Kayvan Mohkam

BACKGROUND: Liver transplantation (LT) from controlled donation after circulatory death (cDCD) was initiated in France in 2015 under a protocol based on the use of normothermic regional perfusion (NRP) before organ procurement. The aim was to compare outcomes following cDCD LT with NRP and donation after brain death (DBD) LT. METHODS: This is a multicenter retrospective study comparing cDCD LT with NRP and DBD LT. A case-matched study (1:2) was performed using the variables such as recipient and donor age, indication of LT. RESULTS: A total of 50 patients from the cDCD group were matched to 100 patients from the DBD group. From postoperative days 1-4, serum transaminase release was significantly lower in the cDCD group compared to the DBD group (P < 0.05). Early allograft dysfunction (cDCD: 18% versus DBD: 32%; P = 0.11), acute kidney injury (26% versus 33%; P = 0.49), 90-d graft loss (2% versus 5%; P = 0.66), and arterial (4% versus 12%; P = 0.19) and biliary (16% versus 17%; P = 0.94) complications were similar between the 2 groups. The 2-y graft survival was 88% for cDCD group and 85% for DBD group (P = 0.91). The 2-y patient survival was 90% for cDCD group and 88% for DBD group (P = 0.68). CONCLUSIONS: This study provides evidence that cDCD LT following postmortem NRP can be safely and effectively performed in selected recipients with similar graft and patient survival outcomes, without increased rates of biliary complications and early graft dysfunction compared to DBD LT.

Pancreatic ductal adenocarcinoma (PDAC) is one of the solid tumors with the poorest prognosis. The stroma of this tumor is abundant and composed of extracellular matrix and stromal cells (including cancer-associated fibroblasts and immune cells). Nerve fibers invading this stroma represent a hallmark of PDAC, involved in neural remodeling, which participates in neuropathic pain, cancer cell dissemination and tumor relapse after surgery. Pancreatic cancer-associated neural remodeling is regulated through functional interplays mediated by physical and molecular interactions between cancer cells, nerve cells and surrounding Schwann cells, and other stromal cells. In the present study, we show that Schwann cells (glial cells supporting peripheral neurons) can enhance aggressiveness (migration, invasion, tumorigenicity) of pancreatic cancer cells in a transforming growth factor beta (TGFβ)-dependent manner. Indeed, we reveal that conditioned medium from Schwann cells contains high amounts of TGFβ able to activate the TGFβ-SMAD signaling pathway in cancer cells. We also observed in human PDAC samples that high levels of TGFβ signaling activation were positively correlated with perineural invasion. Secretome analyses by mass spectrometry of Schwann cells and pancreatic cancer cells cultured alone or in combination highlighted the central role of TGFβ in neuro-epithelial interactions, as illustrated by proteomic signatures related to cell adhesion and motility. Altogether, these results demonstrate that Schwann cells are a meaningful source of TGFβ in PDAC, which plays a crucial role in the acquisition of aggressive properties by pancreatic cancer cells.

OBJECTIVE: To compare HOPE and NRP in liver transplantation from cDCD. SUMMARY OF BACKGROUND DATA: Liver transplantation after cDCD is associated with higher rates of graft loss. Dynamic preservation strategies such as NRP and HOPE may offer safer use of cDCD grafts. METHODS: Retrospective comparative cohort study assessing outcomes after cDCD liver transplantation in 1 Swiss (HOPE) and 6 French (NRP) centers. The primary endpoint was 1-year tumor-death censored graft and patient survival. RESULTS: A total of 132 and 93 liver grafts were transplanted after NRP and HOPE, respectively. NRP grafts were procured from younger donors (50 vs 61 years, P < 0.001), with shorter functional donor warm ischemia (22 vs 31 minutes, P < 0.001) and a lower overall predicted risk for graft loss (UK-DCD-risk score 6 vs 9 points, P < 0.001). One-year tumor-death censored graft and patient survival was 93% versus 86% (P = 0.125) and 95% versus 93% (P = 0.482) after NRP and HOPE, respectively. No differences in non-anastomotic biliary strictures, primary nonfunction and hepatic artery thrombosis were observed in the total cohort and in 32 vs. 32 propensity score-matched recipients CONCLUSION:: NRP and HOPE in cDCD achieved similar post-transplant recipient and graft survival rates exceeding 85% and comparable to the benchmark values observed in standard DBD liver transplantation. Grafts in the HOPE cohort were procured from older donors and had longer warm ischemia times, and consequently achieved higher utilization rates. Therefore, randomized controlled trials with intention-to-treat analysis are needed to further compare both preservation strategies, especially for high-risk donor-recipient combinations.

TGF-β signaling is involved in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis, representing one of the four major pathways genetically altered in 100% of PDAC cases. TGF-β exerts complex and pleiotropic effects in cancers, notably via the activation of SMAD pathways, predominantly SMAD2/3/4. Though SMAD2 and 3 are rarely mutated in cancers, SMAD4 is lost in about 50% of PDAC, and the role of SMAD2/3 in a SMAD4-null context remains understudied. We herein provide evidence of a SMAD2/3 oncogenic effect in response to TGF-β1 in SMAD4-null human PDAC cancer cells. We report that inactivation of SMAD2/3 in SMAD4-negative PDAC cells compromises TGF-β-driven collective migration mediated by FAK and Rho/Rac signaling. Moreover, RNA-sequencing analyses highlight a TGF-β gene signature related to aggressiveness mediated by SMAD2/3 in the absence of SMAD4. Using a PDAC patient cohort, we reveal that SMAD4-negative tumors with high levels of phospho-SMAD2 are more aggressive and have a poorer prognosis. Thus, loss of SMAD4 tumor suppressive activity in PDAC leads to an oncogenic gain-of-function of SMAD2/3, and to the onset of associated deleterious effects.