Pancreatic and bile duct cancer circulating tumor cells (CTC) form immune-resistant multi-cell type clusters in the portal venous circulation

Abstract

Circulating tumor cells (CTC) enter the blood from many carcinomas and represent a likely source of metastatic dissemination. In contrast to the peripheral circulation, KRAS mutation- positive CTC thrive in the portal venous blood of patients with pancreatic ductal adenocarcinoma (PDAC). To analyze the essential interactions that contribute to carcinoma CTC growth and immune resistance, portal venous blood was collected during pancreatico-duodenectomy in 41 patients with peri-ampullary pathologies (PDAC = 11; ampullary adenocarcinoma (AA) = 15; distal cholangiocarcinoma (CC) = 6; IPMN = 7; non-malignant pancreatitis = 2). FACS-isolated cell populations from the portal circulation were reconstituted ex vivo using mixed cell reaction cultures (MCR). During the first 48hr, PDAC, AA, and CC patient CTC were all highly proliferative (mean 1.7 hr/cell cycle, 61.5% ± 20% growing cells) and resistant to apoptosis (mean 39% ± 25% apoptotic cells). PDAC CTC proliferation and resistance to T cell cytotoxicity were decreased among patients who received pre-operative chemotherapy (p = 0.0019, p = 0.0191, respectively). After 7 days in culture, CTC from PDAC, CC, and AA patients recruited multiple immune cell types, including CD105 + CD14 + myeloid fibroblasts, to organize into spheroid-like clusters. It was only in PDAC and CC-derived MCR that cluster formation promoted CTC survival, growth, and fibroblast differentiation. FACS depletion of CTC or myeloid fibroblast cells eliminated cluster network formation, and re-introduction of these cell populations reconstituted such ability. Our findings suggest that PDAC and CC CTC survival within the portal venous circulation is supported by their interactions with immune cells within multi-cell type clusters that could represent vectors of local recurrence and metastatic progression.

Diagnostic and prognostic biomarkers in cholangiocarcinoma

“…Moreover, an elevation of CTCs count over baseline, together with other circulating markers, predicted a worse overall and disease‐free survival in patients with CCA . From a biological point of view, it was hypothesized that CTCs in the bloodstream could be putatively sustained by the interaction of the tumour cells with immune cells and CD105 + CD14 + myeloid fibroblasts, and be responsible for the metastatic spread of CCA . CTCs have also been isolated from portal venous blood in patients with hepatobiliary‐pancreatic malignancies .…”

“…94 From a biological point of view, it was hypothesized that CTCs in the bloodstream could be putatively sustained by the interaction of the tumour cells with immune cells and CD105 + CD14 + myeloid fibroblasts, and be responsible for the metastatic spread of CCA. 81 CTCs have also been isolated from portal venous blood in patients with hepatobiliary-pancreatic malignancies. 95 Although mainly focusing on patients with pancreatic ductal adenocarcinoma, portal vein derived CTCs were also examined in a small subgroup of CCA patients.…”

Pancreatic Ductal Adenocarcinoma (PDAC) Organoids: The Shining Light at the End of the Tunnel for Drug Response Prediction and Personalized Medicine

“…Moreover, mesenchymal features have been observed in CTCs isolated from blood of metastatic cancer patients and these CTCs seem to display a higher metastatic potential than single migratory cells [ 106 ]. Remarkably, CTCs have also been shown to cluster with multiple immune cell types [ 107 ]. Finally, CECs were also isolated from patients with cystic lesions such as intraductal papillary mucinous neoplasia (IPMN), mucinous cystic neoplasm (MCN), and other pancreas diseases such as pancreatitis [ 108 , 109 , 110 ].…”

“…Gao et al demonstrated that organoids can be established from prostate cancer CTCs [ 112 ], and Zhang et al were able to establish lung cancer organoids using a 3D-co-culture system [ 113 ]. In pancreas, CTCs together with immune cells embedded in Matrigel were able to be co-cultured for up to 7 days [ 107 ]. Altogether, these data indicate that it is possible to isolate CTCs from PDAC.…”

Immunotherapies and Metastatic Cancers: Understanding Utility and Predictivity of Human Immune Cell Engrafted Mice in Preclinical Drug Development

“…After being disengaged from the tumor, circulating tumors cells (CTCs) can be killed by different immune cells, which can be prevented by forming multi-cellular aggregated with different immune cells and fibroblasts [35]. CTCs form aggregates with neutrophils, which causes changes in the expression profile of CTCs, favoring metastasis formation [36].…”