TRIB3 promotes lung cancer cell survival and inhibits apoptosis through NRF2 activation / 药学学报

The nuclear transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) plays a crucial role in maintaining cellular redox homeostasis. The aberrant NRF2 signaling confers enhanced antioxidant capacity, which is linked to tumor progression and therapeutic resistance. The current study investigates the biological effects and molecular mechanism of tribbles homolog 3 (TRIB3), a stress-induced protein, in regulating cell survival and apoptosis in lung cancer. This study first performed the RNA sequencing data analysis with 576 lung adenocarcinoma patients from the cancer genome atlas (TCGA) database. The NRF2- antioxidant response element (ARE) signature was enriched in patients with high TRIB3 expression. Dual-luciferase reporter assay and real-time quantitative polymerase chain reaction (PCR) were used to confirm the effect of TRIB3 on the kelch-like ECH-associated protein-1 (KEAP1)-NRF2 pathway. Abrogation of TRIB3 impaired NRF2 transcriptional activity and reduced the expression of its target genes. Moreover, TRIB3 enhanced NRF2 stability via blocking KEAP1-NRF2 interaction. TRIB3-depletion promoted reactive oxygen species (ROS) production, restrained cell proliferation, and enhanced carboplatin-induced apoptosis. In addition, NRF2 overexpression recovered the tumor inhibition effect of TRIB3-depletion. Consistently, TRIB3 failed to modulate apoptosis in NRF2 depletion cells. In summary, this study shows that TRIB3 inhibits the KEAP1-NRF2 interaction and upregulates the transcriptional activity of NRF2, thereby promoting lung cancer cell proliferation and reducing the sensitivity to chemotherapy. Targeting the TRIB3-NRF2 signal axis may become a new strategy for ROS homeostasis and lung cancer treatment.

TRIM25 enhances EGFR stability and signaling activity to promote lung cancer progression / 药学学报

Mutation and amplification of epidermal growth factor receptor (EGFR), one of the most important driver gene, are both reported to participate in the regulation of lung cancer development and progression. Here we investigated the effect and molecular mechanism of tripartite motif 25 (TRIM25) in the regulation of development of lung cancer. CCK-8 and Transwell assays were used to explore the tumor-promoting effect of TRIM25. Results showed that knockdown of TRIM25 significantly inhibited cell proliferation (34% inhibition rate) and invasion (42% inhibition rate). Gene set enrichment analysis (GSEA), Western blot and immunohistochemistry were adopted to detect the effect of TRIM25 on EGFR expression and its downstream signal activity. The results explained that TRIM25 not only up-regulated the expression level of EGFR, but also promoted EGFR signal activation. Co-immunoprecipitation, real-time PCR and cycloheximide (CHX) inhibit protein degradation assays were employed to explore the molecular mechanism of TRIM25 in regulating EGFR stability. Preliminary exploration results indicate that TRIM25 increases the expression level of EGFR and activates its downstream signaling activity through promoting K63-linked ubiquitination of EGFR. Restoration of EGFR expression rescues the phenotype of TRIM25 depletion. In A549 cells, overexpression of EGFR increased cell proliferation rate 1.5-fold and invasion rate 1.6-fold compared with knockdown of TRIM25 cells. Similarly, in H1975 cells, cell proliferation rate was enhanced 2-fold and invasion rate was improved 1.7-fold. These data suggest that TRIM25 promotes lung cancer development via maintaining EGFR stability and continuous EGFR signaling activation. The human lung cancer tissues were obtained from lung cancer patients at Cancer Hospital Chinese Academy of Medical Sciences. Informed consent was obtained from all participants in accordance with the Declaration of Helsinki. The study was approved by the Ethics Committee of the Cancer Hospital Chinese Academy of Medical Sciences.

Macrophage migration inhibitory factor, a critical link between inflammation and cancer / 药学学报

Macrophage migration inhibitory factor (MIF) is a classical pro-inflammatory cytokine that plays an important role in the innate and adaptive immune regulation. In recent years, a large number of studies have demonstrated that the expression level of MIF is significantly increased in a variety of tumor tissues and MIF promotes the occurrence and development of tumors. MIF participates in the regulation of tumor growth, metastasis, angiogenesis, as well as induces and maintains the tumor microenvironment. Targeting MIF has been considered as a candidate strategy against cancer. In this review, the structural features, the signaling pathway, the biological functions of MIF are briefly outlined. Moreover, approaches that target MIF in the treatment of cancer are also summarized.

Advances in the studies of the link between diabetes and cancer / 药学学报

Diabetes and cancer are two major chronic diseases with tremendous impact on human health worldwide. Clinical and basic studies demonstrate that diabetes can promote carcinogenesis and tumor progression. High insulin and high insulin-like growth factor are considered to be the major risk factors for cancer. Chronic inflammation and aberrant metabolism also participate in cancer development. It is noteworthy that therapies used for treatment of diabetes may increase or decrease the risk of cancer. Revealing the mechanisms that connect diabetes to cancer will be crucial for prevention and treatment of diabetes-related cancers.

Changes of secondary metabolites and differential proteomics in mulberry leaves under UV-B induction / 中国药学杂志

OBJECTIVE: To investigate the influence of ultraviolet B (UV-B) induction on the content of two kinds of secondary metabolites in mulberry leaves and differential proteomics under UV-B induction. METHODS: The HPLC chromatograms of secondary metabolites in leaves before and after UV-B induction were established and quantitative analysis of two kinds of secondary metabolites was performed. The subcellular structure of mulberry leaves under UV-B induction was observed using transmission electron microscopy. Proteomic analysis of mulberry leaves was performed using two-dimensonal electrophoresis (2-DE). RESULTS: The subcellular structure of mulberry leaves was destroyed under UV-B induction. The contents of moracin N and chalcomoracin in mulberry leaves were increased with the dark incubation time and they maximized at 36 and 40 h, respectively. The result of proteomics showed that the abundance of chalcone synthase (CHS) which is the key enzyme of flavonoid biosynthesis pathway was increased significantly. CONCLUSION: The secondary metabolism especially for flavonoids biosynthesis in mulberry leaves is changed under UV-B induction and dark incubation, which result in the increased moracin N and chalcomarcin.

Autophagy in ageing and ageing-related diseases / 药学学报

Autophagy is an important homeostatic cellular recycling mechanism responsible for degrading injured or dysfunctional cellular organelles and proteins in all living cells. Aging is a universal phenomenon characterized by progressive deterioration of cells and organs due to accumulation of macromolecular and organelle damage. Growing evidences indicate that the rate of autophagosome formation and maturation and the efficiency of autophagosome/lysosome fusion decline with age. Dysfunctional autophagy has also been observed in age-related diseases. Autophagy disruption resulted accumulation of mutated or misfolded proteins is the essential feature of neurodegenerative disorders. However, in cancers, fibroproliferative diseases or cardiovascular diseases, autophagy can play either a protective or destructive role in different types of disease, and even in different stages of the same disease. The review will discuss the cellular and molecular mechanisms of autophagy and its important role in the pathogenesis of aging and age-related diseases, and the ongoing drug discovery strategies for therapeutic intervention.

Establishment and application of TLR2 receptor-based cell screening model / 药学学报

TLR2 activity plays an important role in the pathogenesis of autoimmune diseases, tumor carcinogenesis and cardio-cerebrovascular diseases. To establish a TLR2 receptor-based cell screening model, NF-kappaB promoter-driven luciferase reporter plasmids were transfected into human embryonic kidney cells (HEK293) stably expressing human TLR2 and co-receptors CD14, TLR1 and TLR6. Single clones were then isolated and characterized. Using this screening system, a human TLR2-binding peptide C8 was obtained from the Ph.D.-7 Phage Display Peptide Library through biopanning and rapid analysis of selective interactive ligands (BRASIL). The binding characteristic of C8 with human TLR2 was evaluated by ELISA, flow cytometry and immunofluorescence. The NF-kappaB luciferase activity assay showed that C8 could activate the TLR2/TLR1 signaling pathway and induce the production of cytokines TNF-alpha and IL-6. In conclusion, the TLR2 receptor-based cell screening system is successfully established and a new TLR2-binding peptide is identified by using this system.