Multiplex Enrichment and Detection of Rare KRAS Mutations in Liquid Biopsy Samples using Digital Droplet Pre-Amplification.

Oncology research is increasingly incorporating molecular detection of circulating tumor DNA (ctDNA) as a tool for cancer surveillance and early detection. However, noninvasive monitoring of conditions with low tumor burden remains challenging, as the diagnostic sensitivity of most ctDNA assays is inversely correlated with total DNA concentration and ctDNA abundance. Here we present the Multiplex Enrichment using Droplet Pre-Amplification (MED-Amp) method, which combines single-molecule emulsification and short-round polymerase chain reaction (PCR) preamplification with digital droplet PCR detection of mutant DNA template. The MED-Amp assay increased mutant signal by over 50-fold with minimal distortion in allelic frequency. We demonstrate detection of as few as three mutant copies in wild-type DNA concentrations ranging from 5 to 50 ng. The MED-Amp assay successfully detected KRAS mutant ctDNA in 86% plasma samples obtained from patients with metastatic pancreatic ductal adenocarcinoma. This assay for high-sensitivity rare variant detection is appropriate for liquid biopsy samples or other limited clinical biospecimens.

Multisite Culinary Medicine Curriculum Is Associated With Cardioprotective Dietary Patterns and Lifestyle Medicine Competencies Among Medical Trainees.

Background. Adherence to Mediterranean dietary patterns reduces the incidence of cardiovascular disease and other major chronic diseases. We aimed to assess the association between participation in kitchen-based nutrition education and Mediterranean diet intake and lifestyle medicine counseling competencies among medical trainees. Methods. The Cooking for Health Optimization with Patients (CHOP) curriculum is a hands-on cooking-based nutrition education program implemented at 32 medical programs (4125 medical trainees) across the United States. Mediterranean diet intake, nutrition attitudes, and lifestyle medicine counseling competencies were assessed via validated surveys. Multivariable-adjusted logistic regression assessed the relationship of CHOP education with Mediterranean diet intake, nutrition attitudes, and lifestyle medicine counseling competencies. Results. Individuals participating in the CHOP program were 82% more likely to follow the Mediterranean diet compared with those receiving traditional nutrition education (OR = 1.82; P < .001). CHOP participants were more likely to satisfy daily intake of fruits (OR = 1.33; P = .019) and vegetables (OR = 2.06; P < .001) and agree that nutrition counseling should be a routine component of clinical care (OR = 2.43; P < .001). Kitchen-based nutrition education versus traditional curricula is associated with a higher likelihood of total counseling competency involving 25 lifestyle medicine categories (OR = 1.67; P < .001). Conclusion. Kitchen-based nutrition education is associated with cardioprotective dietary patterns and lifestyle medicine counseling among medical trainees.

GM-CSF Mediates Mesenchymal-Epithelial Cross-talk in Pancreatic Cancer.

UNLABELLED: Pancreatic ductal adenocarcinoma (PDA) is characterized by a dense stroma consisting of a prevalence of activated fibroblasts whose functional contributions to pancreatic tumorigenesis remain incompletely understood. In this study, we provide the first identification and characterization of mesenchymal stem cells (MSC) within the human PDA microenvironment, highlighting the heterogeneity of the fibroblast population. Primary patient PDA samples and low-passage human pancreatic cancer-associated fibroblast cultures were found to contain a unique population of cancer-associated MSCs (CA-MSC). CA-MSCs markedly enhanced the growth, invasion, and metastatic potential of PDA cancer cells. CA-MSCs secreted the cytokine GM-CSF that was required for tumor cell proliferation, invasion, and transendothelial migration. Depletion of GM-CSF in CA-MSCs inhibited the ability of these cells to promote tumor cell growth and metastasis. Together, these data identify a population of MSCs within the tumor microenvironment that possesses a unique ability, through GM-CSF signaling, to promote PDA survival and metastasis. SIGNIFICANCE: The role of stroma in pancreatic cancer is controversial. Here, we provide the first characterization of MSCs within the human PDA microenvironment and demonstrate that CA-MSCs promote tumorigenesis through the production of GM-CSF. These data identify a novel cytokine pathway that mediates mesenchymal-epithelial cross-talk and is amenable to therapeutic intervention. Cancer Discov; 6(8); 886-99. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 803.