Elevated IGF2 mRNA Binding Protein 3 (IGF2BP3) Expression Is Associated With High-Grade Intraepithelial Lesion in Cervical Brushed Cells

Abstract

Conventional cervical cancer prevention program has prevented majority of cervical cancers in developed countries. The laboratory test to identify molecular markers for cervical precancerous lesion is a new direction with a lower cost, which will benefit the underdeveloped countries. Insulin-like growth factor 2 mRNA-binding protein 3 (IGF2BP3 or IMP3) has demonstrated to be a marker positive for cervical intraepithelial lesions that lead to invasive cervical cancers. This study is to develop a real-time PCR method for detection for IGF2BP3, which is relevant to squamous intraepithelial lesions. Pap smear cervical cells in methanol-based preservatives were collected after cytopathologic diagnosis (ie, 8 specimens with negative findings, 8 specimens with ASCUS, 8 specimens with LGSIL, and 7 specimens with HGSIL). Total RNA was extracted from the preserved cells with regular Trizol method and cDNA was synthesized by reverse transcriptase. Real-time PCR (RT-PCR) experiments were performed with SYBR Green Supermix. RNA extraction from methanol-based preservatives is successful. The expression of IGF2BP3 is detectable in both normal and abnormal cervical cells, with the high-grade squamous intraepithelial lesional cells ~10 times of those normal cervical cells (P = .004). In this study, the ASCUS group has similar IGF2BP3 gene expression as in normal cervical cells, while the LGSIL cells have a variable IGF2BP3 gene expression and an average ~6 times of those in normal cervical cells (P > .05). High expression of IGF2BP3 is indicative of high-grade dysplasia with a sensitivity of 85.7% and a specificity of close to 67% compared with low-grade lesions. Real-time PCR is a reliable method to determine IGF2BP3 mRNA in methanol-based fixed cervical cells. IGF2BP3 may serve as an ancillary or an independent biomarker for high-grade lesions in future cervical screening. To be confirmative, future studies with a large number of cases are required.