Single patient classifier as a prognostic biomarker in pT1N1 gastric cancer:Results from two large Korean cohorts

Objective:Benefits of adjuvant treatment in pT1 N1 gastric cancer(GC)remain controversial.Additionally,an effective biomarker for early GC is the need of the hour.The prognostic and predictive roles of single patient classifier(SPC)were validated in stageⅡ/ⅢGC.In this study,we aimed to elucidate the role of SPC as a biomarker for pT1 N1 GC.Methods:The present retrospective biomarker study(NCT03485105)enrolled patients treated for pT1 N1 GC between 1996 and 2012 from two large hospitals(the Y cohort and S cohort).For SPC,mRNA expression of four classifier genes(GZMB,WARS,SFRP4 and CDX1)were evaluated by real-time reverse transcription-polymerase chain reaction assay.The SPC was revised targeting pT1 stages and the prognosis was stratified as high-and lowrisk group by the expression of SFRP4,a representative epithelial-mesenchymal transition marker.Results:SPC was evaluated in 875 patients(n=391 and 484 in the Y and S cohorts,respectively).Among 864 patients whose SPC result was available,41(4.7%)patients experience GC recurrence.According to revised SPC,254(29.4%)patients were classified as high risk[123(31.5%)and 131(27.1%)in the Y and S cohorts,respectively].The high risk was related to frequent recurrence in both Y and S cohort(log-rank P=0.023,P<0.001,respectively),while there was no difference by GZMB and WARS expression.Multivariable analyses of the overall-cohort confirmed the high risk of revised SPC as a significant prognostic factor[hazard ratio(HR):4.402(2.293-8.449),P<0.001]of GC.A significant difference was not detected by SPC in the prognosis of patients in the presence and absence of adjuvant treatment(log-rank P=0.670).Conclusions:The present study revealed the revised SPC as a prognostic biomarker of pT1 N1 GC and suggested the use of the revised SPC for early-stage GC as like stageⅡ/Ⅲ.

Fluorescent nanoswitch for monitoring specific pluripotency-related microRNAs of induced pluripotent stem cells： Development of polyethyleneimine- oligonucleotide hybridization probes

The isolation of high-grade （i.e. high-pluripotency） human induced pluripotent stem cells （hiPSCs） is a decisive factor for enhancing the purity of hiPSC populations or differentiation efficiency. A non-invasive imaging system that can monitor microRNA （miRNA） expression provides a useful tool to identify and analyze specific cell populations. However, previous studies on the monitoring/isolation of hiPSCs by miRNA expression have limited hiPSCs＇ differentiation system owing to long-term incubation with miRNA imaging probe-nanocarriers. Therefore, we focused on monitoring high-grade hiPSCs without influencing the pluripotency of hiPSCs. We reduced nanoparticle transfection time, because hiPSCs are prone to spontaneous differentiation under external factors during incubation. The fluorescent nanoswitch （＂ON＂ with target miRNA）, which can be applied for either imaging or sorting specific cells by fluorescence signals, contains an miRNA imaging probe （miP） and a PEI-PEG nanoparticle （miP-P）. Consequently, this nanoswitch can sense various endogenous target miRNAs within 30 min in vitro, and demonstrates strong potential for not only imaging but also sorting pluripotent hiPSCs without affecting pluripotency. Moreover, miP-P-treated hiPSCs differentiate well into endothelial cells, indicating that miP-P does not alter the pluripotency of hiPSCs. We envisage that this miRNA imaging system could be valuable for identifying and sorting high-grade hiPSCs for improved practical applications.