结肠癌组织中p53和凋亡相关基因bcl-2、bax的表达及其临床意义

组织芯片已广泛应用于恶性肿瘤的相关研究，但用于研究相关癌基因在结肠癌中表达变化的报道尚较少。目的：研究结肠癌、结肠腺瘤和癌旁结肠黏膜组织中p53和凋亡相关基因bcl-2、bax的表达及其临床意义。方法 取85例结肠癌、18例结肠腺瘤和9例癌旁结肠黏膜组织分别制成72点和104点两块组织芯片，以免疫组化方法检测芯片中p53、bel-2和bax的表达。结果：p53、bcl．2和bax在结肠癌、结肠腺瘤和癌旁结肠黏膜组织中的表达有显著差异（P〈0．01），p53、bel-2在结肠癌中的表达高于结肠腺瘤和癌旁结肠黏膜组织，bax在结肠癌中的表达低于结肠腺瘤和癌旁结肠黏膜组织。p53和bax在不同组织学分化程度结肠癌中的表达有显著差异（P〈0．01，P〈0．05），但两者之间无相关性（L=-0．081，P〉0．05），p53与bcl-2的表达呈正相关（rs=0．245，P〈0．01）。bcl-2的表达与结肠癌临床病理参数无关。结论：p53异常表达可能是结肠癌发生中的较晚期事件，bcl-2高表达和bax低表达可能参与了结肠癌的形成过程。bax低表达的结肠癌细胞更具有恶性分化潜能。     

Pharmacological Inhibition of Protein Kinase C Activity Could Induce Apoptosis in Gastric Cancer Cells by Differential Regulation of Apoptosis-Related Genes

The protein kinase C (PKC) signaling pathwayplays a key role in tumor cell proliferation,differentiation, and apoptosis. Gastric cancer usuallypossesses a higher level of PKC activity than normaltissue. We evaluated inhibition of PKC activity inapoptosis induction of gastric cancer cells and theexpression profile of apoptosis-related genes. Gastriccancer cells (AGS) were incubated with two highlyspecific PKC inhibitors (RO-31-8220 and chelerythrine).Cell viability and cell cycle were determined bymethyl-tetrazolium (MTT) assay and flow cytometry,respectively. Apoptosis was characterized by acridineorange staining, DNA gel electrophoresis, and flowcytometry. The expression of p53,p21^waf/cip1, c-myc, bcl-2, and bax wasdetermined by western blot. The results showed that bothPKC inhibitors hindered cell growth, arrested cells atG₀/G₁ phase and induced apoptosis.The protein level of p53, p21^waf/cip1, c-myc,and bax was elevated while bcl-2 kept unchangedfollowing drug exposure. In conclusion, PKC inhibitorssuppress growth of gastric cancer cells throughapoptosis induction and cell cycle quiescence, which maybe regulated by differential expression ofapoptosis-related genes.     

Early Carcinogenic Events in HNPCC Adenomas: Differences with Sporadic Adenomas

Background Tumorigenesis in hereditary nonpolyposis colorectal cancer (HNPCC) differs from that in sporadic colorectal cancer during the early stage. We examined the expression of proliferation- and apoptosis-regulating proteins in relation to proliferation and apoptosis in HNPCC and sporadic adenomas. Methods Proliferation and apoptosis were quantified, and the expression of cyclin B1, D3 and E, p21, p27, bcl-2, bax, p53 and cox-2 was determined by immunohistochemistry in 100 patients (42 with HNPCC and 48 with sporadic adenomas). Results No differences between the two groups of patients in terms of proliferation and apoptosis were detected. Low-grade dysplastic HNPCC adenomas differed from sporadic ones by expressing bcl-2 more often (69 vs. 42%) and bax less often (50 vs. 73%). In comparison to sporadic adenomas, fewer high-grade dysplastic HNPCC expressed cyclin B1 and E (50 and 38% vs. 87 and 87%, respectively), p21 (6% vs. 53%) and bax (31% vs. 80%). In addition, HNPCC adenomas had a lower overexpression of p53 (5 vs. 19%). Conclusion The expression of cell cycle- and apoptosis-related proteins differs between HNPCC and sporadic adenomas from early through to advanced stages although proliferation and apoptosis are not different. These differences may contribute to the different clinical behavior of HNPCC and sporadic adenomas.     

Prognostic significance of bcl-2, bax,and p53 expression in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLCL) exhibits heterogeneous clinical features and varies markedly in response to treatment and prognosis. Because apoptosis-related proteins may play an important role in predicting the prognosis of DLCL, the current study investigated the prognostic significance of a high level of bcl-2, bax, and p53 expression in relation to clinical characteristics in patients with DLCL. Paraffin-embedded specimens from 94 patients with de novo DLCL were analyzed immunohistochemically for bcl-2, bax, and p53 gene expression. Cases with a positive immunohistological stain in more than 50% of the tumor cells were considered to have DLCL-positive expression. Patients were treated optimally, i.e., with radiotherapy including brief cycles of CHOP or CHOP-like regimens for patients with stage 1-2A diseases and with at least 6 cycles of CHOP or CHOP-like regimens for stage 2B-4 diseases. The responses to therapy and survival were then analyzed in 94 uniformly staged patients. bcl-2 expression was identified in 24 patients (26.4%), bax expression in 35 patients (37.6 %), and p53 expression in 21 patients (22.6%). bax expression proved to be a statistically significant prognostic factor in predicting the overall survival (OS) (P = 0.0015) and disease-free survival (DFS) (P = 0.0052), regardless of other clinical factors or immunohistological results. There was no significant difference in the OS (P = 0.0682) or DFS (P = 0.088) between the bcl-2-positive (n = 24) and bcl-2-negative (n = 67) groups. However, bcl-2 expression was found to be unfavorably associated with the OS (P = 0.0054) in a confined group with low (n = 51) or low intermediate (n = 22) IPI scores. The expression of p53 exhibited no statistical correlation with the OS or DFS. A multivariate analysis revealed that IPI score, bulky mass, and bax expression were all significantly associated with the DFS or OS. bax and bcl-2 should be considered as independent biologic prognostic parameters in DLCL, thereby aiding in the identification of patient risk groups. As such, bcl-2-positive patients with a low or low intermediate IPI score, or without a high level of bax expression could be candidates for more intensive therapy or alternative therapeutic approaches.     

Dynamic expression of apoptosis-related genes during development of laboratory hepatocellular carcinoma and its relation to apoptosis

AIM:To explore the expression of p53,bcl-2,bax,survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma(HCC),the relationship between expression of these genes,its impact on HCC development,and its relation to cell apoptosis.METHONS:Tree shrew HCC was induced with aflatoxin B1(AFB1),and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement.Liver biopsy tisue and HCC tissue were collected from 35pre-cancerous experimental animats at wk 30 and 60 and at the 30th_,60th_,and 90th-wk,Liver biopsy tissues were collected from 13 blank control animals at wk 30,60,and 90.Expression of p53,bcl-2,bax,and survivin at each stage was examined by immunohistochemistry method.Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling(tunel)technique.RESULTS:The apoptosis rate of normal hepatic cells was extremely low,whereas it increased during the formation of HCC.Expression of the apoptosis-related genes p53,bd-2,bax,and suvivin during the formation of HCC presented an increasing tendency.Expression of p53 did not noticeably relate to that of bcl-2,bax,and survivin,whereas expression of bcl-2 and bax was closely related.In HCC,p53 did not present a distinct relation to cell apoptosis,whereas its high level expression was probably related to liver cell proliferation.Survivin negetively correlated apoptosis index,and its overexpression could inhibit cell apoptosis.CONCLUSION:Apoptosis-related genes p53,bcl-2,bax,and survivin are all related to the occurrence of HCC.The anti-apoptosis effect of bcl-2 is influenced by bax,and ratio bcl/bax reflects more correctly the extent of cell apoptosis.     

Doxorubicin and a butyric acid derivative effectively reduce levels of BCL-2 protein in the cells of chronic lymphocytic leukemia patient

B-chronic lymphocytic leukemia (B-CLL) is a disease caused primarily by defects in the apoptosis mechanism. AN-9, a butyric acid (BA) derivative, is a potent differentiating and an anti-cancer drug that induces apoptosis in HL-60 cells. Herein we show the affect of AN-9, alone and in combination with doxorubicin, on cell cultures from B-CLL patients. Cells from 17 patients were cultured and tested for viability, apoptosis, bcl-2 and bax protein expression. Exposure of B-CLL cell cultures to AN-9 was accompanied by apoptosis and a marked viability loss (up to 46%, p=0.0017). AN-9 reduced up to 51% (p=0.0017) the levels of bcl-2 in 57% of the cultures that express bcl-2. The combination of low concentrations of AN-9 and doxorubicin more than additively enhanced apoptosis and reduced bcl-2 levels in B-CLL cultures which were resistant to AN-9. AN-9 enhanced bax expression up to 58%(p=0.008) in cultures from 53% of the patients, but had no effect on bax levels when combined with doxorubicin. In conclusion, AN-9 alone reduced bcl-2 and enhanced bax expression in cultures from B-CLL patients, and the reduction of bcl-2 levels in combination with doxorubicin was greater than additive. These results may be beneficial in possible future combination therapy with AN-9 in B-CLL.     

叶酸对胃癌前病变bcl-2、bax及p53 基因的影响

目的研究叶酸治疗对胃癌前病变组织中bcl-2、bax及p53基因表达的影响.方法胃镜活检经病理证实为胃癌前病变患者38例,利用逆转录聚合酶链式反应(RT-PCR)方法检测胃癌前病变组织bcl-2、bax基因表达率,利用流式细胞仪检测组织p53蛋白表达率.将患者随机分为治疗组(叶酸10mg,每天三次)与对照组(硫糖铝1.0,每天四次)各19例,治疗结束复查组织中bcl-2,bax基因表达率及p53蛋白表达率.结果治疗组治疗后bcl-2基因表达率降低(P<0.05),bax基因表达率无明显变化(P>0.05),p53蛋白表达率增高(P<0.05),对照组治疗后各项指标无明显变化(P>0.05).结论叶酸干预可促进胃癌前病变组织中p53基因的表达,抑制bcl-2基因的表达,而对bax基因表达无明显影响.     

Dynamic expression of apoptosis-related genes during development of laboratory hepatocellular carcinoma and its relation to apoptosis

AIM: To explore the expression of p53, bcl-2, bax, survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma (HCC), the relationship between expression of these genes, its impact on HCC development, and its relation to cell apoptosis. METHODS: Tree shrew HCC was induced with aflatoxin B1 (AFB1), and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement. Liver biopsy tissue and HCC tissue were collected from 35 pre-cancerous experimental animals at wk 30 and 60 and at the 30th-, 60th-, and 90th-wk. Liver biopsy tissues were collected from 13 blank control animals at wk 30, 60, and 90. Expression of p53, bcl-2, bax, and survivin at each stage was examined by immunohistochemistry method. Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) technique. RESULTS: The apoptosis rate of normal hepatic cells was extremely low, whereas it increased during the formation of HCC. Expression of the apoptosis-related genes p53, bd-2, bax, and survivin during the formation of HCC presented an increasing tendency. Expression of p53 did not noticeably relate to that of bcl-2, bax, and survivin, whereas expression of bcl-2 and bax was closely related. In HCC, p53 did not present a distinct relation to cell apoptosis, whereas its high level expression was probably related to liver cell proliferation. Survivin negatively correlated apoptosis index, and its overexpression could inhibit cell apoptosis. CONCLUSION: Apoptosis-related genes p53, bcl-2, bax, and survivin are all related to the occurrence of HCC. The anti-apoptosis effect of bcl-2 is influenced by bax, and ratio bcl/bax reflects more correctly the extent of cell apoptosis.     

Molecular features of primary mediastinal B-cell lymphoma: involvement of p16INK4A, p53 and c-myc

Primary mediastinal B-cell lymphoma (PMBL) shows chromosome 9p anomalies in 50% of cases. Based on reports that p16INK4A gene, located on this chromosomal arm, is frequently altered in aggressive lymphomas, we analysed for alterations of this gene in 27 cases of PMBL, which were part of a series of 32 PMBL cases that have been characterized for alterations in c-myc, p53, N-ras, bcl-1, bcl-2, bcl-6 and for Epstein-Barr virus (EBV) infection. Four cases showed p16INK4A gene anomalies, including three with promoter methylation and one homozygous deletion. Eight PMBLs showed c-myc rearrangements. Three additional cases showed sequence variations in the c-myc P2 promoter, two of which consisted of the same germline variation involving a novel polymorphic XhoI site. Four tumours contained p53 gene mutations and three had clonal EBV infection. One case had a bcl-6 rearrangement. In conclusion, our study shows that p16INK4, c-myc and p53 alterations occur in 15%, 25% and 13% of PMBLs, respectively. EBV monoclonality was found in 9% of cases, whereas no abnormality was detected in bcl-1, bcl-2 and N-ras. Thus, none of the common genetic aberrations seen in other types of non-Hodgkin's lymphomas appears to be stringently involved in the pathogenesis of this unique lymphoma type.     

Expression of p53, bcl-2, and bax as predictors of response to radiotherapy in esophageal cancer

The sensitivity of cancers to radiotherapy or chemotherapy may be influenced by susceptibility to apoptosis. We evaluated whether expression of three proteins regulating apoptosis, p53, bcl-2, and bax, could predict the effect of radiotherapy in esophageal cancers. We used immunohistochemical staining for these protein regulators of apoptosis to study biopsy specimens obtained from 25 patients with esophageal squamous cell carcinoma before they underwent preoperative radiotherapy. Effectiveness of radiotherapy was assessed by barium esophagography, esophagoscopy, and computed tomography. Radiotherapy was effective in 12 patients and ineffective in 13 patients. Biopsy specimens from the 25 patients showed expression of p53, bcl-2, and bax to be 48.0%, 32.0%, and 76.0% respectively. Effectiveness of radiotherapy was correlated with p53 expression (p = 0.047), but bcl-2 and bax expression showed no relationship to effectiveness of radiotherapy. Expression of p53 protein in biopsy specimens may predict effectiveness of preoperative radiotherapy in esophageal cancers.     

Helicobacter pylori infection generated gastric cancer through p53-Rb tumor-suppressor system mutation and telomerase reactivation

AIM: To investigate the relationship between Helicobacterpylori (H. pylori) infection and the expressions of the p53,Rb, c-myc, bcl-2 and hTERT mRNA in a series of diseasesfrom chronic gastritis (CG), intestinal metaplasia type Ⅰ or Ⅱ(IMⅠ-Ⅱ), intestinal metaplasia type Ⅲ (IMⅢ), mild or modestdysplasia (DysⅠ-Ⅱ), severe dysplasia (DysⅢ) to gastric cancer(GC) and to elucidate the mechanism of gastriccarcinogenesis relating to H.pyloriinfection.METHODS: 272 cases between 1998 and 2001 wereavailable for the study including 42 cases of CG, 46 cases ofIMⅠ-Ⅱ, 25 cases of IMⅢ, 48 cases of DysⅠ-Ⅱ, 27 cases ofDysⅢ, 84 cases of GC.-H. pyloriinfection and the expressionsof p53, Rb, c-myc, bcl-2 were detected by means ofstreptavidin-peroxidase (SP) immunohistochemical method.HTERT mRNA was detected byin situ hybridization(ISH).RESULTS: The expressions of p53, Rb, c-myc, hTERT mRNAand bcl-2 were higher in the GC than in CG, IN, Dys. Theexpression of c-myc was higher in IMⅢ with-H.pyloriinfection(10/16) than that without infection (1/9) and the positive ratein DysⅠ-Ⅱ and DysⅢ with-H.pyloriinfection was 18/30 and 13/17, respectively, higher than that without infection (4/18 and3/10, respectively). In our experiment mutated p53 had noassociation with H.pyloriinfection, theexpression of Rb wasassociated with-H. pyloriinfection in GC, but the p53-Rb tumor-suppressor system abnormal in DysⅠ-Ⅱ cases, DysⅢⅡ and GCcases with H. pyloriinfection was 21/30, 15/17 and 48/48respecively, higher than non-infection groups (4/18, 3/10, 28/36). Furthermore the level of hTERT mRNA in GC with H. pyloriinfection (47/48) was higher than that without infection (30/36), however the relationship between bcl-2 and H. pyloriwasonly in IMⅢ. C-myc had a close association with hTERT mRNAin DysⅢ and GC (P＝0.0 253,0.0 305 respectively).CONCLUSION: In the gastric carcinogenesis, H. pylorimightcause the severe imbalance of proliferation and apoptosisin the precancerous lesions (IMⅢ and GysⅢ) first, leadingto p53-Rb tumor-suppressor system mutation and telomerasereactivation, and finally causes gastric cancer.     

Expression of apoptosis regulators Bcl-2 and Bax in childhood acute lymphoblastic leukemia

Twenty-five children (19 M:6 F) with newly diagnosed ALL with median age of 5.5 years (1 month-12 years) were enrolled in the study. Apoptosis regulator proteins bcl-2 and bax were measured in all patients using alkaline phosphatase anti-alkaline phosphatase method. Twenty-one patients were positive for bcl-2 and 23 cases for Bax, although expression levels varied. Patients who presented with splenomegaly or hepatomegaly < 5 cm expressed significantly higher levels of bcl-2 and bax protein expression. Neither of age ( < or >10 years), sex, generalized lymphadenopathy, WBC ( < or >50,000/mul) or FAB subtype was associated with high levels of bcl-2 or bax protein expression. Patients with higher mean hemoglobin levels (p = 0.009), high blast % in bone marrow (p = 0.02), immature immunophenotype (p = 0.001) exhibited signifxicantly higher bcl-2 levels. Bcl-2/bax ratio correlated inversely with TLC at presentation (p = 0.022; r = - 0.456) and in B-lineage leukemic cells as compared to T-lineage cells (p = 0.002). Bcl-2/bax ratio did not correlate with any other variable measured. Bcl-2 and bax protein co-express in ALL and high bcl-2/bax ratio correlates with good prognosis features.     

Growth,invasion, metastasis,differentiation, angiogenesis and apoptosis of gastric cancer regulated by expression of PTEN encoding products

AIM: To investigate expression of PTEN in gastric cancer and to explore its roles in tumorigenesis and progression of gastric cancer.METHODS: Formalin-fixed and paraffin-embedded tissues of adjacent non-tumor mucosa and primary foci from 113cases of gastric cancers were studied for the expression of PTEN and Caspase-3 andmicrovessel density (MVD)by streptavidin-peroxidase (S-P) immunohistochemistry with antibodies against PTEN, Caspase-3, and CD34. The relationship between PTEN and Caspase 3 expression and clinicopathological parameters of tumors was compared.RESULTS: Primary gastric cancer cells expressed PTEN less frequently than adjacent epithelial cells of primary foci (54.9％ vs89.4％; P=0.000, χ2=33.474). PTEN expression was significantly associated with invasive depth (P=0.003,rs=0.274), metastasis (P=0.036, rs=0.197), growth pattern (P=0.008, rs=0.282), Lauren′s classification (P=0.000,rs=0.345), and histological classification (P=0.005, rs=0.262)of tumors, but not with tumor size (P=0.639, rs=0.045),Borrmann′s classification (P=0.544, rs=0.070) or TNM staging (P=0.172, rs=0.129). PTEN expression was negatively correlated with MDV in primary gastric cancer (P=0.020,F=5.558). Primary gastric cancer cells showed less frequent immunoreactivity to Caspase-3 than adjacent epithelial cells of primary foci (32.7 ％ vs 50.4 ％; P=0.007,χ2=7.286).Caspase-3 expression was dependent of PTEN expression in primary gastric cancer cells (P=0.000, χ2=15.266).CONCLUSION: Down-regulated expression of PTEN plays an important role in tumorigenesis, progression, growth,differentiation and angiogenesis of gastric cancer. Low expression of PTEN can decrease expression of Caspase-3to disorder apoptosis of tumor cells, which might explain the molecular mechanisms of PTEN contributions to tumorigenesis and progression of gastric cancer.     

Dual effects of 8-Br-cAMP on differentiation and apoptosis of human esophageal cancer cell line Eca-109

AIM: To investigate the effects of 8-Br-cAMP on differentiation and apoptosis of human esophageal cancer cell line Eca-109, and the related gene expression. METHODS: The cultured Eca-109 cells were divided into four groups: E1 group (co-cultured with 8-Br-cAMP for 24 h); E2 group (co-cultured with 8-Br-cAMP for 48 h); C1 group (treated without 8-Br-cAMP for 24 h); and C2 group (treated without 8-Br-cAMP for 48 h). The same concentration of cell suspension of each group was dropped separately onto the slides and nitrocellulose membranes (NCM). The biotin-labeled cDNA probes for c-myc, wild-type (wt) p53, bcl-2 and iNOS were prepared for in situ hybridization. The expressions of epidermal growth factor receptor (EGFR), p38 kinase, FAS, FasL and caspase-3 were detected using immunocytochemistry, and the NOS activity and the ratio of differentiated cells/proliferating cells were examined by cytochemistry. Immunocytochemistry, cytochemistry, and in situ hybridization were separately carried out on both slides and NCM specimens for each group. In addition, TUNEL was used to detect the cell apoptosis rate in each group. RESULTS: The apoptotic rate of E2 group was significantly higher compared to E1 group, while there was no difference in the ratio of differentiated cells/ proliferating cells between E1 and E2 groups. The signals of wt p53 and iNOS were markedly stronger, while the signals of c-myc and EGFR were obviously weaker in E1 group than those in C1 group (P<0.05). Moreover, the signals of wt p53, iNOS, p38 kinase, caspase-3 and NOS activity were significantly stronger, whereas, the signals of bcl-2, c-myc and Fas/FasL were markedly weaker in E2 group than those in C2 group (P<0.05). CONCLUSION: The differentiation and apoptosis of human esophageal cancer cell Eca-109 can be induced after 24- and 48-h treatment with 8-Br-cAMP, respectively. Upregulation of wt p53, iNOS and downregulation of c-myc may be associated with differentiation and apoptosis of Eca-109 cells. Furthermore, upregulation of FasL, p38 kinase and caspase-3 as well as downregulation of bcl-2, and Fas may be involved in the apoptosis of Eca-109 cells.     

c-myc and bcl-2 modulate p53 function by altering p53 subcellular trafficking during the cell cycle.

We have studied the ability of c-myc and bcl-2 oncogenes to modulate p53 function. Our studies show that coincident expression of human Bcl-2 protein with p53 prolongs survival of murine erythroleukemia cells. This effect was associated with a loss of the G1 specificity of p53-mediated cell cycle arrest. Furthermore, we found that the c-myc and bcl-2 genes cooperate to inhibit p53 functions. Coexpression of bcl-2 and c-myc can totally overcome p53-induced apoptosis and cell cycle arrest by altering the subcellular trafficking of p53 during the cell cycle: the p53 remains in the cytoplasm of the cotransfected cells during a critical period in G1. This finding suggests a mechanism by which normal hematopoietic progenitors can survive and proliferate despite p53 expression and by which the inappropriate expression of bcl-2 and c-myc can cooperate in transformation.     

Relation of overexpression of S phase kinase-associated protein 2 with reduced expression of p27 and PTEN in human gastric carcinoma

AIM: To investigate the significance of S phase kinase associated protein 2 (Skp2) expression in human gastric carcinoma and the relation between expressions of Skp2, p27 and PTEN. METHODS: Immunohistochemical analysis was performed on 138 gastric carcinoma specimens, their paired adjacent mucosa specimens, 102 paired lymphatic metastatic carcinoma tissue specimens, 30 dysplasia specimens, 30 intestinal metaplasia specimens, 10 chronic superficial gastritis specimens and 5 normal gastric mucosa specimens for Skp2 expression and on 138 gastric carcinoma specimens for p27 and PTEN expression. RESULTS: Skp2 labeling frequency was significantly higher in intestinal metaplasia (12.68±0.86) and adjacent mucosa (19.32±1.22) than in normal gastric mucosa (0.53±0.13) and chronic superficial gastritis (0.47±0.19) (P = 0.000); in dysplasia (16.74±0.82) than in intestinal metaplasia (P = 0.000); in gastric primary carcinoma (31.34±2.17) than in dysplasia and adjacent mucosa (P = 0.000); in metastasis gastric carcinoma in lymph nodes (39.76±2.00) than in primary gastric carcinoma (P = 0.037), respectively. Skp2 labeling frequency was positively associated with differentiation degree (rho = 0.315, P = 0.000), vessel invasion (rho = 0.303, P = 0.000) and lymph node metastasis (rho = 0.254, P = 0.000) of gastric cancer. Expression of Skp2 was negatively associated with p27 (rho = -0.451, P = 0.000) and PTEN (rho = -0.480, P = 0.000) expression in gastric carcinoma. p27 expression was positively associated with PTEN expression in gastric carcinoma (rho = 0.642, P = 0.000). CONCLUSION: Skp2 overexpression may be involved in carcinogenesis and progression of human gastric carcinoma in vivo, possibly via p27 proteolysis. PTEN may regulate the expression of p27 by negatively regulating Skp2 expression.     

苦参素注射液联合顺铂对人肝癌SMMC-7721细胞凋亡相关基因c-myc、bcl-2和bax表达的影响

目的探讨苦参素注射液(MI)联合顺铂(DDP)对人肝癌SMMC-7721细胞凋亡相关基因c-myc、bcl-2和bax表达的影响。方法分别采用MI、顺铂及MI联合顺铂干预SMMC-7721细胞。TUNEL法检测细胞凋亡率,半定量RT-PCR法检测c-myc、bcl-2和bax mRNA表达,二步法免疫组化检测c-myc、bcl-2和bax蛋白表达。结果苦参素组、顺铂组和联合用药组细胞凋亡率显著上升,与对照组(不干预)比较差异有统计学意义(P<0.05或P<0.01),联合用药具有单纯相加或协同作用;联合用药组的细胞凋亡率显著增加,bax mRNA和蛋白表达显著升高,c-myc、bcl-2 mRNA和蛋白表达显著减少,与DDP单药组比较差异有统计学意义(P<0.05或P<0.01)。结论苦参素注射液联合顺铂具有单纯相加或协同诱导肝癌SMMC-7721细胞凋亡作用,其机制可能与bax基因表达上调和c-myc、bcl-2基因表达下调有关。     

Influence of the c-erb B-2, nm23, bcl-2 and p53 protein markers on colorectal cancer.

BACKGROUND/AIMS: Under stringent intra-laboratory conditions we evaluated the relationship between the expression of four protein markers and clinicopathologic characteristics of colorectal tumors. METHODS: 124 patients with colorectal cancer from 1999 to 2002 were assessed. RESULTS: The expression of cerb B-2, nm23 and p53 was mostly determined in tumors located in the rectum. However, about 20% of the rectal lesions had bcl-2 expression. p53 and c-erb B-2 expression was significantly demonstrated in the lesions with vascular and lymph node involvement. However, the difference between the markers and staging was not statistically significant (p=0.388, p=0.301). Cerb B-2 and p53 were more frequently expressed in the patients with large tumors (more than 5 cm) with moderate and poor differentiation grade. About half of the tumors expressing c- erb B- 2 and p53 had vascular invasion and more than 70% had N1 and N2 lymphatic invasion as well. In the patients with tumors expressing c-erb B-2 and p53, recurrences often occurred and both disease-free survival (DFS) and overall survival (OS) in the first two years after surgery were shorter than of the patients with tumors expressing nm23 and bcl-2. CONCLUSION: In this study, c-erb B-2 and p53 were frequently expressed in the Astler- Coller stage C large tumors located in the rectum and a high degree of vascular and lymphatic invasion was observed. In the patients with tumors expressing c-erb B-2 and p53, recurrences were determined more frequently and DFS and OS were shorter than in patients with tumors expressing nm23 and bcl-2. Thus, two different protein markers should be taken into consideration when evaluating the clinical outcome of patients with colorectal cancer.