Siglec-15 Enhances Cisplatin Resistance in Cervical Cancer Cells by Promoting Mitochondrial Retrograde Signaling Through Activation of the MAPK Pathway

Chemoresistance constitutes a major cause of poor prognosis in advanced cervical cancer. Our previous studies have confirmed that Siglec-15 affects the progression of cervical cancer, whereas its role in regulating cervical cancer chemoresistance remains unexplored. This study investigates the role of Siglec-15 in cervical cancer chemoresistance and explores its mechanism. Siglec-15 expression and mitochondrial retrograde signaling levels were compared between parental and cisplatin-resistant cervical cancer cells. Lentiviral transfection was used to assess the functional effects of Siglec-15 modulation on the proliferation, apoptosis, and chemosensitivity of resistant cells. Further investigations were conducted to examine the effects of Siglec-15 on the mitogen-activated protein kinase (MAPK) signaling pathway, mitochondrial membrane potential, reactive oxygen species levels, and the expression of retrograde-related proteins. These in vitro findings were subsequently validated in vivo using a xenograft tumor model through immunohistochemistry, Terminal-deoxynucleotidyl transferase-mediated dUTP-nick-end labeling (TUNEL) assays, and western blotting. The results showed that Siglec-15 was markedly upregulated in cisplatin-resistant cervical cancer cells, correlating with enhanced mitochondrial retrograde signaling. Siglec-15 overexpression promoted cisplatin resistance and mitochondrial retrograde signaling, driving proliferation while inhibiting apoptosis. Mechanistically, Siglec-15 regulated mitochondrial retrograde signaling through activation of the MAPK pathway, thereby enhancing chemoresistance in drug-resistant cells. Elevated Siglec-15 expression enhances cisplatin resistance in cervical cancer cells by activating the MAPK pathway to promote mitochondrial retrograde signaling.