ALOX5 deficiency contributes to bladder cancer progression by mediating ferroptosis escape.

Ferroptosis is an iron-dependent form of regulated cell death driven by the lethal lipid peroxides. Previous studies have demonstrated that inducing ferroptosis holds great potential in cancer therapy, especially for patients with traditional therapy failure. However, cancer cells can acquire ferroptosis evasion during progression. To date, the therapeutic potential of inducing ferroptosis in bladder cancer (BCa) remains unclear, and whether a ferroptosis escape mechanism exists in BCa needs further investigation. This study verified that low pathological stage BCa cells were highly sensitive to RSL3-induced ferroptosis, whereas high pathological stage BCa cells exhibited obviously ferroptosis resistance. RNA-seq, RNAi-mediated loss-of-function, and CRISPR/Cas9 experiments demonstrated that ALOX5 deficiency was the crucial factor of BCa resistance to ferroptosis in vitro and in vivo. Mechanistically, we found that ALOX5 deficiency was regulated by EGR1 at the transcriptional level. Clinically, ALOX5 expression was decreased in BCa tissues, and its low expression was associated with poor survival. Collectively, this study uncovers a novel mechanism for BCa ferroptosis escape and proposes that ALOX5 may be a valuable therapeutic target and prognostic biomarker in BCa treatment.

Tumor-derived exosomal lincRNA ROR promotes angiogenesis in nasopharyngeal carcinoma.

Long intergenic noncoding RNAs (lincRNAs) are expressed aberrantly in several malignancies, including nasopharyngeal carcinoma (NPC), where linc-ROR expression was found to be elevated. Being a hallmark of malignant tumors, angiogenesis has prompted us to investigate the impact of linc-ROR on NPC angiogenesis. This study demonstrates that linc-ROR is substantially expressed in serum exosomes from NPC and can be taken up by HUVECs. Using qRT-PCR, the CCK8 test, the transwell migration assay, the wound healing assay, and the tube formation assay, we demonstrated that linc-ROR increases proliferation, migration, and angiogenesis in vitro. Similar to prior research, our results have shown that linc-ROR can stimulate tumor angiogenesis in the zebrafish model. Thus, the p-AKT/p-VEGFR2 pathway is the mechanism by which linc-ROR affects the aforementioned biological activities. By stimulating angiogenesis, linc-ROR appears to play a significant role in the course of NPC and could account for a therapeutic target.

Antifungal immunity mediated by C-type lectin receptors may be a novel target in immunotherapy for urothelial bladder cancer.

Immunotherapies, such as immune-checkpoint blockade and adoptive T-cell therapy, offer novel treatment options with good efficacy for patients with urothelial bladder cancer. However, heterogeneity and therapeutic resistance have limited the use of immunotherapy. Further research into immune-regulatory mechanisms in bladder cancer is urgently required. Emerging evidence demonstrates that the commensal microbiota and its interactions with host immunity play pivotal roles in a variety of physiological and pathological processes, including in cancer. The gut microbiota has been identified as a potentially effective target of treatment that can be synergized with immunotherapy. The urothelial tract is also a key site for multiple microbes, although the immune-regulatory role of the urinary microbiome in the process of carcinogenesis of bladder cancer remains to be elucidated. We performed a comprehensive analysis of the expression and biological functions of C-type lectin receptors (CLRs), which have been recognized as innate pathogen-associated receptors for fungal microbiota, in bladder cancer. In line with previous research on fungal colonization of the urothelial tract, we found that CLRs, including Dectin-1, Dectin-2, Dectin-3, and macrophage-inducible Ca2+-dependent lectin receptor (Mincle), had a significant association with immune infiltration in bladder cancer. Multiple innate and adaptive pathways are positively correlated with the upregulation of CLRs. In addition, we found a significant correlation between the expression of CLRs and a range of immune-checkpoint proteins in bladder cancer. Based on previous studies and our findings, we hypothesize that the urinary mycobiome plays a key role in the pathogenesis of bladder cancer and call for more research on CLR-mediated anti-fungal immunity against bladder cancer as a novel target for immunotherapy in urothelial bladder cancer.

Serum mitochondrial tsRNA serves as a novel biomarker for hepatocarcinoma diagnosis.

Hepatocellular carcinoma (HCC), which makes up the majority of liver cancer, is induced by the infection of hepatitis B/C virus. Biomarkers are needed to facilitate the early detection of HCC, which is often diagnosed too late for effective therapy. The tRNA-derived small RNAs (tsRNAs) play vital roles in tumorigenesis and are stable in circulation. However, the diagnostic values and biological functions of circulating tsRNAs, especially for HCC, are still unknown. In this study, we first utilized RNA sequencing followed by quantitative reverse-transcription PCR to analyze tsRNA signatures in HCC serum. We identified tRF-Gln-TTG-006, which was remarkably upregulated in HCC serum (training cohort: 24 HCC patients vs. 24 healthy controls). In the validation stage, we found that tRF-Gln-TTG-006 signature could distinguish HCC cases from healthy subjects with high sensitivity (80.4%) and specificity (79.4%) even in the early stage (Stage I: sensitivity, 79.0%; specificity, 74.8%; 155 healthy controls vs. 153 HCC patients from two cohorts). Moreover, in vitro studies indicated that circulating tRF-Gln-TTG-006 was released from tumor cells, and its biological function was predicted by bioinformatics assay and validated by colony formation and apoptosis assays. In summary, our study demonstrated that serum tsRNA signature may serve as a novel biomarker of HCC.

Histone Deacetylase 1 Depletion Alleviates Coronary Heart Disease Via the MicroRNA-182-Mediated Transforming Growth Factor ß/Smad Signaling Pathway.

ABSTRACT: Histone deacetylase (HDAC) determines the acetylation status of histones, thereby regulating gene expression. HDAC inhibitors have been demonstrated to suppress cardiomyocyte growth in vitro and in vivo. We assessed here whether HDAC1 exerts an aggravating effect on coronary heart disease (CHD). Epigenetic probe array revealed that HDAC1 was overexpressed in patients with CHD. HDAC1 was then downregulated in rat cardiomyocytes, and microRNA microarray analysis was performed to detect downstream targets of HDAC1, followed by chromatin immunoprecipitation validation. HDAC1 inhibited miR-182 expression through deacetylation. miR-182 was poorly expressed in patients with CHD. Using enzyme-linked immunosorbent assay, Reverse transcription-quantitative PCR, hematoxylin-eosin staining, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling assay, and immunohistochemistry, we observed that HDAC1 downregulation promoted cardiac function, restored lipid levels, reduced myocardial injury markers and inflammatory factors, and alleviated myocardial tissue damage and apoptosis in CHD rats. By contrast, miR-182 downregulation exacerbated injury in rats in the presence of HDAC1 knockdown. Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the target genes of miR-182 were mainly enriched in the transforming growth factor (TGF)-ß/Smad pathway. Western blot also validated that HDAC1/miR-182 modulated the TGF-ß/Smad pathway activity. Our results demonstrated that HDAC1 repressed miR-182 and activated the TGF-ß/Smad pathway to promote CHD.

The Lymph Node Microenvironment May Invigorate Cancer Cells With Enhanced Metastatic Capacities.

Cancer metastasis, a typical malignant biological behavior involving the distant migration of tumor cells from the primary site to other organs, contributed majorly to cancer-related deaths of patients. Although constant efforts have been paid by researchers to elucidate the mechanisms of cancer metastasis, we are still far away from the definite answer. Recently, emerging evidence demonstrated that cancer metastasis is a continuous coevolutionary process mediated by the interactions between tumor cells and the host organ microenvironment, and epigenetic reprogramming of metastatic cancer cells may confer them with stronger metastatic capacities. The lymph node served as the first metastatic niche for many types of cancer, and the appearance of lymph node metastasis predicted poor prognosis. Importantly, multiple immune cells and stromal cells station and linger in the lymph nodes, which constitutes the complexity of the lymph node microenvironment. The active cross talk between cancer cells and immune cells could happen unceasingly within the metastatic environment of lymph nodes. Of note, diverse immune cells have been found to participate in the formation of malignant properties of tumor, including stemness and immune escape. Based on these available evidence and data, we hypothesize that the metastatic microenvironment of lymph nodes could drive cancer cells to metastasize to further organs through epigenetic mechanisms.

Donepezil Prevents ox-LDL-Induced Attachment of THP-1 Monocytes to Human Aortic Endothelial Cells (HAECs).

Oxidized low-density lipoprotein (ox-LDL)- induced endothelial insults plays an important role in the pathogenesis of atherosclerosis. Donepezil is a well-known acetylcholinesterase inhibitor with its primary application being the treatment of Alzheimer's disease. More recently, there has been increased interest in donepezil as an antiatherosclerosis treatment as it possesses a host of relevant and potentially beneficial properties. In the present study, we found that donepezil could reduce the expression of lectin-type oxidized low-density lipoprotein receptor-1 (LOX-1) in human aortic endothelial cells (HAECs). We found that donepezil could suppress the expression of intercellular adhesion molecule-1 (ICAM-1), which recruits monocytes to adhere to the endothelium, by more than half. Another key finding of our study is that donepezil could reduce the expression of tumor necrosis factor receptor-α (TNF-α) and interleukin-6 (IL-6) by more than half at both the mRNA and protein transcriptional levels. Donepezil also reduced the expression of tissue factor (TF), which is considerably upregulated in atherosclerotic lesions, by more than half. Finally, we turned our attention to the early growth response protein-1 (Egr-1) for its potential role in mediating the effects of donepezil. Through our Egr-1 overexpression experiment, we found that overexpression of Egr-1 almost completely abolished the effects of donepezil described above. Thus, the effects of donepezil are likely mediated through downregulation of Egr-1. These findings provide evidence that donepezil may exert protective effects against atherosclerosis.

Erythropoietin enhances mitochondrial biogenesis in cardiomyocytes exposed to chronic hypoxia through Akt/eNOS signalling pathway.

Adaptation of cardiomyocytes to chronic hypoxia in cyanotic patients remains unclear. Mitochondrial biogenesis is enhanced in myocardium from cyanotic patients, which is possibly an adaptive response. Erythropoietin (EPO) in blood and its receptor (EPOR) on cardiomyocytes are upregulated by chronic hypoxia, suggesting that EPO-EPOR interaction is increased, which is inferred to positively regulate mitochondrial biogenesis through protein kinase B (Akt)/endothelial nitric oxide synthase (eNOS) signalling pathway. H9c2 cardiomyocytes were exposed to hypoxia (1% O(2)) for 1 week and treated with different doses of recombinant human erythropoietin (rhEPO). Mitochondrial number, mitochondrial DNA (mtDNA) copy number and peroxisome proliferator activated receptor gamma coactivator alpha (PGC-1α) mRNA expression increased in a dose-dependent manner induced by rhEPO. Akt and eNOS were significantly phosphorylated by rhEPO. Both blocking Akt with Wortmannin and silencing eNOS expression with shRNA plasmid decreased the mtDNA copy number and PGC-1α mRNA expression induced by rhEPO. Blocking Akt was associated with the decreased phosphorylation of Akt and eNOS. RNA interference led to a reduction in the total and phosphorylated proteins of eNOS. Thus EPO enhances mitochondrial biogenesis in cardiomyocytes exposed to chronic hypoxia, at least partly through Akt/eNOS signalling, which might be an adaptive mechanism of cardiomyocytes associated with the increased EPO-EPOR interaction in patients with cyanotic congenital heart disease (CCHD).