Adenosinergic Modulation of Layer 6 Microcircuitry in the Medial Prefrontal Cortex Is Specific to Presynaptic Cell Type.

Adenosinergic modulation in the PFC is recognized for its involvement in various behavioral aspects including sleep homoeostasis, decision-making, spatial working memory and anxiety. While the principal cells of layer 6 (L6) exhibit a significant morphological diversity, the detailed cell-specific regulatory mechanisms of adenosine in L6 remain unexplored. Here, we quantitatively analyzed the morphological and electrophysiological parameters of L6 neurons in the rat medial prefrontal cortex (mPFC) using whole-cell recordings combined with morphological reconstructions. We were able to identify two different morphological categories of excitatory neurons in the mPFC of both juvenile and young adult rats with both sexes. These categories were characterized by a leading dendrite that was oriented either upright (toward the pial surface) or inverted (toward the white matter). These two excitatory neuron subtypes exhibited different electrophysiological and synaptic properties. Adenosine at a concentration of 30 µM indiscriminately suppressed connections with either an upright or an inverted presynaptic excitatory neuron. However, using lower concentrations of adenosine (10 µM) revealed that synapses originating from L6 upright neurons have a higher sensitivity to adenosine-induced inhibition of synaptic release. Adenosine receptor activation causes a reduction in the probability of presynaptic neurotransmitter release that could be abolished by specifically blocking A1 adenosine receptors (A1ARs) using 8-cyclopentyltheophylline (CPT). Our results demonstrate a differential expression level of A1ARs at presynaptic sites of two functionally and morphologically distinct subpopulations of L6 principal neurons, suggesting the intricate functional role of adenosine in neuronal signaling in the brain.

Drugs targeting adenosine signaling pathways: A current view.

Adenosine is an endogenous nucleoside that regulates many physiological and pathological processes. It is derived from either the intracellular or extracellular dephosphorylation of adenosine triphosphate and interacts with cell-surface G-protein-coupled receptors. Adenosine plays a substantial role in protecting against cell damage in areas of increased tissue metabolism and preventing organ dysfunction in pathological states. Targeting adenosine metabolism and receptor signaling may be an effective therapeutic approach for human diseases, including cardiovascular and central nervous system disorders, rheumatoid arthritis, asthma, renal diseases, and cancer. Several lines of evidence have shown that many drugs exert their beneficial effects by modulating adenosine signaling pathways but this knowledge urgently needs to be summarized, and most importantly, actualized. The present review collects pharmaceuticals and pharmacological or diagnostic tools that target adenosine signaling in their primary or secondary mode of action. We overviewed FDA-approved drugs as well as those currently being studied in clinical trials. Among them are already used in clinic A2A adenosine receptor modulators like istradefylline or regadenoson, but also plenty of anti-platelet, anti-inflammatory, or immunosuppressive, and anti-cancer drugs. On the other hand, we investigated dozens of specific adenosine pathway regulators that are tested in clinical trials to treat human infectious and noninfectious diseases. In conclusion, targeting purinergic signaling represents a great therapeutic challenge. The actual knowledge of the involvement of adenosinergic signaling as part of the mechanism of action of old drugs has open a path not only for drug-repurposing but also for new therapeutic strategies.

Gene expression pattern of adenosine receptors in lung tumors.

BACKGROUND: Adenosine, a purine nucleoside, plays an important function in the pathogenesis of cancer through interaction with the cell surface G protein-coupled adenosine receptors. It is important to determine the expression pattern of these receptors in different cancers. Previously in our lab, we found up-regulation of A1 adenosine receptor (AR) in lung tumors playing as a putative target for cancer cell inhibition, and here we aimed to investigate the significance of other adenosine receptor isoforms (A2aAR, A2bAR, and A3AR). METHODS: In this study, first of all, we evaluated the adenosine receptors gene expression in the bioinformatics database (GENT2). Then the genes expression was measured experimentally in the 20 lung cancer tumor tissues in comparison to the matched tumor-adjacent normal tissue (as control). The mRNA expression of receptors was evaluated by real-time PCR. The tumors were categorized by the tumor size and the gene expression change was evaluated. RESULTS: The experimental results indicated a significant increase in A2aAR (p value = .021) and A3AR (p value = .01) expression in lung tumor tissues compared to the adjacent tumor margins which were in accordant to bioinformatics analysis. We found a non-significant increase in A2bAR expression; however, when comparing the patients according to the tumor size, our data showed that the expression of A2bAR adenosine receptor in patients with smaller lung tumor sizes was higher than the other group (p = .011). CONCLUSION: The results of this study showed that adenosine receptors A3AR, and A2aAR are highly expressed in lung tumors relative to tumor-adjacent normal tissue. We suggest that overexpression of adenosine receptors in lung cancer is due to their regulatory role in various aspects of lung cancer.

Identification of Synovial Fibroblast-Associated Neuropeptide Genes and m6A Factors in Rheumatoid Arthritis Using Single-Cell Analysis and Machine Learning.

OBJECTIVES: Synovial fibroblasts (SFs) play an important role in the development and progression of rheumatoid arthritis (RA). However, the pathogenic mechanism of SFs remains unclear. The objective of this study was to investigate how neuropeptides and N6-methyladenosine (m6A) played an important role in the underlying pathogenic processes of SFs that contribute to the development of RA. METHODS: Single-cell RNA sequencing data were examined using single-cell analysis and machine learning. SF subgroups were identified based on the clustering and annotation results of the single-cell analysis. Moreover, cell-cell communication was used to analyse neuropeptide-related receptor and ligand pairs on the surface of SF cell membranes. Machine learning was used to explore the m6A factors acting on these neuropeptide genes. RESULTS: NPR3, GHR, BDKRB2, and CALCRL, four neuropeptide genes, were shown to be differently expressed among SF subgroups. Further investigation of receptor-ligand interactions found that NPR3 (in conjunction with NPPC, OSTN, NPPB, and NPPA) and GHR (in conjunction with GH1 and GH2) may have a role in SF interactions. As predicted by machine learning, IGFBP2 and METTL3 were identified as key factors regulating m6A of NPR3 and GHR. The expression levels and enrichment pathways of METTL3 and IGFBP2 were different among SF subgroups. CONCLUSIONS: Single-cell analysis and machine learning efficiently identified neuropeptide genes and m6A factors that perform important regulatory functions in RA. Our strategy may provide a basis for future studies to identify pathogenic cell subpopulations and molecular mechanisms in RA and other diseases.

N6-methyladenosine-induced SVIL antisense RNA 1 restrains lung adenocarcinoma cell proliferation by destabilizing E2F1.

Accumulating evidence indicates that N6-methyladenosine (m6A) and long noncoding RNAs (lncRNAs) play crucial roles in cancer development. However, the biological roles of m6A and lncRNAs in lung cancer tumorigenesis are largely unknown. In this study, SVIL antisense RNA 1 (SVIL-AS1) was downregulated in lung adenocarcinoma (LUAD) tissues and was associated with a favorable prognosis in patients with LUAD. SVIL-AS1 overexpression suppressed LUAD cell proliferation and blocked cell cycle arrest. Mechanistically, METTL3 increased the m6A modification and transcript stability of SVIL-AS1. The enhanced SVIL-AS1 expression mediated by METTL3 suppressed E2F1 and E2F1-target genes. Moreover, SVIL-AS1 accelerated E2F1 degradation. The reduction in cell proliferation induced by SVIL-AS1 overexpression could be rescued by E2F1 overexpression or METTL3 knockdown. In conclusion, our work demonstrated the role and mechanism of METTL3-induced SVIL-AS1 in LUAD, which connects m6A and lncRNA in lung cancer carcinogenesis.

Characterization of the m6A-related lncRNA signature in predicting prognosis and immune response in patients with colon cancer.

PURPOSE: Colon adenocarcinoma (COAD) is globally one of the most frequently occurring malignant tumors. The patients' 5-year survival rate with colon cancer was poor. There is a usual form of mRNA modification called N6-methyl adenosine (m6A). It is adjusted by the m6A RNA methylation modulator. Nevertheless, few studies of COAD can fully discuss m6A-related lncRNAs' prognostic function. METHODS: From The Cancer Genome Atlas (TCGA) database, this study of COAD samples discussed 23 m6A regulator-related lncRNAs systemically. 2 m6A patterns with various clinical results were recognized, and a remarkable correlation between various m6A clusters and tumor immune microenvironment was discovered. RESULTS: According to prognostic analysis, cluster1 had a higher immune checkpoint programmed death-ligand 1 (PD-L1) expression and a better prognosis. A 6 m6A-related lncRNAs model was constructed through least absolute shrinkage and selection operator (LASSO), univariate, multivariate Cox regression and stratified analysis. The outcomes reported that compared with the low-risk group, high-risk groups that were based on model closely were related to poor overall survival (OS). The study ensured a risk model consisting of 6 m6A-related lncRNAs as independent prognosis predictors. For the expression differences between the two groups, Genomes Pathway Analysis, Kyoto Encyclopedia of Genes (KEGG) and Gene Ontology (GO) biological process analyses were conducted. In addition, on the basis of full analysis of OS, a nomogram based on gender, age, lncRNA feature and the stage was constructed. One year, two years, and three years are the periods when the calibration chart performed best. CONCLUSIONS: The outcomes of the study confirmed the underlying function of m6A-related lncRNAs and offered fresh perspectives to COAD prognosis.

Physio-pathological effects of m6A modification and its potential contribution to melanoma

Methylation of N6-adenosine (m6A) is the most prevalent internal RNA modification and is especially common among the messenger RNAs. These m6A modifications regulate splicing, translocation, stability and translation of RNA through dynamic and reversible interactions with m6A-binding proteins, namely the writers, erasers and readers. RNA methyltransferases catalyze the m6A modifications, while demethylases reverse this methylation. Deregulation of the m6A modification process has been implicated in human carcinogenesis, including melanoma—which carries one of the highest mutant rates. In this review, we provide an up-to-date summary of m6A regulation and its biological impacts on normal and cancer cells, with emphasis on the deregulation of m6A modification and m6A regulators in melanoma. In addition, we highlight the prospective potential of exploiting m6A modification in the treatment of melanoma and non-cancer diseases. (AU)

Emerging roles of dysregulated adenosine homeostasis in brain disorders with a specific focus on neurodegenerative diseases.

In modern societies, with an increase in the older population, age-related neurodegenerative diseases have progressively become greater socioeconomic burdens. To date, despite the tremendous effort devoted to understanding neurodegenerative diseases in recent decades, treatment to delay disease progression is largely ineffective and is in urgent demand. The development of new strategies targeting these pathological features is a timely topic. It is important to note that most degenerative diseases are associated with the accumulation of specific misfolded proteins, which is facilitated by several common features of neurodegenerative diseases (including poor energy homeostasis and mitochondrial dysfunction). Adenosine is a purine nucleoside and neuromodulator in the brain. It is also an essential component of energy production pathways, cellular metabolism, and gene regulation in brain cells. The levels of intracellular and extracellular adenosine are thus tightly controlled by a handful of proteins (including adenosine metabolic enzymes and transporters) to maintain proper adenosine homeostasis. Notably, disruption of adenosine homeostasis in the brain under various pathophysiological conditions has been documented. In the past two decades, adenosine receptors (particularly A1 and A2A adenosine receptors) have been actively investigated as important drug targets in major degenerative diseases. Unfortunately, except for an A2A antagonist (istradefylline) administered as an adjuvant treatment with levodopa for Parkinson's disease, no effective drug based on adenosine receptors has been developed for neurodegenerative diseases. In this review, we summarize the emerging findings on proteins involved in the control of adenosine homeostasis in the brain and discuss the challenges and future prospects for the development of new therapeutic treatments for neurodegenerative diseases and their associated disorders based on the understanding of adenosine homeostasis.

Dysregulated N6-methyladenosine (m6A) processing in hepatocellular carcinoma.

N6-methyladenosine (m6A) is the most thoroughly studied type of internal RNA modification, as this epigenetic modification is the most abundant in eukaryotic RNAs to date. This modification occurs in various types of RNAs and plays significant roles in dominant RNA-related processes, such as translation, splicing, export and degradation. These processes are catalyzed by three types of prominent enzymes: writers, erasers and readers. Increasing evidence has shown that m6A modification is vital for the regulation of gene expression, carcinogenesis, tumor progression and other abnormal changes, and recent studies have shown that m6A is important in the development of hepatocellular carcinoma (HCC). Herein, we summarize the nature and regulatory mechanisms of m6A modification, including its role in the pathogenesis of HCC and related chronic liver diseases. We also highlight the clinical significance and future strategies involving RNA m6A modifications in HCC.

The component of the m6A writer complex VIRMA is implicated in aggressive tumor phenotype, DNA damage response and cisplatin resistance in germ cell tumors.

BACKGROUND: Germ cell tumors (GCTs) are developmental cancers, tightly linked to embryogenesis and germ cell development. The recent and expanding field of RNA modifications is being increasingly implicated in such molecular events, as well as in tumor progression and resistance to therapy, but still rarely explored in GCTs. In this work, and as a follow-up of our recent study on this topic in TGCT tissue samples, we aim to investigate the role of N6-methyladenosine (m6A), the most abundant of such modifications in mRNA, in in vitro and in vivo models representative of such tumors. METHODS: Four cell lines representative of GCTs (three testicular and one mediastinal), including an isogenic cisplatin resistant subline, were used. CRISPR/Cas9-mediated knockdown of VIRMA was established and the chorioallantoic membrane assay was used to study its phenotypic effect in vivo. RESULTS: We demonstrated the differential expression of the various m6A writers, readers and erasers in GCT cell lines representative of the major classes of these tumors, seminomas and non-seminomas, and we evidenced changes occurring upon differentiation with all-trans retinoic acid treatment. We showed differential expression also among cells sensitive and resistant to cisplatin treatment, implicating these players in acquisition of cisplatin resistant phenotype. Knockdown of VIRMA led to disruption of the remaining methyltransferase complex and decrease in m6A abundance, as well as overall reduced tumor aggressiveness (with decreased cell viability, tumor cell proliferation, migration, and invasion) and increased sensitivity to cisplatin treatment, both in vitro and confirmed in vivo. Enhanced response to cisplatin after VIRMA knockdown was related to significant increase in DNA damage (with higher γH2AX and GADD45B levels) and downregulation of XLF and MRE11. CONCLUSIONS: VIRMA has an oncogenic role in GCTs confirming our previous tissue-based study and is further involved in response to cisplatin by interfering with DNA repair. These data contribute to our better understanding of the emergence of cisplatin resistance in GCTs and support recent attempts to therapeutically target elements of the m6A writer complex.

m6A mRNA Methylation Regulates Epithelial Innate Antimicrobial Defense Against Cryptosporidial Infection.

Increasing evidence supports that N6-methyladenosine (m6A) mRNA modification may play an important role in regulating immune responses. Intestinal epithelial cells orchestrate gastrointestinal mucosal innate defense to microbial infection, but underlying mechanisms are still not fully understood. In this study, we present data demonstrating significant alterations in the topology of host m6A mRNA methylome in intestinal epithelial cells following infection by Cryptosporidium parvum, a coccidian parasite that infects the gastrointestinal epithelium and causes a self-limited disease in immunocompetent individuals but a life-threatening diarrheal disease in AIDS patients. Altered m6A methylation in mRNAs in intestinal epithelial cells following C. parvum infection is associated with downregulation of alpha-ketoglutarate-dependent dioxygenase alkB homolog 5 and the fat mass and obesity-associated protein with the involvement of NF-кB signaling. Functionally, m6A methylation statuses influence intestinal epithelial innate defense against C. parvum infection. Specifically, expression levels of immune-related genes, such as the immunity-related GTPase family M member 2 and interferon gamma induced GTPase, are increased in infected cells with a decreased m6A mRNA methylation. Our data support that intestinal epithelial cells display significant alterations in the topology of their m6A mRNA methylome in response to C. parvum infection with the involvement of activation of the NF-кB signaling pathway, a process that modulates expression of specific immune-related genes and contributes to fine regulation of epithelial antimicrobial defense.

The role of N6-methyladenosine (m6A) in eye diseases.

N6-methyladenosine (m6A) is the most common form of internal RNA modification in eukaryotes. The dynamic regulation of m6A modification mainly rely on three proteases, installed by m6A methyltransferase, removed by m6A demethylase and recognized by m6A reader protein, which regulates the metabolism of RNA, thereby regulating the processes of cell proliferation, migration, invasion and apoptosis. Recently, a number of studies have found that m6A aberrant methylation in some eye diseases. This review was to summarize the recent research progress on the role of m6A modification in eye diseases and give a perspective on its prospective applications in eye diseases.

Physio-pathological effects of m6A modification and its potential contribution to melanoma.

Methylation of N6-adenosine (m6A) is the most prevalent internal RNA modification and is especially common among the messenger RNAs. These m6A modifications regulate splicing, translocation, stability and translation of RNA through dynamic and reversible interactions with m6A-binding proteins, namely the writers, erasers and readers. RNA methyltransferases catalyze the m6A modifications, while demethylases reverse this methylation. Deregulation of the m6A modification process has been implicated in human carcinogenesis, including melanoma-which carries one of the highest mutant rates. In this review, we provide an up-to-date summary of m6A regulation and its biological impacts on normal and cancer cells, with emphasis on the deregulation of m6A modification and m6A regulators in melanoma. In addition, we highlight the prospective potential of exploiting m6A modification in the treatment of melanoma and non-cancer diseases.

Lower beta cell yield from donor pancreases after controlled circulatory death prevented by shortening acirculatory warm ischemia time and by using IGL-1 cold preservation solution.

Organs from donors after controlled circulatory death (DCD III) exhibit a higher risk for graft dysfunction due to an initial period of warm ischemia. This procurement condition can also affect the yield of beta cells in islet isolates from donor pancreases, and hence their use for transplantation. The present study uses data collected and generated by our Beta Cell Bank to compare the number of beta cells in isolates from DCD III (n = 141) with that from donors after brain death (DBD, n = 609), before and after culture, and examines the influence of donor and procurement variables. Beta cell number per DCD III-organ was significantly lower (58 x 106 versus 84 x 106 beta cells per DBD-organ; p < 0.001) but their purity (24% insulin positive cells) and insulin content (17 µg / 106 beta cells in DCD III-organs versus 19 µg / 106 beta cells in DBD-organs) were similar. Beta cell number correlated negatively with duration of acirculatory warm ischemia time above 10 min; for shorter acirculatory warm ischemia time, DCD III-organs did not exhibit a lower beta cell yield (74 x 106 beta cells). Use of Institut Georges Lopez-1 cold preservation solution instead of University of Wisconsin solution or histidine-tryptophan-ketoglutarate also protected against the loss in beta cell yield from DCD III-organs (86 x 106 for IGL-1 versus 54 x 106 and 65 x 106 beta cells respectively, p = 0.042). Multivariate analysis indicates that both limitation of acirculatory warm ischemia time and use of IGL-1 prevent the reduced beta cell yield in islet cell isolates from DCD III-organs.

Testicular adenosine acts as a pro-inflammatory molecule: role of testicular peritubular cells.

Extracellular ATP has been described to be involved in inflammatory cytokine production by human testicular peritubular cells (HTPCs). The ectonucleotidases ENTPD1 and NT5E degrade ATP and have been reported in rodent testicular peritubular cells. We hypothesized that if a similar situation exists in human testis, ATP metabolites may contribute to cytokine production. Indeed, ENTPD1 and NT5E were found in situ and in vitro in HTPCs. Malachite green assays confirmed enzyme activities in HTPCs. Pharmacological inhibition of ENTPD1 (by POM-1) significantly reduced pro-inflammatory cytokines evoked by ATP treatment, suggesting that metabolites of ATP, including adenosine, are likely involved. We focused on adenosine and detected three of the four known adenosine receptors in HTPCs. One, A2B, was also found in situ in peritubular cells of human testicular sections. The A2B agonist BAY60-6583 significantly elevated levels of IL6 and CXCL8, a result also obtained with adenosine and its analogue NECA. Results of siRNA-mediated A2B down-regulation support a role of this receptor. In mouse peritubular cells, in contrast to HTPCs, all four of the known adenosine receptors were detected; when challenged with adenosine, cytokine expression levels significantly increased. Organotypic short-term testis cultures yielded comparable results and indicate an overall pro-inflammatory action of adenosine in the mouse testis. If transferable to the in vivo situation, our results may implicate that interference with the generation of ATP metabolites or interference with adenosine receptors could reduce inflammatory events in the testis. These novel insights may provide new avenues for treatment of sterile inflammation in male subfertility and infertility.

ENTPD1 (CD39) Expression Inhibits UVR-Induced DNA Damage Repair through Purinergic Signaling and Is Associated with Metastasis in Human Cutaneous Squamous Cell Carcinoma.

UVR and immunosuppression are major risk factors for cutaneous squamous cell carcinoma (cSCC). Regulatory T cells promote cSCC carcinogenesis, and in other solid tumors, infiltrating regulatory T cells and CD8+ T cells express ectonucleoside triphosphate diphosphohydrolase 1 (ENTPD1) (also known as CD39), an ectoenzyme that catalyzes the rate-limiting step in converting extracellular adenosine triphosphate (ATP) to extracellular adenosine (ADO). We previously showed that extracellular purine nucleotides influence DNA damage repair. In this study, we investigate whether DNA damage repair is modulated through purinergic signaling in cSCC. We found increased ENTPD1 expression on T cells within cSCCs when compared with the expression on T cells from blood or nonlesional skin, and accordingly, concentrations of derivative extracellular adenosine diphosphate (ADP), adenosine monophosphate (AMP), and ADO are increased in tumors compared with those in normal skin. Importantly, ENTPD1 expression is significantly higher in human cSCCs that metastasize than in those that are nonmetastatic. We also identify in a mouse model that ENTPD1 expression is induced by UVR in an IL-27-dependent manner. Finally, increased extracellular ADO is shown to downregulate the expression of NAP1L2, a nucleosome assembly protein we show to be important for DNA damage repair secondary to UVR. Together, these data suggest a role for ENTPD1 expression on skin-resident T cells to regulate DNA damage repair through purinergic signaling to promote skin carcinogenesis and metastasis.

RNA N6-methyladenosine: a new player in autophagy-mediated anti-cancer drug resistance.

Dysregulation of N6-methyladenosine (m6A) modification is associated with cancer development and progression. The m6A modification plays a crucial role in autophagy regulation precipitating anti-cancer drug resistance. In line with this fact, this commentary discusses m6A modification interfering with autophagy machinery as a major contributing factor for drug resistance in cancer.

m6A regulator-mediated RNA methylation modification patterns are involved in immune microenvironment regulation of periodontitis.

The role of epigenetic regulation in immunity is emerging, especially for RNA N6-methyladenosine (m6A) modification. However, little is known about the role of m6A in the regulation of the immune microenvironment of periodontitis. Thus, we aim to investigate the impact of m6A modification in periodontitis immune microenvironment. The RNA modification patterns mediated by 23 m6A-regulators were systematically evaluated in 310 periodontitis samples. The impact of m6A modification on immune microenvironment characteristics was explored, including infiltrating immunocytes, immune reaction gene-sets and HLAs (human leukocyte antigen) gene. m6A phenotype-related immune genes were also identified. 17 m6A regulators were dysregulated and a 15-m6A regulator signature can well distinguish periodontitis and control samples. ALKBH5 and FMR1 are closely related to infiltrating monocyte abundance. ELAVL1 and CBLL1 are significant regulators in immune reaction of TNF_Family_Members_Receptors and Cytokine. The expression of HLA-B and HLA-DOA is affected by ALKBH5 and LRPPRC. 3 distinct RNA modification patterns mediated by 23 m6A regulators were identified. They differ from immunocyte abundance, immune reaction and HLA gene. 1631 m6A phenotype-related genes and 70 m6A-mediated immune genes were identified, and the biological functions of these were explored. Our finding demonstrated the m6A modification plays a crucial role in the diversity and complexity of the immune microenvironment of periodontitis.

Analysis of N6-methyladenosine reveals a new important mechanism regulating the salt tolerance of sweet sorghum.

The N6-methyladenosine (m6A) modification is the most common internal post-transcriptional modification, with important regulatory effects on RNA export, splicing, stability, and translation. Studies on the m6A modifications in plants have focused on Arabidopsis thaliana growth and development. However, A. thaliana is a salt-sensitive and model plant species. Thus, studies aimed at characterizing the role of the m6A modification in the salt stress responses of highly salt-tolerant crop species are needed. Sweet sorghum is cultivated as an energy and forage crop, which is highly suitable for growth on saline-alkaline land. Exploring the m6A modification in sweet sorghum may be important for elucidating the salt-resistance mechanism of crops. In this study, we mapped the m6A modifications in two sorghum genotypes (salt-tolerant M-81E and salt-sensitive Roma) that differ regarding salt tolerance. The m6A modification in sweet sorghum under salt stress was drastically altered, especially in Roma, where the m6A modification on mRNAs of some salt-resistant related transcripts increased, resulting in enhanced mRNA stability, which in turn was involved in the regulation of salt tolerance in sweet sorghum. Although m6A modifications are important for regulating sweet sorghum salt tolerance, the regulatory activity is limited by the initial m6A modification level. Additionally, in M-81E and Roma, the differences in the m6A modifications were much greater than the differences in gene expression levels and are more sensitive. Our study suggests that the number and extent of m6A modifications on the transcripts of salt-resistance genes may be important factors for determining and assessing the salt tolerance of crops.

Loss of CD73 shifts transforming growth factor-ß1 (TGF-ß1) from tumor suppressor to promoter in endometrial cancer.

In many tumors, CD73 (NT5E), a rate-limiting enzyme in adenosine biosynthesis, is upregulated by TGF-ß and drives tumor progression. Conversely, CD73 is downregulated in endometrial carcinomas (EC) despite a TGF-ß-rich environment. Through gene expression analyses of normal endometrium samples of the uterine cancer TCGA data set and genetic and pharmacological studies, we discovered CD73 loss shifts TGF-ß1 from tumor suppressor to promoter in EC. TGF-ß1 upregulated CD73 and epithelial integrity in vivo in the normal endometrium and in vitro in early stage EC cells. With loss of CD73, TGF-ß1-mediated epithelial integrity was abrogated. EC cells developed TGF-ß1-mediated stress fibers and macromolecule permeability, migration, and invasion increased. In human tumors, CD73 is downregulated in deeply invasive stage I EC. Consistent with shifting TGF-ß1 activity, CD73 loss increased TGF-ß1-mediated canonical signaling and upregulated cyclin D1 (CCND1) and downregulated p21 expression. This shift was clinically relevant, as CD73Low/CCND1High expression associated with poor tumor differentiation, increased myometrial and lymphatic/vascular space invasion, and patient death. Further loss of CD73 in CD73Low expressing advanced stage EC cells increased TGF-ß-mediated stress fibers, signaling, and invasiveness, whereby adenosine A1 receptor agonist, CPA, dampened TGF-ß-mediated invasion. These data identify CD73 loss as essential for shifting TGF-ß activity in EC.