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ObjectiveTo screen out the transcriptomes related to the intervention of Wuzi Yanzongwan on the spermatogenic function of semi-castrated male mice， and to explore its potential mechanism in the intervention of the progress of low spermatogenic function. MethodBalb/c mice were randomly divided into sham-operated group， model group， testosterone propionate group（0.2 mg·kg-1·d-1， intramuscular injection） and Wuzi Yanzongwan group（1.56 g·kg-1·d-1， intragastric administration） according to body weight， with 12 mice in each group. The right testicle and epididymis were extracted from the model group and the drug administration group to construct the semi-castrated model of low spermatogenic function， while the fur and the right scrotum of the sham-operated group were only cut and immediately sterilized and sutured. At the end of the intervention， hematoxylin-eosin（HE） staining was used to observe the histopathology of testis， enzyme-linked immunosorbent assay（ELISA） was used to detect the levels of serum testosterone（T）， luteinizing hormone（LH） and follicle stimulating hormone（FSH）. The sperm count and motility of epididymis were measured by automatic sperm detector of small animal. Transcriptomic microarray technology was used to detect the mRNA expression level of testicular tissue in each group， the transcriptome of genes related to the regulation of Wuzi Yanzongwan was screened， and three mRNAs were selected for Real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） to verify the transcriptome data. Through the annotation analysis of Gene Ontology（GO） and the signaling pathway analysis of Kyoto Encyclopedia of Genes and Genomes（KEGG）， the related functions of drugs regulating transcriptome were analyzed. ResultCompared with the sham-operated group， the testicular tissue of mice in the model group showed spermatogenic injury， contraction and vacuolization of the seminiferous tubules， reduction of spermatogenic cells at all levels， widening of the interstitial space， obstruction of spermatogonial cell development and other morphological abnormalities， and serum T significantly decreased， LH significantly increased（P<0.01）， and FSH elevated but no statistically significant difference， the count and vitality of epididymal sperm significantly decreased（P<0.01）. There were 882 differentially expressed mRNAs in the testicular tissues， of which 565 were up-regulated and 317 were down-regulated. Cluster analysis showed that these differentially expressed mRNA could effectively distinguish between the sham-operated group and the model group. Compared with the model group， the damage to testicular tissue in the Wuzi Yanzongwan group was reduced， the structure of the seminiferous tubules was intact， vacuolization was reduced， and the number of spermatogenic cells at all levels was significantly increased and arranged tightly. The serum T significantly increased， LH significantly decreased（P<0.01）， and FSH decreased but the difference was not statistically significant. The count and vitality of sperm in the epididymis were significantly increased（P<0.01）. Moreover， Wuzi Yanzongwan could regulate 159 mRNA levels in the testes of semi-castrated mice， of which 32 were up-regulated and 127 were down-regulated， and the data of the transcriptome assay was verified to be reliable by Real-time PCR. GO and KEGG analysis showed that the transcriptome functions regulated by Wuzi Yanzongwan were involved in the whole cell cycle process of sperm development such as sex hormone production of interstitial cells in testis， renewal， differentiation， metabolism， apoptosis and signal transduction of spermatogenic cells， and were closely related to the biological behaviors of signaling pathways such as spermatogenic stem cell function， endoplasmic reticulum protein processing and metabolic program. ConclusionWuzi Yanzongwan can effectively improve the low spermatogenic function of semi-castrated male mice， and its mechanism may be related to the regulation of testicular transcriptional regulatory network， the synthesis of sex hormones in testicular interstitial cells， the function of spermatogenic stem cells， the whole cell cycle process of spermatogenesis， as well as the expression of endoplasmic reticulum protein processing and metabolic program related genes transcription.
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Objective:To quantitatively analyze the changes of Staphylococcus aureus in different processed products of Angelicae Sinensis Radix. Method:The real-time fluorescence quantitative polymerase chain reaction method （Real-time PCR） was established to quantitatively analyze S. aureus in Angelicae Sinensis Radix decoction pieces which bought from different producing areas， different enterprises and different storage time. The fluorescence quantitative reaction system was SYBR Premix Ex Taq Ⅱ of 10 μL， each of forward primer and reverse primer （10 μmol·L-1） of 0.8 μL， template/genome DNA of 1 μL， double distilled water of 7.4 μL. The reaction conditions of the fluorescence quantitative amplification curve were pre-denaturing for 30 s at 94 ℃， denaturing for 10 s at 94 ℃， annealing for 12 s at 60 ℃， extensing for 30 s at 72 ℃， cycling 45 times， single-point detection signal at 72 ℃. The melting curve was made from 72 ℃， and the step temperature of 0.5 ℃ was kept for 15 s to collect fluorescence. According to the results of Real-time PCR， representative samples were selected from Angelicae Sinensis Radix decoction pieces for comparison between plate counting method and Real-time PCR. Result:The content of S. aureus in different processed products was sorted by rank of raw Angelicae Sinensis Radix>soil-fried Angelicae Sinensis Radix>wine-processed Angelicae Sinensis Radix. The content of S. aureus was the lowest in the samples from Weiyuan area of Gansu province by comparing with other producing areas. Compared with the retail enterprises， the content of S. aureus in raw products and wine-processed products from production and sale enterprises was lower. Different storage time had certain effect on the content of S. aureus in raw products and wine-processed products， and the content of S. aureus increased with the increase of storage time. The detection results of plate counting method were 3-4 orders of magnitude lower than that of Real-time PCR. Conclusion:The established Real-time PCR is superior to plate counting method in specificity， sensitivity， reliability and reporting period， which can provide an effective method for rapid and accurate quantitative detection of S. aureus in different processed products of Angelicae Sinensis Radix.
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OBJECTIVE@#The expression of microRNA-125b in tongue squamous cell carcinoma (TSCC) was detected and analyzed for its relationship with the clinicopathological features of TSCC.@*METHODS@#Real time fluorescence-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of microRNA-125b in 35 TSCC tissues and adjacent normal tissues from 35 TSCC cases. The relationship between the expression of microRNA-125b in TSCC tissues and the clinicopathological features of patients with TSCC was analyzed. In situ hybridization (ISH) was used to detect the expression level of microRNA-125b gene in the TSCC tissues and adjacent normal tissues.@*RESULTS@#RT-qPCR results showed that the relative expression levels of microRNA-125b in the TSCC issues was 2.32±0.69, and that of normal tissues was 0.87±0.32. The statistical results showed that the expression level of microRNA-125b was significantly higher in the TSCC tissues than in the normal tissues (P<0.001). The expression level of microRNA-125b in the TSCC tissues was not significantly correlated with age, gender, pathological grade, and lymph node metastasis but was positively correlated with TNM stage. Patients with high TNM stage had high microRNA-125b expression levels (P<0.05). The ISH results showed that the expression levels of microRNA-125b in the TSCC tissues were 0.010±0.003, and that of normal tissues was 0.004±0.001. The expression levels of microRNA-125b in the 35 TSCC tissues were significantly higher than those in the normal tissues (P<0.05).@*CONCLUSIONS@#MicroRNA-125b is highly expressed in TSCC and associated with TNM stage, suggesting that high microRNA-125b expression may be involved in the development of TSCC.
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Humanos , Carcinoma de Células Escamosas , Metástase Linfática , MicroRNAs , Prognóstico , Reação em Cadeia da Polimerase em Tempo Real , Neoplasias da LínguaRESUMO
Objective To investigate the level and clinical significance of miRNA －106a in non－small cell lung cancer tissues.Methods Paraffin－embedded specimens of non －small cell lung cancer tissues and adjacent tissues from 80 patients with non －small cell lung cancer from January 2012 to December 2013 in Yiwu Central Hospital were selected in this study.The real－time fluorescence quantitative polymerase chain reaction (QRT－PCR) was used to determine the level of miRNA －106a in lung cancer tissues and adjacent tissues.Results The level of miRNA－106a in non－small cell lung cancer tissues (2.42 ±0.23) was higher than that in adjacent tissues (1.00 ± 0.06) (t＝53.433,P＝0.000).The miRNA －106a levels in lung cancer tissues of stage Ⅲ －Ⅳ,lymph node metastasis and recurrence time ＜6 months were high than those of the stage Ⅰ－Ⅱ,no lymph node metastasis and recurrence time≥6 months(t＝7.641,11.115,2.183,P＝0.000,0.000,0.032).The level of miRNA－106a was not associated with age ,gender,pathological type,degree of differentiation and vascular invasion (all P＞0.05).The level of miRNA－106a in non－small cell lung cancer tissues was cut by 2.12.The area under the ROC curve for the diagnosis of non －small cell lung cancer was 0.823(95%CI＝0.820－0.825,P＝0.000),and the sensitivity was 54.37%,the specificity was 89.21%.The cumulative survival rate and progression －free survival rate of patients with low－expression of miRNA －106a in non －small cell lung cancer were higher than those with high expression of miRNA－106a (P＝0.027,0.012).Conclusion The miRNA －106a level is elevated in non －small cell lung cancer tissues.The miRNA－106a may be involved in the development of non －small cell lung cancer and is of great value in the diagnosis and prognosis evaluation of non －small cell lung cancer.
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Objective@#To investigate the level and clinical significance of miRNA-106a in non-small cell lung cancer tissues.@*Methods@#Paraffin-embedded specimens of non-small cell lung cancer tissues and adjacent tissues from 80 patients with non-small cell lung cancer from January 2012 to December 2013 in Yiwu Central Hospital were selected in this study.The real-time fluorescence quantitative polymerase chain reaction (QRT-PCR) was used to determine the level of miRNA-106a in lung cancer tissues and adjacent tissues.@*Results@#The level of miRNA-106a in non-small cell lung cancer tissues (2.42±0.23) was higher than that in adjacent tissues (1.00±0.06) (t=53.433, P=0.000). The miRNA-106a levels in lung cancer tissues of stage Ⅲ-Ⅳ, lymph node metastasis and recurrence time<6 months were high than those of the stage Ⅰ-Ⅱ, no lymph node metastasis and recurrence time ≥ 6 months(t=7.641, 11.115, 2.183, P=0.000, 0.000, 0.032). The level of miRNA-106a was not associated with age, gender, pathological type, degree of differentiation and vascular invasion (all P>0.05). The level of miRNA-106a in non-small cell lung cancer tissues was cut by 2.12.The area under the ROC curve for the diagnosis of non-small cell lung cancer was 0.823(95% CI=0.820-0.825, P=0.000), and the sensitivity was 54.37%, the specificity was 89.21%.The cumulative survival rate and progression-free survival rate of patients with low-expression of miRNA-106a in non-small cell lung cancer were higher than those with high expression of miRNA-106a (P=0.027, 0.012).@*Conclusion@#The miRNA-106a level is elevated in non-small cell lung cancer tissues.The miRNA-106a may be involved in the development of non-small cell lung cancer and is of great value in the diagnosis and prognosis evaluation of non-small cell lung cancer.
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Objective To explore RIZ1 mRNA expression level in different subtypes and risk classification groups of the patients with myelodysplastic syndromes (MDS) and to analyze the correlation between the clinical features and RIZ1 mRNA expression. Methods A total of 46 newly diagnosed as MDS patients and 10 healthy controls who were the donors of hematopoietic stem cell transplantation from Chuiyangliu Hospital Affiliated to Tsinghua University and the Second Hospital of Shanxi Medical University between January 2014 and December 2017 were collected. The real time fluorescence quantitative polymerase chain reaction (RT-PCR) was used to detect the expression level of RIZ1 mRNA in bone marrow cells from MDS patients and the healthy controls. Results Compared with the healthy control group, the relative expression level of RIZ1 mRNA in MDS patients was decreased [the median (P25, P75):1.003 (0.895, 1.812) vs. 0.557 (0.333, 0.815)], and the difference was statistically significant (Z= -2.991, P= 0.0003). According tothe World Health Organization (WHO) classification criteria, compared with the healthy control group, the relative expression of RIZ1 mRNA in refractory anemia/refractory anemia with ring sideroblasts/refractory cytopenia with multiple dysplasia (RA/RAS/RCMD), refractory anemia with excess blasts Ⅰ (RAEB-Ⅰ), RAEB-Ⅱand MDS transformed into acute myeloid leukemia (MDS/AML) groups had statistically significant differences (χ2= 19.500, P< 0.01). Further pairwise comparison showed that the relative expression level of RIZ1 mRNA in RAEB-Ⅰ, RAEB-Ⅱand MDS/AML groups was lower than that in the healthy control group, and the differences were statistically significant (all P < 0.05). According to the international prognostic scoring system (IPSS), compared with the healthy control group, the expression of RIZ1 mRNA in low-risk, inter-risk-1, inter-risk-2 and high-risk group had statistical differences (χ2= 19.214, P= 0.001). Further pairwise comparison showed that the relative expression of RIZ1 mRNA in inter-risk-1, inter-risk-2 and high risk group was lower than that in the healthy control group, and the differences were statistically significant (all P<0.05). And RIZ1 mRNA expression showed a decreasing trend with the increase of disease risk grade. RIZ1 mRNA expression level had no relationship with age, gender, peripheral blood white cell count, the hemoglobin, platelet count and karyotype (all P> 0.05). Conclusion RIZ1 mRNA expression level is decreased in MDS patients, and it is different in various subtypes and risk classification. RIZ1 may involve in the pathogenesis of MDS and play an important role in the progression of MDS.
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Objective To study the detection of cytomegalovirus (CMV)-DNA in different kinds of blood and urine sample .Methods The CMV-DNA loads in 3 different kinds of blood sample from 52 patients and 3 different kinds of urine sample from 85 patients were detected by real-time fluorescence quantitative polymer-ase chain reaction(FQ-PCR) .The differences in CMV-DNA detection rate and virus loads were compared a-mong different kinds of blood and urine samples .Results The CMV-DNA detection rates in serum ,whole blood ,plasma and peripheral blood mononuclear cell (PBMC) from 52 patients were 48 .08％ ,71 .15％ ,57 .69％ and 69 .23％ respectively .The CMV-DNA detection rates of whole blood and PBMC were higher ,the difference was statistically significant (P<0 .05) .The quantitative results of PBMC was higher .The CMV-DNA detec-tion rates of mixed urine ,urine supernatant and urine sediment from 85 patients were 72 .94％ ,62 .35％ and 84 .71％ respectively ,the CMV-DNA detection rate of urine sediment was higher ,while the quantitative re-sults of mixed urine was higher .Conclusion The CMV-DNA detection results of blood and urine have large difference ,therefore using the same kind of sample for conducting detection has an important clinical signifi-cance in the clinical diagnosis ,treatment and monitoring of CM V infection .
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Objective To establish a molecular method for the identification of different serotypes of group B streptococcus(GBS)based on TaqMan fluorescence probe technology,and to lay the foundation for the sub-sequent study of multiple fluorescent probe technology to detect different serotypes of GBS.Methods Primers and probes were designed according to the different serotypes of capsular polysaccharide(CPS).CPS se-quences were amplified by real-time fluorescence quantitative polymerase chain reaction.GBS classification methods of different serotypes were established.The results were compared with latex agglutination test and the method was evaluated from the aspects of sensitivity,specificity and detection of clinical isolates.Results The logarithmic concentration of DNA in the same serotype GBS was linearly correlated with the value of Ct. The detection limit of this method is 1 pg/μL,a probe could only detect the corresponding serotype GBS.The results of TaqMan fluorescence probe test of 10 strains were consistent with the results of latex agglutination test.Conclusion TaqMan fluorescence probe technique is a simple,rapid,highly sensitive and specific method for the detection of different GBS serotypes,and it is better than latex agglutination test for the classification of clinical isolates.
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Objective:To investigate the anti-fatigue phenomenon induced by forced swimming in the mice,and to explore the anti-fatigue effect of argininyl fructoyl glucose (AFG) from red ginseng in the mice and its mechanism.Methods:The AFG was extracted from red ginseng.The ICR mice were divided into blank control group,low dose of AFG group (100 mg · kg-1),middle dose of AFG group (200 mg · kg-1) and high dose of AFG group (400 mg · kg-1) (n=20).The mice mere given a forced swimming test after continuous gavage for 28 d.The weights,organ indexes,time of forced swimming,contents of lactic acid (LD),blood urea nitrogen (BUN),hepatic glycogen (Gly) and expressing levels of PGC-1α in gastrocnemius of the mice in various groups were detected.Results:Compared with blank control group,the weights and organ indexes of the mice in low,middle and high doses of AFG groups had no significant differences (P＞ 0.05).Compared with blank control group,the time of forced swimming,contents of Gly and expressing levels of PGC-1α of the mice in low,middle and high doses of AFG groups were significantly increased (P＜0.05 or P＜0.01) in a dose-dependent manner.Compared with blank control group,The contents of LD and BUN in serum of the mice in low,middle and high doses of AFG groups were significantly decreased (P＜0.01).Conclusion:AFG has anti-fatigue effect in mice,and its mechanism may be related to energy metabolism.
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Objective:To investigate the anti-fatigue phenomenon induced by forced swimming in the mice,and to explore the anti-fatigue effect of argininyl fructoyl glucose (AFG) from red ginseng in the mice and its mechanism.Methods:The AFG was extracted from red ginseng.The ICR mice were divided into blank control group,low dose of AFG group (100 mg · kg-1),middle dose of AFG group (200 mg · kg-1) and high dose of AFG group (400 mg · kg-1) (n=20).The mice mere given a forced swimming test after continuous gavage for 28 d.The weights,organ indexes,time of forced swimming,contents of lactic acid (LD),blood urea nitrogen (BUN),hepatic glycogen (Gly) and expressing levels of PGC-1α in gastrocnemius of the mice in various groups were detected.Results:Compared with blank control group,the weights and organ indexes of the mice in low,middle and high doses of AFG groups had no significant differences (P＞ 0.05).Compared with blank control group,the time of forced swimming,contents of Gly and expressing levels of PGC-1α of the mice in low,middle and high doses of AFG groups were significantly increased (P＜0.05 or P＜0.01) in a dose-dependent manner.Compared with blank control group,The contents of LD and BUN in serum of the mice in low,middle and high doses of AFG groups were significantly decreased (P＜0.01).Conclusion:AFG has anti-fatigue effect in mice,and its mechanism may be related to energy metabolism.
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Objective To investigate the application valve of real-time fluorescence quantitative polymerase chain reaction(RT-PCR) for the detection of tumor M2-pyruvate kinase(tM2-PK) DNA in patients with colorectal cancer(CRC).Methods Fragment of tM2-PK DNA(162 bp) was amplified and inserted into PGM-T vector to construct recombinant plasmid,which was used to develop RT-PCR method.Sensitivity,specificity and repeatability of RT-PCR for the detection of tM2-PK were analyzed.From Jan.2014 to Jun.2016,200 CRC patients and 100 healthy subjects were enrolled and detected for fecal and serum tM2-PK DNA by using RT-PCR,and the detected results were compared with those detected by using enzyme linked immunosorbent assay(ELISA).Results Recombinant plasmid was successfully constructed,which was certified by sequencing.The sensitivity of RT-PCR for the detection of tM2-PK DNA was 10 copy/mL,with high specificity and 0.3%-2.9% of coefficient of variation.In patients,the positive rate of fecal tM2-PK DNA,detected by RT-PCR,was 92.50%,and that of ELISA to detect tM2-PK was 80.00%.Fecal and serum levels of tM2-PK were correlated with the pathologic stages of tumour.Conclusion Self-established RT-PCR could be specificity and sensitivity for the detection of fecal tM2-PK,which could be used for the early diagnosis of CRC.
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Objective To analyze the relationship between the expression of protection of telomeres 1 (POT1) and the pathogenesis of acute myeloid leukemia (AML). Methods 62 patients with de novo AML (case group) and 10 patients with iron deficiency anemia (control group) were enrolled in this study. The quantitative real-time polymerase chain reaction (PCR) and Western blot were used to detect the expression of POT1 in AML patients. Results There were 62 de novo AML patients, including 2 cases M1, 14 cases M2, 12 cases M3, 14 cases M4, 17 cases M5, 2 cases M6 and 1 case AML without classification. According to the risk stratification, high risk group (24 cases), medium risk group (22 cases) and low risk group (16 cases) were divided. Compared with that in the controls, POT1 expression levels in patients with AML were significantly decreased both in mRNA and protein level (P 0.05). Conclusions POT1 may be involved in the pathogenesis of AML. POT1 protein expresses in both cytoplasm and nucleus, and the regulatory mechanism may be related to the telomere length.
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Objective To establish the real-time fluorescence quantitative PCR method for the detection of bifidobacteria in human fecal samples, and to provide an effective means for measuring intestinal bacteria. Methods Total DNA of bacteria was extracted from 60 cases of children's fecal samples. Three primers of bifidobacteria based on the 16S ribosomal RNA (16SrRNA)which possessed specialities of bacteria as amplified region were designed.The part of amplified 16SrRNA gene sequences was used as standard production.The serial dilution of standard was analyzed to build an absolute quantitative standard curve with SYBR GreenⅠ dye method, and the bifidobacterium contents in sixty human fecal samples were calculated. The sensitivity of the reaction was calculated by detecting the lowest detectable standard which determined the sensitivity of the reaction. The PCR products’melting curve was used to evaluate the specificity.The coefficient of variation (CV)of different batches of standard with the same concentration was used to evaluate the stability of reaction.Results The length of PCR product fragment which was used to build the standard curve was about 6 1 3 bp, the sequencing result was consist with the goals, and the standard sample of bifidobacteria was successfully established in real-time fluorescence quantitative PCR.The standard curve showed a good linear relationship with R2=0.999.The minimum detection value was 1.48×102 copies per reaction.The melting curve of real-time fluorescence quantitative PCR was a single peak.The test samples were batched and then examined by fluorescence quantitative PCR.The CV of standards’ Ct values which calculated from the standard (1.48 × 103 -1.48 × 107 copies · μL-1 )were 2.94%, 3.39%, 3.54%,3.08%,and 3.34%,respectively.The contents of bifidobacteria in fecal from 60 children was 7.77± 0.86(copies · g-1 wet fecal)transformed by logarithmic.Conclusion The established real-time fluorescence quantitative PCR method has high sensitivity, strong specificity and good repeatability, which is suitable for detection of human fecal bifidobacteria content.
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Objective Use real-time fluorescence quantitative polymerase chain reaction(PCR)to determine HBV DNA,then calculate the linear range and the minimum detection limit,which are the main performance indicators in the laboratory verification. Methods According to the related documents,by serial dilution of high concentration samples,samples of serial concentrations were obtained which were out of the linear range mentioned in the instructions,then verifid the new linear range.By serial dilution of low concentration,samples were obtained,the concentrations of which were lower than the minimum detection limit of provide by the manufacturer,then the new minimum detection limit was verified.Results The linear range of HBV DNA detection was 8.58× 102 -8.41×107 IU/mL,and the minimum detection limit of HBV DNA detection was 4.07 ×102 IU/mL.Conclusion The linear range and the minimum detection limit of Real-time fluorescence quantitative PCR assessed reaches the expected requirement,and the method and validation scheme are simple and feasible.
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Background Although Leber hereditary optic neuropathy (LHON) and optic neuritis have different causes and managements,their clinical manifestations are difficult to be distinguished.Real-time fluorescence quantitative polymerase chain reaction(RTFQ-PCR) is a high flux,simple,rapid and specific detecting technology,so establishing a specific diagnosis method of LHON with RTFQ-PCR has a practical significance.Objective Purpose of the present study was to establish a real-time Taqman probe for mitochondrial DNA (mtDNA)11778G＞A mutation in LHON patients.Methods Primers and Taqman probe for mtDNA 11778G＞A mutation were designed based on mtDNA complete geneme.Eighty-four patients with LHON were selected from the LHON DNA bank of Molecular Biology Laboratory,Henan Eye Institute,and 40 normal physical examinees aged 18-20 years were from Henan People's Hospital.2 ml of periphery blood was collected from each individual.Based on the double-blindness principle,mtDNA 11778G＞A mutation was tested by both Taqman probe and sequencing to check the reliability of real-time Taqman probe.Results The mtDNA 11778G＞A mutation was found in 23 out of 84 patients,and 61 showed a negative result by the technique of real-time Taqman probe.The Ct values of 23 patients with mtDNA 11778G＞A mutation were 22.993 ±0.708,but those of 5 normal controls were 0.These findings showed a consistent rate of 100％ with the sequencing results.In addition,both the false positive rate and the false negative rate were zero.Conclusions Real-time Taqman probe technique is an accurate,convenient,sensitive,specific and intuitionistic method for the diagnosis of mtDNA 11778G＞A mutation in LHON patients.It is feasible and suitable to screen the LHON patients with mtDNA 11778G＞A mutation in a large scale.
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[Objective]To study the difference in expression of RFC, GST-?, DHFRmRNA between human osteosarcoma U2-OS cell line and the MTX-resisitant variants U2-OS/R1-R3, and to investigate the significance in MTX resistance for human osteosarcoma. [Methods]Three resistant MTX human osteosarcoma cell lines were established by pulse exposure parental cell line(U2-OS) in gradually increased dose of MTX . The expression of RFC,GST-?,DHFRmRNA were assayed by real-time fluorescence quantitative polymerase chain reaction(FQ-PCR).[Results]Three MTX-resistant variants(U2-OS/R1-R3) were successfully established , the results of the FQ-PCR revealed that the MTX resistance was associated with the decreased expression of the RFC mRNA and increased expression of DHFR mRNA and GST-? mRNA.[Conclusion]The author investigated the MTX resistant mechanism of human osteosarcoma cell line at a gene level. The decreased expression of RFC mRNA and the increased expression of DHFR mRNA and GST-? mRNA participate in the MTX resistance in human osteosarcoma cell lines U-2 OS. This provides the evidence for exploring the MTX resistance mechanism in clinical osteosarcoma patients ,and helps to screen the patients who are insensitive to MTX chemotherapy.