Apoptosis In Lung Cancer Cells Research Articles

ACTL6A promotes the growth in non-small cell lung cancer by regulating Hippo/Yap pathway

Purpose: To delve into the related molecular mechanism of ACTL6A on non-small cell lung cancer (NSCLC) cell growth and apoptosis. Methods: Quantitative real-time polymerase chain reaction, immunohistochemical staining, and western blot assays were employed to examine ACTL6A mRNA and protein expression in four NSCLC cell line (NCI-H2170, LTEP-s, NCI-H1703, and PC-9) and normal lung cell line (BEAS-2B). CCK-8 cell viability assays and clone formation assay were applied to verify the cell proliferation of NCI-H2170 cell line after knockdown of ACTL6A. Flow cytometry assays were applied to check the role of ACTL6A in the apoptosis of NSCLC cells. The western blot assays were employed to examine the protein expression of WWC1, YAP, TAZ, and CYR61 in NCI-H2170 after knockdown of ACTL6A. Finally, xenograft tumor was taken out and checked the tumor volumes and weight. Immunohistochemical staining and western blot assays were employed to examine cell proliferation and apoptosis of NSCLC in vivo. Results: In this study, the results showed that the mRNA and protein expression level of ACTL6A was higher in four NSCLC cell line than normal lung cell line, respectively. Suppression of ACTL6A inhibited the growth and promoted apoptosis of NSCLC cells. Meanwhile, ACTL6A promotes tumor growth and inhibits apoptosis of NSCLC in vivo via Hippo/YAP signaling pathway. Conclusion: ACTL6A promotes the proliferation in NSCLC by regulating Hippo/YAP pathway.

TP53-Activated lncRNA GHRLOS Regulates Cell Proliferation, Invasion, and Apoptosis of Non-Small Cell Lung Cancer by Modulating the miR-346/APC Axis.

Non-small cell lung cancer (NSCLC) is the main type of lung cancer with high mortality worldwide. To improve NSCLC therapy, the exploration of molecular mechanisms involved in NSCLC progression and identification of their potential therapy targeting is important. Long noncoding RNAs (lncRNAs) have shown important roles in regulating various tumors progression, including NSCLC. We found lncRNA GHRLOS was decreased in NSCLC cell lines and tissues which correlated with poor prognosis of NSCLC patients. However, the role and underlying mechanisms of lncRNA GHRLOS in NSCLC progression remains elusive. The expression of lncRNA GHRLOS was examined in NSCLC cell lines and biopsy specimens of patients with NSCLC by quantitative real time polymerase chain reaction (qRT-PCR). The effects of GHRLOS on proliferation, invasion and apoptosis of NSCLC cells were determined by both in vitro and in vivo experiments. The interaction between GHRLOS and TP53 was determined by dual-luciferase reporter assay and chromatin immunoprecipitation (ChIP) combined with qRT-PCR analysis. RNA immunoprecipitation (RIP) was conducted to validate the binding between GHRLOS and microRNA-346 (miR-346). Dual-luciferase reporter assays were also carried out to reveal the interaction between miR-346 and the 3’ untranslated region (3’UTR) of adenomatous polyposis coli (APC) mRNA.Our data demonstrated that overexpression of lncRNA GHRLOS suppressed cancer cell proliferation and invasion as well as promoted cell apoptosis by regulating the expression of CDK2, PCNA, E-cadherin, N-cadherin, Bax, and Bcl-2 in NSCLC cells. Moreover, lncRNA GHRLOS was upregulated by the binding of TP53 to the GHRLOS promoter. The binding target of lncRNA GHRLOS was identified to be miR-346. Impressively, overexpression of miR-346 promoted cell proliferation and invasion, as well as inhibited cell apoptosis, however, these effects can be blocked by overexpression of lncRNA GHRLOS both in vitro and in vivo. In summary, this study reveals lncRNA GHRLOS, upregulated by TP53, acts as a molecule sponge of miR-346 to cooperatively modulates expression of APC, a miR-346 target, and potentially inhibits NSCLC progression via TP53/lncRNA GHRLOS/miR-346/APC axis, which represents a novel pathway that could be useful in targeted therapy against NSCLC.

125I Seed Promotes Apoptosis in Non-small Lung Cancer Cells via the p38 MAPK-MDM2-p53 Signaling Pathway.

Purpose: 125I seeds were effective in the treatment of non-small cell lung cancer in previous research. However, the exact signaling pathway-mediated apoptosis mechanism is still unclear. The present study analyzed the effects and potential mechanisms of 125I seed on the growth and migration of A549 cells.Methods: Lung cancer A549 cells were irradiated with 125I seed for various times. MTT, invasion assay, and flow cytometry were used to detect the proliferation, invasion, and apoptosis of treated cells, respectively. A Nimblegen genome-wide expression profile chip was used to evaluate gene expression changes in 125I seed-treated A549 cells. Validation studies were performed using phosphorylated protein chip technology, Western blot, nude mouse tumor xenograft assay, and immunohistochemical experiments. All statistical analyses were performed using unpaired Student's t tests and Kruskal-Wallis test.Results: Irradiation with 125I seed inhibited A549 cell proliferation and invasion and induced apoptosis (primarily early apoptosis). Irradiation with 125I seed also caused the downregulation of p38MAPK, degradation of mouse double-minute 2 homolog (MDM2), and higher expression of p53, which eventually resulted in non-small cell lung cancer cell apoptosis.Conclusion: 125I seed irradiation activated the p38MAPK/MDM2/p53 signaling pathway and promoted non-small cell lung cancer cell apoptosis. Future clinical studies targeting this signal may provide a new potential therapeutic approach for non-small cell lung cancer.

Discovery of novel dihydroartemisinin-cinnamic hybrids inducing lung cancer cells apoptosis via inhibition of Akt/Bad signal pathway

A series of dihydroartemisinin-cinnamic acid hybrids were designed, synthesized and evaluated. Most of the tested compounds showed enhanced anti-proliferative activities than artemisinin and dihydroartemisinin, among which 16 g had the superior potency with IC50 values ranging from 5.07 μM to 7.88 μM against four tested cancer cell lines. The cell cycle arrest revealed that 16 g induced A549 cell cycle arrest at G0/G1 phase via regulation of G1-related protein expression (Cdk4). Further mechanism studies reveal that 16 g induced A549 cells apoptosis via inhibiting Akt/Bad pathway. Moreover, 16 g depolarized the mitochondria membrane potentials and induced ROS generation in A549. Additionally, 16 g blocked migration of A549 cells in a concentration-dependent manner. What’s more, 16 g is barely nontoxic to zebrafish embryos. Overall, the cell cycle arrest, inhibition of Akt/Bad signal pathway, ROS generation and migration blocked might explain the potent anti-proliferative activities of these compounds.

Purpurin, a anthraquinone induces ROS-mediated A549 lung cancer cell apoptosis via inhibition of PI3K/AKT and proliferation.

In this study, we sought to evaluate purpurin, a natural biomedicine and a potential inhibitor in decreasing the growth rate of lung cancer cells by modulating the role of PI3K/AKT signalling-associated proliferation and apoptosis. A549 cells were treated with purpurin (30 μM) for 24 and 48 h incubation, respectively, and it has been analysed for cytotoxicity, ROS-mediated apoptotic staining. Moreover, purpurin-mediated lipid peroxidation and GSH were measured by biochemical estimation. Furthermore, PI3K/AKT signalling-mediated cell proliferation and apoptotic gene expression done were by western blot. In this study, we observed that purpurin could effectively kill A549 cancer cell lines and leads to cell death, thus conforming increased cytotoxicity, production of ROS-mediated enhancement of lipid peroxidation, nuclear fragmentation and apoptosis. Moreover, the GSH content of A549 cell lines was also diminished after treatment with purpurin. This study demonstrates that purpurin inhibits the phosphorylated PI3K/AKT molecules mediated cyclin-D1 and PCNA, thereby inducing apoptosis by observing increased proapoptotic mediators Bax, cleaved PARP, cytochrome-c, caspase-9 and caspase-3; and decreased Bcl-2 expression in the lung cancer cell lines. This result concluded that purpurin eliminates the A549 lung cancer cells by blocking the PI3K/AKT pathway thereby inducing apoptosis.

DNAJC12 promotes lung cancer growth byregulating the activation of β‑catenin.

Lung cancer has become the leading cause of cancer-associated mortality worldwide. However, the under- lying mechanisms of lung cancer remain poorly understood. DnaJ heat shock protein family (HSP40) member C12 (DNAJC12) is a type III member belonging to the HSP40/DNAJ family. The role of DNAJC12 in numerous types of cancer has been previously reported; however, the effect of DNAJC12 in lung cancer remains unknown. The results of the present study indicated that DNAJC12 may be involved in lung cancer proliferation and migration by regulating the β-catenin signaling pathway. Data generated in the present study and from The Cancer Genome Atlas revealed that the DNAJC12 expression levels were significantly upregulated in lung cancer tissues compared with non-cancer lung tissues. The expression of DNAJC12 was subsequently knocked down in A549 and NCI-H1975 lung cancer cells using lentiviral transfections and further experiments demonstrated that the knockdown of DNAJC12 inhibited the proliferation, colony formation, migration and invasion of lung cancer cells. The results of flow cytometric assays also revealed that the knockdown of DNAJC12 induced the apoptosis of lung cancer cells. In addition, the effects of DNAJC12 knockdown on the in vivo growth of lung cancer cells were observed. Signaling pathway analysis revealed that the knockdown of DNAJC12 expression suppressed the phosphorylation of p65 NF-κB, downregulated the expression levels and inhibited the subsequent activation of β-catenin, and downregulated the expression levels of vimentin. Rescue experiments demonstrated that the over- expression of β-catenin, but not that of NF-κB or vimentin, reversed the effects of DNAJC12 knockdown on the proliferation and invasion of lung cancer cells. On the whole, the findings of the present study suggest that DNAJC12 may play a crucial role in lung cancer tumorigenesis by regulating the expression and activation of β-catenin. Therefore, DNAJC12 may represent a novel target for the treatment of lung cancer.

Germacrone induces lung cancer cell apoptosis and cell cycle arrest via the Akt/MDM2/p53 signaling pathway.

Germacrone (GM) displays a wide range of antitumor, antioxidant and anti-inflammatory effects; however, to the best of our knowledge, the effects of GM on lung cancer cell apoptosis and cell cycle arrest have not been previously reported. The aim of the present study was to investigate discussed the effects of GM on the apoptosis and cycle arrest of lung cancer cells. Cell viability, proliferation and apoptosis were assessed by performing Cell Counting Kit-8, colony formation and TUNEL assays, respectively. Western blotting was performed to detect the expression levels of apoptosis-, cell cycle- and Akt/MDM2 proto-oncogene (MDM2)/p53 signaling pathway-related proteins. Compared with the control group, 50, 100 and 200 µM GM significantly inhibited lung cancer cell proliferation, but significantly induced cell apoptosis and G1/S cell cycle arrest. GM also significantly altered the expression levels of Akt/MDM2/p53 signaling pathway-related proteins compared with the control group. Administration of Akt activator SC79 significantly reversed GM-mediated antiproliferative, proapoptotic and pro-cell cycle arrest effects in lung cancer cells. Therefore, the results of the present study demonstrated that GM induced lung cancer cell apoptosis and cell cycle arrest via the Akt/MDM2/p53 signaling pathway.

Dihydroisotanshinone I induced ferroptosis and apoptosis of lung cancer cells

Danshen (Salvia miltiorrhiza Bunge) is broadly utilized in traditional Chinese medicine for lung cancer. However, it’s exact effort and mechanism on lung cancer is fully unclear. In this study, we found that dihydroisotanshinone I (DT), a pure compound extracted from danshen, can inhibit the growth of A549 cells and H460 cells. DT also induced apoptosis and ferroptosis in these lung cancer cells. DT also blocking the protein expression of GPX4 (Glutathione peroxidase 4). For in vivo study, DT treatment can inhibit metastasis of A549 cells in the nude mice model without adverse effects on mice. In conclusion, DT inhibited the growth of lung cancer cells through apoptosis and ferroptosis and inhibited metastasis of A549 cells in the nude mice model. Further studies are warranted to validate the findings of this study.

Antiproliferative effect of cryptotanshinone against human non-small cell lung cancer cells through inactivation of lncRNA HOTAIR /p-Akt signaling pathway

Cryptotanshinone is known as a quinoid diterpene extracted from the root of Salvia miotiorrhiza bunge and can show outstanding anticancer activities. In the present study, we explored the mechanism of action of cryptotanshinone, and its potential efficacy as a promising therapy for the treatment of non-small cell lung cancer (NSCLC) cell line (A549) in vitro. A549 cells were incubated with cryptotanshinone and cell proliferation and apoptosis were investigated using MTT, LDH, ROS, Annexin-V-FITC assays. The expression levels of lncRNA HOTAIR and p-Akt were quantified by quantitative real-time PCR (qPCR) and western blot, respectively. The results showed that cryptotanshinone mitigated cell proliferation in a dose and time-dependent manner through a significant increase in LDH release, ROS production, and apoptosis in A549 lung cancer cells. Treatment of A549 cells with cryptotanshinone also led to downregulation of lncRNA HOTAIR and protein level of p-Akt. Furthermore, the anticancer effect of cryptotanshinone was inhibited in the presence of NAC as a potential antioxidant. In general, it was found that cryptotanshinone is an effective agent in preventing lung cancer cells growth through downregulation of HOTAIR and p-Akt expression which is partially due to high level of ROS.

Targeting CXCR2 inhibits the progression of lung cancer and promotes therapeutic effect of cisplatin

BackgroundDrug-resistance and severe side effects of chemotherapeutic agents result in unsatisfied survival of patients with lung cancer. CXCLs/CXCR2 axis plays an important role in progression of cancer including lung cancer. However, the specific anti-cancer mechanism of targeting CXCR2 remains unclear.MethodsImmunohistochemical analysis of CXCR2 was performed on the microarray of tumor tissues of clinical lung adenocarcinoma and lung squamous cell carcinoma patients. CCK8 test, TUNEL immunofluorescence staining, PI-Annexin V staining, β-galactosidase staining, and Western blot were used to verify the role of CXCR2 in vitro. Animal models of tail vein and subcutaneous injection were applied to investigate the therapeutic role of targeting CXCR2. Flow cytometry, qRT-PCR, enzyme-linked immunosorbent assay (ELISA), and immunohistochemistry analysis were performed for further mechanistic investigation.ResultsThe expression of CXCR2 was elevated in both human lung cancer stroma and tumor cells, which was associated with patients’ prognosis. Inhibition of CXCR2 promoted apoptosis, senescence, epithelial-to-mesenchymal transition (EMT), and anti-proliferation of lung cancer cells. In vivo study showed that tumor-associated neutrophils (TANs) were significantly infiltrate into tumor tissues of mouse model, with up-regulated CXCLs/CXCR2 signaling and suppressive molecules, including Arg-1 and TGF-β. SB225002, a selective inhibitor of CXCR2 showed promising therapeutic effect, and significantly reduced infiltration of neutrophils and enhanced anti-tumor T cell activity via promoting CD8+ T cell activation. Meanwhile, blockade of CXCR2 could enhance therapeutic effect of cisplatin via regulation of neutrophils infiltration.ConclusionsOur finds verify the therapeutic effects of targeting CXCR2 in lung cancer and uncover the potential mechanism for the increased sensitivity to chemotherapeutic agents by antagonists of CXCR2.

Effect of microRNA-4268 on Proliferation and Apoptosis of Non-Small Cell Lung Cancer Cells Through Regulating Signal Transducer and Activator of Transcription 3 Level

STAT3 is closely related to non-small cell lung cancer (NSCLC). miR-4268 is predicted to regulate STAT3 level by MiRDB analysis. Therefore, our study investigated whether miR-4268 affects NSCLC cells by regulating STAT3. The control group (NC group), miR-4268 Mimics group, and miR-4268 Mimics +pFBD-STAT3 group were set up followed by analysis of miR-4268 and STAT3 mRNA level by QRT-PCR, relationship between miR-4268 and STAT3 by dual fluorescein reporter assay, STAT3 and Tubulin protein level by Western blot, cell proliferation by MTT assay and apoptosis by Annexin V-FITC/PI staining. Compared with normal tissue, miR-4268 expression in cancer tissue was significantly reduced (P <0.01), while STAT3 level was elevated (P <0.01). STAT3 was a target gene of miR-4268. Compared with NC group, STAT3 level was significantly reduced in miR-4268 Mimics group (P <0.01) and increased in miR-4268 Mimics+pFBD-STAT3 group compared with miR-4268 Mimics group (P <0.05). Compared to NC group, miR-4268 Mimics group had reduced cell proliferation and increased cell apoptosis and opposite changes were observed in miR-4268 Mimics+pFBD-STAT3 group which had increased cell proliferation and decreased apoptosis (P < 0.05). miR-4268 regulates STAT3 mRNA level and inhibits NSCLC cell proliferation and promotes apoptosis. However, over-expression of STAT3 can inhibit the effect of miR-4268.

Matrine Regulates Proliferation, Apoptosis, Cell Cycle, Migration, and Invasion of Non-Small Cell Lung Cancer Cells Through the circFUT8/miR-944/YES1 Axis.

BackgroundNon-small cell lung carcinoma (NSCLC) is the major histological subtype of cancer cases. In the present study, we investigated the association between Matrine, an active component of Chinese medicine, and circFUT8 in NSCLC cells.MethodsThe proliferation ability of NSCLC cells was assessed by MTT and colony-forming assays. Flow cytometry assay was performed to show the apoptosis and cell cycle distribution in NSCLC cells. The protein expression levels of Bcl-2, Cleaved Caspase-3 (C-Caspase3), and YES proto-oncogene 1 (YES1) were measured by Western blot assay. Migration and invasion of NSCLC cells were determined by transwell assay. The expression levels of circFUT8, miR-944 and YES1 were quantified by real-time quantitative polymerase chain reaction (RT-qPCR) assay. The interaction relationship between miR-944 and circFUT8 or YES1 was confirmed by dual-luciferase reporter assay. The anti-tumor role of Matrine in vivo was explored by a xenograft experiment.ResultsMatrine functioned as a carcinoma inhibitor by repressing proliferation, cell cycle process, migration, and invasion while inducing apoptosis in NSCLC cells. Importantly, overexpression of circFUT8 counteracted Matrine-induced effects on NSCLC cells. MiR-944, interacted with YES1, was a target of circFUT8. Under Matrine condition, overexpression of circFUT8 increased proliferation, migration, and invasion while inhibited apoptosis, which was abolished by the upregulation of miR-944. Whereas the silencing of YES1 counteracted miR-944 inhibitor-induced effects on NSCLC cells. Eventually, we also confirmed that Matrine impeded NSCLC tumor growth in vivo.ConclusionMatrine regulated proliferation, apoptosis, cell cycle, migration, and invasion of NSCLC cells through the circFUT8/miR-944/YES1 axis, which provided novel information for Matrine in NSCLC.

Inhibitory Effect of Immunologically Activated Mesenchymal Stem Cells on Lung Cancer Cell Growth and Metastasis.

Background: Mesenchymal stem cells (MSCs) could inhibit the proliferation of lung cancer cells. The authors' study investigated the effects of immunologically activated human umbilical cord (HUC)-MSCs on A549 lung cancer cells. Materials and Methods: HUC-MSCs were separated from the umbilical cord using the adherence method. Surface markers of HUC-MSCs were detected by flow cytometry for MSC identification. Imiquimod (TLR7 agonist) was incubated with HUC-MSCs for immune activation, and the expression of MSC-specific markers and immune inflammatory molecules was measured by quantitative real-time polymerase chain reaction. HUC A549 cells were cocultured with HUC-MSCs treated with imiquimod, siTLR7 (small interfering RNA for TLR7) or TLR7 overexpression, and then cell viability, proliferation, migration, and invasion, and the expression of phosphatidylinositol-3-kinase (PI3K)/Akt and NF-κB was investigated using MTT assay, clone formation assay, transwell assay, and Western blot, respectively. Results: HUC-MSCs were identified as positive for CD73, CD105, CD44, CD29, and CD90. Expression of MSC markers was inhibited, while those of immune inflammatory molecules expression except IL-6 (interleukin-6) was enhanced after MSCs were immunologically activated by imiquimod. After being cocultured with HUC-MSCs treated with imiquimod or overexpressed TLR7, cell viability, proliferation, and metastasis, and the phosphorylation of P65 and AKT in A549 cells were decreased, but apoptosis was increased, while siTLR7 showed the opposite effect HUC. Conclusions: Immunologically activated HUC-MSCs inhibited the growth and metastasis, yet, promoted the apoptosis of A549 lung cancer cells via regulating the PI3K/Akt and NF-κB pathways.

Ceramide induces the apoptosis of non‑small cell lung cancer cells through the Txnip/Trx1 complex.

Ceramide is a biologically active sphingomyelin that inhibits cell growth and proliferation. In previous studies, it was demonstrated that the use of lipopolysaccharides induces acid sphingomyelinases to produce ceramide, promoting lung cancer cell apoptosis; however, the specific mechanisms of this action remain unclear. Thioredoxin-interacting protein (Txnip) plays an important role in the signal transmission of redox reactions inside and outside the cell. Thus, it was hypothesized that ceramide induces apoptosis in lung adenocarcinoma cells (A549 and PC9) by modulating the Txnip/Trx1 complex. In the present study, the Cell Counting kit-8 method was used to detect cell activity and the drug concentration. Hoechst 33258 staining and flow cytometry were used to detect cell apoptosis, and the positional association between Txnip and Trx1 upregulated by ceramide was observed by immunofluorescence confocal microscopy. Reverse transcription-quantitative polymerase chain reaction and western blot analysis were used to detect the changes in related gene, mRNA and protein expression levels. The results revealed that ceramide treatment resulted in the upregulation of Txnip and in the reduction of Trx1 activities. However, the Txnip inhibitor, verapamil, reversed these changes. The analysis of mRNA expression further verified the changes observed in the protein expression of Txnip, Trx1 and apoptosis-related proteins. On the whole, the present study demonstrates that ceramide induces the apoptosis of lung cancer cells by regulating the Txnip/Trx1 complex.

Sevoflurane induces lung cancer cell apoptosis via inhibition of the expression of miRNA155 gene

Purpose: To determine the apoptotic effect of sevoflurane on lung cancer cells, and the underlying mechanism of action.Methods: Lung adenocarcinoma A549 cells were cultured for 24 h and divided into control group, 1% sevoflurane group and 3% sevoflurane group. The two levels of sevoflurane were provided through a gas monitor connected to each of the sevoflurane groups. The control group was not treated. Flow cytometry was used to analyze A549 cell apoptosis, while qRT-PCR was used for assay of the levels of miRNA155 in A549 cells. The protein expression of Bcl-2 was determined with immunoblotting. The percentage of apoptosis and levels of miRNA155 and Bcl-2 in the two cell lines were compared.Results: Significant differences in miRNA146a level were seen between the 3 % sevoflurane and control groups at 3 h. There was higher apoptosis in the 3 % sevoflurane group, relative to control, but miRNA155 levels in the 3 % sevoflurane group were generally less than that of the control (p < 0.05). There was lower Bcl-2 content in the 3 % sevoflurane group than in control group (p < 0.05).Conclusion: Sevoflurane exerts strong apoptotic and anti-proliferative effects on lung adenocarcinoma A549 cells via a mechanism which may be related to the downregulation of miRNA155, thereby inhibiting the expression of anti-apoptotic protein Bcl-2. This provides a new direction for research on anti-lung adenocarcinoma drugs.
 Keywords: Sevoflurane, Lung cancer cells, Apoptosis, Inhibition, miRNA155, Expression, Induction

LncRNA MIR503HG inhibits cell proliferation and promotes apoptosis in TNBC cells via the miR-224-5p/HOXA9 axis

Triple-negative breast cancer (TNBC) is a highly invasive subtype of breast cancer. This study investigated the molecular mechanism and influences of MIR503HG, miR-224-5p, and homeobox A9 (HOXA9) on TNBC cell growth and migration. Dual-luciferase reporter gene and RNA immunoprecipitation were performed to examine the regulation of MIR503HG, miR-224-5p, and HOXA9. Cell proliferation, apoptosis, migration, and invasion were evaluated by colony formation, flow cytometry, and Transwell assays. Finally, nude mice were employed to investigate the influence of MIR503HG on TNBC tumor growth. HOXA9 protein levels were detected by immunohistochemical staining. MIR503HG and HOXA9 expression were reduced in TNBC, while miR-224-5p was increased. Overexpression of MIR503HG or HOXA9 reduced the cell migration ability and proliferation and promoted apoptosis, and knockdown of MIR503HG or overexpression of miR-224-5p exhibited the opposite effects. Furthermore, MIR503HG promoted HOXA9 expression by inhibiting miR-224-5p. Overexpression of miR-224-5p reversed the effects of MIR503HG overexpression on TNBC cells, while overexpression of HOXA9 reversed the effect of MIR503HG knockdown. Additionally, an in vivo study proved that MIR503HG inhibited TNBC tumor growth via the miR-224-5p/HOXA9 axis. MIR503HG inhibited cell proliferation and promoted the apoptosis of TNBC cells via the miR-224-5p/HOXA9 axis, which may function as a novel target for the treatment of TNBC.

MicroRNA-365b-3p represses the proliferation and promotes the apoptosis of non-small cell lung cancer cells by targeting PPP5C.

MicroRNA (miR)-365b-3p has been recently reported to induce cell cycle arrest and apoptosis in retinoblastoma; however, its expression pattern and biological function in non-small cell lung cancer (NSCLC) remain unknown. The present study aimed to investigate the functional role of miR-365b-3p in NSCLC. The results demonstrated that miR-365b-3p expression level was significantly decreased in NSCLC tissues and cell lines compared with controls using reverse transcriptase quantitative PCR. Furthermore, miR-365b-3p expression level was overexpressed by miR-365b-3p mimics transfection in A549 cells, whereas it was downregulated following H1299 cell transfection with miR-365b-3p inhibitor. Restoration of miR-365b-3p inhibited cell proliferation, induced cell cycle G0/G1 arrest and stimulated apoptosis in A549 cells using CCK-8 assay, colony formation and flow cytometry assay. However, miR-365b-3p inhibitor had the opposite effects in H1299 cells. Furthermore, results from bioinformatics analysis and luciferase reporter assay confirmed that serine/threonine protein phosphatase 5 (PPP5C) was a direct target of miR-365b-3p. In addition, online Kaplan-Meier plotter software demonstrated that high PPP5C expression level was associated with lower overall survival and disease-free survival in patients with NSCLC. Furthermore, PPP5C knockdown imitated the effects of miR-365b-3p mimics on A549 cell proliferation, cell cycle distribution and apoptosis, whereas its overexpression rescued the effects of miR-365b-3p mimics on A549 cell proliferation, cell cycle distribution and apoptosis. In conclusion, the findings from the present study suggested that miR-365b-3p may partly suppress NSCLC cell behaviors by targeting PPP5C, which may represent a promising therapeutic target for patients with NSCLC.

Splicing reprogramming of TRAIL/DISC-components sensitizes lung cancer cells to TRAIL-mediated apoptosis

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) selective killing of cancer cells underlines its anticancer potential. However, poor tolerability and resistance underscores the need to identify cancer-selective TRAIL-sensitizing agents. Apigenin, a dietary flavonoid, sensitizes lung cancer cell lines to TRAIL. It remains unknown, however, whether apigenin sensitizes primary lung cancer cells to TRAIL and its underlying mechanisms. Here we show that apigenin reprograms alternative splicing of key TRAIL/death-inducing-signaling-complex (DISC) components: TRAIL Death Receptor 5 (DR5) and cellular-FLICE-inhibitory-protein (c-FLIP) by interacting with the RNA-binding proteins hnRNPA2 and MSI2, resulting in increased DR5 and decreased c-FLIPS protein levels, enhancing TRAIL-induced apoptosis of primary lung cancer cells. In addition, apigenin directly bound heat shock protein 70 (Hsp70), promoting TRAIL/DISC assembly and triggering apoptosis. Our findings reveal that apigenin directs alternative splicing and inhibits Hsp70 enhancing TRAIL anticancer activity. These findings underscore impactful synergies between diet and cancer treatments opening new avenues for improved cancer treatments.

Quercetin induces pro-apoptotic autophagy via SIRT1/AMPK signaling pathway in human lung cancer cell lines A549 and H1299 in vitro.

BackgroundQuercetin, a natural flavonoid compound, is a potent cancer therapeutic agent widely found in fruit and vegetables. It has been reported to induce growth inhibition and apoptosis in both A549 and H1299 human lung cancer cells. However, the effect of quercetin‐induced autophagy on apoptosis and the possible autophagy mechanism in A549 and H1299 cells have not yet been critically examined.MethodsA549 and H1299 cells were treated with different concentrations of quercetin for 24 hours. Cell growth was measured by cell counting kit‐8 (CCK‐8) assay, whereas apoptosis was assessed by western blotting analysis of apoptotic proteins. The levels of proteins and genes involved in autophagy were determined by western blotting and reverse transcription polymerase chain reaction (RT‐PCR), respectively. Autophagosomes were also observed by transmission electron microscopy (TEM) and LC3 immunofluorescence.ResultsQuercetin inhibited cell viability and induced mitochondria‐dependent apoptosis in both A549 and H1299 cells in a dose‐dependent. Moreover, quercetin also promoted the expression of LC3‐II and beclin 1 and suppressed the expression of p62. The mRNA levels of LC3‐II, beclin 1, Atg5, Atg7, and Atg12 were upregulated by quercetin treatment. Autophagy inhibition with 3‐methyladenine could effectively inhibit quercetin‐induced apoptosis. In addition, quercetin dose‐dependently elevated the levels of SIRT1 protein and the pAMPK–AMPK ratio. Quercetin‐induced autophagy was attenuated by SIRT1 inhibitor EX527 and SirT1 knockdown by small interfering RNA (siRNA).ConclusionsQuercetin‐induced autophagy contributes to apoptosis in A549 and H1299 lung cancer cells, which involved the SIRT1/AMPK signaling pathway.

Bibenzyl analogue DS-1 inhibits MDM2-mediated p53 degradation and sensitizes apoptosis in lung cancer cells

BackgroundLung cancer is a leading fatal malignancy due to the high incidence of treatment failure. Dysfunction of the tumor suppressor p53 contributes to cancer initiation, progression, and therapeutic resistance. Targeting MDM2, a negative regulator of p53, has recently attracted interest in cancer drug research as it may restore tumor suppressive function. PurposeThe present study aimed to investigate the effect of 3,4-dihydroxy-5,4′-dimethoxybibenzyl (DS-1) on targeting MDM2 and restoring p53 function in lung cancer cells. MethodsThe efficacy of DS-1 alone or in combination with cisplatin in lung cancer cells was determined by MTT, nuclear staining, and annexin V/PI assay. The expression of apoptosis-related proteins was determined by western blot analysis. To evaluate the role of DS-1 on the stabilization and degradation of p53, cycloheximide chasing assay and immunoprecipitation were conducted, and the active form of p53 was investigated by immunofluorescent staining assay. To confirm and demonstrate the site interaction between DS-1 and the MDM2 protein, in silico computational analysis was performed. ResultsDS-1 exhibited a cytotoxic effect and sensitized lung cancer cells to cisplatin-induced apoptosis. DS-1 caused a significant increase in the cellular level of p53 protein, while the active form of p53 (phosphorylation at Ser15) was unaltered. DS-1 treatment in combination with cisplatin could enhance activated p-p53 (Ser15) and p53 downstream signaling (Bax, Bcl-2, and Akt), leading to a higher level of apoptosis. Immunoprecipitation analysis revealed that DS-1 decreased the p53-ubiquitin complex, a prerequisite step in p53 proteasomal degradation. Molecular docking simulation further evidenced that DS-1 interacts with MDM2 within the p53-binding domain by carbon–hydrogen bond interaction at Lys27, π–alkyl interactions at Ile37 and Leu30, and van der Waals interactions at Ile75, Val51, Val69, Phe67, Met38, Tyr43, Gly34, and Phe31. Treatment by DS-1 and cisplatin in patient-derivated primary lung cancer cells showed consistent effects by increasing cisplatin sensitivity. ConclusionsOur findings provide evidence that DS-1 is an MDM2 inhibitor and its underlying mechanism involves MDM2 binding and p53 induction, which may benefit the development of this compound for lung cancer treatment.