TERRA stability is regulated by RALY and polyadenylation in a telomere-specific manner.

Telomeric repeat-containing RNA (TERRA) is a long non-coding RNA transcribed from telomeres that plays key roles in telomere maintenance. A fraction of TERRA is polyadenylated, and the presence of the poly(A) tail influences TERRA localization and stability. However, the mechanisms of TERRA biogenesis remain mostly elusive. Here, we show that the stability of TERRA transcripts is regulated by the RNA-binding protein associated with lethal yellow mutation (RALY). RALY depletion results in lower TERRA levels, impaired localization of TERRA at telomeres, and ultimately telomere damage. Importantly, we show that TERRA polyadenylation is telomere specific and that RALY preferentially stabilizes non-polyadenylated TERRA transcripts. Finally, we report that TERRA interacts with the poly(A)-binding protein nuclear 1 (PABPN1). Altogether, our results indicate that TERRA stability is regulated by the interplay between RALY and PABPN1, defined by the TERRA polyadenylation state. Our findings also suggest that different telomeres may trigger distinct TERRA-mediated responses.

The "Sandwich" Schedule: A Well-Tolerated Adjuvant Treatment Both in Intermediate-High- and High-Risk Endometrial Cancer.

(1) Background: In intermediate-high- and high-risk endometrial cancer (EC), radiotherapy (RT) and chemotherapy (CT) play a basic role. However, there is controversy regarding the optimal timing of their combination. The "sandwich" schedule involves adjuvant CT followed by RT and subsequent CT. The aim of this study is to assess the tolerability and efficacy of the "sandwich" schedule. (2) Methods: A retrospective study was conducted in two gynecological oncology units in Torino, Italy, from 1 January 2003 until 31 December 2021. Intermediate-high- and high-risk patients with available clinical data were included. Compliance with treatment, CT and RT toxicities, disease-free survival (DFS), cancer-specific survival (CSS) and overall survival (OS) were analyzed. (3) Results: A total of 118 patients were selected: 27.1% FIGO I-II stages and 72.9% III-IV. Most of the patients (75.4%) received a carboplatin-paclitaxel combination, and as much as 94.9% of CT cycles were completed. Chemotherapy-related G3-4 toxicities were detected in 5.3% of the patients, almost half of which were hematological. Grade 2 gastrointestinal and genitourinary toxicities were reported in 8.4% and 4.2% of cases, respectively. With a median follow-up of 46 months, DFS was 77.6%, CSS was 70% and 5-year OS was 54%. (4) Conclusions: The "sandwich" schedule for CT and RT combination is an effective adjuvant treatment with low toxicity both in intermediate-high- and high-risk EC.

LncRNA EPR-induced METTL7A1 modulates target gene translation.

EPR is a long non-coding RNA (lncRNA) that controls cell proliferation in mammary gland cells by regulating gene transcription. Here, we report on Mettl7a1 as a direct target of EPR. We show that EPR induces Mettl7a1 transcription by rewiring three-dimensional chromatin interactions at the Mettl7a1 locus. Our data indicate that METTL7A1 contributes to EPR-dependent inhibition of TGF-ß signaling. METTL7A1 is absent in tumorigenic murine mammary gland cells and its human ortholog (METTL7A) is downregulated in breast cancers. Importantly, re-expression of METTL7A1 in 4T1 tumorigenic cells attenuates their transformation potential, with the putative methyltransferase activity of METTL7A1 being dispensable for its biological functions. We found that METTL7A1 localizes in the cytoplasm whereby it interacts with factors implicated in the early steps of mRNA translation, associates with ribosomes, and affects the levels of target proteins without altering mRNA abundance. Overall, our data indicates that METTL7A1-a transcriptional target of EPR-modulates translation of select transcripts.

Studying RNP Composition with RIP.

RNA is never left alone throughout its life cycle. Together with proteins, RNAs form membraneless organelles, called ribonucleoprotein particles (RNPs) where these two types of macromolecules strongly influence each other's functions and destinies. RNA immunoprecipitation is still one of the favorite techniques which allows to simultaneously study both the RNA and protein composition of the RNP complex.

TranSNPs: A class of functional SNPs affecting mRNA translation potential revealed by fraction-based allelic imbalance.

Few studies have explored the association between SNPs and alterations in mRNA translation potential. We developed an approach to identify SNPs that can mark allele-specific protein expression levels and could represent sources of inter-individual variation in disease risk. Using MCF7 cells under different treatments, we performed polysomal profiling followed by RNA sequencing of total or polysome-associated mRNA fractions and designed a computational approach to identify SNPs showing a significant change in the allelic balance between total and polysomal mRNA fractions. We identified 147 SNPs, 39 of which located in UTRs. Allele-specific differences at the translation level were confirmed in transfected MCF7 cells by reporter assays. Exploiting breast cancer data from TCGA we identified UTR SNPs demonstrating distinct prognosis features and altering binding sites of RNA-binding proteins. Our approach produced a catalog of tranSNPs, a class of functional SNPs associated with allele-specific translation and potentially endowed with prognostic value for disease risk.

DHX30 Coordinates Cytoplasmic Translation and Mitochondrial Function Contributing to Cancer Cell Survival.

DHX30 was recently implicated in the translation control of mRNAs involved in p53-dependent apoptosis. Here, we show that DHX30 exhibits a more general function by integrating the activities of its cytoplasmic isoform and of the more abundant mitochondrial one. The depletion of both DHX30 isoforms in HCT116 cells leads to constitutive changes in polysome-associated mRNAs, enhancing the translation of mRNAs coding for cytoplasmic ribosomal proteins while reducing the translational efficiency of the nuclear-encoded mitoribosome mRNAs. Furthermore, the depletion of both DHX30 isoforms leads to higher global translation but slower proliferation and lower mitochondrial energy metabolism. Isoform-specific silencing supports a role for cytoplasmic DHX30 in modulating global translation. The impact on translation and proliferation was confirmed in U2OS and MCF7 cells. Exploiting RIP, eCLIP, and gene expression data, we identified fourteen mitoribosome transcripts we propose as direct DHX30 targets that can be used to explore the prognostic value of this mechanism in cancer. We propose that DHX30 contributes to cell homeostasis by coordinating ribosome biogenesis, global translation, and mitochondrial metabolism. Targeting DHX30 could, thus, expose a vulnerability in cancer cells.

Multilayer and MATR3-dependent regulation of mRNAs maintains pluripotency in human induced pluripotent stem cells.

Matrin3 (MATR3) is a nuclear RNA/DNA-binding protein that plays pleiotropic roles in gene expression regulation by directly stabilizing target RNAs and supporting the activity of transcription factors by modulating chromatin architecture. MATR3 is involved in the differentiation of neural cells, and, here, we elucidate its critical functions in regulating pluripotent circuits in human induced pluripotent stem cells (hiPSCs). MATR3 downregulation affects hiPSCs' differentiation potential by altering key pluripotency regulators' expression levels, including OCT4, NANOG, and LIN28A by pleiotropic mechanisms. MATR3 binds to the OCT4 and YTHDF1 promoters favoring their expression. YTHDF1, in turn, binds the m6A-modified OCT4 mRNA. Furthermore, MATR3 is recruited on ribosomes and controls pluripotency regulating the translation of specific transcripts, including NANOG and LIN28A, by direct binding and favoring their stabilization. These results show that MATR3 orchestrates the pluripotency circuitry by regulating the transcription, translational efficiency, and epitranscriptome of specific transcripts.

Is concomitant treatment with steroids and radiotherapy more favorable than sequential treatment in moderate-to-severe graves orbitopathy?

PURPOSE: Glucocorticoids (GCs) and external radiotherapy (RT) are used for treating moderate-to-severe Graves' orbitopathy (GO). We aimed to assess whether GCs and RT were more effective when administered concomitantly or sequentially. METHODS: We retrospectively analyzed clinical outcomes [assessed by Clinical Activity Score (CAS) and NOSPECS classification] in 73 patients treated with both i.v. GCs and RT. The patients were divided in two groups: In group A (53 patients), RT was delivered concomitantly with GCs, and in group B (20 patients) RT was administered subsequently to the end of methylprednisolone. RESULTS: At baseline, CAS (median 4.0) and the percentage of patients encompassing the various grades of the classes 2, 3 and 4 of the NOSPECS score were similar in both groups. Six months after RT, CAS decreased to 2 in both groups (p = 0.0003 vs baseline) as well as NOSPECS class 4 (p < 0.0001 vs baseline). NOSPECS class 2 improved more in group A than in group B (p = 0.016). The median cumulative dose of GCs was lower in group A than in group B (median 4.500 vs 6000 mg, p < 0.007); the overall length of therapy was shorter in group A than in group B (68 vs 106 days, p < 0,02). The most common acute adverse effect was transient conjunctivitis (five in group A and three in group B); seven patients (five in group A and two in group B, age between 60 and 66 years) developed cataract, requiring surgery in five cases. CONCLUSIONS: Concomitant administration of GC and RT showed a favorable effect in moderate-to-severe GO, thus suggesting that RT should be carried out early during steroid therapy, when clinical symptoms do not improve or deteriorate after the first i.v. administrations of GCs.

Publisher Correction: Regulation of cellular sterol homeostasis by the oxygen responsive noncoding RNA lincNORS.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Translation control can shape TP53-dependent cell fate.

The search for mechanisms underlying different cellular responses to the treatment with Nutlin-3, an MDM2 inhibitor that unleashes p53, revealed a translational control mechanism involving the RNA binding proteins PCBP2 and, particularly, DHX30. Sifting through a multi-functional p53-dependent transcriptional output, this translational control can modulate the activation of cell death pathways.

Regulation of cellular sterol homeostasis by the oxygen responsive noncoding RNA lincNORS.

We hereby provide the initial portrait of lincNORS, a spliced lincRNA generated by the MIR193BHG locus, entirely distinct from the previously described miR-193b-365a tandem. While inducible by low O2 in a variety of cells and associated with hypoxia in vivo, our studies show that lincNORS is subject to multiple regulatory inputs, including estrogen signals. Biochemically, this lincRNA fine-tunes cellular sterol/steroid biosynthesis by repressing the expression of multiple pathway components. Mechanistically, the function of lincNORS requires the presence of RALY, an RNA-binding protein recently found to be implicated in cholesterol homeostasis. We also noticed the proximity between this locus and naturally occurring genetic variations highly significant for sterol/steroid-related phenotypes, in particular the age of sexual maturation. An integrative analysis of these variants provided a more formal link between these phenotypes and lincNORS, further strengthening the case for its biological relevance.

SMN-primed ribosomes modulate the translation of transcripts related to spinal muscular atrophy.

The contribution of ribosome heterogeneity and ribosome-associated proteins to the molecular control of proteomes in health and disease remains unclear. Here, we demonstrate that survival motor neuron (SMN) protein-the loss of which causes the neuromuscular disease spinal muscular atrophy (SMA)-binds to ribosomes and that this interaction is tissue-dependent. SMN-primed ribosomes are preferentially positioned within the first five codons of a set of mRNAs that are enriched for translational enhancer sequences in the 5' untranslated region (UTR) and rare codons at the beginning of their coding sequence. These SMN-specific mRNAs are associated with neurogenesis, lipid metabolism, ubiquitination, chromatin regulation and translation. Loss of SMN induces ribosome depletion, especially at the beginning of the coding sequence of SMN-specific mRNAs, leading to impairment of proteins that are involved in motor neuron function and stability, including acetylcholinesterase. Thus, SMN plays a crucial role in the regulation of ribosome fluxes along mRNAs encoding proteins that are relevant to SMA pathogenesis.

Nutlin-Induced Apoptosis Is Specified by a Translation Program Regulated by PCBP2 and DHX30.

Activation of p53 by the small molecule Nutlin can result in a combination of cell cycle arrest and apoptosis. The relative strength of these events is difficult to predict by classical gene expression analysis, leaving uncertainty as to the therapeutic benefits. In this study, we report a translational control mechanism shaping p53-dependent apoptosis. Using polysome profiling, we establish Nutlin-induced apoptosis to associate with the enhanced translation of mRNAs carrying multiple copies of an identified 3' UTR CG-rich motif mediating p53-dependent death (CGPD-motif). We identify PCBP2 and DHX30 as CGPD-motif interactors. We find that in cells undergoing persistent cell cycle arrest in response to Nutlin, CGPD-motif mRNAs are repressed by the PCBP2-dependent binding of DHX30 to the motif. Upon DHX30 depletion in these cells, the translation of CGPD-motif mRNAs increases, and the response to Nutlin shifts toward apoptosis. Instead, DHX30 inducible overexpression in SJSA1 cells leads to decreased translation of CGPD-motif mRNAs.

Conserved Pseudoknots in lncRNA MEG3 Are Essential for Stimulation of the p53 Pathway.

Long non-coding RNAs (lncRNAs) are key regulatory molecules, but unlike with other RNAs, the direct link between their tertiary structure motifs and their function has proven elusive. Here we report structural and functional studies of human maternally expressed gene 3 (MEG3), a tumor suppressor lncRNA that modulates the p53 response. We found that, in an evolutionary conserved region of MEG3, two distal motifs interact by base complementarity to form alternative, mutually exclusive pseudoknot structures ("kissing loops"). Mutations that disrupt these interactions impair MEG3-dependent p53 stimulation in vivo and disrupt MEG3 folding in vitro. These findings provide mechanistic insights into regulation of the p53 pathway by MEG3 and reveal how conserved motifs of tertiary structure can regulate lncRNA biological function.

The hnRNP RALY regulates PRMT1 expression and interacts with the ALS-linked protein FUS: implication for reciprocal cellular localization.

The RBP associated with lethal yellow mutation (RALY) is a member of the heterogeneous nuclear ribonucleoprotein family whose transcriptome and interactome have been recently characterized. RALY binds poly-U rich elements within several RNAs and regulates the expression as well as the stability of specific transcripts. Here we show that RALY binds PRMT1 mRNA and regulates its expression. PRMT1 catalyzes the arginine methylation of Fused in Sarcoma (FUS), an RNA-binding protein that interacts with RALY. We demonstrate that RALY down-regulation decreases protein arginine N-methyltransferase 1 levels, thus reducing FUS methylation. It is known that mutations in the FUS nuclear localization signal (NLS) retain the protein to the cytosol, promote aggregate formation, and are associated with amyotrophic lateral sclerosis. Confirming that inhibiting FUS methylation increases its nuclear import, we report that RALY knockout enhances FUS NLS mutants' nuclear translocation, hence decreasing aggregate formation. Furthermore, we characterize the RNA-dependent interaction of RALY with FUS in motor neurons. We show that mutations in FUS NLS as well as in RALY NLS reciprocally alter their localization and interaction with target mRNAs. These data indicate that RALY's activity is impaired in FUS pathology models, raising the possibility that RALY might modulate disease onset and/or progression.

HuD Is a Neural Translation Enhancer Acting on mTORC1-Responsive Genes and Counteracted by the Y3 Small Non-coding RNA.

The RNA-binding protein HuD promotes neurogenesis and favors recovery from peripheral axon injury. HuD interacts with many mRNAs, altering both stability and translation efficiency. We generated a nucleotide resolution map of the HuD RNA interactome in motor neuron-like cells, identifying HuD target sites in 1,304 mRNAs, almost exclusively in the 3' UTR. HuD binds many mRNAs encoding mTORC1-responsive ribosomal proteins and translation factors. Altered HuD expression correlates with the translation efficiency of these mRNAs and overall protein synthesis, in a mTORC1-independent fashion. The predominant HuD target is the abundant, small non-coding RNA Y3, amounting to 70% of the HuD interaction signal. Y3 functions as a molecular sponge for HuD, dynamically limiting its recruitment to polysomes and its activity as a translation and neuron differentiation enhancer. These findings uncover an alternative route to the mTORC1 pathway for translational control in motor neurons that is tunable by a small non-coding RNA.

Rates, Sites and Times of Recurrence and Clinical Outcome of Endometrial Cancer Patients with Histologically-positive Nodes: An Italian Two-center Retrospective Study.

BACKGROUND/AIM: To assess the patterns of recurrence of node-positive endometrial cancer patients. PATIENTS AND METHODS: This investigation assessed 82 patients who received different postoperative treatments. RESULTS: Recurrence developed in 36 patients after a median time of 13.5 months, and involved the vagina, pelvic nodes, para-aortic nodes and distant sites in 5, 8, 16 and 17 patients, respectively. Five-year progression-free survival (PFS) and 5-year overall survival (OS) were 51.1% and 59.8%. PFS and OS were significantly better for endometrioid than for non-endometrioid tumors. There was a trend towards a better outcome for patients who underwent chemotherapy±radiotherapy compared to those who received radiotherapy alone. Among the former, there was a better 5-year PFS (65.8% versus 33.7%, p=0.038) in patients who received platinum/paclitaxel-based regimens compared to those who received platinum-based chemotherapy. CONCLUSION: Disease recurred in 43.9% of patients, and platinum/paclitaxel-based chemotherapy plus radiotherapy appeared to be the best adjuvant treatment.

Heterotopic ossifications: role of radiotherapy as prophylactic treatment.

BACKGROUND: Heterotopic ossification (HO) is abnormal formation of lamellar bone in soft tissue; the most frequent causes are total hip arthroplasty and trauma. Severe cases can lead to ankilosis with important impact on quality of life. Surgery is the elective treatment, but, especially in high-risk patients, it is important to prevent the re-formation of HO and, in these cases, radiotherapy (RT) can play an important role. MATERIALS AND METHODS: we retrospectively analyzed a mono-institutional casistic of 30 patients (31 sites) at high risk for HO development, treated with surgery and pre- or postoperative RT. The majority of patients received a single RT fraction of 7 Gy, median age was 62, with a prevalence of male and hip as most frequently involved site. Radiological studies and clinical examination were performed in all patients during the follow-up period to evaluate both treatment efficacy and acute or late toxicity. RESULTS: With a median follow up of 67 months, 23 patients had a complete response (CR) with excellent results in term of joint mobility. Two patients with CR showed a relapse of HO in the same site 19 and 12 months after treatment, respectively. Seven patients (22,6%) had a partial response (PR) to RT. One patient who reached CR had a history of previous irradiation in the same site 16 years before. No acute or late reactions have been reported. CONCLUSION: Our data confirm safety and efficacy of RT in preventing HO, especially in high-risk patients, preferring a single fraction of 7 Gy.

The hnRNP RALY regulates transcription and cell proliferation by modulating the expression of specific factors including the proliferation marker E2F1.

The heterogeneous nuclear ribonucleoproteins (hnRNP) form a large family of RNA-binding proteins that exert numerous functions in RNA metabolism. RALY is a member of the hnRNP family that binds poly-U-rich elements within several RNAs and regulates the expression of specific transcripts. RALY is up-regulated in different types of cancer, and its down-regulation impairs cell cycle progression. However, the RALY's role in regulating RNA levels remains elusive. Here, we show that numerous genes coding for factors involved in transcription and cell cycle regulation exhibit an altered expression in RALY-down-regulated HeLa cells, consequently causing impairments in transcription, cell proliferation, and cell cycle progression. Interestingly, by comparing the list of RALY targets with the list of genes affected by RALY down-regulation, we found an enrichment of RALY mRNA targets in the down-regulated genes upon RALY silencing. The affected genes include the E2F transcription factor family. Given its role as proliferation-promoting transcription factor, we focused on E2F1. We demonstrate that E2F1 mRNA stability and E2F1 protein levels are reduced in cells lacking RALY expression. Finally, we also show that RALY interacts with transcriptionally active chromatin in both an RNA-dependent and -independent manner and that this association is abolished in the absence of active transcription. Taken together, our results highlight the importance of RALY as an indirect regulator of transcription and cell cycle progression through the regulation of specific mRNA targets, thus strengthening the possibility of a direct gene expression regulation exerted by RALY.

Identification and dynamic changes of RNAs isolated from RALY-containing ribonucleoprotein complexes.

RALY is a member of the heterogeneous nuclear ribonucleoprotein family (hnRNP), a large family of RNA-binding proteins involved in many aspects of RNA metabolism. Although RALY interactome has been recently characterized, a comprehensive global analysis of RALY-associated RNAs is lacking and the biological function of RALY remains elusive. Here, we performed RIP-seq analysis to identify RALY interacting RNAs and assessed the role of RALY in gene expression. We demonstrate that RALY binds specific coding and non-coding RNAs and associates with translating mRNAs of mammalian cells. Among the identified transcripts, we focused on ANXA1 and H1FX mRNAs, encoding for Annexin A1 and for the linker variant of the histone H1X, respectively. Both proteins are differentially expressed by proliferating cells and are considered as markers for tumorigenesis. We demonstrate that cells lacking RALY expression exhibit changes in the levels of H1FX and ANXA1 mRNAs and proteins in an opposite manner. We also provide evidence for a direct binding of RALY to the U-rich elements present within the 3΄UTR of both transcripts. Thus, our results identify RALY as a poly-U binding protein and as a regulator of H1FX and ANXA1 in mammalian cells.