Apoptosis mechanisms of human gastric cancer cell line MKN-45 infected with human mutant p27

AIM: To explore the inducing effect of human mutant p27 gene on the apoptosis of the human gastric cancer cell line MKN-45 and its associated mechanisms. METHODS: The recombinant adenovirus Ad-p27mt was constructed to infect the human gastric cancer cell line MKN-45. Using flow cytometry, TUNEL assay and DNA fragment analysis, we measured the apoptotic effect of Ad-p27mt on the human gastric cancer cells. RESULTS: Ad-p27mt was successfully constructed and the infection efficiency reached 100%. After 18 h of infection, we observed an apoptotic hypodiploid peak on the flow cytometer before G1-S and apoptotic characteristic bands in the DNA electrophoresis. The apoptotic rate detected by TUNEL method was significantly higher in the Ad-p27mt group (89.4±3.12%)compared to the control group (3.12±0.13%, P ＜ 0.01).CONCLUSION: Human mutant p27 can induce apoptosis of the human gastric cancer cells in vitro.

Success rate of current human-derived gastric cancer organoids establishment and influencing factors:A systematic review and meta-analysis

BACKGROUND Human-derived gastric cancer organoids(GCOs)are widely used in gastric cancer research;however,the culture success rate is generally low.AIM To explore the potential influencing factors,and the literature on successful culture rates of GCOs was reviewed using meta-analysis.METHODS PubMed,Web of Science,and EMBASE were searched for studies.Two trained researchers selected the studies and extracted data.STATA 17.0 software was used for meta-analysis of the incidence of each outcome event.The adjusted Methodological Index for Non-Randomized Studies scale was used to assess the quality of the included studies.Funnel plots and Egger’s test were used to detect publication bias.Subgroup analyses were conducted for sex,tissue source,histo-logical classification,and the pathological tumor-node-metastasis(pTNM)cancer staging system.RESULTS Eight studies with a pooled success rate of 66.6%were included.GCOs derived from women and men had success rates of 67%and 46.7%,respectively.GCOs from surgery or biopsy/endoscopic submucosal dissection showed success rates of 70.9%and 53.7%,respectively.GCOs of poorly-differentiated,moderately-differentiated and signet-ring cell cancer showed success rates of 64.6%,31%,and 32.7%,respectively.GCOs with pTNM stages I-II and III-IV showed success rates of 38.3%and 65.2%,respectively.Y-27632 and non-Y-27632 use showed success rates of 58.2%and 70%,respectively.GCOs generated with collagenase were more successful than those constructed with Liberase TH and TrypLE(72.1%vs 71%,respectively).EDTA digestion showed a 50%lower success rate than other methods(P=0.04).CONCLUSION GCO establishment rate is low and varies by sex,tissue source,histological type,and pTNM stage.Omitting Y-27632,and using Liberase TH,TrypLE,or collagenase yields greater success than EDTA.

Human epidermal growth factor receptor 2 expression level and combined positive score can evaluate efficacy of advanced gastric cancer

BACKGROUND Although treatment options for gastric cancer(GC)continue to advance,the overall prognosis for patients with GC remains poor.At present,the predictors of treatment efficacy remain controversial except for high microsatellite instability.AIM To develop methods to identify groups of patients with GC who would benefit the most from receiving the combination of a programmed cell death protein 1(PD-1)inhibitor and chemotherapy.METHODS We acquired data from 63 patients with human epidermal growth factor receptor 2(HER2)-negative GC with a histological diagnosis of GC at the Cancer Hospital,Chinese Academy of Medical Sciences between November 2020 and October 2022.All of the patients screened received a PD-1 inhibitor combined with chemotherapy as the first-line treatment.RESULTS As of July 1,2023,the objective response rate was 61.9%,and the disease control rate was 96.8%.The median progression-free survival(mPFS)for all patients was 6.3 months.The median overall survival was not achieved.Survival analysis showed that patients with a combined positive score(CPS)≥1 exhibited an extended trend in progression-free survival(PFS)when compared to patients with a CPS of 0 after receiving a PD-1 inhibitor combined with oxaliplatin and tegafur as the first-line treatment.PFS exhibited a trend for prolongation as the expression level of HER2 increased.Based on PFS,we divided patients into two groups:A treatment group with excellent efficacy and a treatment group with poor efficacy.The mPFS of the excellent efficacy group was 8 months,with a mPFS of 9.1 months after excluding a cohort of patients who received interrupted therapy due to surgery.The mPFS was 4.5 months in patients in the group with poor efficacy who did not receive surgery.Using good/poor efficacy as the endpoint of our study,univariate analysis revealed that both CPS score(P=0.004)and HER2 expression level(P=0.015)were both factors that exerted significant influence on the efficacy of treatment the combination of a PD-1 inhibitor and chemotherapy in patients with advanced GC(AGC).Finally,multivariate analysis confirmed that CPS score was a significant influencing factor.CONCLUSION CPS score and HER2 expression both impacted the efficacy of immunotherapy combined with chemotherapy in AGC patients who were non-positive for HER2.

Synergistic anticancer properties of docosahexaenoic acid and 5-fluorouracil through interference with energy metabolism and cell cycle arrest in human gastric cancer cell line AGS cells

AIM: To explore the synergistic effect of docosahexaenoic acid(DHA)/5-fluorouracil(5-FU) on the human gastric cancer cell line AGS and examine the underlying mechanism.METHODS: AGS cells were cultured and treated with a series of concentrations of DHA and 5-FU alone or in combination for 24 and 48 h. To investigate the synergistic effect of DHA and 5-FU on AGS cells, the inhibition of cell proliferation was determined by MTT assay and cell morphology. Flow cytometric analysis was also used to assess cell cycle distribution, and the expression of mitochondrial electron transfer chain complexes(METCs)?Ⅰ, Ⅱ and Ⅴ in AGS cells was further determined by Western blot analysis. RESULTS: DHA and 5-FU alone or in combination could markedly suppress the proliferation of AGS cells in a significant time and dose-dependent manner. DHA markedly strengthened the antiproliferative effect of 5-FU, decreasing the IC50 by 3.56-2.15-fold in an apparent synergy. The morphological changes of the cells were characterized by shrinkage, cell membrane blebbing and decreased adherence. Cell cycle analysis showed a shift of cells into the G0/G1 phase from the S phase following treatment with DHA or 5-FU(G0/G1 phase: 30.04% ± 1.54% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 56.76% ± 3.14% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). Combination treatment of DHA and 5-FU resulted in a significantly larger shift toward the G0/G1 phase and subsequent reduction in S phase(G0/G1 phase: 69.06% ± 2.63% vs 49.05% ± 6.41% and 63.39% ± 6.83%, respectively, P < 0.05; S phase: 19.80% ± 4.30% vs 34.75% ± 2.35% and 25.63% ± 2.21%, respectively, P < 0.05). This synergy was also reflected in the significant downregulation of the expression of METCs in AGS cells.CONCLUSION: Synergistic anticancer properties of DHA and 5-FU may involve interference with energy production of AGS cells via downregulation of METCs and cell cycle arrest.

Anticancer effect of Jinlongshe granules on in situ-transplanted human MKN-45 gastric cancer in nude mice and xenografted sarcoma 180 in Kunming mice and its mechanism

AIM： To study the antitumor effect of Chinese compound Jinlongshe （JLS） granules on sarcoma 180 and MKN-45 human gastric cancer cell lines in vivo and its mechanism. METHODS： After establishment of S180 sarcoma （S180） and MKN-45 gastric cancer model of nude mice, the tumor-bearing mice were divided into 5 groups at random. Three experimental groups were respectively given the aqueous extract of JLS granules at doses of 120 g, 60 g and 20 g/（kg per 6/wk,i.g） for 3 wk in S180 and 6 wk in nude mice model. Positive control was given cyclophosphamide （Cy） at a dose of 50 mg/（kg per 3/wk, i.g） for 3 wk in S180 models and 5-Fluorouracil （5-FU） 20 mg/（kg per 3/wk, i.g） for 3 wk in nude mice model. Negative control was given normal saline （NS） at a dose of 0.18 g/（kg per 6/wk, i.g） respectively. After 3 wk in mice bearing S180 tumor and 6 wk in nude mice model, the experimental animals were sacrificed and the masses of tumor were weighed, and the rates of tumor inhibition of each treated group were calculated respectively. To determine the antitumor mechanisms, the morphological changes, cell cycle and apoptosis were observed in MKN-45 nude mice model. Annexin V-FITC/PI double staining FCM assay was used to further determine the live cells, apoptotic cells, necrotic cells and debris. RESULTS： The inhibitory rates of JLS granules at the doses of 20 g/kg, 60 g/kg and 120 g/kg were 50.31%, 55.94% and 68.13% （P 〈 0.01） in nude mice models and 40.90%, 50.32% and 58.46% （P 〈 0.01） in S180 model. The inhibitory rate of Cy was 85.22% in S180 models and the inhibitory rate of 5-FU was 53.43% in nude mice model （P 〈 0.01）. Nuclear chromatin and margination were observed under a transmission electron microscope （TEM）. The G0/G1 phase was arrested, typical apoptotic peak appeared, the apoptotic rate was 22.81%-38.54% in three JLS granule-treated groups. Annexin V-FITC/PI double staining FCM assay showed that the apoptotic cells were 4.36%, 3.08% and 7.08% in three dosages, most cells were localized in the low right quadrant. CONCLUSION：Jinlongshe granules possess anti-tumor effects on experimental tumor models in vivo, and apoptosis induction is one of its anti-tumor mechanisms.

Characterization of gastric cancer models from different cell lines orthotopically constructed using improved implantation techniques

AIM:To develop orthotopic gastric cancer mouse models from different cell lines and characterize the tumor features to assist further in preclinical trials and clinical treatment strategies.METHODS:Human gastric cancer SGC-7901 and BGC823 cell suspensions were injected subcutaneously into nude mice to develop solid tumors,and tumor tissue pieces were then implanted under the serous coat of the stomach.An autopsy was performed on all animals of the SGC-7901 and BGC-823 models to observe the primary tumor growth and metastases using pathological and immunohistochemical methods.RESULTS:Both models showed large tumors in situ resulting in pressure and infiltration of the adjacent organs.The gastric cavity became smaller,along with stenosis of the cardia or pylorus.There were biological and statistical differences between the two models.The metastasis rate in involved organs (lymph nodes,kidney,spleen,testis) was significantly higher in the BGC-823 model compared to the SGC-7901 model (P < 0.05 or P < 0.01).The median survival of the BGC-823 model was shorter than that of SGC-7901 (23 d vs 84 d,P < 0.05).Histopathologically,the primary tumor and metastatic lesions of the two models showed obvious atypia and mucus in the cytoplasm.Compared with the SGC-7901 model,BGC-823 appeared more poorly differentiated (absence of adenoid structure),had a smaller volume,and richer capillary structure.Immunohistochemical staining revealed cytokeratin 20 and epithelial membrane antigen expression was positive in the SGC-7901 tumors,while negative in BGC-823 ones.CONCLUSION:Models using the SGC-7901 and BGC-823 cell lines were established which could function in gastric cancer research on carcinogenesis mechanism and drug discovery.The two models showed different tumor behavior and the latter was more malignant than the former.

MAPK通路在红托竹荪多糖诱导人胃癌MKN-45细胞凋亡中的作用机制研究

目的:研究红托竹荪多糖对人胃癌MKN-45细胞增殖与凋亡的影响,并基于丝裂原激活的蛋白激酶(MAPK)信号通路探讨其可能的作用机制。方法:体外培养MKN-45细胞,分为对照组,红托竹荪多糖低、中及高剂量组,采用终浓度分别为0、4、6及8 mg/mL的红托竹荪多糖作用于细胞48 h后,采用细胞计数法检测红托竹荪多糖对人胃癌MKN-45细胞增殖的影响;采用倒置显微镜观察不同浓度的红托竹荪多糖作用于人胃癌MKN-45细胞48 h后细胞形态学的变化。设立实验组的红托竹荪多糖终浓度为8 mg/mL,采用膜联蛋白V-异硫氰酸荧光素/碘化丙啶双染色流式细胞技术检测细胞的凋亡率;采用流式细胞术检测细胞周期分布;采用蛋白质印迹法检测红托竹荪多糖作用胃癌细胞后p38蛋白激酶(p38)、磷酸化p38蛋白激酶(p-p38)、细胞外调节蛋白激酶(ERK)、磷酸化细胞外调节蛋白激酶(p-ERK)、C-JUN氨基末端激酶(JNK)、磷酸化C-JUN氨基末端激酶(p-JNK)、B淋巴细胞瘤-2蛋白(Bcl-2)和活化的半胱氨酸蛋白酶-3(cleaved Caspase-3)蛋白的表达,即与3-磷酸甘油醛脱氢酶(GADPH)灰度值比值。结果:作用48 h后,不同浓度的红托竹荪多糖(4、6及8 mg/mL)对人胃癌MKN-45细胞增殖的抑制率分别为(8.27±5.99)%、(21.83±5.77)%和(56.95±5.21)%;在检测的浓度范围下,随着浓度的升高,红托竹荪多糖对MKN-45细胞增殖的抑制率逐渐升高。倒置显微镜下显示,经8 mg/mL的红托竹荪多糖作用48 h后,MKN-45细胞密度与对照组相比明显减少。流式细胞术检测结果显示,与对照组相比,实验组人胃癌MKN-45细胞凋亡率显著升高(P<0.05);细胞周期结果显示,实验组G_(1)期细胞比例明显减少(P<0.05),G_(2)期细胞比例明显增多(P<0.05),S期细胞比例明显减少(P<0.05);蛋白质印迹法结果显示,与对照组相比,实验组MKN-45细胞中cleaved Caspase-3的表达有升高趋势(P<0.05),Bcl-2的表达有降低趋势(P<0.05),p-P38/P38比值、p-ERK/ERK比值与p-JNK/JNK比值均低于对照组(P<0.05),上述差异均有统计学意义。结论:红托竹荪多糖在体外能抑制人胃癌MKN-45细胞增殖并诱导细胞凋亡,使肿瘤细胞阻滞在G_(2)/M期,其作用可能通过调控MAPK信号通路实现。

Direct interaction between Rab5a and Rab4a enhanced epidermal growth factor-stimulated proliferation of gastric cancer cells

BACKGROUND Gastric cancer(GC)is one of the leading causes of cancer-related death worldwide.Although targeted therapies such as antibodies against human epidermal growth factor receptor 2 or vascular endothelial growth factor receptor 2 have been widely used in the treatment of metastatic cancer,the overall outcomes are poor.Therefore,elucidation of the mechanism underlying cancer progression is important to improve prognosis.Overexpression of the Rab5a gene has been confirmed to correlate with tumorigenesis of many cancers,but the mechanism underling,especially of GC,is still unclear.AIM To investigate the effects of Rab5a overexpression on the tumorigenesis of GC.METHODS First,the expression levels of Rab5a and Rab4a in primary tumorous tissues of GC patients diagnosed between 2015 and 2018 were analyzed.Then we constructed HGC-27 cell lines overexpressing green fluorescent protein-Rab5a or red fluorescent protein-Rab4a and investigated the interaction between Rab5a or Rab4a using Western blotting,co-immunoprecipitation,confocal microscopy,and colocalization analysis.Finally,epidermal growth factor-stimulated proliferation of these cell lines was analyzed using cell counting kit-8 cell viability assay.RESULTS Compared with normal gastric tissues,the expression levels of Rab5a and Rab4a increased progressively both in paracancerous tissues and in advanced cancerous tissues.Epidermal growth factor could promote the proliferation of HGC-27 cells,especially Rab5a-overexpressing HGC-27 cells.Notably,Rab5a and Rab4a cooverexpression promoted the proliferation of HGC-27 cells to the greatest extent.Further analysis identified a direct interaction between Rab5a and Rab4a in HGC-27 cells.CONCLUSION Co-overexpression of Rab5a and Rab4a in GC may promote the endosomal recycling of epidermal growth factor receptor,which in turn contributes to poor prognosis and tumor progression in GC patients.Inhibition of Rab5a or Rab4a expression might be a promising therapy for refractory GC.

藤梨根提取物对人胃癌MKN-45细胞增殖及凋亡的影响

目的:探讨太白山藤梨根提取物(Radix Actinidiae extractive,RAE)在体外对胃癌MKN-45细胞增殖与凋亡的影响。方法:用0.01-100μg/ml浓度范围内的RAE和胃癌MKN-45细胞共培养24、48、72、96小时,采用MTT法检测RAE对MKN-45细胞增殖的影响;用流式细胞仪检测其对MKN-45细胞凋亡及细胞周期分布的影响;DNA琼脂糖凝胶电泳检测细胞凋亡。结果:RAE在体外能够显著抑制胃癌MKN-45细胞的增殖,且呈现浓度和时间依赖性;RAE对胃癌细胞的作用表现为周期特异性,使细胞阻滞于G0/G1期,进一步诱导细胞凋亡。对照组凋亡率为0.53%,1μg/ml、10μg/ml、100μg/ml浓度的RAE干预胃癌细胞48小时后均出现凋亡峰,细胞凋亡率分别为3.27%、8.97%、12.6%。DNA琼脂糖凝胶电泳检测细胞凋亡,不同浓度RAE处理的细胞样品中均可看到梯形凋亡条带,并呈现浓度依赖性。结论:RAE在体外对人胃癌MKN-45细胞有显著的抑制细胞增殖及诱导细胞凋亡作用,其作用机制可能是使胃癌细胞周期阻滞于G0/G1期。

金龙蛇颗粒对裸鼠原位移植人胃癌MKN-45细胞凋亡的影响

目的：评价金龙蛇颗粒对裸鼠原位移植入胃癌MKN-45细胞的抑制作用.方法：50只裸鼠建立原位移植人胃癌MKN-45细胞模型,随机分为模型组,金龙蛇颗粒高、中、低剂量组和5-FU干预组.各组裸鼠予以相应药物实施干预.观察各组荷瘤裸鼠一般情况,肿瘤生长情况及抑瘤率.流式细胞仪检测肿瘤细胞周期分布及细胞凋亡情况.采用膜联蛋白V-异硫氰酸荧光素/碘化丙啶（Annexin V-fluorescein isothiocyanate/propidium iodide,Annexin V-FITC/PI）双标记染色法鉴别早期凋亡细胞、晚期凋亡细胞和坏死细胞.电镜下观察肿瘤细胞的超微结构变化.结果：金龙蛇颗粒高、中、低剂量组的抑瘤率分别为68.13%、55.94%和50.31%,呈剂量依赖效应,与5-FU干预组抑瘤率比较,差异无统计学意义.金龙蛇颗粒各剂量组肿瘤细胞凋亡率为22.81%～38.54%,亦呈剂量依赖效应,且肿瘤细胞主要被阻滞于G0/G1期.AnnexinV-FITC/PI双标记染色结果显示,金龙蛇颗粒各剂量组以早期凋亡细胞居多,5-FU干预组则以晚期凋亡细胞和坏死细胞居多.结论：金龙蛇颗粒对裸鼠原位移植人胃癌MKN-45细胞具有较好的抑制作用,促进MKN-45细胞凋亡可能是其抗肿瘤治疗的主要作用机制之一.

参芪抑瘤方药物血清对胃癌MKN-45细胞周期阻滞及抗侵袭转移的影响

目的 探讨不同浓度参芪抑瘤方药物血清对胃癌MKN-45 细胞周期阻滞及抗侵袭转移作用的相关机制.方法 60 只SPF 级Wistar 大鼠,随机分为对照组和参芪抑瘤方低、中、高剂量组,每组15 只.参芪抑瘤方低、中、高剂量组分别给予0.25、0.50、1.00 g 原药材/mL 药液灌胃,空白组给予等量饮用水灌胃,每日2 次,连续7 d,末次灌胃2 h 后取血,分离血清.MKN-45 细胞经不同浓度药物血清处理后,流式细胞术检测细胞周期,免疫组化检测COX-2、PTEN 蛋白表达.结果 药物血清干预后细胞G0～G1 期比例增加,S 期比例减少;药物血清可降低MKN-45 细胞COX-2 蛋白阳性表达率,升高PTEN 蛋白阳性表达率（P〈0.05）.结论 参芪抑瘤方药物血清阻滞细胞周期及抗侵袭转移作用可能与影响COX-2、PTEN 蛋白表达有关.

5-氟尿嘧啶气雾对人胃癌细胞MKN-45增殖、凋亡及周期的影响

目的通过体外模拟5-氟尿嘧啶(5-Fu)腹腔气雾化疗环境,评价5-Fu雾化对人胃癌细胞MKN-45增殖、凋亡及周期的影响。方法运用自主研发的气雾化疗仪将5-Fu雾化,体外模拟腹腔气雾化疗环境,对胃癌细胞进行处理,维持气雾环境压力为8mmHg,作用时间为30min,并设生理盐水雾化作为对照,处理后用MTT法检测细胞增殖情况,流式细胞仪检测细胞凋亡和细胞周期。结果 MTT结果显示,5-Fu气雾化疗组杀伤率显著高于生理盐水组[(31.13±3.51)%比(4.65±1.99)%,P<0.001];流式细胞结果显示,与生理盐水组相比,5-Fu气雾化疗组细胞凋亡率升高[(12.00±0.92)%比(2.65±0.52)%,P<0.001)],G1期细胞增多[(51.83±1.95)%比(36.41±2.33)%,P<0.001]、S期细胞减少[(16.72±2.36)%比(45.20±3.27)%,P<0.001],差异均有统计学意义。结论 5-Fu气雾能有效抑制胃癌细胞的增殖并诱导凋亡,使细胞阻滞于G1期,为气雾化疗的临床应用提供实验依据。

金龙蛇颗粒对原位移植人MKN-45胃癌组织基因表达谱的影响

目的:利用基因表达谱芯片研究金龙蛇颗粒对MKN-45胃癌的分子机制。方法:抽提经金龙蛇颗粒治疗的裸鼠原位移植人MKN-45胃癌组织和生理盐水阴性对照的瘤组织总RNA并纯化mRNA,分别逆转录并进行荧光标记,制作成cDNA探针,与包含4096个人类基因的cDNA表达谱芯片进行杂交,筛选出两组间差异表达基因。结果:在mRNA水平上,筛选出包括与DNA结合、转录和转录因子、蛋白翻译、细胞周期等相关表达差异的基因共341条,其中44条(比值>2)表达上调(占12.9%),297条(比值<0.5)表达下调(占87.1%)。结论:金龙蛇颗粒可引起MKN-45胃癌组织一系列基因表达的改变,金龙蛇颗粒抗胃癌的基因途径可能是多环节、多层次的结果。

人参皂甙Rg3刺激淋巴细胞CD4上调以及对胃癌细胞MKN-45的杀伤作用

目的探讨人参皂甙Rg3对淋巴细胞的免疫刺激作用及其对胃癌细胞MKN-45的影响。方法采用梯度密度分离法分离正常人淋巴细胞,经人参皂甙Rg3刺激后流式细胞术检测人参皂甙Rg3对正常人淋巴细胞CD4表达的影响;用MTT法测定人参皂甙Rg3对MKN-45抑制作用;HE染色法观察人参皂甙Rg3诱导MKN-45的凋亡作用。结果人参皂甙Rg3促进正常人淋巴细胞CD4表达明显高于正常对照组(P<0.05);人参皂甙Rg3对MKN-45抑制率、凋亡率与正常对照组比较有显著性差异(P<0.05)。结论人参皂甙Rg3具有刺激淋巴细胞CD4上调的作用以及抑制MKN-45细胞生长的作用。

盐酸伊利替康及氧化苦参碱对多耐药人胃癌细胞MKN-45的作用

目的:探讨盐酸伊利替康(CPT-11)及氧化苦参碱对裸鼠体内多药耐药人胃癌细胞MKN-45的抑制作用及其抗肿瘤作用的分子机制。方法:建立了多药耐药人胃癌MKN-45细胞的皮下移植瘤模型,随机分成0.9%氯化钠对照组、CPT-11治疗组、氧化苦参碱治疗组和CPT-11联合氧化苦参碱治疗组。每组裸鼠在胃癌组织移植7周后处死,并测算其肿瘤抑制率。采用末端脱氧核酸转移酶原位标记(TUNEL)和流式细胞仪法分析其凋亡指数。结果:CPT-11治疗组(10 mg.L^(-1)、20 mg.L^(-1))对多药耐药MKN-45细胞皮下移植瘤的抑制率显著增加,其凋亡率分别是(11.2±0.18)%和(12.2±1.65)%,两者比较无显著差异(P>0.05);氧化苦参碱联合CPT-11治疗组凋亡指数(AI)为(62.4±6.14)%,显著高于CPT-11治疗组和0.9%氯化钠时照组(1.27±0.11)%,(P<0.01)。结论:CPT-11可以增强氧化苦参碱对多药耐药细胞MKN-45的抑制作用,诱导裸鼠体内人胃癌细胞的凋亡;并能增强裸鼠体内胃癌对化疗的疗效和敏感性。

温热对胃癌MKN-45细胞凋亡及基因Bax表达的影响

目的探讨温热对人胃癌细胞凋亡及基因Bax表达的影响。方法体外培养胃癌细胞MKN45并进行(43.0±0.1)℃温热疗法对癌细胞凋亡的影响;RT-PCR法检测温热后MKN-45细胞Bax mRNA水平的表达变化。结果温热后MKN-45细胞随着处理时间延长凋亡增加;RT-PCR结果显示,Bax mRNA的表达增加(P<0.05)。结论温热对胃癌MKN-45细胞具有明显的促凋亡作用,可能与其上调促凋亡基因Bax的表达有关。

鱼藤素对胃癌细胞MKN-45增殖及凋亡的影响

目的:研究鱼藤素对胃癌细胞增殖及凋亡的影响。方法:利用CCK8检测不同浓度(0、1、10和25μmol/L)鱼藤素作用于胃癌细胞MKN-45 24、48、72和96 h后对其增殖的影响;AnnexinⅤ-FITC/PI检测细胞凋亡;流式细胞仪检测细胞周期;利用倒置相差显微镜观察鱼藤素作用后细胞形态的变化;DAPI及Hoechst染色观察细胞核变化。结果:1μmol/L鱼藤素作用于MKN-45细胞24 h后抑制率为(28.82±0.002)%。随着鱼藤素浓度(10、25μmol/L)增加,作用时间(48、72、96 h)延长,其抑制作用增加,表明其抑制作用呈时间-剂量依赖关系。不同浓度(1、10和25μmol/L)鱼藤素作用于细胞48 h后,早期凋亡率、晚期凋亡率和总凋亡率显示鱼藤素显著促进细胞凋亡。细胞周期检测发现,与对照组比较,1μmol/L鱼藤素作用于细胞48 h后,S期细胞比例升高,G_0/G_1期及G_2/M期细胞比例下降;10μmol/L鱼藤素作用于细胞48 h后,G_2/M期细胞比例升高,G_0/G_1期细胞比例下降(P<0.01)。倒置相差显微镜检查镜下则显示,1、10和25μmol/L鱼藤素作用MKN-45细胞48 h后,可见典型凋亡样改变。DAPI及Hoechst染色可见鱼藤素组细胞核皱缩变小、染色质浓聚和典型的凋亡小体。结论:鱼藤素可明显抑制胃癌细胞的增殖、促进凋亡。机制可能与细胞周期阻滞于S期及G_2/M期有关。

槐耳醇提物抑制人胃癌细胞MKN-45增殖的实验研究

目的观察槐耳不同提取部位对人胃癌MKN-45细胞增殖的影响,并筛选其有效部位。方法用系统溶剂法将槐耳提取为石油醚、乙酸乙酯、正丁醇、乙醇、水五个部位后,用CCK-8显色法,检测不同部位不同浓度的槐耳醇提取物对MKN-45增殖的作用。结果槐耳石油醚、乙酸乙酯、正丁醇、乙醇部位为抗肿瘤有效部位,其中以正丁醇部位效果最佳,其对MKN-45细胞半数抑制率(IC50)为56.142μg·m L-1。结论槐耳醇提物能抑制人胃癌MKN-45细胞增殖,其最有效部位为槐耳正丁醇部位。

siRNA沉默PIM1基因表达对人胃癌MKN-45细胞增殖及凋亡的影响

目的:探讨PIM1基因沉默对人胃癌MKN-45细胞增殖和凋亡的影响。方法:设计2条针对PIM1 mRNA靶序列的干扰RNA正义链和反义链及阴性对照序列,构建重组pSIREN-retroQ质粒载体,并转染胃癌MKN-45细胞。应用实时荧光定量PCR和蛋白质印迹法分别检测PIM1在mRNA水平及蛋白水平的表达。CCK-8法检测胃癌MKN-45细胞的增殖,流式细胞分析胃癌细胞的凋亡,蛋白质印迹法检测凋亡相关蛋白Caspase 3和Caspase 9的表达。结果:重组克隆通过PCR扩增及测序,证明干扰序列插入正确。与正常对照组和阴性对照组相比,两个RNA干扰组胃癌MKN-45细胞PIM1在mRNA及蛋白水平的表达量都显著降低(P<0.05),细胞增殖能力下降(P<0.05)。此外,干扰组细胞凋亡明显增多(P<0.01),Caspase 3和Caspase9蛋白表达上调(P<0.01)。结论:PIM1 siRNA能有效下调靶基因表达,产生特异性基因沉默效应;PIM1基因沉默显著抑制胃癌MKN-45细胞的增殖并促进其凋亡。

槐耳清膏抑制小鼠模型人胃癌MKN-45细胞生长和转移的实验研究

目的研究槐耳清膏对人胃癌MKN-45细胞在裸鼠体内生长和转移的抑制作用,并探讨其作用机制。方法采用BALB/c裸鼠建立人胃癌MKN-45细胞淋巴结转移模型,随机分为槐耳清膏组、空白对照组,每组20只。建模后,每5天测量裸鼠荷瘤并计算肿瘤相对体积(RTV);用药5周后处死裸鼠,Real-time q PCR检测肿瘤组织Wnt、β-catenin、E-cadherin、N-cadherin和VEGF表达水平。结果槐耳清膏组末次测得的足垫瘤RTV为(662.75±450.66)mm3,明显小于空白对照组的(1611.85±611.83)mm3(P<0.01)。槐耳清膏组淋巴结转移率8/20(40%)与对照组15/20(70%)相比,差异有统计学意义(P<0.05)。槐耳清膏组肿瘤组织Wnt、β-catenin、N-cadherin和VEGF的△CT值分别为(11.36±1.32)、(11.31±1.76)、(12.82±2.22)、(13.22±1.52),均高于对照组的(9.48±2.07)、(9.37±1.88)、(7.74±2.64)、(11.04±1.61),而E-cadherin的△CT值(8.26±2.39)低于对照组的(10.64±1.48)(P<0.05)。结论槐耳清膏可抑制人胃癌MKN-45细胞在裸鼠上的生长及转移,其机制可能与抗血管生成和阻碍上皮间质转化(EMT)过程有关。