Inflammatory breast cancer (IBC) is one of the most lethal breast cancer variants; with existing therapy, 5-yr survival rate is only 35%. Current barriers to successful treatment of IBC include frequent infiltration and the presence of tumor cell clusters, termed tumor emboli, within the breast parenchyma and lymphatics. Prior studies have identified the role of anti-apoptotic signaling, in particular hyperactivation of NFκB and its target genes, in IBC pathobiology and therapeutic resistance. The objectives of this study were to: (1) determine if IBC tumor emboli express anti-apoptotic proteins and (2) develop a high content, multiparametric assay to assess the morphology of the IBC 3D spheroids and to optimize a high throughput format to screen for compounds that can inhibit the formation of the IBC tumor clusters/embolic structures. Immunohistochemical analysis of IBC patient tumor samples with documented tumor emboli revealed high NFκB (p65) staining along with expression of XIAP, a potent anti-apoptotic protein known to interact with NFκB signaling in enhancing survival of malignant cells. Subsequently, the high content assay developed allowed for simultaneous imaging and morphometric analysis, including count and viability of spheroids derived from SUM149, rSUM149 and SUM190 cells and its application to evaluate XIAP and NFκB inhibitory agents. We demonstrate the efficacy of the off-patent drug disulfiram when chelated with copper, which we had previously reported to inhibit NFκB signaling, was highly effective in disrupting both IBC spheroids and emboli grown in vitro. Taken together, these results identify a high-throughput approach to target tumor spheroid formation for drug discovery. Finally, disulfiram is a safe and approved drug for management of alcohol abuse, warranting its evaluation for repurposing in IBC therapy.

Thermal destruction kinetics of spores of Clostridium difficile ATCC 17857 was evaluated between 74 and 82°C and characterized using the first‐order log‐linear and Weibull models. Computed decimal reduction times using the first‐order model ranged from 4.39 min at 82°C to 146 min at 74°C, with a z value of 5.17°C. Thermal destruction data were also analyzed using the Weibull model. Based on regression, the predicted one‐D value (first‐order model) and the reliable life (tR) (Weibull model) were 3.86 and 4.05 min at 82°C and 136 and 165 min at 74°C, respectively, indicating the Weibull model to be more conservative yielding higher decimal reduction time values. However, when extended to achieve 2.5, 4, and 6 decimal reductions in C. difficile spores, the calculated process times were more conservative with the first‐order model than with the Weibull model. Moreover, within the experimental range, when data for both models could be compared, predictions from the first‐order model were much closer to the experimental values. Therefore, when used for process calculation for 2.5 or higher log reductions, the first‐order model would give more conservative and safer process times. The study provides destruction kinetics data for C. difficile under a range of temperature conditions. Practical Applications Clostridium difficile is a major cause of antibiotic‐associated diarrhea and pseudomembranous colitis in humans. C. difficile infection is the leading cause of gastroenteritis‐associated death. C. difficile infections have been increasing in recent years, and therefore warrant appropriate remedial measures. Thermal inactivation is the most common method for pathogen control, and often the cooking practices are adjusted to a level pre‐established to make the foods pathogen free. Available information on thermal destruction kinetics is scarce, and therefore the data generated here should be of significant importance for safety considerations.

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