Background Nasopharyngeal carcinoma (NPC) shows highly invasive and metastatic features. This study aims to investigate macrophage migration inhibitory factor (MIF)-induced invasion of NPC cells in vitro and the eff...Background Nasopharyngeal carcinoma (NPC) shows highly invasive and metastatic features. This study aims to investigate macrophage migration inhibitory factor (MIF)-induced invasion of NPC cells in vitro and the effects on matrix metalloproteinases (MMPs) and interleukin-8 (IL-8),and to study the mechanism of tumor cell invasion and metastasis in the early stage of NPC. Methods Two nasopharyngeal carcinoma cell lines,CNE-1 and CNE-2,were adopted in this study. The NPC cell invasion and migration were evaluated by microinvasion assay. The variation of expression percentages of MMP2- or MMP9-positive cells was detected by flow cytometry in two cell lines with or without MIF treatment. Western blotting and RT-PCR were used to assay the protein and mRNA expressions of MMP2 and MMP9. The IL-8 concentration secreted by NPC cells was compared with the cells with different treatments using ELISA. Results After treating with MIF for 48 hours,the cell numbers of CNE-1 and CNE-2 which went through the 8-μm filter membrane were increased. Compared with non-MIF treated NPC cells,significant difference could be found both in CNE-1( P =0.005) and CNE-2 cells ( P =0.001) . The percentages of MMP9-positive cells were significantly increased in both CNE-1 [from (28.5±2.5)% to (82.4±3.5)%, P =0.001] and CNE-2 [from (32.8±3.5)% to (86.1±1.6)%, P =0.002]. The relative intensity of MMP9 protein expression was also enhanced in both cell lines (CNE-1: from 83.1±6.0 to 242.9±22.9, P =0.002;CNE-2: from 84.4±4.3 to 278.9±29.7, P =0.003). Correspondingly,the increased MMP9 mRNA expression level was significantly detectable in both cell lines.The concentration of IL-8 in the supernatant of CNE-2 was higher [(1201.8±593.3) pg/ml] after treatment. It was also remarkably higher than that in the supernatant of CNE-2 without treatment ( P =0.026). However,there was no significant difference in the concentration variation of IL-8 in CNE-1 ( P =0.581), while the IL-8 mRNA level was only enhanced in CNE-2. Conclusions MIF can induce potent invasion of NPC cell lines in vitro , and the infiltrating lymphocytes in NPC might be responsible for the invasion and metastasis of tumor cells. MIF cytokine which is secreted by these infiltrating lymphocytes might contribute to the invasion as well as metastasis of NPC in the early stages by induction of MMP9 and IL-8 in an indirect pathway.展开更多
Worldwide estimates establish gastric carcinoma as the second most frequent cause of cancer deaths. Tumour invasion and metastasis is the biggest impediment to gastric carcinoma cure. Active migration of tumour cells ...Worldwide estimates establish gastric carcinoma as the second most frequent cause of cancer deaths. Tumour invasion and metastasis is the biggest impediment to gastric carcinoma cure. Active migration of tumour cells is now considered as the pivotal step in cancer invasion and metastasis. RhoC is a member of the Ras-superfamily of small guanosine triphosphatases that can regulate many cellular functions, especially cytoskeletal organization and cell locomotion. Overexpressing RhoC in vitro in the poorly metastatic cell line from human melanoma may induce a highly metastatic phenotype.~1 The recent development of laser capture microdissection (LCM) affords the opportunity to further evaluate the role RhoC plays in the invasion and metastasis of gastric carcinoma cells in their native tissue environment.展开更多
Background This study was designed to detect methylation of E-cadherin gene promoter and gene mutation of β-catenin in exon 3 and their expression of protein and mRNA in primary tumor and lymph node metastatic tumor...Background This study was designed to detect methylation of E-cadherin gene promoter and gene mutation of β-catenin in exon 3 and their expression of protein and mRNA in primary tumor and lymph node metastatic tumor of nasopharyngeal carcinoma (NPC), and investigate the mechanism of invasion and metastasis of neoplastic cells in NPC Methods Fourty-two fresh biopsy samples were taken from untreated NPC patients at the Affiliated Hospital of Sun Yat-sen Medical College, Sun Yat-sen University, Guangzhou, China during the period of 1999-2002 Among them 21 were taken from primary tumors and the other 21 from lymph node metastatic tumors The gene promoter methylation of E-cadherin was detected by methylation-specific PCR (MSP) The mutation in exon 3 of β-catenin was detected by direct sequencing analysis RT-PCR, Western blot and immunohistochemical staining were used to detect the mRNA and protein expression patterns in both primary and metastatic tumors of NPC Results Down-regulated expression of E-cadherin in metastatic tumor was compared with that in primary tumor Reduced expression of E-cadherin was found to be correlated with lymph node metastatic tumor of NPC ( P =0 004); but there was no obvious correlation between primary and metastatic tumors in the expression of β-catenin ( P =0 698) The mRNA expression level of E-cadherin in metastatic tumors decreased significantly compared with that in primary tumors However, little change was observed in the mRNA level of β-catenin in different tumor tissues Only 4 samples (19 1%) displayed gene promoter methylation of E-cadherin in primary tumor and 10 samples (47 6%) showed methylated form of E-cadherin The gene promoter methylation of E-cadherin was more common in metastatic tumor than in primary tumor of NPC ( P =0 024) Only 2 (4 76%) of the 42 samples showed mutations in exon 3 of β-catenin at 41 (T41A, ACCGCC) and codon 47 (S47T, AGTACT) The cytoplasmic and nuclear expression of β-catenin in tumor was not found in any samples of NPC Conclusions The results suggest that the downregulation of E-cadherin results from the gene promoter aberrant methylation of E-cadherin and that the methylation of E-cadherin plays an important role in invasion and metastasis of tumor cells in NPC However, β-catenin mutation is an infrequent event in NPC, and β-catenin is not a critical factor influencing the invasion and metastasis of tumor cells in NPC展开更多
基金ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No .3 0 2 0 0 2 5 4)
文摘Background Nasopharyngeal carcinoma (NPC) shows highly invasive and metastatic features. This study aims to investigate macrophage migration inhibitory factor (MIF)-induced invasion of NPC cells in vitro and the effects on matrix metalloproteinases (MMPs) and interleukin-8 (IL-8),and to study the mechanism of tumor cell invasion and metastasis in the early stage of NPC. Methods Two nasopharyngeal carcinoma cell lines,CNE-1 and CNE-2,were adopted in this study. The NPC cell invasion and migration were evaluated by microinvasion assay. The variation of expression percentages of MMP2- or MMP9-positive cells was detected by flow cytometry in two cell lines with or without MIF treatment. Western blotting and RT-PCR were used to assay the protein and mRNA expressions of MMP2 and MMP9. The IL-8 concentration secreted by NPC cells was compared with the cells with different treatments using ELISA. Results After treating with MIF for 48 hours,the cell numbers of CNE-1 and CNE-2 which went through the 8-μm filter membrane were increased. Compared with non-MIF treated NPC cells,significant difference could be found both in CNE-1( P =0.005) and CNE-2 cells ( P =0.001) . The percentages of MMP9-positive cells were significantly increased in both CNE-1 [from (28.5±2.5)% to (82.4±3.5)%, P =0.001] and CNE-2 [from (32.8±3.5)% to (86.1±1.6)%, P =0.002]. The relative intensity of MMP9 protein expression was also enhanced in both cell lines (CNE-1: from 83.1±6.0 to 242.9±22.9, P =0.002;CNE-2: from 84.4±4.3 to 278.9±29.7, P =0.003). Correspondingly,the increased MMP9 mRNA expression level was significantly detectable in both cell lines.The concentration of IL-8 in the supernatant of CNE-2 was higher [(1201.8±593.3) pg/ml] after treatment. It was also remarkably higher than that in the supernatant of CNE-2 without treatment ( P =0.026). However,there was no significant difference in the concentration variation of IL-8 in CNE-1 ( P =0.581), while the IL-8 mRNA level was only enhanced in CNE-2. Conclusions MIF can induce potent invasion of NPC cell lines in vitro , and the infiltrating lymphocytes in NPC might be responsible for the invasion and metastasis of tumor cells. MIF cytokine which is secreted by these infiltrating lymphocytes might contribute to the invasion as well as metastasis of NPC in the early stages by induction of MMP9 and IL-8 in an indirect pathway.
文摘Worldwide estimates establish gastric carcinoma as the second most frequent cause of cancer deaths. Tumour invasion and metastasis is the biggest impediment to gastric carcinoma cure. Active migration of tumour cells is now considered as the pivotal step in cancer invasion and metastasis. RhoC is a member of the Ras-superfamily of small guanosine triphosphatases that can regulate many cellular functions, especially cytoskeletal organization and cell locomotion. Overexpressing RhoC in vitro in the poorly metastatic cell line from human melanoma may induce a highly metastatic phenotype.~1 The recent development of laser capture microdissection (LCM) affords the opportunity to further evaluate the role RhoC plays in the invasion and metastasis of gastric carcinoma cells in their native tissue environment.
基金ThisworkwassupportedbyagrantfromtheNationalNaturalScienceFoundationofChina (No 3 0 2 0 0 2 5 4)
文摘Background This study was designed to detect methylation of E-cadherin gene promoter and gene mutation of β-catenin in exon 3 and their expression of protein and mRNA in primary tumor and lymph node metastatic tumor of nasopharyngeal carcinoma (NPC), and investigate the mechanism of invasion and metastasis of neoplastic cells in NPC Methods Fourty-two fresh biopsy samples were taken from untreated NPC patients at the Affiliated Hospital of Sun Yat-sen Medical College, Sun Yat-sen University, Guangzhou, China during the period of 1999-2002 Among them 21 were taken from primary tumors and the other 21 from lymph node metastatic tumors The gene promoter methylation of E-cadherin was detected by methylation-specific PCR (MSP) The mutation in exon 3 of β-catenin was detected by direct sequencing analysis RT-PCR, Western blot and immunohistochemical staining were used to detect the mRNA and protein expression patterns in both primary and metastatic tumors of NPC Results Down-regulated expression of E-cadherin in metastatic tumor was compared with that in primary tumor Reduced expression of E-cadherin was found to be correlated with lymph node metastatic tumor of NPC ( P =0 004); but there was no obvious correlation between primary and metastatic tumors in the expression of β-catenin ( P =0 698) The mRNA expression level of E-cadherin in metastatic tumors decreased significantly compared with that in primary tumors However, little change was observed in the mRNA level of β-catenin in different tumor tissues Only 4 samples (19 1%) displayed gene promoter methylation of E-cadherin in primary tumor and 10 samples (47 6%) showed methylated form of E-cadherin The gene promoter methylation of E-cadherin was more common in metastatic tumor than in primary tumor of NPC ( P =0 024) Only 2 (4 76%) of the 42 samples showed mutations in exon 3 of β-catenin at 41 (T41A, ACCGCC) and codon 47 (S47T, AGTACT) The cytoplasmic and nuclear expression of β-catenin in tumor was not found in any samples of NPC Conclusions The results suggest that the downregulation of E-cadherin results from the gene promoter aberrant methylation of E-cadherin and that the methylation of E-cadherin plays an important role in invasion and metastasis of tumor cells in NPC However, β-catenin mutation is an infrequent event in NPC, and β-catenin is not a critical factor influencing the invasion and metastasis of tumor cells in NPC
