Evaluation of spheroid head and neck squamous cell carcinoma cell models in comparison to monolayer cultures

Lidocaine induces apoptosis in head and neck squamous cell carcinoma through activation of bitter taste receptor T2R14

Head and neck squamous cell carcinomas (HNSCCs) have high mortality and significant treatment-related morbidity. It is vital to discover effective, minimally invasive therapies that improve survival and quality of life. Bitter taste receptors (T2Rs) are expressed in HNSCCs, and T2R activation can induce apoptosis. Lidocaine is a local anesthetic that also activates bitter taste receptor 14 (T2R14). Lidocaine has some anti-cancer effects, but the mechanisms are unclear. Here, we find that lidocaine causes intracellular Ca2+ mobilization through activation of T2R14 in HNSCC cells. T2R14 activation with lidocaine depolarizes mitochondria, inhibits proliferation, and induces apoptosis. Concomitant with mitochondrial Ca2+ influx, ROS production causes T2R14-dependent accumulation of poly-ubiquitinated proteins, suggesting that proteasome inhibition contributes to T2R14-induced apoptosis. Lidocaine may have therapeutic potential in HNSCCs as a topical gel or intratumor injection. In addition, we find that HPV-associated (HPV+) HNSCCs are associated with increased TAS2R14 expression. Lidocaine treatment may benefit these patients, warranting future clinical studies.

Cancer Wars: Revenge of the AMPs (Antimicrobial Peptides), a New Strategy against Colorectal Cancer

Cancer is a multifaceted health issue that affects people globally and it is considered one of the leading causes of death with a high percentage of victims worldwide. In recent years, research studies have uncovered great advances in cancer diagnosis and treatment. But, there are still major drawbacks of the conventional therapies used including severe side effects, toxicity, and drug resistance. That is why it is critical to develop new drugs with advantages like low cytotoxicity and no treatment resistance to the cancer cells. Antimicrobial peptides (AMPs) have recently attracted attention as a novel therapeutic strategy for the treatment of various cancers, targeting tumor cells with less toxicity to normal tissues. The aim of the study was to discover alternate treatments that do not lead to cancer resistance and have fewer side effects. Here, we report the effects induced by several AMPs, Melittin, Cecropin A, and a Cecropin A-Melittin hybrid, against two human colorectal cancer-derived spheroids. To study the effects of the peptides, cell viability was investigated using MTT, LDH, and ATP assays. Furthermore, cellular senescence and cell cycle were investigated. We found that using different concentrations of these peptides affected the spheroids, their structure being highly compromised by reducing cell viability, and the increase in ATP and LDH levels. Also, the cells are arrested in the G2/M phase leading to an increase in senescent cells. We show that Melittin and the hybrid are most effective against the 3D colorectal cancer cells compared to Cecropin A.

Use of 3D Spheroid Models for the Assessment of RT Response in Head and Neck Cancer

Radiotherapy (RT) is a key player in the treatment of head and neck cancer (HNC). The RT response, however, is variable and influenced by multiple tumoral and tumor microenvironmental factors, such as human papillomavirus (HPV) infections and hypoxia. To investigate the biological mechanisms behind these variable responses, preclinical models are crucial. Up till now, 2D clonogenic and in vivo assays have remained the gold standard, although the popularity of 3D models is rising. In this study, we investigate the use of 3D spheroid models as a preclinical tool for radiobiological research by comparing the RT response of two HPV-positive and two HPV-negative HNC spheroid models to the RT response of their corresponding 2D and in vivo models. We demonstrate that HPV-positive spheroids keep their higher intrinsic radiosensitivity when compared to HPV-negative spheroids. A good correlation is found in the RT response between HPV-positive SCC154 and HPV-negative CAL27 spheroids and their respective xenografts. In addition, 3D spheroids are able to capture the heterogeneity of RT responses within HPV-positive and HPV-negative models. Moreover, we demonstrate the potential use of 3D spheroids in the study of the mechanisms underlying these RT responses in a spatial manner by whole-mount Ki-67 and pimonidazole staining. Overall, our results show that 3D spheroids are a promising model to assess the RT response in HNC.

Head and neck cancer patient-derived tumouroid cultures: opportunities and challenges

Head and neck cancers (HNC) are the seventh most prevalent cancer type globally. Despite their common categorisation, HNCs are a heterogeneous group of malignancies arising in various anatomical sites within the head and neck region. These cancers exhibit different clinical and biological manifestations, and this heterogeneity also contributes to the high rates of treatment failure and mortality. To evaluate patients who will respond to a particular treatment, there is a need to develop in vitro model systems that replicate in vivo tumour status. Among the methods developed, patient-derived cancer organoids, also known as tumouroids, recapitulate in vivo tumour characteristics including tumour architecture. Tumouroids have been used for general disease modelling and genetic instability studies in pan-cancer research. However, a limited number of studies have thus far been conducted using tumouroid-based drug screening. Studies have concluded that tumouroids can play an essential role in bringing precision medicine for highly heterogenous cancer types such as HNC.

Primary head and neck cancer cell cultures are susceptible to proliferation of Epstein-Barr virus infected lymphocytes

BACKGROUND

New concepts for a more effective anti-cancer therapy are urgently needed. Experimental flaws represent a major counter player of this development and lead to inaccurate and unreproducible data as well as unsuccessful translation of research approaches into clinics. In a previous study we have created epithelial cell cultures from head and neck squamous cell carcinoma (HNSCC) tissue.

METHODS

We characterize primary cell populations isolated from human papillomavirus positive HNSCC tissue for their marker expression by RT-qPCR, flow cytometry, and immunofluorescence staining. Their sensitivity to MDM2-inhibition was measured using cell viability assays.

RESULTS

Primary HNSCC cell cultures showed the delayed formation of spheroids at higher passages. These spheroids mimicked the morphology and growth characteristics of other established HNSCC spheroid models. However, expression of epithelial and mesenchymal markers could not be detected in these cells despite the presence of the HNSCC stem cell marker aldehyde dehydrogenase 1 family member A1. Instead, strong expression of B- and T-lymphocytes markers was observed. Flow cytometry analysis revealed a heterogeneous mixture of CD3 + /CD25 + T-lymphocytes and CD19 + B-lymphocytes at a ratio of 4:1 at passage 5 and transformed lymphocytes at late passages (≥ passage 12) with CD45 + CD19 + CD20 + , of which around 10 to 20% were CD3 + CD25 + CD56 + . Interestingly, the whole population was FOXP3-positive indicative of regulatory B-cells (B_regs). Expression of transcripts specific for the Epstein-Barr-virus (EBV) was detected to increase in these spheroid cells along late passages, and this population was vulnerable to MDM2 inhibition. HPV + HNSCC cells but not EBV + lymphocytes were detected to engraft into immunodeficient mice.

CONCLUSIONS

In this study we present a primary cell culture of EBV-infected tumor-infiltrating B-lymphocytes, which could be used to study the role of these cells in tumor biology in future research projects. Moreover, by describing the detailed characteristics of these cells, we aim to caution other researchers in the HNSCC field to test for EBV-infected lymphocyte contaminations in primary cell cultures ahead of further experiments. Especially researchers who are interested in TIL-based adopted immunotherapy should exclude these cells in their primary tumor models, e.g. by MDM2-inhibitor treatment. BI-12-derived xenograft tumors represent a suitable model for in vivo targeting studies.

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.

New Scenarios in Pharmacological Treatments of Head and Neck Squamous Cell Carcinomas

Head and neck squamous cell carcinoma (HNSCC) is one of the most frequent types of cancer with a lethal outcome in half of the diagnosed cases. Mostly, HNSCC develops in the oral cavity, and its development is associated with tobacco and areca nut/betel quid usage, alcohol consumption, and HPV infection. Oral squamous cell carcinoma, as other head and neck cancers, presents a high degree of intratumor heterogeneity, which makes their treatment difficult, and directly correlates with drug resistance. Since the classical treatments for HNSCC oftentimes do not resolve the clinical picture, there is great need for novel therapeutic approaches, models for drug testing, and new drug delivery systems.

Format (2D vs 3D) and media effect target expression and response of patient-derived and standard NSCLC lines to EGFR inhibitors

Three patient-derived NSCLC lines and three well-established NSCLC lines with varied EGFR gene status were compared for expression of EGFR protein, proliferation and epithelial and mesenchymal markers in monolayer, simple spheroid and complex spheroid cultures. The effects of diverse culture conditions and exposure time on the response of the six NSCLC lines to the EGFR inhibitors erlotinib, afatinib, lapatinib, and osimertinib were examined. The clinical Cmax was used as the test concentration to determine whether cells were responsive or resistant to each agent. Among the patient-derived lines, LG0703-F948, which has an EGFR L858R mutation, was responsive to each of the four EGFR inhibitor when grown as spheroids but resistant when grown in monolayer. The HCC827 line, which carries an EGFR E746-A750 deletion, was responsive to each of the four EGFR inhibitors when grown as spheroids or monolayers. NCI-H1975 cells which have an EGFR T790M mutation and an EGFR L858R mutation, were sensitive to osimertinib when propagated as spheroids but not when grown in monolayer. The results suggest that the expression of cell surface targets and response to drugs targeting cell surface proteins varies depending upon cell culture format. These findings may help to explain, in part, the concordance or discordance between cell culture and in vivo findings in experimental systems.

3D Bioprinting for In Vitro Models of Oral Cancer: Toward Development and Validation

The tumor microenvironment (TME) of oral carcinomas has highly complex contents and a dynamic nature which is difficult to study using oversimplified two-dimensional (2D) cell culture systems. By contrast, three dimensional (3D) in vitro models such as spheroids, organoids, and scaffold-based constructs have been able to replicate tumors three-dimensionality and have allowed a better understanding of the role of various microenvironmental cues in the initiation and progression of cancer. However, the heterogeneity of TME cannot be fully reproduced by these traditional tissue engineering strategies since they are unable to control the organization of multiple cell types in a complex architecture. 3D bioprinting is an emerging field that can be leveraged to produce biomimetic and complex tissue structures. Bioprinting allows for controllable and precise placement of multicomponent bioinks composed of multiple biomaterials, different types of cells, and soluble factors according to the natural compartments of the target tissue, aiming to reproduce the equivalent of the complex tissue. As such, 3D bioprinting provides a unique opportunity to fabricate in vitro tumor models with a complexity similar to that of the in vivo oral carcinoma. This will facilitate a thorough investigation of cellular physiology, cancer progression, and anti-cancer drug screening with unprecedented control and reproducibility. In this review, we discuss the role of 3D bioprinting in reconstituting oral cancer, the prospects of application to fill the literature gap, and the challenges that need to be addressed in order to exploit this emerging technology for future work in oral cancer research.

Current Landscape in Organic Nanosized Materials Advances for Improved Management of Colorectal Cancer Patients

Globally, colorectal cancer (CRC) ranks as one of the most prevalent types of cancers at the moment, being the second cause of cancer-related deaths. The CRC chemotherapy backbone is represented by 5-fluorouracil, oxaliplatin, irinotecan, and their combinations, but their administration presents several serious disadvantages, such as poor bioavailability, lack of tumor specificity, and susceptibility to multidrug resistance. To address these limitations, nanomedicine has arisen as a powerful tool to improve current chemotherapy since nanosized carriers hold great promise in improving the stability and solubility of the drug payload and enhancing the active concentration of the drug that reaches the tumor tissue, increasing, therefore, the safety and efficacy of the treatment. In this context, the present review offers an overview of the most recent advances in the development of nanosized drug-delivery systems as smart therapeutic tools in CRC management and highlights the emerging need for improving the existing in vitro cancer models to reduce animal testing and increase the success of nanomedicine in clinical trials.

CAFs affect the proliferation and treatment response of head and neck cancer spheroids during co-culturing in a unique in vitro model

Background

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of tumors for which the overall survival rate worldwide is around 60%. The tumor microenvironment, including cancer-associated fibroblasts (CAFs), is believed to affect the treatment response and migration of HNSCC. The aim of this study was to create a biologically relevant HNSCC in vitro model consisting of both tumor cells and CAFs cultured in 3D to establish predictive biomarkers for treatment response, as well as to investigate the impact of CAFs on phenotype, proliferation and treatment response in HNSCC cells.

Methods

Three different HNSCC patient-derived tumor cell lines were cultured with and without CAFs in a 3D model. Immunohistochemistry of the proliferation marker Ki67, epidermal growth factor receptor (EGFR) and fibronectin and a TUNEL-assay were performed to analyze the effect of CAFs on both tumor cell proliferation and response to cisplatin and cetuximab treatment in tumor spheroids (3D). mRNA expression of epithelial-mesenchymal transition (EMT) and cancer stem cells markers were analyzed using qRT-PCR.

Results

The results demonstrated increased cell proliferation within the tumor spheroids in the presence of CAFs, correlating with increased expression of EGFR. In spheroids with increased expression of EGFR, a potentiated response to cetuximab treatment was observed. Surprisingly, an increase in Ki67 expressing tumor cells were observed in spheroids treated with cisplatin for 3 days, correlating with increased expression of EGFR. Furthermore, tumor cells co-cultured with CAFs presented an increased EMT phenotype compared to tumor cells cultured alone in 3D.

Conclusion

Taken together, our results reveal increased cell proliferation and elevated expression of EGFR in HNSCC tumor spheroids in the presence of CAFs. These results, together with the altered EMT phenotype, may influence the response to cetuximab or cisplatin treatment.

The biology and engineered modeling strategies of cancer-nerve crosstalk

A recent finding critical to cancer aggravation is the interaction between cancer cells and nerves. There exist two main modes of cancer-nerve interaction: perineural invasion (PNI) and tumor innervation. PNI occurs when cancer cells infiltrate the adjacent nerves, and its relative opposite, tumor innervation, occurs when axons extend into tumor bodies. Like most cancer studies, these crosstalk interactions have mostly been observed in patient samples and animal models at this point, making it difficult to understand the mechanisms in a controlled manner. As such, in recent years in vitro studies have emerged that have helped identify various microenvironmental factors responsible for cancer-nerve crosstalk, including but not limited to neurotrophic factors, neurotransmitters, chemokines, cancer-derived exosomes, and Schwann cells. The versatility of in vitro systems warrants continuous development to increase physiological relevance to study PNI and tumor innervation, for example by utilizing biomimetic three-dimensional (3D) culture systems. Despite the wealth of 3D in vitro cancer models, comparatively there exists a lack of 3D in vitro models of nerve, PNI, and tumor innervation. Native-like 3D in vitro models of cancer-nerve interactions may further help develop therapeutic strategies to curb nerve-mediated cancer aggravation. As such, we provide an overview of the key players of cancer-nerve crosstalk and current in vitro models of the crosstalk, as well as cancer and nerve models. We also discuss a few future directions in cancer-nerve crosstalk research.

3D tumour spheroids for the prediction of the effects of radiation and hyperthermia treatments

For multimodality therapies such as the combination of hyperthermia and radiation, quantification of biological effects is key for dose prescription and response prediction. Tumour spheroids have a microenvironment that more closely resembles that of tumours in vivo and may thus be a superior in vitro cancer model than monolayer cultures. Here, the response of tumour spheroids formed from two established human cancer cell lines (HCT116 and CAL27) to single and combination treatments of radiation (0-20 Gy), and hyperthermia at 47 °C (0-780 CEM43) has been evaluated. Response was analysed in terms of spheroid growth, cell viability and the distribution of live/dead cells. Time-lapse imaging was used to evaluate mechanisms of cell death and cell detachment. It was found that sensitivity to heat in spheroids was significantly less than that seen in monolayer cultures. Spheroids showed different patterns of shrinkage and regrowth when exposed to heat or radiation: heated spheroids shed dead cells within four days of heating and displayed faster growth post-exposure than samples that received radiation or no treatment. Irradiated spheroids maintained a dense structure and exhibited a longer growth delay than spheroids receiving hyperthermia or combination treatment at (thermal) doses that yielded equivalent levels of clonogenic cell survival. We suggest that, unlike radiation, which kills dividing cells, hyperthermia-induced cell death affects cells independent of their proliferation status. This induces microenvironmental changes that promote spheroid growth. In conclusion, 3D tumour spheroid growth studies reveal differences in response to heat and/or radiation that were not apparent in 2D clonogenic assays but that may significantly influence treatment efficacy.

Stroma-Rich Co-Culture Multicellular Tumor Spheroids as a Tool for Photoactive Drugs Screening

Conventional 3D multicellular tumor spheroids of head and neck squamous cell carcinoma (HNSCC) consisting exclusively of cancer cells have some limitations. They are compact cell aggregates that do not interact with their extracellular milieu, thus suffering from both insufficient extracellular matrix (ECM) deposition and absence of different types of stromal cells. In order to better mimic in vivo HNSCC tumor microenvironment, we have constructed a 3D stroma-rich in vitro model of HNSCC, using cancer-associated MeWo skin fibroblasts and FaDu pharynx squamous cell carcinoma. The expression of stromal components in heterospheroids was confirmed by immunochemical staining. The generated co-culture FaDu/MeWo spheroids were applied to study penetration, distribution and antitumor efficacy of photoactive drugs such as Temoporfin and Chlorin e6 used in the photodynamic therapy flow cytometry and fluorescence microscopy techniques. We also investigated the distribution of photodiagnostic agent Indocyanine Green. We demonstrated that the presence of stroma influences the behavior of photoactive drugs in different ways: (i) No effect on Indocyanine Green distribution; (ii) lower accumulation of Chlorin e6; (iii) better penetration and PDT efficiency of Temoporfin. Overall, the developed stroma-rich spheroids enlarge the arsenal of in vitro pre-clinical models for high-throughput screening of anti-cancer drugs.

The miR-205-5p/BRCA1/RAD17 Axis Promotes Genomic Instability in Head and Neck Squamous Cell Carcinomas

Defective DNA damage response (DDR) is frequently associated with tumorigenesis. Abrogation of DDR leads to genomic instability, which is one of the most common characteristics of human cancers. TP53 mutations with gain-of-function activity are associated with tumors under high replicative stress, high genomic instability, and reduced patient survival. The BRCA1 and RAD17 genes encode two pivotal DNA repair proteins required for proper cell-cycle regulation and maintenance of genomic stability. We initially evaluated whether miR-205-5p, a microRNA (miRNA) highly expressed in head and neck squamous cell carcinoma (HNSCC), targeted BRCA1 and RAD17 expression. We found that, in vitro and in vivo, BRCA1 and RAD17 are targets of miR-205-5p in HNSCC, leading to inefficient DNA repair and increased chromosomal instability. Conversely, miR-205-5p downregulation increased BRCA1 and RAD17 messenger RNA (mRNA) levels, leading to a reduction in in vivo tumor growth. Interestingly, miR-205-5p expression was significantly anti-correlated with BRCA1 and RAD17 targets. Furthermore, we documented that miR-205-5p expression was higher in tumoral and peritumoral HNSCC tissues than non-tumoral tissues in patients exhibiting reduced local recurrence-free survival. Collectively, these findings unveil miR-205-5p’s notable role in determining genomic instability in HNSCC through its selective targeting of BRCA1 and RAD17 gene expression. High miR-205-5p levels in the peritumoral tissues might be relevant for the early detection of minimal residual disease and pre-cancer molecular alterations involved in tumor development.

Impact of spheroid culture on molecular and functional characteristics of bladder cancer cell lines

The three-dimensional cell culture system is an increasingly important technique for discovering new biological aspects of cancer cells. In the present study it was demonstrated that bladder cancer cell lines, RT4 and 5637, spontaneously formed round multicellular spheroids (MCSs) in suspension by the aggregation method. MCSs consisted of cells differentially expressing luminal/basal markers. Western blotting showed that PPARγ and forkhead box A1 (FOXA1)of luminal markers were expressed to a lesser extent in MCSs than in parental cells grown in two-dimensional (2D) adherent culture. Cells in MCSs in suspension proliferated less efficiently, and were more resistant to cisplatin (CDDP) and gemcitabine than parental cells grown in 2D culture. Culturing cell lines as MCSs in suspension is a notable platform to decipher alternative biological aspects of bladder cancer cells, which could not be unraveled by the conventional 2D adherent culture.

An Effective Primary Head and Neck Squamous Cell Carcinoma In Vitro Model

Head and neck squamous cell carcinoma is a highly malignant disease and research is needed to find new therapeutic approaches. Faithful experimental models are required for this purpose. Here, we describe the specific cell culture conditions enabling the efficient establishment of primary cell culture models. Whereas a classical 10% serum-containing medium resulted in the growth of fibroblast-like cells that outcompeted epithelial cells, we found that the use of specific culture conditions enabled the growth of epithelial tumor cells from HPV+ and HPV- head and neck cancer tissue applicable for research. EpCAM and high Thy-1 positivity on the cell surface were mutually exclusive and distinguished epithelial and fibroblast-like subpopulations in all primary cultures examined and thus can be used to monitor stromal contamination and epithelial cell content. Interestingly, cells of an individual patient developed tumor spheroids in suspension without the use of ultra-low attachment plates, whereas all other samples exclusively formed adherent cell layers. Spheroid cells were highly positive for ALDH1A1 and hence displayed a phenotype reminiscent of tumor stem cells. Altogether, we present a system to establish valuable primary cell culture models from head and neck cancer tissue at high efficiency that might be applicable in other tumor entities as well.

Molecular Modeling-Based Delivery System Enhances Everolimus-Induced Apoptosis in Caco-2 Cells

Several studies have shown that the mammalian target of rapamycin (mTOR) inhibitor; everolimus (EV) improves patient survival in several types of cancer. However, the meaningful efficacy of EV as a single agent for the treatment of colorectal cancer (CRC) has failed to be proven in multiple clinical trials. Combination therapy is one of the options that could increase the efficacy and decrease the toxicity of the anticancer therapy. This study revealed that the β-cyclodextrin (β-CD):FGF7 complex has the potential to improve the antiproliferative effect of EV by preventing FGF receptor activation and by enhancing EV cellular uptake and intracellular retention. Molecular docking techniques were used to investigate the possible interaction between EV, β-CD, and FGF7. Molecular docking insights revealed that β-CD and EV are capable to form a stable inclusion complex with FGF at the molecular level. The aqueous solubility of the inclusion complex was increased (3.1 ± 0.23 μM) when compared to the aqueous solubility of pure EV (1.7 ± 0.16 μM). In addition, the in vitro cytotoxic activity of a FGF7:β-CD:EV complex on Caco-2 cell line was investigated using real-time xCELLigence technology. The FGF7:β-CD:EV complex has induced apoptosis of Caco-2 cells and shown higher cytotoxic activity than the parent drug EV. With the multitargets effect of β-CD:FGF7 and EV, the antiproliferative effect of EV was remarkably improved as the IC₅₀ value of EV was reduced from 9.65 ± 1.42 to 1.87 ± 0.33 μM when compared to FGF7:β-CD:EV complex activity. In conclusion, the findings advance the understanding of the biological combinational effects of the β-CD:FGF7 complex and EV as an effective treatment to combat CRC.

The Limitations of Collagen/CPP Hybrid Peptides as Carriers for Cancer Drugs to FaDu Cells

The in vitro efficacy of cancer prodrugs varies significantly between malignant cell lines. The most commonly identified problems relate to delivery: uptake mechanism, endosomal entrapment, and drug release. Here we present the study of collagen/cell penetrating hybrid (COL/CPP) peptide carriers intended to deliver paclitaxel to the hypopharyngeal carcinoma (FaDu) cells. Confocal microscopy imaging revealed the surprising response of FaDu cell to COL/CPP in comparison to previously studied cancer cell lines: hybrid peptides that carry both COL and CPP domain adsorb on the FaDu cell surface. While the CPP domain was design to facilitate the cellular uptake, in the case of FaDu cells, it also induced detrimental interactions with the cell membrane. Despite surface adsorption, the colocalization study with endosomal markers EEA1 and LAMP1 reveals that COL/CPP is internalized via endosomal pathway, peptides are able to escape before lysosome formation and release paclitaxel. Therefore, the main obstacle for paclitaxel delivery to FaDu cells appears to be related to cell surface properties. This behavior seems specific to FaDu cells, and could be linked to previously reported overexpression of T5, heparanase splice variants that produces protein lacking enzymatic activity of heparanase. This results in increased concentration of HSPG on FaDu cell surface, and possibly creates a barrier for cellular uptake of highly charged COL/CPP.

The effect of 2D and 3D cell cultures on treatment response, EMT profile and stem cell features in head and neck cancer

Background

Head and Neck Squamous Cell Carcinoma (HNSCC) tumors are often resistant to therapies. Therefore searching for predictive markers and new targets for treatment in clinically relevant in vitro tumor models is essential. Five HNSCC-derived cell lines were used to assess the effect of 3D culturing compared to 2D monolayers in terms of cell proliferation, response to anti-cancer therapy as well as expression of EMT and CSC genes.

Methods

The viability and proliferation capacity of HNSCC cells as well as induction of apoptosis in tumor spheroids cells after treatment was assessed by MTT assay, crystal violet- and TUNEL assay respectively. Expression of EMT and CSC markers was analyzed on mRNA (RT-qPCR) and protein (Western blot) level.

Results

We showed that HNSCC cells from different tumors formed spheroids that differed in size and density in regard to EMT-associated protein expression and culturing time. In all spheroids, an up regulation of CDH1, NANOG and SOX2 was observed in comparison to 2D but changes in the expression of EGFR and EMT markers varied among the cell lines. Moreover, most HNSCC cells grown in 3D showed decreased sensitivity to cisplatin and cetuximab (anti-EGFR) treatment.

Conclusions

Taken together, our study points at notable differences between these two cellular systems in terms of EMT-associated gene expression profile and drug response. As the 3D cell cultures imitate the in vivo behaviour of neoplastic cells within the tumor, our study suggest that 3D culture model is superior to 2D monolayers in the search for new therapeutic targets.

Electronic supplementary material

The online version of this article (10.1186/s12935-019-0733-1) contains supplementary material, which is available to authorized users.

Development of an in vitro cell-sheet cancer model for chemotherapeutic screening

Epithelial cancer grows in vivo in a microenvironment that comprises tumour, stroma, and immune cells. A three-dimensional (3D) culture model might be able to mimic the tumour microenvironment in vivo; therefore, we developed a new 3D epithelial cancer model using in vitro cell-sheet engineering and compared the results of treatment with several chemotherapeutic drugs among the 3D cell-sheet model, spheroid culture, and 2D cell culture.

Methods: The cell sheet comprised keratinocytes and a plasma fibrin matrix containing fibroblasts. Cancer spheroids with or without cancer-associated fibroblasts (CAFs) were interposed between the keratinocytes and fibrin layer. Cell growth, viability, and hypoxia were measured using the cell counting kit-8, LIVE/DEAD assay, and propidium iodide and LOX-1 staining. The morphology, invasion, and mRNA and protein expression were compared among the different cell culture models.

Results: Enhanced resistance to sorafenib and cisplatin by cancer spheroids and CAFs was more easily observed in the 3D than in the 2D model. Invasion by cancer-CAF spheroids into the fibrin matrix was more clearly observed in the 3D cell sheet. The expansion of viable cancer cells increased in the 3D cell sheet, particularly in those with CAFs, which were significantly inhibited by treatment with 10 μM sorafenib or 20 μM cisplatin (P < 0.05). TGF-β1, N-cadherin, and vimentin mRNA and protein levels were higher in the 3D cell-sheet model.

Conclusions: The 3D cell sheet-based cancer model could be applied to in vitro observation of epithelial cancer growth and invasion and to anticancer drug testing.

Reconfigurable Microfluidic Magnetic Valve Arrays: Towards a Radiotherapy-Compatible Spheroid Culture Platform for the Combinatorial Screening of Cancer Therapies

We introduce here a microfluidic cell culture platform or spheroid culture chamber array (SCCA) that can synthesize, culture, and enable fluorescence imaging of 3D cell aggregates (typically spheroids) directly on-chip while specifying the flow of reagents in each chamber via the use of an array of passive magnetic valves. The SCCA valves demonstrated sufficient resistance to burst (above 100 mBar), including after receiving radiotherapy (RT) doses of up to 8 Gy combined with standard 37 °C incubation for up to 7 days, enabling the simultaneous synthesis of multiple spheroids from different cell lines on the same array. Our results suggest that SCCA would be an asset in drug discovery processes, seeking to identify combinatorial treatments.

Preclinical models in HNSCC: A comprehensive review

Head and neck cancer remains a significant public health concern. About 60% of patients die within 5years due to local recurrence. Head and neck squamous cell carcinoma (HNSCC) cell lines are important preclinical models in the search for new therapies against this disease. Furthermore, there is a need to test novel drugs before introduction into clinical practice. A preclinical model that closely resembles the in vivo situation would be highly valuable. In the last few decades, a multicellular spheroid model has gained attention as its behavior was comparable to in vivo tumors. Basic research is necessary to achieve an understanding of the normal and pathological state but cannot, in itself, provide sufficient information for clinical applications. Indeed, animal models are an inevitable prelude to assess the efficacy of new therapeutic approaches in HNSCC. The present review proposes an overview of HNSCC pre-clinical models in order to further understand the oncogenic properties for HNSCC and translate these findings into clinic for patients.