Browsing by Author "Letelier, Pablo"

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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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    Immunohistochemical Expression of Vascular Endothelial Growth Factor A in Advanced Gallbladder Carcinoma
    (2014) Letelier, Pablo; García Cañete, Patricia; Leal, Pamela; Ili, Carmen; Buchegger, Kurt; Riquelme, Ismael; Sandoval, Alejandra; Tapia, Oscar; Roa Strauch, Juan Carlos Enrique
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    The Emerging Role of PIWI-Interacting RNAs (piRNAs) in Gastrointestinal Cancers: An Updated Perspective
    (Palgrave Macmillan, 2022) Riquelme, Ismael; Perez Moreno, Pablo; Letelier, Pablo; Brebi, Priscilla; Roa, Juan Carlos
    Simple Summary Gastrointestinal (GI) cancers are high mortality malignancies due to late diagnosis, the presence of metastasis and drug resistance development. Novel and more reliable biomarkers and therapeutic targets are still needed for these diseases. PIWI-interacting RNAs (piRNAs) are small transcripts that are involve in gastrointestinal carcinogenesis and have been proposed as promising diagnostic or prognostic biomarkers and as potential therapeutic targets in these malignancies. This review describes important topics about piRNAs including their molecular characteristics, biosynthesis processes, gene expression silencing mechanisms, and the manner in which these transcripts have been studied in samples and cell lines of GI cancers. In addition, this article discusses the potential clinical usefulness of piRNAs as biomarkers and therapeutic targets in GI cancers. Gastrointestinal (GI) cancers produce ~3.4 million related deaths worldwide, comprising 35% of all cancer-related deaths. The high mortality among GI cancers is due to late diagnosis, the presence of metastasis and drug resistance development. Additionally, current clinical markers do not adequately guide patient management, thereby new and more reliable biomarkers and therapeutic targets are still needed for these diseases. RNA-seq technology has allowed the discovery of new types of RNA transcripts including PIWI-interacting RNAs (piRNAs), which have particular characteristics that enable these molecules to act via diverse molecular mechanisms for regulating gene expression. Cumulative evidence has described the potential role of piRNAs in the development of several tumor types as a likely explanation for certain genomic abnormalities and signaling pathways' deregulations observed in cancer. In addition, these piRNAs might be also proposed as promising diagnostic or prognostic biomarkers or as potential therapeutic targets in malignancies. This review describes important topics about piRNAs including their molecular characteristics, biosynthesis processes, gene expression silencing mechanisms, and the manner in which these transcripts have been studied in samples and cell lines of GI cancers to elucidate their implications in these diseases. Moreover, this article discusses the potential clinical usefulness of piRNAs as biomarkers and therapeutic targets in GI cancers.
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    The PI3K/AKT/mTOR pathway is activated in gastric cancer with potential prognostic and predictive significance
    (2014) Tapia, Oscar; Riquelme, Oscar Ismael; Leal, Pamela; Sandoval, Alejandra; Aedo, Susana; Weber, Helga; Letelier, Pablo; Bellolio, Enrique; Villaseca, Miguel; García Cañete, Patricia; Roa Strauch, Juan Carlos Enrique