Biomedical research requires both in vitro and in vivo studies in order to explore disease processes or drug interactions. Foundational investigations have been performed at the cellular level using two-dimensional cultures as the gold-standard method since the early 20th century. However, three-dimensional (3D) cultures have emerged as a new tool for tissue modeling over the last few years, bridging the gap between in vitro and animal model studies. Cancer has been a worldwide challenge for the biomedical community due to its high morbidity and mortality rates. Various methods have been developed to produce multicellular tumor spheroids (MCTSs), including scaffold-free and scaffold-based structures, which usually depend on the demands of the cells used and the related biological question. MCTSs are increasingly utilized in studies involving cancer cell metabolism and cell cycle defects. These studies produce massive amounts of data, which demand elaborate and complex tools for thorough analysis. In this review, we discuss the advantages and disadvantages of several up-to-date methods used to construct MCTSs. In addition, we also present advanced methods for analyzing MCTS features. As MCTSs more closely mimic the in vivo tumor environment, compared to 2D monolayers, they can evolve to be an appealing model for in vitro tumor biology studies.

Biofilm-forming pathogens are a major cause of persistent infections, showing limited response to antibiotic treatment. The search for alternative strategies has therefore driven extensive research into the antimicrobial potential of beneficial microorganisms. In the present study, the antibacterial and antibiofilm activity of the commercial probiotic strain Lacticaseibacillus casei ATCC 393 (Lc393) was examined against clinical isolates of Staphylococcus aureus, Salmonella enterica subsp. enterica serovar Enteritidis and Escherichia coli. Lc393 reduced pathogen viability and attachment to the colon adenocarcinoma cell line HT-29, with maximal effects recorded against S. aureus. Confocal microscopy visualization of the lactobacilli-pathogens-host interface revealed that Lc393 binds loosely to both host cells and pathogens. The Lc393 cell-free culture supernatant (CFCS) significantly reduced planktonic growth, biofilm mass, and viability of cells in biofilm (>2 logCFU reduction, p < 0.05) and downregulated genes involved in the early stages of biofilm formation in S. aureus (i.e., icaA, fnbpA, eno). In silico analysis of the Lc393 genome identified two bacteriocin clusters, along with genes related to ethanol and organic acid production. Based on in silico predictions and a bacteriocin zymogram, the strain cannot produce functional antimicrobial peptides. Untargeted metabolomics based on UPLC/MS further revealed the presence of putative antimicrobial metabolites. Collectively, our findings highlight the antimicrobial potential of Lc. casei ATCC 393 and support its further investigation for combating clinically relevant human pathogens.

Chromosomal instability (CIN) arising from mitotic errors is a hallmark of cancer progression, yet how specific spindle assembly factors are co-opted to support aggressive tumor phenotypes remains incompletely understood. Hepatoma Upregulated Protein (HURP/DLGAP5), a Ran-regulated microtubule-associated protein essential for kinetochore fiber stabilization and chromosome congression, is frequently overexpressed in aggressive cancers. Here, we investigated HURP’s role across a breast cancer metastatic gradient—immortalized MCF10A, the low-metastatic luminal T47D, and the highly metastatic triple-negative MDA-MB-231 cell lines—integrating quantitative spindle analysis, kinetochore tension measurements, spindle checkpoint profiling, migration dynamics, and three-dimensional spheroid modeling. We show that total HURP protein levels increase with metastatic potential, yet spindle-bound HURP is paradoxically reduced in MDA-MB-231 cells, indicating cytoplasmic mislocalization despite increased total protein levels. HURP silencing induced cell-line-specific defects: moderate disorganization and misorientation in MCF10A and T47D cells, but catastrophic spindle collapse, apoptosis, and G2/M arrest in MDA-MB-231 cells. Mechanistically, HURP depletion disrupted the spindle-associated levels and distributions of TPX2, Aurora-A, and NuMA in a subtype-dependent manner, implicating HURP as a context-dependent stabilizer of this mitotic regulatory axis. HURP loss reduced interkinetochore tension in all cell lines, but only MCF10A and T47D cells mounted a proportional BubR1-dependent checkpoint response; MDA-MB-231 cells showed reduced checkpoint signaling, consistent with constitutive spindle assembly checkpoint (SAC) attenuation in triple-negative breast cancer. Beyond mitosis, HURP depletion impaired collective migration and converted MDA-MB-231 cells from super-diffusive, amoeboid-like motility to sub-diffusive behavior, while minimally affecting the less aggressive cell lines. HURP-depleted MDA-MB-231 spheroids were significantly larger, less compact, and less spherical than controls, linking spindle regulation to tissue-level architectural coherence. These findings establish HURP as a multifunctional regulator coordinating mitotic fidelity, migration plasticity, and tumor architecture in breast cancer, with a selective dependency in highly metastatic cells, positioning it as a promising therapeutic target for aggressive breast cancers.

Chromosomal instability (CIN) arising from mitotic errors is a hallmark of cancer progression. Hepatoma Upregulated Protein (HURP), a microtubule-associated protein essential for spindle assembly, is frequently overexpressed in aggressive cancers. Here, we investigated HURP's role in breast cancer progression using a cell line model of increasing metastatic potential: immortalized MCF10A, low-metastatic T47D, and highly metastatic MDA-MB-231 cells. Elevated HURP expression was observed in cancer cells, with MDA-MB-231 showing the highest levels. Paradoxically, spindle-bound HURP was reduced in MDA-MB-231 cells despite increased total protein, suggesting cytoplasmic mislocalization. HURP silencing induced cell line-specific effects: moderate spindle defects in MCF10A and T47D cells, but severe abnormalities, apoptosis, and G2/M arrest in MDA-MB-231 cells. Mechanistically, HURP depletion perturbed spindle-bound NuMA, TPX2, and Aurora-A levels, implicating HURP in mitotic regulation and metastatic behavior. HURP silencing also impaired collective migration and converted MDA-MB-231 cells from super-diffusive to sub-diffusive motility, while having minimal effects on less aggressive cell lines. These findings establish HURP as a multifunctional regulator coordinating mitotic fidelity, migration plasticity, and tissue architecture in breast cancer, with pronounced effects in highly metastatic cells, positioning it as a promising therapeutic target for aggressive breast cancers.