Human Tumor Tissue-Based 3D In Vitro Invasion Assays

Monastrol suppresses invasion and metastasis in human colorectal cancer cells by targeting fascin independent of kinesin-Eg5 pathway

Rearrangement of the actin cytoskeleton is a prerequisite for carcinoma cells to develop cellular protrusions, which are required for migration, invasion, and metastasis. Fascin is a key protein involved in actin bundling and is expressed in aggressive and invasive carcinomas. Additionally, fascin appears to be involved in tubulin-binding and microtubule rearrangement. Pharmacophoric-based in silico screening was performed to identify compounds with better fascin inhibitory properties than migrastatin, a gold-standard fascin inhibitor. We hypothesized that monastrol displays anti-migratory and anti-invasive properties via fascin blocking in colorectal cancer cell lines. Biophysical (thermofluor and ligand titration followed by fluorescence spectroscopy), biochemical (NMR), and cellular assays (MTT, invasion of human tissue), as well as animal model studies (zebrafish invasion) were performed to characterize the inhibitory effect of monastrol on fascin activity. In silico analysis revealed that monastrol is a potential fascin-binding compound. Biophysical and biochemical assays demonstrated that monastrol binds to fascin and interferes with its actin-bundling activity. Cell culture studies, including a 3D human myoma disc model, showed that monastrol inhibited fascin-driven cytoplasmic protrusions as well as invasion. In silico, confocal microscopy, and immunoprecipitation assays demonstrated that monastrol disrupted fascin-tubulin interactions. These anti-invasive effects were confirmed in vivo. In silico confocal microscopy and immunoprecipitation assays were carried out to test whether monastrol disrupted the fascin-tubulin interaction. This study reports, for the first time, the in vitro and in vivo anti-invasive properties of monastrol in colorectal tumor cells. The number and types of interactions suggest potential binding of monastrol across actin and tubulin sites on fascin, which could be valuable for the development of antitumor therapies.

Novel human lymph node-derived matrix supports the adhesion of metastatic oral carcinoma cells

BACKGROUND

3D culture is increasingly used in cancer research, as it allows the growth of cells in an environment that mimics in vivo conditions. Metastases are the primary cause of morbidity and mortality in cancer patients, and solid tumour metastases are mostly located in lymph nodes. Currently, there are no techniques that model the pre-metastatic lymph node microenvironment in vitro. In this study, we prepared a novel extracellular matrix, Lymphogel, which is derived from lymph nodes, mimicking the tumour microenvironment (TME) of metastatic carcinoma cells. We tested the suitability of the new matrix in various functional experiments and compared the results with those obtained using existing matrices.

METHODS

We used both commercial and patient-derived primary and metastatic oral tongue squamous cell carcinoma (OTSCC) cell lines. We characterized the functional differences of these cells using three different matrices (human uterine leiomyoma-derived Myogel, human pre-metastatic neck lymph node-derived Lymphogel (h-LG), porcine normal neck lymph node-derived Lymphogel (p-LG) in proliferation, adhesion, migration and invasion assays. We also performed proteomic analyses to compare the different matrices in relation to their functional properties.

RESULTS

OTSCC cells exhibited different adhesion and invasion patterns depending on the matrix. Metastatic cell lines showed improved ability to adhere to h-LG, but the effects of the matrices on cell invasion fluctuated non-significantly between the cell lines. Proteomic analyses showed that the protein composition between matrices was highly variable; Myogel contained 618, p-LG 1823 and h-LG 1520 different proteins. The comparison of all three matrices revealed only 120 common proteins. Analysis of cellular pathways and processes associated with proteomes of each matrix revealed similarities of Myogel with h-LG but less with p-LG. Similarly, p-LG contained the least adhesion-related proteins compared with Myogel and h-LG. The highest number of unique adhesion-related proteins was present in h-LG.

CONCLUSIONS

We demonstrated that human pre-metastatic neck lymph node-derived matrix is suitable for studying metastatic OTSCC cells. As a whole-protein extract, h-LG provides new opportunities for in vitro carcinoma cell culture experiments.

Cholesterol depletion affects caveolin-1 expression, migration and invasion of oral tongue squamous cell carcinoma cell lines

INTRODUCTION

Cholesterol is a key lipid molecule within cell membranes. This is especially true in cavelolas, invaginated membrane nanodomains, which present the protein caveolin-1 (CAV-1). It is important to note that this structure is involved in many cell signalling pathways. Additionally, high cholesterol is seen in different tumor types but little is known in regards to oral tongue squamous cell carcinoma (OTSCC). The aim of this study was to evaluate the influence of cholesterol depletion on primary (SCC-25) and metastatic (HSC-3) OTSCC cell lines.

MATERIALS AND METHODS

Cell membrane fluidity, cell viability, gene and protein expression of CAV-1 and of epithelial-mesenchymal transition (EMT) markers, cell migration in Myogel and invasion-myoma assay were evaluated after cholesterol depletion with methyl-β-cyclodextrin (MβCD - 7.5, 10 or 15 mM) RESULTS: Decreased cell viability and increased membrane fluidity of SCC-25 cells was seen with cholesterol depletion but cell viability was less affected and there was no effect on membrane fluidity in HSC-3. Cholesterol depletion also decreased CAV-1 at 6 h but increased it after 24 h.; both epithelial and mesenchymal EMT genes were upregulated after 6 h, followed by downregulation at 24 h in SCC-25. In HSC-3, CAV-1 was downregulated, and E-cadherin gene (ECAD) was upregulated at 6 h. Only the protein β-catenin in SCC-25 was affected, and cell migration of both cell lines was decreased, affecting SCC-25 more intensely. The invasive capacity within human myoma organotypic model was increased in SCC-25 and decreased in HSC-3.

CONCLUSION

Cholesterol depletion affects CAV-1 and ECAD inversely. This affect also depends on cell type since the invasive capacity was augmented in primary cells while decreased in metastatic cells.

Altered glycosylation of several metastasis-associated glycoproteins with terminal GalNAc defines the highly invasive cancer cell phenotype

Several distinct metastasis-associated glycosylation changes have been shown to promote cancer cell invasion and metastasis, the main cause of death of cancer patients. However, it is unclear whether their presence reflects cell- or tissue-specific variations for metastasis, or species needed to drive different phases of the metastatic cascade. To address this issue from a different perspective, we investigated here whether different cancer cell lines share any glycotopes that are common and important for their invasive phenotype. By using lectin microarray glycan profiling and an established myoma tissue-based 3D invasion assay, we identified a single glycotope recognized by Helix Pomatia agglutinin (HPA), whose expression level in different cancer cells correlated significantly with their invasive potential. Lectin pull-down assay and LC-MS/MS analysis in highly- (A431 and SW-48) and poorly invasive (HepG2 and RCC4) cancer cells revealed ~85 glycoproteins of which several metastasis-promoting members of the integrin family of cell adhesion receptors, the epidermal growth factor receptor (EGFR) and the matrix metalloproteinase-14 (MMP-14) were among the abundant ones. Moreover, we showed that the level of the GalNAc glycotope in MMP-14, EGFR, αV-, β1- and β4 integrin in highly and poorly invasive cancer cells correlated positively with their invasive potential. Collectively, our findings suggest that altered glycosylation of several metastasis-associated glycoproteins with terminal GalNAc drives the highly invasive cancer cell phenotype.

SLC4A2 anion exchanger promotes tumour cell malignancy via enhancing net acid efflux across golgi membranes

Proper functioning of each secretory and endocytic compartment relies on its unique pH micro-environment that is known to be dictated by the rates of V-ATPase-mediated H⁺ pumping and its leakage back to the cytoplasm via an elusive "H⁺ leak" pathway. Here, we show that this proton leak across Golgi membranes is mediated by the AE2a (SLC4A2a)-mediated bicarbonate-chloride exchange, as it is strictly dependent on bicarbonate import (in exchange for chloride export) and the expression level of the Golgi-localized AE2a anion exchanger. In the acidic Golgi lumen, imported bicarbonate anions and protons then facilitate a common buffering reaction that yields carbon dioxide and water before their egress back to the cytoplasm via diffusion or water channels. The flattened morphology of the Golgi cisternae helps this process, as their high surface-volume ratio is optimal for water and gas exchange. Interestingly, this net acid efflux pathway is often upregulated in cancers and established cancer cell lines, and responsible for their markedly elevated Golgi resting pH and attenuated glycosylation potential. Accordingly, AE2 knockdown in SW-48 colorectal cancer cells was able to restore these two phenomena, and at the same time, reverse their invasive and anchorage-independent growth phenotype. These findings suggest a possibility to return malignant cells to a benign state by restoring Golgi resting pH.

Adipose-Derived Mesenchymal Stem Cells do not Affect the Invasion and Migration Potential of Oral Squamous Carcinoma Cells

Mesenchymal stem cells (MSCs) are commonly isolated from bone marrow and adipose tissue. Depending on the tissue of origin, MSCs have different characteristics and physiological effects. In various cancer studies, MSCs have been found to have either tumor-promoting or tumor-inhibiting action. This study investigated the effect of adipose tissue-MSCs (AT-MSCs) and bone marrow-MSCs (BM-MSCs) on global long interspersed nuclear element-1 (LINE-1) methylation, the expression level of microenvironment remodeling genes and cell proliferation, migration and invasion of oral tongue squamous cell carcinoma (OTSCC). Additionally, we studied the effect of human tongue squamous carcinoma (HSC-3)-conditioned media on LINE-1 methylation and the expression of microenvironment remodeling genes in AT-MSCs and BM-MSCs. Conditioned media from HSC-3 or MSCs did not affect LINE-1 methylation level in either cancer cells or MSCs, respectively. In HSC-3 cells, no effect of MSCs-conditioned media was detected on the expression of ICAM1, ITGA3 or MMP1. On the other hand, HSC-3-conditioned media upregulated ICAM1 and MMP1 expression in both types of MSCs. Co-cultures of AT-MSCs with HSC-3 did not induce proliferation, migration or invasion of the cancer cells. In conclusion, AT-MSCs, unlike BM-MSCs, seem not to participate in oral cancer progression.

Human myoma tissue-based extracellular matrix models for testing the effects of irradiation on the HPV positive cells

Background

This study was designed to investigate the invasion of human papillomavirus (HPV) positive human cervical carcinoma cell lines in human leiomyoma-based extracellular matrices in vitro, and to test the suitability of the model for studying the irradiation effects on the cancer cell invasion.

Methods

HPV positive cervical carcinoma cell lines SiHa and CaSki, and HPV negative squamous cell carcinoma cell line HSC-3 were used. CaSki cells contain around 600 copies of HPV 16 virus in the genome, whereas SiHa have only 1–2 copies per cell. Cells were analyzed using two different human tumor derived extracellular matrix methods (3D myoma disc model, and Myogel Transwell invasion assay). Cultures were irradiated with 4 Gy. Myoma invasion area and the depth of invasion were measured with ImageJ 1.51j8 software. Statistical analyses were performed with SPSS Statistics (IBM SPSS® Statistics 25).

Results

All cells invaded through Myogel coated Transwell membranes and within myoma discs. In myoma discs, a difference in the invasion depth (p = 0.0001) but not in invasion area (p = 0.310) between the HPV positive cell lines was seen, since SiHa (less HPV) invaded slightly better than CaSki (more HPV). HSC-3 cells (HPV negative) invaded deepest (p = 0.048) than either of the HPV positive cell line cells. No difference was detected in the invasion area (p = 0.892) between HPV positive and HPV negative cells. The ionized radiation significantly reduced the invasion depth of HSC-3 (p = 0.008), SiHa (p = 0.0001) and CaSki (p = 0.005). No significant effect on the invasion area was detected in any of the cell lines. However, a significant difference was observed between SiHa and CaSki in the reduction of the invasion depth after radiation (p = 0.013) as the reduction was greater with SiHa than CaSki.

Conclusions

Both solid and gelatinous human leiomyoma-based extracellular matrix models were suitable platforms to study the invasion of HPV positive cervical carcinoma cells in vitro. SiHa cells with less HPV copy number cells invaded slightly better and were slightly more sensitive to irradiation than CaSki cells with high HPV copy number. However, there was no drastic differences between the invasion properties of these carcinoma cells.

New role of the antidepressant imipramine as a Fascin1 inhibitor in colorectal cancer cells

Serrated adenocarcinoma (SAC) is more invasive, has worse outcomes than conventional colorectal carcinoma (CRC), and is characterized by frequent resistance to anti-epidermal growth factor receptor (EGFR) and overexpression of fascin1, a key protein in actin bundling that plays a causative role in tumor invasion and is overexpressed in different cancer types with poor prognosis. In silico screening of 9591 compounds, including 2037 approved by the Food and Drug Administration (FDA), was performed, and selected compounds were analyzed for their fascin1 binding affinity by differential scanning fluorescence. The results were compared with migrastatin as a typical fascin1 inhibitor. In silico screening and differential scanning fluorescence yielded the FDA-approved antidepressant imipramine as the most evident potential fascin1 blocker. Biophysical and different in vitro actin-bundling assays confirm this activity. Subsequent assays investigating lamellipodia formation and migration and invasion of colorectal cancer cells in vitro using 3D human tissue demonstrated anti-fascin1 and anti-invasive activities of imipramine. Furthermore, expression profiling suggests the activity of imipramine on the actin cytoskeleton. Moreover, in vivo studies using a zebrafish invasion model showed that imipramine is tolerated, its anti-invasive and antimetastatic activities are dose-dependent, and it is associated with both constitutive and induced fascin1 expression. This is the first study that demonstrates an antitumoral role of imipramine as a fascin1 inhibitor and constitutes a foundation for a molecular targeted therapy for SAC and other fascin1-overexpressing tumors.

The antidepressant drug imipramine can block the activity of a protein that contributes to the progression of certain aggressive tumors. Serrated adenocarcinoma (SAC) is a form of colorectal cancer with a poor prognosis. A key factor in SAC development is the overexpression of the protein fascin1, which promotes the formation of structures that help cancer cells move around, thereby leading to metastasis. Pablo Conesa-Zamora at Santa Lucia University Hospital in Cartagena, Horacio Pérez-Sánchez at the Universidad Católica de Murcia in Guadalupe, Spain, and coworkers demonstrated that imipramine shows promise in binding to fascin1 and blocking its activity. The team analyzed over 9500 compounds as potential fascin1 blockers, identifying imipramine as a possible option. In tests on human tissues and in vivo studies using zebrafish, the drug reduced cancer invasion and metastasis.

Novel anti-invasive properties of a Fascin1 inhibitor on colorectal cancer cells

Tumor invasion and metastasis involve processes in which actin cytoskeleton rearrangement induced by Fascin1 plays a crucial role. Indeed, Fascin1 has been found overexpressed in tumors with worse prognosis. Migrastatin and its analogues target Fascin1 and inhibit its activity. However, there is need for novel and smaller Fascin1 inhibitors. The aim of this study was to assess the effect of compound G2 in colorectal cancer cell lines and compare it to migrastatin in in vitro and in vivo assays. Molecular modeling, actin-bundling, cell viability, inmunofluorescence, migration, and invasion assays were carried out in order to test anti-migratory and anti-invasive properties of compound G2. In addition, the in vivo effect of compound G2 was evaluated in a zebrafish model of invasion. HCT-116 cells exhibited the highest Fascin1 expression from eight tested colorectal cancer cell lines. Compound G2 showed important inhibitory effects on actin bundling, filopodia formation, migration, and invasion in different cell lines. Moreover, compound G2 treatment resulted in significant reduction of invasion of DLD-1 overexpressing Fascin1 and HCT-116 in zebrafish larvae xenografts; this effect being less evident in Fascin1 known-down HCT-116 cells. This study proves, for the first time, the in vitro and in vivo anti-tumoral activity of compound G2 on colorectal cancer cells and guides to design improved compound G2-based Fascin1 inhibitors. KEY MESSAGES: • Fascin is crucial for tumor invasion and metastasis and is overexpressed in bad prognostic tumors. • Several adverse tumors overexpress Fascin1 and lack targeted therapy. • Anti-fascin G2 is for the first time evaluated in colorectal carcinoma and compared with migrastatin. • Filopodia formation, migration activity, and invasion in vitro and in vivo assays were performed. • G2 blocks actin structures, migration, and invasion of colorectal cancer cells as fascin-dependent.

Matrix metalloproteinase 9 inhibits the motility of highly aggressive HSC-3 oral squamous cell carcinoma cells

Pro-tumorigenic activities of matrix metalloproteinase (MMP) 9 have been linked to many cancers, but recently the tumour-suppressing role of MMP9 has also been elucidated. The multifaceted evidence on this subject prompted us to examine the role of MMP9 in the behaviour of oral tongue squamous cell carcinoma (OTSCC) cells. We used gelatinase-specific inhibitor, CTT2, and short hairpin (sh) RNA gene silencing to study the effects of MMP9 on proliferation, motility and invasion of an aggressive OTSCC cell line, HSC-3. We found that the migration and invasion of HSC-3 cells were increased by CTT2 and shRNA silencing of MMP9. Proliferation, in turn, was decreased by MMP9 inhibition. Furthermore, arresten-overexpressing HSC-3 cells expressed increased levels of MMP9, but exhibited decreased motility compared with controls. Interestingly, these cells restored their migratory capabilities by CTT2 inhibition of MMP9. Hence, although higher MMP9 expression could give rise to an increased tumour growth in vivo due to increased proliferation, in some circumstances, it may participate in yet unidentified molecular mechanisms that reduce the cell movement in OTSCC.

Effects of ionizing radiation and HPSE1 inhibition on the invasion of oral tongue carcinoma cells on human extracellular matrices in vitro

Chemoradiation is an established approach in the treatment of advanced oral tongue squamous cell carcinoma (OTSCC), but therapy may cause severe side-effects due to signal interchanges between carcinoma and the tumour microenvironment (TME). In this study, we examined the potential use of our human 3D myoma disc and Myogel models in in vitro chemoradiation studies by analysing the effects of ionizing radiation (IR) and the combined effect of heparanase I (HPSE1) inhibitors and IR on OTSCC cell proliferation, invasion and MMP-2 and - 9 production. Finally, we analysed the long-term effects of IR by studying clones of previously irradiated and invaded HSC-3 cells. We found that in both human uterine leiomyoma-based extracellular matrix models IR inhibited the invasion of HSC-3 cells, but blocking HPSE1 activity combined with IR induced their invasion. Low doses of IR increased MMP expression and initiated epithelial-mesenchymal transition in cells cultured on myoma discs. We conclude that myoma models offer consistent methods for testing human carcinoma cell invasion and phenotypic changes during chemoradiation treatment. In addition, we showed that IR had long-term effects on MMP-2 and - 9, which might elicit different HSC-3 invasion responses when cells were under the challenge of HPSE1 inhibitors and IR.