PYCR1 regulates TRAIL­resistance in non­small cell lung cancer cells by regulating the redistribution of death receptors.

Although recombinant human TNF-related apoptosis-inducing ligand (TRAIL) protein exhibits antitumor activity in a number of lung and liver cancer cells and tumor-bearing animals, TRAIL resistance has substantially restricted its clinical application. Pyrroline-5-carboxylate reductase 1 (PYCR1) is a key enzyme in the regulation of proline synthesis. PYCR1 is highly expressed in various types of malignant tumor, in which it has been implicated in 5-fluorouracil resistance. However, the possible relationship between PYCR1 and TRAIL resistance remains unclear. In the present study, both reverse transcription-quantitative PCR and western blotting were performed. The results indicated that H1299 cells had higher PYCR1 expression levels and were less sensitive to TRAIL compared with the TRAIL-sensitive cell line, H460. PYCR1 knockdown in H1299 cells increased TRAIL sensitivity, increased the localization of death receptors (DRs) on the cell surface and activated Caspase-3/8. By contrast, overexpression of PYCR1 in H1299 cells decreased TRAIL sensitivity, reduced the distribution of DRs on the cell surface and suppressed the activation of Caspase-3/8. Taken together, these results suggested that PYCR1 promoted TRAIL resistance in the non-small cell lung cancer cell line, H1299, by preventing redistribution of DRs to the plasma membrane. This in turn inhibited TRAIL-mediated cell apoptosis by reducing the activation of Caspase-3/8.

First report of GI.1aP-GI.2 recombinants of rabbit hemorrhagic disease virus in domestic rabbits in China.

The rabbit hemorrhagic disease virus 2 (RHDV2 or GI.2) is a highly contagious agent leading to lethal disease in rabbits. It frequently recombines with other Lagovirus genus, generating epidemical variants with high pathogenicity. In this study, twenty-two liver samples tested positive for GI.2 VP60 gene, were collected in rabbit farms from several geographical regions in China. All GI.2 positive specimens were submitted for RT-PCR detection, nucleotide sequencing and phylogenetic analysis. In addition, suspected GI.2 recombinants were evaluated for virus virulence. The results showed that nine presumptive recombinants were identified by testing for RdRp-VP60 recombination. In these recombinants, four were selected to fully characterize the genome of novel GI.2 recombinant variants, which were described as GI.1aP-GI.2. The nucleotide sequence of these novel variants showed unique recombination pattern and phylogenetic features compared to currently prevalent GI.2 variants. Furthermore, this distinctive recombination of new variant SCNJ-2021 moderately enhanced the virulence of GI.2, even for rabbits vaccinated against parental GI.2. In conclusion, the novel GI.1aP-GI.2 recombinants were identified in rabbit industry in China for the first time, which expanded the knowledge on the phylodynamics and genomic diversity of GI.2 genotype. The rapid molecular evolution and varied pathogenicity of these virus recombinants highlight the urgent need for epidemiological surveillance and for future prevention of these neglected GI.2 variants.

A 20-Gene Signature Predicting Survival in Patients with Clear Cell Renal Cell Carcinoma Based on Basement Membrane.

Objectives: The most common subtype of renal cell carcinoma, clear cell renal cell carcinoma (ccRCC), has a high heterogeneity and aggressive nature. The basement membrane (BM) is known to play a vital role in tumor metastasis. BM-related genes remain untested in ccRCC, however, in terms of their prognostic significance. Methods: BM-related genes were gleaned from the most recent cutting-edge research. The RNA-seq and clinical data of the ccRCC were obtained from TCGA and GEO databases, respectively. The multigene signature was constructed using the univariate Cox regression and the LASSO regression algorithm. Then, clinical features and prognostic signatures were combined to form a nomogram to predict individual survival probabilities. Using functional enrichment analysis and immune-correlation analysis, we investigated potential enrichment pathways and immunological characteristics associated with BM-related-gene signature. Results: In this study, we built a model of 20 BM-related genes and classified them as high-risk or low-risk, with each having its anticipated risk profile. Patients in the high-risk group showed significantly reduced OS compared with patients in the low-risk group in the TCGA cohort, as was confirmed by the testing dataset. Functional analysis showed that the BM-based model was linked to cell-substrate adhesion and tumor-related signaling pathways. Comparative analysis of immune cell infiltration degrees and immune checkpoints reveals a central role for BM-related genes in controlling the interplay between the immune interaction and the tumor microenvironment of ccRCC. Conclusions: We combined clinical characteristics known to predict the prognosis of ccRCC patients to create a gene signature associated with BM. Our findings may also be useful for forecasting how well immunotherapies would work against ccRCC. Targeting BM may be a therapeutic alternative for ccRCC, but the underlying mechanism still needs further exploration.

Erratum: MUC3A promotes non-small cell lung cancer progression via activating the NFκB pathway and attenuates radiosensitivity.

[This corrects the article DOI: 10.7150/ijbs.59430.].

MUC3A promotes non-small cell lung cancer progression via activating the NFκB pathway and attenuates radiosensitivity.

Mucin 3A (MUC3A) is highly expressed in non-small cell lung cancer (NSCLC), but its functions and effects on clinical outcomes are not well understood. Tissue microarray of 92 NSCLC samples indicated that high levels of MUC3A were associated with poor prognosis, advanced staging, and low differentiation. MUC3A knockdown significantly suppressed NSCLC cell proliferation and induced G1/S accumulation via downregulating cell cycle checkpoints. MUC3A knockdown also inhibited tumor growth in vivo and had synergistic effects with radiation. MUC3A knockdown increased radiation-induced DNA double strain breaks and γ-H2AX phosphorylation in NSCLC cells. MUC3A downregulation inhibited the BRCA-1/RAD51 pathway and nucleus translocation of P53 and XCRR6, suggesting that MUC3A promoted DNA damage repair and attenuated radiation sensitivity. MUC3A knockdown also resulted in less nucleus translocation of RELA and P53 in vivo. Immunoprecipitation revealed that MUC3A interacted with RELA and activated the NFκB pathway via promoting RELA phosphorylation and interfering the binding of RELA to IκB. Our studies indicated that MUC3A was a potential oncogene and associated with unfavorable clinical outcomes. NSCLC patients with a high MUC3A level, who should be more frequent follow-up and might benefit less from radiotherapy.

Small Nucleolar RNA 71A Promotes Lung Cancer Cell Proliferation, Migration and Invasion via MAPK/ERK Pathway.

Objective: Increasing evidence suggested that dysregulated small nucleolar RNAs (snoRNAs) were involved in tumor development. The roles of snoRNA 71A (SNORA71A) in the progression of non-small cell lung cancer (NSCLC) remained unclear. Methods: Dataset GSE19188 from Gene Expression Omnibus (GEO) database was downloaded to detect the expression levels of SNORA71A in NSCLC tissues. The biological significance of SNORA71A was explored by loss-of-function analysis both in vitro and in vivo. Results: SNORA71A was overexpressed in NSCLC tissues compared with normal tissues, and upregulated SNORA71A was significantly associated with worse survival of NSCLC patients. Knockdown of SNORA71A suppressed proliferation of both A549 and PC9 cells, and induced G0/G1 phase arrest. Knockdown of SNORA71A also suppressed xenograft tumor growth in mice. In addition, knockdown of SNORA71A inhibited cell invasion and migration and suppressed epithelial-mesenchymal transition. Furthermore, downregulated SNORA71A decreased the phosphorylation of MEK and ERK1/2 in the MAPK/ERK signal pathway. Conclusion: SNORA71A functions as an oncogene in NSCLC and may serve as a therapeutic target and promising prognostic biomarker of NSCLC.

FePt/GO Nanosheets Suppress Proliferation, Enhance Radiosensitization and Induce Autophagy of Human Non-Small Cell Lung Cancer Cells.

With the advancement of nanotechnology, various nanocomposites have been applied in the diagnostics and treatment of cancer. We synthetized FePt nanoparticles which were assembled on the surface of graphene oxide (GO). These novel FePt/GO nanosheets simultaneously act as a chemotherapy drug and enhance radiosensitivity. In this study, transmission electron microscope, dynamic light scattering, X-ray photoelectron spectroscope and Fourier transform infrared spectroscopy were used to characterize surface morphology and chemical composition of FePt/GO nanosheets (NSs). Their cytotoxicity in various cancer and normal cells was evaluated by cell counting kit-8 assay, and their effects on radiosensitization were determined by colony formation assay. To explore the underlying mechanisms, we measured the intracellular reactive oxygen species levels and autophagy formation. Monodansylcadaverine-staining, Western Blotting and ultrastructure analysis were utilized to assess autophagy. The results demonstrated that FePt/GO NSs not only selectively suppressed the proliferation of cancer cells, but also increased their radiosensitization. Moreover, FePt/GO NSs induced autophagy, which might result in promoted sensibilization of radiotherapy. In conclusion, with good safety and efficacy, FePt/GO NSs are safe and effective to suppress proliferation, enhance radiosensitization and induce autophagy of human non-small cell lung cancer cells. They are potential for the treatment of lung cancer.

Impact of Radiotherapy Concurrent with Anti-PD-1 Therapy on the Lung Tissue of Tumor-Bearing Mice.

Pneumonitis is a common adverse effect found in non-small cell lung cancer patients after radiotherapy or immune checkpoint inhibitor treatment. We investigated the effects of these two therapies, combined, in the lung tissue of an orthotopic tumor-bearing mouse model. The mice received an 8 Gy dose three times with or without 200 µg anti-programmed death-1 (anti-PD-1) antibody intraperitoneal injection every three days. Lung tissues were H&E stained to determine histological changes. The serum levels of cytokines, such as interferon-γ, tumor necrosis factor and interleukin-5, were detected by cytometric bead array. The neutrophil infiltration was evaluated by immunohistochemical staining for myeloperoxidase. The lung injury score was higher in the treated groups than the control group, especially in the combined treatment group, in which the proportion of neutrophils in lung tissues was significantly higher compared to any other groups. Similarly, the CD4/CD8 ratio of the lung tissues in the combined treatment group, as well as the serum levels of interferon-γ, tumor necrosis factor and interleukin-5, were significantly higher than the other groups. These findings indicate that radiation combined with anti-PD-1 treatment leads to more severe lung injury in the orthotopic tumor-bearing mouse model, accompanied by increased neutrophil infiltration and increased inflammatory response.

Protective Role of Nuclear Factor-Erythroid 2-Related Factor 2 Against Radiation-Induced Lung Injury and Inflammation.

Radiation-induced lung injury (RILI) is one of the most common and fatal complications of thoracic radiotherapy. Inflammatory cell infiltration, imbalance of inflammatory cytokines, and oxidative damage were reported to be involved during RILI pathogenesis, especially in the early phase of RILI. Nuclear factor-erythroid 2-related factor 2 (Nrf2) is a key transcriptional regulator of antioxidative cascades, and regulates life span of mice after administration of thoracic irradiation. We investigated the effects of Nrf2 on RILI and inflammation using Nrf2-knockout, Nrf2-overexpression and wild-type mice with or without 15 Gy ionizing radiation to thorax. Our results showed that Nrf2 deficiency aggravated radiation-induced histopathological changes, macrophage and neutrophil infiltration, serum levels of pro-inflammatory cytokines (IL-6, MCP-1, IFN-γ, TNF, and IL-12p70), and the levels of peroxidation products in the mouse lung. Moreover, loss of Nrf2 reduced radiation-induced serum levels of anti-inflammatory cytokine, IL-10, and antioxidative proteins. Nrf2 overexpression significantly alleviated radiation-induced histopathological changes, macrophages and neutrophils infiltration, serum levels of pro-inflammatory cytokines, and the levels of peroxidation products in lung tissues. Nrf2 overexpression also increased the serum levels of IL-10 and antioxidative proteins. These results indicated that Nrf2 had a protective role against radiation-induced acute lung injury and inflammation, and that antioxidative therapy might be a promising treatment for RILI.

ß-catenin decreases acquired TRAIL resistance in non-small-cell lung cancer cells by regulating the redistribution of death receptors.

Tumor necrosis factor­related apoptosis­inducing ligand (TRAIL) exhibits antitumor activity in various types of tumor cell and tumor­bearing animals. However, acquired TRAIL resistance is a common issue that restricts its clinical application. Previous studies have revealed that ß­catenin is associated with TRAIL resistance in melanoma and colorectal tumors. In the present study, an acquired­resistance non­small­cell lung cancer (NSCLC) cell line (H460­TR) was established from parental TRAIL­sensitive H460 cells using a gradient ascent model (8­256 ng/ml TRAIL). Cellular FADD­like interleukin­1ß converting enzyme inhibitory protein and Mcl­1 were upregulated and the cell surface distribution of death receptor (DR)4 and DR5 was downregulated in H460­TR cells compared with the parental H460 cells. The results of reverse transcription­quantitative polymerase chain reaction and western blot analysis indicated that H460 cells expressed increased levels of ß­catenin and were more sensitive to TRAIL compared with H460­TR cells. ß­catenin­knockdown in H460 cells decreased their sensitivity to TRAIL, while upregulation of ß­catenin expression in H460­TR cells increased their sensitivity to TRAIL, increased the cell surface distribution of DRs and activated caspase­3/8. Taken together, the results of the present study suggest that ß­catenin impairs acquired TRAIL resistance in NSCLC cells by promoting the redistribution of DR4 and DR5 to the cytomembrane, and inducing TRAIL­mediated cell apoptosis via caspase­3/8 activation.

Trichosanthin enhances sensitivity of non-small cell lung cancer (NSCLC) TRAIL-resistance cells.

Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) has a specific antitumour activity against many malignant tumours. However, more than half of lung cancer cells are resistant to TRAIL-relevant drugs. Trichosanthin (TCS) is a traditional Chinese medicine with strong inhibitive effects on various malignancies. Nevertheless, its function on TRAIL resistance has not been revealed in non-small cell lung cancer (NSCLC). To examine the molecular mechanisms of TCS-induced TRAIL sensitivity, we administrated TCS to TRAIL-resistance NSCLC cells, and found that the combination treatment of TCS and TRAIL inhibited cancer cell proliferation and invasion, and induced cell apoptosis and S-phase arrest. This combined therapeutic method regulated the expression levels of extrinsic apoptosis-associated proteins Caspase 3/8 and PARP; intrinsic apoptosis-associated proteins BCL-2 and BAX; invasion-associated proteins E-cadherin, N-cadherin, Vimentin, ICAM-1, MMP-2 and MMP-9; and cell cycle-associated proteins P27, CCNE1 and CDK2. Up-expression and redistribution of death receptors (DRs) on the cell surface were also observed in combined treatment. In conclusion, our results indicated that TCS rendered NSCLC cells sensitivity to TRAIL via upregulating and redistributing DR4 and DR5, inducing apoptosis, and regulating invasion and cell cycle related proteins. Our results provided a potential therapeutic method to enhance TRAIL-sensitivity.

FePt-Cys nanoparticles induce ROS-dependent cell toxicity, and enhance chemo-radiation sensitivity of NSCLC cells in vivo and in vitro.

FePt-Cys nanoparticles (FePt-Cys NPs) have been well used in many fields, despite their poor solubility and stability. We synthetized a cysteine surface modified FePt NPs, which exhibited good solubility, stability and biocompatibility. We explored the insight mechanisms of the antitumor effects of this new nanoparticle system in lung cancer cells. In the in vitro study, FePt-Cys NPs induced a reactive oxygen species (ROS) burst, which suppressed the antioxidant protein expression and induced cell apoptosis. Furthermore, FePt-Cys NPs prevented the migration and invasion of H1975 and A549 cells. These changes were correlated with a dramatic decrease in MMP-2/9 expression and enhanced the cellular attachment. We demonstrated that FePt-Cys NPs promoted the effects of chemo-radiation through activation of the caspase system and impairment of DNA damage repair. In the in vivo study, no severe allergies or drug-related deaths were observed and FePt-Cys NPs showed a synergistic effect with cisplatin and radiation. In conclusion, with good safety and efficacy, FePt-Cys NPs could therefore be potential sensitizers for chemoradiotherapy.

Trichosanthin inhibits DNA methyltransferase and restores methylation-silenced gene expression in human cervical cancer cells.

Epigenetic silencing of tumor suppressor genes is a well-established oncogenic process and the reactivation of tumor suppressor genes that have been silenced by promoter methylation is an attractive molecular target for cancer therapy. In this study, we investigated the demethylation activity of trichosanthin (TCS, the main bioactive component isolated from a Chinese medicinal herb) and its possible mechanism of action in cervical cancer cell lines. HeLa human cervical adenocarcinoma and CaSki human cervical squamous carcinoma cells were treated with various concentrations (0, 20, 40 and 80 µg/ml) of TCS for 48 h and the mRNA and protein expression levels of the tumor suppressor genes adenomatous polyposis coli (APC) and tumor suppressor in lung cancer 1 (TSLC1) were detected using reverse transcription (RT)-PCR and western blotting, respectively. We analyzed the methylation status of APC and TSLC1 using methylation-specific PCR (MSP). The expression levels and enzyme activity of DNA methyltransferase 1 (DNMT1) were also examined. The mRNA and protein expression levels of APC and TSLC1 were increased following treatment with various concentrations (0, 20, 40 and 80 µg/ml) of TCS for 48 h. The expression of the APC gene increased 2.55±0.29-, 3.44±0.31- and 4.36±0.14-fold, respectively. The expression of the TSLC1 gene increased 2.28±0.15-, 4.23±0.88- and 6.09±0.23-fold, respectively. MSP detection showed that TCS induced demethylation in HeLa and CaSki cells and that this demethylation activity was accompanied by the decreased expression of DNMT1 and reduced DNMT1 enzyme activity. Our experimental results demonstrate for the first time that TCS is capable of restoring the expression of methylation-silenced tumor suppressor genes and is potentially useful as a demethylation agent for the clinical treatment of human cervical cancer.

[Effect of recombinant trichosanthin on proliferation of human cevical cancer Caski cells].

OBJECTIVE: To observe the effects of high expression of recombinant trichosanthin (rTCS) on the cell proliferation and cell cycle of human cervical cancer Caski cells. METHOD: Eukaryotic expression plasmid pcDNA3.1(-)/6His-TCS was constracted and stably transfected into Caski cells. RT-PCR,Western-blot were used to select the clones with rTCS high-expressing. Using pcDNA3.1(-)-transfected cells as the control, MTT assay and flowcytometry were used to elucidate the effects of rTCS high expression on cell growth and cycle regulation in Caski cells. RESULT: The Caski cells with stable high expression of rTCS was successfully established, which could inhibit the cell growth (P<0.01) and arrest Caski cells in G1 and G2 phases (P<0.05) obviously. CONCLUSION: High expression of rTCS can inhibit the growth of Caski cervical cancer cells, which might provide a new pathway for the therapy of cervical cancer.