Table 1.

Studies using organoids in drug screening and toxicology

Therapeutic drugs
Organoid type	Aim of the study	Key findings	Reference
Oesophageal adenocarcinoma – ASCs	Establishment and characterisation of oesophageal adenocarcinoma organoids. Evaluation of their sensitivity to 24 anticancer compounds, including approved drugs and preclinical targeted agents.	Organoids recapitulated the features of the primary tumour. A range of compound sensitivities, including drug potency and efficacy, was observed, which was consistent with patient responses to therapy (e.g. resistance).	(17)
Ductal pancreatic cancer – ASCs and PSCs	Development of pancreatic tumoroids from PSCs and patient samples that model ductal pancreatic cancer. Assessment of patient tumour organoid responses to gemcitabine and drugs targeting epigenetic regulators.	Patient-derived tumour organoids maintained tumour-specific traits. Treatment with gemcitabine led to poor response with only 30% growth inhibition and treatment with epigenetic regulators decreased proliferation to varied degrees in different organoids.	(70)
Pancreatic tumour – ASCs	Studying human pancreatic tumoroid survival in co-culture with liver organoids after treatment with docetaxel.	Pancreatic tumoroid co-culture with CYP-induced liver organoids showed higher survival rate compared with undifferentiated and differentiated liver after treatment with docetaxel.	(46)
Colon tumour and normal – ASCs	Establishment and characterisation of colon tumour and normal organoid lines. Assessment of organoids for their sensitivity after treatment with a library of 83 compounds including chemotherapeutics, drugs in clinical use or in clinical trials and experimental compounds.	Colon tumour organoids recapitulated several features of the primary tumour and reflected the heterogeneity of the tumours. Differential responses of the organoids to the compounds were seen measured by the IC50, the slope of the dose–response curve and the area under the curve, as well as organoid-drug interactions.	(37)
Rectal – ASCs	Measurement of drug efficacy of the CFTR-modulating treatments (ivacaftor, lumacaftor plus ivacaftor and genistein plus curcumin) in rectal organoids from cystic fibrosis patients and correlation with in vivo effects.	In vitro responses to CFTR modulators (ivacaftor, lumacaftor plus ivacaftor and genistein plus curcumin) and forskolin-induced swelling in the rectal organoids from cystic fibrosis patients correlated with two indicators of therapeutic response in vivo, sweat chloride concentration and pulmonary response.	(39)
Rectal – ASCs	Studying CFTR function of rectal organoids from cystic fibrosis patients and the organoid’s response to the drug treatments ivacaftor and lumacaftor.	CFTR function and response of rectal organoids to treatment with ivacaftor and lumacaftor depended on the CFTR mutation and the genetic background of the patient. Results positively correlated with published data from clinical trials.	(84)
Kidney cancer – ASCs	Establishment of kidney organoid biobank from paediatric cancer patients. Characterisation of tumour kidney organoids and testing their sensitivity towards drugs used in standard chemotherapy.	Kidney tumour organoids maintain key features of the tumour of origin, including their heterogeneity. Tumour organoid lines were more sensitive, based on a dose–response curve, to some therapies than normal kidney organoids.	(35)
Kidney – PSCs	Establishment of kidney organoids and testing their ability to endocytose dextran and to undergo apoptosis in response to cisplatin treatment.	Demonstration of kidney organoid functionality by selective uptake of dextran. The nephrotoxicant cisplatin induced acute apoptosis in kidney organoids.	(76)
Kidney – PSCs	Establishment of kidney organoids and assessment of drug nephrotoxicity by treating them with gentamicin or cisplatin, drugs known to cause proximal tubular toxicity.	Nephrotoxicity was observed after organoid treatment with these drugs, as proximal and distal tubule biomarkers for toxicity, like kidney injury molecule-1, were expressed.	(14)
Bile tract carcinoma – ASCs	Testing a library of drugs used clinically for their ability to suppress the tumoroids derived from intrahepatic cholangiocarcinoma, gall- bladder cancer and neuroendocrine carcinoma of the ampulla of Vater.	The library screening showed that the antifungal drugs amorolfine and fenticonazole suppress tumour organoid growth while little cytotoxicity was seen in normal cells.	(45)
Liver cancer –ASCs	Studying the functional heterogeneity of liver cancer organoids by testing 129 cancer drugs to assess liver cancer heterogeneity.	Liver cancer organoids showed large variability in intra-tumour drug response, with many drugs showing no cytotoxic response and some drugs effective only in certain organoids. A group of drugs used for other cancers rather than liver cancer showed moderate activity in most organoids.	(36)
Testicular – ASCs	Evaluation of testicular organoids as a model for reproductive toxicity by treatment with cisplatin, etoposide, doxorubicin and busulfan. Comparison of results to those obtained in 2D culture of the same cell types.	The testicular organoids showed a dose-dependent response in terms of cell viability after treatment with cisplatin, etoposide, doxorubicin and busulfan and had IC50 values higher than those in the same cell types cultured in 2D.	(41)
Intestinal – ASCs	Studying toxicity and cell death induction in normal intestinal organoids after exposure to cisplatin, 5-fluorouracil, UV or X-ray radiation. Comparison of results to those obtained in colon carcinoma cell lines.	Intestinal organoids were more sensitive to chemotherapeutic drugs than colon carcinoma cell lines, mimicking the in vivo situation. The organoids also responded much more sensitively to radiation exposure than the immortal cell lines.	(42)
Intestinal crypt – ASCs	Studying gene expression of XMEs and activation of xenobiotic nuclear receptors in intestinal organoids after treatment with the anticancer pro-drug camptothecin-11.	Expression of XMEs, such as CYPs, Adh1, Ces, Ugts and Sult and transporters, as well as functional nuclear receptors, like the aryl hydrocarbon receptor, were observed. Organoids metabolised the anticancer prodrug camptothecin-11 by the action of Ces and Ugt1a1.	(44)
Liver – PSCs	1) Characterisation of human PSCs-derived liver organoids and functionality assessment. Study of their toxicity profiles after treatment with compounds such as omeprazole, hepatotoxic compounds and antibiotics, and comparison to a 2D model. 2) Development of a steatosis pathology model and testing L-carnitine, metformin and other compounds for their toxicity and efficiency to treat this condition.	1) Human PSCs-derived liver organoids maintain liver properties including the ability to metabolise drugs and showed toxic responses to drug treatment. Organoids were more sensitive than 2D hepatocyte monolayers at clinically relevant doses. 2) Human PSCs-derived liver organoids displayed steatosis phenotypes after treatment with lipids. Treatment with L-carnitine ameliorated the disease phenotype and further compounds were identified from an autophagy library.	(43)
Liver, cardiac, lung, brain, testes and colon – PSCs	Treatment of liver, cardiac, lung, brain, testes and colon organoids with 10 drugs that were recalled due to adverse effects, including troglitazone, astemizole and bromfenac, in comparison to a number of non-toxic drugs (aspirin, ibuprofen, loratadine, ascorbic acid and quercetin) used as control. Treatment of liver and cardiac organoids was conducted individually and together with the other 4 organoid types in a ‘body-on-chip’ system. Comparison of results obtained with a 2D model.	Toxic concentrations were lower in the organoids compared with those in 2D primary cells and immortalised cell lines. However, organoids were more sensitive to some drugs like astemizole and more resistant to others like rofecoxib. Results from the cell lines were less significant as they showed greater variability. Most drugs considered as non-toxic did not show any toxicity in organoids. Results from the ‘body-on-chip’ system showed that when organoids are used in combination on a chip, one organoid type influences the activity of another organoid type creating more complex responses.	(116)
Environmental and experimental toxicants
Colon – ASCs	Investigating the effect of ethanol exposure in normal colon organoids on gene expression and chromatin accessibility.	Identification of more than 1500 differentially expressed genes and 2000 differentially accessible chromatin regions in normal colon organoids after ethanol treatment.	(87)
Liver and cardiac – PSCs	Viability and cytotoxicity assessment of liver and cardiac organoids after exposure to the environmental pollutants lead, mercury, thallium and glyphosate.	Liver and cardiac organoids showed toxicity after treatment with environmental pollutants (lead, mercury, thallium and glyphosate) with thallium being the most toxic compound tested. All pollutants led to a decrease in cardiac organoid beating activity.	(15)
Mammary – ASCs	Studying the effect on organoid formation and morphology in organoids derived from mammoplasty patients treated with physiologically relevant doses of cadmium.	Cadmium negatively affected mammary organoid formation and branching at the highest concentration tested, 2.5 µM. Gene expression analysis showed the up- regulation of metal response genes, like metallothioneins and zinc transporters, and inhibited hypoxia inducible factor-1α activity.	(86)
Brain (organoid on chip) – PSCs	Assessment of the effects of nicotine in brain organoids on a chip that recapitulated features of the developing foetal human brain at early stages.	Organoids exposed to nicotine showed premature and abnormal neuronal differentiation. Brain regionalisation and development were also affected.	(106)
Intestinal – ASCs	Studying toxicity and cell death induction in normal intestinal organoids after exposure to cisplatin, 5-fluorouracil, UV or X-ray radiation. Comparison of results to those obtained in colon carcinoma cell lines.	Intestinal organoids were more sensitive to chemotherapeutic drugs than colon carcinoma cell lines, mimicking the in vivo situation. The organoids also responded much more sensitively to radiation exposure than the immortal cell lines.	(42)
Small intestine and liver – ASCs	Assessment of drug-metabolising enzymes and evaluation of CYP induction after treatment of organoids with the CYP inducers dexamethasone, β- naphthoflavone and 1,4-bis-2-(3,5-dichloropyridyloxy)-benzene in murine intestinal and liver organoids.	Expression of CYP1A1, CYP1A2, CYP2A12, CYP2C37, CYP3A11 and CYP3A13 in both intestinal and liver organoids. These CYPs were differentially induced indicating high drug-metabolic capacity.	(46)
Kidney – ASCs	Toxicity assessment of hydroxylated generation-5 PAMAM dendrimer (G5- OH) nanoparticles and gold nanoparticles in kidney organoids. Comparison to in vivo models.	PAMAM nanoparticles induced toxicity biomarkers like Kim-1, neutrophil gelatinase- associated lipocalin, osteopontin, clusterin, vimentin, haem oxygenase-1 and cell toxicity in kidney organoids, mirroring previously published in vivo data.	(117)
Lung, liver and mammary –ASCs	Assessment of the in vivo tumorigenicity of organoids after in vitro treatment with ethyl methanesulfonate, acrylamide, diethylnitrosamine and 7,12-dimethylbenz[a]anthracene.	Lung, liver and mammary organoids treated in vitro with ethyl methanesulfonate, acrylamide, diethylnitrosamine and 7,12-dimethylbenz[a]anthracene were injected into mice leading to the formation of subcutaneous nodules in vivo, indicating the carcinogenic potential of the chemicals tested.	(16)
Mammary – ASCs	Studying the effects of bisphenol A, mono-n-butyl phthalate and polychlorinated biphenyl 153 on the proteome in mammary organoids.	Treatment of mammary organoids with bisphenol A, mono-n-butyl phthalate and polychlorinated biphenyl 153 induced differential effects on the proteome. Treatment also altered the abundance of protein splice variants.	(85)
Endometrial –ASCs	Characterisation of the impact of zinc stearate (plastic additive) on the development of organoids from endometrial cells from domestic cats.	Zinc stearate did not affect morphology, viability or cellular composition of endometrial organoids. The model developed could be used in future studies investigating the effects of plastic additives or drugs.	(118)