Surprisingly, quantitative PCR of muscle specific markers showed that expression rates did not correlate with different fibrin concentration rates but were rather associated with the number of cells seeded initially though this variable has been carefully controlled by using the same amount of total RNA.
This genetic drift is accompanied by phenotypic changes such as altered morphology, variable cell surface marker expression, increased growth rate and more aggressive cell growth both in vitro and in vivo.
In general, a high degree of cellular heterogeneity defined by marker expression, cell division rate and ultrastructure, has been observed both within the basal layer of the human IFE (Jones et al., 1995; Li et al., 1998; Jensen et al., 1999) and in the PSU (Cotsarelis et al., 1990; Rochat et al., 1994; Lyle et al., 1998; Ohyama et al., 2006).
Transduction of human primary AML blasts with a lentivector encoding PU.1 increased the myelomonocytic marker expression and decreased proliferation rates together with increasing apoptosis, changes characteristic of restored differentiation in these myeloid leukaemic blasts (58).
To shed light on the characteristics of human dermal MSCs, this study was designed to identify and isolate dermal MSCs by a specific marker expression profile, and subsequently rate their mesenchymal differentiation potential.
There were minimal differences between B6 and C3 clones in their morphology, population doubling rates, molecular marker expression or differentiation potential.
There were no significant differences in the surface marker expression profile or the mean rate of proliferation between these cells and those maintained manually, strongly suggesting that both populations of RAA-derived CSCs contain equal properties.
Beckhove and colleagues [ 18] found that sub-lethal irradiation (3.75 Gy) to further suppress the immune system increased NOD/SCID mouse mortality compared to non-irradiated mice, without improving the engraftment rate or tumor marker expression of intramuscularly implanted tumor tissue (Table 1; 93 versus 90% take rate, respectively).
Also the long-term passaged subclones displayed variations in phenotypic marker expression and showed an increased growth rate in vitro and a more aggressive growth in vivo.
The positive expression rates of molecular markers were 86.6% for Cyclin-D1, 92.8% for EGFR and 85.6% for p53.
