Alpha 2,6-sialyltransferase I expression in the placenta of patients with preeclampsia

Aberrant sialylation in ovarian cancers

Sialylation (the covalent addition of sialic acid to the terminal end of glycoproteins or glycans), tightly regulated cell- and microenvironment-specific process and orchestrated by sialyltransferases and sialidases (neuraminidases) family, is one of the posttranslational modifications, which plays an important biological role in the maintenance of normal physiology and involves many pathological dysfunctions. Glycans have roles in all the cancer hallmarks, referring to capabilities acquired during all steps of cancer development to initiate malignant transformation (a driver of a malignant genotype), enable cancer cells to survive, proliferate, and metastasize (a consequence of a malignant phenotype), which includes sustaining proliferative signaling, evading growth suppressor, resisting cell apoptosis, enabling replicative immortality, inducing angiogenesis, reprogramming of energy metabolism, evading tumor destruction, accumulating inflammatory microenvironment, and activating invasion and accelerating metastases. Regarding the important role of altered sialylation of cancers, further knowledge about the initiation and the consequences of altered sialylation pattern in tumor cells is needed, because all may offer a better chance for developing novel therapeutic strategy. In this review, we would like to update alteration of sialylation in ovarian cancers.

Maternal pregnancy-induced hypertension increases the subsequent risk of transient tachypnea of the newborn: A nationwide population-based cohort study

OBJECTIVE

To determine the association between pregnancy-induced hypertension (PIH) and transient tachypnea of the newborn (TTN) and to identify the predictive risk factors.

MATERIALS AND METHODS

Pregnant women with a newly diagnosed PIH (between 2000 and 2013) from the Taiwan National Health Insurance Research Database (NHIRD) were compared with a matched (with respect to age and year of delivery) cohort of pregnant women without PIH. The occurrence of TTN was evaluated in both cohorts.

RESULTS

Among the 23.3 million individuals registered in the NHIRD, 29,013 patients with PIH and 116,052 matched controls were identified. According to a multivariate analysis, PIH (odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.69-2.03, p < 0.0001), age ≥ 30 years (OR = 1.38, 95% CI = 1.26-1.51, p < 0.0001), primiparity (OR = 1.37, 95% CI = 1.24-1.5, p < 0.0001), preterm birth (OR = 3.4, 95% CI = 3.09-3.75, p < 0.0001), multiple births (OR = 2.54, 95% CI = 2.24-2.89, p < 0.0001), and cesarean section (OR = 1.71, 95% CI = 1.56-1.88, p < 0.0001) were independent risk factors for the development of TTN.

CONCLUSION

Women with PIH have an increased risk of having infants who develop TTN compared with those without PIH. Additionally, age ≥30 years, primiparity, preterm birth, multiple births, and cesarean section were independent risk factors for the development of TTN.

The role of α2,3-linked sialylation on clear cell type epithelial ovarian cancer

OBJECTIVE

Our previous study has shown that high expression of α2,3-sialytransferase type I was associated with advanced stage serous type epithelial ovarian cancer (EOC). The aim of the current study further attempts to evaluate the altered α 2,3-sialylation on the behavior of clear cell type EOC (C-EOC).

MATERIALS AND METHODS

Immunohistochemistry staining, bioinformatics analysis and tissue array were used to disclose the clinical significance of over α2,3-sialylation in C-EOC. An α2,3 sialylation inhibitor, soyasaponin I (SsaI) was used to investigate the behavior change of the C-EOC cell line.

RESULTS

We reconfirmed that α2,3-sialylation, instead of α2,6- sialylation, was associated with late-stage C-EOC. Soyasaponin I could inhibit α2,3-sialylation of C-EOC cell lines and increase E-cadherin expression with subsequently suppressing migration of C-EOC cells.

CONCLUSIONS

The current study demonstrated the important role of α2,3-linked sialylation in C-EOC and targeting of α2,3-linked sialylation might offer as a potential therapeutic strategy in the future.

An oncogenic protein Golgi phosphoprotein 3 up-regulates cell migration via sialylation

Recently, the Golgi phosphoprotein 3 (GOLPH3) and its yeast homolog Vps74p have been characterized as essential for the Golgi localization of glycosyltransferase in yeast. GOLPH3 has been identified as a new oncogene that is commonly amplified in human cancers to modulate mammalian target of rapamycin signaling. However, the molecular mechanisms of the carcinogenic signaling pathway remain largely unclear. To investigate whether the expression of GOLPH3 was involved in the glycosylation processes in mammalian cells, and whether it affected cell behavior, we performed a loss-of-function study. Cell migration was suppressed in GOLPH3 knockdown (KD) cells, and the suppression was restored by a re-introduction of the GOLPH3 gene. HPLC and LC/MS analysis showed that the sialylation of N-glycans was specifically decreased in KD cells. The specific interaction between sialyltransferases and GOLPH3 was important for the sialylation. Furthermore, overexpression of α2,6-sialyltransferase-I rescued cell migration and cellular signaling, both of which were blocked in GOLPH3 knockdown cells. These results are the first direct demonstration of the role of GOLPH3 in N-glycosylation to regulate cell biological functions.