Angiotensin II as a factor modulating protein tyrosine kinase activity in two breast cancer lines — MCF-7 and MDA-MB-231

Wstęp: Angiotensyna II (AngII), peptyd systemu renina-angiotensyna biorący udział w regulacji równowagi wodno-elektrolitowej oraz ciśnienia krwi, jest także związkiem wpływającym na proliferację i wzrost komórek. Efekt działania tego peptydu uzależniony jest od typu receptora. Angiotensyna II po związaniu z receptorem AT1 stymuluje proliferację i wzrost komórek natomiast poprzez aktywację receptora AT2 — hamuje wzrost komórek oraz pobudza proces apoptozy. Proproliferacyjne działanie angiotensyny II zaobserwowano zarówno w komórkach tkanek zdrowych, jak i w komórkach nowotworowych między innymi komórkach przysadki i nadnerczy, ale także raka piersi czy hiperplazji mięśni naczyń krwionośnych. Materiał i metody: Celem pracy było zbadanie wpływu AngII na aktywność białkowych kinaz tyrozynowych dwóch linii nowotworowych gruczołu piersiowego: hormono-zależnej linii MCF-7 i hormono-niezależnej MDA-MB-231. Aktywność kinaz tyrozynowych jest przyjętym markerem proliferacji. Oszacowano także wpływ 17b-estradiolu na zmiany w aktywności kinaz tyrozynowych wywołane angiotensyną II. Wyniki: AngII radykalnie hamowała aktywności kinaz tyrozynowych w linii MDA-MB-231, natomiast 17b-estradiol tylko w stężeniu 10–6 M pogłębiał efekt działania angiotensyny II w stężeniu 10–9 M. W linii hormono-zależnej MCF-7 Ang II miała silny hamujący wpływ na aktywność badanych enzymów w obecności estradiolu 10–6 M. Sam estradiol obniżał aktywność badanych enzymów w obu liniach komórkowych. Obecność receptora angiotensynowego typu 1 została potwierdzona w obydwu badanych liniach raka piersi, natomiast ekspresję receptora typu 2 odnotowano jedynie w komórkach MDA-MB-231. Wnioski: Otrzymane wyniki wskazują, że AngII może modulować aktywność kinaz tyrozynowych w badanych komórkach raka gruczołu sutkowego. (Endokrynol Pol 2011; 62 (2): 151–157)Introduction: Angiotensin II (AngII), a peptide that regulates the water-electrolytic balance and blood pressure, is also known to influence cell proliferation. It can either induce cell growth, when binding to angiotensin type-I receptor, or trigger growth inhibition via angiotensin type-II receptor. AngII stimulates proliferation of some normal and tumour cell lines, e.g. pituitary, adrenal glands and breast cancer. Material and methods: The aim of this study was to evaluate possible AngII effect on the growth of two breast cancer cell lines — hormone-dependent MCF-7 and hormone-independent MDA-MB-231. We measured tyrosine kinase activity as a potential proliferation marker. We also estimated the influence of 17b-oestradiolon AngII-induced changes. Results: In the MDA-MB-231 line, AngII radically slowed the activity of tyrosine kinases and 17b-oestradiol only at a concentration of 10–6 M, while it enhanced the effect of angiotensin II at a concentration of 10–9 M. In MCF-7, Ang II had a strong inhibitory effect in the presence of oestradiol (10–6 M). Oestradiol alone decreased the activity of examined enzymes in both cell lines. AngII receptor type 1 was found in both studied lines, but type 2 only in MDA-MB-231. Conclusions: Our results show that AngII can modulate tyrosine kinase activity in breast tumour cell lines.(Pol J Endocrinol 2011; 62 (2): 151–157

The proteome of developing barley anthers during meiotic prophase I

Flowering plants reproduce sexually by combining a haploid male and female gametophyte during fertilization. Male gametophytes are localized in the anthers, each containing reproductive (meiocyte) and non-reproductive tissue necessary for anther development and maturation. Meiosis, where chromosomes pair and exchange their genetic material during a process called recombination, is one of the most important and sensitive stages in breeding, ensuring genetic diversity. Most anther development studies have focused on transcript variation, but very few have been correlated with protein abundance. Taking advantage of a recently published barley anther transcriptomic (BAnTr) dataset and a newly developed sensitive mass spectrometry-based approach to analyse the barley anther proteome, we conducted high-resolution mass spectrometry analysis of barley anthers, collected at six time points and representing their development from pre-meiosis to metaphase. Each time point was carefully staged using immunocytology, providing a robust and accurate staging mirroring our previous BAnTr dataset. We identified &gt;6100 non-redundant proteins including 82 known and putative meiotic proteins. Although the protein abundance was relatively stable throughout prophase I, we were able to quantify the dynamic variation of 336 proteins. We present the first quantitative comparative proteomics study of barley anther development during meiotic prophase I when the important process of homologous recombination is taking place.</p

Visual probing : cognitive framework for explaining self-supervised image representations

Recently introduced self-supervised methods for image representation learning provide on par or superior results to their fully supervised competitors, yet the corresponding efforts to explain the self-supervised approaches lag behind. Motivated by this observation, we introduce a novel visual probing framework for explaining the self-supervised models by leveraging probing tasks employed previously in natural language processing. The probing tasks require knowledge about semantic relationships between image parts. Hence, we propose a systematic approach to obtain analogs of natural language in vision, such as visual words, context, and taxonomy. Our proposal is grounded in Marr’s computational theory of vision and concerns features like textures, shapes, and lines. We show the effectiveness and applicability of those analogs in the context of explaining self-supervised representations. Our key findings emphasize that relations between language and vision can serve as an effective yet intuitive tool for discovering how machine learning models work, independently of data modality. Our work opens a plethora of research pathways towards more explainable and transparent AI

Visual Probing: Cognitive Framework for Explaining Self-Supervised Image Representations

Recently introduced self-supervised methods for image representation learning provide on par or superior results to their fully supervised competitors, yet the corresponding efforts to explain the self-supervised approaches lag behind. Motivated by this observation, we introduce a novel visual probing framework for explaining the self-supervised models by leveraging probing tasks employed previously in natural language processing. The probing tasks require knowledge about semantic relationships between image parts. Hence, we propose a systematic approach to obtain analogs of natural language in vision, such as visual words, context, and taxonomy. Our proposal is grounded in Marr's computational theory of vision and concerns features like textures, shapes, and lines. We show the effectiveness and applicability of those analogs in the context of explaining self-supervised representations. Our key findings emphasize that relations between language and vision can serve as an effective yet intuitive tool for discovering how machine learning models work, independently of data modality. Our work opens a plethora of research pathways towards more explainable and transparent AI

A high quality Arabidopsis transcriptome for accurate transcript-level analysis of alternative splicing

Alternative splicing generates multiple transcript and protein isoforms from the same gene and thus is important in gene expression regulation. To date, RNA-sequencing (RNA-seq) is the standard method for quantifying changes in alternative splicing on a genome-wide scale. Understanding the current limitations of RNA-seq is crucial for reliable analysis and the lack of high quality, comprehensive transcriptomes for most species, including model organisms such as Arabidopsis, is a major constraint in accurate quantification of transcript isoforms. To address this, we designed a novel pipeline with stringent filters and assembled a comprehensive Reference Transcript Dataset for Arabidopsis (AtRTD2) containing 82,190 non-redundant transcripts from 34 212 genes. Extensive experimental validation showed that AtRTD2 and its modified version, AtRTD2-QUASI, for use in Quantification of Alternatively Spliced Isoforms, outperform other available transcriptomes in RNA-seq analysis. This strategy can be implemented in other species to build a pipeline for transcript-level expression and alternative splicing analyses

Involvement of the nuclear cap-binding protein complex in alternative splicing in Arabidopsis thaliana

The nuclear cap-binding protein complex (CBC) participates in 5′ splice site selection of introns that are proximal to the mRNA cap. However, it is not known whether CBC has a role in alternative splicing. Using an RT–PCR alternative splicing panel, we analysed 435 alternative splicing events in Arabidopsis thaliana genes, encoding mainly transcription factors, splicing factors and stress-related proteins. Splicing profiles were determined in wild type plants, the cbp20 and cbp80(abh1) single mutants and the cbp20/80 double mutant. The alternative splicing events included alternative 5′ and 3′ splice site selection, exon skipping and intron retention. Significant changes in the ratios of alternative splicing isoforms were found in 101 genes. Of these, 41% were common to all three CBC mutants and 15% were observed only in the double mutant. The cbp80(abh1) and cbp20/80 mutants had many more changes in alternative splicing in common than did cbp20 and cbp20/80 suggesting that CBP80 plays a more significant role in alternative splicing than CBP20, probably being a platform for interactions with other splicing factors. Cap-binding proteins and the CBC are therefore directly involved in alternative splicing of some Arabidopsis genes and in most cases influenced alternative splicing of the first intron, particularly at the 5′ splice site

Creation of a Leader of Democratic People’s Republic of Korea

Celem pracy jest ukazanie sylwetki dotychczasowych władców Koreańskiej Republiki Ludowo-Demokratycznej przez pryzmat historii oraz kultury mieszkańców Półwyspu Koreańskiego. Przybliżone zostały dzieje ludności koreańskiej od początku XX w. wraz z ideologiami, które na przestrzeni wieków ukształtowały mentalność jednostki oraz inspirowały politykę władców. Okupacja japońska, która w dalszym ciągu pozostawia traumę w Koreańczykach, użyta została do celów propagandowych by ugruntować wybór kandydata na władcę z ramienia sowieckiego – Kim Ir Sena, który początkowo był nieznanym dowódcą w Armii Czerwonej. Aby ukazać schematyzm działań reżimu oraz kult jednostki, autorka przybliża postać Józefa Stalina. Zabieg ten pozwala zarysować cechy wspólne oraz różnice między polityką kolejnych władców z klanu Kimów, kolejno Kim Ir Sena, Kim Dzong Ila oraz Kim Dzong Una. Praca zawiera porównanie biografii dyktatorów z propagandową iluzją, w którą zmuszeni są wierzyć mieszkańcy Korei Północnej. Oprócz działalności politycznej, przedstawione zostały także cechy osobiste poszczególnych władców, które wskazują na ich indywidualność.The purpose of this publication is to present figures of the rulers of Democratic People’s Republic od Korea through the spectrum of history and culture of inhabitants of Korean Peninsula. The author draws attention to the past of Korean natives from the beginning of 20th century along with the thoughts and philosophies that created mentality of an individual and inspired politics of monarchs. Japanese occupation, which is a traumatising memory for Koreans to this day, was used for indoctrination of an unknown Korean man, with a Red Army past, as a soviet-related candidate to rule the country. The said man was Kim Il Sung himself. The schemes of politics and cult of the individual are shown as a comparative study to Joseph Stalin’s way of ruling. That allows to specify shared traits and differences in politics of following dictators of the Kim dynasty which are Kim Il Sung, Kim Jong Il and Kim Jong Un. The content includes biographies of dictators compared to the propagandist illusion adopted by North Korean citizens. This paper also presents personal features of each ruler to draw attention to their individuality