Placental extracellular vesicles promoted cervical tumour tissue undergoing death

Background

Cervical cancer is a leading cause of death in developing countries. Although the placenta is a tumor-like organ, the placental development, including invasive function, is well controlled. One mechanism is that extracellular vesicles (EVs) released from the placenta contribute to this regulation. Placental EVs carry functional proteins and regulatory RNAs. Our previous study reported that placental EVs inhibited ovarian cancer growth in vitro and in vivo.

Methods

Whether the inhibitory effect induced by placental EVs also applies to cervical cancer, a non-endocrine-related cancer, in this study, we first co-cultured the cervical tumour tissues with placental explants.

Results

Co-culturing cervical tumour tissues (n = 7) with placental explants showed necrotic signs and increased levels of senescence-associated proteins and death-associated miRNAs, including miRNA-143-3p, miRNA-519a-5p and miRNA-199a-3p in tumour tissues. Additionally, treatment of HeLa cells with placental EVs reduced the viability of HeLa cells and inhibited the ability of invasion and migration of HeLa cells. Increased levels of senescence-associated proteins and reduced levels of proliferative proteins may contribute to the inhibitory effects in HeLa cells.

Discussion

placental EVs are involved in regulating placental development, and the delivery of cargo significantly impacts the functions of target cells. This study found that factors released from placental explants, likely placental EVs, had anti-tumour effects on the cervical tumour by inhibiting cervical cancer cell viability, invasion, and migration. Cargo in placental EVs, such as cellular death-associated miRNAs, may contribute to the inhibitory effects on cervical tumour.