Exosome-shuttled bioactive long non-coding RNA, as novel non-invasive biomarkers for cancer diagnosis, has received increasing attention. Here, we aimed to investigate the expression of serum exosomal long non-coding RNA pcsk2-2:1 (Exo-Lnc RNApcsk2-2:1) in patients of gastric cancer and evaluate its diagnostic value as a marker. Patients and methods: Exosomes were isolated from serum sample of gastric cancer using HiPure Exosomekits and identified via transmission electron microscopy, Western blotting, and nanoparticle tracking analysis. The total exosomal RNA was extracted and reverse transcribed to cDNA. The expression of Exo-Lnc RNA PCSK2-2:1 was detected in serum exosomes of 29 healthy people and 63 gastric cancer patients by real-time quantitative reverse transcription PCR (qRT-PCR), and the relationship between the expression level of Exo-Lnc RNA PCSK2-2:1 and clinicopathological parameters of patients was analyzed. Finally, a receiver operating characteristic curve was used to evaluate the clinical value of Exo-Lnc RNA PCSK2-2:1 as an auxiliary diagnostic marker for gastric cancer. Results: Transmission electron microscopy, nanoparticle size analysis, and Western blotting showed successful separation of serum exosomes. qRT-PCR results revealed that compared with the healthy control, Lnc RNA PCSK2-2:1 expression level in serum exosomes of gastric cancer patients was significantly downregulated (p=0.006). Moreover, the expression level of Exo-Lnc RNA PCSK2-2:1 was correlated with tumor size (p=0.0441), tumor stage (p=0.0061), and venous invasion (p=0.0367). The area under the curve of Exo-Lnc RNA PCSK2-2:1 was 0.896. At the optimal cutoff value, the diagnostic sensitivity and specificity were 84% and 86.5%, respectively. Conclusion: Our data indicate that Exo-Lnc RNA PCSK2-2:1 may perform a vital role in the progression of gastric cancer and can be used as a potential marker for the diagnosis of gastric cancer.

Exosomes participate in cellular communications by transmitting active molecules, including long noncoding RNAs (lncRNAs) and are regarded as suitable candidates for disease diagnosis. This study aimed to identify gastric cancer (GC)-specific exosomal lncRNA and investigate the potential diagnostic value of plasma exosomal lncRNA in GC. Patients and Methods: Exosomes from the culture media (CM) of four GC cells (GCCs) and human gastric epithelial cells were isolated. Exosomal RNA was extracted, and lncRNA microarray assay was performed to identify GC-specific exosomal lncRNAs. The expression levels of the candidate exosomal lncRNAs were validated in 120 subjects via quantitative reverse transcription PCR (qRT-PCR). The receiver operating characteristic (ROC) curve and area under curve were used to estimate the diagnostic capacity. We investigated the potential relationship between plasma exosomal lncRNA expression and the clinicopathological parameters of GC. Results: A total of 199 exosomal lncRNAs were expressed at considerable higher levels in GCCs than those in normal controls, among which the top 10 upregulated lncRNAs were selected for further validation in cell, CM, and plasma. qRT-PCR revealed that lnc-SLC2A12-10:1 was remarkably upregulated in exosomes derived from patients with GC and GCCs. The area under the ROC curve was 0.776, which was higher than the diagnostic accuracies of CEA, CA 19-9, and CA72-4. The expression level of exosomal lnc-SLC2A12-10:1 was also significantly correlated with tumor size, TNM stage, lymph node metastasis, and degree of differentiation. The postoperative expression levels of exosomal lnc-SLC2A12-10:1 were lower compared with those of preoperative levels. Conclusion: Our study suggested that exosomal lnc-SLC2A12-10:1 may be a potential noninvasive biomarker for the diagnosis and prognosis monitoring of GC. Further large-scale studies are necessary to validate its performance in GC progression.

Introduction Microscopy has been recognized as the “gold‐standard” cellular analysis of serous cavity effusion. However, this method is time‐consuming, labor‐intensive, and requires accomplished skills. Here, we investigated the efficiency of hematology analyzer in screening malignant cells in serous cavity effusion. Methods A total of 991 serous cavity effusion samples and 370 validation specimens collected from different departments were sent to the clinical laboratory for routine cell count using the automated hematology body fluid (BF) mode and exfoliative cytology simultaneously. High‐fluorescent cells (HFCs) were measured as the relative count (HF%) and absolute count (HF#) by BF mode. Receiver operating characteristic curve analysis was combined with scattergram rules to screen malignant cells. Results HF# and HF% in malignant samples (subgroup) were significantly higher than those in benign samples, and the HF# and HF% levels were different between ascites and pleural effusion (PE). The area under the curve values were also different between ascites and PE. Positive of malignant cells was very high when the ascites or PE sample touching Rule 1 positive and either Rule 2 negative or positive. The cutoff levels of HF# were 5.5 HFC/μL on the basis of Rules 1 and 2 negative, whereas 83.5 HFC/μL on the basis of Rule 1 negative but Rule 2 positive in ascites. By contrast, the cutoff levels of HF% were 0.55 HFC/100 WBC on the basis of Rules 1 and 2 negative, whereas 4.95 HFC/100 WBC on the basis of Rule 1 negative but Rule 2 positive in PE. Conclusions Serous cavity effusion will be increasingly analyzed using the automated hematology analyzer BF mode in the future because of its rapidness and convenience. The combined application of HFC with scattergram rules is a feasible and useful approach to screen malignant cells in serous cavity effusion.

Objectives This study aimed to evaluate the effectiveness and efficiency of competency-oriented clinical laboratory teaching combined with case-based learning (CBL) and improve the examination of students’ competence of laboratory medicine. Methods A total of 107 medical laboratory medicine interns at the Affiliated Hospital of Xuzhou Medical University from June 2017 to July 2019 volunteered to participate in the study and were randomly assigned into a control group with training of the traditional teacher-centered method, and an experimental group under a CBL teaching program. Student basic theory tests and skill assessment were designed to evaluate what the students gained from their internship when they completed their studies at the Affiliated Hospital of Xuzhou Medical University. Results Compared to students in the control group taught with the teacher-centered method, those in the CBL teaching program had significantly higher theory test scores and skill assessment scores on average. Competencies with particularly significant improvement included identification and processing of instrument alarm information, analysis of test results, identification and solution of the problem, as well as identification and reporting of the critical value and clinical communication. Conclusions The competency-oriented teaching method combined with CBL is an effective method for improving students’ professional knowledge, increasing language expression, and enhancing interpersonal relationship and teamwork, which is worthy of being promoted in laboratory medicine teaching.

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