Joshua C Saldivar | Search PubMed

PubMed2026

Anoxia tolerant DNA replication is supported by ATR kinase in the annual killifish Austrofundulus limnaeus.

Hypoxia and anoxia suppress cell proliferation due to an increase in replication stress and activation of DNA damage checkpoints. Embryos of the annual killifish Austrofundulus limnaeus tolerate prolonged anoxia, indicating improved genomic stability under oxygen starvation. We investigated the cell cycle regulation of the anoxia tolerant killifish embryonic cell line PSU-AL-WS40NE during anoxia. Live-cell imaging confirms continued proliferation of WS40NE cells for the first 24 h of anoxia with minimal cell death. Fluorescence imaging shows that cells accumulate in G1 after the first day in anoxia with a rapid entry into S phase upon reoxygenation. Pharmacological inhibition shows a reliance on ataxia telangiectasia and Rad3 related (ATR) signaling, suggesting that increased γH2AX levels are driven by replication stress instead of DNA damage. This conclusion is supported by a lack of induction of a G2 checkpoint, suggesting minimal DNA damage during anoxic exposure. Maintaining cellular proliferation during anoxia and accumulating cells in the G1 phase for extended anoxic exposure is likely one way that embryos of the killifish can survive prolonged anoxia, which provides insight into mechanisms that enable cells to proliferate under metabolic stress.

Animals↗

PubMed2026

Liquid Biopsy Differentiation of Pancreatic Cancer From Non-Cancerous Pancreatic Disease Using Dielectrophoresis-Recovered Nanoparticles Carrying Cell-Free DNA and Protein Biomarkers.

Cancer-derived extracellular vesicle (EV) nanoparticles carry important biomarkers but are difficult to recover from plasma, making EV-based diagnostics a challenge for clinical settings. Here, we demonstrate nanoparticle-based detection of pancreatic cancer using dielectrophoresis (DEP) nanoparticle recovery technology, which purifies nanoparticles from undiluted plasma and quantifies associated biomarkers. We combined both nanoparticle recovery and biomarker quantification on a single device by simultaneously collecting cell-free DNA nanoparticles and EVs followed by on-chip biomarker fluorescent staining for DNA and Glypican-1. Using a blinded cohort, these biomarkers differentiated pancreatic cancer from benign pancreatic diseases, including cysts, pancreatitis, and precancerous low-grade intraductal papillary mucinous neoplasm (IPMN) lesions, with a sensitivity of 0.92, a specificity of 0.83, and an AUC of 0.93. The AUC increased to 0.97 for patients over 50 years old. This is higher than the standard invasive endoscopic ultrasound-guided fine needle aspiration tissue biopsy procedure (AUC 0.79). This study is among the first demonstrating a combined threshold of DNA and protein levels that can distinguish pancreatic cancer from its precursor IPMN lesions. We also demonstrated the detection of early-stage pancreatic cancer and high-grade in situ precancerous lesions. This DEP-based technique shows that multiple types of cancer-derived nanoparticles can be quickly and easily recovered from plasma making it promising for future clinical diagnostics.

Humans↗