Persistence of CD34 Stem Marker in Human Lipoma: Searching for Cancer Stem Cells

Abstract

Background: Lipomas are benign solid tumours that develop in soft tissues with origin in mesenchymal progenitors. Macroscopically, they appear as soft-elastic nodules, varying in volume from a few millimiters to several centimetres and can enlarge progressively. Although they are usually asymptomatic, they can cause symptoms due to nerve or vessel compression. Microscopically they appear as fibrous connective tissue stroma with embedded adipocytes, and absence of inflammation. Up to now no characterisation of stem cell population present in this tissue has been performed.Methods: Cytofluorimetric, biological and molecular biology analyses have been performed in order to test superficial cell markers and gene expression profile related to stemness and apoptotic activity of cells present in lipoma tissues compared to those of adipose tissue's cells.Results: Our results confirmed that CD34+ cells in lipoma were present around small adipocytes, showing several altered biological activity such as proliferation, apoptotis and stemness.Conclusions: The data emerging from the comparison of the lipoma cells and normal adipose tissue, suggests the presence of cell precursors involved in the development of the lipoma. This hypothesis requires further investigation and may indicate new thresholds in the study of benign tumour pathogenesis.

Adipose-Derived Stromal Cells from Lipomas: Isolation, Characterisation and Review of the Literature

“…This is in line with the recent literature, which suggested that CD34+ lipoma cells showed higher vasculogenic properties and increased resistance in aging [14]. The potential roles of the CD34 family include increasing proliferation (replicative capacity) and blocking differentiation of stem or progenitor cells that therefore maintain their undifferentiated progenitor/stem cell phenotype (immaturity or stemness of the cells) [14]. However, a limitation of our study is the lack of ADSCs obtained from subcutaneous adipose tissue from the same donor to really compare biological characteristics of ADSCs from lipoma.…”

“…Potentially, the positivity of CD34 and CD31 might be characteristic for these cells, given the tumoural feature of ADSCs. This is in line with the recent literature, which suggested that CD34+ lipoma cells showed higher vasculogenic properties and increased resistance in aging [14]. The potential roles of the CD34 family include increasing proliferation (replicative capacity) and blocking differentiation of stem or progenitor cells that therefore maintain their undifferentiated progenitor/stem cell phenotype (immaturity or stemness of the cells) [14].…”

“…Totally, 36 articles were identified. Of those, 30 were included in the review: there were 12 case reports [1,9,10,11,26,27,28,29,30,31,32,33,34], 12 reports on basic science or animal studies [4,12,13,35,36,37,38,39,40,41,42,43,44], 2 case series [14,45] and 4 systematic reviews [13,38,46,47]. Totally, more than 60 patients were analysed; 25 articles were studied as a full-text version.…”

“…In the literature, involvement of adipose-derived stromal cells (ADSCs) in the development of lipomas has been proposed [11,12,13,14]. However, the involvement of ADSCs in the impaired adipose tissue expandability is only beginning to be explored.…”

Intramuscular spindle cell lipoma/pleomorphic lipoma unusual site fore arm

“…[1][2] Also there are case reports of the same in tongue and oral cavity. [3][4] CD34 is a marker for hematopoietic and mesenchymal stem cells and its presence is physiologically detectable in the perivascular environment of many tissues of post-natal organisms. 100% of benign cases of lipoma are positive for CD 34, as stated in many studies.…”