Publications by authors named "Leticia da Conceicao Braga"

Triple-negative breast cancer is a heterogeneous disease with high recurrence and mortality, linked to cancer stem cells (CSCs). Our study characterized distinct cell subpopulations and signaling pathways to explore chemoresistance. We observed cellular heterogeneity among and within the cells regarding phenotyping and drug response.

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Background: Queiroz et al. showed that the application of cluster methodology for classifying gastric cancer is suitable and efficient within a Brazilian cohort, which is known for its population heterogeneity. The study highlighted the potential utilization of this method within public health services due to its low-cost, presenting a viable means to improve the diagnosis and prognosis of gastric cancer.

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Article Synopsis
  • Ovarian cancer (OC) is difficult to diagnose and has high relapse rates (up to 90% with standard chemotherapy), highlighting the need for new molecular markers to assess treatment response and disease progression.
  • This study investigated the resistance of three ovarian tumor cell lines (SKOV-3, TOV-21G, OV-90) to cisplatin and paclitaxel, finding that SKOV-3 was the most resistant to both drugs.
  • Notably, after cisplatin treatment, TNFRSF10D expression increased significantly in the resistant SKOV-3 cells, suggesting that this receptor could be a potential biomarker for chemoresistance in ovarian cancer.
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Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare, autosomal dominant tumor predisposition syndrome characterized by variable development of multiple skin and uterus leiomyomas and aggressive forms of renal cell carcinoma (RCC). Mutations in fumarate hydratase (FH), one of the proteins in homologous recombination repair, precede the development of HLRCC with high penetrance. Considering the risk of early metastasis of RCC, FH has been included in mutation screening panels.

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Objective: To investigate the expression of human papillomavirus (HPV), p16, p53, and p63 in non-schistosomiasis-related squamous cell carcinoma of the bladder and to develop an accurate and automated tool to predict histological classification based on clinicopathological features.

Methods: Twenty-eight patients with primary bladder pure squamous cell carcinoma who underwent cystectomy or transurethral resection of bladder tumor (TURBT) for bladder cancer between January 2011 and July 2017 were evaluated. Clinical data and follow-up information were obtained from medical records.

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Objective:  The present study evaluated the profile of germline mutations present in patients who underwent genetic counseling for risk assessment for breast cancer (BC), ovarian cancer (OC), and endometrial cancer (EC) with a possible hereditary pattern.

Methods:  Medical records of 382 patients who underwent genetic counseling after signing an informed consent form were analyzed. A total of 55.

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The identification of the best reference gene is a critical step to evaluate the relative change in mRNA expression of a target gene by RT-qPCR. In this work, we evaluated nineteen genes of different functional classes using Real Time Human Reference Gene Panel (Roche Applied Sciences), to identify the internal housekeeping genes (HKGs) most suitable for gene expression normalization data in human cell lines. Normal cell lines CCD-19LU (lung fibroblast), HEK-293 (epithelial cell of embryonic kidney), WI-26 VA4 (lung fibroblast), and human cancer cells, BT-549 (breast cancer), Hs 578T (breast cancer), MACL-1 (breast cancer), HeLa (cervical carcinoma), U-87 MG (glioblastoma/astrocytoma), RKO-AS45-1 (colorectal carcinoma), and TOV-21G (ovarian adenocarcinoma) were cultivated according to manufacturer's protocol.

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The epithelial-to-mesenchymal transition (EMT) is a phenomenon during which cancer epithelial cells undergo changes in plasticity and lose cell-cell adhesion with consequent remodeling of the extracellular matrix and development of mesenchymal characteristics. Long non-coding RNAs (lncRNAs) have been described as EMT modulation markers, becoming a promising target in the development of new therapies for cancer. The present study aimed to investigate the role of everolimus at 100 nM as inductor of the EMT phenomenon in cell lines derived from human breast (BT-549), colorectal (RKO-AS45-1) and ovary (TOV-21G) cancer.

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Objectives: The objectives of this study were to determine the sensitivity of ovarian cancer (OC) cell lines (TOV-21G and SKOV-3) to cisplatin and to the recombinant human TRAIL (rhTRAIL), and to evaluate the expression profile of TNFRSF10B, TNFRSF10C, TP53TG5, MDM2, BAX, BCL-2 and CASPASE-8 genes and their participation in the resistance/susceptibility mechanism of these tumor cell lines.

Methods: To determine the IC50 values associated with Cisplatin and rhTRAIL, inhibition of cell growth was observed using MTT assays in two human OC cell lines (SKOV-3 and TOV-21G). The analysis of gene expression was performed using quantitative real-time polymerase chain reaction (qRT-PCR).

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Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, with the presence of chemoresistance contributing to the poor prognosis. Heat Shock Proteins (HSPs) genes are activated in response to pathophysiological stress and serve a role in a variety of stages in carcinogenesis, acting primarily as anti-apoptotic agents and in chemotherapy resistance in a variety of tumor types. The current study evaluated the HSP gene expression profile in women with ovarian cancer (OC) and their correlation with clinical and pathological aspects of patients with OC.

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Purpose: Aberrant DNA methylation is present in virtually all types of human cancer. There is no clear evidence that methylation status can predict bad prognosis in patients with CIN recurrence in HIV infected. This study evaluates the relationship between aberrant methylation of CpG islands of CDH1, TIMP3 and MGMT genes and CIN recurrence in HIV-infected and -noninfected women.

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The cancer stem cell (CSC) concept is currently employed to explain the mechanism of multidrug resistance that is implicated in the reduced efficacy of many chemotherapeutic agents, consequently leading to metastatic spread and disease relapse. We searched for potential predictive markers of doxorubicin (DOX) resistance in breast cancer stem cells (BCSCs) of the BT-549 human triple-negative breast cancer (TNBC) cell line classified as a claudin-low subtype. In this study, we show that BT-549 presents a BCSCs-like subset determined by a CD44/CD24/ALDH1 phenotype.

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Epithelial ovarian cancer (EOC) is the most lethal gynecological malignancy, and the lack of chemoresistance biomarkers contributes to the poor prognosis. Cancer stem cells (CSC) have been investigated in EOC to understand its relationship with chemoresistance and recurrence. In this context, in vitro cultivation-models are important tools for CSC studies.

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Despite impressive research efforts, the biology of epithelial ovarian cancer (EOC) remains poorly understood and alterations in the expression of CASPASE-8 contribute to a worse tumor prognosis. This study assesses the methylation of the CpG island within the CASPASE-8 promoter and CASPASE-8 gene expression both in cystadenoma tumors and in primary and metastatic EOC. DNA and RNA were obtained from women with normal ovarian tissues (n=18), ovarian serous cystadenoma tumors (n=11) and EOC (n=16) using Trizol(®).

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Objective: This study assesses TRAIL-R2 (TNF-related apoptosis-inducing ligand receptor 2) and BCL2 (B cell CLL/lymphoma 2) expression as well as CpG island methylation within the TRAIL-R2 promoter in ovarian serous tumors and primary and metastatic serous EOC (epithelial ovarian cancer).

Methods: RNA and DNA were obtained from women with normal ovarian tissues (n = 18), ovarian serous cystadenoma tumors (n = 11) and serous EOC (n = 16) using Trizol®. Quantitative PCR was performed to quantify the relative levels of TRAIL-R2 and BCL2.

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The function of microsatellite instability (MSI) and the optimal panel of markers for epithelial ovarian cancer (EOC) are not well established. This study aimed to use the National Cancer Institute (NCI) markers BAT25, BAT26, D2S123, D5S346 and D17S250 to evaluate MSI in patients with ovarian serous cystadenocarcinoma, compared with ovarian serous cystadenoma and normal ovaries. A total of 37 patients were divided into three groups, as follows: cystadenocarcinoma (n=13), cystadenoma (n=10) and normal ovaries (n=14).

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Objective: To assess the expression of TRAIL-R3 and the methylation of a CpG island within the TRAIL-R3 promoter both in cystadenoma tumors and primary and metastatic epithelial ovarian carcinoma (EOC).

Methods: RNA was obtained from women with normal ovarian (NO) tissues (n=18), ovarian serous cystadenoma tumors (n=11) and EOC (n=16) using Trizol. Quantitative PCR (qRT-PCR) was performed to quantify the relative levels of TRAIL-R3.

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