Epidermal growth factor modulates cell attachment to hyaluronic acid by the cell surface glycoprotein CD44

Gelatin-methacryloyl hydrogels containing turnip mosaic virus for fabrication of nanostructured materials for tissue engineering

Current tissue engineering techniques frequently rely on hydrogels to support cell growth, as these materials strongly mimic the extracellular matrix. However, hydrogels often need ad hoc customization to generate specific tissue constructs. One popular strategy for hydrogel functionalization is to add nanoparticles to them. Here, we present a plant viral nanoparticle the turnip mosaic virus (TuMV), as a promising additive for gelatin methacryloyl (GelMA) hydrogels for the engineering of mammalian tissues. TuMV is a flexuous, elongated, tubular protein nanoparticle (700–750 nm long and 12–15 nm wide) and is incapable of infecting mammalian cells. These flexuous nanoparticles spontaneously form entangled nanomeshes in aqueous environments, and we hypothesized that this nanomesh structure could serve as a nanoscaffold for cells. Human fibroblasts loaded into GelMA-TuMV hydrogels exhibited similar metabolic activity to that of cells loaded in pristine GelMA hydrogels. However, cells cultured in GelMA-TuMV formed clusters and assumed an elongated morphology in contrast to the homogeneous and confluent cultures seen on GelMA surfaces, suggesting that the nanoscaffold material per se did not favor cell adhesion. We also covalently conjugated TuMV particles with epidermal growth factor (EGF) using a straightforward reaction scheme based on a Staudinger reaction. BJ cells cultured on the functionalized scaffolds increased their confluency by approximately 30% compared to growth with unconjugated EGF. We also provide examples of the use of GelMA-TuMV hydrogels in different biofabrication scenarios, include casting, flow-based-manufacture of filaments, and bioprinting. We envision TuMV as a versatile nanobiomaterial that can be useful for tissue engineering.

Expression Patterns of CD44 and AREG Under Treatment With Selective Tyrosine Kinase Inhibitors in HPV+ and HPV- Squamous Cell Carcinoma

BACKGROUND

We investigated the expression patterns of cluster of differentiation (CD) 44 and amphiregulin (AREG), two signaling molecules essential for cell proliferation and differentiation, under the influence of selective tyrosine kinase inhibitors (TKIs) in human papillomavirus (HPV)⁺ and HPV^- squamous carcinoma cell lines.

MATERIALS AND METHODS

The protein expression of CD44 and AREG was determined by sandwich enzyme-linked immunosorbent assay in HPV^- cell lines UMSCC-11A and UMSCC-14C, and HPV⁺ CERV-196 cells after TKI treatment.

RESULTS

The expression of AREG and CD44 was dependent on the cell line's HPV status. AREG expression increased after incubation with nilotinib in HPV⁺ tumor cells. The expression of CD44 was significantly influenced by all drugs; its expression under selective epidermal growth factor receptor inhibition was mostly reduced, whereas nilotinib led to an exceptional increase of CD44 expression.

CONCLUSION

The selective drug treatment options significantly influenced the expression of CD44 and AREG in HPV^- and HPV⁺ tumor cells, constituting the need for personalized treatment options.

A Fra-1-dependent, matrix metalloproteinase driven EGFR activation promotes human lung epithelial cell motility and invasion

We and others have shown a persistently high induction of Fra-1 transcription factor (a dimeric partner of AP-1) levels by respiratory carcinogens in pulmonary epithelial cells. Fra-1 is frequently overexpressed in various human tumors and cancer cells. We have recently shown that Fra-1 significantly promotes growth, motility, and invasion of human pulmonary epithelial cells, the precise molecular mechanisms by which this enhancement occurs are unclear. Because matrix metalloproteinases (MMPs) play key roles in wound healing and lung tumor metastasis, we tested the hypothesis that Fra-1 promotes lung epithelial cell motility and invasion via MMP activation. We show here that MMP-9 and MMP-2 activated signaling plays a critical role in regulating Fra-1-induced lung epithelial cell growth and invasion. Ectopic Fra-1 markedly stimulates MMP-2 and MMP-9 mRNA expression. Inhibition of MMP-2 and MMP-9 activity significantly attenuated Fra-1-driven cell motility and invasion. Furthermore, Fra-1 induced EGFR phosphorylation in an MMP-dependent manner, and an EGFR-specific inhibitor was able to block Fra-1-enhanced cell motility and invasion. Taken together, our data suggest that Fra-1 enhances lung cancer epithelial cell motility and invasion by inducing the activity of MMPs, in particular MMP-2 and MMP-9, and EGFR-activated signaling.