Bone Marrow-Derived Stem Cell Factor Regulates Prostate Cancer-Induced Shifts in Pre-Metastatic Niche Composition

Area of Science:

• Oncology
• Bone Biology
• Cancer Metastasis

Background:

• Skeletal metastasis is a major cause of death in advanced prostate cancer.
• Platelets play a key role in bone remodeling and pre-metastatic niche formation.
• Stem Cell Factor (SCF) is elevated in prostate cancer and linked to metastasis.

Purpose of the Study:

• To investigate the role of bone-derived SCF in prostate cancer progression and bone microenvironment.
• To determine the specific contributions of osteoblast- and platelet-derived SCF.
• To explore SCF's impact on primary tumor growth and pre-metastatic niche formation.

Main Methods:

• Generated cell-specific SCF knockout mouse models (osteoblast- and platelet-specific).
• Utilized two syngeneic androgen-insensitive murine prostate cancer cell lines (RM1 and mPC3).
• Analyzed primary tumor growth, bone histomorphometry, and bone stromal cell composition via flow cytometry.

Main Results:

• Platelet-derived SCF is crucial for mPC3 tumor growth, but not RM1.
• Osteoblast-derived SCF is not required for primary tumor growth but influences bone formation and stromal cell composition.
• SCF source and prostate cancer genetics dictate SCF's effects on tumor growth and bone remodeling.

Conclusions:

• Megakaryocyte/platelet-derived SCF regulates specific prostate cancer growth.
• Osteoblast-derived SCF is involved in pre-metastatic niche formation.
• Targeting the SCF/CD117 axis may offer therapeutic strategies for prostate cancer bone metastasis, depending on cancer genetics.