Biology subjects

von Zuben de Valega Negrao, C.

Publications and source records attributed to von Zuben de Valega Negrao, C..

2 recordsLinked to original sources

bioRxiv2026

Differential Cytotoxicity of PVP-Copper Nanoparticles in Breast Cancer Cell Lines: Insights from Basal Transcriptomic Profiles

Breast cancer is a heterogeneous disease comprising molecular subtypes with distinct therapeutic vulnerabilities. Among emerging therapeutic strategies, copper-based nanoparticles have shown anticancer activity. However, whether these responses differ across breast cancer subtypes and which molecular programs underlie copper sensitivity remain poorly understood. We investigated subtype-specific responses to Polyvinylpyrrolidone-assisted copper nanoparticles (CuNP-PVP) in breast cancer cell lines and the molecular programs underlying copper adaptation. CuNP-PVP were synthesized and evaluated in luminal (MCF-7), HER2-positive (SKBR3), and triple-negative (MDA-MB-231) breast cancer cell lines, with transcriptomic analyses integrated with CCLE and TCGA-BRCA datasets. UV-Vis spectroscopy revealed a plasmon resonance band at 591 nm, while TEM showed spherical nanoparticles with an average diameter of 76.1 +/- 21.0 nm. DLS indicated a larger hydrodynamic diameter, consistent with PVP coating; {zeta}-potential measurements showed a surface charge of -13 mV, and XPS confirmed mixed reduced and Cu(I)/Cu(II) oxidation states. Exposure to 100 g/mL CuNP-PVP induced subtype-dependent effects on cell viability, with MCF-7 showing greater sensitivity, whereas MDA-MB-231 and SKBR3 were less affected. Baseline transcriptomic analyses revealed enrichment of oxidative stress, metabolic adaptation, and lysosomal programs in less sensitive cells, whereas MCF-7 showed higher expression of lipoylation-related genes. These features supported the development of a Potential Biological Copper-Response Index (PBCRI), which captured subtype-associated transcriptional patterns across independent cell lines and patient tumors, with luminal models showing lower scores and basal/TNBC models showing higher scores. Together, these findings identify candidate transcriptional programs associated with subtype-specific responses to CuNP and provide a framework for investigating potential molecular determinants of copper sensitivity.

cancer biology↗

bioRxiv2026

Beyond Capture Efficiency: A Multidimensional Framework for Benchmarking Circulating Tumor Cell Isolation Technologies

Metastasis remains the major cause of cancer-related mortality, and circulating tumor cells (CTCs) are both candidate liquid-biopsy biomarkers and plausible intermediates of metastatic dissemination. Because CTCs are extremely rare in peripheral blood, platform comparisons have often focused solely on recovery. That focus is insufficient for applications that depend on the quality of the recovered material, including single-cell profiling, short-term culture, and functional testing. Here, we compared four CTC isolation approaches: TellDx CTC System, Genesis System, RosetteSep, and flow cytometry, using spike-in experiments in human blood. Capture efficiency was evaluated across all four platforms; purity was assessed for TellDx, Genesis, and RosetteSep; and post-isolation GFP signal persistence in culture was assessed for TellDx and Genesis as an exploratory proxy for short-term post-isolation preservation. Under the conditions tested, TellDx showed the highest recovery (88.1% {+/-} 3.7%), followed by Genesis (40.6% {+/-} 12.1%), RosetteSep (36.5% {+/-} 9.0%), and flow cytometry (7.6% {+/-} 4.5%). TellDx also showed the highest purity score (3.76), whereas Genesis (2.25) and RosetteSep (2.09) did not differ substantially. In the short-term culture assay, TellDx-derived samples retained a higher normalized GFP signal than Genesis-derived samples at 48 h and 72 h. To synthesize these readouts, we propose the Recovery Performance Index (RPI), a composite score integrating recovery, purity, and post-isolation signal persistence. Within this experimental framework, TellDx achieved the highest RPI. These data support two conclusions. First, platform benchmarking for CTC workflows benefits from multidimensional evaluation rather than recovery alone. Second, under this spike-in model and within the specific workflows used here, TellDx performed best among the platforms tested. The principal contribution of this study is therefore the establishment of a practical benchmarking framework that can be expanded in future work using clinical samples, multiple CTC phenotypes, and orthogonal viability assays.

cancer biology↗