GFP Reporter Cell Line - HCC1806

Invasive cancer cells exhibit unique morphological migration and metabolic characteristics when encountering matrix microenvironments with varying biophysical properties during metastasis. Here, researchers used a triple-negative breast cancer cell line to conduct experiments on type I collagen-coated hydrogels that simulated non-cancerous breast tissue and tumor stroma. They observed stronger cell morphological polarization and migration under the latter condition. With decreased lactate and pyruvate levels, researchers further examined the expression of pyruvate kinase M2 (PKM2). The results showed that PKM2 was localized in the nucleus and cytoplasm in softer and harder environments, respectively. In a harder matrix, inhibiting PKM2 activity reduced cancer cell migration and morphological polarization while increasing lactate and pyruvate levels. Conversely, enhancing PKM2 activity in a softer matrix weakened cancer cell migration and elongation. Researchers also examined the localization of the mechanoreceptor protein YAP under PKM2 activity regulation: PKM2 activation increased the nuclear localization of YAP in soft matrix environments. On the hard matrix, pharmacological inhibition of YAP not only reduced cell migration ability but also increased nuclear localization of PKM2 and levels of lactate and pyruvate.

Here, researchers treated HCC1806 cells with the PKM2 cytoplasmic activator TEPP-46 to increase the cytoplasmic localization of PKM2 in cancer cells cultured on a soft gel. They observed that treatment of cells on the soft gel with 40 µM TEPP-46 increased the cytoplasmic localization of PKM2 (Figure 1A). This was also confirmed by assessing the nucleocytoplasmic ratio of PKM2, finding that the nucleocytoplasmic ratio of PKM2 decreased after TEPP-46 treatment (Figure 1A). The average cell area of HCC1806 cells increased, indicating that the cells spread more widely after PKM2 cytoplasmic localization, while the aspect ratio remained unchanged (Figure 1B). Furthermore, to investigate whether PKM2 activation regulates cell migration, the researchers performed time-lapse imaging. Compared with the control group, PKM2 activation significantly increased the migration of cancer cells on the soft gel (Figure 1C; tracing the migration trajectory of GFP-expressing HCC1806 cells, different colors indicate the individual trajectories). These results indicate that increasing the cytoplasmic activity of PKM2 on a softer matrix can mimic its morphological migration behavior on a harder ECM.

Figure 1. HCC1806 breast cancer cell migration increases on soft matrices upon cytoplasmic PKM2 activation. (Banerjee M, et al., 2025)