ABSTRACT
@#Objective To investigate the effects of long non-coding RNA(LncRNA) growth arrest specific transcript 5(GAS5) negatively regulating nucleophosmin 1(NPM1) on cisplatin(DDP) resistance of gastric cancer cells.Methods The normal human gastric mucosa cell line GES-1 and human gastric cancer cell lines BG3-823,MGC-803 and AGS were selected as the research objects,of which the level of LncRNA GAS5 in each cell was measured by qRT-PCR.The drug resistance of AGS cells to DDP(AGS/DDP) was induced,and the experiment was divided into control group,empty plasmid group(BC group),GAS5 nonsense interference group(pLJM-GAS5 NC group) and GAS5 overexpression group(pLJM-GAS5 group).MTT method was used to determine the effect of DDP on the proliferation of AGS and AGS/DDP cells;and the levels of NPM1,multidrug resistance 1(MDR1),excision repair cross complementation group 1(ERCC1),multidrug resistance-associated protein 1(MRP1) and N-cadherin in AGS and AGS/DDP cells were measured by Western blot.Results Compared with the normal gastric mucosa GES-1 cells,the level of LncRNA GAS5 in BG3-823 and AGS cells decreased significantly,and among them,the level of LncRNA GAS5 in AGS cells was the lowest,so AGS cells were used for the follow-up experiments.Compared with the control group,the level of LncRNA GAS5 in AGS cells of BC group and pLJM-GAS5 NC group decreased significantly,while the levels of NPM1,MDRl,ERCC1,MRP1 and N-cadherin increased significantly;compared with BC group and pLJM-GAS5 NC group,the level of LncRNA GAS5 in AGS/DDP cells of pLJM-GAS5 group increased significantly,while the levels of NPM1,MDR1,ERCC1,MRP1 and N-cadherin decreased significantly;after treatment with DDP of the same concentration(except 0 μmol/L),compared with the control group,the inhibition rate of AGS/DDP cell proliferation in BC group and pLJM-GAS5 NC group decreased significantly;compared with BC group and pLJM-GAS5 NC group,the inhibition rate of AGS/DDP cell proliferation in pLJM-GAS5group was significantly higher.The semi inhibitory concentration(IC_(50)) of DDP on AGS/DDP cells in pLJM-GAS5 group for 48 h was(65.38±5.04) μmol/L,which was significantly lower than(120.74±4.17) μmol/L and(120.24±4.29) μmol/L in BC group and pLJM-GAS5 NC group.Conclusion Up-regulating the level of LncRNA GAS5 in AGS/DDP cells can reverse the drug resistance of AGS/DDP cells,which may be related to the down-regulation of NPM1expression
ABSTRACT
ObjectiveTo observe the effect of Feiyanning prescription （FYN） on cisplatin （DDP） resistance in non-small cell lung cancer （NSCLC） and explore the underlying mechanism. MethodCell counting kit-8 （CCK-8） assay was used to detect the proliferation of A549 and A549/DDP （DDP-resistant） cells treated by DDP （0， 2.0， 4.0， 6.0， 8.0， 10.0 mg⋅L-1） and the proliferation of A549/DDP cells treated by FYN （0， 100， 200， 300， 400， 500， 600 mg⋅L-1）. Based on immunofluorescence staining and Western blot （WB）， the expression of epithelial mesenchymal transition （EMT）-related proteins in A549 and A549/DDP groups was observed. A549/DDP cells were classified into control group， FYN group （200 mg⋅L-1）， DDP group （6.0 mg⋅L-1）， and combination group ［FYN （200 mg⋅L-1） + DDP （6.0 mg⋅L-1）］ and respectively treated with corresponding drugs. Then， invasion ability of each group was examined by transwell assay， and the expression of EMT-related proteins in each group by WB. Moreover， real-time fluorescence quantitative polymerase chain reaction（Real-time PCR） and immunofluorescence staining were separately applied to detect the mRNA and protein expression of drug resistance-related factors in each group， respectively. ResultCompared with A549 group， A549/DDP group showed high resistance to DDP （P<0.01）， low expression of E-cadherin， and high protein expression of Vimentin， N-cadherin， and Snail （P<0.05， P<0.01）. As compared with the control group， FYN inhibited the proliferation of A549/DDP cells in a concentration-dependent manner （P<0.01）， and the FYN group， DDP group， and combination group demonstrated low invasion ability （P<0.01）. In addition， the invasion ability in the combination group was particularly lower than that in the DDP group （P<0.01）. The expression of E-cadherin protein was higher and the protein expression of N-cadherin， Vimentin， and Snail was lower in the in FYN group than in the control group （P<0.01）. The protein expression of E-cadherin， N-cadherin， and Vimentin was lower and the expression of Snail was higher in the DDP group than in the control group （P<0.05，P<0.01）. The protein expression of E-cadherin， N-cadherin， Vimentin， and Snail in the combination group decreased as compared with that in the control group （P<0.01）. Compared with the DDP alone， the combination raised the expression of E-cadherin and lowered the protein expression of N-cadherin， Vimentin， and Snail （P<0.01）. The protein and mRNA expression of lung resistance-related protein （LRP） and multidrug resistance 1 （MDR1） was lower and the protein and mRNA expression of topoisomerase Ⅱα （TOPO Ⅱα） was higher in the FYN group than in the control group （P<0.01）. The protein and mRNA expression of LRP， MDR1， and TOPO Ⅱα was higher in the DDP group than in the control group （P<0.01）. The expression of LRP protein and mRNA showed no significant variation， but the protein and mRNA expression of MDR1 and TOPO Ⅱα increased in the combination group compared with those in the control group （P<0.01）. Compared with the DDP group， FYN group and combination group showed low protein and mRNA expression of LRP and MDR1 and high protein and mRNA expression of TOPO Ⅱα （P<0.01）. Compared with FYN， the combination elevated the protein and mRNA expression of LRP， MDR1， and TOPO Ⅱα （P<0.01）. ConclusionFYN prescription can reverse the DDP resistance of NSCLC by modulating EMT.
ABSTRACT
Aim To explore the mechanism of timosaponin A III increasing cisplatin sensitization of non-small cell lung cancer cisplatin-resistant A549/DDP cells. Methods The cell proliferation was detected by CCK8,the cell apoptosis was detected by Annexin V/ PI,and the cell cycle distribution was measured by PI. The effect of the combined drug on cell proliferation was detected by cell clone formation. The mRNA expression levels of C-myc, cysteinyl aspartate-specific protease-3 (caspase-3) were detected by reverse transcription polymerase chain reaction (RT-PCR). Western blot and Flow Cytometry were performed for the mechanism study. Results The results of CCK8 and clone formation showed that the timosaponin AM group significantly increased the sensitivity of cisplatin to A549/DDP cells. Compared with the cisplatin group a-lone,the combination of timosaponin AM and cisplatin significantly elevated the apoptosis rate of A549/DDP cells (P < 0.05) , induced cell cycle arrest in G
ABSTRACT
A series of chemotherapeutic drugs that induce DNA damage, such as cisplatin (DDP), are standard clinical treatments for ovarian cancer, testicular cancer, and other diseases that lack effective targeted drug therapy. Drug resistance is one of the main factors limiting their application. Sensitizers can overcome the drug resistance of tumor cells, thereby enhancing the antitumor activity of chemotherapeutic drugs. In this study, we aimed to identify marketable drugs that could be potential chemotherapy sensitizers and explore the underlying mechanisms. We found that the alcohol withdrawal drug disulfiram (DSF) could significantly enhance the antitumor activity of DDP. JC-1 staining, propidium iodide (PI) staining, and western blotting confirmed that the combination of DSF and DDP could enhance the apoptosis of tumor cells. Subsequent RNA sequencing combined with Gene Set Enrichment Analysis (GSEA) pathway enrichment analysis and cell biology studies such as immunofluorescence suggested an underlying mechanism: DSF makes cells more vulnerable to DNA damage by inhibiting the Fanconi anemia (FA) repair pathway, exerting a sensitizing effect to DNA damaging agents including platinum chemotherapy drugs. Thus, our study illustrated the potential mechanism of action of DSF in enhancing the antitumor effect of DDP. This might provide an effective and safe solution for combating DDP resistance in clinical treatment.
Subject(s)
Female , Male , Humans , Cisplatin/pharmacology , Disulfiram/pharmacology , Testicular Neoplasms/drug therapy , Fanconi Anemia/drug therapy , Alcoholism/drug therapy , Drug Resistance, Neoplasm , Cell Line, Tumor , Substance Withdrawal Syndrome/drug therapy , Apoptosis , Antineoplastic Agents/therapeutic use , Cell ProliferationABSTRACT
Objective:To investigate the role of Caspase-1/gasdermin D (GSDMD) -mediated cell pyroptosis in anti-tumor effect of cisplatin (DDP) in triple-negative breast cancer (TNBC) .Methods:HE staining and immunohistochemical staining were performed to detect the morphological changes and the expression of pyroptosis/apoptosis pathway related proteins in TNBC tissues before and after DDP-based neoadjuvant chemotherapy (NACT) . The TNBC cell line MDA-MB-231 was treated with DDP and the morphological changes were observed. The type of cell death induced by DDP was analyzed by Annexin V-FITC/PI double staining and flow cytometry. Lactate dehydrogenase (LDH) release assay and ELISA were performed to detect the release of LDH and inflammatory factors (IL-18 and IL-1β) in cell culture supernatant after DDP treatment. Western blot (WB) was performed to detect the expression of pyroptosis/apoptosis pathway related proteins in cells after DDP treatment. MDA-MB-231 cells treated with DDP were co-treated with caspase-1 specific inhibitor to inhibit pyroptois or co-treated with caspase-3 specific inhibitor to inhibit apoptosis. The effect of caspase-1 inhibitor or caspase-3 inhibitor on the anti-tumor effect of DDP was detected by MTT assay, clone formation assay, transwell assay and would healing test.Results:Reactive changes in the breast surgical specimen after DDP-based NACT included cell swelling and inflammatory cell aggregation around the tumor bed, which were more similar to pyroptosis. The up-regulation of key molecules of pyroptosis pathway post-NACT was significantly higher than that of key molecules of apoptosis pathway. Further experiments in vitro showed that DDP could induce MDA-MB-231 cells to show pyroptosis-like changes characterized by large bubbles blowing from the cellular membrane. Flow-cytometry analyses showed that the death type of MDA-MB-231 cells caused by DDP was mainly Annexin V +PI + cells (mainly lytic cells, such as pyroptosis) . Additionally, DDP treatment induced significant activation of caspase-1 and GSDMD, increased the release of LDH, IL-18 and IL-1β, however, the activation level of caspase-3, which dominates the apoptosis pathway, was significantly lower than that of caspase-1/GSDMD. Moreover, caspase-1 inhibitors (blocking the classical pyroptosis pathway) had a significantly greater inhibitory effect on the anti-tumor effect of DDP than caspase-3 inhibitors (blocking the apoptosis pathway) . Conclusion:Caspase-1/GSDMD mediated pyroptosis may play a leading role in the anti-tumor effect of DDP in triple-negative breast cancer.
ABSTRACT
AIM: To investigate the mechanism of acquired resistance remodeling to DDP (named cisplatin) by comparing the level of autophagy between the parental and DDP-resistant cells. METHODS: Human lung adenocarcinoma A549 (parental cells) and A549/DDP cells (DDP-resistant cells) were treated with different concentrations of DDP, the drug resistance index (RI) was determined by CCK-8 assay and the autophagy associated proteins, like Beclin 1, LC3Ⅱ and p62 were measured by Western blot. A549 and A549/DDP cells were treated with 10 μmol/L DDP (about IC50 of A549 cells), the cell viability was determined by CCK-8 assay, the autophagy and apoptosis associated proteins (including Beclin 1, LC3Ⅱ, p62, Bcl-2, Bax and cleaved-caspase 3) were measured by Western blot, and the activity of transcription factor FOXO3a and its subcellular localization were detected by Western blot and laser confocal scanning microscopy. Finally, the autophagy inhibitor Baflomycin A1 (Baf A1) and the protein kinase inhibitor of PI3K/Akt signaling pathway were co-treated with DDP respectively to test the mechanism of drug resistance. RESULTS: Compared with the parental A549 cells, the acquired resistant A549/DDP cells showed DDP-resistance and higher level of basal autophagy. More survival count of A549/DDP cells than that of A549 cells in the same environment stress of 10 μmol/L DDP. 10 μmol/L DDP induced A549 cells apoptosis by down-regulated Bcl-2, and increased Bax and cleaved-caspase 3, which followed the inhibition of PI3K/Akt signaling pathway and up-regulated the expression level of transcription factor FOXO3a. While the same concentration of DDP activated A549/DDP cells autophagy by up-regulated Beclin 1 and LC3Ⅱ, down-regulated p62, which followed the inhibition of PI3K/Akt signaling pathway and inhibited the phosphorylation of FOXO3a. CONCLUSION: DDP induces apoptosis by up-regulating the transcription factor FOXO3a via inhibiting the PI3K/Akt/FOXO3a signaling pathway in A549 cells, while activating autophagy by inducing the phosphorylation of FOXO3a via inhibiting the PI3K/Akt/FOXO3a signaling pathway in A549/DDP cells.
ABSTRACT
Aim To investigate the improved effects of Z-guggulsterone on the chemotherapy agents-induced proliferation and apoptosis through regulating PXR(pregnane X receptor)/P-gp(P-glycoprotein)signaling pathway in human hepatocellular carcinoma cells.Methods HepG2 cells were treated with Z-guggulsterone, DDP(cis-platinum)and 5-FU(5-fluorouracil)alone or in combination.CCK-8(Cell Counting Kit-8), Annexin-FITC/PI(Annexin V-fluorescein isothiocyanate isomer/propidium iodide)flow cytometry, RT-qPCR(Real-time quantitively Polymerase Chain Reaction)and Western blot were used to determine cell proliferation, apoptosis, the expression of MDR1 mRNA, PXR and P-gp respectively.Results Compared to DDP or 5-FU treatment alone, Z-guggulsterone(30 μmol·L-1)enhanced the inhibitory effects of DDP or 5-FU on the proliferation and apoptosis of HepG2 cells.Z-guggulsterone(30 μmol·L-1)also significantly reduced the expression levels of PXR,P-gp and MDR1 mRNA in HepG2 cells.Further research demonstrated that rifampicin, one agonist of PXR, increased the expression of PXR and P-gp, while Z-guggulsterone reversed its effects.Meanwhile, the expressions of PXR and P-gp were reduced by ketoconazole, one antagonist of PXR, and further decreased by co-administration with Z-guggulsterone.Conclusion Z-guggulsterone can improve the effects of chemotherapy on the proliferation and apoptosis of hepatocellular carcinoma cell lines by down-regulating the PXR/P-gp signaling pathway.
ABSTRACT
Because the early symptoms of ovarian cancer are not typical and there is a lack of effective screening methods， most patients are diagnosed at an advanced stage， which seriously endangers the health of modern women. Platinum-based chemotherapy after tumor reduction is the first choice for patients with advanced and recurrent ovarian cancer， but almost all patients with recurrent ovarian cancer will eventually develop platinum resistance. Therefore， the search for natural， safe， and effective chemotherapeutic sensitizers has become an urgent and important topic in the study of ovarian cancer. With the increasingly extensive application of traditional Chinese medicine （TCM） in the treatment of cancer， the research on Chinese herbal monomers is also deepening， and the mechanisms of Chinese herbal monomers in intervening in cisplatin （DDP）-induced resistance of ovarian cancer is becoming increasingly clearer. Based on the research status of Chinese herbal monomers available in many Chinese and English databases， it was found that Chinese herbal monomers were involved in the reversal of DDP-induced resistance of ovarian cancer via many routes， mainly through increasing the intracellular drug concentration， reversing the blocked apoptosis， correcting the abnormal intracellular signaling pathway， enhancing DNA damage and inhibiting DNA repair， regulating intracellular autophagy， and suppressing epithelial mesenchymal transition （EMT）. Chinese herbal monomers weaken the resistance of ovarian cancer to DDP from multiple targets and enhance the toxicity of DDP to ovarian cancer cells in vitro and transplanted tumors in vivo. Therefore， Chinese herbal monomers are expected to become natural sensitizers for ovarian cancer chemotherapy with DDP. However， the current studies on Chinese herbal monomers are still confined to the single experimental type， and their action mechanisms and toxic and side effects remain to be further clarified. The application of Chinese herbal monomers for sensitizing DDP chemotherapy still needs to be verified by multi-target， multi-level experimental studies and large-scale clinical studies in the future.
ABSTRACT
OBJECTIVE：To study the reversal effect of quercetin on human cervical squamous carcinoma cisplatin-resistant cell line SiHa/DDP. METHODS ：The drug resistance index of cisplatin to SiHa/DDP cells ，and the reversal resistance multiple of quercetin to SiHa/DDP cells were determined. The effects of quercetin （0.005 μg/mL），cisplatin（2.5 μg/mL），cisplatin combined with quercetin （2.5 μg/mL cisplatin+0.005 μg/mL quercetin），quercetin combined with pathway inhibitor（0.005 μg/mL quercetin+ 20 nmol/L rapamycin ）on the apoptotic rate of SiHa/DDP cells were investigated ，as well as its effects on the expression of phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian rapamycin target protein （mTOR） signaling pathway related proteins （PI3K，Akt，mTOR，P-gp，p70S6K）. RESULTS ：The resistance index of cisplatin to SiHa/DDP cells was 5.19， and reversal resistance multiple of quercetin to SiHa/DDP cells was 4.00. Compared with cisplatin alone and quercetin alone ， cisplatin combined with quercetin ，quercetin combined with rapamycin could significantly increase the apoptotic rate of SiHa/DDP cells（P＜0.05），while decreased the phosphorylation of Akt ，mTOR and p 70S6K protein as well as the expression of P-gp protein （P＜0.05）. CONCLUSIONS ：Quercetin can effectively reverse drug resistance of SiHa/DDP cells to cisplatin ，which may be associated with inhibiting the expression of the protein related to PI 3K/Akt/mTOR signaling pathway.
ABSTRACT
Objective:To investigate the effect and mechanism of saikosaponin A （SSA） on the reversal of cisplatin （DDP） resistance in human lung cancer cell line A549/DDP. Methods:The resistance of A549 and A549/DDP cells to DDP and the inhibitory effects of SSA against the proliferation of A549 and A549/DDP cells were detected using cell counting kit-8 （CCK-8）. The apoptosis rates of A549/DDP cells treated with SSA or DDP or SSA combined with DDP and the changes in reactive oxygen species （ROS） were determined by flow cytometry. The mRNA expression levels of C-myc， B-cell lymphoma 2 （Bcl-2） and cysteinyl aspartate-specific protease-3 （Caspase-3） were detected by real-time polymerase chain reaction （Real-time PCR）， followed by the determination of <italic>β</italic>-catenin transcriptional activity using the TopFish dual-luciferase reporter assay system and the measurement of <italic>β</italic>-catenin protein expression in A549/DDP cells by Western blot. Results:The results of CCK-8 assay showed that the DDP resistance of A549/DDP cells was 12.82 times that of A549 cells （<italic>P</italic><0.05）. SSA inhibited the viability of A549 cells with the half maximal inhibitory concentration （IC<sub>50</sub>） being 34.9 μmol·L<sup>-1</sup>， and also suppressed the viability of A549/DDP cells in a concentration-dependent manner. Since the inhibition rate of 20 μmol/L SSA against A549/DDP cells was less than 10%， the reversal concentration was set at 20 μmol/L. Flow cytometry revealed that compared with the control， DDP alone increased the apoptosis rate of A549/DDP cells （<italic>P</italic><0.05）， stimulated the accumulation of intracellular ROS （<italic>P</italic><0.05）， down-regulated the mRNA expression levels of C-myc and Bcl-2 in A549/DDP cells， up-regulated Caspase-3 mRNA expression， and reduced the transcriptional activity of <italic>β</italic>-catenin （<italic>P</italic><0.05）. Compared with the DDP group， the SSA+DDP group exhibited obviously increased apoptosis of A549/DDP cells， enhanced accumulation of intracellular ROS， down-regulated C-myc and Bcl-2 mRNA expression， up-regulated Caspase-3 mRNA expression （<italic>P</italic><0.05）， and weakened <italic>β</italic>-catenin transcription （<italic>P</italic><0.05）. DDP combined with SSA better decreased the <italic>β</italic>-catenin protein expression in contrast to that of control or DDP （<italic>P</italic><0.05）. Conclusions:SSA enhances the sensitivity of A549/DDP cells to DDP possibly by inhibiting the activation of Wnt/<italic>β</italic>-catenin pathway.
ABSTRACT
Objective To investigate the role and regulatory mechanism of lncRNAs PCAT-1 in the sensitivity of cervical cancer cells to DDP. Methods The expressions of PCAT-1 in human cervical cancer cell lines (HeLa and SiHa) and DDP-resistant cell lines (HeLa/DDP and SiHa/DDP) were analyzed by real-time PCR. After PCAT-1 silencing and overexpression in HeLa/DDP and SiHa/DDP cells, CCK-8 and flow cytometry were used to detect cell viability ability and cell cycle, respectively. Western blot was used to detect the protein expression of STAT3 and PTEN. Results The DDP resistance index of HeLa/DDP cells to HeLa cells was 4.49, while that of SiHa/DDP cells to SiHa cells was 6.87. The expression levels of PCAT-1 in HeLa/DDP and SiHa/DDP cells were significantly higher than those in HeLa and SiHa cells, respectively (P < 0.05). The overexpression of PCAT-1 reduced the sensitivity of HeLa/DDP and SiHa/DDP cells to DDP, enhanced the proportion of S phase in cell cycle, and decreased the proportion of G0-G1 and G2-M phases (P < 0.05). The silencing of PCAT-1 increased the sensitivity of HeLa/DDP and SiHa/DDP cells to DDP, decreased the proportion of S phase in the cell cycle, and enhanced the proportion of G0-G1 and G2-M phase (P < 0.05). Overexpression of PCAT-1 promoted STAT3 protein expression but inhibited PTEN protein expression in HeLa/DDP and SiHa/DDP cells (P < 0.05). The silencing of PCAT-1 inhibited STAT3 protein expression but promoted PTEN protein expression in HeLa/DDP and SiHa/DDP cells (P < 0.05). Conclusion PCAT-1 is upregulated in HeLa/DDP and SiHa/DDP cells. PCAT-1 reduces the sensitivity of HeLa/DDP and SiHa/DDP cells to DDP by upregulating the expression of STAT3 and downregulating the expression of PTEN.
ABSTRACT
Objective To observe the expression difference of lncRNA FAL1 in ovarian cancer cells and their drug-resistant cell lines, and to explore the effect and mechanism of lncRNA FAL1 down-regulation on cell chemotherapy resistance. Methods The expression levels of fal1 gene in SKOV3 and COC1 cells and their drug-resistant cell lines were detected by qRT-PCR. fal1 siRNA was transfected to downregulate fal1 gene expression. MTT was used to detect cell proliferation. Transwell method was used to detect cell invasion ability. Plate clone formation test was used to detect cell clone ability, and Western blot was used to detect MDR-1, mpr-1, ABCG2 and phosphorylation levels of p38 MAPK, ERK1/2 and JNK. SKOV3/DDP and COC1/DDP cells transfected with FAL1-siRNA were injected subcutaneously into BALB/c nude mice. The volume and mass of subcutaneous transplanted tumors were measured. Results Compared with SKOV3 and COC1 cells, SKOV3/DDP and COC1/DDP cells were less sensitive to DDP, and the expression levels of FAL1 gene increased (P < 0.01). After transfection with FAL1-siRNA, the sensitivity of SKOV3/DDP and COC1/DDP cells to DDP increased (P < 0.01), and the invasion (P < 0.05) and cloning ability (P < 0.01) decreased. The expression levels of MDR-1, MPR-1, ABCG2 (P < 0.01) and the phosphorylation levels of p38 MAPK, ERK1/2 and JNK (P < 0.05) decreased. The volume and mass of subcutaneous transplanted tumors were significantly reduced (P < 0.01). Conclusion Down-regulation of lncRNA FAL1 could significantly reduce the chemotherapy resistance of cisplatin-resistant ovarian cancer cell lines and inhibit the proliferation of drug-resistant cells in vivo. Its mechanism is related to inhibiting the activation of MAPK signaling pathway.
ABSTRACT
Objective To study the enhancement of sensitivity to cisplatin (DDP) mediated by the addition of proteasome inhibitor Oprozomib (OZ) in ovarian cancer cells. Methods SKOV3/DDP and A2780/DDP cells were cultured in vitro, and the logarithmic growth phase cells were used in this study. To study the effect of OZ on drug-resistant cell viability, a series dilutions of OZ (0, 3, 9, 27, 81, 243, 729, 2181, and 6561 nmol/L) was used. The effect of DDP was also investigated with a series titrations (0, 3, 9, 27, 81, 243, 729, 2181 and 6561 nmol/L) in the presence of 50 μl of 500 nmol/L OZ. CCK-8 method was used to detect cell viability; flow cytometry was used to detect the apoptosis rate after treated with DDP+OZ. The experiments were divided into the control group and OZ group to detect the effects of OZ on the activity of proteasome chymotrypsin (CT-L), the synthesis of intracellular glutathione (GSH); the expression of intracellular glutathione synthetase (GSS) was examined using western blotting. The experiments were divided into the control group, DDP group, OZ group, DDP+OZ group, DDP+OZ+GSH group and DDP+OZ+Tempol group to detect the ROS level and apoptosis rate. Results The IC50 of OZ to SKOV3/DDP and A2780/ DDP cells were 140 and 350 nmol/L, respectively; In the presence of OZ, the IC50 of DDP to SKOV3/DDP and A2780/DDP cells were 154 and 232 nmol/L, respectively. The apoptosis rate of ovarian cancer cells increased significantly (P<0.01) after treated with DDP+OZ together. OZ can inhibit the CT-L activity of the proteasome in a dose-dependent manner and can inhibit GSH synthesis and GSS protein expression (P<0.01). The decrease of GSH level leads to the obstruction of ROS clearance, and the ROS level was significantly reduced by the ROS scavenger Tempol (P<0.05, P<0.01). Tempol significantly inhibits the apoptosis induced by DDP+OZ (P<0.01). Conclusion OZ enhanced sensitivity of SKOV3/DDP and A2780/DDP to cis-platinum by inhibiting the generation of GHS which resulted in the accumulation of ROS.
ABSTRACT
@#Objective: To study the effects of vitamin C (VC) on reversing cisplatin (DDP) resistance in oral squamous cell carcinoma (OSCC) and the mechanism. Methods: Human OSCC CAL27 cells were cultured in vitro and DDP-resistant CAL27 cell line (CAL27/ DDP) was screened by increasing concentration gradient method. Plate clone formation assay, CCK-8, Wound healing assay, Annexin V-FITC/PI staining flow cytometry were used to determine the effects of DDP alone or in combination with VC on colony formation, proliferation, migration and apoptosis of CAL27/DDP cells. Western blotting was used to detect the expression level of P-gp protein in CAL27 cells, CAL27/DDP cells and VC treated CAL27/DDP cells. Results: The inhibition concentration (IC50) of DDP increased significantly in CAL27/DDP cells as compared with that in CAL27 cells (P<0.05), indicating CAL27/DDP was DDP-resistant.After the combination with VC, the IC50 of DDP on CAL27/DDP cells was significantly reduced compared with that of DDP alone (P<0.05). DDP combined with VC significantly inhibited the migration of CAL27/DDP cells (P<0.01), and promoted the apoptosis rate (P<0.01). The expression level of P-gp protein in CAL27/DDP cells was increased compared with that in CAL27 cells (P<0.05), but decreased after VC intervention (P<0.05). Conclusion: VC can reverse DDP-resistance in OSCC cells by inhibiting P-gp protein expression.
ABSTRACT
@#[Abstract] Objective: To investigate the effect of apatinib (APA) combined with cisplatin (DDP) on the proliferation, invasion and migration capacity of gastric carcinoma (GC) cells and its molecular mechanism. Methods: Cancer and para-cancerous tissue samples resected from 50 GC patients, who were surgically treated in Wuwei People's Hospital from January 2016 to June 2019, were collected for this study; in addition, GC cell lines MGC803 and SGC7901 were also collected. qPCR was used to detect the HMGA2 expression in tissues and mRNA expressions of molecules related to cell proliferation, migration and invasion in GC cell lines. MGC803 and SGC7901 cells were transfected with pcHMGA2 by liposome transfection technology. After treatment with DDP and APA at different concentrations, the cells were divided into NC, pcHMGA2, pcHMGA2+DDP and pcHMGA2+DDP+APA groups. Protein expression of HMGA2 in GC cells was detected by Western blotting, and proliferation, migration and invasion of the cells were detected by MTT and Transwell assay, respectively. Results: The mRNA expression of HMGA2 in GC tissues was higher than that in para-cancerous tissues (P<0.05), and the survival rate of GC patients in the high expression group was significantly reduced (P<0.01). DDP significantly inhibited the proliferation, invasion and migration of MGC803 and SGC7901 cells (all P<0.01); the proliferation, invasion and migration of MGC803 and SGC7901 cells in DDP+APA group significantly decreased (all P<0.01) as compared with DDP group; APA significantly enhanced the inhibitory effect of DDP on HMGA2 expression in GC cells (P<0.01); APA enhanced the anticancer activity of DDP against GC by down-regulating HMGA2 expression. Conclusion: APA promotes the anticancer activity of DDP against GC, and its molecular mechanism is the promotion of the inhibitory effect of DDP on HMGA2 expression.
ABSTRACT
BACKGROUND: Cisplatin resistance (DDP-resistance) remains one of the major causes of poor prognosis in females with ovarian cancer. Long non-coding RNAs (lncRNAs) have been shown to participate in the regulation of cellular processes, including chemoresistance. The aim of this study was to explore the role of HOX transcript antisense RNA (HOTAIR) in DDP-resistant ovarian cancer cells. METHODS: DDP-resistant ovarian cancer cell lines (SKOV3/DDP and A2780/DDP) were established. Real-time PCR, western blot, dual-luciferase reporter assay, and flow cytometry were then used to evaluate the effect of HOTAIR/miR-138-5p axis on chemoresistance of DDP-resistant ovarian cancer cells to DDP. RESULTS: We found that HOTAIR was upregulated in DDP-resistant cells, while miR-138-5p was downregulated. Knockdown of HOTAIR increased the expression of miR-138-5p in DDP-resistant cells and miR-138-5p is directly bound to HOTAIR. Upregulation of miR-138-5p induced by HOTAIR siRNA or by its mimics enhanced the chemosensitivity of DDP-resistant cells and decreased the expression of EZH2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) and SIRT1 (sirtuin 1). Furthermore, the HOTAIR silencing-induced chemosensitivity of DDP-resistant cells was weakened by miR-138-5p inhibitor. CONCLUSIONS: These data demonstrate that HOTAIR acts as a sponge of miR-138-5p to prevent its binding to EZH2 and SIRT1, thereby promoting DDP-resistance of ovarian cancer cells. Our work will shed light on the development of therapeutic strategies for ovarian cancer treatment.
Subject(s)
Humans , Female , Ovarian Neoplasms/genetics , Cisplatin/pharmacology , Drug Resistance, Neoplasm/genetics , RNA, Long Noncoding/genetics , Gene Expression Regulation, Neoplastic/drug effects , Up-Regulation , Apoptosis/drug effects , MicroRNAs/antagonists & inhibitors , Cell Line, Tumor , Gene Knockout Techniques/methods , Sirtuin 1/antagonists & inhibitors , Real-Time Polymerase Chain Reaction , Enhancer of Zeste Homolog 2 Protein/antagonists & inhibitorsABSTRACT
In previous studies, we found interferon-a (IFN-a) could reduce protein levels of p11, 5-hydroxytryptamine receptor 1b(5-HT1b) and 5-hydroxytryptamine receptor 4 (5-HT4), but does not influence their messenger RNA levels in SH-sy5ycells. Thus, we investigated the post-transcriptional modulation of these molecules by IFN-a. SH-sy5y cells were treatedwith IFN-a, NH4Cl or MG132 alone or in combination, and then the protein levels of p11, 5-HT1b and 5-HT4 wereanalyzed by western blots. The regulatory effects of p11 on 5-HT1b and 5-HT4 were also determined in p11 knock-downcells. NH4Cl but not MG132 could reverse the protein level of p11 in IFN-a-treated SH-sy5y cells. MG132 could recoverthe protein levels of 5-HT1b and 5-HT4 in p11 knock-down cells. The down-regulation effects of IFN-a on p11, 5-HT1band 5-HT4 were associated with the lysosome and ubiquitin–proteasome-mediated pathways. p11 was identified as a potentregulator to modulate the ubiquitination of 5-HT1b and 5-HT4. Therefore, it could be potential target therapies in IFN-ainduced depression.
ABSTRACT
Aim To investigate the effects of cryptotanshinone on cell viability Aim To investigate the effects of cryptotanshinone on cell viability and ferroptosis-related gene expression in A549 and A549/DDP cells, and to explore its possible mechanisms. Methods A549 and A549/DDP cells were treated with different concentrations of CTS. Cell viability was measured by CCK-8 assay. The mRNA levels of TFR1, DMT1, IREB2, HSPB1, VDAC2, VDAC3 and GPX4 were measured by qPCR, and the protein levels of TFR1 were measured by Western blot. Results The cell viability was down-regulated by CTS in A549 and A549/DDP cells, while the cisplatin-resistant A549/DDP cells were more susceptible to CTS. After CTS treatment, the mRNA levels of ferroptosis-related genes showed different degrees of change. The mRNA levels of HSPB1 and GPX4 increased in A 5 4 9 cells , of which the mRNA levels of IREB2, VDAC2 and VDAC3 were reduced and the mRNA levels of TFR1 and DMT1 exhibited no significant change. The mRNA levels of TFR1 and IREB2 increased in A549/DDP cells, while the mRNA levels of VDAC3 decreased, and the expression levels of DMT1, HSPB1, VDAC2 and GPX4 did not changesignificantly. Conclusions Cryptotanshinone may inhibit the proliferation of lung cancer A549 and A549/DDP cells, and affect the expression of ferroptosis-re-lated genes.
ABSTRACT
@#Objective: To study the regulatory effects and possible mechanism of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) on chemotherapy sensitivity to cisplatin (DDP) of colorectal cancer (CRC)．Methods: A total of 112 pairs of matched cancer and adjacent non-cancerous tissues were obtained from the CRC patients who underwent surgical resection in the First Affiliated Hospital of Xinxiang Medical University betweenApril 2006 and March 2011.All specimens were confirmed by pathological examinations. Tumor tissues and corresponding adjacent non-cancerous tissues from 30 cisplatin-sensitive CRC patients and 30 cisplatin-resistant patients were selected. Human CRC cell lines (HT29, SW480, HCT116, RKO and LoVo) and normal colonic epithelial cell line NCM460 were also collected for this study; and DDP-resistant RKO/DDP and LoVo/DDP cell lines were constructed. siPVT1, siNC, LV-PVT1 and LV-NC were transfected into LoVo and RKO cells or LoVo/DDP and RKO/DDP cells using lipofectamineTM2000. The expression of lncRNA PVT1 in CRC tissues and cells was tested by Real-time qPCR. CCK-8 assay, flow cytometry and WB were performed to test the effect of PTV1 knockout or enforcement on cell proliferation, apoptosis and expressions of apoptosis-related proteins, respectively. The CRC subcutaneous transplanted xenograft model was established on athymic nude mice to study the effect of PVT1 over-expression on tumor growth and DDP resistance. Results: PVT1 was highly expressed in the cancer tissues and CRC cells, and its expression was positively associated with cisplatin resistance of CRC. After knockdown of PVT1, the proliferation of cisplatinresistant CRC cells was significantly suppressed, while the apoptosis was significantly enhanced (P<0.05 or P<0.01); Mechanically, the levels of drug resistance-associated molecules, including MDR1 and MRP1, as well as the expression of anti-apoptotic Bcl-2 were significantly downregulated whereas the levels of pro-apoptotic Bax and cleaved caspase-3 were increased in PVT1-silenced DDP-resistant CRC cells. Over-expression of PVT1 reversely increased proliferation and decreased apoptosis of CRC cells (P<0.05 or P<0.01). In addition, PVT1 over-expression in CRC cells significantly promoted DDP-resistance in vivo (P<0.05). Conclusion: Collectively, knockdown of PVT1 expression can significantly suppress cell proliferation and promote apoptosis of DDP-resistant CRC cells. Overexpression of PVT1 can significantly promote the growth of CRC cells in vitro and transplanted xenograft in vivo. PVT1 regulates endogenous apoptosis pathways and further promotes the sensitivity of CRC cells to cisplatin chemotherapy via inhibiting the expressions of MDR1 and MRP1.
ABSTRACT
OBJECTIVE Despite the status of cisplatin (DDP) as a classical chemotherapeutic agent in the treatment of cancer, the development of multidrug resistance often leads to a failure of DDP therapy.Traditional Chinese medicine(TCM)as adjuvant chemotherapy of cancer drugs in China has been widely used in cancer treatment.ZuoJin WAN (ZJW),a TCM formula,was proved reversing drug resistance in gastric cancer,but its exact mechanism was still unclear. METHODS CCK-8 assay was used to detect the cell viability. The levels of proteins and mRNA were evaluated using Western blot and q-PCR. Mitochondrial membrane potential was measured by fl ow cytometry. Depolymerisa-tion of F-actin and translocation of G-actin(gamma-actin)from the cytoplasm to the mitochondria was detected using an immuno fl uorescence assay. RESULTS phosphorylated coflin-1 (p-coflin-1) was overexpressed in the DDP-resistant human gastric cancer cell lines SGC7901/DDP and BGC823/DDP, relative to the respective parent cell lines(SGC7901 and BGC823),and DDP induced the dephosphory-lation of p-coflin-1 in both parent lines but not in the DDP-resistant lines. However, ZJW could induce the dephosphorylation of pcoflin-1 and promote coflin-1 translocation from the cytoplasm into the mito-chondria in both SGC7901/DDP and BGC823/DDP cells. This mitochondrial translocation of coflin-1 was found to induce the conversion of flamentous actin to globular-actin, activate mitochondrial dam-age and calcium overloading, and induce the mitochondrial apoptosis pathway. These effects of ZJW on DDP-resistant human gastric cancer cell lines could be reversed via transfection with coflin-1-specifc siRNA,or treatment with a PP1 and PP2A inhibitor.CONCLUSION ZJW can be used as an inhibitor of chemoresistance in gastric cancer, which may partly be due to dephosphorylation of p-coflin-1 via the activation of PP1 and PP2A.