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Chinese materia medica can inhibit the proliferation, invasion, migration and expression of drug-resistant proteins of lung cancer stem cells (LCSCs), and induce apoptosis and delay self-renewal, as well as exert anti-tumor effects by interfering with their ecological niche, immune microenvironment and aerobic glycolysis, etc. The biomarkers involved mainly include CD133, CD44, ALDH and ABCG2, while the related signaling pathways are Wnt/β-catenin, Hedgehog, and Notch. The research on the intervention of LCSCs by Traditional Chinese Medicine (TCM) is generally few, mostly concentrated in basic research, and the selected experimental indicators have a high repetition rate, involving fewer cell types and signaling pathways; there is a relative lack of clinical trials, which lack an organic connection with basic experiments. In the future, the quality of research is expected to be improved, and in-depth study of TCM with anti-lung cancer stem cell effect should be carried out, with the purpose to promote the precise treatment of lung cancer.
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Objective To investigate the effect of sulforaphane (SFN) on the proliferation and self-renewal of lung cancer stem cells and its regulatory mechanism. Methods MTT method was used to detect the effect of SFN on the proliferation of lung adenocarcinoma cell lines H460 and A549; tumor sphere formation experiment was used to detect the ability of tumor sphere formation; Western blot was applied to explore the expression of stemness-related proteins (such as β-catenin, Klf4, c-myc) in lung adenocarcinoma cells before and after SFN treatment; NGS sequencing was used to analyze the effect of SFN on the expression profile of tumor cell miRNAs. qRT-PCR verified the changes in the transcription level of key miRNAs by SFN. Western blot was used to detect the effect of SFN on the expression of DNMTs in tumor cells. We constructed miR-200c promoter-GFP plasmid, and applied IF, methylation PCR and DNA sequencing methods to detect the effect of SFN on the methylation level of tumor spheres and miRNA promoter. Results The miRNAs expression profile of lung adenocarcinoma tumor spheres changed significantly after SFN (5.0μmol/L) treatment, and miRNA-200c increased the most. Compared with the control group, the expression of β-catenin, Klf4, c-myc and Vimentin genes in H460 and A549 cells of SFN-S group decreased, and the protein expression levels of DNMT1 and DNMT3a were also significantly decreased. Compared with the control group, H460 and A549 cells stably expressing pEGFP-R200c plasmid in SFN-S group significantly reduced tumor sphere diameter, while tumor sphere fluorescence intensity increased, and GFP protein expression was up-regulated. There were 9 CpG-rich regions in the miR-200c promoter region in the above-mentioned pEGFP-R200c plasmid cell line, and the methylation levels were 88.9%, 44.4% and 38.8% in the control group, SFN-S group and 5-Aza-dC group, respectively. Conclusion SFN may downregulate the expression of stem-related genes in lung cancer stem cells by epigenetically decreasing the methylation level of miR-200c promoter and promoting the transcription of miR-200c.
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Objective: Lung cancer is the leading cause of cancer-related death worldwide with a relatively low 5-year relative survival rate of 16%. Novel and efficient therapeutic approach for lung cancer is desperately needed. Materials and Methods: Targeting cancer stem cells (CSCs) provides a promising strategy to eradicate malignancies. The Notch signaling pathway plays an important role in the control of cell fates and developmental processes including CSCs. The function of Notch1 in the regulation of CSCs and whether targeting Notch1 could be a potential therapy for lung cancer were explored in this study. Lung CSCs (LCSCs) were isolated from A549 cells and identified as CD44+/CD24– cells by magnetic-assisted cell sorting, then the putative LCSCs were treated with Notch1 inhibitor and Notch1 small interfering RNAs (siRNAs); the growth and proliferation of LCSCs were investigated to test the effect of Notch1 blocking on the growth and viability of LCSCs. Results: CD44+/CD24– cells isolated from A549 cells possessed stem cell-like properties with high expression of Notch1. Blocking Notch1 by inhibitor DAPT or siRNA both inhibited the growth capacity of LCSCs. Conclusion: Our discovery demonstrated a depression of growth in CD44+/CD24– and A549 cells caused by blockade of Notch signaling pathway. Further studies are needed to demonstrate the detailed effects of Notch1 blocking on the LCSCs. Nevertheless, targeting the Notch pathway has exhibited great potential to be an improved lung cancer treatment
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To explore the methods of screening and biological characteristics of lung cancer stem cells. We selected the ABCG2 and ABCG2 cells from SPC-A-1/adriamycin(ADM)cell line induced by ADM and analyzed the tumorigenicity of ABCG2 and ABCG2 cells by flow cytometry and transplantation in nude mice. The average fluorescence intensity of SPC-A-1 cells was(1.001±0.014)×10 ,which was significantly lower than that of SPC-A-1/ADM cells [(10.257±0.023) ×10 ](=17.320,=0.001);the difference was also statistically significant between the ABCG2/BCRP-FITC treatment group and the SPC-A-1 control group(=5.269,=0.021) and the SPC-A-1 control group(=6.869, =0.012) and between the SPC-A-1/ADM cell control group and the SPC-A-1/ADM cell homotype control group(=8.112,=0.015).The positive rate of SPC-A-1/ADM cells treated with ABCG2/BCRP-FITC was 9.8%,39.84 times higher than that of SPC-A-1 cells;it showed significant difference between the ABCG2/BCRP-FITC group and the SPC-A-1/ADM group(=9.120,=0.005) and the SPC-A-1/ADM group(=8.257,= 0.006).The positive rate of group B cells was 684 times that of group A cells,and the difference was statistically significant(=11.235,=0.001),and the fluorescence intensity of group B cells was strong.The average tumorigenic volume of the mice inoculated with SPC-A-1 cells,group A cells,and group B cells was(6.96±1.82),(6.70±2.55),and(9.17±2.41) mm ,respectively.Among them,group B was the highest,but there was no significant difference among these three groups(=2.362,=0.086).The tumorigenic rate of group B cells was 75.00%,which was significantly higher than that of SPC-A-1 cells and group A cells(=19.780,=0.002). ABCG2 cells from human lung adenocarcinoma SPC-A-1/ADM cell line can be isolated by ABCG2 antibody combined with immunomagnetic beads sorting method,and the tumor formation rate in nude mice can be observed to explore the identification and biological characterization of lung cancer stem cells.
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Objective: To investigate the specific mechanism of Xiaoyan Decoction in the metastasis of non-small cell lung cancer. Methods: The detection method of Western blotting method and quantitative PCR Xiaoyan Decoction intervention expression of many inflammatory proteins and cytokines in the lower lung cancer stem Xiaoyan Decoction explore the possible mechanism of effect of non small cell lung cancer metastasis. Results: Western blotting detection showed that the expression of IL-6, TGF-β, p-Smad3, and MMP-9 protein in both experimental group and control group decreased significantly (P < 0.05), the difference was statistically significant; RT-PCR showed that the experimental group compared with the control group IL-6, TGF-β, TNF-α, MMP-2, alpha beta MMP-9 gene expression decreased significantly (P < 0.05), the difference was statistically significant. Conclusion: Xiaoyan Decoction mainly affects the metastasis of non-small cell lung cancer by inhibiting the transmission of TGF-β/Smad3 signaling pathway in the inflammatory microenvironment of lung cancer.
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With high morbidity and mortality, lung cancer is a major threat to human health and one of the focuses of tumor researches. Lung cancer stem cells (LCSCs) are regarded as a subpopulation of cells within lung cancer tissues with the capacity of self-renewal and differentiation, and might be related to tumorigenesis and heterogeneity of lung cancer. Tumor recurrence, metastasis and drug resistance of lung cancers could be clarified by LCSC hypothesis. Thus it's therapeutically prospective to target at these cells. This review summarizes the biomarkers of LCSCs and their aberrant signal pathways, as well as the therapeutic strategies targeting at LCSCs.
Subject(s)
Animals , Humans , Lung Neoplasms , Drug Therapy , Pathology , Molecular Targeted Therapy , Methods , Neoplastic Stem Cells , Pathology , Signal TransductionABSTRACT
Objective To investigate the killing effect of ethacrynic acid (EA) on lung cancer A549 cells derived spheres and explore the underlying mechanism.Methods A549 spheres were cultured in serum-free medium,and the protein expression of CD133,SOX2,EpCAM and ABCG2 was detected by Western blotting.MTT assay was used to evaluate the cell viability of A549 spheres and A549 cells after treated by 1,2,5,10 and 20 mg/mL cisplatin (DDP) for 48 h.The activity of glutathione S-transferase (GST) was measured by colorimetric method after A549 spheres were treated with 10,50,100 and 200 μmol/L EA,respectively.Flow cytometry,Western blotting,real-time PCR and luciferase assay were used to analyze the levels of cellular reactive oxygen species (ROS),formation of A549 spheres,mRNA and protein expression levels of β-catenin,Sox2 and ABCG2,and promoter activity of β-catenin upon 200 μmol/L EA treated cells for 48 h.A549 sphere was infected with β-catenin adenovirus for 24 h,followed by 200 μmol/L EA treatment (in presence or absence of 5 mg/mL DDP) for 24 h.The expression of β-catenin,Sox2 and ABCG2 at mRNA and protein levels was detected by real-time PCR and Western blotting,and cell growth of A549 spheres was evaluated by MTT assay.Results The A549 spheres,with high expression of tumor stem cells markers CD133,SOX2,EpCAM and drug resistance related molecule ABCG2,and resistance to DDP at different doses,were successfully derived.After 200 μmol/L EA had treated A549 sphere for 48 h,the levels of ROS were significantly increased (P ＜ 0.05),and the mRNA and protein levels of β-catenin,Sox2 and ABCG2,and promoter activity of β-catenin were notably decreased (P ＜ 0.05).The treatment of 200 μmol/L EA enhanced the inhibitory effect on proliferation and the promoting effect on apoptosis in A549 spheres induced by 5 mg/mL DDP (P ＜ 0.05).Up-regulation of β-catenin by adenoviral infection partly reversed the effects of 200 μmol/L EA on suppressing the expression levels of β-catenin,Sox2 and ABCG2,compared to the spheres infected with blank adenovirus.Additionally,β-catenin over-expression significantly remitted the inhibitory effect of 200 μmol/L EA and 5 mg/mL DDP on the proliferation in A549 spheres.Conclusion EA exerts inhibitory effect on the proliferation and stemness of A549 spheres through suppressing GST activity and β-catenin expression,and then promotes cell apoptosis.EA might be a novel drug in treatment of lung cancer and cancer stem cells.
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Objective: To examine whether and how Viticis Fructus total flavonoids (VFTF) inhibit the capacity of self-renewal in lung cancer stem cells (LCSCs) derived from human small cell lung cancer NCI-H446 cell line. Methods: NCI-H446 cell line was cultured in vitro. LCSCs were obtained and amplified by Magnetically activated cell sorting system (MACS) and suspended culture with serum-free conditioned medium. The capacity of self-renewal was detected by tumor sphere-forming assay. The protein expression levels of the self-renewal associated transcription factors, Bmi1 and p-Akt, were analyzed using Western blotting. Results: VFTF significantly suppressed the capacity of self-renewal in LCSCs, in a concentration-dependent manner (P < 0.05). The expression levels of Bmi1 and p-Akt were elevated in LCSCs, compared with parental cells. VFTF effectively down-regulated the expression levels of Bmi1 and p-Akt in LCSCs. In addition, LY294002, a PI3K specific inhibitor, enhanced the inhibition of VFTF on the capacity of self-renewal in LCSCs. Conclusion: VFTF could inhibit the self-renewal capacity of LCSCs derived from NCI-H446 cell line, which is associated with down-regulation of the expression of p-Akt and self-renewal associated transcription factors Bmi1.