Receptor tyrosine kinase-like orphan receptor 1:A novel antitumor target in gastrointestinal cancers

Receptor tyrosine kinase-like orphan receptor 1(ROR1)is a member of the type I receptor tyrosine kinase family.ROR1 is pivotal in embryonic development and cancer,and serves as a biomarker and therapeutic target.It has soluble and membrane-bound subtypes,with the latter highly expressed in tumors.ROR1 is conserved throughout evolution and may play a role in the development of gastrointestinal cancer through multiple signaling pathways and molecular mechanisms.Studies suggest that overexpression of ROR1 may increase tumor invasiveness and metastasis.Additionally,ROR1 may regulate the cell cycle,stem cell characteristics,and interact with other signaling pathways to affect cancer progression.This review explores the structure,expression and role of ROR1 in the development of gastrointestinal cancers.It discusses current antitumor strategies,outlining challenges and prospects for treatment.

Lowered HGK expression inhibits cell invasion and adhesion in hepatocellular carcinoma cell line HepG2

AIM:To investigate the effects of RNA interference tar-geting hepatocyte progenitor kinase-like kinase(HGK) in the invasion and adhesion of hepatocellular carcinoma(HCC) cell line HepG2.METHODS:Three paired insert DNA fragments specif ic to HGK gene and one negative control DNA fragment were synthesized and inserted into RNAi-Ready pSIREN-RetroQ-ZsGreen vector.Western blotting assay and real-time reverse transcriptase polymerase chain reaction(RT-PCR) were used to screen the vector with a highest inhibitory rate.The vector was used to generate recom-binant retrovirus specif ic to HGK.3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2h-tetrazolium bromide(MTT) assay was used to examine cell growth;wound closure assay and cell adhesion assay were employed to investigate cell migration and adhesion respectively;and transwell assay and three-dimensional culture invasion assay were used to detect cell invasion.The expressions of matrix metalloproteinase(MMP)-2,MMP-9 and nuclear factor(NF)-κB were detected by Western blotting assay.RESULTS:The real time RT-PCR and Western blotting assay showed that cells transfected with retrovirus me-diating RNAi targeting of HGK(RV-shHGK)-1 vector had the strongest inhibition of HGK protein,with an inhibi-tion rate of 76%,and this vector was used to generate recombinant retrovirus RV-shHGK-1.Cell adhesion assay and MTT assay found that cell adhesion and growth of the cells infected with RV-shHGK-1 were significantly lower than those of the control cells(P < 0.05).Wound closure assay,transwell assay and three-dimensional culture invasion assay showed that the cell invasiveness was significantly less in HGK knockdown cells than in the control cells(P < 0.05).The expressions of MMP-2,MMP-9 and NF-κB were inhibited in HepG2 cells infected with RV-shHGK-1.CONCLUSION:Down-regulation of HGK can obviously inhibit the migration and invasion of HepG2 cells in vitro.HGK may be a new therapeutic target for treatment of HCC.

Neuroprotective role of edaravone and the effects of endoplasmic reticulum stress in an adult rat model of focal cerebral ischemia/reperfusion

BACKGROUND： Endoplasmic reticulum （ER） stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral ischemia. Edaravon （3-methyl-1-phenyl-2-pyrazolin-5-one） is a potent and novel scavenger of free radicals that inhibit delayed neuronal death, as demonstrated by in vitro and animal studies. However, its effect on ER stress and induced neuronal apoptosis in a rat model of brief middle cerebral artery occlusion remains unclear. OBJECTIVE： To explore the effects of edaravone on the expression of ER stress-related factors and neuronal apoptosis, based on the hypothesis that edaravone influences ER stress in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING： A randomized, controlled, animal study was performed at the Laboratory of Department of Neurology, Xiangya Hospital and the Department of Laboratory Animals, Xiangya Medical College, Central South University in China from June 2005 to May 2006. MATERIALS： Edaravone was purchased from Simcere Pharmaceutical Group, China. METHODS： A total of 216 adult, male, Sprague Dawley rats were randomly assigned to sham-surgery, model and edaravone groups, with 72 rats in each group, Brief middle cerebral artery occlusion was established in the model and edaravone groups. In addition, the edaravone group rats were injected with 3 mg/kg edaravone through the tail vein. MAIN OUTCOME MEASURES： RNA-dependent protein kinase-like endoplasmic reticulum eukaryotic translation initiation factor 2a kinase （PERK） and C/EBP homology protein （CHOP） mRNA expression in the ischemic parietal cortex was determined by reverse transcriptionpolymerase chain reaction; phosphorylated PERK and CHOP protein expression was detected by immunohistochemistry; neuronal apoptosis was detected by TdT-mediated-dUTP nick end labeling. RESULTS： Neurological deficit scores were significantly reduced in the edaravone group compared to the model group at 12, 24, and 72 hours following reperfusion （P〈 0.05）. In addition, PERK and CHOP mRNA as well as phosphorylated PERK and CHOP protein expression were significantly reduced in the edaravone group compared to the model group at 1,3, and 6 hours following reperfusion （P 〈 0.05, P 〈 0.01）. CHOP mRNA expression was decreased in the edaravone group compared to the model group at 3, 6, 12, and 24 hours following reperfusion （P〈 0.01）, while CHOP protein expression was less than the model group at 6, 12, and 24 hours following reperfusion （P 〈 0.05）. CONCLUSION： Edaravone treatment resulted in decreased PERK and CHOP expression following ischemia/reperfusion, as well as reduced neuronal apoptosis. Edaravone exhibited a neuroprotective role by inhibiting endoplasmic reticulum stress.

Neuroprotective effects of atorvastatin against cerebral ischemia/reperfusion injury through the inhibition of endoplasmic reticulum stress

Cerebral ischemia triggers secondary ischemia/reperfusion injury and endoplasmic reticulum stress initiates cell apoptosis. However, the regulatory mechanism of the signaling pathway remains unclear. We hypothesize that the regulatory mechanisms are mediated by the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α in the endoplasmic reticulum stress signaling pathway. To verify this hypothesis, we occluded the middle cerebral artery in rats to establish focal cerebral ischemia/reperfusion model. Results showed that the expression levels of protein kinase-like endoplasmic reticulum kinase and caspase-3, as well as the phosphorylation of eukaryotic initiation factor 2α, were increased after ischemia/reperfusion. Administration of atorvastatin decreased the expression of protein kinase-like endoplasmic reticulum kinase, caspase-3 and phosphorylated eukaryotic initiation factor 2α, reduced the infarct volume and improved ultrastructure in the rat brain. After salubrinal, the specific inhibitor of phosphorylated eukaryotic initiation factor 2α was given into the rats intragastrically, the expression levels of caspase-3 and phosphorylated eukaryotic initiation factor 2α in the were decreased, a reduction of the infarct volume and less ultrastructural damage were observed than the untreated, ischemic brain. However, salubrinal had no impact on the expression of protein kinase-like endoplasmic reticulum kinase. Experimental findings indicate that atorvastatin inhibits endoplasmic reticulum stress and exerts neuroprotective effects. The underlying mechanisms of attenuating ischemia/reperfusion injury are associated with the protein kinase-like endoplasmic reticulum kinase/eukaryotic initiation factor 2α/caspase-3 pathway.

ROR2 promotes invasion and chemoresistance of triple-negative breast cancer cells by activating PI3K/AKT/mTOR signaling

Objective:This study aimed to investigate the role of receptor tyrosine kinase-like orphan receptor 2(ROR2)in triple-negative breast cancer(TNBC).Methods:ROR2 expression in primary TNBC and metastatic TNBC tissues was analyzed by immunohistochemical staining and PCR.ROR2 expression in TNBC cell lines was detected by PCR and Western blot analysis.The migration,invasion and chemosensitivity of TNBC cells with overexpression or knockdown of ROR2 were examined.Results:ROR2 expression was high in metastatic TNBC tissues.ROR2 knockdown suppressed the migration,invasion and chemoresistance of TNBC cells.ROR2 overexpression in MDA-MB-435 cells promoted the migration,invasion,and chemoresistance.Moreover,ROR2 knockdown in HC1599 and MDA-MB-435 adriamycin-resistant cells enhanced chemosensitivity to adriamycin.ROR2 could activate PI3K/AKT/mTOR signaling in TNBC cells.Conclusion:ROR2 is upregulated and promotes metastatic phenotypes of TNBC by activating PI3K/AKT/mTOR signaling.

ROR2 gene is associated with risk of non-syndromic cleft palate in an Asian population

Background The receptor tyrosine kinase-like orphan receptor 2 （ROR2） gene has been recently shown to play important roles in palatal development in animal models and resides in the chromosomal region linked to non syndromic cleft lip with or without cleft palate in humans.The aim of this study was to investigate the possible association between ROR2 gene and non-syndromic oral clefts.Methods Here we tested 38 eligible single-nucleotide polymorphisms （SNPs） in ROR2 gene in 297 non-syndromic cleft lip with or without cleft palate and in 82 non-syndromic cleft palate case parent trios recruited from Asia and Maryland.Family Based Association Test was used to test for deviation from Mendelian inheritance.Plink software was used to test potential parent of origin effect.Possible maternally mediated in utero effects were assessed using the TRlad Multi-Marker approach under an assumption of mating symmetry in the population.Results Significant evidence of linkage and association was shown for 3 SNPs （rs7858435,rs10820914 and rs3905385） among 57 Asian non-syndromic cleft palate trios in Family Based Association Tests.P values for these 3 SNPs equaled to 0.000068,0.000115 and 0.000464 respectively which were all less than the significance level （0.05/38=0.0013） adjusted by strict Bonferroni correction.Relevant odds ratios for the risk allele were 3.42 （1.80-6.50）,3.45 （1.75-6.67） and 2.94 （1.56-5.56）,respectively.Statistical evidence of linkage and association was not shown for study groups other than non-syndromic cleft palate.Neither evidence for parent-of-origin nor maternal genotypic effect was shown for any of the ROR2 markers in our analysis for all study groups.Conclusion Our results provided evidence of linkage and association between the ROR2 gene and a gene controlling risk to non-syndromic cleft palate.