Browsing by Subject "cancer"

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  • Uoti, Arttu (Helsingin yliopisto, 2021)
    Background and objectives: Cancer is one of the leading causes of death worldwide, and resistance to current treatments demands the continuous development of novel cancer therapies. Cancer immunotherapy aims to induce anticancer immune responses that selectively target cancer cells. Viruses can also be harnessed to elicit tumor-specific immune responses and to improve the response rates of other concomitant cancer therapies. The purpose of this study was to develop a novel viral vector-based cancer vaccine for intratumoral immunotherapy. By using the previously developed PeptiENV cancer vaccine platform, the vector viruses were coated with cell-penetrating peptide (CPP) sequence-containing tumor peptides in an attempt to further drive the immune responses elicited by the vector against cancer cells. The efficacy of the PeptiENV complex as a cancer vaccine was assessed by following its effects on tumor growth and the development of local and systemic antitumor immune responses. Methods: The PeptiENV complex formation was assessed by a surface plasmon resonance (SPR) analysis. Dendritic cell (DC) activation and antigen cross-presentation were studied using the murine JAWS II dendritic cell line. The development of cellular immune responses against tumor antigens was first studied by immunizing mice with the PeptiENV complex. The antitumor efficacy and immunity of intratumoral PeptiENV administration were then studied using the murine melanoma models B16.OVA and B16.F10.9/K1. In addition to intratumoral PeptiENV treatment, some of the B16.F10.9/K1-implanted mice were also treated with an anti-PD-1 immune checkpoint inhibitor (ICI) to study the PeptiENV complex as a biological adjuvant for ICIs. Results: The SPR analysis confirmed that CPP-containing peptides can be stably anchored onto the viral envelope of the viral vector. The in vitro results showed that the PeptiENV complex does not hamper the presentation of antigens at the surface of DCs. Additionally, the viral vector was found to activate DCs seen as a change in the cells’ morphology and surface protein expression. Immunizing mice with the PeptiENV complex induced a robust antigen-specific cytotoxic T cell response. Upon intratumoral administration in vivo, the PeptiENV cancer vaccine was not capable of inducing tumor growth control against B16.OVA melanoma, although it did still elicit robust systemic and local antitumor T cell responses. In the treatment of B16.F10.9/K1 melanoma, however, the PeptiENV complex induced efficient tumor growth control, which resulted in a significant survival benefit. Additionally, co-administration of anti-PD-1 resulted in an additive therapeutic effect. Discussion and conclusions: The present study describes a novel, highly immunogenic viral vector-based cancer vaccine that has the potential to be used as an adjuvant treatment for ICI therapy. Subsequent studies could be conducted to gain a deeper understanding of the immunological mechanisms underlying the antitumor efficacy of the cancer vaccine complex. Moreover, this novel PeptiENV complex could also be further developed as an infectious disease vaccine platform against emerging pandemics. However, the effects of pre-existing antiviral immunity on the efficacy of the cancer vaccine should be explored in future studies.
  • Spjuth, Ola; Karlsson, Andreas; Clements, Mark; Humphreys, Keith; Ivansson, Emma; Dowling, Jim; Eklund, Martin; Jauhiainen, Alexandra; Czene, Kamila; Gronberg, Henrik; Sparen, Par; Wiklund, Fredrik; Cheddad, Abbas; Palsdottir, Porgerodur; Rantalainen, Mattias; Abrahamsson, Linda; Laure, Erwin; Litton, Jan-Eric; Palmgren, Juni (2017)
    Objective: We provide an e-Science perspective on the workflow from risk factor discovery and classification of disease to evaluation of personalized intervention programs. As case studies, we use personalized prostate and breast cancer screenings. Materials and Methods: We describe an e-Science initiative in Sweden, e-Science for Cancer Prevention and Control (eCPC), which supports biomarker discovery and offers decision support for personalized intervention strategies. The generic eCPC contribution is a workflow with 4 nodes applied iteratively, and the concept of e-Science signifies systematic use of tools from the mathematical, statistical, data, and computer sciences. Results: The eCPC workflow is illustrated through 2 case studies. For prostate cancer, an in-house personalized screening tool, the Stockholm-3 model (S3M), is presented as an alternative to prostate-specific antigen testing alone. S3M is evaluated in a trial setting and plans for rollout in the population are discussed. For breast cancer, new biomarkers based on breast density and molecular profiles are developed and the US multicenter Women Informed to Screen Depending on Measures (WISDOM) trial is referred to for evaluation. While current eCPC data management uses a traditional data warehouse model, we discuss eCPC-developed features of a coherent data integration platform. Discussion and Conclusion: E-Science tools are a key part of an evidence-based process for personalized medicine. This paper provides a structured workflow from data and models to evaluation of new personalized intervention strategies. The importance of multidisciplinary collaboration is emphasized. Importantly, the generic concepts of the suggested eCPC workflow are transferrable to other disease domains, although each disease will require tailored solutions.
  • Teixidó, Joaquin; Hidalgo, Andres; Fagerholm, Susanna (2019)
  • Finotello, Francesca; Calura, Enrica; Risso, Davide; Hautaniemi, Sampsa; Romualdi, Chiara (2020)
  • Heiniö, Camilla; Sorsa, Suvi; Siurala, Mikko; Grönberg-Vähä-Koskela, Susanna; Havunen, Riikka; Haavisto, Elina; Koski, Anniina; Hemminki, Otto; Zafar, Sadia; Cervera-Carrascon, Victor; Munaro, Eleonora; Kanerva, Anna; Hemminki, Akseli (2019)
    After the discovery and characterization of the adenovirus in the 1950s, this prevalent cause of the common cold and other usually mild diseases has been modified and utilized in biomedicine in several ways. To date, adenoviruses are the most frequently used vectors and therapeutic (e.g., oncolytic) agents with a number of beneficial features. They infect both dividing and nondividing cells, enable high-level, transient protein expression, and are easy to amplify to high concentrations. As an important and versatile research tool, it is of essence to understand the limits and advantages that genetic modification of adenovirus vectors may entail. Therefore, a retrospective analysis was performed of adenoviral gene therapy constructs produced in the same laboratory with similar methods. The aim was to assess the impact of various modifications on the physical and functional titer of the virus. It was found that genome size (designed within "the 105% golden rule") did not significantly affect the physical titer of the adenovirus preparations, regardless of the type of transgene (e.g., immunostimulatory vs. other), number of engineered changes, and size of the mutated virus genome. One statistically significant exception was noted, however. Chimeric adenoviruses (5/3) had a slightly lower physical titer compared to Ad5-based viruses, although a trend for the opposite was true for functional titers. Thus, 5/3 chimeric viruses may in fact be appealing from a safety versus efficacy viewpoint. Armed viruses had lower functional and physical titers than unarmed viruses, while five genomic modifications started to decrease functional titer. Importantly, even highly modified armed viruses generally had good titers compatible with clinical testing. In summary, this paper shows the plasticity of adenovirus for various vector, oncolytic, and armed oncolytic uses. These results inform future generations of adenovirus-based drugs for human use. This information is directly transferable to academic laboratories and the biomedical industry involved in vector design and production optimization.
  • Mohamed, Hesham; Haglund, Caj; Jouhi, Lauri; Atula, Timo; Hagström, Jaana; Mäkitie, Antti (2020)
    Oropharyngeal squamous cell carcinoma (OPSCC) is subclassified by the World Health Organization into two different entities: human papillomavirus (HPV)-positive and HPV-negative tumors. HPV infection promotes the epithelial-to-mesenchymal transition (EMT) and transformation of keratinocyte stem cells into cancer stem cells. EMT is a crucial process in the carcinogenesis of epithelial-derived malignancies, and we aimed to study the role of its markers in OPSCC. This study consists of 202 consecutive OPSCC patients diagnosed and treated with curative intent. We examined E-cadherin, beta-catenin, and vimentin expression using immunohistochemistry and compared these with tumor and patient characteristics and treatment outcome. We found that the cell-membranous expression of beta-catenin was stronger in HPV-positive than in HPV-negative tumors, and it was stronger in the presence of regional metastasis. The stromal vimentin expression was stronger among HPV-positive tumors. A high E-cadherin expression was associated with tumor grade. No relationship between these markers and survival emerged. In conclusion, beta-catenin and vimentin seem to play different roles in OPSCC: the former in the tumor tissue itself, and the latter in the tumor stroma. HPV infection may exploit the beta-catenin and vimentin pathways in carcinogenic process. More, beta-catenin may serve as a marker for the occurrence of regional metastasis:
  • Alkasalias, Twana; Moyano-Galceran, Lidia; Arsenian-Henriksson, Marie; Lehti, Kaisa (2018)
    Tumorigenesis is a complex process involving dynamic interactions between malignant cells and their surrounding stroma, including both the cellular and acellular components. Within the stroma, fibroblasts represent not only a predominant cell type, but also a major source of the acellular tissue microenvironment comprising the extracellular matrix (ECM) and soluble factors. Normal fibroblasts can exert diverse suppressive functions against cancer initiating and metastatic cells via direct cell-cell contact, paracrine signaling by soluble factors, and ECM integrity. The loss of such suppressive functions is an inherent step in tumor progression. A tumor cell-induced switch of normal fibroblasts into cancer-associated fibroblasts (CAFs), in turn, triggers a range of pro-tumorigenic signals accompanied by distraction of the normal tissue architecture, thus creating an optimal niche for cancer cells to grow extensively. To further support tumor progression and metastasis, CAFs secrete factors such as ECM remodeling enzymes that further modify the tumor microenvironment in combination with the altered adhesive forces and cell-cell interactions. These paradoxical tumor suppressive and promoting actions of fibroblasts are the focus of this review, highlighting the heterogenic molecular properties of both normal and cancer-associated fibroblasts, as well as their main mechanisms of action, including the emerging impact on immunomodulation and different therapy responses.
  • McNeil, Robyn J.; McCarthy, Maria; Dunt, David; Thompson, Kate; Kosola, Silja; Orme, Lisa; Drew, Sarah; Sawyer, Susan (2019)
    This study examined the financial impact of cancer and the use of income support in adolescents and young adults (AYAs) with cancer and their parent caregivers. As part of a national Australian study exploring the psychosocial impacts of cancer, 196 AYAs ages 15 to 25 years, six to 24 months from diagnosis, and 204 parent caregivers from 18 cancer sites were surveyed. Logistic regression and chi-square analyses were conducted to assess the influence of clinical and sociodemographic variables on financial status. Qualitative responses were coded, and key themes were identified using thematic analysis. The findings indicate that more than half of AYAs and parents reported financial issues as a consequence of AYA cancer. Financial issues resulted from direct medical costs, associated costs from treatment, and indirect costs from loss of income. AYAs and parents reported that it was important for them to receive income support, both during and after cancer treatment. However, large proportions of those who reported needing income support had difficulty accessing it. AYAs and their families are substantially financially disadvantaged by cancer, many for a prolonged time. Patient- and family-centered assessments and interventions are required to reduce the financial burden of AYA cancer.
  • Martins, Beatriz (Helsingin yliopisto, 2020)
    According to the latest estimations, cancer is the second leading cause of death worldwide. Despite the significant advances in the range of drugs and treatment modalities to treat cancer, the number of deaths is estimated to continue rising, posing serious challenges for the patients, their families, and the healthcare systems. Conventional treatments tend to be associated with severe adverse side effects and treatment resistance. Consequently, safer and more efficient therapy options are urgently needed, especially for the treatment of metastatic tumors refractory to conventional treatments. A new and revolutionizing field in oncology is immunotherapy, in which oncolytic viruses are included. Oncolytic viruses have an inherent or acquired selectivity to replicate exclusively in tumor cells, ultimately destroying them. Simultaneously, they also activate the dormant host’s immune system to fight against the tumor. Adenoviruses, particularly, have shown to be safe, inducing only mild adverse side effects in clinical trials, making them a great candidate for further clinical development. Adenoviruses can be genetically modified to increase their infectivity or improve the anti-cancer immune responses induced by the virus, e.g., through the expression of immunostimulatory molecules. The focus of this thesis was to develop and characterize several genetically modified oncolytic adenoviruses expressing either OX40L alone or OX40L and CD40L, two co-stimulatory molecules capable of engaging both the innate and adaptive arms of the immune system to fight the tumor. The insertion of the transgenes into the E3B-14.7k region of the Ad5/3-∆24 adenovector plasmid was performed using Gibson Assembly® cloning approach. After successful cloning, the recombinant viral genomes were transfected into A549 cells for viral amplification, followed by CsCl purification to produce a high titer viral preparation. The expression of the transgenes was studied in vitro by ELISA and functional assays, showing promising expression levels of functional OX40L and CD40L. However, when the infectivity and virus killing potency were analyzed, in vitro by immunocytochemistry and MTS assay; and in vivo using an immunodeficient mouse model, the data showed that the cloned viruses performed sub-optimally when compared to the control unarmed virus (Ad5/3-∆24). These findings suggest that the insertion of the two transgenes in place of the E3-14.7k gene was detrimental to the fitness of the virus.
  • Wei, Gong-Hong; Badis, Gwenael; Berger, Michael F.; Kivioja, Teemu; Palin, Kimmo; Enge, Martin; Bonke, Martin; Jolma, Arttu; Varjosalo, Markku; Gehrke, Andrew R.; Yan, Jian; Talukder, Shaheynoor; Turunen, Mikko; Taipale, Mikko; Stunnenberg, Hendrik G.; Ukkonen, Esko; Hughes, Timothy R.; Bulyk, Martha L.; Taipale, Jussi (2010)
  • Arasu, Uma Thanigai; Deen, Ashik Jawahar; Pasonen-Seppänen, Sanna; Heikkinen, Sami; Lalowski, Maciej; Kärnä, Riikka; Härkönen, Kai; Mäkinen, Petri; Lazaro-Ibañez, Elisa; Siljander, Pia R-M; Oikari, Sanna; Levonen, Anna-Liisa; Rilla, Kirsi (2020)
    Intercellular communication is fundamental to the survival and maintenance of all multicellular systems, whereas dysregulation of communication pathways can drive cancer progression. Extracellular vesicles (EVs) are mediators of cell-to-cell communication that regulate a variety of cellular processes involved in tumor progression. Overexpression of a specific plasma membrane enzyme, hyaluronan synthase 3 (HAS3), is one of the factors that can induce EV shedding. HAS3, and particularly its product hyaluronan (HA), are carried by EVs and are known to be associated with the tumorigenic properties of cancer cells. To elucidate the specific effects of cancerous, HAS3-induced EVs on target cells, normal human keratinocytes and melanoma cells were treated with EVs derived from GFP-HAS3 expressing metastatic melanoma cells. We found that the HA receptor CD44 participated in the regulation of EV binding to target cells. Furthermore, GFP-HAS3-positive EVs induced HA secretion, proliferation and invasion of target cells. Our results suggest that HAS3-EVs contains increased quantities of IHH, which activates the target cell hedgehog signaling cascade and leads to the activation of c-Myc and regulation of claspin expression. This signaling of IHH in HAS3-EVs resulted in increased cell proliferation. Claspin immunostaining correlated with HA content in human cutaneous melanocytic lesions, supporting our in vitro findings and suggesting a reciprocal regulation between claspin expression and HA synthesis. This study shows for the first time that EVs originating from HAS3 overexpressing cells carry mitogenic signals that induce proliferation and epithelial-to-mesenchymal transition in target cells. The study also identifies a novel feedback regulation between the hedgehog signaling pathway and HA metabolism in melanoma, mediated by EVs carrying HA and IHH.
  • Miikkulainen, Petra; Högel, Heidi; Seyednasrollah, Fatemeh; Rantanen, Krista; Elo, Laura L.; Jaakkola, Panu M. (2019)
    Most clear cell renal cell carcinomas (ccRCCs) have inactivation of the von Hippel-Lindau tumor suppressor protein (pVHL), resulting in the accumulation of hypoxia-inducible factor -subunits (HIF-) and their downstream targets. HIF-2 expression is particularly high in ccRCC and is associated with increased ccRCC growth and aggressiveness. In the canonical HIF signaling pathway, HIF-prolyl hydroxylase 3 (PHD3) suppresses HIF-2 protein by post-translational hydroxylation under sufficient oxygen availability. Here, using immunoblotting and immunofluorescence staining, qRT-PCR, and siRNA-mediated gene silencing, we show that unlike in the canonical pathway, PHD3 silencing in ccRCC cells leads to down-regulation of HIF-2 protein and mRNA. Depletion of other PHD family members had no effect on HIF-2 expression, and PHD3 knockdown in non-RCC cells resulted in the expected increase in HIF-2 protein expression. Accordingly, PHD3 knockdown decreased HIF-2 target gene expression in ccRCC cells and expression was restored upon forced HIF-2 expression. The effect of PHD3 depletion was pinpointed to HIF2A mRNA stability. In line with these in vitro results, a strong positive correlation of PHD3 and HIF2A mRNA expression in ccRCC tumors was detected. Our results suggest that in contrast to the known negative regulation of HIF-2 in most cell types, high PHD3 expression in ccRCC cells maintains elevated HIF-2 expression and that of its target genes, which may enhance kidney cancer aggressiveness.
  • Hemminki, Otto; Parviainen, Suvi; Juhila, Juuso; Turkki, Riku; Linder, Nina; Lundin, Johan; Kankainen, Matti; Ristimaki, Ari; Koski, Anniina; Liikanen, Ilkka; Oksanen, Minna; Nettelbeck, Dirk M.; Kairemo, Kalevi; Partanen, Kaarina; Joensuu, Timo; Kanerva, Anna; Hemminki, Akseli (2015)
    Oncolytic viruses that selectively replicate in tumor cells can be used for treatment of cancer. Accumulating data suggests that virus induced oncolysis can enhance anti-tumor immunity and break immune tolerance. To capitalize on the immunogenic nature of oncolysis, we generated a quadruple modified oncolytic adenovirus expressing granulocyte-macrophage colony-stimulating factor (GMCSF). Ad5/3-E2F-Delta 24-GMCSF (CGTG-602) was engineered to contain a tumor specific E2F1 promoter driving an E1 gene deleted at the retinoblastoma protein binding site ("Delta 24"). The fiber features a knob from serotype 3 for enhanced gene delivery to tumor cells. The virus was tested preclinically in vitro and in vivo and then 13 patients with solid tumors refractory to standard therapies were treated. Treatments were well tolerated and frequent tumor-and adenovirus-specific T-cell immune responses were seen. Overall, with regard to tumor marker or radiological responses, signs of antitumor efficacy were seen in 9/12 evaluable patients (75%). The radiological disease control rate with positron emission tomography was 83% while the response rate (including minor responses) was 50%. Tumor biopsies indicated accumulation of immunological cells, especially T-cells, to tumors after treatment. RNA expression analyses of tumors indicated immunological activation and metabolic changes secondary to virus replication.
  • Sokka, Iris (Helsingin yliopisto, 2019)
    Cancer is a worldwide health problem; in 2018 9.6 million people died of cancer, meaning that about 1 in 6 deaths was caused by it. The challenge with cancer drug therapy has been the development of cancer drugs that are effective against cancer but are not harmful to the healthy cells. One of the solutions to this has been antibody-drug conjugates (ADCs), where a cytotoxic drug is bound to an antibody. The antibody binds to specific antigen present on the surface of the cancer cell, thus working as a vessel to carry the drug specifically to the cancer cells. Monomethyl auristatin E (MMAE) and monomethyl auristatin F (MMAF) are mitosis preventing cancer drugs. The auristatins are pentapeptides that were developed from dolastatin 10. MMAE consist of monomethyl valine (MeVal), valine (Val), dolaisoleiune (Dil), dolaproine (Dap) and norephedrine (PPA). MMAF has otherwise similar structure, but norephedrine is replaced by phenylalanine (Phe). They prevent cell division and cancer cell proliferation by binding to microtubules and are thus able to kill any kind of cell. By attaching the auristatin to an antibody that targets cancer cells, they can effectively be used in the treatment of cancer. MMAE and MMAF exist as two conformers in solution, namely as cis- and trans-conformers. The trans-conformer resembles the biologically active conformer. It was recently noted that in solution 50-60 % of the MMAE and MMAF-molecules exist in the biologically inactive cis-conformer. The molecule changes from one conformer to the other by the rotation of an amide bond. However, this takes several hours in body temperature. As the amount of the cis-conformer is significant, the efficacy of the drug is decreased, and the possibility of side effects is increased. It is possible that the molecule leaves the cancer cell in its inactive form, migrates to healthy cells and tissue, and transforms to the active form there, damaging the healthy cell. The goal of this study was to modify the structure of the auristatins so that the cis/trans-equilibrium would change to favor the biologically active trans-conformer. The modifications were done virtually, and the relative energies were computed using high-level quantum chemical methods, at density functional theory (DFT), 2nd order perturbation theory (MP2) and coupled cluster levels. Intramolecular interactions were analyzed computationally, employing symmetry-adapted perturbation theory and the non-covalent interactions analysis. The results suggest that simple halogenation of the benzene ring para-position is able to significantly shift the cis/trans-equilibrium to favor the trans-conformer. This is due to changes in intramolecular interactions that favor the trans-conformer after halogenation. For example, the NCI analysis shows that the halogen atom invokes stabilizing intramolecular interactions with the Dil amino acid; there is no such interaction between the para-position hydrogen and Dil in the original molecules. We also performed docking studies that show that the halogenated molecules can bind to microtubules, thus confirming that the modified structures have potential to be developed into new, more efficient and safe cancer drugs. The most promising drug candidates are Cl-MMAF, F-MMAF, and F-MMAE where 94, 90, and 79 % of the molecule is predicted to exist in the biologically active trans-conformer, respectively.
  • Tallbacka, Kaj; Pettersson, Tom; Pukkala, Eero (Helsingin yliopisto, 2017)
    Objective: The aim of this study was to assess the cancer risk in a cohort of Finnish systemic lupus erythematosus (SLE) patients when followed long-term. Methods: The cohort consisted of 182 female and 23 male SLE patients treated at the Helsinki University Central Hospital, from 1967 to 1987. The cohort was linked to the Finnish Cancer Registry and followed for cancer incidence from 1967 to 2013. Standardized incidence ratios (SIRs) were calculated by dividing the number of observed cases with the number of expected cases for different types of cancer. Results: The mean duration of follow-up was 25.7 years. 45 patients out of 205 were diagnosed with cancer, with an increased risk of overall malignancy (SIR 1.90, 95% CI 1.39 to 2.54, p<0.001). The incidence for soft-tissue sarcoma (SIR 12.1, 95% CI 1.47 to 43.7, p<0.05), non-Hodgkin lymphoma (SIR 12.1, 95% CI 5.82 to 22.3, p<0.001) and kidney cancer (SIR 7.79, 95% CI 2.53 to 18.2, p<0.01) were significantly elevated. Conclusion: This long-term study confirms that patients with SLE have an increased risk of cancer, particularly non-Hodgkin lymphoma and kidney cancer.
  • Kukkonen, Pyry (Helsingfors universitet, 2017)
    Tutkielman tarkoitus on tuoda tunnettujen riskitekijöiden rinnalle tuore tieteellinen näkemys suuinfektioiden ja syövän yhteydestä. Tavoitteena on myös vahvistaa käsitystä suunterveyden merkityksestä ihmisen yleisterveyteen. Tutkielma on toteutettu kirjallisuuskatsauksena. Tutkielmassa havaittiin tilastollisesti suuinfektioiden lisäävän potilaan riskiä sairastua syöpään. Tutkielmassa tarkastelluista aineistosta voidaan todeta, että tilastollinen yhteys suuinfektioiden ja syövän välillä on havaittu, mutta mahdollisen kausaliteetin osoittaminen vaatii runsaasti lisätutkimuksia. Suuinfektiot ovat hoidettavissa ja ennaltaehkäistävissä, jolloin voidaan mahdollisesti myös alentaa potilaan riskiä sairastua syöpään.
  • Scala, Giovanni; Federico, Antonio; Fortino, Vittorio; Greco, Dario; Majello, Barbara (2020)
    The explosion of omics data availability in cancer research has boosted the knowledge of the molecular basis of cancer, although the strategies for its definitive resolution are still not well established. The complexity of cancer biology, given by the high heterogeneity of cancer cells, leads to the development of pharmacoresistance for many patients, hampering the efficacy of therapeutic approaches. Machine learning techniques have been implemented to extract knowledge from cancer omics data in order to address fundamental issues in cancer research, as well as the classification of clinically relevant sub-groups of patients and for the identification of biomarkers for disease risk and prognosis. Rule induction algorithms are a group of pattern discovery approaches that represents discovered relationships in the form of human readable associative rules. The application of such techniques to the modern plethora of collected cancer omics data can effectively boost our understanding of cancer-related mechanisms. In fact, the capability of these methods to extract a huge amount of human readable knowledge will eventually help to uncover unknown relationships between molecular attributes and the malignant phenotype. In this review, we describe applications and strategies for the usage of rule induction approaches in cancer omics data analysis. In particular, we explore the canonical applications and the future challenges and opportunities posed by multi-omics integration problems.
  • Nieminen, Mikko T.; Salaspuro, Mikko (2018)
    The resident microbiome plays a key role in exposure of the upper gastrointestinal (GI) tract mucosa to acetaldehyde (ACH), a carcinogenic metabolite of ethanol. Poor oral health is a significant risk factor for oral and esophageal carcinogenesis and is characterized by a dysbiotic microbiome. Dysbiosis leads to increased growth of opportunistic pathogens (such as Candida yeasts) and may cause an up to 100% increase in the local ACH production, which is further modified by organ-specific expression and gene polymorphisms of ethanol-metabolizing and ACH-metabolizing enzymes. A point mutation in the aldehyde dehydrogenase 2 gene has randomized millions of alcohol consumers to markedly increased local ACH exposure via saliva and gastric juice, which is associated with a manifold risk for upper GI tract cancers. This human cancer model proves conclusively the causal relationship between ACH and upper GI tract carcinogenesis and provides novel possibilities for the quantitative assessment of ACH carcinogenicity in the human oropharynx. ACH formed from ethanol present in “non-alcoholic” beverages, fermented food, or added during food preparation forms a significant epidemiologic bias in cancer epidemiology. The same also concerns “free” ACH present in mutagenic concentrations in multiple beverages and foodstuffs. Local exposure to ACH is cumulative and can be reduced markedly both at the population and individual level. At best, a person would never consume tobacco, alcohol, or both. However, even smoking cessation and moderation of alcohol consumption are associated with a marked decrease in local ACH exposure and cancer risk, especially among established risk groups.
  • Niemi, Katriina Viola Elisabeth (Helsingin yliopisto, 2020)
    Matriksin metalloproteinaasi 8 on kollageenia hajottava ihmisen elimistön erittämä entsyymi. Se osallistuu normaaliin kudosten muokkaamiseen ja tulehduksellisiin sairauksiin, kuten syöpään, parodontiittiin ja sydän- ja verisuonitauteihin. Tässä tutkimuksessa aineistona ovat Pubmedistä haetut artikkelit ja FINRISK-tutkimuksessa vuonna 1997 kerätty aineisto 8349 henkilöltä. MMP-8-pitoisuus määritettiin tutkimushenkilöiden seerumista IFMA-menetelmällä. FINRISK-tutkimusaineistoa analysoitiin IMB SPSS Statistics-ohjelman avulla. Tulokseksi saatiin, että seerumin matriksin metalloproteinaasi 8:n pitoisuus on terveillä korkeampi kuin sairailla, kun tarkastellaan koko väestöä. Ikäryhmittäin tarkasteltuna ikäryhmien sisällä pitoisuus on kuitenkin sairailla korkeampi kuin terveillä. Matriksin metalloproteinaasi 8:n pitoisuus laskee iän myötä. Erot pitoisuudessa terveiden ja sairaiden välillä pienentyvät iän myötä. Viitearvot määritettiin tässä tutkimuksessa, ja ne ovat 5,33-241,2 ng/ml kaikille, naisille 5,61-250,1 ng/ml ja miehille 4,96-217,9 ng/ml. Terveillä ja sairailla tupakoitsijoilla pitoisuudet ovat käytännössä samat. Tupakoinnin lopettaneilla erot pitoisuudessa ovat terveiden ja sairaiden välillä suhteellisen suuret. Henkilöillä, joilla on metabolinen oireyhtymä, on matala matriksin metalloproteinaasi 8:n pitoisuus. Pitoisuus on tilastollisesti merkitsevästi matalampi myöhemmin puhkeavan diabeteksen suhteen. Tässä tutkimuksessa MMP-8:n pitoisuudet olivat sydän- ja verisuonisairauksia sairastavilla tutkittavilla henkilöillä matalat. Matriksin metalloproteinaasi 8:n pitoisuus korreloi positiivisesti CRP:n ja erityisen voimakkaasti fibrinogeenin kanssa. Vaikuttaa siltä, että kroonisesti sairailla pitoisuudet ovat matalat, akuutissa tilanteessa pitoisuudet nousevat ja ajan kuluessa laskevat takaisin mataliksi. Tämä koskee erityisesti sydän- ja verisuonitauteja. Hypoteesi tarvitsisi lisää tutkimusta, jotta pystyisimme MMP-8:n avulla seuraamaan ja ennustamaan taudinkulkua paremmin. (212 sanaa)
  • Raza, Shaffaq (Helsingin yliopisto, 2020)
    Growth differentiation factor 15 (GDF15), a member of TGF-β super family is a soluble cytokine that is associated with different pathological conditions including cancer, cardiac and renal failure and obesity. Its high serum levels are linked with symptoms like cachexia/anorexia in cancer patients and can be used as a marker for these diseases. Its crucial role in weight regulation and energy homeostasis has been demonstrated by treating obese mice with GDF15, which results in weight lose along with improved glucose metabolism and increased insulin tolerance. It is now known that GDF15 exerts its metabolic effect by binding to a GDNF receptor -α-Like (GFRAL) receptor along with co-receptor RET. Interestingly, these two receptors co-localize only in the brain stem area of mice and humans indicating involvement of a neuronal circuit in GDF15 mediated effects. Despite its implications in major health disorders, little is known about the interaction of GDF15 with its receptors and how this interaction in turn modulates different cellular signalling and functions. The aim of the thesis was to study the mechanism and factors involved in endocytosis of GDF15. I employed high content imaging and flow cytometry techniques to visualize and analyse the internalization of ligand-receptor complex and investigate the role of actin, dynamin and phosphoinositide 3 kinase in the process. The results suggest that similar to the internalization of other cellular growth factors, the uptake of GDF15 is affected by disruption of the actin cytoskeleton. The role of dynamin is still unclear. I also discovered that the internalization of GDF15 was inefficient even in cells that expressed the receptor GFRAL, with large cell-to-cell variation. By following the intracellular localization of the receptor GFRAL, my results revealed that the receptor GFRAL is not efficiently exported to the plasma membrane and most of the protein is retained in the Golgi compartment of cells. This phenomenon was stronger in murine fibroblast cells, where the receptor was almost exclusively trapped in the secretory compartment, explaining why the uptake of the ligand GDF15 is so inefficient in these cells. The system developed during this project will now be used to analyse different factors involved in the uptake of GDF15 and eventually uncover the possible endocytic pathway. Moreover, the Golgi retention of the receptor opens up new questions to investigate like whether the physiological function of GDF15 is regulated by receptor export signals. This will help deciphering the complex and mysterious interaction of GDF15 with its receptor GFRAL.