Propofol Regulates the Proliferation and Migration of Lung Cancer Cells Through Atr Signaling Pathway

Aims: Here we aim to investigate the regulation of propofol on DNA damage caused by replication fork arrest in esophageal squamous cell carcinoma cells.Methods: A549 and NCI-H460 cells were treated with propofol and hydroxyurea (HU) in vitro. CCK-8 assay was used to examine cell proliferation. Transwell assay was employed to investigate cell migration and invasion abilities. Western blotting was carried out to study the activities of ATR signals. Laser confocal microscopy was utilized to study the formation of p-RPA32 foci.Results: Propofol treatment promoted the apoptosis and suppresses the proliferation, migration and invasion, possibly by increasing the sensitivity of A549 and NCI-H460 cells against DNA damage. Propofol treatment enhanced the sensitivity of A549 and NCI-H460 cells to damages caused by replication fork arrest, as well as the activity of ATR signaling pathway. Propofol regulated the sensitivity of A549 and NCI-H460 cells to DNA replication damage by affecting the level of H3K27me3.Conclusions: The present study demonstrates that propofol up-regulates the expression of H3K27me3 in lung cancer cells, promotes the recruitment of exonuclease MUS81 in stagnant replication fork, induces apoptosis caused by DNA damage, and thus inhibits the proliferation and metastasis of tumor cells.

Sesquiterpene from Polygonum Barbatum Disrupt Mitochondrial Membrane Potential to Induce Apoptosis and Inhibits Metastasis by Downregulating Matrix Metalloproteinase and Osteopontin in NCI-H460 Cells

Background: Globally, lung cancer accounts for 18% of cancer-associated mortalities. Among the subtypes, non-small-cell lung cancer (NSCLC) is the most prevalent one. The increased resistance and poor survival rates, signifies disease aggressiveness and thus require a search for an alternative anticancer molecule. Hypothesis/Purpose: Earlier, the isolated sesquiterpene i.e. compound 1 ((E)-Methyl 6-acetoxy-7-methoxy-1-(2-methylpropylidene)-1H-indene-3-carboxylate) from P. barbatum was isolated, characterized by us and reported for preliminary anticancer activity. Considering its potent activity, this study was designed to explore the underlying molecular mechanism of apoptosis and metastasis against NCI-H460 cells. Method: The molecular mechanism of compound 1 inducing apoptosis and inhibiting metastasis was elucidated by analyzing mitochondrial membrane potential, DNA fragmentation, clonogenic assay, invasion assay and expression of apoptotic (Caspases 3, 6, 8, 9 and BAK) and metastatic markers (MMP 2, 9 and osteopontin). Results: Compound 1 significantly inhibited cell proliferation and induced apoptosis via intrinsic route i.e. the mitochondrial pathway by disrupting mitochondrial membrane potential. The enhanced expression of caspases 6, 9, BAK and HRK with downregulation of Bcl-2L1 and Ki67 further confirmed the involvement of the intrinsic apoptotic pathway. Moreover, compound 1 restricted the invasive nature of NCI-H460 cells evinced by reduced cell invasion in Boyden chamber invasion assay and downregulating the expression of metastatic markers i.e. matrix metalloproteinase 2 / 9 and VEGF. It was also found that it blocks osteopontin by negatively regulating its expression; a marker protein in cancer management. Conclusion: Conclusively, this sesquiterpene exhibited potent anticancer and anti-metastatic activity and can be explored further as possible pharmacophores

Curcumin increases crizotinib sensitivity through the inactivation of autophagy via epigenetic modulation of the miR-142-5p/Ulk1 axis in non-small cell lung cancer

Drug resistance is a critical factor responsible for the recurrence of non-small cell lung cancer (NSCLC). Previous studies suggest that curcumin acts as a chemosensitizer and radiosensitizer in human malignancies, but the underlying mechanism remains elusive. In the present study, we explored how curcumin regulates the expression of miR-142-5p and sensitizes NSCLC cells to crizotinib. We found that miR-142-5p is significantly downregulated in NSCLC tissue samples and cell lines. Curcumin could increase crizotinib cytotoxicity by epigenetically restoring the expression of miR-142-5p. Furthermore, curcumin treatment suppressed the expression of DNA methylation-related enzymes, including DNMT1, DNMT3A, and DNMT3B, in NSCLC cells. In addition, the upregulation of miR-142-5p expression increased crizotinib cytotoxicity and induced apoptosis in tumor cells in a similar manner to that of curcumin. Strikingly, miR-142-5p overexpression suppressed crizotinib-induced autophagy in A549 and H460 cells. Mechanistically, miR-142-5p inhibited autophagy in lung cancer cells by targeting Ulk1. Overexpression of Ulk1 abrogated the miR-142-5p-induced elevation of crizotinib cytotoxicity in A549 and H460 cells. Collectively, our findings demonstrate that curcumin sensitizes NSCLC cells to crizotinib by inactivating autophagy through the regulation of miR-142-5p and its target Ulk1.

Morphine promotes the malignant biological behavior of non-small cell lung cancer cells through the MOR/Src/mTOR pathway

Background Morphine, a µ-opioid receptor (MOR) agonist, has been shown to be related to the activity of cancer cells, and a higher morphine dosage reduces the survival time of patients with lung cancer. However, the effect of morphine on the malignant behavior of lung cancer cells remains unclear. The aim of this study was to investigate the specific molecular mechanism by which morphine regulates the malignant biological behavior of non-small cell lung cancer. Methods Immunofluorescence staining and Western blot analyses were performed to detect MOR expression. H460 non-small cell lung cancer cells were used in this study, and cell proliferation, the cell cycle and apoptosis were evaluated using Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Cell migration and invasion were detected using wound healing and Transwell assays. The effect of morphine on lung cancer development in vivo was examined by performing a xenograft tumor assay following morphine treatment. Results Morphine promoted the growth of H460 cells both in vivo and in vitro. Morphine enhanced cell migration and invasion, modified cell cycle progression through the S/G2 transition and exerted an antiapoptotic effect on H460 cells. Additionally, morphine increased Rous sarcoma oncogene cellular homolog (Src) phosphorylation and activated the phosphoinositide 3 kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. Treatment with the MOR antagonist methylnaltrexone (MNTX) and the Src inhibitor protein phosphatase 1 (PP1) reduced the phosphorylation induced by morphine. Furthermore, MNTX, PP1, and the PI3K/AKT inhibitor deguelin reversed the antiapoptotic effect of morphine on lung cancer cells. Conclusion Morphine promotes the malignant biological behavior of H460 cells by activating the MOR and Src/mTOR signaling pathways.

GRP78/BiP determines senescence evasion cell fate after cisplatin-based chemotherapy

Cisplatin (CDDP) induces senescence characterized by senescence-associated secretory phenotypes (SASP) and the unfolded protein response (UPR). In this study, we investigated the proteins related to the UPR during the senescence cell fate. Strikingly, we found that one of the critical ER-resident proteins, GRP78/BiP, was significantly altered. Here we show that GRP78 levels differentially expressed depending on non-small lung cancer subtypes. GRP78 indeed regulates the evasion of senescence in adenocarcinoma A549 cells, in which the increased GRP78 levels enable them to re-proliferate after CDDP removal. Conversely, GRP78 is downregulated in the senescence H460 cells, making them lacking senescence evasion capability. We observed that the translational regulation critically contributed to the GRP78 protein levels in CDDP-induces senescence. Furthermore, the increased GRP78 level during senescence confers resistance to senolytic drug, Bortezomib, as observed by a twofold increase in IC50 in A549 senescence cells compared to the wild-type. This observation is also consistent in the cells that have undergone genetic manipulation by transfection with pcDNA3.1(+)-GRP78/BiP plasmids and pSpCas9(BB)-2A-Puro containing guide RNA sequence targeting GRP78 exon 3 to induce the overexpression and downregulation of GRP78 in H460 cells, respectively. Our findings reveal a unique role of GRP78 on the senescence evasion cell fate and senolytic drug resistance after cisplatin-based chemotherapy.

Phosphorylated Osteopontin Secreted from Cancer Cells Induces Cancer Cell Motility

Osteopontin (OPN) plays a pivotal role in cancer cell invasion and metastasis. Although OPN has a large number of phosphorylation sites, the functional significance of OPN phosphorylation in cancer cell motility remains unclear. In this study, we attempted to investigate whether phosphorylated OPN secreted from cancer cells affect cancer cell migration. Quantitative PCR and Western blot analyses revealed that MDA-MB435S, A549, and H460 cells highly expressed OPN, whereas the OPN expression levels in H358, MIAPaca-2, and Panc-1 cells were quite low or were not detected. Compared with the cancer cell lines with a low OPN expression, the high OPN-expressing cancer cell lines displayed a higher cell migration, and the cell migration was suppressed by the anti-OPN antibody. This was confirmed by the OPN overexpression in H358 cancer cells with a low endogenous OPN. Phos-tag ELISA showed that phosphorylated OPN was abundant in the cell culture media of A549 and H460 cells, but not in those of MDA-MB435S cells. Moreover, the A549 and H460 cell culture media, as well as the MDA-MB435S cell culture media with a kinase treatment increased cancer cell motility, both of which were abrogated by phosphatase treatment or anti-OPN antibodies. These results suggest that phosphorylated OPN secreted from cancer cells regulates cancer cell motility.

Cisplatin-induced hydroxyl radicals mediate pro-survival autophagy in human lung cancer H460 cells

Background Accumulated evidence demonstrates cisplatin, a recommended chemotherapy, modulating pro-survival autophagic response that contributes to treatment failure in lung cancer patients. However, distinct mechanisms involved in cisplatin-induced autophagy in human lung cancer cells are still unclear. Results Herein, role of autophagy in cisplatin resistance was indicated by a decreased cell viability and increased apoptosis in lung cancer H460 cells pre-incubated with wortmannin, an autophagy inhibitor, prior to treatment with 50 µM cisplatin for 24 h. The elevated level of hydroxyl radicals detected via flow-cytometry corresponded to autophagic response, as evidenced by the formation of autophagosomes and autolysosomes in cisplatin-treated cells. Interestingly, apoptosis resistance, autophagosome formation, and the alteration of the autophagic markers, LC3-II/LC3-I and p62, as well as autophagy-regulating proteins Atg7 and Atg3, induced by cisplatin was abrogated by pretreatment of H460 cells with deferoxamine, a specific hydroxyl radical scavenger. The modulations in autophagic response were also indicated in the cells treated with hydroxyl radicals generated via Fenton reaction, and likewise inhibited by pretreatment with deferoxamine. Conclusions In summary, the possible role of hydroxyl radicals as a key mediator in the autophagic response to cisplatin treatment, which was firstly revealed in this study would benefit for the further development of novel therapies for lung cancer.

β-Thujaplicin Enhances TRAIL-Induced Apoptosis via the Dual Effects of XIAP Inhibition and Degradation in NCI-H460 Human Lung Cancer Cells

Background: β-thujaplicin, a natural tropolone derivative, has anticancer effects on various cancer cells via apoptosis. However, the apoptosis regulatory proteins involved in this process have yet to be revealed. Methods: Trypan blue staining, a WST-8 assay, and a caspase-3/7 activity assay were used to investigate whether β-thujaplicin sensitizes cancer cells to TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Additionally, western blotting was performed to clarify the effects of β-thujaplicin on X-linked inhibitor of apoptosis protein (XIAP) in NCI-H460 cells and a fluorescence polarization binding assay was used to evaluate the binding-inhibitory activity of β-thujaplicin against XIAP-BIR3. Results: β- and γ-thujaplicins decreased the viability of NCI-H460 cells in a dose-dependent manner; they also sensitized the cells to TRAIL-induced cell growth inhibition and apoptosis. β-thujaplicin significantly potentiated the apoptosis induction effect of TRAIL on NCI-H460 cells, which was accompanied by enhanced caspase-3/7 activity. Interestingly, β-thujaplicin treatment in NCI-H460 cells decreased XIAP levels. Furthermore, β-thujaplicin was able to bind XIAP-BIR3 at the Smac binding site. Conclusions: These findings indicate that β-thujaplicin could enhance TRAIL-induced apoptosis in NCI-H460 cells via XIAP inhibition and degradation. Thus, the tropolone scaffold may be useful for designing novel nonpeptidic small-molecule inhibitors of XIAP and developing new types of anticancer drugs.

The Role and Mechanism of ATM-Mediated Autophagy in the Transition From Hyper-Radiosensitivity to Induced Radioresistance in Lung Cancer Under Low-Dose Radiation

Objective: This study aimed to investigate the effect of ataxia telangiectasia mutated (ATM)–mediated autophagy on the radiosensitivity of lung cancer cells under low-dose radiation and to further investigate the role of ATM and its specific mechanism in the transition from hyper-radiosensitivity (HRS) to induced radioresistance (IRR).Methods: The changes in the HRS/IRR phenomenon in A549 and H460 cells were verified by colony formation assay. Changes to ATM phosphorylation and cell autophagy in A549 and H460 cells under different low doses of radiation were examined by western blot, polymerase chain reaction (PCR), and electron microscopy. ATM expression was knocked down by short interfering RNA (siRNA) transfection, and ATM-regulated molecules related to autophagy pathways were screened by transcriptome sequencing analysis. The detection results were verified by PCR and western blot. The differential metabolites were screened by transcriptome sequencing and verified by colony formation assay and western blot. The nude mouse xenograft model was used to verify the results of the cell experiments.Results: (1) A549 cells with high expression of ATM showed positive HRS/IRR, whereas H460 cells with low expression of ATM showed negative HRS/IRR. After the expression of ATM decreased, the HRS phenomenon in A549 cells increased, and the radiosensitivity of H460 cells also increased. This phenomenon was associated with the increase in the autophagy-related molecules phosphorylated c-Jun N-terminal kinase (p-JNK) and autophagy/Beclin 1 regulator 1 (AMBRA1). (2) DL-Norvaline, a product of carbon metabolism in cells, inhibited autophagy in A549 cells under low-dose radiation. DL-Norvaline increased the expression levels of ATM, JNK, and AMBRA1 in A549 cells. (3) Mouse experiments confirmed the regulatory role of ATM in autophagy and metabolism and its function in HRS/IRR.Conclusion: ATM may influence autophagy through p-JNK and AMBRA1 to participate in the regulation of the HRS/IRR phenomenon. Autophagy interacts with the cellular carbon metabolite DL-Norvaline to participate in regulating the low-dose radiosensitivity of cells.

UBE2S Activates NF-κB Signaling By Binding With IκBα and Promotes Metastasis of Lung Adenocarcinoma Cell

BackgroundNuclear factor (NF)-κB signaling in cancer cells was reported to be involved in tumorigenesis. Phosphorylation and degradation of inhibitor of NF-κBα (IκBα) is a canonical pathway of NF-κB signaling. Herein, we report non-canonical activation of NF-κB signaling without phosphorylation of IκB but by directly binding by ubiquitin-conjugating enzyme E2S (UBE2S) for degradation in adenocarcinoma cells.MethodsTCGA and the Human Atlas Protein Database were used to analyze the survival rate and expression of UBE2S. PC9, H460, H441 and A549 cells were used in this study. PC9 and H460 cells were used for further analysis because of different protein levels of UBE2S. Specific IKK inhibitors, PS1145 and SC514, were used to analyze the phosphorylation of IκBα. Western blotting experiment was used to analyze the protein levels PC9 and H460 cells. Wound-healing experiment was used to analyze the migrative ability of PC9 and H460 cells. Overexpression and knockdown of UBE2S in H460 and PC9 cells were used to analyze the downstream proteins levels. Immunoprecipitation, immunofluorescent staining, a glutathione S transferase (GST) pull-down assay, and an in vitro binding assay were used to analyze the interaction of UBE2S and IκBα. Luciferase assay was used to analyze the activation of NF-κB signaling regulated by UBE2S. Zebrafish xenograft model was used analyzed the metastasis of PC9 cells regulated by UBE2S.Results UBE2S in lung adenocarcinoma patients was negatively related to the survival rate. The protein levels of UBE2S and IκBα were shown opposite change in PC9 and H460 cells. PC9 cells showed higher UBE2S expression and migrative ability than H460 cells. Phosphorylation of IκBα was not changed by treatment with IKK specific inhibitors, PS1145 and SC514, in PC9 and H460 cells. Overexpression and knockdown of UBE2S in H460 and PC9 cells showed the protein levels of IκBα were regulated. Immunoprecipitation, immunofluorescent staining, a glutathione S transferase (GST) pull-down assay, and an in vitro binding assay showed the direct binding of UBE2S with IκBα. Protein levels of nuclear p65 and luciferase assay showed the NF-κB signaling was regulated UBE2S. EMT markers and migrative ability of cancer cells were also regulated by UBE2S. Zebrafish xenograft tumor model showed the reduction of migrative PC9 cells by knockdown of UBE2S.ConclusionHigher UBE2S expressed in lung adenocarcinomas could bind with IκBα for activation of NF-κB signaling to promote metastasis of cancer cells. UBE2S might be a potential therapeutic target for lung adenocarcinomas.