Promoter methylation of ADAMTS1 and BNC1 as potential biomarkers for early detection of pancreatic cancer in blood
CLINICAL EPIGENETICS
Authors: Eissa, Maryam A. L.; Lerner, Lane; Abdelfatah, Eihab; Shankar, Nakul; Canner, Joseph K.; Hasan, Nesrin M.; Yaghoobi, Vesal; Huang, Barry; Kerner, Zachary; Takaesu, Felipe; Wolfgang, Christopher; Kwak, Ruby; Ruiz, Michael; Tam, Matthew; Pisanic, Thomas R.; Iacobuzio-Donahue, Christine A.; Hruban, Ralph H.; He, Jin; Wang, Tza-Huei; Wood, Laura D.; Sharma, Anup; Ahuja, Nita
Abstract
BackgroundDespite improvements in cancer management, most pancreatic cancers are still diagnosed at an advanced stage. We have recently identified promoter DNA methylation of the genes ADAMTS1 and BNC1 as potential blood biomarkers of pancreas cancer. In this study, we validate this biomarker panel in peripheral cell-free tumor DNA of patients with pancreatic cancer.ResultsSensitivity and specificity for each gene are as follows: ADAMTS1 87.2% and 95.8% (AUC=0.91; 95% CI 0.71-0.86) and BNC1 64.1% and 93.7% (AUC=0.79; 95% CI 0.63-0.78). When using methylation of either gene as a combination panel, sensitivity increases to 97.3% and specificity to 91.6% (AUC=0.95; 95% CI 0.77-0.90). Adding pre-operative CA 19-9 values to the combined two-gene methylation panel did not improve sensitivity. Methylation of ADAMTS1 was found to be positive in 87.5% (7/8) of stage I, 77.8% (7/9) of stage IIA, and 90% (18/20) of stage IIB disease. Similarly, BNC1 was positive in 62.5% (5/8) of stage I patients, 55.6% (5/9) of stage IIA, and 65% (13/20) of patients with stage IIB disease. The two-gene panel (ADAMTS1 and/or BNC1) was positive in 100% (8/8) of stage I, 88.9% (8/9) of stage IIA, and 100% (20/20) of stage IIB disease. The sensitivity and specificity of the two-gene panel for localized pancreatic cancer (stages I and II), where the cancer is eligible for surgical resection with curative potential, was 94.8% and 91.6% respectively. Additionally, the two-gene panel exhibited an AUC of 0.95 (95% CI 0.90-0.98) compared to 57.1% for CA 19-9 alone.ConclusionThe methylation status of ADAMTS1 and BNC1 in cfDNA shows promise for detecting pancreatic cancer during the early stages when curative resection of the tumor is still possible. This minimally invasive blood-based biomarker panel could be used as a promising tool for diagnosis and screening in a select subset of high-risk populations.
Structural and biochemical characterization of EDTA monooxygenase and its physical interaction with a partner flavin reductase
MOLECULAR MICROBIOLOGY
Authors: Jun, Se-Young; Lewis, Kevin M.; Youn, Buhyun; Xun, Luying; Kang, ChulHee
Abstract
Ethylenediaminetetraacetate (EDTA) is currently the most abundant organic pollutant due to its recalcitrance and extensive use. Only a few bacteria can degrade it, using EDTA monooxygenase (EmoA) to initiate the degradation. EmoA is an FMNH2-dependent monooxygenase that requires an NADH:FMN oxidoreductase (EmoB) to provide FMNH2 as a cosubstrate. Although EmoA has been identified from Chelativorans (ex. Mesorhizobium) sp. BNC1, its catalytic mechanism is unknown. Crystal structures of EmoA revealed a domain-like insertion into a TIM-barrel, which might serve as a flexible lid for the active site. Docking of MgEDTA(2-) into EmoA identified an intricate hydrogen bond network connected to Tyr(71), which should potentially lower its pKa. Tyr(71), along with nearby Glum and a peroxy flavin, facilitates a keto-enol transition of the leaving acetyl group of EDTA. Further, for the first time, the physical interaction between EmoA and EmoB was observed by ITC, molecular docking and enzyme kinetic assay, which enhanced both EmoA and EmoB activities probably through coupled channelling of FMNH2.