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.
Non-small cell lung cancer (NSCLC) is one of the most common types of cancer in the world and is an important cause for cancer death. Although the application of immunotherapy in recent years has greatly improved the prognosis of NSCLC, there are still huge challenges in the treatment of NSCLC. The immune microenvironment plays an important role in the process of NSCLC development, infiltration and metastasis, and they can interact and influence each other, forming a vicious circle. Notably, single-cell RNA sequencing enables high-resolution analysis of individual cells and is of great value in revealing cell types, cell evolution trajectories, molecular mechanisms of cell differentiation, and intercellular regulation within the immune microenvironment. Single-cell RNA sequencing is expected to uncover more promising immunotherapies. This article reviews the important researches and latest achievements of single-cell RNA sequencing in the immune microenvironment of NSCLC, and aims to explore the significance of applying single-cell RNA sequencing to analyze the immune microenvironment of NSCLC.
Objective To predict clinical chemotherapy sensitivity of primary non-small cell lung cancer（NSCLC） by methylthiazal （MTT） tumor chemosensitivity assay method in vitro and detection of multidrug resistance gene1 （MDR1）, and provide reference for clinical individualized treatment. Methods We selected 80 fresh primary NSCLC samples from NSCLC patients who underwent surgical resection in Zibo Central Hospital Affiliated to Binzhou Medical College between January 2009 and December 2011. There were 46 male patients and 34 female patients with their median age of 54 （29 to 81）years. Viable NSCLC cells obtained from malignant tissue were tested for their sensitivity to cisplatin （DDP）, gemcitabine （GEM）, docetaxe （DOC）, etoposide （VP-16） ,and vinorelbine （NVB） using MTT assay in vitro. Fluorescent quantitative reverse transcriptase-polymerase chain reaction （RT-PCR） was used to analysis the expression level of multidrug resistance gene1 （MDR1）. Results After exposure to antitumor drugs, morphologic changes, decrease of metabolic activity, and apoptosis were detected in NSCLC cells. MTT results showed that different individual cancer cells had different chemosensitivity to antitumor drugs, and cancer cells also had different chemosensitivity to different antitumor drugs. Inhibitory rates of cancer cells exposed to DOC, GEM, and VP-16 were significantly higher than those of cancer cells exposed to DDP and NVB （42.5%±9.5%, 40.5%±6.5%, 38.4%±7.6% versus 31.5%±8.5%，32.5%±7.8%, P＜0.05）.The positive rate of MDR1 in tumor tissues was 40.0% （32/80）. The expression of MDR1 was not associated with tumor histological type, degree of differentiation, lymph node metastasis and TNM stage. The expression of MDR1 was associated with resistance to NVB （χ2=5.209，P=0.022），GEM （χ2=4.769，P=0.029），VP-16 （χ2=4.596，P=0.032），and DDP（χ2=6.086，P=0.014）, but not associated with resistance to DOC（χ2=0.430，P=0.512）. Conclusion MTT chemosensitivity assay can effectively predict clinical chemotherapy sensitivity. Detection of MDR1, together with MTT chemosensitivity assay, can more accurately predict NSCLC chemosensitivity and be a guide for individualized chemotherapy of NSCLC.
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.
【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.
Objective To investigate nosocomial non-fermented bacterial infection in lower respiratory tract and the risk factors for multi-drug resistant bacterial infection. Methods 229 patients with nosocomial nonfermented bacterial infection in lower respiratory tract from January to December in 2007 in Xiangya Hospital were analyzed retrospectively. The distribution and drug sensitivity of pathogens were recorded. Of those 229 patients,183 cases were infected by non-fermented multi-drug resistant bacteria( MDRB) . The risk factors for non-fermented MDRB infection in lower respiratory tract were analyzed by multi-factor logistic multiple regression analysis.Results The top four non-fermented bacteria isolated were Pseudomonas aeruginosa( 47.6%) , Acinetobacter baumannii( 36. 3% ) , Acinetobacter spp( 8. 6% ) , and Stenotrophomonas maltophilia( 5. 1%) . Higher isolatated rate was found in neurosurgery ( 25. 7% ) and central ICU( 22. 9% ) . The isolated non-fermented bacteria except Stenotrophomonas maltophilia were resistant to all antibiotics except cefoperazone-sulbactam and meropenem. ICU stay( P lt; 0. 001) , tracheotomy or tracheal intubation( P = 0. 001) , and previous use of carbapenemantibiotics( P =0. 032) were independent risk factors for non-fermented MDRB infection. Conclusion Non-fermented bacillus were important pathogens of nosocomial infection in lower respiratory tract with high rates of antibiotic resistance. It is important to prevent non-fermented MDRB infection by strict limitation on the indication of ICU stay,tracheotomy and use of carbapenem.
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.
Objective To investigate the role of long non-coding RNA metastasis-associated in colon cancer 1-antisense RNA （MACC1-AS1）in cisplatin resistant gastric cancer and its possible mechanism. Methods Human gastric cancer cell line BGC823 and cisplatin resistant gastric cancer cell line (BGC823/DDP) were selected as the research objects. BGC823/DDP cells were transfected and divided into negative control group (si-NC group, transfected with si-NC empty plasmid) and MACC1-AS1 gene silencing group (si-MACC1-AS1 group, transfected with si-MACC1-AS1 plasmid). The BGC823 cells were transfected and divided into positive control group (pcDNA-NC group, transfected with pcDNA-NC empty plasmid) and MACC1-AS1 gene overexpression group (pcDNA-MACC1-AS1 group, transfected with pcDNA-MACC1-AS1 plasmid). MTT was used to detect the inhibition and 50% inhibition concentration (IC50). Flow cytometry was used to detect apoptosis. Real-time fluorescence quantitative PCR was used to detect the mRNA expression levels of MACC1-AS1, B-lymphoma-2 gene (Bcl-2), Bcl-2 related X gene (Bax), mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), protein kinase B (AKT), and phosphorylated AKT (p-AKT). Western blot was used to detect the protein expression levels of Bax, Bcl-2, p-mTOR, mTOR, AKT, and p-AKT. Results The relative expression level of MACC1-AS1 mRNA in BGC823/DDP cells was higher than that in BGC823 gastric cancer cells (P<0.01). The relative expression level of MACC1-AS1 mRNA in the si-MACC1-AS1 group cells was lower than that in the si-NC group cells (P<0.01). The relative expression level of MACC1-AS1 mRNA in the pcDNA-MACC1-AS1 group cells was higher than that in the pcDNA-NC group cells (P<0.01). The cell growth inhibition rate and IC50 of the si-MACC1-AS1 group were higher than those of the si-NC group (P<0.01). The cell growth inhibition rate and IC50 of the pcDNA-MACC1-AS1 group were lower than those of the pcDNA-NC group (P<0.01). The mRNA and protein relative expression levels of Bcl-2, p-AKT/AKT and p-mTOR/mTOR in the pcDNA-MACC1-AS1 group were significantly higher than those in the pcDNA-NC group (P<0.01). The relative expression levels of Bax protein and mRNA in the pcDNA-MACC1-AS1 group were significantly lower than those in the pcDNA-NC group (P<0.01). The apoptosis rate of the pcDNA-MACC1-AS1 group was significantly lower than that of the pcDNA-NC group (P<0.01). The mRNA and protein relative expression levels of Bcl-2, p-AKT/AKT and p-mTOR/mTOR in the si-MACC1-AS1 group were significantly lower than those in the si-NC group (P<0.01). The relative expression levels of Bax protein and mRNA in the si-MACC1-AS1 group were significantly higher than those in the si-NC group (P<0.01). The apoptosis rate of the si-MACC1-AS1 group was significantly higher than that of the si-NC group (P<0.01). Conclusions MACC1-AS1 highly expresses in cisplatin resistant gastric cancer cells. Overexpression of MACC1-AS1 regulates AKT/mTOR pathway mediated apoptosis and enhances cisplatin resistance of gastric cancer cells.
ObjectiveTo summarize the latest research progress and related mechanisms of cancer-associated fibroblasts (CAFs) in invasion, metastasis and drug resistance of breast cancer, so as to seek the best treatment strategy for patients with breast cancer metastasis and drug resistance. MethodThe literatures about CAFs research in breast cancer in recent years were searched and summarized. ResultsCAFs was the main stromal cell in tumor microenvironment (TME). By changing TME, the biological characteristics of CAFs could be changed and the growth and invasion of breast cancer cells could be induced. CAFs in breast cancer promotes the invasion and metastasis of breast cancer cells by interacting with inflammatory factors and promoting the formation of pre-transplantation ecosystems, and CAFs also mediates chemotherapy resistance to breast cancer, target resistance, endocrine resistance, and radiation resistance through the secretion of various cellular factors. ConclusionsAt present, some progress has been made in the research of CAFs in breast cancer, but there is still a certain gap to clinical application CAFs has a variety of functional phenotypes, so it is necessary to identify and characterize specific CAFs subtypes when studying new anti-CAFs therapeutic strategies. It has been proved that CAFs has great potential as a specific target for breast cancer treatment, but CAFs still lacks specific biomarkers. Therefore, an in-depth understanding of the biological characteristics and heterogeneity of CAFs can provide a reliable theoretical basis for developing drugs targeting CAFs.
ObjectiveTo summarize the recent advances in the relationship between long non-coding RNA (LncRNA) and tumor autophagy, autophagy and drug resistance regulation.MethodsReviewed the relevant literatures at home and abroad, and reviewed the recent research progress of LncRNA regulation of autophagy to affect tumor resistance.ResultsDrug resistance was a common problem in the process of anti-tumor therapy. Autophagy played an important role in the process of tumor resistance as an important mechanism to maintain cell homeostasis. Abnormal regulation of LncRNA could contribute to the occurrence and development of tumors, and could also mediate the resistance of tumor cells to anti-tumor drugs by promoting or inhibiting autophagy.ConclusionsLncRNA can mediate tumor autophagy in a positive or negative direction, and autophagy is a " double-edged sword” for tumor resistance. LncRNA may improve tumor resistance to drugs by regulating autophagy.
