Assessment of a nuclear affinity labeling method for tracking implanted mesenchymal stem cells.

Therapeutic implantation of mesenchymal stem cells (MSCs) is entering the realm of clinical trials for several human diseases, and yet much remains uncertain regarding their dynamic distribution and cell fate after in vivo application. Discrepancies in the literature can be attributed in part to the use of different cell labeling/tracking methods and cell administration protocols. To identify a stem cell detection method suitable for myocardial implantation in a large animal model, we experimented on three different MSC labeling methods: adenovirus-mediated expression of enhanced green fluorescence protein (EGFP) and beta-galactosidase (LacZ), and nuclear staining with DAPI. Intramuscular and intracoronary administrations of labeled porcine MSCs identified the nuclear affinity dye to be a reliable stem cell tracking marker. Stem cell identification is facilitated by an optimized live cell labeling condition generating bright blue fluorescence sharply confined to the nucleus. DAPI-labeled MSCs retained full viability, ceased proliferation, and exhibited an increased differentiation potential. The labeled MSCs remained fully active in expressing key growth factor and cytokine genes, and notably exhibited enhanced expression of the chemokine receptor CXCR4 and its ligand SDF1, indicating their competency in response to tissue injury. Histological analysis revealed that approximately half a million MSCs or approximately 2% of the administered MSCs remained localized in the normal pig heart 2 weeks after coronary infusion. That the vast majority of these identified MSCs were interstitial indicated the ability of MSCs to migrate across the coronary endothelium. No evidence was obtained indicating MSC differentiation to cardiomyocyte.

Improved prognosis assessment for patients with bladder carcinoma.

Urothelial carcinomas are heterogeneous diseases with an aggressive clinical potential. To date, the most used prognostic factors for bladder carcinomas are grade and stage, which are based on histopathological parameters that are often not reliable in predicting a clinical outcome. Here, we evaluated the clinical outcome of 100 patients with urothelial carcinomas with follow-up information for more than 2 years after surgery in relation to the expression of two cell surface antigens, ie, E-cadherin and autocrine motility factor receptor (AMF-R, gp78). Frozen bladder tissues were serially cut, stained either with hematoxylin and eosin for grading, with the anti-gp78 antibodies, or with anti-E-cadherin antibodies to determine level of expression. Of 63 patients presented at the time of diagnosis with pathological loss of E-cadherin associated with increased gp78 expression, 39 (62%) succumbed to tumor progression or death. Of 37 patients with normal E-cadherin and gp78 expression positive and negative, respectively, 36 (97%) had favorable disease outcomes (P < 0.0001). The results suggest that in bladder carcinomas abnormal expression of both E-cadherin and gp78 results in a poor disease outcome, independent of tumor stage and grade.