Mesenchymal stromal cells, colony-forming unit fibroblasts, from bone marrow of untreated advanced breast and lung cancer patients suppress fibroblast colony formation from healthy marrow.

We have shown that bone marrow (BM) from untreated advanced lung and breast cancer patients (LCP and BCP) have a reduced number of colony-forming unit fibroblasts (CFU-Fs) or mesenchymal stem cells (MSCs). Factors that regulate the proliferation and differentiation of CFU-F are produced by the patients' BM microenvironment. We have now examined whether conditioned media (CM) from patients' CFU-F-derived stromal cells also inhibits the colony-forming efficiency (CFE) of CFU-F in primary cultures from healthy volunteers (HV)-BM. Thus the number and proliferation potential of HV-CFU-F were also found to be decreased and similar to colony numbers and colony size of patients' CFU-F. Stromal cells from both of these types of colonies appeared relatively larger and lacked the characteristic spindle morphology typically seen in healthy stromal cells. We developed an arbitrary mesenchymal stromal cell maturational index by taking three measures consisting of stromal cell surface area, longitudinal and horizontal axis. All stromal indices derived from HV-CFU-F grown in patients' CM were similar to those from stromal elements derived from patients' CFU-F. These indices were markedly higher than stromal indices typical of HV-CFU-F cultured in healthy CM or standard medium [alpha-medium plus 20% heat-inactivated fetal bovine serum (FBS)]. Patients' CM had increased concentrations of the CFU-F inhibitor, GM-CSF, and low levels of bFGF and Dkk-1, strong promoters of self-renewal of MSCs, compared to the levels quantified in CM from HV-CFU-F. Moreover, the majority of patients' MSCs were unresponsive in standard medium and healthy CM to give CFU-F, indicating that the majority of mesenchymal stromal cells from patients' CFU-F are locked in maturational arrest. These results show that alterations of GM-CSF, bFGF, and Dkk-1 are associated with deficient cloning and maturation arrest of CFU-F. Defective autocrine and paracrine mechanisms may be involved in the BM microenvironments of LCP and BCP.

Efficacy of extended thrombo-prophylaxis in major abdominal surgery: what does the evidence show? A meta-analysis.

Venous thromboembolism (VTE) is a frequent complication following major abdominal surgery. The use of low-molecular-weight heparins (LMWH) to prevent thrombotic events in these patients is a common and well documented practice. However, there is some controversy surrounding the duration of the prophylaxis, as it has been suggested that the risk persists for several weeks after surgery. The objective of this meta-analysis is to systematically review the clinical studies that compared safety and efficacy of extended use of LMWH (for three to four weeks after surgery) versus conventional in-hospital prophylaxis. An electronic data base search was performed. Only randomized, controlled studies were eligible. Data on the incidence of deep vein thrombosis (DVT), VTE and bleeding were extracted. Only three studies fulfilled the inclusion criteria. The indication for surgery was neoplastic disease in 70.6% (780/1104) of patients. The administration of extended LMWH prophylaxis significantly reduced the incidence of VTE, 5.93% (23/388) versus 13.6% (55/405), RR 0.44 (CI 95% 0.28 - 0.7); DVT 5.93% (23/388) versus 12.9% (52/402), RR 0.46 (CI 95% 0.29 - 0.74); proximal DVT 1% (4/388) versus 4.72% (19/402), RR 0.24 (CI 95% 0.09 - 0.67). We found no significant difference in major or minor bleeding between the two groups: 3.85% (21/545) in the extended thrombo-prophylaxis (ETP) group versus 3.48% (19/559) in the conventional prophylaxis group; RR 1.12 (CI 95% 0.61 - 2.06). There was no heterogeneity between the studies. We conclude that ETP with LMWH should be considered as a safe and useful strategy to prevent VTE in high-risk major abdominal surgery.

Alteration on the expression of IL-1, PDGF, TGF-beta, EGF, and FGF receptors and c-Fos and c-Myc proteins in bone marrow mesenchymal stroma cells from advanced untreated lung and breast cancer patients.

Previously, we reported a deficient cloning capacity of the bone marrow (BM) mesenchymal stem cells to give colony-forming unit fibroblast (CFU-F) and an inefficient confluence capacity of BM stromal cells in advanced untreated lung cancer patients (LCP) and breast cancer patients (BCP). Moreover, a decreased level of bFGF at day 7 in the conditioned media from BM CFU-F cultures was found in both cancer groups when compared to the normal range. The current study was specially undertaken, to evaluate the percentage of subconfluent fibroblasts expressing receptors (R) of interleukin-1 (IL-1), platelet-derived growth factor (PDGF), fibroblast growth factor (FGF), transforming growth factor (TGF-beta), epidermal growth factor (EGF), and the proteins c-Fos and c-Myc in BM primary cultures from untreated LCP and BCP. An immunocytochemical study on subconfluent BM fibroblast cultures from 13 healthy patients, 16 LCP, and 8 BCP was performed, using as primary antibodies, anti-type I of IL-1 R (IL-1R-1), anti-alpha, beta chains of PDGF R (PDGFR-alpha, PDGFR-beta), anti-type I of FGF R (FGFR-I), anti-type I, II, and III of TGF-beta R (TGF-betaR-I, TGF- betaR-II, and TGF-betaR-III), anti-EGF R, anti-c-Fos, and anti-c-Myc. A diminished percentage of subconfluent fibroblasts expressing PDGFR-alpha, TGFbetaR-I, II, III, EGFR, and FGFR-I was found in LCP and BCP compared to healthy patients. A diminished percentage of subconfluent fibroblasts expressing c-Fos and c-Myc was found in patients when compared to healthy patients. The alterations we describe could help to explain the deficiency regarding the proliferative and confluence capacity of BM stroma cells in cancer patients.