Human Non-small Cell Lung Cancer Research Articles

Deciphering the effect of Potentilla fulgens root extract against healthy HUVEC cell line and cancer cell lines (A549 and SKOV-3)

BackgroundPotentilla fulgens, a highly valued indigenous medicinal herb grown in high altitudes of the Himalayan region with anticancer, hypoglycaemic, antibacterial, anti-inflammatory, and antiulcerogenic properties, are used in traditional systems of medicine. This study was aimed to investigate the effect of P. fulgens root extract, as one of the natural alternatives to chemotherapeutic drugs used in cancer treatment, on proliferation, apoptosis, and autophagy of human non-small cell lung cancer cell line (A549), human ovarian cancer cell line (SKOV-3), and healthy human umbilical vein endothelial cell line (HUVEC). MethodsAnti-proliferative effect was assessed by MTT assay. The expression of autophagy and apoptosis-related proteins was evaluated by western blotting. Total oxidant status (TOS) and total antioxidant capacity (TAC) test were determined using standard kit methods. ResultsOur results showed that the extract inhibited proliferation of HUVEC, A549, and SKOV-3 cells in a dose-dependent manner. MTT assay analysis revealed that the extract significantly (P<0.05) induced mortality in HUVEC, A549, and SKOV-3 cells. Western blot results revealed increased expression of NF-κB after the extract treatment but led to the down-regulation in Beclin-1, Bax, extracellular-signal-related kinase 1 and 2, Sequestosome-1, and Cleaved Casp-3 levels. Treatment groups showed an increase in TOS and TAC values in A549 and SKOV-3 cell lines, while HUVEC cell line showed an increase in TAC and a decrease in TOS values, compared to the control group. ConclusionsOur findings indicated that P. fulgens root extract inhibited the proliferation of healthy cells and cancer cells through cell cycle arrest, representing its limited application as therapeutic agent in cancer treatment.

Cisplatin-resistance and aggressiveness are enhanced by a highly stable endothelin-converting enzyme-1c in lung cancer cells

BackgroundLung cancer constitutes the leading cause of cancer mortality. High levels of endothelin-1 (ET-1), its cognate receptor ETAR and its activating enzyme, the endothelin-converting enzyme-1 (ECE-1), have been reported in several cancer types, including lung cancer. ECE-1 comprises four isoforms, which only differ in their cytoplasmic N-terminus. Protein kinase CK2 phosphorylates the N-terminus of isoform ECE-1c, increasing its stability and leading to enhanced invasiveness in glioblastoma and colorectal cancer cells, which is believed to be mediated by the amino acid residue Lys-6, a conserved putative ubiquitination site neighboring the CK2-phosphorylated residues Ser-18 and Ser-20. Whether Lys-6 is linked to the acquisition of a cancer stem cell (CSC)-like phenotype and aggressiveness in human non–small cell lung cancer (NSCLC) cells has not been studied.MethodsIn order to establish the role of Lys-6 in the stability of ECE-1c and its involvement in lung cancer aggressiveness, we mutated this residue to a non-ubiquitinable arginine and constitutively expressed the wild-type (ECE-1cWT) and mutant (ECE-1cK6R) proteins in A549 and H1299 human NSCLC cells by lentiviral transduction. We determined the protein stability of these clones alone or in the presence of the CK2 inhibitor silmitasertib, compared to ECE-1cWT and mock-transduced cells. In addition, the concentration of secreted ET-1 in the growth media was determined by ELISA. Expression of stemness genes were determined by Western blot and RT-qPCR. Chemoresistance to cisplatin was studied by MTS viability assay. Migration and invasion were measured through transwell and Matrigel assays, respectively, and the side-population was determined using flow cytometry.ResultsECE-1cK6R displayed higher stability in NSCLC cells compared to ECE-1cWT-expressing cells, but ET-1 secreted levels showed no difference up to 48 h. Most importantly, ECE-1cK6R promoted expression of the stemness genes c-Myc, Sox-2, Oct-4, CD44 and CD133, which enhance cellular self-renewal capability. Also, the ECE-1cK6R-expressing cells showed higher cisplatin chemoresistance, correlating with an augmented side-population abundance due to the increased expression of the ABCG2 efflux pump. Finally, the ECE-1cK6R-expressing cells showed enhanced invasiveness, which correlated with the regulated expression of known EMT markers.ConclusionsOur findings suggest an important role of ECE-1c in lung cancer. ECE-1c is key in a non-canonical ET-1-independent mechanism which triggers a CSC-like phenotype, leading to enhanced lung cancer aggressiveness. Underlying this mechanism, ECE-1c is stabilized upon phosphorylation by CK2, which is upregulated in many cancers. Thus, phospho-ECE-1c may be considered as a novel prognostic biomarker of recurrence, as well as the CK2 inhibitor silmitasertib as a potential therapy for lung cancer patients.

Nerolidol inhibits proliferation and triggers ROS-facilitated apoptosis in lung carcinoma cells via the suppression of MAPK/STAT3/NF-κB and P13K/AKT pathways.

Lung cancer (LC) is the leading cause of malignancy-related mortalities globally, and the existing treatment interventions are associated with harmful side effects. In the current study, we evaluated the anti-tumor efficiency of nerolidol (NRD) on human non-small cell lung cancer (NSCLC) cells. Nerolidol is a sesquiterpene alcohol extracted from the essential oils of aromatic flora with known anti-cancer activities. The latent action of NRD on antiproliferative and apoptotic effects in A549 cells is uncertain. Thus, our work is designed to explore the antiproliferative and apoptotic actions of NRD (20 and 25 μM/mL) against A549 cells. The activity of NRD on A549 cell cytotoxicity, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), apoptosis, anti-apoptotic proteins, and MAPK/TAT3/NF-κB and P13K/AKT signaling pathways were assessed using MTT tests, dichlorodihydrofluorescein diacetate (DCFH-DA), dual acridine orange/ethidium bromide (AO/EB), DAPI, Rh-123, reverse transciption polymerase chain reaction (RT-PCR), and western blot analyses. We found that NRD could inhibit NSCLC cell viability through elevated intracellular ROS and MMP loss and elicited apoptosis in a quantity-dependent manner. Similarly, NRD can reduce inflammatory cytokines and anti-apoptotic elements, as well as trigger apoptotic signaling pathways. Our data established that NRD decreases A549 cell proliferation through ROS-mediated apoptosis, triggering the MAPK/STAT3/NF-κB and P13K/AKT pathways, suggesting that NRD is a possible protective remedy for NSCLC.

GOLPH3 inhibition overcomes cisplatin resistance by restoring the glutathione/reactive oxygen species balance in the A549 non‑small cell lung cancer cell line.

Cisplatin resistance is common in non‑small cell lung cancer (NSCLC); however, the molecular mechanisms remain unclear. The present study aimed to identify a new function of Golgi phosphoprotein 3 (GOLPH3) in NSCLC‑associated cisplatin resistance. Using A549 human NSCLC cells and the cisplatin‑resistant variant, stable cell lines with GOLPH3 knockdown or overexpression were established using lentiviral vectors. Through Cell Counting Kit‑8 and EdU assays, it was revealed that knockdown of GOLPH3 significantly enhanced cisplatin sensitivity in NSCLC cells. Specifically, flow cytometric analysis showed that GOLPH3 knockdown promoted apoptosis and G2‑phase cell cycle arrest in A549 cells. Mechanistically, intracellular reactive oxygen species (ROS) and glutathione (GSH) levels were measured using assay kits, and it was demonstrated that GOLPH3 knockdown decreased intracellular GSH levels, and further attenuated intracellular cisplatin efflux and GSH/ROS imbalance. In addition, tumor‑sphere formation assays verified that GOLPH3 knockdown mitigated the stem cell‑like phenotype of NSCLC cells. In conclusion, the present findings indicated the relevance of GOLPH3 in NSCLC‑associated cisplatin resistance, and thus targeting GOLPH3 may be developed into a combination therapy to overcome cisplatin resistance.

One-pot synthesis of fused isoxazolo[4′,5′:4,5]thiopyrano[2,3-d]pyrimidines as potent EGFR targeting anti-lung cancer agents

The requirement for scaffolds has prompted synthetic chemists to devise simple and effective methods for optimal synthesis, which are critical in the medical industry. Under comparatively optimized conditions, a click followed by a CC bond coupling reaction between iodoalkyne (4) and substituted nitrile oxide was utilized to explore the synthesis of fused isoxazoles containing thiopyrano[2,3-d]pyrimidine under microwave irradiation. The synthesized compounds were tested for their anticancer activity against EGFR wild-type human non-small cell lung cancer cells (NCI-H460 and A549). The compounds 6i and 6l have shown more potent activity against both cancer cell lines as compared to standard drugs doxorubicin and erlotinib. And also compounds 6e, 6j, and 6k have shown more potent activity as compared to Doxorubicin and moderate activity compared to erlotinib. Later, in vitro EGFR results of more potent compounds revealed that compounds 6l and 6k have shown potent EGFR activity compared to standard erlotinib. To evaluate the molecular interactions of more potent compounds with the human epidermal growth factor receptor. It was observed that all the potent compounds exhibited greater binding energies in comparison to the standard drug erlotinib.

Zongertinib (BI 1810631), an irreversible HER2 TKI, spares EGFR signaling and improves therapeutic response in preclinical models and patients with HER2-driven cancers.

Mutations in HER2 occur in 2-4% of non-small cell lung cancer (NSCLC) and confer poor prognosis. ERBB-targeting tyrosine kinase inhibitors, approved for treating other HER2-dependent cancers, are ineffective in HER2 mutant NSCLC due to dose-limiting toxicities or suboptimal potency. We report the discovery of zongertinib (BI 1810631), a covalent HER2 inhibitor. Zongertinib potently and selectively blocks HER2, while sparing EGFR, and inhibits the growth of cells dependent on HER2 oncogenic driver events, including HER2-dependent human cancer cells resistant to trastuzumab deruxtecan. Zongertinib displays potent anti-tumor activity in HER2-dependent human NSCLC xenograft models and enhances the activities of antibody-drug conjugates and KRASG12C inhibitors, without causing obvious toxicities. The preclinical efficacy of zongertinib translates in objective responses in patients with HER2-dependent tumors, including cholangiocarcinoma (SDC4-NRG1 fusion) and breast cancer (V777L HER2 mutation) thus supporting the ongoing clinical development of zongertinib.

USP5 Stabilizes IKBKG Through Deubiquitination to Suppress Ferroptosis and Promote Growth in Non-small Cell Lung Cancer.

Ferroptosis, a distinctive modality of cell mortality, has emerged as a critical regulator in non-small cell lung cancer (NSCLC). The deubiquitinating enzyme USP5 has established an oncogenic role in NSCLC. However, its biological relevance in NSCLC cell ferroptosis is currently unexplored. Expression analysis was performed by quantitative PCR (qPCR), immunohistochemistry (IHC) and immunoblotting. Animal xenograft studies were used to detect USP5's role in tumor growth. Cell proliferation, colony formation and apoptotic ratio were assessed by CCK-8, colony formation and flow cytometry assays, respectively. Cell ferroptosis was evaluated by gauging ROS, MDA, GSH, SOD, and Fe2+ contents. The USP5/IKBKG relationship and the ubiquitinated IKBKG were evaluated by Co-IP experiments. USP5 expression was elevated in human NSCLC. USP5 depletion suppressed NSCLC cell in vitro and in vivo growth and enhanced cell apoptosis. Moreover, USP5 depletion induced ferroptosis in NSCLC cell lines. Mechanistically, USP5 could enhance the stability of IKBKG protein through deubiquitination. Re-expression of IKBKG partially but significantly abolished USP5 depletion-mediated anti-growth and pro-ferroptosis effects in NSCLC cells. Our study demonstrates that USP5 suppresses ferroptosis and enhances growth in NSCLC cells by stabilizing IKBKG protein through deubiquitination. Targeting USP5 expression is an encouraging strategy to block NSCLC progression.

Design, synthesis and antitumor effects of lupeol quaternary phosphonium salt derivatives

Lupeol is a natural pentacyclic triterpenoid with a wide range of biological activities. To improve the water solubility and targeting of lupeol, in the following study, we synthesized 27 lupeol derivatives in the first series by introducing lipophilic cations with lupeol as the lead compound. Through the screening of different cancer cells, we found that some of the derivatives showed better activity than cisplatin against human non-small cell lung cancer A549 cells, among which compound 6c was found to have an IC50 value of 1.83 μM and a selectivity index of 21.02 (IC50MRC-5/IC50A549) against A549 cells. To further improve the antiproliferative activity of the compounds, we replaced the ester linkage of the linker with a carbamate linkage and synthesized a second series of five lupeol derivatives which were screened for activity, among which compound 14f was found to have an IC50 value of 1.36 μM and a selectivity index of 15.60 (IC50MRC-5/IC50A549) against A549 cells. We further evaluated the bioactivity of compounds 6c and 14f and found that both compounds induced apoptosis in A549 cells, promoted an increase in intracellular reactive oxygen species and decrease in mitochondrial membrane potential, and inhibited the cell cycle in the S phase. Of the compounds, compound 14f showed stronger bioactivity than compound 6c. We then selected compound 14f for molecular-level Western blot evaluation and in vivo evaluation in the zebrafish xenograft A549 tumor cell model. Compound 14f was found to significantly downregulate Bcl-2 protein expression and upregulate Bax, Cyt C, cleaved caspase-9, and cleaved caspase-3 protein expression, and 14f was found to be able to inhibit the proliferation of A549 cells in the zebrafish xenograft model. The above results suggest that compound 14f has great potential in the development of antitumor drugs targeting mitochondria.

Iridoids and lignans from Valeriana officinalis and their bioactivities

Seven undescribed iridoids, identified as valeriridoids A-E (compounds 1, 5, 18, 19a, 19b, 20a, and 20b), were isolated from the roots and rhizomes of Valeriana officinalis L., along with sixteen known iridoids and nine known lignans. The structures were elucidated using NMR and MS spectroscopy, and the absolute configurations of the undescribed iridoids were determined through ECD calculations. Valeriridoids D and E were found to be epimeric and scalemic mixtures, which were successfully resolved through a chiral column. These isolated iridoids were evaluated for their antiproliferative activities, with valeriridoid A, jatamanvaltrates P, and Q showing significant effects against human non-small cell lung cancer cells, with IC50 values of 14.68, 8.77, and 10.07 μM, respectively. Furthermore, the antihyperglycemic properties of the compounds were investigated in insulin-resistant human hepatoblastoma cells induced by palmitic acid treatment, revealing that valeriridoid A, jatamanvaltrates P, and Q at a concentration of 10 μM led to a notable increase in glucose consumption.

A Novel Tryptanthrin Derivative D6 Induces Apoptosis and DNA Damage in Non-small-cell Lung Cancer Cells Through Regulating the EGFR Pathway.

Non-small-cell lung cancer is a prevalent malignancy associated with significant morbidity and mortality rates. Tryptanthrin and its derivatives have exhibited potent antitumor activity. This study aims to investigate the inhibitory effect of a novel synthesized tryptanthrin derivative D6 on proliferation and the possible mechanism of human non-small cell lung cancer cell lines (A549) in vitro. In this study, MTT assay, cell migration, colony formation assay, cell cycle analysis, cell apoptosis, JC- 1 staining assay, reactive oxygen species analysis, proteomics, western blotting, high content screening and absorption titrations analysis were performed. We found that D6 inhibited both the proliferation and migration, induced cell cycle arrest in the G2/M phase, increased levels of ROS, decreased mitochondrial membrane potential, and promoted apoptosis in A549 cells. Further mechanistic studies found that D6 reduced EGFR expression in A549 cells and inhibited the EGFR pathway by decreasing phosphorylation levels of EGFR, Stat3, AKT and Erk1/2. Moreover, DNA damage induced by D6 involved an increase in p53/MDM2 ratio and concentration-dependent accumulation of micronuclei. D6 demonstrated significant antitumor activity against A549 cells by inhibiting the EGFR signaling pathway, inducing DNA damage, and subsequently leading to oxidative stress, apoptosis, and cell cycle arrest. Our findings suggest that D6 exhibits potential as an NSCLC drug, owing to its attributes such as antiproliferative activity and ability to induce apoptosis by attenuating the EGFR-mediated signaling pathway.

Combined inhibition of MET and VEGF enhances therapeutic efficacy of EGFR TKIs in EGFR-mutant non-small cell lung cancer with concomitant aberrant MET activation

Abstract Background Aberrant activation of mesenchymal epithelial transition (MET) has been considered to mediate primary and acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) in EGFR-mutant non-small cell lung cancer (NSCLC). However, mechanisms underlying this process are not wholly clear and the effective therapeutic strategy remains to be determined. Methods The gefitinib-resistant NSCLC cell lines were induced by concentration increase method in vitro. Western blot and qPCR were used to investigate the relationship between MET and vascular endothelial growth factor (VEGF)/VEGF receptor 2 (VEGFR2) signaling pathway. Double luciferase reporter gene and co-immunoprecipitation were used to further reveal the regulation mechanism between MET and VEGF/VEGFR2. The effect of combined inhibition of MET and VEGF/VEGFR2 signaling pathway on the therapeutic sensitivity of EGFR-TKI in gefitinib resistant cell lines with MET aberration was verified ex vivo and in vivo. Results We successfully obtained two gefitinib-resistant NSCLC cell lines with EGFR mutation and abnormal activation of MET. We observed that MET formed a positive feedback loop with the VEGF/VEGFR2 signaling, leading to persistent downstream signaling activation. Specifically, MET up-regulated VEGFR2 expression in a MAPK/ERK/ETS1-dependent manner, while VEGF promoted physical interaction between VEGFR2 and MET, thereby facilitating MET phosphorylation. A MET inhibitor, crizotinib, combined with an anti-VEGF antibody, bevacizumab, enhanced the sensitivity of NSCLC cells to gefitinib and synergistically inhibited the activation of downstream signaling in vitro. Dual inhibition of MET and VEGF combined with EGFR TKIs markedly restrained tumor growth in both human NSCLC xenograft models and in an EGFR/MET co-altered case. Conclusions Our work reveals a positive feedback loop between MET and VEGF/VEGFR2, resulting in continuous downstream signal activation. Combined inhibition of MET and VEGF/VEGFR2 signaling pathway may be beneficial for reversing EGFR TKIs resistance.

Hydrogen sulfide-mediated persulfidation regulates homocysteine metabolism and enhances ferroptosis in non-small cell lung cancer

Hydrogen sulfide (H₂S), a metabolite of the transsulfuration pathway, has been implicated in ferroptosis, a unique form of cell death caused by lipid peroxidation. While the exact mechanisms controlling ferroptosis remain unclear, our study reveals that H₂S sensitizes human non-small cell lung cancer (NSCLC) cells to this process, particularly when cysteine levels are low. Combining H₂S with cystine depletion significantly enhances the effectiveness of ferroptosis-based cancer therapy. Mechanistically, H₂S persulfidates the 195th cysteine on S-adenosyl homocysteine hydrolase (SAHH), reducing its enzymatic activity. This leads to decreased homocysteine levels, subsequently lowering cysteine and glutathione concentrations under cystine depletion conditions. These changes ultimately increase the vulnerability of NSCLC cells to ferroptosis. Our findings establish H₂S as a key regulator of homocysteine metabolism and a critical factor in determining NSCLC cell susceptibility to ferroptosis. These results highlight the potential of H₂S-based therapies to improve the efficacy of ferroptosis-targeted cancer treatments for NSCLC.

Therapeutic effects of paeonol on non‑small cell lung cancer cells via regulation of the MAPK pathway.

The present study aimed to investigate the molecular mechanisms by which paeonol impedes DNA damage repair, induces apoptosis and inhibits cell viability via the mitogen-activated protein kinase (MAPK) pathway. Firstly, normal human bronchial epithelial cells (BEAS-2B) and non-small cell lung cancer cells (H1299) were employed in the study as cellular models. Following cultivation, the cells were divided into experimental and control groups, and were treated with different concentrations of paeonol. Subsequently, various techniques, including western blotting, Cell Counting Kit-8, colony formation, TUNEL and comet assays were conducted to evaluate the effects of paeonol on cell viability, colony-forming ability, apoptosis levels and DNA damage in H1299 cells. According to the experimental results, paeonol significantly reduced the viability and colony formation ability of H1299 cells, but substantially increased apoptosis and DNA damage. These effects were enhanced in response to higher concentrations of paeonol. Furthermore, western blot analysis revealed that paeonol treatment decreased the protein levels of B-cell lymphoma 2 and breast cancer susceptibility gene 1, while it increased the expression levels of cleaved-PARP, cleaved-caspase 3, γH2AX and P21. Additionally, the phosphorylated levels of extracellular signal-regulated kinase 1, c-Jun N-terminal kinase and P38 within the MAPK signaling pathway were diminished. Collectively, the present study demonstrated that paeonol may inhibit the metabolic activity and proliferative capability of H1299 cells, and that it could promote apoptosis and obstruct DNA damage repair by modulating the MAPK signaling pathway.

5-Azacytidine treatment inhibits the development of lung cancer models via epigenetic reprogramming and activation of cellular pathways with anti-tumor activity

Background and aims. Non-small cell lung cancer (NSCLC) treatment is challenged by late detection and limited therapeutic options. Aberrant DNA methylation, a common epigenetic alteration in NSCLC, offers new therapeutic avenues. This study aims to evaluate the combined effects of 5-Azacytidine (5- Aza), an epigenetic modifier, and ionizing radiation (IR) on NSCLC, exploring the underlying molecular mechanisms and therapeutic potential. Methods. In this study, we examined the effects of 5-Aza combined with IR in both in vitro and in vivo models of NSCLC. Five human NSCLC cell lines were treated with 5-Aza and IR. Cell viability, colony formation, wound healing, and transwell migration assays were performed to assess treatment effects. Microarray and qPCR analyses were conducted to identify gene expression changes. Additionally, subcutaneous and orthotopic xenograft models were used to evaluate the treatment’s efficacy in vivo. Results. Treatment with 5-Aza and IR resulted in significant reductions in cell viability, colony formation, and migration in NSCLC cell lines. Microarray analysis revealed significant changes in gene expression, including the upregulation of apoptosis-related genes and the downregulation of cell proliferation-related genes. In vivo studies demonstrated a notable reduction in tumor growth and metastasis in both subcutaneous and orthotopic NSCLC models following 5-Aza and IR treatment. Histological and bioluminescent imaging confirmed the therapeutic effects of the combined treatment. Conclusions. The combination of 5-Aza and IR shows promise as an effective treatment for NSCLC, enhancing apoptosis and reducing tumor growth through epigenetic modulation.

Fascin Inhibitor NP-G2-044 Decreases Cell Metastasis and Increases Overall Survival of Mice-Bearing Lung Cancers.

Fascin is an actin-binding protein that promotes tumor metastasis. The inhibition of fascin on the progress of non-small cell lung cancer (NSCLC) is not very clear. Hence, this study explored the potential effect of NP-G2-044, a novel fascin inhibitor, in human NSCLC lines and the Lewis lung cancer (LCC) mice model. The growth of cells was analyzed via CCK-8 assays, and the flow cytometry was adopted for cell cycle and apoptosis analysis, as well as the migration and invasion of NSCLC cells with or without NP-G2-044. The therapy of NP-G2-044, which synergizes with cisplatin and PD-1, was evaluated in the established xenograft Lewis's lung cancer of mice. Fascin was overexpressed in human NSCLC cells, and inhibition of fascin by NP-G2-044 attenuated NSCLC cell growth and remarkably undermined the ability of migration and invasion in vitro, which was related to the reduced epithelialmesenchymal transition (EMT) including downregulation of N-cadherin and vimentin, and upregulation of E-cadherin. Further results implied that the above changes may be partially mediated by the Wnt/β-catenin pathway. In vivo, NP-G2-044 slowed down tumor development and enhanced overall survival alone, leading to synergistic anticancer effects with cisplatin or PD-1 inhibitor. Fascin inhibition could inhibit the metastasis of NSCLC and has the potential to enhance the efficacy of cisplatin and PD-1 inhibitors by blocking the Wnt/β- catenin pathway.

Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in non-small cell lung cancer.

Non-small cell lung cancer (NSCLC) is a highly aggressive type of lung cancer with poor responses to traditional therapies such as surgery, radiotherapy, and chemotherapy. While immunotherapy has become an effective approach for treating multiple types of cancer, solid tumors frequently exhibit immune escape through various mechanisms, including downregulation of MHC I expression. However, whether the upregulation of MHC I expression can improve the immunotherapeutic effect on NSCLC remains unexplored. Suberoylanilide hydroxamic acid (SAHA) is a potent histone deacetylase (HDAC) inhibitor that has been applied clinically to treat lymphoma, but a high dose of SAHA kills tumor cells and normal cells without preference. Here, we report that low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by upregulating MHC I expression in NSCLC cells. Flow cytometric analysis, quantitative real-time PCR and western blot were used to analyze the expression of MHC I, STAT1 and Smad2/3 in both human and mouse NSCLC cell lines after SAHA treatment. The nuclear translocation of phosphorylated STAT1 and Smad2/3 was investigated by western blot and immunofluorescence staining. The mechanisms underlying STAT1 and Smad2/3 upregulation were analyzed through database searches and chromatin immunoprecipitation-qPCR. Finally, we assessed the antitumor effect of specific CD8+ T cells with SAHA treatment in vivo and in vitro. We showed that low-dose SAHA upregulated the expression of MHC I in NSCLC cell lines without affecting cell viability. We also provided evidence that high levels of MHC I induced by SAHA promoted the activation, proliferation, and cytotoxicity of specific CD8+ T cells in mouse models. Mechanistically, low-dose SAHA increased the levels of H3K9ac and H3K27ac in the promoters of the STAT1, Smad2 and Smad3 genes in NSCLC cells by inhibiting HDAC activity, resulting in elevated expression levels of STAT1, Smad2 and Smad3. The nuclear translocation of phosphorylated STAT1 and Smad2/3 markedly upregulated the expression of MHC I in NSCLC cells. Low-dose SAHA enhances CD8+ T cell-mediated antitumor immunity by boosting MHC I expression in NSCLC cells. Thus, we revealed a key mechanism of SAHA-mediated enhanced antitumor immunity, providing insights into a novel immunotherapy strategy for NSCLC.

Association of Wild-Type TP53 with Downregulation of Lovastatin Sensitivity in Human Non-Small Cell Lung Cancer Cells.

Statins inhibit 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the rate-limiting enzyme of the mevalonate pathway, and reduce cholesterol synthesis. They also have been demonstrated to improve prognosis in patients with various cancers, suggesting a potential anti-cancer effect of statins. However, there is no consensus on the molecular targets of statins for their anti-cancer effects. Docetaxel (DOC) is a microtubule-stabilizing agent currently used as a chemotherapeutic drug in several cancers, including lung cancer. Interestingly, the anti-cancer effects of either drug that are related to abnormal or wild-type TP53 gene have been implied. Therefore, the drug sensitivity of DOC and lovastatin in human lung cancer cells was evaluated. We found that H1355 (mutant TP53-E285K), CL1 (mutant TP53-R248W), and H1299 (TP53-null) human non-small cell lung cancer cells were more sensitive to lovastatin than A549 and H460 cells expressing wild-type TP53. Conversely, A549 and H460 cells showed higher sensitivity to DOC than H1299 and CL1 cells, as demonstrated by the MTT assay. When endogenous TP53 activity was inhibited by pifithrin-α in A549 and H460 cells, lovastatin sensitivities significantly increased, and cancer cell viabilities markedly reduced. These results indicate that TP53 status is associated with the anti-cancer effect of statins in human lung cancer cells. Mutated or null TP53 status is correlated with higher statin sensitivity. Furthermore, DOC-resistant H1299 (H1299/D8) cells showed significant sensitivity to lovastatin treatment compared to DOC-resistant A549 (A549/D16) cells, indicating a potential application of statins/chemotherapy combination therapy to control wild-type and abnormal TP53-containing human lung tumors.

The therapeutic effect of DX2 inhibition in nicotine-induced lung cancer progression

Alternative splicing products of AIMP2 and AIMP2-DX2 (DX2) have been reported to be associated with human lung cancer. In fact, DX2 expression is elevated in human lung cancers and DX2 transgenic mice also develop lung cancer, in particular, Small Cell Lung Cancer (SCLC). However, the mechanism by which DX2 is induced during cancer progression has not been clearly elucidated. Here, we show that DX2 is induced by nicotine, the main component of smoking-related chemicals, which can stabilize the human epidermal growth factor receptor 2 (HER2) protein and transcriptionally increase sonic hedgehog (Shh). Indeed, nicotine showed tumorigenicity via DX2 by promoting spheroid formation and in vivo lung and kidney cancer progression. Moreover, the elimination of DX2 using siRNA or an optimized inhibitor (SNU-14) blocked the induction of HER2, Shh and completely suppressed tumor sphere formation in response to nicotine. These results indicate that DX2 is critical for lung cancer progression, and a specific DX2 inhibitor would be useful for the treatment of human cancers, including SCLC and Non-Small Cell Lung Cancer (NSCLC).

Bone sialoprotein stimulates cancer cell adhesion through the RGD motif and the αvβ3 and αvβ5 integrin receptors.

Being implicated in bone metastasis development, bone sialoprotein (BSP) expression is upregulated in patients with cancer. While BSP regulates cancer cell adhesion to the extracellular matrix, to the best of our knowledge, the specific adhesive molecular interactions in metastatic bone disease remain unclear. The present study aimed to improve the understanding of the arginine-glycine-aspartic acid (RGD) sequence of BSP and the integrin receptors αvβ3 and αvβ5 in BSP-mediated cancer cell adhesion. Human breast cancer (MDA-MB-231), prostate cancer (PC-3) and non-small cell lung cancer (NSCLC; NCI-H460) cell lines were cultured on BSP-coated plates. Adhesion assays with varying BSP concentrations were performed to evaluate the effect of exogenous glycine-arginine-glycine-aspartic acid-serine-proline (GRGDSP) peptide and anti-integrin antibodies on the attachment of cancer cells to BSP. Cell attachment was assessed using the alamarBlue® assay. The present results indicated that BSP supported the adhesion of cancer cells. The RGD counterpart GRGDSP peptide reduced the attachment of all tested cancer cell lines to BSP by ≤98.4%. Experiments with anti-integrin antibodies demonstrated differences among integrin receptors and cancer cell types. The αvβ5 antibody decreased NSCLC cell adhesion to BSP by 84.3%, while the αvβ3 antibody decreased adhesion by 14%. The αvβ3 antibody decreased PC-3 cell adhesion to BSP by 46.4%, while the αvβ5 antibody decreased adhesion by 9.5%. Adhesion of MDA-MB-231 cells to BSP was inhibited by 54.7% with αvβ5 antibody. The present results demonstrated that BSP-induced cancer cell adhesion occurs through the binding of the RGD sequence of BSP to the cell integrin receptors αvβ3 and αvβ5. Differences between cancer types were found regarding the mediation via αvβ3 or αvβ5 receptors. The present findings may explain why certain cancer cells preferentially spread to the bone tissue, suggesting that targeting the RGD-integrin binding interaction could be a promising novel cancer treatment option.

Overcoming drug-resistant tumors with selection gene drives

Drug resistance is a major hurdle prohibiting effective treatment of many diseases, including cancer. Using model-guided designs, Leighow etal.1 engineered a dual-switch selection gene drive system custom designed to combat drug-resistant tumors. By demonstrating remarkable killing efficacies in preclinical models using human non-small lung cancer cells invitro and in mice, this work describes an attractive mindset to develop next-generation anticancer therapies.