Melittin kills A549 cells by targeting mitochondria and blocking mitophagy flux.

Melittin, a naturally occurring polypeptide found in bee venom, has been recognized for its potential anti-tumor effects, particularly in the context of lung cancer. Our previous study focused on its impact on human lung adenocarcinoma cells A549, revealing that melittin induces intracellular reactive oxygen species (ROS) burst and oxidative damage, resulting in cell death. Considering the significant role of mitochondria in maintaining intracellular redox levels and ROS, we further examined the involvement of mitochondrial damage in melittin-induced apoptosis in lung cancer cells. Our findings demonstrated that melittin caused changes in mitochondrial membrane potential (MMP), triggered mitochondrial ROS burst (Figure 1), and activated the mitochondria-related apoptosis pathway Bax/Bcl-2 by directly targeting mitochondria in A549 cells (Figure 2). Further, we infected A549 cells using a lentivirus that can express melittin-Myc and confirmed that melittin can directly target binding to mitochondria, causing the biological effects described above (Figure 2). Notably, melittin induced mitochondrial damage while inhibiting autophagy, resulting in abnormal degradation of damaged mitochondria (Figure 5). To summarize, our study unveils that melittin targets mitochondria, causing mitochondrial damage, and inhibits the autophagy-lysosomal degradation pathway. This process triggers mitoROS burst and ultimately activates the mitochondria-associated Bax/Bcl-2 apoptotic signaling pathways in A549 cells.

Short-term outcomes of robot-assisted versus thoracoscopic-assisted Mckeown esophagectomy.

BACKGROUND: Thoracoscopic-assisted and robot-assisted Mckeown esophagectomy are currently two common surgical methods, but there is no clear statement on the advantages and disadvantages of the two. METHODS: This study conducted a single-centre retrospective analysis of esophageal cancer patients diagnosed and treated at Lanzhou University Second Hospital from 1 February 2020 to 31 July 2022. According to the inclusion and exclusion criteria, 126 patients were finally included in the RAM group and 169 patients in the TAM group. RESULTS: There was no significant difference between the RAM and TAM groups in the number of lymph node dissections, operative time, the length of stay in the intensive care unit after surgery, the incidence of hoarseness, postoperative pulmonary complications, surgery-related complications, use of opioids after surgery, the length of postoperative hospital stay, and 30-day mortality. CONCLUSIONS: RAM is a minimally invasive alternative to TAM and has similar short-term oncological efficacy.

Melittin induces ferroptosis and ER stress-CHOP-mediated apoptosis in A549 cells.

Melittin is a natural polypeptide present in bee venom, with significant anti-tumor activity. Melittin has been reported to induce cell death in lung carcinoma cell line A549 cells, suggesting an excellent potential for treating lung cancer. However, the core mechanism underlying melittin-induced cell death in A549 cells remains unclear. This work reports that melittin induces reactive oxygen species (ROS) burst, upregulates intracellular Fe2+ levels, disrupts the glutathione-glutathione peroxidase 4 antioxidant system, and increases lipid peroxide accumulation, eventually inducing cell death, indicating that ferroptosis may be involved in the antitumor effects of melittin in A549 cells. Furthermore, A549 cells treated with the ferroptosis inhibitors ferrostatin-1 and deferoxamine demonstrated that these inhibitors could reverse the cell death induced by melittin, further confirming that melittin induces A549 cell death via ferroptosis. Furthermore, the results also illustrated that melittin activated the endoplasmic reticulum (ER) stress-CHOP (C/EBP homologous protein) apoptotic signal, closely associated with high-level intracellular ROS. The ER stress inhibitor, 4-Phenylbutyric acid, was used to confirm that ER stress-CHOP apoptotic signaling is another molecular mechanism of melittin-induced A549 cell death. Thus, our results demonstrate that ferroptosis and ER stress-CHOP signaling are key molecular mechanisms of melittin-induced cell death in lung cancer.KEY POLICY HIGHLIGHTSMelittin upregulates intracellular Fe2+ levels, leading to the accumulation of lipid peroxides in A549 cells.Melittin disrupts the glutathione-glutathione peroxidase 4 antioxidant system in A549 cells.Melittin induces activation of endoplasmic reticulum stress-C/EBP homologous protein apoptosis signal.Ferroptosis and ER stress are the core molecular mechanisms underlying melittin-induced cell death in A549 cells.

SYNGR2 serves as a prognostic biomarker and correlates with immune infiltrates in esophageal squamous cell carcinoma.

BACKGROUND: Synaptogyrin-2 (SYNGR2) plays an important role in regulating membrane traffic in non-neuronal cells. However, the role of SYNGR2 in esophageal squamous cell carcinoma (ESCC) remains unclear. METHODS: All original data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and integrated via R 3.5.3. SYNGR2 expression was explored in the TCGA and GEO databases. The correlations between SYNGR2 and cancer immune characteristics were analyzed via the TIMER and TISIDB databases. RESULTS: In general, SYNGR2 was predominantly overexpressed and had reference values in the diagnosis and prognostic estimation of ESCC. Upregulated SYNGR2 was associated with poorer overall survival, disease-specific survival and T stage in ESCC. Mechanistically, we identified hub genes that included a total of 38 SYNGR2-related genes, which were tightly associated with the protein polyubiquitination pathway in ESCC patients. SYNGR2 expression was negatively related to the infiltrating levels of T helper cells. SYNGR2 methylation was positively correlated with the expression of chemokines (CCL2 and CXCL12), chemokine receptors (CCR1 and CCR2), immunoinhibitors (CXCL12 and TNFRSF4) and immunostimulators (CSF1R and PDCD1LG2) in ESCC. CONCLUSION: SYNGR2 may be used as a biomarker for determining prognosis and immune infiltration in ESCC.

DUS4L Silencing Suppresses Cell Proliferation and Promotes Apoptosis in Human Lung Adenocarcinoma Cell Line A549.

PURPOSE: This study aims to investigate the potential role of DUS4L (dihydrouridine synthase 4 like) in lung adenocarcinoma (LUAD) and explore its associated pathways in human LUAD. METHODS: Firstly, we evaluated the relationships between clinicopathological characteristics and DUS4L expression via analysis of TCGA RNA sequencing data and other publicly available databases. Then, DUS4L was effectively silenced in LUAD cell line A549 using the lentiviral shRNA (short-hairpin RNA) transfection to assess its effects on cell proliferation, cycle and apoptosis in LUAD cells. RNA-seq technology was applied to shDUS4L and shCtrl-transfected cells to generate the corresponding gene expression profiles. Differentially expressed genes (DEGs) were identified using the DESeq2 program package. Also, DEGs were subjected to Gene Ontology (GO) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analysis to explore the associated molecular signaling pathways and relevant biological functions. RESULTS: Analysis of TCGA data revealed that DUS4L was highly upregulated in LUAD tissues which was related to clinical T and TNM stages of LUAD. The knockdown of DUS4L effectively inhibited cell proliferation and promoted apoptosis in A549 cells. Furthermore, the DEGs between the shDUS4L and shCtrl A549 cells were mainly enriched in biological processes associated with spliceosome, ribosome, RNA catabolic process, ncRNA (non-coding RNA) processing, and p53 signaling pathway. CONCLUSION: Altogether, our results suggest that DUS4L is significantly associated with tumorigenesis and could be utilized as a novel biomarker and therapeutic target for LUAD.

PlantRegMap: charting functional regulatory maps in plants.

With the goal of charting plant transcriptional regulatory maps (i.e. transcription factors (TFs), cis-elements and interactions between them), we have upgraded the TF-centred database PlantTFDB (http://planttfdb.cbi.pku.edu.cn/) to a plant regulatory data and analysis platform PlantRegMap (http://plantregmap.cbi.pku.edu.cn/) over the past three years. In this version, we updated the annotations for the previously collected TFs and set up a new section, 'extended TF repertoires' (TFext), to allow users prompt access to the TF repertoires of newly sequenced species. In addition to our regular TF updates, we are dedicated to updating the data on cis-elements and functional interactions between TFs and cis-elements. We established genome-wide conservation landscapes for 63 representative plants and then developed an algorithm, FunTFBS, to screen for functional regulatory elements and interactions by coupling the base-varied binding affinities of TFs with the evolutionary footprints on their binding sites. Using the FunTFBS algorithm and the conservation landscapes, we further identified over 20 million functional TF binding sites (TFBSs) and two million functional interactions for 21 346 TFs, charting the functional regulatory maps of these 63 plants. These resources are publicly available at PlantRegMap (http://plantregmap.cbi.pku.edu.cn/) and a cloud-based mirror (http://plantregmap.gao-lab.org/), providing the plant research community with valuable resources for decoding plant transcriptional regulatory systems.

Clinicopathological and prognostic significance of epithelial cell transforming sequence 2 expression in cancers: a systematic review and meta-analysis.

Numerous studies have investigated the prognostic significance of ECT2 (epithelial cell transforming sequence 2) expression in patients with cancer. Nevertheless, conflicting results have been obtained. We thus performed a meta-analysis to systematically assess the prognostic significance of ECT2 in cancer. Electronic databases (PubMed and EMBASE) were searched for eligible studies. Hazard ratios (HR) and odds ratios (OR) with 95% confidence intervals (CIs) were used to estimate effect sizes. A total of 5,305 patients from 19 articles and 21 studies were included. The pooled results revealed that high ECT2 expression was correlated with advanced TNM stage (OR = 2.17; 95% CI: 1.42-3.32), positive lymph node metastasis (OR = 2.98; 95% CI: 2.28-3.89), distant metastasis (OR = 2.25; 95% CI: 1.03-4.92), and poor tumour differentiation (OR = 2.25; 95% CI: 1.03-4.92). More importantly, high ECT2 expression was significantly associated with poor overall survival (HR = 2.26; 95% CI, 1.84-2.78) and recurrence-free survival (HR = 1.52; 95% CI, 1.24-1.86). Our results suggested that ECT2 is a promising prognostic indicator and therapeutic target for cancer.

MiR-629-3p-induced downregulation of SFTPC promotes cell proliferation and predicts poor survival in lung adenocarcinoma.

The long-term prognosis of patients with lung cancer remains poor and thus it is imminent to further elucidate the molecular mechanism for the oncogenesis of lung cancer. In this study, we observed that surfactant protein C (SFTPC) expression was downregulated in human lung adenocarcinoma tissues and cell lines, and low SFTPC expression correlated with poor overall survival of lung adenocarcinoma patients. Moreover, we found that overexpression of SFTPC could inhibit lung cancer cell proliferation in vitro and in vivo, but downregulation of SFTPC showed the opposite results. Besides, it was observed that miR-629-3p expression was upregulated in human lung adenocarcinoma tissues and cell lines. More importantly, we found that miR-629-3p could downregulate SFTPC expression by directly binding to the SFTPC 3'-UTR and inhibit the regulatory effect of SFTPC on lung adenocarcinoma cell proliferation. In conclusion, these data suggested that miR-629-3p-meditated downregulation of SFTPC may promote lung adenocarcinoma progression.

Tumor-derived exosomal HMGB1 promotes esophageal squamous cell carcinoma progression through inducing PD1+ TAM expansion.

Macrophages constitute one of the most common components of immune cells, which penetrate tumors and they have a key role in tumor prognosis. Here, we identified an unrecognized macrophage subpopulation, which favors tumorigenesis. These macrophages express programmed cell death protein 1 (PD1) in a constitutive manner and accumulates in esophageal squamous cell carcinoma (ESCC) in advanced stage of the disease and is negatively associated with the survival of ESCC patients. The PD1+ tumor-associated macrophages (PD1+ TAMs) displayed surface pattern and function akin to M2: a substantial enhancement in CD206 and IL-10 expression; a specific reduction in HLA-DR, CD64, and IL-12 expression; and a significant increase in the ability to inhibit CD8+ T-cell proliferation. Triggering of PD1 signal is effective in increasing PD1+ TAM function. Moreover, exosomal HMGB1 obtained from tumors are efficient in triggering differentiation of monocytes into PD1+ TAMs, which display phenotypic and functional properties of M2. Overall, our work is the first finding to confirm that exosomal HMGB1 obtained from ESCC can successfully trigger clonal expansion of PD1+ TAM. Further, as the macrophages exhibit an M2-like surface profile and function, thereby creating conditions for development of ESCC. Thus, effective methods of treatment include combining immunotherapy with targeting PD1+ TAMs and tumor-derived exosomal HMGB1 to resuscitate immune function in individuals suffering from ESCC.

CPC2: a fast and accurate coding potential calculator based on sequence intrinsic features.

With advances in next-generation sequencing technologies, numerous novel transcripts in a large number of organisms have been identified. With the goal of fast, accurate assessment of the coding ability of RNA transcripts, we upgraded the coding potential calculator CPC1 to CPC2. CPC2 runs ∼1000 times faster than CPC1 and exhibits superior accuracy compared with CPC1, especially for long non-coding transcripts. Moreover, the model of CPC2 is species-neutral, making it feasible for ever-growing non-model organism transcriptomes. A mobile-friendly web server, as well as a downloadable standalone package, is freely available at http://cpc2.cbi.pku.edu.cn.

PlantTFDB 4.0: toward a central hub for transcription factors and regulatory interactions in plants.

With the goal of providing a comprehensive, high-quality resource for both plant transcription factors (TFs) and their regulatory interactions with target genes, we upgraded plant TF database PlantTFDB to version 4.0 (http://planttfdb.cbi.pku.edu.cn/). In the new version, we identified 320 370 TFs from 165 species, presenting a more comprehensive genomic TF repertoires of green plants. Besides updating the pre-existing abundant functional and evolutionary annotation for identified TFs, we generated three new types of annotation which provide more directly clues to investigate functional mechanisms underlying: (i) a set of high-quality, non-redundant TF binding motifs derived from experiments; (ii) multiple types of regulatory elements identified from high-throughput sequencing data; (iii) regulatory interactions curated from literature and inferred by combining TF binding motifs and regulatory elements. In addition, we upgraded previous TF prediction server, and set up four novel tools for regulation prediction and functional enrichment analyses. Finally, we set up a novel companion portal PlantRegMap (http://plantregmap.cbi.pku.edu.cn) for users to access the regulation resource and analysis tools conveniently.

Prognostic role of neutrophil-lymphocyte ratio in operable esophageal squamous cell carcinoma.

AIM: To determine the prognostic significance of preoperative serum neutrophil-lymphocyte ratio (NLR) in esophageal squamous cell carcinoma (ESCC). METHODS: Data from 371 eligible patients with ESCC who had undergone surgery with curative intent at our institution between October 2000 and May 2007 were retrospectively recruited for analysis. The cutoff value of NLR was 3.0 as determined by the receiver operating characteristic curve, which discriminated between survival and death; the area under the curve was 0.709, and the sensitivity and specificity were 66.1% and 69.1%, respectively, at the cutoff point. The correlation between the NLR and clinicopathological characteristics was analyzed using a χ(2) test. The prognostic influence of the NLR and other clinicopathological factors on cancer-specific survival (CSS) and recurrence-free survival (RFS) was studied using the Kaplan-Meier method. To evaluate the independent prognostic value of NLR, multivariate Cox regression models were applied. RESULTS: The median age of the patients was 57.0 years, and 276/371 (74.4%) patients were male. The NLR was ≤ 3.0 in 80.1% (297/371) of the patients, and the remaining 19.9% (74/371) had an NLR > 3.0. Median postoperative follow-up was 66.0 mo [interquartile range (IQR): 49.0-76.0 mo], with a follow-up rate of 94%. Follow-up was not significantly different between patients with an NLR ≤ and > 3.0 (63.13 ± 1.64 vs 61.52 ± 3.66, P = 0.711). However, higher preoperative serum NLR was associated with significantly increased risks of higher pathological tumor status (P = 0.007). A significant, independent association between high preoperative serum NLR and poor clinical outcome was identified in a multivariate analysis for CSS (HR = 1.591; P = 0.007) and RFS (HR = 1.525; P = 0.013). Moreover, when patients were stratified by pathological tumor-node-metastasis (TNM) staging, the adverse effects of preoperative serum NLR on CSS (HR = 2.294; P = 0.008) and RFS (HR = 2.273; P = 0.008) were greatest in those patients with stage IIIA disease. CONCLUSION: Preoperative serum NLR is a useful prognostic marker to complement TNM staging for operable ESCC patients, particularly in patients with stage IIIA disease.