Objective:To explore the expression of polypyrimidine tract-binding protein 1 (PTBP1) in gastric cancer (GC) tissues and GC cell lines, and the role of PTBP1 in the proliferation and metastasis of GC cells.Methods:From January to June in 2019 at The First Affiliated Hospital of Xi′an Jiaotong University, the cancer tissues and corresponding para-cancer tissues of GC patients underwent surgical resection were collected. The Kaplan-Meier Plotter database was used to analyze the survival of GC patients. The expression of PTBP1 was down-regulated by transfecting small interfering RNA (siRNA) in human GC cell lines SGC7901 and AGS with relatively high expression of PTBP1. The cells were divided into blank control group, negative control group, and PTBP1 knockdown group. The expression of PTBP1 at mRNA and protein level were detected by real-time fluorescence quantification polymerase chain reaction (RT-qPCR) and Western blotting. At 24, 48, 72 and 96-hour after transfection, the effect of PTBP1 on the proliferation of GC cells was observed by 3-(4, 5 dimethylthiazol)-2, 5 diphenyltetrazolium bromide (MTT) experiment. The changes of invasion and migration of GC cells after down-regulation of PTBP1 were detected by transwell assay. The expression changes of epithelial-mesenchymal transition (EMT) markers E-cadherin, N-cadherin and vimentin after down-regulation of PTBP1 in GC cells were determined by Western blotting. Indenpendent samples t test, analysis of variance and rank sum test were used for statistical analysis. Results:The Kaplan-Meier Plotter prognostic analysis showed that the overall survival of GC patients with high PTBP1 expression was shorter than that of GC patients with low PTBP1 expression (9.2 months, 6.2 months to 17.2 months vs. 19.0 months, 14.5 months to 28.4 months), and the difference was statistically significant ( Z=5.31, P<0.05). The results of RT-qPCR showed that in GC cell lines SGC7901 and AGS, the expression of PTBP1 at mRNA level of PTBP1 knockdown group was lower than that of blank control group and negative control group (SGC7901: 0.78±0.11 vs.3.10±0.19 and 2.99±0.23; AGS: 0.80±0.09 vs. 3.55±0.24 and 3.50±0.18), and the differences were statistically significant ( tSGC7901=10.57 and 8.08, tAGS=10.91 and 13.42; all P<0.01). The results of Western blotting indicated that in GC cell lines SGC7901 and AGS, the expression of PTBP1 at protein level of PTBP1 knockdown group was lower than those of blank control group and negative control group (SGC7901: 0.38±0.04 vs. 1.42±0.05 and 1.35±0.09; AGS: 0.17±0.02 vs. 1.52±0.08 and 1.38±0.45), and the differences were statistically significant ( tSGC7901=15.94 and 10.57, tAGS=16.60 and 20.80; all P<0.01). The results of MTT showed that at 48, 72 and 96-hour after transfection the absorbance values of PTBP1 knockdown group decreased by 0.25±0.01, 0.38±0.02, and 0.84±0.04 as compared with those of negative control group, and the decrease was the most significant at 96-hour after transfection, and the differences were statistically significant ( t=10.21、14.32, both P<0.01). The results of transwell experiment demonstrated that the number of invasion and migration cells of PTBP1 knockdown group were both less than that of the blank control group and the negative control group (SGC7901: 42.00±5.91 vs. 116.40±10.23 and 114.40±10.43; 39.60±6.77 vs. 125.80±11.51 and 122.40±5.90; AGS: 40.20±7.25 vs. 115.60±14.63 and 117.40±9.12; 36.00±5.20 vs. 122.40±12.10 and 125.40±12.74), and the differences were statistically significant ( tSGC7901=14.07, 13.50, 14.43 and 20.62; tAGS=10.27, 14.75, 14.68 and 16.76; all P<0.01). The results of Western blotting showed that the expression of E-cadherin of PTBP1 knockdown group was higher than that of the blank control group and the negative control group (SGC7901: 1.42±0.05 vs. 0.53±0.05 and 0.57±0.03; AGS: 1.34±0.04 vs. 0.54±0.03 and 0.61±0.01), however the expression levels of N-cadherin and vimentin were both lower than those of the blank control group and the negative control group (SGC7901: 0.50±0.03 vs. 1.64±0.05 and 1.46±0.07; 0.32±0.07 vs. 1.42±0.07 and 1.33±0.07; AGS: 0.37±0.06 vs. 1.47±0.04 and 1.36±0.04; 0.41±0.04 vs. 1.53±0.06 and 1.37±0.04), and the differences were statistically significant ( tSGC7901=11.63, 13.19, 18.83, 11.68, 11.43 and 10.43; tAGS= 15.02, 16.23, 14.67, 12.97, 14.45 and 17.18; all P<0.01). Conclusions:The expression levels of PTBP1 increase in GC tissues and cells, which may be involved in regulating the proliferation, metastasis and EMT of GC cells.

Objective To use superparamagnetic iron oxide nanoparticles(SPIONs)to label chimeric antigen receptor(CAR)T cells targeting carcinoembryonic antigen(CEA),and perform magnetic resonance imaging(MRI)to real time trace CEA CAR-T cells in vivo.Methods Appropriate amount of ferumoxytol,heparin sodium and protamine sulfate were mixed at high(ferumoxytol 100 μg/mL,heparin sodium 4 IU/mL,protamine sulfate 120 μg/mL),medium(ferumoxytol 50 μg/mL,heparin sodium 2 IU/mL,protamine sulfate 60 μg/mL),and low(ferumoxytol 25 μg/mL,heparin sodium 1 IU/mL,protamine sulfate 30 μg/mL)concentrations to form a SPIONs complex ferumoxytol/heparin/protamine(FHP),and then co-incubated with CEA CAR-T cells for cell labeling.The biocompatibility of FHP was detected by CCK-8 assay,EdU assay and flow cytometry.The uptake of FHP was detected by Prussian blue staining,and SPIONs content in the cells was quantitatively detected by inductively coupled plasma-mass spectrometry(ICP-MS).Flow cytometry was used to detect the lytic effect of FHP-labeled CEA CAR-T cells on tumor cells,and MRI was employed to scan FHP-labeled CEA CAR-T cells.Results FHP at high,medium,and low concentrations had no significant effect on the activity of CEA CAR-T cells,with cell activity above 100％determined by CCK-8 assay.DNA proliferation was above 94.3％in EdU assays.Prussian blue staining showed that CEA CAR-T cells could take FHP up,with the uptake increased with the increment of FHP concentration.ICP-MS showed that the intracellular Fe content was 440.23±189.36 ng/mL.Tumor cell killing experiment showed that FHP-labeled CEA CAR-T cells had excellent killing capability against tumor cells.MRI scans indicated that T2WI signals of FHP-labeled CEA CAR-T cells were significantly reduced with increasing FHP concentration(P＜0.01).Conclusion SPIONs complex FHP shows good biocompatibility and can effectively label CEA CAR-T cells.SPIONs complex FHP can be used as a magnetic marker for CEA CAR-T cells and a feasible MRI tracer for clinical application.

[Abstract] Objective: To explore the regulatory effect of long non-coding RNA (lncRNA) SNHG5 on invasion and migration of hypoxia-induced hepatocellular carcinoma (HCC) cells. Methods: A total of 20 pairs of cancer and para-cancerous tissue specimens resected from HCC patients in the First Affiliated Hospital of Xi'an Jiaotong University from January 2017 to June 2018, and human HCC cell lines (HepG2, MHCC-97L, MHCC-97H , Huh7) as well as immortalized human liver LO2 cells were collected for this study. Bioinformatics methods were used to analyze the binding sites between hypoxia-inducible factor 1α (HIF-1α) and SNHG5. pCMVHIF-1α and shRNA-SNHG5 (sh-SNHG5) plasmids were transfected into HCC cells, respectively. qPCR was used to detect the expres‐ sion level of SNHG5 in HCC tissues and hypoxia-induced HCC cells. Western botting was used to detect the expression level of HIF-1α protein in HCC cells, and Transwell chamber method was used to detect the migration and invasion ability of HCC cells after SNHG5 si‐ lence under normoxia and hypoxia condition. Results: Compared with para-cancerous tissues and immortalized human liver LO2 cells, the expression of SNHG5 was significantly up-regulated in HCC tissues and cell lines (all P<0.01). Hypoxia promoted the expression level of SNHG5 in HCC cells, and its mechanism might be related to the combination of hypoxia-activated HIF-1α and SNHG5 promoter to promote its transcription. Hypoxia promoted the invasion and migration ability of HepG2 and MHCC-97L cells (all P< 0.01), but knockdown of SNHG5 significantly inhibited the invasion and migration ability of HepG2 and MHCC-97L cells under hy‐ poxic conditions (all P<0.01). Conclusion: SNHG5 is highly expressed in HCC tissues and cell lines and plays an important role in the invasion and migration of HCC cells induced by hypoxia.

【Objective】 To study the role and mechanism of sinomenine in the macrophage polarization induced by gastric cancer cells. 【Methods】 Sinomenine was added to gastric cancer cells BGC-823 and MKN-45， cell viability was measured by CCK-8， cell proliferation was measured by colony formation experiment， Co-culture and Transwell cell migration experiments were used to evaluate the recruitment and polarization of macrophages by sinomenine， flow cytometry was used to evaluate the polarization of macrophages， and qRT-PCR and Western blot were used to detect the expression of gene RNA and protein levels. 【Results】 Sinomenine could inhibit the proliferation of gastric cancer cells and the recruitment of gastric cancer cells to macrophages， thus promoting macrophage M2 polarization. It simultaneously inhibited the expression of STAT6 as well as the expression and phosphorylation of C/EBPβ. When STAT6 is overexpressed， it could reduce these inhibitory effects of sinomenine on gastric cancer cells. Further research found that STAT6 mediated the secretion of IL-6 by gastric cancer cells， which was the cause of sinomenine-mediated macrophage recruitment and M2 polarization. 【Conclusion】 The natural drug sinomenine has a good tumor-suppressing ability against gastric cancer， directly inhibits the survival and migration of gastric cancer cells， and inhibits the expression of IL-6 and the M2 phenotype in the tumor microenvironment， reshapes the tumor environment， and reduces the risk of M2 type macrophages for gastric cancer tumors.