title: Detection of mutant KRAS and TP53 DNA in circulating exosomes from healthy individuals and patients with pancreatic cancer.
abstract: Pancreatic cancer presents with a dismal mortality rate and is in urgent need of methods for early detection with potential for timely intervention. All living cells, including cancer cells, generate exosomes. We previously discovered double stranded genomic DNA in exosomes derived from the circulation of pancreatic cancer patients, which enabled the detection of prevalent mutations associated with the disease. Here, we report a proof-of-concept study that demonstrates the potential clinical utility of circulating exosomal DNA for identification of KRASG12Dand TP53R273Hmutations in patients with pancreas-associated pathologies, including pancreatic ductal adenocarcinoma (PDAC), chronic pancreatitis (CP) and intraductal papillary mucinous neoplasm (IPMN), and in healthy human subjects. In 48 clinically annotated serum samples from PDAC patients, digital PCR analyses of exosomal DNA identified KRASG12Dmutation in 39.6% of cases, and TP53R273Hmutation in 4.2% of cases. KRASG12Dand TP53R273Hmutations were also detected in exosomal DNA from IPMN patients (2 out of 7 with KRASG12D, one of which also co-presented with TP53R273Hmutation). Circulating exosomal DNA in 5 out of 9 CP patients enabled the detection of KRASG12Dmutation. In 114 healthy subject-derived circulating exosomal DNA, 2.6% presented with KRASG12Dmutation and none with TP53R273Hmutation. This study highlights the value of circulating exosomal DNA for a rapid, low-cost identification of cancer driving mutations. The identification of mutations in IPMN patients and healthy subjects suggests that liquid biopsies may allow potential assessment of cancer risk but with a cautionary note that detection of clinical cancer cannot be assumed.
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Sujuan
authors.initials: S
authors.lastname: Yang
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Sara P Y
authors.initials: SP
authors.lastname: Che
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Kurywchak
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Jena L
authors.initials: JL
authors.lastname: Tavormina
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Liv B
authors.initials: LB
authors.lastname: Gansmo
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Pedro
authors.initials: P
authors.lastname: Correa de Sampaio
authors.affiliation: b Department of General , Visceral and Thoracic Surgery, University Medical Center of Hamburg-Eppendorf , Hamburg , Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Tachezy
authors.affiliation: b Department of General , Visceral and Thoracic Surgery, University Medical Center of Hamburg-Eppendorf , Hamburg , Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Bockhorn
authors.affiliation: b Department of General , Visceral and Thoracic Surgery, University Medical Center of Hamburg-Eppendorf , Hamburg , Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Gebauer
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Haltom
authors.affiliation: c Instituto de Investigação e Inovação em Saúde, Universidade do Porto , Porto , Portugal (I3S).|d Institute of Pathology and Molecular Immunology of the University of Porto (IPATIMUP) , Porto , Portugal.
authors.forename: Sonia A
authors.initials: SA
authors.lastname: Melo
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Valerie S
authors.initials: VS
authors.lastname: LeBleu
authors.affiliation: a Department of Cancer Biology , Metastasis Research Center, University of Texas MD Anderson Cancer Center , Houston , TX , USA.
authors.forename: Raghu
authors.initials: R
authors.lastname: Kalluri
mesh_terms: D016022:Case-Control Studies; D045744:Cell Line, Tumor; D004247:DNA / Q000097:blood / Q000235:genetics*; D004273:DNA, Neoplasm / Q000097:blood / Q000235:genetics*; D055354:Exosomes / Q000235:genetics*; D006801:Humans; D009154:Mutation; D010190:Pancreatic Neoplasms / Q000097:blood / Q000235:genetics* / Q000473:pathology; D016133:Polymerase Chain Reaction / Q000379:methods; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; C117307:KRAS protein, human; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D004247:DNA; D016283:Proto-Oncogene Proteins p21(ras)
keywords: Circulating exosomal DNA; KRAS; TP53; digital PCR; exosome; liquid biopsy; pancreatic cancer