【Abstract】 Objective To detect the expression of lung resistance protein (LRP) and investigate its significance in pancreatic carcinoma cell lines (SW1990, PCT-2, PCT-3, PCT-4, Aspc-1, Capan-1, Mia-PaCa-2 and Panc-1). Methods Reverse transcription PCR (RT-PCR) and immunocytochemistry (ICC) were carried out to investigate the expression of LRP. Results LRP mRNA was absent in PCT-2 cell line by RT-PCR. Mild to moderate expression level was found in other pancreatic carcinoma cell lines. PCT-4, Aspc-1 and Panc-1 presented the highest LRP mRNA expression level, in contrast, SW1990, PCT-3, Capan-1 and Mia-PaCa-2 showed moderate LRP mRNA expression. The median value was 0.56±0.33. LRP was further validated by ICC. Absent to weak protein expression of LRP was found in PCT-2 and PCT-3. Overexpressed LRP was present in SW1990, Capan-1 and Aspc-1, furthermore, the highest expression of LRP was found in Panc-1, Mia-PaCa-2 and PCT-4 cell lines. Conclusion All these data showed that LRP might play an important role in multidrug resistance of pancreatic carcinoma.
ObjectiveTo explore the prognostic risk factors of bloodstream infections caused by Acinetobacter baumannii in the hospital, to provide a basis for clinical diagnosis and treatment.MethodsA retrospective analysis was performed on the medical records of patients diagnosed with Acinetobacter baumannii bloodstream infection in Guangxi Zhuang Autonomous Region People’s Hospital between January 2013 and December 2018. The patients were divided into survival group and non-survival group according to the outcome within 30 days after blood culture was collected. Univariate and multivariate logistic analyses were used to identify the risk factors of Acinetobacter baumannii bloodstream infections.ResultsA total of 123 patients were included, including 48 in the survival group and 75 in the non-survival group. Third generation cephalosporins [odds ratio (OR)=2.492, 95% confidence interval (CI) (2.125, 2.924), P<0.001], carbapenems [OR=1.721, 95%CI (1.505, 1.969), P<0.001], multidrug resistant-Acinetobacter baumannii infection [OR=1.240, 95%CI (1.063, 1.446), P=0.006], post-operation [OR=0.515, 95%CI (0.449, 0.590), P<0.001], mechanical ventilation [OR=1.182, 95%CI (1.005, 1.388), P=0.043], indwelling central venous catheter [OR=0.116, 95%CI (0.080, 0.169), P<0.001], mixed infection or septic shock [OR=3.935, 95%CI (2.740, 5.650), P<0.001], APACHE Ⅱ score (≥15) [OR=5.939, 95%CI (5.029, 7.013), P<0.001], chronic kidney disease [OR=1.440, 95%CI (1.247, 1.662), P<0.001], immune system disease [OR=28.620, 95%CI (17.087, 47.937), P<0.001], use of corticosteroids [OR=0.520, 95%CI (0.427, 0.635), P<0.001], and combined antifungal agents [OR=0.814, 95%CI (0.668, 0.992), P=0.041] were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii.ConclusionsThe third generation cephalosporins, carbapenem, MDR-Acinetobacter baumannii infection, post-operation, mechanical ventilation, indwelling central venous catheter, mixed infection or septic shock, APACHE Ⅱ score (≥15), chronic kidney disease, immune system disease, use of corticosteroids, and combined antifungal agents were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii. In the clinical work, it is needed to carry out timely detection of microbial etiology, timely report, and reasonable treatment.
【Abstract】Objective To review the advances in overcoming multidrug resistance of tumors caused by mdr1 gene.Methods Different ways of overcoming multidrug resistance of tumors caused by mdr1 gene in the literatures were reviewed. Results One of the important reasons causing multidrug resistance was due to the overexpression of mdr1 gene and its product Pglycoprotein. There were two ways to overcome multidrug resistance of tumors through mdr1 genes mRNA and its product Pglycoprotein effectively.Conclusion The clinical test of the unitary way to overcome multidrug resistance of tumors is unsatisfactory, combining different ways to overcome multidrug resistance of tumors will be the hot spot of tumors research in the future.
Objective To detect the characteristic of multidrug resistance gene products expressions in gastric cancer tissues, including glutathione-s-transferase π (GST-π), P-glycoprotein (P-gp), topoisomerase Ⅱ (Topo-Ⅱ), thymidylate synthase (TS), and multidrug resistance related protein (MRP), and analyze their clinical significance for the therapy of gastric cancer. Methods SP immunohistochemical stain was used to detect GST-π, P-gp, Topo-Ⅱ, TS and MRP expressions in sample of 48 gastric cancer tissues and 10 normal gastric mucosa. And their corresponding clinical data were comprehensive analyzed. Results The expressions of GST-π, P-gp, Topo-Ⅱ, TS and MRP had notable differences between the gastric cancer tissues and normal gastric mucosa (GST-π： P＜0.01； P-gp： P＜0.01； Topo-Ⅱ： P＜0.01； TS： P＜0.05； MRP： P＜0.05). Positive expression rates of GST-π, P-gp, Topo-Ⅱ, TS and MRP in gastric cancer tissues were 72.9% (35/48), 56.3% (27/48), 83.3% (40/48), 41.7% (20/48) and 39.6% (19/48), and positive expression rates of them in normal gastric mucosa were 10.0% (1/10), 0 (0/10), 0 (0/10), 0 (0/10) and 0 (0/10) corresponding. Their positive expression rates were closely relevant to the degree of differentiation (P＜0.01), but not to the patients’ sex, age, tumour site, size of tumour, invasive depth and lymph node metastasis (Pgt;0.05). Conclusions The expressions of GST-π, P-gp, Topo-Ⅱ, TS and MRP in gastric cancer tissues exist obvious heterogeneity. Their overexpression underlie the multidrug resistance of gastric cancer. The joint detection of GST-π, P-gp, Topo-Ⅱ, TS and MRP can be looked as an important symbol for guiding its chemotherapy.
ObjectiveTo evaluate the effect of neoadjuvant chemotherapy and find the mechanism of multidrug resistance. MethodsTwenty patients with gastric cancer and 31 patients with colorectal cancer underwent neoadjuvant chemotherapy and then operations. The preoperative specimens were stained by immunohistochemical techniques for testing p53,multidrug resistanceassociated protein (MRP), glutathione S transferase（GST）, telomerase. Resection specimens were evaluated for chemotherapy effect by routine histology; at the same time, the postoperative morbidity and mortality were observed. ResultsIn 51 patients, the response rate of neoadjuvant chemotherapy was 27.45%(14/51),so multidrug resistance was a kind of common phenomena in gastrointestinal carcinomas. The postoperative morbidity was 15.69%(8/15), the main operation complication was infection,the mortality was 1.96%(1/51),only one person died from severe infection.The expression rate of p53, MRP, GST, telomerase was 58.0%,51.0%,66.7%,74.0%respectively, the location of p53 was at cell nucleus,location of MRP,GST was at cell memberane and cytoplasm,location of telomerase was at cytoplasm.The response rate had nothing to do with age, sex and metastasis. But it was related with p53 and telomerase expression. ConclusionNeoadjuvant chemotherapy is an effective, safe therapy. But the rate of drug resistance is high in gastrointestinal carcinomas, and the response rate is related to p53, telomerase expression.
ObjectiveTo explore the relationship between mdr1 gene expression of hepatocellular carcinoma (HCC) and pathological characteristics,chemotherapy and prognosis. MethodsThe mdr1 gene expression of HCC in 56 patients with the methods of immunohistochemistry was studied. The results were analysed with the pathological data by statistic methods. ResultsThe positive expression of mdr1 gene in cancer tissues and pericancerous tissues of HCC were 30/56(53.6%) and 19/56 (33.9%) respectively. The difference was statistically significant (χ2=4.39,P＜0.05). The positive expression of mdr1 gene in cancer tissues of untreated patients and in recurrent patients were 22/48(45.8%) and 8/8(100%) respectively.The expression of mdr1 gene was not associated with tumor size, number, tumor thrombus, differentiation, HBsAg and liver cirrhosis. The patients with positive mdr1 expression had a shorter survival time than that of negative ones. But the difference was not statistically significant. Conclusion The positive expression of mdr1 in HCC is 53.6%. It is not associated with tumor size, number, tumor thrombus, tumor differentiation, HBsAg and liver cirrhosis. There are innate multidrug resistance in HCC.
Objective To dynamically study the formation of multidrug resistance(MDR) of human hepatocellular carcinoma cell SMMC-7721 induced by Adriamycin (ADM) and the role of multidrug resistance-associated protein(MRP) in its mechanisms.Methods Hepatocellular carcinoma cell SMMC-7721 was cultured in RPMI-1640 medium containing ADM with progressively increased concentration or directly cultured in medium containing different concentrations of ADM. Resistant index of drug-resistant variants of SMMC-7721 cell was determined by drawing cell dosage-reaction curves.Levels of MRP mRNA expression were detected by reverse transcription-polymerase chain reaction(RTPCR). Intracellular rubidomycin(DNR) concentration was examined by flow cytometry(FCM).Results With progressive increasing of ADM concentration in medium resistant index and levels of MRP mRNA expression were correspondingly increased but intracellular DNR concentration was markly reduced. When parental cells were directly cultured in medium containing different concentrations of ADM, the higher the ADM concentration, the higher the level of MRP mRNA expression, but intracellular DNR concentration was kept at the similar high level and most cells died. Conclusion ADM may progressively induce SMMC-7721 cell resistant to multiple chemotherapeutic drugs with reduced intracellular DNR accumulation associated with the overexpression of MRP gene.
Objective To study the expression and significance of multidrug resistance-associated protein (MRP) gene in hepatocellular carcinoma (HCC). Methods Reverse transcription polymerase chain reaction (RT-PCR) assay was used to detect the expression of MRP mRNA in 25 fresh specimens of the primary HCC and its surrounding liver tissues. Immunohistochemistry LSAB technique was adopted to test MRP in 60 HCC specimens. The drug sensitivity was also tested by flow cytometry.Results The positive expression rates of MRP mRNA and MRP protein in primary HCC were 44.00%(11/25) and 45.00%(27/60) respectively. All the intensity of expression was low, but significant higer than its surrouding liver tissues (P＜0.05). The intensity and expression rate of MRP protein in 5 recurrent HCC had a tendency to increase. There was a correlation between the expression of MRP mRNA and MRP protein in 25 patients using RT-PCR and immunohistochemistry assay (Plt;0.05). Detected by flow cytometry, the average sensitivity of drugs in vitro of 60 HCC sp-cimens were 5-FU （15.80±7.63）%，DDP（18.45±9.59）%，ADM（17.95±7.99）%，MMC（16.60±8.69）% and CTX（17.40±10.14）%. Only 5FU and ADM were significantly affected by the expression of MRP protein (Plt;0.05).Conclusion The expression of MRP in primary HCC may be one of the important mechanisms of the intrinsic and acquired drug resistance in HCC. To study the expression of MRP could give a predictive value in HCC chemotherapy.
【Abstract】ObjectiveTo construct an mdr1 expression vector and detect its expression in HepG2 cells in vitro. MethodsThe 4.5-kb mdr1 cDNA was obtained from the plasmid pHaMDR1 cloned into the PCIneo mammalian expression vector, which was later transferred into human hepatocarcinoma cell line HepG2 by liposome. Then the HepG2 cells resisting G418 were clustered and proliferated，and the specific fragment of mdr1 cDNA, mRNA and the Pgp in these HepG2 cells were detected by means of PCR, RT-PCR and FCM respectively. ResultsThe mdr1 expression vector was constructed successfully，and the stable multidrug resistance(MDR) hepatocarcinoma cell line （HepG2/mdr1） was developed as well. The outcome of PCR analysis showed that the specific fragment of mdr1 cDNA could be found in HepG2/mdr1 cells, but not in the nontransfection HepG2 cells. Furthermore,the content of the specific fragment of mdr1 mRNA and the expression of P-gp in HepG2/mdr1 cells were (59.7±7.9)% and (12.5±5.45)% respectively, the corresponding value in HepG2 cells were (16.9±3.2)% and (4.63±2.59)% respectively. The difference was statistically significant (P＜0.05). ConclusionIt is praticable to develop MDR hepatocarcinoma cell line by transferring mdr1 cDNA into HepG2 cells, which is useful in the research of MDR mechanism.
Objective To investigate the effect of phosphorothioate antisense oligonucleotides(AS-ODN) on suppressing multidrug resistance-associated protein gene(MRP) in human drug-resistant hepatocellular carcinoma cell line (SMMC-7721/ADM). Methods Cell line was transfected with a synthetic S-ODN complementary to the coding region of MRP mRNA, Lipofectamine acting as carrier. The drug sensitivity was measured by MTT assay. The expression of MRP mRNA was detected by RT-PCR and the expression of P190 was detected by flow cytometry. Results AS-ODN inhibited expression of MRP mRNA and P190 and promoted sensitivity to daunorubicinum and adriamycinum. Conclusion AS-ODN can reduce the expression of MRP gene. MDR caused by MRP is an important cause of multidrug resistance of SMMC-7721/ADM.