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Objective To investigate whether endogenous nociceptin/orphanin FQ (N/OFQ) can inhibit arrhythmia and expression of β1-adrenergic receptor (β1-AR) on the surface of myocardial cell membrane in acute myocardial ischemia rats by Raf kinase inhibitory protein (RKIP). Methods ① Experiment one: according to random number table method, 30 adult male Sprague-Dawley (SD) rats with only 6 weeks of age were divided into Sham group (open the chest but do not ligate the coronary artery), myocardial ischemia model group (coronary ligation of left anterior descending branch), and endogenous N/OFQ antagonists UFP-101 pretreatment group (UFP-101 group, preoperative 10 minutes after tail vein injection of 1 mL/kg UFP-101), with 10 rats in each group. Arrhythmia was recorded within 15 minutes after operation. The expression of phosphorylated RKIP (p-RKIP) was detected by Western Blot. ② Experiment two: according to the random number table method, 304-week-old male SD rats were divided into UFP-101 control group, RKIP over expression group and RKIP antagonism group, with 10 rats in each group. The UFP-101 control group was intraperiton eally injected with corn oil every day, while the other two groups were injected with up adjuster of RKIP (Didymin). The rats in the three groups were all ligated after 4 weeks of feeding, and UFP-101 was injected through the tail vein 10 minutes before the operation. The RKIP antagonist group received intraperitoneal injection of the RKIP-specific antagonist locostatin 2 hours before surgery. Arrhythmia results were recorded within 15 minutes after operation. Western Blot was used to detect the expression of p-RKIP in myocardial tissue and expression of β1-AR on the surface of myocardial cell membrane 15 minutes after surgery. Results ①Experiment one: compared with Sham group, ventricular ectopic beat (VEB), ventricular tachycardia (VT) and ventricular fibrillation (VF) increased significantly in the model group and UFP-101 group, and arrhythmia score increased significantly. In addition, compared with the Sham group, p-RKIP expression was increased in the model group and decreased in the UFP-101 group. Compared with the model group, preconditioning with UFP-101 significantly reduced the occurrence of arrhythmia [arrhythmia score: 1.5 (0.3, 5.0) vs. 4.0 (2.0, 5.0), P < 0.05], and the expression of p-RKIP in myocardial tissue significantly decreased (p-RKIP/total RKIP: 0.20±0.11 vs. 0.43±0.11, P < 0.05). This indicated that antagonistic N/OFQ could reduce the phosphorylation of RKIP and the occurrence of arrhythmia. ② Experiment two:compared with the UFP-101 control group, overexpression of RKIP significantly increased the occurrence of arrhythmia events, and the expression of β1-AR on the surface of the myocardial cell membrane significantly increased. And antagonism RKIP overexpression could make the occurrence of arrhythmia eased [arrhythmia score: 3.0 (2.0, 3.0) vs. 4.0 (2.0, 5.0), P < 0.05], and significantly reduce the expression of myocardial cell membrane surface β1-AR (β1-AR/Na+-K+-ATPase: 0.88±0.09 vs. 1.02±0.08, P < 0.05), while there was no significant difference in total RKIP expression (total RKIP/GAPDH: 5.40±0.21 vs. 5.36±0.19, P > 0.05). This indicated that endogenous N/OFQ affected the expression of plasma β1-AR on the surface of myocardial cell membrane and ischemic arrhythmia in rats through RKIP. Conclusion Endogenous N/OFQ can affect the expression of plasma β1-AR on the membrane surface of ischemic myocardium and arrhythmia in rats via increased expression of RKIP phosphorylation.
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Objective@#To investigate whether endogenous nociceptin/orphanin FQ (N/OFQ) can inhibit arrhythmia and expression of β1-adrenergic receptor (β1-AR) on the surface of myocardial cell membrane in acute myocardial ischemia rats by Raf kinase inhibitory protein (RKIP).@*Methods@#① Experiment one: according to random number table method, 30 adult male Sprague-Dawley (SD) rats with only 6 weeks of age were divided into Sham group (open the chest but do not ligate the coronary artery), myocardial ischemia model group (coronary ligation of left anterior descending branch), and endogenous N/OFQ antagonists UFP-101 pretreatment group (UFP-101 group, preoperative 10 minutes after tail vein injection of 1 mL/kg UFP-101), with 10 rats in each group. Arrhythmia was recorded within 15 minutes after operation. The expression of phosphorylated RKIP (p-RKIP) was detected by Western Blot. ② Experiment two: according to the random number table method, 30 4-week-old male SD rats were divided into UFP-101 control group, RKIP over expression group and RKIP antagonism group, with 10 rats in each group. The UFP-101 control group was intraperiton eally injected with corn oil every day, while the other two groups were injected with up adjuster of RKIP (Didymin). The rats in the three groups were all ligated after 4 weeks of feeding, and UFP-101 was injected through the tail vein 10 minutes before the operation. The RKIP antagonist group received intraperitoneal injection of the RKIP-specific antagonist locostatin 2 hours before surgery. Arrhythmia results were recorded within 15 minutes after operation. Western Blot was used to detect the expression of p-RKIP in myocardial tissue and expression of β1-AR on the surface of myocardial cell membrane 15 minutes after surgery.@*Results@#①Experiment one: compared with Sham group, ventricular ectopic beat (VEB), ventricular tachycardia (VT) and ventricular fibrillation (VF) increased significantly in the model group and UFP-101 group, and arrhythmia score increased significantly. In addition, compared with the Sham group, p-RKIP expression was increased in the model group and decreased in the UFP-101 group. Compared with the model group, preconditioning with UFP-101 significantly reduced the occurrence of arrhythmia [arrhythmia score: 1.5 (0.3, 5.0) vs. 4.0 (2.0, 5.0), P < 0.05], and the expression of p-RKIP in myocardial tissue significantly decreased (p-RKIP/total RKIP: 0.20±0.11 vs. 0.43±0.11, P < 0.05). This indicated that antagonistic N/OFQ could reduce the phosphorylation of RKIP and the occurrence of arrhythmia. ② Experiment two: compared with the UFP-101 control group, overexpression of RKIP significantly increased the occurrence of arrhythmia events, and the expression of β1-AR on the surface of the myocardial cell membrane significantly increased. And antagonism RKIP overexpression could make the occurrence of arrhythmia eased [arrhythmia score: 3.0 (2.0, 3.0) vs. 4.0 (2.0, 5.0), P < 0.05], and significantly reduce the expression of myocardial cell membrane surface β1-AR (β1-AR/Na+-K+-ATPase: 0.88±0.09 vs. 1.02±0.08, P < 0.05), while there was no significant difference in total RKIP expression (total RKIP/GAPDH: 5.40±0.21 vs. 5.36±0.19, P > 0.05). This indicated that endogenous N/OFQ affected the expression of plasma β1-AR on the surface of myocardial cell membrane and ischemic arrhythmia in rats through RKIP.@*Conclusion@#Endogenous N/OFQ can affect the expression of plasma β1-AR on the membrane surface of ischemic myocardium and arrhythmia in rats via increased expression of RKIP phosphorylation.
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PURPOSE: Hepatocellular carcinoma (HCC) is the most common malignant liver tumor. To reduce the mortality and improve the effectiveness of therapy, it is important to search for changes in tumor‑specific biomarkers whose function may involve in disease progression and which may be useful as potential therapeutic targets. MATERIALS AND METHODS: In this study, we use two‑dimensional polyacrylamide gel electrophoresis (2‑DE) and matrix‑assisted laser desorption/ionization time‑of‑flight mass spectrometry to observe proteome alterations of 12 tissue pairs isolated from HCC patients: Normal and tumorous tissue. Comparing the tissue types with each other, 40 protein spots corresponding to fifteen differentially expressed between normal and cancer part of HCC patients. RESULTS: Raf kinase inhibitor protein (RKIP), an inhibitor of Raf‑mediated activation of mitogen‑activated protein kinase/extracellular signal‑regulated kinase, may play an important role in cancer metastasis and cell proliferation and migration of human hepatoma cells. RKIP may be considered as a marker for HCC, because its expression level changes considerably in HCC compared with normal tissue. In addition, we used the methods of Western blotting and real time‑polymerase chain reaction to analysis the protein expression and gene expression of RKIP. The result showed RKIP protein and gene expression in tumor part liver tissues of HCC patient is lower than peritumorous non‑neoplastic liver tissue of the corresponding HCC samples. CONCLUSION: These results strongly suggest that RKIP may be considered to be a marker for HCC and RKIP are down‑regulated in liver cancer cell.
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Raf kinase inhibitor protein (RKIP) belongs to the family of phosphatidyle ethanolamine?binding protein, which plays an important role in the regulation of multiple signaling pathways in cells. Researches showed that RKIP was one of the malignant tumor suppressor factors,and its low expression was the important reason for the occurrence and development of malignant tumors,such as prostate cancer,lung cancer,breast cancer,colorectal cancer,acute myeloid leukemia,but the mechanism of RKIP low expression was still not very clear.Further research about RKIP not only can provide a new method for the diagnosis of malignant tumors,but also can provide a new way for the treatment of malignant tumors,also can provide a basis for predicting the recurrence and prognosis of malignant tumors.
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Objective To detect Snail and Raf kinase inhibitor protein (RKIP) expressions in NSCLC (Non-Small Cell Lung Cancer) and their relationship with the pathological characteristics of tumor. Methods Immunohistochemistry was used to detect Snail and RKIP expression in 124 NSCLC samples and 67 paraneoplastic normal lung tissue samples. Snail and RKIP positive expression rates were compared upon clinicopathologic characteristics. Correlation of Snail expres-sion with RKIP expression was also analyzed. Results Positive expression rate of Snail was 79.03%in lung cancer, which is higher than that in normal lung tissue 19.40%(χ2=63.538, P＜0.01);positive expression rate of RKIP was 36.29%in lung cancer which is lower than that in normal lung tissue 77.61%(χ2=29.716,P＜0.01), Snail and RKIP expressions are corre-lated with tumor differentiation, TNM stage, lymph node metastasis and postoperative survival time ( P＜0.05, respectively) . Snail protein expression is negatively correlated with RKIP expression in NSCLC (P＜0.05). Conclusion High Snail ex-pression and the low RKIP expression might be important biological markers for invasion and metastasis of NSCLC, which might be used as important prognostic indicators in NSCLC.
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Raf kinase inhibitor protein (RKIP)is a member of the phosphatidylethanolamine-binding protein family, which can inhibit the metastasis of tumor cells and is closely associated with the occurrence and development of tumor. Matrix metalloproteinase-9 (MMP-9)is a endopeptidase that can degrade extracellular matrix and plays an important role in invasion and metastasis of tumor.This article reviewed the advances in studies on RKIP and MMP-9 in colorectal cancer.
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Objective To investigate the relationship between RKIP expression and the efficiency of radiotherapy in NPC patients and evaluate the possibility of using RKIP as a predictor of radiosensitivity.Methods A total of 180 patients with NPC in Sun Yat-sen University Cancer Center without evidence of distant metastasis at initial diagnosis were enrolled in this study,who had received intensity-modulated radiotherapy alone.Patients were classified into 2 groups according to criteria below:patients with biopsy proven recurrent diseases occurring at nasopharynx and/or neck within 5 years after radiotherapy were classified as the radioresistant group.The pathological type at relapse was the same as the previous one before treatment.Patients with a minimum follow-up of 5 years after radiotherapy without evidence of recurrence at the original site of the tumor were classified as the radiosensitive group.Patients in the 2 groups were matched according to the factors related with radiosensitivity.RKIP was examined by immunohistochemical staining before radiotherapy.The relationship between RKIP expression and the effect of radiotherapy were analyzed.Results The positive rate of the RKIP expression in the radiosensitive group versus the radioresistant group was 80.0％ versus 26.7％.The positive rate (x2 =12.498,P ＜0.01) and the intensity of the RKIP expression (x2 =51.429,P ＜ 0.01) were significantly different between 2 groups with a negative correlation with radio-resistance to NPC (r =-0.344,-0.535,respectively,P ＜ 0.01).Based on the RKIP expression,the radiosensitivity,specificity,accuracy,positive predictive value,negative predictive value,false positive and false negative were predicted as follows:80.0％,73.3％,77.2％,75.0％,78.6％,26.7％,and 20.0％,respectively.Conclusions RKIP protein shows negative correlation with radioresistance to NPC and could serve as a biomarker in preliminarily screening the intrinsic radiosensitivity of NPC.
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Objective To detect the expression of Raf kinase inhibitor protein (RKIP) and NF-κB in renal tissue of diabetic kidney disease (DKD) rats model,and to investigate the effect of rituximab (RTX) on the expression of RKIP in the renal tissue of DKD rats. Methods SD rats were randomly divided into normal group (N),DKD model group (M) and RTX treatment group (D).Blood glucose and 24-hour urine protein of rats were determined in three groups.RKIP protein and NF-κB protein were determined by immunohistochemistry staining. RKIP protein expression was detected by Western blotting. Results Compared with N group,blood glucose,24-hour urine protein and NF-κB expression in M group increased significantly (all P＜ 0.01),the expression of RKIP in M group decreased significantly (P＜0.05).Compared with M group,the expression of RKIP increased significantly in D group (P＜0.05),and 24-hour urine protein and NF-κB expression decreased in D group (all P＜0.05).NF-κB protein expression was negatively correlated with RKIP expression in M group. Conclusions The NF-κB pathway regulated by RKIP plays an important role in the development and pathogenesis of diabetic nephropathy.Rituximab may have a role in treatment of DKD.
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Objective To investigate differential expression of Raf kinase inhibitor protein (RKIP)in gastric cancer and its clinical significance.Methods Pure gastric adenocarcinoma cells (GAC)and paracancerous gastric epithelial cells(NGEC)in 12 patient with gastric cancer were obtained using laser capture microdissection(LCM).After trypsin digestion all specimens were labeled with18O/16O.Quantitatively identification of differentially expressed proteins between GCC and NGEC was conducted using Nano-HPLC-MS/MS.The expression of RKIP in GAC was determined by Western blotting.Immunohistochemistry(IHC)was used to detect the expression of RKIP in gastric cancer(n=118),non-cancerous mucosa tissues(n=70)and matched positive lymph node tissues(n=35).Results A total of 78 differentially expressed proteins were identified and RKIP was downexpressed in GCC compared with NGEC(1:4.37).IHC examination revealed that positive expression of RKIP in gastric cancer had negative relation with deeper invasion,TNM stage and lymphoid node metastasis,while it had positive relation with histological differentiation(P＜0.05).Conclusion Down-regulation of RKIP in gastric cancer tissues might affect the biological behavior of gastric cancer.
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Objective: To investigate the expression and clinical significance of Raf kinase inhibitor protein (RKIP) and phosphorylated-extracellular signal regulated kinase (P-ERK) in hepatocellular carcinoma (HCC) and their correlations with the invasion and metastasis of HCC. Methods: Immunohistochemistry was used to detect the expressions of RKIP and P-ERK in HCC tissues, paracancerous tissues, and normal liver tissues. Statistical analysis was used to determine the relationship between their expressions and clinicopathological parameters. Results: Statistical analysis revealed that RKIP-positive staining rate was lower in tumor tissues than that in tumor-surrounding tissues and in normal liver tissues. But P-ERK-positive staining rate was significantly higher in tumor tissues than that in tumor-surrounding tissues and normal liver tissues. The difference was significant. RKIP expression had negative correlation with P-ERK expression (r = - 0.227, P = 0.039); RKIP expression in HCC was associated with intrahepatic or lymphatic metastasis and tumor differentiation (P < 0.05). P-ERK expression in HCC was related with tumor differentiation, tumor thrombosis, and intrahepatic or lymphatic metastasis (P < 0.05). Conclusions: These findings indicate that down-regulation or loss of RKIP expression is closely related with HCC development and progression. The down-regulation or loss of RKIP expression stimulates migration and metastasis of HCC by up-regulating P-ERK expression.
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Objective: To investigate the effects of the cyclic uniaxial compressive stress on RKIP and its mRNA in the rat condylar chondrocytes. Methods:The third-passage chondrocytes were harvested from the mandibular condyles of 2-day-old rats, and a cellular compressive stress device (self-made four-point bending system. Patent No: 01129166.4 & 01256849.x) was used to apply stress on cells at 4 000 ?strain ( 0.5 Hz frequency) for 0, 15, 30, 60, 120 and 240 min. The effects of the cyclic uniaxial compressive stress on RKIP and its mRNA in the rat mandibular condylar chondrocytes were examined by REAL-TIME PCR and Western blot. Results:The results showed that the expression of RKIP and its mRNA changed obviously with 4 000 ?strain compressive stress loading, there are reverse tendency in the expression between RKIP and its mRNA. RKIP mRNA significantly increased at 30min (P