Analysis of The Correlation Between inhA Gene Mutation and Resistance to Protionamide in Drug-Resistant Mycobacterium Tuberculosis

Objective: To investigate the characteristics of katG and inhA gene mutations in multidrug-resistant tuberculosis (MDR-TB), pre-extensively drug-resistant tuberculosis (preXDR-TB), and their correlation with resistance to protionamide (Pto). Methods: A total of 229 patients with MDR-TB and pre-XDR-TB diagnosed in the Eighth Affiliated Hospital of Xinjiang Medical University from January 2020 to February 2024 were selected to analyze the characteristics of katG and inhA mutations in MTB clinical isolates and their correlation with Pto resistance. Results: The mutation rate of katG (with or without inhA mutation) was 85.2%. The mutation rates in MDR-TB and pre-XDR-TB were 87.4% (125/143) and 81.4% (70/86), respectively. The mutation rate of inhA (including katG mutation) was 14.8% (34/229), which was 12.6% (18/143) and 18.6% (16/86) in MDR-TB and pre-XDR-MTB, respectively. There was no difference in mutation (P > 0.05). Conclusion: The total resistance rate to Pto in 229 strains was 8.7% (20/229), which was 8.4% (12/143) and 9.3% (8/86) in MDR-TB and pre-XDR-TB, respectively. Among the inhA mutant strains, 13 were resistant to the Pto phenotype, and the resistance rate was 65% (13/20). In MDR-TB and pre-XDR-TB strains resistant to Pto, inhA gene mutations occurred in 66.7% (6/9) and 63.6% (7/11), respectively. The resistance rates of MDR-MTB and pre-XDR-TB strains without inhA gene mutation to Pto were 2.4% (3/125) and 5.7% (4/70), respectively.

SCN1A rs6732655A/T polymorphism:Diagnostic and therapeutic insights for drug-resistant epilepsy

BACKGROUND A significant subset of individuals with epilepsy fails to respond to currently available antiepileptic drugs,resulting in heightened mortality rates,psychosocial challenges,and a diminished quality of life.Genetic factors,particularly within the SCN1A gene,and the pro-inflammatory cytokine response is important in intricating the drug resistance in idiopathic epilepsy cases.In this extended study,we determined the correlation of rs6732655A/T single nucleotide polymorphism to understand the causative association of SCN1A gene with epilepsy drug resistance and inflammatory response.AIM To find the correlation of SCN1A gene rs6732655A/T polymorphism with the drug-resistant epilepsy and inflammatory response.METHODS The study enrolled 100 age and sex-matched patients of both drug-resistant and drug-responsive epilepsy cases.We analysed the rs6732655A/T polymorphism to study its association and causative role in drug-resistant epilepsy cases using restriction fragment length polymorphism technique.The diagnostic performance of interleukin(IL)-1β,IL-6,and high mobility group box 1(HMGB1)protein levels was evaluated in conjunction with genotypic outcome receiver operating characteristic analysis.RESULTS AT and AA genotypes of rs6732655 SCN1A gene polymorphism were associated with higher risk of drug resistance epilepsy.Serum biomarkers IL-6,IL1βand HMGB1 demonstrated diagnostic potential,with cutoff values of 4.63 pg/mL,59.52 pg/mL and 7.99 ng/mL,respectively,offering valuable tools for epilepsy management.Moreover,specific genotypes(AA and AT)were found to be linked to the elevated levels of IL-1βand IL-6 and potentially reflecting increased oxidative stress and neuro-inflammation in drug-resistant cases supporting the previous reported outcome of high inflammatory markers response in drug resistance epilepsy.CONCLUSION SCN1A genotypes AA and AT are linked to higher drug-resistant epilepsy risk.These findings underscore the potential influence of inflammation and genetics on epilepsy treatment resistance.

Mutation Characteristics of inhA and katG Genes in Isoniazid-Resistant Mycobacterium Tuberculosis Patients in Xinjiang

Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tuberculosis were amplified through fluorescence quantitative PCR,and the amplified products were sequenced and compared.Results:The inhA gene mutation rate of 148 strains of isoniazid-resistant mycobacterium tuberculosis was 13.51%(20/148),among which the inhA gene mutation rate among patients of Han,Uygur,and Kazakh ethnicity were 15.87%,13.21%,and 17.65%,respectively.There was no significant difference in the inhA mutation rate among nationalities(c^(2)=2.897,P>0.05).The mutation rate of the katG gene was 84.46%(125/148),among which the mutation rates of patients of Han,Uyghur,and Kazak ethnicities were 82.54%,84.91%,and 76.47%,respectively.The Hui and other ethnic groups were all affected by the katG gene mutation.There was no significant difference in the mutation rate of the katG gene among different ethnicities(c^(2)=3.772,P>0.05).The mutation rates of the inhA gene in southern Xinjiang,northern Xinjiang,and other provinces were 18.60%,9.28%,and 37.50%,respectively.The mutation rates of the inhA gene in different regions were statistically different(c^(2)=6.381,P<0.05).There was no significant difference in the inhA mutation rate between patients from southern and northern Xinjiang(c^(2)=2.214,P>0.05)and between southern Xinjiang and other provinces(c^(2)=1.424,P>0.05).However,the mutation rate of the inhA gene in patients from other provinces was higher than that in northern Xinjiang(c^(2)=5.539,P<0.05).The mutation rates of the katG gene in southern Xinjiang,northern Xinjiang,and other provinces were 81.40%,87.63%,and 62.50%,respectively.There was no significant difference in the mutation rates of the katG gene among different regions(c^(2)=3.989,P>0.05).Conclusion:katG gene mutation was predominant in isoniazid-resistant tuberculosis patients in Xinjiang Uygur Autonomous Region,and inhA and katG gene mutation were no different among different ethnic groups.

Anticancer Drug Resistance of HeLa Cells Transfected With Rat Glutathione S-transferase pi Gene

To establish a cytologic expressing system of rat glutathione S-transferase pi (GST-pi) cDNA for detecting the resistance of HeLa cells to anticancer drugs. Methods The assessment was made with various anticancer drugs (adriamycin, mitomycin, cisplatinum and vincristine) that showed different cytotoxicities in transfectant HeLa cells with pSV-GT containing rat GST-pi cDNA (HeLa/pSV-GT) or control pSV-neo (HeLa/pSV-neo). Expression levels of GST-pi mRNA in HeLa/pSV-GT and HeLa/pSV-neo were measured by in situ hybridization using Digoxin-labelled cDNA probe. Results HeLa/pSV-GT expressed significantly high degree of GST-pi mRNA, whereas both HeLa/pSV-neo and HeLa cells had very low expression. Cytotoxicities of HeLa/pSV-GT and HeLa/pSV-neo with 4 anticancer drugs were measured by MTT assay. Drug concentrations for yielding 50% inhibition (IC50) in HeLa/pSV-GT by adriamycin, mitomycin and cisplatinum were 70.13 靏/mL, 10.95 靏/mL and 16.52 靏/mL, respectively. In contrast, IC50 in HeLa/pSV-neo was 10.34 靏/mL, 7.48 靏/mL and 13.70 靏/mL, respectively. The cytotoxicities of vincristine on both HeLa/pSV-GT and HeLa/pSV-neo were not significantly different. Conclusions Our findings suggest that HeLa/pSV-GT containing rat GST-pi cDNA is resistant to some anticancer drugs due to overexpression of GST-pi. Also, HeLa/pSV-GT cell line could serve as a useful cytogenetic model for further research.

Clinical Study of Multi-drug Resistance Gene(MDR1) Expression in Primary Ovarian Cancer

This study was designed to measure the multi-drug resistance gene (MDR1) mRNA content and analyze clinical relationship between MDR1 expression and drug resistance in primary ovarian cancer. Reverse transcription PCR (RT-PCR) was used to measure MDR1 mRNA content in biopsy sample of 31 primary ovarian cancers (experimental group) and 30 gynecological tumors (control group). The level of 95.2% (20/21) MDR1 expression was relatively low, and the detected rate of MDR1 expression was 67.7%(21/31) in experimental group,which was higher than that in control group (40.0%, P<0.05). The differences of MDR1 expression between the effective group and no effect group after combined chemotherapy was significant (P<0.05). No significant relationship was found between MDR1 expression and clinical stage or histological classification or grade of differentiation in experimental group. We are led to concluded that primary ovarian cancers have drug-resistance clones which might express MDR1 spontaneously and expression of MDR1 may be used as a prognostic and predictive indicator for clinical response of ovarian cancers to combined chemotherapy.

Expression and Prognostic Significance of Multidrug Resistance Associated Protein (MRP) Gene in Non-small Cell Lung Cancer by in Site Hybridization

Objective: To study on the effect of MRP gene overexpression on prognosis of patients with non-small lung cancer (NSCLC). Methods: Paraffin-embedded tissues from 47 cases of NSCLC who had undergone radical tumor resection were examined for expression of MRP gene mRNA by in situ hybridization using labelled digoxigenin probes combined with immunohistochemistry. All the patients were retrospectively followed-up. Results: All of the 47 lung cancer specimens were found to have overexpression of MRP gene mRNA. It was significantly correlated with patients' survival time, response to chemotherapy, recurrence or metastases after surgery, but was not correlated with histology, tumor size, node status, TNM stage, degree of differentiation, age and sex. Conclusion: Overexpression of MRP gene is a marker of prognostic significance in patients with NSCLC.

In vitro study of the influence of GST-π gene transfer on drug-resistance of human cord blood CD34^+ cells

Objective:To investigate the influence of GST-π gene transfer on drug-resistance of human cord blood CD34 + cells.Methods:CD34 + cells were purified from cord blood from normal full-term pregnancy.Gene transduction into human cord blood CD34 + cells was carried out using GST-π gene containing retrovirus vector.The GST-π gene expression in transduced CD34 + cell was confirmed by RT-PCR.After confirmation of GST-π gene transfer,the transfected CD34 + cells were cultured by colony assay in the presence of carboplatin.Results:GST-π mRNA was detected in 30% of CFU-GM derived from GST-π gene transduced CD34 + cells.In vitro drug resistance test showed that the number of CFU-GM formed was significantly higher (2～3 fold) in GST-π gene transduced CD34 + cells than untransduced CD34 +cells.Conclusion:GST-π gene transfer can confer resistance to hematopoietic progenitors against carboplatin in vitro.

EXPRESSION AND REVERSION OF DRUG RESISTANCE-AND APOPTOSIS-RELATED GENES OF A DDP-RESISTANT LUNG ADENOCARCINOMA CELL LINE

Objective: To investigate the co-expression of drug resistance- and apoptosis-related genes of cisplatin (CDDP)-selected lung adenocarcinoma cell line A 549 DDP for compared to the parental cell line A549, and reverse of drug resistance by antisense s-oligodeoxynucleotides (S-ODNs) of differentially expressed genes. Methods: Sense and antisense S-ODN were transferred into A 549 DDP cells by lipofectin. The expression of drug resistance and apoptosis related genes was examined by RT-PCR, immunocytochemistry and flow cytometry, respectively. Apoptostic cells were identified by DNA electrophoresis and terminal deoxynucleotidyl transferase (TdT)-mediated biotin dUTP nick end-labeling(TUNEL). Drug resistance of tumor cells was detected by a cell viability (MTT) assay. Results: The expression of bcl-2 was positive and that of multidrug resistance-associated protein (MRP) at mRNA and protein level was increased in A 549 DDP compared to A549 cells. MDR1, c-myc and topoisomeras II (TOPO II) were similarly co-expressed in two cell lines. Both cell lines were negative for c-erbB-2 expression. In A 549 DDP cells, the expression of bcl-2 and MRP was significantly inhibited by their respective antisense S-ODNs. Antisense S-ODNs could also decrease significantly drug resistance of A 549 DDP cells to CDDP by promoting cell apoptosis. Conclusion: Both intrinsic and acquired drug resistance were involved in co-expression of multiple MDR-related genes in lung adenocarcinoma. Cooperation of bcl-2 and MRP genes appeared to play an important action to confer the resistance of A 549 DDP cells to CDDP. Their antisense S-ODNs are responsible for the decrease of drug resistance of this cell line by promoting apoptosis.

Liposome-mediated Functional Expression of Multiple Drug Resistance Gene in Human Bone Marrow CD34^+ Cells

Summary: The expression and functional activity of multiple drug resistance (MDR1) gene in human normal bone marrow CD34+ cells was observed. Human normal bone marrow CD34+ cells were enriched with magnetic cell sorting (MACS) system, and then liposome-mediated MDR1 gene was transferred into bone marrow CD34+ cells. Fluorescence-activated cell sorter was used to evaluate the expression and functional activity of P-glycoprotein (P-gp) encoded by MDR1 gene. It was found that the purity of bone marrow CD34+ cells was approximately (91±4.56) % and recovery rate was (72.3±2.36) % by MACS. The expression of P-gp in the transfected CD34+cells was obviously higher than that in non-transfected CD34+ cells. The amount of P-gp in non-transfected CD34+ cells was (11.2±2.2) %, but increased to (23.6±2.34) % 48 h after gene transfection (P<0.0l). The amount of P-gp was gradually decreased to the basic level one week later. The accumulation and extrusion assays showed that the overexpression of P-gp could efflux Rh-123 out of cells and there was low fluorescence within the transfected cells. The functional activity of P-gp could be inhibited by 10 μg/ml verapamil. It was suggested that the transient and highly effective expression and functional activity of P-gp could be obtained by liposome-mediated MRD1 transferring into human normal bone marrow CD34+ cells.

Association of KRAS Gene and microRNA-124-3p in Sporadic Colorectal Tumours

Aim: To reveal the exonic and 3’UTR sequences of KRAS, TP53, APC, BRAF, PIK3CA genes in sporadic colorectal tumors and to investigate the clinical relevance of 3’UTR variations in miRNA profiles. Methods: In the study, the exonic and 3’UTR sequences of five genes in 12 sporadic colorectal tumors were extracted by next generation sequencing. In tumors with variation in the 3’UTR region, the changes caused by the variation in the miRNA binding profile were detected. The expression profile of these miRNAs in colorectal and other solid tumors compared to normal tissue was determined. Pathway analysis was performed to determine which signaling pathways miRNAs affect. Results: Case-10 in our study was wild type KRAS and received cetuximab treatment and developed drug resistance. In this case, it was concluded that the expression of KRAS increased and tumorigenesis progressed due to miRNAs that do not bind to this region due to variations in the 3’UTR region. Among these miRNAs, hsa-miR-124-3p was found to have decreased expression in colorectal tumors and to be associated with the ECM-receptor interaction pathway. Conclusion: Variations in the 3’UTR regions of genes critical in the process of carsinogenesis are associated with drug resistance and the process of tumorigenesis.

Identification and Evaluation of Insect and Disease Resistance in Transgenic Cry1Ab13-1 and NPR1 Maize

PCR detection,quantitative real-time PCR(q-RTPCR),outdoor insect resistance,and disease resistance identification were carried out for the detection of genetic stability and disease resistance through generations(T2,T3,and T4)in transgenic maize germplasms(S3002 and 349)containing the bivalent genes(insect resistance gene Cry1Ab13-1 and disease resistance gene NPR1)and their corresponding wild type.Results indicated that the target genes Cry1Ab13-1 and NPR1 were successfully transferred into both germplasms through tested generations;q-PCR confirmed the expression of Cry1Ab13-1 and NPR1 genes in roots,stems,and leaves of tested maize plants.In addition,S3002 and 349 bivalent gene-transformed lines exhibited resistance to large leaf spots and corn borer in the field evaluation compared to the wild type.Our study confirmed that Cry1Ab13-1 and NPR1 bivalent genes enhanced the resistance against maize borer and large leaf spot disease and can stably inherit.These findings could be exploited for improving other cultivated maize varieties.

Suppression of P-gp induced multiple drug resistance in a drug resistant gastric cancer cell line by overexpression of Fas

AIM To observe the drug sensitizing effect andrelated mechanisms of fas gene transduction onhuman drug-resistant gastric cancer cellSGC7901/VCR(resistant to Vincristine).METHODS The cell cycle alteration wasobserved by FACS.The sensitivity of gastriccancer cells to apoptosis was determined by invitro apoptosis assay.The drug sensitization ofcells to several anti-tumor drugs was observedby MTT assay.Immunochemical method wasused to show expression of P-gp and Topo Ⅱ ingastric cancer cells.RESULTS Comparing to SGC7901 and pBK-SGC7901/VCR,fas-SGC7901/VCR showeddecreasing G2 cells and increasing S cells,theG2 phase fraction of pBK-SGC7901/VCR wasabout 3.0 times that of fas-SGC7901/VCR,but Sphase fraction of fas-SGC7901/VCR was about1.9 times that of pBK-SGC7901/VCR,indicatingS phase arrest of fas-SGC7901/VCR.FACS alsosuggested apoptosis of fas-SGC7901/VCR,fas-SGC7901/VCR was more sensitive to apoptosisinducing agent VM-26 than pBK-SGC7901/VCR.MTT assay showed increased sensitization offas-SGC7901/VCR to DDP,MMC and 5-FU,butsame sensitization to VCR according to pBK-SGC7901/VCR.SGC7901,pBK-SGC7901/ VCRand fas-SGC7901/VCR had positively stainedTopo Ⅱ equally.P-gp staining in pBK- SGC7901/VCR was stronger than in SG07901,but there was little staining of P-gp in fas.SGC7901/VCR.CONCLUSION fas gene transduction couldreverse the MDR of human drug-resistant gastriccancer cell SGC7901/VCR to a degree,possiblybecause of higher sensitization to apoptosis anddecreased expression of P-gp.

Transduction of Fas gene or Bcl-2 antisense RNA sensitizes cultured drug resistant gastric cancer cells to chemotherapeutic drugs

AIM To compare the expression level of Fas gene and Bcl-2 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, to transduce Fas cDNA and Bcl-2 antisense nucleic acid into SGC7901/VCR cells respectively, and to observe the expression of two genes in transfectants and non-transfectants as well as their drug sensitivity.METHODS Eukaryotic expression vector pBK-Fas cDNA and pDOR-anti Bcl-2 were constructed and transfected into SGC7901/VCR cells by lipofectamine, respectively. Northern blot and Western blot were used to detect the expression of mRNA and protein in SGC7901/VCR and SGC7901 cells and transfectants, and drug sensitivity of transfectants for VCR, CDDP and 5-FU was analyzed with MTT assay.RESULTS After gene transfection, 80 for Fas and 120 for antisense Bcl-2 drug-resistant clones were selected from 2×105 cells, transfection rate being 0.04% and 0.06%. Two clones of SGC7901 Fas/VCR cells and SGC7901 anti Bcl-2/VCR cells were randomly selected for further incubation. Hybridization results showed that the expression level of Fas mRNA and protein in SGC7901/VCR cells was much lower, but that of Bcl-2 mRNA and protein was higher than that in SGC7901 cells. The expression of Fas mRNA and protein in SGC7901 Fas/VCR cells was higher, and of Bcl-2 mRNA and protein was lower in SGC7901 anti Bcl-2/VCR cells than that in non-transfectants. MTT assay showed that transfectants were more sensitive to VCR, CDDP, 5-FU than non-transfectants.CONCLUSION Bcl-2 gene displayed high expression while Fas gene had low expression in drug resistant gastric cancer cells. Expression of Bcl-2 protein was effectively blocked in SGC7901 anti Bcl-2/VCR cells by gene transfection. In contrast, the expression of Fas mRNA and protein in SGC7901 Fas/VCR cells increased. Fas gene and Bcl-2 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to chemotherapeutic drugs. These results suggest cell apoptosis plays an important role in the mechanism of MDR, and enhancing apoptosis might reverse MDR.

Screening for metronidazole-resistance associated gene fragments of H pylori by suppression subtractive hybridization

AIM： To screen for metronidazole （MTZ）-resistance associated gene fragments of H pylori by suppression subtractive hybridization （SSH）. METHODS： Five MTZ-resistant （tester, T） and 1 MTZ- susceptible （driver, D） clinical H pylori isolates were selected. Genomic DNAs were prepared and submitted to Rsa I digestion. Then two different adaptors were ligated respectively to the 5＇-end of two aliquots of the tester DNA fragments and SSH was made between the tester and driver DNAs. The specific inserts of tester strains were screened and MTZ-resistance related gene fragments were identified by dot blotting. RESULTS： Among the randomly selected 120 subtractive colonies, 37 DNA fragments had a different number of DNA copies （≥ 2 times） in resistant and susceptible strains and 17 of them had a significantly different number of DNA copies （≥ 3 times）. Among the sequences obtained from the 17 DNA fragments, new sequences were found in 10 DNA fragments and duplicated sequences in 7 DNA fragments, representing respectively the sequences of depeptide ABC transporter periplasmic dipeptide-binding protein （dppA）, permease protein （dppB）, ribosomal protein S4 （rps4）, ribonuclease Ⅲ （rnc）, protease （pqqE）, diaminopimelate epimerase （dapF）, acetatekinase （ackA）, H pylori plasmid pHP51 and Hpylori gene 1334. CONCLUSION： Gene fragments specific to MTZ-resistant H pylori strains can be screened by SSH and may be associated with MTZ-resistant Hpylori.

Drug resistance gene expression and chemotherapy sensitivity detection in Chinese women with different molecular subtypes of breast cancer

Objective:The aim of the study was to identify specific chemosensitivity drugs for various molecular subtypes of breast tumors in Chinese women,by detecting the expression of drug resistance genes and by using the drug sensitivity test on different molecular subtypes of breast cancers.Methods:The expression of drug resistance genes including Topo Ⅱ,GST-π,P-gp,LRP,and CD133 were detected with immunohistochemistry in a tissue microarray.Drug sensitivity tests included those for paclitaxel,epirubicin,carboplatin,vinorelbine,and fluorouracil and were conducted on primary cancer tissue cells and cell lines,including the T47 D,BT-474,and MDA-MB-231 cells and human breast cancer xenografts in nude mice.Results:The different drug resistant genes Topo Ⅱ,GST-π,P-gp,and LRP were differentially expressed among different molecular subtypes of breast cancers(P<0.05).Positive expression of CD133 was highest in basal-like breast cancer(P<0.05).Kaplan-Meier survival analysis showed that positive expressions of Topo Ⅱ and CD133 both correlated with shorter disease-free survival(DFS)(P<0.05)and overall survival(P<0.05),and positive expression of LRP correlated only with shorter DFS(P<0.05).BT-474 showed chemosensitivity to paclitaxel and epirubicin,while MDA-MB-231 showed chemosensitivities to paclitaxel,epirubicin,carboplatin,and fluorouracil(T/C≤50%).The basal-like and HER2+breast cancer primary cells showed chemosensitivities to paclitaxel and epirubicin with significant differences compared with luminal breast cancer primary cells(P<0.05).Conclusions:The differential expression of drug resistance genes and the differential chemosensitivities of drugs in different molecular subtype of breast cancers suggested that individual treatment should be given for each type of breast cancer.

Antimicrobial Resistance,Virulence Profile,and Molecular Characterization of Listeria monocytogenes Isolated from Ready-to-eat Food in China,2013-2014

We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus

Comparison of extended spectrum β-lactamasesproducing Escherichia coli with non-ESBLsproducing E.coli:drug-resistance and virulence

The virulent factors of Escherichia coil （E.cofi） play an important role in the process of pathopoiesis. The study aimed to compare drug-resistant genes and virulence genes between extended spectrum β-1actamases （ESBLs）-producing E.coli and non-ESBLs-producing E.cofi to provide a reference for physicians in management of hospital infection. From October 2010 to August 2011,96 drug-resistant strains of E. coli isolated were collected from the specimens in Qingdao Municipal Hospital, Qingdao, China. These bacteria strains were divided into a ESBLs-producing group and a non-ESBLs-producing group. Drug sensitivity tests were performed using the Kirby-Bauer （K-B） method. Disinfectant gene, qacEAl-sull and 8 virulence genes （CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1） were tested by polymerase chain reaction （PCR）. Among the 96 E.coli isolates, the ESBLs-producing E.coli comprised 46 （47.9%） strains and the non-ESBLs-producing E.cofi consisted of 50 （52.1%） strains. The detection rates of multiple drug-resistant strain, qacEAl-sull, CNF2, hlyA, eaeA,VT1, est, bfpA, elt, and CNF1 in 46 ESBLs-producing E.coli isolates were 89.1%, 76.1%, 6.5%, 69.6%, 69.6%, 89.1%, 10.9%, 26.1%, 8.7%, and 19.6%, respectively. In the non-ESBLs-producing E.cofi strains, the positive rates of multiple drug-resistant strain, qacEAl-sull, CNF2, hlyA, eaeA, VT1, est, bfpA, elt, and CNF1 were 62.0%, 80.0%, 16.0%, 28.0%, 64.0%, 38.0%, 6.0%, 34.0%, 10.0%, and 24.0%, respectively. The difference in the detection rates of multiple drug-resistant strain, hlyA and VT1 between the ESBLs-producing E.cofi strains and the non-ESBLs-producing E.cofi strains was statistically significant （P〈0.05）. The positive rate of multiple drug-resistant strains is higher in the ESBLs-producing strains than in the non-ESBLs-producing strains. The expression of some virulence genes hlyA and VT1 varies between the ESBLs-producing strains and the non-ESBLs-producing strains. Increased awareness of clinicians and enhanced testing by laboratories are required to reduce treatment failures and prevent the spread of multiple drug-resistant strains.

THE CLINICAL SIGNIFICANCE OF MULTIDRUG RESISTANCE GENE(mdr1) EXPRESSION IN ACUTE LEUKEMIA

Objective: To study the clinical significance of multidrug resistance gene expression in acute leukemia. Methods: The relationships between drug resistance of leukemia cells and prognosis, multidrug resistance gene (mdr1) were examined in 85 patients with acute leukemia and 20 normal controls by reverse transcriptase polymerase chain reaction (RTPCR). Results: The mdr1 positive rate in untreated group was 44.7%. The complete remission (CR) rate of mdr1 positive patients (23.9%) was significantly lower than that of mdr1 negative patients (88.5%) (P<0.005). The mdr1 expression level in relapsedrefractory group was higher than that of CR group. A gradually increased mdr1 mRNA level in CR patients indicated early relapse. Conclusion: The mdr1 positive rate in normal control and longterm survival patients was very low. The mdr1 expression was correlated with FrenchAmericanBritish Cooperative Group (FAB) classification. The mdr1 expression level was correlated with chemotherapeutic effect and prognosis. It is an unfavorable prognostic factor for patients with acute leukemia.

Correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression

Objective: To investigate the correlation of Kif2a and HPK1 expression in breast cancer with the oncogene and drug resistance gene expression. Methods: A total of 91 patients with breast cancer and 85 patients with breast adenoma who accepted surgical treatment in our hospital between August 2016 and February 2018 were selected, and the breast cancer tissues and breast adenoma tissues were collected respectively as the research samples. Fluorescence quantitative PCR method was used to detect the expression of Kif2a and HPK1 genes as well as oncogenes and drug resistance genes in sample tissues, and Pearson test was used to evaluate the inner link of Kif2a and HPK1 gene expression in breast cancer tissue with oncogene and drug resistance gene expression. Results: Kif2a mRNA expression in breast cancer tissues was higher than that in breast adenoma tissues whereas HPK1 mRNA expression was lower than that in breast adenoma tissues;oncogenes DEK, iASPP-SV, Stat3, MDM2 and Fra-1 mRNA expression were higher than those in breast adenoma tissues;drug resistance genes ESR1, MDR1, P-gp, MRP1 and GST- mRNA expression were higher than those in breast adenoma tissues whereas BCRP mRNA expression was lower than that in breast adenoma tissues. Correlation analysis showed that the Kif2a and HPK1 gene expression in breast cancer tissues were directly correlated with the expression of oncogenes and drug resistance genes. Conclusion: Kif2a gene is abnormally highly expressed whereas HPK1 gene is abnormally lowly expressed in breast cancer tissues, and they are involved in the regulation of oncogene and drug resistance gene expression.

Reversal of Multi-Drug Resistance by Vector-Based-ShRNA-Mdr1 In Vitro and In Vivo

In order to investigate the effects of vector-based hairpin small interference RNA （shRNA） on the reversal of multi-drug resistance （mdr） of A2780/Taxol cells, a novel vector pEGFP-HI/mdrl containing mdrl-shRNA targeting at position 2943-2963 of mdrl was designed and synthesized. Subsequently, A2780/Taxol cells were transfected with pEGFP-H1/rndrl, and the expression ofmdrl mRNA and P-gp was detected by using RT-PCR and Western blot respectively. MTT was used to measure the 50% inhibition concentration （IC50） of Taxol to A2780/Taxol cells. The results showed that at the 24th and 48th h after transfection, the expression of mdrl mRNA was decreased to （52.1±1.0）% and （0.01±1.7）%, and that of P-gp decreased to （88.3±2.1）% and 0%, respectively. At the 48th h after transfection, the relative reversal rate of A2780/Taxol cells to Taxol was 69.54%. In vivo, the nude mice xenografts were injected with pEGFP-H1/mdrl, and then administrated Taxol. The tumor volume in pEGFP-H1/mdrl-transfected group was significantly reduced as compared with that in blank control group or pEGFP-Hl-transfected group （807.20±103.16 vs 1563.78±210.54 or 1480.78±241.24 mm^3, both P〈0.01）. These results suggested that transfection of pEGFP-HI/mdrl could efficiently down-regulate the expression of mdrl mRNA and P-gp in A2780/Taxol cells, and effectively restore the sensitivity of A2780/Taxol ceils to Taxol both in vitro and in vivo.