Organoid Culture Of Breast Cancer And Individualized Treatment

BackgroundOrganoid culture is a newly developed three-dimensional cultural technology.Lancaster published a review on《Science》in 2014 and clearly defined organoid as cells resembling an organ which has multiple organ-specific cell types,be capable of recapitulating some organ-specific function and major processes of self-organization during development.Compared with traditional in vitro models,including cell line and patient-derived xenograft model,organoid shows great advantages with its higher recapitulate fitting degree,shorter cultural cycle,more stable quality during passaging and etc.Organoid has been widely used in malignant tumor researches around the world and scientists have already successfully achieved organogenesis in a dish of liver,pancreas,lung,kidney,retina,cortex and so on.In 2018,Professor Hans Clevers’ laboratory first announced to have established practical methods to construct breast cancer organoid models and have built a living biobank of breast cancer which including over 100 organoid lines,named as HUB.Research concerning organoids of breast cancer is at its early stage and limited efforts have been made in China.Objectives1.To explore practical experimental protocol to construct organoids of breast cancer;2.To conduct histopathological and genetic evaluation on successfully constructed organoid lines;3.To detect drug sensitivity of organoids,compare it with clinical efficacy and evaluate the possibility of being used in clinical practice.Methods1.Female outpatients over 18 years old who visited Cancer Hospital Chinese Academy of Medical Sciences for breast cancer from Nov,2017 to Apr,2018 were included in this study.2.Ultrasound guided percutaneous biopsies were conducted and tissues were cultured in Matrigel-based medium to form patient-derived organoids.Growth status of organoids were observed by optical microscopy.3.Paraffin sections made from successfully constructed organoids were stained with hematoxylin and eosin(HE staining).Immunohistochemical staining was also conducted.4.DNA libraries were built with extracted DNA of organoids.Collected CNVs and SNVs data after next-generation sequencing and analyzed using a series of bioinformatics software.5.Treated organoids with different drugs and detected cellular activities.Draw curves accordingly to evaluate drug sensitivity and compare it with clinical efficacy.Results1.15 biopsy samples were collected and 3 organoid lines were formed in this study.2.Through HE staining,organoid paraffin sections showed tumor-specific nuclear-cytoplasmic ratio and cellular pleomorphism.IHC staining results were partially identical with primary tumors.3.CNVs and SNVs analysis indicated that potentially pathogenic genes were involved in cell growth,cell proliferation,tumor-related angiogenesis and tumor apoptosis inhibition.4.Drug sensitivity had some common with clinical efficacy.ConclusionsIn this experiment,culture conditions for human breast cancer organoids were initially established in China.However,the success rate was much lower than that was reported by a foreign laboratory.Histological and genetic features of those organoids accorded with their malignant nature while more complete evaluation and larger number of samples were needed,especially the comparison with the original tumors.Drug sensitivities of organoids had some common with clinical efficacy,but robust evidences were needed for organoids’application in clinical practice.