Carbocisteine attenuates TNF-α-induced inflammation in human alveolar epithelial cells in vitro through suppressing NF-κB and ERK1/2 MAPK signaling pathways.

AIM: We previously proven that carbocisteine, a conventional mucolytic drug, remarkably reduced the rate of acute exacerbations and improved the quality of life in the patients with chronic obstructive pulmonary disease. In this study we investigated the mechanisms underlying the anti-inflammatory effects of carbocisteine in human alveolar epithelial cells in vitro. METHODS: Human lung adenocarcinoma cell line A549 was treated with TNF-α (10 ng/mL). Carbocisteine was administered either 24 h prior to or after TNF-α exposure. The cytokine release and expression were measured using ELISA and qRT-PCR. Activation of NF-κB was analyzed with Western blotting, immunofluorescence assay and luciferase reporter gene assay. The expression of ERK1/2 MAPK signaling proteins was assessed with Western blotting. RESULTS: Carbocisteine (10, 100, 1000 µmol/L), administered either before or after TNF-α exposure, dose-dependently suppressed TNF-α-induced inflammation in A549 cells, as evidenced by diminished release of IL-6 and IL-8, and diminished mRNA expression of IL-6, IL-8, TNF-α, MCP-1 and MIP-1ß. Furthermore, pretreatment with carbocisteine significantly decreased TNF-α-induced phosphorylation of NF-κB p65 and ERK1/2 MAPK, and inhibited the nuclear translocation of p65 subunit in A549 cells. In an NF-κB luciferase reporter system, pretreatment with carbocisteine dose-dependently inhibited TNF-α-induced transcriptional activity of NF-κB. CONCLUSION: Carbocisteine effectively suppresses TNF-α-induced inflammation in A549 cells via suppressing NF-κB and ERK1/2 MAPK signaling pathways.

[Role of matrix metalloproteinase (MMP)-2 and -9 and vascular endothelial growth factor C in lymph node metastasis of breast cancer].

OBJECTIVE: To study the expression of matrix metalloproteinase (MMP)-2, MMP-9 and vascular endothelial growth factor (VEGF)-C in breast cancer and their role in lymph node metastasis. METHODS: Immunohistochemical staining was used to detect the expression of VEGF-C, MMP-2, MMP-9 and LYVE-1 in 84 cases of breast cancer, including 52 cases with and 32 cases without lymph node metastases. The recombinant vector (pSIREN-VEGF-C) was transfected into human breast cancer cell MCF-7 by liposome, and the RNA expression of MMP-2, MMP-9 and VEGF-C in MCF-7 cells after transfection was detected by PCR. RESULTS: The expressions of MMP-2, MMP-9 and VEGF-C were 98.1% (51/52), 88.5% (46/52), and 94.2% (49/52) respectively for the metastatic group, and 75.0% (24/32), 53.1% (17/32), and 65.6% (21/32) respectively for the non metastatic group, and there was significant difference between these groups (P < 0.05). The lymphatic vessel density between these two groups was also significantly different (P < 0.05). Increased expression of MMP-2, MMP-9 and VEGF-C was also associated with increased number of lymphatic vessels had also increased (P < 0.05). The expression of MMP-2, MMP-9 and VEGF-C in MCF-7 cells after gene transfection decreased significantly (P < 0.05). CONCLUSION: MMP-2 and MMP-9 in conjunction with VEGF-C, promote lymphangiogenesis and lymph node metastasis of breast cancer.