Objective To dynamically study the formation of multidrug resistance(MDR) of human hepatocellular carcinoma cell SMMC-7721 induced by Adriamycin (ADM) and the role of multidrug resistance-associated protein(MRP) in its mechanisms.Methods Hepatocellular carcinoma cell SMMC-7721 was cultured in RPMI-1640 medium containing ADM with progressively increased concentration or directly cultured in medium containing different concentrations of ADM. Resistant index of drug-resistant variants of SMMC-7721 cell was determined by drawing cell dosage-reaction curves.Levels of MRP mRNA expression were detected by reverse transcription-polymerase chain reaction(RTPCR). Intracellular rubidomycin(DNR) concentration was examined by flow cytometry(FCM).Results With progressive increasing of ADM concentration in medium resistant index and levels of MRP mRNA expression were correspondingly increased but intracellular DNR concentration was markly reduced. When parental cells were directly cultured in medium containing different concentrations of ADM, the higher the ADM concentration, the higher the level of MRP mRNA expression, but intracellular DNR concentration was kept at the similar high level and most cells died. Conclusion ADM may progressively induce SMMC-7721 cell resistant to multiple chemotherapeutic drugs with reduced intracellular DNR accumulation associated with the overexpression of MRP gene.
Objective To investigate the effect of mitochondrial fission mediated by mitochondrial dynamics related protein 1 (DRP1) on glucose metabolism reprogramming in lung cancer cells, and the regulatory mechanism on phosphatidylinositol-3-kinases (PI3K)/protein kinase B (Akt) signaling pathway. Methods Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of DRP1 in lung cancer tissue and lung cancer cells. Mitochondrial fission inhibitor (Mdivi-1) and Mdivi-1+PI3K/Akt signaling pathway activator 740Y-P were used to treat H1299 cells. Mitochondrial fission agonist (WY14643) + signal inhibitor LY294002 were used to intervene PC14 cells. The reagent kit was used to detect the glucose consumption, lactate release, and ATP production of each group of cells. 5-ethynyl-2-deoxyuridine (EdU) labeling experiment was used to detect the proliferation of cells in each group, and acridine orange/ethidium bromide (AO/EB) staining was used to detect the apoptosis of cells in each group. MitoTracker Red CMXRos was used to detect the mitochondrial morphology of each group of cells. Tetramethylrhodamine ethyl ester (TMRE) staining was used to detect the mitochondrial membrane potential of cells. Dihydroethidium (DHE) staining was used to detect the level of reactive oxygen species (ROS) in cells. Western blot was used to detect was used to detect the expression of pyruvate kinase M2 (PKM2), hexokinase 2 (HK2), phosphofructokinase-1 (PFK1), DRP1, phosphorylated DRP1 (p-DRP1), PI3K, Akt, phosphorylated PI3K (p-PI3K), and phosphorylated Ak t(p-Akt) in each group of cells. Results The mRNA expression of DRP1 was significantly increased in lung cancer tissue and lung cancer cells. Mdivi-1 promoted the development of lung cancer and exerts anticancer effects, while activating PI3K/Akt signaling could partially reverse the anticancer effects of Mdivi-1. WY14643 exerted a pro-cancer effect, and inhibiting PI3K/Akt signaling could partially reverse the pro-cancer effect of WY14643, and the differences were statistically significant (all P<0.05). Conclusions In lung cancer, the expression of DRP1 is significantly increased, and DRP1 affects the glycolysis process and proliferation performance of lung cancer cells by regulating the activation of PI3K/Akt signaling.
目的 通过检测人睾丸生殖细胞肿瘤中的Skp2蛋白质异常表达,探讨相关意义。 方法 应用S-P免疫组织化学法检测睾丸生殖细胞肿瘤，正常睾丸组织和慢性睾丸炎组织中Skp2的表达。 结果 睾丸生殖细胞肿瘤中Skp2阳性表达率为74.5%，正常睾丸组织中Skp2阳性表达率为20.0%，在慢性睾丸炎组织中Skp2阳性表达率为40.0%，在3种不同睾丸组织中表达差异有统计学意义（P＜0.05）；Skp2表达与不同组织学类型的睾丸生殖细胞肿瘤无相关性（P＞0.05）；随着临床分期的增高，睾丸生殖细胞肿瘤中的Skp2表达增多，差异无统计学意义（P＞0.05）。 结论 在人睾丸生殖细胞肿瘤中的Skp2高表达，提示细胞周期的异常调控在睾丸生殖细胞肿瘤的发生、分化中起着重要的作用。
ObjectiveTo explore the expression of growth associated protein-43 (GAP-43) in spasm segment and expansion segment of hirschsprung disease (HD), and to explore the pathogenesis of HD. MethodsThe expression of GAP-43 in 30 patients with HD who underwent surgical resection for absence of enteric plexuses from Jan. 2012 to Jun. 2013 in Shen zhen Children's Hospital were analyzed by using immunohistochemistry method and real-time PCR method. Aganglionic tissues of all patients were included as spasm group, and ganglionic tissues of the same patients were served as expansion group. Then comparison of the expression levels of GAP-43 mRNA and its protein between 2 groups was performed. Resultsof real-time RCR showed that the expression level of GAP-43 mRNA in expansion group was higher than that of spasm group (0.119 0 vs. 0.052 8, P<0.05). Immunohistochemistry results showed that GAP-43 protein expressed both in the myenteric plexus and ganglionic plexus of submucos in all patients, but lighter in spasm group. Compared with ganglionic plexus of circular muscle layer and longitudinal muscle layer/ganglionic plexus of submucosa in expansion group, the average optical density values at corresponding sites of intestinal tissues in spasm group were both lower (P<0.05). ConclusionExpression of GAP-43 protein is lower in spastic intestinal tissue of patients with HD, which suggests that down-regulation of GAP-43 protein may be a risk factor for HD.
ObjectiveTo construct the recombinant adenovirus vector carrying antisense multidrug resistanceassociated protein (MRP) and transfect the human drugresistant hepatocellular carcinoma cell line(SMMC7721/ADM). MethodsThe fragment of MRP gene encoding 5′region was cloned reversely into the shuttle plasmid pAdTrackCMV, with the resultant plasmid and the backbone plasmid pAdEasy1,the homologous recombination took place in the bacteria and the recombinant adenoviral plasmid was generated. The adenoviruses were packaged and amplified in 293 cells. Then the cell line of SMMC7721/ADM was transfected with the resultant adenoviruses.ResultsThe recombinant adenovirus vector carrying antisense MRP was constructed successfully. The viral titer was 2.5×109 efu/ml, and more than 90% SMMC7721/ADM cells could be transfected when the multiplicity of infection（MOI） was 100. ConclusionThe recombinant adenovirus vector constructed by us could introduce the antisense MRP into the human drugresistant hepatocellular cell line effectively, which would provide experimental basis for the mechanisms and reversal methods of the multidrug resistance in human hepatocellular carcinoma.
ObjectiveTo summarize the autophagy and its research progress in gastric cancer. MethodsIn combination with available literatures published in recent years involving the relationship between autophagy and gastric cancer, the characteristics of autophagy, molecular marker, control factors, and the significance and role in gastric cancer were reviewed. ResultsAutophagy not only promotes cell death, but also can prolong the survival of cancer cells during the tumor formation. Reagents (including traditional Chinese medicine) regulating autophagy have broad prospect of application in cancer therapy, but anti-tumor therapeutic effect based on the regulation of autophagy depends on the actual level of intracellular autophagy. ConclusionThe autophagy in the gastric cancer is still poorly understood, and to clarify the molecular mechanism of autophagy and kill cancer cells by reasonable regulation of autophagy still needs more further in-depth studies.
Abstract： Stem cell paracrine has been considered as the main mechanism to promote infarcted myocardium regeneration and repair of damaged cardiomyocytes. With further research, secreted frizzled-related protein 2 （Sfrp 2） and stem cell paracrine are closely linked to each other. Sfrp 2 can competitively bind to the specific receptor Fz in Wnt signaling pathway, inhibit Wnt signaling pathway to regulates apoptosis, differentiation, and other life processes of stem cells, and therefore becomes a research hotspot in recent years. This review focuses on the mechanism of Sfrp 2/Wnt signal way in stem cell therapy for myocardial infarction.
Objective To observe the effects of neural stem cells(NSCs) transplantation on the glial cell line-derived neurotrophic factor (GDNF) and growth associated protein 43(GAP-43) after the spinal cord injury(SCI), and to investigate the mechanism of repairing the SCI by NSCs transplantation. Methods The neural stem cells from the hippocampus of rats’ embryo were cultured and identified by immunocytochemistry. The SCI model was made by the modified Allen device. Sixty adult Wistar rats were randomly divided into three groups: spinal cord injury was treated with transplantation of NSCs (group A, n=24), with DMEM solution(group B, n=24) and normal control group without being injured(group C, n=12). Seven days after the operation of SCI, the NSCs were transplanted into the injured site. Then GAP-43 and GDNF expressions were tested by RT-PCR and immunohistochemistry. Results Compared with group B, the GDNF mRNA expression of group A increased by 23.3％ on the 1st day, by 26.8% on the 3rd day and by 32.7% on the 7th day; the GAP-43 mRNA expression increased by 19.5% on the 1st day, 21.6% on the 3rd day and 23.1% on the 7th day. There were statistically significant differences(Plt;0.05). Conclusion The transplantation of NSCs can change the microenvironment injured site and promote the regeneration of axon by enhancing the expressions of GDNF mRNA and GAP-43 mRNA. It is one of the mechanisms of repairing the SCI by NSCs transplantation.