147 research outputs found

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    Investigation of DNA and RNA markers by novel technologies demonstrates DNA content intratumoral heterogeneity and long non-coding RNA aberrations in breast tumors

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    BACKGROUND: Breast cancer is the most commonly diagnosed cancer and second leading cancer death cause among females in the U.S.A. About 1 in 8 women in U.S will develop invasive breast cancer over the course of her lifetime. In 2013, 234,580 new invasive breast cancer cases are expected to occur in women within the US and approximately 64,640 non-invasive carcinomas in situ were diagnosed in 2013, most of which were ductal carcinoma in situ (DCIS). Along with technological advances, a wide variety of candidate biomarkers have been proposed for cancer diagnosis and prognosis, including DNA content and non-coding RNA. Current techniques for detecting DNA content abnormalities in formalin-fixed, paraffin-embedded (FFPE) tissue samples by flow cytometric analysis have used cells recovered from ≥50µm whole tissue sections. Here, in our first study, a novel core punch sampling method was investigated for assessing DNA content abnormalities and intratumoral heterogeneity in FFPE specimens. Secondly, long non-coding RNAs (lncRNAs) has been examined. LncRNA participates in a broad spectrum of biological activities by diverse mechanisms and its dysregulation is associated with tumorgenesis. Some lncRNAs may function as oncogenes (O) and others as tumor suppressor genes (TSG). To date, lncRNA has been investigated primarily by qRT-PCR and RNA sequencing. This study has examined the relationship of lncRNA expression patterns to breast tumor pathology by chromogenic in situ hybridization (CISH). METHODS: Firstly, FFPE breast carcinoma specimens were selectively targeted using 1.0 mm diameter punch needles. Extracted cores were assayed by flow cytometry using a modified-Headley method. Secondly, the lncRNA expression levels of 6 lncRNAs: HOTAIR, H19, KCNQ1OT1, MEG3, MALAT11 and Zfas1, was examined by RNAscope® CISH using FFPE breast tissue microarrays (TMAs) comprising normal adjacent epithelia (NA), DCIS, and invasive carcinoma (IC) from 46 patients. LncRNA associate polycomb complex protein EZH2 was evaluated by immunohistochemistry (IHC). LncRNA data was also compared to standard breast tumor data including ER, PR, Her2 and Ki67 IHC. SYSTAT version 11 statistical package was used to perform for all the tests. RESULTS: Following optimization experiments of the core punch flow cytometric approach, DNA index and percent S-phase fraction intratumoral heterogeneities were detected in 10/23 (44%) and 11/23 (47%) specimens respectively. The lncRNA CISH study utilized a TMA that contained 36 spots of NA breast tissues, 34 DCIS spots and 43 IC spots. HOTAIR CISH staining was significantly stronger in IC than DCIS (p CONCLUSION: Core-punching is an effective alternative to whole specimen sectioning and shows that macro-level genomic heterogeneity is common even within a single FFPE block. The interrelationship of DNA content heterogeneity to other forms of heterogeneity requires further study. RNAscope CISH supports bright-field microscopy investigations of lncRNA expression in FFPE tissue specimens. HOTAIR, H19 and KCNQ1OT1 may be potential breast cancer biomarkers, both HOTAIR and H19 may be a marker for DCIS at increased risk of progression to invasive cancer. HOTAIR, in particular, may be a predictor for invasive cancer grade

    Use of upconversion fluorescent nanoparticles for simultaneous imaging, detection and delivery of sirna

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    Ph.DDOCTOR OF PHILOSOPH

    Development of Fluorescent nanoparticles “Quantum Dots” for biomedical application

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    Background: Quantum dots (QDs) have emerged as one of the most exciting fluorescent nanoparticles with a potential for diagnostic and therapeutic application in the field of nanomedicine. The aim of this study was to synthesize water soluble QDs; bio-conjugating these QDs with RGD peptides prior to linking the QD-conjugated peptide to cancer cells with the aim to study cytotoxicity and assess its feasibility for in vivo studies. Methods: Water soluble Cadmium Telluride (CdTe) QDs were synthesized by the reaction of cadmium chloride with sodium tellurite in the presence of buffer solution of Mercaptosuccinic acid (MSA) as a capping ligand. Water soluble red emitting QDs thus obtained were characterized using spectrophotometric analysis. These QDs revealed a wide absorption spectrum with an excitonic absorption peak of 380nm and a narrow symmetrical emission spectrum of 630nm. The size and pattern of these QDs were studied using Transmission Electron Microscopy (TEM). These nanocrystals revealed their configuration in the form of isolated crystals or clusters measuring from 5-10nm in diameter. X-ray microanalysis combined with TEM permitted analysis of the elemental configuration of these QDs. These CdTe QDs were subsequently bound to HT 29 colon cancer cells to study the interaction of QDs in vitro. As colon cancer cells over-express integrins, QDs were conjugated with RGD (Lysine) and RGD (Cysteine) peptides for the purpose of active binding with HT29 colon cancer cells. The conjugated QDs were applied to colorectal cancer cells to assess their affinity to cellular adhesion molecules. The toxicity of naked and conjugated QDs was also assessed by analyzing cell survival and cell death after exposure to C2C12 mouse skeletal muscle cells. In vivo experiment using Sprague 5 Dawley (SD) rat established feasibility of biodistribution studies with a small dose of 10μg/ml. Results: These water soluble fluorescent CdTe nanocrystals were synthesized using relatively stable precursors. It was possible to demonstrate binding of these red emitting QDs to the HT29 colon cancer cells in vitro. Significant and stable binding was noted after QDs were conjugated with RGD peptides. Toxicity assay evaluation studies suggested that both nonconjugated and conjugated QDs were nontoxic to C2C12 mouse skeletal muscle cells at a concentration of 50 μg /ml indicating that they are less toxic to normal cells, and are safe to be applied to in vivo models. Further in vivo experimentation in SD rats established feasibility for imaging sentinel lymph nodes following interdigital web space injection of QDs. Conclusions: RGD-conjugated QDs can selectively target HT29 colorectal cancer cells with low toxicity to normal muscle cells offering a potential novel detection strategy for colorectal cancer. This property can be explored for early diagnostic and therapeutic purpose by selectively targeting cancer cells. Further studies are required in an in vivo model to analyze systemic biodistribution and toxicity studies

    Tracking and analysis of movement at different scales: from endosomes to humans

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    Movement is apparent across all spatio-temporal scales in biology and can have a significant effect on the survival of the individual. For this reason, it has been the object of study in a wide range of research fields, i.e. in molecular biology, pharmaceutics, medical research but also in behavioural biology and ecology. The aim of the thesis was to provide methodologies and insight on the movement patterns seen at different spatio-temporal scales in biology; the intra-cellular, the cellular and the organism level. At the intra-cellular level, current thesis studied the compartmental inheritance in Human Osteosarcoma (U2-OS) cells. The inheritance pattern of the endosomal quantum dot fluorescence across two consecutive generations was for first time empirically revealed. In addition, a in silico model was developed to predict the inheritance across multiple generations. At the cellular level, a semi-automated routine was developed that can realize long-term nuclei tracking in U2-OS cell populations labeled with a cell cycle marker in their cytoplasm. A method to extract cell cycle information without the need to explicitly segment the cells was proposed. The movement behaviour of the cellular population and their possible inter-individual differences was also studied. Lastly, at the organism level, the focus of the thesis was to study the emergence of coordination in unfamiliar free-swimming stickleback fish shoals. It was demonstrated that there exist two different phases, the uncoordinated and the coordinated. In addition, the significance of uncoordinated phase to the establishment of the group’s social network was for first time evinced. The adaptation of the stickleback collectives was also studied over time, i.e. the effect of group’s repeated interactions on the emergence of coordination. Findings at the intra-cellular and cellular level can have significant implications on medical and pharmaceutical research. Findings at the organism level can also contribute to the understanding of how social interactions are formed and maintained in animal collectives

    Digital Histopathology of Cancer

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    Syöpä on merkittävä ja yleistyvä kansansairaus. Maailman terveysjärjestön mukaan syöpä on maailmanlaajuisesti toiseksi yleisin kuolinsyy sydän- ja verisuonitautien jälkeen. Jos ei-melanoottisia ihosyöpiä ei oteta huomioon, ovat tavallisimmat syöpätyypit naisilla rintasyöpä ja miehillä keuhkosyöpä ja eturauhassyöpä. Sitä mukaa kun syövän biologisten syntymekanismien ymmärrys on lisääntynyt, ovat myös hoitovaihtoehdot lisääntyneet. Useampi kuin joka neljäs uusi lääke, joka lanseerattiin vuosina 2010-2018, oli tarkoitettu syövän hoitoon. Jotta potilas voisi hyötyä tarjolla olevasta laajasta syöpälääkevalikoimasta ja minimoida lääkkeiden haittavaikutukset, tulee hoito kohdistaa hänen yksilölliseen syöpäänsä. Tätä varten syöpä on sekä diagnosoitava luotettavasti että luokiteltava yksityiskohtaisesti. Vaikka kajoamattomat kuvantamistutkimukset kuten magneettikuvaus ovat viime vuosina kehittyneet huomattavasti, on syöpädiagnostiikan perusta edelleen histopatologiassa eli leikkauksessa tai neulanäytteenotossa poistetun kudoksen mikroskooppisessa tutkimuksessa. Valomikroskooppi on pysynyt patologin pääasiallisena työvälineenä yli puolentoista vuosisadan ajan. Se on sallinut kudoksen tarkastelun aina solutasolle saakka ja jopa sitä pienempiin rakenteisiin. Tärkeitä lisätutkimuksia tavallisen valomikroskooppisen tutkimuksen lisäksi ovat proteiiniantigeenien osoittamistutkimukset, kuten immunohistokemia ja in situ - hybridisaatio, joita voidaan käyttää syöpäkudoksen luokittelemiseen. Syövän tarkalla diagnosoimisella ja luokittelulla on haasteensa. Yksi sellainen on Suomessa ja ulkomailla vallitseva pula patologeista. Toinen haaste liittyy kasvainten välisen vaihtelun arviointiin, joka on tärkeää kasvainten kasvutaipumuksen luokittelussa (esim. eturauhassyövän Gleason-luokitus) ja tiettyjen värjäysten tulkinnassa (esim. rintasyövän HER2-värjäytyminen). Todellisen biologisen vaihtelun lisäksi vaihtelua esiintyy patologien välisissä arvioissa (interobserver variation) sekä saman patologin luokitteluissa eri ajan hetkellä (intraobserver variation). Kolmas haaste on itse valomikroskooppi. Vaikka se on luotettava, halpa ja helppokäyttöinen diagnostiikkalaite, on sillä omat puutteensa modernin patologian laboratorion työnkulussa. Digitaalihistopatologia edustaa uutta tapaa toteuttaa patologin pääasiallinen työtehtävä syöpäpotilaan hoidossa: asettaa diagnoosi ja luokitella syöpä yksityiskohtaisesti. Siirtyminen valomikroskoopista tietokoneympäristöön tarjoaa monia etuja, joista muutamia on tutkittu tässä väitöskirjassa. Tämän tutkimuksen tarkoituksena oli kehittää ja testata digitaalipatologian sovelluksia syöpädiagnostiikan parantamiseksi. Osatöissä tutkittiin eturauhassyövän Gleason-luokituksen opettamista ja standardointia, rinta- ja eturauhassyövän immunohistokemiallisten värjäysten tulkintaa, digitaalinäytteille kehitettyä kuvanpakkausmenetelmää, sekä näyteskannerin optimaalisen kuvausresoluution määrittämistä. Väitöskirjassa osoitetaan, että digitaalinäytteitä voi käyttää eturauhaskoepalan Gleason-luokituksen tekemiseen ja että internet-pohjainen ohjelma voi edistää tulkitsijoiden välisen vaihtelun määrittämistä sekä Gleason-luokituksen opettamista ja standardisointia. Gleason-luokituksen ohella toinen tärkeä osa eturauhassyövän histopatologiaa on immunohistokemiallisten värjäysten tulkinta. Tässä väitöskirjassa esitetään menetelmä, jolla kahta digitaalinäytettä voidaan tutkia yhtäaikaisesti ja synkronoidusti. Menetelmää testattiin eturauhassyövän immunohistokemiallisella AMACR–p63-kaksoisvärjäyksellä yhdessä rutiininomaisen hematoksyliini–eosiini- värjäyksen kanssa. Tutkimuksessa osoitettiin, että tekniikkaa voidaan käyttää hyväksi histopatologian opetuksessa ja valikoiduissa tapauksissa kliinisessä diagnostiikassa. Keskeinen asia rintasyövän diagnostiikassa on HER2-statuksen tutkiminen, koska kasvaimia, joissa HER2 on yli-ilmentynyt, voidaan hoitaa anti-HER2- lääkkeillä. Yhdessä osatöistä tutkittiin digitaalisen kuva-analyysin käyttöä niin valomikroskooppikuvilla kuin digitaalinäytteillä tarkoituksena auttaa patologia määrittämään kirurgisesti poistetun kasvainkudoksen HER2-status. Työssä osoitettiin, että ilmaista ja kaikille avointa ohjelmistoa käyttämällä voitiin vähentää HER2-statuksen suhteen vaikeatulkintaisten tapausten määrää. Digitaalihistopatologian käyttöönotto rutiinidiagnostiikkaan on laajentumassa nopeasti. Yksi tekninen haaste on digitaalinäytteiden vaatiman suuren tallennuskapasiteetin hallinta. Tarve tallentaa suuria määriä tietoa edellyttää digitaalinäytteiden kuvanlaadun ja tiedostokoon yhteensovittamista. Yhdessä tämän väitöskirjan osatöistä tutkittiin skannerimikroskoopin optimaalisen kuvausresoluution määrittämistä. Menetelmää voidaan hyödyntää esimerkiksi vertailtaessa skannereita ennen hankintaa. Toisessa osatyössä esiteltiin uusi kuvanpakkausmenetelmä, joka suunniteltiin varta vasten histopatologisia digitaalinäytteitä varten niiden tiedostokoon minimoimiseksi ja siten tallennuskustannusten pienentämiseksi. Tämän väitöskirjan kaksi ensimmäistä osatyötä edustavat digitaalipatologian alkutaivalta ja tutkimuskenttä on kehittynyt sittemmin, mahdollisesti pieneltä osin edellä mainittujen tutkimusten löydösten myötä. Yhteenvetona osatyöt toivottavasti vievät digitaalipatologian alaa eteenpäin ja siten edesauttavat syöpäpotilaiden hoitoa.Cancer is a significant and growing public health concern. According to the World Health Organisation's estimates it is – after cardiovascular diseases – the second leading cause of death worldwide. Excluding non-melanoma skin cancers the most common types of cancer are for women breast cancer and for men lung cancer followed by prostate cancer. While the biological understanding of cancer has expanded, so too has the selection of available treatments. More than one fourth of all new medicines entering the market during 2010-2018 were for treating cancer. In order for a patient to benefit from the wide variety of cancer treatments, and avoid adverse effects, their unique cancer has to be matched with the appropriate treatment. For this the cancer needs to be both diagnosed accurately and classified in detail. Although non-invasive imaging methods, such as magnetic resonance imaging, have evolved substantially in recent years, the basis of cancer diagnosis is still in histopathology, that is, the pathological evaluation of tissue removed through surgery or needle biopsy. The light microscope has remained the pathologist's main diagnostic tool for a century and a half allowing for the examination of tissue down to cellular – and even subcellular – level. Important adjuncts to routine histopathological staining of tissue, needed for light microscopy, are techniques allowing for the visualization of protein antigens and nucleic acid in the tissue. These techniques, among which are immunohistochemistry and in situ hybridization, respectively, can be used for instance in the molecular characterization of cancer. There are challenges in meeting the need for accurate diagnosing and characterization of cancer. One such challenge is posed by the shortage of pathologists observed in Finland and elsewhere. Another challenge is the variability in the interpretation of the tumor growth pattern (grading, such as Gleason grading in prostate cancer) and in the interpretation of certain tissue staining patterns (such as the immunohistochemical staining of the HER2 molecule in breast cancer). This variability manifests itself both between pathologists (interobserver variation) and also in the same pathologist's work over time (intraobserver variation). A third challenge is presented by the fact that the light microscope – although a reliable, cheap, and easy-to-use diagnostic tool – has shortcomings in the modern day pathology service. Digital histopathology presents a new way of carrying out the central task of a pathologist in managing cancer patients, namely making the diagnosis and characterising the tumor in detail. Making the shift from a light microscope to a computer environment offers many benefits, some of which have been examined in this dissertation. The present study was carried out with the purpose of developing and testing applications of digital pathology in order to improve the histopathological diagnosis of cancer. The individual studies looked at advancing the teaching and standardization of Gleason grading or prostate cancer, aiding in the interpretation of immunohistochemical staining of prostate and breast cancer, as well as facilitating the implementation of digital pathology by way of a novel whole slide image optimised image compression algorithm and mapping the determinants of an optimal imaging resolution for a whole slide scanner. We demonstrated that whole slide images can be used to assess the Gleason grade of a prostate biopsy and that the use of an internet based platform can be beneficial in assessing interobserver variation in the grading and teaching and standardising the grading. Besides Gleason grading another important aspect of prostate histopathology is the interpretation of immunohistochemistry. We created a method of viewing two whole slide images simultaneously and synchronously and tested this method in visualising the AMACR-p63 double stain along with normal hematoxylin and eosin staining of prostate biopsies. We showed that this technique can be used for histopathology education as well as in clinical diagnostics in selected cases. A key issue in breast cancer diagnostics is defining the HER2 status of a tumor, that is, whether the tumor overexpresses the molecule and can then be treated with HER2 antibody based drugs. We studied the use of digital image analysis, using both photomicrographs and whole slide images, in aiding the pathologist in defining the HER2 status on a breast cancer surgical resection specimen. We showed that using a free and publicly available image analysis software can help to resolve cases otherwise deemed equivocal by conventional light microscopy. The introduction of digital histopathology into routine diagnostic work is underway. One technical challenge is managing the large amounts of image data generated by whole slide images. When there is a need to store large numbers of whole slide images it is essential to strike a balance between image fidelity and file size. To deal with this issue we studied the optimal imaging resolution of a whole slide scanner using a methodology that can be utilised for instance in comparing whole slide scanners before acquiring one. In addition we introduced a novel way of image compression suited for whole slide images in order to reduce the storage footprint, and cost, of whole slide images. The first two studies in this dissertation represent the very beginnings of whole slide imaging in pathology, and the field has advanced since then, perhaps in small part due to the findings in these studies. Taken together, the findings in this dissertation can hopefully advance the use of digital pathology in cancer diagnostics and thereby improve the care of cancer patients

    Diagnostic Significance of Exosomal miRNAs in the Plasma of Breast Cancer Patients

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    Poster Session AbstractsBackground and Aims: Emerging evidence that microRNAs (miRNAs) play an important role in cancer development has opened up new opportunities for cancer diagnosis. Recent studies demonstrated that released exosomes which contain a subset of both cellular mRNA and miRNA could be a useful source of biomarkers for cancer detection. Here, we aim to develop a novel biomarker for breast cancer diagnosis using exosomal miRNAs in plasma. Methods: We have developed a rapid and novel isolation protocol to enrich tumor-associated exosomes from plasma samples by capturing tumor specific surface markers containing exosomes. After enrichment, we performed miRNA profiling on four sample sets; (1) Ep-CAM marker enriched plasma exosomes of breast cancer patients; (2) breast tumors of the same patients; (3) adjacent non-cancerous tissues of the same patients; (4) Ep-CAM marker enriched plasma exosomes of normal control subjects. Profiling is performed using PCR-based array with human microRNA panels that contain more than 700 miRNAs. Results: Our profiling data showed that 15 miRNAs are concordantly up-regulated and 13 miRNAs are concordantly down-regulated in both plasma exosomes and corresponding tumors. These account for 25% (up-regulation) and 15% (down-regulation) of all miRNAs detectable in plasma exosomes. Our findings demonstrate that miRNA profile in EpCAM-enriched plasma exosomes from breast cancer patients exhibit certain similar pattern to that in the corresponding tumors. Based on our profiling results, plasma signatures that differentiated breast cancer from control are generated and some of the well-known breast cancer related miRNAs such as miR-10b, miR-21, miR-155 and miR-145 are included in our panel list. The putative miRNA biomarkers are validated on plasma samples from an independent cohort from more than 100 cancer patients. Further validation of the selected markers is likely to offer an accurate, noninvasive and specific diagnostic assay for breast cancer. Conclusions: These results suggest that exosomal miRNAs in plasma may be a novel biomarker for breast cancer diagnosis.link_to_OA_fulltex

    Desarrollo y aplicación de métodos bioinformáticos al análisis de datos de expresión genómica y datos de supervivencia de pacientes con cáncer

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    [EN] The development of robust omic technologies (genomics, transcriptomics, proteomics, etc) to generate and understand genome-wide alterations is already having an impact on health care, with a particular relevance on cancer and oncology. Within the current context of Personalised Medicine, Precision Medicine and Genomic Medicine (Roden and Tyndale, 2013), modern cancer research has to be done considering an adecuate use of the large-scale data derived from these new omic technologies. Some of these technologies, such as transcriptomic expression pro ling, have been already applied to thousands of human samples (see public database GEO (NCBI, 2019)), and provide information about the expression status of all the known genes in the analised individuals. In order to be useful and applicable to medical research, such omic data should be integrated with the corresponding clinical data using adequate computational and bioinformatic tools and methods. This is a main framework where the current Doctoral Thesis work is proposed

    Doctor of Philosophy

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    dissertationIn this dissertation, we explored the synthesis of water-soluble and photoluminescence behavior near infrared emitting (610 nm) gold nanoparticles terminated by mercaptoalkanoic acid and possessing UV range (200~350 nm) excitation. Different effects were monitored as a function of reaction condition including different gold and ligand concentrations, types of ligands, solvents and pH. It is understood that Gold-thiol complexes were formed and developed into nanoparticle-supported complexes. Analyses of the excitation spectra suggests the origin of the photoluminescence to be transitions from the triplet energy state of LMMCT with the electrons transferred from excited orbitals of Au/Au(I) sites of the gold surface. It is also the reason for the enhanced photostability compared with those produced as free molecules via other synthesis methods. The pH dependency of the emission intensity and excitation spectra alteration of the gold nanoparticles was also explored. The emission intensity of the gold nanoparticle showed linear dependency on the pH change in the weak acidic to basic region above the pH 6 with a small peak appearance at pH 4. This trend was accompanied by a distinctive excitation peak wavelength change from 280-290 nm to 250-260 nm at pH 6.. A brush configuration change of the surface ligands was proposed to explain the pH dependency. In the charged and extended form of the carboxylic acid ligands, the accessibility of water to the gold nanoparticles surface is greater than in the uncharged collapsed form. Thus, in the collapsed form, the local hydrophobicity at the gold surface is higher and theCT excitation spectrum shifts to the blue. Its biocompatibility, as suggested by the cytotoxicity test and reactive oxygen species (ROS) generation test, provides broader opportunities for this product to be utilized in biological systems
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