Role of extracellular matrix on colonic cancer cell migration and proliferation

Recent Advances in Multicellular Tumor Spheroid Generation for Drug Screening

Multicellular tumor spheroids (MCTs) have been employed in biomedical fields owing to their advantage in designing a three-dimensional (3D) solid tumor model. For controlling multicellular cancer spheroids, mimicking the tumor extracellular matrix (ECM) microenvironment is important to understand cell-cell and cell-matrix interactions. In drug cytotoxicity assessments, MCTs provide better mimicry of conventional solid tumors that can precisely represent anticancer drug candidates' effects. To generate incubate multicellular spheroids, researchers have developed several 3D multicellular spheroid culture technologies to establish a research background and a platform using tumor modelingvia advanced materials science, and biosensing techniques for drug-screening. In application, drug screening was performed in both invasive and non-invasive manners, according to their impact on the spheroids. Here, we review the trend of 3D spheroid culture technology and culture platforms, and their combination with various biosensing techniques for drug screening in the biomedical field.

Migration of breast cancer cell lines in response to pulmonary laminin 332

Because tumor cell motility is a requirement for metastasis, we hypothesized that lung tissue harbors substances that induce tumor cell migration. MCF-7 breast carcinoma cells exposed to small airway epithelial cells and conditioned medium exhibited dose-dependent tumor cell migration. Among the extracellular matrix proteins in the conditioned medium identified by mass spectrometry, laminin 332 (LM332) had the greatest contribution to the migration of MCF-7 cells. Immunoblotting and immunohistochemistry for LM332-specific chains identified LM332 in the lung and in pulmonary epithelial cells. Antibodies to either LM332 or its integrin receptor inhibited MCF-7 motility, and knockdown of LM332 chains also reduced its migration-inducing activity. Taken together, these findings implicate LM332 as a component of lung tissue that can induce motility in breast carcinoma cells that have been transported to lung during metastasis. Earlier studies on LM332 in tumor progression have examined LM332 expression in tumor cells. This investigation, in comparison, provides evidence that the tumor promoting potential of LM332 may originate in the lung microenvironment rather than in tumor cells alone. Furthermore, this study provides evidence that the motility-inducing properties of the microenvironment can reside in epithelial cells. The findings raise the possibility that LM332 plays a role in the pulmonary metastases of breast carcinoma and may provide a target for antimetastasis therapy.

Genetic and Immunohistochemical Expression of Integrins ITGAV, ITGA6, and ITGA3 As Prognostic Factor for Colorectal Cancer: Models for Global and Disease-Free Survival

Objective

To evaluate the relationship between the expression profiles of 84 extracellular matrix (ECM) genes and the prognosis of patients with colorectal cancer (CRC).

Methods

This retrospective study included 114 patients with stage I–IV CRC who underwent primary tumour resection. Quantitative real-time PCR and immunohistochemistry assays were conducted using primary tumour samples. Kaplan-Meier survival curves were also generated to identify differences in global survival (GS) and disease-free survival (DFS) for the hypo- or hyperexpression status of each marker. The log-rank test was used to verify whether the differences were significant. Stepwise Cox regression models were also used to identify the risk factors associated with GS and DFS in a multivariate mode, and then were used to score the risk of death associated with each marker, either independently or in association.

Results

In the univariate analyses, significant differences in GS in relation to the expression profiles of ITGAV (p = 0.001), ITGA3 (p = 0.002), ITGA6 (p = 0.001), SPARC (p = 0.036), MMP9 (p = 0.034), and MMP16 (p = 0.038) were observed. For DFS, significant differences were observed in associated with ITGAV (p = 0.004) and ITGA3 (p = 0.001). However, only the ITGAV and ITGA6 gene markers for GS (hazard ratio (HR) = 3.209, 95% confidence interval (CI) = 1.412–7.293, p = 0.005 and HR = 3.105, 95% CI = 1.367–7.055, p = 0.007, respectively), and ITGA3 for DFS (HR = 3.806, 95% CI = 1.573–9.209, p = 0.003), remained in the final Cox regression models. A scoring system was developed to evaluate the risk of patient death based on the number of markers for the components of the final GS model. Scores of 0, 1, or 2 were associated with the following mean survival rates [CI]: 47.162 [44.613–49.711], 39.717 [35.471–43.964], 30.197 [24.030–36.327], respectively.

Conclusions

Multivariate mathematical models demonstrated an association between hyperexpression of the ITGAV and ITGA6 integrins and GS, and also between the ITGA3 integrin and DFS, in patients with colorectal tumours. A risk scoring system based on detected hyperexpression of 0, 1, or 2 markers (e.g., ITGAV and/or ITGA6) was also found to accurately correlate with the GS curves generated for the present cohort.

Collective cell migration of smooth muscle and endothelial cells: impact of injury versus non-injury stimuli

Background

Cell migration is a vital process for growth and repair. In vitro migration assays, utilized to study cell migration, often rely on physical scraping of a cell monolayer to induce cell migration. The physical act of scrape injury results in numerous factors stimulating cell migration – some injury-related, some solely due to gap creation and loss of contact inhibition. Eliminating the effects of cell injury would be useful to examine the relative contribution of injury versus other mechanisms to cell migration. Cell exclusion assays can tease out the effects of injury and have become a new avenue for migration studies. Here, we developed two simple non-injury techniques for cell exclusion: 1) a Pyrex® cylinder - for outward migration of cells and 2) a polydimethylsiloxane (PDMS) insert - for inward migration of cells. Utilizing these assays smooth muscle cells (SMCs) and human umbilical vein endothelial cells (HUVECs) migratory behavior was studied on both polystyrene and gelatin-coated surfaces.

Results

Differences in migratory behavior could be detected for both smooth muscle cells (SMCs) and endothelial cells (ECs) when utilizing injury versus non-injury assays. SMCs migrated faster than HUVECs when stimulated by injury in the scrape wound assay, with rates of 1.26 % per hour and 1.59 % per hour on polystyrene and gelatin surfaces, respectively. The fastest overall migration took place with HUVECs on a gelatin-coated surface, with the in-growth assay, at a rate of 2.05 % per hour. The slowest migration occurred with the same conditions but on a polystyrene surface at a rate of 0.33 % per hour.

Conclusion

For SMCs, injury is a dominating factor in migration when compared to the two cell exclusion assays, regardless of the surface tested: polystyrene or gelatin. In contrast, the migrating surface, namely gelatin, was a dominating factor for HUVEC migration, providing an increase in cell migration over the polystyrene surface. Overall, the cell exclusion assays - the in-growth and out-growth assays, provide a means to determine pure migratory behavior of cells in comparison to migration confounded by cell wounding and injury.

Electronic supplementary material

The online version of this article (doi:10.1186/s13036-015-0015-y) contains supplementary material, which is available to authorized users.

Ring cell migration assay identifies distinct effects of extracellular matrix proteins on cancer cell migration

Background

Alterations in cell migration are a hallmark of cancer cell invasion and metastasis. In vitro assays commonly used to study cell migration, including the scratch wound healing assay, Boyden chamber assay, and newly developed advanced systems with microfluidics, each have several disadvantages.

Findings

Here we describe an easy and cost-effective in vitro assay for cell migration employing cloning rings to create gaps in the cell monolayer (“ring cell migration assay”). The assay was used to quantitate innate differences in cell motility and the effect of various extracellular matrix proteins on migration of five cancer cell lines: U87 and U251N glioma cells, MDA-MB-231and MCF-7 breast cancer cells, and HeLa cervical cancer cells. Interestingly, collagen was a general promoter of cell migration for all five cancer cell lines, without affecting cell proliferation.

Conclusions

Taken together, the ring cell migration assay is an easy, convenient and cost-effective assay to study cell migration in vitro.

Chemoattraction of progenitor cells by remodeling extracellular matrix scaffolds

The chemotactic properties of a biologic scaffold composed of extracellular matrix (ECM) and subjected to in vivo degradation and remodeling were evaluated in a mouse model of Achilles tendon reconstruction. Following a segmental resection of the Achilles tendon in both C57BL/6 and MRL/MpJ mice, the defect was repaired with either an ECM scaffold composed of urinary bladder matrix (UBM) or resected autologous tendon. The surgically repaired and the contralateral tendons were harvested at 3, 7, and 14 days following surgery from each animal. Chemotaxis of multipotential progenitor cells toward the harvested tissue was quantified using a fluorescent-based cell migration assay. Results showed greater migration of progenitor cells toward tendons repaired with UBM-ECM scaffold compared to both the tendons repaired with autologous tissue and the normal contralateral tendon in both the MRL/MpJ and C57BL/6 mice. The magnitude and temporal pattern of the chemotactic response differed between the two mouse strains.

Is there a genetic signature for liver metastasis in colorectal cancer?

Even though liver metastasis accounts for the vast majority of cancer deaths in patients with colorectal cancer (CRC), fundamental questions about the molecular and cellular mechanisms of liver metastasis still remain unanswered. Determination of gene expression profiles by microarray technology has improved our knowledge of CRC molecular pathways. However, defined gene signatures are highly variable among studies. Expression profiles and molecular markers have been specifically linked to liver metastases mechanistic paths in CRC. However, to date, none of the identified signatures or molecular markers has been successfully validated as a diagnostic or prognostic tool applicable to routine clinical practice. To obtain a genetic signature for liver metastasis in CRC, measures to improve reproducibility, to increase consistency, and to validate results need to be implemented. Alternatives to expression profiling with microarray technology are continuing to be used. In the recent past, many genes codifying for proteins that are directly or indirectly involved in adhesion, invasion, angiogenesis, survival and cell growth have been linked to mechanisms of liver metastases in CRC.

Differential effects of matrix and growth factors on endothelial and fibroblast motility: application of a modified cell migration assay

Cell migration is crucial in virtually every biological process and strongly depends on the nature of the surrounding matrix. An assay that enables real-time studies on the effects of defined matrix components and growth factors on cell migration is not available. We have set up a novel, quantitative migration assay, which enables unharmed cells to migrate along a defined matrix. Here, we used this so-called barrier-assay to define the contribution of fibronectin (FN) and Collagen-I (Col-I) to vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and lysophosphatidic acid (LPA)-induced cell migration of endothelial cells (EC) and fibroblasts. In EC, both FN and Col-I stimulated migration, but FN-induced motility was random, while net movement was inhibited. Addition of bFGF and VEGF overcame the effect of FN, with VEGF causing directional movement. In contrast, in 3T3 fibroblasts, FN stimulated motility and this effect was enhanced by bFGF. This motility was more efficient and morphologically completely different compared to LPA stimulation. Strikingly, directional migration of EC was not paralleled by higher amounts of stable microtubules (MT) or an increased reorientation of the microtubule-organizing centre (MTOC). For EC, the FN effect appeared concentration dependent; high FN was able to induce migration, while for fibroblasts both low and high concentrations of FN induced motility. Besides showing distinct responses of the different cells to the same factors, these results address contradictive reports on FN and show that the interplay between matrix components and growth factors determines both pattern and regulation of cell migration. J. Cell. Biochem. 99: 1536-1552, 2006. (c) 2006 Wiley-Liss, Inc.

Colorectal cancer: genetics of development and metastasis

It has been well documented that there are two major pathways in colorectal carcinogenesis. One is the chromosomal instability pathway (adenoma-carcinoma sequence), which is characterized by allelic losses on chromosome 5q (APC), 17p (p53), and 18q (DCC/SMAD4), and the other is a pathway that involves microsatellite instability. Recent progress in molecular biology, however, has shown that colorectal carcinogenesis is not necessarily clearly divided into these two pathways, but is in fact more complicated. Other routes, including the transforming growth factor-beta/SMAD pathway, the serrated pathway, and the epigenetic pathway, have been reported. Cross talk among these pathways has also been reported. In the invasion and metastasis steps of colorectal cancers, many more genes have now been identified as being involved in proteolysis, adhesion, angiogenesis, and cell growth. Recently accumulated evidence indicates that colorectal cancer is a genetically heterogeneous and complicated disease.

Antitumor and antimetastatic effect of warfarin and heparins

Experimental and clinical studies have shown an anticancer effect of anticoagulant drugs. The aim of this study is to review the mechanisms by which the common types of anticoagulants influence the primary tumor and metastatic processes of solid tumors. The review evaluates the interference of unfractionated heparin (UFH), low molecular weight heparin (LMWH) and warfarin on the growth of primary tumors and on the development of metastases. The first part of the review evaluates the effect on the growth and development of primary tumors. Attention is paid to the interference with proliferation of cancer cells, tumor angiogenesis and to the interference with the immune system. The second part of the review describes the metastatic process and the effect of anticoagulants on the cell motility and cancer cell adhesion. The third part refers to the outcomes of clinical studies with anticoagulant treatment in patients with cancer. The problem of thromboembolic disease in patients with advanced cancer is also mentioned. The anticoagulants are more effective in inhibition of stages of the metastatic cascade than in the influence on primary tumors. They can interfere with tumor angiogenesis, immunity system, cancer cell motility and adhesion. The first clinical trials showed an effect on the development of primary tumors and survival of patients namely with lung cancer.

Simultaneous changes in the function and expression of beta 1 integrins during the growth arrest of poorly differentiated colorectal cells (LISP-1)

Cells usually lose adhesion and increase proliferation and migration during malignant transformation. Here, we studied how proliferation can affect the other two characteristics, which ultimately lead to invasion and metastasis. We determined the expression of beta 1 integrins, as well as adhesion and migration towards laminin-1, fibronectin, collagens type I and type IV presented by LISP-1 colorectal cancer cells exposed to 2.5% dimethyl sulfoxide (DMSO), an agent capable of decreasing proliferation in this poorly differentiated colorectal cell line. Untreated cells (control), as shown by flow cytometry and monoclonal antibodies, expressed alpha 2 (63.8 11.3% positive cells), alpha 3 (93.3 7.0%), alpha 5 (50.4 12.0%) and alpha 6 (34.1 4.9%) integrins but not alpha1, alpha 4, alpha v or 4. Cells adhered well to laminin-1 (73.4 6.0%) and fibronectin (40.0 2.0%) substrates but very little to collagens. By using blocking monoclonal antibodies, we showed that alpha 2, alpha 3 and alpha 6 mediated laminin-1 adhesion, but neither alpha 3 nor alpha 5 contributed to fibronectin adherence. DMSO arrested cells at G0/G1 (control: 55.0 2.4% vs DMSO: 70.7 2.5%) while simultaneously reducing alpha 5 (24.2 19%) and alpha 6 (14.3 10.8%) expression as well as c-myc mRNA (7-fold), the latter shown by Northern blotting. Although the adhesion rate did not change after exposure to DMSO, alpha 3 and alpha 5 played a major role in laminin-1 and fibronectin adhesion, respectively. Migration towards laminin-1, which was clearly increased upon exposure to DMSO (control: 6 2 cells vs DMSO: 64 6 cells), was blocked by an antibody against alpha 6. We conclude that the effects of DMSO on LISP-1 proliferation were accompanied by concurrent changes in the expression and function of integrins, consequently modulating adhesion/migration, and revealing a complex interplay between function/expression and the proliferative state of cells.

Strategies for the purification of laminin-10 for studies on colon cancer metastasis

Signals from the epidermal growth factor (EGF) receptor family are thought to combine with integrin-dependent adhesion to laminins to contribute to disease progression and metastasis in cancer. To date, little is known about the mechanisms by which these signals interact. Recently, we have shown that the colon cancer cell line LIM1215 secretes and adheres to laminin-10 through multiple integrin receptors, and that EGF stimulates spreading and migration of these cells on the same substrate. Additionally laminin-10/11 has been shown by immunohistochemistry to be present at the invasive edge of moderately differentiated colon cancers. To enable detailed structure-function studies to be undertaken, it is important to be able to rapidly obtain highly purified native laminin-10 from bulk biological samples in reasonable yield. The development of a multidimensional micropurification scheme to achieve this is presented and compared with other reported methods for the purification of laminins.

Expression of the ets-1 proto-oncogene in human colorectal carcinoma

The proto-oncogene, ets-1, is a transcription factor known to control the expression of a number of genes involved in extracellular matrix remodeling and has been postulated to play a role in cell migration and tumor invasion. To elucidate the involvement of ets-1 in human colorectal carcinomas, we examined 41 cases of colorectal adenoma and 122 cases of colorectal carcinoma by immunohistochemistry and compared the degree of Ets-1 expression with the depth of carcinoma invasion. In adenomas, 12 of 41 cases (29.3%) showed immuno-positivity for Ets-1. 12 of 27 cases (44.4%) of adenoma with high grade dysplasia showed immunopositivity for Ets-1. However, there was no positive case in low or moderate dysplasia of adenoma. In contrast, 103 of 122 cases (84.4%) of colorectal adenocarcinoma showed immunoreactivity for Ets-1 in the carcinoma cells themselves. We investigated the relationship between pathological features in colorectal carcinoma and Ets-1 immunoreactivity of the tumor cells. Among the 122 cases of invasive carcinomas, Ets-1 immunoreactivity was significantly correlated with the depth grading of tumor invasion (P < .0001), the presence of lymph node metastasis (P < .05), lymphatic invasion (P < .01) and venous invasion (P < .05). However, Ets-1 expression did not correlate with histological differentiation. In situ hybridization also confirmed the presence of ets-1 mRNA in colorectal carcinomas. Expression of ets-1 mRNA was also detected in two of three human colorectal carcinoma tissues and in four of six different kinds of carcinoma cell lines by the reverse transcription polymerase chain reaction method. These findings suggest that the expression of Ets-1 is one of the important factors related to carcinogenesis and/or tumor invasion of colorectal carcinoma.

Prevention of entrance into G2 cell cycle phase by mimosine decreases locomotion of cells from the tumor cell line SW480

Cellular proliferation of tumor cells is thought to impede migratory activity. Using continuous single cell migration analysis of the colon carcinoma cell line SW480 for up to 72 h, we were able to show that cells locomote constantly and stop only for actual cell division. These findings indicate that proliferation (from G1 phase to early mitosis) and migration do occur simultaneously. The presence of the cell cycle marker Ki-67 in individual migrating cells substantiated this observation. Inhibition of cell cycle progression by mimosine (MIM), a reversible cell cycle blocker, reduced the percentage of migrating cells; release from MIM block restored migratory capacity. The corresponding cell cycle phase distributions were confirmed by flow cytometry. In our test system cell cycle events and migration were shown to occur at the same time. Interference with cell cycle progression reduced migratory activity indicating that migration depends on an unhampered cell cycle.

Colon cancer cells adhesion and spreading on autocrine laminin-10 is mediated by multiple integrin receptors and modulated by EGF receptor stimulation

Epidermal growth factor (EGF) receptor ligands such as EGF and transforming growth factor-alpha (TGF-alpha) play an important role in controlling the proliferation, survival, morphology, and motility of colonic epithelial cells. There is also increasing evidence that growth factors and extracellular matrix (ECM) proteins cooperate to regulate these cellular processes. We have reported previously that autocrine TGF-alpha and an unidentified ECM protein in the serum-free conditioned medium of the human colon carcinoma cell line LIM1215 synergize to induce spreading of these cells in low-density cultures. We have now purified the ECM protein secreted by LIM1215 cells and show that it synergizes with EGF to induce spreading of LIM1215 cells and other human cell lines from the colon and other tissues. The purified ECM migrated as a single protein band with an apparent molecular mass of approximately 800 kDa on SDS-PAGE under nonreducing conditions and, under reducing conditions, as three protein bands of approximately 360, 210, and 200 kDa. Immunoblotting experiments and mass spectrometry analysis of tryptic digests on the purified protein identified the 360-, 210-, and 200-kDa protein bands as laminin alpha5, beta1, and gamma1 chains, respectively, indicating that LIM1215 cells secrete laminin-10 (alpha5 beta1 gamma1). In serum-free medium, LIM1215 cells adhere to laminin-10 primarily via alpha2 beta1 and alpha3 beta1 integrin receptors. EGF-induced spreading of LIM1215 cells on laminin-10 is partially inhibited by pretreatment of the cells with blocking antibodies directed against integrin alpha3 or beta1 but not alpha2, alpha6, or beta4 subunits. Spreading is almost completely inhibited by blocking alpha3 + alpha2, alpha3 + alpha6, or beta1 + beta4 integrin chains and results in cell death. Increased spreading in the presence of EGF correlates with up-regulation of alpha6 beta4 integrins in these cells after exposure to EGF. These results indicate that colon cancer cells attach and spread on laminin-10 via multiple integrin receptors and suggest a critical role for alpha3 beta1 integrins in the spreading response. Together, our results support the concept that the adhesive properties of colon cancer cells are modulated by autocrine production of TGF-alpha and laminin-10 and autocrine induction of appropriate integrins.

Influence of laminin substratum on cell proliferation and CALC I gene expression in medullary thyroid carcinoma C cell lines

Medullary thyroid carcinoma (MTC) originates from C cells, which secrete calcitonin (CT) and CT gene-related peptide (CGRP), the two splice peptide products of the CALC I gene. Normal and hyperplastic C cells are intrafollicular, in contact with the basement membrane (BM) that is maintained around the differentiated tumors. To investigate the relationships between MTC evolution and BM constituents, we examined the modifications induced by laminin-1 and -2 (merosin), two isoforms colocalized in the follicular BM, on three MTC cell lines: murine rMTC 6-23 and CA-77 cells, and human TT cells. Laminin exerted a mitogenic activity on rMTC 6-23 and on TT cells, causing a concurrent decrease in both CT and CGRP mRNA levels and production of the peptides. Conversely, laminin reduced the proliferation rate and enhanced CGRP synthesis and secretion in CA-77 cells. This antiproliferative response, which coincides with an increase in differentiation markers, is comparable to that reported in normal cells and also in the neoplastic Caco-2 cell line. This suggests that laminin could exert opposite effects depending on the stage of tumor evolution.

Protein kinases C-gamma and -delta are involved in insulin-like growth factor I-induced migration of colonic epithelial cells

BACKGROUND & AIMS

The mechanisms by which epithelial cells migrate during the repair of damaged colonic mucosa are poorly understood. This study investigated the insulin-like growth factor I (IGF-I) signaling pathway leading to HT29-D4 human colonic epithelial cell line migration.

METHODS

IGF-stimulated cell migration was determined using a wound model in the presence or absence of kinase inhibitors. Activation of protein kinase C (PKC) was determined by immunodetection.

RESULTS

IGF-I and insulin induce cell migration without affecting cell proliferation through their cognate receptors. Des(1-3)-IGF-I, a truncated analogue of IGF-I, was more potent than IGF-I, suggesting that IGF-binding proteins secreted in the medium modulated IGF-I-induced cell migration. Inhibition of phosphatidylinositol 3-kinase, PKC, and mitogen-activated protein kinases eliminated cell restitution. Long-term exposure of cells to phorbol myristate acetate caused the depletion of PKC-delta and -gamma and prevented also IGF-I-induced cell motility. IGF-I also induced activation of PKC-delta and -gamma only.

CONCLUSIONS

IGF-I stimulates colonic restitution through the activation of multiple signaling pathways including activation of phosphatidylinositol 3-kinase, PKC-delta and -gamma, and mitogen-activated protein kinases.

The role of the cytoskeleton in migration and proliferation of a cultured human gastric cancer cell line using a new metastasis model

Using an in vitro model for investigating the mechanism of migration and proliferation of a cultured human gastric cancer cell line which we established recently, we studied the suppressive effect of inhibitors of the cytoskeleton proteins, actin and myosin, on the migration and proliferation of cancer cells. These inhibitors suppressed the capacity of cancer cells to migrate and proliferate dose-dependently. Thus the integrity of the cytoskeletal system may play an important role in the mechanism of metastasis of gastric cancer cells.