(F-210) Novel Drug Tomatidine Increases Chemosensitivity of Standard-of-care Gemcitabine In 3D Pancreatic Tumor Organoids

Introduction:: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a five-year survival rate of only 11%. Standard-of-care chemotherapy includes administering Gemcitabine. Other forms of chemotherapy are often ineffective owing to immune suppression. Also, there is a shortage of 3D in-vitro models with which to replicate and study the chemotherapeutic effects of these drugs. Moreover, tumor architecture and microenvironment also dictate the extent of chemotherapeutic success.
Tomatidine is a novel tomato-based alkaloid which can inhibit the often-upregulated Activating Transcription Factor 4 (ATF4)-dependent signaling in various diseases. This study uses Tomatidine, with and without gemcitabine, to evaluate response in 3D PDAC organoids as compared to traditional 2D and murine models.

Materials and Methods:: Organoids were made with a methacrylated collagen type I- thiolated hyaluronic acid-based hydrogel and, using murine and human pancreatic tumor cell lines (MT5 and Panc1 respectively). In a small conical tube, 52 μL of the collagen are mixed with 18.76 μL of the hyaluronic acid. To this, 4.41 μL of neutralizing solution (for photo-collagen) are added as well as the cells. From this resulting mixture, cells are pipetted onto each well of a 24-well plate and photopolymerized in place via a brief UV light pulse to initiate cross-linking of the hydrogel. The organoids were then treated with several concentrations of Tomatidine and Gemcitabine, as well as a combinational dose of the two drugs. Cell viability was measured using ATP and live-dead viability/cytotoxicity assays.

Results, Conclusions, and Discussions:: With respect to day 4 (D4), in the control or ‘no drug’ condition, the pancreatic cancer cell morphology is visible. 7 μg/mL (lowest concentration of tomatidine used), equivalent to the 2D IC50 dosage, was not enough to cause similar chemotherapeutic effects in the 3D models used, suggesting that a much higher dosage is needed to affect cell growth in 3D. Also, cell viability was lowest in the organoids treated with the combinational drug dose. Here, in comparison to the tomatidine alone, there are more spatial gaps within the cellular architecture in addition to the high number of dead cells. Therefore, tomatidine can augment gemcitabine chemosensitivity and provide stronger response.

Acknowledgements (Optional): : The James Cancer Centre and Solove Research Institute (OSUCCC), The National Pancreas Foundation, The Pelotonia Scholars Program

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