Expression of c-Met and c-Src in non-small cell lung cancer and its relationship with prognosis / 中国医师进修杂志

Objective To explore the expressions of c-Met and c-Src in non-small cell lung cancer (NSCLC), and its relationship with clinical pathological characters and prognosis. Methods The c-Met and c-Src expressions were detected by immunohistochemistry in 88 patients with NSCLC from April 2011 to January 2013. The relationship between the expressions of c-Met and c-Src and clinical pathological features and prognosis were analyzed. Results The c-Met and c-Src were all significantly expressed in NSCLC tissues, and no expression showed in interstitial and normal lung tissues. The expressions of c-Met and c-Src in patients with NSCLC were associated with sex, differentiation, pathology type, T staging and TNM staging (P<0.05 or <0.01); and the expression of c-Met was associated with lymph node metastasis (P<0.01). The expressions of c-Met and c-Src in patients with NSCLC were not associated with age, and the expression of c-Src was not associated with lymph node metastasis (P>0.05). Pearson correlation analysis result showed that the expressions of c-Met and c-Src in lung cancer tissues was positive correlation (r=0.662, P<0.01). Kaplan-Meier survival curve analysis result showed that the disease free survival time (DFS) and overall survival time (OS) in c-Met high expression patients (51 cases) were significantly shorter than those in c-Met low expression patients (37 cases): (18.08 ± 1.34) months vs. (23.76 ± 1.79) months and (33.63 ± 1.95) months vs. (42.24 ± 2.68) months, the DFS and OS in c-Src high expression patients (25 cases) were significantly shorter than those in c-Src low expression patients (63 cases): (16.96 ± 2.56) months vs. (21.86 ± 1.15) months and (27.84 ± 2.89) months vs. (40.98 ± 1.81) months, the DFS and OS in both c-Met and c-Src high expression patients (25 cases) were significantly shorter than those in both c-Met and c-Src low expression patients (37 cases): (16.96 ± 2.56) months vs. (23.76 ± 1.79) months and (27.84 ± 2.89) months vs. (42.24 ± 2.68) months, and there were statistical differences (P<0.05). Cox multiplicity result showed that T staging (RR=2.174, 95％CI 1.354 to 3.490, P=0.001) and high expressions of c-Met and c-Src (RR=1.447, 95％CI 1.114 to 1.880, P=0.006) were the independent risk factors of DFS in patients with NSCLC;pathology type (RR=0.610, 95％CI 0.377 to 0.986, P=0.044), T staging (RR=2.215, 95％CI 1.357 to 3.616, P=0.001) and high expressions of c-Met and c-Src (RR=1.979, 95％CI 1.455 to 2.692, P = 0.000) were the independent risk factors of OS in patients with NSCLC. Conclusions The c-Met and c-Src are involved in the development of NSCLC and affect the prognosis of patients with NSCLC.

Endoplasmic reticulum stress (ER-stress) by 2-deoxy-D-glucose (2DG) reduces cyclooxygenase-2 (COX-2) expression and N-glycosylation and induces a loss of COX-2 activity via a Src kinase-dependent pathway in rabbit articular chondrocytes

Endoplasmic reticulum (ER) stress regulates a wide range of cellular responses including apoptosis, proliferation, inflammation, and differentiation in mammalian cells. In this study, we observed the role of 2-deoxy-D-glucose (2DG) on inflammation of chondrocytes. 2DG is well known as an inducer of ER stress, via inhibition of glycolysis and glycosylation. Treatment of 2DG in chondrocytes considerably induced ER stress in a dose- and time-dependent manner, which was demonstrated by a reduction of glucose regulated protein of 94 kDa (grp94), an ER stress-inducible protein, as determined by a Western blot analysis. In addition, induction of ER stress by 2DG led to the expression of COX-2 protein with an apparent molecular mass of 66-70kDa as compared with the normally expressed 72-74 kDa protein. The suppression of ER stress with salubrinal (Salub), a selective inhibitor of eif2-alpha dephosphorylation, successfully prevented grp94 induction and efficiently recovered 2DG-modified COX-2 molecular mass and COX-2 activity might be associated with COX-2 N-glycosylation. Also, treatment of 2DG increased phosphorylation of Src in chondrocytes. The inhibition of the Src signaling pathway with PP2 (Src tyrosine kinase inhibitor) suppressed grp94 expression and restored COX-2 expression, N-glycosylation, and PGE2 production, as determined by a Western blot analysis and PGE2 assay. Taken together, our results indicate that the ER stress induced by 2DG results in a decrease of the transcription level, the molecular mass, and the activity of COX-2 in rabbit articular chondrocytes via a Src kinase-dependent pathway.

Lysophosphatidic acid receptor 2 and Gi/Src pathway mediate cell motility through cyclooxygenase 2 expression in CAOV-3 ovarian cancer cells

Lysophosphatidic acid (LPA) is a bioactive phospholipids and involves in various cellular events, including tumor cell migration. In the present study, we investigated LPA receptor and its transactivation to EGFR for cyclooxygenase-2 (COX-2) expression and cell migration in CAOV-3 ovarian cancer cells. LPA induced COX-2 expression in a dose-dependent manner, and pretreatment of the cells with pharmacological inhibitors of Gi (pertussis toxin), Src (PP2), EGF receptor (EGFR) (AG1478), ERK (PD98059) significantly inhibited LPA- induced COX-2 expression. Consistent to these results, transfection of the cells with selective Src siRNA attenuated COX-2 expression by LPA. LPA stimulated CAOV-3 cell migration that was abrogated by pharmacological inhibitors and antibody of EP2. Higher expression of LPA2 mRNA was observed in CAOV-3 cells, and transfection of the cells with a selective LPA2 siRNA significantly inhibited LPA-induced activation of EGFR and ERK, as well as COX-2 expression. Importantly, LPA2 siRNA also blocked LPA-induced ovarian cancer cell migration. Collectively, our results clearly show the significance of LPA2 and Gi/Src pathway for LPA-induced COX-2 expression and cell migration that could be a promising drug target for ovarian cancer cell metastasis.