In models of single colonic crypts composed of stem cells, differentiated cells and transit cells, increased proliferation, decreased differentiation or decreased apoptosis all lead to a net increase in cell number (67).
Conversely EGF treatment of a serum-free epidermal culture model resulted in decreased differentiation [ 2] and an elevated expression of EGFR in differentiating cells, and presumably therefore activation of EGFR signaling, resulted in hyperproliferation [ 22].
We demonstrate that this reduction in process extension corresponds to increased proliferation and decreased differentiation in Nf1 knockout OPCs.
Time-lapse recordings showed that IGF-I at 100 ng/ml decreased differentiation and increased proliferation of single AHPs.
The neoplastic transformation of OPC and OL and formation of gliomas are associated with increased proliferation, decreased differentiation, changes in the tumor microenvironment53, and a decrease in ACD2.
This effect resulted from a decreased differentiation and resorbing activity of osteoclasts and increased osteoclast apoptosis.
The down-regulation of both E-cadherin and β-catenin was correlated with decreased differentiation and increased tumour grade.
Accordingly, PLX4720-treated TFEBS142E tumors exhibited a sarcomatoid appearance, as opposed to the polygonal cells in TFEBS142A tumors (Supplementary Fig. 11a, b and Fig. 8d), suggesting decreased differentiation, as also supported by immunoblot analyses (Supplementary Figs. 10d and 11e, f).
In the chondrogenic differentiation assay (Supplementary Fig. 2 C, F), Type II collagen immunofluorescent staining showed a decreased differentiation rate in the Cy group (~30.84% vs. ~51.87%, P < 0.01, Student's t-test).
Dynamic conditions improved cell proliferation (Day 21 cell numbers with dynamic and with static groups were 180.4 × 104 and 157.7 × 104, respectively) but decreased differentiation (Day 14 specific ALP values on the films of static and dynamic groups were 6.6 and 3.5 nmol/min/cell, respectively).
