Thymosin β4 Regulates Focal Adhesion Formation in Human Melanoma Cells and Affects Their Migration and Invasion

Abstract

Thymosin β4 (Tβ4), a multifunctional 44-amino acid polypeptide and a member of actin-binding proteins (ABPs), plays an important role in developmental processes and wound healing. In recent years an increasing number of data has been published suggesting Tβ4's involvement in tumorigenesis. However, Tβ4's role in melanoma tumor development still remains to be elucidated. In our study we demonstrate that Tβ4 is crucial for melanoma adhesion and invasion. For the purpose of our research we tested melanoma cell lines differing in invasive potential. Moreover, we applied shRNAs to silence TMSB4X (gene encoding Tβ4) expression in a cell line with high TMSB4X expression. We found out that Tβ4 is not only a component of focal adhesions (FAs) and interacts with several FAs components but also regulates FAs formation. We demonstrate that Tβ4 level has an impact on FAs' number and morphology. Moreover, manipulation with TMSB4X expression resulted in changes in cells' motility on non-coated and Matrigel TM (resembling basement membrane composition)-coated surfaces and drastically decreased invasion abilities of the cells. Additionally, a correlation between Tβ4 expression level and exhibition of mesenchymal-like [epithelialmesenchymal transition (EMT)] features was discovered. Cells with lowered TMSB4X expression were less EMT-progressed than control cells. Summarizing, obtained results show that Tβ4 by regulating melanoma cells' adhesion has an impact on motility features and EMT. Our study not only contributes to a better understanding of the processes underlying melanoma cells' capacity to create metastases but also highlights Tβ4 as a potential target for melanoma management therapy.

The origin of the expressed retrotransposed gene ACTBL2 and its influence on human melanoma cells’ motility and focal adhesion formation

“…No similar research was done so far on tumor cells regarding β-or γ-actin mRNA distribution in the whole population of a given cell line. Intriguingly, among the cell lines tested here, A375 and Hs294T had the highest migration potential 75 . We show here that actbl2 presence in melanoma cells is meager in comparison to β and γ actin.…”

“…Clonings and transfections. pLVX-hPGK-Puro and pLVX-hPGK-Puro-Actbl2 plasmids were obtained based on pLVX-IRES-Puro-Tβ4 plasmid described elsewhere 75 . Here, the CMV promoter present in the pLVX-IRES-Puro-Tβ4 plasmid was substituted with hPGK promoter using ClaI and EcoRI restriction sites.…”

“…Invasion assay. The assay is described elsewhere 75 . Briefly, the test was performed using Transwell filters (BD Bioscience) coated with Matrigel (BD Bioscience).…”

“…Time-lapse photos were captured using IncuCyte Live Cell Analysis Imaging System for 72 h with a time interval of 2 h. For the evaluation of cellular trajectory, velocity and distance covered by single-cell Manual Tracking plug-in (ImageJ, F. Cordelieres, Institute Curie, Paris, France) were used. End-point directionality was calculated as the ratio between the straight-line displacement (distance to the origin, DTO) and the total path traveled by the cell (total distance, TD) 75 . For each parameter, 30 cells (3 clones) per group were analyzed.…”

The viral vectored vaccine targeting Thymosin β10 controls tumour growth in a murine model of prostate cancer

“…They are involved in many cellular processes such as cellular motility, angiogenesis, inflammation, cell survival and wound healing. Recently, a role for βthymosins has been proposed in the process of carcinogenesis as both peptides were detected in several types of cancer and played a key role in facilitating tumour metastasis and angiogenesis [28][29][30][31][32].…”