Expression of survivin in primary and metastatic gastric cancer cells obtained by laser capture microdissection

AIM:Survivin, a recently identified member of the inhibitor of apoptosis protein family, is expressed during development and in various human cancers. However, its expression in normal tissues and clinical relevance in cancers are still debated. In the present study, we analyzed the expression of the survivin gene in human primary and metastatic gastric cancer cells as well as in paired epithelial cells from normal gastric mucosa by means of a novel laser capture microdissection (LCM) technique coupled with reverse transcription -polymerase chain reaction (RT-PCR).METHODS: Thirty patients who had undergone gastrectomy with lymph node dissection for gastric cancer without preoperative treatments were included. Neoplastic tissue, metastatic lymph nodes, and apparently uninvolved normal tissue were collected from each patient. LCM-captured 'pure' cell groups were respectively subjected to RT-PCR analysis with primers specific for the survivin gene.RESULTS: Of the paired samples from 30 gastric cancer patients studied, 24 (80%) primary gastric cancer cell groups and 7 (23%) adjacent morphologically 'normal' gastric epithelial cell groups were shown to have a detectable survivin expression. There was a statistically significant difference in suvivin expression between these two groups (P<0.01). Meanwhile, 95% (19/20) of the metastatic gastric cancer cell groups from lymph nodes had a clear expression of the survivin gene. However, no significant correlation between survivin expression and clinicopathological features of gastric cancer was observed in the present study. CONCLUSION: Survivin expression is present in the majority of gastric cancer cell groups obtained by LCM techniques. The high expression rate in metastatic lesions suggests a possible role of survivin in cancer invasiveness and metastasis. It may contribute to the detection of gastric cancer micrometastasis as a potential molecular marker. In addition, the high expression percentage renders survivin a potential target in the therapy for gastric cancer.

EFFECT OF PEROXISOME PROLIFERATOR-ACTIVATED RECEPTOR ACTIVATORS ON TUMOR NECROSIS FACTOR-αEXPRESSION IN NEONATAL RAT CARDIAC MYOCYTES

Objective To investigate the effect of peroxisome proliferator-activated receptor-α(PPARα) and PPARγactivators on tumor necrosis factor-α(TNFα) expression in neonatal rat cardiac myocytes. Methods Primary cultures of cardiac myocytes from 1- to 3-day-old Wistar rats were prepared, and myocytes were ex-posed to lipopolysaccharide (LPS) and varying concentrations of PPARαor PPARγactivator (fenofibrate or pioglitazone).RT-PCR and ELISA were used to measure TNFα, PPARα, and PPARγexpression in cultured cardiac myocytes. Transient tr-ansfection of TNFαpromoter with or without nuclear factor-kappaB (NF-κB) binding site to cardiac myocytes was performed. Results Pretreatment of cardiac myocytes with fenofibrate or pioglitazone inhibited LPS-induced TNFαmRNA and protein expression in a dose-dependent manner. However, no significant changes were observed on PPARαor PPARγmRNA expression when cardiac myocytes were pretreated with fenofibrate or pioglitazone. Proportional suppression of TNFαpromoter activity was observed when myocytes was transiently transfected with whole length of TNFαpromoter (-721/+17) after being stimulated with LPS and fenofibrate or pioglitazone, whereas no change of promoter activity was observed with transfection of TNFαreporter construct in deletion of NF-κB binding site (-182/+17). Conclusions PPARαand PPARγactivators may inhibit cardiac TNFαexpression but not accompanied by change of PPARαor PPARγmRNA expression. Therefore PPARαand PPARγactivators appear to play a role in anti-inflammation. The mechanism may partly be involved in suppression of the NF-κB pathway.

Transcriptome analysis of leaves,roots and flowers of Panax notoginseng on ginsenoside and alkaloid biosynthesis and amelioration of vascular insufficiency conditions by saponins from the flower buds

OBJECTIVE To investigate the transcriptomic details on the biosynthetic pathways in different parts of the Panax notoginseng and the pharmacological activity of the saponins extracted from the flower(FS)on vascular insufficiency conditions.METHODS RNA sequencing of three different Panax notoginseng tissues was performed using next generation DNA sequencing and differential gene expression was validated by real-time PCR.In order to determine pro-angiogenic and therapeutic effects of FS on myocardial infraction(MI),FS was examined on the endothelial cell migration assay,vascular insufficiency model in zebrafish and MI model in rats.RESULTS After assembling the high quality sequencing reads into 107 340 unigenes,biochemical pathways were predicted and 9 908 unigenes were assigned to 135 KEGG pathways.Among them,270 unigenes were identified to be involved in triterpene saponin biosynthesis as well as 350 and 342unigenes were predicted to encode cytochrome P450 sand glycosyltransferases,respectively.One unigene was annotated as CYP716A53v2,probably participates in the formation of protopanaxatriol from protopanaxadiol and the differential expression of this gene was confirmed by real-time PCR.In addition,the pharmacological evaluation demonstrate that FS significantly promoted vascular endothelial growth factor(VEGF)induced the migration of human umbilical vein endothelial cells(HUVECs)and partially restored defective intersegmental vessels in a chemically induced vascular insufficiency model of zebrafish larva.Moreover,the two week posttreatment of the rat MI model with FS(25-50mg·kg-1·d-1)induced approximately 3-fold upregulation of VEGF mRNA expression,with a concomitant increase in blood vessel density in the peri-infarct area of the heart by 50.7%,compared to 41.4%in the MI group.Furthermore,TUNEL analysis indicates a reduction in the mean apoptotic nuclei per field in peri-infarct myocardium upon FS treatment.CONCLUSION We have established a global transcriptome dataset for Panax notoginseng and provided additional genetic information for further genome-wide research and analyses.Candidate genes involved in ginsenoside biosynthesis,including putative cytochrome P450 sand glycosyltransferases were obtained.The transcriptomes in different plant tissues also provide invaluable resources for future study of the differences in physiological processes and secondary metabolites in different parts of P.notoginseng.And the significant pro-angiogenic effect of FS in multiple experimental models renders the purified saponin preparation as potential preventive and therapeutic agent for cardiovascular diseases yet to be developed.