Identification of a human TFPI-2 splice variant that is upregulated in human tumor tissues

Prakasha Kempaiah, Hitendra S. Chand, Walter Kisiel

Research output: Contribution to journalArticlepeer-review

Abstract

Background: Previous studies have shown that the expression of tissue factor pathway inhibitor-2 (TFPI-2), a matrix-associated Kunitz-type serine proteinase inhibitor, is markedly down-regulated in several tumor cells through hypermethylation of the TFPI-2 gene promoter. In the present study, RT-PCR analysis of total RNA from both human normal and tumor cells revealed a novel 289 nucleotide splice variant of the TFPI-2 transcript designated as aberrantly-spliced TFPI-2 (asTFPI-2). Results: Nucleotide sequence analyses indicated that asTFPI-2 consists of complete exons II and V, fused with several nucleotides derived from exons III and IV, as well as six nucleotides derived from intron C. 5′- and 3′-RACE analyses of total RNA amplified exclusively the wild-type TFPI-2 transcript, indicating that asTFPI-2 lacks either a 5′-untranslated region (UTR) or a 3′-poly (A)+ tail. Quantitative real-time RT-PCR analyses revealed that several human tumor cells contain 4 to 50-fold more copies of asTFPI-2 in comparison to normal cells. In spite of the absence of a 5′-UTR or poly (A)+ tail, the asTFPI-2 variant exhibited a half-life of ∼16 h in tumor cells. Conclusion: Our studies reveal the existence of a novel, aberrantly-spliced TFPI-2 transcript predominantly expressed in tumor cells and provides suggestive evidence for an additional mechanism for tumor cells to down-regulate TFPI-2 protein expression enhancing their ability to degrade the extracellular matrix.

Original languageEnglish (US)
Article number20
JournalMolecular cancer
Volume6
DOIs
StatePublished - Mar 12 2007

ASJC Scopus subject areas

  • Molecular Medicine
  • Oncology
  • Cancer Research

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