Sleep deprivation and false confessions

Hypoxic stabilization of RIPOR3 mRNA via METTL3-mediated m6A methylation drives breast cancer progression and metastasis

Dysregulated N6-methyladenosine (m6A) modification has been associated with breast cancer pathogenesis. Hypoxia which characterizes solid tumors is known to reprogram the m6A epitranscriptome, but the underlying mechanisms of how this process contributes to breast cancer progression remain poorly understood. Through integrative analyses of m6A-RIP sequencing and RNA sequencing databases, we reveal a cluster of mRNAs with upregulated m6A methylation and expression under hypoxia, that are enriched by many oncogenic pathways, including PI3K-Akt signaling. Furthermore, we identify the mRNA, RIPOR3, as a target of METTL3-mediated m6A methylation in response to hypoxia. We find that m6A methylation stabilizes RIPOR3, increasing its protein expression in a METTL3 catalytic activity-dependent manner, and consequently driving breast tumor growth and metastasis. RIPOR3 is found to be overexpressed in breast cancer cell lines and tumor tissues from breast cancer patients, in whom elevated RIPOR3 is associated with a worse prognosis. Mechanistically, we show that RIPOR3 interacts with EGFR and is essential for the PI3K-Akt pathway activation. In conclusion, we identify RIPOR3 as a hypoxia-stabilized oncogenic driver via METTL3-mediated m6A methylation, thus provide a potential therapeutic target for breast cancer.

In situ bioorthogonal-modulation of m6A RNA methylation in macrophages for efficient eradication of intracellular bacteria

N6-Methyladenosine (m6A) methylation plays a critical role in controlling the RNA fate. Emerging evidence has demonstrated that aberrant m6A methylation in immune cells such as macrophages could alter cell homeostasis and function, which can be a promising target for disease treatment. Despite tremendous progress in regulating the level of m6A methylation, the current methods suffer from the time-consuming operation and annoying off-target effect, which hampers the in situ manipulation of m6A methylation. Here, a bioorthogonal in situ modulation strategy of m6A methylation was proposed. Well-designed covalent organic framework (COF) dots (CIDM) could deprotect the agonist prodrug of m6A methyltransferase, resulting in a considerable hypermethylation of m6A modification. Simultaneously, the bioorthogonal catalyst CIDM showed oxidase (OXD)-mimic activity that further promoted the level of m6A methylation. Ultimately, the potential therapeutic effect of bioorthogonal controllable regulation of m6A methylation was demonstrated through intracellular bacteria eradication. The remarkable antimicrobial outcomes indicate that upregulating m6A methylation in macrophages could reprogram them into the M1 phenotype with high bactericidal activity. We believe that our bioorthogonal chemistry-controlled epigenetics regulatory strategy will provide a unique insight into the development of controllable m6A methylation.

Progression of m6A in the tumor microenvironment: hypoxia, immune and metabolic reprogramming

Recently, N6-methyladenosine (m6A) has aroused widespread discussion in the scientific community as a mode of RNA modification. m6A comprises writers, erasers, and readers, which regulates RNA production, nuclear export, and translation and is very important for human health. A large number of studies have found that the regulation of m6A is closely related to the occurrence and invasion of tumors, while the homeostasis and function of the tumor microenvironment (TME) determine the occurrence and development of tumors to some extent. TME is composed of a variety of immune cells (T cells, B cells, etc.) and nonimmune cells (tumor-associated mesenchymal stem cells (TA-MSCs), cancer-associated fibroblasts (CAFs), etc.). Current studies suggest that m6A is involved in regulating the function of various cells in the TME, thereby affecting tumor progression. In this manuscript, we present the composition of m6A and TME, the relationship between m6A methylation and characteristic changes in TME, the role of m6A methylation in TME, and potential therapeutic strategies to provide new perspectives for better treatment of tumors in clinical work.

Cancer stem cells: advances in knowledge and implications for cancer therapy

Cancer stem cells (CSCs), a small subset of cells in tumors that are characterized by self-renewal and continuous proliferation, lead to tumorigenesis, metastasis, and maintain tumor heterogeneity. Cancer continues to be a significant global disease burden. In the past, surgery, radiotherapy, and chemotherapy were the main cancer treatments. The technology of cancer treatments continues to develop and advance, and the emergence of targeted therapy, and immunotherapy provides more options for patients to a certain extent. However, the limitations of efficacy and treatment resistance are still inevitable. Our review begins with a brief introduction of the historical discoveries, original hypotheses, and pathways that regulate CSCs, such as WNT/β-Catenin, hedgehog, Notch, NF-κB, JAK/STAT, TGF-β, PI3K/AKT, PPAR pathway, and their crosstalk. We focus on the role of CSCs in various therapeutic outcomes and resistance, including how the treatments affect the content of CSCs and the alteration of related molecules, CSCs-mediated therapeutic resistance, and the clinical value of targeting CSCs in patients with refractory, progressed or advanced tumors. In summary, CSCs affect therapeutic efficacy, and the treatment method of targeting CSCs is still difficult to determine. Clarifying regulatory mechanisms and targeting biomarkers of CSCs is currently the mainstream idea.

ZFHX3 acts as a tumor suppressor in prostate cancer by targeting FTO-mediated m6A demethylation

Zinc-finger homeobox 3 (ZFHX3, also known as ATBF1) suppresses prostatic tumorigenesis. ZFHX3 is frequently found to have numerous deletions in human prostate cancer (PCa). However, the underlying molecular function of ZFHX3 during prostatic tumorigenesis is not well understood. N6-methyladenosine (m6A) modification in RNA plays a critical role in the development of cancers; however, the relationship between ZFHX3 and m6A modification is largely unknown in PCa. In this study, we found that ZFHX3 knockdown decreased total m6A levels through enhancing the transcriptional activity of FTO in PCa cells. Importantly, FTO inhibition suppressed cell proliferation and rescued the promoting function of ZFHX3 knockdown on cell proliferation. In vivo, we verified that FTO was upregulated and ZFHX3 was decreased in PCa patients and that a high level of ZFHX3 is indispensable for low FTO expression and is correlated with better patient survival. Through transcriptome sequencing and MeRIP sequencing, we revealed that E2F2 and CDKN2C were the direct targets of FTO-mediated m6A modification and ZFXH3 was required for the regulation of FTO on E2F2 and CDKN2C expression. Unexpectedly, we uncovered that ZFHX3 expression was in return regulated by FTO in an m6A-dependent way. These findings establish a novel crosstalk mechanism between ZFHX3 and FTO in prostatic tumorigenesis.

Medical malpractice litigation and daylight saving time

STUDY OBJECTIVES

Daylight saving time (DST) constitutes a natural quasi-experiment to examine the influence of mild sleep loss and circadian misalignment. We investigated the acute effects of spring transition into DST and the chronic effects of DST (compared to standard time) on medical malpractice claims in the United States over 3 decades.

METHODS

We analyzed 288,432 malpractice claims from the National Practitioner Data Bank. To investigate the acute effects of spring DST transition, we compared medical malpractice incidents/decisions 1 week before spring DST transition, 1 week following spring DST transition, and the rest of the year. To investigate the chronic effects of DST months, we compared medical malpractice incidents/decisions averaged across the 7-8 months of DST vs the 4-5 months of standard time.

RESULTS

With regard to acute effects, spring DST transitions were significantly associated with higher payment decisions but not associated with the severity of medical incidents. With regard to chronic effects, the 7-8 DST months were associated with higher average payments and worse severity of incidents than the 4-5 standard time months.

CONCLUSIONS

The mild sleep loss and circadian misalignment associated with DST may influence the incidence of medical errors and decisions on medical malpractice payments both acutely and chronically.

CITATION

Gao C, Lage C, Scullin MK. Medical malpractice litigation and daylight saving time. J Clin Sleep Med. 2024;20(6):933-940.

New horizons for the role of RNA N6-methyladenosine modification in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignancy, presenting a formidable challenge to the medical community owing to its intricate pathogenic mechanisms. Although current prevention, surveillance, early detection, diagnosis, and treatment have achieved some success in preventing HCC and controlling overall disease mortality, the imperative to explore novel treatment modalities for HCC remains increasingly urgent. Epigenetic modification has emerged as pivotal factors in the etiology of cancer. Among these, RNA N6-methyladenosine (m6A) modification stands out as one of the most prevalent, abundant, and evolutionarily conserved post-transcriptional alterations in eukaryotes. The literature underscores that the dynamic and reversible nature of m6A modifications orchestrates the intricate regulation of gene expression, thereby exerting a profound influence on cell destinies. Increasing evidence has substantiated conspicuous fluctuations in m6A modification levels throughout the progression of HCC. The deliberate modulation of m6A modification levels through molecular biology and pharmacological interventions has been demonstrated to exert a discernible impact on the pathogenesis of HCC. In this review, we elucidate the multifaceted biological functions of m6A modifications in HCC, and concurrently advancing novel therapeutic strategies for the management of this malignancy.

RNA m6A methylation and regulatory proteins in pulmonary arterial hypertension

m6A (N6‑methyladenosine) is the most common and abundant apparent modification in mRNA of eukaryotes. The modification of m6A is regulated dynamically and reversibly by methyltransferase (writer), demethylase (eraser), and binding protein (reader). It plays a significant role in various processes of mRNA metabolism, including regulation of transcription, maturation, translation, degradation, and stability. Pulmonary arterial hypertension (PAH) is a malignant cardiopulmonary vascular disease characterized by abnormal proliferation of pulmonary artery smooth muscle cells. Despite the existence of several effective and targeted therapies, there is currently no cure for PAH and the prognosis remains poor. Recent studies have highlighted the crucial role of m6A modification in cardiovascular diseases. Investigating the role of RNA m6A methylation in PAH could provide valuable insights for drug development. This review aims to explore the mechanism and function of m6A in the pathogenesis of PAH and discuss the potential targeting of RNA m6A methylation modification as a treatment for PAH.

LINC00115 promotes chemoresistant breast cancer stem-like cell stemness and metastasis through SETDB1/PLK3/HIF1α signaling

BACKGROUND

Cancer stem-like cell is a key barrier for therapeutic resistance and metastasis in various cancers, including breast cancer, yet the underlying mechanisms are still elusive. Through a genome-wide lncRNA expression profiling, we identified that LINC00115 is robustly upregulated in chemoresistant breast cancer stem-like cells (BCSCs).

METHODS

LncRNA microarray assay was performed to document abundance changes of lncRNAs in paclitaxel (PTX)-resistant MDA-MB-231 BCSC (ALDH+) and non-BCSC (ALDH-). RNA pull-down and RNA immunoprecipitation (RIP) assays were performed to determine the binding proteins of LINC00115. The clinical significance of the LINC00115 pathway was examined in TNBC metastatic lymph node tissues. The biological function of LINC00115 was investigated through gain- and loss-of-function studies. The molecular mechanism was explored through RNA sequencing, mass spectrometry, and the CRISPR/Cas9-knockout system. The therapeutic potential of LINC00115 was examined through xenograft animal models.

RESULTS

LINC00115 functions as a scaffold lncRNA to link SETDB1 and PLK3, leading to enhanced SETDB1 methylation of PLK3 at both K106 and K200 in drug-resistant BCSC. PLK3 methylation decreases PLK3 phosphorylation of HIF1α and thereby increases HIF1α stability. HIF1α, in turn, upregulates ALKBH5 to reduce m6A modification of LINC00115, resulting in attenuated degradation of YTHDF2-dependent m6A-modified RNA and enhanced LINC00115 stability. Thus, this positive feedback loop provokes BCSC phenotypes and enhances chemoresistance and metastasis in triple-negative breast cancer. SETDB1 inhibitor TTD-IN with LINC00115 ASO sensitizes PTX-resistant cell response to chemotherapy in a xenograft animal model. Correlative expression of LINC00115, methylation PLK3, SETDB1, and HIF1α are prognostic for clinical triple-negative breast cancers.

CONCLUSIONS

Our findings uncover LINC00115 as a critical regulator of BCSC and highlight targeting LINC00115 and SETDB1 as a potential therapeutic strategy for chemotherapeutic resistant breast cancer.

Investigative fatigue: how sleep-circadian factors shape criminal investigations

Investigating criminal complaints and identifying culprits to be prosecuted in the court of law is an essential process for law-enforcement and public safety. However, law-enforcement investigators operate under very challenging conditions due to stressful environments, understaffing, and public scrutiny, which factors into investigative errors (e.g. uncleared cases). This paper argues that one contributing factor to investigative failures involves sleep and circadian disruption of investigators themselves, known to be prevalent among law-enforcement. By focusing on investigative interviewing, this analysis illustrates how sleep and circadian disruption could impact investigations by considering three broad phases of (1) preparation, (2) information elicitation, and (3) assessment and corroboration. These phases are organized in a framework that outlines theory-informed pathways in need of empirical attention, with special focus on effort and decision-making processes critical to investigations. While existing evidence is limited, preliminary findings support some elements of investigative fatigue. The paper concludes by placing investigative fatigue in a broader context of investigative work while providing recommendations for future research throughout. This paper is part of the Sleep and Circadian Health in the Justice System Collection.

The epigenetic downregulation of LncGHRLOS mediated by RNA m6A methylase ZCCHC4 promotes colorectal cancer tumorigenesis

BACKGROUND

m6A modification is currently recognized as a major driver of RNA function that maintains cancer cell homeostasis. Long non-coding (Lnc) RNAs control cell proliferation and play an important role in the occurrence and progression of colorectal cancer (CRC). ZCCHC4 is a newly discovered m6A methyltransferase whose role and mechanism in tumors have not yet been elucidated.

METHODS

The EpiQuik m6A RNA methylation kit was used to detect the level of total RNA m6A in six types of digestive tract tumors. The Kaplan-Meier method and receiver operating characteristic curve were used to evaluate the prognostic and diagnostic value of the newly discovered m6A methyltransferase, ZCCHC4, in CRC. The effects on CRC growth in vitro and in vivo were studied using gain- and loss-of-function experiments. The epigenetic mechanisms underlying ZCCHC4 upregulation in CRC were studied using RIP, MeRIP-seq, RNA pull-down, and animal experiments.

RESULTS

We reported that the ZCCHC4-LncRNAGHRLOS-KDM5D axis regulates the growth of CRC in vitro and in vivo. We found that ZCCHC4 was upregulated in primary CRC samples and could predict adverse clinical outcomes in patients with CRC. Mechanistically, ZCCHC4 downregulated LncRNAGHRLOS to promote CRC tumorigenesis. As a downstream molecule of LncRNAGHRLOS, KDM5D directly controls CRC cell proliferation, migration, and invasion.

CONCLUSION

This study suggests that the ZCCHC4 axis contributes to the tumorigenesis and progression of CRC and that ZCCHC4 may be a potential biomarker for this malignancy.

Cancer epigenetics: from laboratory studies and clinical trials to precision medicine

Epigenetic dysregulation is a common feature of a myriad of human diseases, particularly cancer. Defining the epigenetic defects associated with malignant tumors has become a focus of cancer research resulting in the gradual elucidation of cancer cell epigenetic regulation. In fact, most stages of tumor progression, including tumorigenesis, promotion, progression, and recurrence are accompanied by epigenetic alterations, some of which can be reversed by epigenetic drugs. The main objective of epigenetic therapy in the era of personalized precision medicine is to detect cancer biomarkers to improve risk assessment, diagnosis, and targeted treatment interventions. Rapid technological advancements streamlining the characterization of molecular epigenetic changes associated with cancers have propelled epigenetic drug research and development. This review summarizes the main mechanisms of epigenetic dysregulation and discusses past and present examples of epigenetic inhibitors in cancer diagnosis and treatment, with an emphasis on the development of epigenetic enzyme inhibitors or drugs. In the final part, the prospect of precise diagnosis and treatment is considered based on a better understanding of epigenetic abnormalities in cancer.

CD24 May Serve as an Immunotherapy Target in Triple-Negative Breast Cancer by Regulating the Expression of PD-L1

Purpose

CD24 mediates a "don't eat me" signal to escape the immune environment. However, the correlation between CD24 and PD-L1 is unclear. This study aimed to assess if CD24 can serve as a target for immunotherapy of triple-negative breast cancer (TNBC).

Methods

Data on CD24 expression in breast cancer were acquired using the Oncomine and UALCAN tools. The role of CD24 expression on the prognosis of patients with TNBC was assessed using Kaplan-Meier analyses. Subsequently, STRING and TISIDB databases were used to construct protein-protein interaction networks and to explore immune-related molecules regulated by CD24. Immunofluorescence and immunohistochemistry assays were conducted to validate CD24 and PD-L1 expression and tumor infiltration lymphocyte (TIL) level. Survival analysis was also performed to explore the effect of CD24 and PD-L1 expression and TIL level in patients with TNBC. ShRNA was also used to explore the regulation role of CD24 on PD-L1 expression.

Results

CD24 expression was significantly higher in breast cancer than in normal tissues, with high expression being significantly associated with a worse prognosis. CD24 was found to be significantly regulated by chemokines, immunoinhibitors, immunostimulators and TILs. Furthermore, CD24 expression showed a significant positive correlation with PD-L1 expression and a negative correlation with TIL level. In association with PD-L1, CD24 was found to positively regulate lymphocyte costimulation, T cell costimulation, and leukocyte activation. Furthermore, CD24 and PD-L1 co-expression contributed to worse survival outcomes. In addition, CD24 expression was found to attenuate the positive effects of high-level TILs on the prognosis of patients with TNBC. CD24 can also regulate the expression of PD-L1 in TNBC cells.

Conclusion

CD24 may attenuate the positive effects of high TIL levels on survival and may facilitate the immune escape of TNBC by regulating PD-L1 expression. Thus, it is a potential target for immunotherapy in TNBC.

Exploration and validation of a combined Hypoxia and m6A/m5C/m1A regulated gene signature for prognosis prediction of liver cancer

BACKGROUND

It is widely acknowledged that hypoxia and m6A/m5C/m1A RNA modifications promote the occurrence and development of tumors by regulating the tumor microenvironment. This study aimed to establish a novel liver cancer risk signature based on hypoxia and m6A/m5C/m1A modifications.

METHODS

We collected data from The Cancer Genome Atlas (TCGA-LIHC), the National Omics Data Encyclopedia (NODE-HCC), the International Cancer Genome Consortium (ICGC), and the Gene Expression Omnibus (GEO) databases for our study (GSE59729, GSE41666). Using Cox regression and least absolute shrinkage and selection operator (LASSO) method, we developed a risk signature for liver cancer based on differentially expressed genes related to hypoxia and genes regulated by m6A/m5C/m1A modifications. We stratified patients into high- and low-risk groups and assessed differences between these groups in terms of gene mutations, copy number variations, pathway enrichment, stemness scores, immune infiltration, and predictive capabilities of the model for immunotherapy and chemotherapy efficacy.

RESULTS

Our analysis revealed a significantly correlated between hypoxia and methylation as well as m6A/m5C/m1A RNA methylation. The three-gene prognosis signature (CEP55, DPH2, SMS) combining hypoxia and m6A/m5C/m1A regulated genes exhibited strong predictive performance in TCGA-LIHC, NODE-HCC, and ICGC-LIHC-JP cohorts. The low-risk group demonstrated a significantly better overall survival compared to the high-risk group (p < 0.0001 in TCGA, p = 0.0043 in NODE, p = 0.0015 in ICGC). The area under the curve (AUC) values for survival at 1, 2, and 3 years are all greater than 0.65 in the three cohorts. Univariate and Multivariate Cox regression analyses of the three datasets indicated that the signature could serve as an independent prognostic predictor (p < 0.001 in the three cohorts). The high-risk group exhibited more genome changes and higher homologous recombination deficiency scores and stemness scores. Analysis of immune infiltration and immune activation confirmed that the signature was associated with various immune microenvironment characteristics. Finally, patients in the high-risk group experienced a more favorable response to immunotherapy, and various common chemotherapy drugs.

CONCLUSION

Our prognostic signature which integrates hypoxia and m6A/m5C/m1A-regulated genes, provides valuable insights for clinical prediction and treatment guidance for liver cancer patients.

Metronomic and single high-dose paclitaxel treatments produce distinct heterogenous chemoresistant cancer cell populations

More than 75% of epithelial ovarian cancer (EOC) patients experience disease recurrence after initial treatment, highlighting our incomplete understanding of how chemoresistant populations evolve over the course of EOC progression post chemotherapy treatment. Here, we show how two paclitaxel (PTX) treatment methods- a single high dose and a weekly metronomic dose for four weeks, generate unique chemoresistant populations. Using mechanically relevant alginate microspheres and a combination of transcript profiling and heterogeneity analyses, we found that these PTX-treatment regimens produce distinct and resilient subpopulations that differ in metabolic reprogramming signatures, acquisition of resistance to PTX and anoikis, and the enrichment for cancer stem cells (CSCs) and polyploid giant cancer cells (PGCCs) with the ability to replenish bulk populations. We investigated the longevity of these metabolic reprogramming events using untargeted metabolomics and found that metabolites associated with stemness and therapy-induced senescence were uniquely abundant in populations enriched for CSCs and PGCCs. Predictive network analysis revealed that antioxidative mechanisms were likely to be differentially active dependent on both time and exposure to PTX. Our results illustrate how current standard chemotherapies contribute to the development of chemoresistant EOC subpopulations by either selecting for intrinsically resistant subpopulations or promoting the evolution of resistance mechanisms. Additionally, our work describes the unique phenotypic signatures in each of these distinct resistant subpopulations and thus highlights potential vulnerabilities that can be exploited for more effective treatment.

CSTF2 mediated mRNA N6-methyladenosine modification drives pancreatic ductal adenocarcinoma m6A subtypes

N6-methyladenosine (m6A) modification of gene transcripts plays critical roles in cancer. Here we report transcriptomic m6A profiling in 98 tissue samples from 65 individuals with pancreatic ductal adenocarcinoma (PDAC). We identify 17,996 m6A peaks with 195 hyper-methylated and 93 hypo-methylated in PDAC compared with adjacent normal tissues. The differential m6A modifications distinguish two PDAC subtypes with different prognosis outcomes. The formation of the two subtypes is driven by a newly identified m6A regulator CSTF2 that co-transcriptionally regulates m6A installation through slowing the RNA Pol II elongation rate during gene transcription. We find that most of the CSTF2-regulated m6As have positive effects on the RNA level of host genes, and CSTF2-regulated m6As are mainly recognized by IGF2BP2, an m6A reader that stabilizes mRNAs. These results provide a promising PDAC subtyping strategy and potential therapeutic targets for precision medicine of PDAC.

The roles and implications of RNA m6A modification in cancer

N6-Methyladenosine (m6A), the most prevalent internal modification in eukaryotic mRNA, has been extensively and increasingly studied over the past decade. Dysregulation of RNA m6A modification and its associated machinery, including writers, erasers and readers, is frequently observed in various cancer types, and the dysregulation profiles might serve as diagnostic, prognostic and/or predictive biomarkers. Dysregulated m6A modifiers have been shown to function as oncoproteins or tumour suppressors with essential roles in cancer initiation, progression, metastasis, metabolism, therapy resistance and immune evasion as well as in cancer stem cell self-renewal and the tumour microenvironment, highlighting the therapeutic potential of targeting the dysregulated m6A machinery for cancer treatment. In this Review, we discuss the mechanisms by which m6A modifiers determine the fate of target RNAs and thereby influence protein expression, molecular pathways and cell phenotypes. We also describe the state-of-the-art methodologies for mapping global m6A epitranscriptomes in cancer. We further summarize discoveries regarding the dysregulation of m6A modifiers and modifications in cancer, their pathological roles, and the underlying molecular mechanisms. Finally, we discuss m6A-related prognostic and predictive molecular biomarkers in cancer as well as the development of small-molecule inhibitors targeting oncogenic m6A modifiers and their activity in preclinical models.

3D Biomimetic Models to Reconstitute Tumor Microenvironment In Vitro: Spheroids, Organoids, and Tumor-on-a-Chip

Decades of efforts in engineering in vitro cancer models have advanced drug discovery and the insight into cancer biology. However, the establishment of preclinical models that enable fully recapitulating the tumor microenvironment remains challenging owing to its intrinsic complexity. Recent progress in engineering techniques has allowed the development of a new generation of in vitro preclinical models that can recreate complex in vivo tumor microenvironments and accurately predict drug responses, including spheroids, organoids, and tumor-on-a-chip. These biomimetic 3D tumor models are of particular interest as they pave the way for better understanding of cancer biology and accelerating the development of new anticancer therapeutics with reducing animal use. Here, the recent advances in developing these in vitro platforms for cancer modeling and preclinical drug screening, focusing on incorporating hydrogels are reviewed to reconstitute physiologically relevant microenvironments. The combination of spheroids/organoids with microfluidic technologies is also highlighted to better mimic in vivo tumors and discuss the challenges and future directions in the clinical translation of such models for drug screening and personalized medicine.

Coordination of RNA modifications in the brain and beyond

Gene expression regulation is a critical process throughout the body, especially in the nervous system. One mechanism by which biological systems regulate gene expression is via enzyme-mediated RNA modifications, also known as epitranscriptomic regulation. RNA modifications, which have been found on nearly all RNA species across all domains of life, are chemically diverse covalent modifications of RNA nucleotides and represent a robust and rapid mechanism for the regulation of gene expression. Although numerous studies have been conducted regarding the impact that single modifications in single RNA molecules have on gene expression, emerging evidence highlights potential crosstalk between and coordination of modifications across RNA species. These potential coordination axes of RNA modifications have emerged as a new direction in the field of epitranscriptomic research. In this review, we will highlight several examples of gene regulation via RNA modification in the nervous system, followed by a summary of the current state of the field of RNA modification coordination axes. In doing so, we aim to inspire the field to gain a deeper understanding of the roles of RNA modifications and coordination of these modifications in the nervous system.

K235 acetylation couples with PSPC1 to regulate the m6A demethylation activity of ALKBH5 and tumorigenesis

N6-methyladenosine (m⁶A) modification plays important roles in bioprocesses and diseases. AlkB homolog 5 (ALKBH5) is one of two m⁶A demethylases. Here, we reveal that ALKBH5 is acetylated at lysine 235 (K235) by lysine acetyltransferase 8 and deacetylated by histone deacetylase 7. K235 acetylation strengthens the m⁶A demethylation activity of ALKBH5 by increasing its recognition of m⁶A on mRNA. RNA-binding protein paraspeckle component 1 (PSCP1) is a regulatory subunit of ALKBH5 and preferentially interacts with K235-acetylated ALKBH5 to recruit and facilitate the recognition of m⁶A mRNA by ALKBH5, thereby promoting m⁶A erasure. Mitogenic signals promote ALKBH5 K235 acetylation. K235 acetylation of ALKBH5 is upregulated in cancers and promotes tumorigenesis. Thus, our findings reveal that the m⁶A demethylation activity of ALKBH5 is orchestrated by its K235 acetylation and regulatory subunit PSPC1 and that K235 acetylation is necessary for the m⁶A demethylase activity and oncogenic roles of ALKBH5.

Silencing Notch4 promotes tumorigenesis and inhibits metastasis of triple-negative breast cancer via Nanog and Cdc42

Elucidation of individual Notch protein biology in specific cancer is crucial to develop safe, effective, and tumor-selective Notch-targeting therapeutic reagents for clinical use [1]. Here, we explored the Notch4 function in triple-negative breast cancer (TNBC). We found that silencing Notch4 enhanced tumorigenic ability in TNBC cells via upregulating Nanog expression, a pluripotency factor of embryonic stem cells. Intriguingly, silencing Notch4 in TNBC cells suppressed metastasis via downregulating Cdc42 expression, a key molecular for cell polarity formation. Notably, downregulation of Cdc42 expression affected Vimentin distribution, but not Vimentin expression to inhibit EMT shift. Collectively, our results show that silencing Notch4 enhances tumorigenesis and inhibits metastasis in TNBC, indicating that targeting Notch4 may not be a potential strategy for drug discovery in TNBC.

m6A methylation regulates hypoxia-induced pancreatic cancer glycolytic metabolism through ALKBH5-HDAC4-HIF1α positive feedback loop

Pancreatic cancer (PC) is the most hypoxic cancer type among solid tumors. The dynamic changes of RNA N6-methyl-adenosine (m6A) contribute to tumor cells adaption to hypoxic microenvironmental. However, the regulatory mechanisms of hypoxia response in PC remains elusive. Here, we reported that the m6A demethylase ALKBH5 mediated a decrease of total mRNA m6A modification during hypoxia. Subsequently, methylated RNA immunoprecipitation sequencing (MeRIP-seq) combined with RNA sequencing (RNA-seq) revealed transcriptome-wide gene expression alteration and identified histone deacetylase type 4 (HDAC4) as a key target gene of m6A modification under hypoxic conditionds. Mechanistically, m6A methylation recognized by m6A reader-YTHDF2 enhanced the stability of HDAC4, and then promoted glycolytic metabolism and migration of PC cells. Our assays also demonstrated that hypoxia-induced HDAC4 enhanced HIF1a protein stability, and overexpressed HIF1a promoted transcription of ALKBH5 in hypoxic pancreatic cancer cells. Together, these results found a ALKBH5/HDAC4/HIF1α positive feedback loop for cellular response to hypoxia in pancreatic cancer. Our studies uncover the crosstalk between histone acetylation and RNA methylation modification on layer of epigenetic regulation.

TMT-based quantitative proteomic analysis of spheroid cells of endometrial cancer possessing cancer stem cell properties

BACKGROUND

Cancer stem cells (CSCs) play an important role in endometrial cancer progression and it is potential to isolate CSCs from spheroid cells. Further understanding of spheroid cells at protein level would help find novel CSC markers.

METHODS

Spheroid cells from endometrial cancer cell lines, Ishikawa and HEC1A, exhibited increased colony forming, subsphere forming, chemo-drug resistance, migration, invasion ability and tumorigenicity, verifying their cancer stem-like cell properties. The up-regulated CD90, CD117, CD133 and W5C5 expression also indicated stemness of spheroid cells. TMT-based quantitative proteomic analysis was performed to explore the potential alterations between parent cells and cancer stem-like spheroid cells. HK2-siRNA was transfected to Ishikawa and HEC1A cells to explore the roles and molecular mechanism of HK2 in endometrial cancer.

RESULTS

We identified and quantified a total of 5735 proteins and 167 overlapped differentially expressed proteins of two cell types, 43 proteins were up-regulated and 124 were down-regulated in spheroid cells comparing with parent cells. KEGG pathway revealed a significant role of HIF-1 pathway in spheroid cells. qRT-PCR and western blot results of GPRC5A, PFKFB3 and HK2 of HIF-1 pathway confirmed their elevated expressions in spheroid cells which were consistent with proteomic results. HK2 promoted cancer stemness in endometrial cancer.

CONCLUSION

These findings indicate that spheroid cells from endometrial cancer cell lines possess cancer stem-like cell properties and enrich CSCs. HIF-1 pathway is activated in endometrial cancer stem-like spheroid cells.

The impact of alertness vs. fatigue on interrogators in an actigraphic study of field investigations

Investigative interviews (e.g., interrogations) are a critical component of criminal, military, and civil investigations. However, how levels of alertness (vs. sleepiness) of the interviewer impact outcomes of actual interviews is unknown. To this end, the current study tracked daily fluctuations in alertness among professional criminal investigators to predict their daily experiences with actual field interviews. Fifty law-enforcement investigators wore a sleep-activity tracker for two weeks while keeping a daily-diary of investigative interviews conducted in the field. For each interview, the investigators indicated how well they established rapport with the subject, how much resistance they encountered, how well they maintained their own focus and composure, and the overall utility of intelligence obtained. Daily alertness was biomathematically modeled from actigraphic sleep duration and continuity estimates and used to predict interview characteristics. Investigators consistently reported more difficulties maintaining their focus and composure as well as encountering more subject resistance during interviews on days with lower alertness. Better interview outcomes were also reported on days with subjectively better sleep, while findings were generally robust to inclusion of covariates. The findings implicate adequate sleep as a modifiable fitness factor for collectors of human intelligence.

m6A methylation: a process reshaping the tumour immune microenvironment and regulating immune evasion

N6-methyladenosine (m⁶A) methylation is the most universal internal modification in eukaryotic mRNA. With elaborate functions executed by m⁶A writers, erasers, and readers, m⁶A modulation is involved in myriad physiological and pathological processes. Extensive studies have demonstrated m⁶A modulation in diverse tumours, with effects on tumorigenesis, metastasis, and resistance. Recent evidence has revealed an emerging role of m⁶A modulation in tumour immunoregulation, and divergent m⁶A methylation patterns have been revealed in the tumour microenvironment. To depict the regulatory role of m⁶A methylation in the tumour immune microenvironment (TIME) and its effect on immune evasion, this review focuses on the TIME, which is characterized by hypoxia, metabolic reprogramming, acidity, and immunosuppression, and outlines the m⁶A-regulated TIME and immune evasion under divergent stimuli. Furthermore, m⁶A modulation patterns in anti-tumour immune cells are summarized.

Biological roles of the RNA m6A modification and its implications in cancer

The N⁶-Methyladenosine (m⁶A) modification of RNA transcripts is the most prevalent and abundant internal modification in eukaryotic messenger RNAs (mRNAs) and plays diverse and important roles in normal biological processes. Extensive studies have indicated that dysregulated m⁶A modification and m⁶A-associated proteins play critical roles in tumorigenesis and cancer progression. However, m⁶A-mediated physiological consequences often lead to opposite outcomes in a biological context-dependent manner. Therefore, context-related complexity must be meaningfully considered to obtain a comprehensive understanding of RNA methylation. Recently, it has been reported that m⁶A-modified RNAs are closely related to the regulation of the DNA damage response and genomic integrity maintenance. Here, we present an overview of the current knowledge on the m⁶A modification and its function in human cancer, particularly in relation to the DNA damage response and genomic instability.

m6A demethylase ALKBH5 promotes tumor cell proliferation by destabilizing IGF2BPs target genes and worsens the prognosis of patients with non-small-cell lung cancer

The modification of N6-methyladenosine (m6A) in RNA and its eraser ALKBH5, an m6A demethylase, play an important role across various steps of human carcinogenesis. However, the involvement of ALKBH5 in non-small-cell lung cancer (NSCLC) development remains to be completely elucidated. The current study revealed that the expression of ALKBH5 was increased in NSCLC and increased expression of ALKBH5 worsened the prognosis of patients with NSCLC. In vitro study revealed that ALKBH5 knockdown suppressed cell proliferation ability of PC9 and A549 cells and promoted G1 arrest and increased the number of apoptotic cells. Furthermore, ALKBH5 overexpression increased the cell proliferation ability of the immortalized cell lines. Microarray analysis and western blotting revealed that the expression of CDKN1A (p21) or TIMP3 was increased by ALKBH5 knockdown. These alterations were offset by a double knockdown of both ALKBH5 and one of the IGF2BPs. The decline of mRNAs was, at least partly, owing to the destabilization of these mRNAs by one of the IGF2BPs. In conclusions, the ALKBH5-IGF2BPs axis promotes cell proliferation and tumorigenicity, which in turn causes the unfavorable prognosis of NSCLC.

Targeting RNA N6-methyladenosine modification: a precise weapon in overcoming tumor immune escape

Immunotherapy, especially immune checkpoint inhibitors (ICIs), has revolutionized the treatment of many types of cancer, particularly advanced-stage cancers. Nevertheless, although a subset of patients experiences dramatic and long-term disease regression in response to ICIs, most patients do not benefit from these treatments. Some may even experience cancer progression. Immune escape by tumor cells may be a key reason for this low response rate. N⁶-methyladenosine (m⁶A) is the most common type of RNA methylation and has been recognized as a critical regulator of tumors and the immune system. Therefore, m⁶A modification and related regulators are promising targets for improving the efficacy of tumor immunotherapy. However, the association between m⁶A modification and tumor immune escape (TIE) has not been comprehensively summarized. Therefore, this review summarizes the existing knowledge regarding m⁶A modifications involved in TIE and their potential mechanisms of action. Moreover, we provide an overview of currently available agents targeting m⁶A regulators that have been tested for their elevated effects on TIE. This review establishes the association between m⁶A modifications and TIE and provides new insights and strategies for maximizing the efficacy of immunotherapy by specifically targeting m⁶A modifications involved in TIE.

The m6A demethylase ALKBH5-mediated upregulation of DDIT4-AS1 maintains pancreatic cancer stemness and suppresses chemosensitivity by activating the mTOR pathway

Background

Chemoresistance is a major factor contributing to the poor prognosis of patients with pancreatic cancer, and cancer stemness is one of the most crucial factors associated with chemoresistance and a very promising direction for cancer treatment. However, the exact molecular mechanisms of cancer stemness have not been completely elucidated.

Methods

m⁶A-RNA immunoprecipitation and sequencing were used to screen m⁶A-related mRNAs and lncRNAs. qRT-PCR and FISH were utilized to analyse DDIT4-AS1 expression. Spheroid formation, colony formation, Western blot and flow cytometry assays were performed to analyse the cancer stemness and chemosensitivity of PDAC cells. Xenograft experiments were conducted to analyse the tumour formation ratio and growth in vivo. RNA sequencing, Western blot and bioinformatics analyses were used to identify the downstream pathway of DDIT4-AS1. IP, RIP and RNA pulldown assays were performed to test the interaction between DDIT4-AS1, DDIT4 and UPF1. Patient-derived xenograft (PDX) mouse models were generated to evaluate chemosensitivities to GEM.

Results

DDIT4-AS1 was identified as one of the downstream targets of ALKBH5, and recruitment of HuR onto m⁶A-modified sites is essential for DDIT4-AS1 stabilization. DDIT4-AS1 was upregulated in PDAC and positively correlated with a poor prognosis. DDIT4-AS1 silencing inhibited stemness and enhanced chemosensitivity to GEM (Gemcitabine). Mechanistically, DDIT4-AS1 promoted the phosphorylation of UPF1 by preventing the binding of SMG5 and PP2A to UPF1, which decreased the stability of the DDIT4 mRNA and activated the mTOR pathway. Furthermore, suppression of DDIT4-AS1 in a PDX-derived model enhanced the antitumour effects of GEM on PDAC.

Conclusions

The ALKBH5-mediated m⁶A modification led to DDIT4-AS1 overexpression in PDAC, and DDIT-AS1 increased cancer stemness and suppressed chemosensitivity to GEM by destabilizing DDIT4 and activating the mTOR pathway. Approaches targeting DDIT4-AS1 and its pathway may be an effective strategy for the treatment of chemoresistance in PDAC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12943-022-01647-0.

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.

Rational Design and Optimization of m6A-RNA Demethylase FTO Inhibitors as Anticancer Agents

Aberrant regulation of N⁶-methyladenosine (m⁶A) RNA modification has been implicated in the progression of multiple diseases, including cancer. Previously, we identified a small molecule inhibitor of the m⁶A demethylase fat mass- and obesity-associated protein (FTO), which removes both m⁶A and N⁶,2′-O-dimethyladenosine (m⁶A_m) RNA modifications. In this work, we describe the rational design and optimization of a new class of FTO inhibitors derived from our previous lead FTO-04 with nanomolar potency and high selectivity against the homologous m⁶A RNA demethylase ALKBH5. The oxetanyl class of compounds comprise competitive inhibitors of FTO with potent antiproliferative effects in glioblastoma, acute myeloid leukemia, and gastric cancer models where lead FTO-43 demonstrated potency comparable to clinical chemotherapeutic 5-fluorouracil. Furthermore, FTO-43 increased m⁶A and m⁶A_m levels in a manner comparable to FTO knockdown in gastric cancer cells and regulated Wnt/PI3K-Akt signaling pathways. The oxetanyl class contains significantly improved anticancer agents with a variety of applications beyond glioblastoma.

Mutual regulation between N6-methyladenosine (m6A) modification and circular RNAs in cancer: impacts on therapeutic resistance

The resistance of tumor cells to therapy severely impairs the efficacy of treatment, leading to recurrence and metastasis of various cancers. Clarifying the underlying mechanisms of therapeutic resistance may provide new strategies for overcoming cancer resistance. N6-methyladenosine (m6A) is the most prevalent RNA modification in eukaryotes, and is involved in the regulation of RNA splicing, translation, transport, degradation, stability and processing, thus affecting several physiological processes and cancer progression. As a novel type of multifunctional non-coding RNAs (ncRNAs), circular RNAs (circRNAs) have been demonstrated to play vital roles in anticancer therapy. Currently, accumulating studies have revealed the mutual regulation of m6A modification and circRNAs, and their interaction can further influence the sensitivity of cancer treatment. In this review, we mainly summarized the recent advances of m6A modification and circRNAs in the modulation of cancer therapeutic resistance, as well as their interplay and potential mechanisms, providing promising insights and future directions in reversal of therapeutic resistance in cancer.

N6-methyladenosine modification-mediated mRNA metabolism is essential for human pancreatic lineage specification and islet organogenesis

Pancreatic differentiation from human pluripotent stem cells (hPSCs) provides promising avenues for investigating development and treating diseases. N⁶-methyladenosine (m⁶A) is the most prevalent internal messenger RNA (mRNA) modification and plays pivotal roles in regulation of mRNA metabolism, while its functions remain elusive. Here, we profile the dynamic landscapes of m⁶A transcriptome-wide during pancreatic differentiation. Next, we generate knockout hPSC lines of the major m⁶A demethylase ALKBH5, and find that ALKBH5 plays significant regulatory roles in pancreatic organogenesis. Mechanistic studies reveal that ALKBH5 deficiency reduces the mRNA stability of key pancreatic transcription factors in an m⁶A and YTHDF2-dependent manner. We further identify that ALKBH5 cofactor α-ketoglutarate can be applied to enhance differentiation. Collectively, our findings identify ALKBH5 as an essential regulator of pancreatic differentiation and highlight that m⁶A modification-mediated mRNA metabolism presents an important layer of regulation during cell-fate specification and holds great potentials for translational applications.

Ma et al. profile the dynamic landscape of m⁶A during pancreatic differentiation, and identify ALKBH5 as an essential m⁶A regulator supporting pancreatic differentiation, indicating a role for m⁶A-mediated mRNA metabolism in cell-fate specification.

m6A methylated EphA2 and VEGFA through IGF2BP2/3 regulation promotes vasculogenic mimicry in colorectal cancer via PI3K/AKT and ERK1/2 signaling

Exploring the epigenetic regulation mechanism of colorectal cancer (CRC) from the perspective of N6-methyladenosine (m6A) modification may provide a new target for tumor therapy. Analysis using high-throughput RNA-seq profile from TCGA found that the gene expression of Methyltransferase-like 3 (METTL3) was significantly upregulated among 20 m6A binding proteins in CRC, which was also validated in CRC cancer tissues and cell lines. Moreover, transcriptome sequencing in METTL3 knockdown cells using CRISPR/Cas9 editing suggested that EphA2 and VEGFA were differential expression, which were enriched in the vasculature development, PI3K/AKT and ERK1/2 signal pathway through the functional enrichment analysis. The results in vitro revealed that METTL3 as the m6A "writers" participates the methylation of EphA2 and VEGFA, which were recognized by the m6A "readers", insulin-like growth factor 2 mRNA binding protein 2/3 (IGF2BP2/3), to prevent their mRNA degradation. In addition, EphA2 and VEGFA targeted by METTL3 via different IGF2BP-dependent mechanisms were found to promote vasculogenic mimicry (VM) formation via PI3K/AKT/mTOR and ERK1/2 signaling in CRC. The study suggests that intervention with m6A-binding proteins (METTL3 and IGF2BP2/3) may provide a potential diagnostic or prognostic target of VM-based anti-metastasis drugs for CRC.

The m6A demethylase ALKBH5 promotes tumor progression by inhibiting RIG-I expression and interferon alpha production through the IKKε/TBK1/IRF3 pathway in head and neck squamous cell carcinoma

BACKGROUND

N6-methyladenosine (m6A) RNA modification plays a critical role in various physiological and pathological conditions. However, the role of m6A modification in head and neck squamous cell carcinoma (HNSCC) remains elusive.

METHODS

In this study, the expression of m6A demethylases was detected by HNSCC tissue microarray. m6A-RNA immunoprecipitation (MeRIP) sequencing and RNA sequencing were used to identify downstream targets of ALKBH5. Comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS) was used to explore the m6A "readers". Tumor-infiltrating lymphocytes were analyzed in SCC7-bearing xenografts in C3H mice.

RESULTS

Here, we demonstrate the downregulation of m6A status and upregulation of two demethylases in HNSCC. Silencing the m6A demethylase alkB homolog 5, RNA demethylase (ALKBH5) suppresses tumor progression in vitro and in vivo. m6A-RNA immunoprecipitation sequencing reveals that ALKBH5 downregulates the m6A modification of DDX58 mRNA. Moreover, RIG-I, encoded by the DDX58 mRNA, reverses the protumorigenic characteristics of ALKBH5. ChIRP-MS demonstrates that HNRNPC binds to the m6A sites of DDX58 mRNA to promote its maturation. ALKBH5 overexpression inhibits RIG-I-mediated IFNα secretion through the IKKε/TBK1/IRF3 pathway. The number of tumor-infiltrating lymphocytes in C3H immunocompetent mice is reduced by ALKBH5 overexpression and restored by IFNα administration. Upregulation of AKLBH5 negatively correlates with RIG-I and IFNα expression in HNSCC patients.

CONCLUSIONS

These findings unveil a novel mechanism of immune microenvironment regulation mediated by m6A modification through the ALKBH5/RIG-I/IFNα axis, providing a rationale for therapeutically targeting epitranscriptomic modulators in HNSCC.

Roles and action mechanisms of bile acid-induced gastric intestinal metaplasia: a review

Gastric intestinal metaplasia (IM) is a precancerous lesion that increases the risk of subsequent gastric cancer (GC) development. Therefore, the mechanism of IM has been the focus of basic and clinical research. Helicobacter pylori (H. pylori) infection has been recognized as the main pathogenesis of gastric IM. However, more and more studies have shown that chronic inflammation of gastric mucosa caused by bile reflux is the key pathogenic factor of gastric IM. Bile reflux activates the expression of IM biomarkers via the bile acid receptor. In addition, microRNAs, exosomes, and epigenetics are also involved in the occurrence and development of bile acid-induced gastric IM. Currently, the relevant research is still very few. The molecular mechanism of the phenotypic transformation of gastrointestinal epithelial cells induced by bile acids has not been fully understood. This article mainly reviews the physiology and pathology of bile acid, mechanism of gastric IM induced by bile acid, bile acid receptors, and so on, in order to provide reference for further research.

YTHDF1 upregulation mediates hypoxia-dependent breast cancer growth and metastasis through regulating PKM2 to affect glycolysis

N6-methyladenosine modification is the most common RNA modification mechanism in mammals. YTHDF1, a m⁶A reader, can recognize the m⁶A of mRNAs to facilitate the interaction with the mRNA ribosome assembly and recruitment of translation initiators to promote translation. From a clinical perspective, YTHDF1 upregulation is frequently observed in breast cancer, but its involvement in those cancer-related events is still unclear. Here we report that YTHDF1 is a cancer driver capable of facilitating the proliferation and invasion of breast cancer cells as well as enhancing tumorigenicity and metastasis through promoting glycolysis. We found that tumor hypoxia can transcriptionally induce HIF1α and post-transcriptionally inhibit the expression of miR-16-5p to promote YTHDF1 expression, which could sequentially enhance tumor glycolysis by upregulating PKM2 and eventually increase the tumorigenesis and metastasis potential of breast cancer cells. Inhibiting YTHDF1 via gene knockdown or miR-16-5p would significantly abolish YTHDF1-dependent tumor growth and metastasis. In summary, we identified the role of the YTHDF1-PKM2 signal axis in the occurrence and development of breast cancer, which can be used as a potential target for breast cancer treatment.

A novel HIF-2α targeted inhibitor suppresses hypoxia-induced breast cancer stemness via SOD2-mtROS-PDI/GPR78-UPRER axis

Hypoxic tumor microenvironment (TME) plays critical roles in induction of cancer stem cell-like phenotype in breast cancer and contribute to chemoresistance. However, the mechanism underlying stemness reprogramming of breast cancer cells (BCs) by hypoxic TME remains largely unknown. In the present study, we illustrated that HIF-2α, but not HIF-1α, induces stemness in BCs under hypoxia through SOD2-mtROS-PDI/GRP78-UPR^ER pathway, linking mitochondrial metabolic state to endoplasmic reticulum (ER) response via mitochondrial reactive oxygen species (mtROS) level. HIF-2α activates endoplasmic reticulum unfolded protein response (UPR^ER) in drug-sensitive MCF7 and T47D cells to induce drug-resistant stem-like phenotype. Genetic depletion or pharmacological inhibition (YQ-0629) of HIF-2α abolished hypoxia-induced stem-like phenotype in vitro and in vivo. Mechanistically, HIF-2α activates transcription of superoxide dismutase 2 (SOD2) under hypoxia and thereby decreases mtROS level. With less mtROS transported to endoplasmic reticulum, the expression and activity of protein disulfide isomerase (PDI) is suppressed, allowing glucose-regulated protein 78 (GRP78) to dissociate from receptor proteins of UPR^ER and bind misfolded protein to activate UPR^ER, which eventually confer chemoresistance and stem-like properties to BCs. Moreover, the increase in mtROS and PDI levels caused by HIF-2α knockdown and the subsequent UPR^ER inhibition could be substantially rescued by mitoTEMPOL (a mtROS scavenger), 16F16 (a PDI inhibitor), or GRP78 overexpression. Overall, we reported the critical roles of HIF-2α-SOD2-mtROS-PDI/GRP78-UPR^ER axis in mediating hypoxia-induced stemness in BCs, highlighting the interaction between organelles and providing evidence for further development of targeted HIF-2α inhibitor as a promising therapeutic strategy for chemoresistant breast cancer.

The role of m6A RNA methylation in cancer metabolism

Metabolic reprogramming is one of the main characteristics of malignant tumors, which is due to the flexible changes of cell metabolism that can meet the needs of cell growth and maintain the homeostasis of tissue environments. Cancer cells can obtain metabolic adaptation through a variety of endogenous and exogenous signaling pathways, which can not only promote the growth of malignant cancer cells, but also start the transformation process of cells to adapt to tumor microenvironment. Studies show that m6A RNA methylation is widely involved in the metabolic recombination of tumor cells. In eukaryotes, m6A methylation is the most abundant modification in mRNA, which is involved in almost all the RNA cycle stages, including regulation the transcription, maturation, translation, degradation and stability of mRNA. M6A RNA methylation can be involved in the regulation of physiological and pathological processes, including cancer. In this review, we discuss the role of m6A RNA methylation modification plays in tumor metabolism-related molecules and pathways, aiming to show the importance of targeting m6A in regulating tumor metabolism.

Modulation of DNA/RNA Methylation by Small-Molecule Modulators and Their Implications in Cancer

Chromatin is an organized complex of DNA, histone proteins, and RNA. Chromatin modifications include DNA methylation, RNA methylation, and histone acetylation and methylation. The methylation of chromatin complexes predominantly alters the regulation of gene expression, and its deregulation is associated with several human diseases including cancer. Cancer is a disease characterized by dynamic changes in the genetic and epigenetic architecture of a cell. Altered DNA methylation by DNA methyltransferases (DNMTs) and m6A RNA methylation facilitate tumor initiation and progression and thus serve as critical targets for cancer therapy. Small-molecule modulators of these epigenetic targets are at the hotspots of current cancer drug discovery research. Indeed, recent studies have led to the discovery of several chemical modulators against these targets, some of which have already gained approval for cancer therapy while others are undergoing clinical trials. In this chapter, we will focus on the role of small-molecule modulators in regulating DNA/RNA methylation and their implications in cancer.

Detection of m6A from direct RNA sequencing using a multiple instance learning framework

RNA modifications such as m6A methylation form an additional layer of complexity in the transcriptome. Nanopore direct RNA sequencing can capture this information in the raw current signal for each RNA molecule, enabling the detection of RNA modifications using supervised machine learning. However, experimental approaches provide only site-level training data, whereas the modification status for each single RNA molecule is missing. Here we present m6Anet, a neural-network-based method that leverages the multiple instance learning framework to specifically handle missing read-level modification labels in site-level training data. m6Anet outperforms existing computational methods, shows similar accuracy as experimental approaches, and generalizes with high accuracy to different cell lines and species without retraining model parameters. In addition, we demonstrate that m6Anet captures the underlying read-level stoichiometry, which can be used to approximate differences in modification rates. Overall, m6Anet offers a tool to capture the transcriptome-wide identification and quantification of m6A from a single run of direct RNA sequencing.

Sleep and interrogation: does losing sleep impact criminal history disclosure?

STUDY OBJECTIVES

Despite centuries of using sleep deprivation to interrogate, there is virtually no scientific evidence on how sleep shapes behavior within interrogation settings. To evaluate the impact of sleeplessness on participants' behavior during investigative interviews, an experimental study examined the impact of sleep restriction on disclosure of past illegal behavior.

METHODS

Healthy participants from a university community (N = 143) either maintained or curbed their sleep (up to 4 h a night) across 2 days with sleep monitored via actigraphy. They were then asked to disclose past illegal acts and interviewed about them. Next, they were reinterviewed following an example of a detailed memory account (model statement). Disclosures were blindly coded for quantity and quality by two independent raters.

RESULTS

Sleep-restricted individuals reported similar offenses, but less information during their disclosure with slightly less precision. Model statement increased disclosure but did not reduce the inhibiting impact of sleep loss. Mediation analysis confirmed the causal role of sleep as responsible for experimental differences in amount of information, and participants' reports suggested impaired motivation to recall information played a role.

CONCLUSIONS

The findings suggest that even moderate sleep loss can inhibit criminal disclosure during interviews, point to motivational factors as responsible, and suggest investigators should be cautious when interrogating sleepy participants.

Psychological torture: Characteristics and impact on mental health

Torture has been illegal in most of Europe and the United States for over a century but persisted in other parts of the world. The changing geopolitical landscape has led to its resurgence in recent years. The public rejection of traditional forms of torture that rely on the infliction of physical pain has paradoxically increased the reliance on psychological methods of torture. This critical commentary aims to define and characterize psychological torture (PT) while exploring practical, legal, ethical and therapeutic implications relevant to clinicians and policymakers. Psychological torture comes in a range of forms. It is being increasingly justified and adopted by legitimate authorities in the name of national security. The emphasis on the avoidance of physical pain leads to the assumption that PT does not produce the levels of suffering and harm that are associated with physically violent forms of torture. This same assumption has allowed for the implication of mental health professionals in theorizing and providing legitimacy for the actions of perpetrators. Psychological torture is still poorly defined with limited understanding of its long-term psychiatric impact on those who are subjected to it. The role of mental health professionals in preventing or addressing psychological torture remains ambiguous and needs to be reinforced.

RNA methylation in hematological malignancies and its interactions with other epigenetic modifications

Hematological malignancies are a class of malignant neoplasms attributed to abnormal differentiation of hematopoietic stem cells (HSCs). The systemic involvement, poor prognosis, chemotherapy resistance, and recurrence common in hematological malignancies urge researchers to look for novel treatment targets and mechanisms. In recent years, epigenetic abnormalities have been shown to play a vital role in tumorigenesis and progression in hematological malignancies. In addition to DNA methylation and histone modifications, which are most studied, RNA methylation has become increasingly significant. In this review, we elaborate recent advances in the understanding of RNA modification in the pathogenesis, diagnosis and molecular targeted therapies of hematological malignancies and discuss its intricate interactions with other epigenetic modifications, including DNA methylation, histone modifications and noncoding RNAs.

A novel hypoxic long noncoding RNA KB-1980E6.3 maintains breast cancer stem cell stemness via interacting with IGF2BP1 to facilitate c-Myc mRNA stability

The hostile hypoxic microenvironment takes primary responsibility for the rapid expansion of breast cancer tumors. However, the underlying mechanism is not fully understood. Here, using RNA sequencing (RNA-seq) analysis, we identified a hypoxia-induced long noncoding RNA (lncRNA) KB-1980E6.3, which is aberrantly upregulated in clinical breast cancer tissues and closely correlated with poor prognosis of breast cancer patients. The enhanced lncRNA KB-1980E6.3 facilitates breast cancer stem cells (BCSCs) self-renewal and tumorigenesis under hypoxic microenvironment both in vitro and in vivo. Mechanistically, lncRNA KB-1980E6.3 recruited insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) to form a lncRNA KB-1980E6.3/IGF2BP1/c-Myc signaling axis that retained the stability of c-Myc mRNA through increasing binding of IGF2BP1 with m6A-modified c-Myc coding region instability determinant (CRD) mRNA. In conclusion, we confirm that lncRNA KB-1980E6.3 maintains the stemness of BCSCs through lncRNA KB-1980E6.3/IGF2BP1/c-Myc axis and suggest that disrupting this axis might provide a new therapeutic target for refractory hypoxic tumors.

Pathogenic diversity of RNA variants and RNA variation-associated factors in cancer development

Recently, with the development of RNA sequencing technologies such as next-generation sequencing (NGS) for RNA, numerous variations of alternatively processed RNAs made by alternative splicing, RNA editing, alternative maturation of microRNA (miRNA), RNA methylation, and alternative polyadenylation have been uncovered. Furthermore, abnormally processed RNAs can cause a variety of diseases, including obesity, diabetes, Alzheimer’s disease, and cancer. Especially in cancer development, aberrant RNAs caused by deregulated RNA modifiers or regulators are related to progression. Accumulating evidence has reported that aberrant RNAs promote carcinogenesis in many cancers, including liver cancer, leukemia, melanoma, lung cancer, breast cancer, and other cancers, in which abnormal RNA processing occurs in normal cells. Therefore, it is necessary to understand the precise roles and mechanisms of disease-related RNA processing in various cancers for the development of therapeutic interventions. In this review, the underlying mechanisms of variations in the RNA life cycle and the biological impacts of RNA variations on carcinogenesis will be discussed, and therapeutic strategies for the treatment of tumor malignancies will be provided. We also discuss emerging roles of RNA regulators in hepatocellular carcinogenesis.

A single gene can generate a variety of RNA products, and changes in this final RNA output can directly contribute to cancer onset and progression. The initial transcription of each DNA sequence yields a raw RNA strand that subsequently undergoes a variety of modification processes that shape its function. Hee Doo Yang and Suk Woo Nam, The Catholic University of Korea, Seoul, have reviewed the potential impact of these mechanisms on malignancy. Some cancers, for example, express RNA sequences that have been inappropriately edited by an enzymatic process called splicing, yielding abnormal RNAs that drive metastasis. Other tumors contain RNAs with atypical chemical modifications, or in which individual nucleotides have been enzymatically converted into other nucleotides. A deeper understanding of these RNA alterations and their impacts could lead to more effective and targeted cancer treatments.

Cumulative Disadvantage: A Psychological Framework for Understanding How Innocence Can Lead to Confession, Wrongful Conviction, and Beyond

False confessions are a contributing factor in almost 30% of DNA exonerations in the United States. Similar problems have been documented all over the world. We present a novel framework to highlight the processes through which innocent people, once misidentified as suspects, experience cumulative disadvantages that culminate in pernicious consequences. The cumulative-disadvantage framework details how the innocent suspect's naivete and the interrogator's presumption of guilt trigger a process that can lead to false confession, the aftereffects of which spread to corrupt evidence gathering, bias forensic analysis, and virtually ensure wrongful convictions at trial or through pressured false guilty pleas. The framework integrates nascent research underscoring the enduring effects of the accumulated disadvantages postconviction and even after exoneration. We synthesize findings from psychological science, corroborating naturalistic evidence, and relevant legal precedents to explain how an innocent suspect's disadvantages can accumulate through the actions of law enforcement, forensic examiners, prosecutors, defense attorneys, judges, juries, and appeals courts. We conclude with prescribed research directions that can lead to empirically driven reforms to address the gestalt of the multistage process.