Prospective Cancer Therapies Using Stimuli-Responsive DNA Nanostructures

Nanostructures based on DNA self-assembly present an innovative way to address the increasing need for target-specific delivery of therapeutic molecules. Currently, most of the chemotherapeutics being used in clinical practice have undesired and exceedingly high off-target toxicity. This is a challenge in particular for small molecules, and hence, developing robust and effective methods to lower these side effects and enhance the antitumor activity is of paramount importance. Prospectively, these issues could be tackled with the help of DNA nanotechnology, which provides a route for the fabrication of custom, biocompatible, and multimodal structures, which can, to some extent, resist nuclease degradation and survive in the cellular environment. Similar to widely employed liposomal products, the DNA nanostructures (DNs) are loaded with selected drugs, and then by employing a specific stimulus, the payload can be released at its target region. This review explores several strategies and triggers to achieve targeted delivery of DNs. Notably, different modalities are explained through which DNs can interact with their respective targets as well as how structural changes triggered by external stimuli can be used to achieve the display or release of the cargo. Furthermore, the prospects and challenges of this technology are highlighted.Peer reviewe

Adenovirukseen liitettyjen E3 ja CMV promoottorien transgeeni ekspression tehokkuuden vertailu ihmis- ja hiirisolulinjoissa

Viral promoters are an essential part of a normally functioning virus. Their main task is to drive the transcription of genes which govern hijacking of cell function and replication of viral particles. In addition to supporting normal function of a virus, they can be used to drive the transcription of transgenes which can be used in different therapies. In oncolytic therapies, transgenes can be used to prime the host system against neoplasms which has been shown to generate long term anti-tumour immunity. Human adenoviruses (Ad) are commonly used as a platform for oncolytic virotherapies. Human Ad’s replicate poorly in mouse tumour cell lines, yet some promoters, which are included in the viral constructs to drive the transcription of beneficial transgenes, are able to function. Currently it is unknown whether E3, the native promoter of adenovirus 5 of the E3 region, is capable of functioning in murine cell lines. In this thesis we study whether human cytomegalovirus promoter (CMV) and E3 differ in their efficacy to drive the transcription of the mOX40L and mCD40L transgenes. In the experimental part of this thesis, we compared the efficacies of two viral promoters, AdE3 and AdCVM, in transcribing mOX40Land mCD40L in vitro. Efficacy of transcription was assessed through immunofluorescence and flow cytometry in human and murine cell lines. Furthermore, the effects of promoters on viral infection, killing and replication were evaluated in burst assay and the colorimetric MTS proliferation assay. MTS and burst assay were conducted to confirm if viral infection, killing and replication occurs in human and murine cell lines. Both AdE3 and AdCMV were able to infect and kill human cell lines and cell viability decreased in correlation to the number of viral particles used. In murine cell lines, no decrease in cell viability was detected in the 4T1 cell line. In burst assay, viral replication was observed for both AdE3 and AdCMV in the human MDA-MB-436 cell line. In murine CT26 cell line, no replication was observed for AdE3 or AdCMV constructs. Immunofluorescence assay was performed to visualize transgene expression and localization. Results indicated that mOX40L was localized on cell surface while mCD40L was detected both outside and inside of the cytosolic compartment. Flow cytometry results revealed that both AdE3 and AdCMV constructs are capable of efficiently transcribing mOX40L in human cell lines. In the flow cytometry results for AdE3, two large cell populations with different fluorescence intensities were detected. AdCMV lacked this feature which is postulated to be due to higher lytic activity of the viral construct. In murine cell lines, HCMV could produce mOX40L, but production in murine cell lines was severely attenuated compared to human cell lines. mOX40L produced by the AdE3 construct did not differ from the baseline and was deemed incapable of producing mOX40L in murine cell lines. For the purpose of studying novel virotherapeutics the results of this thesis would indicate that human CMV can be used to drive expression of transgenes in murine cell lines. Despite this, it is preferable to use host specific viruses and promoter sequences for a better translation between mice and humans. Viruksen promoottorit ovat keskeisessä osassa toimintakykyisessä viruksessa. Virus promoottorin päätarkoituksena on geenien transkriptio, mitkä vastaavat solun keskeisten toimintojen kaappaamisesta ja virus partikkeleiden replikaatiosta. Näiden toimintojen lisäksi promoottoreita voidaan käyttää transgeenien transkriptiossa, mitä voidaan hyödyntää sairauksien hoidossa. Onkolyyttisissä terapioissa transgeenejä voidaan käyttää virittämään kehon immuunipuolustus taistelemaan kasvainkudosta vastaan. Ihmisen adenovirusta käytetään usein onkolyyttisten viroterapioiden alustana. Ihmisen adenovirus (Ad) replikoituu hyvin heikosti hiiren syöpäsoluissa, mutta osa adenovirukseen sisälletyistä eksogeenisistä promoottoreista, joita käytetään terapeuttisten transgeenien transkription ajamiseen, kykenee toimimaan ja tuottamaan haluttua proteiinia. Tällä hetkellä ei tiedetä, kykeneekö E3, joka on adenoviruksen E3 lokuksen promoottori, toimimaan hiiren solulinjoissa. Tässä tutkielmassa selvitämme ihmisen sytomegalovirus promoottorin (CMV) ja E3 eroa niiden tehossa ajaa mOX40L ja mCD40L transgeenien transkriptiota. Kokeellisessa osuudessa vertailimme kahden virus promoottorin, E3 ja CMV, eroa niiden tehossa ajaa mCD40L ja mOX40L transkriptiota in vitro. Transkription tehoa tutkittiin immunofluoresenssin ja virtaussytometrian avulla ihmisen ja hiiren syöpäsolulinjoissa. Tämän lisäksi promoottorien vaikutusta virus infektioon, replikaatioon ja kykyyn tappaa soluja arvioitiin burst kokeella ja kolorimetrisellä MTS menetelmällä. MTS ja burst kokeiden avulla varmistettiin AdE3 ja AdCMV virusten kyky infektoida, tappaa ja replikoitua ihmisen ja hiiren syöpäsolulinjoissa. Sekä Ad3 ja AdCMV todettiin kykenevän infektoimaan ja tappamaan ihmissyöpäsoluja ja solujen viabiliteetin lasku korreloi virus partikkeleiden määrän kanssa. Hiiren 4T1 syöpäsoluissa ei todettu solujen viabiliteetin laskevan. Burst kokeessa havaitsimme sekä AdE3 että AdCMV kykenevän replikoitumaan ihmisen MDA-MB-436 solulinjassa. Hiiren CT26 solulinjassa kummankaan viruksen ei havaittu kykenevän replikoitumaan. Immunofluoresenssi kokeessa visualisoimme transgeenien ilmentymisen ja paikantumisen. Tulokset osoittivat, että mOX40L paikantui solun pinnalle. mCD40L havaittiin puolestaan sekä solun ulkopuolella että sytosolissa. Virtaussytometria kokeen tulokset osoittivat, että sekä AdE3 ja AdCMV pystyivät tehokkaasti ilmentämään mOX40L ihmisen solulinjoissa. AdE3 virtausytometria tuloksissa löydettiin kaksi solupopulaatiota, joilla oli toisistaan poikkeavat fluoresenssi intensiteetit. Tätä ilmiötä ei havaittu AdCMV:lla infektoiduilla soluilla, mikä saattoi johtua korkeammasta lyyttisestä aktiivisuudesta. Hiirisolulinjoissa CMV kykeni ilmentämään mOX40L, mutta transkription teho oli selvästi alhaisempi verrattuna ihmissolulinjoihin. E3 promoottorin ilmentämä mOX40L ei eronnut kontrollista ja sen todettiin olevan kykenemätön tuottamaan mOX40L hiirisolulinjoissa. Tuloksemme osoittavat, että ihmisen CMV promoottori kykenee ilmentämään transgeenejä hiiren 4T1 ja CT26 solulinjoissa. On kuitenkin huomattava, että isäntälajille natiivien virusten ja promoottorien käyttö olisi tarkoituksenmukaisempaa tulosten käännettävyyden kannalta hiiristä ihmisiin

The HEALTHGRAIN Wheat Diversity Screen: Effects of Genotype and Environment on Phytochemicals and Dietary Fiber Components

Analysis of the contents of bioactive components (tocols, sterols, alkylresorcinols, folates, phenolic acids, and fiber components) in 26 wheat cultivars grown in six site × year combinations showed that the extent of variation due to variety and environment differed significantly between components. The total contents of tocols, sterols, and arabinoxylan fiber were highly heritable and hence an appropriate target for plant breeding. However, significant correlations between the contents of bioactive components and environmental factors (precipitation and temperature) during grain development also occurred, with even highly heritable components differing in amount between grain samples grown in different years on different sites

The HEALTHGRAIN Wheat Diversity Screen: Effects of Genotype and Environment on Phytochemicals and Dietary Fiber Components

Analysis of the contents of bioactive components (tocols, sterols, alkylresorcinols, folates, phenolic acids, and fiber components) in 26 wheat cultivars grown in six site x year combinations showed that the extent of variation due to variety and environment differed significantly between components. The total contents of tocols, sterols, and arabinoxylan fiber were highly heritable and hence an appropriate target for plant breeding. However, significant correlations between the contents of bioactive components and environmental factors (precipitation and temperature) during grain development also occurred, with even highly heritable components differing in amount between grain samples grown in different years on different sites.status: publishe

Effects of Genotype and Environment on the Content and Composition of Phytochemicals and Dietary Fiber Components in Rye in the HEALTHGRAIN Diversity Screen

The effects of genotype and environment on the content of bioactive components in rye were determined with four varieties being grown on one site for three years and on three additional sites in the third year and a fourth variety being included in all trials except year 1. Clear differences were observed in the extent to which the contents of dietary fiber components (arabinoxylan, beta-glucan, total dietary fiber) and phytochemicals (folates, alkylresorcinols, sterols, tocols, phenolic acids) varied between varieties and between the same varieties grown in different sites (United Kingdom, France, Hungary, Poland) and years (2005-2007 in Hungary), with sterols being the most stable and phenolic acids the least. However, no single variety could be selected as having the highest overall level of bioactive components or as being more stable in comparison across environments.status: publishe

Cardiopulmonary resuscitation in adults over 80 : outcome and the perception of appropriateness by clinicians

OBJECTIVES: To determine the prevalence of clinician perception of inappropriate cardiopulmonary resuscitation (CPR) regarding the last out‐of‐hospital cardiac arrest (OHCA) encountered in an adult 80 years or older and its relationship to patient outcome. DESIGN: Subanalysis of an international multicenter cross‐sectional survey (REAPPROPRIATE). SETTING: Out‐of‐hospital CPR attempts registered in Europe, Israel, Japan, and the United States in adults 80 years or older. PARTICIPANTS: A total of 611 clinicians of whom 176 (28.8%) were doctors, 123 (20.1%) were nurses, and 312 (51.1%) were emergency medical technicians/paramedics. RESULTS AND MEASUREMENTS: The last CPR attempt among patients 80 years or older was perceived as appropriate by 320 (52.4%) of the clinicians; 178 (29.1%) were uncertain about the appropriateness, and 113 (18.5%) perceived the CPR attempt as inappropriate. The survival to hospital discharge for the “appropriate” subgroup was 8 of 265 (3.0%), 1 of 164 (.6%) in the “uncertain” subgroup, and 2 of 107 (1.9%) in the “inappropriate” subgroup (P = .23); 503 of 564 (89.2%) CPR attempts involved non‐shockable rhythms. CPR attempts in nursing homes accounted for 124 of 590 (21.0%) of the patients and were perceived as appropriate by 44 (35.5%) of the clinicians; 45 (36.3%) were uncertain about the appropriateness; and 35 (28.2%) perceived the CPR attempt as inappropriate. The survival to hospital discharge for the nursing home patients was 0 of 107 (0%); 104 of 111 (93.7%) CPR attempts involved non‐shockable rhythms. Overall, 36 of 543 (6.6%) CPR attempts were undertaken despite a known written do not attempt resuscitation decision; 14 of 36 (38.9%) clinicians considered this appropriate, 9 of 36 (25.0%) were uncertain about its appropriateness, and 13 of 36 (36.1%) considered this inappropriate. CONCLUSION: Our findings show that despite generally poor outcomes for older patients undergoing CPR, many emergency clinicians do not consider these attempts at resuscitation to be inappropriate. A professional and societal debate is urgently needed to ensure that first we do not harm older patients by futile CPR attempts. J Am Geriatr Soc 68:39–45, 201