Eribulin sensitizes oral squamous cell carcinoma cells to cetuximab via induction of mesenchymal-to-epithelial transition

Monoclonal antibody cetuximab impairs matrix metalloproteinases 2 and 9, epithelial-mesenchymal transition and cell migration in feline oral squamous cell carcinoma in vitro

Feline oral squamous cell carcinoma (FOSCC) is characterised by invasive and metastatic behaviour and is poorly responsive to current treatments, hence the need for new therapeutic strategies. FOSCC shares molecular targets with human head and neck squamous cell carcinoma (HNSCC), among these the epidermal growth factor receptor. Cetuximab is an anti-epidermal growth factor receptor monoclonal antibody employed in the therapy of HNSCC and, interestingly, previous work in vitro suggested that it displays cytostatic and cytotoxic properties also against FOSCC. With the present study, we aimed at further investigating the effects of cetuximab on invasion and metastasis pathways proven to be relevant in human patients. To this purpose, FOSCC cell lines SCCF1, SCCF2 and SCCF3 were treated with cetuximab for 48/72 h and subjected to Western blot for matrix metalloproteinases-2/9 (MMP-2/9) and epithelial-mesenchymal transition markers vimentin, E-, P- and N-cadherin. Treatment with cetuximab resulted in downregulation of MMP-2/-9 in all of the three cell lines in a dose-dependent manner. Moreover, cetuximab downregulated vimentin and P-cadherin in SCCF1, upregulated E-cadherin whilst downregulating P-/N-cadherins in SCCF2, and impaired P-/N-cadherins in SCCF3. An in vitro scratch test also demonstrated that cetuximab delayed cell migration in SCCF3. These data suggest that cetuximab mitigates invasion and metastasis processes by impairing MMPs and epithelial-mesenchymal transition pathways in FOSCC, indicating that this monoclonal antibody may help to counteract malignant progression and improve the management of locally invasive disease.

Effect of eribulin on epithelial-mesenchymal transition plasticity in metastatic breast cancer: An exploratory, prospective study

Epithelial-mesenchymal transition (EMT) plays a pivotal role in cancer metastasis and treatment resistance, which worsens prognosis. In phase III trials, eribulin improved overall survival in metastatic breast cancer (MBC) patients. In preclinical studies, eribulin suppressed EMT. However, clinical data on the use of eribulin for MBC patients are limited. In this exploratory, prospective study, we examined the effect of eribulin on EMT in MBC patients. Twenty-two patients aged 44-82 years with recurrent breast cancer or MBC were treated with eribulin. Breast cancer tissue samples were obtained before treatment and on Day 15 ± 5 of the first cycle of eribulin treatment. EMT markers (E-cadherin, claudin-3, vimentin, and N-cadherin) were analyzed using western blotting. EMT changes were evaluated based on the ratio of epithelial to mesenchymal markers before and after treatment in individual tumors. E-cadherin/vimentin, claudin-3/vimentin, E-cadherin/N-cadherin, and claudin-3/N-cadherin ratios were significantly higher after treatment (p = .007, p = .005, p = .006, and p = .011, respectively). Based on E-cadherin/vimentin, 65.0% of tumors shifted to an epithelial phenotype, as compared to 66.7% based on claudin-3/vimentin, 84.6% based on E-cadherin/N-cadherin, and 71.4% based on claudin-3/N-cadherin ratios. Thus, our results showed that eribulin suppressed EMT in breast cancer tissues.

Systematic Analysis of Genetic and Pathway Determinants of Eribulin Sensitivity across 100 Human Cancer Cell Lines from the Cancer Cell Line Encyclopedia (CCLE)

Eribulin, a natural product-based microtubule targeting agent with cytotoxic and noncytotoxic mechanisms, is FDA approved for certain patients with advanced breast cancer and liposarcoma. To investigate the feasibility of developing drug-specific predictive biomarkers, we quantified antiproliferative activities of eribulin versus paclitaxel and vinorelbine against 100 human cancer cell lines from the Cancer Cell Line Encyclopedia, and correlated results with publicly available databases to identify genes and pathways associated with eribulin response, either uniquely or shared with paclitaxel or vinorelbine. Mean expression ratios of 11,985 genes between the most and least sensitive cell line quartiles were sorted by p-values and drug overlaps, yielding 52, 29 and 80 genes uniquely associated with eribulin, paclitaxel and vinorelbine, respectively. Further restriction to minimum 2-fold ratios followed by reintroducing data from the middle two quartiles identified 9 and 13 drug-specific unique fingerprint genes for eribulin and vinorelbine, respectively; surprisingly, no gene met all criteria for paclitaxel. Interactome and Reactome pathway analyses showed that unique fingerprint genes of both drugs were primarily associated with cellular signaling, not microtubule-related pathways, although considerable differences existed in individual pathways identified. Finally, four-gene (C5ORF38, DAAM1, IRX2, CD70) and five-gene (EPHA2, NGEF, SEPTIN10, TRIP10, VSIG10) multivariate regression models for eribulin and vinorelbine showed high statistical correlation with drug-specific responses across the 100 cell lines and accurately calculated predicted mean IC50s for the most and least sensitive cell line quartiles as surrogates for responders and nonresponders, respectively. Collectively, these results provide a foundation for developing drug-specific predictive biomarkers for eribulin and vinorelbine.

A monoclonal antibody against basic fibroblast growth factor attenuates cisplatin resistance in lung cancer by suppressing the epithelial-mesenchymal transition

Objectives: To investigate the underlying mechanisms of how the basic fibroblast growth factor monoclonal antibody (bFGFmAb) attenuates cisplatin (DDP) resistance in lung cancer using A549 cells and cisplatin-resistant A549 cells (A549/DDP). Methods: Cancer cell proliferation, cell viability, and 50% inhibitory concentration (IC50) of cisplatin were assessed. Transwell assays were utilized to evaluate the invasion activity of tumor cells in response to treatment. Epithelial-to-mesenchymal transition markers and drug resistance proteins were analysed using Western blots. Results: We demonstrate that the bFGFmAb inhibits the proliferation and invasion of both A549 and A549/DDP cells. The bFGFmAb increases cisplatin sensitivity of both A549 and A549/DDP cells as evidenced by an increase in the IC50 of cisplatin in A549 and A549/DDP cells. Furthermore, bFGFmAb significantly increases the expression of E-cadherin, whilst decreasing the expression of N-cadherin and bFGF in both cell lines, thereby showing inhibition of epithelial-to-mesenchymal transition. In addition, we demonstrate that bFGFmAb significantly reduces the expression of the lung resistance protein. Conclusions: Our data suggests that the humanized bFGFmAb is a promising agent to attenuate cisplatin resistance in NSCLC. The underlying mechanism for this effect of bFGFmAb may be associated with the inhibition of epithelial-to-mesenchymal transition and reduced expression of lung resistance protein.

Approaches for Head and Neck Cancer Research - Current Status and the Way Forward

Head and neck cancers (HNCs) are seeing an increasing trend in their prevalence among both genders and are the seventh most common cancer type occurring at the global level. Studies addressing both the cancer cell physiology and individual differences in response to a specific treatment modality should be understood for arriving at effective treatment and management of the HNCs. In this article, we discuss the trends in HNC research and their various approaches starting from 2D in vitro models, which are the traditional experimental materials to recently established Cancer-Tissue Originated Spheroids (CTOS) distinctly contributing towards personalized or precision medicine.

The role of non-coding RNAs in drug resistance of oral squamous cell carcinoma and therapeutic potential

Oral squamous cell carcinoma (OSCC), the eighth most prevalent cancer in the world, arises from the interaction of multiple factors including tobacco, alcohol consumption, and betel quid. Chemotherapeutic agents such as cisplatin, 5-fluorouracil, and paclitaxel have now become the first-line options for OSCC patients. Nevertheless, most OSCC patients eventually acquire drug resistance, leading to poor prognosis. With the discovery and identification of non-coding RNAs (ncRNAs), the functions of dysregulated ncRNAs in OSCC development and drug resistance are gradually being widely recognized. The mechanisms of drug resistance of OSCC are intricate and involve drug efflux, epithelial-mesenchymal transition, DNA damage repair, and autophagy. At present, strategies to explore the reversal of drug resistance of OSCC need to be urgently developed. Nano-delivery and self-cellular drug delivery platforms are considered as effective strategies to overcome drug resistance due to their tumor targeting, controlled release, and consistent pharmacokinetic profiles. In particular, the combined application of new technologies (including CRISPR systems) opened up new horizons for the treatment of drug resistance of OSCC. Hence, this review explored emerging regulatory functions of ncRNAs in drug resistance of OSCC, elucidated multiple ncRNA-meditated mechanisms of drug resistance of OSCC, and discussed the potential value of drug delivery platforms using nanoparticles and self-cells as carriers in drug resistance of OSCC.

Loss of CPAP causes sustained EGFR signaling and epithelial-mesenchymal transition in oral cancer

Higher epidermal growth factor receptor (EGFR) signaling can contribute to tumor metastasis and resistance to therapies in oral squamous cell carcinoma (OSCC). EGFR signaling can promote epithelial-mesenchymal transition (EMT) in OSCC. EMT is a process by which epithelial cells acquire invasive properties and it can contribute to tumor metastasis. Not only do the abnormal functions of microtubule and microtubule-organizing centers (MTOC) such as centrosomes lead to cancers, but also the malignant tissues are characterized by aberrant centriolar features and amplified centrosomes. Microtubule inhibition therapies increase the sensitivity to EGFR targeting drugs in various cancers. In this study, we show that the loss of expression of a microtubule/tubulin binding protein, centrosomal protein 4.1-associated protein (CPAP), which is critical for centriole biogenesis and normal functioning of the centrosome, caused an increase in the EGFR levels and its signaling and, enhanced the EMT features and invasiveness of OSCC cells. Further, depletion of CPAP enhanced the tumorigenicity of these cells in a xeno-transplant model. Importantly, CPAP loss-associated EMT features and invasiveness of multiple OSCC cells were attenuated upon depletion of EGFR in them. On the other hand, we found that CPAP protein levels were higher in EGF treated OSCC cells as well as in oral cancer tissues, suggesting that the frequently reported aberrant centriolar features of tumors are potentially a consequence, but not the cause, of tumor progression. Overall, our novel observations show that, in addition to its known indispensable role in centrosome biogenesis, CPAP also plays a vital role in suppressing tumorigenesis in OSCC by facilitating EGFR homeostasis.

The potential influence of long non-coding RNA PRKG1-AS1 on oral squamous cell carcinoma: A comprehensive study based on bioinformatics and in vitro validation

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most frequent malignancies in oral cancer. Herein, we aimed to investigate the influence of lncRNA protein kinase cGMP-dependent type I-Antisense RNA 1 (PRKG1-AS1) in OSCC progression.

METHODS

Basing on the data acquired from TCGA database, the expression and prognostic value of PRKG1-AS1 in OSCC patients were assessed. The expression of PRKG1-AS1 in OSCC cells was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell growth was evaluated by Cell Counting Kit-8 (CCK8) and colony-forming assays. Transwell assay was employed to test cell invasion and migration. The protein expression of epithelial-mesenchymal transition (EMT)-related markers was detected by Western blotting.

RESULTS

The consequences displayed that PRKG1-AS1 was highly expressed in OSCC tissues and high expression of PRKG1-AS1 predicted poor outcomes. The expression of PRKG1-AS1 was higher in CAL27, SCC-9, and SCC-4 than that in normal human oral keratinocytes (NHOK). The results of biological experiments showed that deficiency of PRKG1-AS1 suppressed cell growth, invasion, and migration in CAL27 cells, and over-expression of PRKG1-AS1 accelerated cell growth, invasion, and migration in SCC-4 cells. Finally, silencing of PRKG1-AS1 obviously facilitated the protein expression levels of E-cadherin and reduced levels of N-cadherin, Vimentin, and Snail in CAL27 cells whereas over-expression of PRKG1-AS1 led to opposite results in SCC-4 cells.

CONCLUSION

These outcomes indicated that PRKG1-AS1 functioned as a facilitator in OSCC cell growth, migration, and invasion, which all might be achieved by regulating EMT.

Selectively high efficacy of eribulin against high-grade invasive recurrent and/or metastatic squamous cell carcinoma of the head and neck

Patients with recurrent and/or metastatic squamous cell carcinoma of the head and neck (R/M SCCHN) have a poor prognosis. Over the past decade, a major development in the first-line treatment of R/M SCCHN was the introduction of cetuximab in combination with platinum plus 5-fluorouracil chemotherapy. Currently, a promising novel treatment option in R/M SCCHN has emerged, termed immune checkpoint inhibitors. However, only a few patients presenting with R/M SCCHN have exhibited meaningful tumor regression with these agents. Therefore, novel agents are required to order improve the overall survival of patients with R/M SCCHN. Recently, we demonstrated that R/M SCCHN cells are highly sensitive to eribulin. In the present study, the effects of eribulin, paclitaxel and vinblastine were investigated in R/M SCCHN (OLC-01 and OSC-19) and locally advanced SCCHN (OSC-20) cells. Tumour-inhibitory activities of eribulin against R/M SCCHN were evaluated in orthotopic xenograft models. The data revealed that eribulin has sub-nM growth inhibitory activities in vitro against OLC-01 cells, and that it is more potent than paclitaxel and vinblastine. The reduced expression of Tubulin Beta 3 Class III (TUBB3) following treatment was correlated with a high sensitivity to eribulin. Histological analysis of OLC-01 cells in NOD-SCID mice demonstrated that they had a higher invasiveness in the tissue around the alveolar cancer when compared with the histology of OSC-19 cells, which has been reported in our previous study. Treatment with eribulin revealed marked inhibitory activities in vivo at 0.125 mg/kg against OLC-01 cells orthotopic xenografts. In conclusion, the results highlight the existence of invasive-type heterogeneity in R/M SCCHN with respect to eribulin sensitivity. Eribulin is already an approved clinical agent; therefore, the continued investigation of its preclinical antitumor attributes may contribute significantly to the future process of identifying novel uses of eribulin against R/M SCCHN.

Elimination of tumor hypoxia by eribulin demonstrated by 18F-FMISO hypoxia imaging in human tumor xenograft models

BACKGROUND

Eribulin, an inhibitor of microtubule dynamics, shows antitumor potency against a variety of solid cancers through its antivascular activity and remodeling of tumor vasculature. ¹⁸F-Fluoromisonidazole (¹⁸F-FMISO) is the most widely used PET probe for imaging tumor hypoxia. In this study, we utilized ¹⁸F-FMISO to clarify the effects of eribulin on the tumor hypoxic condition in comparison with histological findings.

MATERIAL AND METHODS

Mice bearing a human cancer cell xenograft were intraperitoneally administered a single dose of eribulin (0.3 or 1.0 mg/kg) or saline. Three days after the treatment, mice were injected with ¹⁸F-FMISO and pimonidazole (hypoxia marker for immunohistochemistry), and intertumoral ¹⁸F-FMISO accumulation levels and histological characteristics were determined. PET/CT was performed pre- and post-treatment with eribulin (0.3 mg/kg, i.p.).

RESULTS

The ¹⁸F-FMISO accumulation levels and percent pimonidazole-positive hypoxic area were significantly lower, whereas the number of microvessels was higher in the tumors treated with eribulin. The PET/CT confirmed that ¹⁸F-FMISO distribution in the tumor was decreased after the eribulin treatment.

CONCLUSIONS

Using ¹⁸F-FMISO, we demonstrated the elimination of the tumor hypoxic condition by eribulin treatment, concomitantly with the increase in microvessel density. These findings indicate that PET imaging using ¹⁸F-FMISO may provide the possibility to detect the early treatment response in clinical patients undergoing eribulin treatment.

Carcinogenic epithelial-mesenchymal transition initiated by oral cancer exosomes is inhibited by anti-EGFR antibody cetuximab

Overexpression and increased signaling from the epidermal growth factor receptor (EGFR) often changes oral squamous cell carcinoma (OSCC) and thus EGFR is frequently targeted molecularly by the therapeutic antibody cetuximab. We assessed the roles of OSCC-derived extracellular vesicles (EVs), including exosomes in the trafficking of cetuximab and in epithelial-mesenchymal transition (EMT) of epithelial cells. OSCC cells abundantly expressed EGFR, which was secreted from cells with OSCC-EVs upon EGF stimulations. The OSCC-EGFR-EVs were then able to enter into and transform epithelial cells leading to increased mesenchymal traits with increased vimentin and spindle-like shapes. EGF priming of OSCC cells further increased this EMT-initiating effect of the OSCC-EVs. The internalization and pro-EMT effects of the OSCC-EVs were largely blocked by cetuximab. Thus, OSCC-derived EVs transform normal epithelial cells into a mesenchymal phenotype and anti-EGFR therapeutic antibody cetuximab inhibits such a carcinogenic effect of the OSCC-EVs.

Cell culture models of oral mucosal barriers: A review with a focus on applications, culture conditions and barrier properties

Understanding the function of oral mucosal epithelial barriers is essential for a plethora of research fields such as tumor biology, inflammation and infection diseases, microbiomics, pharmacology, drug delivery, dental and biomarker research. The barrier properties are comprised by a physical, a transport and a metabolic barrier, and all these barrier components play pivotal roles in the communication between saliva and blood. The sum of all epithelia of the oral cavity and salivary glands is defined as the blood-saliva barrier. The functionality of the barrier is regulated by its microenvironment and often altered during diseases. A huge array of cell culture models have been developed to mimic specific parts of the blood-saliva barrier, but no ultimate standard in vitro models have been established. This review provides a comprehensive overview about developed in vitro models of oral mucosal barriers, their applications, various cultivation protocols and corresponding barrier properties.

Combination of two anti-tubulin agents, eribulin and paclitaxel, enhances anti-tumor effects on triple-negative breast cancer through mesenchymal-epithelial transition

Improved prognosis for triple-negative breast cancer (TNBC) has currently plateaued and the development of novel therapeutic strategies is required. Therefore, we aimed to explore the anti-tumor effect of eribulin and paclitaxel combination therapy for TNBC. The effect of eribulin and paclitaxel in combination was tested, with both concurrent and sequential administration, using four TNBC cell lines (MDA-MB-231, Hs578T, MDA-MB-157, and Mx-1) in vitro and in an MDA-MB-231 BALB/c-nu/nu mouse xenograft model. The expression of epithelial-mesenchymal phenotypic markers was analyzed by western blotting and immunohistochemical analyses. Simultaneous administration of eribulin and paclitaxel resulted in a synergistic anti-tumor effect with MDA-MB-231 and Hs578T cells, but not MDA-MB-157 and Mx-1 cells, in vitro. Moreover, pre-treatment with one drug significantly enhanced sensitivity to the subsequently administrated second drug in MDA-MB-231 and Hs578T cells. Eribulin increased E-cadherin expression and decreased the expression of mesenchymal markers in MDA-MB-231 and Hs578T cells. In contrast, paclitaxel increased the expression of mesenchymal markers. When epithelial-mesenchymal transition was induced by TGF-β1, eribulin sensitivity was enhanced. In contrast, a TGF-β receptor kinase inhibitor decreased eribulin sensitivity. In MDA-MB-231 tumor-bearing mice, concurrent administration of low doses of eribulin and paclitaxel significantly inhibited tumor growth compared to that with either monotherapy. Moreover, single administration of eribulin before the initiation of paclitaxel treatment decreased vimentin expression and reduced the average tumor volume in a mouse xenograft model. Eribulin and paclitaxel show synergistic anti-tumor effect by altering the epithelial-mesenchymal phenotype. This combination therapy could represent a novel therapeutic strategy for TNBC.

Advances in the treatment of soft tissue sarcoma: focus on eribulin

Eribulin mesylate is a synthetic derivative of halichondrin B isolated from a marine sponge. Its mechanism of action is through microtubule inhibition, which is different from that of taxanes. Eribulin has been approved for the treatment of metastatic breast cancer and more recently for non-operable or metastatic liposarcoma in patients who have received prior anthracycline chemotherapy. The major side effects of eribulin are bone marrow suppression including neutropenia, leukopenia, anemia, and fatigue/weakness, which can be well managed. In this article, we reviewed evidence from the latest published data on eribulin and its use in the treatment of soft tissue sarcomas. We explored the drug’s mechanism of action, pharmacodynamics, pharmacokinetics, and metabolism. Lastly, we reviewed all preclinical studies as well as clinical trials that investigated eribulin.

Regulation of programmed-death ligand in the human head and neck squamous cell carcinoma microenvironment is mediated through matrix metalloproteinase-mediated proteolytic cleavage

Recurrent and/or metastatic head and neck squamous cell carcinoma (R/M HNSCC) is a devastating malignancy with a poor prognosis. According to recent clinical studies, tumour growth can be effectively reduced and survival can be improved by blocking the programmed death receptor-1 (PD-1)/programmed death-ligand 1 (PD-L1) pathway. PD-L1 expression has been proposed as a potential causative mechanism, as HNSCC is highly immunosuppressive. However, anti-PD-1 treatment is beneficial only for certain patients. Therefore, the mechanisms controlling PD-L1 expression warrant further investigation in order to provide a better understanding of the predicting efficacy of and optimising anti-PD-1 therapy, alone or in combination. In this study, PD-L1 protein extracted from the cell membrane was found to be downregulated in OSC-20 cells compared with OSC-19 cells, despite a higher PD-L1 expression in the total cell lysate of the OSC-20 compared with the OSC-19 cells. Several matrix metalloproteinases (MMPs) were found to be upregulated in HNSCC; in particular, MMP-7 and -13 were upregulated in the OSC-20 compared with the OSC-19 cells. Purified PD-L1 was degraded by recombinant MMP-13 and -7. The expression of PD-L1 was significantly restored by a specific inhibitor of MMP-13 (CL82198), which suggested the involvement of MMP-13 in the shedding/cleavage of PD-L1 in the OSC-20 cells. Among the anticancer drugs conventionally used in the treatment of patients with HNSCC, paclitaxel increased MMP-13 expression in R/M HNSCC cells (HOC313 cells) co-cultured without/with dendritic cells (DCs). These results suggest that the shedding/cleavage of PD-L1 by MMP-13 is one of the mechanisms behind the protective effect against invasion and metastasis. Thus, MMP-13 has potential value as a marker predictive of the decreased efficacy of anti-PD-1 therapy. In addition, paclitaxel is a particularly promising candidate for combination therapy in R/M HNSCC with anti-PD-1 therapy.