Co-expression of NF-κB-p65 and phosphorylated NF-κB-p105 is associated with poor prognosis in surgically resectable non-small cell lung cancer

RNF182 induces p65 ubiquitination to affect PDL1 transcription and suppress immune evasion in lung adenocarcinoma

BACKGROUND

The RING finger (RNF) proteins are a large group of ubiquitin ligases whose aberrant expression is often associated with disease progression. This study examines the function of RNF protein 182 (RNF182) in lung adenocarcinoma (LUAD) cells and its impact on p65 and programmed death ligand 1 (PDL1) regulation.

METHODS

Expression of RNF182, p65, and PDL1 in LUAD tissues and cells was measured using immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR), and/or western blot (WB) assays. LUAD cells were induced to overexpress RNF182 and p65, followed by cell counting kit-8, colony formation, Transwell, and flow cytometry assays to evaluate the cells' malignant phenotype. Coimmunoprecipitation and WB assays were used to verify RNF182's effect on p65 ubiquitination. Chromatin immunoprecipitation-qPCR and luciferase assays were used to analyze p65's transcriptional regulation of PDL1. Coculture of LUAD with CD8+ cytotoxic T cells was performed to detect lactate dehydrogenase release and interferon-γ and interleukin-2 concentrations. LUAD cells were implanted in mice to analyze tumorigenicity.

RESULTS

RNF182 was poorly expressed, while p65 and PDL1 were highly expressed in LUAD tissues and cells. RNF182 overexpression suppressed the malignant properties of LUAD cells, and it promoted p65 ubiquitination and protein degradation. p65 activated PDL1 transcription. Overexpression of RNF182 suppressed the PDL1 expression, increased the cytotoxicity in LUAD cells cocultured with CD8+ T cells, and suppressed the tumorigenesis of cancer cells in vivo. However, these tumor-suppressive effects of RNF182 on LUAD cells were blocked by p65 restoration.

CONCLUSION

This research demonstrates that RNF182 induces p65 ubiquitination to suppress PDL1 transcription and immunosuppression in LUAD.

Hyperglycemia induces gastric carcinoma proliferation and migration via the Pin1/BRD4 pathway

Diabetes is a potential risk factor for gastric cancer (GC). Pin1, a peptidyl–prolyl cis/trans isomerase, promotes GC cell proliferation and migration. The role and underlying mechanism of the Pin1/BRD4 axis in hyperglycemia-induced proliferation and migration of GC cells were analyzed in vivo and in vitro. Proliferation and migration of GC cells were measured; Pin1 and BRD4 expression of the cell cycle were determined. Pin1 and BRD4 were downregulated by transfecting Pin1 shRNA lentivirus into GC cells and JQ1-intervention GC cells. Tumor formation and lung metastasis were assessed in vivo. Inhibition of Pin1 and BRD4 significantly suppressed high-glucose (HG)-induced GC cell proliferation and migration. HG enhanced G1/S cell-cycle transition, associated with increased Pin1 and BRD4 expression. Silencing Pin1 significantly downregulated the expression of BRD4 and NAP1L1 and upregulated that of P21 in GC cells. In vivo studies indicated that hyperglycemia promotes tumor growth and lung metastasis by inducing Pin1 and BRD4 expression. Thus, Pin1/BRD4 plays an important role in hyperglycemia-promoted tumor growth. The significance of these findings toward improved prognosis of diabetic patients with GC cannot be underestimated.

Long non-coding RNA NKILA regulates expression of HSP90α, NF-κB and β-catenin proteins in the MCF-7 breast cancer cell line

Non-coding RNAs are increasingly being investigated and have shown great potential for diagnosis, prognosis and treatment of cancer. Thus, we have investigated a possible regulatory mechanism between NF-κB suppressor-NKILA, and HSP90, NF-κB, and β-catenin molecules in MCF-7 breast cancer cells. HSP90 is an important stress protein and together with β-catenin and NF-κB molecules can be responsible for cancer cell development. However, there is no comprehensive data available on the novel molecule NKILA unlike for HSP90, β-catenin and NF-κB alone. Therefore, we suggest there might be a correlation between NKILA and these proteins. To investigate the NKILA role on HSP90, NF-κB and β-catenin proteins we inhibited the NKILA by using transfection in MCF-7 breast cancer cells. NKILA-siRNA transfected cells were incubated for 5 h. Then, cells were collected and proteins were extracted to be separated by SDS-PAGE. The aforementioned proteins of siRNA transfected group were evaluated by quantification and comparison of their relative expression levels with the control group by immunoblotting. Results showed, HSP90 and NF-κB/p105, NF-κB/p65 and NF-κB/p50 subunits significantly increased while the level of β-catenin decreased after NKILA inhibition. For the first time we have demonstrated that HSP90 and expression levels of beta-catenin are associated with NKILA levels which may be closely related to the canonical NF-κB pathway in MCF-7 cells. These novel findings may have significant implications in cancer cells development and possibly present important hints for the future studies of the cancer cell targeted therapy.

Cyclooxygenase-2 mediates gefitinib resistance in non-small cell lung cancer through the EGFR/PI3K/AKT axis

Gefitinib is a potent inhibitor of EGFR and represents the front-line treatment for non-small cell lung cancer (NSCLC) therapeutics. However, NSCLC patients are prone to develop acquired resistance through as yet, undefined mechanisms of resistance. Here, we investigated the role of COX-2 during gefitinib resistance in NSCLC cells and revealed its underlying mechanism(s) of action. We report the upregulation of COX-2 in gefitinib-resistant NSCLC tissues and cells, which is associated with poor prognosis. In vitro assays in NSCLC cells (PC9/GR) showed that COX-2 facilitates gefitinib resistance in NSCLC cells through its effects on P-gp, MRP1, and BCRP, and cancer cell migration and invasion. In vivo, COX-2 silencing could repress tumor growth. We found that the overexpression of COX-2 enhances the transcription of MMP-2, MMP-7, and MMP-9 which mediates PI3K-AKT activation. In summary, we demonstrate that COX-2 mediates the gefitinib resistance of NSCLC cells through its interaction with EGFR and the PI3K-AKT axis. This highlights COX-2 as a novel molecular target for NSCLC.

Effects of genistein on lipopolysaccharide-induced injury of mouse alveolar epithelial cells and its mechanism

Alveolar and bronchial epithelial cells have critical functions in acute respiratory distress syndrome progress. Genistein could protect the lungs from acute lung injury, however, whether genistein protects the alveolar epithelial cells from LPS-induced injury was less studied. Spectrophotometric method 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and enzyme-linked immunosorbent assay (ELISA) were performed to detect cell viability and levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. Flow cytometry and western blot assay were performed to detect cells apoptosis and protein levels. In LPS-induced model of mouse lung epithelial (MLE)-12 cells, PBEF (proinflammatory cytokine) expression, and cell apoptosis were increased and cell viability was decreased, whereas NF-κB was activated and expression levels of TNF-α, IL-1β, and IL-6 were increased. However, genistein partly reversed the effect of LPS, and it plays a protective role in lung injury by reducing expression of PBEF, inhibiting the activation of NF-κB and alleviating inflammatory response of cells.

Mechanism of Viscum coloratum polysaccharide to regulate proliferation, migration, and invasion of gastric cancer cells

BACKGROUND

Gastric cancer (GC) is the fifth most common cancer globally and the third leading cause of cancer death. Traditional Chinese medicine treatment can alleviate patients' pain and improve postoperative recurrence. Viscum coloratum polysaccharide is one of the main anti-tumor active components of Viscum coloratum and can inhibit proliferation and induce apoptosis of cancer cells.

AIM

To investigate the effect of Viscum coloratum polysaccharide on the proliferation, migration, and invasion of human gastric cancer cells (SGC-7901) and the underlying mechanism.

METHODS

Viability of SGC-7901 cells treated with Viscum coloratum polysaccharide at 20 μg/mL, 40 μg/mL, 60 μg/mL, 80 μg/mL, and 100 μg/mL for 48 h was detected by MTT assay. Cell migration and invasion were detected by Transwell assays, and the protein expression of cyclin-dependent kinases 4 (CDK4), matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9), and nuclear factor κB (NF-κB) p65 in SGC-7901 cells was detected by Western blot.

RESULTS

Different concentrations of Viscum coloratum polysaccharide could inhibit the viability of SGC-7901 cells in a dose-dependent manner (P < 0.05). The results of Western blot indicted that the protein expression of CDK4, MMP-2, MMP-9, and NF-κB p65 in SGC-7901 cells treated with 100 μg/mL Viscum coloratum polysaccharide was down-regulated (P < 0.05), and Transwell assays showed that the numbers of migratory and invaded cells in the visual field were significantly decreased (P < 0.05).

CONCLUSION

Viscum coloratum polysaccharide may inhibit the proliferation, migration, and invasion of SGC-7901 cells by regulating the NF-κB signaling pathway and the expression of CDK4, MMP-2, and MMP-9 proteins.

Identification of key genes and specific pathways potentially involved in androgen-independent, mitoxantrone-resistant prostate cancer

Background

Resistance to mitoxantrone (MTX), an anthracenedione antineoplastic agent used in advanced and metastatic androgen-refractory prostate cancer (PCa), seriously limits therapeutic success.

Methods

Xenografts from two human PCa cell lines (VCaP and CWR22) were established in male severe combined immunodeficiency mice, and MTX was administered, with or without concurrent castration, three times a week until tumors relapsed. Microarray technology was used to screen for differentially expressed genes (DEGs) in androgen-independent, MTX-resistant PCa xenografts. Gene expression profiles of MTX-treatment xenografts and their respective parental cell lines were performed using an Agilent whole human genome oligonucleotide microarray and analyzed using Ingenuity Pathway Analysis software.

Results

A total of 636 genes were differentially expressed (fold change ≥1.5; P<0.05) in MTX-resistant castration-resistant prostate cancer (CRPC) xenografts. Of these, 18 were selected to be validated and showed that most of these genes exhibited a transcriptional profile similar to that seen in the microarray (Pearson’s r=0.87). Western blotting conducted with a subset of genes deregulated in MTX-resistant CRPC tumors was shown through network analysis to be involved in androgen synthesis, drug efflux, ATP synthesis, and vascularization.

Conclusion

The present data provide insight into the genetic alterations underlying MTX resistance in androgen-independent PCa and highlight potential targets to improve therapeutic outcomes.

Long Noncoding RNA LINC00460 Promotes the Gefitinib Resistance of Nonsmall Cell Lung Cancer Through Epidermal Growth Factor Receptor by Sponging miR-769-5p

The vital roles of long noncoding RNAs (lncRNAs) in the nonsmall cell lung cancer (NSCLC) tumorigenesis are increasingly important. This work aims to investigate the role of lncRNA LINC00460 in the gefitinib resistance of NSCLC cells and discover its relevant mechanism. Our finding reveals that the expression of lncRNA LINC00460 is upregulated in the gefitinib-resistant NSCLC tissue and cells, and closely correlated with advanced tumor stage and clinical poor prognosis outcome. Gain and loss functional assays are performed in gefitinib-resistant NSCLC cells (A549/GR), stating that LINC00460 facilitates the 50% inhibitive concentration of gefitinib for NSCLC cells, multidrug-resistant-related proteins (P-gp, MRP1, and BCRP), as well as the invasion. In vivo, LINC00460 silencing represses the tumor growth. Bioinformatics prediction tools and luciferase analysis confirm that the upregulated LINC00460 sponged miR-769-5p in NSCLC cells; moreover, epidermal growth factor receptor (EGFR) is identified as a direct target gene of miR-769-5p. Verification experiments confirm that the restoration of EGFR could weaken the sensibility of NSCLC cells toward the gefitinib. In conclusion, our result demonstrates that LINC00460 plays a pivotal role in gefitinib resistance of NSCLC cells by targeting EGFR through sponging miR-769-5p. This finding might serve as a therapeutic target for NSCLC.

NFKB1 and Cancer: Friend or Foe?

Current evidence strongly suggests that aberrant activation of the NF-κB signalling pathway is associated with carcinogenesis. A number of key cellular processes are governed by the effectors of this pathway, including immune responses and apoptosis, both crucial in the development of cancer. Therefore, it is not surprising that dysregulated and chronic NF-κB signalling can have a profound impact on cellular homeostasis. Here we discuss NFKB1 (p105/p50), one of the five subunits of NF-κB, widely implicated in carcinogenesis, in some cases driving cancer progression and in others acting as a tumour-suppressor. The complexity of the role of this subunit lies in the multiple dimeric combination possibilities as well as the different interacting co-factors, which dictate whether gene transcription is activated or repressed, in a cell and organ-specific manner. This review highlights the multiple roles of NFKB1 in the development and progression of different cancers, and the considerations to make when attempting to manipulate NF-κB as a potential cancer therapy.