LKB1蛋白在非小细胞肺癌中的表达及临床意义

目的探讨LKB1蛋白在非小细胞肺癌中的表达情况及临床意义。方法应用免疫组化方法检测76例非小细胞肺癌中LKB1蛋白的表达情况。结果 LKB1蛋白在肺癌组织及癌旁正常肺组织中均有表达,LKB1在正常肺组织的阳性表达率显著高于癌组织(90.78%vs 65.79%,P<0.01)。LKB1蛋白在肺鳞癌和腺癌组织中的表达无显著性差异。LKB1蛋白在高分化肿瘤中的表达阳性率明显高于中-低分化肿瘤(81.82%vs53.49%,P<0.05)。LKB1蛋白在无淋巴结转移组的阳性表达率明显高于淋巴结转移阳性组(89.29%vs 52.08%,P<0.01)。结论 LKB1蛋白的低表达与肺癌的发生有关,并且影响肿瘤的分化及淋巴结转移,可能影响肺癌的预后。     

LKB1和VEGFR_2在不同分期非小细胞肺癌中的表达

目的检测LKB1、VEGFR2在不同TNM分期非小细胞肺癌(NSCLC)中的表达情况。方法选取88例经手术治疗的不同TNM分期的非小细胞肺癌患者,切取癌组织及癌周5 cm以上无转移的正常肺组织,应用免疫组化方法测定LKB1和VEGFR2的表达情况。结果 LKB1和VEGFR2在肺癌组织及正常肺组织中均有表达。LKB1蛋白表达率在正常肺组织中明显高于癌组织(P0.01),VEGFR2在癌组织的表达率显著高于正常肺组织(P0.01);LKB1和VEGFR2在不同分期肺癌组织中的表达有显著差异(P0.05)。结论 LKB1和VEGFR2在非小细胞肺癌中的表达情况可能帮助判断非小细胞肺癌的分期及预后。     

p21WAF1/CIP1 基因转染对胃癌细胞生物学活性的影响

目的探讨p21^WAF1／CIP1基因(p21基因)对人胃癌细胞系(BGC)生物学活性的影响。方法应用分子克隆技术构建p21^WAF1／CIP1基因真核表达载体，然后用脂质体法将其导入到人胃癌细胞BGC中，经G418筛选获得可稳定表达p21^WAF1／CIP1的人胃癌细胞克隆，用中性红摄入法观察细胞生长速率，流式细胞仪(FcM)检测细胞周期变化。结果p21导入胃癌BGC细胞后，肿瘤细胞增值能力明显受到抑制，并出现细胞周期G1期阻滞。结论p21基因具有抑制胃癌细胞增殖的作用，可作为胃癌基因治疗的靶基因．     

LKB1、VEGFR2在非小细胞肺癌组织中表达及临床意义的研究

目的探究人Liver kinase B1(LKB1)与血管内皮生长因子受体-2(VEGFR2)在非小细胞肺癌组织中的表达情况,并探究其临床意义。方法采用免疫组化方法测定65例非小细胞肺癌组织及40例癌旁组织LKB1、VEGFR2表达情况。分析LKB1、VEGFR2表达情况与临床病理特征的相关性。结果肺癌组织中LKB1阳性率低于癌旁组织,VEGFR2阳性率高于癌旁组织。LKB1在腺癌中的表达阳性率高于鳞癌,VEGFR2在腺癌中的表达阳性率低于鳞癌。在具有吸烟史、淋巴转移、临床低分期以及低分化程度中LKB1阳性率更低,VEGFR2阳性率更高,差异均有统计学意义(均P0.05)。结论腺癌组织中LKB1表达水平高于鳞癌组织;非小细胞肺癌组织中LKB1、VEGFR2呈现相反的表达趋势。LKB1低表达与VEGFR2高表达提示肺癌患者具有吸烟史、出现淋巴转移、高临床分期以及低分化程度。     

脂联素通过LKB1途径激活腺苷酸活化蛋白激酶

目的 探讨脂联素是否通过LKB1途径激活骨骼肌及肝脏中腺苷酸活化蛋白激酶(AMPK).方法 将28只6周龄雄性Sprague-Dawley大鼠分为普通饮食组(NC组,n=15)和高脂饮食组(HF组,n=13).喂养16 周后,取空腹静脉血测定血清游离脂肪酸(FFA)、甘油三酯(TG)、总胆固醇(TC)、空腹血糖(FPG)、空腹胰岛素(FINS)及脂联素.采用Western印迹法测定各组大鼠骨骼肌及肝脏组织中AMPKα、磷酸化的AMPKcα和LKB1蛋白的表达.将原代培养的骨骼肌细胞及肝细胞分别予以脂联素和根赤壳菌素干预,免疫荧光技术测定各组细胞中AMPKα、磷酸化AMPKα和LKB1蛋白的表达.结果 与NC组比较,HF组大鼠体重、FFA、TG、FPG、FINS均升高(均P＜0.05),脂联素水平降低(P＜0.05).骨骼肌及肝组织巾AMPKα磷酸化和LKB1蛋白表达水平降低(均P＜0.05).原代培养大鼠骨骼肌细胞及肝细胞中脂联素显著增加AMPKα磷酸化及LKB1表达水平(均P＜0.05).加入根赤壳菌素表达明显降低(均P＜0.05).结论 脂联素在大鼠骨骼肌和肝脏组织可能通过LKB1途径激活AMPK.     

细胞周期蛋白H在细胞周期调节中的作用

细胞周期是指正常连续分裂的细胞从前一次有丝分裂结束到下一次有丝分裂完成所经历的连续动态过程，也是多阶段、多因子参与的精确而有序的调控过程，可分为5期：即G0期（Gap0，静息期）、G1期（Gap1，DNA合成前期）、S期（DNA synthesis phase，DNA合成期）、G2期（DNA合成后期）、M期（Mitosis，有丝分裂期），有两个主要限制点，即G1／S限制点和G2／M限制点。     

细胞周期蛋白D1在老年肺癌组织中表达的实验研究

目的：探讨细胞周期蛋白D1(cyclin D1）与肺癌的关系。方法：利用免疫组化（SP）法检测108例老年肺癌石蜡包埋组织中cyclin D1的表达,结果：cyclin D1只在肺癌组织中表达,阳性率为48．15％（52／108）,在非小细胞肺癌中表达阳性率为53．26％（49／92）,在小细胞肺癌中的表达率为18．75％（3／16）,cyclin D1的表达与肺癌组织的分化程度,呈正相关（P＜0．05）,与鳞癌的淋巴结转移呈负相关;与吸烟无相关性（P＞0．05）,结论：cyclin D1主要在非小细胞肺癌中呈过过表达状态,促进肿瘤细胞分化,参与鳞癌的淋巴结转移。     

LKB1和血管内皮生长因子在胃癌组织中的表达及其临床意义

目的探讨LKB1和血管内皮生长因子(VEGF)在胃癌中的表达及临床意义。方法采用免疫组织化学(SP)法检测115例胃癌组织和20例胃正常组织中LKB1和VEGF的表达,并探讨其与胃癌分期、淋巴结转移、Lauren's分型及预后的关系。结果 LKB1在胃癌组织中的阳性率为20.9%,低于正常胃组织中的95.0%(P0.01);VEGF在胃癌组织中的阳性率为64.3%,高于正常胃组织中的5.0%(P0.01)。LKB1在胃癌组织中的低表达与胃癌的TNM分期、淋巴结转移、Lauren's分型及预后有关(P0.05);VEGF在胃癌中的表达与淋巴结转移、远处转移、TNM分期及预后相关(P0.05)。结论 LKB1的低表达与胃癌的发生、发展有关,对胃癌恶性生物学行为的评估及预后判断具有重要的指导意义。     

E1A基因对人肺腺癌细胞增殖和细胞周期的影响

目的 探讨E1A基因对人肺腺癌细胞增殖的抑制作用与细胞周期的关系及作用机制。方法 利用细胞增殖曲线和裸小鼠体内致瘤性实验研究E1A基因对人肺腺癌细胞增殖的影响,采用流式细胞术分析人肺腺癌细胞周期,以蛋白印迹方法分析P16、P21、P53和cyclin B1水平变化。结果 转染E1A基因后,人肺腺癌细胞（Anip973-E1A）生长缓慢,体内致瘤性降低。Anip973-E1A细胞周期出现明显的S期抑制和G2/M阻滞,周期调控蛋白P16、P21、P53水平无明显变化,但cyclin B1表达明显下降。结论 E1A基因能显著抑制人肺腺癌细胞的体内外增殖,降低周期蛋白cyclin B1的表达,使细胞周期阻滞于G2/M,这可能与A1A基因抑制作用有关。     

Effects of allitridi on cell cycle arrest of human gastric cancer cells

AIM: To determine the effect of allitridi on cell cycle of human gastric cancer (HGC) cell lines MGC803 and SGC7901 and its possible mechanism. METHODS: Trypan blue dye exclusion was used to evaluate the proliferation, inhibition of cells and damages of these cells were detected with electron microscope. Flow cytometry and cell mitotic index were used to analyze the change of cell cycle, immunohistochemistry, and RTPCR was used to examine expression of the p21~(WAF1) gene. RESULTS: MGC803 cell growth was inhibited by allitridi with 24 h IC_(50) being 6.4 μg/mL. SGC7901 cell growth was also inhibited by allitridi with 24 h IC_(50) being 7.3 μg/mL After being treated with allitridi at the concentration of 12 μg/mL for 24 h, cells were found to have direct cytotoxic effects, including broken cellular membrane, swollen and vesiculated mitochondria and rough endoplasmic reticula, and mass lipid droplet. When cells were treated with allitridi at the concentration of 3, 6, and 9 μg/mL for 24 h, the percentage of G_0/G_1 phase cells was decreased and that of G_2/M phase cells was significantly increased (P=0.002) compared with those in the group. When cells were treated with allitridi at the concentration of 6 μg/mL, cell mitotic index was much higher (P=0.003) than that of control group, indicating that allitridi could cause gastric cancer cell arrest in M phase. Besides, the expression levels of p21~(WAF1)gene of MGC803 cells and p21~(WAF1) gene of SGC7901 cells were remarkably upregulated after treatment. CONCLUSION: Allitridi can cause gastric cancer cell arrest in M phase, and this may be one of the mechanisms for inhibiting cell proliferation. Effect of allitridi on cells in M phase may be associated with the upregulation of p21~(WAF1) genes. This study provides experimental data for clinical use of allitridi in the treatment of gastric carcinoma.     

曲古菌素A对食管癌EC1细胞增殖和细胞周期的影响及其分子机制

目的:探讨不同浓度曲古菌素A对食管癌细胞系EC1 细胞增殖、细胞周期的影响及其对细胞周期调控基因p21 WAF1/CIP1 表达的影响. 方法:用0.3,0.5,1.0 μmol/L 的TSA 处理EC1 细胞,MTT 检测TSA 作用24 、48 h 对EC1 细胞的抑制作用,流式细胞仪检测0.3,0.5,1.0 μmol/L 的TSA 作用24 h 后EC1 细胞周期的改变,Western blot 法检测p21 WAF1/CIP1 变化. 结果:TSA 在0.5 μmol/L 以上时对EC1 细胞有抑制作用;0.3 μmol/L TSA 处理细胞后细胞周期与对照组相比,无明显变化;0.5 μmol/L TSA 处理EC1 细胞后,G0/G1期细胞较对照组明显增加,S 期细胞较对照组明显减少(74.56% ±1.34% vs 62.12%±0.52%;14.52%±1.81% vs 27.50%±0.66%,均P <0.05);0.5,1.0 μmol/L TSA 处理细胞后p21 WAF1/CIP1 表达明显增加(均P<0.05). 结论:一定浓度的TSA 对人食管癌细胞EC 具有的增殖抑制作用,引起EC1 细胞发生G0/G1 期阻滞,其部分机制与p21 WAF1/CIP1 上调有关.     

松花粉抗成纤维细胞复制性衰老的机制

目的 研究松花粉对衰老成纤维单细胞面积、β-半乳糖苷酶染色(SA-β-gal)阳性率、p16INK4A和p21CIP-1表达以及细胞周期的影响.方法 以二倍体成纤维(2BS)细胞建立衰老细胞模型.生物体视学法分析单细胞面积变化;免疫组化法测SA-β-gal阳性率;流式细胞术分析细胞周期;RT-PCR法测定p16INK4A、p21CIP-1基因mRNA表达量.结果 56代细胞出现典型的衰老细胞形态改变,同时SA-β-gal染色阳性率与G1期细胞比例均增高.经松花粉处理后,衰老细胞的单细胞面积、SA-β-gal染色阳性率与G1期细胞比例均显著减少(P＜0.05);p16INK4A与p21CIP-1mRNA的表达量均较衰老模型组明显下调(P＜0.05). 结论松花粉具有改善细胞复制性衰老的作用,其分子机制可能与下调p16INK4A及p21CIP-1基因mRNA的表达从而改善衰老细胞G1期阻滞有关.     

LKB1 expression and the prognosis of lung cancer: A meta-analysis

Background:In the past few decades, many lines of evidence implicate the importance of liver kinase B1 (LKB1) as a tumor suppressor gene in the development and progression of solid tumours. However, the prognostic and clinicopathological value of LKB1 in patients with lung cancer are controversial. This article aimed to investigate the latest evidence on this question.Methods:A systematic literature searched in the PubMed, Web of Science, Embase, Cochrane library, Scopus until September 20, 2020. The association between overall survival (OS), relapse-free survival (RFS), progression-free survival (PFS), clinicopathological features and LKB1 were analysed by meta-analysis.Results:Eleven studies including 1507 patients were included in this meta-analysis. The pooled results revealed that low LKB1 expression was significantly associated with poor overall survival (OS) (HR = 1.67, 95% CI: 1.07–2.60, P = .024) in lung cancer. However, no association was found between LKB1 expression and DFS/PFS (HR = 1.29, 95% CI: 0.70–2.39, P = .410). Pooled results showed that low LKB1 expression was associated with histological differentiation (poor vs moderate or well, OR = 4.135, 95% CI:2.524–6.774, P < .001), nodal metastasis (absent vs present, OR = 0.503, 95% CI: 0.303–0.835, P = .008) and smoking (yes vs no, OR = 1.765, 95% CI: 1.120–2.782, P = .014).Conclusion:These results suggest that low expression of LKB1 can be considered as a unfavorable prognostic biomarker for human lung cancer, which should be further researched.     

The essential role of p21 in radiation-induced cell cycle arrest of vascular smooth muscle cell

The biologic mechanisms for the success and failure of intravascular radiation therapy after angioplasty have not been well studied. We investigated the molecular mechanism of radiation-induced cell cycle arrest in vascular smooth muscle cell (VSMC) and examined whether p21 knock-out is a cause of radiation failure. Using different dosages of gamma radiation, we evaluated the effect of radiation on VSMC apoptosis and cell cycle progression, and its action mechanism. Irradiation significantly retarded the growth of cultured VSMC, which was not due to induction of apoptosis but mainly due to cell cycle arrest. Radiation showed remarkable cell cycle arrest at G1 and G2 phase (G0/G1:S:G2/M phases = 61%:34%:5% with 0 Gy versus 61%:9%:30% with 16 Gy, 12 h after radiation). In immunoblot analysis and kinase assay, radiation increased the expression of p21 and decreased the expression and activity of CDK2 and 1. In contrast, radiation did not affect the expression and activity of CDK4 and 6, nor the expression of p27 and p16. When p21 was knocked out, cell cycle of VSMC was not arrested by radiation, leading to increased proliferation. These finding provide the evidence that radiation inhibits VSMC proliferation through cell cycle arrest by enhancing p21 expression and suppressing CDK1 and 2. This observation supports the key role of p21 in radiation-induced cell cycle arrest and the degree of p21 expression may be the possible mechanism of radiation failure and delayed restenosis.     

Effect of p27(KIP1) on cell cycle and apoptosis in gastric cancer cells

AIM: To elucidate the effect of p27KIP1 on cell cycle and apoptosis regulation in gastric carcinoma cells. METHODS: The whole length of p27KIP1 cDNA was transfected into human gastric cancer cell line SCG7901 by lipofectamine. Expression of p27KIP1 protein or mRNA was analyzed by Western blot and RNA dot blotting, respectively. Effect of p27KIP1 on cell growth was observed by MTT assay and anchorage-independent growth in soft agar. Tumorigenicity in nude mice was used to assess the in vivo biological effect of p27KIP1. Flow cytometry, TUNEL, and electron microscopy were used to assess the effect of p27KIP1 on cell cycle and apoptosis. RESULTS: Expression of p27KIP1 protein or mRNA increased evidently in SCG7901 cells transfected with p27KIP1. The cell growth was reduced by 31% at 48 h after induction with zinc determined by cell viability assay. The alteration of cell malignant phenotype was evidently indicated by the loss of anchorage-independent growth ability in soft agar. The tumorigenicity in nude mice was reduced evidently (0.55±0.14 cm vs 1.36±0.13 cm, P<0.01). p27KIP1 overexpression caused cell arrest with 36% increase (from 33.7% to 69.3%, P<0.01) in G1 population. Prolonged p27KIP1 expression induced apoptotic cell death reflected by pre-G1 peak in the histogram of FACS, which was also confirmed by TUNEL assay and electron microscopy. CONCLUSION: p27KIP1 can prolong cell cycle in G1 phase and lead to apoptosis. p27KIP1 may be a good candidate for cancer gene therapy.     

Differential expression of cell cycle regulators in HCV-infection and related hepatocellular carcinoma

AIM: To investigate cell cycle proteins in chronic hepatitis C virus infection in order to analyze their role in the process of hepatocyte transformation and to characterize their prognostic properties.METHODS: Subjects of the current study included 50 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with liver cirrhosis (LC), and 30 cases of hepatitis C-related hepatocellular carcinoma (HCC) admitted to the Department of Hepato-Gastroenterology, Theodor Bilharz Research Institute (TBRI), Giza, Egypt. Fifteen wedge liver biopsies, taken during laparoscopic cholecystectomy, were also included as normal controls. Laboratory investigations including urine and stool analysis, liver function tests and prothrombin concentration; serologic markers for viral hepatitis and ultrasonography were done for all cases of the study together with immunohistochemical analysis using primary antibodies against Cyclin D1, Cyclin E, p21, p27 and Rb/p105 proteins.RESULTS: Normal wedge liver biopsies didn’t express Cyclin E or Rb/p105 immunostaining but show positive staining for Cyclin D1, p21 and p27. Cyclin D1 expressed nuclear staining that was sequentially increased from CHC to LC (P < 0.01) to HCC (P < 0.001) cases; meanwhile, Cyclin E revealed nuclear positivity only in the case of HCCs patients that was directly correlated to Rb/p105 immuno-reactivity. The expression of p21 and p27 was significantly increased in CHC and LC cases compared to normal controls and HCCs with no significant difference between well- and poorly-differentiated tumors. p21 showed only a nuclear pattern of staining, while, p27 presented with either cytoplasmic and/or nuclear reactivity in all studied cases. Correlation analysis revealed a direct relation between Cyclin D1 and p21 in CHC cases (P < 0.001), between Cyclin D1 and Cyclin E in HCCs (P < 0.01); however, an inverse relationship was detected between Cyclin D1 and p21 or p27 (P < 0.001) and between p21 and Rb/p105 (P < 0.05) in HCCs.CONCLUSION: Upregulation of Cyclin D1 in CHC plays a vital role in the development and differentiation of HCC; while, Cyclin E may be a useful marker formonitoring tumor behavior. p21 and p27 can be used as predictive markers for HCC. Furthermore, higher expression of Rb/p105 as well as inverse relation with p21 and histologic grades suggests its important role in hepatic carcinogenesis.