Title: Predictive and Functional Evaluation of Patients derived Tumor Spheroids and Organoids-Investigating the Relationship between Size and Testing Performance

Abstract:

Pancreatic Cancer has proven to be one of the most severe forms of cancer with the worst anticipated prognosis. Mortality due to pancreatic cancer is expected to surpass that of breast and colorectal cancer combined by 2030 due to several reasons including aging, the advanced stage when pancreatic cancer is detected in patients, lack of effective treatment strategy, particularly in Pancreatic Ductal Adeno Carcinoma PDAC cases. PDAC contributes to more than 7 % of cancer-associated deaths worldwide with an overall survival rate of 8.5% for 6-11 months only in patients with advanced stages of the disease. Pathological, genomic, and clinical studies on PDAC patients have shown three different progressive forms of the disease Pancreatic Intraepithelial Neoplasia PanINs, Intraductal Mucinous Papillary Neoplas IPMN, and Pancreatic Mucinous Cystic Neoplasm MCN which all express different stages of epithelial dysplasia, lobulocentric atrophy and ductal metaplasia. Treatment options for PDAC sound to be very limited and mostly include combined chemotherapy with gemcitabine/nab-paclitaxel together with surgical interference. Activation of KRAS oncogene via single point mutation in codon 12, inactivation of tumor suppressor genes CDKN2A, TP53, SMAD4 and R1 and RII receptors of TGF-B, and activation of certain signaling pathways that include NFKB, STAT3, and SRC were found to be characteristic for PanINs and its progression to PDAC. Patient-derived xenografts PDXs have been validated as an effective tool to study PDAC but they required a large number of tissues and a longer time to generate. However, Genetically Engineered Mouse Models GEMMs were found to be more precisely recapitulating the pathophysiological features of human PDA across different stages of the disease progression. Previous studies have shown that both human PDA and GEMMs share common histological features including extensive stromal structure, diminished vasculature infiltration, and less neoplastic cellularity content. This makes PDA patient-derived organoids and spheroids more difficult to culture as the limited amount of epithelium-derived cancer cells are available to isolate. While 2D culture conditions couldn't support the growth of normal or untransformed non-neoplastic pancreatic cells, 3D cultures were found to support both normal and transformed cells but otherwise allowed minimal propagation.