RM-1 Metastatic Tumor Model Service for Prostate Cancer

The RM-1 metastatic tumor model for prostate cancer is an aggressive syngeneic in vivo platform in which Ras/Myc-transformed murine prostate carcinoma cells grow and disseminate in fully immunocompetent C57BL/6 hosts. Alfa Cytology provides complete RM-1 metastatic model services—spanning subcutaneous, orthotopic, and bone-directed engraftment, non-invasive imaging, treatment administration, and in-depth tumor-immune endpoint analysis—to support your preclinical prostate cancer and immuno-oncology programs.

Overview of RM-1 Metastatic Tumor Model for Prostate Cancer

RM-1 is a murine prostate carcinoma line established in the mid-1990s from a urogenital sinus reconstitution system. Researchers took prostate tissue from a 17-day-old male C57BL/6 fetus, reconstituted it under the renal capsule of adult hosts, and transformed the outgrowth in vitro with the recombinant retrovirus Zipras/myc9, which delivers v-Ha-Ras and v-Myc. The resulting tumor lines—RM-1 among them—form poorly differentiated carcinomas with high frequency. Cytokeratin 18 positivity confirms a luminal epithelial origin, and the cells express a functional androgen receptor with stable binding kinetics, showing a clear mitogenic response to testosterone in serum-free culture. Because the line is fully congenic with C57BL/6, it engrafts in immunocompetent mice, preserving the complete host-tumor immune dialogue.

Fig 1. The RM1-GFP immunocompetent bone pain model: orthotopic intratibial injection of C57BL/6 mice (A), serial bioluminescence imaging from day 0 to 20 showing exponential signal increase in the injected hindlimb (B), total flux quantification over time (C), radiographs of sham versus RM1-GFP femora at days 0/7/14/20 with bone destruction (arrows, D), and bone radiograph scoring (E) — the validated bone metastasis endpoint suite for the RM-1 metastatic model. (Jimenez-Andrade, Juan Miguel, et al., 2023)

In in vivo practice, RM-1 is valued as a fast, aggressive, and well-characterized syngeneic prostate cancer system. Subcutaneous implantation of as few as 5×10⁵ cells produces tumors with a 100% take rate, a volume doubling time of roughly two days, and progression to euthanasia criteria within about two weeks—an ideal schedule for rapid efficacy screening. Equally important is the tumor's immune phenotype: profiling studies classify RM-1 as a nonimmunogenic, immunologically “cold” tumor with sparse CD4⁺ and CD8⁺ T-cell infiltration but dominant granulocytic and monocytic MDSC populations, driven in part by tumor-derived GM-CSF that recruits macrophages and suppressor cells. This suppressive microenvironment—together with documented NK-cell and CD8⁺ T-cell-mediated control under certain conditions—makes RM-1 a stringent testbed for checkpoint blockade, myeloid-targeting agents, and combination strategies designed to convert cold tumors hot. For dissemination questions, RM-1 can be implanted orthotopically, injected via tail vein or intracardiac routes to model hematogenous spread, or inoculated intraosseously to interrogate osteolytic and osteoblastic interactions within the bone stroma.

Cell Line Information: RM-1

The table below compiles the principal characteristics of RM-1 most relevant to syngeneic metastatic model studies.

Our Services

Bringing focused know-how in syngeneic prostate cancer systems, Alfa Cytology delivers tailored RM-1 metastatic tumor model services covering the full preclinical arc—cell authentication and expansion, reporter engineering, subcutaneous or orthotopic engraftment plus systemic and bone-directed dissemination formats, in vivo imaging, dosing, and integrated endpoint analysis of metastases, histopathology, and tumor-immune infiltrates—so every study is configured around your compound's mechanism and your program's decision points.

Workflow of RM-1 Metastatic Tumor Model Construction

A disciplined, stepwise process underpins reproducible RM-1 metastatic studies in immunocompetent hosts. The workflow below summarizes how the model is established and evaluated.

1. Cell authentication and expansion: RM-1 cells are identity-verified by STR profiling, confirmed mycoplasma-negative, and expanded under standardized conditions to ensure uniform viability and aggressive, consistent growth at inoculation.
2. Reporter labeling (optional): Where longitudinal tracking is required, cells are stably transduced with luciferase or fluorescent reporters and validated for signal stability prior to animal use.
3. Model format and route selection: The study design defines the format—subcutaneous engraftment for rapid pharmacology screening, orthotopic prostate implantation for organ-specific growth and spontaneous spread, tail vein or intracardiac injection for experimental metastasis, or intraosseous delivery for bone-interaction studies—with matched male C57BL/6 mice (typically 4- to 8-week-old).
4. Mouse preparation and inoculation: Mice are acclimated and randomized; RM-1 cells (commonly 5×10⁵ to 1×10⁶ cells per mouse, resuspended in PBS or medium depending on the route) are implanted under sterile, ethically approved surgical conditions.
5. Tumor and metastasis monitoring: Tumor volume and body weight are measured on schedule, and metastatic burden is tracked by in vivo bioluminescence or fluorescence imaging in reporter-labeled studies, with continuous health and survival monitoring.
6. Treatment administration: When tumors reach predefined thresholds, animals are randomized to treatment arms and dosed with checkpoint inhibitors, myeloid-targeting agents, radiopharmaceuticals, chemotherapy, or combinations per the study plan.
7. Endpoint analysis: At the study endpoint, prostate, draining lymph nodes, lungs, bones, and other organs are examined; metastatic lesions are counted, and tissues undergo H&E histopathology, immunohistochemistry, and immune profiling (e.g., flow cytometric analysis of TILs, MDSCs, and macrophages).
8. Data analysis and reporting: Tumor growth curves, imaging time courses, metastasis counts, survival data, and immune readouts are analyzed statistically and consolidated into a comprehensive, decision-ready report.

Fig 2. RM-1 Metastatic Tumor Model construction workflow.

Case Study-RM-1 Metastatic Tumor Model Development

Alfa Cytology has developed and applied RM-1 metastatic tumor models across a range of preclinical prostate cancer programs. The platform has served to evaluate immunotherapeutic and combination approaches against aggressive tumor growth and metastatic spread, to benchmark regimens against reference standards, and to profile tumor-immune dynamics under controlled in vivo conditions. Representative case information and study data are available to clients upon request, and study parameters can be adjusted to match each program's specific objectives.

Why Choose Alfa Cytology?

Alfa Cytology combines hands-on syngeneic prostate cancer expertise with rigorous, responsive study execution. Clients select our RM-1 metastatic model service for the following reasons:

• Proven proficiency with the RM-1/C57BL/6 syngeneic platform and its aggressive, well-characterized growth behavior in vivo.
• A fully immunocompetent host setting that preserves tumor-immune interactions for credible immunotherapy evaluation.
• Flexible engraftment options—subcutaneous, orthotopic, tail vein, intracardiac, and intraosseous—matched to each scientific question.
• Integrated immune-profiling endpoints, including TIL, MDSC, and macrophage analysis by flow cytometry.
• Optional luciferase or fluorescent labeling for non-invasive in vivo longitudinal monitoring.
• Strict STR authentication and mycoplasma screening, with clear, on-schedule reporting throughout the project.

Contact Us

If your prostate cancer program calls for a fast, aggressive, immunocompetent metastatic model, our team is ready to help. Contact us to discuss how the RM-1 metastatic tumor model can be tailored to your study, and reach out today to let Alfa Cytology deliver the preclinical evidence your project needs.

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