MISpheroID: a knowledgebase and transparency tool for minimum information in spheroid identity.

Spheroids are three-dimensional cellular models with widespread basic and translational application across academia and industry. However, methodological transparency and guidelines for spheroid research have not yet been established. The MISpheroID Consortium developed a crowdsourcing knowledgebase that assembles the experimental parameters of 3,058 published spheroid-related experiments. Interrogation of this knowledgebase identified heterogeneity in the methodological setup of spheroids. Empirical evaluation and interlaboratory validation of selected variations in spheroid methodology revealed diverse impacts on spheroid metrics. To facilitate interpretation, stimulate transparency and increase awareness, the Consortium defines the MISpheroID string, a minimum set of experimental parameters required to report spheroid research. Thus, MISpheroID combines a valuable resource and a tool for three-dimensional cellular models to mine experimental parameters and to improve reproducibility.

Establishment and characterization of a cell line and patient-derived xenograft (PDX) from peritoneal metastasis of low-grade serous ovarian carcinoma.

Peritoneal spread indicates poor prognosis in patients with serous ovarian carcinoma (SOC) and is generally treated by surgical cytoreduction and chemotherapy. Novel treatment options are urgently needed to improve patient outcome. Clinically relevant cell lines and patient-derived xenograft (PDX) models are of critical importance to therapeutic regimen evaluation. Here, a PDX model was established, by orthotopic engraftment after subperitoneal tumor slurry injection of low-grade SOC, resulting in an early-stage transplantable peritoneal metastasis (PM)-PDX model. Histology confirmed the micropapillary and cribriform growth pattern with intraluminal tumor budding and positivity for PAX8 and WT1. PM-PDX dissociated cells show an epithelial morphotype with a 42 h doubling time and 40% colony forming efficiency, they are low sensitive to platinum derivatives and highly sensitive to paclitaxel (IC50: 6.3 ± 2.2 nM, mean ± SEM). The patient primary tumor, PM, PM-PDX and derived cell line all show a KRAS c.35 G > T (p.(Gly12Val)) mutation and show sensitivity to the MEK inhibitor trametinib in vitro (IC50: 7.2 ± 0.5 nM, mean ± SEM) and in the PM mouse model. These preclinical models closely reflecting patient tumors are useful to further elucidate LGSOC disease progression, therapy response and resistance mechanisms.

Heterocellular 3D scaffolds as biomimetic to recapitulate the tumor microenvironment of peritoneal metastases in vitro and in vivo.

Peritoneal metastasis is a major cause of death and preclinical models are urgently needed to enhance therapeutic progress. This study reports on a hybrid hydrogel-polylactic acid (PLA) scaffold that mimics the architecture of peritoneal metastases at the qualitative, quantitative and spatial level. Porous PLA scaffolds with controllable pore size, geometry and surface properties are functionalized by type I collagen hydrogel. Co-seeding of cancer-associated fibroblasts (CAF) increases cancer cell adhesion, recovery and exponential growth by in situ heterocellular spheroid formation. Scaffold implantation into the peritoneum allows long-term follow-up (>14 weeks) and results in a time-dependent increase in vascularization, which correlates with cancer cell colonization in vivo. CAF, endothelial cells, macrophages and cancer cells show spatial and quantitative aspects as similarly observed in patient-derived peritoneal metastases. CAF provide long-term secretion of complementary paracrine factors implicated in spheroid formation in vitro as well as in recruitment and organization of host cells in vivo. In conclusion, the multifaceted heterocellular interactions that occur within peritoneal metastases are reproduced in this tissue-engineered implantable scaffold model.

Age and cellular context influence rectal prolapse formation in mice with caecal wall colorectal cancer xenografts.

In patients with rectal prolapse is the prevalence of colorectal cancer increased, suggesting that a colorectal tumor may induce rectal prolapse. Establishment of tumor xenografts in immunodeficient mice after orthotopic inoculations of human colorectal cancer cells into the caecal wall is a widely used approach for the study of human colorectal cancer progression and preclinical evaluation of therapeutics. Remarkably, 70% of young mice carrying a COLO320DM caecal tumor showed symptoms of intussusception of the large bowel associated with intestinal lumen obstruction and rectal prolapse. The quantity of the COLO320DM bioluminescent signal of the first three weeks post-inoculation predicts prolapse in young mice. Rectal prolapse was not observed in adult mice carrying a COLO320DM caecal tumor or young mice carrying a HT29 caecal tumor. In contrast to HT29 tumors, which showed local invasion and metastasis, COLO320DM tumors demonstrated a non-invasive tumor with pushing borders without presence of metastasis. In conclusion, rectal prolapse can be linked to a non-invasive, space-occupying COLO320DM tumor in the gastrointestinal tract of young immunodeficient mice. These data reveal a model that can clarify the association of patients showing rectal prolapse with colorectal cancer.