Differential gene expression pattern between normal human trophoblast and choriocarcinoma cell lines: downregulation of heat shock protein-27 in choriocarcinoma in vitro and in vivo

Objective: Our purpose was to identify potential differences in gene expression between normal trophoblast and choriocarcinoma cells.

Methods: The Atlas human cDNA expression array hybridization technique was used to study the gene expression pattern in normal trophoblast and choriocarcinoma cell lines. Furthermore, to confirm heat shock protein-27 (Hsp-27) expression data, reverse transcriptase-PCR (RT-PCR), Western blot, and immunohistochemical analyses were used in vitro with cell lines and in vivo with paraffin sections.

Results: The expression of nine genes was strongly different comparing a normal trophoblast cell line with choriocarcinoma cells on the Atlas membranes. Compared to normal trophoblast cells, six genes were upregulated and three were downregulated in choriocarcinoma cells. Furthermore, the downregulation of Hsp-27 in choriocarcinoma cells was confirmed both in vitro with cell lines and in vivo with paraffin sections using RT-PCR, Western blot, and immunohistochemical techniques.

Conclusion: cDNA expression array is a useful technique for identifying differentially expressed gene patterns in normal trophoblast and choriocarcinoma cells. The strong expression of Hsp-27 in placental villous trophoblast cells may play a role in trophoblast differentiation. The downregulation of Hsp-27 in choriocarcinoma may contribute to the extreme sensitivity of trophoblastic tumors to chemotherapy.