BRAFV600E induces reversible mitotic arrest in human melanocytes via microrna-mediated suppression of AURKB

Benign melanocytic nevi frequently emerge when an acquired BRAFV600E mutation triggers unchecked proliferation and subsequent arrest in melanocytes. Recent observations have challenged the role of oncogene-induced senescence in melanocytic nevus formation, necessitating investigations into alternative mechanisms for the establishment and maintenance of proliferation arrest in nevi. We compared the transcriptomes of melanocytes from healthy human skin, nevi, and melanomas arising from nevi and identified a set of microRNAs as highly expressed nevus-enriched transcripts. Two of these microRNAs—MIR211-5p and MIR328-3p—induced mitotic failure, genome duplication, and proliferation arrest in human melanocytes through convergent targeting of AURKB. We demonstrate that BRAFV600E induces a similar proliferation arrest in primary human melanocytes that is both reversible and conditional. Specifically, BRAFV600E expression stimulates either arrest or proliferation depending on the differentiation state of the melanocyte. We report genome duplication in human melanocytic nevi, reciprocal expression of AURKB and microRNAs in nevi and melanomas, and rescue of arrested human nevus cells with AURKB expression. Taken together, our data describe an alternative molecular mechanism for melanocytic nevus formation that is congruent with both experimental and clinical observations.

OncomiR miR-182-5p Enhances Radiosensitivity by Inhibiting the Radiation-Induced Antioxidant Effect through SESN2 in Head and Neck Cancer

Radiotherapy is routinely used for the treatment of head and neck squamous cell carcinoma (HNSCC). However, the therapeutic efficacy is usually reduced by acquired radioresistance and locoregional recurrence. In this study, The Cancer Genome Atlas (TCGA) analysis showed that radiotherapy upregulated the miR-182/96/183 cluster and that miR-182 was the most significantly upregulated. Overexpression of miR-182-5p enhanced the radiosensitivity of HNSCC cells by increasing intracellular reactive oxygen species (ROS) levels, suggesting that expression of the miR-182 family is beneficial for radiotherapy. By intersecting the gene targeting results from three microRNA target prediction databases, we noticed that sestrin2 (SESN2), a molecule resistant to oxidative stress, was involved in 91 genes predicted in all three databases to be directly recognized by miR-182-5p. Knockdown of SESN2 enhanced radiation-induced ROS and cytotoxicity in HNSCC cells. In addition, the radiation-induced expression of SESN2 was repressed by overexpression of miR-182-5p. Reciprocal expression of the miR-182-5p and SESN2 genes was also analyzed in the TCGA database, and a high expression of miR-182-5p combined with a low expression of SESN2 was associated with a better survival rate in patients receiving radiotherapy. Taken together, the current data suggest that miR-182-5p may regulate radiation-induced antioxidant effects and mediate the efficacy of radiotherapy.

The Effect of Inhibin Immunization in Seminiferous Epithelium of Yangzhou Goose Ganders: A Histological Study

The current study investigated the effect of inhibin immunization on germ cell numbers (spermatogonia, spermatocytes, round, and elongated spermatids), seminiferous tubules (ST) diameter, Johnsen’s score, epithelial height (μm), luminal tubular diameter (μm), and number of ST per field (ST/field) of Yangzhou goose ganders. Histological evaluation showed apoptosis and regression of testes after inhibin (INH) immunization, with a concomitantly marked reduction in the round and elongated spermatids in the experiment (INH) group compared to the control group. The diameter of seminiferous tubules (ST) and epithelial height (EH) were positively correlated at 181, 200, and 227 days of age. In comparison, luminal tubular diameter (LD) was negatively correlated on day 227 to ST diameter and epithelial height. On day 227, many seminiferous tubules per field (ST/field) were negatively correlated to ST diameter, EH, and LD. INH immunization elevated ST diameter, EH, and LD, while Johnsen’s score and number of ST/field had reciprocal expression. In conclusion, the concomitant effect of INH immunization and seasonality in breeding regressed germ cells and damaged spermatogenesis in seminiferous epithelium Yangzhou ganders.

Reflexive and Reciprocal Encoding in the Australian Mixed Language, Light Warlpiri

Mixed languages combine significant amounts of grammatical and lexical material from more than one source language in systematic ways. The Australian mixed language, Light Warlpiri, combines nominal morphology from Warlpiri with verbal morphology from Kriol (an English-lexified Creole) and English, with innovations. The source languages of Light Warlpiri differ in how they encode reflexives and reciprocals—Warlpiri uses an auxiliary clitic for both reflexive and reciprocal expression, while English and Kriol both use pronominal forms, and largely have separate forms for reflexives and reciprocals. English distinguishes person and number in reflexives, but not in reciprocals; the other source languages do not distinguish person or number. This study draws on naturalistic and elicited production data to examine how reflexive and reciprocal events are encoded in Light Warlpiri. The study finds that Light Warlpiri combines near-maximal distinctions from the source languages, but in a way that is not a mirror of any. It retains the person and number distinctions of English reflexives and extends them to reciprocals, using the same forms for reflexives and reciprocals (like Warlpiri). Reflexives and reciprocals occur within a verbal structure (perhaps under influence from Warlpiri). The results show that a mixed language can have discrete contributions from three languages, that the source languages can influence different subsystems to different extents, and that near-maximal distinctions from the source languages can be maintained.

Reciprocal modulation of Linc-223 and its ligand miR-125a on the basis of platelet function level

Background Cardiovacular diseases (CVD) are the leading cause of death worldwide. Platelet play a key role in the pathophysiology of multiple CVD. LincRNAs are long non-coding RNAs transcribed from intergenic DNA segments. Some members of this class were recently associated with human disease. Linc-223 is co-transcribed together with mir-223 and was recently shown to bind to miR-125. Both miR-223 and miR-125 are highly expressed in platelets. Purpose In light of the capability of Linc-223 to bind to miR-125, we aimed to investigate whether their reciprocal expression levels might reflect the degree of platelet activity. Methods RNA was extracted using miRVANA. MiRNAs and lncRNAs were measured by means of quantitative Real Time RT-PCR. Results We found a significant reduction of Linc-223 levels (p<0.05) along with a significant increase in miR-125 levels (p<0.05) after initiation of any antiplatelet treatment (n=30) compared to naïve patients (n=10). Moreover, the upgrade to a higher-intensity antiplatelet treatment with ASA+ticagrelor from ASA+clopidogrel (n=30) was associated to a further down-regulation of Linc-223 (p<0.05) along with a further increase of miR-125. (p<0.05). Finally, these results were validated in a larger cohort of 300 patients from the ATLANTIS study, demonstrating significant modulation of both miR-223 and miR-125 in patients with high on-treatment platelet aggregation levels compared to antiplatelet-responsive patients. Conclusions We identify a reciprocal modulation of Linc-223 and miR-125, its ligand upon different levels of platelet aggregations. These results are compatible with previous evidence from patients with Acute Myeloid Leukemia, that Linc-223 might bind to and sponge miR-125, inhibiting its effect. These results suggest that plasma levels of Linc-223, miR-125 and miR-223 might be used a biomarkers of platelet finction in a clinical context, for risk stratification of patients or to assess the responsiveness to antiplatelet treatments. Funding Acknowledgement Type of funding source: None

ABAS1 from soybean is a 1R-subtype MYB transcriptional repressor that enhances ABA sensitivity

Transcription factors (TFs) help plants respond to environmental stresses by regulating gene expression. Up till now, studies on the MYB family of TFs have mainly focused on the highly abundant R2R3-subtype. While the less well-known 1R-subtype has been generally shown to enhance abscisic acid (ABA) sensitivity by acting as transcriptional activators, the mechanisms of their functions are unclear. Here we identified an ABA sensitivity-associated gene from soybean, ABA-Sensitive 1 (GmABAS1), of the 1R-subtype of MYB. Using the GFP-GmABAS1 fusion protein, we demonstrated that GmABAS1 is localized in the nucleus, and with yeast reporter systems, we showed that it is a transcriptional repressor. We then identified the target gene of GmABAS1 to be Glyma.01G060300, an annotated ABI five-binding protein 3 and showed that GmABAS1 binds to the promoter of Glyma.01G060300 both in vitro and in vivo. Furthermore, Glyma.01G060300 and GmABAS1 exhibited reciprocal expression patterns under osmotic stress, inferring that GmABAS1 is a transcriptional repressor of Glyma.01G060300. As a further confirmation, AtAFP2, an orthologue of Glyma.01G060300, was down-regulated in GmABAS1-transgenic Arabidopsis thaliana, enhancing the plant’s sensitivity to ABA. This is the first time a 1R-subtype of MYB from soybean has been reported to enhance ABA sensitivity by acting as a transcriptional repressor.