Patient-Derived Tumor Organoids (PDTO)

Patient-derived tumor organoids are three-dimensional cultures established directly from patient tumor tissue. They retain much of the architecture, differentiation state, and genetic composition of the donor tumor, which monolayer culture progressively eliminates, and they can be expanded from small input, which patient-derived animal models cannot.

That combination addresses the central practical constraint of working with patient material. A biopsy sufficient for a single in vivo arm can, after organoid expansion, support a screening cascade and an in vivo validation study from the same donor. Altogen Labs establishes organoid lines, expands and characterizes them, conducts drug screening, and carries selected lines into organoid-derived xenograft studies within the same facility.

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Establishment and characterization

Tumor tissue is dissociated and established in three-dimensional culture under conditions appropriate to the tissue of origin, since medium composition differs substantially between tumor types and a single formulation will establish some and fail others. Establishment is not guaranteed for any individual sample, and rates differ by tumor type and by the quality and quantity of material received.

Characterization before a line enters a study covers morphology, growth characteristics, and confirmation that the culture is tumor rather than the adjacent normal epithelium that frequently outgrows it in early passage. Where donor material permits, histological and molecular comparison against the parent tumor establishes how closely the line represents it.

Drug screening

Organoid screening is conducted within this service rather than as a separate offering. Compounds or combinations are tested across concentration ranges with viability and, where relevant, morphological endpoints, and assay conditions are held constant across the lines being compared so a difference in response reflects biology rather than assay drift.

Screening in organoids differs from monolayer screening in ways that matter. Compounds whose activity depends on penetration behave differently in a three-dimensional structure, and hypoxic and quiescent populations present in organoids are absent from a monolayer. Where both formats are run, disagreement between them is informative rather than an error.

Applications

Applications include drug sensitivity screening from limited patient material, personalized oncology work where a donor-specific line is tested against candidate therapies, resistance studies using material collected after clinical progression, biomarker validation, and generation of material for in vivo engraftment.

Applied examples

Screen then validate. Organoids from a colorectal biopsy are expanded and screened against a panel of agents, with the two most active progressed into xenografts from the same line, so in vivo confirmation occurs in matched genetic background.

Comparison against monolayer. The same compound set is tested in organoids and in a monolayer line of the same indication, with the difference in ranking used to identify agents whose activity depends on three-dimensional structure.

Post-progression material. A line established from tissue collected after clinical progression is screened against next-line candidates, using material that carries the resistance biology that arose in the patient.

Interpretive considerations

Culture imposes selection, and the composition of an organoid line can shift relative to the donor tumor over passage. The magnitude is line dependent and not predictable in advance, which is why passage number at the point of use is recorded and screening is conducted at defined early passage where possible.

Organoid cultures generally lack stromal, vascular, and immune components. A mechanism depending on any of those will not be represented, and the appropriate escalation is an in vivo model rather than a modified culture.

Ethics, documentation, and material handling

Patient-derived material requires institutional review board approval and written informed consent, and provenance documentation is maintained from receipt. Tissue viability declines from the moment of resection, so transport conditions and the interval before processing materially affect whether a line establishes. Culture medium composition, passage number, expansion duration, and characterization performed are recorded per line, since these determine reproducibility and are not recoverable retrospectively. Established lines are cryopreserved so that later work can return to the same material rather than to a further-passaged version of it.

Send indication, tissue availability, and screening objectives, or request a quote.