- Email: [email protected]
6 CD98 identifies a clinically relevant subpopulation of head and neck squamous cell carcinoma cells with stem cell properties
Abstracts / Oral Oncology 51 (2015) e27–e55
treatment schedule. First results may be available at the time of presentation. doi:10.1016/j.oraloncology.2015.02.008
Session 2 – Mechanisms of tumor progression and metastasis 6 CD98 identifies a clinically relevant subpopulation of head and neck squamous cell carcinoma cells with stem cell properties S.R. Martens-de Kemp a, M.M. Rietbergen a, A. Brink a, M. Stigter-van Walsum a, E. Bloemena a, W.N. van Wieringen a, M. Slijper b, B.J.M. Braakhuis a, C.R. Leemans a, R.H. Brakenhoff a a b
Amsterdam, Netherlands Utrecht, Netherlands
Introduction: Patients with advanced head and neck squamous cell carcinomas (HNSCC) are often treated with concomitant chemotherapy and radiotherapy, but only 50% is cured. A possible explanation for treatment failure is therapy resistance of the cancer stem cells (CSCs). The application of compounds specifically targeting these CSCs, in addition to routinely used therapeutics, would likely improve clinical outcome. We set out to identify the CSC population in HNSCC. Previously, we found that the antibody K984 specifically targets the cells composing the squamous basal cell layer, the area where HNSCC CSCs likely reside. Materials and methods: Immunoprecipitation and mass spectrometry was used to identify the antigen targeted by the K984 antibody. Next, flow cytometry was used to separate cell populations with high and low K984 antigen expression and these populations were tested for tumorigenicity in immunodeficient mice. Gene expression arraying was applied to further characterize the cell populations. In addition, to investigate the clinical importance of CSC presence in HNSCC, a large cohort of oropharyngeal tumors was immunohistochemically examined for K984 antigen positivity, as well as for CD44 expression, and the scoring results were associated with clinical outcome. Results: We demonstrated that the monoclonal antibody K984 recognizes the CD98 cell surface protein and showed that CD98high cells, in contrast to CD98low cells, are able to generate tumors in immunodeficient mice. This indicates that CD98high cells have stem cell characteristics. Furthermore, the CD98high subpopulation expressed high levels of cell cycle control and DNA repair genes, while the CD98low fraction showed expression patterns that represent the more differentiated cells that form the bulk of the tumor. HPV-positive tumors expressed lower levels of CSC markers CD44 and CD98 than HPV-negative tumors. The number of CD98-positive cells was significantly associated with outcome in HPV-positive tumors, but not in HPV-negative tumors. CD44 expression was not associated with clinical outcome. Conclusion: CD98 is a promising CSC enrichment marker in HNSCC. Our data support the CSC concept in head and neck cancer and the potential relevance of these cells for treatment outcome. doi:10.1016/j.oraloncology.2015.02.009
7 Tumor budding as a prognostic marker in head and neck cancer – A systematic review A. Almangush Helsinki, Finland
e29
Introduction: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. For the histopathological prognostication of HNSCC, pathologist evaluates characteristics which reveal the biological aggressiveness of tumor. The invasive front (IF) has been suggested as the aggressive part of HNSCC and several histopathological parameters were evaluated at IF. One of these parameters is the tumor budding which defined as presence of single cancer cells or small clusters (<5 cells) at the tumor IF. Tumor budding has been suggested as the result of interaction between the cancer invasive front and the tumor microenvironment. Although numerous reports have studied tumor budding in several cancers during the last decades, the first report evaluated this feature in HNSCC was introduced in 2010 [1]. Later on, our group [2] and other [3] reported a strong prognostic power for tumor budding in tongue carcinoma. This systematic review aims to highlight the importance of tumor budding in HNSCC. Material and methods: The term ‘tumor budding’ was searched in the following databases: PubMed, Scopus and Web of Science. The search was limited to the English language literature published before March 2014. Results of the literature searching: Of the literature searching: We retrieved 122 citations. However, only 5 studies were eligible for the review process and each of them have studied the tumor budding in the squamous cell carcinoma in one of the following location: larynx, nasopharynx, tongue, oral tongue, and oral cavity. The findings of these reports suggested tumor budding as a marker of many important events in HNSCC which include: epithelial-mesenchymal transition, invasion, metastasis, and subsequent prognosis. Conclusion: In HNSCC, there is a strong association between tumor budding and tumor progression, in addition to strong correlation with patient prognosis. Further research is required to better understand the molecular background of budding cells and to standardize the scoring method and the cutoff point. References 1. Sarioglu S et al.. Pathol Res Pract 2010;206:88–92. 2. Almangush A et al.. Head Neck 2013;36:811–8. 3. Xie N et al.. J Oral Pathol Med. doi:10.1111/jop.12242. doi:10.1016/j.oraloncology.2015.02.010
8 Therapy resistance in HNSCC – Enhanced levels of the cytoprotective protein survivin is mediated by down-regulation of microRNA-542-3p D. Gößwein a, S. Bäcker b, S. Schlesiger b, M. Epple b, D. Wünsch a, B. Wollenberg c, R. Stauber a, S. Knauer b a
Mainz, Germany Essen, Germany c Lübeck, Germany b
Introduction: Head and neck squamous cell carcinomas (HNSCC) are characterized by overexpression of anti-apoptotic proteins (IAP). Survivin’s dual role as an apoptosis inhibitor and a mitotic effector positioned this smallest member of the IAP family in the front line of cancer research. Survivin plays an essential role in mediating resistance to chemo- and radiation-therapy and thus, has direct clinical relevance. Methods and results: MicroRNAs (miRNAs) are deregulated in a variety of human cancers, including HNSCC. Among several miRNAs, miR-542-3p was found to be down-regulated in HNSCC tumors from patients and established HNSCC tumor cell lines. When analyzing the pathobiological relevance of miR-542 in HNSCC tumor biology,
treatment schedule. First results may be available at the time of presentation. doi:10.1016/j.oraloncology.2015.02.008
Session 2 – Mechanisms of tumor progression and metastasis 6 CD98 identifies a clinically relevant subpopulation of head and neck squamous cell carcinoma cells with stem cell properties S.R. Martens-de Kemp a, M.M. Rietbergen a, A. Brink a, M. Stigter-van Walsum a, E. Bloemena a, W.N. van Wieringen a, M. Slijper b, B.J.M. Braakhuis a, C.R. Leemans a, R.H. Brakenhoff a a b
Amsterdam, Netherlands Utrecht, Netherlands
Introduction: Patients with advanced head and neck squamous cell carcinomas (HNSCC) are often treated with concomitant chemotherapy and radiotherapy, but only 50% is cured. A possible explanation for treatment failure is therapy resistance of the cancer stem cells (CSCs). The application of compounds specifically targeting these CSCs, in addition to routinely used therapeutics, would likely improve clinical outcome. We set out to identify the CSC population in HNSCC. Previously, we found that the antibody K984 specifically targets the cells composing the squamous basal cell layer, the area where HNSCC CSCs likely reside. Materials and methods: Immunoprecipitation and mass spectrometry was used to identify the antigen targeted by the K984 antibody. Next, flow cytometry was used to separate cell populations with high and low K984 antigen expression and these populations were tested for tumorigenicity in immunodeficient mice. Gene expression arraying was applied to further characterize the cell populations. In addition, to investigate the clinical importance of CSC presence in HNSCC, a large cohort of oropharyngeal tumors was immunohistochemically examined for K984 antigen positivity, as well as for CD44 expression, and the scoring results were associated with clinical outcome. Results: We demonstrated that the monoclonal antibody K984 recognizes the CD98 cell surface protein and showed that CD98high cells, in contrast to CD98low cells, are able to generate tumors in immunodeficient mice. This indicates that CD98high cells have stem cell characteristics. Furthermore, the CD98high subpopulation expressed high levels of cell cycle control and DNA repair genes, while the CD98low fraction showed expression patterns that represent the more differentiated cells that form the bulk of the tumor. HPV-positive tumors expressed lower levels of CSC markers CD44 and CD98 than HPV-negative tumors. The number of CD98-positive cells was significantly associated with outcome in HPV-positive tumors, but not in HPV-negative tumors. CD44 expression was not associated with clinical outcome. Conclusion: CD98 is a promising CSC enrichment marker in HNSCC. Our data support the CSC concept in head and neck cancer and the potential relevance of these cells for treatment outcome. doi:10.1016/j.oraloncology.2015.02.009
7 Tumor budding as a prognostic marker in head and neck cancer – A systematic review A. Almangush Helsinki, Finland
e29
Introduction: Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. For the histopathological prognostication of HNSCC, pathologist evaluates characteristics which reveal the biological aggressiveness of tumor. The invasive front (IF) has been suggested as the aggressive part of HNSCC and several histopathological parameters were evaluated at IF. One of these parameters is the tumor budding which defined as presence of single cancer cells or small clusters (<5 cells) at the tumor IF. Tumor budding has been suggested as the result of interaction between the cancer invasive front and the tumor microenvironment. Although numerous reports have studied tumor budding in several cancers during the last decades, the first report evaluated this feature in HNSCC was introduced in 2010 [1]. Later on, our group [2] and other [3] reported a strong prognostic power for tumor budding in tongue carcinoma. This systematic review aims to highlight the importance of tumor budding in HNSCC. Material and methods: The term ‘tumor budding’ was searched in the following databases: PubMed, Scopus and Web of Science. The search was limited to the English language literature published before March 2014. Results of the literature searching: Of the literature searching: We retrieved 122 citations. However, only 5 studies were eligible for the review process and each of them have studied the tumor budding in the squamous cell carcinoma in one of the following location: larynx, nasopharynx, tongue, oral tongue, and oral cavity. The findings of these reports suggested tumor budding as a marker of many important events in HNSCC which include: epithelial-mesenchymal transition, invasion, metastasis, and subsequent prognosis. Conclusion: In HNSCC, there is a strong association between tumor budding and tumor progression, in addition to strong correlation with patient prognosis. Further research is required to better understand the molecular background of budding cells and to standardize the scoring method and the cutoff point. References 1. Sarioglu S et al.. Pathol Res Pract 2010;206:88–92. 2. Almangush A et al.. Head Neck 2013;36:811–8. 3. Xie N et al.. J Oral Pathol Med. doi:10.1111/jop.12242. doi:10.1016/j.oraloncology.2015.02.010
8 Therapy resistance in HNSCC – Enhanced levels of the cytoprotective protein survivin is mediated by down-regulation of microRNA-542-3p D. Gößwein a, S. Bäcker b, S. Schlesiger b, M. Epple b, D. Wünsch a, B. Wollenberg c, R. Stauber a, S. Knauer b a
Mainz, Germany Essen, Germany c Lübeck, Germany b
Introduction: Head and neck squamous cell carcinomas (HNSCC) are characterized by overexpression of anti-apoptotic proteins (IAP). Survivin’s dual role as an apoptosis inhibitor and a mitotic effector positioned this smallest member of the IAP family in the front line of cancer research. Survivin plays an essential role in mediating resistance to chemo- and radiation-therapy and thus, has direct clinical relevance. Methods and results: MicroRNAs (miRNAs) are deregulated in a variety of human cancers, including HNSCC. Among several miRNAs, miR-542-3p was found to be down-regulated in HNSCC tumors from patients and established HNSCC tumor cell lines. When analyzing the pathobiological relevance of miR-542 in HNSCC tumor biology,