High CXCR3 on Leukemic Cells Distinguishes IgHVmut from IgHVunmut in Chronic Lymphocytic Leukemia: Evidence from CD5high and CD5low Clones

Despite the shared pattern of surface antigens, neoplastic cells in chronic lymphocytic leukemia (CLL) are highly heterogeneous in CD5 expression, a marker linked to a proliferative pool of neoplastic cells. To further characterize CD5high and CD5low neoplastic cells, we assessed the chemokine receptors (CCR5, CCR7, CCR10, CXCR3, CXCR4, CXCR5) and adhesion molecules (CD54, CD62L, CD49d) on the CD5high and CD5low subpopulations, defined by CD5/CD19 coexpression, in peripheral blood of CLL patients (n=60) subgrouped according to the IgHV mutational status (IgHVmut, n=24; IgHVunmut, n=36). CD5high subpopulation showed a high percentage of CXCR3 (P<0.001), CCR10 (P=0.001), and CD62L (P=0.031) and high levels of CXCR5 (P=0.005), CCR7 (P=0.013) compared to CD5low cells expressing high CXCR4 (P<0.001). Comparing IgHVmut and IgHVunmut patients, high levels of CXCR3 on CD5high and CD5low subpopulations were detected in the IgHVmut patients, with better discrimination in CD5low subpopulation. Levels of CXCR3 on CD5low subpopulation were associated with time to the next treatment, thus further confirming its prognostic value. Taken together, our analysis revealed higher CXCR3 expression on both CD5high and CD5low neoplastic cells in IgHVmut with a better prognosis compared to IgHVunmut patients. Contribution of CXCR3 to CLL pathophysiology and its suitability for prognostication and therapeutic exploitation deserves future investigations.

Gastric squamous-columnar junction contains a large pool of cancer-prone immature osteopontin responsive Lgr5−CD44+ cells

Areas of a junction between two types of epithelia are known to be cancer-prone in many organ systems. However, mechanisms for preferential malignant transformation at the junction areas remain insufficiently elucidated. Here we report that inactivation of tumor suppressor genes Trp53 and Rb1 in the gastric squamous-columnar junction (SCJ) epithelium results in preferential formation of metastatic poorly differentiated neoplasms, which are similar to human gastroesophageal carcinoma. Unlike transformation-resistant antral cells, SCJ cells contain a highly proliferative pool of immature Lgr5−CD44+ cells, which are prone to transformation in organoid assays, comprise early dysplastic lesions, and constitute up to 30% of all neoplastic cells. CD44 ligand osteopontin (OPN) is preferentially expressed in and promotes organoid formation ability and transformation of the SCJ glandular epithelium. OPN and CD44 overexpression correlate with the worst prognosis of human gastroesophageal carcinoma. Thus, detection and selective targeting of the active OPN-CD44 pathway may have direct clinical relevance.

Coevolution in the timing of GABAergic and pyramidal neuron maturation in primates

The cortex of primates is relatively expanded compared with many other mammals, yet little is known about what developmental processes account for the expansion of cortical subtype numbers in primates, including humans. We asked whether GABAergic and pyramidal neuron production occurs for longer than expected in primates than in mice in a sample of 86 developing primate and rodent brains. We use high-resolution structural, diffusion MR scans and histological material to compare the timing of the ganglionic eminences (GE) and cortical proliferative pool (CPP) maturation between humans, macaques, rats, and mice. We also compare the timing of post-neurogenetic maturation of GABAergic and pyramidal neurons in primates (i.e. humans, macaques) relative to rats and mice to identify whether delays in neurogenesis are concomitant with delayed post-neurogenetic maturation. We found that the growth of the GE and CPP are both selectively delayed compared with other events in primates. By contrast, the timing of post-neurogenetic GABAergic and pyramidal events (e.g. synaptogenesis) are predictable from the timing of other events in primates and in studied rodents. The extended duration of GABAergic and pyramidal neuron production is associated with the amplification of GABAerigc and pyramidal neuron numbers in the human and non-human primate cortex.

Особливості клітинного циклу мезенхімальних стовбурових клітин з жирової тканини собаки за різних пасажів культивування

The features of the cell cycle of culture of adipose-derived mesenchymal stem cells from the for different cultivating passages were studied. Mesenchymal stem cells were obtained from the adipose tissue of the dog under a laminar flow hood by an explant method in our modification. Cell cultivation was carried out at 37 °C, 100% moisture and 5% CO2 in Dulbecco’s modified Eagle’s medium (DMEM) containing 10% fetal bovine serum (FBS) and 1% antibiotic-antimycotic. The culture medium was changed 2–3 times per week and the cells were selected by their capacity to attach to the flask surface. When culture flasks became 80% confluence, cells were detached with 0.25% trypsin containing 1 mmol/L EDTA and subsequently replayed at a concentration of 104 cells/cm2 for next passaging. A cells culture of adipose derived mesenchymal stem cells was obtained on the 2nd, 7th and 12th passages. The method of flow cytometry determined the level of aneuploid cells and the distribution in the cell cycle phases. The morphology of cells of different passages was studied using an inverted microscope Axiovert 40. It was investigated that the culture of mesenchymal stem cells from adipose tissue in the 2nd passage contains a significant number of the proliferative pool (S + G2/M) cells and it was 29.51 ± 3.56% of the total number of diploid cells. The number of aneuploid cells was 1.55 ± 0.43%. All cells had fibroblast-like morphology. It was established that in the middle passages (7th) in the culture of mesenchymal stem cells from the adipose tissue of the dog no significant changes were found in the distribution of cells in the phases of the cell cycle. The number of diploid cells of the proliferative pool S + G2/M and the G0/G1 pre-synthetic period remains unchanged. The level of aneuploidy increases only within the tendency. Morphologically, cells had fibroblast-like form. It was determined on 12th passage of cultivation, a significant decrease in the number of cells of the proliferative pool (S+G2/M), which was 18.93 ± 0.66% of the total number of diploid cells compared to the 2nd passage. The number of aneuploid cells increased and it was 3.49 ± 0.38%. Morphologically, separate cells had processes. The indicator of the effect of cells cultivation on the content of diploid cells of the proliferative pool (S+G2/M) in culture is ɳ2x = 70% (P < 0.05). So, first characteristic properties of the aging of the culture of canine adipose-derived mesenchymal stem cells appear on the 12th passage of cultivation.

Human placental conditioned medium reverses apparent commitment to differentiation of human promyelocytic leukemia cells (HL60)

Using a system of sequential daughter cell transfers in semisolid medium, we have analyzed self-renewal and differentiation of human promyelocytic leukemia cells (HL60) in presence of all-trans retinoic acid and human placental conditioned medium (HPCM). We find that retinoic acid induces coordinated losses of self-renewal potential which are followed by phenotypic differentiation. The latter occurs as an all-or-none event and is reversible in the presence of HPCM. Thus, HL60 cells that apparently had terminally differentiated (as estimated by the ability to reduce nitroblue tetrazolium [NBT]) can lose their differentiation marker and reenter the proliferative pool.

Human placental conditioned medium reverses apparent commitment to differentiation of human promyelocytic leukemia cells (HL60)

Using a system of sequential daughter cell transfers in semisolid medium, we have analyzed self-renewal and differentiation of human promyelocytic leukemia cells (HL60) in presence of all-trans retinoic acid and human placental conditioned medium (HPCM). We find that retinoic acid induces coordinated losses of self-renewal potential which are followed by phenotypic differentiation. The latter occurs as an all-or-none event and is reversible in the presence of HPCM. Thus, HL60 cells that apparently had terminally differentiated (as estimated by the ability to reduce nitroblue tetrazolium [NBT]) can lose their differentiation marker and reenter the proliferative pool.

Epidermal cell proliferation in the bottlenose dolphin (Tursiops truncatus)

Epidermal cell proliferation in four bottlenose dolphins, Tursiops truncatus, was studied using radioactively labelled thymidine. The epidermal proliferation index (PI) of 7.4 ± 0.6% is 1.3 to 1.9 times higher than that reported for terrestrial mammals. The size of the proliferative pool, a function of the ratio of basal to surface area of the epidermis, was found to be 13.1:1. These two factors combine to give a large proliferative capacity, which contributes to the unusual thickness of the epidermis of Tursiops.