**4. Possible TC roles**

108 Sex Steroids

TCs were enriched in primary culture by magnetically-activated cell sorting, after being identified as c-kit positive cells with characteristic morphology. Indeed TCs were found in a higher percentage after magnetic cell sorting: approximately 30 ± 0.8% (n = 516) compared to 9.9 ± 0.9% (n = 324) (Popescu, 2005). The sorted populations underwent subsequent passages, because according to our previous experience, the number of TCs increases with

*In vitro* double staining on Fallopian tube samples showed that desmin-positive cells (SMC) tested negative for ER-α or PR-A and c-kit-positive cells (telocytes) tested positive for ER-α or PR-A (Fig. 21 A,B). Moreover, double staining for c-kit (green fluorescence) and PR-A or ER-α (red fluorescence) revealed that only cells positive for c-kit were also positive for ER-α and PR-A at nuclear level (Fig. 22 A-F). PR-A expression at nuclear level was more intense

Fig. 21. A,B. Human Fallopian tube cell culture, fourth passage. The expression of ER-α (A) and PR-A (B) demonstrated by immunocytochemical staining. TCs (arrows) stained positive for ER and PR (brown nuclei). Scale bar = 5 μm. With kind permission from Springer Science+Business Media: Journal of Molecular Histology, Interstitial Cajal-like cells of human Fallopian tube express estrogen and progesterone receptors, 40, 2009, 387-394,

Cretoiu, S.M.;Cretoiu, D.;Suciu, L.&Popescu, L.M., figure 4.

than for ER-α. SMC were weakly positive or completely negative.

each passage.
