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  • 1
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 5011-5011
    Abstract: Background: Standard two-dimensional cell cultures do not retain the key characteristics of the human cancers from which they are derived and treatment effects are not always able to be replicated in vivo, making the development of alternative culturing systems paramount. Specifically, commercially available cell lines do not fully represent the mutation profiles seen in human cancers. Here we investigate the feasibility of three-dimensional PDOCS to more accurately represent the cancers from which they are derived and to predict treatment sensitivity in a clinically meaningful time frame. Methods: Surgical resection, core needle biopsies, paracentesis or thoracentesis samples from patients with various types of cancer were obtained under an approved IRB protocol, digested and spheroid cultures grown suspended in Matrigel. PDOCS were grown for up to two weeks and passaged at least once prior to treatment. PDOCS were imaged using brightfield imaging (4X) prior to treatment with vehicle or 5-fluorouracil (5-FU; 1, 10, or 100 µM) and/or radiation (2 or 5 Gy). After 2 days of treatment, the 5-FU was removed and the cultures were allowed to grow for an additional 2 days. PDOCS were re-imaged and the relative change in diameter was calculated using ImageJ software and compared to untreated controls. Optical metabolic imaging (OMI) was performed with a multiphoton microscope to probe the fluorescence lifetime and optical redox ratio of metabolic co-enzymes NAD(P)H and FAD. Single-cell analysis of each image was completed using Cell Profiler software to parse resistant cell populations in each PDOCS sample tested. DNA for mutation profile analysis was isolated and sequenced using a QIAseq targeted panel. Results: PDOCS were successfully isolated from a variety of cancers including colorectal (CRC), pancreas, lung, neuroendocrine, liver, breast, and ovarian. Key phenotypic characteristics of the tumors were retained in PDOCS cultured including crypt-like structures, mucin production and Ki67 proliferation rates. Cancer hot spot sequencing was performed comparing PDOCS and the tumors from which they were derived. Over 90% of the nonsynonymous mutations were identical, except in the setting of microsatellite instability. All driver mutations were identical (i.e., APC, KRAS, PIK3CA, TP53). Differential sensitivity to chemoradiation was observed among 4 different colorectal PDOCS treated with 5-FU and radiation (Median % PDOCS diameter change vs control: Patient A 17.1, p=0.64; Patient B -3.05, p=0.02; Patient C -19.4, p=2x10-5; Patient D -31.3, p=0.002). Similar response data were determined using OMI; however, single-cell analyses identified potentially resistant cell populations. Conclusions: PDOCS retain key characteristics of the cancers from which they are derived and can be utilized for treatment sensitivity testing in a clinically meaningful time frame. Citation Format: Cheri A. Pasch, Peter F. Favreau, Alex E. Yueh, Kwang P. Nickel, Christopher P. Babiarz, Philip B. Emmerich, Rosabella T. Pitera, Susan N. Payne, Demetra P. Korkos, Joseph T. Sharick, Carley M. Sprackling, Linda Clipson, Kristina A. Matkowskyj, Michael A. Newton, Melissa C. Skala, Michael F. Bassetti, Randall J. Kimple, Dustin A. Deming. Patient-derived organotypic cancer spheroids (PDOCS) as predictive models for the treatment of cancer in a clinically meaningful time frame [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 5011.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
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  • 2
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2018
    In:  Cancer Research Vol. 78, No. 13_Supplement ( 2018-07-01), p. 3472-3472
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 78, No. 13_Supplement ( 2018-07-01), p. 3472-3472
    Abstract: Background: Pancreatic cancer is one of the most deadly cancer diagnoses with limited long-term survival for patients, even with early-stage disease. 3-5% of these cancers have mutations in the phosphoinositide 3-kinase (PI3K) signaling pathway. There is growing interest in targeting cancers with this mutation using specific pathway inhibitors. We have previously proven that dual PI3K/mTOR inhibition is sufficient to decrease tumor growth in mice with a PI3K p110* transgene. Here we aim to determine if this treatment can induce a response in pancreatic cancers with the human PIK3CA H1047R hotspot mutation. Methods: Transgenic mice were developed using a cre lox-p system (Pdx1-cre) to develop PIK3CA H1047R (PCPK mice) pancreatic adenocarcinomas. Tumors were harvested and grown in spheroid culture. These were treated with increasing concentrations of BEZ235, a dual PI3K/mTOR inhibitor. Treatment groups were compared using spheroid diameter changes and metabolic activity via NADH and FAD+ quantitation. Additionally, immunofluorescence staining was performed and quantified on treated spheroid cultures. PET/CT diagnostics were performed and analyzed pre- and post- treatment with BEZ-235 on a cohort of these experimental mice. Treated tissues were resected for immunohistochemistry and Western blot analyses. Results: Organotypic PCPK spheroid cultures were treated with BEZ235 in the culture media for 48 hours. Pre- and post-brightfield imaging demonstrated a modest reduction in the percent change in spheroid diameter compared to control (control: 41.8%, BEZ235 100nM: 9%, BEZ235 200nM: -7.7%, BEZ235 400nM: -14.3%; p & lt;0.001). This stability of the spheroid size correlated with minimal differences between the control and treated spheroids using the optical metabolic imaging, including nonsignificant changes in NADH lifetime, FAD+ lifetime and the optical redox ratio (p=NS). PCPK mice (n=10) aged until they developed cancers and then were treated with BEZ235 for 14 days. Pre- and post-positron emission tomography/computed tomography (PET/CT) were performed. Nonsignificant changes in tumor volume and PET avidity were seen between the treatment groups. Both in vitro and in vivo treatments with BEZ235 proved to have no significant change in tumor avidity in this model. Immunoblotting demonstrated persistent activation of the PI3K pathway despite BEZ235 treatment in these spheres and mice as measured by persistent phosphorylation of RPS6 and 4EBP1. Conclusions: Despite significant responses being previously detected in mice with pancreatic tumors initiated by the PI3K p110* transgene, BEZ235 did not result in a similar treatment effect in PCPK mice possessing the human PIK3CA H1047R hotspot mutation. Further studies will examine the potential resistance mechanisms of these tumors to this therapy and potential ways in which to overcome this resistance. Citation Format: Susan Payne, Mitchell Depke, Alex Yueh, Joseph T. Sharick, Peter F. Favreau, Cheri A. Pasch, Linda Clipson, Kristina A. Matkowskyj, Melissa Skala, Dustin A. Deming. Dual PI3K/mTOR inhibition in PIK3CA mutant pancreatic cancers [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 3472.
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
    RVK:
    RVK:
    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2018
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
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