Isolation and Characterization of a Head and Neck Squamous Cell Carcinoma Subpopulation Having Stem Cell Characteristics

Despite advances in the understanding of head and neck squamous cell carcinomas (HNSCC) progression, the five-year survival rate remains low due to local ...

Evaluation of the Cell Invasion and Migration Process: A Comparison of the Video Microscope-based Scratch Wound Assay and the Boyden Chamber Assay

The invasion and migration abilities of tumor cells are main contributors to cancer progression and recurrence. Many studies have explored the migration ...

Université de Lyon

Hospices-Civils-de-Lyon, Centre Hospitalier Lyon-Sud

Université Lyon 1

Centre Hospitalier Lyon-Sud

Recent evidences suggest that many types of cancers contain a cell population presenting stem cell properties. While the great majority of tumor cells are destined to differentiate, and eventually stop dividing, only a minority population of cells, termed cancer stem cells (CSCs), possesses extensive self-renewal capability and can recapitulate tumor pathophysiology in an immune-compromised animal model. Tumor initiating cells have been identified and isolated in many tumor types including brain, colon and prostate. They are virtually resistant to radiation and may contribute to treatment resistance and recurrence. Therefore, therapies specifically targeting CSCs will likely be needed for complete tumor eradication. The present study reviews published reports identifying the mechanisms of radioresistance of CSCs and potential targets based on the pathways of self-renewal. Further elucidation of pathways that regulate CSCs may provide insights into the development of novel innovative therapies.

[Cancer stem cells: Radiotherapeutic features and therapeutic targets].

Radiation therapy is a cornerstone of head and neck cancer management. Technological improvements in recent years in radiation therapy, with intensity-modulated techniques, reinforce even more its role. However, both local and locoregional relapses are still observed. Understanding biological mechanisms of treatment resistance is a topic of major interest. From the cancer cell itself, its ability to repair and proliferate, its microenvironment and oxygenation conditions, migratory and invasive capacity, to biological parameters related to the patient, there are many mechanisms involving radiosensitivity and/or radioresistance of head and neck cancer. The present study explores the main biological mechanisms involved in radiation resistance of head and neck cancer, and describes promising therapeutic approaches.

[Radiosensitivity and/or radioresistance of head and neck cancers: Biological angle].

Head and neck squamous cell cancer (HNSCC) is the sixth most common cancer in the world. Effective therapeutic modalities such as surgery, radiation, chemotherapy and combinations of each are used in the management of the disease. In most cases, treatment fails to obtain total cancer cure. In recent years, it appears that one of the key determinants of treatment failure may be the presence of cancer stem cells (CSCs) that escape currently available therapies. CSCs form a small portion of the total tumor burden but may play a disproportionately important role in determining outcomes. CSCs have stem features such as self-renewal, high migration capacity, drug resistance, high proliferation abilities. A large body of evidence points to the fact that CSCs are particularly resistant to radiotherapy and chemotherapy. In HNSCC, CSCs have been increasingly shown to have an integral role in tumor initiation, disease progression, metastasis and treatment resistance. In the light of such observations, the present review summarizes biological characteristics of CSCs in HNSCC, outlines targeted strategies for the successful eradication of CSCs in HNSCC including targeting the self-renewal controlling pathways, blocking epithelial mesenchymal transition, niche targeting, immunotherapy approaches and highlights the need to better understand CSCs biology for new treatments modalities.

Targeting head and neck tumoral stem cells: From biological aspects to therapeutic perspectives.

Nowadays, head and neck squamous cell carcinoma (HNSCC) treatment failure is mostly explained by locoregional progression or intrinsic radioresistance. Radiotherapy (RT) has recently evolved with the emergence of heavy ion radiations or new fractionation schemes of photon therapy, which modify the dose rate of treatment delivery. The aim of the present study was then to evaluate the in vitro influence of a dose rate variation during conventional RT or carbon ion hadrontherapy treatment in order to improve the therapeutic care of patient. In this regard, two HNSCC cell lines were irradiated with photons or 72 MeV/n carbon ions at a dose rate of 0.5, 2, or 10 Gy/min. For both radiosensitive and radioresistant cells, the change in dose rate significantly affected cell survival in response to photon exposure. This variation of radiosensitivity was associated with the number of initial and residual DNA double-strand breaks (DSBs). By contrast, the dose rate change did not affect neither cell survival nor the residual DNA DSBs after carbon ion irradiation. As a result, the relative biological efficiency at 10% survival increased when the dose rate decreased. In conclusion, in the RT treatment of HNSCC, it is advised to remain very careful when modifying the classical schemes toward altered fractionation. At the opposite, as the dose rate does not seem to have any effects after carbon ion exposure, there is less need to adapt hadrontherapy treatment planning during active system irradiation.

Influence of Dose Rate on the Cellular Response to Low- and High-LET Radiations.

Cancer Stem Cells (CSCs) in Head and Neck Squamous Cell Carcinoma (HNSCC) have extremely aggressive profile (high migratory and invasive potential). These characteristics can explain their resistance to conventional treatment. Efficacy of photon and carbon ion irradiation with addition of cetuximab (5 nM) is studied on clonogenic death, migration and invasion of two HNSCC populations: SQ20B and SQ20B/CSCs. SQ20B express E-cadherin and overexpress EGFR while SQ20B/CSCs express N-cadherin and low EGFR. Cetuximab strongly inhibits SQ20B proliferation but has no effect on SQ20B/CSCs. 2 Gy photon irradiation enhances migration and invasiveness in both populations (p < 0.05), while cetuximab only stops SQ20B migration (p < 0.005). Carbon irradiation significantly inhibits invasion in both populations (p < 0.05), and the association with cetuximab significantly inhibits invasion in both populations (p < 0.005). These results highlight CSCs characteristics: EGFRLow, cetuximab-resistant, and highly migratory. Carbon ion irradiation appears to be a very promising therapeutic modality counteracting migration/invasion process in both parental cells and CSCs in contrast to photon irradiation.

Carbon ion irradiation withstands cancer stem cells' migration/invasion process in Head and Neck Squamous Cell Carcinoma (HNSCC).

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.

Preclinical models in HNSCC: A comprehensive review.

Head and neck squamous cell carcinoma (HNSCC) are resistant to standard treatments, partly due to cancer stem cells (CSCs) localised in hypoxic niches. Compared to X-rays, carbon ion irradiation relies on better ballistic properties, higher relative biological effectiveness and the absence of oxygen effect. Hypoxia-inducible factor-1α (HIF-1α) is involved in the resistance to photons, whereas its role in response to carbon ions remains unclear.

Differential pattern of HIF-1α expression in HNSCC cancer stem cells after carbon ion or photon irradiation: one molecular explanation of the oxygen effect.

Hadrontherapy presents the major advantage of improving tumor sterilization while sparing surrounding healthy tissues because of the particular ballistic (Bragg peak) of carbon ions. However, its efficacy is still limited in the most resistant cancers, such as grade III-IV head and neck squamous cell carcinoma (HNSCC), in which the association of carbon ions with gadolinium-based nanoparticles (AGuIX(®)) could be used as a Trojan horse. We report for the first time the radioenhancing effect of AGuIX(®) when combined with carbon ion irradiation in human tumor cells. An increase in relative biological effectiveness (1.7) in three HNSCC cell lines (SQ20B, FaDu, and Cal33) was associated with a significant reduction in the radiation dose needed for killing cells. Radiosensitization goes through a higher number of unrepaired DNA double-strand breaks. These results underline the strong potential of AGuIX(®) in sensitizing aggressive tumors to hadrontherapy and, therefore, improving local control while lowering acute/late toxicity.

Gadolinium-based nanoparticles as sensitizing agents to carbon ions in head and neck tumor cells.

Head and neck cancer stem cells (CSCs) are highly resistant to treatment. When EGFR is overexpressed in head and neck squamous cell carcinoma (HNSCC), HER2 and HER3 are also expressed. The aim of the present study was to investigate the effect of HER1/2/3 blockade through a combination of cetuximab and pertuzumab, with or without photon irradiation, on the proliferation and migration/invasion capabilities of an HNSCC chemo- and radioresistant human cell line (SQ20B) and its corresponding stem cell subpopulation. Cell proliferation, migration and invasion were studied after treatment with cetuximab +/- pertuzumab +/- 10 Gy photon irradiation. EGFR, phospho-EGFR, HER2 and HER3 protein expression levels were studied. Activation or inhibition of the RAS/MAPK and AKT-mTOR downstream signalling cascades was investigated through phospho-AKT and phospho-MEK1/2 expression. Cetuximab strongly inhibited SQ20B and FaDu cell proliferation, migration and invasion, whereas it had little effect on SQ20B-CSCs. Cetuximab-pertuzumab combined with radiation significantly inhibited SQ20B and FaDu cell and SQ20B-CSC proliferation, migration and invasion. Cetuximab-pertuzumab with 10 Gy photon irradiation switched off both phospho-AKT and phospho-MEK1/2 expression in the three populations. The triple therapy is therefore thought to inhibit SQ20B cells, SQ20B-CSCs and FaDu cells through an AKT-mTOR and Ras-MAPK downstream signalling blockade.

Anne-Sophie Wozny

UCBL1,
UMR/CNRS 5822,
Laboratoire de Radiobiologie Cellulaire Moléculaire,
UCBL1, UMR/CNRS 5822, Laboratoire de Radiobiologie Cellulaire Moléculaire

Université de Lyon

Isolation and Characterization of a Head and Neck Squamous Cell Carcinoma Subpopulation Having Stem Cell Characteristics

Evaluation of the Cell Invasion and Migration Process: A Comparison of the Video Microscope-based Scratch Wound Assay and the Boyden Chamber Assay

Anne-Sophie Wozny

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}UCBL1,UMR/CNRS 5822,Laboratoire de Radiobiologie Cellulaire Moléculaire,UCBL1, UMR/CNRS 5822, Laboratoire de Radiobiologie Cellulaire Moléculaire

Université de Lyon

Isolation and Characterization of a Head and Neck Squamous Cell Carcinoma Subpopulation Having Stem Cell Characteristics

Evaluation of the Cell Invasion and Migration Process: A Comparison of the Video Microscope-based Scratch Wound Assay and the Boyden Chamber Assay

UCBL1,
UMR/CNRS 5822,
Laboratoire de Radiobiologie Cellulaire Moléculaire,
UCBL1, UMR/CNRS 5822, Laboratoire de Radiobiologie Cellulaire Moléculaire