Effects of stereochemistry, saturation, and hydrocarbon chain length on the ability of synthetic constrained azacyclic sphingolipids to trigger nutrient transporter down-regulation, vacuolation, and cell death.

Constrained analogs containing a 2-hydroxymethylpyrrolidine core of the natural sphingolipids sphingosine, sphinganine, N,N-dimethylsphingosine and N-acetyl variants of sphingosine and sphinganine (C2-ceramide and dihydro-C2-ceramide) were synthesized and evaluated for their ability to down-regulate nutrient transporter proteins and trigger cytoplasmic vacuolation in mammalian cells. In cancer cells, the disruptions in intracellular trafficking produced by these sphingolipids lead to cancer cell death by starvation. Structure activity studies were conducted by varying the length of the hydrocarbon chain, the degree of unsaturation and the presence or absence of an aryl moiety on the appended chains, and stereochemistry at two stereogenic centers. In general, cytotoxicity was positively correlated with nutrient transporter down-regulation and vacuolation. This study was intended to identify structural and functional features in lead compounds that best contribute to potency, and to develop chemical biology tools that could be used to isolate the different protein targets responsible for nutrient transporter loss and cytoplasmic vacuolation. A molecule that produces maximal vacuolation and transporter loss is expected to have the maximal anti-cancer activity and would be a lead compound

Consequences of anastomotic leaks after minimally invasive esophagectomy: A single-center experience

Background: Anastomotic leak (AL) after minimally invasive esophagectomy (MIE) is a well-described source of morbidity for patients undergoing surgical treatment of esophageal neoplasm. With improved early recognition and endoscopic management techniques, the long-term impact remains unclear. Methods: A retrospective review was conducted of patients who underwent MIE for esophageal neoplasm between January 2015 and June 2021 at a single institution. Cohorts were stratified by development of AL and subsequent management. Baseline demographics, perioperative data, and post-operative outcomes were examined. Results: During this period, 172 MIEs were performed, with 35 of 172 (20.3%) complicated by an AL. Perioperative factors independently associated with AL were post-operative blood transfusion (leak rate 52.9% versus 16.8%; p = 0.0017), incompleteness of anastomotic rings (75.0% vs 19.1%; p = 0.027), and receiving neoadjuvant therapy (18.5% vs 30.8%; p < 0.0001). Inferior short-term outcomes associated with AL included number of esophageal dilations in the first post-operative year (1.40 vs 0.46, p = 0.0397), discharge disposition to a location other than home (22.9% vs 8.8%, p = 0.012), length of hospital stay (17.7 days vs 9.6 days; p = 0.002), and time until jejunostomy tube removal (134 days vs 79 days; p = 0.0023). There was no significant difference in overall survival between patients with or without an AL at 1 year (79% vs 83%) or 5 years (50% vs 47%) (overall log rank p = 0.758). Conclusions: In this large single-center series of MIEs, AL was associated with inferior short-term outcomes including hospital length of stay, discharge disposition other than to home, and need for additional endoscopic procedures, without an accompanying impact on 1-year or 5-year survival. Key message: In this large, single-center series of minimally invasive esophagectomies, anastomotic leak was associated with worse short-term outcomes including hospital length of stay, discharge disposition other than to home, and need for additional endoscopic procedures, but was not associated with worse long-term survival. The significant association between neoadjuvant therapy and decreased leak rates is difficult to interpret, given the potential for confounding factors, thus careful attention to modifiable pre- and peri-operative patient factors associated with anastomotic leak is warranted