Effects of wound fluid on breast cancer-derived spheroids in a 3D culture system: a case series study

Surgery is the standard treatment for breast malignancies, although local and distant relapses might occur. Previous studies have shown that surgery-induced wound fluid (WF) contains tumor-initiating and progressing factors; however, these experiments have only been performed on breast cancer cell lines. Since a cancerous tumor includes various components like malignant cells, recruited non-malignant cells and extracellular matrix, those investigations that only focused on cancer cell lines themselves are not adequate to establish WF's effects. We conducted a 3D model study where we mimicked the in vivo tumor microenvironment to re-assess previous in vitro findings. We generated human-derived breast tumor spheroids from 23 patient specimens, dissociated and cultured them in microfluidic devices. The spheroids from each sample were treated with the patients’ WF or RPMI medium. The proportion of live and dead cells was assessed using live/dead assays and fluorescent imaging on day 6. In 22 samples, the percentage of live cells was significantly higher in the WF-treated group than in the RPMI-treated group. In one sample, we observed an opposite trend. The results were contrary in one of the samples, and we reported that case with more details. We compared the two groups using the 3D culture environment of human-derived tumor spheroids prepared from different microfluidic devices to mimic the tumor environment heterogeneity. Our findings showed that most patients with breast cancer benefit from surgical wound healing. However, removal of the surgical-induced serum may not be a method of inhibiting the tumor in all patients.