The LPS-Pretreated MSCs Supply a Positive Microenvironment for Tumor Cell Proliferation and Clone Formation.

In this study, the culture supernatant of LPS-treated MSCs was collected and served as a conditioned medium (CM). It was found that the LPS-CM promoted the proliferation of tumor cells (SKBR3, MDA-MB-231, A549, 95D and HepG2). In addition, the colony formation ability was also enhanced by LPS-CM incubation. The inflammatory cytokines, IL-6 and IL-8, were demonstrated to be up-regulated in the LPS-CM, which we supposed to function in the tumor-growth promotion in vitro.