Abstract B60: Perturbation biology of colorectal cancer organoids reveals patient-specific signaling rewiring and interference with immunity

Colorectal cancer (CRC), a cancer with 1.4 million new cases diagnosed annually worldwide, is refractory to immunotherapy (with the exception of a minority of tumors with microsatellite instability). This is somehow paradoxical as CRC is a cancer which we have shown is under immunologic control and that tumor-infiltrating lymphocytes represent a strong independent predictor of survival (1). Based on our previous work showing that the immunophenotypes are determined by the genotypes (2), we hypothesized that mutations are rewiring signaling pathways and thereby modulate the recognition of tumor cells by T cells. In order to investigate rewiring of signaling networks and their interference with immunity for individual patients, we developed an experimental-computational concept using perturbation experiments with patient-derived tumor organoids. A biobank of CRC organoids was generated from histologically verified tumor samples, normal tissue, and liver metastases obtained from CRC patients (n=22). Comprehensive characterization of the organoids (exome sequencing, RNA sequencing, and proteomics) and of the tumors (multiplexed immunofluorescence for 6 immune cell types) was carried out and the resulting data were used to prioritize perturbation experiments. Patient-derived organoids were then perturbed with kinase inhibitors (MEKi, PI3Ki, mTORi, TBK1i, IKKi, BRAFi, and TAKi) and large-scale phosphoproteomic profiling using data-independent acquisition (SWATH-MS) was carried out. Deep phosphoproteomic profiling of perturbed organoids enabled reconstruction of patient-specific signaling networks and revealed profound rewiring by targeted drugs and interference with immune-related pathways, suggesting possible pharmacologic modulation by approved targeted agents to induce immunogenic effects. We show for the first time that systematic and comprehensive analysis of the signaling rewiring can provide a mechanistic rationale for immunotherapy-based combination regimens in CRC. This work is an important step towards the development of a precision immuno-oncology platform that integrates tumor organoids with high-throughput and high-content data for making therapeutic recommendations for individual patients.

References

1. Galon J, Costes A, Sanchez-Cabo F, Kirilovsky A, Mlecnik B, Lagorce-Pages C, Tosolini M, Camus M, Berger A, Wind P, et al. Type, density, and location of immune cells within human colorectal tumors predict clinical outcome. Science 2006;313:1960-1964.

2. Angelova M, Charoentong P, Hackl H, Fischer ML, Snajder R, Krogsdam AM, Waldner MJ, Bindea G, Mlecnik B, Galon J, Trajanoski Z: Characterization of the immunophenotypes and antigenomes of colorectal cancers reveals distinct tumor escape mechanisms and novel targets for immunotherapy. Genome Biol 2015;16:64.

Citation Format: Giorgia Lamberti, Christina Plattner, Peter Blattner, Stefan Scheidl, Francesca Finotello, Dietmar Rieder, Anne Krogsdam, Henner Farin, Florian Greten, Dietmar Öfner-Velano, Noel de Miranda, Ruedi Aebersold, Lukas Huber, Zlatko Trajanoski. Perturbation biology of colorectal cancer organoids reveals patient-specific signaling rewiring and interference with immunity [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B60.

Necrotizing fasciitis of the lower extremity caused by perforated sigmoid diverticulitis-a case report

Diverticulosis of the sigmoid colon is a common condition and occurs more often in elderly patients. A well-known complication is infection or even perforation which often requires surgery. Necrotizing fasciitis as a complication of perforated diverticulitis is very rare. Here, we present a case of a covered perforated diverticulitis in an immunosuppressed patient leading to life-threatening necrotizing fasciitis requiring extracorporeal membrane oxygenation. Either hematogenous or local dissemination via the inguinal canal seemed the most probable mechanism of leg infection leading to hip articulation.

Integrating interventional oncology in the treatment of liver tumors

Background

Percutaneous ablation techniques offer a vast armamentarium for local, minimally invasive treatment of liver tumors, nowadays representing an established therapeutic option, which is integrated in treatment algorithms, especially for non-resectable liver tumors. The results of ablative treatment compare very well to surgical treatment in liver lesions, and confirm that these techniques are a valuable option for bridging for transplantation. Different techniques have been established to perform tumor ablation, and the feasibility varies according to the procedure and technical skills of the operator, depending on the size and location of the liver lesion. In recent years, stereotactic multi-needle techniques using 3D trajectory planning, general anesthesia, and tube disconnection during needle placement have had a strong impact on the application range of ablation for liver tumors.

Conclusion

It is well known that creating a sufficient ablation margin and overlapping ablation zones is one key issue to enable ablation of large liver lesions with tumor-free margins (A0 ablation in analogy to R0 resection). Image fusion during treatment and follow-up assure highly accurate staging procedures and interventional planning.

Novel aspects

Review on the standards in ablation techniques for the treatment of liver tumors. Update on different ablation techniques, indications, and contraindications for percutaneous liver tumor treatment. Summary of recently published reports on liver tumor ablation.

Prediction of delayed graft function and long-term graft survival by serum and urinary neutrophil gelatinase-associated lipocalin during the early postoperative phase after kidney transplantation

Neutrophil gelatinase-associated lipocalin (NGAL) has emerged as an early marker protein for kidney dysfunction in various clinical settings. In this prospective study we evaluated serial changes of serum and urinary NGAL within the first 7 days after kidney transplantation in 170 consecutive recipients. The main focus of this study was to assess the performance of serum and urinary NGAL in the prediction of delayed graft function (DGF) and two-year graft and patient survival. Serum and urine samples of 170 patients undergoing primary kidney transplantation from October 2010 to December 2012 were prospectively collected from day 0 to 7. NGAL was analyzed by ELISA. Multivariate regression models, receiver-operating characteristics (ROC), and areas under ROC curves (AUC) were used to identify predictors of DGF. DGF occurred in 52 patients (30.6%). Serum (AUC = 0.869) and urinary NGAL (AUC = 0.872) on postoperative day (POD) 2 could accurately predict DGF compared to serum creatinine (AUC = 0.619). Multivariate analyses revealed donor age, serum and urinary NGAL significantly associated with DGF (p<0.001). Recipient age was the only significant factor in a cox regression model influencing two-year graft and patient survival. In conclusion, serum and urinary NGAL are early predictors of DGF after kidney transplantation.