Browsing by Subject "Organoids"

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  • Piki, Emilia (Helsingin yliopisto, 2021)
    Ovarian cancers (OCs) are gynecological malignancies that cause the most gynecological cancer related deaths due to asymptomatic early-stage development and late diagnosis. The treatment of OC has not improved significantly during the last decades, and challenges are often caused by chemoresistance and the heterogeneity of cancer cell populations. Therefore, there is an urgent need to improve OC treatment outcome and implement new targeted therapies that could address the subtype specific characteristics. The most common type of OC is epithelial ovarian cancer (EOC), that can be further divided into five subtypes with distinct molecular and histological characteristics. High-grade serous subtype represents majority of cases with up to 75% of EOC patients, while other subtypes such as low-grade serous, mucinous, clear cell and endometrioid OC being less common. Considerable progress has been made in cancer treatment via precision oncology, in which individual cancer biology and tumor molecular features are investigated and used to improve treatment decisions. For this purpose, the development of patient-derived cancer cells (PDCs) offers a good opportunity to study cancer biology in vitro and to build models for preclinical molecular profiling and functional testing. PDCs can be used to establish 2D and 3D models, and most recently, wide interest has been focused on patient-derived organoids (PDOs), that offer a better model of tumor and its microenvironment, while allowing long-term culture, cryopreservation, modification and high-throughput opportunities. In this study, the aim was to establish PDO cultures using tumor cells from low-grade serous OC patients for molecular profiling and functional drug testing. PDOs were generated from both fresh and frozen tumor tissue or ascitic samples resulting to successful development of long-term PDOs from three of the five models. In order to identify optimal culturing conditions for low-grade serous OC PDOs, two previously unpublished growth mediums were tested in parallel. The more complex of the mediums showed slightly better PDO growth in general. The immunohistochemistry staining with pan-cytokeratin and PAX8 was used to confirm the epithelial and ovarian origin of PDOs. In addition, cancer panel sequencing was performed to identify mutation profiles. Importantly, the small-scale drug testing, which was performed using conventional chemotherapeutics cisplatin and paclitaxel and targeted drugs gedatolisib and trametinib, showed sample-specific responses. In conclusion, the results from this project show that PDOs are good models for ex vivo precision medicine functional studies. Importantly, we managed to establish PDOs from frozen tumor cells, suggesting that PDOs could be initiated from living biobank samples. However, the challenges related to culturing of PDOs for functional assays included slower growth rate compared to 2D cancer cell cultures and technical challenges related to Matrigel, limiting the possibilities of high-throughput drug testing. By improving these factors, PDOs will offer an efficient 3D model for preclinical use.
  • Patomo, Joonatan (Helsingin yliopisto, 2022)
    Yksilöity lääketiede (personalized medicine, precision medicine) on lääketieteen suuntaus, jossa hoito räätälöidään potilaan ja hänen sairautensa tarkan tuntemuksen perusteella. Syövän hoidossa se liittyy läheisesti kohdennettuun hoitoon (targeted therapy), jolla tarkoitetaan syövälle ominaisten molekyylitason muutosten hyödyntämistä täsmälääkkeiden kohteena. Kohdennetun hoidon räätälöinnissä käytetään biomarkkereita, joiden avulla voidaan valita ne potilaat jotka hyötyvät tietystä täsmälääkkeestä. Mahasyöpä on heterogeeninen sairaus, jonka molekylaarisissa piirteissä on havaittu potentiaalia kohdennettuun hoitoon. Kliinisissä kokeissa täsmälääkkeet eivät pääsääntöisesti ole tehonneet toivotulla tavalla valikoimattomassa potilasjoukossa. Toisaalta mahasyövästä on löydetty useita mahdollisia biomarkkereita mutta niiden merkitys tunnetaan vaillinaisesti. Syöpäorganoidimalli on prekliininen syöpätutkimusmenetelmä, jossa potilaan kasvaimesta saatuja soluja voidaan kasvattaa ja tutkia laboratorio-olosuhteissa. Solut kasvavat kiinteässä väliaineessa muodostaen organoideiksi kutsuttuja rakenteita, jotka muistuttavat potilaan kasvainta pienoiskoossa. Lääketehoseulonta on syöpäorganoidimallin sovellus, jossa organoidien lääkevasteita tutkitaan samanaikaisesti suurella määrällä solunsalpaaja- tai täsmälääkkeitä. Kirjallisuuskatsauksessa tutkittiin mahasyöpäorganoidimallin soveltuvuutta valikoitujen täsmälääkkeiden lääketehoseulontaan sekä lääkevasteita ennustavien biomarkkerien tutkimiseen. Tutkielmassa käsiteltiin mahasyövän molekylaarista luokittelua, valikoituja täsmälääkkeitä ja syöpäorganoidimallia. Biomarkkereita käsiteltiin kunkin aihepiirin kohdalla. Lisäksi tutkielmassa esitettiin yleisluontoinen katsaus mahasyövästä ja sen hoidosta. Kirjallisuuskatsauksessa havaittiin, että lääketehoseulonta on osoitettu toimivaksi konseptiksi mahasyöpäorganoidimallissa. Organoideissa on kuvattu useita mahdollisina biomarkkereina toimivia muutoksia. Kirjallisuuden perusteella syöpäorganoidimalli soveltuu useiden, mutta ei kaikkien tarkasteltujen täsmälääkkeiden tutkimiseen.
  • Lou, Yan-Ru; Leung, Alan W. (2018)
    Organoids are in vitro cultures of miniature fetal or adult organ-like structures. Their potentials for use in tissue and organ replacement, disease modeling, toxicology studies, and drug discovery are tremendous. Currently, major challenges facing human organoid technology include (i) improving the range of cellular heterogeneity for a particular organoid system, (ii) mimicking the native micro- and matrix-environment encountered by cells within organoids, and (iii) developing robust protocols for the in vitro maturation of organoids that remain mostly fetal-like in cultures. To tackle these challenges, we advocate the principle of reverse engineering that replicates the inner workings of in vivo systems with the goal of achieving functionality and maturation of the resulting organoid structures with the input of minimal intrinsic (cellular) and environmental (matrix and niche) constituents. Here, we present an overview of organoid technology development in several systems that employ cell materials derived from fetal and adult tissues and pluripotent stem cell cultures. We focus on key studies that exploit the self-organizing property of embryonic progenitors and the role of designer matrices and cell-free scaffolds in assisting organoid formation. We further explore the relationship between adult stem cells, niche factors, and other current developments that aim to enhance robust organoid maturation. From these works, we propose a standardized pipeline for the development of future protocols that would help generate more physiologically relevant human organoids for various biomedical applications.
  • Andersson, Simon; Luopajärvi, Kalle; Pentinmikko, Nalle; Katajisto, Pekka (2019)