RESUMO
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide and is characterized by a fast-paced growth. Like other solid tumors, the HNSCC growth rate results in the development of hypoxic regions identified by the expression of hypoxia-inducible factor 1α (HIF-1α). Interestingly, clinical data have shown that pharmacological induction of intratumoral hypoxia caused an unexpected rise in tumor metastasis and the accumulation of cancer stem cells (CSCs). However, little is known on the molecular circuitries involved in the presence of intratumoral hypoxia and the augmented population of CSCs. Here we explore the impact of hypoxia on the behavior of HNSCC and define that the controlling function of phosphatase and tensin homolog (PTEN) over HIF-1α expression and CSC accumulation are de-regulated during hypoxic events. Our findings indicate that hypoxic niches are poised to accumulate CSCs in a molecular process driven by the loss of PTEN activity. Furthermore, our data suggest that targeted therapies aiming at the PTEN/PI3K signaling may constitute an effective strategy to counteract the development of intratumoral hypoxia and the accumulation of CSCs.-Nascimento-Filho, C. H. V., Webber, L. P., Borgato, G. B., Goloni-Bertollo, E. M., Squarize, C. H., Castilho, R. M. Hypoxic niches are endowed with a protumorigenic mechanism that supersedes the protective function of PTEN.
Assuntos
Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias de Cabeça e Pescoço/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/fisiopatologia , Células-Tronco Neoplásicas/patologia , PTEN Fosfo-Hidrolase/metabolismo , Animais , Apoptose , Movimento Celular , Proliferação de Células , Feminino , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Camundongos Nus , Invasividade Neoplásica , Células-Tronco Neoplásicas/metabolismo , PTEN Fosfo-Hidrolase/genética , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Patient-derived xenograft (PDX) involve the direct surgical transfer of fresh human tumor samples to immunodeficient mice. This systematic review aimed to identify publications of head and neck cancer PDX (HNC-PDX) models, describing the main methodological characteristics and outcomes. METHODS: An electronic search was undertaken in four databases, including publications having used HNC-PDX. Data were analyzed descriptively. RESULTS: 63 articles were yielded. The nude mouse was one most commonly animal model used (38.8 %), and squamous cell carcinoma accounted for the majority of HNC-PDX (80.6 %). Tumors were mostly implanted in the flank (86.3 %), and the latency period ranged from 30 to 401 days. The successful rate ranged from 17 % to 100 %. Different drugs and pathways were identified. CONCLUSION: HNC-PDX appears to significantly recapitulate the morphology of the original HNC and represents a valuable method in translational research for the assessment of the in vivo effect of novel therapies for HNC.