PLAGL1 gene transcription during HCC cell proliferation

VEGA BENEDETTI A.F.; VANNI R.; CARIA P,; ZAVATTARI P.; PARADA L.A.

Ferrara

Congreso; 56th Annual Meeting of the Italian Cancer Society - DANGEROUS LIAISONS; 2014

Societa Italiana di Cancerologia

Introduction: PLAGL1 gene encodes a homonym Zinc-finger protein that regulates cell cycle arrest and apoptosis. Regulation occurs through convergent mechanisms including the induction of the expression of p21Cip1 and PPARγ and the interaction with p53. Deletion of chromosome 6q is a common finding in hepatocellular carcinoma (HCC). The important tumorigenic event associated with this abnormality has been the loss of the tumor suppressor gene IGFIIR (6q25.3). However we speculate that PLAGL1 (6q24.1) may also have an important role in HCC development. In fact, abnormal promoter methylation of this gene is a frequent event in ovary and breast tumors. We studied the transcriptional level of PLAGL1 in the context of proliferation of hepatoma cells. Materials and methods: Human HCC cell lines HepG2, Huh7, PLC and SkHep1 were plated onto 75 cm2 flasks for proliferation assays, and cultured in D-MEMF12 media supplented with 10% FBS. Normal fibroblasts were used as control. Cell count and Real Time PCR (RT-PCR) for PLAGL1 and PPIA (reference gene) was performed at 48h, 72h and 96h during cell proliferation. The transcription level of PLAGL1 and PPIA was quantified using the 2-ΔΔCt method. The  statistical analysis were performed by 1 way ANOVA.Results: We determined that the cancer cell lines have higher proliferation rates, and significant lower level of PLAGL1 mRNA than fibroblasts. Significant differences were found in the transcription level of PLAGL1 in fibroblast between the different time points. Whereas the tumor cell lines did not exhibit changes in the transcription level of PLAGL1 during the experimental period, except for SkHep1 at 96h. Comparing the level among tumor cell lines, significant differences were found, being SkHep1 cells those whith the lowest expression.Conclusions: We conclude that the low transcription level of PLAGL1 could be associated with abnormal proliferation of HCC cells.