Browsing by Author "Ortega, Lorena"

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    Corrigendum to "The Ω-3 fatty acid docosahexaenoic acid selectively induces apoptosis in tumor-derived cells and suppress tumor growth in gastric cancer"
    (2021) Ortega, Lorena; Reyna, Mauricio; Erwin, de la Fuente; Castro, Patricio; Lobos-González, Lorena; Bernal, Giuliano; Coddou, Claudio; Cerda, Daniela
    Despite current achievements and innovations in cancer treatment, conventional chemotherapy has several limitations, such as unsatisfactory long-term survival, cancer drug resistance and toxicity against non-tumoral cells. In the search for safer therapeutic alternatives, docosahexaenoic acid (DHA) has shown promising effects inhibiting tumor growth without significant side effects in several types of cancer, but in gastric cancer (GC) its effects have not been completely described. In this study, we characterized the effects of DHA in GC using in vivo and in vitro models. Among all of the evaluated Ω-3 and Ω-6 fatty acids, DHA showed the highest antiproliferative potency and selectivity against the GC-derived cell line AGS. 10–100 μM DHA decreased AGS cell viability in a concentration-dependent manner but had no effect on non-tumoral GES-1 cells. To evaluate if the effects of DHA were due to apoptosis induction, cells were stained with Annexin V-PI, observing that 75 and 100 μM DHA increased apoptosis in AGS, but not in GES-1 cells. Additionally, levels of several proapoptotic and antiapoptotic regulators were assessed by qPCR, western blot and activity assays, showing similar results. In order to evaluate DHA efficacy in vivo, xenografts in an immunodeficient mouse model (BALB/cNOD-SCID) were used. In these experiments, DHA treatment for six weeks consistently reduced subcutaneous tumor size, ascitic fluid volume and liver metastasis. In summary, we found that DHA has a selective antiproliferative effect on GC, being this effect driven by apoptosis induction. Our investigation provides promising features for DHA as potential therapeutic agent in GC
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    The centrality of immigrant students within teacher-student interaction networks: A relational approach to educational inclusion
    (2020) Ortega, Lorena; Boda, Zsófia; Treviño, Ernesto; Arriagada, Verónica; Gelber, Denisse; Escribano, María del Rosario
    The conceptualizations of educational inclusion, previously restricted to securing access to formal education, recently highlight the promotion of equitable social and academic relations as well. This study investigates the inclusion of students with immigrant background within their class’ teacher-student interaction networks, while distinguishing by the initiator and content of interactions. Data from 38 Chilean mathematics teachers/classrooms and 933 seventh graders were collected and analyzed using systematic observation, social network visualization and multilevel models. Results show that the inclusion of students depends significantly on their country of origin. There is also significant variation in teacher-immigrant student interactions across classrooms.
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    The Ω-3 fatty acid docosahexaenoic acid selectively induces apoptosis in tumor-derived cells and suppress tumor growth in gastric cancer
    (2021) Ortega, Lorena; Lobos-González, Lorena; Reyna-Jeldes, Mauricio; Cerda, Daniela; De la Fuente-Ortega, Erwin; Castro, Patricio; Bernal, Giuliano; Coddou, Claudio
    Despite current achievements and innovations in cancer treatment, conventional chemotherapy has several limitations, such as unsatisfactory long-term survival, cancer drug resistance and toxicity against non-tumoral cells. In the search for safer therapeutic alternatives, docosahexaenoic acid (DHA) has shown promising effects inhibiting tumor growth without significant side effects in several types of cancer, but in gastric cancer (GC) its effects have not been completely described. In this study, we characterized the effects of DHA in GC using in vivo and in vitro models. Among all of the evaluated Ω-3 and Ω-6 fatty acids, DHA showed the highest antiproliferative potency and selectivity against the GC-derived cell line AGS. 10-100 μM DHA decreased AGS cell viability in a concentration-dependent manner but had no effect on non-tumoral GES-1 cells. To evaluate if the effects of DHA were due to apoptosis induction, cells were stained with Annexin V-PI, observing that 75 and 100 μM DHA increased apoptosis in AGS, but not in GES-1 cells. Additionally, levels of several proapoptotic and antiapoptotic regulators were assessed by qPCR, western blot and activity assays, showing similar results. In order to evaluate DHA efficacy in vivo, xenografts in an immunodeficient mouse model (BALB/cNOD-SCID) were used. In these experiments, DHA treatment for six weeks consistently reduced subcutaneous tumor size, ascitic fluid volume and liver metastasis. In summary, we found that DHA has a selective antiproliferative effect on GC, being this effect driven by apoptosis induction. Our investigation provides promising features for DHA as potential therapeutic agent in GC.

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