Abstract 5780: 3D ex-vivo assay platform using primary lung cancer cells in malignant pleural effusions as predictor for clinical outcome of personalized chemotherapy

Background: Despite advances in therapeutic programs to treat various cancer types, dismal overall response rates for several entities has posed dilemma for oncologists and researchers alike. Therefore, there is an immense need in accelerating therapeutic programs towards clinical success in cancer patients. It is well established that patients suffering from same cancer type may respond very differently to a given chemotherapeutic regimen. We propose the development of a unique patient-derived 3D ex-vivo drug testing platform as a valid decision making tool for 2 nd or 3 rd line treatment regimens. Materials and Methods: In this ex-vivo platform freshly collected malignant pleural effusions from patients were processed for cytological diagnosis on cell blocks, using respective immune-histochemical markers. Effusions were prepared for a 96 well based 3D ex vivo assay format using the hanging drop method and a parallel 2D cell culture format. Subsequently, we compared the original cell composition of the malignant effusion with respective microtumors generated in the 3D format. Microtumors were then fixed, embedded in paraffin and processed like original cell blocks. IHC including respective markers for tumour cells such as TTF1, CDX2 and oestrogen receptor and for non-tumour cellular fractions like calretinin, CD45, and MPO were processed. Results: The microtumors generated (ranging from 300 to 500µm) retained the native tumor morphology and cellular composition, thereby presenting tumour microenvironment like conditions in this ex vivo system. These cultures contain all cellular components of a malignant effusion at the beginning. Next to cancer cells, mesothelial cells, lymphocytes and granulocytes were main constituents. Cellular ratios were measured by computerized image analysis. Both cell sediments and supernatants are amenable to profiling strategies by next generation sequencing and mass spectrometry. Conclusion: Our model presents an optimal condition to conduct chemosensitivity/-resistance profiling in individual cancer patients using standard drug combinations. Furthermore, we are currently developing an immune competent 3D model to access cancer cell interaction with surrounding immune cells. We expect that original immune cells will be quenched out during culture, thus these micro tumors can be supplemented with activated effectors in particular, T and NK cells (autologous system) to investigate novel drug combination approaches including immune-stimulating agents such as anti-PD-L1 antibodies. Citation Format: Cheng-guang Wu, Francesca Chiovaro, Tamara Tanos, Alex Soltermann, Sumeer Dhar. 3D ex-vivo assay platform using primary lung cancer cells in malignant pleural effusions as predictor for clinical outcome of personalized chemotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5780. doi:10.1158/1538-7445.AM2017-5780