Lumican, a small leucine rich proteoglycan, inhibits MMP-14 activity and melanoma cell migration in vitro and in vivo. Snail triggers epithelial-mesenchymal transitions endowing epithelial cells with migratory and invasive properties during tumor progression. The aim of this work was to investigate lumican effects on MMP-14 activity and migration of Snail overexpressing B16F1 (Snail-B16F1) melanoma cells and HT-29 colon adenocarcinoma cells. Lumican inhibits the Snail induced MMP-14 activity in B16F1 but not in HT-29 cells. In Snail-B16F1 cells, lumican inhibits migration, growth, and melanoma primary tumor development. A lumican-based strategy targeting Snail-induced MMP-14 activity might be useful for melanoma treatment.

No abstract

Class III β-tubulin (TUBB3) is a marker of drug resistance expressed in a variety of solid tumors. Originally, it was described as an important element of chemoresistance to taxanes. Recent studies have revealed that TUBB3 is also involved in an adaptive response to a microenvironmental stressor, e.g. low oxygen levels and poor nutrient supply in some solid tumors, independently of the microtubule targeting agent. Furthermore, it has been demonstrated that TUBB3 is a marker of biological aggressiveness associated with modulation of metastatic abilities in colon cancer. The epithelial-to-mesenchymal transition (EMT) is a basic cellular process by which epithelial cells lose their epithelial behavior and become invasive cells involved in cancer metastasis. Snail is a zinc-finger transcription factor which is able to induce EMT through the repression of E-cadherin expression. In the presented studies we focused on the analysis of the TUBB3 role in EMT-induced colon adenocarcinoma cell lines HT-29 and LS180. We observed a positive correlation between Snail presence and TUBB3 upregulation in tested adenocarcinoma cell lines. The cellular and behavioral analysis revealed for the first time that elevated TUBB3 level is functionally linked to increased cell migration and invasive capability of EMT induced cells. Additionally, the post-transcriptional modifications (phosphorylation, glycosylation) appear to regulate the cellular localization of TUBB3 and its phosphorylation, observed in cytoskeleton, is probably involved in cell motility modulation.

␣ 1 -Acid glycoprotein, one of the major acute phase proteins, was found to interact with plasminogen activator inhibitor type 1 (PAI-1) and to stabilize its inhibitory activity toward plasminogen activators. This conclusion is based on the following observations: (a) ␣ 1 -acid glycoprotein was identified to bind PAI-1 by a yeast two-hybrid system. Three of 10 positive clones identified by this method to interact with PAI-1 contained almost the entire sequence of ␣ 1 -acid glycoprotein; (b) this protein formed complexes with PAI-1 that could be immunoprecipitated from both the incubation mixtures and blood plasma by specific antibodies to either PAI-1 or ␣ 1 -acid glycoprotein. Such complexes could be also detected by a solid phase binding assay; and (c) the real-time bimolecular interactions monitored by surface plasmon resonance indicated that the complex of ␣ 1 -acid glycoprotein with PAI-1 is less stable than that formed by vitronectin with PAI-1, but in both cases, the apparent K D values were in the range of strong interactions (4.51 ؉ 1.33 and 0.58 ؉ 0.07 nM, respectively). The on rate for binding of PAI-1 to ␣ 1 -glycoprotein or vitronectin differed by 2-fold, indicating much faster complex formation by vitronectin than by ␣ 1 -acid glycoprotein. On the other hand, dissociation of PAI-1 bound to vitronectin was much slower than that from the ␣ 1 -acid glycoprotein, as indicated by 4-fold lower k off values. Furthermore, the PAI-1 activity toward urokinase-type plasminogen activator and tissue-type plasminogen activator was significantly prolonged in the presence of ␣ 1 -acid glycoprotein. These observations suggest that the complex of PAI-1 with ␣ 1 -acid glycoprotein can play a role as an alternative reservoir of the physiologically active form of the inhibitor, particularly during inflammation or other acute phase reactions.

These results demonstrate the local inhibitory effects of chloroquine on UVB-induced upregulation in the mRNA expression of proinflammatory cytokines in irradiated skin of SLE patients, and provide further insight into the apparent immunomodulatory, anti-inflammatory and photoprotective properties of chloroquine.

The repeated low doses of UVB protected to a limited extent against the effects of an erythemal UVB dose on cytokine expression and thymine dimer formation, but not on CHS or COX enzymes.

Skin tissue scar formation and fibrosis are often characterized by the increased production and deposition of extracellular matrix components, accompanied by the accumulation of a vast number of myofibroblasts. Scaring is strongly associated with inflammation and wound healing to regain tissue integrity in response to skin tissue injury. However, increased and uncontrolled inflammation, repetitive injury, and individual predisposition might lead to fibrosis, a severe disorder resulting in the formation of dense and stiff tissue that loses the physical properties and physiological functions of normal tissue. Fibrosis is an extremely complicated and multistage process in which bone marrow-derived leukocytes act as both pro- and antifibrotic agents, and therefore, few, if any, effective therapies are available for the most severe and lethal forms of fibrosis. Herein, we discuss the current knowledge on the multidimensional impact of leukocytes on the induction of fibrosis, focusing on skin fibrosis.

Epithelial-to-mesenchymal transition (EMT) in cancer cells, represents early stages of metastasisand is a promising target in colorectal cancer (CRC) therapy. There have been many attempts to identify markers and key pathways induced throughout EMT but the process is complex and depends on the cancer type and tumour microenvironment. Here we used the colon cancer cell line HT29, which stably overexpressed Snail, the key transcription factor in early EMT, as a model for colorectal adenocarcinoma cells with a pro-metastatic phenotype. We investigated miRNA expression regulation during that phenotypic switching. We found that overexpression of Snail in HT29 cells triggered significant changes in individual miRNA levels but did not change the global efficiency of miRNA processing. Snail abundance repressed the expression of miR-192 and miR-194 and increased miR-205, let-7i and SNORD13 levels. These identified changes correlated with the reported transcriptomic alterations in Snail-overexpressing HT29 cells. We also investigated how Snail affected the miRNA content of extracellular vesicles (EVs) released from HT29 cells. Our data suggest that the presence of Snail significantly alters the complex mRNA/miRNA interactions in the early steps of metastasis and also has an impact on the content of EVs released from HT29 cells.According to the newest projections published by the American Cancer Society, despite significant overall reductions in colorectal cancer (CRC) incidence and mortality, there is a need for further efforts to advance therapies on the early stage of cancer and metastasis development 1 . To escape from the primary tumour site and to form metastatic lesions, epithelial cancer cells must acquire a more migratory phenotype to overcome several anatomical barriers. The process of conversion of the epithelial cell phenotype towards a more mesenchymal phenotype (EMT process) is considered to be an initial and critical for metastasis. Although there are many concepts of how EMT is modified in cancer, (reviewed by Gurzu et al. 2 ), the mechanism of EMT is still incompletely elucidated and there are many conflicting results published. During cancer EMT, there is a dynamic modulation of the interplay between transcription factors, gene expression and miRNAs (microRNAs /small non-coding RNAs) 3 . Thus, the understanding of the molecular interactions during the phenotype switch towards more mesenchymal and invasive cells has become important for future therapeutic strategies.We previously performed a global transcriptomic and phenotypic characteristic of the HT29 colorectal adenocarcinoma cell line affected by the transcription factor Snail (Snai1), a core regulator of the early stages of the epithelial phenotype conversion that initiates metastasis. We have shown that upregulation of Snail in HT29 cells results in an incomplete phenotype conversion, up to the intermediate epithelial state 4 . We and others have found that enhanced Snail expression is associated with a more aggressive phenotype, poorer clinical outc...