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Background: Cyclin-dependent kinase 9 (CDK9) is a promising prognostic marker and therapeutic target in cancers. Bufalin is an effective anti-tumour agent; however, the clinical application of bufalin is limited due to its high toxicity. Acetyl-bufalin, the bufalin prodrug, was designed and synthesised with higher efficiency and lower toxicity.Methods: Three non-small-cell lung cancer (NSCLC) cell lines, a xenograft model and a patient-derived xenograft (PDX) model were used to examine the effects of acetyl-bufalin. CDK9/STAT3 involvement was investigated by knockdown with siRNA, proteome microarray assay, western blot analysis and co-immunoprecipitation experiments. Acute toxicity test and pharmacokinetics (PK) study were conducted to assess the safety and PK. The human NSCLC tissues were analysed to verify high CDK9 expression.Results: We showed that CDK9 induced NSCLC cell proliferation and that this effect was associated with STAT3 activation, specifically an increase in STAT3 phosphorylation and transcription factor activity. Acetyl-bufalin is an effective and safety inhibitor of the CDK9/STAT3 pathway, leading to the impediment of various oncogenic processes in NSCLC. Molecular docking and high-throughput proteomics platform analysis uncovered acetyl-bufalin directly binds to CDK9. Consequently, acetyl-bufalin impaired the complex formation of CDK9 and STAT3, decreased the expressions of P-STAT3, and transcribed target genes such as cyclin B1, CDC2, MCL-1, Survivin, VEGF, BCL2, and it upregulated the expression levels of BAX and caspase-3 activity. Acetyl-bufalin inhibited tumour growth in NSCLC xenograft and PDX models.Conclusions: Acetyl-bufalin is a novel blocker of the CDK9/STAT3 pathway thus may have potential in therapy of NSCLC and other cancers. [ABSTRACT FROM AUTHOR]

Purpose: We sought to investigate the role of PAX2 in renal epithelial-to-mesenchymal transition (EMT), examining the influence of PAX2 on ADAM10 expression during renal EMT and ADAM10 expression in fibrotic kidneys.Methods: A rat renal tubular epithelial cell line, NRK52E, was transfected with lentivirus carrying PAX2, and E-cadherin and α-SMA expressions were measured. The influence of PAX2 on ADAM10 promoter activity was evaluated using chromatin immunoprecipitation (CHIP) and dual-luciferase reporter assay. We also treated NRK52E with ADAM10-specific over-expression vector and inhibitors and measured E-cadherin and α-SMA expression. In vivo, Wistar rats (n = 36) were subjected to unilateral ureteral obstruction (UUO) (n = 18) or sham surgery (n = 18), with tissues from post-operative day 3, 7, and 14 days examined, and PAX2/ADAM10 activity measured. ADAM10 expression was also assessed in kidneys from patients with chronic kidney disease (CKD).Results: In NRK52E overexpressing PAX2, ADAM10 and α-SMA levels were increased, while E-cadherin levels were decreased. CHIP and dual-luciferase reporter assay showed that PAX2 directly bound to a specific site within the ADAM10 promoter, and over-expression of PAX2 significantly activated ADAM10 transcription. NRK52E with ADAM10 over-expression also significantly decreased E-cadherin and increased α-SMA levels. In the fibrotic kidneys of rats with UUO, E-cadherin levels were increased and α-SMA levels were decreased, and expression of PAX2 and ADAM10 increased. ADAM10 expression also elevated in the renal tissues of CKD patients.Conclusions: PAX2 directly increased expression of ADAM10, the presence of which contributed to EMT in renal tubular epithelia and hence plays an important role in renal fibrosis. [ABSTRACT FROM AUTHOR]

A series of amphiphilic N-(2-hydroxy)propyl-3-trimethylammonium-chitosan-cholic acid (HPTA-CHI-CA) polymers were synthesized by grafting cholic acid (CA) and glycidyltrimethylammonium chloride onto chitosan. The self-assembly behavior of HPTA-CHI-CA was studied by fluorescence technique. The polymers were able to self-assemble into NPs in phosphate buffered saline with a critical aggregation concentration (CAC) in the range of 66–26 mg/L and the CAC decreased with the increasing of the degree of substitution (DS) of CA. The size of cationic HPTA-CHI-CA NPs ranges from 170 to 220 nm (PDI < 0.2). It was found that doxorubicin (DOX) could be encapsulated into HPTA-CHI-CA NPs based on self-assembly. The drug loading content and efficiency varies depending on the DS of CA and feeding ratio of DOX to polymer. In vitro release studies suggested that DOX released slowly from HPTA-CHI-CA NPs without any burst initial release. Besides, the confocal microscopic measurements indicated that DOX-HPTA-CHI-CA NPs could easily be uptaken by breast cancer (MCF-7) cells and release DOX in cytoplasm. Anti-tumor efficacy results showed that DOX-HPTA-CHI-CA NPs have a significant activity of inhibition MCF-7 cells growth. These results suggest cationic HPTA-CHI-CA may have great potential for anticancer drug delivery. [ABSTRACT FROM AUTHOR]