Browsing by Subject "syöpä"

Even though cancer treatment modalities have improved during last decades, there is still lack of specific, efficient and curative treatments especially in case of advanced and metastatic cancers. One relatively new approach is to use oncolytic adenoviruses, which selectively infect and kill cancerous cells leaving healthy cells unharmed. These viruses have shown to be effective especially when administered intratumorally and in combination with chemotherapeutics. However this approach has multiple challenges like rapid clearance by antibody neutralization in systemic administration. Another challenge is the cell entry of oncolytic adenovirus, which is mainly mediated by the Coxsackie-Adenovirus receptor and this receptor is downregulated in various cancer cells. Rapid clearance and reduced cell entry thus lead to decreased amount of oncolytic adenovirus in target cells and decreased efficacy. In order to overcome these limitations, this study explored the possibility to use cancer cell derived extracellular vesicles (EVs) as drug delivery system for oncolytic adenovirus. Since oncolytic adenoviruses have shown to be effective especially in combination with chemotherapeutics, the ability of EVs to deliver both oncolytic adenoviruses and chemotherapeutic drug paclitaxel was studied. The aims of this study were to i) study whether oncolytic adenoviruses could be encapsulated inside EVs (EV-virus complex) and load this complex with paclitaxel (EV-virus-PTX complex), ii) discover whether the surface charge or size distribution of EV-virus and EV-virus-PTX complexes differs from the control EVs and iii) study the infectivity/efficacy of EV-virus and EV-virus-PTX complex in comparison to noncapsulated adenovirus in vitro. Since this is a novel approach, the literature review focused on the characteristics, advantages and challenges of oncolytic adenoviruses and EVs. In order to determine whether cancerous cell are able to encapsulate oncolytic adenoviruses inside EVs, A549 lung cancer and PC-3 prostate cancer cells were infected with oncolytic adenovirus and the formed EVs were isolated form conditioned media using differential centrifugation. Paclitaxel was loaded into these EV-virus complexes with incubation. EV-virus complexes were imaged using transmission electron microscopy (TEM) (i). The characteristics of these EV-virus and EV-virus-paclitaxel complexes were studied by determining the surface charge by electrophoretic light scattering and the size distribution by nanoparticle tracking analysis (ii). In order to determine the infectivity/efficacy of these complexes in autologous use, three in vitro level assays were performed (cell viability, immunocytochemistry and transduction assay) (iii). In addition confocal microscopy was used to observe the localization of EV-virus complexes inside the cell. These studies pointed out that both cell lines were able to encapsulate oncolytic adenovirus inside EVs, which was observed by TEM. The size distribution of these EV-virus and EV-virus-PTX complexes may support this observation and the size was in range 50-500 nm. In addition the determined surface charge was shown to be similar in EV-virus and EV-virus-PTX- complexes when compared to control EVs derived from noninfected cells - however more specific assays in order to characterize the surface properties of EV-virus complexes are needed. As a main finding, these EV-virus and EV-virus-PTX complexes were shown to significantly increase the efficacy of oncolytic adenovirus in comparison to free oncolytic adenovirus, paclitaxel and paclitaxel+virus combination in all three in vitro assays. In addition localization of the EV-virus complex was seen with confocal microscopy imaging. These results indicate that EVs may enhance the delivery of oncolytic adenovirus into cancerous cells. Using EVs as a drug delivery system for both oncolytic adenovirus and chemotherapeutic drug paclitaxel was shown to increase the efficacy of oncolytic adenovirus in comparison to free virus. This characteristic could potentially enhance the targeting ability to cancerous cells and thus lead to decreased amount of side-effects of healthy tissues especially in case of chemotherapeutics. These promising results of this novel approach are however preliminary due to relatively low number of repetitions (n~3) and more research is needed especially in order to characterize, purify and concentrate the EV-virus complexes.

Ensuring patient and medication safety is a widely acknowledged challenge in health care. Key concepts in medication safety are: a patient safety incident, a safety barrier, and a medication error. A patient safety incident is an incident which has led or could have led to harm for the patient. A safety barrier is a structure built into the medication use process, and it is designed to improve medication safety. A medication error is a deviation from the medication process. The medication safety of cancer patients is especially important. Chemotherapeutic agents usually have a narrow therapeutic index and they have toxic side effects even in therapeutic doses. Accordingly, chemotherapeutic agents are classified as high alert medications. This means that they have an increased risk for patient harm if used improperly. Cancer patients are often elderly people and they have comorbid diseases. As a result, they are more susceptible to adverse drug effects. Moreover, the use of anticancer drugs varies between patients and the different indications of a drug, and supportive therapies are often needed. Thus, cancer pharmacotherapy is complicated. In this registry study, safety in the medication process of cancer treatment was studied using voluntary patient safety incident reports in one university hospital district in Finland. The aim of this study was to describe medication errors in cancer treatment, and safety barriers in the medication use process. The reported medication safety incidents were analysed by combining quantitative and qualitative methods. Altogether 176 incident reports were analysed relating to the use of anticancer drugs and supportive therapies. The most common medication errors were administration (27 %), prescribing (11 %), and ordering errors (10 %). These medication errors were typically omission errors. There were safety barriers in the medication process, such as double-checking of medicines, but they were not always fully effective. Some barriers were missing, for example, computer programs lacked important safety features. Safety barriers are needed, and should be further developed especially in the prescribing, ordering and administration phases of the process. More effective barriers would increase patient and medication safety in cancer treatment. The classification of medication errors in patient safety incidents was not always correct. Therefore, reporting and analysing of reports should be improved. The results of this study can be utilised for improving medication safety in all organisations giving cancer pharmacotherapy.

During the past few decades, the explosion of discovery in cancer and immunological research has led to the increased understanding of the interactions between the immune system and tumors. These developments have provided vital information about the immune system’s role in cancer development. It is evidenced that the immunity system is capable to distinguish tumor cells from normal tissue by recognizing tumor antigens that are exclusively expressed on tumor cells or are presented in greater amounts on tumor cells than normal cells. Consequently, the immune cells start to attack tumors for protecting the host. The possibility to use the immune system as a weapon against cancer cells leaded to the promising innovation – cancer immunotherapy – which aims to activate the body’s own immune system and its components to mount antitumor immune responses for eliminating cancer cells. The antitumor efficacy and high safety profile of several immunotherapeutic strategies have already been demonstrated thereby resulting in their integration into clinical practice. However, most patients have not benefited from cancer immunotherapy as a single treatment. In this regard, new innovative methods are clearly needed to overcome the obstacles hindering the clinical success of this field. Therapeutic cancer vaccines are emerging as attractive immunotherapies currently being evaluated in both pre-clinical and clinical studies. The purpose of cancer vaccines is to eradicate tumor cells by eliciting antitumor CD8+ T cell responses against the injected tumor antigens. Due to the ability to specifically kill tumor cells and simultaneously trigger immune responses against tumor antigens via direct oncolysis and by encoding transferred tumor antigens, oncolytic viruses are of significant interest for being used as in situ cancer vaccines. Despite these unique properties, several factors such as tumor immunosuppression and immune tolerance to targeted tumor antigens resembling antigens of normal tissues hamper the use of oncolytic vaccines in clinic. Instead of focusing only on CD8+ T cells, it has been suggested that giving more attention to CD4+ T helper cells, which are required for priming and expansion of CD8+ T cell responses, could be the key to improve the efficacy of cancer vaccines. Researchers have also demonstrated that an ongoing antigen-specific CD4+ T cell response can lead to the bystander activation of surrounding T cells with unrelated antigen specificities. Based on this theory, the hypothesis of this study was to employ the pre-existing immunological CD4+ memory against infectious pathogens in generating bystander CD8+ immunity against solid tumors. In this study, mice transplanted with poorly immunogenic B16-OVA tumors were pre-immunized with the chosen vaccine to induce immunological CD4+ memory against an infectious pathogen. Tumors were then treated with already developed cancer vaccine, which was peptide-coated conditionally replicating adenovirus (PeptiCRAd) complex. PeptiCRAd was constructed by electrostatically coating adenovirus with both pathogen-derived and tumor-derived peptide. The intratumorally injected double-coated PeptiCRAd complex was assumed to activate peptide-specific T cells and thus, result in anti-pathogen CD4+ T cell recall responses and the following bystander activation of antitumor CD8+ T cells, which can then mount an effective immune response to destroy cancer cells. The efficacy of this treatment was observed in pre-immunized mice by measuring the growth of injected tumors. The experiment was repeated identically with non-immunized naïve mice to see the difference in the results. The immunological background of this treatment approach was investigated by analyzing mouse tissue samples with standard immunological techniques including ELISA, IFN-γ ELISPOT and flow cytometry. This study showed that long-term immunological memory against the pathogen was successfully accomplished and the strongest inhibition of tumor growth in pre-immunized mice was achieved with double-coated PeptiCRAd, whereas the antitumor efficacy was not seen in naïve mice. Additionally, a new ex vivo method to detect pathogen-specific CD4+ T cells from spleen was developed and the stimulation of cell-mediated immunity by this treatment was supported by finding the highest levels of pathogen-specific CD4+ Th1 cells from mice treated with double-coated PeptiCRAd. Some encouraging results concerning the beneficial immune cell composition of tumors and tumor draining lymph nodes were also obtained from other performed experiments. Though further immunological analyses are required for understanding the precise mechanisms of action behind the treatment, the increased immunogenicity and antitumor efficacy of double-coated PeptiCRAd can still be considered as a consequence of the bystander effect, which can possibly be utilized for developing improved strategies to win the fight against cancer.

Biologiset lääkkeet ovat keskeinen osa syöpäsairauksien hoitoa. Ne ovat usein perinteisiä pienimolekyylisiä lääkkeitä kalliimpia, ja niiden aiheuttamia kustannuksia potilaalle ja yhteiskunnalle voidaan hillitä edullisempien biosimilaarien eli vertailukelpoisten biologisten lääkkeiden käytöllä. Tutkimuksen tavoitteena oli tutkia kyselyaineiston perusteella syöpäpotilaiden näkemyksiä lääkärin toteuttamasta biologisten lääkkeiden lääkevaihdosta ja niihin vaikuttavia tekijöitä avoterveydenhuollossa. Lisäksi tutkittiin, miten yleisesti syöpäpotilaat tunnistavat biologisen lääkkeen ja biosimilaarin käsitteet, ja potilaiden syöpälääkitystään koskevia lääketiedon lähteitä. Tutkimuksen osana toteutettiin järjestelmälliseen kirjallisuushakuun perustuva katsaus syöpäpotilaiden näkemyksistä biologisista lääkkeistä ja/tai biosimilaareista ja niiden lääkevaihdosta. Tutkimus perustui Yliopiston Apteekin ja Helsingin yliopiston yhteistyössä Suomen Syöpäpotilaat ry:n kanssa toteuttamaan tutkimuskyselyyn syöpäpotilaille tammikuussa 2021. Tutkimuskutsu lähetettiin Yliopiston Apteekin kanta-asiakkaille tutkimusuutiskirjeenä ja Suomen Syöpäpotilaat ry tiedotti tutkimuksesta sähköisessä viestinnässään. Tutkimuksen kohderyhmänä olivat aikuiset, joilla oli lääkärin toteama syöpäsairaus ja jotka olivat käyttäneet syöpäsairautensa hoitoon lääkärin määräämä lääkehoitoa kyselyä edeltävän 12 kuukauden aikana. Tutkimusaineisto koostui 294 kohderyhmän potilaasta. Ensisijaisella tulosmuuttujalla (summamuuttuja) tutkittiin syöpäpotilaiden näkemyksiä lääkärin toteuttamasta biologisten lääkkeiden lääkevaihdosta. Vastaajilla oli keskimäärin myönteinen näkemys lääkärin toteuttamasta biologisten lääkkeiden lääkevaihdosta, mutta lääkevaihdon toteuttamiseen liittyi potilaiden kokemaa epävarmuutta (summamuuttuja: Cronbachin alfa 0,808; keskiarvo 3,29/5,00, 95 % lv 3,20–3,38). Myönteinen näkemys oli yhteydessä potilaiden myönteisiin näkemyksiin biosimilaarien ja geneeristen lääkkeiden ominaisuuksista, kuten tehosta, haittavaikutuksista ja käytettävyydestä sekä vastaajan korkeampaan koulutustasoon ja vähäisempiin huoliin yleisesti omasta lääkehoidostaan. Enemmistö (72 %) vastaajista tunnisti biologisen lääkkeen käsitteen, biosimilaari-käsite tunnistettiin heikommin (19 %). Vastaajien käytetyimmät lääketiedon lähteet syöpälääkityksestään olivat terveydenhuollon ammattilaiset (48–88 %) ja pakkausseloste (80 %). Syöpäpotilaiden näkemyksiin biologisten lääkkeiden lääkärin toteuttamasta lääkevaihdosta vaikuttivat useat tekijät, kuten näkemykset biosimilaarien ja geneeristen lääkkeiden ominaisuuksista. Vaikka useat syöpäpotilaat suhtautuivat keskimäärin myönteisesti lääkärin toteuttamaan biologisten lääkkeiden lääkevaihtoon, siihen liittyi usein epävarmuutta. Tulevaisuudessa tulisi tutkia tarkemmin syöpäpotilaiden tietämystä biologisista lääkkeistä ja biosimilaareista. Lisäksi tulisi tutkia millaista lääkeinformaatiota potilaat tarvitsevat päätöksenteon tueksi biologisten lääkkeiden lääkevaihdossa.