Melissa officinalis L. ethanolic extract inhibits the growth of a lung cancer cell line by interfering with the cell cycle and inducing apoptosis.

Melissa officinalis is a plant from the family Lamiaceae, native in Europe particularly in the Mediterranean region. Given our interest in identifying extracts and compounds capable of inhibiting tumor cell growth, and given the antioxidant content and the high consumption of Melissa officinalis in Portugal, this study aimed to test the tumor cell growth inhibitory activity of five different extracts of this plant (aqueous, methanolic, ethanolic, hydromethanolic and hydroethanolic) in three human tumor cell lines: MCF-7, AGS and NCI-H460. All extracts decreased cell growth in all cell lines in a concentration-dependent manner. The ethanolic extract was the most potent one, presenting a GI50 concentration of approximately 100.9 µg mL-1 in the NCI-H460 lung cancer cells. This extract was characterized by LC-DAD-ESI/MS regarding its phenolic composition, revealing rosmarinic acid as the most abundant compound. The GI75 concentration of this extract affected the cell cycle profile of these cells. In addition, both the GI50 and the GI75 concentrations of the extract induced cellular apoptosis. Moreover, treatment of NCI-H460 cells with this extract caused a decrease in pro-caspase 3 and an increase in p53 levels. This study emphasizes the relevance of the study of natural products as inhibitors of tumor cell growth.

Expression of coronin-3 (coronin-1C) in diffuse gliomas is related to malignancy.

Coronin-3 (coronin-1C), a homotrimeric F-actin binding protein, has been shown to be important for cell migration and brain morphogenesis. Here, we present for the first time a detailed analysis of the expression pattern of coronin-3 in human brain tumours and demonstrate that coronin-3 expression correlates with malignant phenotype in diffuse gliomas. In general, the expression of coronin-3 varies in different brain tumour entities. However, in diffuse gliomas, the number of coronin-3 expressing tumour cells correlates with the degree of malignancy. High-grade gliomas, such as anaplastic astrocytomas, anaplastic oligodendrogliomas, anaplastic oligoastrocytomas and glioblastomas, show high numbers of tumour cells positive for coronin-3, while diffuse low-grade gliomas, such as diffuse astrocytomas, oligodendrogliomas and oligoastrocytomas, exhibit low numbers of coronin-3-positive tumour cells. In order to explore and verify a contribution of coronin-3 to the malignant phenotype of diffuse gliomas, we employed an efficient shRNA-mediated coronin-3 knockdown in U373 and A172 human glioblastoma cells. Coronin-3 knockdown glioblastoma cells exhibited reduced levels of cell proliferation, cell motility and invasion into extracellular matrix compared to control cells. Together, our findings demonstrate evidence for a contribution of coronin-3 expression in the malignant progression of diffuse gliomas.