Glycogen phosphorylase B (PYGB), the rate-determining enzyme in glycogen degradation, plays a critical role in progression of various tumors. The present study focused on the potential molecular mechanism toward PYGB in non-small cell lung cancer (NSCLC) progression.Expression of PYGB in NSCLC tissues and cell lines was evaluated via quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry. Cell viability, proliferation and apoptosis were investigated using 3-(4,5-Dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-bromo-2-deoxyuridine (BrdU) and flow cytometry, respectively. Cell migration and invasion ability were detected by wound healing and transwell invasion assays, respectively. The in vivo effect of PYGB on NSCLC tumor growth was determined via subcutaneous xenotransplanted tumor model.PYGB was upregulated in NSCLC tissues and cell lines, suggesting a poor prognosis in NSCLC patients. In vitro functional assays indicated that knockdown of PYGB suppressed cell viability, proliferation, migration and invasion, while promoted cell apoptosis in NSCLC. Mechanistically, we found that overexpression of PYGB could activate phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway, while these effects were effectively reversed by knockdown of PYGB. In vivo tumorigenesis and PI3K/AKT signaling pathway were also inhibited by PYGB knockdown.Knockdown of PYGB suppressed NSCLC progression, suggesting PYGB as a novel biomarker and potential molecular therapeutic target for further investigation in NSCLC.
This study was designed to investigate epidermal growth factor receptor (EGFR) mutation types affecting lung cancer treatment in patients in Xinjiang, China. We detected and analyzed differences in the EGFR mutation points of Uighur and Han patients with lung adenocarcinoma. We examined 181 specimens of lung adenocarcinoma tissue embedded with paraffin (76 Uighur and 105 Han patients) for mutations in the EGFR gene in exon 18-21 by the amplification refractory mutation system (ARMS) method. We used the chi-square statistical method to analyze the relationship between mutations and patients' clinical parameters.EGFR somatic mutations were detected in 59 of 181 cases (32.6%). The mutation rate was higher in Han patients (45.7%) than in Uighur patients (15.8%) (P < 0.001). The main mutation types were the exon 19 deletion and the L858R point mutation in exon 21. In Han patients we found 21 (44.7%) cases of exon 19 deletion, 24 (51.1%) cases of L858R in exon 21, 1 case (2.1%) with mutations in both exon 19 and exon 21, and 1 case (2.1%) with T790 mutation in exon 20. In Uighur patients we found 8 (66.7%) cases of exon 19 deletion and 4 (33.3%) cases of L858R in exon 21.In comparing these groups, the exon 19 deletion was more common than L858R in exon 21 in Uighur patients. In Han patients, EGFR-sensitive mutations occurred in female, never-smoking patients with well-differentiated tumors; but for Uighur patients only smoking history showed an obvious correlation.
Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) are the standard first-line treatment for EGFR-mutant nonsmall cell lung cancer (NSCLC) patients. However, studies have reported that not all NSCLC patients harboring kinase domain mutations in epidermal growth factor receptor (EGFR) show significant clinical benefits from EGFR-targeted tyrosine kinase inhibitors (TKIs). Therefore, it is necessary to establish feasible biomarkers to predict the prognosis of EGFR-mutant NSCLC patients treated with EGFR-TKIs. This study aimed to determine biomarkers using inflammatory parameters from complete blood counts to predict the prognosis of EGFR-mutant NSCLC patients treated with EGFR-TKIs. We retrospectively investigated 127 stage IIIB/IV NSCLC patients with activating EGFR mutations who were treated with EGFR-TKIs. We used receiver operating characteristic (ROC) curves to determine the optimal cut-off for the inflammatory markers as prognostic factors. Additionally, univariate and multivariate analyses were used to identify prognostic factors for progression-free survival (PFS) and overall survival (OS) of EGFR-mutant NSCLC patients treated with EGFR-TKIs. The receiver operating characteristic analysis indicated that the lymphocyte-to-monocyte ratio (LMR) and neutrophil-to-lymphocyte ratio (NLR) cut-off values were 3.37 and 2.90, respectively. The univariate analysis showed that a high LMR (>3.37) and low NLR (≤2.90) were significantly correlated with long-term PFS and OS (LMR, P = .007; NLR, P < .001). The multivariate Cox regression analysis revealed that only low NLR was an independent prognostic factor for long-term PFS and OS (PFS, HR = 0.573, 95% CI: 0.340–0.964, P = .036; OS, HR = 0.491, 95% CI: 0.262–0.920, P = .026). The data show that a low NLR was a good prognostic factor in EGFR-mutant NSCLC patients receiving EGFR-TKIs treatment. Moreover, the NLR measurement has better prognostic value than LMR.
To the editor; Increased Nucleobindin-2 level has been determined as an independent prognostic factor for overall survival of patients. However, pathophysiological significance of Nucleobindin-2 in lung cancers remains unclear. In the present study, we examined Nucleobindin-2 mRNA level in various types of human lung cancer cell lines.
Abstract Background: Gefitinib resistance has become a major obstacle for cancer therapy of non-small cell lung cancer (NSCLC). Exosome-mediated transfer of long noncoding RNAs (lncRNAs) is associated with the drug-resistance in various tumors. However, the role of NSCLC-specific exosomal lncRNAs remains largely unknown. The aim of this study is to explore the role of exosomal Hox transcript antisense intergenic RNA (HOTAIR) on gefitinib resistance in NSCLC. Methods: We investigated the expression of lncRNAs in 5 paired gefitinib-sensitive and gefitinib-resistant tissues of NSCLC by microarray analysis. The qRT-PCR analysis was to investigate the expression pattern of HOTAIR in gefitinib-resistant NSCLC patient tissues and cell lines. Then, we investigated the effects of HOTAIR on gefitinib resistance in vitro and in vivo . Results: In this study, we found HOTAIR was evidently up-regulated in both tissues and serum exosome of gefitinib-resistant NSCLC patients. Moreover, by knocking down HOTAIR, we found that HOTAIR promoted the proliferation of NSCLC cells in vitro , as well as inhibited cell apoptosis and cell sensitivity to gefitinib. Extracellular HOTAIR could be incorporated into exosomes and transmitted to sensitive cells, thus disseminated gefitinib resistance. The expression level of HOTAIR from circulating exosomes is significantly higher in NSCLC patients with gefitinib resistance than those without gefitinib resistance. Mechanistically, bioinformatic analysis coupled with dual luciferase assay revealed that HOTAIR served as miR-216a sponge, and MAP1S was identified as a functional target of miR-216a. Conclusions: In conclusion, these data suggest that exosomal HOTAIR serves as an oncogenic role in gefitinib resistance of NSCLC cells CRC through activating miR-216a/MAP1S signaling pathway, providing a novel avenue for the treatment of NSCLC.
Hyperglycemia mediates oxidative stress, thus inducing transcription factor nuclear factor kappa B (NF-κB) activation, increasing endothelial adhesion molecule expression and monocyte/endothelial interaction, and resulting in endothelial injury. Ketamine was reported to attenuate oxidative stress in many cases. In this research, we determined whether and how ketamine protects against high-glucose-mediated augmentation of monocyte/endothelial interaction and endothelial adhesion molecule expression in human umbilical vein endothelial cells. High glucose augmented monocyte/endothelial adhesion and endothelial adhesion molecule expression. High glucose induced reactive oxygen species (ROS) production and augmented phospho-protein kinase C (p-PKC) βII expression and PKC activity. Moreover, high glucose inhibited the inhibitory subunit of nuclear factor-κBα (IκBα) expression in the cytoplasm and induced NF-κB nuclear translocation. Importantly, the effects induced by high glucose were counteracted by ketamine treatment. Further, CGP53353, a PKC βII inhibitor, inhibited high-glucose-mediated NF-κB nuclear translocation, attenuated adhesion molecule expression, and reduced monocyte/endothelial interaction. Further, these effects of ketamine against high-glucose-induced endothelial injury were inhibited by phorbol 12-myristate 13-acetate, a PKC βII activator. In conclusion, ketamine, via reducing ROS accumulation, inhibited PKC βII Ser660 phosphorylation and PKC and NF-κB activation and reduced high-glucose-induced expression of endothelial adhesion molecules and monocyte/endothelial interaction.
Lung cancer remains the leading cause of cancer-associated mortality worldwide, and non-small-cell lung cancer (NSCLC) contributes to ~80% of these deaths. However, both primary and acquired cisplatin resistance frequently occurs within the disease and represents a huge clinical treatment problem. The underlying molecular mechanisms are not yet completely understood, but in recent years, microRNAs (miR) have been reported to play vital roles in the development of lung cancer and chemoresistance. In the present study, it was revealed that there were increased expression levels of miR-103a-3p in both NSCLC cell lines and human NSCLC samples that exhibited resistance to cisplatin. The results also revealed that the inhibition of miR-103a-3p in A549/cisplatin cells significantly sensitized these cells to cisplatin, while inhibition of miR-103a-3p expression inhibited tumor growth and enhanced the function of cisplatin in a xenograft animal model. Furthermore, the present study demonstrated that miR-103a-3p regulates cisplatin resistance by targeting neurofibromatosis 1 (NF1) via activating ERK signaling in vitro and in vivo. In conclusion, NF1 was identified as a special miR-103a-3p target in the present study, and it was revealed that targeting NF1 via miR-103a-3p may help reverse chemoresistance and provide a biomarker to cisplatin responsiveness in NSCLC.
Tyrosine kinase inhibitors (TKIs) bring significant benefits for patients with cancers harboring epidermal growth factor receptor (EGFR) mutations. However, after treatment for a certain period, most patients ultimately acquire resistance. Numerous studies indicated that PI3K has an important role in tumor cell growth and drug sensitivity. Furthermore, inhibition of PI3K may lead to sensitization of non-small cell lung cancer (NSCLC) cells to EGFR-TKIs. The aim of the present study was to explore whether LY294002, an inhibitor of PI3K, is able to improve the sensitivity of NSCLC cell lines with wild-type EGFR to the EGFR-TKI erlotinib. An MTT assay was used to examine the effect of combined treatment with LY294002 and erlotinib on cell survival of two EGFR wild-type NSCLC cell lines, NCI-H661 and NCI-H460. Furthermore, flow cytometry was used to assess apoptosis in NCI-H661 and NCI-H460 cells after treatment with erlotinib and LY294002. In addition, the expression of downstream proteins was detected by western blot analysis. The results indicated that the number of viable NCI-H661 and NCI-H460 cells was dose-dependently reduced by erlotinib or LY294002. Compared to treatment with erlotinib alone, the cell apoptosis was enhanced if combined treatment of erlotinib and LY294002 was performed in NCI-H661 cells. Furthermore, combination treatment of erlotinib and LY294002 resulted in a significant reduction of phosphorylated p70S6K levels in NCI-H661 [PI3K catalytic subunit alpha (PI3KCA) wild-type] cells. However, this phenomenon was not observed in the NCI-H460 cell line (PIK3CA mutant-type). In conclusion, the present study indicated that inhibition of PI3K may have the potential to improve the sensitivity of NSCLC cells to an EGFR-TKI. However, the therapeutic effect may depend on the mutation status of PIK3CA.
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