344SQ Syngeneic Model Service for Lung Cancer

The 344SQ syngeneic model of lung cancer engrafts a Kras/p53-mutant murine lung adenocarcinoma line with inherent metastatic plasticity into immunocompetent 129/Sv hosts, where subcutaneous implants reliably seed spontaneous lung metastases. Alfa Cytology delivers the complete 344SQ workflow—authenticated cell banking, subcutaneous or orthotopic implantation, burden-balanced randomization, scheduled dosing and metastasis-inclusive endpoint analysis—giving sponsors decision-ready preclinical datasets shaped to their program, strictly within a preclinical scope.

Overview of 344SQ Syngeneic Model for Lung Cancer

344SQ belongs to one of the most influential cell-line panels in metastasis research. In 2009, Gibbons and colleagues reported a series of lung adenocarcinoma lines derived from genetically engineered Kras^LA1/+; p53^R172HΔG/+ mice—animals engineered to develop lung cancer through mutant K-ras and mutant p53 acting together—and named each line by its mouse of origin and derivation site: “P” for primary lung tumor, “LN” for lymph-node metastasis, and “SQ” for subcutaneous metastasis. 344SQ therefore began as the spontaneous subcutaneous deposit of mouse #344. The cells carry heterozygous Kras^LA1 (G12D) and p53^R172HΔG alleles, retain the surfactant protein C positivity of type II alveolar cells, and exhibit the aneuploid complexity of human disease—centrosomal amplification, aberrant mitotic spindles and chromosomal translocations. Phenotypically the line sits at the mesenchymal end of the panel (epithelial 393P is its comparator), and its signature is plasticity: in laminin-rich three-dimensional culture it assembles polarized epithelial spheres, yet TGF-β or an in vivo niche flips it through epithelial–mesenchymal transition—a reversible program controlled by the miR-200/ZEB axis whose forced expression abolishes invasion and metastasis. Within the population, CD133-positive cells with high Notch ligand Jagged1 mark the metastasis-prone fraction; Jagged1 knockdown or PI3K inhibition abrogates their metastatic activity.

Fig 1. Generation and validation of anti-PD-1-resistant 344SQ syngeneic lung cancer models — workflow of in vivo anti-PD-1 selection from KP mice, rechallenge growth curves of 344SQPD1S1–3 (initial response, eventual resistance) versus 344SQPD1R1–3 (upfront resistance), KP GEMM micro-CT imaging, and PD-L1 Western blot across parental, sensitive and resistant cell lines. (Konen, Jessica M., et al., 2023)

In vivo, the model performs its famous trick from the flank: one million cells injected subcutaneously grow as measurable primaries and, by necropsy five to six weeks later, have seeded widespread lung metastases—in immunocompetent recipients, engaging host inflammation and angiogenesis as human disease does. Its immune biology is well mapped: the cells are BMP4-high, a state that reduces infiltrating CD8⁺ T cells, enriches PD1⁺TIM3⁺ exhausted cells and regulatory T cells, and drives PD-L1 through STAT3; depleting CD8⁺ cells erases the growth advantage of BMP4-knockdown tumors, proving immune control is real—and checkpoint blockade works here, with anti-PD-L1 monotherapy delaying growth and the anti-PD-L1/anti-CTLA-4 combination enhancing both primary control and metastasis inhibition. An anti-PD-1-resistant derivative (344SQ_R) has been selected for resistance studies, and pharmacology runs the gamut from dasatinib’s Src-axis metastasis suppression to TUSC2 nanovesicle plus anti-PD-1 combinations and Notch-pathway inhibition. An orthotopic intrapulmonary variant recreates lung-context growth with nodal and distant spread but at the cost of faster morbidity. Practical caveats: syngeneicity is defined by the 129/Sv (129S2/SvPas) background of the founding GEMM strain rather than the more familiar C57BL/6; metastatic readout requires necropsy; and the orthotopic format compresses monitoring windows.

Cell Line Information: 344SQ

Key characteristics of 344SQ and its documented derivatives are summarized below.

Our Services

With in vivo oncology specialists guiding each stage and pathology, bioluminescence imaging and immune-profiling capabilities in-house, Alfa Cytology molds every 344SQ engagement around the sponsor’s question—selecting flank or orthotopic formats, calibrating inoculum and schedule, and pairing dosing with metastasis counts, EMT-marker analysis and flow-cytometric immune readouts for clean, decision-grade preclinical data.

Workflow of 344SQ Syngeneic Model Construction

Construction of the 344SQ syngeneic model is an implantation workflow whose quality rests on verified cells, 129/Sv recipients, format-matched technique and a disciplined measurement cadence. A standard engagement proceeds as follows:

1. Source and qualify cells: 344SQ or labeled (GFP/luciferase) stocks are cleared by mycoplasma qPCR and authenticated by STR fingerprinting; EMT-plasticity markers (miR-200/ZEB axis, BMP4 baseline) are documented, and reporter expression is titrated in vitro before expansion.
2. Prepare recipients: 129/Sv mice (typically 8 weeks or older) complete acclimation and health screening and are individually marked before implantation.
3. Prepare the inoculum: log-phase cells are harvested, washed, counted and resuspended in PBS (commonly 1 × 10⁷/mL for a 100 µL dose).
4. Implant: 1 × 10⁶ cells are injected subcutaneously into the flank with consistent anatomical positioning; the orthotopic format delivers the same dose into the lung parenchyma or via intratracheal instillation under anesthesia for organ-context studies.
5. Randomize: when flank tumors reach 50–100 mm³, animals are assigned to groups balanced by tumor volume and body weight; orthotopic cohorts are randomized at implantation.
6. Dose and follow: test articles are administered on schedule; flank tumors are measured with calipers two to three times weekly (volume typically 0.5 × length × width²), with bioluminescence substituted for labeled cohorts; body weight and morbidity signs are logged daily for orthotopic animals.
7. Terminate and analyze: primary tumors are resected and weighed; lungs are inspected for surface metastatic nodules and confirmed histologically; lymph nodes and distant organs are examined; tumor-infiltrating lymphocytes are profiled by flow cytometry (CD8, Treg, PD1/TIM3 exhaustion panels); EMT markers (E-cadherin, ZEB1, vimentin) are assayed by qPCR/IHC; tissues enter histopathology and molecular analysis.

Fig 2. 344SQ Syngeneic Model construction workflow.

Case Study-344SQ Syngeneic Model Development

Alfa Cytology keeps an active file of preclinical case studies on the 344SQ platform: establishment-phase optimization of inoculum and format, in vivo growth tracking by caliper or bioluminescence, metastasis- and immuno-oncology-focused intervention studies (including checkpoint combinations and kinase targeting), and systematic lung metastasis quantification with matched EMT-marker and immune-phenotyping readouts. Representative growth curves, metastasis datasets and endpoint summaries can be shared upon request and will be updated as new programs conclude.

Why Choose Alfa Cytology?

344SQ’s value lies in its metastatic honesty—spontaneous spread from a flank implant—and in an EMT-immune axis that rewards careful design; both are where Alfa Cytology invests:

• Format-flexible execution spanning flank, intrapulmonary orthotopic and intratracheal designs in 129/Sv hosts.
• Authenticated 344SQ banks with STR verification, documented BMP4/miR-200 baselines and labeled derivatives.
• Spontaneous lung metastasis from subcutaneous implants—a genuinely metastatic readout in immunocompetent mice.
• EMT-aware endpoint design covering miR-200/ZEB markers and CD133/Jagged biology.
• Checkpoint-combination experience reflecting the documented PD-L1/CTLA-4 response landscape.
• Orthotopic expertise with morbidity-aware monitoring schedules.
• One accountable project contact with milestone-by-milestone visibility.
• A strictly preclinical scope—every study is planned, executed and reported as non-clinical research.

Contact Us

Interested in the 344SQ syngeneic lung cancer model for your next preclinical program? Reach out to us with your agent, timeline and endpoint wish-list, and the Alfa Cytology team will respond with a customized plan covering model setup, dosing strategy and analysis workflow—contact us today and move your program forward with confidence.

For research use only. Not intended for any clinical use.