These observations indicate that BCCFs may differ from normal fibroblasts and may play a regulatory role in BCC biology.

Tumor-derived stromal fibroblasts acquire distinct properties to shape a microenvironment conducive to altering the phenotypic characteristics of normal epithelial cells in vitro.

No abstract

Background/Aims: Bone marrow-derived endothelial progenitor cells (EPCs) are believed to contribute to endothelial repair after vascular damage. To investigate the potential for microvascular repair in patients with ANCA-associated vasculitis (AAV), we conducted a cross-sectional study determining the number of circulating EPCs in patients with AAV, chronic uremia, atherosclerosis, and in healthy volunteers. Methods: The number of circulating EPCs was determined by colony-forming assay in 41 patients with AAV, 15 hemodialysis patients (without vasculitis), 13 patients with peripheral arterial occlusive disease (PAOD), and 25 healthy controls. Results: Patients with AAV had a significantly lower number of CFU-Hill than healthy subjects (median 0.3 vs. 19.5 CFU-Hill/ml blood, p < 0.0001), but not than patients on hemodialysis or with PAOD. Neither institution of treatment nor entering remission increased the number of EPCs in AAV patients. The number of EPCs did not correlate with markers of disease activity. AAV patients with glomerular filtration rate <15 ml/min had an even lower number of circulating EPCs than patients with better preserved renal function (median 0.05 vs. 1.2 CFU-Hill/ml, p = 0.015) and patients with anti-MPO positivity had a trend towards a higher number of EPCs than patients with anti-PR3 antibodies (median 3.1 vs. 0.18 CFU-Hill/ml, p = 0.06). Conclusion: Patients with AAV have a significant and persistent deficiency of circulating EPCs. A low number of EPCs could reflect an impaired mechanism of vascular repair and may contribute to repeated relapses in these patients.

Our objective was to study the kinetics of circulating endothelial cells (EC) and endothelial precursor cells (EPC) in hematological patients during chemotherapy and autologous stem cell transplantion (ASCT). Eighteen newly diagnosed patients and 17 patients undergoing ASCT were studied and compared to healthy controls. ECs were evaluated as CD146+CD31+Lin- cells, while EPCs were evaluated as CD34+CD133+Lin-, or CD34+VEGFR2+Lin- cells, or CFU-En colony forming units. Numbers of these cells were evaluated before and after treatment, and, in patients treated with ASCT, during mobilization of hematopoietic progenitors. Both newly diagnosed patients and patients before ASCT had significantly higher number of CD146+CD31+Lin- cells and significantly lower number of CFU-En colonies than healthy controls. These parameters did not return to normal for at least 3 months after chemotherapy or ASCT. Numbers of CFU-En did not correlate either with numbers of CD34+CD133+Lin- cells or with numbers of CD34+VEGFR2+Lin- cells but they did correlate with numbers of CD4+ lymphocytes and NK cells. In conclusion, we have found that hematological patients have higher number of EC and lower numbers of CFU-En than healthy controls and that these parameters do not return to normal after short-term follow-up. Furthermore, our observations support emerging data that CFU-En represent cell population different from flowcytometrically defined EC and endothelial precursors and that their development requires cooperation of monocytes and CD4+ lymphocytes. However, cells forming CFU-En express endothelial surface markers and can contribute to proper endothelial function by NO production.