Is There Such a Thing as a Genuine Cancer Stem Cell Marker? Perspectives from the Gut, the Brain and the Dental Pulp

Immunolocalization of the mechanogated ion channels PIEZO1 and PIEZO2 in human and mouse dental pulp and periodontal ligament

PIEZO1 and PIEZO2 are essential components of mechanogated ion channels, which are required for mechanotransduction and biological processes associated with mechanical stimuli. There is evidence for the presence of PIEZO1 and PIEZO2 in teeth and periodontal ligaments, especially in cell lines and mice, but human studies are almost nonexistent. Decalcified permanent human teeth and mouse molars were processed for immunohistochemical detection of PIEZO1 and PIEZO2. Confocal laser microscopy was used to examine the co-localization of PIEZO 1 and PIEZO2 with vimentin (a marker of differentiated odontoblasts) in human teeth. In the outer layer of the human dental pulp, abundant PIEZO1- and PIEZO2-positive cells were found that had no odontoblast morphology and were vimentin-negative. Based on their morphology, location, and the absence of vimentin positivity, they were identified as dental pulp stem cells or pre-odontoblasts. However, in mice, PIEZO1 and PIEZO2 were ubiquitously detected and colocalized in odontoblasts. Intense immunoreactivity of PIEZO1 and PIEZO2 has been observed in human and murine periodontal ligaments. Our findings suggest that PIEZO1 and PIEZO2 may be mechanosensors/mechanotransducers in murine odontoblasts, as well as in the transmission of forces by the periodontal ligament in humans and mice.

The TERT Promoter: A Key Player in the Fight for Cancer Cell Immortality

The review describes the role of telomeres and telomerase in tumor progression, as well as various mechanisms of the activation of telomerase reverse transcriptase (TERT) expression in CNS tumors and other cancers. The main mechanism of TERT activation involves acquisition of somatic mutations by the TERT gene promoter (TERTp). The article presents information on the TERTp structure and transcription factors directly interacting with TERTp and regulating its transcription. The prospects of using the mutational status of TERTp as a prognostic marker of CNS malignancies and other tumors with a common profile of TERTp mutations are discussed.

[Protein CD133 as a tumor stem cell marker]

The CD133 protein is a large transmembrane glycoprotein. Despite multiple studies, the role of CD133 protein in cells is still poorly understood. Nevertheless, there is an association of CD133 protein with neoplastic transformation. This review summarizes data on CD133 protein, its structure, regulation of expression, molecular interactions and representation in cells that have undergone malignant transformation. Available data suggest that CD133 may have a great potential for predicting survival in various solid tumors. This protein can also be a marker of glioma.

Low Molecular Weight Hyaluronic Acid Effect on Dental Pulp Stem Cells In Vitro

Hyaluronic acid (HA) and dental pulp stem cells (DPSCs) are attractive research topics, and their combined use in the field of tissue engineering seems to be very promising. HA is a natural extracellular biopolymer found in various tissues, including dental pulp, and due to its biocompatibility and biodegradability, it is also a suitable scaffold material. However, low molecular weight (LMW) fragments, produced by enzymatic cleavage of HA, have different bioactive properties to high molecular weight (HMW) HA. Thus, the impact of HA must be assessed separately for each molecular weight fraction. In this study, we present the effect of three LMW-HA fragments (800, 1600, and 15,000 Da) on DPSCs in vitro. Discrete biological parameters such as DPSC viability, morphology, and cell surface marker expression were determined. Following treatment with LMW-HA, DPSCs initially presented with an acute reduction in proliferation (p < 0.0016) and soon recovered in subsequent passages. They displayed significant size reduction (p = 0.0078, p = 0.0019, p = 0.0098) while maintaining high expression of DPSC markers (CD29, CD44, CD73, CD90). However, in contrast to controls, a significant phenotypic shift (p < 0.05; CD29, CD34, CD90, CD106, CD117, CD146, CD166) of surface markers was observed. These findings provide a basis for further detailed investigations and present a strong argument for the importance of HA scaffold degradation kinetics analysis.