FTO demethylates m6A modifications in HOXB13 mRNA and promotes endometrial cancer metastasis by activating the WNT signalling pathway

FTO attenuates TNF-α-induced damage of proximal tubular epithelial cells in acute pancreatitis-induced acute kidney injury via targeting AQP3 in an N6-methyladenosine-dependent manner

BACKGROUND

Acute kidney injury (AKI) is a frequent complication of severe acute pancreatitis (SAP). Previous investigations have revealed the involvement of FTO alpha-ketoglutarate-dependent dioxygenase (FTO) and aquaporin 3 (AQP3) in AKI. Therefore, the aim of this study is to explore the association of FTO and AQP3 on proximal tubular epithelial cell damage in SAP-induced AKI.

METHODS

An in-vitro AKI model was established in human proximal tubular epithelial cells (PTECs) HK-2 via tumor necrosis factor-α (TNF-α) induction (20 ng/mL), after which FTO and AQP3 expression was manipulated and quantified by quantitative real-time PCR and Western blotting. The viability and apoptosis of PTECs under various conditions, and reactive oxygen species (ROS), superoxide dismutase (SOD), and malonaldehyde (MDA) levels within these cells were measured using commercial assay kits and flow cytometry. Methylated RNA immunoprecipitation and mRNA stability assays were performed to elucidate the mechanism of FTO-mediated N6-methyladenosine (m6A) modification. Western blotting was performed to quantify β-catenin protein levels in the PTECs.

RESULTS

FTO overexpression attenuated the TNF-α-induced decrease in viability and SOD levels, elevated apoptosis, increased levels of ROS and MDA, and diminished TNF-α-induced AQP3 expression and reduced β-catenin expression, but its silencing led to contradictory results. FTO negatively modulates AQP3 levels in RTECs in an m6A-depednent manner and compromises AQP3 stability. In addition, all FTO overexpression-induced effects in TNF-α-induced PTECs were neutralized following AQP3 upregulation.

CONCLUSION

FTO alleviates TNF-α-induced damage to PTECs in vitro by targeting AQP3 in an m6A-dependent manner.

Overexpression of zinc finger DHHC-type containing 1 is associated with poor prognosis and cancer cell growth and metastasis in uterine corpus endometrial carcinoma

The zinc finger DHHC-type containing 1 (ZDHHC1) gene is implicated in the pathogenesis and progression of various malignant tumors, but its precise involvement in uterine corpus endometrial carcinoma (UCEC) remains unknown. Thus, this study investigated ZDHHC1 expression in UCEC using publicly available TCGA and Xena databases and elucidated the functions and mechanisms of the ZDHHC1 gene in UCEC progression using bioinformatics and in vitro experiments. The correlation between ZDHHC1 expression and prognosis, clinical features, immune cells, and RNA modifications of UCEC was evaluated using nomograms, correlation, ROC, and survival analyses. The impacts of ZDHHC1 overexpression on UCEC progression and mechanisms were explored with bioinformatics and in vitro experiments. Our study revealed that ZDHHC1 expression was significantly downregulated in UCEC and correlated with poor prognosis, cancer diagnosis, clinical stage, age, weight, body mass index, histological subtypes, residual tumor, tumor grade, and tumor invasion. Notably, Cox regression analysis and constructed nomograms showed that downregulated ZDHHC1 expression was a prognostic factor associated with poor prognosis in patients with UCEC. Conversely, above-normal ZDHHC1 expression inhibited the cell growth, cell cycle transition, migration, and invasion of UCEC cells, which may be related to the cell cycle, DNA replication, PI3K-AKT, and other pathways that promote tumor progression. Altered ZDHHC1 expression in UCEC was significantly associated with RNA modifications and the changes in cancer immune cell populations, such as CD56 bright NK cells, eosinophils, Th2 cells, and cell markers. In conclusion, considerably reduced ZDHHC1 expression in UCEC is associated with cancer cell growth, metastasis, poor prognosis, immune infiltration, and RNA modifications, revealing the promising potential of ZDHHC1 as a prognostic marker for UCEC.

Demethylases in tumors and the tumor microenvironment: Key modifiers of N6-methyladenosine methylation

RNA methylation modifications are widespread in eukaryotes and prokaryotes, with N6-methyladenosine (m6A) the most common among them. Demethylases, including Fat mass and obesity associated gene (FTO) and AlkB homolog 5 (ALKBH5), are important in maintaining the balance between RNA methylation and demethylation. Recent studies have clearly shown that demethylases affect the biological functions of tumors by regulating their m6A levels. However, their effects are complicated, and even opposite results have appeared in different articles. Here, we summarize the complex regulatory networks of demethylases, including the most important and common pathways, to clarify the role of demethylases in tumors. In addition, we describe the relationships between demethylases and the tumor microenvironment, and introduce their regulatory mechanisms. Finally, we discuss evaluation of demethylases for tumor diagnosis and prognosis, as well as the clinical application of demethylase inhibitors, providing a strong basis for their large-scale clinical application in the future.

A comprehensive review of m6A research in cervical cancer

Cervical cancer (CC) remains one of the most common malignancies among women worldwide, posing a serious threat to women's health. N6-methyladenosine (m6A) modification, as the most abundant type of RNA methylation modification, and has been found to play a crucial role in various cancers. Current research suggests a close association between RNA m6A modification and the occurrence and progression of CC, encompassing disruptions in m6A levels and its regulatory machinery. This review summarizes the current status of m6A modification research in CC, explores the mechanisms underlying m6A levels and regulators (methyltransferases, demethylases, reader proteins) in CC and examines the application of small-molecule inhibitors of m6A regulators in disease treatment. The findings provide new insights into the future treatment of CC.

LncRNA GAS5 regulated by FTO-mediated m6A demethylation promotes autophagic cell death in NSCLC by targeting UPF1/BRD4 axis

Long non-coding RNA (lncRNA) growth arrest-specific transcript 5 (GAS5) has been shown to be a regulator for many cancers, including non-small cell lung cancer (NSCLC). Therefore, its role and mechanism in the process of NSCLC deserve to be further revealed. The expression levels of GAS5, fat mass and obesity-associated protein (FTO) and bromodomain-containing protein 4 (BRD4) were detected by quantitative real-time PCR. Western blot analysis was used to examine the protein expression of FTO, BRD4, up-frameshift protein 1 (UPF1) and autophagy-related markers. Methylated RNA immunoprecipitation was used to assess the m6A level of GAS5 regulated by FTO. Cell proliferation and apoptosis were determined using MTT assay, EdU assay and flow cytometry. Autophagy ability was assessed by immunofluorescence staining and transmission electron microscope. Xenograft tumor model was constructed to explore the effects of FTO and GAS5 on NSCLC tumor growth in vivo. The interaction between UPF1 and GAS5 or BRD4 was confirmed by pull-down assay, RIP assay, dual-luciferase reporter assay, and chromatin immunoprecipitation. Fluorescent in situ hybridization was used to analyze the co-localization of GAS5 and UPF1. Actinomycin D treatment was employed to evaluate BRD4 mRNA stability. GAS5 was downregulated in NSCLC tissues and was associated with poor prognosis in NSCLC patients. FTO was highly expressed in NSCLC, and it inhibited GAS5 expression by reducing GAS5 m6A methylation level. GAS5 suppressed by FTO could promote the autophagic death of NSCLC cells in vitro and inhibit NSCLC tumor growth in vivo. In addition, GAS5 was able to interact with UPF1 to reduce the mRNA stability of BRD4. Knockdown of BRD4 reversed the inhibition of GAS5 or UPF1 silencing on the autophagic cell death of NSCLC. The findings of the study showed that lncRNA GAS5 mediated by FTO could contribute to the autophagic cell death of NSCLC by interacting with UPF1 to reduce BRD4 mRNA stability, suggesting that GAS5 might be a vital therapy target for NSCLC progression.

FTO overexpression expedites wound healing and alleviates depression in burn rats through facilitating keratinocyte migration and angiogenesis via mediating TFPI-2 demethylation

Burn injury is a serious traumatic injury that leads to severe physical and psychosocial impairment. Wound healing after burn injury is a substantial challenge in medical community. This study investigated the biological effects of the demethylase fat mass and obesity-associated protein (FTO) on burn injury. FTO protein level in burn skin tissues of patients was measured with Western blot assay. Keratinocytes (HaCaT cells) were given heat stimulation to induce an in vitro burn injury model, and then transfected with overexpression plasmids of FTO (pcDNA-FTO) or small interfering RNA against FTO (si-FTO). Cell proliferation, migration, and angiogenesis in keratinocytes were evaluated with CCK-8, Transwell, and tube formation assays, respectively. Tissue factor pathway inhibitor-2 (TFPI-2) m6A methylation level was detected with MeRIP‑qPCR assay. Then rescue experiments were conducted to explore the effects of FTO/TFPI-2 axis on keratinocyte functions. Lentivirus carrying FTO overexpression plasmids was injected into a burn rat model to detect its effects on wound healing and depressive-like behaviors in burn rats. FTO was downregulated in burn skin and heat-stimulated keratinocytes. FTO prominently augmented proliferation, migration and angiogenesis in heat-stimulated keratinocytes, while FTO knockdown showed the opposite results. FTO inhibited TFPI-2 expression by FTO-mediated m6A methylation modification. TFPI-2 overexpression abrogated FTO mediated enhancement of proliferation, migration and angiogenesis in keratinocytes. Additionally, FTO overexpression accelerated wound healing and improved depressive-like behaviors in burn rat model. FTO prominently augmented proliferation, migration and angiogenesis in heat-stimulated keratinocytes though inhibiting TFPI-2, and then improved wound healing and depressive-like behaviors.

RNA N6-methyladenosine demethylase FTO targets MOXD1 promoting the malignant phenotype of gastric cancer

BACKGROUND

The m6A modified demethylase FTO affects the progression of gastric cancer (GC), and the role mechanism of FTO in GC is still unclear. We, here, explored the role of FTO and unrevealed the mechanisms of its function in GC.

METHODS

The expression and clinical prognosis of FTO in GC were examined via UALCAN and GEPIA online databases. Effect of FTO shRNA on GC cellular malignant phenotype were proved by CCK-8, Transwell, Wound healing assay and Flow cytometric assay. RNA-sequencing data of FTO depleted AGS cells were downloaded to analyze differentially expressed genes of FTO downstream. The GO and KEGG pathway enrichment were performed for the DEGs by DAVID. RT-qPCR and RIP-qPCR assay were applied to verify the MOXD1 mRNA and methylated mRNA in FTO shRNA group. The expression and clinical prognosis of MOXD1 in GC were explored via UALCAN, GEPIA and Kaplan-Meier plotter. The role and mechanism and of MOXD1 in GC cell lines were detected and analyzed.

RESULTS

The expression of FTO was found to be elevated in GC tissues compared with normal tissues, and worse survival were strongly related to high expression of FTO in GC. FTO silencing suppressed the proliferation, migration and promoted apoptosis of GC cells. A total of 5856 DEGs were obtained in between NC and FTO depleted AGS cell groups, and involved in the cancer related pathways. Here, FTO targets MOXD1 mRNA and promotes its expression via m6A methylation. MOXD1 upregulation was associated to poor prognosis of GC. MOXD1 silencing suppressed the malignant phenotype of GC cells. MOXD1 activated cancer -related signaling pathway (MAPK, TGF-β, NOTCH and JAK/STAT).

CONCLUSIONS

Our study demonstrated that FTO silencing decreased MOXD1 expression to inhibit the progression of GC via m6A methylation modification. FTO/MOXD1 may be potential targets for the treatment and prognosis of GC.

Metastases and Recurrence Risk Factors in Endometrial Cancer-The Role of Selected Molecular Changes, Hormonal Factors, Diagnostic Methods and Surgery Procedures

The presence of metastatic endometrial cancer (EC) is a key problem in treatment failure associated with reduced overall survival rates. The most common metastatic location is the pelvic lymph nodes, and the least common is the brain. The presence of metastasis depends on many factors, including the molecular profile of cancer (according to the TCGA-Genome Atlas), the activity of certain hormones (estrogen, prolactin), and pro-inflammatory adipocytokines. Additionally, an altered expression of microRNAs affecting the regulation of numerous genes is also related to the spread of cancer. This paper also discusses the value of imaging methods in detecting metastases; the primary role is attributed to the standard transvaginal USG with the tumor-free distance (uTFD) option. The influence of diagnostic and therapeutic methods on EC spread is also described. Hysteroscopy, according to the analysis discussed above, may increase the risk of metastases through a fluid medium, mainly performed in advanced stages of EC. According to another analysis, laparoscopic hysterectomy performed with particular attention to avoiding risky procedures (trocar flushing, tissue traumatization, preserving a margin of normal tissue) was not found to increase the risk of EC dissemination.

Cancer metastasis under the magnifying glass of epigenetics and epitranscriptomics

Most of the cancer-associated mortality and morbidity can be attributed to metastasis. The role of epigenetic and epitranscriptomic alterations in cancer origin and progression has been extensively demonstrated during the last years. Both regulations share similar mechanisms driven by DNA or RNA modifiers, namely writers, readers, and erasers; enzymes responsible of respectively introducing, recognizing, or removing the epigenetic or epitranscriptomic modifications. Epigenetic regulation is achieved by DNA methylation, histone modifications, non-coding RNAs, chromatin accessibility, and enhancer reprogramming. In parallel, regulation at RNA level, named epitranscriptomic, is driven by a wide diversity of chemical modifications in mostly all RNA molecules. These two-layer regulatory mechanisms are finely controlled in normal tissue, and dysregulations are associated with every hallmark of human cancer. In this review, we provide an overview of the current state of knowledge regarding epigenetic and epitranscriptomic alterations governing tumor metastasis, and compare pathways regulated at DNA or RNA levels to shed light on a possible epi-crosstalk in cancer metastasis. A deeper understanding on these mechanisms could have important clinical implications for the prevention of advanced malignancies and the management of the disseminated diseases. Additionally, as these epi-alterations can potentially be reversed by small molecules or inhibitors against epi-modifiers, novel therapeutic alternatives could be envisioned.

The effects of N6-methyladenosine RNA methylation on the nervous system

Epitranscriptomics, also known as "RNA epigenetics", is a type of chemical modification that regulates RNA. RNA methylation is a significant discovery after DNA and histone methylation. The dynamic reversible process of m6A involves methyltransferases (writers), m6A binding proteins (readers), as well as demethylases (erasers). We summarized the current research status of m6A RNA methylation in the neural stem cells' growth, synaptic and axonal function, brain development, learning and memory, neurodegenerative diseases, and glioblastoma. This review aims to provide a theoretical basis for studying the mechanism of m6A methylation and finding its potential therapeutic targets in nervous system diseases.

FTO: a critical role in obesity and obesity-related diseases

In recent years, obesity is a growing pandemic in the world and has likely contributed to increasing the incidence of obesity-related diseases. Fat mass and obesity-associated gene (FTO) is the first gene discovered which has a close connection with fat. Recent studies suggested that FTO gene has played an important role in the molecular mechanisms of many diseases. Obesity is considered to be a hereditary disease and can evoke many kinds of diseases, including polycystic ovary syndrome (PCOS), type 2 diabetes mellitus (T2DM), cancer, etc., whose exact possible molecular mechanisms responsible for the effect of FTO on obesity and obesity-related diseases remain largely unknown. In this review, we comprehensively discuss the correlation between FTO gene and obesity, cancer, PCOS, T2DM, as well as the molecular mechanism involved in these diseases.

Decoding the Influence of Obesity on Prostate Cancer and Its Transgenerational Impact

In recent decades, the escalating prevalence of metabolic disorders, notably obesity and being overweight, has emerged as a pressing concern in public health. Projections for the future indicate a continual upward trajectory in obesity rates, primarily attributable to unhealthy dietary patterns and sedentary lifestyles. The ramifications of obesity extend beyond its visible manifestations, intricately weaving a web of hormonal dysregulation, chronic inflammation, and oxidative stress. This nexus of factors holds particular significance in the context of carcinogenesis, notably in the case of prostate cancer (PCa), which is a pervasive malignancy and a leading cause of mortality among men. A compelling hypothesis arises from the perspective of transgenerational inheritance, wherein genetic and epigenetic imprints associated with obesity may wield influence over the development of PCa. This review proposes a comprehensive exploration of the nuanced mechanisms through which obesity disrupts prostate homeostasis and serves as a catalyst for PCa initiation. Additionally, it delves into the intriguing interplay between the transgenerational transmission of both obesity-related traits and the predisposition to PCa. Drawing insights from a spectrum of sources, ranging from in vitro and animal model research to human studies, this review endeavors to discuss the intricate connections between obesity and PCa. However, the landscape remains partially obscured as the current state of knowledge unveils only fragments of the complex mechanisms linking these phenomena. As research advances, unraveling the associated factors and underlying mechanisms promises to unveil novel avenues for understanding and potentially mitigating the nexus between obesity and the development of PCa.

SHMT2 regulates esophageal cancer cell progression and immune Escape by mediating m6A modification of c-myc

BACKGROUND

In recent years, the role of altered cellular metabolism in tumor progression has attracted widespread attention. Related metabolic enzymes have also been considered as potential cancer therapeutic targets. Serine hydroxymethyltransferase 2 (SHMT2) has been reported to be upregulated in several cancers and associated with poor prognosis. However, there are few studies of SHMT2 in esophageal cancer (EC), and the related functions and mechanisms also need to be further explored.

METHODS

In this study, we first analyzed SHMT2 expression in EC by online database and clinical samples. Then, the biological functions of SHMT2 in EC were investigated by cell and animal experiments. The intracellular m6A methylation modification levels were also evaluated by MeRIP. Linked genes and mechanisms of SHMT2 were analyzed by bioinformatics and rescue experiments.

RESULTS

We found that SHMT2 expression was abnormally upregulated in EC and associated with poor prognosis. Functionally, SHMT2 silencing suppressed c-myc expression in an m6A-dependent manner, thereby blocking the proliferation, migration, invasion and immune escape abilities of EC cells. Mechanistically, SHMT2 encouraged the accumulation of methyl donor SAM through a one-carbon metabolic network, thereby regulating the m6A modification and stability of c-myc mRNA in a METTL3/FTO/ALKBH5/IGF2BP2-dependent way. In vivo animal experiments also demonstrated that SHMT2 mediated MYC expression by m6A-methylation modification, thus boosting EC tumorigenesis.

CONCLUSION

In conclusion, our data illustrated that SHMT2 regulated malignant progression and immune escape of EC cell through c-myc m6A modification. These revealed mechanisms related to SHMT2 in EC and maybe offer promise for the development of new therapeutic approaches.

Shining a spotlight on m6A and the vital role of RNA modification in endometrial cancer: a review

RNA modifications are mostly dynamically reversible post-transcriptional modifications, of which m6A is the most prevalent in eukaryotic mRNAs. A growing number of studies indicate that RNA modification can finely tune gene expression and modulate RNA metabolic homeostasis, which in turn affects the self-renewal, proliferation, apoptosis, migration, and invasion of tumor cells. Endometrial carcinoma (EC) is the most common gynecologic tumor in developed countries. Although it can be diagnosed early in the onset and have a preferable prognosis, some cases might develop and become metastatic or recurrent, with a worse prognosis. Fortunately, immunotherapy and targeted therapy are promising methods of treating endometrial cancer patients. Gene modifications may also contribute to these treatments, as is especially the case with recent developments of new targeted therapeutic genes and diagnostic biomarkers for EC, even though current findings on the relationship between RNA modification and EC are still very limited, especially m6A. For example, what is the elaborate mechanism by which RNA modification affects EC progression? Taking m6A modification as an example, what is the conversion mode of methylation and demethylation for RNAs, and how to achieve selective recognition of specific RNA? Understanding how they cope with various stimuli as part of in vivo and in vitro biological development, disease or tumor occurrence and development, and other processes is valuable and RNA modifications provide a distinctive insight into genetic information. The roles of these processes in coping with various stimuli, biological development, disease, or tumor development in vivo and in vitro are self-evident and may become a new direction for cancer in the future. In this review, we summarize the category, characteristics, and therapeutic precis of RNA modification, m6A in particular, with the purpose of seeking the systematic regulation axis related to RNA modification to provide a better solution for the treatment of EC.

New insights for gynecological cancer therapies: from molecular mechanisms and clinical evidence to future directions

Advanced and recurrent gynecological cancers lack effective treatment and have poor prognosis. Besides, there is urgent need for conservative treatment for fertility protection of young patients. Therefore, continued efforts are needed to further define underlying therapeutic targets and explore novel targeted strategies. Considerable advancements have been made with new insights into molecular mechanisms on cancer progression and breakthroughs in novel treatment strategies. Herein, we review the research that holds unique novelty and potential translational power to alter the current landscape of gynecological cancers and improve effective treatments. We outline the advent of promising therapies with their targeted biomolecules, including hormone receptor-targeted agents, inhibitors targeting epigenetic regulators, antiangiogenic agents, inhibitors of abnormal signaling pathways, poly (ADP-ribose) polymerase (PARP) inhibitors, agents targeting immune-suppressive regulators, and repurposed existing drugs. We particularly highlight clinical evidence and trace the ongoing clinical trials to investigate the translational value. Taken together, we conduct a thorough review on emerging agents for gynecological cancer treatment and further discuss their potential challenges and future opportunities.

RNA epigenetic modifications in ovarian cancer: The changes, chances, and challenges

Ovarian cancer (OC) is the most common female cancer worldwide. Patients with OC have high mortality because of its complex and poorly understood pathogenesis. RNA epigenetic modifications, such as m6 A, m1 A, and m5 C, are closely associated with the occurrence and development of OC. RNA modifications can affect the stability of mRNA transcripts, nuclear export of RNAs, translation efficiency, and decoding accuracy. However, there are few overviews that summarize the link between m6 A RNA modification and OC. Here, we discuss the molecular and cellular functions of different RNA modifications and how their regulation contributes to the pathogenesis of OC. By improving our understanding of the role of RNA modifications in the etiology of OC, we provide new perspectives for their use in OC diagnosis and treatment. This article is categorized under: RNA Processing > RNA Editing and Modification RNA in Disease and Development > RNA in Disease.

TMEM41A overexpression correlates with poor prognosis and immune alterations in patients with endometrial carcinoma

BACKGROUND

Expression levels of transmembrane protein 41A (TMEM41A) are related to the progression of malignant tumors. However, the association between TMEM41A expression and endometrial carcinoma (EC) remains unclear. This study aims to identify the roles of TMEM41A expression in the prognosis of patients with EC and its correlation with EC progression.

METHODS

The TMEM41A expression and its correlation with the survival of patients with EC were assessed. Cox regression analysis was used to identify the prognostic factors, while nomograms were used to examine the association between the prognostic factors and the survival of patients with EC. Finally, the link between TMEM41A level and immune microenvironment and RNA modifications was investigated in EC.

RESULTS

TMEM41A was overexpressed in EC. TMEM41A overexpression could diagnose the EC and evaluate the poor prognosis of patients. Overexpression of TMEM41A was associated with clinical stage, age, weight, histological subtype, tumor grade, and survival status of patients with EC. Clinical stage, age, tumor grade, radiotherapy, and TMEM41A overexpression were factors of poor prognosis in patients with EC. The nomograms revealed the correlation between the TMEM41A level and survival time of patients with EC at 1, 3, and 5 years. Furthermore, TMEM41A overexpression was significantly correlated with the level of the stromal score, immune score, estimate score, NK CD56 bright cells, iDC, NK cells, eosinophils, pDC, T cells, TReg, cytotoxic cells, mast cells, Th17 cells, neutrophils, aDC, NK CD56 dim cells, TFH, Th2 cells, CD8 T cells, macrophages, immune cell markers, and RNA modifications.

CONCLUSIONS

TMEM41A is overexpressed in EC tissues and is associated with the prognosis, immune microenvironment, and RNA modification. Our preliminary studies indicate that overexpression of TMEM41A can potentially serve as a biomarker for EC treatment.

The Functional Role and Regulatory Mechanism of FTO m6A RNA Demethylase in Human Uterine Leiomyosarcoma

Uterine leiomyosarcoma (uLMS) is the most frequent subtype of uterine sarcoma that presents a poor prognosis and high rates of recurrence and metastasis. The origin and molecular mechanism underlying and driving its clinical and biological behavior remain largely unknown. Recently, we and others have revealed the role of microRNAs, DNA methylation, and histone modifications in contributing to the pathogenesis of uLMS. However, the connection between reversible m6A RNA methylation and uLMS pathogenesis remains unclear. In this study, we assessed the role and mechanism of FTO m6A RNA demethylase in the pathogenesis of uLMS. Immunohistochemistry analysis revealed that the levels of RNA demethylases FTO and ALKBH5 were aberrantly upregulated in uLMS tissues compared to adjacent myometrium with a significant change by histochemical scoring assessment (p < 0.01). Furthermore, the inhibition of FTO demethylase with its small, potent inhibitor (Dac51) significantly decreased the uLMS proliferation dose-dependently via cell cycle arrest. Notably, RNA-seq analysis revealed that the inhibition of FTO with Dac51 exhibited a significant decrease in cell-cycle-related genes, including several CDK members, and a significant increase in the expression of CDKN1A, which correlated with a Dac51-exerted inhibitory effect on cell proliferation. Moreover, Dac51 treatment allowed the rewiring of several critical pathways, including TNFα signaling, KRAS signaling, inflammation response, G2M checkpoint, and C-Myc signaling, among others, leading to the suppression of the uLMS phenotype. Moreover, transcription factor (TF) analyses suggested that epitranscriptional alterations by Dac51 may alter the cell cycle-related gene expression via TF-driven pathways and epigenetic networks in uLMS cells. This intersection of RNA methylation and other epigenetic controls and pathways provides a framework to better understand uterine diseases, particularly uLMS pathogenesis with a dysregulation of RNA methylation machinery. Therefore, targeting the vulnerable epitranscriptome may provide an additional regulatory layer for a promising and novel strategy for treating patients with this aggressive uterine cancer.

FTO-stabilized miR-139-5p targets ZNF217 to suppress prostate cancer cell malignancies by inactivating the PI3K/Akt/mTOR signal pathway

As one of the most important demethylases for RNA N6-methyladenosine (m6A) modifications, fat mass and obesity-associated protein (FTO) plays anti-cancer role during prostate cancer (PC), but it is still unclear the detailed molecular mechanisms. Here, this study verified that FTO inactivated the tumor-accelerating PI3K/Akt/mTOR pathway to hamper PC development through regulating the downstream miR-139-5p/zinc finger protein 217 (ZNF217) axis. Through performing clinical analysis, it was revealed that FTO was apparently ablated in the cancerous tissues compared to the normal tissues collected from PC patients, and patients with high-expressed FTO predicted a favorable prognosis. Functional experiments confirmed that overexpression of FTO suppressed cell proliferation, mitosis, epithelial-mesenchymal transition (EMT), tumorigenesis and lung metastasis both in vitro and in vivo. The following mechanical experiments verified that FTO stabilized miR-139-5p to increase its expression levels in a m6A-dependent manner, and elevated miR-139-5p induced degradation of ZNF217 through binding to ZNF217 mRNA, resulting in the inactivation of the PI3K/Akt/mTOR signal pathway. Finally, our rescuing experiments confirmed that overexpressed FTO-induced tumor-suppressing effects on PC cells were abrogated by miR-139-5p ablation and ZNF217 overexpression. Collectively, this study firstly validated that FTO exerted its anti-tumor effects in PC through regulating the miR-139-5p/ZNF217 axis in a m6A-dependent manner, providing novel biomarkers for the advancement of anti-cancer agents for PC treatment.

Effects of Helicobacter pylori on the expression of the FTO gene and its biological role in gastric cancer

Helicobacter pylori (Hp) is a primary risk factor for gastric cancer. The fat mass and obesity-associated (FTO) gene is associated with the development and progression of various cancer types such as glioma, leukemia, breast cancer and colorectal cancer. The aim of the present study was to investigate the effect of Hp infection on the expression of FTO and its roles in gastric cancer. It was found that the expression levels of both FTO mRNA and protein were significantly increased in Hp-infected human gastric mucosal epithelial cells and Mongolian gerbil gastric tissues. The expression of FTO in gastric cancer tissues was higher than that in para-cancer tissues. Data from The Cancer Genome Atlas demonstrated that FTO expression in gastric cancer tissues was significantly higher than that in normal tissues. Patient survival rate was significantly decreased in patients with high expression levels of FTO. It was also demonstrated that FTO expression was associated with several pathological parameters, such as tumor stage, metastasis stage and the American Joint Committee on Cancer stage. The FTO gene was positively correlated with 16,601 genes in gastric cancer and negatively correlated with 3,623 genes. Gene Ontology enrichment analysis demonstrated that FTO was significantly enriched in the regulation of gene expression and oxidative RNA demethylase activity, and it was associated with components such as the RNA N6-methyladenosine methyltransferase complex and nuclear speckle. In addition, knockdown of the FTO gene inhibited the migration and invasion of Hp-infected cells. In conclusion, the data suggests that Hp infection leads to upregulation of the FTO gene, which may be related to patient survival rate, tumor staging and other pathological parameters of patients with gastric cancer. It also suggests that FTO promotes proliferation and migration of gastric cancer cells, which may be involved in the pathogenesis of Hp-induced gastric cancer.

The role of RNA methyltransferase METTL3 in gynecologic cancers: Results and mechanisms

N6-methyladenosine (m6A) methylation is the most prevalent mRNA modification in eukaryotes, and it is defined as the methylation of nitrogen atoms on the six adenine (A) bases of RNA in the presence of methyltransferases. Methyltransferase-like 3 (Mettl3), one of the components of m6A methyltransferase, plays a decisive catalytic role in m6A methylation. Recent studies have confirmed that m6A is associated with a wide spectrum of biological processes and it significantly affects disease progression and prognosis of patients with gynecologic tumors, in which the role of Mettl3 cannot be ignored. Mettl3 is involved in numerous pathophysiological functions, such as embryonic development, fat accumulation, and tumor progression. Moreover, Mettl3 may serve as a potential target for treating gynecologic malignancies, thus, it may benefit the patients and prolong survival. However, there is a need to further study the role and mechanism of Mettl3 in gynecologic malignancies. This paper reviews the recent progression on Mettl3 in gynecologic malignancies, hoping to provide a reference for further research.

The role of demethylase AlkB homologs in cancer

The AlkB family (ALKBH1-8 and FTO), a member of the Fe (II)- and α-ketoglutarate-dependent dioxygenase superfamily, has shown the ability to catalyze the demethylation of a variety of substrates, including DNA, RNA, and histones. Methylation is one of the natural organisms’ most prevalent forms of epigenetic modifications. Methylation and demethylation processes on genetic material regulate gene transcription and expression. A wide variety of enzymes are involved in these processes. The methylation levels of DNA, RNA, and histones are highly conserved. Stable methylation levels at different stages can coordinate the regulation of gene expression, DNA repair, and DNA replication. Dynamic methylation changes are essential for the abilities of cell growth, differentiation, and division. In some malignancies, the methylation of DNA, RNA, and histones is frequently altered. To date, nine AlkB homologs as demethylases have been identified in numerous cancers’ biological processes. In this review, we summarize the latest advances in the research of the structures, enzymatic activities, and substrates of the AlkB homologs and the role of these nine homologs as demethylases in cancer genesis, progression, metastasis, and invasion. We provide some new directions for the AlkB homologs in cancer research. In addition, the AlkB family is expected to be a new target for tumor diagnosis and treatment.

N6-methyladenosine reader YTHDF family in biological processes: Structures, roles, and mechanisms

As the most abundant and conserved internal modification in eukaryote RNAs, N6-methyladenosine (m6A) is involved in a wide range of physiological and pathological processes. The YT521-B homology (YTH) domain-containing family proteins (YTHDFs), including YTHDF1, YTHDF2, and YTHDF3, are a class of cytoplasmic m6A-binding proteins defined by the vertebrate YTH domain, and exert extensive functions in regulating RNA destiny. Distinct expression patterns of the YTHDF family in specific cell types or developmental stages result in prominent differences in multiple biological processes, such as embryonic development, stem cell fate, fat metabolism, neuromodulation, cardiovascular effect, infection, immunity, and tumorigenesis. The YTHDF family mediates tumor proliferation, metastasis, metabolism, drug resistance, and immunity, and possesses the potential of predictive and therapeutic biomarkers. Here, we mainly summary the structures, roles, and mechanisms of the YTHDF family in physiological and pathological processes, especially in multiple cancers, as well as their current limitations and future considerations. This will provide novel angles for deciphering m6A regulation in a biological system.

Emerging role of mRNA methylation in regulating the hallmarks of cancer

The dynamic chemical modifications of DNA, RNA, and proteins can transform normal cells into malignant ones. While the DNA and protein modifications in cancer have been described extensively in the literature, there are fewer reports about the role of RNA modifications in cancer. There are over 100 forms of RNA modifications and one of these, mRNA methylation, plays a critical role in the malignant properties of the cells. mRNA methylation is a reversible modification responsible for regulating protein expression at the post-transcriptional level. Despite being discovered in the 1970s, a complete understanding of the different proteins involved and the mechanism behind mRNA methylation remains largely unknown. However, these mRNA methylations have been shown to foster cancer hallmarks via specific cellular targets inside the cell. In this review, we provide a brief overview of mRNA methylation and its emerging role in regulating the various hallmarks of cancer.

Long intergenic non-protein coding RNA 00858 participates in the occurrence and development of esophageal squamous cell carcinoma through the activation of the FTO-m6A-MYC axis by recruiting ZNF184

OBJECTIVES

We aimed at probing impact of LINC00858 on esophageal squamous cell carcinoma (ESCC) progression via ZNF184-FTO-m⁶A-MYC axis.

METHODS

Expression of related genes (LINC00858, ZNF184, FTO, and MYC) was detected in ESCC tissues or cells and their relationships were assessed. After expression alterations in ESCC cells, cell proliferation, invasion, migration, and apoptosis were detected. Tumor formation in nude mice was conducted.

RESULTS

LINC00858, ZNF184, FTO, and MYC were overexpressed in ESCC tissues and cells. LINC00858 enhanced ZNF184 expression to upregulate FTO, which augmented MYC expression. LINC00858 knockdown diminished ESCC cell proliferative, migratory, and invasive properties while elevating apoptosis, which was negated by FTO overexpression. FTO knockdown exerted similar functions of LINC00858 knockdown on ESCC cell movements, which was annulled by MYC upregulation. Silencing LINC00858 repressed tumor growth and related gene expression in nude mice.

CONCLUSIONS

LINC00858 modulated MYC m⁶A modification via FTO by recruiting ZNF184, thus facilitating ESCC progression.

Role of m6A modification in dysregulation of Wnt/β-catenin pathway in cancer

N6-methyladenosine (m⁶A) modification is the most abundant post-transcriptional regulation of RNAs in eukaryotes. Dysregulation of m⁶A readers, writers, and erasers can significantly promote tumorigenesis by altering the expression of various genes. Wnt/β-catenin is an evolutionarily conserved signaling pathway that has recently been linked to the pathogenesis of many cancers. Given the significance of this pathway in regulating normal tissue homeostasis and stem cell differentiation, a subtle understanding of the molecular mechanism underlying its dysregulation is required for effective targeting. There is mounting evidence that m⁶A regulators are highly implicated in the dysregulation of the Wnt/β-catenin signaling pathway. Since m⁶A regulators can affect Wnt pathway components and dysregulation of either leads to carcinogenesis, this study aims to clarify the relationship between m⁶A regulators and the Wnt/β-catenin signaling pathway to investigate their combined impact on tumorigenesis.

Roles and therapeutic implications of m6A modification in cancer immunotherapy

Recent studies have demonstrated that N6-methyladenosine (m6A), the most abundant, dynamic, and reversible epigenetic RNA modification in eukaryotes, is regulated by a series of enzymes, including methyltransferases (writers), demethylases (erasers), and m6A recognition proteins (readers). Aberrant regulation of m6A modification is pivotal for tumorigenesis, progression, invasion, metastasis, and apoptosis of malignant tumors. Immune checkpoint inhibitors (ICIs) has revolutionized cancer treatment, as recognized by the 2018 Nobel Prize in Medicine and Physiology. However, not all cancer patients response to ICI therapy, which is thought to be the result of intricate immune escape mechanisms. Recently, numerous studies have suggested a novel role for m6A epigenetic modification in the regulation of tumor immune evasion. Herein, we review the relevant mechanisms of m6A regulators in regulating various key signaling pathways in cancer biology and how m6A epigenetic modifications regulate the expression of immune checkpoints, opening a new window to understand the roles and mechanisms of m6A epigenetic modifications in regulating tumor immune evasion. In addition, we highlight the prospects and development directions of future combined immunotherapy strategies based on m6A modification targeting, providing directions for promoting the treatment outcomes of immune checkpoint inhibitors.

Proteomics analysis of meclofenamic acid‐treated small cell lung carcinoma cells revealed changes in cellular energy metabolism for cancer cell survival

Small cell lung carcinoma (SCLC) is a highly aggressive cancer with low survival rate. Although initial response to chemotherapy in SCLC patients is well-rated, the treatments applied after the disease relapses are not successful. Drug resistance is accepted to be one of the main reasons for this failure. Therefore, there is an urgent need for new treatment strategies for SCLC. Meclofenamic acid, a nonsteroidal anti-inflammatory drug, has been shown to have anticancer effects on various types of cancers via different mechanisms. The aim of this study was to investigate the alterations that meclofenamic acid caused on a SCLC cell line, DMS114 using the tools of proteomics namely two-dimensional gel electrophoresis coupled to MALDI-TOF/TOF and nHPLC coupled to LC-MS/MS. Among the proteins identified by both methods, those showing significantly altered expression levels were evaluated using bioinformatics databases, PANTHER and STRING. The key altered metabolism upon meclofenamic acid treatment appeared to the cellular energy metabolism. Glycolysis was suppressed, whereas mitochondrial activity and oxidative phosphorylation were boosted. The cells underwent metabolic reprogramming to adapt into their new environment for survival. Metabolic reprogramming is known to cause drug resistance in several cancer types including SCLC. The identified differentially regulated proteins in here associated with energy metabolism hold value as the potential targets to overcome drug resistance in SCLC treatment.

Roles of N6-methyladenosine (m6A) modifications in gynecologic cancers: mechanisms and therapeutic targeting

Uterine and ovarian cancers are the most common gynecologic cancers. N6−methyladenosine (m6A), an important internal RNA modification in higher eukaryotes, has recently become a hot topic in epigenetic studies. Numerous studies have revealed that the m6A-related regulatory factors regulate the occurrence and metastasis of tumors and drug resistance through various mechanisms. The m6A-related regulatory factors can also be used as therapeutic targets and biomarkers for the early diagnosis of cancers, including gynecologic cancers. This review discusses the role of m6A in gynecologic cancers and summarizes the recent advancements in m6A modification in gynecologic cancers to improve the understanding of the occurrence, diagnosis, treatment, and prognosis of gynecologic cancers.

The controversial role and therapeutic development of the m6A demethylase FTO in renal cell carcinoma

Fat mass and obesity-associated (FTO) protein, the first m6A demethylase identified in 2011, regulates multiple aspects of RNA biology including splicing, localization, stability, and translation. Accumulating data show that FTO is involved in numerous physiological processes and is implicated in multiple cancers including renal cell carcinoma (RCC). However, the exact role of FTO in RCC remains controversial. Some studies demonstrated that decreased FTO expression was associated with aggressive clinical features and shorter overall survival in clear cell RCC (ccRCC) patients, while others found that FTO inhibition selectively reduced the growth and survival of VHL-deficient ccRCC cells in vitro and in vivo. Here, we review the evidence supporting either a promoting or suppressive role of FTO in kidney cancers, the mechanisms of action of FTO, and recent progress in developing FTO inhibitors.

WTAP promotes oesophageal squamous cell carcinoma development by decreasing CPSF4 expression in an m6A-dependent manner

m⁶A is a widespread RNA modification. However, the mechanism through which m⁶A regulated the progress of oesophageal squamous cell carcinoma (ESCC) remains undetermined. The levels and prognosis of WTAP were analysed using an ESCC tissue microarray (87 ESCC and 44 paracancerous tissues). TCGA and Oncolnc databases validate WTAP expression and prognosis. CCK8, colony formation (CF), wound healing, transwell cell invasion (CI), and migration (CM) assays were employed for the detection of the biological impacts of WTAP. Expression of tumour stemness-related genes was assessed via qRT-PCR and western blotting. The m⁶A RNA methylation (m⁶AMe) quantitative kit was employed for cellular methylation level detection. Arraystar m⁶A-mRNA and lncRNA epitranscriptomic microarray analyses were used to screen low methylation, high expression, and prognosis-related candidate gene CPSF4. KEGG enrichment analysis was used to screen the downstream signalling pathways of CPSF4. WTAP, a methyltransferase "writer", was markedly enhanced in ESCC and was strongly correlated with poor patient outcome. WTAP knockdown inhibited the cell proliferation (CP), CI, CM, and stemness of ESCC cells in vitro and reduced the overall m⁶A modification (m⁶AMo) percentage of ESCC cells. CPSF4 is a target of WTAP-based m⁶AMo. WTAP-based m⁶AMo of CPSF4 transcript reduced the stability of CPSF4 by relying on YTHDF2. We identified the significant role of WTAP-catalysed m⁶AMo in ESCC tumourigenesis, wherein it facilitates ESCC tumour growth and metastasis through decreasing CPSF4 expression in an m⁶A-dependent manner.

FTO promotes clear cell renal cell carcinoma progression via upregulation of PDK1 through an m6A dependent pathway

FTO, as an m⁶A mRNA demethylase, is involved in various cancers. However, the role of FTO in clear cell renal cell carcinoma (ccRCC) remains unclear. In the present study, we discovered FTO is upregulated in ccRCC. Functionally, knockdown of FTO significantly impairs the proliferation and migration ability of ccRCC cells. Mechanistically, our data suggest FTO promotes the proliferation and migration of ccRCC through preventing degradation of PDK1 mRNA induced by YTHDF2 in an m⁶A-dependent mechanism. Overall, our results identify the protumorigenic role of FTO through the m⁶A/YTHDF2/PDK1 pathway, which could be a promising therapeutic target for ccRCC.

Role of m6A writers, erasers and readers in cancer

The N(6)-methyladenosine (m6A) modification is the most pervasive modification of human RNAs. In recent years, an increasing number of studies have suggested that m6A likely plays important roles in cancers. Many studies have demonstrated that m6A is involved in the biological functions of cancer cells, such as proliferation, invasion, metastasis, and drug resistance. In addition, m6A is closely related to the prognosis of cancer patients. In this review, we highlight recent advances in understanding the function of m6A in various cancers. We emphasize the importance of m6A to cancer progression and look forward to describe future research directions.

Upregulated keratin 15 links to the occurrence of lymphovascular invasion, stromal cervical invasion as well as unfavorable survival profile in endometrial cancer patients

Keratin 15 (KRT15) overexpression links with tumor initiation, metastasis, and poor survival in several solid carcinomas. While its clinical relevance is scarcely reported in endometrial cancer (EC). Therefore, the current study aimed to investigate the abnormal expression of KRT15 and its correlation with clinical characteristics, survival in EC patients. Totally, 135 surgical EC patients were enrolled. KRT15 protein expression in formalin-fixed and paraffin-embedded tumor and adjuvant tissues was detected by immunohistochemical staining; meanwhile, KRT15 mRNA expression in fresh-frozen tumor and adjacent tissues was detected by reverse transcription-quantitative polymerase chain reaction. KRT15 protein and mRNA expressions were higher in tumor tissue compared with adjacent tissue (both P < .001). Elevated KRT15 protein expression was correlated with the occurrence of lymphovascular invasion (P = .010) and more advanced International Federation of Gynecology and Obstetrics stage (P = .018); meanwhile, elevated KRT15 mRNA expression was linked with more advanced International Federation of Gynecology and Obstetrics stage (P = .038) and marginally associated with the occurrence of stromal cervical invasion (P = .052). Besides, KRT15 protein and mRNA expressions were not correlated with other clinical features (all P > .05). KRT15 protein high was marginally correlated with poor accumulating disease-free survival (DFS) (P = .091) and overall survival (OS) (P = .059); meanwhile, the correlation of KRT15 mRNA expression with accumulating DFS (P = .212) and OS (P = .092) was even weaker. However, multivariate Cox's regressions showed that tumor KRT15 protein (high vs low) was independently correlated with poor DFS (P = .045) and OS (P = .043). KRT15 is abnormally increased in EC tissue, meanwhile, its upregulation links to the occurrence of lymphovascular invasion, stromal cervical invasion, and poor prognosis in EC patients.

N6-methyladenosine (m6A) modification in gynecological malignancies

N6-methyladenosine (m6A) modification is one of the most abundant modifications in eukaryotic mRNA, regulated by m6A methyltransferase and demethylase. m6A modified RNA is specifically recognized and bound by m6A recognition proteins, which mediate splicing, maturation, exonucleation, degradation, and translation. In gynecologic malignancies, m6A RNA modification-related molecules are expressed aberrantly, significantly altering the posttranscriptional methylation level of the target genes and their stability. The m6A modification also regulates related metabolic pathways, thereby controlling tumor development. This review analyzes the composition and mode of action of m6A modification-related proteins and their biological functions in the malignant progression of gynecologic malignancies, which provide new ideas for the early clinical diagnosis and targeted therapy of gynecologic malignancies.

Comprehensive immunohistochemical analysis of N6-methyladenosine (m6A) writers, erasers, and readers in endometrial cancer

PURPOSE

N6-methyladenosine (m6A) is the most frequent type of messenger RNA (mRNA) modification and is implicated in diverse physiological processes. The procedure of m6A RNA modification is regulated by a dynamic interaction of writers (METTL3, METTL4, METTL14, WTAP, KIAA1429), erasers (FTO, ALKBH5), and readers (HNRNPA2B1, HNRNPC, YTHDC1, YTHDC1, YTHDF1-3). In the oncological context, alterations in m6A were identified to be critically involved in tumorigenesis, proliferation, angiogenesis, and drug resistance across diverse cancer entities including endometrial cancer (EC).

METHODS

In this study, we comprehensively examined the protein expression of m6A writers, readers and erasers by immunohistochemical staining in a cohort of N = 65 EC patients. Protein expression data were analyzed with regard to clinical outcomes.

RESULTS

We identified enhanced protein expression levels of METTL3, METTL14, FTO, HNRNPA2B1, and HNRNPC, respectively to be of prognostic value and linked to a shortened overall survival in EC.

CONCLUSION

Overall, our study points toward dysregulated m6A modification in EC and its possibility to serve as a promising prognostic biomarker.

Progress Toward a Multiomic Understanding of Traumatic Brain Injury: A Review

Traumatic brain injury (TBI) is not a single disease state but describes an array of conditions associated with insult or injury to the brain. While some individuals with TBI recover within a few days or months, others present with persistent symptoms that can cause disability, neuropsychological trauma, and even death. Understanding, diagnosing, and treating TBI is extremely complex for many reasons, including the variable biomechanics of head impact, differences in severity and location of injury, and individual patient characteristics. Because of these confounding factors, the development of reliable diagnostics and targeted treatments for brain injury remains elusive. We argue that the development of effective diagnostic and therapeutic strategies for TBI requires a deep understanding of human neurophysiology at the molecular level and that the framework of multiomics may provide some effective solutions for the diagnosis and treatment of this challenging condition. To this end, we present here a comprehensive review of TBI biomarker candidates from across the multiomic disciplines and compare them with known signatures associated with other neuropsychological conditions, including Alzheimer’s disease and Parkinson’s disease. We believe that this integrated view will facilitate a deeper understanding of the pathophysiology of TBI and its potential links to other neurological diseases.

The Potential Value of m6A RNA Methylation in the Development of Cancers Focus on Malignant Glioma

N6-methyladenosine (m6A) RNA methylation is an epigenetic modification that has emerged in the last few years and has received increasing attention as the most abundant internal RNA modification in eukaryotic cells. m6A modifications affect multiple aspects of RNA metabolism, and m6A methylation has been shown to play a critical role in the progression of multiple cancers through a variety of mechanisms. This review summarizes the mechanisms by which m6A RNA methylation induced peripheral cancer cell progression and its potential role in the infiltration of immune cell of the glioblastoma microenvironment and novel immunotherapy. Assessing the pattern of m6A modification in glioblastoma will contribute to improving our understanding of microenvironmental infiltration and novel immunotherapies, and help in developing immunotherapeutic strategies.

Recent Advances of m6A Demethylases Inhibitors and Their Biological Functions in Human Diseases

N6-methyladenosine (m6A) is a post-transcriptional RNA modification and one of the most abundant types of RNA chemical modifications. m6A functions as a molecular switch and is involved in a range of biomedical aspects, including cardiovascular diseases, the central nervous system, and cancers. Conceptually, m6A methylation can be dynamically and reversibly modulated by RNA methylation regulatory proteins, resulting in diverse fates of mRNAs. This review focuses on m6A demethylases fat-mass- and obesity-associated protein (FTO) and alkB homolog 5 (ALKBH5), which especially erase m6A modification from target mRNAs. Recent advances have highlighted that FTO and ALKBH5 play an oncogenic role in various cancers, such as acute myeloid leukemias (AML), glioblastoma, and breast cancer. Moreover, studies in vitro and in mouse models confirmed that FTO-specific inhibitors exhibited anti-tumor effects in several cancers. Accumulating evidence has suggested the possibility of FTO and ALKBH5 as therapeutic targets for specific diseases. In this review, we aim to illustrate the structural properties of these two m6A demethylases and the development of their specific inhibitors. Additionally, this review will summarize the biological functions of these two m6A demethylases in various types of cancers and other human diseases.

An m6A-Related lncRNA Signature Predicts the Prognosis of Hepatocellular Carcinoma

Objective: The purpose of this study was to establish an N6-methylandenosine (m6A)-related long non-coding RNA (lncRNA) signature to predict the prognosis of hepatocellular carcinoma (HCC).

Methods: Pearson correlation analysis was used to identify m6A-related lncRNAs. We then performed univariate Cox regression analysis and least absolute shrinkage and selection operator (LASSO) Cox regression analysis to construct an m6A-related lncRNA signature. Based on the cutoff value of the risk score determined by the X-title software, we divided the HCC patients into high -and low-risk groups. A time-dependent ROC curve was used to evaluate the predictive value of the model. Finally, we constructed a nomogram based on the m6A-related lncRNA signature.

Results: ZEB1-AS1, MIR210HG, BACE1-AS, and SNHG3 were identified to comprise an m6A-related lncRNA signature. These four lncRNAs were upregulated in HCC tissues compared to normal tissues. The prognosis of patients with HCC in the low-risk group was significantly longer than that in the high-risk group. The M6A-related lncRNA signature was significantly associated with clinicopathological features and was established as a risk factor for the prognosis of patients with HCC. The nomogram based on the m6A-related lncRNA signature had a good distinguishing ability and consistency.

Conclusion: We identified an m6A-related lncRNA signature and constructed a nomogram model to evaluate the prognosis of patients with HCC.

FTO m6A Demethylase in Obesity and Cancer: Implications and Underlying Molecular Mechanisms

Fat mass and obesity-associated protein (FTO) is the first reported RNA N6-methyladenosine (m6A) demethylase in eukaryotic cells. m6A is considered as the most abundant mRNA internal modification, which modulates several cellular processes including alternative splicing, stability, and expression. Genome-wide association studies (GWAS) identified single-nucleotide polymorphisms (SNPs) within FTO to be associated with obesity, as well as cancer including endometrial cancer, breast cancer, pancreatic cancer, and melanoma. Since the initial classification of FTO as an m6A demethylase, various studies started to unravel a connection between FTO’s demethylase activity and the susceptibility to obesity on the molecular level. FTO was found to facilitate adipogenesis, by regulating adipogenic pathways and inducing pre-adipocyte differentiation. FTO has also been investigated in tumorigenesis, where emerging studies suggest m6A and FTO levels are dysregulated in various cancers, including acute myeloid leukemia (AML), glioblastoma, cervical squamous cell carcinoma (CSCC), breast cancer, and melanoma. Here we review the molecular bases of m6A in tumorigenesis and adipogenesis while highlighting the controversial role of FTO in obesity. We provide recent findings confirming FTO’s causative link to obesity and discuss novel approaches using RNA demethylase inhibitors as targeted oncotherapies. Our review aims to confirm m6A demethylation as a risk factor in obesity and provoke new research in FTO and human disorders.

Insight into the structure, physiological function, and role in cancer of m6A readers—YTH domain-containing proteins

YT521-B homology (YTH) domain-containing proteins (YTHDF1-3, YTHDC1-2) are the most crucial part of N6-methyladenosine (m6A) readers and play a regulatory role in almost all stages of methylated RNA metabolism and the progression of various cancers. Since m6A is identified as an essential post-transcriptional type, YTH domain-containing proteins have played a key role in the m6A sites of RNA. Hence, it is of great significance to study the interaction between YTH family proteins and m6A-modified RNA metabolism and tumor. In this review, their basic structure and physical functions in RNA transcription, splicing, exporting, stability, and degradation as well as protein translation are introduced. Then we discussed the expression regulation of YTH domain-containing proteins in cancers. Furthermore, we introduced the role of the YTH family in cancer biology and systematically demonstrated their functions in various aspects of tumorigenesis and development. To provide a more institute understanding of the role of YTH family proteins in cancers, we summarized their functions and specific mechanisms in various cancer types and presented their involvement in cancer-related signaling pathways.

FTO in cancer: functions, molecular mechanisms, and therapeutic implications

N⁶-methyladenosine (m⁶A) is the most abundant internal modification in mRNA that affects RNA processing, stability, and translation. Discovered as the first RNA m⁶A demethylase, the fat mass and obesity-associated protein (FTO) is frequently dysregulated and plays important roles in various types of cancers. Targeting FTO holds promising therapeutic significance via suppressing tumor growth, potentiating immunotherapy, and attenuating drug resistance. Here, we review recent advances in our understanding of the functions and underlying molecular mechanisms of FTO in tumor development, cancer stem cell (CSC) self-renewal, microenvironment regulation, immunity, and metabolism and discuss the therapeutic potential of targeting FTO for cancer treatment.

Oxycodone Alleviates Endometrial Injury via the TLR4/NF-κB Pathway

Endometrial injury is a common female disease. This study was designed to illustrate the effects of oxycodone on mifepristone-induced human endometrial stromal cells (hEndoSCs) injury and delineate the underlying molecular mechanism. hEndoSCs were stimulated with mifepristone to generate the endometrial injury in vitro model. hEndoSCs viability, cytotoxicity, and apoptosis were measured by methyl thiazolyl tetrazolium (MTT) assay, lactate dehydrogenase assay (LDH), and flow cytometry (FCM) analysis, respectively. Meanwhile, quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blot assay were conducted to evaluate gene and protein expressions. The secretions of inflammatory cytokines (TNF-α, IL-1β, and IL-6) were measured using enzyme-linked immunosorbent assay (ELISA). The data revealed that mifepristone exposure memorably inhibited hEndoSCs viability and promoted cell apoptosis and inflammatory cytokines secretion, and oxycodone had no cytotoxicity on hEndoSCs. Oxycodone increased hEndoSCs growth, blocked cell apoptosis, enhanced Bcl-2 expression, reduced Bax levels, and decreased the secretion of inflammatory cytokines in mifepristone-induced hEndoSCs, exhibiting the protective effects in endometrial injury. In addition, the TLR4/NF-κB pathway-related protein levels (TLR4 and p-p65) in mifepristone-treated hEndoSCs were enhanced, while these enhancements were inhibited by oxycodone treatment. In conclusion, oxycodone exhibited the protective role in mifepristone-triggered endometrial injury via inhibiting the TLR4/NF-κB signal pathway.

Methylation recognition protein YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) regulates the proliferation, migration and invasion of osteosarcoma by regulating m6A level of CCR4-NOT transcription complex subunit 7 (CNOT7)

N6-methyladenosine (m6A) is one of the most significant modifications in human mRNAs. Emerging evidence indicates that m6A participates in the initiation and development of malignant tumors. Nevertheless, the biological roles and mechanism of m6A in osteosarcoma (OS) remain unclear. The purpose of this study was to investigate the role and mechanism of the methylation recognition protein-YTH N6-methyladenosine RNA binding protein 1 (YTHDF1) in OS. The YTHDF1 expression in OS was detected by qRT-PCR and Western blot assay. M6A quantification was utilized to measure the methylation level of OS. Cell counting kit-8 (CCK8), 5-Ethynyl-2’-deoxyuridine (EdU) assay and transwell experiments were conducted to confirm the biological effects of YTHDF1 on OS cells. The bioinformatics websites and in vitro assays were conducted to analyze the downstream targets of YTHDF1 was upregulated in OS tissues at mRNA and protein level. The results showed that the expression level of YTHDF1 might be closely associated with the poor prognosis for OS patients. Inhibition of YTHDF1 could suppress the proliferation, migration and invasion of the OS cells. Moreover, we found that CCR4-NOT transcription complex subunit 7 (CNOT7) might be the potential target of YTHDF1, which was upregulated in OS tissues. YTHDF1 could recognize the m6A sites of CONT7 and promote its expression in an m6A manner. Moreover, methyltransferase-like 3 (METTL3) could promote the m6A level of CONT7. YTHDF1 was upregulated in OS and could promote cell proliferation, migration and invasion. The METTL3-CONT7-YTHDF1 regulatory axis might be the potential target for the prognosis and therapy of OS.

Emerging Roles of m6A RNA Methylation Regulators in Gynecological Cancer

Gynecological cancers seriously affect the reproductive system of females; diseases include ovarian tumors, uterine tumors, endometrial cancers, cervical cancers, and vulva and vaginal tumors. At present, the diagnosis methods of gynecological cancer are insufficiently sensitive and specific, leading to failure of early disease detection. N⁶-methyladenosine (m⁶A) plays various biological functions in RNA modification and is currently studied extensively. m⁶A modification controls the fate of transcripts and regulates RNA metabolism and biological processes through the interaction of m⁶A methyltransferase (“writer”) and demethylase (“erasers”) and the binding protein decoding m⁶A methylation (“readers”). In the field of epigenetics, m⁶A modification is a dynamic process of reversible regulation of target RNA through its regulatory factors. It plays an important role in many diseases, especially cancer. However, its role in gynecologic cancers has not been fully investigated. Thus, we review the regulatory mechanism, biological functions, and therapeutic prospects of m⁶A RNA methylation regulators in gynecological cancers.

FTO promotes Bortezomib resistance via m6A-dependent destabilization of SOD2 expression in multiple myeloma

Drug resistance is the main reason for the failure of Bortezomib (Bort) in the treatment of multiple myeloma (MM), which seriously affects the efficacy of Bort. Therefore, the exploration of Bort resistance to treat MM will be very beneficial. Thus, this study aims to study the function and mechanism of Fat mass and obesity associated (FTO) on the Bort resistance of MM. In the present study, we demonstrated that FTO promotes Bort resistance via m6A-dependent destabilization of SOD2 expression in MM. These findings may provide a substantial evidence for the Bort resistance in MM.

Characterization of m6A Regulator-Mediated Methylation Modification Patterns and Tumor Microenvironment Infiltration in Ovarian Cancer

Introduction: Studies have demonstrated the epigenetic regulation of immune responses in various cancers. However, little is known about the RNA N6-methyladenosine (m6A) modification patterns of the microenvironment (TME) cell infiltration in ovarian cancer (OC). Methods: We evaluated the correlation between m6A modification patterns and TME cell infiltration based on 459 OC samples from the Cancer Genome Atlas and Gene-Expression Omnibus database. We constructed an m6Ascore system to quantify m6A modification patterns using principal component analysis. Results: Based on unsupervised clustering, three m6A modification patterns were identified. Gene set variation analysis showed that the antigen presentation signal pathway, the NOTCH signaling pathway, and the metabolism-related pathway differed significantly across m6A modificaiton patterns. The m6Ascore is closely correlated with TME cell infiltration. OC patients with lower m6Ascores had worse outcomes. There was better risk stratification with combined m6Ascore and tumor mutation burden. The responses to immune checkpoint inhibitor treatment significantly differed between high and low m6Ascore groups. Conclusion: M6A modification plays an essential role in TME cell infiltration in OC. Evaluating the m6A modification patterns in OC patients could enhance our understanding of TME infiltration characterization and guide immunotherapy strategies.

Downstream of the HOX genes: explaining conflicting tumour suppressor and oncogenic functions in cancer

The HOX genes are a highly conserved group of transcription factors that have key roles in early development, but which are also highly expressed in most cancers. Many studies have found strong associative relationships between the expression of individual HOX genes in tumours and clinical parameters including survival. For the majority of HOX genes, high tumour expression levels seem to be associated with a worse outcome for patients, and in some cases this has been shown to result from the activation of pro-oncogenic genes and pathways. However, there are also many studies that indicate a tumour suppressor role for some HOX genes, sometimes with conclusions that contradict earlier work. In this review, we have attempted to clarify the role of HOX genes in cancer by focusing on their downstream targets as identified in studies that provide experimental evidence for their activation or repression. On this basis, the majority of HOX genes would appear to have a pro-oncogenic function, with the notable exception of HOXD10, which acts exclusively as a tumour suppressor. HOX proteins regulate a wide range of target genes involved in metastasis, cell death, proliferation, and angiogenesis, and activate key cell signalling pathways. Furthermore, for some functionally related targets, this regulation is achieved by a relatively small subgroup of HOX genes.