Caki-2 / Caki-2-luc Orthotopic Mouse Model Service for Renal Cancer

The Caki-2 / Caki-2-luc orthotopic mouse model of renal cancer implants a well-characterized human renal carcinoma line into the kidney of immunodeficient mice, where it develops primary tumors that retain the papillary-type architecture of the patient’s original lesion. From authenticated cell expansion and subcapsular implantation surgery to serial luciferase imaging, primary tumor excision and detailed histological workup, Alfa Cytology delivers complete Caki-2 / Caki-2-luc orthotopic study programs structured around each sponsor’s compound, regimen and decision point—exclusively within preclinical research.

Overview of Caki-2 / Caki-2-luc Orthotopic Mouse Model for Renal Cancer

Caki-2 was established in the 1970s by Jorgen Fogh from the primary renal adenocarcinoma of a 69-year-old male patient, and it forms a unique matched pair with Caki-1, a line derived from a metastasis of the same individual—one of the few primary-versus-metastatic renal cancer pairs available for comparative study. For decades Caki-2 was used as a conventional clear cell renal carcinoma model, yet tumors grown from it in nude mice display cystic, papillary morphology, and molecular profiling has since supplied the explanation: the cells express high levels of MET and LRRK2 and carry chromosome 8 aberrations characteristic of papillary renal cell carcinoma, leading many investigators to re-classify Caki-2 as a papillary-type line. Its hypoxia pathway is equally atypical—Caki-2 expresses no HIF-2α and only low HIF-1α, and reports on its VHL gene status remain inconsistent—so it complements, rather than duplicates, VHL-null lines such as 786-O in vitro.

Fig 1. High-magnification hrUS images of the orthotopic Caki-2 renal tumor with outlined lesion regions for volume quantification at weeks 6, 10 and 12. (Linxweiler, Johannes, et al., 2017)

In the orthotopic setting, Caki-2 cells placed under the renal capsule recruit genuine kidney stroma and vascular support and assemble into cystic papillary tumors that echo the architecture of the donor’s primary lesion, with a growth pace (population doubling of roughly 30–40 hours in vitro) that affords wider treatment windows than faster renal lines. The luciferase-tagged Caki-2-luc variant carries a lentivirally introduced Luc2 reporter whose activity is verified in vitro by luminometer and remains stable over extended passaging, enabling non-invasive, longitudinal bioluminescence tracking of tumor establishment after D-luciferin administration in vivo. Because engraftment requires an immunocompromised host, the model is geared toward tumor-biology, MET-pathway, targeted-therapy and comparative primary-versus-metastasis questions rather than immuno-oncology, and its comparatively moderate drug sensitivity—Caki-2 responds less readily to 5-fluorouracil and sorafenib than its sister line—makes it a demanding, informative testbed for preclinical efficacy studies.

Cell Line Information: Caki-2 / Caki-2-luc

Caki-2 and its luciferase-labeled derivative Caki-2-luc derive from the same human primary renal tumor; the reporter line additionally stably expresses the Luc2 firefly luciferase for optical imaging. Key characteristics are summarized below.

Our Services

Combining practiced in vivo surgical skill with in-house bioluminescence imaging and histopathology, Alfa Cytology configures every Caki-2 / Caki-2-luc orthotopic engagement to the sponsor’s scientific question—fine-tuning inoculum density, Matrigel ratio, dosing onset and endpoint panels so each study returns clear, decision-grade preclinical data.

Workflow of Caki-2 / Caki-2-luc Orthotopic Mouse Model Construction

Orthotopic construction of the Caki-2 / Caki-2-luc model is a survival-surgery workflow carried out under inhalation anesthesia, with aseptic technique, scheduled analgesia and daily post-operative welfare checks consistent with institutional animal-care standards. A typical engagement unfolds in the following stages:

1. Cell line qualification: Caki-2 or Caki-2-luc vials are mycoplasma-tested by PCR and STR-verified against the reference profile; luciferase-positive cells are confirmed in vitro by luminometer after D-luciferin addition, with expression stability tracked across passages.
2. Animal preparation: athymic nude mice (typically 4–6 weeks old) are acclimatized, health-screened and randomized by body weight ahead of surgery.
3. Anesthesia and asepsis: mice are anesthetized with isoflurane, the flank is clipped and disinfected, and a sterile field with sterile instruments is maintained throughout.
4. Surgical exposure: a small flank incision opens the abdominal wall, and the kidney is gently exteriorized onto sterile gauze to present the renal capsule under magnification.
5. Subcapsular inoculation: Caki-2 / Caki-2-luc cells (commonly 1 × 10⁶ in 20–50 µL PBS, optionally mixed 1:1 with 50% Matrigel) are injected beneath the renal capsule with a fine needle, forming a controlled subcapsular bleb.
6. Repositioning, closure and analgesia: the kidney is returned to the abdomen, muscle and skin are closed with absorbable sutures and wound clips, and buprenorphine or meloxicam is dosed on schedule until full recovery.
7. Longitudinal monitoring: tumor growth is tracked in vivo by weekly bioluminescence imaging after intraperitoneal D-luciferin for Caki-2-luc, alongside body-weight measurement and clinical scoring; ultrasound or MRI can be added to follow cystic tumor architecture.
8. Endpoint and analysis: at termination the tumor-bearing kidney is excised and tumor mass determined against the contralateral kidney, tumor dimensions are recorded, lungs are inspected for metastasis, and tissues are processed for histopathology (with attention to papillary morphology), IHC, molecular assays and downstream profiling.

Fig 2. Caki-2 / Caki-2-luc orthotopic mouse model construction workflow.

Case Study-Caki-2 / Caki-2-luc Orthotopic Mouse Model Development

Alfa Cytology maintains a growing preclinical case-study collection for the Caki-2 / Caki-2-luc orthotopic platform, covering establishment-phase optimization of inoculum and implantation technique, longitudinal bioluminescence tracking of primary renal tumors in vivo, targeted-therapy and MET-pathway intervention studies, and systematic histological confirmation of cystic papillary tumor morphology at endpoint. Illustrative materials—including imaging series, tumor growth trajectories and endpoint summaries—are available on request and are refreshed as further programs conclude.

Why Choose Alfa Cytology?

Sponsors entrust this model to Alfa Cytology because each phase is executed with the care a histologically nuanced line demands:

• A practiced orthotopic surgery group delivering fast, high-survival subcapsular implantation.
• STR-verified Caki-2 and stably luciferase-labeled Caki-2-luc banks ready for immediate mobilization.
• Quantitative bioluminescence supporting signal-based randomization and within-animal longitudinal readouts.
• Authentic cystic papillary tumor architecture that mirrors the patient’s primary lesion.
• A configurable endpoint menu spanning efficacy, histopathology, IHC and molecular analysis.
• Direct experience with the Caki-1 / Caki-2 matched pair for primary-versus-metastatic comparisons.
• Responsive, single-point project communication with milestone-based progress reporting.
• An exclusively preclinical mandate, with all studies designed, conducted and reported as non-clinical research.

Contact Us

If the Caki-2 / Caki-2-luc orthotopic renal cancer model aligns with your next preclinical objective, contact us to share your compound, timeline and preferred endpoints. The Alfa Cytology team will reply with a customized plan covering model setup, imaging cadence and analysis strategy—reach out today and move your program forward with confidence.

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