Cisplatin In Lung Cancer Cells Research Articles

Celecoxib enhances the response of tumor cells to cisplatin through upregulating PUMA in non–small cell lung cancer carrying wild-type p53

Abstract Celecoxib, a cyclooxygenase-2 inhibitor, can enhance the efficacy of chemotherapy; however, its effect seems inconsistent. In this study, we investigated whether celecoxib would increase the antiproliferative effects of cisplatin in human lung cancer cells. Our data demonstrated the synergistic effects of celecoxib with cisplatin in wild-type p53 cells and their antagonistic effects in mutated or deleted p53 cells. Combination indices of 0.82 to 0.93 reflected a synergistic effect between celecoxib and cisplatin in lung cancer cells with wild-type p53. Combination indices of 1.63 to 3.00 reflected antagonism between celecoxib and cisplatin in lung cancer cells with mutated or deleted p53. Compared with that in cells with mutated or deleted p53, apoptosis significantly increased with the addition of celecoxib and cisplatin in wild-type p53 cells (P < 0.05). Moreover, the results in vivo were similar to those in vitro: celecoxib combined with cisplatin slowed tumor growth in wild-type p53 groups and not in mutated or deleted p53 groups. In addition, celecoxib promoted p53 translocation into the nucleus and upregulated active p53 expression in wild-type p53 cells. Celecoxib combined with cisplatin upregulated PUMA (PUMA is a downstream gene of p53) after active p53 increased in wild-type p53 cells. In summary, the combination of celecoxib and cisplatin demonstrates clear synergistic effects in wild-type p53 cells and antagonistic effects in mutated or deleted p53 cells. The synergistic effect was achieved by apoptosis, induced by upregulating PUMA. Our results will provide a new treatment strategy for patients carrying wild-type p53, insensitive to cisplatin.

MiR-192/NKRF axis confers lung cancer cell chemoresistance to cisplatin via the NF-κB pathway.

BackgroundChemoresistance influences the therapeutic effect of cisplatin and remains a major obstacle to its clinical use. MicroRNAs are associated with drug resistance of various tumors. However, the association between microRNAs and cisplatin in lung cancer remains largely unclear.MethodsMicroRNA expression profile was identified by microRNA microarray between the lung cancer cisplatin‐sensitive cell line A549 (A549) and cisplatin‐resistant cell line A549/DDP (A549/DDP) and confirmed by quantitative real‐time‐PCR (qRT‐PCR). In vitro loss‐ and gain‐of‐function studies were performed to reveal the biological function of miR‐192 and related mechanism of the microRNA‐192/NKRF axis in lung cancer cell cisplatin resistance.ResultsIncreased miR‐192 expression was detected in A549/DDP cells compared to A549. High miR‐192 expression significantly suppressed apoptosis, enhanced proliferation, and conferred resistance to cisplatin in lung cancer cells. NF‐κB repressing factor (NKRF), which is involved in the regulation of the NF‐κB signaling pathway, was identified as a direct target of miR‐192. Overexpression of miR‐192 significantly increased the nuclear protein amount and transcriptional activation of NF‐κB and expression of cIAP1, cIAP2, Bcl‐xl and XIAP, whereas decreased miR‐192 expression did the opposite. Inhibition of the NF‐κB signal pathway by curcumin reversed the effect of upregulation of miR‐192 on proliferation, apoptosis and cisplatin‐resistance in lung cancer cells. These results indicated that miR‐192/ NKRF axis enhances the cisplatin resistance of lung cancer cells through activating the NF‐κB pathway in vitro.ConclusionsMiR‐192 plays a crucial role in cisplatin‐resistance of lung cancer cells. Thus, MiR‐192 may represent a therapeutic target for overcoming resistance to cisplatin‐based chemotherapy in lung cancer.

MicroRNA-106a-5p alleviated the resistance of cisplatin in lung cancer cells by targeting Jumonji domain containing 6

BackgroundCisplatin (DDP) is used for lung cancer therapy. MicroRNAs, small non-coding RNAs, may contribute to tumorigenesis as well as to drug resistance. We examined regulatory functions of miR-106a-5p in DDP-resistant lung cancer cells. MethodsDifferentially expressed miRNAs were provided by Gene Expression Omnibus (GEO) datasets and RT-qPCR examined RNA levels of miR-106a-5p and Jumonji domain-containing protein 6 (JMJD6), an enzyme causing lysine hydroxylation and arginine demethylation. Bindings were determined by luciferase reporter assay. Additionally, the half maximal inhibitory concentration (IC50) of DDP was determined through Cell Counting Kit-8 (CCK-8) after treated by DDP (0, 6.25, 12.5, 25, 50 and 75 μM) and apoptosis rates were analyzed using flow cytometry. Besides that, migratory ability and invasiveness were examined by transwell. Western blot was for measuring protein levels of Bcl-2, Bax in apoptosis and E-cadherin, N-cadherin in epithelial-mesenchymal transition (EMT). ResultsThe IC50 value of DDP-resistant A549 (A549/DDP) cells was higher, so were migration, invasion and N-cadherin in EMT while the apoptosis and E-cadherin in EMT were lower versus the parental A549 cells (no DDP resistance). MiR-106a-5p was low expressed in A549/DDP cells while its overexpression caused decreased migration, invasiveness and EMT but promoted apoptosis. JMJD6 was directly targeted and negatively regulated by miR-106a-5p. Inhibited JMJD6 decreased migratory ability, invasion and EMT but improved apoptosis. Moreover, knockdown of miR-106a-5p induced high level of JMJD6, migration, invasiveness and EMT but low apoptosis rates, which were restrained by JMJD6 suppression. ConclusionMiR-106a-5p/JMJD6 axis accelerated cell apoptosis and suppressed invasiveness, migration and EMT in A549/DDP cells.

Proteomic Analysis of the Non-genetic Response to Cisplatin in Lung Cancer Cells

Background: Drug resistance is the main cause of therapy failure in advanced lung cancer. Although non-genetic mechanisms play important roles in tumor chemoresistance, drug-induced epigenetic reprogramming is still poorly understood. Materials and Methods: The A549 cell line was used to generate cells with non-genetic resistance to cisplatin (CDDP), namely A549/CDDP cells. Bioorthogonal non-canonical amino acid tagging (BONCAT) and mass spectrometry were used to identify proteins modulated by CDDP in A549 and A549/CDDP cells. Results: Proteins related to proteostasis, telomere maintenance, cell adhesion, cytoskeletal remodeling, and cell redox homeostasis were found enriched in both cell lines upon CDDP exposure. On the other hand, proteins involved in drug response, metabolic pathways and mRNA processing and splicing were up-regulated by CDDP only in A549/CDDP cells. Conclusion: Our study revealed proteome dynamics involved in the non-genetic response to CDDP, pointing out potential targets to monitor and overcome epigenetic resistance in lung cancer.

PRMT5 Selective Inhibitor Enhances Therapeutic Efficacy of Cisplatin in Lung Cancer Cells.

As a therapeutic approach, epigenetic modifiers have the potential to enhance the efficacy of chemotherapeutic agents. Protein arginine methyltransferase 5 (PRMT5), highly expressed in lung adenocarcinoma, was identified to be involved in tumorigenesis. In the current study, we examined the potential antineoplastic activity of PRMT5 inhibitor, arginine methyltransferase inhibitor 1 (AMI-1), and cisplatin on lung adenocarcinoma. Bioinformatic analyses identified apoptosis, DNA damage, and cell cycle progression as the main PRMT5-associated functional pathways, and survival analysis linked the increased PRMT5 gene expression to worse overall survival in lung adenocarcinoma. Combined AMI-1 and cisplatin treatment significantly reduced cell viability and induced apoptosis. Cell cycle arrest in A549 and DMS 53 cells was evident after AMI-1, and was reinforced after combination treatment. Western blot analysis showed a reduction in demethylation histone 4, a PRMT5- downstream target, after treatment with AMI-1 alone or in combination with cisplatin. While the combination approach tackled lung cancer cell survival, it exhibited cytoprotective abilities on HBEpC (normal epithelial cells). The survival of normal bronchial epithelial cells was not affected by using AMI-1. This study highlights evidence of novel selective antitumor activity of AMI-1 in combination with cisplatin in lung adenocarcinoma cells.

The Mechanisms of Yu Ping Feng San in Tracking the Cisplatin-Resistance by Regulating ATP-Binding Cassette Transporter and Glutathione S-Transferase in Lung Cancer Cells.

Cisplatin is one of the first line anti-cancer drugs prescribed for treatment of solid tumors; however, the chemotherapeutic drug resistance is still a major obstacle of cisplatin in treating cancers. Yu Ping Feng San (YPFS), a well-known ancient Chinese herbal combination formula consisting of Astragali Radix, Atractylodis Macrocephalae Rhizoma and Saposhnikoviae Radix, is prescribed as a herbal decoction to treat immune disorders in clinic. To understand the fast-onset action of YPFS as an anti-cancer drug to fight against the drug resistance of cisplatin, we provided detailed analyses of intracellular cisplatin accumulation, cell viability, and expressions and activities of ATP-binding cassette transporters and glutathione S-transferases (GSTs) in YPFS-treated lung cancer cell lines. In cultured A549 or its cisplatin-resistance A549/DDP cells, application of YPFS increased accumulation of intracellular cisplatin, resulting in lower cell viability. In parallel, the activities and expressions of ATP-binding cassette transporters and GSTs were down-regulated in the presence of YPFS. The expression of p65 subunit of NF-κB complex was reduced by treating the cultures with YPFS, leading to a high ratio of Bax/Bcl-2, i.e. increasing the rate of cell death. Prim-O-glucosylcimifugin, one of the abundant ingredients in YPFS, modulated the activity of GSTs, and then elevated cisplatin accumulation, resulting in increased cell apoptosis. The present result supports the notion of YPFS in reversing drug resistance of cisplatin in lung cancer cells by elevating of intracellular cisplatin, and the underlying mechanism may be down regulating the activities and expressions of ATP-binding cassette transporters and GSTs.

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.

PD-0332991 combined with cisplatin inhibits nonsmall cell lung cancer and reversal of cisplatin resistance.

Background: Acquired resistance of chemotherapy, especially cisplatin, is a major challenge in lung cancer treatment. We conducted this study to examine whether a cyclin D kinase 4/6 (CDK4/6) inhibitor, PD 0332991, could reverse cisplatin resistance in human lung cancer cells. In addition, we explored the underlying mechanisms. Method: We used CCK‐8 assay to got the IC50 of PD‐0332991 and cisplatin in A549 and A549/CDDP respectively. CCK‐8 assay, CalcuSyn 2.0 software, cell cycle distribution and apoptosis used to identify PD‐0332991 could reverse the acquired resistance of cisplatin. At last, western‐blot used to show the mechanism of PD‐0332991 enhances the effects of cisplatin. Results: We found that PD‐0332991 potentiated cisplatin‐induced growth inhibition in both cisplatin‐sensitive (A549) and cisplatin‐resistant (A549/CDDP) cells via downregulation of the proliferation, induction of apoptosis (A549 increased to 7.06%; A549/CDDP increased to 7.03%), and G0/G1 cell cycle arrest (A549 increased to 9.15%; A549/CDDP increased to 49.92%). Western blot analysis revealed that PD‐0332991 enhance the effect of cisplatin through inhibit Rb‐E2Fs pathway. Conclusions: These findings suggest that PD‐0332991 could reverse the acquired resistance of cisplatin in lung cancer cells and provide a novel treatment strategy for lung cancer patients with cisplatin resistance.

Circulating exosomes in obstructive sleep apnea increased the growth and proliferation of lung cancer cells through activation of ERK/C-MYC axis and decreased cytotoxicity of cisplatin in lung cancer cells

Circulating exosomes in obstructive sleep apnea increased the growth and proliferation of lung cancer cells through activation of ERK/C-MYC axis and decreased cytotoxicity of cisplatin in lung cancer cells

PTC-209 Anti-Cancer Effects Involved the Inhibition of STAT3 Phosphorylation.

Introduction: Lung, breast, and colorectal cancers are the leading causes of cancer-related deaths despite many therapeutic options, including targeted therapy and immunotherapies. Methods: Here, we investigated the impact of PTC-209, a small-molecule Bmi-1 inhibitor, on human cancer cell viability alone and in combination with anticancer drugs, namely, cisplatin, oxaliplatin, 5-fluorouracil, camptothecin, and Frondoside-A and its impact on cellular migration and colony growth in vitro and on tumor growth in ovo. Results: We demonstrate that PTC-209 causes a concentration- and time-dependent decrease in the cellular viability of lung cancer cells (LNM35 and A549), breast cancer cells (MDA-MB-231 and T47D), and colon cancer cells (HT-29, HCT8/S11, and HCT-116). Similarly, treatment with PTC-209 significantly decreased the growth of LNM35, A549, MDA-MB-231, and HT-29 clones and colonies in vitro and LNM35 and A549 tumor growth in the in ovo tumor xenograft model. PTC-209 at the non-toxic concentrations significantly reduced the migration of lung (LNM35 and A549) and breast (MDA-MB-231) cancer cells. Moreover, we show that PTC-209, at a concentration of 1 μM, enhances the anti-cancer effects of Frondoside-A in lung, breast, and colon cancer cells, as well as the effect camptothecin in breast cancer cells and the effect of cisplatin in lung cancer cells in vitro. However, PTC-209 failed to enhance the anti-cancer effects of oxaliplatin and 5-fluorouracil in colon cancer cells. Treatment of lung, breast, and colon cancer cells with PTC-209 (1 and 2.5 μM) for 48 h showed no caspase-3 activation, but a decrease in the cell number below the seeding level suggests that PTC-209 reduces cellular viability probably through inhibition of cell proliferation and induction of cell death via a caspase-3–independent mechanism. Molecular mechanism analysis revealed that PTC-209 significantly inhibited the STAT3 phosphorylation by decreasing the expression level of gp130 as early as 30 min post-treatment. Conclusion: Our findings identify PTC-209 as a promising anticancer agent for the treatment of solid tumors either alone and/or in combination with the standard cytotoxic drugs cisplatin and camptothecin and the natural product Frondoside-A.

P1.03-42 Angiotensin System Inhibitors Improve Survival in Stage IIIA NSCLC and Show Anti-Tumor Effect in Combination with Chemotherapy in a Model of NSCLC

There is increasing interest in the renin-angiotensin system and its influence on tumor microenvironment. This study investigates the anti-tumor effect of angiotensin system inhibitors (ASI) on the multi-modality treatment of stage IIIA NSCLC and examines a potential mechanism in a murine model of lung cancer. We retrospectively reviewed the medical records of 125 patients at a single institution diagnosed with clinical stage IIIA NSCLC who underwent induction chemo-radiotherapy followed by surgery between 2009-2015. Overall survival was compared in patients on or off ASI's. To assess the antitumor efficacy and mechanism of ASI’s, cell culture models of lung cancer were treated with losartan or combination losartan+cisplatin and assessed cell survival. Mechanism was investigated with markers of epithelial-mesenchymal transition or surrogates of other signaling pathways (AKT, Stat3, PD-L1). Losartan was then tested in a murine model of lung cancer. ASI was associated with improved overall survival on multi-variate analysis of patients treated with multi-modality therapy for stage IIIA NSLC (p =0.047) [Figure 1A]. Losartan(≥0.5μM) significantly inhibited proliferation and migration of multiple human lung cancer cells, (H441, H358, H1299, SW1573) and a murine lung cancer adenocarcinoma, TC-1. The combination of Losartan and cisplatin significantly improved the cytotoxic effect of cisplatin in lung cancer cells in vitro (SW1573 p =0.020, TC-1 p =0.012) and reduced the tumor volume of (SW1573-Nude mice, p =0.045 [Figure 1B]; TC-1-C57BL/6 mice, G, p =0.001) in a murine flank tumor model as compared to single drug treatment. Combination treatment also significantly inhibited epithelial to mesenchymal transition and down-regulated the expression of AKT, Stat3, and PD-L1. ASI treatment influences survival in stage IIIA NSCLC. Losartan improves the anti-tumor effect of cytotoxic chemotherapy in lung cancer invitro and significantly reduces tumor burden in a murine lung cancer model. This study suggests a role for ASI therapy in the treatment of lung cancer.

Renoprotective effect of scutellarin on cisplatin-induced renal injury in mice: Impact on inflammation, apoptosis, and autophagy

Cisplatin remains the standard first-line chemotherapeutic agent in the treatment of many types of cancers, but its clinical application is hindered by its severe nephrotoxicity. Previous studies reported that scutellarin enhanced the anti-cancer activity of cisplatin in lung cancer cells, with no confirmation on cisplatin-induced renal damage. Here, we investigated the nephroprotective effect of scutellarin on cisplatin-induced renal injury and its underlying mechanisms. Renal function, histological change, inflammation, apoptosis, autophagy and involved pathways were investigated. Pretreatment with scutellarin prevented cisplatin-induced decline of renal function including BUN, CRE, and histological damage. Scutellarin also reduced renal inflammation by suppressing the levels of pro-inflammatory cytokine, TNF-α and IL-6. Similarly, scutellarin administration inhibited apoptosis triggered by cisplatin through reducing the expressions of Cleaved caspase-3, Cleaved PARP, p53, and the ratio of Bax/Bcl-2. Moreover, scutellarin prevented cisplatin-induced inhibition of autophagy via enhancing LC3-II/LC3-I and Atg7, and inhibition of p62. Of note, the activations of JNK, ERK, p38 and stat3 induced by cisplatin were strikingly attenuated in scutellarin-treated mice. Thus, these results provide compelling evidence that scutellarin is a novel nephroprotectant against cisplatin-induced renal toxicity.

Correction: EGFR kinase domain mutation positive lung cancers are sensitive to intrapleural perfusion with hyperthermic chemotherapy (IPHC) complete treatment.

[This corrects the article DOI: 10.18632/oncotarget.6491.].

P1.03-14 Interaction Between Celecoxib and Cisplatin is Dependent on The p53 Status in Human NSCLC Cell Lines

As a cyclooxygenase-2 inhibitor, the potential of celecoxib, to enhance the efficacy of chemotherapy is being investigated in clinical trials related to cancer treatment. In this study, we investigated whether celecoxib would increase the anti-proliferative effects of cisplatin in human lung cancer cell lines. The results demonstrated the synergistic effects of celecoxib with cisplatin in wild-type p53 cells and their antagonistic effects in mutated or deleted p53 cells. Combination indices of 0.82–0.93 reflected a synergistic effect between celecoxib and cisplatin in lung cancer cells with wild-type p53. Combination indices of 1.63–3.00 reflected antagonism between celecoxib and cisplatin in lung cancer cells with mutated or deleted p53. Apoptosis was shown to increase with the addition of celecoxib and cisplatin. Apoptosis was accomplished by the downregulation of slug expression. Celecoxib increased the nuclear localization of active p53 in lung cancer cells of wild-type p53. Taken together, our data demonstrated clear synergistic effects in wild-type p53 cells and antagonistic effects in mutated or deleted p53 cells when celecoxib and cisplatin are combined.

Inhibiting Glycine Decarboxylase Suppresses Pyruvate-to-Lactate Metabolism in Lung Cancer Cells.

Glycine decarboxylase (GLDC) gene is frequently upregulated in various types of cancer including lung, prostate and brain. It catabolizes glycine to yield 5,10-methylenetetrahydrofolate, an important substrate in one-carbon metabolism for nucleotide synthesis. In this study, we used exon splicing modulating steric hindrance antisense oligonucleotide (shAON) to suppress GLDC expression and investigated its effect on pyruvate metabolism via hyperpolarized carbon-13 magnetic resonance spectroscopy (MRS). The MRS technique allows us to study in vivo metabolic flux in tumor tissues with/without GLDC-shAON intervention. Here, we show that GLDC-shAON treatment is able to suppress lung cancer cell growth and tumorigenesis, both in vitro and in vivo. The carbon-13 MRS results indicated that the conversion of pyruvate into lactate in GLDC-shAON-treated tumor tissues was significantly reduced, when compared with the control groups. This observation corroborated with the reduced activity of lactate dehydrogenase and pyruvate dehydrogenase in GLDC-shAON-treated lung cancer cells and tumor tissues. Glycolysis stress test showed that extracellular acidification rate was significantly suppressed after GLDC-shAON treatment. Besides lung cancer, the antitumor effect of GLDC-shAON was also observed in brain, liver, cervical, and prostate cancer cell lines. Furthermore, it enhanced the treatment efficacy of cisplatin in lung cancer cells. Taken together, our findings illustrate that pyruvate metabolism decreases upon GLDC inhibition, thereby starving cancer cells from critical metabolic fuels.

MicroRNA-130b targets PTEN to induce resistance to cisplatin in lung cancer cells by activating Wnt/β-catenin pathway.

More and more studies indicate the relevance of miRNAs in inducing certain drug resistance. Our study aimed to investigate whether microRNA‐130b‐3p (miR‐130b) mediates the chemoresistance as well as proliferation of lung cancer (LC) cells. MTS assay and apoptosis analysis were conducted to determine cell proliferation and apoptosis, respectively. Binding sites were identified using a luciferase reporter system, whereas mRNA and protein expression of target genes was determined by RT‐PCR and immunoblot, respectively. Mouse xenograft model was used to evaluate the role of miR‐130b in cisplatin resistance in vivo. The rising level of miR‐130b in cisplatin resistance LC cell lines (A549/CR and H446/CR) versus its parental cell lines, indicated its crucial relevance for LC biology. We identified PTEN as miR‐130b's major target and inversely correlated with miR‐130b expression in LC. Moreover, excessive miR‐130b expression promoted drug resistance and proliferation, decreased apoptosis of A549 cells. Suppression of miR‐130b enhanced drug cytotoxicity and reduced proliferation of A549/CR cells both internally and externally. Particularly, miR‐130b mediated Wnt/β‐catenin signalling pathway activities, chemoresistance and proliferation in LC cell, which was partially blocked following knockdown of PTEN. These findings suggest that miR‐130b targets PTEN to mediate chemoresistance, proliferation, and apoptosis via Wnt/β‐catenin pathway. The rising level of miR‐130b in cisplatin resistance LC cell lines (A549/CR and H446/CR) versus its parental cell lines, indicated its crucial relevance for LC biology. Moreover, excessive miR‐130b expression promoted drug resistance and proliferation, decreased apoptosis of A549 cells. These findings suggest that miR‐130b targets PTEN to mediate chemoresistance, proliferation, and apoptosis via Wnt/β‐catenin pathway.

NDRG1 Downregulates ATF3 and Inhibits Cisplatin-Induced Cytotoxicity in Lung Cancer A549 Cells.

N-myc downstream regulated gene 1 (NDRG1) plays a variety of roles in human cancers. Our previous studies showed that NDRG1 expression is elevated in non-small cell lung cancer and contributes to cancer growth. However, its function in apoptosis and chemoresistance in malignant tumors, including lung cancer, is not yet fully understood. In this study, we investigated the roles of NDRG1 in chemoresistance to cisplatin in lung cancer cells. We found that overexpression of NDRG1 significantly reduced cisplatin-induced cytotoxicity in lung cancer A549 cells, while overexpression of activating transcription factor 3 (ATF3), a stress-inducible gene found to be associated with apoptosis in some human cancers, significantly promoted cytotoxicity (P < 0.05). Further investigation showed that overexpression of NDRG1 significantly downregulated ATF3 and P53 expression in A549 cells, while overexpression of ATF3 significantly upregulated P53 expression (P < 0.05). In addition, cisplatin significantly upregulated ATF3, phospho-P53(ser46), and cleaved caspase 3 expression in lung cancer cells, but overexpression of NDRG1 in the presence of cisplatin reduced the level of these proteins elevated by cisplatin (P < 0.05). While, overexpression of ATF3 significantly promoted the cytoxicity induced by cisplatin in 1299 cells (p<0.05) (Figure 4), but overexpression of NDRG1 didn't regulate the cytoxicity induced by cisplatin (p>0.05). These results indicate that NDRG1 may contribute to cisplatin-resistance in lung cancer, possibly due to its function in the regulation of ATF3 expression.

The anti-cancer effects and mechanisms of Scutellaria barbata D. Don on CL1-5 lung cancer cells.

Lung cancer, with a poor prognosis and resistance to chemotherapy, is the most common malignant tumor and has the highest mortality rate worldwide. Scutellaria barbata D. Don (SB), which is derived from the dried whole plant of Labiatae, is a well-known anti-inflammatory and anti-cancer herb. The aim of this study was to examine the anti-cancer effects and precise regulatory mechanisms of SB in CL1-5 lung cancer cells. In an in vitro assay, we found that the anti-tumor mechanism of SB was due to P38/SIRT1-regulated cell apoptosis through G2/M phase arrest and ER stress-, intrinsic mitochondrial-, and extrinsic FAS/FASL-mediated pathways. Autophagy also plays a key role in SB-induced CL1-5 cell cytotoxicity. In addition, SB exerts additive effects with etoposide or cisplatin in lung cancer cells. In an in vivo assay, we found that SB significantly reduces tumor size with decreased proliferation and angiogenesis, as well as increased apoptosis and autophagy in CL1-5 tumor-bearing mice. These findings provided experimental evidence for the application of SB in the treatment of lung cancer.

Knockdown of REV3 synergizes with ATR inhibition to promote apoptosis induced by cisplatin in lung cancer cells.

It has been demonstrated that REV3, the catalytic subunit of the translesion synthesis (TLS) polymerase ζ, play an important role in DNA damage response (DDR) induced by cisplatin, and Ataxia-telangietasia mutated and Rad-3-related (ATR) knase is a central player in activating cell cycle checkpoint, stabilizing replication forks, regulating DDR, and promoting repair of DNA damage caused by cisplatin. Cancer cells deficient in either one of REV3 and ATR are more sensitive to cisplatin. However, whether co-inhibition of REV3 and ATR can further increase sensitivity of non-small cell lung cancer (NSCLC) cells to cisplatin is not clear. In this study, we show that REV3 knockdown combined with ATR inhibition further enhance cytotoxicity of cisplatin in NSCLC cells, including cisplatin-sensitive and -resistant cell lines, compared to individual knockdown of REV3 or ATR, which are accompanied by markedly caspase-dependent apoptosis response, pronounced DNA damage accumulation and severe impediment of interstrand crosslink (ICL), and double strand break (DSB) repair. Our results suggest that REV3 knockdown synergize strongly with ATR inhibition to significantly increase sensitivity of cisplatin in NSCLC cells by inhibiting ICL and DSB repair. Thus simultaneously targeting REV3 and ATR may represent one approach to overcome cisplatin resistance and improve chemotherapeutic efficacy in NSCLC treatment.

Fentanyl induces autophagy via activation of the ROS/MAPK pathway and reduces the sensitivity of cisplatin in lung cancer cells.

Cancer pain is the most common complication of lung carcinoma. Opioid agonist fentanyl is widely used for relieving pain in cancer patients, and cisplatin (DDP)‑based chemotherapy is commonly used for the treatment of advanced lung cancer; these two drugs are always used together in lung carcinoma patients. However, the mechanisms and related biological pathways by which fentanyl influences cisplatin sensitivity are relatively poorly reported. Here, we found that fentanyl reduces the sensitivity of cisplatin in human lung cancer cells and induces autophagy. Fentanyl induced reactive oxygen species (ROS) generation and JNK activation. N-acetyl‑L‑cysteine is a ROS scavenger and antioxidant, and the inhibition of JNK with SP600125 prevented fentanyl‑induced autophagy. We also found that 3-methyladenine (3-MA; an autophagy inhibitor) increased the sensitivity of DDP and weakened the inhibition of fentanyl. In conclusion, fentanyl reduces the sensitivity of cisplatin in lung cancer cells through the ROS-JNK-autophagy pathway, whereas the autophagy inhibitor 3-MA may weaken this effect.