丝裂原活化蛋白激酶激酶4与肿瘤转移

丝裂原活化蛋白激酶激酶4(MKK4)是丝裂原活化蛋白激酶(MAPK)信号转导通路组成的成员之一.研究发现,MKK4与肿瘤的发生和转移密切相关,作用机制复杂,能抑制肿瘤发生,近5%不同组织来源的肿瘤均有MKK4基因的功能突变缺失.MKK4基因也是一个转移抑制基因,能抑制多种肿瘤的转移.     

Dietary supplementation with methylseleninic acid, but not selenomethionine, reduces spontaneous metastasis of Lewis lung carcinoma in mice

The present study investigated the effects of dietary supplementation with methylseleninic acid (MSeA), in comparison with selenomethionine (SeMet), on spontaneous metastasis of Lewis lung carcinoma (LLC) in male C57BL/6 mice using intramuscular and subcutaneous injection models. Mice were fed AIN93G control diet or that diet supplemented with MSeA or SeMet at 2.5 mg selenium/kg for 4 weeks at which time they were injected intramuscularly or subcutaneously with 2.5 × 10(5) viable LLC cells. Experiments were terminated 2 weeks later for mice injected intramuscularly or 2 weeks after surgical removal of primary tumors from mice subcutaneously injected with cancer cells. Dietary supplementation with MSeA significantly reduced pulmonary metastatic yield when compared with the controls (p < 0.05) in both models; however, SeMet did not have such an effect. Supplementation with MSeA significantly decreased plasma concentrations of urokinase-type plasminogen activator (p < 0.05) and plasminogen activator inhibitor-1 (p < 0.05). Furthermore, MSeA significantly reduced plasma concentrations of vascular endothelial growth factor (p < 0.05), fibroblast growth factor basic (p < 0.05) and platelet-derived growth factor-BB (p < 0.05) when compared with the controls. Selenomethionine did not affect any of the aforementioned measurements. These results demonstrate that MSeA reduces spontaneous metastasis of LLC in mice, perhaps through inhibition of the urokinase plasminogen activator system and reducing angiogenesis.     

Novel markers for poor prognosis in head and neck cancer

Head and neck cancer (HNSCC) is one of the most distressing human cancers, causing pain and affecting the basic survival functions of breathing and swallowing. Mortality rates have not changed despite recent advances in radiotherapy and surgical treatment. We have compared the expression of over 13,000 unique genes in 7 cases of matched HNSCC and normal oral mucosa. Of the 1,260 genes that showed statistically significant differences in expression between normal and tumor tissue at the mRNA level, the three top ranking of the top 5% were selected for further analysis by immunohistochemistry on paraffin sections, along with the tumor suppressor genes p16 and p53, in a total of 62 patients including 55 for whom >4-year clinical data was available. Using univariate and multivariate survival analysis, we identified SPARC/osteonectin as a powerful independent prognostic marker for short disease-free interval (DFI) (p < 0.002) and poor overall survival (OS) (p = 0.018) of HNSCC patients. In combination with other ECM proteins found in our analysis, PAI-1 and uPA, the association with DFI and OS became even more significant (p < 0.001). Our study represents the first instance of SPARC as an independent prognostic marker in HNSCC.     

ELAM-1在鼻咽癌裸鼠移植瘤中的表达及其与转移的关系

目的 建立裸鼠鼻咽癌转移模型并探讨 E-选择素（ELAM-1）与鼻咽癌转移的相关性。方法 将鼻咽癌5-8F细胞悬液注射于裸鼠左后肢爪垫，观察裸鼠状态、成瘤情况并测量裸鼠体重及移植瘤长短径；采用连续病理切片苏木精-伊红染色观察移植瘤及转移情况，将16只人鼻咽癌荷瘤裸鼠分为转移组和非转移组；采用免疫组织化学法检测两组移植瘤组织中ELAM-1的表达。 结果 16只裸鼠均成瘤，成瘤率为100.0%，其中10只裸鼠出现转移瘤，转移率为62.5%。建模前，两组裸鼠体重差异无统计学意义［（13.83±0.56）g vs （14.62±0.30） g，t=1.026，P=0.071］。建模后4~7周，裸鼠瘤体体积呈指数增长，且转移组移植瘤增长速度较非转移组快，非转移组裸鼠瘤体体积小于转移组［（198.91 ± 163.29） mm³ vs （268.76 ±174.31） mm³，t=4.376，P=0.005］。ELAM-1在鼻咽癌裸鼠移植瘤、淋巴结转移灶及远处转移灶中的表达均为阳性，主要表达于细胞膜。转移组移植瘤光密度值高于非转移组（0.4497±0.0705 vs 0.0435±0.0082，t=4.388，P＝0.001）。结论 本研究成功构建稳定性好、转移率高的鼻咽癌裸鼠移植瘤转移模型，且ELAM-1在裸鼠移植瘤中高表达，可促进鼻咽癌裸鼠移植瘤生长和转移。     

LIM kinase 1 increases tumor metastasis of human breast cancer cells via regulation of the urokinase-type plasminogen activator system

Mammalian LIM kinase 1 (LIMK1) phosphorylates and inactivates the actin-binding and -depolymerizing factor cofilin and induces actin cytoskeletal changes. LIMK1 is reported to play an important role in cell motility, but the mechanism of induction of cell motility and the role of LIMK1 in tumor growth, angiogenesis and invasion are poorly understood. Here we show that expression of LIMK1 in MDA-MB-435 human breast cancer cells enhanced cell proliferation and cell invasiveness and promoted in vitro angiogenesis. Since tumor metastasis requires degradation of the extracellular matrix by the serine protease urokinase type plasminogen activator (uPA), we examined the role of LIMK1 in the regulation of uPA/uPAR system. LIMK1 overexpression in breast cancer cells upregulated the uPA system, increased uPA promoter activity, induced uPA and uPAR mRNA and protein expression and induced uPA secretion. In contrast, cells transfected with the catalytically inactive LIMK mutant D460N-LIMK1 did not exhibit these phenotypic changes. Blocking antibodies against uPA and uPAR suppressed LIMK1-induced cell invasiveness. In addition, LIMK1 overexpression increased tumor growth in female athymic nude mice, promoted tumor angiogenesis and induced metastasis to livers and lungs, possibly by increasing uPA expression in the tumors. Finally, LIMK1 and uPAR were coordinately overexpressed in human breast tumors. These results suggested an important role for LIMK1 signaling in breast cancer tumor growth, angiogenesis and invasion and a regulatory connection between LIMK1 and the uPA system.     

Correlation between Expression of P38 MAPK-Signaling and uPA in Breast Cancer

OBJECTIVE To study the expression of phosphorylated p38 mitogen-activated protein kinase(p-p38)and uPA and the correlation of their expression with breast cancer clinicopathological characteristics,and to investigate the role of the p38MAPK-signaling pathway in regulating uPA expression in breast cancer cells. METHODS Immunohistochemistry(S-P) was used to test the expression of p-p38 and uPA in 60 specimens of breast cancer tissues.Western blots were adopted to detect expression of the p-p38 and uPA proteins in MDA-MB-231 and MCF-7 breast cancer cells,and uPA expression a er treatment with SB203580,a specific inhibitor of p38 MAPK. RESULTS The positive rate of the p-p38 protein and uPA protein expression in the breast cancer tissues was 56.7% and 60.0%,respectively.The expression of p-p38 was positively related to the expression of uPA(r=0.316,P<0.05).The expression of p-p38 and uPA was related to lymph node metastas is and the TNM stage(P<0.05),but it was not related to the patient’s age or tumor size(P>0.05).The expression of p-p38 and uPA in MDA-MB-231 cells was higher than that in MCF-7 cells.SB203580 inhibited the p38 MAPK pathway and reduced uPA protein expression. CONCLUSION The p38 MAPK-signaling pathway promotes breast cancer malignant progression by up-regulating uPA expression,and it may be an important process in breast cancer invasion and metastasis.     

Y-box factor YB-1 predicts drug resistance and patient outcome in breast cancer independent of clinically relevant tumor biologic factors HER2, uPA and PAI-1.

Intrinsic or acquired resistance to chemotherapy is responsible for failure of current treatment regimens in breast cancer patients. The Y-box protein YB-1 regulates expression of the P-glycoprotein gene mdr1, which plays a major role in the development of a multidrug-resistant tumor phenotype. In human breast cancer, overexpression and nuclear localization of YB-1 is associated with upregulation of P-glycoprotein. In our pilot study, we analyzed the clinical relevance of YB-1 expression in breast cancer (n = 83) after a median follow-up of 61 months and compared it with tumor-biologic factors already used for clinical risk-group discrimination, i.e., HER2, urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1). High YB-1 expression in tumor tissue and surrounding benign breast epithelial cells was significantly associated with poor patient outcome. In patients who received postoperative chemotherapy, the 5-year relapse rate was 66% in patients with high YB-1 expression. In contrast, in patients with low YB-1 expressions, no relapse has been observed so far. YB-1 expression thus indicates clinical drug resistance in breast cancer. Moreover, YB-1 correlates with breast cancer aggressiveness: in patients not treated with postoperative chemotherapy, those with low YB-1 expression are still free of disease, whereas the 5-year relapse rate in those with high YB-1 was 30%. There was no significant correlation between YB-1 expression and either HER2 expression or uPA and PAI-1 levels. Risk-group assessment achieved by YB-1 differed significantly from that by HER2 or uPA/PAI-1. In conclusion, YB-1 demonstrated prognostic and predictive significance in breast cancer by identifying high-risk patients in both the presence and absence of postoperative chemotherapy, independent of tumor-biologic factors currently available for clinical decision making.     

小鼠可移植性网织细胞肉瘤L_Ⅱ自发转移性的观察

本实验将小鼠可移植性网织细胞肉瘤ＬⅡ接种子近交系６１５小鼠体内进行自发转移特性的观察。实验分为两组，Ａ组将定量（１×１０）的ＬⅡ瘤细胞接种于小鼠右后肢肌肉内，Ｂ组将等量的瘤细胞接种于小鼠右肋部皮下，待荷瘤小鼠自然死亡或濒死状态时处死，取出全肺及各部位淋巴结进行组织学检查。结果发现２４只右后肢肌肉接种的动物，中间存活时间为２８天，全部实验动物均发生淋巴结和肺转移；２３只右肋皮下接种的动物，中间存活时间为３９天，有９５．７％（２２／２３只）发生淋巴结转移，６０．９％（１４／２３只）出现肺转移，而淋巴结合并肺转移者５６．５％（１３／２３只）。结果表明，本瘤株具有淋巴结合并肺部双向转移的特性。     

Two distinct expression patterns of urokinase,urokinase receptor and plasminogen activator inhibitor‐1 in colon cancer liver metastases

Metastatic growth and invasion by colon cancer cells in the liver requires the ability of the cancer cells to interact with the new tissue environment. Plasmin(ogen) is activated on cell surfaces by urokinase‐type PA (uPA), and is regulated by uPAR and plasminogen activator inhibitor‐1 (PAI‐1). To compare the expression patterns of uPA, uPAR and PAI‐1 in colon cancer with that in their liver metastases, we analysed matched samples from 14 patients. In all 14 primary colon cancers, we found upregulation of uPAR, uPA mRNA and PAI‐1 in primarily stromal cells at the invasive front. In 5 of the 14 liver metastases, we found intense expression of uPAR, uPA‐mRNA and PAI‐1 in primarily stromal cells at the metastases periphery, and in an expression pattern similar to that found in the primary tumours. In the remaining 9 liver metastases, uPAR and uPA‐mRNA were only seen associated with the presence of necrosis within the liver metastases. In addition, PAI‐1‐immunoreactivity was in all liver metastases seen in hepatocytes at the metastases periphery. Interestingly, the former 5 liver metastases positive for uPAR, uPA mRNA and PAI‐1 at the metastasis periphery all had a predominantly desmoplastic reaction, whereas 8 of the remaining 9 showed direct contact between the cancer cells and the liver parenchyma. We conclude that there are 2 distinct patterns of expression of uPAR, uPA and PAI‐1 in colon cancer liver metastases and that these correlate closely with 2 morphological growth patterns. These findings may have implication for the treatment of patients with metastatic disease. © 2008 Wiley‐Liss, Inc.     

Deletion of cyclooxygenase-2 inhibits K-ras–induced lung carcinogenesis

The purpose of this study was to identify the role COX-2 plays in K-ras–induced lung carcinogenesis. We crossed COX-2–homozygous knockout mice with K-ras^LA1 (G12D) expressing mice to obtain COX-2–deficient mice with K-ras expression (K-ras/COX-2^−/− mice) and COX-2 wild type mice with K-ras expression (K-ras mice). At 3.5 months of age, the K-ras/COX-2^−/− mice had significantly fewer lung adenocarcinomas and substantially smaller tumors than K-ras mice. K-ras/COX-2^−/− mice also had significantly fewer bronchioalveolar hyperplasias than K-ras mice. Compared with lung tumors from K-Ras mice, the levels of prostaglandin E₂ (PGE₂) were significantly lower, whereas levels of the PGE₂ metabolite 13,14-dihydro-15-keto-PGE₂ were significantly higher, in lung tumors from K-ras/COX-2^−/− mice. In addition, K-ras/COX-2^−/− mice had strikingly lower rates of tumor cell proliferation and expressed less MEK and p-Erk1/2 protein than K-ras mice did. In line with this, knocking down COX-2 in mutant K-ras non-small cell lung cancer A549 cells reduced colony formation, PGE₂ synthesis and ERK phosphorylation compared to that of vector control cells. Taken together, these findings suggest that COX-2 deletion contributes to the repression of K-ras–induced lung tumorigenesis by reducing tumor cell proliferation, decreasing the production of PGE₂, and increasing the production of 13,14-dihydro-15-keto-PGE₂, possibly via the MAPK pathway. Thus, COX-2 is likely important in lung tumorigenesis, and COX-2 and its product, PGE₂, are potential targets for lung cancer prevention.     

非小细胞肺癌淋巴结转移相关因素的研究

目的：检测尿激酶纤溶酶原激活物（uPA）、尿激酶纤溶酶原激活物抑制剂（PAI-1）、血管内皮生长因子（VEGF）和微m管密度（MVD）在非小细胞肺癌（NSCLC）组织中的表达以及与淋巴结转移的关系。方法：采用免疫组织化学方法联合检测52例NSCLC组织中uPA、PAI—1、VEGF和MVD的表达水平。结果：uPA、PAI—1、VEGF和MVD在NSCLC中的表达显著高于正常肺组织,影响淋巴结转移的相关因素是TNM分期（P〈0．001）、肿瘤侵犯程度（P=0．034）、uPA表达（P=0．048）、VEGF表达（P=0．047）。多因素分析表明VEGF高表达是淋巴结转移的独立影响因素（P=0．043）。结论：uPA、VEGF高表达与NSCLC的淋巴结转移密切相关,促进了肿瘤转移。     

Nm23 GENE EXPRESSION AND ITS CORRELATION WITH LYMPH NODE METASTASIS IN HUMAN LUNG CANCER

雷文东，张汝刚，阎水忠，王秀琴，牟巨伟，张大为，吴Ｎｍ２３ＧＥＮＥＥＸＰＲＥＳＳＩＯＮＡＮＤＩＴＳＣＯＲＲＥＬＡＴＩＯＮＷＩＴＨＬＹＭＰＨＮＯＤＥＭＥＴＡＳＴＡＳＩＳＩＮＨＵＭＡＮＬＵＮＧＣＡＮＣＥＲ￥ＬｅｉＷｅｎｄｏｎｇ；ＺｈａｎｇＲｏｕｇｉｎｇ；...     

甘氨双唑钠对H22肝癌移植小鼠肺转移的影响

目的研究新型放射增敏剂甘氨双唑钠对远处转移的影响。方法建立昆明小鼠皮下H22肝癌移植模型,设对照组、单放组、甘氨双唑钠 照射组、氟尿嘧啶 照射组。治疗后比较各组肺转移情况,并进一步研究该药对肿瘤增殖核抗原(PCNA)、血管内皮生长因子(VEGF)、肿瘤内微血管密度(MVD)表达及血浆T细胞亚群的影响。结果甘氨双唑钠 照射组未发现转移,其余组均有转移。对照组、单放组、氟尿嘧啶 照射组、甘氨双唑钠 照射组PCNA计数分别为120.29、59.71、55.43、21.86(F=245.00,P<0.01),VEGF评分分别为4.64、5.86、4.89、3.27(F=4.56,P<0.05),MVD计数分别为37.29、53.29、40.14、27.43(F=7.48,P<0.01)。甘氨双唑钠 照射组与单放组比CD4、CD8、CD4/CD8无明显差异。结论小鼠皮下H22肝癌移植模型显示甘氨双唑钠能减少肺转移,可能与肿瘤内VEGF、MVD表达减少有关,但对T细胞亚群则无明显影响。     

Role of skip metastasis to mediastinal lymph nodes in non-small cell lung cancer

BACKGROUND: Skip metastasis to mediastinal lymph nodes is a well-known phenomenon in non-small cell lung cancer (NSCLC). Little is reported in the literature about its clinical importance. It is still under discussion whether any prognostic differences exist between resected NSCLC with either skip metastases or continuous mediastinal lymph node metastases (N2). PATIENTS AND METHODS: We analyzed retrospectively the data of 45 patients with a pN2-stage, who underwent resection for NSCLC. Seventeen of these patients (37.8%), showing no metastatic involvement of hilar (N1) lymph nodes, were compared to the remaining 28 patients with infiltration of hilar nodes (N1) as well as N2 nodes. RESULTS: Multivariate analysis showed no statistically significant difference between the skip metastasis and the continuous N2 group regarding sex, age, histology, T- or M-status. The frequency of skip metastasis was higher in patients with a primary tumor in the upper lobe (n = 12, 71%) compared to the lower lobe (n = 5, 29%). This difference was not statistically significant. In patients with a non-continuous lymph node spread, 29 out of 119 resected mediastinal lymph nodes were infiltrated (1.7 per patient, range: 1-10). Compared to 83 metastatic involved lymph nodes out of 198 resected mediastinal nodes (three per patient, range: 1-10) in patients with involvement of N1 and N2 nodes (P = 0.034, Mann-Whitney test). The 5-year survival rate of pN2 patients with skip metastasis was 41% compared to 14% in patients with involvement of N1 and N2 nodes (P = 0.019). CONCLUSIONS: pN2 patients with mediastinal lymph node skip metastasis have a more favorable prognosis compared to pN2 patients with continuous infiltration of the regional lymph nodes. Patients with a continuous lymph node involvement show an increased number of infiltrated mediastinal lymph nodes per patient compared to patients with a non-continuous spread. Skip metastasis is an independent prognostic factor of survival. The presence of skip metastasis seems to be a unique subgroup of pN2 disease in NSCLC.