Chromatin modifiers - Coordinators of estrogen action.

A group of hormones, called estrogens, are pivotal drivers of various physiological processes. Expectedly, estrogen-driven actions are also relevant modulators of pathophysiological changes, including cancer. Different transcriptional and tissue-specific responses are elicited mainly by two estrogen receptor (ER) isoforms, ERα and ERß. Although perturbations of ER subtype-specific expression are correlated with clinical outcomes of cancer, the result strongly depends on co-regulators. Co-regulator acts as a 'bridge' that helps form large protein complexes to modulate transcriptional activity on target gene chromatin. ERs, as transcription factors, may be positively or negatively influenced by the utilisation of different tissue-specific co-regulators. These co-regulators are enzymes that create the epigenetic landscape of histone and DNA modifications, along with proteins that read these modifications and ATP-dependent chromatin remodelers. This review provides an overview and update on ER-driven responses, focusing on the complex interaction between ERs and chromatin modifiers, and discusses how chromatin accessibility and epigenetic modifications contribute to ER recruitment and transactivation.

The m6A RNA Modification Quantity and mRNA Expression Level of RNA Methylation-Related Genes in Head and Neck Squamous Cell Carcinoma Cell Lines and Patients.

RNA methylation at the nitrogen sixth of adenosine (m6A, N6-methyladenosine) is the most abundant RNA modification which plays a crucial role in all RNA metabolic aspects. Recently, m6A modification has been assigned to mediate the biological processes of cancer cells, but their significance in HNSCC development is still poorly described. Thus, the main aim of this study was to globally quantify m6A modification by the mass spectrometry approach and determine the mRNA expression level of selected m6A RNA methyltransferase (METTL3), demethylase (FTO), and m6A readers (YTHDF2, YTHDC2) in 45 HNSCC patients and 4 cell lines (FaDu, Detroit 562, A-253 and SCC-15) using qPCR. In the results, we have not observed differences in the global amount of m6A modification and the mRNA level of the selected genes between the cancerous and paired-matched histopathologically unchanged tissues from 45 HNSCC patients. However, we have found a positive correlation between selected RNA methylation machinery genes expression and m6A abundance on total RNA and characterized the transcript level of those genes in the HNSCC cell lines. Moreover, the lack of global m6A differences between cancerous and histopathologically unchanged tissues suggests that m6A alterations in specific RNA sites may specifically influence HNSCC tumorigenesis.

Head and Neck Squamous Cell Carcinoma: Epigenetic Landscape.

Head and neck squamous carcinoma (HNSCC) constitutes the sixth most prevalent cancer worldwide. The molecular pathogenesis of HNSCC includes disorders in cell cycle, intercellular signaling, proliferation, squamous cell differentiation and apoptosis. In addition to the genetic mutations, changes in HNSCC are also characterized by the accumulation of epigenetic alterations such as DNA methylation, histone modifications, non-coding RNA activity and RNA methylation. In fact, some of them may promote cancer formation and progression by controlling the gene expression machinery, hence, they could be used as biomarkers in the clinical surveillance of HNSCC or as targets for therapeutic strategies. In this review, we focus on the current knowledge regarding epigenetic modifications observed in HNSCC and its predictive value for cancer development.

A new quill mite Torotrogla emberizae sp. nov. (Acariformes: Syringophilidae) from the Chestnut-eared Bunting (Passeriformes: Emberizidae) in Japan (morphology and DNA barcode data).

A new quill mite Torotrogla emberizae sp. nov. (Acariformes: Syringophilidae) parasitizing the Chestnut-eared Bunting Emberiza fucata Pallas, 1776 (Passeriformes: Emberizidae) in Japan is described based on the external morphology and DNA barcode data (mitochondrial cytochrome c oxidase subunit I sequences, COI). Females of T. emberizae sp. nov. differ from T. volgini Skoracki and Mironov, 2013 by having the short, wide and blunt-ended hypostomal protuberances (vs long, thin and sharp-ended), setae h1 ca. twice shorter than f1 (vs h1 longer than f1), the fan-like setae p' and p" of legs III-IV provided with ca. 10 tines (vs 7-8 tines) and lengths of setae vi 70-105 (vs 55-65), ve 105-135 (vs 85-90) and h1 55-60 (vs 95-120).

Combined description (morphology with DNA barcode data) of a new quill mite Torotrogla paenae n. sp. (Acariformes: Syringophilidae) parasitising the Kalahari scrub-robin Cercotrichas paena (Smith) (Passeriformes: Muscicapidae) in Namibia.

A new quill mite species Torotrogla paenae n. sp. (Acariformes: Syringophilidae) parasitising the Kalahari scrub-robin Cercotrichas paena (Smith) (Passeriformes: Muscicapidae) in Namibia is described based on the external morphology and DNA barcode data (the mitochondrial cytochrome c oxidase subunit 1 sequences, cox1). Females of T. paenae n. sp. morphologically differ from the most similar species T. lusciniae Skoracki, 2004 by the total body length (780-830 vs 645-715 µm in T. lusciniae) and the presence of hysteronotal shields (vs absence), apunctate propodonotal and pygidial shields (vs punctate), apunctate coxal fields (vs punctate), the fan-like setae p' and p" of legs III-IV provided with c.10 tines (vs 14-15) and the length of setae si (140-180 vs 190-210 µm) and se (160-185 vs 210-225 µm). The male of T. paenae n. sp. morphologically differs from T. lusciniae by the lateral branch of peritremes composed of 4 chambers (vs 7-8 chambers) and lengths of setae ve (45 vs 70-75 µm) and se (120 vs 165 µm).