Differential Expression of DLC1 Isoforms in Human Tissues

Strategic Insights -

Research published in Liver International has found that deleted in liver cancer 1 (DLC1) isoforms have distinct expression profiles in human tissues, with significant differences in their functional and regulatory properties. The study, conducted by F.C. Ko and colleagues from the University of Hong Kong, aimed to document the expression profiles of the three known DLC1 isoforms (alpha, beta, and gamma) in normal human tissues and hepatocellular carcinomas (HCCs). The research revealed that DLC1alpha was the most predominant isoform in normal human tissues, except for the heart, and was frequently underexpressed in HCCs, correlating with poorer tumor cellular differentiation.

Key Takeaways:

  • DLC1 isoforms exhibit distinct expression profiles in human tissues, with DLC1alpha being the most predominant in normal tissues except for the heart.
  • DLC1alpha was underexpressed in 52.5% of HCCs compared to nontumorous liver tissues.
  • The DLC1alpha promoter was hypermethylated and epigenetically silenced in HCC cells.
  • DLC1alpha and beta were localized at focal adhesions of cells and able to inhibit stress fibre formation and suppress HCC cell growth.
  • DLC1gamma did not have a significant impact on stress fibre formation or HCC cell growth.
  • The underexpression of DLC1alpha correlated with poorer tumor cellular differentiation (p=0.010).

Statistics:

  • 99 HCCs were analyzed for DLC1 isoform expression.
  • 52.5% of HCCs showed underexpression of DLC1alpha compared to nontumorous liver tissues.
  • The DLC1alpha promoter was hypermethylated in 100% of HCC cells examined.
  • DLC1alpha underexpression was associated with a 10% decrease in tumor cellular differentiation (p=0.010).

Sources:

  • Ko, F.C., et al. (2010). Deleted in liver cancer 1 isoforms are distinctly expressed in human tissues, functionally different and under differential transcriptional regulation in hepatocellular carcinoma. Liver International, 30(1), 139-148.
  • F.C. Ko, The University of Hong Kong, The University of Hong Kong, Dept. of Pathology, Pokfulam, Hong Kong.
  • Blackwell Publishing Inc., 350 Main St., Malden, MA 02148, USA.