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.
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.
【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 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 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.
【Abstract】ObjectiveTo construct a mrp1 expression vector and investigate its biological characteristics in HepG2 cells in vitro. MethodsThe 6.5 kb multidrug resistanceassociated protein （MRP) cDNA obtained from plasmid pGEM-mrp1 was cloned into the pCI-neo 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 mrp1 mRNA and MRP in these HepG2 cells were detected by means of RT-PCR and FCM respectively. ResultsThe mrp1 expression vector was established successfully, and the stable MDR hepatocarcinoma cell line (HepG2/mrp1) was developed as well. The content of the specific fragment of mrp1 mRNA was (56.8±6.37)% and MRP was 7.89 in the HepG2/mrp1 cells, the corresponding value in HepG2 cells was (9.67±3.26)% and 0.79 respectively. The difference was statistically significant (P＜0.05). ConclusionIt is practicable to establish MDR hepatocarcinoma cell line by transferring mrp1 cDNA into HepG2 cells, which is useful in the research of MDR mechanism.
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.
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 investigate the clinical characteristics and drug sensitivity of patients with Gram-negative bacilli infection, and evaluate the risk factors related to infection, so as to provide a theoretical basis for clinical prevention and treatment of hospital-acquired infection. Methods The complete medical records of 181 patients with Gram-negative bacilli infection in the Department of Respiratory and Critical Care Medicine of Beijing Anzhen Hospital from January 2018 to September 2021 were retrospectively collected. They were divided into a Carbapenem-resistant Gram-negative bacillus (CR-GNB) group and a Carbapenem-sensitive Gram-negative bacillus (CS-GNB) group according to their different sensitivities to carbapenems. Results A total of 238 strains of Gram-negative bacilli were detected, including 108 strains of CR-GNB and 130 strains of CS-GNB. Acinetobacter baumannii was the most common, followed by Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Escherichia coli and Serratia marcescens. Univariate analysis showed that the risk factors of CR-GNB infection were heart disease and cerebrovascular disease, receiving invasive mechanical ventilation, deep venous catheterization and indwelling catheter, hypoproteinemia, renal insufficiency, pre-infection exposure to tigecycline, carbapenems, vancomycin, polymyxin, and combined use of antibiotics. Hypoproteinemia and deep venous catheterization were independent risk factors for CR-GNB infection. The resistance rates of CR-GNB to cefepime, ceftazidime, levofloxacin and ciprofloxacin were 88.0%, 88.0%, 86.1% and 75.0%, respectively. The resistance rate to cefuroxime, amika, ceftriaxone, gentamicin and cotrimoxazole was low, and the resistance rate to ceftazidime avibactam was the lowest (3.7%). Except tetracycline, tigecycline, cefuroxime, polymyxin, cefazolin and ampicillin, the drug resistance rates of CR-GNB group to other antibacterial drugs were higher than those of CS-GNB group, and the differences were statistically significant (P<0.05). The all-cause mortality in CR-GNB group (42.4%) was significantly higher than that in CS-GNB group (6.3%), and the difference was statistically significant (P<0.05). Conclusions The disease burden caused by CR-GNB infection is becoming heavier and heavier, which has a serious impact on the prognosis of hospitalized patients. The increase of antibiotic resistance leads to poor efficacy of antimicrobial therapy. Therefore, early identification of high-risk groups of infection and reasonable and prudent application of antimicrobial therapy can achieve the purpose of reducing the mortality of infection and improving the prognosis of hospitalized patients.
Objective To investigate the reversal of the multidrug resistant gene mdr1 in vivo by antisense oligodeoxynucleotide （ASODN） on the basis of study in vitro. Methods The cultured drug-resistant human hepatocellular carcinoma cells were injected under the skin of axilla to establish the tumor model of nude mice. mdr1 ASODN accompanied by Lipofectamine were injected locally and ADM was injected intraperitoneally. Control 1 and control 2 were locally injected by Lipofectamine and normal saline separately, and ADM was also injected intraperitoneally. Results As time went on the tumor size increased and from the 5th day on alterations were marked, tumor size in different time phase showed marked difference to the prior time phase with significant difference (P＜0.05）. Tumor size in group ASODN was marked smaller than that of other 3 groups after the 5th day (P＜0.05)，while tumor size of group control 1,2 and group SODN in different phase showed no significant difference (Pgt;0.05). The results suggested that SODN and Lipofectamine showed no marked effect on tumor growth of nude mice and ASODN had marked inhibition effect on tumor growth. Conclusion mdr1 ASODN can also reverse multidrug resistance of drug-resistant human hepatocellular carcinoma cells in vivo. After the treatment the tumor’s growth in nude mice will slow down in a range of time.
