RESUMO
Proteoglycans are involved in tumor development and may regulate the Hedgehog (HH) pathway. This study aimed to investigate the gene and protein expression of glypican-1 (GPC1), -3 (GPC3), and -5 (GPC5) in oral squamous cell carcinoma (OSCC) and tumor-free lateral margins (TM) and their association with the HH pathway. Quantitative PCR was performed for GPC1, GPC3, GPC5, SHH, PTCH1, SMO, and GLI1 genes in samples of OSCC (n=31), TM (n=12), and non-neoplastic oral mucosa (NNM) of healthy patients (n=6), alongside an immunohistochemical evaluation of GPC1, GPC3, and GPC5 proteins and HH proteins SHH and glioma-associated oncogene homolog 1 (GLI1). Double staining for GPC3/SHH, GPC5/SHH, GPC3/tubulin [ac Lys40], GPC5/Tubulin [ac Lys40], and GPC5/GLI1 was also performed. Overexpression of GPC1 and GPC5 in tumor samples and underexpressed levels of GPC3 gene transcripts were observed when compared with TM (standard sample). HH pathway mRNA aberrant expression in OSCC samples and a negative correlation between GPC1 and GPC5 at transcription levels were detected. GPC1 staining was rare in OSCC, but positive cells were found in NNM and TM. Otherwise positive immunostaining for GPC3 and GPC5 was observed in OSCCs, but not in NNM and TM. Blood vessels adjacent to tumor islands were positive for GPC1 and GPC5. Co-localization of GPC3-positive and GPC5-positive cells with SHH and Tubulin [ac Lys40] proteins was noted, as well as of GPC5 and GLI1. The absence of the GPC1 protein in neoplastic cells, underexpression of the GPC3 gene, and co-localization of GPCs and HH proteins may indicate the maintenance of aberrant HH pathway activation in OSCC.
Assuntos
Regulação Neoplásica da Expressão Gênica , Glipicanas , Neoplasias de Cabeça e Pescoço , Proteínas Hedgehog , Proteínas de Neoplasias , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Adulto , Feminino , Glipicanas/biossíntese , Glipicanas/genética , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , 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/patologiaRESUMO
Insulin-like growth factor II mRNA-binding protein 3 (IMP3) is strongly expressed in malignant tumors and has been associated with their aggressive behavior. The aim of this study was to evaluate the presence of IMP3 in a series of salivary gland tumors. The sample consisted of 9 pleomorphic adenomas (PA), 14 adenoid cystic carcinomas (ACC), and 13 mucoepidermoid carcinomas (MEC) that were investigated by immunohistochemical technique. All cases of PA and MEC were positive for IMP3 particularly in the cytoplasm. PA showed 4 cases as high expression and 6 as low expression. MEC showed 10 cases as low expression and 3 as high expression. For ACC, 4 cases were high expression, whereas 6 cases were low expression. No significant difference was observed between tumors (P>0.05, Fisher's test) when both scores of IMP3 were compared. This study showed that MEC seems to be more sensitive to IMP3 than ACC and provided an insight into this protein in salivary gland tumors. Furthermore, although IMP3 is not a specific diagnostic marker to distinguish the tumors studied, it seems to mediate cell adhesion and migration in these tumors. Further studies should be performed to better understand the IMP3 biology in salivary gland tumors.