CircMRPS35 suppresses gastric cancer progression via recruiting KAT7 to govern histone modification

The Applications of CircRNA in the Diagnosis and Treatment of Alzheimer's Disease

Early diagnosis and intervention are key to the treatment of Alzheimer's disease (AD). There is an urgent need for new biomarkers and molecular targets for the detection and treatment of early Alzheimer's pathology. Circular RNA (circRNA) is a newly discovered non-coding RNA with a special type of covalently closed single strand, with potential preventive and therapeutic applications in a variety of diseases. New studies in the field of circRNA in AD have made many exciting new discoveries in recent years, some of which have not received sufficient attention but have important research implications. This review will focus on existing studies of circRNA in AD and discuss future translational perspectives of proposed circRNA strategies for clinical application in AD.

KAT7 suppresses tumorigenesis in clear cell renal cell carcinoma (ccRCC) by regulating cell cycle and ferroptosis sensitivity

Clear cell renal cell carcinoma (ccRCC) is one of the most aggressive malignancies in the urological system, known for its high immunogenicity. However, its pathogenesis remains unclear. This study utilized bioinformatics algorithms and in vitro experiments to investigate the role of KAT7 in ccRCC. The results indicate that KAT7 is significantly downregulated in ccRCC tissues and cell lines, which is linked to distant metastasis and unfavorable outcomes in ccRCC patients. Overexpression of KAT7 in vitro notably decreased the proliferation, migration, and invasion of renal cancer cells and inhibited Epithelial-Mesenchymal Transition (EMT). Additionally, Gene Set Enrichment Analysis (GSEA) demonstrated that KAT7-related gene functions are associated with cell cycle and ferroptosis transcription factors. Treatment with a KAT7 acetylation inhibitor in ccRCC cell lines reversed the S phase arrest caused by KAT7 overexpression. Similarly, ferroptosis inhibitors alleviated ferroptosis induced by overexpressed KAT7. In conclusion, the findings suggest that KAT7 acts as a tumor suppressor in ccRCC by modulating the cell cycle and ferroptosis sensitivity, underscoring its potential as a therapeutic target and prognostic biomarker for renal cell carcinoma patients.

Circular RNA circMRPS35 represses malignant progression in osteosarcoma cells via targeting miR-105-5p/FOXO1

Osteosarcoma is a highly metastatic, aggressive bone cancer that occurs in children and young adults worldwide. Circular RNAs (circRNAs) are crucial molecules for osteosarcoma progression. In this study, we aimed to investigate the impact of circMRPS35 overexpression and its interaction with FOXO1 via evaluating apoptosis, cell cycle, and bioinformatic analyses on the malignant development of osteosarcoma in MG63 and MNNG/HOS cells. We found that circMRPS35 overexpression reduced osteosarcoma cell viability and inhibited tumor growth in vivo. It increased the apoptosis rate and induced cell cycle arrest in osteosarcoma cells. We identified a potential interaction between circMRPS35 and FOXO1 with miR-105-5p using bioinformatics analysis. Overexpression of circMRPS35 decreased miR-105-5p expression, whereas miR-105-5p mimic treatment increased its expression. This mimic also suppressed the luciferase activity of circMRPS35 and FOXO1 and reduced FOXO1 expression. Overexpression of circMRPS35 elevated FOXO1 protein levels, but this effect was reversed by co-treatment with the miR-105-5p mimic. We demonstrated that inhibiting miR-105-5p decreased viability and induced apoptosis. Overexpression of FOXO1 or treatment with a miR-105-5p inhibitor could counteract the effects of circMRPS35 on viability and apoptosis in osteosarcoma cells. Therefore, we concluded that circMRPS35 suppressed the malignant progression of osteosarcoma via targeting the miR-105-5p/FOXO1 axis.

A novel hsa_circ_0006903 circular RNA promotes tumor development and dendritic cells activated expression in infantile hemangioma

Background

Increasing reports revealed that circular RNAs (circRNAs) and immune cells infiltration were related with tumor development. However, its role in infantile hemangioma (IH) is unknown. We will explore a novel hsa_circ_0006903-based ceRNA network and investigate the landscape of dendritic cells activated expression in IH.

Material and methods

Differentially expressed circRNAs (DECs) were identified from Gene Expression Omnibus (GEO) database. Regulatory networks and functional enrichment analysis were constructed. CIBERSORT was used to characterize immune cells composition. qRT-PCR was performed to detect the expression of hsa_circ_0006903 in cell lines. Then, the role of hsa_circ_0006903 in IH were validated in vitro using transwell assay. Immunofluorescence was applied to the colocalization of CD11b for dendritic cells activated as a biomarker in IH tissues.

Results

Using GEO database, a total of 67 DECs were screened out in IH. Hsa_circ_0006903 was the most significant DECs. Then, a novel hsa_circ_0006903 circular RNA-ceRNA network was constructed. Mechanistically, functional enrichment analysis showed that the p53 signaling pathway played the most important roles, and hsa_circ_0006903/miR-6721-5p/CACNA2D2 and hsa_circ_0006903/miR-4786-3p/ATP13A4 axis were identified. CACNA2D2, ATP13A4, and P53 were significantly downregulated in IH cell lines. We validated that dendritic cell activated was significantly overexpressed. Moreover, CD11b as a biomarker of dendritic cells activated were tested in IH tissues. Finally, hsa_circ_0006903 was significantly overexpressed, and hsa_circ_0006903 promoted infantile hemangioma cell proliferation, invasion, and migration in vitro.

Conclusion

Overall, our study revealed that a novel hsa_circ_0006903 promoted tumor progression, and indicated a potential biomarker CD11b of dendritic cells activated in IH.

Decoding the Structural Diversity: A New Horizon in Antimicrobial Prospecting and Mechanistic Investigation

The escalating crisis of antimicrobial resistance (AMR) underscores the urgent need for novel antimicrobials. One promising strategy is the exploration of structural diversity, as diverse structures can lead to diverse biological activities and mechanisms of action. This review delves into the role of structural diversity in antimicrobial discovery, highlighting its influence on factors such as target selectivity, binding affinity, pharmacokinetic properties, and the ability to overcome resistance mechanisms. We discuss various approaches for exploring structural diversity, including combinatorial chemistry, diversity-oriented synthesis, and natural product screening, and provide an overview of the common mechanisms of action of antimicrobials. We also describe techniques for investigating these mechanisms, such as genomics, proteomics, and structural biology. Despite significant progress, several challenges remain, including the synthesis of diverse compound libraries, the identification of active compounds, the elucidation of complex mechanisms of action, the emergence of AMR, and the translation of laboratory discoveries to clinical applications. However, emerging trends and technologies, such as artificial intelligence, high-throughput screening, next-generation sequencing, and open-source drug discovery, offer new avenues to overcome these challenges. Looking ahead, we envisage an exciting future for structural diversity-oriented antimicrobial discovery, with opportunities for expanding the chemical space, harnessing the power of nature, deepening our understanding of mechanisms of action, and moving toward personalized medicine and collaborative drug discovery. As we face the continued challenge of AMR, the exploration of structural diversity will be crucial in our search for new and effective antimicrobials.

Biological functions of circRNA in regulating the hallmarks of gastrointestinal cancer (Review)

Circular RNA (circRNA) was first observed in the cytoplasm of eukaryotic cells in 1979, but it was not characterized in detail until 2012, when high‑throughput sequencing technology was more advanced and available. Consequently, the mechanism of circRNA formation and its biological function have been progressively elucidated by researchers. circRNA is abundant in eukaryotic cells and exhibits a certain degree of organization, timing and disease‑specificity. Additionally, it is poorly degradable, meeting the characteristics of an ideal clinical biomarker. In the present review, the recent research progress of circRNAs in digestive tract malignant tumors was primarily discussed. This included the roles, biological functions and clinical significance of circRNA, providing references for its research value and clinical potential in gastrointestinal cancer.

CircROR1 upregulates CCNE1 expression to promote melanoma invasion and metastasis by recruiting KAT2A

Circular RNAs (circRNAs) play important roles in cancer occurrence and progression. To explore and elucidate the clinical significance of specific circular RNA in melanoma and its potential molecular mechanism. CircROR1 expression in melanoma cells and tissues was confirmed by qRT-PCR and ISH. qRT-PCR and Western blotting were performed to measure the levels of CCNE1, KAT2A, MMP9 and TIMP2. MTT, Transwell and wound healing assays were performed to evaluate cell proliferation, invasion and metastasis. A xenograft mouse model was established to further verify the CircROR1/CCNE1 axis in vivo. RNA pull-down and RIP assays were performed to detect the direct interaction KAT2A and CircROR1. A ChIP assay was used to investigate the enrichment of H3K9ac acetylation in the CCNE1 promoter. CircROR1 was significantly upregulated in metastatic melanoma cells and tissues, promoting proliferation, invasion and metastasis in vitro and tumour growth in vivo. CircROR1 overexpression increased CCNE1 and MMP9 protein expression and decreased TIMP2 protein expression. Functional rescue assays demonstrated that CircROR1 played a role in promoting malignant progression through CCNE1. CircROR1 specifically bound to the KAT2A protein without affecting its expression. CircROR1 overexpression increased the level of H3K9ac modification in the CCNE1 promoter region by recruiting KAT2A, thus upregulating CCNE1 expression. CircROR1 upregulates CCNE1 expression through KAT2A-mediated histone acetylation. Our research confirms the critical role of CircROR1 in melanoma invasion and metastasis, and CircROR1 could serve as a potential therapeutic target for melanoma treatment.

Role and regulation of FOXO3a: new insights into breast cancer therapy

Breast cancer is the most common malignancy in the world, particularly affecting female cancer patients. Enhancing the therapeutic strategies for breast cancer necessitates identifying molecular drug targets that effectively eliminate tumor cells. One of these prominent targets is the forkhead and O3a class (FOXO3a), a member of the forkhead transcription factor subfamily. FOXO3a plays a pivotal role in various cellular processes, including apoptosis, proliferation, cell cycle regulation, and drug resistance. It acts as a tumor suppressor in multiple cancer types, although its specific role in cancer remains unclear. Moreover, FOXO3a shows promise as a potential marker for tumor diagnosis and prognosis in breast cancer patients. In addition, it is actively influenced by common anti-breast cancer drugs like paclitaxel, simvastatin, and gefitinib. In breast cancer, the regulation of FOXO3a involves intricate networks, encompassing post-translational modification post-translational regulation by non-coding RNA (ncRNA) and protein-protein interaction. The specific mechanism of FOXO3a in breast cancer urgently requires further investigation. This review aims to systematically elucidate the role of FOXO3a in breast cancer. Additionally, it reviews the interaction of FOXO3a and its upstream and downstream signaling pathway-related molecules to uncover potential therapeutic drugs and related regulatory factors for breast cancer treatment by regulating FOXO3a.

Chromosomal copy number amplification-driven Linc01711 contributes to gastric cancer progression through histone modification-mediated reprogramming of cholesterol metabolism

BACKGROUND

Chromosome gains or localized amplifications are frequently observed in human gastric cancer (GC) and are major causes of aberrant oncogene activation. However, the significance of long non-coding RNAs (LncRNAs) in the above process is largely unknown.

METHODS

The copy number aberrations (CNAs) data of GC samples were downloaded and analyzed from the TCGA database. qRT-PCR and fluorescence in situ hybridization were used to evaluate the expression of Linc01711 in GC. The effects of Linc01711 on GC progression were investigated through in vitro and in vivo assays. The mechanism of Linc01711 action was explored through transcriptome sequencing, chromatin immunoprecipitation sequencing, RNA immunoprecipitation, RNA pull-down and chromatin isolation by RNA purification (ChIRP) assays.

RESULTS

We report for the first time a novel DNA copy number amplification-driven LncRNA on chromosome 20q13, designated Linc01711 in human GC, which is highly associated with malignant features. Functionally, Linc01711 significantly accelerates the proliferation and metastasis of GC. Mechanistically, Linc01711 acts as a modular scaffold to promote the binding of histone acetyltransferase HBO1 and histone demethylase KDM9. By coordinating the localization of the HBO1/KDM9 complex, Linc01711 specifies the histone modification pattern on the target genes, such as LPCAT1, and consequently facilitates the cholesterol synthesis, thereby contributing to tumor progression.

CONCLUSIONS

Our findings suggest that copy number amplification-driven Linc01711 may serve as a promising prognostic predictor for GC patients and targeting Linc01711-related cholesterol metabolism pathway may be meaningful in anticancer strategies.

Emerging roles of circular RNAs in tumorigenesis, progression, and treatment of gastric cancer

With an estimated one million new cases reported annually, gastric cancer (GC) ranks as the fifth most diagnosed malignancy worldwide. The early detection of GC remains a major challenge, and the prognosis worsens either when patients develop resistance to chemotherapy or radiotherapy or when the cancer metastasizes. The precise pathogenesis underlying GC is not well understood, which further complicates its treatment. Circular RNAs (circRNAs), a recently discovered class of noncoding RNAs that originate from parental genes through "back-splicing", have been shown to play a key role in various biological processes in both eukaryotes and prokaryotes. CircRNAs have been linked to cardiovascular diseases, diabetes, hypertension, Alzheimer's disease, and the occurrence and progression of tumors. Prior studies have established that circRNAs play a crucial role in GC, impacting tumorigenesis, diagnosis, progression, and therapy resistance. This review aims to summarize how circRNAs contribute to GC tumorigenesis and progression, examine their roles in the development of drug resistance, discuss their potential as biotechnological drugs, and summarize their response to therapeutic drugs and microorganism in GC.

Epigenetic alterations dictating the inflammation: A view through pancreatitis

Pancreatitis is a severe inflammation in the pancreas and accounts for one of the leading gastrointestinal disorders worldwide, and presently pacing up with the morbidity and mortality rates. It has been noted that severe recurrences of acute pancreatitis lead to chronic inflammation and fibrosis of the pancreas which may further result to a long-term risk of pancreatic carcinogenesis which has a lower survival rate and worse prognosis. Several genetic and epigenetic mechanisms have been reported to orchestrate disease development. Intriguingly, concurrent epigenetic alterations can also control the genes responsible for the pathophysiology of several inflammatory pathways. Deciphering how epigenetic changes affect the inflammatory processes in pancreatitis and body's response to various therapeutic modalities may help to manage the condition more effectively. The current review will concentrate on several epigenetic changes in general and how specifically they are implicated in pancreatitis pathogenesis. Further, this review summarizes the involvement of inflammation in pancreatitis from an epigenetic perspective.

Silencing hsa_circ_0032449 inhibits the pancreatic differentiation of human embryonic stem cells via the hsa_miR-195-5p/CCND1/PI3K/AKT signaling pathway

Stem cell-derived β cells (SC-β cells) differentiated from stem cell-derived pancreatic progenitor (PP) cells are promising tools for enabling normal glucose control of islet transplants and have therapeutic potential for type 1 diabetes treatment. Pancreatic specification is essential for SC-β cell induction in vitro and low-quality PP cells may convert into derivatives of non-pancreatic lineages both in vivo and in vitro, impeding PP-derived β cell safety and differentiation efficiency. Circular RNA (circRNA) commonly determines the fate of stem cells by acting as competing endogenous RNA (ceRNA). Currently, the relationships between endogenous circRNA and pancreatic specification remain elusive. Herein, we used whole transcriptome sequencing analysis and functional experiments to reveal that deficiency of hsa_circ_0032449 resulted in posterior foregut-derived PP cells with a weakened the progenitor state with decreased expression of PDX1, NKX6.1 and CCND1. As differentiation processed into maturation, silencing of hsa_circ_0032449 suppressed PP cell development into functionally mature and glucose-responsive SC-β cells. These SC-β cells exhibited lower serum C-peptide levels compared with those of control groups in nude mice and had difficulties in reversing hyperglycemia in STZ-induced diabetic nude mice. Mechanistically, loss of hsa_circ_0032449 participated in PI3K-AKT signaling transduction by acting as a ceRNA to sponge miR-195-5p and by influencing the expression of the downstream target CCND1 at transcription and translation levels. Overall, our findings identified hsa_circ_0032449 as an essential PP cell-fate specification regulator, indicating a promising potential in clinical applications and basic research.

Hsa_circ_0020134 promotes liver metastasis of colorectal cancer through the miR-183-5p-PFN2-TGF-β/Smad axis

Circular RNAs (circRNAs) are a distinct class of non-coding RNAs that play regulatory roles in the initiation and progression of tumors. With advancements in transcriptome sequencing technology, numerous circRNAs that play significant roles in tumor-related genes have been identified. In this study, we used transcriptome sequencing to analyze the expression levels of circRNAs in normal adjacent tissues, primary colorectal cancer (CRC) tissues, and CRC tissues with liver metastasis. We successfully identified the circRNA hsa_circ_0020134 (circ0020134), which exhibited significantly elevated expression specifically in CRC with liver metastasis. Importantly, high levels of circ0020134 were associated with a poor prognosis among patients. Functional experiments demonstrated that circ0020134 promotes the proliferation and metastasis of CRC cells both in vitro and in vivo. Mechanistically, upregulation of circ0020134 was induced by the transcription factor, PAX5, while miR-183-5p acted as a sponge for circ0020134, leading to partial upregulation of PFN2 mRNA and protein levels, thereby further activating the downstream TGF-β/Smad pathway. Additionally, downregulation of circ0020134 inhibited epithelial-mesenchymal transition (EMT) in CRC cells, which could be reversed by miR-183-5p inhibitor treatment. Collectively, our findings confirm that the circ0020134-miR-183-5p-PFN2-TGF-β/Smad axis induces EMT transformation within tumor cells, promoting CRC proliferation and metastasis, thus highlighting its potential as a therapeutic target for patients with CRC liver metastasis.

Antitumor effect of luteolin proven by patient-derived organoids of gastric cancer

Luteolin (Lut) has been shown to inhibit gastric cancer (GC); however, its efficacy compared to other clinical drugs has not been examined in human samples. This study aimed to elucidate the antitumor activity of Lut in GC patient-derived organoids (PDOs). PDOs were established from GC cancer tissues, and the characterization of tissues and PDOs was performed using whole-exome sequencing. Drug sensitivity tests were performed by treating PDOs with Lut, norcantharidin (NCTD), and carboplatin (CP). RNA sequencing of PDOs was performed to elucidate the antitumor mechanism of Lut, which was further verified in three GC cell lines. Eleven PDOs were successfully constructed, and were highly consistent with the pathophysiology and genetic changes in the corresponding tumors. The IC50s of Lut, NCTD, and CP of PDOs were 27.19, 23.9, and 37.87 μM, respectively. Lut treatment upregulated FOXO3, DUSP1, and CDKN1A expression and downregulated IL1R1 and FGFR4 expression in GC cell lines, which was consistent with the results of PDOs. We demonstrate that Lut exerted stronger antitumor effects than CP, but a similar effect to that of NCTD, which was obtained in an in vitro PDO system. Additionally, Lut exerted varying degrees of antitumor effects against the PDOs, thereby indicating that PDO may be a useful preclinical drug screening tool for personalized treatment.

Morusinol Extracted from Morus alba Inhibits Cell Proliferation and Induces Autophagy via FOXO3a Nuclear Accumulation-Mediated Cholesterol Biosynthesis Obstruction in Colorectal Cancer

The incidence rate of colorectal cancer (CRC) has been increasing significantly in recent years, and it is urgent to develop novel drugs that have more effects for its treatment. It has been reported that many molecules extracted from the root bark of Morus alba L. (also known as Cortex Mori) have antitumor activities. In our study, we identified morusinol as a promising anticancer agent by selecting from 30 molecules extracted from Morus alba L. We found that morusinol treatment suppressed cell proliferation and promoted apoptosis of CRC cells in vitro. Besides this, we observed that morusinol induced cytoprotective autophagy. The GO analysis of differentially expressed genes from RNA-seq data showed that morusinol affected cholesterol metabolism. Then we found that key enzyme genes in the cholesterol biosynthesis pathway as well as the sterol regulatory element binding transcription factor 2 (SREBF2) were significantly downregulated. Furthermore, additional cholesterol treatment reversed the anti-CRC effect of morusinol. Interestingly, we also found that morusinol treatment could promote forkhead box O3 (FOXO3a) nuclear accumulation, which subsequently suppressed SREBF2 transcription. Then SREBF2-controlled cholesterol biosynthesis was blocked, resulting in the suppression of cell proliferation, promotion of apoptosis, and production of autophagy. The experiments in animal models also showed that morusinol significantly impeded tumor growth in mice models. Our results suggested that morusinol may be used as a candidate anticancer drug for the treatment of CRC.

Histone lactylation regulates cancer progression by reshaping the tumor microenvironment

As a major product of glycolysis and a vital signaling molecule, many studies have reported the key role of lactate in tumor progression and cell fate determination. Lactylation is a newly discovered post-translational modification induced by lactate. On the one hand, lactylation introduced a new era of lactate metabolism in the tumor microenvironment (TME), and on the other hand, it provided a key breakthrough point for elucidation of the interaction between tumor metabolic reprogramming and epigenetic modification. Studies have shown that the lactylation of tumor cells, tumor stem cells and tumor-infiltrating immune cells in TME can participate in the development of cancer through downstream transcriptional regulation, and is a potential and promising tumor treatment target. This review summarized the discovery and effects of lactylation, as well as recent research on histone lactylation regulating cancer progression through reshaping TME. We also focused on new strategies to enhance anti-tumor effects via targeting lactylation. Finally, we discussed the limitations of existing studies and proposed new perspectives for future research in order to further explore lactylation targets. It may provide a new way and direction to improve tumor prognosis.

Circ-CCT2 Activates Wnt/β-catenin Signaling to Facilitate Hepatoblastoma Development by Stabilizing PTBP1 mRNA

BACKGROUND & AIMS

Circ-CCT2 (hsa_circ_0000418) is a novel circular RNA that stems from the CCT2 gene. However, the expression of circ-CCT2 and its roles in hepatoblastoma are unknown. Our study aims to study the circ-CCT2 roles in hepatoblastoma development.

METHODS

Hepatoblastoma specimens were collected for examining the expression of circ-CCT2, TAF15, and PTBP1. CCK-8 and colony formation assays were applied for cell proliferation analysis. Migratory and invasive capacities were evaluated through wound healing and Transwell assays. The interaction between circ-CCT2, TAF15, and PTBP1 was validated by fluorescence in situ hybridization, RNA pull-down, and RNA immunoprecipitation. SKL2001 was used as an agonist of the Wnt/β-catenin pathway. A subcutaneous mouse model of hepatoblastoma was established for examining the function of circ-CCT2 in hepatoblastoma in vivo.

RESULTS

Circ-CCT2 was significantly up-regulated in hepatoblastoma. Overexpression of circ-CCT2 activated Wnt/β-catenin signaling and promoted hepatoblastoma progression, whereas knockdown of circ-CCT2 exerted opposite effects. Moreover, both TAF15 and PTBP1 were up-regulated in hepatoblastoma tissues and cells. TAF15 was positively correlated with the expression of circ-CCT2 and PTBP1 in hepatoblastoma. Furthermore, circ-CCT2 recruited and up-regulated TAF15 protein to stabilize PTBP1 mRNA and trigger Wnt/β-catenin signaling in hepatoblastoma. Overexpression of TAF15 or PTBP1 reversed knockdown of circ-CCT2-mediated suppression of hepatoblastoma progression. SKL2001-mediated activation of Wnt/β-catenin signaling reversed the anti-tumor effects of silencing of circ-CCT2, TAF15, or PTBP1.

CONCLUSIONS

Circ-CCT2 stabilizes PTBP1 mRNA and activates Wnt/β-catenin signaling through recruiting and up-regulating TAF15 protein, thus promoting hepatoblastoma progression. Our findings deepen the understanding of hepatoblastoma pathogenesis and suggest potential therapeutic targets.

Histone regulator KAT2A acts as a potential biomarker related to tumor microenvironment and prognosis of diffuse large B cell lymphoma

BACKGROUND

Recent studies have indicated that epigenetic alterations contribute significantly to lymphoma pathogenesis. A type of epigenetic regulation known as histone acetylation plays a crucial role in transcriptional regulation in eukaryotic cells. Specifically, a significant effect of histone acetylation modifications on the abnormal progression and microenvironment of diffuse large B-cell lymphoma (DLBCL) has been observed.

METHODS

To provide insight into the significance of histone acetylation-related genes, we developed a HAscore model for analyzing histone acetylation patterns in DLBCL samples. Furthermore, KAT2A, a regulator of histone acetylation, was knocked down in DLBCL cell lines to investigate its role in proliferation, cell cycle, and apoptosis.

RESULTS

The HAscore model has been demonstrated to provide insight into the significance of these patterns, showing that patients with a low HAscore have distinct tumor immune microenvironments and poorer prognoses. Besides, KAT2A was identified as a potential biomarker related to immune infiltration and malignant pathways in DLBCL.

CONCLUSION

According to these findings, it is evident that the histone acetylation pattern score model is helpful in describing the immune status of DLBCL and that KAT2A may be used as a biomarker for its treatment.

The circular RNA Rap1b promotes Hoxa5 transcription by recruiting Kat7 and leading to increased Fam3a expression, which inhibits neuronal apoptosis in acute ischemic stroke

Circular RNAs can regulate the development and progression of ischemic cerebral disease. However, it remains unclear whether they play a role in acute ischemic stroke. To investigate the role of the circular RNA Rap1b (circRap1b) in acute ischemic stroke, in this study we established an in vitro model of acute ischemia and hypoxia by subjecting HT22 cells to oxygen and glucose deprivation and a mouse model of acute ischemia and hypoxia by occluding the right carotid artery. We found that circRap1b expression was remarkably down-regulated in the hippocampal tissue of the mouse model and in the HT22 cell model. In addition, Hoxa5 expression was strongly up-regulated in response to circRap1b overexpression. Hoxa5 expression was low in the hippocampus of a mouse model of acute ischemia and in HT22-AIS cells, and inhibited HT22-AIS cell apoptosis. Importantly, we found that circRap1b promoted Hoxa5 transcription by recruiting the acetyltransferase Kat7 to induce H3K14ac modification in the Hoxa5 promoter region. Hoxa5 regulated neuronal apoptosis by activating transcription of Fam3a, a neuronal apoptosis-related protein. These results suggest that circRap1b regulates Hoxa5 transcription and expression, and subsequently Fam3a expression, ultimately inhibiting cell apoptosis. Lastly, we explored the potential clinical relevance of circRap1b and Hoxa5 in vivo. Taken together, these findings demonstrate the mechanism by which circRap1b inhibits neuronal apoptosis in acute ischemic stroke.

The Regulation of Ferroptosis by Noncoding RNAs

As a novel form of regulated cell death, ferroptosis is characterized by intracellular iron and lipid peroxide accumulation, which is different from other regulated cell death forms morphologically, biochemically, and immunologically. Ferroptosis is regulated by iron metabolism, lipid metabolism, and antioxidant defense systems as well as various transcription factors and related signal pathways. Emerging evidence has highlighted that ferroptosis is associated with many physiological and pathological processes, including cancer, neurodegeneration diseases, cardiovascular diseases, and ischemia/reperfusion injury. Noncoding RNAs are a group of functional RNA molecules that are not translated into proteins, which can regulate gene expression in various manners. An increasing number of studies have shown that noncoding RNAs, especially miRNAs, lncRNAs, and circRNAs, can interfere with the progression of ferroptosis by modulating ferroptosis-related genes or proteins directly or indirectly. In this review, we summarize the basic mechanisms and regulations of ferroptosis and focus on the recent studies on the mechanism for different types of ncRNAs to regulate ferroptosis in different physiological and pathological conditions, which will deepen our understanding of ferroptosis regulation by noncoding RNAs and provide new insights into employing noncoding RNAs in ferroptosis-associated therapeutic strategies.

CircRREB1 mediates lipid metabolism related senescent phenotypes in chondrocytes through FASN post-translational modifications

Osteoarthritis is a prevalent age-related disease characterized by dysregulation of extracellular matrix metabolism, lipid metabolism, and upregulation of senescence-associated secretory phenotypes. Herein, we clarify that CircRREB1 is highly expressed in secondary generation chondrocytes and its deficiency can alleviate FASN related senescent phenotypes and osteoarthritis progression. CircRREB1 impedes proteasome-mediated degradation of FASN by inhibiting acetylation-mediated ubiquitination. Meanwhile, CircRREB1 induces RanBP2-mediated SUMOylation of FASN and enhances its protein stability. CircRREB1-FASN axis inhibits FGF18 and FGFR3 mediated PI3K-AKT signal transduction, then increased p21 expression. Intra-articular injection of adenovirus-CircRreb1 reverses the protective effects in CircRreb1 deficiency mice. Further therapeutic interventions could have beneficial effects in identifying CircRREB1 as a potential prognostic and therapeutic target for age-related OA.

RNF112-mediated FOXM1 ubiquitination suppresses the proliferation and invasion of gastric cancer

Forkhead box M1 (FOXM1) plays a critical role in development physiologically and tumorigenesis pathologically. However, insufficient efforts have been dedicated to exploring the regulation, in particular the degradation of FOXM1. Here, the ON-TARGETplus siRNA library targeting E3 ligases was used to screen potential candidates to repress FOXM1. Of note, mechanism study revealed that RNF112 directly ubiquitinates FOXM1 in gastric cancer, resulting in a decreased FOXM1 transcriptional network and suppressing the proliferation and invasion of gastric cancer. Interestingly, the well-established small-molecule compound RCM-1 significantly enhanced the interaction between RNF112 and FOXM1, which further promoted FOXM1 ubiquitination and subsequently exerted promising anticancer effects in vitro and in vivo. Altogether, we demonstrate that RNF112 suppresses gastric cancer progression by ubiquitinating FOXM1 and highlight the RNF112/FOXM1 axis serves as both prognosis biomarker and therapeutic target in gastric cancer.

Post-translational modifications of histones: Mechanisms, biological functions, and therapeutic targets

Histones are DNA-binding basic proteins found in chromosomes. After the histone translation, its amino tail undergoes various modifications, such as methylation, acetylation, phosphorylation, ubiquitination, malonylation, propionylation, butyrylation, crotonylation, and lactylation, which together constitute the "histone code." The relationship between their combination and biological function can be used as an important epigenetic marker. Methylation and demethylation of the same histone residue, acetylation and deacetylation, phosphorylation and dephosphorylation, and even methylation and acetylation between different histone residues cooperate or antagonize with each other, forming a complex network. Histone-modifying enzymes, which cause numerous histone codes, have become a hot topic in the research on cancer therapeutic targets. Therefore, a thorough understanding of the role of histone post-translational modifications (PTMs) in cell life activities is very important for preventing and treating human diseases. In this review, several most thoroughly studied and newly discovered histone PTMs are introduced. Furthermore, we focus on the histone-modifying enzymes with carcinogenic potential, their abnormal modification sites in various tumors, and multiple essential molecular regulation mechanism. Finally, we summarize the missing areas of the current research and point out the direction of future research. We hope to provide a comprehensive understanding and promote further research in this field.

KAT7 promotes radioresistance through upregulating PI3K/AKT signaling in breast cancer

Chromatin-modifying enzymes are commonly altered in cancers, but the molecular mechanism by which they regulate cancers remains poorly understood. Herein, we demonstrated that Lysine acetyltransferase 7 (KAT7) was upregulated in breast cancer. KAT7 expression negatively correlated with the survival of breast cancer patients, and KAT7 silencing suppressed breast cancer radioresistance in vitro. Mechanistically, KAT7 activated Phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) transcription, leading to enhanced PI3K/AKT signaling and radioresistance. Overexpression of AKT or PIK3CA restored radioresistance suppression induced by KAT7 inhibition. Moreover, overexpression of KAT7, but not KAT7 acetyltransferase activity-deficient mutants promoted AKT phosphorylation at the Ser473 site, PIK3CA expression and radioresistance suppression due to KAT7 inhibition. In conclusion, KAT7 has huge prospects for clinical application as a new target for predicting radioresistance in breast cancer patients.

Identification of circular RNAs expression pattern in caprine fetal fibroblast cells exposed to a chronic non-cytotoxic dose of graphene oxide-silver nanoparticle nanocomposites

The widespread use of graphene oxide-silver nanoparticle nanocomposites (GO-AgNPs) in biomedical sciences is increasing the chances of human and animal exposure to its chronic non-toxic doses. Exposure to AgNPs-related nanomaterials may result in the negative effect on the dam, fetus and offspring. However, there are only little available information for profound understanding of the epigenetic alteration in the cells and animals caused by low-dose chronic exposure of GO-AgNPs. The present study investigated the effect of 0.5 μg/mL GO-AgNPs for 10 weeks on the differential expression of circular RNAs (circRNAs) in caprine fetal fibroblast cells (CFFCs), and this dose of GO-AgNPs did not affect cell viability and ROS level. We predicted the functions of those differentially expressed (DE) circRNAs in CFFCs by bioinformatics analysis. Furthermore, we validated the expression of ten DE circRNAs using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR) to ensure the reliability of the sequencing data. Our results showed that the DE circRNAs may potentially regulate the GO-AgNPs-inducing epigenetic toxicity through a regulatory network consisted of circRNAs, miRNAs and messenger RNAs (mRNAs). Therefore, the epigenetics toxicity is essential to assess the biosafety level of GO-AgNPs.

Epigenetic regulation in metabolic diseases: mechanisms and advances in clinical study

Epigenetics regulates gene expression and has been confirmed to play a critical role in a variety of metabolic diseases, such as diabetes, obesity, non-alcoholic fatty liver disease (NAFLD), osteoporosis, gout, hyperthyroidism, hypothyroidism and others. The term 'epigenetics' was firstly proposed in 1942 and with the development of technologies, the exploration of epigenetics has made great progresses. There are four main epigenetic mechanisms, including DNA methylation, histone modification, chromatin remodelling, and noncoding RNA (ncRNA), which exert different effects on metabolic diseases. Genetic and non-genetic factors, including ageing, diet, and exercise, interact with epigenetics and jointly affect the formation of a phenotype. Understanding epigenetics could be applied to diagnosing and treating metabolic diseases in the clinic, including epigenetic biomarkers, epigenetic drugs, and epigenetic editing. In this review, we introduce the brief history of epigenetics as well as the milestone events since the proposal of the term 'epigenetics'. Moreover, we summarise the research methods of epigenetics and introduce four main general mechanisms of epigenetic modulation. Furthermore, we summarise epigenetic mechanisms in metabolic diseases and introduce the interaction between epigenetics and genetic or non-genetic factors. Finally, we introduce the clinical trials and applications of epigenetics in metabolic diseases.

Circular RNAs: New layer of complexity evading breast cancer heterogeneity

Advances in high-throughput sequencing techniques and bioinformatic analysis have refuted the "junk" RNA hypothesis that was claimed against non-coding RNAs (ncRNAs). Circular RNAs (circRNAs); a class of single-stranded covalently closed loop RNA molecules have recently emerged as stable epigenetic regulators. Although the exact regulatory role of circRNAs is still to be clarified, it has been proven that circRNAs could exert their functions by interacting with other ncRNAs or proteins in their own physiologically authentic environment, regulating multiple cellular signaling pathways and other classes of ncRNAs. CircRNAs have also been reported to exhibit a tissue-specific expression and have been associated with the malignant transformation process of several hematological and solid malignancies. Along this line of reasoning, this review aims to highlight the importance of circRNAs in Breast Cancer (BC), which is ranked as the most prevalent malignancy among females. Notwithstanding the substantial efforts to develop a suitable anticancer therapeutic regimen against the heterogenous BC, inter- and intra-tumoral heterogeneity have resulted in an arduous challenge for drug development research, which in turn necessitates the investigation of other markers to be therapeutically targeted. Herein, the potential of circRNAs as possible diagnostic and prognostic biomarkers have been highlighted together with their possible application as novel therapeutic targets.

Identification of Chromatin Regulatory Factors Related to Immunity and Treatment of Alzheimer's Disease

Alzheimer's disease is one of the common neurodegenerative diseases in the elderly, which mainly manifests as progressively severe cognitive impairment, which seriously affects the quality of life of patients. Chromatin regulators have been shown to be associated with a variety of biological processes, and we mainly explore the relationship between chromatin regulators and Alzheimer's disease. Eight hundred seventy chromatin regulators were collected from previous studies, and data related to Alzheimer's disease patients were downloaded from the GEO database. Finally, we screened chromatin regulators related to Alzheimer's disease immunity, established prediction models, and screened related drugs and miRNAs. We screened 160 differentially expressed CRs, constructed an interaction network, obtained 10 hub genes, successfully constructed a prediction model based on immune-related 5 CRs, and obtained 520 related drugs and 3 related miRNA, which provided an idea for the treatment of Alzheimer's disease. Our study identified 5 chromatin regulators related to Alzheimer's disease, which are expected to be new targets for Alzheimer's disease immunotherapy.

The chromatin-associated RNAs in gene regulation and cancer

Eukaryotic genomes are prevalently transcribed into many types of RNAs that translate into proteins or execute gene regulatory functions. Many RNAs associate with chromatin directly or indirectly and are called chromatin-associated RNAs (caRNAs). To date, caRNAs have been found to be involved in gene and transcriptional regulation through multiple mechanisms and have important roles in different types of cancers. In this review, we first present different categories of caRNAs and the modes of interaction between caRNAs and chromatin. We then detail the mechanisms of chromatin-associated nascent RNAs, chromatin-associated noncoding RNAs and emerging m⁶A on caRNAs in transcription and gene regulation. Finally, we discuss the roles of caRNAs in cancer as well as epigenetic and epitranscriptomic mechanisms contributing to cancer, which could provide insights into the relationship between different caRNAs and cancer, as well as tumor treatment and intervention.

Circ-sh3rf3/GATA-4/miR-29a regulatory axis in fibroblast-myofibroblast differentiation and myocardial fibrosis

The transdifferentiation from cardiac fibroblasts to myofibroblasts is an important event in the initiation of cardiac fibrosis. However, the underlying mechanism is not fully understood. Circ-sh3rf3 (circular RNA SH3 domain containing Ring Finger 3) is a novel circular RNA which was induced in hypertrophied ventricles by isoproterenol hydrochloride, and our work has established that it is a potential regulator in cardiac hypertrophy, but whether circ-sh3rf3 plays a role in cardiac fibrosis remains unclear, especially in the conversion of cardiac fibroblasts into myofibroblasts. Here, we found that circ-sh3rf3 was down-regulated in isoproterenol-treated rat cardiac fibroblasts and cardiomyocytes as well as during fibroblast differentiation into myofibroblasts. We further confirmed that circ-sh3rf3 could interact with GATA-4 proteins and reduce the expression of GATA-4, which in turn abolishes GATA-4 repression of miR-29a expression and thus up-regulates miR-29a expression, thereby inhibiting fibroblast-myofibroblast differentiation and myocardial fibrosis. Our work has established a novel Circ-sh3rf3/GATA-4/miR-29a regulatory cascade in fibroblast-myofibroblast differentiation and myocardial fibrosis, which provides a new therapeutic target for myocardial fibrosis.

Associations of selenoprotein expression and gene methylation with the outcome of clear cell renal carcinoma

Selenoproteins are a ubiquitous class of proteins defined by having a selenocysteine amino acid residue. While many of the selenoproteins have been well characterized with important roles in oxidation-reduction reactions and hormone synthesis among others, there exist some whose biological roles are not as well understood as denoted by the "SELENO" root. In this study, we explored associations between the reported RNA levels of "SELENO" proteins and clear cell renal cell carcinoma (ccRCC), the most common subtype of renal carcinoma in the US. Utilizing The Cancer Genome Atlas (TCGA) alongside other in silico tools, we discovered higher mRNA expression of Selenoprotein I, T, and P was associated with better overall survival outcomes and differential expression of other selenoproteins based on tumor stage. Additionally, we uncovered relative hypomethylation among selenoproteins in primary ccRCC tumor samples compared to normal tissue. Network and enrichment analysis showed numerous genes through which selenoproteins may modulate cancer progression and outcomes such as DERL1, PNPLA2/3, MIEN1, and FOXO1 which have been well-described in other cancers. In light of our findings highlighting an association of selenoprotein methylation and expression patterns with ccRCC outcome, further wet lab research is warranted.

Emerging roles of circular RNAs in gastric cancer metastasis and drug resistance

Gastric cancer (GC) is an aggressive malignancy with a high mortality rate and poor prognosis, primarily caused by metastatic lesions. Improved understanding of GC metastasis at the molecular level yields meaningful insights into potential biomarkers and therapeutic targets. Covalently closed circular RNAs (circRNAs) have emerged as crucial regulators in diverse human cancers including GC. Furthermore, accumulating evidence has demonstrated that circRNAs exhibit the dysregulated patterns in GC and have emerged as crucial regulators in GC invasion and metastasis. However, systematic knowledge regarding the involvement of circRNAs in metastatic GC remains obscure. In this review, we outline the functional circRNAs related to GC metastasis and drug resistance and discuss their underlying mechanisms, providing a comprehensive delineation of circRNA functions on metastatic GC and shedding new light on future therapeutic interventions for GC metastases.

Exosomal circPABPC1 promotes colorectal cancer liver metastases by regulating HMGA2 in the nucleus and BMP4/ADAM19 in the cytoplasm

Liver metastasis is the leading cause of death in colorectal carcinoma (CRC). However, little is known about the mechanisms of transferring effector messages between the primary tumor and the site of metastasis. Exosomes provide a novel transfer message method, and exosomal circular RNAs (circRNAs) play critical regulatory roles in cancer biology. In this study, the results showed that the expression of circPABPC1 was aberrantly upregulated in CRC tissues and exosomes. Exosomal circPABPC1 was considered an oncogene by functional experimental analysis in vitro and in vivo. Mechanistically, circPABPC1 recruited KDM4C to the HMGA2 promoter, reduced its H3K9me3 modification and initiated the transcription process in the nucleus. Moreover, cytoplasmic circPABPC1 promoted CRC progression by protecting ADAM19 and BMP4 from miR-874-/miR-1292-mediated degradation. Our findings indicated that exosomal circPABPC1 is an essential regulator in CRC liver metastasis progression by promoting HMGA2 and BMP4/ADAM19 expression. CircPABPC1 is expected to be a novel biomarker and antimetastatic therapeutic target in CRC.

Construction of a synthetic methodology-based library and its application in identifying a GIT/PIX protein-protein interaction inhibitor

In recent years, the flourishing of synthetic methodology studies has provided concise access to numerous molecules with new chemical space. These compounds form a large library with unique scaffolds, but their application in hit discovery is not systematically evaluated. In this work, we establish a synthetic methodology-based compound library (SMBL), integrated with compounds obtained from our synthetic researches, as well as their virtual derivatives in significantly larger scale. We screen the library and identify small-molecule inhibitors to interrupt the protein-protein interaction (PPI) of GIT1/β-Pix complex, an unrevealed target involved in gastric cancer metastasis. The inhibitor 14-5-18 with a spiro[bicyclo[2.2.1]heptane-2,3'-indolin]-2'-one scaffold, considerably retards gastric cancer metastasis in vitro and in vivo. Since the PPI targets are considered undruggable as they are hard to target, the successful application illustrates the structural specificity of SMBL, demonstrating its potential to be utilized as compound source for more challenging targets.

MACC1 promotes pancreatic cancer metastasis by interacting with the EMT regulator SNAI1

Metastasis is the dominant cause of cancer-related mortality. Metastasis-associated with colon cancer protein 1 (MACC1) has been proven to play a critical role in cancer metastasis. However, the prometastatic role of MACC1 in regulating the pancreatic cancer (PC) metastatic phenotype remains elusive. Here, we report that MACC1 is highly expressed in The Cancer Genome Atlas (TCGA) and tissue microarray (TMA) and identified as a good indicator for poor prognosis. Overexpression or knockdown of MACC1 in PC cells correspondingly promoted or inhibited pancreatic cancer cell migration and invasion in a MET proto-oncogene receptor tyrosine kinase (MET)-independent manner. Notably, knockdown of MACC1 in PC cells markedly decreased the liver metastatic lesions in a liver metastasis model. Mechanistically, MACC1 binds to the epithelial-mesenchymal transition (EMT) regulator snail family transcriptional repressor 1 (SNAI1) to drive EMT via upregulating the transcriptional activity of SNAI1, leading to the transactivation of fibronectin 1 (FN1) and the trans-repression of cadherin 1 (CDH1). Collectively, our results unveil a new mechanism by which MACC1 drives pancreatic cancer cell metastasis and suggest that the MACC1-SNAI1 complex-mediated mesenchymal transition may be a therapeutic target in pancreatic cancer.

Circular RNAs as diagnostic biomarkers for gastric cancer: A comprehensive update from emerging functions to clinical significances

The incidence and mortality of gastric cancer ranks as a fouth leading cause of cancer death worldwide, especially in East Asia. Due to the lack of specific early-stage symptoms, the majority of patients in most developing nations are diagnosed at an advanced stage. Therefore, it is urgent to find more sensitive and reliable biomarkers for gastric cancer screening and diagnosis. Circular RNAs (circRNAs), a novel type of RNAs with covalently closed loops, are becoming a latest hot spot in the field of. In recent years, a great deal of research has demonstrated that abnormal expression of circRNAs was associated with the development of gastric cancer, and suggested that circRNA might serve as a potential biomarker for gastric cancer diagnosis. In this review, we summarize the structural characteristics, formation mechanism and biological function of circRNAs, and elucidate research progress and existing problems in early screening of gastric cancer.

Research progress on the circRNA/lncRNA-miRNA-mRNA axis in gastric cancer

Gastric cancer is one of the most common malignant tumours worldwide. Genetic and epigenetic alterations are key factors in gastric carcinogenesis and drug resistance to chemotherapy. Competing endogenous RNA (ceRNA) regulation models have defined circRNA/lncRNA as miRNA sponges that indirectly regulate miRNA downstream target genes. The ceRNA regulatory network is related to the malignant biological behaviour of gastric cancer. The circRNA/lncRNA-miRNA-mRNA axis may be a marker for the early diagnosis and prognosis of gastric cancer and a potential therapeutic target for gastric cancer. Exosomal ncRNAs play an important role in gastric cancer and are expected to be ideal biomarkers for the diagnosis, prognosis, and treatment of gastric cancer. This review summarizes the specific ceRNA regulatory network (circRNA/lncRNA-miRNA-mRNA) discovered in gastric cancer in recent years, which may provide new ideas or strategies for early clinical diagnosis, further development, and application.

Circular RNA Controls Tumor Occurrence and Development via Cell Cycle Regulation

Circular RNAs (circRNAs) participate in the occurrence and development of various diseases through different mechanisms, such as by acting as a microRNA (miRNA) sponge, interacting with RNA-binding proteins, and regulating gene transcription and protein translation. For example, the abnormal expression of specific circRNAs in tumor cells can alter key regulatory factors and the cell cycle network, resulting in cell cycle disorders and the development and metastasis of tumors. Here, we summarize the mechanisms involved in the circRNA-mediated processes that lead to uncontrolled cell cycle and tumor cell proliferation. Extensive studies investigating the abnormal expression of circRNAs in different cancer types have been conducted. The unique characteristics of circRNAs and their ability to regulate the cell cycle through diverse mechanisms is extremely valuable in tumor diagnosis, treatment, and prognosis. Our review may assist in further understanding the circRNA-mediated regulation of the cell cycle in tumors and provide insights for research on circRNA-based therapeutic strategies and biological diagnosis for cancer.

Promising Roles of Circular RNAs as Biomarkers and Targets for Potential Diagnosis and Therapy of Tuberculosis

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, remains one of the most threatening infectious diseases worldwide. A series of challenges still exist for TB prevention, diagnosis and treatment, which therefore require more attempts to clarify the pathological and immunological mechanisms in the development and progression of TB. Circular RNAs (circRNAs) are a large class of non-coding RNA, mostly expressed in eukaryotic cells, which are generated by the spliceosome through the back-splicing of linear RNAs. Accumulating studies have identified that circRNAs are widely involved in a variety of physiological and pathological processes, acting as the sponges or decoys for microRNAs and proteins, scaffold platforms for proteins, modulators for transcription and special templates for translation. Due to the stable and widely spread characteristics of circRNAs, they are expected to serve as promising prognostic/diagnostic biomarkers and therapeutic targets for diseases. In this review, we briefly describe the biogenesis, classification, detection technology and functions of circRNAs, and, in particular, outline the dynamic, and sometimes aberrant changes of circRNAs in TB. Moreover, we further summarize the recent progress of research linking circRNAs to TB-related pathogenetic processes, as well as the potential roles of circRNAs as diagnostic biomarkers and miRNAs sponges in the case of Mtb infection, which is expected to enhance our understanding of TB and provide some novel ideas about how to overcome the challenges associated TB in the future.

Molecular mechanisms and therapeutic effects of different vitamins and minerals in COVID-19 patients

COVID-19 is a rapidly spreading disease, which has caught the world by surprise. Millions of people suffer from illness, and the mortality rates are dramatically high. Currently, there is no specific and immediate treatment for this disease. Remedies are limited to supportive regiments and few antiviral and anti-inflammatory drugs. The lack of a definite cure for COVID-19 is the reason behind its high mortality and global prevalence. COVID-19 can lead to a critical illness with severe respiratory distress and cytokine release. Increased oxidative stress and excessive production of inflammatory cytokines are vital components of severe COVID-19. Micronutrients, metalloids, and vitamins such as iron, manganese, selenium, Zinc, Copper, vitamin A, B family, and C are among the essential and trace elements that play a pivotal role in human nutrition and health. They participate in metabolic processes that lead to energy production. In addition, they support immune functions and act as antioxidants. Therefore, maintaining an optimal level of micronutrients intake, particularly those with antioxidant activities, is essential to fight against oxidative stress, modulate inflammation, and boost the immune system. Therefore, these factors could play a crucial role in COVID-19 prevention and treatment. In this review, we aimed to summarize antiviral properties of different vitamins and minerals. Moreover, we will investigate the correlation between them and their effects in COVID-19 patients.

CircSMARCA5: A key circular RNA in various human diseases

Circular RNAs (circRNAs) are recognized as a novel type of single-stranded endogenous noncoding RNA molecule with the characteristics of tissue specificity, sequence conservation and structural stability. Accumulating studies have shown that circRNAs play a unique biological role in different kinds of diseases. CircRNAs can affect tumor proliferation, migration, metastasis and other behaviors by modulating the expression of downstream genes. CircSMARCA5, an example of a circRNA, is dysregulated in various noninfectious diseases, such as tumors, osteoporosis, atherosclerosis and coronary heart disease. Furthermore, recent studies have demonstrated that circSMARCA5 is associated with the occurrence and development of a variety of tumors, including gastric cancer, glioblastoma, hepatocellular carcinoma, multiple myeloma, colorectal cancer, breast cancer and osteosarcoma. Mechanistically, circSMARCA5 primarily acts as a sponge of miRNAs to regulate the expression of downstream genes, and can serve as a potential biomarker for the diagnosis of malignant tumors. This review summarizes the biological roles of circSMARCA5 and its molecular mechanism of action in various diseases. Moreover, the meta-analysis of some publications showed that the expression of circSMARCA5 was significantly correlated with the prognosis of patients and tumor TNM stage, showing that circSMARCA5 has the potential to be a prognostic marker.

Circular RNA hsa_circ_0002360 Promotes Proliferation and Invasion and Inhibits Oxidative Stress in Gastric Cancer by Sponging miR-629-3p and Regulating the PDLIM4 Expression

Many studies have found that circRNA hsa_0002360 (circ0002360) plays an important role in cancer onset and progression. However, its role in gastric cancer (GC) remains uncertain. Circ0002360 was found to be upregulated in GC cells using QRT-PCR. Furthermore, miR-629-3p, a target miRNA of circ0002360, was the most suppressed miRNA following circ0002360 overexpression. RNA immunoprecipitation (RIP), dual-luciferase reporter analyses, clone formation, transwell, DCFH-DA, and ELISA assays demonstrated that circ0002360-targeted miR-629-3p promotes cell proliferation and migration while inhibiting oxidative stress. GC-related mRNA microarrays from the GEO and TCGA databases, including GSE103236, GSE79973, GSE33429, GSE22804, GSE84437, and TCGA-STAD datasets, were used to find hub biomarkers between normal and gastric cancer samples. WGCNA and uni-Cox analysis were used to identify 27 survival-related risk genes, which were then used to build a risk model for prognosis prediction. Following that, all patients from the GSE84437 and TCGA-STAD datasets with 27 survival-related genes and enough data on survival status and time were randomly assigned to train (n = 433) and test (n = 375) cohorts. Furthermore, ROC and Kaplan-Meier (KM) analyses were used to validate the risk model for both cohorts. randomForest analysis indicated that PDLIM4 was the target gene of miR-629-3p, whose level was increased by circ0002360 but reversed by miR-629-3p mimics. Finally, this study confirmed that circ0002360 sponged miR-629-3p and then upregulated PDLIM4 expression. As a result, circ0002360 may be a useful marker for predicting GC prognosis and an anti-GC treatment target.

Circular RNA circMRPS35 regulates progression and autophagy in osteosarcoma cells by recruiting KAT6B to govern FOXO3

Osteosarcoma serves as frequently occurred bone malignancy that displays low survival rate and high incidence of metastasis. Circular RNAs (circRNAs) have been reported as the crucial molecules in osteosarcoma development. However, the effect of circRNA circMRPS35 on osteosarcoma remains unclear. Here, we aimed to explore the function of circMRPS35 in the regulation of autophagy and progression of osteosarcoma. The colony formation numbers and Edu-positive osteosarcoma cells were repressed by the overexpression of circMRPS35. Meanwhile, the overexpression of circMRPS35 increased the apoptosis rate of osteosarcoma cells. The expression levels of autophagy markers, including LC3 and Beclin1, were enhanced by the overexpression of circMRPS35 in osteosarcoma cells. Mechanically, the depletion of circMRPS35 reduced the enrichment of histone H3 lysine 23 acetylation (H3K23ac) on forkhead box O3 (FOXO3) promoter in osteosarcoma cells. The interaction of circMRPS35 and KAT6B was identified. The knockdown of KAT6B reduced the enrichment of H3K23ac on FOXO3 promoter in osteosarcoma cells. The depletion of circMRPS35 repressed the expression of FOXO3 in the MG63 and MNNG/HOS cells, whereas the overexpression of KAT6B reversed the effect. Significantly, KAT6B promotes apoptosis and autophagy of osteosarcoma cells. The overexpression of circMRPS35 induced the apoptosis and autophagy of osteosarcoma cells, in which the depletion of KAT6B or FOXO3 reversed the effect. The overexpression of circMRPS35 inhibited the tumor growth in vivo , whereas the depletion of KAT6B could reverse the effect in the mice. Therefore, we concluded that circRNA circMRPS35 repressed progression and induced autophagy of osteosarcoma cells.

Tumor vessel normalization and immunotherapy in gastric cancer

Gastric cancer (GC) is a common malignant tumor, and patients with GC have a low survival rate due to limited effective treatment methods. Angiogenesis and immune evasion are two key processes in GC progression, and they act synergistically to promote tumor progression. Tumor vascular normalization has been shown to improve the efficacy of cancer immunotherapy, which in turn may be improved through enhanced immune stimulation. Therefore, it may be interesting to identify synergies between immunomodulatory agents and anti-angiogenic therapies in GC. This strategy aims to normalize the tumor microenvironment through the action of the anti-vascular endothelial growth factor while stimulating the immune response through immunotherapy and prolonging the survival of GC patients.

circRNA: A New Biomarker and Therapeutic Target for Esophageal Cancer

Circular RNAs (circRNAs) comprise a large class of endogenous non-coding RNA with covalently closed loops and have independent functions as linear transcripts transcribed from identical genes. circRNAs are generated by a “back-splicing” process regulated by regulatory elements in cis and associating proteins in trans. Many studies have shown that circRNAs play important roles in multiple processes, including splicing, transcription, chromatin modification, miRNA sponges, and protein decoys. circRNAs are highly stable because of their closed ring structure, which prevents them from degradation by exonucleases, and are more abundant in terminally differentiated cells, such as brains. Recently, it was demonstrated that numerous circRNAs are differentially expressed in cancer cells, and their dysfunction is involved in tumorigenesis and metastasis. However, the crucial functions of these circRNAs and the dysregulation of circRNAs in cancer are still unknown. In this review, we summarize the recent reports on the biogenesis and biology of circRNAs and then catalog the advances in using circRNAs as biomarkers and therapeutic targets for cancer therapy, particularly esophageal cancer.

The FOXO family of transcription factors: key molecular players in gastric cancer

Gastric cancer (GC) is the fifth most frequently diagnosed cancer worldwide and the third leading cause of cancer-related death with an oncological origin. Despite its decline in incidence and mortality in recent years, GC remains a global public problem that seriously threatens patients' health and lives. The forkhead box O proteins (FOXOs) are a family of evolutionarily conserved transcription factors (TFs) with crucial roles in cell fate decisions. In mammals, the FOXO family consists of four members FOXO1, 3a, 4, and 6. FOXOs play crucial roles in a variety of biological processes, such as development, metabolism, and stem cell maintenance, by regulating the expression of their target genes in space and time. An accumulating amount of evidence has shown that the dysregulation of FOXOs is involved in GC progression by affecting multiple cellular processes, including proliferation, apoptosis, invasion, metastasis, cell cycle progression, carcinogenesis, and resistance to chemotherapeutic drugs. In this review, we systematically summarize the recent findings on the regulatory mechanisms of FOXO family expression and activity and elucidate its roles in GC progression. Moreover, we also highlight the clinical implications of FOXOs in GC treatment.

Impact of Amarogentin on Gastric Carcinoma Cell Multiplication, Apoptosis and Migration via circKIF4A/miR-152-3p

Objective

The active ingredients extracted from natural plants have anti-GC actions and can slow down gastric carcinoma (GC) progression. To investigate the impact of Amarogentin (AG) on GC cell multiplication, apoptosis and migration and the possible mechanisms.

Methods

qRT-PCR quantification of circKIF4A and miR-152-3p in GC tissues and normal counterparts as well as HGC-27 (human GC cell strain) and GES-1 (human gastric mucosal epithelial cell strain) was performed. HGC-27 cells were intervened by AG of various concentrations. si-NC, si-circKIF4A were further transfected into HGC-27 cells. Besides, pcDNA and pcDNA-circKIF4A were transfected into HGC-27 cells, after which 60 mmol/L AG was added for intervention. Cell multiplication, clone formation, as well as apoptosis and migration measurements were made by MTT, plate clone formation, flow cytometry and Transwell assays, respectively; Double luciferase reporter assay was performed for targeting relationship identification between circKIF4A and miR-152-3p; Western blots were carried out to measure Bax and Bcl-2 protein levels.

Results

circKIF4A increased (P <0.05) and miR-152-3p decreased (P <0.05) in GC tissues and cell strains. Concentration-dependently, AG intervention contributed to enhanced cell multiplication inhibitory rate, apoptosis rate, miR-152-3p expression and Bax protein level (P <0.05), together with declined number of cell clones formed, migrating cells, circKIF4A expression and Bcl-2 protein level (P <0.05). After transfection of si-circKIF4A, cell multiplication inhibition rate, apoptosis rate and Bax protein level enhanced (P <0.05), while cell clones formed and migrating cells as well as Bcl-2 protein level reduced (P <0.05). miR-152-3p can be controlled by circKIF4A; pcDNA-circKIF4A transfection antagonized AG's effects on HGC-27 cell multiplication, clone formation, apoptosis and migration.

Conclusion

AG can decrease GC multiplication, clone formation and migration and induce apoptosis via modulating circKIF4A/miR-152-3p expression.

Integrated lncRNA function upon genomic and epigenomic regulation

Although some long noncoding (lnc)RNAs are known since the 1950s, the past 25 years have uncovered myriad lncRNAs with diverse sequences, structures, and functions. The advent of high-throughput and sensitive technologies has further uncovered the vast heterogeneity of lncRNA-interacting molecules and patterns of expressed lncRNAs. We propose a unifying functional theme for the expansive family of lncRNAs. At an elementary level, the genomic program of gene expression is elicited via canonical transcription and post-transcriptional mRNA assembly, turnover, and translation. Building upon this regulation, an epigenomic program refines the basic genomic control by modifying chromatin architecture as well as DNA and RNA chemistry. Superimposed over the genomic and epigenomic programs, lncRNAs create an additional regulatory dimension: by interacting with the proteins and nucleic acids that regulate gene expression in the nucleus and cytoplasm, lncRNAs help establish robust, nimble, and specific transcriptional and post-transcriptional control. We describe our present understanding of lncRNA-coordinated control of protein programs and cell fate and discuss challenges and opportunities as we embark on the next 25 years of lncRNA discovery.

circFCHO2 promotes gastric cancer progression by activating the JAK1/STAT3 pathway via sponging miR-194-5p

circFCHO2 has been revealed to be overexpressed in gastric cancer (GC) patients. This article identified the function of circFCHO2 on GC progression. The expression of circFCHO2, miR-194-5p and JAK1 in 30 GC patients and cells was monitored by quantitative reverse transcription-polymerase chain reaction. circFCHO2 localization in GC cells was monitored by RNA fluorescence in situ hybridization. Cell counting kit-8 assay, 5-ethynyl-2-deoxyuridine staining, transwell experiment, tube formation and sphere formation experiments were applied to detect GC cell proliferation, invasion, angiogenesis and cancer stem cell characteristics. Dual-luciferase reporter gene assay, RNA pull down assay and RNA immunoprecipitation experiment were utilized to research the binding between two genes. In vivo tumorigenesis and lung metastasis were studied using nude mice. Immunohistochemistry and hematoxylin-eosin staining were conducted. Protein expression was assessed by Western blot. Serum exosomes of GC patients and healthy participants were isolated. circFCHO2 up-modulation in GC patients was related to poor outcome. circFCHO2 was located in the cytoplasm of GC cells. circFCHO2 silencing weakened the proliferation, invasion, angiogenesis and stem cell characteristics of GC cells. miR-194-5p knockdown counteracted this effect. circFCHO2 activated the JAK1/STAT3 pathway by sponging miR-194-5p. miR-194-5p overexpression attenuated the malignant phenotypes of GC cells. JAK1 overexpression abrogated this effect. circFCHO2 silencing weakened GC cells growth and lung metastasis in vivo. circFCHO2 was up-modulated in serum exosomes of GC patients. circFCHO2 was an oncogene in GC by activating the JAK1/STAT3 pathway via sponging miR-194-5p. circFCHO2 might be a novel target and diagnostic marker for GC.