Yinghao Yu

IL-1β-induced activation of p38 promotes metastasis in gastric adenocarcinoma via upregulation of AP-1/c-fos, MMP2 and MMP9.

BackgroundInterleukin-1β (IL-1β) has been implicated in the progression of gastric adenocarcinoma (GA); however, the molecular mechanisms of action of IL-1β in GA are poorly characterized. P38 and JNK are the major MAPK family members that regulate IL-1β signaling pathways. Here, we investigated the role of both p38 and JNK in IL-1β-induced GA cell migration, invasion and metastatic potential.MethodsThe effects of IL-1β-induced p38 and JNK activation in GA cells were determined using in vitro Transwell migration and invasion assays of MKN-45 and AGS cells, or an in vivo metastasis assay in nude mice. The IL-1β-induced p38 signaling pathway was further characterized in GA cells. Activation of the IL-1β/p38 signaling pathway was also assessed in human primary GA tissues by immunohistochemistry.ResultsIL-1β-induced activation of p38 increased GA cell migration and invasion in vitro and promoted the metastatic potential of GA cells in vivo; these effects were attenuated by p38 siRNA or the p38 inhibitor SB202190. MMP2 or MMP9 siRNAs and the MMP2/9 inhibitor BiPS also inhibited IL-1β-induced GA cell migration and invasion in vitro. IL-1β-induced p38 activation significantly increased MMP2 and MMP9 mRNA and protein expression and activity. Luciferase reporter assays demonstrated that the activator protein-1 (AP-1) and the AP-1 binding sites of the MMP9 promoter (−670/MMP9) were activated by IL-1β-induced p38 activation. Phospho-p38 was significantly upregulated in human GA tissues (compared to matched non-neoplastic tissues), and significantly associated with lymph node metastasis, and invasion beyond the serosa. Expression of phospho-p38 significantly correlated with IL-1β, MMP2, MMP9, and c-fos expression in both human GA tissues and GA cell metastases in the lungs of nude mice. IL-1β was also capable of activating JNK in GA cells, but activation of JNK was not associated with GA cell migration and invasion. Therefore, IL-1β-induced the migration and invasion in GA cells were regulated by p38, but not by JNK.ConclusionsIL-1β-induced p38 activation and the IL-1β/p38/AP-1(c-fos)/MMP2 & MMP9 pathway play an important role in metastasis in GA; this pathway may provide a novel therapeutic target for GA.

HER-2/neu overexpression is an independent prognostic factor for intestinal-type and early-stage gastric cancer patients.

Goals: To evaluate the HER-2/neu protein level by immunohistochemistry (IHC) and its gene amplification by fluorescence in situ hybridization (FISH) in gastric cancer samples, and the relevance to the prognosis of gastric cancer patients. Study: HER-2/neu overexpression and gene amplification were examined with semiquantitative standardized IHC in 775 formalin-fixed paraffin-embedded gastric cancer samples, and 252 of these cases were analyzed with FISH. Results: Of the 775 gastric cancer samples examined by IHC, a total of 88 (11%) cases were positive for HER-2/neu overexpression at a score of 3+; another 44 (6%) cases were equivocal with a score of 2+; and the rest 643 (83%) cases were negative scored as 0/1+. Intestinal-type and early-stage cancers exhibited higher rate of HER-2/neu overexpression than those of diffuse/mixed-type and advanced cancers (P<0.05). Intestinal-type and early-stage cancers with HER-2/neu overexpression also exhibited short 5 year survival rates (21% vs. 47%, P=0.027; 29% vs. 60%, P=0.037) than HER-2/neu-negative cases, but not in the diffuse/mixed-type and advanced stage cancers. By FISH analysis, it was shown that 70% (60/86) of IHC 3+ had HER-2/neu gene amplication. In contrast, only 14% (6/43) of IHC 2+ cases, and 2.5% (3) of the 120 cases with IHC 0/1+ randomly selected showed HER-2/neu gene amplification. Conclusions: HER-2/neu overexpression may be used as an independent prognostic factor for intestinal-type and early-stage gastric cancer patients. IHC 3+ and 2+ cases should be further detected by FISH to assess HER-2/neu gene status. Patients with HER-2/neu amplification also might constitute potential candidates for targeted therapy with trastuzumab.

Additive effects of EGF and IL-1β regulate tumor cell migration and invasion in gastric adenocarcinoma via activation of ERK1/2

Growth and inflammatory factors are associated with poor prognosis in gastric adenocarcinoma (GA); however, the additive effects of growth and inflammatory factors in GA remain unclear. In this study, we investigated the ability of epidermal growth factor (EGF) and interleukin (IL-1β) to activate extracellular signal-regulated kinase (ERK)1/2 in GA cells, and correlated the relationships between their roles with the metastatic potential both in GA cells and GA tissues. The effects of EGF, IL-1β and EGF plus IL-1β in AGS and MKN-45 GA cells were examined using western blotting, Transwell migration and invasion assays, immunocytochemical staining and an activator protein (AP)-1 luciferase reporter gene assay, and was further characterized in GA tissues by immunohistochemistry. The results exhibited that EGF and IL-1β additively activated ERK1/2, increased migration and invasion than either EGF or IL-1β alone in AGS and MKN-45 cells. The mechanisms were involved in upregulating MMP-9 expression through increasing AP-1 transcriptional activity via ERK1/2 pathway; these effects were dose-dependently inhibited by silencing ERK1/2 or using U0126. In vivo data also confirmed that the overexpression of p-ERK1/2 in GA tissues correlated well with the EGF, IL-1β, EGF plus IL-1β, and was associated with metastasis, which was well correlation with the expression of MMP-9 and c-fos (AP-1). The results demonstrate that growth and inflammatory factors play an important role in metastasis of GA by additively activating ERK-1/2 and AP-1, and upregulating MMP-9. As both cytokines contribute to the migration and invasion of GA cells, EGF/IL-1β/ERK1/2 pathways may be key pathways closely associated with GA progression.

Single Nucleotide Polymorphism of the Enhancer of Zeste Homolog 2 Gene rs2072408 is Associated with Lymph Node Metastasis and Depth of Primary Tumor Invasion in Gastric Cancer.

BACKGROUND The single nucleotide polymorphism (SNP) rs2072408 is located in an intron of the enhancer of zeste homolog 2 (EZH2) gene. Its role in gastric cancer (GC) has not been determined. METHODS In the present study, the genotype of (EZH2) rs2072408 and the relationship of genotype with lymph node metastasis (LNM) and the invasive depth of gastric wall (T stage) was determined in 330 patients with GC, and the association between the genotype and recurrence and survival was determined in 253 patients with GC. RESULTS The TT genotype was identified to be significantly associated with LNM [P = 0.013; odds ratio (OR), 6.49 (95% confidence interval (CI), 1.47 - 28.59)] and T stage [T1 + T2 vs. T3 + T4, p = 0.017, OR, 3.02 (95% CI, 1.22 - 7.44)]. The overall rates of LNM and T3 + T4 stage in the present study were 70.6% and 60.6%, respectively, the rates increased 23.8% and 20.0% in patients with the TT genotype. CONCLUSIONS These results suggest that the TT genotype of EZH2 (rs2072408) was associated with LNM and the depth of gastric wall invasion in patients with GC.

Expression and prognostic significance of cyclin‑dependent kinase inhibitor 1A in patients with resected gastric adenocarcinoma

Cyclin-dependent kinase inhibitor 1A (CDKN1A) is an important cell cycleregulator, and has been identified to exhibit aberrant expression in various types of cancer tissues. However, the association between CDKN1A expression level and prognosis in patients with resected gastric adenocarcinoma (RGA) requires additional elucidation. In the present study, the CDKN1A expression profile in RGA tissues obtained from 217 patients were analyzed using immunohistochemistry. Its prognostic significance was evaluated by using the χ2 test, Kaplan-Meier curves and the log-rank test, and a multivariate Cox model analysis, during a median follow-up time of 51 months. The results demonstrated that CDKN1A expression was significantly correlated with lymph node metastasis (LNM; P=0.001), recurrence (P<0.001) and overall survival (OS; P<0.001). In addition, the recurrence-free survival (RFS) and OS times were significantly shorter in patients with low CDKN1A expression compared with those with high CDKN1A expression (RFS, 20 months vs. 69 months, P<0.001; and OS, 32 months vs. 70 months, P<0.001, respectively). Multivariate analysis additionally confirmed that low CDKN1A expression was significantly correlated with an increased risk of LNM (P=0.001), recurrence (P<0.001) and mortality (P<0.001). Therefore, these data suggest that low expression of CDKN1A has independent prognostic significance indicative of tumor progression and poor survival in patients with RGA. Evaluation of CDKN1A expression may assist in determining prognosis in patients with RGA.