Lens placode modulates extracellular matrix formation during early eye development.

The role extracellular matrix (ECM) in multiple events of morphogenesis has been well described, little is known about its specific role in early eye development. One of the first morphogenic events in lens development is placodal thickening, which converts the presumptive lens ectoderm from cuboidal to pseudostratified epithelium. This process occurs in the anterior pre-placodal ectoderm when the optic vesicle approaches the cephalic ectoderm and is regulated by transcription factor Pax6 and secreted BMP4. Since cells and ECM have a dynamic relationship of interdependence and modulation, we hypothesized that the ECM evolves with cell shape changes during lens placode formation. This study investigates changes in optic ECM including both protein distribution deposition, extracellular gelatinase activity and gene expression patterns during early optic development using chicken and mouse models. In particular, the expression of Timp2, a metalloprotease inhibitor, corresponds with a decrease in gelatinase activity within the optic ECM. Furthermore, we demonstrate that optic ECM remodeling depends on BMP signaling in the placode. Together, our findings suggest that the lens placode plays an active role in remodeling the optic ECM during early eye development.

Lens Placode Modulates Extracellular Matrix Formation During Early Eye Development.

The role extracellular matrix (ECM) in multiple events of morphogenesis has been well described, little is known about its specific role in early eye development. One of the first morphogenic events in lens development is placodal thickening, which converts the presumptive lens ectoderm from cuboidal to pseudostratified epithelium. This process occurs in the anterior pre-placodal ectoderm when the optic vesicle approaches the cephalic ectoderm. Since cells and ECM have a dynamic relationship of interdependence and modulation, we hypothesized that the ECM evolves with cell shape changes during lens placode formation. This study investigates changes in optic ECM including both protein distribution deposition, extracellular gelatinase activity and gene expression patterns during early optic development using chicken and mouse models. In particular, the expression of Timp2 , a metalloprotease inhibitor, corresponds with a decrease in gelatinase activity within the optic ECM. Furthermore, we demonstrate that optic ECM remodeling depends on BMP signaling in the placode. Together, our findings suggest that the lens placode plays an active role in remodeling the optic ECM during early eye development.

Downregulation of metallothionein 2A reduces migration, invasion and proliferation activities in human squamous cell carcinoma cells.

BACKGROUND: The invasive behaviour of squamous cell carcinoma (SCC), a common malignant tumour of the mouth, is a process mediated by cell proliferation, extracellular matrix proteolysis and other factors. Studies have shown a potential relationship between growth factors, metallothionein 2A (MT2A) and matrix metalloproteinase (MMP) activation in malignant tumours. The aim of this study was to downregulate MT2A in cells (Cal27) derived from human squamous cell carcinoma. METHODS: Cal27 cells with reduced MT2A were subjected to proliferation, migration and invasion assays. Immunofluorescence and western blot confirmed MT2A depletion by siRNA. Growth curve assays assessed cell proliferation. Indirect immunofluorescence analysed the expression of MT2A, MMP-2, MMP-9, epidermal growth factor (EGF), transforming growth factor alpha (TGF-α), tumour necrosis factor alpha (TNF-α) and Ki67. Zymography evaluated the effects of MT2A silencing on MMP-2 and -9 expression. Migration and invasion activities were evaluated using migration and invasion assays. RESULTS: CAL27 cells displayed MT2A, MMP-2, MMP-9, EGF, TGF-α, TNF-α and Ki67. MT2A depletion decreased MMP-9, EGF, TGF-α and Ki67 protein levels, while increasing TNF-α. CONCLUSIONS: MT2A downregulation reduced cell proliferation, migration and invasion activities. Therefore, MT2A has an important role in cell proliferation, migration and invasion in human oral SCC cells.

Progesterone decreases ovarian cancer cells migration and invasion.

The progression of cancer depends on the interaction between the cells and their microenvironment. Progesterone is a steroid and progestogen sex hormone produced by the corpus luteum, which is a transitory endocrine gland in female mammals and prepares the endometrium for implantation. Also, progesterone is involved in antitumorigenic process in different types of cancer. Our goal is to investigate the role of progesterone in cell invasion and migration. Ovarian cells were treated with different concentrations of progesterone. 500 nM or 1 µM progesterone decreased the migration of the cells in 24 h or less without affecting the viability. Immunoblot showed that treatment with 1 µM progesterone decreased the phosphorylated forms of Src and FAK, and the cells were less polarized. Our results suggest that progesterone interferes with migration and invasion of ovarian cells. Inhibitory experiments inferred the progesterone receptor playing a role in migration and invasion. Decreased phosphorylation of molecules involved in these processes was also found.

Laminin-derived peptide C16 regulates Tks expression and reactive oxygen species generation in human prostate cancer cells.

Laminin peptides influence cancer biology. We investigated the role of a laminin-derived peptide C16 regulating invadopodia molecules in human prostate cancer cells (DU145). C16 augmented invadopodia activity of DU145 cells, and stimulated expression Tks4, Tks5, cortactin, and membrane-type matrix metalloproteinase 1. Reactive oxygen species generation is also related to invadopodia formation. This prompted us to address whether C16 would induce reactive oxygen species generation in DU145 cells. Quantitative fluorescence and flow cytometry showed that the peptide C16 increased reactive oxygen species in DU145 cells. Furthermore, significant colocalization between Tks5 and reactive oxygen species was observed in C16-treated cells. Results suggested that the peptide C16 increased Tks5 and reactive oxygen species in prostate cancer cells. The role of C16 increasing Tks and reactive oxygen species are novel findings on invadopodia activity.

ADAMTS-1 disrupts HGF/c-MET signaling and HGF-stimulated cellular processes in fibrosarcoma.

Extracellular matrix (ECM) serves as a reservoir for biologically active factors, such as growth factors and proteases that influence the tumor cell behavior. ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a secreted protease that has the ability to modify the ECM during physiological and pathological processes. Here, we analyzed the role played by ADAMTS-1 regulating HGF and TGF-ß1 activities in the high-grade fibrosarcoma cell line (HT1080). We generated HT1080 and HEK293T cells overexpressing ADAMTS-1. HT1080 cells overexpressing ADAMTS-1 (HT1080-MPA) exhibited a significant decrease in cell proliferation and migration velocity, both in presence of HGF. We obtained similar results with ADAMTS-1-enriched conditioned medium from other cell type. However, ADAMTS-1 overexpression failed to affect TGF-ß1 activity associated with HT1080 cell proliferation and migration velocity. Immunoblotting showed that ADAMTS-1 overexpression disturbs c-Met activation upon HGF stimulation. Downstream ERK1/2 and FAK signaling pathways are also influenced by this protease. Additionally, ADAMTS-1 decreased the size of the fibrosarcospheres, both under normal conditions and in the presence of HGF. Likewise, in presence of HGF, ADAMTS-1 overexpression in HT1080 disrupted microtumors formation in vivo. These microtumors, including individual cells, presented characteristics of non-invasive lesions (rounded morphology). Our results suggest that ADAMTS-1 is involved in regulating HGF-related functions on fibrosarcoma cells. This protease may then represent an endogenous mechanism in controlling the bioavailability of different growth factors that have a direct influence on tumor cell behavior.

Role of HIF-1α and CASPASE-3 in cystogenesis of odontogenic cysts and tumors.

OBJECTIVES: Odontogenic cysts and tumors are the most relevant lesions that affect the gnathic bones. These lesions have in common the formation of cystic areas and this common feature may suggest involvement of similar mechanisms. The hypoxia inducible factor 1 alpha (HIF-1α), a responsive protein to hypoxia and caspase-3, an irreversible apoptosis marker, may contribute to cyst formation. Thus, this study aimed to investigate the immunoexpression of these proteins in odontogenic cysts and tumors. MATERIAL AND METHODS: Twenty cases of ameloblastoma, keratocystic odontogenic tumor (KOT) (n = 20), radicular cyst (RC) (n = 18), dentigerous cyst (DC) (n = 11), calcifying cystic odontogenic tumor (n = 8), and dental follicle (DF) (n = 10) were used to investigate HIF-1α and caspase-3 expression in sequential serial cuts by immunohistochemistry. RESULTS: HIF-1α was overexpressed in RC, DC, and ameloblastoma when compared with DF. The basal and sometimes the lower suprabasal layer showed no or very low expression in DC, KOT, and ameloblastoma, the last also showing strong expression in solid epithelial areas and initial cystic formation regions. Caspase-3 was found to be overexpressed in all lesions, with the highest expression in odontogenic cysts compared to tumors. HIF-1α and caspase-3 were localized in similar areas of the same lesions, especially in the epithelium surrounding cystic formations. CONCLUSIONS: This study showed distinct immunoexpression of HIF-1α and caspase-3 in odontogenic cyst and tumors, with higher expression observed in odontogenic cysts. CLINICAL RELEVANCE: These findings suggest a possible correlation between hypoxia, apoptosis, and cystogenesis, leading to understand the mechanisms responsible to cystic formation in odontogenic lesions.

The laminin-derived peptide C16 regulates GPNMB expression and function in breast cancer.

Breast cancer is an important public health problem, and its progression may be related to the extracellular matrix (ECM), which acts as a structural scaffold and instruction source for neoplastic cells. Laminins are ECM proteins regulating tumor biology. The laminin-derived peptide C16 regulates different properties of tumor cells. Here we analyzed C16-induced differential gene expression in MDA-MB-231 breast cancer cells. MCF-10A normal-like breast cells served as control. Among different cancer-related genes, C16 induced overexpression of GPNMB. This gene encodes a transmembrane protein GPNMB (glycoprotein non-metastatic B), involved with malignant phenotype of breast cancer cells. Immunoblot validated microarray results. To correlate gene and protein expression with cellular function, we investigated whether C16 would regulate invasion in breast cancer cells. siRNA experiments strongly suggested that C16 and GPNMB cooperate to regulate invasion of highly aggressive MDA-MB-231 cancer cells. We addressed regulatory mechanisms involved in C16-mediated increase of GPNMB protein levels in MDA-MB-231 cells, and observed that C16 stimulates ß1 integrin and Src phosphorylation. Furthermore, Src inhibition decreases peptide-induced GPNMB expression levels. To contextualize in vivo our results in vitro, we addressed GPNMB immunostaining in breast cancer human tissue microarrays. Quantitative immunohistochemistry showed that GPNMB is significantly more expressed in breast cancer compared to normal tissue. We concluded that laminin-derived peptide C16 regulates gene and protein expression of GPNMB in breast cancer cells. C16 and GPNMB may cooperate to regulate invasion of highly aggressive MDA-MB-231 cells, probably through Src signaling. GPNMB presented increased expression in breast cancer in vivo compared to normal breast tissue.

ADAMTS-1 Is Found in the Nuclei of Normal and Tumoral Breast Cells.

Proteins secreted in the extracellular matrix microenvironment (ECM) by tumor cells are involved in cell adhesion, motility, intercellular communication and invasion. The tumor microenvironment is expansively modified and remodeled by proteases, resulting in important changes in both cell-cell and cell-ECM interactions and in the generation of new signals from the cell surface. Metalloproteinases belonging to the ADAMTS (a disintegrin and metalloprotease with thrombospondin motifs) family have been implicated in tissue remodeling events observed in cancer development, growth and progression. Here we investigated the subcellular localization of ADAMTS-1 in normal-like (MCF10-A) and tumoral (MCF7 and MDA-MB-231) human breast cells. ADAMTS-1 is a secreted protease found in the extracellular matrix. However, in this study we show for the first time that ADAMTS-1 is also present in the nuclei and nucleoli of the three mammary cell lines studied here. Our findings indicate that ADAMTS-1 has proteolytic functions in the nucleus through its interaction with aggrecan substrate.

AHNAK enables mammary carcinoma cells to produce extracellular vesicles that increase neighboring fibroblast cell motility.

Extracellular vesicles play important roles in tumor development. Many components of these structures, including microvesicles and exosomes, have been defined. However, mechanisms by which extracellular vesicles affect tumor progression are not fully understood. Here, we investigated vesicular communication between mammary carcinoma cells and neighboring nontransformed mammary fibroblasts. Nonbiased proteomic analysis found that over 1% of the entire proteome is represented in these vesicles, with the neuroblast differentiation associated protein AHNAK and annexin A2 being the most abundant. In particular, AHNAK was found to be the most prominent component of these vesicles based on peptide number, and appeared necessary for their formation. In addition, we report here that carcinoma cells produce vesicles that promote the migration of recipient fibroblasts. These data suggest that AHNAK enables mammary carcinoma cells to produce and release extracellular vesicles that cause disruption of the stroma by surrounding fibroblasts. This paradigm reveals fundamental mechanisms by which vesicular communication between carcinoma cells and stromal cells can promote cancer progression in the tumor microenvironment.

Laminin-111 peptide C16 regulates invadopodia activity of malignant cells through ß1 integrin, Src and ERK 1/2.

Laminin peptides influence tumor behavior. In this study, we addressed whether laminin peptide C16 (KAFDITYVRLKF, γ1 chain) would increase invadopodia activity of cells from squamous cell carcinoma (CAL27) and fibrosarcoma (HT1080). We found that C16 stimulates invadopodia activity over time in both cell lines. Rhodamine-conjugated C16 decorates the edge of cells, suggesting a possible binding to membrane receptors. Flow cytometry showed that C16 increases activated ß1 integrin, and ß1 integrin miRNA-mediated depletion diminishes C16-induced invadopodia activity in both cell lines. C16 stimulates Src and ERK 1/2 phosphorylation, and ERK 1/2 inhibition decreases peptide-induced invadopodia activity. C16 also increases cortactin phosphorylation in both cells lines. Based on our findings, we propose that C16 regulates invadopodia activity over time of squamous carcinoma and fibrosarcoma cells, probably through ß1 integrin, Src and ERK 1/2 signaling pathways.

ß2-Adrenoceptor is involved in connective tissue remodeling in regenerating muscles by decreasing the activity of MMP-9.

We investigated the role of ß2-adrenoceptors in the connective tissue remodeling of regenerating muscles from ß2-adrenoceptor knockout (ß2KO) mice. Tibialis anterior muscles from ß2KO mice were cryolesioned and analyzed after 3, 10, and 21 days. Regenerating muscles from ß2KO mice showed a significant increase in the area density of the connective tissue and in the amount of collagen at 10 days compared with wild-type (WT) mice. A greater increase occurred in the expression levels of collagen I, III, and IV in regenerating muscles from ß2KO mice evaluated at 10 days compared with WT mice; this increase continued at 21 days, except for collagen III. Matrix metalloproteinase (MMP-2) activity increased to a similar extent in regenerating muscles from both ß2KO and WT mice at 3 and 10 days. This was also the case for MMP-9 activity in regenerating muscles from both ß2KO and WT mice at 3 days; however, at 10 days post-cryolesion, this activity returned to baseline levels only in WT mice. MMP-3 activity was unaltered in regenerating muscles at 10 days. mRNA levels of tumor necrosis factor-α increased in regenerating muscles from WT and ß2KO mice at 3 days and, at 10 days post-cryolesion, returned to baseline only in WT mice. mRNA levels of interleukin-6 increased in muscles from WT mice at 3 days post-cryolesion and returned to baseline at 10 days post-cryolesion but were unchanged in ß2KO mice. Our results suggest that the ß2-adrenoceptor contributes to collagen remodeling during muscle regeneration by decreasing MMP-9 activity.

EGFR signaling downstream of EGF regulates migration, invasion, and MMP secretion of immortalized cells derived from human ameloblastoma.

Ameloblastoma is an odontogenic tumor characterized by local invasiveness and frequent recurrence. The surrounding stroma, composed of different cell types and extracellular matrix (ECM), may influence ameloblastoma invasive behavior. Furthermore, tumor and stromal cells secrete matrix metalloproteases (MMPs), which, in turn, can modulate the matrix and promote the release of ECM-bound growth factors. Among these growth factors, epidermal growth factor (EGF) and its receptor, EGFR, have already been shown to stimulate MMP synthesis, suggesting that an interdependent mechanism, involving MMP activity and growth factors release, may contribute to tumor invasiveness. The aim of this study was to evaluate the effects of the EGF/EGFR signaling pathway on migration, invasion, and MMP activity, in a primary cell line derived from human ameloblastoma. We established and characterized a primary cell line (AME-1) from a human ameloblastoma sample. This cell line was transduced with human papillomavirus type 16 (HPV16) E6/E7 oncogenes, generating the AME-HPV continuous cell line. EGF, MMP2, and MMP9 expression in ameloblastoma biopsies and in the AME-HPV cell line was analyzed by immunohistochemistry and immunofluorescence, respectively. Migratory activity of EGF-treated AME-HPV cells was investigated using monolayer wound assays and Transwell chambers. EGF-induced invasion was assessed in Boyden chambers coated with Matrigel. Conditioned medium from EGF-treated cells was subjected to zymography. EGFR expression in AME-HPV cells was silenced by small interfering RNA (siRNA), to verify the relationship between this receptor and MMP secretion. Ameloblastoma samples and AME-HPV cells expressed EGF, EGFR, MMP2, and MMP9. AME-HPV cells treated with EGF showed increased rates of migration and invasion, as well as enhanced MMP2 and MMP9 activity. EGFR knockdown decreased MMP2 and MMP9 levels in AME-HPV cells. EGFR signaling downstream of EGF probably regulates migration, invasion, and MMP secretion of ameloblastoma-derived cells.

A novel cell line derived from pleomorphic adenoma expresses MMP2, MMP9, TIMP1, TIMP2, and shows numeric chromosomal anomalies.

Pleomorphic adenoma is the most common salivary gland neoplasm, and it can be locally invasive, despite its slow growth. This study aimed to establish a novel cell line (AP-1) derived from a human pleomorphic adenoma sample to better understand local invasiveness of this tumor. AP-1 cell line was characterized by cell growth analysis, expression of epithelial and myoepithelial markers by immunofluorescence, electron microscopy, 3D cell culture assays, cytogenetic features and transcriptomic study. Expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) was also analyzed by immunofluorescence and zymography. Furthermore, epithelial and myoepithelial markers, MMPs and TIMPs were studied in the tumor that originated the cell line. AP-1 cells showed neoplastic epithelial and myoepithelial markers, such as cytokeratins, vimentin, S100 protein and smooth-muscle actin. These molecules were also found in vivo, in the tumor that originated the cell line. MMPs and TIMPs were observed in vivo and in AP-1 cells. Growth curve showed that AP-1 exhibited a doubling time of 3.342 days. AP-1 cells grown inside Matrigel recapitulated tumor architecture. Different numerical and structural chromosomal anomalies were visualized in cytogenetic analysis. Transcriptomic analysis addressed expression of 7 target genes (VIM, TIMP2, MMP2, MMP9, TIMP1, ACTA2 e PLAG1). Results were compared to transcriptomic profile of non-neoplastic salivary gland cells (HSG). Only MMP9 was not expressed in both libraries, and VIM was expressed solely in AP-1 library. The major difference regarding gene expression level between AP-1 and HSG samples occurred for MMP2. This gene was 184 times more expressed in AP-1 cells. Our findings suggest that AP-1 cell line could be a useful model for further studies on pleomorphic adenoma biology.

Expression of molecules related to AKT pathway as putative regulators of ameloblastoma local invasiveness.

BACKGROUND: Ameloblastoma is an odontogenic neoplasm with local invasiveness and high recurrence. We previously suggested that growth factors, matrix metalloproteinases (MMPs), and TIMPs influence ameloblastoma invasiveness (Pathol. Res. Pract., 208, 2012, 225; Oral. Surg. Oral. Med. Oral. Pathol. Oral Radiol. Endod., 111, 2011, 474). Signals generated by this molecular network would be transduced by ERK 1/2 pathway (Oral. Surg. Oral. Med. Oral. Pathol. Oral Radiol. Endod., 111, 2011, 474). Others signaling pathways may influence ameloblastoma biology. Here, we studied expression of AKT and related molecules in ameloblastoma. METHODS: Fourteen cases of solid/multicystic ameloblastomas were examined. Immunohistochemistry was carried out to detected AKT (phospho-AKT), NF-қB (phospho-NF-қB), ß-catenin, cyclin-D1, and COX-2 in ameloblastoma samples. These molecules were evaluated in neoplastic cells and stroma. RESULTS: All proteins were detected in ameloblastoma. Expression of these markers was quantified and compared. Spearman's rank test was carried out to address positive correlations between proteins (P < 0.05). Ameloblastoma had a significant positive correlation of AKT (phospho-AKT) with ß-catenin. ß-catenin correlated with Cyclin-D1 and COX-2 in neoplastic cells. AKT (phospho-AKT) correlated with ß-catenin; ß-catenin with Cyclin-D1; AKT (phospho-AKT) with NF-қB (phospho-NF-қB); and NF-қB (phospho-NF-қB) with COX-2 in stromal cells. CONCLUSIONS: Results suggest that proteins studied are present and probably involved in a functional pathway in neoplastic cells and stroma and may therefore influence the local invasiveness of ameloblastoma.

Decreased expression of ADAMTS-1 in human breast tumors stimulates migration and invasion.

BACKGROUND: ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motifs) is a member of the ADAMTS family of metalloproteases. Here, we investigated mRNA and protein levels of ADAMTS-1 in normal and neoplastic tissues using qPCR, immunohistochemistry and immunoblot analyses, and we addressed the role of ADAMTS-1 in regulating migration, invasion and invadopodia formation in breast tumor cell lines. RESULTS: In a series of primary breast tumors, we observed variable levels of ADAMTS-1 mRNA expression but lower levels of ADAMTS-1 protein expression in human breast cancers as compared to normal tissue, with a striking decrease observed in high-malignancy cases (triple-negative for estrogen, progesterone and Her-2). This result prompted us to analyze the effect of ADAMTS-1 knockdown in breast cancer cells in vitro. MDA-MB-231 cells with depleted ADAMTS-1 expression demonstrated increased migration, invasion and invadopodia formation. The regulatory mechanisms underlying the effects of ADAMTS-1 may be related to VEGF, a growth factor involved in migration and invasion. MDA-MB-231 cells with depleted ADAMTS-1 showed increased VEGF concentrations in conditioned medium capable of inducing human endothelial cells (HUVEC) tubulogenesis. Furthermore, expression of the VEGF receptor (VEGFR2) was increased in MDA-MB-231 cells as compared to MCF7 cells. To further determine the relationship between ADAMTS-1 and VEGF regulating breast cancer cells, MDA-MB-231 cells with reduced expression of ADAMTS-1 were pretreated with a function-blocking antibody against VEGF and then tested in migration and invasion assays; both were partially rescued to control levels. CONCLUSIONS: ADAMTS-1 expression was decreased in human breast tumors, and ADAMTS-1 knockdown stimulated migration, invasion and invadopodia formation in breast cancer cells in vitro. Therefore, this series of experiments suggests that VEGF is involved in the effects mediated by ADAMTS-1 in breast cancer cells.

Matrix metalloproteinases, tissue inhibitors of metalloproteinases, and growth factors regulate the aggressiveness and proliferative activity of keratocystic odontogenic tumors.

OBJECTIVE: The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs). STUDY DESIGN: The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT). RESULTS: KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1. CONCLUSIONS: MMP-9, TIMP-2, EGF and transforming growth factor α act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT.

Laminin-111 derived peptides AG73 and C16 regulate invadopodia activity of a human adenoid cystic carcinoma cell line.

Adenoid cystic carcinoma is a frequently occurring malignant salivary gland neoplasm with high level of recurrence and distant metastasis long time after treatment. Metastatic tumor cells that actively migrate and invade surrounding tissues rely on invadopodia to degrade extracellular matrix (ECM) barriers. Invadopodia are actin-rich membrane protrusions that localize enzymes required for ECM degradation. Breakdown of ECM macromolecules releases fragments and bioactive peptides. We have already demonstrated that laminin-111 and its derived peptides regulate migration, invasion and protease activity of adenocarcinoma cells. Here we addressed the role of laminin-111 peptides AG73 and C16 in invadopodia activity of cells (CAC2) derived from human adenoid cystic carcinoma. CAC2 cells were treated by AG73 and C16, and subjected to fluorescent gelatin substrate degradation assay. In this assay invadopodia activity areas appear as black dots in a fluorescent background. Both peptides significantly increased invadopodia formation and activity compared to controls. We analyzed putative receptors and signaling pathways related to peptide effects. ß1 integrin silencing by siRNA decreased AG73- and C16-induced invadopodia. Furthermore inhibition of Rac1 and ERK signaling pathways decreased both C16- and AG73-related invadopodia activities. We propose that laminin-111 peptides AG73 and C16 increase invadopodia activity in CAC2 cells through ß1 integrin. Rac1 and ERK1/2 signaling pathways would transduce signals generated by both peptides.

Collagen hydrolysate intake increases skin collagen expression and suppresses matrix metalloproteinase 2 activity.

The effect of daily ingestion of collagen hydrolysate (CH) on skin extracellular matrix proteins was investigated. Four-week-old male Wistar rats were fed a modified AIN-93 diet containing 12% casein as the reference group or CH as the treatment group. A control group was established in which animals were fed a non-protein-modified AIN-93 diet. The diets were administered continuously for 4 weeks when six fresh skin samples from each group were assembled and subjected to extraction of protein. Type I and IV collagens were studied by immunoblot, and activities of matrix metalloproteinase (MMP) 2 and 9 were assessed by zymography. The relative amount of type I and IV collagens was significantly (P < .05) increased after CH intake compared with the reference diet group (casein). Moreover, CH uptake significantly decreased both proenzyme and active forms of MMP2 compared with casein and control groups (P < .05). In contrast, CH ingestion did not influence on MMP9 activity. These results suggest that CH may reduce aging-related changes of the extracellular matrix by stimulating anabolic processes in skin tissue.