No abstract

Colorectal carcinomas (CRC) are one of the most common malignant tumors. Due to its heterogeneity and high probability to metastasize, the disease is often incurable and novel, improved therapies are needed. Enhanced, physiologically relevant in-vitro tumor models significantly increase the success rate in new drug development, reduce the number of animal experiments and result finally in better therapies for cancer patients. Furthermore, they have the potential to offer new approaches to personalized oncology. In recent years, 3D cell cultures were established as relevant preclinical cancer models, suitable for high-throughput-screening. However, their capacity to model and/or measure physiological processes can still be enhanced. In this project, we developed a tumor organoid-on-chip platform (TumOC) by combining most recent technological advances: We integrated patient-derived 3D cell cultures (organoids) from colorectal carcinomas and microsensor particles measuring oxygen concentration and therefore allowing assessment of cell vitality in real time in a microfluidic system. The resulting TumOC platform allows for defined exposition of cytostatic drugs including dynamic treatments. Measurements of cell vitality in real time enables analysis of not only the final effect of a drug treatment, but also the kinetics of drug response. At the same time, utilizing organoids allows for recapitulating tumor architecture and heterogeneity. Here we report the first proof of principle results generated with this system. We measured the cell vitality in real time over 72 hours during treatment with classic chemotherapeutics or targeted cancer drugs and compared the results to end-point measurements on the same organoids in a static system. In conclusion, our TumOC platform with its ability to recapitulate tumor heterogeneity in combination with dynamic treatments and real-time cell vitality assessment is an in-vitro tumor model closely recapitulating the physiological situation in a patient. TumOC provides an impressive opportunity to test and, consequently, predict the effectiveness of anti-cancer therapies. Therefore, this system is of interest not only for pre-clinical drug development but also for personal oncology. Citation Format: Marie Flechner, Juergen Loskutov, Ulrike Pfohl, Katja Osman, Christian R. Regenbrecht, Katja Uhlig, Lena Wedeken. TumOC: A tumor organoid-on-chip platform for real-time cell vitality measurements [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6209.

Enhanced, physiologically relevant in-vitro tumor models significantly increase the success rate in new drug development, reduce the number of animal experiments and result finally in better therapies for cancer patients. Furthermore, they have the potential to offer new approaches to personalized oncology. In recent years, 3D cell cultures were established as relevant preclinical cancer models, suitable for high-throughput-screening. However, their capacity to model and/or measure physiological processes can still be enhanced. Colorectal carcinomas (CRC) are one of the most common malignant tumors. Due to its heterogeneity and high probability to metastasize, the disease is often incurable and novel, improved therapies are urgently needed. In this project, we developed a tumor organoid-on-chip platform (TumOC) by combining most recent technological advances: We integrated CRC patient-derived 3D cell cultures (organoids) and microsensor particles that enable assessment of cell vitality in real time by measuring oxygen concentration in a microfluidic system. The resulting TumOC platform allows for defined exposition of cytostatic drugs including dynamic and combination treatments. Measurements of cell vitality in real time enables analysis of not only the final effect of a drug treatment, but also the kinetics of drug response. At the same time, utilizing organoids allows for recapitulating tumor architecture and heterogeneity. Using the TumOC platform, we measured the cell vitality in real time over several days during treatment with classic chemotherapeutics or targeted cancer drugs and compared the results to end-point measurements on the same organoids in a static system. We assessed the effect of intra- and intertumoral heterogeneity and developed a protocol for treatment with clinically used combination regimes. In conclusion, our TumOC platform with its ability to recapitulate tumor heterogeneity in combination with dynamic treatments and real-time cell vitality assessment is an in-vitro tumor model closely recapitulating the physiological situation in a patient. TumOC provides an impressive opportunity to test and, consequently, predict the effectiveness of anti-cancer therapies. Therefore, this system is of interest not only for pre-clinical drug development but also for personalized oncology. Citation Format: Marie Flechner, Juergen Loskutov, Madeleine Nadolny, Ulrike Pfohl, Christian R. Regenbrecht, Katja Uhlig, Lena Wedeken. Personalized identification of cancer treatments in real-time: TumOC - a tumor organoid-on-chip platform for online cell vitality measurements [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 190.

Triple negative breast cancer (TNBC) is the most aggressive subtype of all breast cancers. However, unlike other breast cancer subtypes, current treatments for TNBC are restricted and this scarcity of viable options is the key contributor to the poorer prognosis. Despite early response, almost all the targeted drugs tested in TNBC eventually fail due to the development of resistance. Patients’ data have shown that the expression level of Mediator kinases CDK8 and CDK19 are elevated in TNBC, and that higher expression of CDK8/19 is correlated with more advanced diseases and worse prognosis. Selective CDK8/19 inhibitor SNX631, when used as a single agent, inhibited the growth of several TNBC cell lines in vitro, cell-derived xenografts (CDXs) as well as patient derived xenografts (PDXs) in vivo, suggesting the potential of targeting CDK8/19 in treating TNBC. We also analyzed the effect of CDK8/19 inhibition on the outcome of treatment with mTORC1 inhibitor everolimus (RAD001), an approved drug for several cancers with mutations of PTEN or PI3KCA. SNX631 exhibited a synergistic effect in combination with everolimus on suppressing TNBC cell growth in vitro. In vivo treatment with everolimus alone achieved a strong tumor growth inhibition in TNBC xenograft models but all the tumors eventually resumed growth, indicated the development of resistance. Significantly, the addition of a CDK8/19 inhibitor prevented the emergence of in vivo everolimus resistance both in CDX and PDX tumors upon treatment for up to 150 days, suggesting a potential for extending remission or even achieving cures in TNBC. Transcriptomic analysis demonstrated that this effect was due to the prevention of transcriptional reprogramming associated with everolimus resistance in tumor cells. Citation Format: Xiaokai Ding, Hao Ji, Amanda C. Sharko, Juergen Loskutov, Zachary Mack, Jadyn Myers, Mengqian Chen, Elena Pugacheva, Igor Roninson, Eugenia Broude. PD5-10 Dual therapeutic targeting of CDK8/19 and mTOR in triple negative breast cancer [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD5-10.

Cancer represents a huge health problem worldwide and is well-recognized as an extremely heterogeneous disease affecting all the tissues and organs. The incidence of the particular cancer type is directly connected to the availability of specific medication and amount of the research focused on it, resulting in a high unmet medical need for treatment options for rare cancers. Currently, NCI defines “rare cancer” as cancer with an incidence rate below 15 per 10^5 people per year and recently the term “ultra-rare cancer” was defined as cancer with an incidence rate below 1 per 10^6 people per year. These encompass drastically understudied entities, usually with poor prognosis and grim outlook for an improvement in treatment. Low incidence of such cancers makes development of targeted therapies not interesting from a commercial point of view and completely abolishes the possibility of large-scale clinical trials. Therefore, a personalized medicine approach appears to be the most promising strategy for the patients to get adequate care. Here we report our experience with personalized oncology solutions for rare and ultra-rare cancers. We utilized patient derived 3D (PD3D) cultures to evaluate prospective therapeutic options in these exceptional cases to support the oncologists in providing personalized care to the patients. Fresh surgical specimens underwent several steps of mechanical and chemical dissociation. Subsequently, cell aggregates were seeded into 24 well plates in matrix-like scaffolds and allowed to grow until they started forming colonies. After harvesting, the cells underwent pathology evaluation to confirm origin and diagnosis. Therapies, recommended by the case leading oncologist, were used for drug sensitivity testing after transferring cells semi- automatically to 384-well plates. Over the last 18 months, we handled 6 cases classified as rare or ultra-rare cancers. The diagnoses included: clear cell sarcoma, extra-skeletal myxoid chondrosarcoma, CIC-rearranged round cell sarcoma, pleomorphic liposarcoma, cardiac angiosarcoma and clear cell endometrial carcinoma. In all cases we were able to successfully establish PD3D cultures and perform a drug screen, identifying a potential treatment for the patient. Overall, our results indicate that it is feasible to utilize our testing strategy for rare and ultra-rare cancer entities. Further research and rigorous follow up is required to confirm the benefit of the personalized approach vs current strategies. However, a demand for personalized care in such cases is clearly visible. Citation Format: Juergen Loskutov, Manuela Regenbrecht, Rica Sauer, Sabine Finkler, Maya Niethard, Christoph Reinhard, Christian Regenbrecht. The bad, the ugly and the ultra-rare: All cancers are equal in the face of personalized medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6224.