Abstract 1159: Development of uterine leiomyoma 3D in vitro models for high-throughput drug and chemical compound screenings: Towards personalized medicine
Authors: Bramante Simona , Pietiäinen Vilja , Paavolainen Lassi , Pasanen Annukka , Mäkinen Netta , Heinonen Hanna-Riikka , Ikonen Pirjo , Heikinheimo Oskari , Sjöberg Jari , Bützow Ralf , Aaltonen Lauri 
Published: August 2018

Uterine leiomyomas (ULs) are extremely common smooth muscle tumors, occurring in an estimated 77% of women of reproductive age. Although benign, ULs form a major burden to women's health and are the leading cause of hysterectomy worldwide. Recent findings show that ULs can be classified into at least three distinct molecular subclasses, each with a characteristic genetic driver aberration and global gene expression profile: MED12 (mediator complex subunit 12) mutation-positive, HMGA2 (high mobility group AT-hook 2)-overexpressing, FH (fumarate hydratase)-deficient. However, ULs are currently treated without taking into account the possible different subclasses. The aim of this project is to develop and characterize 3D in vitro models of ULs. The models will be used to examine responses to existing treatments in different subclasses of UL and to identify subclass-specific novel lead compounds for drugs. The work is based on the hypothesis that different molecular UL subclasses have distinct sensitivity and resistance patterns to existing treatment options. Therefore, ULs should not be treated as a single entity. The study material consists of UL tissue belonging to different subclasses and myometrium, collected from hysterectomy patients during surgery in Helsinki University Hospital, Finland. Freshly operated samples are processed to initiate primary cell cultures. The primary cells are seeded on Ultra-Low Attachment (ULA) multiwell plates and grown to form 3D spheroids. In case of MED12-mutated tumors, the spheroids are screened for MED12 mutations by Sanger sequencing. MED12-wild type samples and spheroids are analyzed for overexpression of HMGA2 and FH-deficiency. Immunofluorescence staining is performed to characterize different cell types in the spheroid structure. The presence of live/dead cells in spheroids is monitored during the drug treatments in 384-well plates with high-content confocal microscopy. The approach will first focus on the most common subclasses (MED12-mutated and HMGA2-overexpressing tumors) and most common treatment options. Here, we have set up novel patient-derived cell models for ULs. We have characterized myometrium and UL-derived spheroids and show that they retain the characteristics and genetic driver aberration of the original samples. Furthermore, we show they are composed mostly of live cells. Subsequent in vitro high-throughput drug screening will lead to characterization of drug sensitivities and identification of novel lead compounds for drugs. This information is important for rational drug design, where the effects of candidate drugs can be evaluated in light of the molecular class of the respective tumors. This work will lead to new knowledge towards precision medicine, which has potential for scientific breakthrough, since it would avoid exposing the patients to ineffective treatment options.

Citation Format: Simona Bramante, Vilja Pietiäinen, Lassi Paavolainen, Annukka Pasanen, Netta Mäkinen, Hanna-Riikka Heinonen, Pirjo Ikonen, Oskari Heikinheimo, Jari Sjöberg, Ralf Bützow, Lauri Aaltonen. Development of uterine leiomyoma 3D in vitro models for high-throughput drug and chemical compound screenings: Towards personalized medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1159.