Inhibitory effects of polyphyllins I and VII on human cisplatin-resistant NSCLC via p53 upregulation and CIP2A/AKT/mTOR signaling axis inhibition

Cancerous inhibitor of protein phosphatase 2A(CIP2A) is a human oncoprotein that is overexpressed in multiple kinds of cancers including non-small cell lung cancer(NSCLC). CIP2A plays an ’oncogenic nexus’ to participate in the tumorigenesis and chemoresistance in several cancer types. AKT and m TORC1 overactivation are detected in NSCLC and many other cancers. Previous studies found that the CIP2A/AKT/m TOR pathway controls cell growth, apoptosis, autophagy process. Polyphyllin I(PPI) and polyphyllin VII(PPVII) are natural components extracted from Paris polyphylla that display anti-cancer properties. In the present study, we investigated whether PPI and PPVII can be used in the cisplatin(DDP)-resistant human NSCLC cell line A549/DDP. Results demonstrated that PPI and PPVII treatment significantly suppressed A549/DDP cell proliferation, migration, invasion and EMT, induced apoptosis and autophagy. Further examination of the mechanism revealed that the PPI and PPVII significantly upregulated the p53, induced caspase-dependent apoptosis and suppressed the CIP2A/AKT/m TOR pathway. The activation of autophagy was mediated through PPI and PPVII induced inhibition of m TOR. We propose that PPI and PPVII might be developed as candidate drugs for DDP-resistant NSCLC.

Magnetic iron oxide nanoparticles carrying PTEN gene to reverse cisplatin-resistance of A549/CDDP cell lines

To evaluate the feasibility of using magnetic iron oxide nanoparticle as wild PTEN gene carrier for transfection in vitro to reverse cisplatin-resistance of A549/CDDP cells, A549/CDDP cells were transfected with the wild PTEN gene expression plasmid (pGFP-PTEN) by magnetic iron nanoparticle and lipo2000. The transfection efficiency was detected by fluorescence microscope and flow cytometer. The expression levels of PTEN mRNA and protein were detected by reverse transcription polymerase chain reaction (RT-PCR) and immunocytochemistry analysis. The effect of PTEN transfection on cell cycle enhances the sensitivity of A549/CDDP to cisplatin and nanoparticle-mediated transfection has a higher efficiency than that of the liposome-mediated group. The apoptosis level was up-regulated in PTEN transfection group. The magnetic iron oxide nanoparticle could be used as one of the ideal gene carriers for PTEN gene delivery in vitro. PTEN can be an effective target for reversing cisplatin-resistance in lung cancer.

Low-dose fractionated radiation reverses cisplatin resistance in ovarian cancer cells via PI3K/AKT/GSK-3β signaling

Objective To investigate whether low-dose fractionated radiation(LDFRT) could enhance cisplatin sensitivity in drug-resistant human ovarian cancer cells SKOV3/DDP, and to further explore the underlying mechanism.Methods SKOV3/DDP ovarian cancer cells were divided into three groups as follows: control, LDFRT, and conventional-dose radiation groups. Cells from all three groups were treated with different concentrations of cisplatin(0, 1.25, 2.5, 5, 10, and 20 μg/m L) for 48 h. The proliferation inhibition rate was investigated using the cell counting kit 8(CCK8). The rate of apoptosis was determined by flow cytometry(FCM). Protein levels of AKT, P-AKT, GSK-3β, P-GSK-3β, P21, cyclin D1, and P27 were examined by Western blotting. Results As expected, LDFRT significantly reduced the half-maximal inhibitory concentration(IC50) of cisplatin and promoted apoptosis in SKOV3/DDP cells. Moreover, in the LDFRT group, protein levels of P-AKT, P-GSK-3β, and cyclin D1 were markedly decreased, those of P21 and P27 were greatly increased, and total AKT and GSK-3β levels showed no significant difference compared to those in both the control and conventional-dose radiation groups.Conclusion LDFRT sensitizes resistant SKOV3/DDP ovarian cancer cells to cisplatin through inactivation of PI3 K/AKT/GSK-3β signaling.

Mitochondria-targeted nanoparticles overcome chemoresistance via downregulating BACH1/CD47 axis in ovarian carcinoma

The platinum-based chemotherapy is a routine strategy for the treatment of ovarian cancer,while it is prone to chemoresistance in clinical,which hinders the treatment.Therefore,it is urgently needed to elucidate the underlying mechanism of drug resistance and form the appropriate strategy.The sequencing results showed that cisplatin(DDP)resistant ovarian cancer overexpressed BTB and CNC homology 1(BACH1),and up-regulated the“don’t eat me”signal CD47.We identified that hemin,a BACH1 inhibitor,could effectively down-regulate BACH1 and simultaneously inhibit CD47.Moreover,hemin has a synergistic effect with DDP.We designed a pH-responsive nanoparticle(H/D@FA-CaP-NPs)in which folic acid(FA)ensured targeting of ovarian cancer cells,while hemin inhibited BACH1 as well as down-regulated CD47,achieving the promotion of apoptosis of tumor cells and inducing phagocytosis of tumors by macrophages.Moreover,hemin has a synergistic effect with DDP to promote apoptosis of tumor cells.Structurally,hemin and DDP was encapsulated within hydrophobic 1,2-distearoyl-sn-glycero-3-phosphoethanolamine(DSPE)to form a tight core,and hydrophilic polyethylene glycol 2000(PEG2000)and calcium phosphate(CaP)formed the outside shell,and FA was modified on the surface of nanoparticles.In terms of function,(a)FA enhanced the active targeting of nanoparticles to tumors;(b)NPs targeted mitochondria to induce reactive oxygen species(ROS)production;(c)hemin encapsulated in nanoparticles could specifically target BACH1,thereby down regulating CD47;(d)hemin had a synergistic effect with DDP,thus augmenting the chemotherapy.Altogether,mitochondria-targeted nanoparticles H/D@FA-CaP-NPs promoted tumor apoptosis and mobilized phagocytosis to treat tumor,providing a novel scheme for clinical treatment of cisplatin-resistant ovarian carcinoma.

Shenmai injection enhances cisplatin-induced apoptosis through regulation of Mfn2-dependent mitochondrial dynamics in lung adenocarcinoma A549/DDP cells

Aim:Chemoresistance is the biggest obstacle in cancer treatment.Our previous study demonstrated that Shenmai injection(SMI),a Chinese herbal medicine,enhanced the antitumor effect of cisplatin via glucose metabolism reprogramming.This study aimed to further determine whether the SMI sensitizes the non-small cell lung cancer(NSCLC)cells to cisplatin through regulation mitochondrial dynamics.Methods:The Kaplan-Meier Plotter database was used to investigate the relationship between mRNA expression of mitofusin-2(Mfn2)and the survival analysis of NSCLC patients.The protein expression of Mfn2 in a lung adenocarcinoma tissue chip was detected by immunohistochemistry staining.The expression of Mfn2 and ATAD3A were compared between cisplatin-sensitive A549 and cisplatin-resistant A549/DDP cells.Additionally,A549/DDP cells were co-treated with cisplatin and SMI to detect mitochondrial morphology by fluorescent staining,apoptosis-related protein expression with Western blotting,and mitochondrial membrane potential(ΔΨm)with flow cytometry analysis.Results:The mean survival time of the Mfn2^(low) group was significantly lower than that of the Mfn2^(high) group by Kaplan-Meier Plotter database analysis,and the Mfn2 protein expression level was lower in cancer tissues than in adjacent tissues.The combination of SMI and cisplatin induced dynamic changes in A549/DDP cells,with increased mitochondrial fusion followed by upregulation of Mfn2 and downregulation of ATAD3A and reduced mitochondrial mass and ΔΨm.Moreover,SMI significantly enhanced cisplatin-induced A549/DDP apoptosis,upregulated Bax and the active subunit of caspase-3,and downregulated Bcl-2 expression,as shown via Hoechst staining and flow cytometry analysis.Conclusion:Our findings suggest SMI enhances cisplatin-induced apoptosis through regulation of Mfn2-dependent mitochondrial dynamics in cisplatin-resistant lung adenocarcinoma cells.

miRNA-200c对卵巢癌A2780/DDP细胞顺铂耐药性的影响

目的观察微小RNA-200c(miRNA-200c)过表达对卵巢癌A2780顺铂耐药细胞(A2780/DDP)的影响。方法建立A2780/DDP耐药细胞株,未经处理的对数生长期A2780细胞为对照组,将对数生长期A2780/DDP细胞分为空转染组和增强组,增强组使用miRNA-200c前体片段转染A2780/DDP细胞,实时荧光定量PCR检测各组细胞miRNA-200c表达水平,四甲基偶氮唑蓝法检测各组细胞对DDP药物敏感性,克隆形成实验检测各组细胞增殖能力,流式细胞术检测细胞凋亡变化,实时荧光定量PCR检测MDR1 mRNA表达水平,Western blot检测P-gp蛋白的表达。结果与对照组、空转染组比较,增强组miRNA-200c相对表达量增高为(4.65±1.23)、IC50明显降低为(11.20±1.62)μg/ml、克隆集落的数量较少、细胞凋亡率明显增高为(21.1±2.1)%、MDR1 mRNA相对表达量减少为(0.61±0.12)、P-gp蛋白相对表达量减少为(0.52±0.21),差异均有统计学意义(P<0.05)。结论 miRNA-200c可能通过抑制细胞增殖、诱导凋亡、降低MDR1 mRNA及P-gp蛋白的表达水平降低A2780/DDP细胞对DDP的耐药性。