Stable Lentiviral Transduction of 3D Tumor Microtissues
ProNAMs provides custom lentiviral transduction services for 3D Tumor Microenvironment (TME) models and patient-derived 3D tumor microtissues. We establish stable engineered lines — reporters, knockdown, knockout, and overexpression constructs — and deliver them with documented quality control for downstream in vitro oncology evaluation.
Why Choose Lentiviral Transduction for 3D Tumor Models?
Transient transfection methods such as lipofection show limited penetration in dense extracellular matrices and give only short-term expression. Lentiviral vectors integrate the gene of interest into the host genome, so the modification is carried through subsequent passages rather than diluted out.
Lentiviruses transduce both dividing and non-dividing cells, which matters for patient-derived 3D tumor models: these consist of a heterogeneous population including quiescent and actively proliferating cells. A transduction method restricted to dividing cells would sample that population unevenly. Genetic stability across passages is verified as part of the QC described below.
Our Methodology: Technical Considerations in 3D Tumor Engineering
Transducing 3D in vitro tumor models differs from working with 2D cell lines. The matrix acts as a physical barrier to viral particles, and the compact cellular architecture limits penetration into the interior of the structure. Dissociating the model to expose more surface area addresses this, but introduces a second problem, that is, detachment-induced apoptosis (anoikis) in cells adapted to a 3D context.
Our protocols are designed around this trade-off: dissociation conditions are optimized per tissue origin, apoptosis inhibitors are included in the transduction medium, and recovery conditions are set to support re-establishment of 3D structure. We work across a range of solid tumor origins including colorectal, gastric, breast, and pancreatic. Protocol parameters are tissue-origin specific and are documented in the study protocol.
Our Technical Workflow
Vector Design & Viral Preparation
Custom lentiviral vectors (shRNA, sgRNA, reporters, or target genes) are designed and packaged. Working titer is confirmed per batch, typically in the 10⁸ TU/mL range, and the MOI is set per tissue origin during feasibility. Clients may also supply their own vector or packaged virus - see submission requirements.
3D Microtissue Dissociation
Models are recovered from the ECM and enzymatically dissociated to single cells or small clusters. Digestion time is optimized per tissue origin to balance dissociation extent against viability, which is measured before proceeding.
Spinoculation
Cells are resuspended with the viral preparation, a polycationic transduction enhancer, and apoptosis inhibitors. Centrifugation is applied to promote virus–cell contact. Conditions are specified in the study protocol.
Re-embedding & Recovery
Transduced cells are re-embedded in fresh ECM hydrogel and returned to culture to allow re-establishment of 3D structure before any selective pressure is applied.
Selection & Enrichment
Following recovery, transduced cells are enriched by antibiotic selection (e.g. puromycin, blasticidin) or by fluorescence-based sorting for reporter-positive cells. Selection is applied after 3D structure has re-formed, with a defined interval to clear non-surviving cells from the matrix before assessment.
Expansion & QC Release
Enriched lines are expanded to the agreed delivery quantity and assessed against release criteria before cryopreservation.
Two formats are available and the choice is made during study design:
| Format | Description | Typical Use |
|---|---|---|
| Polyclonal Pool | Retains the heterogeneity of the parental model; represents the transduced population as a whole | Most applications, and required wherever heterogeneity is part of the biology under study |
| Clonally Derived Line | Established by an additional single-cell isolation and expansion step following enrichment | Where a defined genetic background is needed, e.g. single-copy integration for quantitative knockdown work |
Service Workflow
Projects typically progress through six stages. Criteria for each stage are documented in the study protocol; work generally advances once those criteria are addressed.
| Stage | Activity | Client Input | Indicative Duration |
|---|---|---|---|
| 1. Scoping | Consultation to define the construct, tissue origin, delivery format, and intended downstream use | Target gene or reporter, tumor origin, model source, downstream application | 3–5 business days |
| 2. Design & Quotation | Written protocol covering vector design, MOI strategy, selection approach, release criteria, and delivery specification | Protocol review and sign-off; vector sequence approval | 5–10 business days |
| 3. Material Receipt & Feasibility | Receipt of client-supplied model and/or vector; parental model viability check; small-scale transduction to establish working MOI (see submission requirements below) | Model or vector shipment, documentation | 2–3 weeks |
| 4. Vector Packaging | Packaging and titration of the lentiviral preparation | - | 2–3 weeks; may run in parallel with Stage 3 |
| 5. Transduction, Selection & Expansion | Full-scale transduction, recovery, enrichment, and expansion to delivery quantity | - | Highly variable by tissue origin; commonly 6–12 weeks |
| 6. QC & Delivery | Release assessment, cryopreservation, report issuance, shipment arrangement | Import documentation where applicable | 2–3 weeks |
Lines are evaluated against pre-defined release criteria before delivery. These typically cover:
- Viability and recovery - post-thaw viability and re-establishment of 3D structure from a test vial
- Transgene presence - genomic PCR or qPCR confirmation of integration
- Integration copy number - qPCR-based estimate, reported where the application requires it
- Expression - reporter-positive fraction by imaging or flow cytometry, or transcript/protein-level confirmation for non-reporter constructs
- Passage stability - expression assessed at an early and a later passage within the expansion window, to indicate whether the construct is maintained
- Morphology - 3D structure formation compared against the parental model
- Sterility - mycoplasma testing and general sterility
Browse Deliverables & Timelines
NOTE: All timelines, quantities and deliverables described on this page are indicative.
Applications
Stable engineered 3D tumor lines support a range of in vitro oncology endpoints:
Gene Function Validation (Loss / Gain of Function)
Stably knock down, knock out, or overexpress specific oncogenes or tumor suppressors, and assess the effect on 3D growth, morphology, and metabolic readouts.
Long-Term Live-Cell Imaging & Lineage Tracing
Fluorescent protein (GFP, mCherry) or luciferase reporter lines support extended live-cell imaging within the 3D model - growth kinetics, structure formation, and lineage tracking - without the endpoint sampling required by fixed-timepoint assays. Reporter lines are also compatible with imaging workflows clients run in their own systems.
Drug Screening & Resistance Modeling
Engineer 3D TME models to express defined resistance-associated mutations (e.g. EGFR T790M) for evaluation of targeted therapies. Reporter models such as FUCCI cell cycle sensors can be established to track and quantify cell cycle effects of test compounds within the 3D context.
Tumor Heterogeneity & Clonal Evolution Studies
Lentiviral DNA barcoding applied to patient-derived 3D tumor models before treatment allows surviving clones to be tracked by sequencing after drug exposure, generating data on clonal dynamics under selective pressure. This application requires the polyclonal delivery format, as clonal derivation removes the heterogeneity being measured.
Why Partner with ProNAMs?
Protocols Developed Per Tissue Origin
Dissociation, MOI and recovery conditions are established separately for each solid tumor origin rather than applied as a single generic protocol.
Both Delivery Formats Supported
Polyclonal pools for applications where heterogeneity is part of the biology; clonally derived lines where a defined background is needed. The choice is made on scientific grounds during study design.
Customizable Vector Design
Promoter, tag, and selection marker configured to the intended application, with sequence approval before packaging.
Documented QC
Lines are delivered with a QC report covering viability, integration, expression, passage stability, morphology and sterility, with the underlying data included.
Downstream Continuity
Established lines can be carried directly into our in vitro NAMs efficacy evaluation services, or delivered as cryopreserved material for use in your own workflows.
Advance Your Genetically Engineered 3D Oncology Research
Contact our technical team for a project assessment covering tissue origin, construct design, delivery format, and indicative timeline.
Schedule a Consultation