REC8 suppresses tumor angiogenesis by inhibition of NF-κB-mediated vascular endothelial growth factor expression in gastric cancer cells

Regulation of VEGF-A expression and VEGF-A-targeted therapy in malignant tumors

Vascular endothelial growth factor A (VEGF-A), a highly conserved dimeric glycoprotein, is a key regulatory gene and a marker molecule of angiogenesis. The upregulation of VEGF-A facilitates the process of tumor vascularization, thereby fostering the initiation and progression of malignant neoplasms. Many genes can adjust the angiogenesis of tumors by changing the expression of VEGF-A. In addition, VEGF-A also exhibits immune regulatory properties, which directly or indirectly suppresses the antitumor activity of immune cells. The emergence of VEGF-A-targeted therapy alone or in rational combinations has revolutionized the treatment of various cancers. This review discusses how diverse mechanisms in various tumors regulate VEGF-A expression to promote tumor angiogenesis and the role of VEGF-A in tumor immune microenvironment. The application of drugs targeting VEGF-A in tumor therapy is also summarized including antibody molecule drugs and traditional Chinese medicine.

REC8 regulates neuroblastoma cell proliferation, migration, invasion, and angiogenesis via STAT3/VEGF signaling

BACKGROUND

Neuroblastoma, one of the most prevalent childhood cancers, is often treated with surgery, radiation, and chemotherapy. However, prognosis and survival are still dismal for children with neuroblastoma at high risk. Consequently, it is vital to identify new and effective treatment targets. As a component of the meiotic cohesion complex, REC8 is involved in a wide range of malignancies. The current work assessed the impact of REC8 knockdown on SH-SY5Y and SK-N-AS neuroblastoma cells and delved into the molecular mechanism behind this effect.

METHODS

Knockdown of REC8 using the small interfering (si) RNA technology, and the results were verified by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and western blot. The Cell Counting Kit-8 (CCK-8) was used to examine cell proliferation, while flow cytometry was used to examine cell cycle progression and apoptosis. Analyses of angiogenesis included tube formation experiments. Transwell tests were used to examine cell migration and invasion.

RESULTS

The data showed that downregulation of the REC8 led to a substantial decrease in cell proliferation by stopping the cell cycle in the G1 phase. REC8 knockdown significantly reduced neuroblastoma cell proliferation, migration, invasion, angiogenesis, induced cell cycle arrest, and enhanced apoptosis. We also discovered that repressing REC8 expression in neuroblastoma cell lines SH-SY5Y and SK-N-AS reduced their ability to activate the STAT3/VEGF signaling pathway.

CONCLUSIONS

Neuroblastoma therapy may benefit from targeting REC8 and its downstream targets.

Nanosilver-functionalized polysaccharides as a platform for wound dressing

Polysaccharides that are naturally sourced have enormous promise as wound dressings, due to their wider availability and reasonable cost and good biocompatibility. Furthermore, nanosilver extensively applied in wound treatment is attributed to its broad spectrum of antimicrobial effects and lesser drug resistance. Consequently, wound dressings in corporating nanosilver have attracted wide-scale interest in wound healing, and nanosilver-functionalized polysaccharide-based wound dressings present an affordable option for healing of chronic wounds. This review encompasses preparation methods, classification, and antibacterial performances of nanosilver wound dressings. The prospective research arenas of nanosilver-based wound polysaccharide dressings are also elaborated. The review attempts to include a summary of the most recent advancements in silver nanotechnology as well as guidance for the investigation of nanosilver-functionalized polysaccharide-based wound dressings.

Secreted phosphoprotein 1 promotes angiogenesis of glioblastoma through upregulating PSMA expression via transcription factor HIF-1α

Glioblastoma multiforme (GBM) is a highly vascularized malignant brain tumor. Our previous study showed that prostate-specific membrane antigen (PSMA) promotes angiogenesis of GBM. However, the specific mechanism underlying GBM-induced PSMA upregulation remains unclear. In this study, we demonstrate that the GBM-secreted cytokine phosphoprotein 1 (SPP1) can regulate the expression of PSMA in human umbilical vein endothelial cells (HUVECs). Our mechanistic study further reveals that SPP1 regulates the expression of PSMA through the transcription factor HIF1α. Moreover, SPP1 promotes HUVEC migration and tube formation. In addition, HIF1α knockdown reduces the expression of PSMA in HUVECs and blocks the ability of SPP1 to promote HUVEC migration and tube formation. We further confirm that SPP1 is abundantly expressed in GBM, is associated with poor prognosis, and has high clinical diagnostic value with considerable sensitivity and specificity. Collectively, our findings identify that the GBM-secreted cytokine SPP1 upregulates PSMA expression in endothelial cells via the transcription factor HIF1α, providing insight into the angiogenic process and promising candidates for targeted GBM therapy.

The KDM6A-SPARCL1 axis blocks metastasis and regulates the tumour microenvironment of gastrointestinal stromal tumours by inhibiting the nuclear translocation of p65

BACKGROUND

It is urgent to explore the pathogenic mechanism of gastrointestinal stromal tumours (GISTs). KDM6A, a histone demethylase, can activate gene transcription and has not been reported in GISTs. SPARCL1 may serve as a metastasis marker in GIST, but the molecular mechanism remains to be further explored. This study aimed to explore the biological function and molecular mechanism of KDM6A and SPARCL1 in GIST.

METHODS

CCK-8, live cell count, colony formation, wound-healing and Transwell migration and invasion assays were employed to detect the cell proliferation, migration and invasion. A xenograft model and hepatic metastasis model were used to assess the role of KDM6A and SPARCL1 in vivo.

RESULTS

KDM6A inhibited the proliferation, migration and invasion of GIST cells. Mechanistically, KDM6A promotes the transcription of SPARCL1 by demethylating histone H3 lysine trimethylation and consequently leads to the inactivation of p65. SPARCL1 affected the metastasis of GIST cells in a mesenchymal-epithelial transition- and matrix-metalloproteinase-dependent manner. SPARCL1 knockdown promoted angiogenesis, M2 polarisation and macrophage recruitment by inhibiting the phosphorylation of p65. Moreover, KDM6A and SPARCL1 inhibited hepatic metastasis and macrophage infiltration in vivo.

CONCLUSIONS

Our findings establish the critical role of the KDM6A-SPARCL1-p65 axis in restraining the malignancy of GIST.

REC8 inhibits proliferation, migration and invasion of breast cancer cells by targeting CDC20

Breast cancer is one of the most types of common malignant tumor in women. REC8 is a known tumor suppressor in several types of cancer; however, the role of REC8 in breast cancer remains unknown. The purpose of the present study was to investigate the effects and underlying mechanism of REC8 on the proliferation, migration and invasion of breast cancer cells. The expression of REC8 in normal and breast cancer cells was detected by reverse transcription‑quantitative PCR and western blotting. Stable REC8‑overexpressing breast cancer cells were constructed to modify the expression of REC8. The expression of cell division cycle 20 (CDC20) in breast cancer cells was altered using the CDC20 inhibitor apcin. Cell viability, proliferation, migration, invasion and apoptosis were determined by Cell Counting Kit‑8, colony formation, wound healing, Transwell and TUNEL assays, respectively. Western blotting was performed to measure the expression of matrix metalloproteinase‑2/9 and apoptosis‑associated proteins [Bcl‑2, caspase‑3, cleaved caspase‑3 and cleaved poly (ADP‑ribose) polymerase]. Compared with normal breast cells, the expression of REC8 was lower in breast cancer cells. Search Tool for the Retrieval of Interacting Genes/Proteins online database was used to predict the interaction between REC8 and CDC20. Overexpression of REC8 significantly inhibited the proliferation, migration and invasion of breast cancer cells in vitro; these changes were reversed by CDC20 overexpression. In conclusion, the present study demonstrated that REC8 decreased proliferation, migration and invasion of breast cancer cells by inhibiting CDC20.

The role of REC8 in the innate immune response to viral infection

REC8 meiotic recombination protein (REC8) is a member of structural maintenance of chromosome (SMC) protein partners, which play an important role in meiosis, anti-tumor, and sperm formation. As the adapter proteins of RLR signaling and cGAS-DNA signaling, the activity and stability of MAVS (also known as VISA, Cardif and IPS-1) and STING (also known as MITA) are critical for innate immunity. Here, we report that REC8 interacts with MAVS and STING, and inhibits their ubiquitination and subsequent degradation, thereby promoting innate antiviral signaling. REC8 is upregulated through the JAK-STAT signaling pathway under viral infection. Knockdown of REC8 impair the innate immune responses against VSV (Vesicular Stomatitis Virus), NDV (Newcastle disease virus) and HSV (herpes simplex virus). Mechanistically, under the infection of viruses, the SUMOylated REC8 is transferred from the nucleus to the cytoplasm and then interacts with MAVS and STING to inhibit their K48-linked ubiquitination triggered by RNF5. Moreover, REC8 promotes the recruitment of TBK1 to MAVS and STING. Thus, REC8 functions as a positive modulator of innate immunity. Our work highlights a previously undocumented role of meiosis-associated protein REC8 in regulating innate immunity. IMPORTANCE The innate immune response is crucial for the host to resist the invasion of viruses and other pathogens. STING and MAVS play a critical role in the innate immune response to DNA and RNA viral infection, respectively. In this study, REC8 promotes the innate immune response by targeting STING and MAVS. Notably, REC8 interacts with MAVS and STING in the cytoplasm and inhibits K48-linked ubiquitination of MAVS and STING triggered by RNF5, stabilizing MAVS and STING protein to promote innate immunity and gradually inhibiting viral infection. Our study provides a new insight for the study of antiviral innate immune.

Qiguiyin Decoction Improves Multidrug-Resistant Pseudomonas aeruginosa Infection in Rats by Regulating Inflammatory Cytokines and the TLR4/MyD88/NF-κB Signaling Pathway

Pseudomonas aeruginosa (PA), a Gram-negative bacterium, has a high detection rate in hospital-acquired infections. Recently, the frequent appearance of multidrug-resistant (MDR) PA strain with high morbidity and mortality rates has aggravated the difficulty in treating infectious diseases. Due to its multiple resistance mechanisms, the commonly used antibiotics have gradually become less effective. Qiguiyin decoction (QGYD) is a clinically experienced prescription of Chinese herbal medicine, and its combined application with antibiotics has been confirmed to be effective in the clinical treatment of MDR PA infection, which could be a promising strategy for the treatment of drug-resistant bacterial infections. However, the mechanism of QGYD restoring antibiotics susceptibility to MDR PA remains unclear. In the present study, we investigated the effects of QGYD and levofloxacin (LEV) singly or in combination on MDR PA-induced pneumonia rat models. Further analysis was carried out in the serum differential expression profiles of inflammatory cytokines by cytokine antibody array. Besides, the lung TLR4/MyD88/NF-κB signaling pathway was detected by RT-qPCR. Our results showed that based on the treatment of MDR PA-infected rat model with LEV, the combination of QGYD improved the general state and immune organ index. Furthermore, it moderately increased the expressions of proinflammatory cytokines including IL-1β, IL-6, and TNF-α in the early stage of infection and decreased their release rapidly in the later stage, while regulated the same phase change of anti-inflammatory cytokine IL-10. In addition, the adhesion molecule ICAM-1 was significantly downregulated after QGYD combined with LEV treatment. Moreover, the mRNA expressions of TLR4, MyD88, NF-κB, and ICAM-1 were significantly downregulated. These results indicated that the mechanism of QGYD restoring LEV susceptibility to MDR PA was related to its regulation of inflammatory cytokines and the TLR4/MyD88/NF-κB signaling pathway, which provides theoretical support for the clinical application of QGYD combined with LEV therapy to MDR PA infection.

REC8 enhances stemness and promotes metastasis of colorectal cancer through BTK/Akt/β-catenin signaling pathway

Cancer/testis antigens (CTAs) are often aberrantly expressed in cancer stem cells (CSCs) which are responsible for tumor metastasis. Rec8 meiotic recombination protein (REC8), a member of CTAs, shares distinct roles in various cancers, while its contribution to CSCs and colorectal cancer (CRC) remains unclear. We found that overexpression of REC8 facilitated the migration and invasion of CRC cells (DLD-1 and SW480 cells) in vitro and promoted the liver metastasis of CRC in vivo. Moreover, REC8 is highly expressed in CRC stem-like cells and is required for the maintenance of CSC stemness. Mechanistic studies suggested that REC8 mediated through the activation of Bruton tyrosine kinase (BTK). Inhibition of BTK by ibrutinib not only suppressed the migration and invasion-promoting ability, but also declined the increased expression of p-BTK, p-Akt, β-catenin, and CSC markers upon REC8 overexpression. Importantly, high expression of REC8 in cancerous tissues was related to advanced clinical stage and lymph node metastasis of 62 CRC patients, and REC8 was enriched in the cancerous cells positive for CSC markers. Collectively, our results indicate that REC8 promotes CRC metastasis by increasing cell stemness through BTK/Akt/β-catenin pathway.

Identification of key molecular markers of acute coronary syndrome using peripheral blood transcriptome sequencing analysis and mRNA-lncRNA co-expression network construction

Acute coronary syndrome (ACS) is a term used to describe major cardiovascular diseases, and treatment of in-stent restenosis in patients with ACS remains a major clinical challenge. Further investigation into molecular markers of ACS may aid early diagnosis, and the treatment of ACS and post-treatment recurrence. In the present study, total RNA was extracted from the peripheral blood samples of 3 patients with ACS, 3 patients with percutaneous coronary intervention (PCI)_non-restenosis, 3 patients with PCI_restenosis and 3 healthy controls. Subsequently, RNA library construction and high-throughput sequencing were performed. DESeq2 package in R was used to screen genes that were differentially expressed between the different samples. Moreover, the intersection of the differentially expressed mRNAs (DEmRNAs) and differentially expressed long noncoding RNAs (DElncRNAs) obtained. GeneCodis4.0 was used to perform function enrichment for DEmRNAs, and lncRNA-mRNA co-expression network was constructed. The GSE60993 dataset was utilized for diagnostic analysis, and the aforementioned investigations were verified using in vitro studies. Results of the present study revealed a large number of DEmRNAs and DElncRNAs in the different groups. We selected genes in the top 10 of differential expression and also involved in the co-expression of lncRNA-mRNA for diagnostic analysis in the GSE60993 dataset. The area under curve (AUC) of PDZK1IP1 (0.747), PROK2 (0.769) and LAMP3 (0.725) were all >0.7. These results indicated that the identified mRNAs and lncRNAs may act as potential clinical biomarkers, and more specifically, PDZK1IP1, PROK2 and LAMP3 may act as potential biomarkers for the diagnosis of ACS.

DNMT1-induced miR-378a-3p silencing promotes angiogenesis via the NF-κB signaling pathway by targeting TRAF1 in hepatocellular carcinoma

BACKGROUND

Angiogenesis plays an important role in the occurrence, development and metastasis of hepatocellular carcinoma (HCC). According to previous studies, miR-378a participates in tumorigenesis and tumor metastasis, but its exact role in HCC angiogenesis remains poorly understood.

METHODS

qRT-PCR was used to investigate the expression of miR-378a-3p in HCC tissues and cell lines. The effects of miR-378a-3p on HCC in vitro and in vivo were examined by Cell Counting Kit-8 (CCK-8), Transwell, tube formation and Matrigel plug assays, RNA sequencing, bioinformatics, luciferase reporter, immunofluorescence and chromatin immunoprecipitation (ChIP) assays were used to detect the molecular mechanism by which miR-378a-3p inhibits angiogenesis.

RESULTS

We confirmed that miR-378a-3p expression was significantly downregulated and associated with higher microvascular density (MVD) in HCC; miR-378a-3p downregulation indicated a short survival time in HCC patients. miR-378a-3p knockdown led to a significant increase in angiogenesis in vitro and in vivo. We found that miR-378a-3p directly targeted TNF receptor associated factor 1 (TRAF1) to attenuate NF-κB signaling, and then downregulated secreted vascular endothelial growth factor. DNA methyltransferase 1 (DNMT1)-mediated hypermethylation of miR-378a-3p was responsible for downregulating miR-378a-3p. Moreover, a series of investigations indicated that p65 initiated a positive feedback loop that could upregulate DNMT1 to promote hypermethylation of the miR-378a-3p promoter.

CONCLUSION

Our study indicates a novel DNMT1/miR-378a-3p/TRAF1/NF-κB positive feedback loop in HCC cells, which may become a potential therapeutic target for HCC.

The Good and Bad of Nrf2: An Update in Cancer and New Perspectives in COVID-19

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a well-known transcription factor best recognised as one of the main regulators of the oxidative stress response. Beyond playing a crucial role in cell defence by transactivating cytoprotective genes encoding antioxidant and detoxifying enzymes, Nrf2 is also implicated in a wide network regulating anti-inflammatory response and metabolic reprogramming. Such a broad spectrum of actions renders the factor a key regulator of cell fate and a strategic player in the control of cell transformation and response to viral infections. The Nrf2 protective roles in normal cells account for its anti-tumour and anti-viral functions. However, Nrf2 overstimulation often occurs in tumour cells and a complex correlation of Nrf2 with cancer initiation and progression has been widely described. Therefore, if on one hand, Nrf2 has a dual role in cancer, on the other hand, the factor seems to display a univocal function in preventing inflammation and cytokine storm that occur under viral infections, specifically in coronavirus disease 19 (COVID-19). In such a variegate context, the present review aims to dissect the roles of Nrf2 in both cancer and COVID-19, two widespread diseases that represent a cause of major concern today. In particular, the review describes the molecular aspects of Nrf2 signalling in both pathological situations and the most recent findings about the advantages of Nrf2 inhibition or activation as possible strategies for cancer and COVID-19 treatment respectively.