Browsing by Author "Brebi, Priscilla"

Now showing 1 - 15 of 15
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    Assessment of Gastritis and Gastric Cancer Risk in the Chilean Population Using the OLGA System
    (2019) Bellolio, Enrique; Riquelme, Ismael; Riffo Campos, Angela L.; Rueda, Carlos; Ferreccio Readi, Catterina; Villaseca, Miguel; Brebi, Priscilla; Muñoz, Sergio R.; Araya, Juan Carlos
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    Cellular FLICE-like Inhibitory Protein Long Form (c-FLIPL) Overexpression is Related to Cervical Cancer Progression
    (2013) Ili, Carmen Gloria; Brebi, Priscilla; Tapia, Oscar; Sandoval, Alejandra; López, Jaime; García Muñoz, Patricia; Leal, Pamela; Sidransky, David; Guerrero Preston, Rafael; Roa Strauch, Juan Carlos Enrique
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    Connective Tissue Growth Factor Immunohistochemical Expression Is Associated With Gallbladder Cancer Progression
    (2013) García Cañete, Patricia; Leal, Pamela; Álvarez, Héctor; Brebi, Priscilla; Ili, Carmen Gloria; Tapia, Oscar; Roa Strauch, Juan Carlos Enrique
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    Detection and genotyping of human papillomavirus virus (HPV): a comparative analysis of clinical performance in cervical and urine samples in Chilean women
    (2018) Buchegger, Kurt; Viscarra, Tamara; Andana, Alejandra; Ili, Carmen; Lopez, Jaime; Zanella, Louise; Ines Carmona-Lopez, Maria; Jose Fernandez, Juan; Cartas Espinel, Irene; Sanchez, Raul; Carlos Roa, Juan; Brebi, Priscilla
    Human papillomavirus (HPV) is the most common sexually transmitted infectious agent and is the main cause of cervical cancer (CC). In Chile, CC is the second leading cause of death by cancer in women aged 20-44 years, four times higher than in developed countries. Currently, the detection of HPV infection using a cervical brush is recommended; however, this is an invasive procedure that many women try to avoid. The aim of this study was to evaluate the clinical performance of a self-collected, urine-based HPV detection method using conventional PCR followed by a reverse line blot. A PCR-based HPV genotyping was performed on 190 paired cervical and urine samples from gynecological exams at public health centers in the Araucania Region, Chile. HPV DNA detection and genotyping were performed by PCR and reverse line blot assay. Carcinogenic HPV types were present in 64.7% and 65.8% of the cervical and urine samples; the infection rates of HPV16 were 34.7% and 33.2%, respectively. The overall percent agreement between carcinogenic HPV detection in cervical and urine samples was 73.7%, with a moderate concordance rate of carcinogenic HPV detection (kappa = 0.42). Clinical sensitivities for cervical and urine-based sampling methods to diagnose cervical intraepithelial neoplasia 2/3 (CIN2/3) by histology were 93.4% and 90.2%, respectively. These results suggest that both cervical brush and urine-based sampling show a good clinical performance in the detection of HPV infection. The urine-based sampling method represents a valuable alternative with a great impact on public health, allowing increased cervical cancer screening coverage among women who do not undergo pelvic examinations.
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    Diagnóstico de la infección por virus papiloma humano en el hombre
    (2013) Silva, Ramón; León, Daniela; Brebi, Priscilla; Lli, Carmen Gloria; Roa Strauch, Juan Carlos Enrique; Sánchez, Raúl
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    Effects of c-FLIPL Knockdown in Cervical Uterine Carcinoma Cell Lines
    (2015) Ili, Carmen G.; Brebi, Priscilla; García Cañete, Patricia; Leal, Pamela; Lopez, Jaime; Tapia, Oscar; Letelier, Pablo; Weber, Helga; Castillo, Jonathan; Roa Strauch, Juan Carlos Enrique
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    Effects of c-FLIPL Knockdown in Cervical Uterine Carcinoma Cell Lines
    (2015) Ili, Carmen G.; Brebi, Priscilla; Garcia, Patricia; Leal, Pamela; Lopez, Jaime; Tapia, Oscar; Letelier, Pablo; Weber, Helga; Castillo, Jonathan; Roa, Juan C.
    Overexpression of Short and Raji variants of Cellular FLICE-like inhibitory protein (c-FLIP) is capable of inhibiting apoptosis, while the function of the Long isoform depends of c-FLIPL concentration in cells. The aim of this study was to determine the effects of c-FLIPL knockdown in cervical cell lines. SiHa, C-4I and C-33A cervical cancer cell lines were analyzed. c-FLIPL level expression was determined by quantitative real-time PCR and western blotting. c-FLIPL was transiently downregulated by siRNA. The effects of knockdown of c-FLIPL on cell viability, proliferation and apoptosis were assessed by comparing with scrambled siRNA-transfected cells. SiHa and C-4I c-FLIPL knockdown cells showed increased viability compared with scrambled siRNA-transfected cells (P<0.05), while C-33A cells did not show significant differences. Ki-67 and PCNA immunocytochemistry was performed to evaluate proliferation on these cervical cancer cell lines. SiHa cells with c-FLIPL knockdown showed elevated expression of Ki-67 protein compared with their scrambled counterparts (P<0.0001), while C-33A c-FLIPL knockdown cells showed a significantly lower in PCNA expression (P<0.01) compared with control. All three c-FLIP-transfected cell lines showed a higher level of apoptosis compared with their scrambled controls. Our results suggest that c-FLIPL could have effects in proliferation and apoptosis in cervical cancer cell lines.
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    Environmental and Lifestyle Risk Factors in the Carcinogenesis of Gallbladder Cancer
    (2022) Pérez Moreno, Pablo; Riquelme, Ismael; García Cañete, Patricia; Brebi, Priscilla; Roa, Juan Carlos
    Gallbladder cancer (GBC) is an aggressive neoplasm that in an early stage is generally asymptomatic and, in most cases, is diagnosed in advanced stages with a very low life expectancy because there is no curative treatment. Therefore, understanding the early carcinogenic mechanisms of this pathology is crucial to proposing preventive strategies for this cancer. The main risk factor is the presence of gallstones, which are associated with some environmental factors such as a sedentary lifestyle and a high-fat diet. Other risk factors such as autoimmune disorders and bacterial, parasitic and fungal infections have also been described. All these factors can generate a long-term inflammatory state characterized by the persistent activation of the immune system, the frequent release of pro-inflammatory cytokines, and the constant production of reactive oxygen species that result in a chronic damage/repair cycle, subsequently inducing the loss of the normal architecture of the gallbladder mucosa that leads to the development of GBC. This review addresses how the different risk factors could promote a chronic inflammatory state essential to the development of gallbladder carcinogenesis, which will make it possible to define some strategies such as anti-inflammatory drugs or public health proposals in the prevention of GBC.
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    Epigallocatechin Gallate Enhances MAL-PDT Cytotoxic Effect on PDT-Resistant Skin Cancer Squamous Cells
    (2020) Leon, Daniela; Buchegger, Kurt; Silva, Ramon; Riquelme, Ismael; Viscarra, Tamara; Mora-Lagos, Barbara; Zanella, Louise; Schafer, Fabiola; Kurachi, Cristina; Roa, Juan Carlos; Ili, Carmen; Brebi, Priscilla
    Photodynamic therapy (PDT) has been used to treat certain types of non-melanoma skin cancer with promising results. However, some skin lesions have not fully responded to this treatment, suggesting a potential PDT-resistant phenotype. Therefore, novel therapeutic alternatives must be identified that improve PDT in resistant skin cancer. In this study, we analyzed the cell viability, intracellular protoporphyrin IX (PpIX) content and subcellular localization, proliferation profile, cell death, reactive oxygen species (ROS) detection and relative gene expression in PDT-resistant HSC-1 cells. PDT-resistant HSC-1 cells show a low quantity of protoporphyrin IX and low levels of ROS, and thus a low rate of death cell. Furthermore, the resistant phenotype showed a downregulation of HSPB1, SLC15A2, FECH, SOD2 and an upregulation of HMBS and BIRC5 genes. On the other hand, epigallocatechin gallate catechin enhanced the MAL-PDT effect, increasing levels of protoporphyrin IX and ROS, and killing 100% of resistant cells. The resistant MAL-PDT model of skin cancer squamous cells (HSC-1) is a reliable and useful tool to understand PDT cytotoxicity and cellular response. These resistant cells were successfully sensitized with epigallocatechin gallate catechin. The in vitro epigallocatechin gallate catechin effect as an enhancer of MAL-PDT in resistant cells is promising in the treatment of difficult skin cancer lesions.
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    Evaluation of DNA methylation in promoter regions of SFRP4 and ZAR1 in urine and plasma of women with cervical lesions
    (2017) Hoffstetter, Rene; Riquelme, Ismael; Andana, Alejandra; Ili, Carmen G.; Buchegger, Kurt; Vargas, Hernan; Brebi, Priscilla; Roa Strauch, Juan Carlos Enrique
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    Exploring the Genetic Diversity of Epstein–Barr Virus among Patients with Gastric Cancer in Southern Chile
    (2023) Reyes, María Elena; Zanella, Louise; Riquelme, Ismael; Buchegger, Kurt; Mora-Lagos, Bárbara; Guzmán, Pablo; García Cañete, Patricia; Roa Strauch, Juan Carlos Enrique; Gloria Ili, Carmen; Brebi, Priscilla
    The Epstein–Barr virus (EBV) has been associated with gastric cancer (GC), one of the deadliest malignancies in Chile and the world. Little is known about Chilean EBV strains. This study aims to investigate the frequency and genetic diversity of EBV in GC in patients in southern Chile. To evaluate the prevalence of EBV in GC patients from the Chilean population, we studied 54 GC samples using the gold standard detection method of EBV-encoded small RNA (EBER). The EBV-positive samples were subjected to amplification and sequencing of the Epstein–Barr virus nuclear protein 3A (EBNA3A) gene to evaluate the genetic diversity of EBV strains circulating in southern Chile. In total, 22.2% of the GC samples were EBV-positive and significantly associated with diffuse-type histology (p = 0.003). Phylogenetic analyses identified EBV-1 and EBV-2 in the GC samples, showing genetic diversity among Chilean isolates. This work provides important information for an epidemiological follow-up of the different EBV subtypes that may cause GC in southern Chile.
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    Frecuencia de la infección por Chlamydia trachomatis en un grupo de mujeres de la Región de la Araucanía, Chile
    (2013) Silva, Ramón; León, Daniela; Viscarra, Támara; Ili, Carmen; Roa Strauch, Juan Carlos Enrique; Sánchez, Raúl; Guzmán, Pablo; Brebi, Priscilla
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    LINC00662 Promotes Aggressive Traits by Modulating OCT4 Expression through miR-335-5p in Gallbladder Cancer Cells
    (MDPI, 2024) Perez-Moreno, Pablo; Riquelme, Ismael; Bizama Soto, Carolina Del Carmen; Vergara-Gomez, Luis; Tapia, Julio C.; Brebi, Priscilla; Garcia Canete, Patricia Del Carmen; Roa Strauch, Juan Carlos Enrique
    Long non-coding RNAs (lncRNAs) are nucleotide sequences that participate in different biological processes and are associated with different pathologies, including cancer. Long intergenic non-protein-coding RNA 662 (LINC00662) has been reported to be involved in different cancers, including colorectal, prostate, and breast cancer. However, its role in gallbladder cancer has not yet been described. In this article, we hypothesize that LINC00662 has an important role in the acquisition of aggressiveness traits such as a stem-like phenotype, invasion, and chemoresistance in gallbladder cancer. Here, we show that LINC00662 is associated with larger tumor size and lymph node metastasis in patients with gallbladder cancer. Furthermore, we show that the overexpression of LINC00662 promotes an increase in CD133+/CD44+ cell populations and the expression of stemness-associated genes. LINC00662 promotes greater invasive capacity and the expression of genes associated with epithelial-mesenchymal transition. In addition, the expression of LINC00662 promotes resistance to cisplatin and 5-fluorouracil, associated with increased expression of chemoresistance-related ATP-binding cassette (ABC) transporters in gallbladder cancer (GBC) cell lines. Finally, we show that the mechanism by which LINC00662 exerts its function is through a decrease in microRNA 335-5p (miR-335-5p) and an increase in octamer-binding transcription factor 4 (OCT4) in GBC cells. Thus, our data allow us to propose LINC00662 as a biomarker of poor prognosis and a potential therapeutic target for patients with GBC.
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    Reprimo, a Potential p53-Dependent Tumor Suppressor Gene, Is Frequently Hypermethylated in Estrogen Receptor α-Positive Breast Cancer
    (2017) Buchegger, Kurt; Riquelme, Ismael; Viscarra, Tamara; Ili, Carmen; Brebi, Priscilla; Hui-Ming Huang, Tim; Roa Strauch, Juan Carlos Enrique
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    The ERK/MAPK pathway is overexpressed and activated in gallbladder cancer
    (2017) Buchegger, Kurt; Silva, Ramón; López, Jaime; Lli, Carmen; Araya, Juan Carlos; Leal, Pamela; Brebi, Priscilla; Riquelme, Ismael; Roa Strauch, Juan Carlos Enrique