Intense expression of the b7-2 antigen presentation coactivator is an unfavorable prognostic indicator for differentiated thyroid carcinoma of children and adolescents

Previous observations suggest that an immune response against thyroid carcinoma could be important for long-term survival. We recently found that infiltration of thyroid carcinoma by proliferating lymphocytes is associated with improved disease-free survival, but the factors that control lymphocytic infiltration and proliferation are largely unknown. We hypothesized that the antigen presentation coactivators (B7-1 and B7-2), which are important in other immune-mediated thyroid diseases, might be important in lymphocytic infiltration of thyroid carcinoma. To test this, we determined B7-1 and B7-2 expression by immunohistochemistry [absent (grade 0) to intense (grade 3)] in 27 papillary (PTC) and 8 follicular (FTC) thyroid carcinomas and 9 benign thyroid lesions. B7-1 and B7-2 were expressed by the majority of PTC and FTC (78% of PTC and 100% of FTC expressed B7-1; 88% of PTC and 88% of FTC expressed B7-2). B7-1 expression was more intense in PTC (1.4 +/- 0.2; P = 0.01) and FTC (2.6 +/- 0.2; P < 0.001) than in benign tumors (0.57 +/- 0.30) or presumably normal adjacent thyroid (0.07 +/- 0.07) and was more intense in carcinoma that contained lymphocytes (1.95 +/- 0.21) than in carcinoma that did not (1.08 +/- 0.26; P = 0.016). B7-2 expression was of similar intensity in benign and malignant tumors (PTC, 1.6 +/- 0.2; FTC, 2.1 +/- 0.4; benign, 1.86 +/- 0.4), but was more intense than in presumably normal adjacent thyroid (0.64 +/- 0.25; P 相似文献   

The expression of vascular endothelial growth factor and the type 1 vascular endothelial growth factor receptor correlate with the size of papillary thyroid carcinoma in children and young adults.

Vascular endothelial growth factor (VEGF) is essential for the growth of many solid tumors, but there are little data regarding VEGH in childhood thyroid cancers. We examined the relationships between VEGF, the type 1 VEGF receptor (FLT-1) and clinical outcome for a group of thyroid cancers in children and young adults. The expression of VEGF and FLT-1 were determined by immunohistochemistry using archival, paraffin-embedded thyroid tissue blocks and compared with the retrospective clinical outcome for each patient. The study included 67 children and young adults with papillary thyroid carcinoma (PTC, n = 42), follicular thyroid carcinoma (FTC, n = 8), benign lesions (n = 15), or controls (n = 2). VEGF expression was greater in PTC (mean intensity 2.23 +/- 0.25, p = 0.002) and FTC (2.8 +/- 0.73, p = 0.01) than benign lesions (1.0 +/- 0.27), and correlated with PTC size (r = 0.42, p = 0.008). FLT-1 expression was greater in PTC (mean intensity 2.8 +/- 0.17) than FTC (1.9 +/- 0.25, p = 0.015) and benign lesions (1.7 +/- 0.32, p = 0.002); and correlated with PTC size (r = 0.41, p = 0.01) as well as VEGF expression (r = 0.52, p = 0.002). Recurrent disease developed exclusively in patients with PTC which expressed VEGF (7/28, 95% CI 10.6%-44.2%). PTC that did not express VEGF (0/8, 95% CI = 0%-31.2%) did not recur; however, the difference was not statistically significant (p = 0.15). We conclude that the expression of VEGF and FLT-1 are directly correlated with the size of PTC in children and young adults.     

Thyroid carcinomas that express telomerase follow a more aggressive clinical course in children and adolescents

With each cell division, DNA is lost from the telomeres, limiting the number of divisions, and leading to senescence. Malignant tumors maintain immortality by expressing a specific DNA repair enzyme, telomerase, that replaces this DNA. We hypothesized that tumors which express telomerase would have the highest recurrence risk and we tested this by determining telomerase expression in 27 papillary thyroid carcinomas (PTC), 5 follicular thyroid carcinomas (FTC) and 13 benign thyroid lesions from children and adolescents. Patients were 6-21 yr of age (mean+/-SE=16.6+/-4.1 yr) and followed from 0-14.1 yr (mean+/-SE=4.71+/-3.5 yr). Original tumors were sectioned, and immunostained for telomerase. Telomerase-specific staining was determined by two independent, blind examiners and graded from absent (Grade 0) to intense (Grade 3). Telomerase was detected in a similar majority of benign (11/13, 85%) and malignant tumors (24/32, 75%). However, the intensity of telomerase expression was greater among FTC (mean+/-SE=2.4+/-0.5 relative intensity) followed by PTC (mean+/-SE=1.9+/-1.0 relative intensity) and benign tumors (mean+/-SE=1.8+/-1.0 relative intensity). Autoimmune lesions had lower telomerase expression (mean+/-SE=1.25+/-0.5 relative intensity) compared to FTC (p=0.01), PTC (p=0.06) and benign lesions (p=0.15). Among PTC, 19 (70%) expressed telomerase, and 8 (30%) did not. Direct invasion (no.=4, 21%), distant metastasis (no.=2, 10%) and recurrence (no.=7, 37%) developed exclusively in PTC that expressed telomerase (p=0.02). Disease-free survival was also shorter for PTC that expressed telomerase (p=0.06). Recurrence developed in 1/2 (50%) FTC that expressed telomerase. We conclude that childhood thyroid cancers which express telomerase have an increased risk of tissue invasion, metastasis, and recurrence.     

The prognostic value of metalloproteinases and angiogenic factors in ovarian carcinoma

The objective of this study was to analyze the correlation between matrix metalloproteinases (MMPs) and angiogenic genes and survival in advanced-stage ovarian carcinomas. Primary and metastatic ovarian carcinomas from patients diagnosed with FIGO stage III-IV disease and followed up to 20 years were studied using mRNA in situ hybridization (ISH). Expression of MMP-2, MMP-9, membrane-type 1-MMP (MT1-MMP), the MMP inhibitor TIMP-2, vascular endothelial growth factor (VEGF), interleukin-8 (IL-8) and basic fibroblast growth factor (bFGF) was studied. MMP-2, MMP-9 and TIMP-2 mRNA was detected in both tumor and stromal cells, while MT1-MMP was largely confined to tumor cells. In univariate analysis of primary tumors, TIMP-2 and MMP-9 mRNA expression correlated with poor outcome. In metastatic lesions, mRNA expression of TIMP-2, MMP-2, and MT1-MMP correlated with poor survival. In a multivariate analysis of primary tumors, TIMP-2 expression in stromal cells (P=0.006) and MMP-9 expression in tumor cells (P=0.011) retained their predictive value. Intense expression of bFGF mRNA and weak expression of IL-8 mRNA was detected in both stromal and tumor cells in most cases, while VEGF mRNA expression was limited to a few cases. Angiogenic mRNA expression showed no correlation with disease outcome in survival analysis (P>0.05). We conclude that bFGF is the major angiogenic factor expressed in ovarian carcinoma at the mRNA level. MMP-2, MMP-9, MT1-MMP and TIMP-2 are valid markers of poor survival in advanced-stage ovarian carcinoma.     

Nitrotyrosine,inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) are increased in thyroid tumors from children and adolescents

Nitric oxide (NO) is a reactive cell signal that controls vascular tone and is generated by inducible (iNOS), endothelial (eNOS) and neuronal (nNOS) NO synthase (NOS). We hypothesized that NO could be important for growth of thyroid tumors and tested this hypothesis, by staining 41 papillary thyroid carcinoma (PTC), 9 follicular thyroid carcinoma (FTC), and 15 benign thyroid lesions for iNOS, eNOS and nitrotyrosine (N-TYR). Staining intensity was determined by 2 blinded, independent examiners, and quantified from grade 1 (absent) to grade 4 (intense). Average N-TYR staining of benign adenomas (2.5+/-0.42, p=0.009), PTC (3.10+/-0.12, p=0.001), FTC (2.44+/-0.30, p=0.001), and autoimmune lesions (3.25+/-0.48, p=0.019) were greater than that of multinodular goiter (1.0 for all 3) and surrounding normal thyroid (1.1+/-0.1). Average iNOS staining of benign adenomas (2.6+/-0.37), PTC (2.7+/-0.16), FTC (2.4+/-0.26) and autoimmune lesions (3.5+/-0.29) were all greater than that of surrounding normal thyroid (1.1+/-0.1, p<0.008), but there were too few multinodular goiters to achieve a significant difference (no.=2, 3.0+/-1.0). Average eNOS staining of benign adenomas (2.9+/-0.40), multinodular goiters (3.5+/-0.5), PTC (3.24+/-0.18), FTC (3.5+/-0.50), and autoimmune lesions (2.8+/-0.6) were also greater than that of surrounding normal thyroid (mean=1.4+/-0.2, p<0.001). N-TYR staining correlated with that of vascular endothelial growth factor (VEGF, r=0.36, p=0.007) and the number of lymphocytes/high power field (r=0.39, p=0.004). Recurrent disease developed only from carcinoma with moderate-intense N-TYR staining, but there were too few recurrent tumors to achieve statistical significance (p=0.08). We conclude that NO is produced by benign adenomas, PTC and FTC suggesting that NO could be important in vascularization of thyroid tumors and autoimmune thyroid diseases.     

Over-expression of hepatocyte growth factor/scatter factor (HGF/SF) and the HGF/SF receptor (cMET) are associated with a high risk of metastasis and recurrence for children and young adults with papillary thyroid carcinoma

OBJECTIVE: The study determined if hepatocyte growth factor/scatter factor (HGF/SF) or the HGF/SF receptor (cMET) might be important for metastasis in thyroid cancer. DESIGN: We examined HGF/SF and cMET expression by immunohistochemistry in a retrospective group of benign and malignant thyroid lesions from children and young adults, and correlated the intensity of expression with clinical outcome. PATIENTS: Patients included 42 children and young adults with papillary thyroid carcinomas (PTC), seven with follicular thyroid carcinomas (FTC), two with medullary thyroid carcinomas (MTC), 14 with benign thyroid disorders, and two with normal thyroids. MEASUREMENTS: Expression of cMET was graded from 0 (absent) to 4 (intense); and HGF/SF expression was graded from 0 (absent-minimal) to 3 (diffuse and intense). RESULTS: cMET staining was greater in PTC (mean intensity 2.3 +/- 0.4 vs. 0.8 +/- 0.2, P < 0.005) and FTC (2.4 +/- 0.6 vs. 0.8 +/- 0.2, P = 0.04) than benign lesions (0.8 +/- 0.2) or normal thyroids (0.4 +/- 0.5). PTC with intense cMET staining had shorter disease free survival (P = 0.05) and increased HGF/SF staining (r = 0.39, P = 0.017). HGF/SF correlated with the extent of disease at diagnosis (r = 0.33, P = 0.049). Patients with PTC were stratified into quartiles based on combined cMET and HGF/SF staining. Those with intense cMET and HGF/SF staining were younger (P = 0.05), and had reduced disease free survival (P = 0.03). CONCLUSIONS: We conclude that increased cMET and HGF/SF expression is associated with a high risk for metastasis and recurrence in children and young adults with papillary thyroid carcinoma.     

Overexpression of MT3-MMP in hepatocellular carcinoma correlates with capsular invasion

BACKGROUND/AIMS: Extracellular matrix-degrading matrix metalloproteinases (MMPs) are invariably up-regulated in epithelial cancers and are key agonists of angiogenesis, invasion and metastasis. Recent studies have shown high levels of various MMPs, including MT1-MMP, MMP-1, MMP-2 and MMP-9, and their involvement in tumor progression in human hepatocellular carcinoma (HCC). However, the expression and role of MT3-MMP in HCC remains unclear. METHODOLOGY: We examined the immunohistochemical expression of MT3-MMP in surgically resected HCCs (n=58), hepatitis C virus (HCV) and hepatitis B virus (HBV)-related chronic hepatitis (n=34) and cirrhosis (n=24). RESULTS: MT3-MMP expression was observed in all non-cancerous liver tissues. In HCCs, 52% (30/58) of patients showed high MT3-MMP expression while the remaining 48% (28/58) of patients showed low expression. A clinicopathological survey demonstrated a significant correlation between high MT3-MMP expression and capsular invasion of carcinoma (p = 0.034) although there was no correlation between high MT3-MMP expression in HCC and overall survival or disease-free survival. CONCLUSIONS: MT3-MMP was expressed not only in chronic hepatitis and liver cirrhosis, but also in HCC, and high MT3-MMP expression correlated significantly with capsular invasion of carcinoma.     

Enhanced Cell Surface Expression of Matrix Metalloproteinases and Their Inhibitors, and Tumor-Induced Host Response in Progression of Human Gastric Carcinoma

The cell surface and/or intracellular expression of the matrix metalloproteinases (MMP -2, 7, and -9 and MT1-MMP) and their inhibitors (TIMP-2 and -4) were investigated in tumor and tumor-infiltrating lymphocytes (TIL) in gastric carcinoma (n = 15) from the primary locus, metastatic gastric carcinoma (n = 20) from malignant ascites, and benign gastric mucosa (n = 20) for the control. The quantitative analysis was based on the percentage of positive cells by flow cytometry. The results clearly showed increased cell surface expression of MMP-2, -7, and -9, MT1-MMP, and TIMP-2 and -4 in both tumor cells and TIL during the development of invasion and/or metastasis of gastric carcinoma. There were equilateral correlations with cancer progression and frequency of cell surface expression of MMPs and their inhibitors, TIMPs, suggesting not only the aggressive nature of particularly metastatic gastric carcinoma, but also the presence of MMPs complexed with TIMPs on tumor cells and TIL. The enhanced cell surface expression of MMPs and TIMPs on TIL within metastatic carcinoma nests showed the result of a host response induced by tumors. These suggest that the increased cell surface expression of MMPs and TIMPs, and tumor-induced host response play a key role in gastric cancer invasion and/or metastasis.     

Expression of membrane type 1 matrix metalloproteinase, matrix metalloproteinase 2 and tissue inhibitor of metalloproteinase 2 in human cartilaginous tumors with special emphasis on mesenchymal and dedifferentiated chondrosarcoma

Membrane type 1 matrix metalloproteinase (MT1-MMP) has been identified as an activator of the proenzyme of matrix metalloproteinase 2 (MMP-2: gelatinase A), and has also been shown to play a crucial role in tumor invasion by activating proMMP2 in both lung and gastric carcinoma. The tissue inhibitor of metalloproteinase 2 (TIMP-2) plus the MT1-MMP complex also plays an important role in the activation of proMMP-2. In this study, the expressions of MT1-MMP, MMP-2 and TIMP-2 were evaluated in 10 enchondromas, 34 conventional chondrosarcomas, 5 clear-cell chondrosarcomas, 7 mesenchymal chondrosarcomas and 8 dedifferentiated chondrosarcomas. The expressions were immunohistochemically visualized on paraffin sections and the levels of expression were assessed semiquantitatively. The extent of staining was assessed by the extent score in order to determine the overall level of expression. The extent scores of MT1-MMP, MMP-2 and TIMP-2 in grade 2 chondrosarcoma were significantly higher than those in either enchondroma or grade 1 chondrosarcoma (P < 0.05). In conventional chondrosarcoma, significant correlations were found between the extent scores of MT1-MMP and MMP-2 (P < 0.001), MT1-MMP and TIMP-2 (P < 0.01), and MMP-2 and TIMP-2 (P < 0.01). The undifferentiated small round tumor cells of mesenchymal chondrosarcoma showed lower positive rates and extent scores for MT1-MMP (2/7, 0.7 ± 0.5) and MMP-2 (3/7, 0.7 ± 0.4) than for cartilaginous components of mesenchymal chondrosarcoma [MT1-MMP (4/7, 1.3 ± 0.5) and MMP-2 (7/7, 1.9 ± 0.3)] or conventional chondrosarcoma. In dedifferentiated chondrosarcoma, the extent scores of MT1-MMP, MMP-2 and TIMP-2 in low-grade cartilaginous components were not significantly different from those in conventional chondrosarcoma; however, the high-grade anaplastic components showed high extent scores for MT1-MMP, MMP-2 and TIMP-2, compared with the low-grade cartilaginous components of dedifferentiated chondrosarcoma or conventional chondrosarcoma. According to our results, the expression of MT1-MMP as well as that of MMP-2 or TIMP-2 demonstrated a significant correlation with the tumor grade in human cartilaginous tumors. Furthermore, the expressions of MT1-MMP, MMP-2 and TIMP-2 were also found to play a crucial role in invasion in the high-grade components of dedifferentiated chondrosarcoma. Received: 17 February 1999 / Accepted: 21 April 1999     

膜型基质金属蛋白酶-1与肝细胞癌侵袭转移性的关系

目的 探索膜型基质金属蛋白酶－１（ｍｅｍｂｒａｎｅ－ｔｙｐｅ１ｍａｔｒｉｘ ｍｅｔａｌｌｏｐｒｏｔｅｉｎａｓｅ,ＭＴ１－ＭＭＰ）与肝细胞癌（ＨＣＣ）侵袭转移性的关系及以ＭＴ１－ＭＭＰ来判断肝细胞癌侵袭转移性的可能性和方法。方法 通过ＲＴ－ＰＣＲ对正常肝、ＨＣＣ及其癌旁组织、癌栓组织,裸鼠人肝癌高、低转移模型中的ＭＴ１－ＭＭＰｍＲＮＡ进行半定量研究,并与ＨＣＣ侵龚转移的病理指标进行统计分析,结果 正     

Survivin gene expression in endometriosis

Survivin is a novel inhibitor of apoptosis and is expressed during fetal development and in cancer tissues, but its expression has not been reported in normal adult tissues or benign diseases. We investigated survivin gene and protein expression in a tumor-like benign disease, endometriosis, and correlated them with apoptosis and invasive phenotype of endometriotic tissues. Gene expression levels of survivin, matrix metalloproteinase (MMP)-2, MMP-9, and membrane type 1 (MT1)-MMP in 63 pigmented or nonpigmented endometriotic tissues surgically obtained from 35 women with endometriosis were compared with those in normal eutopic endometrium obtained from 12 women without endometriosis. Survivin, MMP-2, MMP-9, and MT1-MMP mRNA expression levels in clinically aggressive pigmented lesions were significantly higher than those in normal eutopic endometrium, and survivin gene expression in pigmented lesions was also higher than that in nonpigmented lesions (P < 0.05). There was a close correlation between survivin and MMP-2, MMP-9, or MT1-MMP gene expression levels in 63 endometriotic tissues examined (P < 0.01). Apoptotic cells detected by the dUTP nick-end labeling were rare in 11 ovarian endometriotic tissues, which showed positive immunohistochemical expression for survivin and MMPs. Our findings suggest that up-regulation of survivin and MMPs may cooperatively contribute to survival and invasion of endometriosis.     

Membrane-type matrix metalloproteinase-1 (MT1-MMP) is down-regulated in estrogen-deficient rat osteoblast in vivo

Our previous study showed that estrogen stimulates membrane-type matrix metalloproteinases-1 (MT1-MMP) production in osteoblastic cells culture, but has no effect on MMP-2 and TIMP-2 synthesis. Osteoblast-derived MT1-MMP have been recently implied to play a role in bone metabolism by degrading tumor necrosis factor-alpha (TNF-alpha), resolving extracellular matrix and activating proMMP-2, which requires the process of activation mediated by MT1-MMP/tissue inhibitor of metalloproteinase (TIMP-2) complex on the cell surface. To investigate the mechanism of bone loss following estrogen deficiency, we examined the effects of estrogen on osteoblast synthesis of MT1-MMP, MMP-2 and TIMP-2. In situ hybridization and immunohistochemistry of rat bone samples were used to document the synthesis of MT1-MMP, MMP-2, and TIMP-2 mRNA and protein. Osteoblasts from distal femoral head showed an increase in the pattern of MT1-MMP mRNA and protein production in sham-operated controls and 17beta-estradiol (E2)-treated rats, compared with the ovariectomized group; the synthesis of MMP-2 and TIMP-2 mRNA and protein was unaffected. Our data show a down-regulation of MT1-MMP synthesis by osteoblast in vivo following estrogen withdrawal, and treatment with E2 resulted in induced MT1-MMP expression in vivo. There is evidence suggesting a role for MT1-MMP in the process of bone loss during the pathogenesis of osteoporosis.     

TIMP-2、MMP-2和MT1-MMP在活化肝星状细胞中的表达及对细胞外基质合成分泌的影响

目的 研究金属蛋白酶组织抑制剂-2(TIMP-2)、基质金属蛋白酶-2(MMP-2)和膜型基质金属蛋白酶-1(MT1-MMP)在活化肝星状细胞(HSCs)中的表达,观察其对细胞外基质(ECM)合成分泌的影响.方法 原代分离培养大鼠HSCs活化后,分别给予40～160 pmol化学合成经修饰抗TIMP-2 siRNA进行干预,检测培养细胞上清液透明质酸(HA)、Ⅲ型前胶原(PCⅢ)和羟脯氨酸(Hyp)的含量,采用荧光实时定量PCR法检测TIMP-2、MMP-2、MT1-MMP、MMP-13、COL Ⅰ和COL Ⅲ mRNA的表达,western印迹检测TIMP-2、MT1-MMP和MMP-13蛋白表达及明胶酶谱法检测MMP-2蛋白表达.结果 应用化学合成经修饰抗TIMP-2 siRNA后,TIMP-2、MMP-2、MT1-MMP、COL Ⅰ和COL Ⅲ的表达明显降低,而MMP-13的表达则明显增加,培养细胞上清液中HA、PCⅢ和Hyp的含量也明显减少.结论 TIMP-2通过MT1-MMP介导MMP-2的活化,抑制TIMP-2的表达,MT1-MMP和MMP-2的表达随之降低,而HSCs合成分泌ECM也相应减少.     

1,25-二羟维生素D3对人成骨细胞基质金属蛋白酶及其抑制因子的作用

目的　研究 1, 25 二羟维生素D3 [ 1α, 25 (OH)2D3 ]对人成骨细胞基质金属蛋白酶(MMP) 1、MMP 2、膜型基质金属蛋白酶 1 (MT1 MMP)、基质金属蛋白酶抑制因子 1 (TIMP 1 )的影响,探讨 1α, 25(OH)2D3 调节骨代谢作用机制。方法　人成骨细胞用 1α, 25 (OH)2D3 干预。Western杂交检测MT1 MMP蛋白质表达。MMP 1、MMP 2、TIMP 1的分泌及MMP 2的活性用ELISA检测。Northern杂交检测维生素D受体、MT1 MMPmRNA表达。结果　 1α, 25 (OH)2D3 对人成骨细胞MMP 1、MMP 2、TIMP 1表达无影响, 10-10 ~ 10-8 mol/L 1α, 25 (OH)2D3 干预诱导成骨细胞MT1 MMP表达呈剂量依赖性 (P值均 <0 05);促进MMP 2激活呈剂量依赖性 [MMP 2活性分别为(42 3 ± 8 6)、(64 4 ±11 4)、(93 5 ±9 9)μg/L, P值均<0 05]。结论　由于MT1 MMP在骨吸收过程中起着关键作用, 1α, 25(OH)2D3 可通过诱导成骨细胞MT1 MMP表达刺激骨吸收。     

Effects of hypoxia, hyperoxia on the regulation of expression and activity of matrix metalloproteinase-2 in hepatic stellate cells

AIM To study the effects of hypoxia,hyperoxia on theregulation of expression and activity of matrixmetalloproteinase-2 (MMP-2) in hepatic stellate cells(HSC).METHODS The expressions of MMP-2,tissue inhibitor ofmatrix metalloproteinass-2 (TIMP-2) and membrane typematrix matalloproteinass-1 (MT1-MMP) in cultured rat HSCwere detected by immunocytochemistry (ICC) and in situhybridization (ISH).The contents of MMP-2 and TIMP-2 inculture supernatant were detected with ELISA and theactivity of MMP-2 in supernatant was revealed byzymography.RESULTS In the situation of hypoxia for 12h,theexpression of MMP-2 protein was enhanced (hypoxiagroup positive indexes:5.7±2.0,n=10;control:3.2±1.0,n=7;P<0.05),while TIMP-2 protein was decreasedin HSC (hypoxla group positive indexes:2.5±0.7,n=10;control:3.6±1.0,n=7;P<0.05),and the activity(total A) of MMP-2 in suparnatant declined obviously(hypoxla group:7.334±1.922,n=9;control:17.277±7.424,n=11;P<0.01).Compared the varied duration ofhypoxia,the changes of expressions Including mRNA andprotein level as well as activity of MMP-2 were mostnotable in 6 h group.The highest value (Ahypoxla~-Acontrol) ofthe protein and the most intense signal of mRNA were inthe period of hypoxia for 6 h,along with the lowestactivity of MMP-2.In the situation of hyparoxia for 12 h,the contents (A_(450)) of MMP-2 and TIMP-2 in supernatantwere both higher than those in the control,especially theTIMP-2 (hyperoxla group:0.0499±0.0144,n=16;control:0.0219±0.0098,n=14;P<0.01),and so wasthe activity of MMP-2 (hyperoxia group:5.252±0.771,n=14;control:4.304±1.083,n=12;P<0.05),and the expression of MT1-MMP was increased.CONCLUSION HSC is sensitive to the oxygen,hypoxiaenhances the expression of MMP-2 and the effect is moremarked at the early stage;hyperoxia mainly raises theactivity of MMP-2.     

Apoptosis of human hepatic myofibroblasts promotes activation of matrix metalloproteinase-2

Liver fibrosis is potentially reversible after removal of the injurious agent. Fibrosis resolution is characterized by apoptosis of hepatic myofibroblasts and degradation of extracellular matrix components. Matrix metalloproteinase-2 (MMP-2) is involved in matrix remodeling. In the liver, it is synthesized by myofibroblasts, secreted as a proenzyme, and activated by membrane type-MMPs (MT-MMP) such as MT1-MMP. The goal of this work was to determine whether apoptosis induction in human hepatic myofibroblasts modulates the gene expression of MMP-2 and/or its activation by MT1-MMP. Induction of apoptosis by cytochalasin D or C(2)-ceramide did not modulate MMP-2 mRNA expression. In contrast, apoptosis was associated with marked activation of pro-MMP-2, as shown by gelatin zymography, which revealed the presence of the 59-kd active form, whereas untreated cells only expressed the 66-kd proform. SB-203580, a specific inhibitor of p38 (MAPK), selectively abrogated both C(2)-ceramide-induced apoptosis and pro-MMP-2 activation. Apoptosis-induced pro-MMP-2 activation was inhibited by the tissue inhibitors of metalloproteinases (TIMP)-2 but not by TIMP-1, implying involvement of an MT-MMP-mediated process. Induction of apoptosis by cytochalasin D and C(2)-ceramide upregulated MT1-MMP protein expression and MT1-MMP mRNA expression. In conclusion, apoptosis of hepatic myofibroblasts induces pro-MMP-2 activation through increased MT1-MMP expression. HEPATOLOGY 2002;36:615-622.)