RESUMO
The high mobility group A (HMGA) proteins are found to be aberrantly expressed in several tumors. Studies (in vitro and in vivo) have shown that HMGA protein overexpression has a causative role in carcinogenesis process. HMGA proteins regulate cell cycle progression through distinct mechanisms which strongly influence its normal dynamics along malignant transformation. Tumor protein p53 (TP53) is the most frequently altered gene in cancer. The loss of its activity is recognized as the fall of a barrier that enables neoplastic transformation. Among the different functions, TP53 signaling pathway is tightly involved in control of cell cycle, with cell cycle arrest being the main biological outcome observed upon p53 activation, which prevents accumulation of damaged DNA, as well as genomic instability. Therefore, the interaction and opposing effects of HMGA and p53 proteins on regulation of cell cycle in normal and tumor cells are discussed in this review. HMGA proteins and p53 may reciprocally regulate the expression and/or activity of each other, leading to the counteraction of their regulation mechanisms at different stages of the cell cycle. The existence of a functional crosstalk between these proteins in the control of cell cycle could open the possibility of targeting HMGA and p53 in combination with other therapeutic strategies, particularly those that target cell cycle regulation, to improve the management and prognosis of cancer patients.
Assuntos
Pontos de Checagem do Ciclo Celular/fisiologia , Proteínas HMGA/metabolismo , Neoplasias/patologia , Proteína Supressora de Tumor p53/metabolismo , Dano ao DNA , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica , Proteínas HMGA/genética , Humanos , Neoplasias/genética , Neoplasias/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genéticaRESUMO
Endometrioid endometrial carcinomas (EEC) are the most common malignant gynecologic tumors. Despite the increase in EEC molecular knowledge, the identification of new biomarkers involved in disease's development and/or progression would represent an improvement in its course. High-mobility group A protein (HMGA) family members are frequently overexpressed in a wide range of malignancies, correlating with a poor prognosis. Thus, the aim of this study was to analyze HMGA1 and HMGA2 expression pattern and their potential role as EEC biomarkers. HMGA1 and HMGA2 expression was initially evaluated in a series of 46 EEC tumors (stages IA to IV), and the findings were then validated in The Cancer Genome Atlas (TCGA) EEC cohort, comprising 381 EEC tumors (stages IA to IV). Our results reveal that HMGA1 and HMGA2 mRNA and protein are overexpressed in ECC, but only HMGA1 expression is associated with increased histological grade and tumor size. Moreover, HMGA1 but not HMGA2 overexpression was identified as a negative prognostic factor to EEC patients. Finally, a positive correlation between expression of HMGA1 pseudogenes-HMGA1-P6 and HMGA1-P7-and HMGA1 itself was detected, suggesting HMGA1 pseudogenes may play a role in HMGA1 expression regulation in EEC. Thus, these results indicate that HMGA1 overexpression possesses a potential role as a prognostic biomarker for EEC.
Assuntos
Carcinoma Endometrioide/genética , Neoplasias do Endométrio/genética , Proteína HMGA1a/genética , Proteína HMGA2/genética , Adulto , Biomarcadores Tumorais/biossíntese , Biomarcadores Tumorais/genética , Carcinoma Endometrioide/metabolismo , Neoplasias do Endométrio/metabolismo , Feminino , Proteína HMGA1a/biossíntese , Proteína HMGA2/biossíntese , Humanos , Pessoa de Meia-Idade , Prognóstico , TranscriptomaRESUMO
FOXM1 (forkhead box protein M1) is a transcription factor that participates in all stages of tumor development, mainly through the control of cell cycle and proliferation, regulating the expression of genes involved in G1/S and G2/M transition and M phase progression. The ubiquitin conjugating enzyme E2 (UBE2C) is a member of the anaphase promoting complex/cyclosome, promoting the degradation of several target proteins along cell cycle progression, during metaphase/anaphase transition. FOXM1 and UBE2C have been found overexpressed in a wide range of different solid tumors. Therefore, the aim of this study was to investigate whether UBE2C is a transcriptional target of FOXM1, using esophageal squamous cell carcinoma (ESCC) as a model, in addition to several cancer-deposited data. Our results show that FOXM1 and UBE2C expression present a positive correlation in normal tissues and in 25 distinct tumor types, including ESCC, where these genes are overexpressed. Moreover, FOXM1 binds to UBE2C promoter region in ESCC cell line and transcriptionally activates it, leading to UBE2C upregulation. In conclusion, this study provides evidences that FOXM1 transcriptionally regulates UBE2C expression in ESCC and their deregulation may be a general phenomenon in human neoplasias.
RESUMO
AIMS: Malignant tumours from the upper aerodigestive tract are grouped collectively in the class of head and neck squamous cell carcinoma (HNSCC). The head and neck tumours were responsible for more than 500 000 cancer cases in 2012, accounting for the sixth highest incidence rate and mortality worldwide among all tumour types. Laryngeal squamous cell carcinoma (LSCC) possesses the second highest incidence rate among all HNSCC. Despite significant advances in surgery and radiotherapy during the last few decades, no treatment has been shown to achieve a satisfactory therapeutic outcome and the mortality rate of LSCC is still high, with a 5-year survival rate of 64%. Therefore, further investigations are required to identify the pathogenesis of LSCC. METHODS AND RESULTS: In order to search for new LSCC biomarkers, we have analysed the expression of the HMGA family members, HMGA1 and HMGA2, by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunohistochemistry. HMGA proteins are usually absent in the healthy adult tissues. In contrast, their constitutive expression is a feature of several neoplasias, being associated with a highly malignant phenotype and reduced survival. Here, we report HMGA2 overexpression in larynx carcinomas. Conversely, HMGA1 does not show any differences in its expression between normal and carcinoma tissues. Interestingly, HMGA2 overexpression appears associated with that of two HMGA1-pseudogenes, HMGA1P6 and HMGA1P7, acting as a sponge for HMGA1- and HMGA2-targeting microRNAs and involved in several human cancers. CONCLUSIONS: Therefore, HMGA2 overexpression appears to be a strong feature of larynx carcinoma, supporting its detection as a valid tool for the diagnosis of these malignancies.
Assuntos
Carcinoma/genética , Regulação Neoplásica da Expressão Gênica , Proteína HMGA1a/genética , Proteína HMGA2/genética , Neoplasias Laríngeas/genética , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinoma/metabolismo , Carcinoma/patologia , Feminino , Proteína HMGA1a/metabolismo , Proteína HMGA2/metabolismo , Humanos , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patologia , Laringe/metabolismo , Laringe/patologia , Masculino , MicroRNAs/genética , MicroRNAs/metabolismo , Pessoa de Meia-IdadeRESUMO
The esophageal squamous cell carcinoma (ESCC) is widely known as a highly lethal and poor understood cancer, then requiring the search for novel molecular markers to improve its management and patients survival. Recently, ubiquitin-conjugating enzyme E2C (UBE2C) has been figuring as a prominent tumor biomarker candidate, once it has been recognized as a key player in cell cycle progression. In this way, the aim of this study was to evaluate the expression profile of UBE2C gene and protein in ESCC samples, as well as its diagnostic and prognostic marker potential, and its contribution to ESSC genesis and/or progression by performing in vitro functional assays. The analysis of UBE2C gene expression in 52 paired ESCC samples (tumor and respective histologically normal surrounding tissue), by qRT-PCR, revealed that this gene is overexpressed in 73% of ESCC samples. Subsequently, immunohistochemical analysis confirmed that UBE2C protein expression was upregulated in all ESCC cases, but absent in the histologically normal tumor surrounding tissues. Moreover, we showed that UBE2C mRNA expression was able to accurately discriminate ESCC tissue from both healthy esophageal and histologically normal tumor surrounding tissues, pointing out its role as a diagnostic marker for this cancer. Finally, we report that UBE2C affects proliferation rates and cell cycle profile of ESCC cell lines, by directly interfering with cyclin B1 protein levels, suggesting its involvement in crucial steps of ESCC carcinogenesis.
Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/patologia , Proliferação de Células , Neoplasias Esofágicas/patologia , Regulação Neoplásica da Expressão Gênica , Enzimas de Conjugação de Ubiquitina/metabolismo , Adulto , Idoso , Apoptose , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/cirurgia , Ciclo Celular , Progressão da Doença , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Prognóstico , Taxa de Sobrevida , Células Tumorais Cultivadas , Enzimas de Conjugação de Ubiquitina/genéticaRESUMO
Esophageal Squamous Cell Carcinoma (ESCC) is the most common esophageal tumor worldwide. However, there is still a lack of deeper knowledge about biological alterations involved in ESCC development. High Mobility Group A (HMGA) protein family has been related with poor outcome and malignant cell transformation in several tumor types. In this way, the aim of this study was to analyze the expression of HMGA1 and HMGA2 expression in ESCC and their role in crucial cellular features. We evaluated HMGA1 and HMGA2 mRNA expression in 52 paired ESCC and normal surrounding tissue samples by qRT-PCR. Here, we show that HMGA2, but not HMGA1, is overexpressed in ESCC samples. This result was further confirmed by the immunohistochemical analysis. Indeed, accordingly to mRNA expression data, HMGA2, but not HMGA1, was overexpressed in approximately 90% of ESCC samples, while it was barely expressed in the respective control. Conversely, HMGA1, but not HMGA2, was overexpressed in esophageal adenocarcinoma samples. Interestingly, HMGA2 abrogation attenuated the malignant phenotype of two ESCC cell lines, suggesting that HMGA2 overexpression is involved in ESCC progression.