Drug resistance in non-small cell lung Cancer (NSCLC): Impact of genetic and non-genetic alterations on therapeutic regimen and responsiveness

IGFBP2/ITGA5 promotes gefitinib resistance via activating STAT3/CXCL1 axis in non-small cell lung cancer

There is a paucity of comprehensive knowledge pertaining to the underlying mechanisms leading to gefitinib resistance in individuals diagnosed NSCLC harboring EGFR-sensitive mutations who inevitably develop resistance to gefitinib treatment within six months to one year. In our preceding investigations, we have noted a marked upregulation of IGFBP2 in the neoplastic tissues of NSCLC, predominantly in the periphery of the tissue, implying its plausible significance in NSCLC. Consequently, in the current research, we delved into the matter and ascertained the molecular mechanisms that underlie the participation of IGFBP2 in the emergence of gefitinib resistance in NSCLC cells. Firstly, the expression of IGFBP2 in the bronchoalveolar lavage fluid and lung cancer tissues of 20 NSCLC patients with gefitinib tolerance was found to be significantly higher than that of non-tolerant patients. Furthermore, in vitro and in vivo experiments demonstrated that IGFBP2 plays a significant role in the acquisition of gefitinib resistance. Mechanistically, IGFBP2 can activate STAT3 to enhance the transcriptional activity of CXCL1, thereby increasing the intracellular expression level of CXCL1, which contributes to the survival of lung cancer cells in the gefitinib environment. Additionally, we identified ITGA5 as a key player in IGFBP2-mediated gefitinib resistance, but it does not function as a membrane receptor in the process of linking IGFBP2 to intracellular signaling transduction. In conclusion, this study demonstrates the promoting role and mechanism of IGFBP2 in acquired gefitinib resistance caused by non-EGFR secondary mutations, suggesting the potential of IGFBP2 as a biomarker for gefitinib resistance and a potential intervention target.

First-line penpulimab combined with paclitaxel and carboplatin for metastatic squamous non-small-cell lung cancer in China (AK105-302): a multicentre, randomised, double-blind, placebo-controlled phase 3 clinical trial

BACKGROUND

Penpulimab is a novel programmed death (PD)-1 inhibitor. This study aimed to establish the efficacy and safety of first line penpulimab plus chemotherapy for advanced squamous non-small-cell lung cancer.

METHODS

This multicentre, randomised, double-blind, placebo-controlled, phase 3 clinical trial enrolled patients with locally advanced or metastatic squamous non-small-cell lung cancer from 74 hospitals in China. Eligible participants were aged 18-75 years, had histologically or cytologically confirmed locally advanced (stage IIIb or IIIc) or metastatic (stage IV) squamous non-small-cell lung cancer, were ineligible to complete surgical resection and concurrent or sequential chemoradiotherapy, had an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, did not have previous systemic chemotherapy for locally advanced or metastatic non-small-cell lung cancer, and had one or more measurable lesions according to RECIST (version 1.1). Participants were randomly assigned (1:1) to receive intravenous penpulimab 200 mg or placebo (excipient of penpulimab injection), plus paclitaxel 175 mg/m2 and carboplatin AUC of 5 intravenously on day 1 every 3 weeks for four cycles, followed by penpulimab or placebo as maintenance therapy. Stratification was done according to the PD-L1 tumour proportion score (<1% vs 1-49% vs ≥50%) and sex (male vs female). The participants, investigators, and other research staff were masked to group assignment. The primary outcome was progression-free survival assessed by the masked Independent Radiology Review Committee in the intention-to-treat population and patients with a PD-L1 tumour proportion score of 1% or more (PD-L1-positive subgroup). The primary analysis was based on the intention-to-treat analysis set (ie, all randomly assigned participants) and the PD-L1-positive subgroup. The safety analysis included all participants who received at least one dose of study drug after enrolment. This trial was registered with ClinicalTrials.gov (NCT03866993).

FINDINGS

Between Dec 20, 2018, and Oct 10, 2020, 485 patients were screened, and 350 participants were randomly assigned (175 in the penpulimab group and 175 in the placebo group). Of 350 participants, 324 (93%) were male and 26 (7%) were female, and 347 (99%) were of Han ethnicity. In the final analysis (June 1, 2022; median follow-up, 24·7 months [IQR 0-41·4]), the penpulimab group showed an improved progression-free survival compared with the placebo group, both in the intention-to-treat population (median 7·6 months, 95% CI 6·8--9·6 vs 4·2 months, 95% CI 4·2-4·3; HR 0·43, 95% CI 0·33-0·56; p<0·0001) and in the PD-L1-positive subgroup (8·1 months, 5·7-9·7 vs 4·2 months, 4·1-4·3; HR 0·37, 0·27-0·52, p<0·0001). Grade 3 or worse treatment-emergent adverse events occurred in 120 (69%) 173 patients in the penpulimab group and 119 (68%) of 175 in the placebo group.

INTERPRETATION

Penpulimab plus chemotherapy significantly improved progression-free survival in patients with advanced squamous non-small-cell lung cancer compared with chemotherapy alone. The treatment was safe and tolerable. Penpulimab combined with paclitaxel and carboplatin is a new option for first-line treatment in patients with this advanced disease.

FUNDING

The National Natural Science Foundation of China, Shanghai Municipal Health Commission, Chia Tai Tianqing Pharmaceutical, Akeso.

CRISPR/Cas9-mediated silencing of CD44: unveiling the role of hyaluronic acid-mediated interactions in cancer drug resistance

A comprehensive overview of CD44 (CD44 Molecule (Indian Blood Group)), a cell surface glycoprotein, and its interaction with hyaluronic acid (HA) in drug resistance mechanisms across various types of cancer is provided, where CRISPR/Cas9 gene editing was utilized to silence CD44 expression and examine its impact on cancer cell behavior, migration, invasion, proliferation, and drug sensitivity. The significance of the HA-CD44 axis in tumor microenvironment (TME) delivery and its implications in specific cancer types, the influence of CD44 variants and the KHDRBS3 (KH RNA Binding Domain Containing, Signal Transduction Associated 3) gene on cancer progression and drug resistance, and the potential of targeting HA-mediated pathways using CRISPR/Cas9 gene editing technology to overcome drug resistance in cancer were also highlighted.

Frequency and functional characterization of fusion genes in squamous cell carcinoma of the lung

INTRODUCTION

In contrast to lung adenocarcinoma (LUAD), targetable genetic alterations are less frequently detected in squamous cell carcinoma of the lung (LUSC). Over the last years, gene fusions have become promising targets in many solid cancers. Here, we analysed a cohort of LUSC, identified recurrent fusion genes and functionally characterised these tumour genomes.

METHODS

A subset of 1608 squamous cell carcinomas of the lung was analysed by means of the FusionPlex® Lung Panel to identify potentially targetable gene fusions using targeted next-generation sequencing. Cases harbouring recurrent gene fusions were further analysed using FISH, Cytoscan HD arrays and cell culture experiments.

RESULTS

We found both, known and novel gene fusions in about 3 % of the cases. Known fusions occurring in lung cancer included ALK::EML4, EGFRvIII, EZR::ROS1 and FGFR3::TACC. We further identified recurrent gene fusions of currently unknown biological function, involving EGFR::VSTM2A and NSD3::FGFR1 and showed that the occurrence of the EGFR::VSTM2A fusion is accompanied by high-level amplification of EGFR. Our analyses further revealed that the genomes of these LUSC patients are chromosomally unstable, which leads us to believe that such non-actionable genomic rearrangements may be a result of "chromosomal chaos" most probably not representing exclusive cancer-driving genes in this cancer entity.

CONCLUSIONS

We emphasise that caution should be taken when novel fusions are found and that the appearance of new gene fusions should always be interpreted in the molecular context of the respective disease.

KIAA1199 Correlates With Tumor Microenvironment and Immune Infiltration in Lung Adenocarcinoma as a Potential Prognostic Biomarker

Background: KIAA1199 has been considered a key regulator of carcinogenesis. However, the relationship between KIAA1199 and immune infiltrates, as well as its prognostic value in lung adenocarcinoma (LUAD) remains unclear. Methods: The expression of KIAA1199 and its influence on tumor prognosis were analyzed using a series of databases, comprising TIMER, GEPIA, UALCAN, LCE, Prognoscan and Kaplan-Meier Plotter. Further, immunohistochemistry (IHC), western blot (WB) and receiver operating characteristic (ROC) curve analyses were performed to verify our findings. The cBioPortal was used to investigate the genomic alterations of KIAA1199. Prediction of candidate microRNA (miRNAs) and transcription factor (TF) targeting KIAA1199, as well as GO and KEGG analyses, were performed based on LinkedOmics. TIMER and TISIDB databases were used to explore the relationship between KIAA1199 and tumor immune infiltration. Results: High expression of KIAA1199 was identified in LUAD and Lung squamous cell carcinoma (LUSC) patients. High expression of KIAA1199 indicated a worse prognosis in LUAD patients. The results of IHC and WB analyses showed that the expression level of KIAA1199 in tumor tissues was higher than that in adjacent tissues. GO and KEGG analyses indicated KIAA1199 was mainly involved in extracellular matrix (ECM)-receptor interaction and extracellular matrix structure constituent. KIAA1199 was positively correlated with infiltrating levels of CD4+ T cells, macrophages, neutrophil cells, dendritic cells, and showed positive relationship with immune marker subsets expression of a variety of immunosuppressive cells. Conclusion: High expression of KIAA1199 predicts a poor prognosis of LUAD patients. KIAA1199 might exert its carcinogenic role in the tumor microenvironment via participating in the extracellular matrix formation and regulating the infiltration of immune cells in LUAD. The results indicate that KIAA1199 might be a novel biomarker for evaluating prognosis and immune cell infiltration in LUAD.

The Interaction of the IFNγ/JAK/STAT1 and JAK/STAT3 Signalling Pathways in EGFR-Mutated Lung Adenocarcinoma Cells

Purpose. It was reported that the EGFR (epidermal growth factor receptor) mutation status was related to primary immune resistance in NSCLC (non-small-cell lung cancer). ICIs (immune checkpoint inhibitors) have poor efficacy and large side effects for people with EGFR mutation. EGFR mutation was considered as a sign of immune therapeutic resistance, but its underlying mechanism is difficult to be determined. Combined with our research basis, we tried to explore the possible mechanism of primary drug resistance in EFGR mutant lung adenocarcinoma through the interaction between the JAK/STAT1 and JAK/STAT3 pathway. Materials and Methods. Cell apoptosis and viability test were used to study the role of the JAK/STAT signalling pathway in lung adenocarcinoma cell survival. Western blot, RT-PCR, and flow cytometry were employed to explore the changes of expression in JAK1/2, STAT1/3, PD-L1, and related signal molecules in the case of activation or inhibition of the JAK/STAT3 signalling pathway. Results. With inhibition of inhibiting the JAK/STAT3 signalling pathway by STAT3 inhibitors, we found IFNγ-JAK-STAT1 pathway activation by IFNγ could further keep lung adenocarcinoma cells from proliferation and promote its apoptosis. The inhibition of the JAK/STAT3 pathway results in the upregulation of JAK1/2, STAT1, IRF1, IRF9, and PD-L1 and downregulation of STAT3 and SOCS1. Conclusions. The absence of the IFNγ-JAK-STAT1 signal pathway is one of the main mechanisms for the ICI endogenous resistance. The abnormal activation of the downstream JAK/STAT3 pathway in cells with EGFR mutation may have antagonistic effects on the STAT1 induced antitumor immune response, which may cause the IFNγ-JAK-STAT1 pathway to lose its function. The mechanism may result in production of the immune tolerance of the EGFR mutant, which promotes immune escape.

The potential application of branch-PCR assembled PTEN gene nanovector in lung cancer gene therapy

Gene therapy offers an alternative and promising avenue to lung cancer treatment. Here, we used dibenzocyclooctyne (DBCO)-branched primers to construct a kind of PTEN gene nanovector (NP-PTEN) through branch-PCR. NP-PTEN showed the nanoscale structure with the biocompatible size (84.7 ± 11.2 nm) and retained the improved serum stability compared to linear DNA. When transfected into NCI-H1299 cancer cells, NP-PTEN could overexpress PTEN protein to restore PTEN function through the deactivation of PI3K-AKT-mTOR signaling pathway to inhibit cell proliferation and induce cell apoptosis. The apoptosis rate of NCI-H1299 cancer cells could reach up to 54.5% ± 4.6% when the transfection concentration of NP-PTEN was 4.0 μg/mL. In mice bearing NCI-H1299 tumor xenograft intratumorally administrated with NP-PTEN, the average tumor volume and tumor weight was separately reduced by 61.7% and 63.9% compared with the PBS group on the 18 th day of administration. The anticancer efficacy of NP-PTEN in NCI-H1299 tumor xenograft suggested the promising therapeutic potential of this branch-PCR assembled PTEN gene nanovectors in lung cancer gene therapy and also provided more opportunities to introduce two or more tumor suppressor genes as the all-in-one gene nanovectors for multiple gene-based cancer gene therapy.

KLF4 suppresses the proliferation and metastasis of NSCLC cells via inhibition of MSI2 and regulation of the JAK/STAT3 signaling pathway

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KLF4 is downregulated, while MSI2 is upregulated in NSCLC tissues.

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Overexpression of KLF4 suppresses NSCLC cell migration and invasion.

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Knockdown of MSI2 suppresses the migration and invasion of NSCLC cells.

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KLF4 inhibits the transcription of MSI2 in NSCLC cells.

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KLF4 suppressed the invasion and migration of NSCLC cells via inhibition of JAK2/STAT3 signalling pathway.

Background

Non-small cell lung cancer (NSCLC) remains an aggresive tumor with poor survival rates. Krüppel-like factor 4 (KLF4) is known to be involved in progression of NSCLC; however, the detailed mechanism by which KLF4 regulates the progression of NSCLC remains unclear.

Methods

In order to investigate the function of KLF4 in NSCLC, cell proliferation was measured by MTT and colony formation assays. The migration and invasion of NSCLC cells were detected via wound healing and Transwell assays, respectively. Then, the interaction between KLF4 and MSI2 was confirmed using a dual-luciferase reporter assay, and the mechanism by which KLF4 regulates the tumorigenesis of NSCLC was assessed by RT-qPCR and Western blotting.

Results

The results showed that KLF4 was downregulated, while MSI2 was upregulated in NSCLC. Additionally, KLF4 could inhibit transcription of MSI2, and overexpression of KLF4 or knockdown of MSI2 could inhibit the proliferation, migration and invasion of NSCLC cells. Moreover, KLF4 could inhibit JAK2/STAT3 signalling pathway.

Conclusions

In conclusion, KLF4 significantly inhibited the proliferation, invasion and migration of NSCLC cells via inactivation of MSI2/JAK2/STAT3 signalling pathway. Thereby, our finding might shed new lights on exploring the new strategies against NSCLC.

Sensitization of Non-Small Cell Lung Cancer Cells to Gefitinib and Reversal of Epithelial-Mesenchymal Transition by Aloe-Emodin Via PI3K/Akt/TWIS1 Signal Blockage

Objective

To explore the impacts of AE (aloe-emodin) in gefitinib-resistant NSCLC (non-small cell lung cancer) cells and the corresponding mechanism.

Methods

PC9 and PC9-GR cells were cultured and treated by gefitinib, AE, or the combination of the two drugs. Then, viability, apoptosis, migration and invasion of cells were investigated using CCK-8, TUNEL, wound healing assay, and transwell assay, respectively. Female BALB/c nude mice were employed for the establishment of xenograft tumor models to examine the role of AE in tumor growth.

Results

PC9-GR cells showed reduced apoptosis and enhanced cell viability, migration and invasion upon treatment by gefitinib, compared with PC9 cells. E-cahherin in PC9-GR cells was down-regulated, while Vimentin, Snail2 (or Slug) and Twist1 in PC9-GR cells were up-regulated, compared with PC9 cells. Meanwhile, treatment by a combination of gefitinib and AE significantly strengthened apoptosis of PC9-GR cells, while attenuated their migration and invasion, compared with the control group or treatment by gefitinib or AE alone. WB results showed that AE could reverse EMT and activation of PI3K/AKT signalling pathway in PC9-GR cells. In vivo experiments showed that tumor growth and EMT of PC9-GR cells were dramatically repressed after treatment by a combination of AE and gefitinib. Additionally, the use of SC97 (a PI3K/Akt pathway activator) could counteract the effects of AE in gefitinib-resistant PC9 cells.

Conclusions

AE could enhance the gefitinib sensitivity of PC9-GR cells and reverse EMT by blocking PI3K/Akt/TWIS1 signal pathway.

Combining EGFR-TKI With SAHA Overcomes EGFR-TKI-Acquired Resistance by Reducing the Protective Autophagy in Non-Small Cell Lung Cancer

Nowadays, lung cancer has the highest mortality worldwide. The emergence of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has greatly improved the survival of patients with non-small cell lung cancer (NSCLC) having EGFR-TKI-sensitive mutations. Unfortunately, acquired resistance happens for most patients. In the present research, we found that EGFR-TKIs (such as gefitinib and osimertinib) can induce autophagy in NSCLC cell lines. Compared with parental sensitive cells, drug-resistant cells have higher autophagy activity. The use of an autophagy inhibitor could enhance the toxicity of gefitinib and osimertinib, which indicates that the enhancement of protective autophagy might be one of the mechanisms of EGFR-TKI resistance in NSCLC. In addition, increased autophagy activity is associated with decreased enhancer of zeste homolog 2 (EZH2) expression. Knockdown of EZH2 or EZH2 inhibitor treatment could lead to increased autophagy in NSCLC cells, indicating that EZH2 is a negative regulator of autophagy. We revealed that the increase in autophagy caused by the reduction of EZH2 was reversed in vitro and in vivo when combining gefitinib or osimertinib with suberoylanilide hydroxamic acid (SAHA), a broad-spectrum histone deacetylase inhibitor (HDACi). In conclusion, our results indicated that the combination of EGFR-TKIs and SAHA may be a new strategy to overcome EGFR-TKIs acquired resistance.

Circular RNA circ_0002360 regulates the Taxol resistance and malignant behaviors of Taxol-resistant non-small cell lung cancer cells by microRNA-585-3p-dependent modulation of G protein regulated inducer of neurite outgrowth 1

Drug resistance has become the major obstacle for the treatment of non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) are tightly linked to the development of drug resistance of NSCLC. Herein, we tested the function of circ_0002360 in the Taxol resistance of NSCLC. Circ_0002360, microRNA (miR)-585-3p and G protein regulated inducer of neurite outgrowth 1 (GPRIN1) were quantified by quantitative real-time PCR (qRT-PCR). To identify the circular structure of circ_0002360, RNase R digestion was applied. To detect cell proliferation, colony formation and 5-ethynyl-2’-deoxyuridine (EdU) assays were used. For assessment of cell apoptosis, flow cytometry was adopted. For motility and invasion analyses, transwell assay was employed. Our data showed that circ_0002360 was mainly located in the cytoplasm and was highly expressed in the Taxol-resistant NSCLC. Silencing of circ_0002360 inhibited cell Taxol resistance, proliferation, motility, and invasiveness and induced apoptosis in vitro. MiR-585-3p was underexpressed in Taxol-resistant NSCLC and was targeted by circ_0002360. MiR-585-3p knockdown alleviated the influence of circ_0002360 silence on Taxol-resistant cells. GPRIN1 was directly targeted by miR-585-3p. The influence of miR-585-3p on cell Taxol resistance and functional behaviors was reversed by GPRIN1 overexpression. Moreover, circ_0002360 modulated GPRIN1 through miR-585-3p. Additionally, silencing of circ_0002360 weakened the growth of xenografts in vivo. Our study demonstrated that silencing of circ_0002360 enhanced the Taxol sensitivity and suppressed the malignant behaviors of Taxol-resistant NSCLC cells by miR-585-3p/GPRIN1 axis, providing novel targets for improving the anti-tumor efficacy of Taxol in NSCLC.

Rhein Inhibits the Progression of Chemoresistant Lung Cancer Cell Lines via the Stat3/Snail/MMP2/MMP9 Pathway

Chemotherapy is a common drug for lung cancer. Nevertheless, the development of drug resistance greatly limits their clinical efficacy. Therefore, to reduce drug resistance, we need to constantly explore new treatments. This study is aimed at determining the role of rhein in the proliferation and metastasis of lung cancer cell. Our study found that rhein significantly inhibits the proliferation and migration of lung cancer cells. Additionally, the mRNA expression and protein levels of Snail, MMP2, and MMP9 are decreasing in lung cancer cells treated by rhein. Our results showed that rhein plays a vital role in proliferation and metastasis of chemosensitive and chemoresistant lung cancer cells, and the mechanism may be related to the Stat3/Snail/MMP2/MMP9 pathway.

Cutting-edge Nanotechnological Approaches for Lung Cancer Therapy

Lung cancer is the second leading cancer with a high rate of mortality. It can be treated using different intervention techniques such as chemotherapy, radiation therapy, surgical removal, and photodynamic therapy. All of these interventions lack specificity, implying that it harms the normal cells adjacent to the infected ones. Nanotechnology provides a promising solution that increases the bioavailability of anticancer drugs at the tumor site with reduced toxicity and improved therapeutic efficacy. Nanotechnology also improves the way lung cancer is diagnosed and treated. Various nanocarriers like liposomes, polymeric nanoparticles, magnetic nanoparticles, and different theranostic approaches are already approved for medical use, while various are under clinical and preclinical stages. This review article covers the details about lung cancer, types of overexpressed receptors, and cutting-edge nanocarriers used for treating lung cancer at its specific target.

AZD9291-resistant non-small cell lung cancer cell-derived exosomal lnc-MZT2A-5:1 induces the activation of fibroblasts

Background

AZD9291 resistance is still a challenge in the treatment of non-small cell lung cancer (NSCLC) and fibroblasts in the tumor microenvironment (TME) play a key role in the malignant phenotype of NSCLC. The study aimed to investigate the role of exosomes derived from AZD9291-resistant cells on the phenotypes of lung fibroblasts and the underlying mechanism.

Methods

The supernatants and exosomes of wild type and AZD9291-resistant NSCLC (H1975/PC9) cells were collected, and co-cultured with lung fibroblasts (MRC-5 cells) respectively. Transwell and quantitative real-time PCR (qRT-PCR) assays were used to evaluate migration and inflammation levels. Exosomes were collected by ultracentrifugation, and identified by nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and western blots. Microarray was used to screen dysregulated exosomal lncRNAs from the resistant cells. Candidate lncRNAs were selected by bioinformatical annotation of their target genes and verified by qRT-PCR. The target lncRNA was then selected for further confirmation.

Results

Both the supernatant and exosomes from resistant cells significantly promoted the migration of MRC-5 cells, and the exosomes also upregulated mRNA levels of inflammation cytokines. Microarray identified 159 dysregulated exosomal lncRNAs. Fifteen candidate lncRNAs were selected following the biological roles of their target genes. qRT-PCR validation indicated that lnc-MZT2A-5:1 had the highest fold change. Finally, we found that lnc-MZT2A-5:1 could promote the migration ability and inflammation cytokines expression level of MRC-5 cells.

Conclusions

Our study clarified that lnc-MZT2A-5:1 from AZD9291-resistant NSCLC cell lines could promote the activation of MRC-5 cells, thus to uncover a new mechanism for AZD9291 resistance and provide new potential targets for the treatment of NSCLC.

A simple "signal off-on" fluorescence nanoplatform for the label-free quantification of exosome-derived microRNA-21 in lung cancer plasma

A simple nanoplatform based on molybdenum disulfide (MoS₂) nanosheets, a fluorescence quencher (signal off), and a hybridization chain reaction (HCR) signal amplification (signal on) used for the enzyme-free, label-free, and low-background signal quantification of microRNA-21 in plasma exosome is reported. According to the sequence of microRNA-21, carboxy-fluorescein (FAM)-labeled hybridization probe 1 (FAM-H1) and hybridization probes 2 (FAM-H2) were designed with excitation maxima at 488 nm and emission maxima at 518 nm. MoS₂ nanosheets could adsorb FAM-H1 and FAM-H2 and quenched their fluorescence signals to reduce the background signal. However, HCR was triggered when microRNA-21 was present. Consequently, HCR products containing a large number of FAM fluorophores can emit a strong fluorescence at 518 nm and could realize the detection of microRNA-21 as low as 6 pmol/L and had a wide linear relation of 0.01-25 nmol/L. This assay has the ability of single-base mismatch recognition and could identify microRNA-21 with high specificity. Most importantly, this approach was successfully applied to the detection of plasma exosomal microRNA-21 in patients with lung cancer, and it is proposed that other targets can also be detected by changing the FAM-H1 and FAM-H2 corresponding to the target sequence. Thus, a novel, hands-on strategy for liquid biopsy was proposed and has a potential application value in the early diagnosis of lung cancer.

Identification of circ_0058357 as a regulator in non-small cell lung cancer cells resistant to cisplatin by miR-361-3p/ABCC1 axis

Background

Drug resistance is a major clinical drawback behind the failure of chemotherapy in non‐small cell lung cancer (NSCLC). In this study, we undertook to identify the precise role of circular RNA (circRNA) circ_0058357 in the functional properties of DDP‐resistant NSCLC cells.

Methods

Circ_0058357, miR‐361‐3p and ATP‐binding cassette (ABC) subfamily C member 1 (ABCC1) were quantified by qRT‐PCR and western blot. Cell survival and viability were gauged by MTT assay. Cell proliferation, apoptosis, invasion and migration were measured by EdU, flow cytometry, transwell and wound‐healing assays, respectively. The direct relationship between miR‐361‐3p and circ_0058357 or ABCC1 was validated by dual‐luciferase reporter assay.

Results

Our data showed that circ_0058357 was highly expressed in DDP‐resistant NSCLC tissues and cells. Inhibition of circ_0058357 repressed cell growth, invasion, migration, and promoted DDP sensitivity and cell apoptosis of H1299/DDP and A549/DDP cells in vitro. Moreover, inhibition of circ_0058357 diminished the growth of A549/DDP cells and sensitized them to the cytotoxic effect of DDP in vivo. Mechanistically, circ_0058357 contained a miR‐361‐3p binding site and miR‐361‐3p was identified as a molecular mediator of circ_0058357 regulation. MiR‐361‐3p suppressed ABCC1 expression by binding to ABCC1 3′UTR, and miR‐361‐3p‐mediated inhibition of ABCC1 affected the growth, invasion, migration, apoptosis and DDP sensitivity of H1299/DDP and A549/DDP cells. Furthermore, circ_0058357 regulated ABCC1 expression by competitively binding to shared miR‐361‐3p.

Conclusions

Our findings identified that inhibition of circ_0058357 suppresses the growth and metastasis of H1299/DDP and A549/DDP cells and sensitizes them to DDP therapy partially by targeting the miR‐361‐3p/ABCC1 axis.

Circular RNAs in Lung Cancer: Recent Advances and Future Perspectives

Globally, lung cancer is the most commonly diagnosed cancer and carries with it the greatest mortality rate, with 5-year survival rates varying from 4–17% depending on stage and geographical differences. For decades, researchers have studied disease mechanisms, occurrence rates and disease development, however, the mechanisms underlying disease progression are not yet fully elucidated, thus an increased understanding of disease pathogenesis is key to developing new strategies towards specific disease diagnoses and targeted treatments. Circular RNAs (circRNAs) are a class of non-coding RNA widely expressed in eukaryotic cells, and participate in various biological processes implicated in human disease. Recent studies have indicated that circRNAs both positively and negatively regulate lung cancer cell proliferation, migration, invasion and apoptosis. Additionally, circRNAs could be promising biomarkers and targets for lung cancer therapies. This review systematically highlights recent advances in circRNA regulatory roles in lung cancer, and sheds light on their use as potential biomarkers and treatment targets for this disease.

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.

Identification of proteins related with pemetrexed resistance by iTRAQ and PRM-based comparative proteomic analysis and exploration of IGF2BP2 and FOLR1 functions in non-small cell lung cancer cells

Pemetrexed (PEM), a multi-target folate antagonist, has been extensively used for the treatment of non-small cell lung cancer (NSCLC). However, the therapeutic efficacy of PEM is limited by tumor resistance. In this project, iTRAQ and parallel reaction monitoring (PRM)-based LC-MS/MS comparative proteomic analysis was performed to identify protein determinants of PEM resistance in A549/PEM cells versus A549 parental cells. A total of 567 differentially expressed proteins (DEPs) were identified by iTRAQ analysis. The function and classification of DEPs were analyzed through GO and KEGG Pathway databases. Moreover, PRM analysis further validated the expression changes of 14 DEPs identified by iTRAQ analysis. Moreover, insulin-like growth factor (IGF) 2 mRNA-binding protein 2 (IGF2BP2) or folate receptor alpha (FOLR1) knockdown weakened PEM resistance, reduced cell viability and promoted cell apoptosis in A549/PEM cells. IGF2BP2 depletion inhibited cell migration, invasion and epithelial-mesenchymal transition (EMT), while FOLR1 loss had no much effect on cell migration, invasion and EMT in A549/PEM cells. Our study can provide a deep insight into molecular mechanisms of PEM resistance in NSCLC and contribute to the development of more effective therapeutic schedules. SIGNIFICANCE: Our study can provide deeper insight into molecular mechanisms of PEM resistance in NSCLC and contribute to the development of more effective therapeutic schedules.

Novel nano-pomegranates based on astragalus polysaccharides for targeting ERα-positive breast cancer and multidrug resistance

Chemotherapy is an important method for treating breast cancer. However, multidrug resistance is one of the major challenges in breast cancer chemotherapy. There is an urgent need to develop novel, effective antitumor strategies that will perfect existing therapeutic regimens. In this study, the double-targeted nanocarrier, Quercetin-3'3-dithiodipropionic acid-Astragalus polysaccharides-Folic acid (QDAF), was successfully synthesized and self-assembled into a neoteric nano-targeted delivery strategy, named nano-pomegranates, and which were utilized to effectively inhibit multidrug resistance in estrogen receptor α (ERα)-positive breast tumor. The outstanding abilities of nano-pomegranates to release the drug in a reducing environment was determined by in vitro release assay. The cellular studies in MCF-7 cells were examined that nano-pomegranates have remarkable efficiencies of enhancing cellular uptake, inhibition and necrosis and apoptosis. In vivo antitumor experiments showed that nano-pomegranates have better anti-tumor effects and lower systemic toxicity than free Cur. In conclusion, nano-pomegranates have great potential in anti-breast cancer treatment.

Hypoxia-induced Tie1 drives stemness and cisplatin resistance in non-small cell lung carcinoma cells

Background

Drug resistance and metastasis involving hypoxic tumor environments and persistent stem cell populations are detrimental to the survival of patients with non-small cell lung carcinoma (NSCLC). Tie1 is upregulated in hypoxia and is believed to counteract the effectiveness of platinum agents by promoting the stemness properties in cells. We have investigated the association of Tie1 with HIF-1α and cisplatin resistance in NSCLC cell lines.

Methods

The expression of Tie1 in a pulmonary microvascular endothelial cell line (HPMEC) and NSCLC cell lines was detected using qRT-PCR and western blotting. The effect of Tie1 on cell stemness and migration was examined by sphere-forming and transwell assays in NSCLC cells with Tie1 silenced. The regulation of Tie1 by HIF-1α was evaluated by a dual-luciferase reporter assay and chromatin immunoprecipitation.

Results

We found that hypoxia could induce stemness and cisplatin resistance in vitro. Tie1 was expressed at low levels in NSCLC cells when compared with human pulmonary microvascular endothelial cells, however, its expression was increased by hypoxia. Additionally, Tie1 knockdown could reduce stemness properties and increase sensitivity to cisplatin in vitro and in a xenograft mouse model. The promoter of Tie1 contains two predicted hypoxia-response elements (HREs). We mutated both HRE sites and conducted chromatin immune-precipitation and promoter luciferase reporter assays and were able to conclude that the induction of Tie1 by hypoxia was HIF-1α-dependent.

Conclusions

Our findings indicated that Tie1 is upregulated in a hypoxic environment by HIF-1α and contributes to tumorigenesis and cisplatin resistance through the promotion of stemness in NSCLC cells.

Establishment and Characterization of a Topotecan Resistant Non-small Cell Lung Cancer NCI-H460/TPT10 Cell Line

While topotecan (TPT) is a first- and second-line chemotherapeutic drug in treating lung cancer, the development of drug resistance in tumors still reserves as a major obstacle to chemotherapeutic success. Therefore, a better understanding of the mechanisms of topotecan resistance is critical. In this study, the first topotecan-resistant human non-small cell lung cancer (NSCLC) cell line, termed NCI-H460/TPT10, was established from the parental NCI-H460 cell line. NCI-H460/TPT10 cells exhibited a 394.7-fold resistance to TPT, and cross-resistance to SN-38, mitoxantrone, and doxorubicin, compared to parental NCI-H460 cells. Overexpression of ABCG2 localized on the cell membrane, but not ABCB1 or ABCC1, was found in NCI-H460/TPT10 cells, indicating that ABCG2 was likely to be involved in topotecan-resistance. This was confirmed by the abolishment of drug resistance in NCI-H460/TPT10 cells after ABCG2 knockout. Moreover, the involvement of functional ABCG2 as a drug efflux pump conferring multidrug resistance (MDR) was indicated by low intracellular accumulation of TPT in NCI-H460/TPT10 cells, and the reversal effects by ABCG2 inhibitor Ko143. The NCI-H460/TPT10 cell line and its parental cell line can be useful for drug screening and developing targeted strategies to overcome ABCG2-mediated MDR in NSCLC.

Molecular testing and targeted therapy for non-small cell lung cancer: Current status and perspectives

Molecular testing has become a mandatory component of the non-small cell lung cancer (NSCLC) management. The detection of EGFR, BRAF and MET mutations as well as the analysis of ALK, ROS1, RET and NTRK translocations have already been incorporated in the NSCLC diagnostic standards, and the inhibitors of these kinases are in routine clinical use. There are emerging biomarkers, e.g., KRAS G12C substitutions and HER2 activating alterations, which are likely to enter NSCLC guidelines upon the approval of the corresponding drugs. In addition to genetic examination, NSCLCs are usually subjected to the analysis of PD-L1 protein expression in order to direct the use of immune checkpoint inhibitors. Comprehensive NSCLC testing for multiple predictive markers requires the analysis of distinct biological molecules (DNA, RNA, proteins) and, therefore, the involvement of different analytical platforms (PCR, DNA sequencing, immunohistochemistry, FISH). There are ongoing efforts aimed at the integration of multiple NSCLC molecular assays into a single diagnostic pipeline.

Identification of Potential Long Non-coding RNA Expression Quantitative Trait Methylations in Lung Adenocarcinoma and Lung Squamous Carcinoma

There are associations between DNA methylation and the expression of long non-coding RNA (lncRNA), also known as lncRNA expression quantitative trait methylations (lnc-eQTMs). Lnc-eQTMs may induce a wide range of carcinogenesis pathways. However, lnc-eQTMs have not been globally identified and studied, and their roles in lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC) are largely unknown. In the present study, we identified some differential methylation sites located in genes of long intergenic non-coding RNAs (lincRNAs) and other types of lncRNAs in LUAD and LUSC. An integrated pipeline was established to construct two global cancer-specific regulatory networks of lnc-eQTMs in LUAD and LUSC. The associations between eQTMs showed common and specific features between LUAD and LUSC. Some lnc-eQTMs were also related with survival in LUAD- and LUSC-specific regulatory networks. Lnc-eQTMs were associated with cancer-related functions, such as lung epithelium development and vasculogenesis by functional analysis. Drug repurposing analysis revealed that these lnc-eQTMs may mediate the effects of some anesthesia-related drugs in LUAD and LUSC. In summary, the present study elucidates the roles of lnc-eQTMs in LUAD and LUSC, which could improve our understanding of lung cancer pathogenesis and facilitate treatment.

Low OCEL1 expression is associated with poor prognosis in human non-small cell lung cancer

BACKGROUND

Occludin/ELL domain containing 1 (OCEL1) is a novel discovered protein with its molecular functions remaining unknown and its role in lung cancer has not been directly explored.

OBJECTIVES

This study focused on the role of OCEL1 in the progression and prognosis of non-small cell lung cancer (NSCLC).

METHODS

A public database and tissue samples (80 NSCLC tissue samples and paired normal lung samples) were used to compare differences in OCEL1 expression and investigate its relationship with clinical characteristics and prognosis.

RESULTS

Compared to adjacent normal lung tissue samples, OCEL1 expression was significantly down-regulated in tumor tissues. In addition, there was a negative correlation between OCEL1 and Ki67 expression levels. Low OCEL1 expression was significantly associated with lymph node metastasis, higher TNM stage, and poor prognosis. Importantly, multivariate analysis identified OCEL1 expression as an independent predictor for unfavorable NSCLC prognosis.

CONCLUSIONS

These results indicated that OCEL1 protein may serve as a novel prognostic biomarker in NSCLC.

A prognostic model for elderly patients with squamous non-small cell lung cancer: a population-based study

Background

Squamous cell carcinoma (SCC) is a main pathological type of non-small cell lung cancer. It is common among elderly patients with poor prognosis. We aimed to establish an accurate nomogram to predict survival for elderly patients (≥ 60 years old) with SCC based on the Surveillance, Epidemiology, and End Results (SEER) database.

Methods

The gerontal patients diagnosed with SCC from 2010 to 2015 were collected from the Surveillance, Epidemiology, and End Results (SEER) database. The independent prognostic factors were identified using multivariate Cox proportional hazards regression analysis, which were utilized to conduct a nomogram for predicting survival. The novel nomogram was evaluated by Concordance index (C-index), calibration curves, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).

Results

32,474 elderly SCC patients were included in the analysis, who were randomly assigned to training cohort (n = 22,732) and validation cohort (n = 9742). The following factors were contained in the final prognostic model: age, sex, race, marital status, tumor site, AJCC stage, surgery, radiation and chemotherapy. Compared to AJCC stage, the novel nomogram exhibited better performance: C-index (training group: 0.789 vs. 0.730, validation group: 0.791 vs. 0.733), the areas under the receiver operating characteristic curve of the training set (1-year AUC: 0.846 vs. 0.791, 3-year AUC: 0.860 vs. 0.801, 5-year AUC: 0.859 vs. 0.794) and the validation set (1-year AUC: 0.846 vs. 0.793, 3-year AUC: 0.863 vs. 0.806, 5-year AUC: 0.866 vs. 0.801), and the 1-, 3- and 5-year calibration plots. Additionally, the NRI and IDI and 1-, 3- and 5-year DCA curves all confirmed that the nomogram was a great prognosis tool.

Conclusions

We constructed a novel nomogram that could be practical and helpful for precise evaluation of elderly SCC patient prognosis, thus helping clinicians in determining the appropriate therapy strategies for individual SCC patients.

Identification of a novel subpopulation of Caspase-4 positive non-small cell lung Cancer patients

BACKGROUND

Therapy/prognosis of Non-Small Cell Lung Cancer (NSCLC) patients are strongly related to gene alteration/s or protein expression. However, more than 50% of NSCLC patients are negative to key drugable biomarkers.

METHODS

We used human samples of NSCLC and mouse models of lung adenocarcinoma.

RESULTS

We showed that caspase-4 was highly present in the tumor mass compared to non-cancerous human tissues. Interestingly, the orthologue murine caspase-11 promoted lung carcinogenesis in mice. Carcinogen-exposed caspase-11 knockout mice had lower tumor lesions than wild type mice, due to the relevance of caspase-11 in the structural lung cell as demonstrated by bone marrow transplantation and adoptive transfer experiments. Similarly to what observed in mice, caspase-4 was correlated to the stage of lung cancer in humans in that it induced cell proliferation in a K-Ras, c-MyC and IL-1α dependent manner. Caspase-4 positive adenocarcinoma (79.3%) and squamous carcinoma (88.2%) patients had lower median survival than patients who had lower levels of caspase-4. Moreover, PD-L1 expression and gene mutation (i.e. EGFR) were not correlated to caspase-4 expression. Instead, NSCLC patients who had K-Ras or c-MyC gene alteration were positively correlated to higher levels of caspase-4 and lower survival rate.

CONCLUSIONS

We identified a subgroup of NSCLC patients as caspase-4 positive among which double and triple positive caspase-4, K-Ras and/or c-MyC patients which prognosis was poor. Because K-Ras and c-MyC are still undrugable, the identification of caspase-4 as a novel oncoprotein could introduce novelty in the clinical yet unmet needs for NSCLC patients.

Potential monoamine oxidase A inhibitor suppressing paclitaxel-resistant non-small cell lung cancer metastasis and growth

BACKGROUND

High expression of monoamine oxidase A (MAOA) in non-small cell lung cancer (NSCLC) is related to epithelial-mesenchymal transition (EMT) and the development of clinicopathological features of NSCLC. Nevertheless, the role of MAOA in drug resistance still remains unclear. Hence, the aim of this article was to evaluate a previously synthesized MAOA inhibitor (G11) on inhibiting paclitaxel-resistant NSCLC metastasis and growth.

METHODS

First, MAOA expression level was evaluated in several NSCLC cell lines. An MTT assay was used to validate the inhibitory effect of G11 on NSCLC cells in vitro. Second, gene expression in G11-treated H460/PTX cells was analyzed by microarray gene expression. Third, transwell assay was performed to assess the invasion and metastasis of G11-treated A549/PTX and H460/PTX cells and western blot assay used to analyze vital protein expression level in G11-treated H460/PTX cells. Finally, the antimetastatic effect of G11 was tested in an NSCLC in vivo model.

RESULTS

Our data revealed that G11 significantly inhibited the viability of paclitaxel (PTX)-resistant NSCLC cell lines (A549/PTX and H460/PTX). G11 dramatically reduced the expression of MAOA in A549/PTX and H460/PTX cells, which exhibited relatively high MAOA expression levels. Additionally, G11 was found to hinder A549/PTX and H460/PTX cell migration and invasion. Furthermore, the in vivo study indicated that the coadministration of G11 and paclitaxel significantly suppressed tumor metastasis in H460/PTX lung metastasis models.

CONCLUSIONS

These findings indicated G11 showed a moderate inhibitory effect on paclitaxel-resistant NSCLC metastasis and growth, and support further investigation on MAOA potentially as a promising therapeutic target for paclitaxel-resistant NSCLC treatment.

KEY POINTS

SIGNIFICANT FINDINGS OF THE STUDY: Inhibition of MAOA might contribute to the suppression of metastasis and growth in PTX-resistant NSCLC cells. What this study adds This study explored the potential function of MAOA in drug-resistant NSCLC and might consider MAOA as a promising target for the treatment of drug-resistant NSCLC.

Altered lung tissue lipidomic profile in caspase-4 positive non-small cell lung cancer (NSCLC) patients

Lung cancer is by far the leading cause of cancer death. Metabolomic studies have highlighted that both tumor progression and limited curative treatment options are partly due to dysregulated glucose metabolism and its associated signaling pathways. In our previous studies, we identified caspase-4 as a novel diagnostic tool for non-small cell lung cancer (NSCLC). Here, we analyzed the metabolomic profile of both plasma and tumor tissues of NSCLC patients stratified as caspase-4 positive or negative. We found that circulating caspase-4 was correlated to LDH. However, this effect was not observed in caspase-4 positive tumor tissues, where instead, fatty acid biosynthesis was favoured in that the malonic acid and the palmitic acid were higher than in non-cancerous and caspase-4 negative tissues. The glycolytic pathway in caspase-4 positive NSCLC tissues was bypassed by the malonic acid-dependent lipogenesis. On the other hand, the dysregulated glucose metabolism was regulated by a higher presence of succinate dehydrogenase (SDHA) and by the gluconeogenic valine which favoured Krebs’ cycle.

In conclusion, we found that the recently identified caspase-4 positive subpopulation of NSCLC patients is characterized by a lipidomic profile accompanied by alternative pathways to guarantee glucose metabolism in favour of tumor cell proliferation.

Deoxyshikonin inhibits cisplatin resistance of non-small-cell lung cancer cells by repressing Akt-mediated ABCB1 expression and function

Drug resistance is a large challenge for the treatment of non-small-cell lung cancer (NSCLC). Deoxyshikonin is the naphthoquinol compound with anticancer activity. However, the role and mechanism of deoxyshikonin in cisplatin resistance of NSCLC remain poorly understood. Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity. We found that cisplatin-resistant A549/cis and H1299/cis cells had higher cisplatin resistance than A549 and H1299 cells, respectively. Deoxyshikonin contributed to cisplatin-induced viability inhibition and apoptosis in A549/cis and H1299/cis cells. Moreover, deoxyshikonin inhibited phosphorylation of Akt and the expression and function of ATP-binding cassette subfamily B member 1 (ABCB1). Activation of protein kinase B (Akt) pathway attenuated the effect of deoxyshikonin on cisplatin resistance and ABCB1 expression and function in A549/cis and H1299/cis cells. In conclusion, deoxyshikonin suppressed cisplatin resistance in cisplatin-resistant NSCLC cells by repressing Akt signaling-mediated ABCB1 expression.

In vitro and in vivo synergistic efficacy of ceritinib combined with programmed cell death ligand-1 inhibitor in anaplastic lymphoma kinase-rearranged non-small-cell lung cancer

Both ceritinib (CER) and programmed cell death (PD)‐1/PD ligand‐1 (PD‐L1) have brought significant breakthroughs for anaplastic lymphoma kinase (ALK)‐rearranged non‐small‐cell lung cancer (NSCLC). However, the overall clinical efficacy of either CER or PD‐1/PD‐L1 inhibitor monotherapy has been limited to a large extent. In addition, the antitumor effect of combined CER and PD‐L1 inhibitor in ALK‐rearranged NSCLC is not fully understood. In H2228 cells, we examined the tumor killing effect of CER plus PD‐L1 inhibitor in vitro by quantitative RT‐PCR, flow cytometry, ELISA, western blot analysis, PBMC coculture system, and plasmid and transfection experiments. A Ba/F3 (EML4‐ALK‐WT) xenograft mouse model was also utilized to further evaluate the synergistic anticancer effects of CER and PD‐L1 inhibitor in vivo. The coculture system of PBMCs with H2228 cells promotes the expression of PD‐L1 and phospho‐ERK, and combined treatments facilitate lymphocyte proliferation and activation, inhibit PD‐L1 expression, and enhance lymphocyte cytotoxicity and cell death. In the in vivo NSCLC xenograft model, the volumes of tumors treated with CER and PD‐L1 inhibitor in combination were significantly smaller than those treated with CER or PD‐L1 alone. The relative tumor growth inhibitions were 84.9%, 20.0%, and 91.9% for CER, PD‐L1 inhibitor, and CER plus PD‐L1 groups, respectively. Ceritinib could synergize with PD‐1/PD‐L1 blockade to yield enhanced antitumor responses along with favorable tolerability of adverse effects. Ceritinib and PD‐L1 inhibitor combined produced a synergistic antineoplastic efficacy in vitro and in vivo, which provides a key insight and proof of principle for evaluating CER plus PD‐L1 blockade as combination therapy in clinical therapeutic practice.

Natural Oral Anticancer Medication in Small Ethanol Nanosomes Coated with a Natural Alkaline Polysaccharide

Oral medication is the most acceptable therapy to treat chronic diseases. Natural drugs and excipients have unique advantages, such as low cost and high safety. We first investigated modified ethanol nanosomes for tumor treatment via oral administration. We loaded curcumin (CM) into small ethanol nanosomes coated with the natural alkaline polysaccharide chitosan (CCSET) for increased absorption and bioavailability and enhanced efficacy against small cell lung cancer (SCLC). Compared to CM and noncoated ethanol nanosomes, CCSETs exhibited superior physicochemical, in vitro-in vivo kinetic, and absorptive properties and treatment efficacy at the cellular and animal levels. The interaction of CM and serum albumin (the quantitative binding force) was analyzed. The bioavailability of CCSET increased by 11.84-fold and the tumor growth inhibition rate increased markedly compared to CM. We first confirmed the effect of CM on SCLC stem cells, and CCSET greatly enhanced this action. We first reported that CM had an antitumor effect on SCLC at the animal level and that CCSET enhanced this effect. Natural alkaline polysaccharide-coated small ethanol nanosomes delivering natural medicine may be a potential oral anticancer strategy.

CT2-3, a novel magnolol analogue suppresses NSCLC cells through triggering cell cycle arrest and apoptosis

Magnolol, a major bioactive component found in Magnolia officinalis with anti-inflammation and anti-oxidation activities as well as minimized cytotoxic effects. Although magnolol has a wide range of clinical applications, the anti-tumor activity of magnolol is not efficient. Herein, we reported the synthesis and anti-cancer activities of three novel magnolol analogues CT2-1, CT2-2, CT2-3, among which CT2-3 revealed more efficient anti-non-small cell lung cancer (NSCLC) activity than magnolol. Our data showed that CT2-3 could significantly inhibit the proliferation of human NSCLC cells in a dose-dependent manner. In addition, we revealed CT2-3 could induce cell cycle arrest through down-regulating mRNA expression of CDK4, CDK6 and cyclin D1. Moreover, we verified that CT2-3 could cause ROS generation, leading to apoptosis of human NSCLC cells. Further more, we also provided strong evidences that CT2-3 down-regulates the expression of c-Myc and topoisomerases, and contributes to the apoptosis of human NSCLC cells. Taken together, the current study is the first to report a promising new chemotherapeutic drug candidate CT2-3 that can efficiently eliminate human NSCLC cells through triggering cell cycle arrest as well as ROS-mediated and c-Myc/topoisomerases-mediated apoptosis.

Up-Regulation of MiRNA-125a-5p Inhibits Cell Proliferation and Increases EGFR-TKI Induced Apoptosis in Lung Cancer Cells

BACKGROUND

Despite the dramatic efficacy of erlotinib, an EGFR tyrosine kinase inhibitor (TKI), most of non-small cell lung cancer (NSCLC) patients ultimately acquire resistance to this agent. Different studies indicated that miRNA-125a-5p is down-regulated in human lung cancer cells and may function as a tumor suppressor by targeting EGFR. However, the biological function of miRNA-125a-5p in NSCLC resistance to EGFR-TKIs is not fully understood. In this study the effect of miRNA-125a-5p on cell proliferation, apoptosis and sensitivity of the A549 lung cancer cells to erlotinib was investigated.

METHODS

After miRNA-125a-5p transfection, the expression levels of EGFR mRNA were measured by QRT-PCR. Trypan blue assays were performed to evaluate the proliferation of the A549 lung cancer cells. The cytotoxic effects of miRNA-125a-5p and erlotinib, alone and in combination, were determined using MTT assay. Combination index study was performed using the method of Chou-Talalay. Apoptosis was assessed using an ELISA cell death assay kit.

RESULTS

MiRNA-125a-5p clearly reduced the expression of EGFR mRNA in a time dependent manner, causing marked cell proliferation inhibition and spontaneous apoptosis (p<0.05, relative to control). Pretreatment with miRNA-125a-5p synergistically increased the cytotoxic effect of erlotinib and decreased its IC50. Furthermore, miRNA-125a-5p significantly enhanced the apoptotic effect of erlotinib. Negative control miRNA had no significant effect on biological parameter of the tumor cells.

CONCLUSIONS

Our data suggest that suppression of EGFR by miRNA-125a-5p can effectively trigger apoptosis and overcome EGFR-TKs resistance of lung cancer cells. Therefore, miRNA-125a-5p may be a potential therapeutic adjuvant in patients with lung cancer.
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