Human mesenchymal stromal cells from adult and neonatal sources: comparative analysis of their morphology, immunophenotype, differentiation patterns and neural protein expression

BACKGROUND

Bone marrow (BM) has been recognized as the main source of mesenchymal stromal cells (MSC); however, MSC have also been detected in umbilical cord blood (UCB) and placenta (PL). In the present study, we obtained MSC from these three sources and characterized them in a comparative manner.

METHODS

MSC were obtained from BM, UCB and PL samples and analyzed to determine their morphology, cell-surface antigen (Ag) expression and differentiation potential. Particular emphasis was placed on the expression of neural markers.

RESULTS

MSC were detected in 9/9, 11/104 and 5/5 samples from BM, UCB and PL, respectively. MSC populations comprised several morphologically distinct cell types, including neural-like cells. MSC were positive for 'mesenchymal' Ag (CD105, CD73 and CD90), although CD90 expression was very heterogeneous. Interestingly, CD13 expression was high in all three sources. In all cases, MSC showed osteogenic and chondrogenic differentiation; however, UCB MSC showed no adipogenic potential. Furthermore, MSC from UCB produced a different type of cartilage compared with MSC from BM and PL. It is noteworthy that in all three sources we detected the expression of neural proteins without any neural differentiation stimuli. A significant increase in the proportion of neural marker-positive MSC was observed in the presence of neural inducers.

DISCUSSION

Our results indicate that PL may prove to be a more appropriate source for obtaining MSC than UCB, and suggest the possibility that a subpopulation of MSC may possess neural potential, which is favored by neural inducers.

Expression of telomerase enzyme as predictive factor of response to first line chemotherapy with gemcitabine/carboplatin in advanced non-small cell lung cancer (IIIB and IV)

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Background: Non-small cell lung cancer (NSCLC) is the most frequent neoplasia in the world and the main cause of death for cancer. The palliative chemotherapy is the elected treatment for patients in stage III and IV. The telomerase enzyme is expressed in 82% of neoplasias and its activity is implied in the genomic instability, apoptosis inhibition and cell immortalization. Objective: To determine the predictive value of the expression of the telomerase enzyme with the first line regimen gemcitabine (1 gr/m2 SC, days 1 and 8) and carboplatino (AUC of 5 in day 1) every 28 days in patients with NSCLC clinical stages IIIB and IV. The response and toxicity rate was also determined. Methods: Patients were recruited in a period between 04/01/2004 and 11/30/2004, ages between 18 and 80, ECOG ≤ 2, measured disease (RECIST), virgin to treatment, permissible hematic biometry for chemotherapy and optimal kidney function. A total of 17 patients with an average age of 61 (range 44 to 77 years old) 9/17 (53%) males and 8/17 (47%) females, 4/17 with clinical stage IV (23%) and 13/17 with clinical stage IIIB (77%) from which: 8/13 (61%) presented pleural effusion. From the total number of patients, 1/17 presented ECOG 0 (6%), 14/17 ECOG 1 (82%) and 2/17 ECOG 2 (12%). The histopathologic diagnosis was adenocarcinoma in 12/17 (70%) and epidermoid carcinoma in 5/17 (30%). A rabbit polyclonal antibody was used to asses the expression of the telomerase enzyme by the immunohistochemical method. Results and Conclusions: It was demonstrated in 11/17 patients that the high expression of telomerase enzyme is directly correlated to the lack of response to treatment (3/11 patients stable disease and 4/11 with progressive disease); and a low or absent expression (4/11 patients) was correlated to a response higher than 30% (p = 0.045). The obtained response rate was lower that the previous ones reported with the regimen gemcitabine (days 1, 8 every 21 days and 1, 8 and 15 every 28 days) presenting a minimum hematologic toxicity. This analysis suggests that the telomerase enzyme could be a response predictive marker in the NSCLC with this therapeutic regimen.

No significant financial relationships to disclose.

Neuronal differentiation of chromaffin cells in vitro, induced by extremely low frequency magnetic fields or nerve growth factor: a histological and ultrastructural comparative study

The application of nerve growth factor (NGF) to primary adrenal medulla chromaffin cell cultures induces phenotypic changes characterized mainly by the presence of neurites. A similar effect has been seen when these cells are stimulated by extremely low frequency magnetic fields (ELFMF). In this study, newborn rat chromaffin cells were cultured and subjected to NGF or ELFMF in order to compare their histological and ultrastructural characteristics. Cells cultured in the presence of NGF developed cytoplasmic projections and their distal ends showed growth cones as well as filopodia. With scanning and transmission electron microscopy, an increased submembranous electron density was observed in the nuclei of cells as well as irregular, wavy neuritic projections with a moderate number of varicosities, as well as the prevalence of intermediate filaments among the cytoskeleton components. Cells stimulated with ELFMF presented straighter neuritic extensions with a greater number of varicosities. With the transmission electron microscope, numerous neurotubules were observed, both in the cell soma and in their neuritic extensions. In both groups, growth cones were clearly identified by their ultrastructural characteristics. The differences seen in the cytoskeleton of cells stimulated with NGF or ELFMF suggest differential stimulation mechanisms possibly determining the biochemical, electrophysiological, and morphological characteristics in both types of cell cultures.