169followed up after an year and the promising findings of the study include no mass
formation, inflammation or abnormalities at injection sites. Ejection fraction of the
patient increased from 30% to 40% and there was a significant decrease in basic
natriuretic peptide values. Further, radiological examination of the chest and lateral
x-ray did not reveal any abnormalities. In the year 2012, Medistem Inc together with
ERCell LLC initiated a clinical trial utilising endometrial regenerative cells (ERCs)
for treating heart failure in a double blind, placebo controlled phase II trial [ 59 ]. The
trial was successful in the preliminary round and is permitted to continue by the
Data Safety Monitoring Board.
Though these reports showcase the potential benefits of endometrial stem cell
mediated cardiac regeneration and its potential suitability to be pronounced as “off
the shelf” biologically competent limitless sources of stem cells, the exact mecha-
nism of cardiac regeneration is still unknown. Whether cardiac regeneration is the
result of EnSCs undergoing differentiation to functional cardiac cells or executed
via paracrine effects deliberated by secreted cytokines that activate survival path-
ways by recruiting endogenous progenitor stem cells is yet to be unravelled.
10.9 Pros and Cons of EnSC Therapy
Clinical trials have demonstrated the potential use of EnSCs in repairing damaged
tissues and in correcting degenerative disorders without underlying immune com-
plications and/or rejections. The ease of access, isolation and maintenance of EnSCs
in culture for several generations and their diverse differentiation potential provide
them an advantage for therapeutic usages. Certain non-invasive procedures are in
place for obtaining menstrual blood for isolation of EnSCs using menstrual cups,
which collect menstrual blood on day 2–3 of the menstrual period without any com-
plications. Even though the techniques involved in harvesting EnSCs are stan-
dardised by a number of research groups, in terms of their clinical use, the existing
procedures have a major disadvantage owing to contamination with cells other than
stem cells majorly fibroblasts. In this context, it is important to note that, a signifi-
cant portion of the current research on the plasticity of EnSCs was based on the cell
population without purification. Lack of a specific identification system thus limits
the setting of exact cGMP protocols in place for the production of EnSCs and
emphasizes the need for further research in this area. Harvesting EnSCs from repro-
ductive age women holds several advantages in comparison to MSC from other
sources, mainly due to a greater ease of supply and the extended availability during
a woman’s lifetime with limited ethical concerns. The same, however, would not be
possible in case of post-menopausal women and non-invasive techniques have to be
used for harvesting EnSCs by obtaining endometrial biopsy samples. Furthermore,
there is no information regarding the potency of EnSCs in post-menopausal women
published in the literature.
Another major factor to consider for use of stem cells in therapy is their tendency
for transdifferentiation, which is associated with a discrete change in the programme
10 Uterine Stem Cells and Their Future Therapeutic Potential in Regenerative Medicine