Proteomic identification of predictive biomarkers for malignant transformation in complete hydatidiform moles

Protein expression in cells are associated with oncogenesis. This study aims to explore proteomic profiles and discover potential biomarkers that can predict malignant transformation of hydatidiform mole.

Retrospective analysis was done in 14 cases of remission hydatidiform mole and 14 cases of hydatidiform mole who later developed malignancy (GTN group). Molar tissues were retrieved from -70 °C frozen tissue. Subsequently, a large-scale proteomic analysis was performed to identify proteins and compare their abundance levels in the preserved molar tissues from these two groups using a dimethyl-labeling technique coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS).

A total of 2,153 proteins were identified from all samples. 22 and 10 proteins were significantly up-regulated and down-regulated, respectively, in the GTN group compared with the mole group. These altered proteins were found in several biological groups such as cell-cell adhesion, secreted proteins, and ribonucleoproteins. Several hormone-related proteins were among the most up-regulated proteins in the GTN group including choriogonadotropin subunit beta (β-hCG) and alpha (α-hCG), growth/differentiation factor 15, as well as both pregnancy-specific beta-1-glycoproteins 2 and 3. In contrast, protein S100-A11 and l-lactate dehydrogenase A chain, were down-regulated in molar tissue from most patients in the GTN group.

This study identified a set of differentially expressed proteins in molar tissues that could potentially be further examined as predictive biomarkers for the malignant transformation of CHMs. A molar proteome database was constructed and can be accessible online at http://sysbio.chula.ac.th/Database/GTD_DB/Supplementary_Data.xlsx.