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1.
Oncologist ; 27(3): e251-e264, 2022 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-35274725

RESUMO

BACKGROUND: Gynecologic cancers standard treatment often requires the removal of some reproductive organs, making fertility preservation a complex challenge. Despite heightened oncofertility awareness, knowledge about fertility attitudes and decisions of young patients with gynecologic cancer is scarce. The aim of this systematic review was to highlight what is currently known about knowledge, attitudes, and decisions about fertility, fertility preservation, and parenthood among these patients. METHODS: Peer-reviewed journals published in English were searched in PubMed, Web of Science and EMBASE from January 1, 2000 to July 1, 2020. Childbearing, fertility, fertility preservation, pregnancy, and parenthood attitudes/decisions after gynecologic cancer from women's perspective were evaluated. RESULTS: A total of 13 studies comprised the review. Most of the women valued fertility preservation procedures that could be regarded as a means to restore fertility. A unique feature identified was that fertility preservation was seen also as a way to restore gender identity perceived to be lost or threatened during diagnosis and treatment. Fertility counseling was suboptimal, with wide variability among studies reviewed. Comparisons between gynecologic cancers and other cancer types about fertility counseling rates were inconclusive. The potential negative impact of impaired fertility on patients' mental health and quality of life was also documented. CONCLUSIONS: Fertility and parenthood were important matters in patients' lives, with the majority of patients expressing positive attitudes toward future childbearing. Results confirm that the inclusion of patients with gynecologic cancer in research studies focusing on this topic still remains low. Additionally, the provision of fertility counseling and referral by health professionals is still suboptimal.


Assuntos
Preservação da Fertilidade , Neoplasias dos Genitais Femininos , Feminino , Fertilidade , Preservação da Fertilidade/métodos , Identidade de Gênero , Neoplasias dos Genitais Femininos/complicações , Neoplasias dos Genitais Femininos/terapia , Humanos , Masculino , Gravidez , Qualidade de Vida
3.
Int J Mol Sci ; 21(23)2020 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-33261131

RESUMO

Alternative splicing (AS) is a critical post-transcriptional regulatory mechanism used by more than 95% of transcribed human genes and responsible for structural transcript variation and proteome diversity. In the past decade, genome-wide transcriptome sequencing has revealed that AS is tightly regulated in a tissue- and developmental stage-specific manner, and also frequently dysregulated in multiple human cancer types. It is currently recognized that splicing defects, including genetic alterations in the spliced gene, altered expression of both core components or regulators of the precursor messenger RNA (pre-mRNA) splicing machinery, or both, are major drivers of tumorigenesis. Hence, in this review we provide an overview of our current understanding of splicing alterations in cancer, and emphasize the need to further explore the cancer-specific splicing programs in order to obtain new insights in oncology. Furthermore, we also discuss the recent advances in the identification of dysregulated splicing signatures on a genome-wide scale and their potential use as biomarkers. Finally, we highlight the therapeutic opportunities arising from dysregulated splicing and summarize the current approaches to therapeutically target AS in cancer.


Assuntos
Processamento Alternativo/genética , Biomarcadores Tumorais/genética , Neoplasias/tratamento farmacológico , Neoplasias/genética , Biomarcadores Tumorais/metabolismo , Humanos , Modelos Biológicos , Sítios de Splice de RNA/genética , Transdução de Sinais/genética
4.
Adv Exp Med Biol ; 1157: 1-27, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31342435

RESUMO

mRNA processing events introduce an intricate layer of complexity into gene expression processes, supporting a tremendous level of diversification of the genome's coding and regulatory potential, particularly in vertebrate species. The recent development of massive parallel sequencing methods and their adaptation to the identification and quantification of different RNA species and the dynamics of mRNA metabolism and processing has generated an unprecedented view over the regulatory networks that are established at this level, which contribute to sustain developmental, tissue specific or disease specific gene expression programs. In this chapter, we provide an overview of the recent evolution of transcriptome profiling methods and the surprising insights that have emerged in recent years regarding distinct mRNA processing events - from the 5' end to the 3' end of the molecule.


Assuntos
Processamento Alternativo , RNA Mensageiro , Análise de Sequência de RNA , Transcriptoma , Perfilação da Expressão Gênica , RNA Mensageiro/metabolismo
5.
Biochim Biophys Acta ; 1866(1): 51-63, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27345584

RESUMO

A recently acknowledged morphological pathway to colorectal cancer originates from precursor polyps with a serrated appearance due to branching and folding of the colon epithelium. This serrated origin accounts for up to 30% of all colorectal tumors but these are heterogeneous regarding molecular characteristics and patient outcome. Here we review the current knowledge about the classification of this tumor subtype and its association with five key features: mutation status of the BRAF or KRAS genes, the CpG island methylation phenotype, microsatellite instability, immune cell infiltration, and overexpression of GTPase RAC1b. Subsequently, available therapeutic approaches for targeting these molecular characteristics are presented and critically discussed.


Assuntos
Neoplasias Colorretais/genética , Metilação de DNA/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas rac1 de Ligação ao GTP/genética , Colo/metabolismo , Colo/patologia , Neoplasias Colorretais/patologia , Ilhas de CpG/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Instabilidade de Microssatélites , Mutação , Transdução de Sinais , Proteínas rac1 de Ligação ao GTP/biossíntese
6.
Biochim Biophys Acta ; 1852(12): 2712-21, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26407519

RESUMO

Mucopolysaccharidosis II is a lysosomal storage disorder caused by mutations in the IDS gene, including exonic alterations associated with aberrant splicing. In the present work, cell-based splicing assays were performed to study the effects of two splicing mutations in exon 3 of IDS, i.e., c.241C>T and c.257C>T, whose presence activates a cryptic splice site in exon 3 and one in exon 8, i.e., c.1122C>T that despite being a synonymous mutation is responsible for the creation of a new splice site in exon 8 leading to a transcript shorter than usual. Mutant minigene analysis and overexpression assays revealed that SRSF2 and hnRNP E1 might be involved in the use and repression of the constitutive 3' splice site of exon 3 respectively. For the c.1122C>T the use of antisense therapy to correct the splicing defect was explored, but transfection of patient fibroblasts with antisense morpholino oligonucleotides (n=3) and a locked nucleic acid failed to abolish the abnormal transcript; indeed, it resulted in the appearance of yet another aberrant splicing product. Interestingly, the oligonucleotides transfection in control fibroblasts led to the appearance of the aberrant transcript observed in patients' cells after treatment, which shows that the oligonucleotides are masking an important cis-acting element for 5' splice site regulation of exon 8. These results highlight the importance of functional studies for understanding the pathogenic consequences of mis-splicing and highlight the difficulty in developing antisense therapies involving gene regions under complex splicing regulation.

7.
RNA ; 20(4): 474-82, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24550521

RESUMO

The premessenger RNA of the majority of human genes can generate various transcripts through alternative splicing, and different tissues or disease states show specific patterns of splicing variants. These patterns depend on the relative concentrations of the splicing factors present in the cell nucleus, either as a consequence of their expression levels or of post-translational modifications, such as protein phosphorylation, which are determined by signal transduction pathways. Here, we analyzed the contribution of protein kinases to the regulation of alternative splicing variant Rac1b that is overexpressed in certain tumor types. In colorectal cells, we found that depletion of AKT2, AKT3, GSK3ß, and SRPK1 significantly decreased endogenous Rac1b levels. Although knockdown of AKT2 and AKT3 affected only Rac1b protein levels suggesting a post-splicing effect, the depletion of GSK3ß or SRPK1 decreased Rac1b alternative splicing, an effect mediated through changes in splicing factor SRSF1. In particular, the knockdown of SRPK1 or inhibition of its catalytic activity reduced phosphorylation and subsequent translocation of SRSF1 to the nucleus, limiting its availability to promote the inclusion of alternative exon 3b into the Rac1 pre-mRNA. Altogether, the data identify SRSF1 as a prime regulator of Rac1b expression in colorectal cells and provide further mechanistic insight into how the regulation of alternative splicing events by protein kinases can contribute to sustain tumor cell survival.


Assuntos
Processamento Alternativo/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Western Blotting , Núcleo Celular/genética , Neoplasias Colorretais/metabolismo , Éxons/genética , Imunofluorescência , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/genética , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Humanos , Microscopia de Fluorescência , Proteínas Nucleares/genética , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Processamento de Serina-Arginina , Transdução de Sinais , Células Tumorais Cultivadas , Proteínas rac1 de Ligação ao GTP/metabolismo
9.
J Nerv Ment Dis ; 200(5): 395-400, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22551792

RESUMO

This prospective longitudinal study investigated depressive symptoms and its association with students' demographic, academic, and health factors in undergraduate students of pharmacy in Syria. Students attending any year (1st to 5th year) were assessed in the first semester (time 1) and in the second semester (time 2). An academic year comprises two semesters of 16 weeks each. Data for 450 students were analyzed at time 1, and 262 students were assessed at the two time points. Our results showed that most of the students experienced depressive symptoms, with a substantial percentage presenting moderate to severe levels of symptoms (35% or 450 students at time 1; 23% or 262 students at time 2). Across the two semesters, a significant decrease in depressive symptoms was observed for students with complete data at the two time points. Depressive symptoms at time 2 increased significantly with increasing depressive scores at time 1 and decreasing students' expectations about their academic performance. Our results support the clear need for dynamic, full-time, and accessible psychological services at the university to promote and assess mental health and to deliver psychological interventions to students at need.


Assuntos
Depressão/epidemiologia , Estudantes de Farmácia/psicologia , Escolaridade , Feminino , Humanos , Estudos Longitudinais , Masculino , Escalas de Graduação Psiquiátrica , Estudantes de Farmácia/estatística & dados numéricos , Inquéritos e Questionários , Síria/epidemiologia , Adulto Jovem
10.
Hum Mol Genet ; 18(19): 3696-707, 2009 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-19602482

RESUMO

The small GTPase Rac1 regulates signaling pathways controlling actin-dependent cell motility as well as gene transcription. An alternative splicing variant Rac1b is overexpressed in a subset of colorectal tumors and is required to sustain tumor cell viability. Thus, it is of therapeutic interest to understand the molecular mechanism behind the overexpression of Rac1b through alternative splicing. Here we describe that ASF/SF2 and SRp20 are two antagonistic splicing factors regulating Rac1b expression in colorectal tumor cells. Using an Rac1 minigene, we identified that SRp20 increased skipping of alternative exon 3b in HT29 colorectal cells, whereas ASF/SF2 increased its inclusion. The depletion of the endogenous expression of these splicing factors by specific small interfering RNA confirmed that ASF/SF2 acts as an enhancer of endogenous Rac1b splicing, whereas SRp20 acts as a silencer. Point mutations in exon 3b defined two adjacent regulatory regions required for skipping or inclusion of exon 3b, which are recognized in vitro by SRp20 and ASF/SF2, respectively. Both splicing factors were found to be regulated by upstream signaling pathways: the inhibition of the phosphatidylinositol 3-kinase pathway increased protein levels of ASF/SF2 and promoted Rac1b, whereas activation of beta-catenin/TCF4 increased expression of SRp20 and inhibited that of Rac1b. Together, these data reveal that signaling pathways act in concert to target independent splicing factors and achieve the correct combinatorial code to regulate alternative splicing of the small GTPase Rac1.


Assuntos
Processamento Alternativo , Neoplasias Colorretais/genética , Proteínas Nucleares/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas de Ligação a RNA/metabolismo , Transdução de Sinais , Proteínas Wnt/metabolismo , Proteínas rac1 de Ligação ao GTP/genética , Sequência de Bases , Linhagem Celular Tumoral , Neoplasias Colorretais/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/genética , Fosfatidilinositol 3-Quinases/genética , Ligação Proteica , Proteínas de Ligação a RNA/genética , Alinhamento de Sequência , Fatores de Processamento de Serina-Arginina , Proteínas Wnt/genética , Proteínas rac1 de Ligação ao GTP/metabolismo
11.
Cancers (Basel) ; 13(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34638222

RESUMO

It is well established that fertility is an important issue for young women with cancer at reproductive age, as many have not initiated or completed their parenthood goals when diagnosed. Because cancer treatments may impair fertility, women face fertility decisions that are often complex and surrounded by uncertainty. This may put patients at risk for psychological distress and the experience of regret regarding decisions made at diagnosis, which may be associated with a negative impact on women's QoL. This narrative review addresses current knowledge about decisional regret regarding fertility preservation decisions in adult female cancer patients at reproductive age. Electronic searches were conducted on Pubmed database for articles published in English from 1 January 2000 to 1 July 2021 that assessed decisional regret following fertility decisions in young women diagnosed at childbearing age. Of the 96 articles identified, nine provided information on decisional regret regarding fertility decisions. Studies reported that, overall, decisional regret regarding oncofertility decisions was low. Factors associated with the experience of decisional regret were patients' perceived quality and satisfaction with fertility counseling received, the decision to undergo fertility preservation, desire for children and decisional conflict. Health providers should be aware of the factors that are potentially modifiable and prone to improvement in order to reduce decisional regret. All efforts should be made to improve availability of and access to tailored high quality fertility counseling and fertility preservation. Given the growing evidence that decision aids (DAs) are effective in increasing knowledge and reducing decisional conflict and regret, their use in a routine and timely manner to complement fertility counseling is recommended.

12.
RNA ; 14(12): 2538-49, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18952824

RESUMO

Gene expression programs can become activated in response to extracellular signals. One evolutionarily conserved example is binding of Wnt glycoproteins to their receptor, which triggers a signal transduction cascade that stabilizes cytoplasmic beta-catenin protein, allowing it to translocate into the nucleus. There, beta-catenin binds to TCF/Lef family transcription factors and promotes the expression of target genes. Mutations in either the beta-catenin gene itself or its partner protein APC are responsible for the oncogenic activation of this pathway in colorectal tumors. Here we report the splicing factor SRp20 as a novel target gene of beta-catenin/TCF4 signaling. Transfection of activated beta-catenin mutants into colorectal cells increased expression of endogenous SRp20 transcript and protein and also stimulated a luciferase reporter construct containing the SRp20 gene promoter. In contrast, inhibition of endogenous beta-catenin signaling by a dominant-negative TCF4 construct down-regulated both luciferase reporter and SRp20 expression. We further demonstrate that the beta-catenin/TCF4-mediated increase in SRp20 protein levels is sufficient to modulate alternative splicing decisions in the cells. In particular, we observed a change in the alternative splicing pattern in a control minigene reporter as well as in the endogenous SRp20-regulated CD44 cell adhesion protein. These results demonstrate that the beta-catenin/TCF4 pathway not only stimulates gene transcription, but also promotes the generation of transcript variants through alternative splicing. Our data support the recent notion that transcription and alternative splicing represent two different layers of gene expression and that signaling pathways act upon a coordinated network of transcripts in each layer.


Assuntos
Neoplasias Colorretais/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Proteínas de Ligação a RNA/metabolismo , Fatores de Transcrição/metabolismo , beta Catenina/metabolismo , Processamento Alternativo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Linhagem Celular Tumoral , Humanos , Receptores de Hialuronatos/metabolismo , Fatores de Processamento de Serina-Arginina , Fator de Transcrição 4
13.
Curr Opin Obstet Gynecol ; 22(1): 30-5, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19809316

RESUMO

PURPOSE OF REVIEW: This review addresses current knowledge about long-term quality of life (QOL) in survivors of gynecological cancer. RECENT FINDINGS: Survivors of gynecological cancer have generally good long-term QOL, equivalent to healthy controls; however, specific deficits are more prevalent than in women without cancer. Ovarian cancer survivors have good QOL, with few physical symptoms. Psychological distress and sexual impairments exist. No differences in QOL occur between survivors of early and advanced stage disease. Cervical cancer survivors treated with radiotherapy reported more QOL impairments than survivors treated with other approaches. There were no differences on sexuality and sexual function among survival time periods. In general, cervical cancer survivors seem to have a positive attitude towards sexuality. Self-esteem is an important psychological variable in the study of long-term QOL. SUMMARY: When considering specific diseases, ovarian and cervical cancers were the most researched. Endometrial cancer was underreported in recent literature. Studies addressing vulvar and vaginal cancers are lacking. Physical, psychosocial and sexuality were the most investigated QOL domains. Advances are observed in current research; however, more rigorous and larger studies are required to further understand long-term QOL. Available findings are crucial to develop interventions to support those at risk for QOL impairments.


Assuntos
Neoplasias dos Genitais Femininos/psicologia , Qualidade de Vida , Sobreviventes/psicologia , Feminino , Humanos
14.
Rev Iberoam Micol ; 27(3): 119-24, 2010 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-20403455

RESUMO

BACKGROUND: The ability of the Candida species to colonize surfaces can be considered as a risk factor for oral infection. AIMS: To establish oral Candida carriage in patients attending a dental clinic in Braga, Portugal. METHODS: A total of 97 patients were analysed. Swab samples were collected and directly cultured onto CHROMagar Candida. Representative yeasts were identified by polymerase chain reaction. RESULTS: From the samples analysed 54.6% (n=53) were Candida positive, and Candida albicans was the most frequently isolated species, accounting for 79% of all the species identified. Non-C. albicans Candida (NCAC) species recovered included Candida parapsilosis, Candida glabrata, Candida tropicalis, and Candida guilliermondii. There was a lack of association between the presence of C. albicans or NCAC species, and age, gender, or prostheses wearing in this population. In 17% of the cases (n=9), polymicrobial cultures, with two different Candida species, were identified. CONCLUSIONS: This study shows a high Candida carriage rate among this population, thus pointing to the relevance of an accurate diagnostic approach in Candida species identification.


Assuntos
Candida/isolamento & purificação , Portador Sadio , Boca/microbiologia , Clínicas Odontológicas , Feminino , Humanos , Masculino , Portugal
15.
J Clin Psychol Med Settings ; 17(2): 167-73, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20490630

RESUMO

This longitudinal study investigated levels of anxiety and depression in women who underwent clinical investigations to diagnose a possible ovarian cancer. Women completed the Hospital Anxiety and Depression Scale (HADS), prior to clinical investigations (Time 1), after receiving diagnostic results (Time 2) and at 3 months follow-up (Time 3). Thirty women completed the assessments at Time 1 and Time 2, and 22 women were re-assessed at Time 3. The majority of the sample (56%) scored as a case of anxiety prior to clinical investigations. A significant decrease in anxiety and depression across time was found. Levels of anxiety and depression between women with a subsequent cancer diagnosis and women with a benign result were not significantly different. This study showed that clinical investigations are a highly anxiety-provoking event. In addition, the diagnosis of cancer did not significantly elevate or maintain levels of anxiety and depression compared to a benign diagnosis.


Assuntos
Transtornos de Adaptação/diagnóstico , Transtornos de Adaptação/psicologia , Transtornos de Ansiedade/psicologia , Transtorno Depressivo/psicologia , Neoplasias Ovarianas/psicologia , Adaptação Psicológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Ansiedade/diagnóstico , Transtorno Depressivo/diagnóstico , Feminino , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Doenças Ovarianas/diagnóstico , Doenças Ovarianas/psicologia , Neoplasias Ovarianas/diagnóstico , Inventário de Personalidade/estatística & dados numéricos , Psicometria
16.
Cancer Med ; 9(20): 7375-7380, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32864852

RESUMO

Oncofertility has evolved over the years, with a prodigious amount of research documenting the importance of fertility for young patients with cancer, and the potential impact that fertility impairments due to cancer treatments has on their Quality of Life (QoL). Multiple professional bodies and scientific societies have included fertility as an integral part of clinical management. Clinical guidelines advocate that health professionals have the duty to discuss the risk of infertility and fertility preservation options as early as possible and refer to fertility specialists when appropriate. Collectively, fertility decisions are regarded as difficult for both patients and providers. Since providing fertility-related information is vital for better decision making, researchers and policy makers have concentrated their efforts in developing educational tools to aid decisions and guidelines to optimize the delivery of this information, focusing mainly on patients-providers and largely neglecting the role and influence that partners play in this process. Here, we reflect on the importance of partners in fertility decisions, with a focus on the provision of fertility-related information that is also geared towards partner. We highlight the need to involve partners in fertility discussions, and that their needs should be taken into account in both clinical guidelines and in the development of educational tools, for an optimal decision-making process.


Assuntos
Preservação da Fertilidade/estatística & dados numéricos , Preservação da Fertilidade/tendências , Fertilidade , Neoplasias/epidemiologia , Adulto , Fatores Etários , Tomada de Decisão Clínica , Técnicas de Apoio para a Decisão , Gerenciamento Clínico , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/estatística & dados numéricos , Medicina Baseada em Evidências/tendências , Feminino , Humanos , Neoplasias/diagnóstico , Neoplasias/terapia , Guias de Prática Clínica como Assunto , Vigilância em Saúde Pública
17.
Oncotarget ; 11(47): 4421-4437, 2020 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-33315986

RESUMO

A major risk factor promoting tumor development is chronic inflammation and the use of nonsteroidal anti-inflammatory drugs (NSAID), including ibuprofen, can decrease the risk of developing various types of cancer, including colorectal cancer (CRC). Although the molecular mechanism behind the antitumor properties of NSAIDs has been largely attributed to inhibition of cyclooxygenases (COXs), several studies have shown that the chemopreventive properties of ibuprofen also involve multiple COX-independent effects. One example is its ability to inhibit the alternative splicing event generating RAC1B, which is overexpressed in a specific subset of BRAF-mutated colorectal tumors and sustains cell survival. Here we describe the mechanism by which ibuprofen prevents RAC1B alternative splicing in a BRAF mutant CRC cell line: it leads to decreased translocation of SRPK1 and SRSF1 to the nucleus and is regulated by a WNK1/GSK3ß/SRPK1 protein kinase complex. Surprisingly, we demonstrate that ibuprofen does not inhibit the activity of any of the involved kinases but rather promotes disassembly of this regulatory complex, exposing GSK3ß serine 9 to inhibitory phosphorylation, namely by AKT, which results in nuclear exclusion of SRPK1 and SRSF1 hypophosphorylation. The data shed new light on the biochemical mechanisms behind ibuprofen's action on alternative spliced RAC1B and may support its use in personalized approaches to CRC therapy or chemoprevention regimens.

18.
Vet Sci ; 7(3)2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899831

RESUMO

Canine leishmaniosis (CanL) is a chronic and potentially fatal disease. The prognosis of CanL depends on the severity of the clinical signs and clinicopathological abnormalities presented by the dog at the time of diagnosis. This study aims to estimate the survival time of dogs with CanL, determining the prognostic value of different clinical and clinicopathological parameters. Medical records of 99 dogs diagnosed with CanL in five veterinary centers of the Alentejo region (Portugal) were examined retrospectively. The majority of dogs presented hyperproteinemia, moderate normocytic normochromic anemia, normal blood urea and creatinine levels and were classified as stage 1 according to the International Interest Society (IRIS) guidelines at the time of diagnosis. The severity of anemia, presence of concomitant infectious diseases at the time of diagnosis and the anti-Leishmania therapy were correlated with the survival time. The influence of renal dysfunction was evaluated by Receiver Operating Characteristic (ROC) curve and survival analysis. Survival analysis demonstrated that patients classified as IRIS 1 at the time of diagnosis survived more than four years, in contrast with dogs classified as IRIS 2 that survived around two and half years and dogs classified as IRIS 3-4 that survived around one month. IRIS stage deteriorated during the course of CanL in one third of the dogs and was the principal cause of death or euthanasia in a high proportion of animals. In some cases, dogs did not receive anti-Leishmania treatment or abandoned the veterinary follow-ups, which may have considerable repercussions for animal wellbeing and public health. This study reinforces the value of blood urea and creatinine levels as prognostic factors in CanL.

19.
Gastroenterology ; 135(3): 899-906, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18602919

RESUMO

BACKGROUND & AIMS: In colorectal tumors, activating BRAF mutations occur alternative to KRAS oncogenic mutations, but in cell culture possess a much lower transforming capacity. Rac1b, a hyperactive Rac1 spliced variant, is over expressed in some colorectal tumors and activates the transcription factor nuclear factor-kappaB, which initiates a transcriptional response that promotes cell cycle progression and inhibits apoptosis. The aim of this study was to determine whether Rac1b overexpression is associated with B-Raf(V600E) in primary colorectal tumors and whether a functional cooperation between these 2 proteins exists in colorectal cells with a wild-type KRAS genotype. METHODS: Screening of BRAF and KRAS mutations by direct sequencing and Rac1b mRNA expression analysis by quantitative real-time polymerase chain reaction were conducted in 74 samples (13 normal colonic mucosa, 45 primary colorectal tumors, and 16 colorectal cancer [CRC] cell lines). RNA interference and focus formation assays were used to assess the cooperation between Rac1b and B-Raf(V600E) in cancer cell viability. RESULTS: Rac1b overexpression and B-Raf(V600E) are significantly associated in primary colorectal tumors (P = .008) and colorectal cell lines. The simultaneous suppression of both proteins dramatically decreased CRC cell viability through impaired cell-cycle progression and increased apoptosis. CONCLUSIONS: Our data demonstrate that Rac1b and B-Raf(V600E) functionally cooperate to sustain colorectal cell viability and suggest they constitute an alternative survival pathway to oncogenic K-Ras. These results reveal a novel molecular characteristic of colon tumors containing B-Raf mutations and should help in defining novel targets for cancer therapy.


Assuntos
Processamento Alternativo , Sobrevivência Celular/genética , Neoplasias Colorretais/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas rac1 de Ligação ao GTP/genética , Ciclo Celular/genética , Morte Celular/genética , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Genes ras/genética , Humanos , Mutação , Interferência de RNA , Transdução de Sinais , Células Tumorais Cultivadas
20.
Mutat Res ; 662(1-2): 33-6, 2009 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-19111562

RESUMO

A missense mutation at codon 640 in the APC gene was identified in a familial adenomatous polyposis (FAP) patient, however, its pathological consequence remained unclear. Here we found that this missense mutation interferes at the nucleotide level with an exonic splicing regulatory element and leads to aberrant splicing of the mutant APC transcript rather than exerting its effect through the observed amino acid change. Analysis of the patient RNA revealed complete skipping of exon 14 in transcripts from the mutant APC allele, leading to a frameshift and a premature stop codon. When cloned into a splicing reporter minigene and transfected into colorectal cell lines, the exon 14 point mutation c.1918C>G (pR640G) was found sufficient to cause the observed exon skipping. Bioinformatic analysis predicted the mutation to change SRp55, hnRNP A1 or ASF/SF2 splicing factor binding sites. Using RNA interference methodology these predictions were experimentally validated and revealed that only ASF/SF2 was required for exon 14 inclusion. These research data identify APC mutation c.1918C>G (pR640G) as pathogenic and indicate a mechanism involving disruption of an ASF/SF2 exonic splicing enhancer element. The results allow genetic diagnosis of a hereditary tumour predisposition but also illustrate the need to complement in silico prediction by splicing reporter assays.


Assuntos
Proteína da Polipose Adenomatosa do Colo/genética , Processamento Alternativo/genética , Elementos Facilitadores Genéticos/genética , Éxons/genética , Mutação de Sentido Incorreto/genética , Proteínas Nucleares/genética , Polipose Adenomatosa do Colo/genética , Genes Reporter , Humanos , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA , Fatores de Processamento de Serina-Arginina
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