In this issue of Cell Stem Cell, Lõhmussaar et al. (2021) describe a versatile platform for generating long-term patient-derived organoids from hysterectomies and Pap brush cells. They establish malignant and benign cervix tissue organoids from both endo- and ectocervix that have applications ranging from precision medicine to infection modeling.

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Tumor organoids are promising tools for cancer biology investigations and preclinical drug screenings because they are often representative of the histology and drug responses of patients. Here, we introduce a facile protocol to overcome technical limitations by generating patient-derived tumor organoids using a simplified ring-like geometry. This facilitates media exchange and drug treatment for histopathology characterization and automated high-throughput drug screenings. For complete details on the use and execution of this protocol, please refer to Phan et al. (2019).

The aggregation of α-synuclein (α-Syn) is believed to be one of the key steps driving the pathology of Parkinson's disease and related neurodegenerative disorders. One of the present hypotheses is that the onset of such pathologies is related to the rise of α-Syn levels above a critical concentration at which toxic oligomers or mature fibrils are formed. In the present study, we find that α-Syn aggregation in vitro is a spontaneous process arising at bulk concentrations as low as 1 nM and below in the presence of both hydrophilic glass surfaces and cell membrane mimicking supported lipid bilayers (SLBs). Using three-dimensional supercritical angle fluorescence (3D-SAF) microscopy, we observed the process of α-Syn aggregation in situ. As soon as α-Syn monomers were exposed to the surface, they started to adsorb and aggregate along the surface plane without a prior lag phase. However, at a later stage of the aggregation process, a second type of aggregate was observed. In contrast to the first type, these aggregates showed an extended structure being tethered with one end to the surface and being mobile at the other end, which protruded into the solution. While both types of α-Syn aggregates were found to contain amyloid structures, their growing mechanisms turned out to be significantly different. Given the clear evidence that surface-induced α-Syn aggregation in vitro can be triggered at bulk concentrations far below physiological concentrations, the concept of a critical concentration initiating aggregation in vivo needs to be reconsidered.

Tumor organoids maintain cell-cell interactions, heterogeneity, microenvironment, and drug response of the sample they originate from. Thus, there is increasing interest in developing tumor organoid models for drug development and personalized medicine applications. Although organoids are in principle amenable to high-throughput screenings, progress has been hampered by technical constraints and extensive manipulations required by current methods. Here we introduce a miniaturized method that uses a simplified geometry by seeding cells around the rim of the wells (mini-rings). This allows high-throughput screenings in a format compatible with automation as shown using four patient-derived tumor organoids established from two ovarian and one peritoneal high-grade serous carcinomas and one carcinosarcoma of the ovary. Using our automated screening platform, we identified personalized responses by measuring viability, number, and size of organoids after exposure to 240 kinase inhibitors. Results are available within a week from surgery, a timeline compatible with therapeutic decision-making.

Localized cutaneous neurofibromas (cNFs) are benign tumors that arise in the dermis of patients affected by neurofibromatosis type 1 syndrome. cNFs are benign lesions: they do not undergo malignant transformation or metastasize. Nevertheless, they can cover a significant proportion of the body, with some individuals developing hundreds to thousands of lesions. cNFs can cause pain, itching, and disfigurement resulting in substantial socio-emotional repercussions. Currently, surgery and laser desiccation are the sole treatment options but may result in scarring and potential regrowth from incomplete removal. To identify effective systemic therapies, we introduce an approach to establish and screen cNF organoids. We optimized conditions to support the ex vivo growth of genomically diverse cNFs. Patient-derived cNF organoids closely recapitulate cellular and molecular features of parental tumors as measured by immunohistopathology, methylation, RNA sequencing, and flow cytometry. Our cNF organoid platform enables rapid screening of hundreds of compounds in a patient- and tumor-specific manner.

Chordomas are rare tumors of notochordal origin, most commonly arising in the sacrum or skull base. Chordomas are considered insensitive to conventional chemotherapy, and their rarity complicates running timely and adequately powered trials to identify effective treatments. Therefore, there is a need for discovery of novel therapeutic approaches. Patient-derived organoids can accelerate drug discovery and development studies and predict patient responses to therapy. In this proof-of-concept study, we successfully established organoids from seven chordoma tumor samples obtained from five patients presenting with tumors in different sites and stages of disease. The organoids recapitulated features of the original parent tumors and inter- as well as intrapatient heterogeneity. High-throughput screenings performed on the organoids highlighted targeted agents such as PI3K/mTOR, EGFR, and JAK2/STAT3 inhibitors among the most effective molecules. Pathway analysis underscored how the NF-κB and IGF-1R pathways are sensitive to perturbations and potential targets to pursue for combination therapy of chordoma.

Chordomas are rare tumors of notochordal origin, most commonly arising in the sacrum or skull base. Primary treatment of chordoma is surgery, however complete resection is not always feasible due to their anatomic location, and recurrence rates remain high. Chordomas are considered insensitive to conventional chemotherapy, and their rarity complicates running timely and adequately powered trials to identify effective regimens. Therefore, there is a need for discovery of novel therapeutic approaches. Drug discovery efforts in chordoma have been mostly limited to cell line models. Patient-derived organoids can accelerate drug discovery studies and predict patient responses to therapy. In this proof-of-concept study, we successfully established organoids from seven chordoma tumor samples obtained from five patients presenting with tumors in different sites and stages of disease. The organoids recapitulated features of the original parent tumors and inter-as well as intra-patient heterogeneity. High-throughput screenings performed on the organoids highlighted targeted agents such as PI3K/mTOR, EGFR, and JAK2/STAT3 inhibitors among the most effective molecules. Pathway analysis underscored how the NF-kB and IGF-1R pathways are sensitive to perturbations and potential targets to pursue for combination therapy of chordoma.