Quantitative real-time reverse transcription-polymerase chain reaction （qPCR） is widely used to investigate transcriptional changes following experimental manipulations to the nervous system. Despite the widespread ...Quantitative real-time reverse transcription-polymerase chain reaction （qPCR） is widely used to investigate transcriptional changes following experimental manipulations to the nervous system. Despite the widespread utilization of qPCR, the interpretation of results is marred by the lack of a suitable reference gene due to the dynamic nature of endogenous transcription. To address this inherent deficiency, we investigated the use of an exogenous spike-in mRNA, luciferase, as an internal reference gene for the 2ct normalization method. To induce dynamic transcription, we systemically administered capsaicin, a neurotoxJn selective for C-type sensory neurons expressing the TRPV-1 receptor, to adult male Sprague-Dawley rats. We later isolated nodose ganglia for qPCR analysis with the reference being either exogenous luciferase mRNA or the commonly used endogenous reference 13-111 tubulin. The exogenous luciferase mRNA reference clearly demonstrated the dynamic expression of the endogenous reference. Furthermore, variability of the endogenous reference would lead to misinterpretation of other genes of interest. In conclusion, traditional reference genes are often unstable under physiologically normal situations, and certainly unstable following the damage to the nervous system. The use of exogenous spike-in reference provides a consistent and easily implemented alternative for the analysis of qPCR data.展开更多
Objective: To detect circulating hepatocellular carcino-ma by demonstrating hepatocellular carcinoma cells orhepatocyte-associated mRNA in the nuclear cell com-ponent of peripheral blood (PBL).Methods: Peripheral bloo...Objective: To detect circulating hepatocellular carcino-ma by demonstrating hepatocellular carcinoma cells orhepatocyte-associated mRNA in the nuclear cell com-ponent of peripheral blood (PBL).Methods: Peripheral blood (5 ml) samples were ob-tained from 93 patients with hepatocellular carcinoma(HCC) and from 33 control subjects (9 with liver cir-rhosis after hepatitis B,14 with chronic hepatitis B,10with normal liver function). To identify HCC cells inperipheral blood, liver-specific human alpha-fetopro-tein (AFP) mRNA was amplified from total RNA ex-tracted from whole blood by reverse transcription-polymerase chain reaction.Results: AFPmRNA was detected in 50 blood samplesfrom the HCC patients (50/93, 53.8%). In contrast,there were no clinical control patients whose samplesshowed detectable AFPmRNA in PBL. The presence ofAFPmRNA in blood seemed to be correlated with thestage (by TNM classification) of HCC, the serum AFPvalue, and the presence of intrahepatic metastasis,portal vein thrombosis, tumor diameter and/or distantmetastasis. In addition, AFPmRNA was detected in theblood of 21 patients with metastasis at extrahepaticorgans (100%) in contrast to 29 (40.3%)of 72 pa-tients without metastasis.Conclusion: The presence of AFPmRNA in peripheralblood may be an indicator of malignant hepatocytes,which might predict hematogenous spreading metasta-sis of tumor cells in patients with HCC.展开更多
An easy and reliable method was developed for construction and quantification of competitive templates, which shared the same sequence as the amplified target DNA except for a 20 bp insertion in the middle by recombi...An easy and reliable method was developed for construction and quantification of competitive templates, which shared the same sequence as the amplified target DNA except for a 20 bp insertion in the middle by recombinant polymerase chain reaction (PCR). Among the advantages of competitive PCR is that any predictable or unpredictable variable that affects amplification has the same effect on both target and competitor species and that the final ratio of amplified products reflects exactly the initial targets. The utilization of a thermostable reverse transcriptase in the RT step was proposed to overcome the problem of the efficiency of target cDNA synthesis. In addition, to obtain reliable measurements, it was recommended to perform four PCR with amounts of competitive template flanking the concentration of the target mRNA.展开更多
In order to detect circulating cells of hepatocellular carcinoma(HCC) in the peripheral blood with reverse transcripition polymerase chain reaction (RT-PCR ), alpha-fetoprotein (AFP ) mRNA was tested in the blood samp...In order to detect circulating cells of hepatocellular carcinoma(HCC) in the peripheral blood with reverse transcripition polymerase chain reaction (RT-PCR ), alpha-fetoprotein (AFP ) mRNA was tested in the blood samples of 113 cases of HCC and 69 controls (including 30 cases of liver cirrhosis, 9 cases of metastatic liver cancer and 30 normal subjects). 20/43 (46. 5% ) cases of HCC and 2/30 (6. 7% ) cases of liver cirrhosis are positive and the cases of nletastatic liver cancer and normal controls were negative for human AFP(hAFP) rnRNA. The presence of hAFP mRNA in the peripheral blood seems to be correlated with intrahepatic and distant nletastasls of HCC and portal vein thrombosis. It is concluded that the presence of hAFP mRNA in the peripheral hloocl is an indicator of circulating HCC cells and can be used to diagnose the rnetastasisof HCC through henlatogenous route and RT-PCR amplification of hAFP mRNA is a sensitive and specificprocedure for detecting circulating cells of HCC.展开更多
AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl trans...AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.展开更多
A reproducible,quantitative,non-radioactive method for the analysis of mRNA expression is described.After RNA preparation and cDNA synthesis,the cDNA was co-amplified with an internal standard in the same PCR system.T...A reproducible,quantitative,non-radioactive method for the analysis of mRNA expression is described.After RNA preparation and cDNA synthesis,the cDNA was co-amplified with an internal standard in the same PCR system.The PCR products containing both targen and internal standard amplificates were electrophoresed and detected on an ABI 377 DNA Sequencer.For each sample,β-actin was also quantified by an identical procedure to compensate for relative differences between samples in the integrity of the individual RNA samples and for variations in reverse transcription.Due to the linear relationship between cDNA content and PCR product ratio of target cDNA template and competitive standard,a single PCR reaction was sufficient for quantification of a sample.The experimental results showed that the method is a mRNA quantitative RT-PCR method with high sensitivity and good reproducibility.It can be used in large-scale accurate quantitative analyses of mRNA expression of any gene.展开更多
AIM: To study preliminarily the properties of myosin light chain kinase (MLCK) in rabbit liver. METHODS: The expression of MLCK was detected by reverse transcription-polymerase chain reaction(RT-PCR); the MLCK was obt...AIM: To study preliminarily the properties of myosin light chain kinase (MLCK) in rabbit liver. METHODS: The expression of MLCK was detected by reverse transcription-polymerase chain reaction(RT-PCR); the MLCK was obtained from rabbit liver, and its activity was analyzed by gamma-(32)P incorporation technique to detect the phosphorylation of myosin light chain. RESULTS: MLCK was expressed in rabbit liver, and the activity of the enzyme was similar to rabbit smooth muscle MLCK, and calmodulin-dependent. When the concentration was 0.65 mg x L(-1), the activity was at the highest level. CONCLUSION: MLCK expressed in rabbit liver may catalyze the phosphorylation of myosin light chain, which may play important roles in the regulation of hepatic cell functions.展开更多
基金This project was supported by the Washington State University Start-up Funds, George W. Bagby Research Fund
文摘Quantitative real-time reverse transcription-polymerase chain reaction （qPCR） is widely used to investigate transcriptional changes following experimental manipulations to the nervous system. Despite the widespread utilization of qPCR, the interpretation of results is marred by the lack of a suitable reference gene due to the dynamic nature of endogenous transcription. To address this inherent deficiency, we investigated the use of an exogenous spike-in mRNA, luciferase, as an internal reference gene for the 2ct normalization method. To induce dynamic transcription, we systemically administered capsaicin, a neurotoxJn selective for C-type sensory neurons expressing the TRPV-1 receptor, to adult male Sprague-Dawley rats. We later isolated nodose ganglia for qPCR analysis with the reference being either exogenous luciferase mRNA or the commonly used endogenous reference 13-111 tubulin. The exogenous luciferase mRNA reference clearly demonstrated the dynamic expression of the endogenous reference. Furthermore, variability of the endogenous reference would lead to misinterpretation of other genes of interest. In conclusion, traditional reference genes are often unstable under physiologically normal situations, and certainly unstable following the damage to the nervous system. The use of exogenous spike-in reference provides a consistent and easily implemented alternative for the analysis of qPCR data.
文摘Objective: To detect circulating hepatocellular carcino-ma by demonstrating hepatocellular carcinoma cells orhepatocyte-associated mRNA in the nuclear cell com-ponent of peripheral blood (PBL).Methods: Peripheral blood (5 ml) samples were ob-tained from 93 patients with hepatocellular carcinoma(HCC) and from 33 control subjects (9 with liver cir-rhosis after hepatitis B,14 with chronic hepatitis B,10with normal liver function). To identify HCC cells inperipheral blood, liver-specific human alpha-fetopro-tein (AFP) mRNA was amplified from total RNA ex-tracted from whole blood by reverse transcription-polymerase chain reaction.Results: AFPmRNA was detected in 50 blood samplesfrom the HCC patients (50/93, 53.8%). In contrast,there were no clinical control patients whose samplesshowed detectable AFPmRNA in PBL. The presence ofAFPmRNA in blood seemed to be correlated with thestage (by TNM classification) of HCC, the serum AFPvalue, and the presence of intrahepatic metastasis,portal vein thrombosis, tumor diameter and/or distantmetastasis. In addition, AFPmRNA was detected in theblood of 21 patients with metastasis at extrahepaticorgans (100%) in contrast to 29 (40.3%)of 72 pa-tients without metastasis.Conclusion: The presence of AFPmRNA in peripheralblood may be an indicator of malignant hepatocytes,which might predict hematogenous spreading metasta-sis of tumor cells in patients with HCC.
文摘An easy and reliable method was developed for construction and quantification of competitive templates, which shared the same sequence as the amplified target DNA except for a 20 bp insertion in the middle by recombinant polymerase chain reaction (PCR). Among the advantages of competitive PCR is that any predictable or unpredictable variable that affects amplification has the same effect on both target and competitor species and that the final ratio of amplified products reflects exactly the initial targets. The utilization of a thermostable reverse transcriptase in the RT step was proposed to overcome the problem of the efficiency of target cDNA synthesis. In addition, to obtain reliable measurements, it was recommended to perform four PCR with amounts of competitive template flanking the concentration of the target mRNA.
文摘In order to detect circulating cells of hepatocellular carcinoma(HCC) in the peripheral blood with reverse transcripition polymerase chain reaction (RT-PCR ), alpha-fetoprotein (AFP ) mRNA was tested in the blood samples of 113 cases of HCC and 69 controls (including 30 cases of liver cirrhosis, 9 cases of metastatic liver cancer and 30 normal subjects). 20/43 (46. 5% ) cases of HCC and 2/30 (6. 7% ) cases of liver cirrhosis are positive and the cases of nletastatic liver cancer and normal controls were negative for human AFP(hAFP) rnRNA. The presence of hAFP mRNA in the peripheral blood seems to be correlated with intrahepatic and distant nletastasls of HCC and portal vein thrombosis. It is concluded that the presence of hAFP mRNA in the peripheral hloocl is an indicator of circulating HCC cells and can be used to diagnose the rnetastasisof HCC through henlatogenous route and RT-PCR amplification of hAFP mRNA is a sensitive and specificprocedure for detecting circulating cells of HCC.
基金Supported by grant from Fundamental Research Grant Scheme by Ministry of Higher Education(MoHE)600-IRMI/FRGS 5/3(101/2019).
文摘AIM:To investigate the stability of the seven housekeeping genes:beta-actin(ActB),glyceraldehyde-3-phosphate dehydrogenase(GAPDH),18s ribosomal unit 5(18s),cyclophilin A(CycA),hypoxanthine-guanine phosphoribosyl transferase(HPRT),ribosomal protein large P0(36B4)and terminal uridylyl transferase 1(U6)in the diabetic retinal tissue of rat model.METHODS:The expression of these seven genes in rat retinal tissues was determined using real-time quantitative reverse transcription polymerase chain reaction(RT-qPCR)in two groups;normal control rats and streptozotocininduced diabetic rats.The stability analysis of gene expression was investigated using geNorm,NormFinder,BestKeeper,and comparative delta-Ct(ΔCt)algorithms.RESULTS:The 36B4 gene was stably expressed in the retinal tissues of normal control animals;however,it was less stable in diabetic retinas.The 18s gene was expressed consistently in both normal control and diabetic rats’retinal tissue.That this gene was the best reference for data normalisation in RT-qPCR studies that used the retinal tissue of streptozotocin-induced diabetic rats.Furthermore,there was no ideal gene stably expressed for use in all experimental settings.CONCLUSION:Identifying relevant genes is a need for achieving RT-qPCR validity and reliability and must be appropriately achieved based on a specific experimental setting.
文摘A reproducible,quantitative,non-radioactive method for the analysis of mRNA expression is described.After RNA preparation and cDNA synthesis,the cDNA was co-amplified with an internal standard in the same PCR system.The PCR products containing both targen and internal standard amplificates were electrophoresed and detected on an ABI 377 DNA Sequencer.For each sample,β-actin was also quantified by an identical procedure to compensate for relative differences between samples in the integrity of the individual RNA samples and for variations in reverse transcription.Due to the linear relationship between cDNA content and PCR product ratio of target cDNA template and competitive standard,a single PCR reaction was sufficient for quantification of a sample.The experimental results showed that the method is a mRNA quantitative RT-PCR method with high sensitivity and good reproducibility.It can be used in large-scale accurate quantitative analyses of mRNA expression of any gene.
基金Supported by the National Natural Science Foundation of China(39870324,YW)Key Innovation Project of Chinese Academy of Science,P.R.China(KSCX 2-2-01,XB Yao)Grant for Excellent Young Teachers of Ministry of Education of China(99044312,YW)
文摘AIM: To study preliminarily the properties of myosin light chain kinase (MLCK) in rabbit liver. METHODS: The expression of MLCK was detected by reverse transcription-polymerase chain reaction(RT-PCR); the MLCK was obtained from rabbit liver, and its activity was analyzed by gamma-(32)P incorporation technique to detect the phosphorylation of myosin light chain. RESULTS: MLCK was expressed in rabbit liver, and the activity of the enzyme was similar to rabbit smooth muscle MLCK, and calmodulin-dependent. When the concentration was 0.65 mg x L(-1), the activity was at the highest level. CONCLUSION: MLCK expressed in rabbit liver may catalyze the phosphorylation of myosin light chain, which may play important roles in the regulation of hepatic cell functions.
