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find Keyword "drug resistance" 48 results
  • Research progress on the relationship between cuproptosis and breast cancer

    ObjectiveTo summarize the latest advances in copper and cuproptosis in the field of breast cancer, and to provide a reference for clinical treatment decisions. MethodThe literatures related to copper and cuproptosis in recent years were read and summarized, and the research progress on the role of copper in breast cancer, the application of cuproptosis in the diagnosis and treatment of breast cancer were reviewed. ResultsCuproptosiswas a novel form of programmed cell death, which occurred via direct binding of copper to lipoylated components of the tricarboxylic acid (TCA) cycle, this resulted in lipoylated protein aggregation and subsequent iron-sulfur cluster protein loss, leading to proteotoxic stress and ultimately cell death. Cuproptosis induced proliferation and migration of breast cancer cell , mediated personalized immunotherapy, and participated in endocrine and chemotherapeutic drug resistance. ConclusionExploring the mechanism of cuproptosis provides potential applications for subsequent immunotherapy, endocrine therapy, and chemotherapy for breast cancer, leading to new effective strategies for patients.

    Release date:2024-03-23 11:23 Export PDF Favorites Scan
  • Research progress and prospects of exosomal microRNAs in bone malignancies

    Bone malignancies exhibit the characteristics of high incidence, poor prognosis, and strong chemoresistance. Exosomal microRNAs can regulate the proliferation of bone malignant cells, improve chemoresistance, influence cell communication and the microenvironment, and have significant potential in the diagnosis and treatment of bone malignancies. Due to their stability, exosomal microRNAs can serve as non-invasive biomarkers for diagnosis and prognosis. However, their widespread application in clinical settings requires standardized research. This review summarizes the progress of exosomal microRNA research in various bone malignancies including osteosarcoma, chondrosarcoma, Ewing sarcoma, and fibrosarcoma, to provide new theoretical foundations and perspectives for the field.

    Release date:2024-12-27 02:33 Export PDF Favorites Scan
  • A New Tool for Medical Research ——ATP-Binding Cassette Transporter Families

    Objective  To review the application advancements of ATP-binding cassette (ABC) transporter in medical research.Methods  Relevant literatures about the applications of ABC families in medical research were reviewed. Results  ABC families mainly took roles in transporting substances across cell membrane. Some of them were useful for the prediction of drug resistance and the prognosis of malignant tumors. Others were target s for molecular researches. Their expressions or mutations might be related with the occurrence of diseases. Conclusion ABC families are very important in the diagnosis and therapy for diseases. Thus they are very promising tools for future medical research.

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  • Evaluation of Neoadjuvant Chemotherapy and Expression of Multidrug Resistance Indicater in Gastrointestinal Carcinomas

    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 resistanceassociated 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.

    Release date:2016-08-28 04:48 Export PDF Favorites Scan
  • THE ROLE OF MULTIDRUG RESISTANCE-ASSOCIATED PROTEIN IN THE FORMATION OF ADRIAMYCININDUCED MULTIDRUG RESISTANCE TO HEPATOCELLULAR CANCER CELL SMMC-7721 IN HUMAN HEPATOCELLULAR CARCINOMA

    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(RTPCR). 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.

    Release date:2016-08-28 05:29 Export PDF Favorites Scan
  • Analysis on multidrug-resistant organisms monitoring between 2013 and 2015 in a high-rank comprehensive hospital

    Objective To investigate the detection of multidrug-resistant organisms (MDRO) by targeted monitoring in a tertiary hospital, and to understand the distribution of MDRO. Methods We retrospectively analyzed the detection and distribution of methicillin-resistantStaphylococcus aureus (MRSA), carbon black alkeneAcinetobacter baumannii (CRABA), carbapenem-resistantPseudomonas aeruginosa (CRPAE), vancomycin-resistantEnterococci (VRE) and carbapenem-resistantEnterobacter (CRE) in clinical samples collected from 2013 to 2015. Results A total of 990 multidrug-resistant bacteria strains were isolated from 2013 to 2015, of which 445 were MRSA (44.95%), 328 were CRABA (33.13%), 99 were CRPAE (10.00%), 12 were VRE (1.21%), and 106 were CRE (10.71%). They were mainly distributed in the Department of Burn, Comprehensive ICU, Department of Neurosurgery, Department of Respiratory Medicine and Department of Orthopedic Surgery. The detection rates of multidrug-resistant organisms of 2013-2015 were 10.85% (352/3 244), 9.20% (304/3 303), and 7.11% (334/4 699) respectively, which reduced year by year with significant difference (χ2= 34.42,P< 0.001). The detection rates of CRPAE, CRE and VRE all reduced with significant differences (P< 0.05). Conclusions The detection rate of multidrug-resistant organisms under targeted monitoring shows an obvious downward trend. MRSA and CRABA are still the major MDROs, which show no obvious change. The detection rates of CRPAE, VRE and CRE show obvious downward trend. Department of Burn, Comprehensive ICU, Department of Neurosurgery, Department of Respiratory Medicine and Department of Orthopedic Surgery have the highest risks of MDRO. In the future, we should strengthen the monitoring of high-risk departments, and focus on the reasonable choice of special antimicrobial agents to avoid special MDROs.

    Release date:2017-03-27 11:42 Export PDF Favorites Scan
  • The Expression and Significance of Multidrug Resistant Gene mdr1 in Hepatocellular Carcinoma

    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.

    Release date:2016-08-28 04:49 Export PDF Favorites Scan
  • Molecular mechanism of metastasis-associated protein 3 involvement in glioma drug resistance through reactive oxygen

    ObjectiveTo investigate the molecular mechanism by which metastasis-associated protein 3 (MTA3) participates in glioma resistance through reactive oxygen species. Methods Protein expression in glioma stem cells (GSCs) and non-GSCs was detected using Western blotting. GSCs included U87 and SHG44 cells, while non-GSCs included U87s and SU-2 cells. After overexpressing MTA3, U87 and SHG44 cells were divided into Lv-scr and Lv-MTA3 groups. The self-renewal capacity of glioma cells was assessed through a neurosphere formation assay. Cell survival fractions were examined following exposure to 0, 2, 4, 6, 8, and 10 Gy X-ray irradiation under normoxic or hypoxic conditions. Apoptosis and reactive oxygen species expression were analyzed using flow cytometry. Immunofluorescence staining was performed to detect the stem cell markers CD133 and nestin, as well as the differentiation markers glial fibrillary acidic protein (GFAP, for astrocytes) and neuronal class Ⅲ β-tubulin. Results In GSCs, MTA3 expression was lower in the U87s and SU-2 groups. After MTA3 overexpression, Lv-MTA3 expression was higher in U87s and SU-2 compared to the Lv-scr group. Under normoxic or hypoxic conditions, U87 and SU-2 showed greater radioresistance compared to glioma cell lines U87 and SHG44. Compared to non-GSCs, basal reactive oxygen species formation was reduced in GSCs, while reactive oxygen species generation was increased in non-GSCs. Following exposure to different doses of X-rays under normoxic or hypoxic conditions, GSCs with MTA3 overexpression exhibited greater radiosensitivity than those with stable integration. Additionally, MTA3 overexpression slightly increased the oxygen enhancement ratio (OER) in GSCs. MTA3 overexpression reduced the immunoreactivity of CD133 and nestin in both stem cell lines, and increased immunofluorescence staining of GFAP and neuronal class Ⅲ β-tubulin, with statistically significant differences (P<0.05). Conclusions MTA3 is downregulated in GSCs. Overexpression of MTA3 reduces the radioresistance and stemness of GSCs both in vitro and in vivo. MTA3 plays a crucial role in regulating the radiosensitivity and stemness of GSCs through reactive oxygen species.

    Release date:2024-06-24 02:56 Export PDF Favorites Scan
  • Expression and Functional Significance of Lung Resistance Protein in Pancreatic Adenocarcinoma Cell

    【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.

    Release date:2016-09-08 11:53 Export PDF Favorites Scan
  • Advances in Overcoming Multidrug Resistance of Tumors Caused by mdr1Gene

    【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 Pglycoprotein. There were two ways to overcome multidrug resistance of tumors through mdr1 genes mRNA and its product Pglycoprotein 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.

    Release date:2016-08-28 04:44 Export PDF Favorites Scan
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