背景:妊娠滋养细胞疾病(GTD)包括一系列起源于滋养细胞组织的罕见的恶性前和恶性实体,包括部分葡萄胎,完整的葡萄胎和绒毛膜癌。β-半乳糖苷α2,6唾液酸转移酶1(ST6Gal1),负责添加α2,6唾液酸的初级唾液酸转移酶,与几种肿瘤类型的发生和发展密切相关。然而,ST6Gal1/α2,6-唾液酸化对滋养层细胞在GTD中的作用尚不清楚。
方法:研究了ST6Gal1在GTD和人永生化滋养细胞HTR-8/SVneo细胞和人妊娠绒毛膜癌JAR细胞中的表达。我们评估了ST6Gal1对滋养细胞增殖和干性的影响。我们还检测了内部miR-199a-5p对ST6Gal1表达的影响。还探讨了ST6Gal1在调节α2,6-唾液酸化整合素β1中的作用及其在整合素β1/粘着斑激酶(FAK)信号通路激活中的意义。
结果:观察到ST6Gal1在GTD中高度表达。ST6Gal1过表达促进HTR-8/SVneo细胞的增殖和干性,而ST6Gal1的敲除抑制了JAR细胞的活力和干性。MiR-199a-5p靶向并抑制滋养细胞中ST6Gal1的表达。此外,我们发现整合素β1在JAR细胞中高度α2,6-唾液酸化。抑制ST6Gal1可降低JAR细胞中整合素β1的α2,6-唾液酸化作用,抑制整合素β1/FAK通路,从而影响其生物学功能。
结论:本研究表明,ST6Gal1在GTD中通过整合素β1信号通路促进增殖和干性中起重要作用。因此,ST6Gal1可能在GTD的发生发展中具有潜在的作用。
BACKGROUND: Gestational trophoblastic disease (GTD) encompasses a spectrum of rare pre-malignant and malignant entities originating from trophoblastic tissue, including partial hydatidiform mole, complete hydatidiform mole and
choriocarcinoma. β-galactoside α2,6 sialyltransferase 1 (ST6Gal1), the primary sialyltransferase responsible for the addition of α2,6 sialic acids, is strongly associated with the occurrence and development of several tumor types. However, the role of ST6Gal1/α2,6 -sialylation of trophoblast cells in GTD is still not well understood.
METHODS: The expression of ST6Gal1 was investigated in GTD and human immortalized trophoblastic HTR-8/SVneo cells and human gestational
choriocarcinoma JAR cells. We evaluated the effect of ST6Gal1 on proliferation and stemness of trophoblastic cells. We also examined the effect of internal miR-199a-5p on ST6Gal1 expression. The role of ST6Gal1 in regulating α2,6-sialylated integrin β1 and its significance in the activation of integrin β1/focal adhesion kinase (FAK) signaling pathway were also explored.
RESULTS: ST6Gal1 was observed to be highly expressed in GTD. Overexpression of ST6Gal1 promoted the proliferation and stemness of HTR-8/SVneo cells, whereas knockdown of ST6Gal1 suppressed the viability and stemness of JAR cells. MiR-199a-5p targeted and inhibited the expression of ST6Gal1 in trophoblastic cells. In addition, we revealed integrin β1 was highly α2,6-sialylated in JAR cells. Inhibition of ST6Gal1 reduced α2,6-sialylation on integrin β1 and suppressed the integrin β1/FAK pathway in JAR cells, thereby affecting its biological functions.
CONCLUSIONS: This study demonstrated that ST6Gal1 plays important roles in promoting proliferation and stemness through the integrin β1 signaling pathway in GTD. Therefore, ST6Gal1 may have a potential role in the occurrence and development of GTD.