Veranstaltungsprogramm

Background

Autologous fat grafting is widely used in breast reconstruction and regenerative surgery. Despite its clinical benefits, concerns remain regarding the oncological safety of adipose-derived components, particularly in patients with a history of breast cancer. Increasing evidence suggests that the biological effects of adipose-derived stem cells (ASCs) are predominantly mediated by paracrine mechanisms, especially through exosomes, which may influence fibroblast behavior and extracellular matrix (ECM) composition within breast tissue.

Methods

ASC-derived exosomes were isolated and characterized in vitro. Their biological effects were assessed using established breast cancer cell lines and stromal cell models. Cell viability and cytotoxicity were evaluated using metabolic assays and lactate dehydrogenase (LDH) release. Gene expression analyses focused on apoptosis-related, proliferation-associated, and angiogenesis-related markers. In parallel, the impact of ASC-derived exosomes on fibroblast activity and ECM-related pathways was analyzed to investigate their role in tissue remodeling.

Results

ASC-derived exosomes demonstrated a distinct biological profile compared to ASC-conditioned medium. Exosome-treated breast cancer cells showed reduced metabolic activity and increased expression of proapoptotic genes, including TP53, Bax, Bad, Casp3, and RB1, while markers associated with proliferation and angiogenesis were comparatively reduced. LDH release indicated a controlled cytotoxic effect at higher exosome concentrations, consistent with regulated cellular stress rather than unspecific toxicity. At the stromal level, exosomal signaling modulated fibroblast activity, influencing pathways involved in ECM composition and remodeling, suggesting a shift toward a less pro-oncogenic tissue microenvironment.

Conclusion

ASC-derived exosomes exert relevant paracrine effects on both tumor and stromal components of breast tissue by regulating fibroblast activity and extracellular matrix composition. Their ability to induce proapoptotic signaling in breast cancer cells while modulating stromal behavior supports a cooperative, biologically controlled role of adipose-derived components in tissue remodeling. These findings provide experimental evidence that supports the oncological safety of lipofilling and suggests that ASC-derived exosomes are not contraindicated in breast reconstruction, including in patients with a history of breast cancer.