Objective To analyze the differences in microRNA (miRNA) expression between A549 and A549/DDP cells and explore the association between miRNA expression and drug resistance in non-small cell lung cancer (NSCLC).Methods The drug resistance of A549/DDP cells was evaluated using CCK-8 assay and flow cytometry.Microarray technique and RT-PCR were used to analyze the differential expression of the miRNA between A549 and A549/DDP cells.Enforced or inhibited target miRNA expression in cisplatin resistant cell was used to investigate whether miRNA involve in modulating the sensitivity of NSCLC cells to chemotherapeutic agent,exploiting the emerging knowledge of miRNA for the development of new human therapeutic applications for overcoming anticancer drug resistance and trying to discover biomarkers that were better able to predict the cancer chemotherapy sensitivity.Results The drug resistance index of A549/DDP cells relative to the parental A549 cells was 18.Microarray analysis of A549 and A549/DDP cells identified 51 differentially expressed genes (≥4-fold),including 24 up-regulated and 27 down-regulated genes in A549/DDP cells.RT-PCR identified 9 miRNA that were differentially expressed between A549 and A549/DDP cells.Of these differentially expressed miRNA,miR-376c,miR-31,miR-29a,miR-221 showed significantly increased expression,and miR-196a,miR-20a,miR-20b,miR-17,miR-451 showed significantlylowered expression in A549/DDP cells as indicated by the results of microarray analysis and RT-PCR.DDP sensitivity was increased 11.7 ％ in A549/DDP cells transfected with miR-17,but the chemosensitivity was decreased when miR-451 was over-expressed or miR-29a was inhibited by selective inhibitor,the reduction was 15.5 ％,12.9 ％,respectively,whereas chemosensitivity did not change when miR-376c,miR-31,miR-221 were inhibited or miR-196a,miR-20b,miR-20a were over-expressed.Conclusion A549/DDP cells show a different miRNA expression profile from its parental A549 cells,suggesting the involvement of miRNA in tumor cell drug resistance.miR-17 has the potential to be an efficient agent for preventing and reversing DDP-resistance in NSCLC.These results provide a strong rationale for the development of miRNA-based therapeutic strategies aiming to overcome cancer cell resistance.

Objective To detect the expressions of nm23-H1 and heat shock protein 27 (HSP27) and their clinical significance on development and metastasis in non-small cell lung carcinoma (NSCLC).Methods 75 tumor tissues from patients with NSCLC were included as experimental group and 28 pulmonary benign lesion tissues were as control group.The expressions of nm23-H1 and HSP27 in patients with different clinical and pathological characters were detected by immunohistochemistry.Results nm23-H1 and HSP27 were mainly expressed in cytoplasm,the positive rates of nm23-H1 and HSP27 were significantly higher in the experimental group than that in control group [41.3 ％ (31/75) vs 7.1％ (2/28),x2 =10.946,P =0.001,80.0 ％ (60/75) vs 46.4 ％ (13/28),x2 =11.131,P =0.001].Compared with control group,the positive rate of HSP27 was correlated with the degree of tumor differentiation (x2 =4.191,P =0.041).nm23-H1 was related with HSP27 in lung cancer (r =0.284,P =0.013).Conclusion nm23-H1 and HSP27 are related to the occurrence and development of NSCLC.The joint detection of nm23-H1 and HSP27 should be helpful to the diagnosis and judge the biological behavior of NSCLC.

Objective:To study the relationship and the role of leptin in children with biliary atresia and hepatic fibrosis to provide a treatment basis for these patients.Methods:The clinical data of children with biliary atresia or congenital biliary dilatation (CBD) who underwent surgical treatment at the Department of General Surgery of Tianjin Children's Hospital from August 2019 to August 2021 were retrospectively analyzed. Of 31 children included in this study, there were 14 males and 17 females, with age of 60 (30, 63) d. Children with biliary atresia served as the study group ( n=26) and children with CBD served as the control group ( n=5). Leptin protein, α-smooth muscleactin (α-SMA) and phosphorylation of extracellular-regulated protein kinase 1/2 (p-ERK1/2) in liver tissues were detectd by immunohistochemistry (IHC). The expression level of leptin mRNA in liver tissues were detected by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Results:The average optical density values of leptin protein, α-SMA protein and p-ERK1/2 protein in the liver tissues of children in the study group were significantly higher than the control group ( P<0.05). The expression levels of leptin, α-SMA and p-ERK1/2 in liver tissues of children with biliary atresia significantly increased with increase in fibrosis degree ( P<0.05). The expression level of leptin in liver tissues of children with biliary atresia was positively correlated with the liver fibrosis grade ( rs=0.876), α-SMA ( r=0.723) and p-ERK1/2 ( r=0.725) ( P<0.01). The results of qRT-PCR showed that the content of leptin mRNA in liver tissues of children with biliary atresia was significantly higher than that of children with CBD ( P<0.05). Conclusion:Expressions of leptin increased with aggravation of degrees of hepatic fibrosis in biliary atresia. Leptin may be involved in activation of HSCs through the ERK1/2 signaling pathway in the process of hepatic fibrosis due to biliary atresia.