RESUMEN
Genetic analysis in model systems using bioinformatic approaches provides a rich context for a concrete and conceptual understanding of gene structure and function. With the intent to engage students in research and explore disease biology utilizing the nematode Caenorhabditis elegans model, we developed a semester-long course-based undergraduate research experience (CURE) in a hybrid (online/in-person) learning environment-the gene-editing and evolutionary nematode exploration CURE (GENE-CURE). Using a combination of bioinformatic and molecular genetic tools, students performed structure-function analysis of disease-associated variants of uncertain significance (VUS) in human orthologs. With the aid of a series of workshop-style research sessions, students worked in teams of two to six members to identify a conserved VUS locus across species and design and test a polymerase chain reaction-based assay for targeted editing of a gene in the nematode and downstream genotyping. Research session discussions, responsible conduct of research training, electronic laboratory notebook, project reports, quizzes, and group poster presentations at a research symposium were assessed for mastery of learning objectives and research progress. Self-reflections were collected from students to assess engagement, science identity, and science efficacy. Qualitative analysis of these reflections indicated several gains suggesting that all students found many aspects of the GENE-CURE rewarding (learning process of research, self-confidence in research and science identity, and personal interest) and challenging (iterative research and failure, time management, COVID-19 pandemic, and life issues).
RESUMEN
AIM: To investigate the mechanism of action of lipophilic antidepressant fluoxetine (FLX) in representative molecular subtypes of breast cancer. METHODS: The anti-proliferative effects and mechanistic action of FLX in triple-negative (SUM149PT) and luminal (T47D and Au565) cancer cells and non-transformed MCF10A were investigated. Reverse phase protein microarray (RPPM) was performed with and without 10 µmol/L FLX for 24 and 48 h to determine which proteins are significantly changed. Viability and cell cycle analysis were also performed to determine drug effects on cell growth. Western blotting was used to confirm the change in protein expression examined by RPPM or pursue other signaling proteins. RESULTS: The FLX-induced cell growth inhibition in all cell lines was concentration- and time-dependent but less pronounced in early passage MCF10A. In comparison to the other lines, cell growth reduction in SUM149PT coincided with significant induction of endoplasmic reticulum (ER) stress and autophagy after 24 and 48 h of 10 µmol/L FLX, resulting in decreased translation of proteins along the receptor tyrosine kinase/Akt/mammalian target of rapamycin pathways. The increase in autophagy marker, cleaved microtubule-associated protein 1 light chain 3, in SUM149PT after 24 h of FLX was likely due to increased metabolic demands of rapidly dividing cells and ER stress. Consequently, the unfolded protein response mediated by double-stranded RNA-dependent protein kinase-like ER kinase resulted in inhibition of protein synthesis, growth arrest at the G1 phase, autophagy, and caspase-7-mediated cell death. CONCLUSION: Our study suggests a new role for FLX as an inducer of ER stress and autophagy, resulting in death of aggressive triple negative breast cancer SUM149PT.
