Objective To explore the correlation between serum lipoprotein-related phospholipase A2 (Lp-PLA2), cystatin C (Cys-C) levels and disease severity in patients with hepatitis B cirrhosis (HBC). Methods Clinical data of 110 HBC patients in the hospital from October 2017 to May 2019 were retrospectively analyzed. According to Child-Pugh classification criteria of liver cirrhosis, they were divided into grade A (n=42), grade B (n=37) and grade C groups (n=31). Another 30 healthy controls during the same period were enrolled as control group. The levels of serum Lp-PLA2 and Cys-C were detected. And their correlation with disease severity was analyzed. Results Levels of serum Lp-PLA2 and Cys-C in HBC group were higher than those in control group (P<0.05). The levels of serum Lp-PLA2 and Cys-C were the highest in grade C group, followed by grade B group and grade A group (P<0.05). The areas under the ROC curve (AUC) of serum Lp-PLA2 combined with Cys-C for evaluating grade A and B, grade B and C HBC were 0.875 and 0.837, which were higher than those of Lp-PLA2 (0.772, 0.750) and Cys-C (0.750, 0.691) alone (P<0.05). Spearmann rank correlation analysis showed that levels of serum Lp-PLA2 and Cys-C were positively correlated with disease severity (r=0.659, 0.561, P<0.05). Conclusion The levels of serum Lp-PLA2 and Cys-C are significantly increased in HBC patients, which are gradually increased with the aggravation of HBC. The two indexes are positively correlated with disease severity, which are of diagnostic efficiency for the classification of liver cirrhosis.

Objective: To investigate the role of exosome (EXO) transporting Let-7a to regulate MYC gene in the malignant biological behaviors of triple negative breast cancer (TNBC) cell, and to explore the underlying mechanism. Methods: After the completion of cell culture, the gene and protein expressions of MYC and Let-7a in TNBC MDA-MB-231cells were detected by qPCR and WB, respectively. Recombinant lenti-virus vector carrying Let-7a and Crisper/Cas-9 system with MYC knockdown were transfected into MDA-MB-231 cells; MTT assay, Transwell assay and Scratch healing assay were performed to examine the proliferation, invasion and migration of MDA-MB-231 cells. Luciferase activity assay was performed to validate the binding between MYC and Let-7a. EXO was isolated and identified by transmission electron microscopy and WB assay in wild-type and Let-7a over-expressed MDA-MB-231 cells, respectively. After co-incubation of two types of EXO and MDA-MB-231 cells, the effects of Let-7a on biological behaviors of MDAMB-231 cells via EXO were detected by qPCR, WB, MTT and Transwell etc. Results: Let-7a was negatively correlated with MYC in breast cancer tissues and cell lines (all P<0.05); MYC promoted while Let-7a inhibited the proliferation, migration and invasion of breast cancer cells (all P<0.01); Let-7a silenced MYC by acting on 3'UTR of MYC gene, thereby reducing the expression of MYC protein (P<0.05); Let-7a was enveloped by EXO and transported to cancer cells, there by inhibiting the proliferation, migration and invasion of MDA-MB-231 cells. Conclusion: EXO some mediated Let-7a silences MYC gene by acting on its 3'UTR region, thus inhibiting the proliferation, migration and invasion of MDA-MB-231 cells.