BACKGROUND:Studies have shown that cancer stem cels play an important role in tumor invasion and metastasis, but studies on the role of gastric cancer stem cels in invasion and metastasis of gastric cancer cels were rarely reported.
OBJECTIVE:To study the effect of gastric cancer stem cels CSC-G on invasion and metastasis of gastric cancer cels.
METHODS: Gastric cancer stem cels CSC-G and gastric cancer cels SGC7901 were culturedin vitro for 10 days folowed by spherical colony formation assay, western blot assay for detecting OCT4, SOX2, E-cadherin and CD44 protein expression levels in gastric cancer stem cels CSC-G and gastric cancer cels SGC7901, and Transwel assay for detecting the invasion and migration of gastric cancer stem cels and gastric cancer cels SGC7901.
RESULTS AND CONCLUSION:Gastric cancer cels SGC7901 in RPMI1640 medium presented with adherent growth and were quadrilateral or polygonal after passage; gastric cancer stem cels CSC-G in serum-free medium presented with suspension growth, and adherent gastric cancer stem cels were spindle-shaped or round. Compared with gastric cancer cels SGC7901, the protein expressions of OCT4, SOX2 and CD44, the number of cancer cel spheres and the number of trans-membrane cels were significantly increased in the gastric cancer stem cels CSC-G (P < 0.05), and the expression of E-cadherin protein was significantly decreased (P < 0.05). These findings indicate that the gastric cancer stem cels CSC-G can be successfuly cultured in vitro, and have enhanced invasion and migration compared with the gastric cancer cels SGC7901, which play an important role in gastric cancer invasion and metastasis.

Objective To identify and confirm a novel HLA allele.Methods A new human leukocyte antigen A allele was found during routine HLA genotyping by polymerase chain reaction-sequence specific oligonucleotide probes(PCR-SSOP) and sequencing-based typing (SBT).HLA-A locus was amplified from exon 1 through exon 8,and the nucleotide sequence of exon 2 to exon 4 for HLA-A were sequenced in both directions.Results The novel HLA-A * 31 allele is identical to A * 31 ∶ 01 ∶ 02 with an exception of one base substitution at position 245 of exon 2 where an ' A' change to ' C' resulting in codon 82 changed from GAG to GCG.Conclusion A novel HLA allele,A * 31 ∶ 22,was identified,and was named officially by the WHO Nomenclature Committee for factors of the HLA system.

Objective: To construct the recombinant adenoviral containing fructose 1, 6-biphosphatase 1 (FBP1), and to investigate whether FBP1 has effect on autophagy and proliferation in liver cancer cells (HepG2). Methods: FBP1 cDNA sequence was amplified by PCR and cloned in adenovirus vector pAdTrack-TO4, and then recombinant adenovirus plasmid pAdTrack-FBP1 was constructed. The recombinant adenovirus plasmid was transfected into HEK293 cells by Lipofectamine 3000. High-titer of recombinant adenovirus AdFBP1 was obtained by packaging and amplification. HepG2 cells were infected with recombinant adenovirus AdFBP1, and the Mock and AdGFP group were set at the same time. Western blot and confocal laser scanning microscopy were used to observe the effect of FBP1 on the level of autophagy in hepatocellular carcinoma cells, and the effect of FBP1on the proliferation was observed by MTS and colony formation assay. A t-test and one-way ANOVA were used to compare the mean between group. Results: A high-titer recombinant adenovirus FBP1 was successfully constructed. Western blot and confocal laser scanning microscopy showed that the level of autophagy in AdFBP1 group was significantly lower than that in AdGFP group. Western blot results showed that LC3-II protein expression level in AdGFP was 1.10 ± 0.10 and 0.30 ± 0.01 in AdFBP1 group, F = 90.36, P < 0.01. Confocal laser scanning microscopy analysis showed that the average number of autophages in AdGFP was 28.33 ± 1.53 and 12.33 ± 1.53 in AdFBP1group, F = 97.40, P < 0.01. In addition, the results of colony formation assay and MTS assay showed that the proliferation of liver cancer cells in the AdFBP1 group was significantly inhibited compared with the AdGFP group. The results of colony formation showed that the cell clones in the AdGFP group was 65.66 ± 2.57 and 34.00 ± 2.00 in AdFBP1 group, F = 141.50, P < 0.01. MTS results showed that the absorbance of AdGFP group at 96h was 39.13 ± 2.21 and 30.61 ± 3.33 in AdFBP1 group, F = 7.80, P < 0.05. Conclusion FBP1 inhibited the autophagy and proliferation in liver cancer cells (HepG2).

Objective: To evaluate the value of combined detection of negative costimulatory molecule B7-H4 and carcinoembryonic antigen (CEA) in diagnosing malignant and benign pleural effusion. Methods: Ninety-seven pleural effusion specimen were collected, 55 of which were diagnosed as malignant pleural effusion and 42 were benign pleural effusion. Enzyme-linked immunosorbent assay(ELISA) was used to examine the concentration of B7-H4 and CEA in pleural effusion. Electro-chemiluminescence immunoassay was used to detect the CEA level in pleural effusion. Receiver operating characteristic (ROC) curve was established to analyze and evaluate the single or combined detection of B7-H4 and CEA in diagnosing malignant and benign pleural effusion. Results: The concentrations of B7-H4 and CEA in malignant pleural effusion (MPE) group were (60.08±35.04) ng/ml and (41.49±37.16) ng/ml, respectively, obviously higher than (27.26±9.55) ng/ml and (2.41±0.94) ng/ml of benign pleural effusion (BPE) group (both P<0.01). Area under curve (AUC) of B7-H4 was 0.884 in MPE groupand the diagnostic sensitivity and specificity were 81.8% and 90.5%, respectively, at the optimized cut off value of 37.25 ng/ml. Likewise, area under curve (AUC) of CEA was 0.954 and the sensitivity and specificity were 87.3% and 95.2%, respectively, at the cut off value of 4.18 ng/ml. When B7-H4 >37.25 ng/ml or CEA>4.18 ng/ml, the sensitivity of diagnosis as MPE was down-regulated to 90.9% and the specificity was elevated to 88.1%. When B7-H4 >37.25 ng/ml and CEA>4.18 ng/ml, the sensitivity of diagnosis as MPE was down-regulated to 78.2% and the specificity was elevated to 97.6%. The sensitivity and specificity of combined detection of B7-H4 and CEA to diagnose MPE were elevated to 90.9% and 97.6%, respectively. The level of B7-H4 in MPE and BPE were both positively correlated with CEA (r=0.670, P=0.001 in MPE and r=0.002, P=0.001 in BEP). Conclusions B7-H4 is a potential tumor marker in diagnosing the benign and malignant pleural effusion. Although the diagnostic value of B7-H4 may not precede to CEA, the combined detection of B7-H4 and CEA can improve the diagnostic sensitivity and specificity of MPE.