Qun Zhao

Anti-tumor effects of CIK combined with oxaliplatin in human oxaliplatin-resistant gastric cancer cells in vivo and in vitro

BackgroundDrug resistance remains a great challenge in the treatment of gastric cancer. The goal of this study was to explore the anti-tumor effects and mechanism of cytokine-induced killer (CIK) cell combined with oxaliplatin (L-OHP) in human oxaliplatin-resistant gastric cancer cells.MethodsAfter producing oxaliplatin-resistant gastric cancer cells, cell morphology, growth and doubling time were observed, followed by detection of cell cycle distribution and apoptosis, drug sensitivity (e.g., L-OHP) and expression of P-gp and livin. MTT assay, in vivo pharmacodynamics and pathomorphology experiments were used to detect killing activities of CIK combined with L-OHP.ResultsCompared with parental gastric cancer cells, oxaliplatin-resistant gastric cancer cells in S phase were reduced and cell apoptosis rate was increased (P < 0.05), the inhibition rate of 10 chemotherapeutics on oxaliplatin-resistant gastric cancer cells was significantly lower and the expression of P-gp was significantly higher (P < 0.05). However, there was no significant difference in livin expression between parental gastric cancer cells and oxaliplatin-resistant gastric cancer cells (P > 0.05). The in vitro killing activity of CIK combined with L-OHP on parental cells and oxaliplatin-resistant cells were significantly enhanced compared with L-OHP or CIK alone. And it showed greater synergetic effects against oxaliplatin-resistant cells compared with parental cells (P < 0.05). In addition, survival rate, abdominal circumference and pathomorphology results revealed stronger in vivo anti-tumor effects when the two therapies were combined.ConclusionsThe mechanism of oxaliplatin-resistant cell secondary multidrug resistance was correlated with the variation of cell cycle distribution, extension of doubling time and upregulation of P-gp expression. The synergistic effect of CIK in combination with L-OHP on killing activity against oxaliplatin-resistant cells was shown in vivo and in vitro.

Identification of aberrantly expressed long non-coding RNAs in stomach adenocarcinoma

Aim Stomach adenocarcinoma (STAD) is a common malignancy worldwide. This study aimed to identify the aberrantly expressed long non-coding RNAs (lncRNAs) in STAD. Results Total of 74 DElncRNAs and 449 DEmRNAs were identified in STAD compared with paired non-tumor tissues. The DElncRNA/DEmRNA co-expression network was constructed, which covered 519 nodes and 2993 edges. The qRT-PCR validation results of DElncRNAs were consistent with our bioinformatics analysis based on RNA-sequencing. The DEmRNAs co-expressed with DElncRNAs were significantly enriched in gastric acid secretion, complement and coagulation cascades, pancreatic secretion, cytokine-cytokine receptor interaction and Jak-STAT signaling pathway. The expression levels of the nine candidate DElncRNAs in TCGA database were compatible with our RNA-sequencing. FEZF1-AS1, HOTAIR and LINC01234 had the potential diagnosis value for STAD. Materials and Methods The lncRNA and mRNA expression profile of 3 STAD tissues and 3 matched adjacent non-tumor tissues was obtained through high-throughput RNA-sequencing. Differentially expressed lncRNAs/mRNAs (DElncRNAs/DEmRNAs) were identified in STAD. DElncRNA/DEmRNA co-expression network construction, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted to predict the biological functions of DElncRNAs. Quantitative real-time polymerase chain reaction (qRT-PCR) was subjected to validate the expression levels of DEmRNAs and DElncRNAs. Moreover, the expression of DElncRNAs was validated through The Cancer Genome Atlas (TCGA) database. The diagnosis value of candidate DElncRNAs was accessed by receiver operating characteristic (ROC) analysis. Conclusions Our work might provide useful information for exploring the tumorigenesis mechanism of STAD and pave the road for identification of diagnostic biomarkers in STAD.

HIF-1α Induces Multidrug Resistance in Gastric Cancer Cells by Inducing MiR-27a

This study aimed to determine the correlation between HIF-1α and miR-27a expression and to evaluate the effect of inhibition of HIF-1α expression on miR-27a expression and drug resistance in gastric cancer (GC). In the present study, real time-PCR and Western blot were performed to detect the expression of HIF-1α in GC tissues and cell lines. Then, OCUM-2MD3/L-OHP cells were transfected with HIF-1α-siRNA, a miR-27a mimic or pcDNA-HIF-1α, and cell survival was determined via the MTT assay. The expression of HIF-1α, miR-27a, and MDR-related genes was measured via real time-PCR and Western blot. ChIP and dual luciferase activity assays were performed to assess the transcriptional regulation of HIF-1α and miR-27a. The results revealed that transfection with HIF-1α-siRNA markedly decreased the levels of miR-27a, resulting in dramatically enhanced inhibition of the proliferation rate of OCUM-2MD3/L-OHP cells. Compared to non-transfected cells, the survival rate was significantly reduced in the cells transfected with HIF-1α-siRNA after treatment with L-OHP. The cell survival rate was significantly increased in OCUM-2MD3/L-OHP cells transfected with the miR-27a mimic, whereas HIF-1α overexpression did not result in any clear change in cell survival. The results of the dual luciferase activity assay demonstrated that HIF-1α enhances the transcriptional activity of the miR27a promoter in cells transfected with a reporter plasmid containing the upstream promoter region of miR27a together with pcDNA-HIF-1α. ChIP analysis suggested that HIF-1α directly binds to the promoter region of miR27a. Inhibition of HIF-1α or miR27a expression decreased MDR1/P-gp, LRP, and Bcl-2 expression in OCUM-2MD3/L-OHP cells. Thus, we found that HIF-1α is closely associated with MDR in GC and that HIF-1α may suppress MDR1/P-gp, LRP and Bcl-2 expression by inhibiting miR-27a expression.

Inhibition of Vav3 gene can promote apoptosis of human gastric cancer cell line MGC803 by regulating ERK pathway.

Previous studies proved that Vav3 gene was overexpressed in cancers. However, the molecular mechanism of Vav3 in apoptosis still keeps unclear; therefore, the relationship between Vav3 gene and apoptosis of gastric cancer (GC) was explored in the present study. Vav3-siRNA was transfected into MGC803 cells, and then cell activity and apoptosis rate were tested with MTT and FCM; apoptosis-related genes and proteins in MAPK signaling pathway were also tested. Results showed that Vav3 was overexpressed in GC than in adjacent normal tissues (all Pu2009<u20090.05), and expression of Vav3 was related to degree of histological differentiation, cancer invasion depth, and lymphatic metastasis (Χ2u2009=u20097.185, Pu2009=u20090.007; Χ2u2009=u200918.654, Pu2009<u20090.001; Χ2u2009=u20095.058, Pu2009=u20090.025). Vav3 silencing inhibited activity of MGC803 cells, and apoptosis rate of cells was affected. Vav3-siRNA transfection led to changes of apoptosis-related genes such as Survivin, xIAP, Bcl-2, caspase-3, and Bax (all Pu2009<u20090.01). After transfection, ratio of phosphorylation of ERK significantly reduced. We concluded that Vav3 inhibition can suppress cell activity and promote apoptosis by regulating the apoptosis-related genes through the ERK pathway.

Zerumbone induces gastric cancer cells apoptosis: Involving cyclophilin A

Gastric cancer is one of the leading causes for cancer death. There is an urgent need to develop new therapeutic approaches targeting metastatic gastric cancer. It has been reported that zerumbone has the anti-cancer effects in various malignant cells. However, the effect and the mechanism of zerumbone on melanoma cells is still largely unknown. In the study, we determined the actions of zerumbone on the human gastric cancer cell line SGC-7901.We also observed the mechanism by which zerumbone induced gastric cancer cell apoptosis. Our data indicated that zerumbone significantly inhibited the growth of human gastric cancer cells in a dose-dependent manner and apoptosis was the main cause of decreased cell viability in zerumbone -treated cells. The treatment with zerumbone downregulated Cyp A and Bcl-2 levels, upregulated Bax levels, and caused Cytochrome c (Cyt-C) to release, activating Caspase-3. In summary, our study suggests that zerumbone mightinduced human gastric cancer cells apoptosis through down-regulating Cyp A and mitochondria-mediated pathways.

Concurrent Neoadjuvant Chemoradiotherapy for Siewert II and III Adenocarcinoma at Gastroesophageal Junction

Objective:This study was conducted to investigate the efficacy and safety of using a concurrent neoadjuvant chemoradiotherapy (a XELOX regimen) to treat adenocarcinoma of the gastroesophageal junction. Methods:Seventy-six patients having resectable adenocarcinoma at the gastroesophageal junction (T3/4, N+, M0) were recruited to participate and randomly assigned to either a chemoradiotherapy group or a surgery group. Patients in the chemoradiotherapy group were orally given capecitabine (1,000 mg/m2, twice daily for 14 days, days 1–14) and intravenous oxaliplatin (130 mg/m2 on day 1) for 2 cycles. Radiotherapy was performed with a total of 45 Gy administered in 25 sessions for 5 weeks. Patients in the surgery group received only surgical intervention. Results:In the concurrent chemoradiotherapy group, the overall response rate was 55.6% (20/36), tumor control rate was 100% and a pathological complete response was achieved in 16.7% (6/36). The entire chemoradiotherapy group had R0 resections as did 80% of the surgery group (32/40) (P < 0.05). In the concurrent chemoradiotherapy group, 6 patients developed grade 3 side effects. Treatment was either discontinued or the dose adjusted. Major hematological side effects in the chemoradiotherapy group included leukopenia, neutropenia, anemia and thrombocytopenia. Nonhematological side effects included nausea, vomiting and appetite loss. Chemoradiotherapy-related death was not observed. Conclusions:Concurrent neoadjuvant chemoradiotherapy administration increased the rate of R0 resection and demonstrated favorable safety in patients with Siewert II or III adenocarcinoma at the gastroesophageal junction. These results support the use of neoadjunctive chemoradiotherapy in the treatment of adenocarcinoma of the gastroesophageal junction.

Formononetin inhibits colon carcinoma cell growth and invasion by microRNA‑149‑mediated EphB3 downregulation and inhibition of PI3K/AKT and STAT3 signaling pathways

Formononetin (Form), a phytoestrogen extracted from the roots of Astragalus membranaceus, is one of the fundamental herbs used in traditional Chinese medicine because of its protective effects against certain malignant tumors. However, its role in colon carcinoma cells and the underlying molecular mechanisms have not been completely elucidated. The present study aimed to demonstrate that Form significantly inhibited the proliferation and invasion of the colon carcinoma cell lines SW1116 and HCT116. Mechanistic studies have suggested that Form suppresses colon carcinoma cell growth by downregulating cell cycle-associated protein (cyclin D1) expression and arresting the cell cycle at the G0-G1 checkpoint. Further studies revealed that treatment with Form inhibits matrix metalloproteinase (MMP)2 and MMP9 expression. Aditionally, the results demonstrated that Form significantly increased microRNA (miR)-149 expression. Following miR-149 overexpression in SW1116 and HCT116 cells using an miR-149 mimic, cell viability and Ephrin type-B receptor 3 (EphB3) levels decreased. Furthermore, the inhibitory effects of Form were associated with phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) and signal transducer and activator of transcription 3 (STAT3) signaling pathways. These results indicated the suppressive effect of Form on colon carcinoma cell proliferation and invasion, possibly via miR-149-induced EphB3 downregulation and the inhibition of the PI3K/AKT and STAT3 signaling pathways. Overall, Form may be used as a novel candidate for the clinical treatment of colorectal cancer in the future.

Clinical value of peripheral blood microRNA detection in evaluation of SOX regimen as neoadjuvant chemotherapy for gastric cancer

Neoadjuvant chemotherapy has been widely applied in treating advanced gastric cancer (GC). However, little research has been conducted on evaluating the effect of neoadjuvant chemotherapy. Purpose of this study was to evaluate the effect of SOX regimen as neoadjuvant chemotherapy by detecting some microRNAs.

Expression of IMP3 as a marker for predicting poor outcome in gastroenteropancreatic neuroendocrine neoplasms

The aim of the present study was to investigate the expression and clinical significance of oncofetal protein insulin-like growth factor (IGF) II mRNA-binding protein 3 (IMP3) in the differentiation of gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). A total of 162 patients who were diagnosed with GEP-NEN, and who underwent surgical or endoscopic resection from January 2006 to March 2013, were enrolled in the study, including 85 cases of grade (G)1 neuroendocrine tumors, 40 cases of G2 neuroendocrine tumors, 28 cases of G3 neuroendocrine carcinomas and 9 cases of mixed stage adenoneuroendocrine carcinomas. The clinical and pathological data were recorded for analysis. The expression of IMP3, cluster of differentiation (CD)44, IGF1 receptor (IGF1R) and matrix metalloproteinase (MMP)2 was determined by immunohistochemistry. SPSS 13.0 software was used for data processing and analyses, and P<0.05 was used to determine significance. Oncofetal protein IMP3 exhibited a high expression rate (74.69%) in GEP-NEN. IMP3-positive cases demonstrated significantly decreased overall and disease-free survival times, as compared with IMP3-negative cases (P=0.012). Overexpression of IMP3 was correlated with tumor grade, clinical stage, tumor size and poor prognosis (all P<0.05). Therefore, patients with overexpressed IMP3 had a poorer prognosis (P<0.01); COX regression analysis revealed that the overexpression of IMP3, the tumor grade, tumor size and metastasis of GEP-NEN were each associated with the clinical outcomes. The results also indicated that the expression rates of CD44, IGF1R and MMP2 in GEP-NEN were 19.75, 53.7 and 55.56%, respectively. While it was negatively associated with the expression of CD44 (r=-0.131; P=0.096), the expression of IMP3 was positively correlated with the expression of IGF1R and MMP2 (r=0.288, P<0.01; r=0.208, P=0.008). In addition, the expression levels of IGF1R and MMP2 were positively associated (r=0.687; P<0.01). In conclusion, high IMP3 expression levels were determined to be associated with a high disease stage in patients with GEP-NEN, thus it may serve as a predictor for metastasis and poor clinical outcomes in GEP-NEN.

Effect of annexin A7 suppression on the apoptosis of gastric cancer cells

Understanding the molecular mechanism of gastric cancer cell apoptosis is pivotal for the development of precise therapies targeting this disease. In the present study, we examined the effects of annexin A7 inhibition on the apoptosis of gastric cancer cells and the growth of tumour xenografts in vivo. Expression of annexin A7 in BGC823 cells was suppressed by small interference RNA, and cells apoptosis was assessed by flow cytometry. The mechanism by which annexin A7 mediates apoptosis in BGC823 cells was explored by determining the expression of key apoptosis regulators. In addition, by suppressing annexin A7 in BGC823 cells with small hairpin RNA, we studied the effects of annexin A7 inhibition on in vivo tumour growth. Our results showed that inhibiting annexin A7 expression induced more than fivefold increase in BGC823 cell apoptosis in vitro. This was in concord with a significant decrease of Bcl-2 expression and increases of Bax, Caspase-3, and Caspase-9. The activities of caspase-3 and caspase-9 were increased by 2.95u2009±u20090.18 and 3.70u2009±u20090.33 times, respectively, upon the annexin A7 downregulation in BGC823 cells. Importantly, suppressing annexin A7 showed the same apoptotic mechanism in vivo and significantly inhibited the growth of BGC823 xenografts in mice. These data suggest that annexin A7 likely protects gastric cells from apoptosis and targeting it may represent a valuable strategy in future therapeutic development.