Real-world Imatinib Mesylate Treatment in Patients with Chronic Myeloid Leukemia: The Importance of Molecular Monitoring and the Early Molecular Response.

INTRODUCTION: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia (Ph) chromosome. After the introduction of imatinib mesylate (IM) in 2000, the natural history of the disease changed. Data on the treatment of CML with IM are from randomized clinical trials. Establishing whether these results can be reproduced or if caution is needed when extrapolating data to the general population with CML is essential. OBJECTIVES: To evaluate the molecular response (MR) in patients with chronic-phase CML (CML-CP) not included in clinical studies and correlate them with the responses obtained in clinical trials. METHODS: Between January 2007 and January 2017, 227 patients newly diagnosed with CML-CP treated with IM as first-line treatment were included. This study is an observational, retrospective, and single-center study. RESULTS: At a median follow-up time of 7.3 years, 60.3% of the 227 patients who started IM were still on IM. Early molecular response (EMR) at 3 and 6 months was achieved by 74.2% and 65%, respectively. The median time to a MMR was nine months. The MR4.0 and MR4.5 were 67.2% and 51.1%, respectively. The overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) of the patients who exclusively used IM were 91%, 91%, and 85.1%, respectively. CONCLUSION: The results presented are similar to those described in prospective and randomized trials, demonstrating that the outcomes are reproducible in the real world. EMR at 3 and 6 months reflects better long-term responses, including higher rates of deeper molecular responses. Considering treatment costs, the absence of literature evidence of an impact on overall survival demonstrated by first-line second-generation tyrosine kinase inhibitors (TKIs), and the global OS of 85.8%, imatinib mesylate (IM) is still an excellent therapeutic option.

Differential expression of genes encoding proteins of the HGF/MET system in insulinomas.

BACKGROUND: Insulinomas are the most common functional pancreatic neuroendocrine tumors, whereas histopathological features do not predict their biological behaviour. In an attempt to better understand the molecular processes involved in the tumorigenesis of islet beta cells, the present study evaluated the expression of genes belonging to the hepatocyte growth factor and its receptor (HGF/MET) system, namely, MET, HGF; HGFAC and ST14 (encode HGF activator and matriptase, respectively, two serine proteases that catalyze conversion of pro-HGF to active HGF); and SPINT1 and SPINT2 (encode serine peptidase inhibitors Kunitz type 1 and type 2, respectively, two inhibitors of HGF activator and of matriptase). METHODS: Quantitative real-time reverse transcriptase polymerase chain reaction was employed to assess RNA expression of the target genes in 24 sporadic insulinomas: 15 grade 1 (G1), six grade 2 (G2) and three hepatic metastases. Somatic mutations of MET gene were searched by direct sequencing of exons 2, 10, 14, 16, 17 and 19. RESULTS: Overexpression of MET was observed in the three hepatic metastases concomitantly with upregulation of the genes encoding HGF and matriptase and downregulation of SPINT1. A positive correlation was observed between MET RNA expression and Ki-67 proliferation index while a negative correlation was detected between SPINT1 expression and the mitotic index. No somatic mutations were found in MET gene. CONCLUSION: The final effect of the increased expression of HGF, its activator (matriptase) and its specific receptor (MET) together with a decreased expression of one potent inhibitor of matriptase (SPINT1) is probably a contribution to tumoral progression and metastatization in insulinomas.

HOXB7 mRNA is overexpressed in pancreatic ductal adenocarcinomas and its knockdown induces cell cycle arrest and apoptosis.

BACKGROUND: Human homeobox genes encode nuclear proteins that act as transcription factors involved in the control of differentiation and proliferation. Currently, the role of these genes in development and tumor progression has been extensively studied. Recently, increased expression of HOXB7 homeobox gene (HOXB7) in pancreatic ductal adenocarcinomas (PDAC) was shown to correlate with an invasive phenotype, lymph node metastasis and worse survival outcomes, but no influence on cell proliferation or viability was detected. In the present study, the effects arising from the knockdown of HOXB7 in PDAC cell lines was investigated. METHODS: Real time quantitative PCR (qRT-PCR) (Taqman) was employed to assess HOXB7 mRNA expression in 29 PDAC, 6 metastatic tissues, 24 peritumoral tissues and two PDAC cell lines. siRNA was used to knockdown HOXB7 mRNA in the cell lines and its consequences on apoptosis rate and cell proliferation were measured by flow cytometry and MTT assay respectively. RESULTS: Overexpression of HOXB7 mRNA was observed in the tumoral tissues and in the cell lines MIA PaCa-2 and Capan-1. HOXB7 knockdown elicited (1) an increase in the expression of the pro-apoptotic proteins BAX and BAD in both cell lines; (2) a decrease in the expression of the anti-apoptotic protein BCL-2 and in cyclin D1 and an increase in the number of apoptotic cells in the MIA PaCa-2 cell line; (3) accumulation of cell in sub-G1 phase in both cell lines; (4) the modulation of several biological processes, especially in MIA PaCa-2, such as proteasomal ubiquitin-dependent catabolic process and cell cycle. CONCLUSION: The present study confirms the overexpression of HOXB7 mRNA expression in PDAC and demonstrates that decreasing its protein level by siRNA could significantly increase apoptosis and modulate several biological processes. HOXB7 might be a promising target for future therapies.

Apoptosis through Bcl-2/Bax and cleaved caspase up-regulation in melanoma treated by boron neutron capture therapy.

Boron neutron capture therapy (BNCT) is a binary treatment involving selective accumulation of boron carriers in a tumor followed by irradiation with a thermal or epithermal neutron beam. The neutron capture reaction with a boron-10 nucleus yields high linear energy transfer (LET) particles, alpha and (7)Li, with a range of 5 to 9 µm. These particles can only travel very short distances and release their damaging energy directly into the cells containing the boron compound. We aimed to evaluate proliferation, apoptosis and extracellular matrix (ECM) modifications of B16F10 melanoma and normal human melanocytes after BNCT. The amounts of soluble collagen and Hsp47, indicating collagen synthesis in the ECM, as well as the cellular markers of apoptosis, were investigated. BNCT decreased proliferation, altered the ECM by decreasing collagen synthesis and induced apoptosis by regulating Bcl-2/Bax in melanoma. Additionally, BNCT also increased the levels of TNF receptor and the cleaved caspases 3, 7, 8 and 9 in melanoma. These results suggest that multiple pathways related to cell death and cell cycle arrest are involved in the treatment of melanoma by BNCT.

Hyperinsulinism/hyperammonemia (HI/HA) syndrome due to a mutation in the glutamate dehydrogenase gene / Síndrome de hiperinsulinemia/hiperamonemia devido a uma mutação no gene da glutamato desidrogenase

The hyperinsulinism/hyperammonemia (HI/HA) syndrome is a rare autosomal dominant disease manifested by hypoglycemic symptoms triggered by fasting or high-protein meals, and by elevated serum ammonia. HI/HA is the second most common cause of hyperinsulinemic hypoglycemia of infancy, and it is caused by activating mutations in GLUD1, the gene that encodes mitochondrial enzyme glutamate dehydrogenase (GDH). Biochemical evaluation, as well as direct sequencing of exons and exon-intron boundary regions of the GLUD1 gene, were performed in a 6-year old female patient presenting fasting hypoglycemia and hyperammonemia. The patient was found to be heterozygous for one de novo missense mutation (c.1491A>G; p.Il497Met) previously reported in a Japanese patient. Treatment with diazoxide 100 mg/day promoted complete resolution of the hypoglycemic episodes. Arq Bras Endocrinol Metab. 2012;56(8):485-9.

A síndrome de hiperinsulinemia/hiperamonemia (HI/HA) é uma condição rara, de herança autossômica dominante, que se manifesta por sintomas de hipoglicemia desencadeada por jejum ou refeições de alto conteúdo proteico, juntamente com elevação da concentração de amônia sérica. HI/HA é a segunda causa de hipoglicemia hiperinsulinêmica da infância e é causada por mutações ativadoras no GLUD1, o gene que codifica a enzima mitocondrial glutamato desidrogenase (GDH). A avaliação bioquímica, bem como o sequenciamento direto dos éxons e junções éxon-íntron do gene GLUD1, foi realizada em uma paciente de 6 anos de idade com hipoglicemia de jejum e hiperamonemia. A paciente apresentava uma mutação de novo missense (c.1491A>G; p.Il497Met) em heterozigose, que havia sido previamente relatada em um paciente japonês. O tratamento com diazóxido 100 mg/dia promoveu resolução completa dos episódios hipoglicêmicos. Arq Bras Endocrinol Metab. 2012;56(8):485-9.

Thalidomide treatment down-regulates SDF-1alpha and CXCR4 expression in multiple myeloma patients.

The chemokine stromal-derived factor-1alpha (SDF-1alpha) and its receptor CXCR4 are critically involved in directional migration and homing of plasma cells in multiple myeloma. Here, we show that the expression of SDF-1alpha and CXCR4 was significantly down-regulated in patients treated with thalidomide (n=10) as compared to newly diagnosed MM patients (n=31) and MM patients treated with other drugs (n=38). SDF-1 alpha and CXCR4 expression was also significantly decreased in a RPMI 8226 cell line treated with 10 and 20micromol/L of thalidomide. Our findings indicate that thalidomide therapy induces down-regulation of CXCR4 and its ligand SDF-1alpha in multiple myeloma.

Association between tumoral GH-releasing peptide receptor type 1a mRNA expression and in vivo response to GH-releasing peptide-6 in ACTH-dependent Cushing's syndrome patients.

OBJECTIVE: GH secretagogues (GHS) produce exaggerated ACTH and cortisol responses in Cushing's disease (CD) patients, attributable to their direct action on GH-releasing peptide receptor type 1a (GHSR-1a). However, there are no studies correlating the in vivo response to GHS and GHSR-1a mRNA expression in ACTH-dependent Cushing's syndrome (CS) patients. The aim of this study is to correlate the patterns of ACTH and cortisol response to GH-releasing peptide-6 (GHRP-6) to GHSR-1a expression in ACTH-dependent CS patients. DESIGN: Prospective study in a tertiary referral hospital center. Fifteen CD patients and two ectopic ACTH syndrome (EAS) patients were studied. METHODS: Tumor fragments were submitted to RNA extraction, and GHSR-1a expression was studied through real-time qPCR and compared with normal tissue samples. The patients were also submitted to desmopressin test and vasopressin receptor type 1B (AVPR1B) mRNA analysis by qPCR. RESULTS: GHSR-1a expression was similar in normal pituitary samples and in corticotrophic tumor samples. GHSR-1a expression was higher in patients (CD and EAS) presenting in vivo response to GHRP-6. Higher expression of AVPR1B was observed in the EAS patients responsive to desmopressin, as well as in corticotrophic tumors, as compared with normal pituitary samples, but no correlation between AVPR1B expression and response to desmopressin was observed in the CD patients. CONCLUSIONS: Our results revealed a higher expression of GHSR-1a in the ACTH-dependent CS patients responsive to GHRP-6, suggesting an association between receptor gene expression and in vivo response to the secretagogue in both the CD and the EAS patients.

Hepatocyte growth factor-regulated tyrosine kinase substrate (HGS) and guanylate kinase 1 (GUK1) are differentially expressed in GH-secreting adenomas.

Pituitary tumors, adenomas in their vast majority, represent around 10-15% of the intracranial neoplasms. Pituitary carcinomas are exceedingly rare. Clinically, these neoplasms cause hormonal dysfunctions, and mass effect symptoms as headache and visual disorders in the case of macroadenomas. Pituitary tumorigenesis is still poorly understood. In order to investigate the expression of cancer-related genes in pituitary tumors, we employed a human cancer cDNA macroarray membrane with 1176 well-characterized human genes related to cancer and tumor biology. We were able to identify several differentially expressed genes, among them hepatocyte growth factor-regulated tyrosine kinase substrate (HGS) and guanylate kinase 1 (GUK1) which were over expressed in a pool of clinically nonfunctioning pituitary adenomas, compared with a spinal cord metastasis of a nonfunctioning pituitary carcinoma. HGS and GUK1 mRNA expression were chosen to be validated by quantitative RT-qPCR, however, only GUK1 had the differential expression confirmed between the adenomas and the metastasis of a pituitary carcinoma. We have also investigated HGS and GUK1 mRNA expressions in a series of 46 pituitary adenomas (18 nonfunctioning, 12 GH-secreting, nine PRL-secreting, and seven ACTH-secreting adenomas). HGS and GUK1 were significantly over expressed in GH-secreting adenomas, compared with ACTH-secreting adenomas and nonfunctioning tumors, and with PRL-secreting adenomas, respectively. We have shown that these genes, involved in tumorigenesis in other tissues, are as well over expressed in the pituitary tumors, however, their role in the oncogenesis of these tumors need to be further investigated.

Identificação de genes diferencialmente expressos em tumores hipofisários / Identifications of differentially expressed genes in pituitary adenomas

Nesse estudo foi utilizado um sistema de expressão gênica em larga escala para comparar duas situações distintas; a metástase de um carcinoma hipofisário não funcionante e a mistura de quatro adenomas não funcionantes. O gene da metalotioneína 3 identificado nesse sistema se mostrou mais expresso na mistura dos adenomas não funcionantes em relação à metástase. Estudamos esse gene em uma série de 52 adenomas dos vários subtipos por PCR em tempo real. Identificamos sua maior expressão em tumores secretores de ACTH e menor expressão no carcinoma. A reduzida expressão do gene da metalotioneína 3 no carcinoma poderia ser devido ao fenômeno da metilação a que a região promotora desse gene está sujeita, elevando os radicais livres intracelulares. Já a maior expressão da metalotioneína 3 observada nos tumores secretores de ACTH poderia evidenciar o seu papel na modulação de diferentes fatores de transcrição dependentes de zinco que estariam associados com a diferenciação das células adenohipofisárias nos vários subtipos, bem com sua secreção / We used a high performance system with 19.881 probes for compare expression profile of spinal cord metastasis of a non-functioning pituitary carcinoma and a pool of four non-functioning pituitary adenomas. We identified several different expressed genes among them metallothionein-3 was over-expressed in non-functioning pituitary adenomas as compared with a matastasis of pituitary carcinoma. Next we employed RT-qPCR analysis for this gene in a larger series of different types of pituitary adenomas. There was a significant over expression of this gene in ACTH and non-functioning adenomas in comparison to PRL and GH secreting tumors. The more abundant expression of this gene in ACTH and NF pituitary tumours suggest that metallothionein 3 could be differently expressed in regarding distinct pituitary lineage maybe regulating the activity of some transcription factor of importance in hormone production and/or secretion...