High‐throughput live‐cell imaging reveals differential inhibition of tumor cell proliferation by human fibroblasts

Abstract

Increasing evidence indicates that cancer development requires changes both in the precancerous cells and in their microenvironment. To study one aspect of the microenvironmental control, we departed from Michael Stoker's observation (Stroker et al, J Cell Sci 1966;1:297-310) that normal fibroblasts can inhibit the growth of admixed cancer cells (neighbour suppression). We have developed a high-throughput microscopy and image analysis system permitting the examination of live mixed cell cultures growing on 384-well plates, at the single cell level and over time. We have tested the effect of 107 samples of low passage number (<5) primary human fibroblasts from pediatric and adult donors, on the growth of six human tumor cell lines. Three of the lines were derived from prostate carcinomas, two from lung carcinomas and one was an EBVtransformed lymphoblastoid line. Labeled tumor cells were grown in the presence of unlabeled fibroblasts. The majority of the tested fibroblasts inhibited the proliferation of the tumor cells, compared to the control cultures where labeled tumor cells were co-cultured with unlabeled tumor cells. The proliferation inhibiting effect of the fibroblasts differed depending on their site of origin and the age of the donor. Inhibition required direct cell contact. Mouse 3T3 fibroblasts inhibited the growth of SV40-transformed 3T3 cells and human tumor cells, showing that the inhibitory effect could prevail across the species barrier. Our high-throughput system allows the quantitative analysis of the inhibitory effect of fibroblasts on the population level and the exploration of differences depending on the source of the normal cells.

Control of cyclooxygenase-2 expression and tumorigenesis by endogenous 5-methoxytryptophan

“…There is increasing evidence that cancer-associated fibroblasts (CAFs) are "educated" by cancer and converted to a phenotype that promotes cancer growth (15)(16)(17)(18)(19)(20)(21). However, CAFs are heterogeneous (17,22), and several reports have shown that fibroblasts inhibit cancer cell proliferation through generation of soluble factors or direct cellular contact (23)(24)(25). We were curious whether fibroblasts in cancer are capable of producing cytoguardins.…”

Fibroblasts prolong serum prostate-specific antigen decline after androgen deprivation therapy in prostate cancer

“…39 Recent studies have also demonstrated that normal human fibroblasts can inhibit the proliferation of tumor cells. 40,41 We hypothesize that these 'protective' fibroblasts could also preserve the AR dependence of PCa cells after ADT. Moreover, Banerjee et al demonstrated that epigenetic changes in prostatic fibroblasts could cause DNA damage, mediating prostate tumor progression.…”

From sentinel cells to inflammatory culprits: cancer‐associated fibroblasts in tumour‐related inflammation

“…Others have reported that stromal ablation of the tumour suppressor Pten during mammary carcinogenesis results in accelerated tumourigenesis, via Ets2 inactivation, suggesting multiple pathways by which fibroblasts can inhibit neoplastic growth [30,31]. In vitro co-culture studies using primary normal fibroblasts isolated from various human tissues, when cultured with human prostate, lung, and lymphoblastoid tumour cell lines, support a role for fibroblasts in restricting the proliferative potential of tumour cells in a contact-dependent manner [32]. Some of the growth-inhibiting activity provided by fibroblasts may be directly associated with their role as sentinel cells, capable of 'sensing' tissue damage, associated with aberrant epithelial proliferation: Experimental analysis using a mouse model of intestinal inflammation revealed that colonic fibroblasts express NLRP6 (NOD-like receptor family pyrin domain containing 6), a stress-associated molecular pattern recognition receptor.…”