Exosomal miRNA-107 induces myeloid-derived suppressor cell expansion in gastric cancer.

  Myeloid-derived suppressor cells (MDSCs) promote immunosuppression in the tumor microenvironment, support tumor growth and survival, and may contribute to immunotherapy resistance. Recent studies showed that tumor-derived exosomes (TDEs) can induce MDSCs accumulation and expansion, the mechanisms of which are largely unknown. The morphologies and sizes of the exosomes was observed by using a JEM-1400 transmission electron microscope.

Artemisinin inhibits gastric cancer cell proliferation through upregulation of p53.

Recent population studies suggest that the use of artemisinin is associated with reduced incidence and improved prognosis of certain cancers. In the current study, we assessed the effect of artemisinin on gastric cancer cells (AGS and MKN74 cells). We found that artemisinin inhibited growth and modulated expression of cell-cycle regulators in these cells.

Endoplasmic reticulum stress-mediated signaling pathway of gastric cancer apoptosis.

Background/aims: To investigate ER stress-mediated CHOP-signaling pathway of gastric cancer apoptosis in vitro and in vivo.

Methodology: Based on the dose-and time-response experiments about tunicamycin (TM),gastric cancer cell line BGC823 was treated with 10tg/mL of TM for 24h. BGC823 apoptosis was detected with TUNEL assay and ultrastructural changes in BGC823 cells under ER stress were observed with transmission electron microscopy (TEM).

Amplifications of NCOA3 gene in colorectal cancers in a Chinese population.

Aim: To investigate the copy number variation of NACO3 gene in colorectal cancer (CRC) and its correlation with tumor progression.

Methods: A total of 142 samples of case-matched CRC tissues and adjacent normal tissues were obtained from patients undergoing bowel resection. Quantitative real-time polymerase chain reaction method was used to investigate the copy number variations of NCOA3 as well as gene expression in the collected tissues.

Genotypic variants at 2q33 and risk of esophageal squamous cell carcinoma in China: a meta-analysis of genome-wide association studies.

Genome-wide association studies have identified susceptibility loci for esophageal squamous cell carcinoma (ESCC). We conducted a meta-analysis of all single-nucleotide polymorphisms (SNPs) that showed nominally significant P-values in two previously published genome-wide scans that included a total of 2961 ESCC cases and 3400 controls. The meta-analysis revealed five SNPs at 2q33 with P< 5 × 10(-8), and the strongest signal was rs13016963, with a combined odds ratio (95% confidence interval) of 1.

Induction of ER stress protects gastric cancer cells against apoptosis induced by cisplatin and doxorubicin through activation of p38 MAPK.

We investigated the role of endoplasmic reticulum (ER) stress response and p38 MAPK pathways in the resistance of gastric cancer cells to chemotherapy. Pretreatment of the gastric cancer cells with the ER stress inducer drastically decreased the apoptotic rate induced by cisplatin or doxorubicin. Induction of ER stress also led to the activation of p38.

Pax6 haploinsufficiency causes abnormal metabolic homeostasis by down-regulating glucagon-like peptide 1 in mice.

Heterozygosity for the Pax6 allele is associated with impaired glucose tolerance in humans. With a Pax6 mutant mouse model, we found many of the metabolic abnormalities were consistent with the effects of down-regulating the expression of glucagon-like peptide 1 (GLP-1). In addition to impaired glucose tolerance, adult heterozygous mutant mice (Pax6(m/+)) secreted less insulin responding to glucose and arginine administration compared with control mice.

[Expression of CD45RA and CD45RO thymocyte subset and related cytokine in patients with myasthenia gravis].

Aim: To study the relationship between the abnormal differentiation thymocytes and the pathogenesis of myasthenia gravis (MG).

Methods: The gene expression of some ILs, IFN and their receptors was examined by cDNA array. The percentage of CD45RO(+) and D45RA(+) thymocytes was measured by flow cytometry (FCM).

[Expression and significance of B7-H1 and its receptor PD-1 in human gastric carcinoma].

Objective: The B7-H1/PD-1 co-signaling pathway has recently been found to play a pivotal role in the immune evasion of tumor cells from host immune system. The aim of this study was to examine the B7-H1 and PD-1 expression and TILs status in gastric cancer and to elucidate the clinical relevance of B7-H1 and PD-1 to the pathogenesis of gastric carcinoma.

Methods: Immunohistochemistry and ANAE histochemical staining were used to investigate the in situ expression of B7-H1 and PD-1 and TILs status in the gastric tissues.

[mRNA expression level of nucleostemin in esophageal squamous cell carcinoma tissue].

Objective: To investigate the mRNA expression levels of nucleostemin (NS) in human esophageal squamous cell carcinoma tissue.

Methods: Real-time PCR was used to quantify the mRNA expression of NS in the samples of esophageal squamous cell carcinoma tissue and their matched normal esophageal mucosa tissue from 62 patients, 36 males and 26 females, aged (61 +/- 10) (38-75). The relationship between NS mRNA expression level and clinical pathological features was analyzed.

[Expression of nucleostemin mRNA and protein in the esophageal squamous cell carcinoma].

Objective: To investigate the mRNA and protein expression of nucleostemin (NS) in human esophageal squamous cell carcinoma.

Methods: The mRNA and protein expression of NS were detected in 31 mucosal atypical hyperplasia specimens, 62 esophageal squamous cell carcinoma specimens and the matched normal esophageal mucosa samples by RT-PCR and immunohistochemistry method, respectively.

Results: The positive expression rate of NS protein in normal esophageal mucosa, atypical hyperplasia and esophageal squamous cell carcinoma was 17.

[Construction and identification of a eukaryotic expression vector for the small interfering RNA targeting nucleostemin gene].

Objective: To construct a eukaryotic expression vector for the small interfering RNA (siRNA) targeting nucleostemin (NS) gene.

Methods: The siRNA targeting NS gene was designed according to the sequence of NS mRNA available in GenBank. Three siRNA sequences were obtained, and the corresponding cDNAs were synthesized and inserted into plasmid pRNAT-U6.

[Effect of hTERT ASODN on the oncogenicity and the inductive apoptosis of HL-60 cells].

Objective: To investigate the effect of hTERT antisense oligodeoxynucleotide (ASODN) on the oncogenicity and the inductive apoptosis of HL-60 cells.

Methods: Apoptosis of HL-60 cells was detected by flow cytometry (FCM) and agarose gel electrophoresis. Both treated and untreated HL-60 cells were collected and transplanted into 5 BALB/c nude mice respectively, the formation of transplanted neoplasm and its morphologic change were observed.

[Inhibition of hTERT antisense oligodeoxynucleotide on proliferation and telomerase activity in HL-60 cells].

This study was purposed to investigate the inhibition of hTERT antisense oligodeoxynucleotide (ASODN) on the proliferation and telomerase activity in HL-60 cells and to explore the relativity between the telomerase activity and the expression of hTERT gene in HL-60 cells. After treated by hTERT ASODN the expression of hTERT was detected by RT-PCR, the morphological changes of HL-60 cells was observed with inverted microscopy, the cell proliferation was measured by MTT method, and the telomerase activity was determined with TRAP-ELISA and TRAP-PAGE. The results showed that after sealing hTERT gene with ASODN for 72 hours, the expression of hTERT gene was significantly inhibited, the cell growth was repressed and the ability of proliferation decreased, and the effect was specific in sequence and dependent in dose and time.

[Screening effective sequences of small interfering RNAs targeting MDR1 gene in human gastric cancer SGC7901/VCR cells].

Objective: To screen effective sequences of small interfering RNA targeting MDR1 gene in human gastric cancer SGC7901/VCR cells.

Methods: Four siRNAs (MDR1si326, MDR1si1513, MDR1si2631 and MDR1si3071) targeting MDR1 gene were designed and synthesized by in vitro transcription. The siRNA duplexes were used to transfect into the human gastric cancer SGC7901/VCR cells.

[Detection of methylation of hMSH2 gene promoter region of esophageal cancer].

Objective: To detect methylation in promoter region of hMSH2 gene in esophageal cancer.

Methods: Specimens of cancer and normal tissues freshly removed from 32 cases of esophageal cancer patients without previous radiotherapy, chemotherapy or other treatment were preserved at -80 degrees C within 30 min. Methylation specific PCR (MSP) was used to detect methylation of mismatch repair gene (MMR) hMSH2 in promoter region in esophageal cancer and normal esophageal tissues.

[Effects of c-myc antisense oligodeoxynucleotide on the telomerase activity and the induction of apoptosis in HL-60 cells].

To investigate the effects of c-myc antisense oligodeoxynucleotide (ASODN) on the telomerase activity and the induction of apoptosis in HL-60 cells, and to explore the relationship between the telomerase activity and the expression of c-myc gene in HL-60 cells, after treatment by c-myc ASODN, the expression of c-myc was detected by RT-PCR, the apoptosis, cell cycle were detected with agarose gel electrophoresis and flow cytomety, and the telomerase activity was determined with TRAP-ELISA. The results showed that after blocking c-myc gene with ASODN for 72 hours, it is obvious that the expression of c-myc gene was inhibited. The percentage of S phase HL-60 cells decreased from 55.

[Expression of hMSH2 gene in esophageal cancer].

Objective: To observe the expression of DNA mismatch repair gene hMSH2 mRNA in esophageal cancer tissues.

Methods: This study included 32 esophageal cancer patients who received no previous radiotherapy, chemotherapy or other treatments. Within 30 min following surgical removal of the tumor tissues, specimens of the tumor, the tissue adjacent to the tumor and normal tissue at the esophageal stump (1 cmx1 cmx1 cm in size for each specimen) were obtained for examining hMSH2 expression with hMSH2 ISH detection kit.

Comparison of nuclear matrix proteins between gastric cancer and normal gastric tissue.

Aim: To study the alteration of nuclear matrix proteins (NMPs) in gastric cancer.

Methods: The NMPs extracted from 22 cases of gastric cancer and normal gastric tissues were investigated by SDS-PAGE technique and the data were analyzed using Genetools analysis software.

Results: Compared with normal gastric tissue, the expression of 30 ku and 28 ku NMPs in gastric cancer decreased significantly (P=0.

Studies on microsatellite instability in p16 gene and expression of hMSH2 mRNA in human gastric cancer tissues.

Aim: To detect the loss of heterozygosity (LOH) frequency of microsatellite sites D9s171, D9s1604 of p16 gene and expression of hMSH2 mRNA in various differentiated types of gastric cancer, adjacent cancer tissues and normal gastric mucosa.

Methods: LOH was detected by polymerase chain reaction (PCR)-denaturing polyacrylamide gel electrophoresis-silver staining. The expression of hMSH2 mRNA was examined with in situ hybridization.

Methylation and mutation analysis of p16 gene in gastric cancer.

Aim: To study methylation, frequencies of homozygous deletion and mutation of p16 gene in gastric carcinoma.

Methods: The methylation pattern in exon 1 and exon 2 of p16 gene was studied with polymerase chain reaction (PCR), using methylation sensitive restriction endonuclease HpaII and methylation insensitive restriction endonuclease MspI. PCR technique was used to detect homozygous deletions of exon 1 and exon 2 of p16 gene and single strand conformation polymorphism (SSCP) technique was used to detect the mutation of the gene.

Expression of somatostatin mRNA in various differentiated types of gastric carcinoma.

AIM:To investigate the expression of somatostatin mRNA in various differentiated types of gastric carcinoma.METHODS: By using in situ hybridization and immunohistochemical techniques, the expression of somatostatin mRNA and somatostatin immunoreactivity in the normal gastric mucosa, the poorly, moderately and well-differentiated gastric carcinomas, and various clinical stages of carcinoma were observed.RESULTS: In comparison with the normal gastric mucosa, the significantly increased expression of somatostatin mRNA positive cells was displayed in gastric carcinoma (t = 2.