SRC Knockdown Impairs Proliferation, Migration, and Invasion While Promoting Apoptosis in HTR8/SVneo Trophoblast Cells via Activation of the PI3K/Akt/Bcl-2 Signaling Pathway

Abstract

SRC knockdown inhibits trophoblast cell proliferation, migration, and invasion while inducing apoptosis via activation of the PI3K/Akt/Bcl-2 signaling pathway. Trophoblast dysfunction is central to pregnancy disorders such as preeclampsia and miscarriage, yet the role of SRC, a non-receptor tyrosine kinase, in these cells remains poorly understood. This study aimed to elucidate the functional impact of SRC on trophoblast behavior and its underlying mechanism. Using siRNA-mediated knockdown in HTR8/SVneo cells, we confirmed efficient reduction of SRC mRNA and protein expression via RT-qPCR and Western blot. Functional assays demonstrated that SRC silencing significantly suppressed cell proliferation (CCK-8), migration (wound healing), and invasion (Transwell), while promoting apoptosis, evidenced by increased Annexin V-FITC/PI staining and upregulated Caspase-3 and Caspase-9 protein levels. Mechanistically, Western blot analysis revealed that SRC knockdown upregulated PI3K, Akt1, and Bcl-2 protein expression without altering IRS1 levels, indicating activation of the PI3K/Akt/Bcl-2 pro-survival pathway. This paradoxical activation appears to be a compensatory feedback insufficient to overcome SRC loss-induced dysfunction. Our findings identify SRC as a critical positive regulator of trophoblast proliferation, motility, and survival, acting through a non-canonical, IRS1-independent negative regulation of PI3K/Akt signaling. This study provides novel insights into trophoblast biology and suggests SRC as a potential therapeutic target for pregnancy complications; future in vivo studies are warranted to validate these mechanisms.