. 3048-3048
    Kurzfassung: Introduction: Colorectal cancer (CRC) treatment is becoming increasingly individualized as clinical mutation profiling is a standard of care. Oncogenic mutations of the PIK3CA gene induce a constitutively active phosphatidylinositol 3-kinase with downstream effects that promote tumor initiation and progression. Effective clinical therapeutic strategies targeting this subtype of colorectal cancer have remained elusive. Here we develop a high-throughput organoid drug screening platform to examine combination strategies targeting PIK3CA mutant CRC. Methods: Murine-derived CRC organoids (MDCOs) were derived from a transgenic mouse model of PIK3CA and APC mutated colorectal cancer (F1 (FVBxB6) Apcfl/+ Pik3caH1047R), matured for 48 hours and plated in 96 well plates. A total of 96 compounds chosen from clinically available anticancer drugs and select drugs in clinical development were analyzed for their efficacy in reducing organoid growth on their own, as well as in combination with copanlisib (PI3K/MTOR inhibitor) over 48 hours. Select treatments were confirmed using our standard 24 well plate assay. Additionally, irinotecan (SN38; topoisomerase-I inhibitor), panitumumab (EGFR inhibitor), and olaparib (PARP inhibitor) were investigated alone and in combination with copanlisib based on clinical use for this population or recent promising clinical trial data. Results: SN38, olaparib, and panitumumab yielded insignificant changes in spheroid size in the combination regimen compared to copanlisib alone (median relative change in organoid diameter - copanlisib -8%, p & lt;0.001; SN38 combo -8%, p=0.5; olaparib combo -13%, p=0.6; and panitumumab combo 1%, p=0.9). The MDCOs were successfully utilized for the high-throughput drug screen. Differential sensitivity was identified using change in organoid diameter without the need for reagents or dyes which could complicate the screening method. Of the 96 compounds investigated in the high-throughput screen, 12 resulted in enhanced treatment effect when combined with copanlisib. Three of these 12 compounds inhibit microtubule formation, and others inhibit components of the RAS pathway. Two of these drug combinations were examined further and significant treatment responses were confirmed. Conclusion: Advances in the understanding of the molecular basis of cancer allow for a more precise approach to cancer treatment. High-throughput techniques are needed to better identify novel treatment strategies for molecular subtypes. Here we describe a label free murine-derived cancer organoid method to screen drugs for combination treatment strategies. Citation Format: Alyssa K. DeZeeuw, Rebecca A. DeStefanis, Gioia Sha, Cheri A. Pasch, Linda Clipson, Dustin A. Deming. Murine-derived colorectal cancer organoid culture high-throughput drug screening to identify novel combinations targeting PIK3CA mutant cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3048.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
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    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2020
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
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  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 2936-2936
    Kurzfassung: Background: Intrinsic resistance to agents targeting the PI3K/AKT/mTOR pathway has been commonly encountered in clinical trials of patients with PIK3CA mutant colorectal cancer (CRC). Upregulation of antiapoptotic signaling has been proposed as a mechanism of resistance to these therapies, including upregulation of BCL-2 and BCL-xL. To investigate if inhibition of BCL-2 family members would sensitize Pik3ca mutant cancers to MTORC1/2 inhibition, treatment studies were performed with TAK-228 (MTORC1/2 inhibitor), BEZ235 (dual PI3K/mTOR inhibitor), navitoclax (ABT-263; BCL-2, BCL-xL and BCL-w inhibitor) and the combination of navitoclax with either TAK-228 or BEZ235. Methods: Therapeutic investigations with 200 nM TAK-228 or 200 nM BEZ235 and 250 nM navitoclax were performed in murine CRC spheroids with loss of APC and a constitutively active PI3K. Images were taken both pre- and post-treatment and changes in spheroid diameter were measured. Parallel treatment studies were performed on patient-derived organotypic CRC spheroids. Additionally, treatment studies were performed in vivo using a novel transgenic mouse model carrying Apc and Pik3ca mutations. The mice were treated with the combination of BEZ235 and navitoclax or with a single agent alone for 7 consecutive days. Results: Treatment of CRC spheroids with TAK-228 resulted in a reduction of sphere size by 16% while control treated spheres increased by 77% of their size at day 0. No response was seen with navitoclax treatment alone. A profound synergistic treatment response was observed with the combination of TAK-228 and navitoclax (reduction of 26%, p & lt;0.001), with most spheroids undergoing complete collapse. A similar treatment response was observed with BEZ235 and navitoclax. Human CRC spheroids treated with TAK-228 and/or navitoclax demonstrated a variable response with 3 of 5 lines having a greater than 15% reduction in sphere size when treated with the combination of TAK-228 and navitoclax (p & lt;0.001). This enhanced treatment response correlated with an increase in apoptosis as measured by cleaved caspase 3. No enhanced activity was observed with the combination of BEZ235 and ABT-199 (selective BCL-2 inhibitor). In transgenic mice with Apc and Pik3ca mutant cancers, a median change in lumen occlusion of -42% was observed with the combination of BEZ235 and navitoclax compared to -15% with BEZ235 alone (one-sided p & lt;0.03, n=34 mice). Conclusion: Synergistic activity was seen with the combination of TAK-228 or BEZ235 and navitoclax. This combination deserves further study in future clinical trials. Citation Format: Stephanie L. Fricke, Susan N. Payne, Cheri A. Pasch, Demetra P. Korkos, Gioia Sha, Alex E. Yueh, Christopher Babiarz, Linda Clipson, Kristina A. Matkowskyj, Michael A. Newton, Dustin A. Deming. MTORC1/2 inhibition in combination with BCL-2/BCL-xL inhibition in APC and PIK3CA mutant colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2936.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2018
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 5
    Online-Ressource
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    American Association for Cancer Research (AACR) ; 2021
    In:  Cancer Research Vol. 81, No. 13_Supplement ( 2021-07-01), p. 2969-2969
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 81, No. 13_Supplement ( 2021-07-01), p. 2969-2969
    Kurzfassung: Impact of baseline culture condition on the growth and treatment response of mouse derived cancer organoidsAuthors: Autumn Olson, Rebecca A. DeStefanis, Alyssa DeZeeuw, Samantha Anderson, Gioia Sha, Jeremy Kratz, Cheri Pasch, Linda Clipson, Dustin A. DemingIntroduction: Colorectal cancer (CRC) is a leading cause of cancer related deaths and there has been an increased focus on developing therapies targeted to the mutational profile of individual patients. Mouse derived cancer organoids (MDCOs) are used as a model for therapeutic drug testing. How the culture conditions can impact the determination of treatment response from MDCOs has been understudied and is the focus of these investigations. Here, we examine how baseline size, passage number, plating density, location within the Matrigel droplet, and lineage impact MDCO growth and treatment response.Methods: CRC MDCOs were derived from multiple tumors across several Apc and Pik3ca mutant mice (Fc1 Apcfl/+ Pik3caH1047R/+) totaling 3,152 individual MDCOs. Untreated MDCO growth was analyzed across 902 MDCOs. Additionally, the PI3K pathway inhibitors, AZD2014, Everolimus, BEZ235, MLN0128, Palbociclib, and Copanlisib were analyzed across 2,250 MDCOs. In each study, baseline brightfield images of the MDCOs were taken and following 48 hours. Individual MDCOs were evaluated for the impact of baseline size, passage number (passage 1-15), plating density, location within the Matrigel droplet, and the generation of MDCOs across different mice on MDCO growth and treatment response. A change point analysis was used to assess the impact of baseline size. The percent relative change in diameter over 48 hours was compared to each other culture condition by calculating an R2 value.Results: A change in the organoid baseline growth rate was observed if the MDCOs were greater than 0.373 mm in baseline was identified. There were no significant differences in growth due to changes in the other culture conditions for the untreated MDCOs. The R2 values comparing the percent relative change in diameter over 48 hours to the culture conditions of passage number, plating density, location within the Matrigel droplet, and from which mouse the MDCOs were derived from were 0.0103, 0.0243, 0.0001, and 0.0295, respectively. There were no significant differences in the response to PI3K pathway inhibition of the MDCOs related to passage number, plating density, location within the Matrigel droplet, and from which mouse the MDCOs were derived from (R2 values: 0.1174, 0.0979, 0.0221, and 0.1267, respectively).Conclusions: Mouse derived cancer organoids are a useful tool in modeling drug response of cancers with specific mutational profiles. While the baseline size of MDCOs can change the growth rate, the growth rate and treatment response of MDCOs is not impacted by the passage number, plating density, location within the Matrigel, and from which mouse the MDCOs were derived. Citation Format: Autumn Olson, Rebecca A. DeStefanis, Alyssa DeZeeuw, Samantha Anderson, Gioia Sha, Jeremy Kratz, Cheri Pasch, Linda Clipson, Dustin A. Deming. Impact of baseline culture condition on the growth and treatment response of mouse derived cancer organoids [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2969.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2021
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 6
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 3146-3146
    Kurzfassung: Background: Infiltration of CD8+ T cells has shown important prognostic implications in colorectal cancers (CRC). Our group has recently correlated proteolysis of an extracellular matrix proteoglycan, versican (VCAN), with infiltration of CRCs by CD8+ T cells. Cleavage by ADAMTS proteases generates a bioactive fragment of versican, versikine (VKINE). VKINE stimulates Batf3-driven dendritic cell activation and maturation, which are critical for immunotherapy efficacy. Methods: CT26 murine CRC cells were transfected to constitutively express VKINE. BALB/c mice between 50 and 70 days of age were orthotopically injected with either 105 empty vector (CT26-EV) or VKINE-expressing (CT26-VKINE) cells. Tumor growth was tracked weekly with colonoscopy and growth rate assessed using percent lumen occlusion. Mice were euthanized and dissected once moribund. Tissues were formalin-fixed and paraffin-embedded (FFPE). Immunohistochemical (IHC) staining was performed using standard procedures. Additionally, FFPE samples from human CRC liver metastases (n=9) were obtained under the University of Wisconsin Translational Science Biocore Institutional Review Board-approved protocol and IHC performed for VCAN, VKINE and CD8. The number of CD8+ tumor-infiltrating lymphocytes (TILs) per high-powered field (HPF) within the malignant epithelium was calculated using four separate 400x magnification fields of view. Results: CT26-EV and CT26-VKINE injected mice both had a ~70% tumor initiation rate and these tumors averaged ~50% lumen occlusion by 14 days post injection. Survival data for each group were compared using a log-rank test. A trend towards improved survival was observed in those mice injected with CT26-VKINE (average survival of 27 days for CT26-VKINE compared to 22 days for CT26-EV, p=0.41, n=13). The average number of CD8+ TILs for each tumor were compared. For mice with CT26-VKINE, the average number of CD8+ TILs per HPF was 7.6, compared to 4.7 for mice with CT26-EV (p=0.39). Human CRC liver metastases were analyzed for VCAN, VKINE, and CD8+ T cells. Several lesions had little to no VCAN staining, whereas others had intense pockets or peripheral staining. VKINE staining was more abundant in metastatic CRC lesions than in primary lesions. CD8+ T cells were excluded in the setting of increased VCAN staining and infiltration was noted specifically in areas of VCAN proteolysis (low VCAN and high VKINE staining). These areas of proteolysis were more often present at the tumor margin and correlated with ADAMTS1 expression. Conclusions: Immunotherapies offer a unique treatment option for cancer patients, but their use is limited in CRC. VCAN proteolysis and the generation of bioactive VKINE has potential to influence the ability of CD8+ T cells to infiltrate the tumor in both primary and metastatic CRC, indicating the potential to utilize VCAN and VKINE as immune biomarkers or therapeutic targets. Citation Format: Philip B. Emmerich, Susan N. Payne, Connor J. Maloney, Rosabella T. Pitera, Hanna Rainiero, Gioia Sha, Athanasios T. Papadas, Adam C. Pagenkopf, Michael F. Bassetti, Kristina A. Matkowskyj, Fotis Asimakopoulos, Dustin A. Deming. Versican proteolysis: A novel immunostimulatory component of CD8+ T cell responses to colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3146.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2018
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 7
    In: Molecular Cancer Research, American Association for Cancer Research (AACR), Vol. 18, No. 10_Supplement ( 2020-10-01), p. B27-B27
    Kurzfassung: Colorectal cancer (CRC) is a leading cause of cancer-related death. PIK3CA mutations are common, leading to a constitutively active phosphoinositide-3 kinase (PI3K). An effective means to target this pathway has yet to be identified. We investigated the use of a panel of inhibitors targeting the PI3K pathway including copanlisib (dual PI3K/mTOR), BYL-719 (alpha isomer specific PI3K), GDC-0941 (pan PI3K), and TAK-228 (MTORC1/2). To test the efficacy of these inhibitors in CRC, murine organotypic cancer spheroids (MDOCS) were generated from the invasive adenocarcinomas of Apc and Pik3ca transgenic mice. These inhibitors were investigated at clinically relevant doses (100-400nM). Copanlisib and TAK-228 were the only inhibitors to result in a significant reduction in the size of the MDOCS (200nM; 27% p-value & lt;0.001, 18% p-value & lt;0.001, respectively). This result correlated with a decrease in the phosphorylation of AKT (ser473), RPS6, and 4EBP1. Minimal induction of apoptosis was observed using these inhibitors alone as measured by cleaved PARP and cleaved caspase 3. These results were confirmed in vivo using transgenic mice with TAK-228 (1mg/kg/day) and copanlisib (10mg/kg q2d x5) resulting in a reduction in lumen occlusion of the colon tumors. Persistent BCL-2 and BCL-xL signaling was hypothesized to be preventing the induction of apoptosis. To determine if inhibition of these BCL-2 family members would further sensitize these MDOCS to copanlisib and TAK-228, these inhibitors were tested in combination with navitoclax (ABT-263; BCL-2 family inhibitor). A dramatic enhanced sensitivity was observed in MDOCS (30% p-value & lt;0.001, 23% p-value & lt;0.001, respectively). This correlated with an induction of apoptosis as measured by cleaved caspase 3. Next a panel of eight CRC patient-derived organotypic cancer spheroids (PDOCS) were treated with the combination of TAK-228 and navitoclax. Differential sensitivity was observed across the panel (25% resistant, 37.5% intermediate, and 37.5% highly sensitive) owing to the importance of mutational profile with targeted therapies. These studies indicate the benefit of MTORC1/2 for the treatment of PIK3CA mutant CRC and with enhanced activity of the combination of MTORC1/2 inhibition in combination with BCL-2 family inhibition. These therapies deserve further investigation for the treatment of patients with PIK3CA mutant CRC. Citation Format: Rebecca A. DeStefanis, Susan N. Payne, Devon Miller, Cheri A. Pasch, Christopher Babiarz, Alyssa DeZeeuw, Stephanie L. Fricke, Carley Sprackling, Alexander E. Yueh, Demetra P. Korkos, Dana R. Van De Hey, Gioia Sha, Aurora Greane, Jeremy D. Kratz, Linda Clipson, Kristina A. Matkowskyj, Michael A. Newton, Dustin A. Deming. MTORC1/2 inhibition as a treatment strategy for PIK3CA mutant colorectal cancer [abstract]. In: Proceedings of the AACR Special Conference on Targeting PI3K/mTOR Signaling; 2018 Nov 30-Dec 8; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Res 2020;18(10_Suppl):Abstract nr B27.
    Materialart: Online-Ressource
    ISSN: 1541-7786 , 1557-3125
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2020
    ZDB Id: 2097884-4
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 8
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 80, No. 16_Supplement ( 2020-08-15), p. 75-75
    Kurzfassung: Colorectal cancer (CRC) is a leading cause of cancer related death with PIK3CA mutations occurring in ~18% of all cases. Mutations in this gene lead to constitutive activation of the phosphoinositide-3 kinase (PI3K) oncogene. Previously we've shown that MTORC1/2 inhibition is sufficient to induce a therapeutic response both in vitro and in vivo with minimal induction of apoptosis. BCL-xL is a well-known negative regulator of apoptosis in solid tumors. We therefore investigated whether inhibition of the BCL-2 family, and more specifically BCL-xL, would enhance therapeutic response and induction of apoptosis. Murine-derived cancer organoids (MDCOs) were generated from invasive colon adenocarcinomas of Apc and Pik3ca transgenic mice (F1 (FVBxB6) Apcfl/+ Pik3caH1047R). MDCOs were allowed to mature for 24 hours, baseline brightfield imaging performed and therapeutic agents added at concentrations outlined below. Median relative change in organoid diameter after 48 hours of treatment was determined. In vivo response was measured in F1 (FVBxB6) Apcfl/+ Pik3caP110* mice as change in endoscopic tumor lumen occlusion over 14 days. Immunoblotting (IB) and immunofluorescence (IF) were utilized to evaluate for induction of apoptosis. Navitoclax (BCL-2/BCL-xL/BCL-w inhibitor, 250nM) was evaluated alone and in combination with a panel of MTORC1/2 inhibitors (BEZ-235 (BEZ), TAK-228 (TAK), copanlisib (Cop), 200nM). Navitoclax did not induce a treatment response as a single agent. Enhanced response was seen with the combination compared to the MTORC1/2 inhibitors alone (Bez 56% vs combo -100%, p & lt;0.001; TAK -27% vs combo -100%, p & lt;0.001; Cop -16% vs -100%; p & lt;0.001). Results were confirmed in vivo with BEZ-235 (30mg/kg/day), navitoclax (80mg/kg/day), or the combination with the greatest reduction in lumen occlusion of colon tumors in the combination therapy (control +15%, navitoclax +1%, BEZ -15%, and combo -42%, p & lt;0.003 BEZ vs combo). IB of cleaved PARP, a main cleavage target of cleaved caspase 3 (CC3) once apoptosis is induced, and IF of CC3 confirmed induction of apoptosis was highest in the combination therapy in both in vitro and in vivo studies. This induction was found as early as 6 hours post treatment in the MDCOs. To confirm inhibition of BCL-xL was the primary anti-apoptotic protein necessary for this induction of apoptosis, MDCOs were treated with copanlisib (200nM) alone or in combination with WEHI-539 (BCL-xL inhibitor, 250nM) or ABT-199 (BCL-2 inhibitor, 250nM). An enhanced sensitivity was observed when MTORC1/2 inhibition was combined with the inhibition of BCL-xL compared to BCL-2. These studies indicate that BCL-xL signaling reduces MTORC1/2 inhibitor response and targeting BCL-xL in combination with MTORC1/2 enhances both the treatment response and the induction of apoptosis in PIK3CA mutant CRC. Citation Format: Rebecca A. DeStefanis, Alyssa DeZeeuw, Gioia Sha, Susan N. Payne, Christopher P. Babiarz, Devon Miller, Demetra K. Korkos, Cheri A. Pasch, Linda Clipson, Kristina Matkowskyj, Dustin A. Deming. BCL-xL inhibition enhances therapeutic response of MTORC1/2 inhibition and induction of apoptosis in PIK3CA mutant colorectal cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 75.
    Materialart: Online-Ressource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2020
    ZDB Id: 2036785-5
    ZDB Id: 1432-1
    ZDB Id: 410466-3
    Standort Signatur Einschränkungen Verfügbarkeit
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  • 9
    In: Molecular Cancer Therapeutics, American Association for Cancer Research (AACR), Vol. 18, No. 2 ( 2019-02-01), p. 346-355
    Kurzfassung: PIK3CA mutations are common in clinical molecular profiling, yet an effective means to target these cancers has yet to be developed. MTORC1 inhibitors are often used off-label for patients with PIK3CA mutant cancers with only limited data to support this approach. Here we describe a cohort of patients treated with cancers possessing mutations activating the PI3K signaling cascade with minimal benefit to treatment with the MTORC1 inhibitor everolimus. Previously, we demonstrated that dual PI3K/mTOR inhibition could decrease proliferation, induce differentiation, and result in a treatment response in APC and PIK3CA mutant colorectal cancer. However, reactivation of AKT was identified, indicating that the majority of the benefit may be secondary to MTORC1/2 inhibition. TAK-228, an MTORC1/2 inhibitor, was compared with dual PI3K/mTOR inhibition using BEZ235 in murine colorectal cancer spheroids. A reduction in spheroid size was observed with TAK-228 and BEZ235 (−13% and −14%, respectively) compared with an increase of & gt;200% in control (P & lt; 0.001). These spheroids were resistant to MTORC1 inhibition. In transgenic mice possessing Pik3ca and Apc mutations, BEZ235 and TAK-228 resulted in a median reduction in colon tumor size of 19% and 20%, respectively, with control tumors having a median increase of 18% (P = 0.02 and 0.004, respectively). This response correlated with a decrease in the phosphorylation of 4EBP1 and RPS6. MTORC1/2 inhibition is sufficient to overcome resistance to everolimus and induce a treatment response in PIK3CA mutant colorectal cancers and deserves investigation in clinical trials and in future combination regimens.
    Materialart: Online-Ressource
    ISSN: 1535-7163 , 1538-8514
    Sprache: Englisch
    Verlag: American Association for Cancer Research (AACR)
    Publikationsdatum: 2019
    ZDB Id: 2062135-8
    SSG: 12
    Standort Signatur Einschränkungen Verfügbarkeit
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