Studies on the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer

AIM To study the relationship between the point mutation of ras oncogenes and the prognosis of patients with gastric cancer.

Effects of endotoxin on expression of ras, p53 and bcl-2 oncoprotein in hepatocarcinogenesis induced by thioacetamide in rats

AIM To evaluate the relationship between expression of ras, p53, bcl 2 gene products, and hepatocarcinogenesis since endotoxemia produced from lipopolysaccharide admi nistration and/or the hypophagocytic state of splenectomy significantly accelerated hepatocarcinogenesis induced by thioacetamide. 〖WTH4〗METHODS〓〖WTXFZ〗The hepatocarcinoma model was induced by oral intake of 0 03% thioacetamide for six months. During the induction of hepatocarcinoma model, rats were additionally treated with splenectomy and/or lipopolysaccharide administration. The techniques of flow cytometry, immunohistochemistry and immunoelectronmicroscopy were applied to quantitative analysis of the expression of oncogene proteins. RESULTS In this model system, overexpression of ras p21 protein mainly occurred on precancerous cell population or in early stage of hepatocyte transformation. And the levels of ras p21 declined when nuclear DNA aneuploid increased. Expression of bcl 2 protein slowly and steadily rose with more hepatocytes staying in S+G2M phases as the hepatocarcinoma became more malignant. P53 was moderately expressed during the hepatocarcinogenesis. There was no statistical correlation between endotoxemia levels and the changes of ras, p53 and bcl 2 gene products. CONCLUSION Over expression of oncogene ras p21 was likely to be a precursor of the premalignant hepatocytes and it might be responsible for the initiation of hepatocarcinogenesis. Bcl 2 protein expression is proportional to the severity of the malignancies. P53 may be a key pathway on the transformation and development of hepatocarcinoma. This study confirmed the hypothesis that there are multiple genes and multiple steps involved in hepatocarcinogenesis. Expressions of oncogene proteins reflected the properties of the premalignant and malignant cells, but not directly related to endotoxemia statistically.[JP]

Effect of miR-184 and miR-205 on the tumorigenesis of conjunctival mucosa associated lymphoid tissue lymphoma through regulating RasL10B and TNFAIP8

AIM:To explore the effect of miR-184 and miR-205 on the proliferation and metastasis of conjunctival mucosa associated lymphoid tissue(MALT)lymphoma.METHODS:Tissue of tumor and adjacent normal control from 5 patients with conjunctival MALT was included.RPMI8226 cell line was selected to verify the effect of mi RNAs in B cells.The function of micro RNA on the RPMI8226 cell apoptosis,migration and invasion was evaluated by apoptosis assay and Transwell assay.The m RNA and protein expression were examined by quantitative RT-PCR and Western blotting.The effect of micro RNA on regulation of downstream gene expression was evaluated by luciferase report assay.RESULTS:A decreased level of miR-184 and miR-205 was observed in MALT lymphoma tissue.Exogenous miR-184 and miR-205 analogues promoted apoptosis,and inhibited the survival,migration,and invasion of RPMI8226 cells.miR-184 and miR-205 inhibitor reversed the process.The RNA and protein level of Ras L10 B and TNFAIP8 were downregulated in MALT lymphoma tissue.The exogenous of miR-184 and miR-205 promoted the expression of Ras L10 B and TNFAIP8.Meanwhile,inhibition of miR-184 and miR-205 repressed the expression of target gene,Ras L10 B and TNFAIP8.CONCLUSION:miR-184 and miR-205 suppresses the tumorigenesis of conjunctival MALT lymphoma through regulating Ras L10 B and TNFAIP8.

A study of point mutation of ras genes in human gastric cancer

The point mutation at codons 12 and 61 of c-Ha-ras gene,at codon 12 of N-ras gene and at codons 12 and 13 of K-ras gene was observed in formalin-fixed and paraffin-embedded tissue specimens of 42 cases of gastric cancer with PCR-RFLP method. It was found that the point mutation at codon 12 of c-Ha-ras occurred in 14 cases out of the 42(33. 3%) and that at codon 12 of K-ras in 2 cases(4. 8%). Statistical analysis showed that the point mutation of ras genes plays an itnportant role in the prognosis for the patients with gastric cancer.

Expression of Ras and Fos Oncogenes in Human Cirrhotic Livers

By in situ hybridization and immunohistochemistry, the expression of c H ras, c fos, c jun and p 53 genes was studied in 11 human cirrhotic liver fragments and 7 histologically normal livers. The results showed that no abnormal expression was found in normal livers. By contrast, 10 out of 11 cirrhotic speciments(91%) displayed abnormally overexpression of c H ras transcripts; five cirrhotic samples revealed increased level of c fos mRNA; only one case exhibited increased level of c jun mRNA. Mutated p 53 protein was all negative, as assessed by immunohistochemistry, in the cirrhotic livers. These data suggest that the overexpression of ras and fos genes might consititute part of an early event of gene abnormality predisposing to the later development of hepatocellular carcinoma.

Polymorphism in the Ras andβ-Glucosidase Genes and Their Association with Growth Traits in the Pacific Oyster Crassostrea gigas

The Ras gene,a conserved member of the insulin pathway,andβ-glucosidase gene,an important cellulase,are two important growth-related genes.However,there is no study on the association between mutations of these two genes and growth traits in bivalves.Here,the polymorphism of these two genes in Crassostrea gigas were revealed.Their association with growth traits was evaluated in 290 oysters from five families,and was further confirmed in another 186 oysters from three fast-growing strains.Seventeen and twelve SNPs were identified in the Ras gene andβ-glucosidase gene,respectively.Among these SNPs,four SNPs in each gene(Ras:C.86C>A,C.90T>C,C.112A>G and C.118G>A;β-glucosidase:C.247G>A,C.284C>T,C.1260C>T and C.1293T>C)were significantly(P<0.05)associated with the growth of these oysters.Furthermore,eight and nine haplotypes were constructed in the Ras gene andβ-glucosidase gene,respectively.Oysters with both haplotypes R-Hap5(CCAA)andβ-Hap7(ACCT),or with both R-Hap 6(ATGG)andβ-Hap 6(ACTC),or with both R-Hap 6 andβ-Hap 9(ACTT),or with both R-Hap 7(ATAA)andβ-Hap 7,showed the highest growth performances.These results provide candidate markers for selecting C.gigas with fast growth.

Synergy of DNA methylation and histone deacetylase inhibitors in the re-expression of RASSF1A and P16 genes silenced in QBC cells

Objective: To investigate the effects of DNA methylation and histone deacetylase inhibitors in the re-expression of P16 and RASSIF1A of QBC939. Methods: The QBC939 cells were treated with hydralazine and valproate either alone or combined, and the control group was added with RPIM-1640 culture medium. After 48 h, the expression of P16 and RASSF1A genes were evaluated by reverse transcription-PCR, Western blot, and the methylation status of the two genes were detected with MSP (methylation specific PCR). Results: Hydralazine and valproate could induce demethylation of the promoter region of the two genes, and could make them re-active. The expressions of P16 and RASSF1A of cells treated with both drugs were higher than that of the cells treated with either hydralazine or valproate (P < 0.01). There was no RASSF1A gene, and few P16 gene expressing in the control group. The demethylation effect could be found in the groups treated with hydralazine or both drugs, whereas no demethylation effect happened in the valproate group. Conclusion: The two drugs could synergistically re-express P16 and RASSF1A genes silenced in QBC939, and they exerted a great anti-tumour effect on QBC cells.

Gastric cancer induced by N-methyl-N'-nitro-N-nitrosoguanidine in rat with ulcers and expressions of ras and c-erbB2 genes

Objective: To observe the series of pathological changes during the development of gastric adenocarcinoma in ulcerative rats induced by N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), and the expression profile of related oncogenic protein.Methods: MNNG was administered in rats with ulcers due to acetic acid treatment to induce gastric cancer, and the protein expressions of ras and c-erbB2 genes in the ulcer were examined immunohistochemically along with pathological examination.Results: The incidence of gastric adenocarcinoma in the model group reaches 40% (6/15), while none of the rats developed cancer in the control group with ulcers.Positive expressions of the proteins of p21ras and c-erbB2 were observed in the tissues undergoing canceration in the 6 rats of model group, but were not observed in the 5 control rats; p53 protein expression, however, failed to be detected in both groups.Conclusion: A new animal model of gastric cancer has been established in rats with gastric ulcer after MNNG treatment, which may facilitate the pharmacological research of gastric cancer.

Development of a rapid and efficient system for CR genes identification based on hairy root transformation in Brassicaceae

Many economically important crops and vegetables belonging to the cruciferous family are heavily endangered by clubroot disease caused by Plasmodiophora brassicae infection.Breeding of clubroot resistant cultivars based on mapping and cloning of resistant genes is commonly regarded as the most cost-effective and efficient way to fight against this disease.The traditional way of R gene functional validation requires stable transformation that is both time-and labor-consuming.In this study,a rapid and efficient hairy-root transgenic protocol mediated by Agrobacterium rhizogenes was developed.The transformation positive rate was over 80%in Brassica napus showed by GUS reporter gene and this transformation only took 1/6 of the time compared with stable transformation.The system was applicable to different B.napus varieties and other cruciferous crops including Brassica rapa and Brassica oleracea.In particular,two known CR genes,CRA3.7.1 and CRA8.2.4 were used respectively,as example to show that the system works well for CR gene study combined with subsequent P.brassicae infection in B.napus.Most importantly,it works both in over-expression that led to disease resistance,as well as in RNAi which led to disease susceptible phenotype.Therefore,this system can be used in batch-wise identification of CR genes,and also offered the possibility of manipulating key genes within the P.brassicae genome that could improve our knowledge on host-pathogen interaction.

Turnip mosaic virus pathogenesis and host resistance mechanisms in Brassica

Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae plants.We urgently need more information and understanding of TuMV pathogenesis and the host responses involved in disease development in cruciferous crops.TuMV displays great versatility in viral pathogenesis,especially in its replication and intercellular movement.Moreover,in the coevolutionary arms races between TuMV and its hosts,the virus has evolved to co-opt host factors to facilitate its infection and counter host defense responses.This review mainly focuses on recent advances in understanding the viral factors that contribute to the TuMV infection cycle and the host resistance mechanism in Brassica.Finally,we propose some future research directions on TuMV pathogenesis and control strategies to design durable TuMV-resistant Brassica crops.

Comprehensive analysis of the potential pathogenesis of COVID-19 infection and liver cancer

BACKGROUND A growing number of clinical examples suggest that coronavirus disease 2019(COVID-19)appears to have an impact on the treatment of patients with liver cancer compared to the normal population,and the prevalence of COVID-19 is significantly higher in patients with liver cancer.However,this mechanism of action has not been clarified.Gene sets for COVID-19(GSE180226)and liver cancer(GSE87630)were obtained from the Gene Expression Omnibus database.After identifying the common differentially expressed genes(DEGs)of COVID-19 and liver cancer,functional enrichment analysis,protein-protein interaction network construction and scree-ning and analysis of hub genes were performed.Subsequently,the validation of the differential expression of hub genes in the disease was performed and the regulatory network of transcription factors and hub genes was constructed.RESULTS Of 518 common DEGs were obtained by screening for functional analysis.Fifteen hub genes including aurora kinase B,cyclin B2,cell division cycle 20,cell division cycle associated 8,nucleolar and spindle associated protein 1,etc.,were further identified from DEGs using the“cytoHubba”plugin.Functional enrichment analysis of hub genes showed that these hub genes are associated with P53 signalling pathway regulation,cell cycle and other functions,and they may serve as potential molecular markers for COVID-19 and liver cancer.Finally,we selected 10 of the hub genes for in vitro expression validation in liver cancer cells.CONCLUSION Our study reveals a common pathogenesis of liver cancer and COVID-19.These common pathways and key genes may provide new ideas for further mechanistic studies.

Identification of hub genes associated with Helicobacter pylori infection and type 2 diabetes mellitus:A pilot bioinformatics study

BACKGROUND Helicobacter pylori(H.pylori)infection is related to various extragastric diseases including type 2 diabetes mellitus(T2DM).However,the possible mechanisms connecting H.pylori infection and T2DM remain unknown.AIM To explore potential molecular connections between H.pylori infection and T2DM.METHODS We extracted gene expression arrays from three online datasets(GSE60427,GSE27411 and GSE115601).Differentially expressed genes(DEGs)commonly present in patients with H.pylori infection and T2DM were identified.Hub genes were validated using human gastric biopsy samples.Correlations between hub genes and immune cell infiltration,miRNAs,and transcription factors(TFs)were further analyzed.RESULTS A total of 67 DEGs were commonly presented in patients with H.pylori infection and T2DM.Five significantly upregulated hub genes,including TLR4,ITGAM,C5AR1,FCER1G,and FCGR2A,were finally identified,all of which are closely related to immune cell infiltration.The gene-miRNA analysis detected 13 miRNAs with at least two gene cross-links.TF-gene interaction networks showed that TLR4 was coregulated by 26 TFs,the largest number of TFs among the 5 hub genes.CONCLUSION We identified five hub genes that may have molecular connections between H.pylori infection and T2DM.This study provides new insights into the pathogenesis of H.pylori-induced onset of T2DM.

Transcriptome Analysis During Tetrasporogenesis of Gracilariopsis lemaneiformis and Preliminary Study of the Expressions of Its Meiotic Genes

The transcriptomes of three different parts of the fertile tetrasporophyte of Gracilariopsis lemaneiformis,including tip(T),middle(M),and subjacent(S)parts,with a gradual tetrasporangium maturity were analyzed and compared to identify the genes involved in the process of tetrasporogenesis.The number of differentially expressed genes(DEGs)for the Gple-S versus Gple-T comparison was 10296,and the numbers of DEGs for the Gple-S versus Gple-M and Gple-T versus Gple-M comparisons were 7435 and 1337,respectively.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses were performed,and the results showed the enrichment of 132 KEGG pathways(corrected P<0.05).A total of 58 DEGs related to meiosis were screened and blasted against 18 meiosis-related genes(dmc1,mlh1,mnd1,msh4,msh2,msh6,mre11,pds5,pms1,rad21,rad50,rad51,smc1,smc2,smc4,smc5,smc6,and spo11),including four meiosis-specific genes.The transcriptome comparison indicated that in the T part,the meiosis,ribosome,and RNA transport-related genes were mostly up-regulated compared with those in the other two groups.In the M part,the genes related to ribosomes and the endoplasmic reticulum were also up-regulated compared with those in the lower part.Finally,in the S part,the genes associated with photosynthesis were mostly up-regulated,which might be helpful to the recovery from spore formation and release.

Key genes and regulatory networks for diabetic retinopathy based on hypoxia-related genes:a bioinformatics analysis

AIM:To prevent neovascularization in diabetic retinopathy(DR)patients and partially control disease progression.METHODS:Hypoxia-related differentially expressed genes(DEGs)were identified from the GSE60436 and GSE102485 datasets,followed by gene ontology(GO)functional annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis.Potential candidate drugs were screened using the CMap database.Subsequently,a protein-protein interaction(PPI)network was constructed to identify hypoxia-related hub genes.A nomogram was generated using the rms R package,and the correlation of hub genes was analyzed using the Hmisc R package.The clinical significance of hub genes was validated by comparing their expression levels between disease and normal groups and constructing receiver operating characteristic curve(ROC)curves.Finally,a hypoxia-related miRNA-transcription factor(TF)-Hub gene network was constructed using the NetworkAnalyst online tool.RESULTS:Totally 48 hypoxia-related DEGs and screened 10 potential candidate drugs with interaction relationships to upregulated hypoxia-related genes were identified,such as ruxolitinib,meprylcaine,and deferiprone.In addition,8 hub genes were also identified:glycogen phosphorylase muscle associated(PYGM),glyceraldehyde-3-phosphate dehydrogenase spermatogenic(GAPDHS),enolase 3(ENO3),aldolase fructose-bisphosphate C(ALDOC),phosphoglucomutase 2(PGM2),enolase 2(ENO2),phosphoglycerate mutase 2(PGAM2),and 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3(PFKFB3).Based on hub gene predictions,the miRNA-TF-Hub gene network revealed complex interactions between 163 miRNAs,77 TFs,and hub genes.The results of ROC showed that the except for GAPDHS,the area under curve(AUC)values of the other 7 hub genes were greater than 0.758,indicating their favorable diagnostic performance.CONCLUSION:PYGM,GAPDHS,ENO3,ALDOC,PGM2,ENO2,PGAM2,and PFKFB3 are hub genes in DR,and hypoxia-related hub genes exhibited favorable diagnostic performance.

Transcriptional Regulation of 10 Mitochondrial Genes in Different Tissues of NCa CMS System in Brassica napus L. and Their Relationship with Sterility

Northern blot analysis was conducted with mitochondrial RNA from seedling leaves, floral buds, and developing seeds of NCa CMS, maintainer line and fertile F1 using ten mitochondrial genes as probes. The results revealed that 9 out of the 10 mitochondrial genes, except for atp6, showed no difference in different tissues of the corresponding materials of NCα CMS system and that they might be constitutively expressed genes. Eight genes, such as orf139, orf222, atpl, cox1, cox2, cob, rm5S, and rm26S, showed no difference among the three tissues of all the materials detected. So the expression of these eight genes was not regulated by nuclear genes and was not tissue-specific. The transcripts of atp9 were identical among different tissues, but diverse among different materials, indicating that transcription of atp9 was neither controlled by nuclear gene nor tissue-specific. Gene atp6 displayed similar transcripts with the same size among different tissues of all the materials but differed in abundance among tissues of corresponding materials and its expression might be tissue-specific under regulation of nuclear gene. Moreover, three transcripts of orf222 were detected in the floral buds of NCa cms and fertile F1, but no transcript was detected in floral buds of the maintainer line.The transcription of orf139 was similar to that of orf222 but only two transcripts of 0.8 kb and 0.6 kb were produced. The atp9 probe detected a single transcript of 0.6 kb in NCa cms and in maintainer line and an additional transcript of 1.2 kb in fertile F1. The relationship of expression of orf222, orf139, and atp9 with NCa sterility was discussed.

Identification and Validation of Vascular-Associated Biomarkers for the Prognosis and Potential Pathogenesis of Hypertension Using Comprehensive Bioinformatics Methods

Background: Hypertension, also known as increased blood pressure, is a phenomenon in which blood flows in blood vessels and causes persistently higher-than-normal pressure on the vessel wall. The identification of novel prognostic and pathogenesis biomarkers plays a key role in the management of hypertension. Methods: The GSE7483 and GSE75815 datasets from the gene expression omnibus (GEO) database were used to identify the genes associated with hypertension that were differentially expressed genes (DEGs). The functional role of the DEGs was elucidated by gene body (GO) enrichment analysis. In addition, we performed an immune infiltration assay and GSEA on the DEGs of hypertensive patients and verified the expression of novel DEGs in the blood of hypertensive patients by RT-qPCR. Results: A total of 267 DEGs were identified from the GEO database. GO analysis revealed that these genes were associated mainly with biological processes such as fibroblast proliferation, cell structural organization, extracellular matrix organization, vasculature development regulation, and angiogenesis. We identified five possible biomarkers, Ecm1, Sparc, Sphk1, Thbsl, and Mecp2, which correlate with vascular development and angiogenesis characteristic of hypertension by bioinformatics, and explored the clinical expression levels of these genes by RT-qPCR, and found that Sparc, Sphk1, and Thbs1 showed significant up-regulation, in agreement with the results of the bioinformatics analysis. Conclusion: Our study suggested that Sparc, Sphk1 and Thbs1 may be potential novel biomarkers for the diagnosis, treatment and prognosis of hypertension and that they are involved in the regulation of vascular development and angiogenesis in hypertension.

Spacer Length Variation in Rice 5SrRNA Genes Revealed by Polymerase Chain Reaction

Polymerase chain reaction(PCR) was used to amplify 5S rRNA spacer from wild rice(Oryza rufipogon and O.nivara) and cultivated rice(indica and japonica varieties of O.sativa L).The results show that there is spacer length variation within and between species,and the typical indica and japonica varieties have their unique banding patterns of amplified 5S rRNA spacers,whereas intermediate showed no specific amplification profile of spacer regions.The 5S rRNA genes in intermediate are either identical with that of indica variety or that of japonica variety.These data suggest that the spacer length polymorphisms can be used to distinguish between closely ralated species and subspecies.

Genome-wide identification and comparative analysis of drought related genes in roots of two maize inbred lines with contrasting drought tolerance by RNA sequencing

Drought is one of the most important abiotic stresses affecting maize growth and development and therefore resulting in yield loss.Thus it is essential to understand molecular mechanisms of drought stress responses in maize for drought tolerance improvement.The root plays a critical role in plants sensing water deficit.In the present study,two maize inbred lines,H082183,a drought-tolerant line,and Lv28,a drought-sensitive line,were grown in the field and treated with different water conditions(moderate drought,severe drought,and well-watered conditions)during vegetative stage.The transcriptomes of their roots were investigated by RNA sequencing.There were 1428 and 512 drought-responsive genes(DRGs)in Lv28,688 and 3363 DRGs in H082183 under moderate drought and severe drought,respectively.A total of 31 Gene Ontology(GO)terms were significantly over-represented in the two lines,13 of which were enriched only in the DRGs of H082183.Based on results of Kyoto encyclopedia of genes and genomes(KEGG)enrichment analysis,"plant hormone signal transduction"and"starch and sucrose metabolism"were enriched in both of the two lines,while"phenylpropanoid biosynthesis"was only enriched in H082183.Further analysis revealed the different expression patterns of genes related to abscisic acid(ABA)signal pathway,trehalose biosynthesis,reactive oxygen scavenging,and transcription factors might contribute to drought tolerance in maize.Our results contribute to illustrating drought-responsive molecular mechanisms and providing gene resources for maize drought improvement.

Genome-wide identification and expression analysis of anthocyanin biosynthetic genes in Brassica juncea

Anthocyanins confer the wide range of colors for plants and also play beneficial health roles as potentially protective factors against heart disease and cancer. Brassica juncea is cultivated as an edible oil resource and vegetable crop worldwide, thus elucidating the anthocyanin biosynthetic pathway would be helpful to improve the nutritional quality of Brassica juncea through the breeding and cultivating of high anthocyanin content varieties. Herein, 129 genes in B. juncea were identified as orthologs of 41 anthocyanin biosynthetic genes(ABGs) in Arabidopsis thaliana by comparative genomic analyses. The B. juncea ABGs have expanded by whole genome triplication and subsequent allopolyploidizatoin, but lost mainly during the whole genome triplication between B. rapa/B. nigra and A. thaliana, rather than the allopolyploidization process between B. juncea and B. rapa/B. nigra, leading to different copy numbers retention of A. thaliana homologous genes. Although the overall expansion levels ABGs were similar to the whole genome, more negative regulatory genes were retained in the anthocyanin biosynthesis regulatory system. Transcriptional analysis of B. juncea with different anthocyanin accumulation showed that BjDFR, BjTT19, BjTT8 are significantly up-regulated in plants with purple leaves as compared with green leaves. The overexpression of BjTT8 and these target genes which were involved in late anthocyanin biosynthesis and transport might account for increasing levels of anthocyanin accumulation in purple leaves. Our results could promote the understanding of the genetic mechanism of anthocyanin biosynthesis in B. juncea.

Are polymorphisms of N-acetyltransferase genes susceptible to primary liver cancer in Luoyang, China?

AIM: To identify whether the polymorphisms of the Nacetyltransferase (NAT) genes are susceptible to primary liver cancer (PLC) in Luoyang, a PLC low-incidence area of China.METHODS: The NAT1 and NAT2 genotypes of 96 PLC cases and 173 controls were determined by PCR-RFLP.Both interaction between NAT1 or NAT2 and environmental risk factors were analyzed based on case control study.RESULTS: Compared to the control group, the frequencies of alleles NAT1*3, NAT1*4, NAT1*10, NAT1*14B and alleles NAT2*4, NAT2*6, NAT2*7 in PLC group showed no statistically significant difference (x2 = 2.61 and 4.16,respectively, both P＞0.05). The frequencies of NAT1 genotypes NAT1*3/*3, NAT1*3/*4, NAT1*3/*10,NAT1*3/*14B, NAT1*4/*4, NAT1*4/*10, NAT1*4/*14B,NAT1*10/*10, NAT1*10/*14B, and NAT2 genotypes NAT2*4/*4, NAT2*4/*6, NAT2*4/*7, NAT2*6/*6,NAT2*6/*7 and NAT2*7/*7 also had no statistically significant difference between the two groups (x2 = 11.86 and 2.94respectively both, P＞0.05). Neither the frequencies of rapid and slow NAT1 acetylators nor the frequencies of rapid and slow NAT2 acetylators were significantly different between the two groups (x2 = 0.598 and 0.44,respectively, both P＞0.05). The interaction betweenNAT1*10 and occupational exposures was found significant with an odds ratio of 3.40 (x2 = 8.42, P = 0.004,OR 95%CI:1.03-11.22). But no interaction was found between NAT2 and any environmental risk factors.CONCLUSION: The polymorphisms of NAT1 and NAT2are not susceptible to PLC in Luoyang. Allele NAT1*10interacts with occupational exposures.