Expression of Glutathione S-transferase π in Human Bladder Cancer

The purpose of this study was to investigate the expression of glutathione stransferase (GST) and its clinical significance in human bladder cancer. GST immunoreactivity was assessed respectively in 49 bladder cancers and 30 normal bladder mucosas by avidin biotin peroxidase complex (ABC) techniques. The corelationship of GST expression and clinical and biological feature of bladder cancer was studied. Positive GST was observed in 44 cases of bladder cancer mucosa (89.8%) and in 18 cases of normal bladder mucosa (60%). In 42 cases of stage G\-\{12\} and 7 cases of stage G\-3 cancer patients the positive GST expression rate was 80.9%(34/42) and 100%(7/7) respectively. In 14 cases of recurrent bladder cancer the total positive expression rate was 92.9% (13/14), meanwhile in 19 cases of stage T23 the positive nuclear staining was seen in 10. Higher rate of GST expression was found in bladder cancer than in normal bladder mucosa, which was implied that the resistance to chemotheraputic drugs in bladde r cancer might be related to the expression of GST. GST expression was correlated with tumor grade. Furthermore, increased intranuclear GST expression might be associated with bladder cancer progression.

CircRNA_0084927 promotes colorectal cancer progression by regulating miRNA-20b-3p/glutathione S-transferase mu 5 axis

BACKGROUND Colorectal cancer(CRC)is the third most common cancer and the second most common cause of cancer-related death worldwide.The 5-year survival rate of patients with early-stage CRC could reach 90%,but it is very low in patients with advanced-stage CRC.Recent studies have shown that circular RNAs play important roles in regulating the migration and invasion of CRC cells.AIM To elucidate the role of circRNA_0084927(circ_0084927)in the migration and invasion of CRC cells and its underlying mechanism.METHODS Clinical tissue samples and cells were collected,and the expression of circ_0084927 was detected by quantitative polymerase chain reaction(qPCR).The diagnostic performance of circ_0084927 was assessed by receiver operating characteristic curve analysis.The role of circ_0084927 in CRC cell proliferation,migration,and invasion was determined using cell counting kit-8 assay,wound healing assay,and transwell assay,respectively.The regulatory relationship among circ_0084927,miRNA-20b-3p(miR-20b-3p),and glutathione S-transferase mu 5(GSTM5)was identified using databases,luciferase reporter assay,qPCR,and Western blot analysis.AKT-mTOR signaling was also verified after circ_0084927 knockdown or miR-20b-3p mimic treatment.RESULTS The expression of circ_0084927 was significantly increased in CRC tissues and cells,and it was higher in advanced-stage CRC compared with early-stage CRC.The area under the curve(AUC)of circ_0084927 was 0.806[95%confidence interval(CI):0.683-0.896].In addition,the AUC was 0.874(95%CI:0.738-0.956)in patients with advanced-stage CRC and 0.713(95%CI:0.555-0.840)in those with early-stage CRC.Knockdown of circ_0084927 inhibited the migration and invasion of HCT116 cells.Moreover,circ_0084927 was found to act as a sponge of miR-20b-3p.MiR-20b-3p activation reduced the circ_0084927 level,whereas miR-20b-3p inhibition increased the circ_0084927 level.But the effect was not found after circ_0084927 mutation.In addition,miR-20b-3p expression in CRC patients was also reduced and negatively correlated with circ_0084927 expression.The function of circ_0084927 in HCT116 cells with circ_0084927 knockdown was rescued by miR-20b-3p.Moreover,GSTM5 expression was significantly decreased after overexpressing miR-20b-3p or inhibiting circ_0084927,but its expression was rescued when circ_0084927 and miR-20b-3p were both inhibited.Finally,AKTmTOR signaling was markedly regulated by circ_0084927 and miR-20b-3p.CONCLUSION The expression of circ_0084927 is significantly increased in CRC and higher in advanced-stage CRC than in early-stage CRC.Moreover,circ_0084927 potentially regulates CRC cell migration and invasion via the miR-20b-3p/GSTM5/AKT/mTOR pathway.

“Pincer movement”:Reversing cisplatin resistance based on simultaneous glutathione depletion and glutathione S-transferases inhibition by redox-responsive degradable organosilica hybrid nanoparticles

The therapeutic efficacy of cisplatin has been restricted by drug resistance of cancers.Intracellular glutathione(GSH)detoxification of cisplatin under the catalysis of glutathione S-transferases(GST)plays important roles in the development of cisplatin resistance.Herein,a strategy of“pincer movement”based on simultaneous GSH depletion and GST inhibition is proposed to enhance cisplatin-based chemotherapy.Specifically,a redox-responsive nanomedicine based on disulfide-bridged degradable organosilica hybrid nanoparticles is developed and loaded with cisplatin and ethacrynic acid(EA),a GST inhibitor.Responding to high level of intracellular GSH,the hybrid nanoparticles can be gradually degraded due to the break of disulfide bonds,which further promotes drug release.Meanwhile,the disulfide-mediated GSH depletion and EA-induced GST inhibition cooperatively prevent cellular detoxification of cisplatin and reverse drug resistance.Moreover,the nanomedicine is integrated into microneedles for intralesional drug delivery against cisplatin-resistant melanoma.The in vivo results show that the nanomedicine-loaded microneedles can achieve significant GSH depletion,GST inhibition,and consequent tumor growth suppression.Overall,this research provides a promising strategy for the construction of new-type nanomedicines to overcome cisplatin resistance,which extends the biomedical application of organosilica hybrid nanomaterials and enables more efficient chemotherapy against drug-resistant cancers.