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A multistep sorting method for enrichment of rare cells, such as circulating tumor cells, in the blood without cumbersome pretreatments required by most flow cytometry-based methods, which lead to high cost and decreased detection efficiency, was developed.After only hemolysis and cell staining, cancer cells are enriched by repetitive sorting (3×) based on nuclear-positive, cytokeratin-positive, and CD45-negative expression.Experiments using spikes of PC-9 cells showed a mean recovery of 65% and mean purity of 83%, which was retained up to 72 hours after blood draw using preservative tubes. Significant differences in expression level of programmed death-ligand 1 or vimentin were observed between high- and low-expressing cell lines, concurrently with enrichment. Next-generation sequencing analysis of recovered PC-9, A549, and MDA-MB231 cells successfully detected all known mutations.This novel isolation method applicable for preserved samples with sufficient recovery and purity may be substantially beneficial for recovering cells for subsequent molecular analysis.

Background/aim To explore the safety of osimertinib plus ramucirumab in patients with EGFR-mutated lung adenocarcinoma. Patients and methods Six advanced lung adenocarcinoma patients with EGFR mutation were treated with osimertinib 80 mg/day plus ramucirumab 10 mg/kg, every two weeks. Defined dose-limiting toxicity (DLT) was assessed within the first two treatment cycles. Results Of those enrolled, five patients had both EGFR exon 20 T790M mutation and sensitizing mutation. DLT was observed in one patient (grade 3 appetite loss). During the entire period, no other severe adverse event was observed. Five patients showed partial response and one disease progression. Median progression-free survival for patients with EGFR T790M was 9.2 months. In an exploratory analysis, changes of cell-free DNA at 2 weeks predicted radiological tumor responses. Conclusion The safety results of osimertinib plus ramucirumab in Japanese lung adenocarcinoma patients with EGFR mutation will lead to further efficacy investigation.

Background/aim Molecular targeted agents have been successfully developed against solid tumors and their use is also being investigated for the treatment of malignant pleural mesothelioma (MPM). We have previously reported von Hippel Lindau (VHL) mutations detected by massive parallel sequencing technology in samples of patients with MPM. Here, we conducted an in vitro study to investigate the therapeutic approaches in VHL-mutant MPM. Materials and methods Three MPM cell lines with or without a VHL mutation were used and the effects of molecular-targeted agents on growth inhibition were evaluated. Based on the characteristics of the molecular targeted agents that exhibited growth inhibitory effect, the effects of knockdown by siRNA were also evaluated. Results NCI-H28 MPM cells harboring the VHL L89H mutation were sensitive to YC-1, known as an inhibitor of hypoxia inducible factor (HIF)-1α, and YC-1treatment induced massive apoptosis in a dose-and-time-dependent manner. Knockdown of HIF-1α by siRNA partially inhibited the growth of NCI-H28 cells, suggesting that an additional blockade may be required to completely inhibit growth signaling. Conclusion The VHL mutation may predict tumor responses to YC-1, a HIF-1α inhibitor.