J Korean Cancer Assoc.  2000 Jun;32(3):553-562.

Alterations of p15INK4B, p16INK4A and Methylthioadenosine Phosphorylase Gene in Korean Hepatdegrees Cellular Carcinoma

• Pyun HY
• Cho JW
• Baik WK
• Park JW
• Park JP
• Suh MH
• Suh SI

Abstract

PURPOSE: We analyzed the gene status of p16INK4A, p15INK4B and MTAP (methylthio adenosine phophorylase) in Korean hepatdegrees Cellular carcinoma (HCC) to investigate whether the inactivation of these genes participated in hepatdegrees Carcinogenesis, and evaluated MTAP-targeted chemotherapy in MTAP-deficient cell lines. MATERIAL AND METHODS: We examined eleven primary HCC and 8 SNU cell lines using PCR, Southern blot analysis, PCR-SSCP, DNA sequencing, methylation-specific PCR, Western blot analysis, MTT assay, and crystal violet staining.
RESULTS
Mutations or deletion of the p16INK4A, 15INK4B, and MTAP genes were rare, but methylation of the p16INK4A promoter region was common in HCC. The base alterations of 3' untranslated region of p16INK4A exon 3 were also detected in 3 samples. In SNU cells, p16INK4A was not detectable, when treated with demethylating agent, high levels of re-expressed p16INK4A protein were detected. In MTAP-targeted chemotherapy experiment, methylthioadeno sine (MTA) was able to rescue MTAP positive cell lines but not MTAP negative cell lines from growth inhibition by depletion of methionine and MTX treatment.
CONCLUSION
These results suggest that de novo methylation of the p16INK4A promoter region seems to play an important role in the pathogenesis of HCC. And treatment of MTX, combined with methionine depletion in the presence of MTA, may be a high selective treatment for MTAP negative HCC.

Keyword

Hepatdegrees Cellular carcinoma; p16INK4A; Methylation; Methylthioadenosine phos phorylase

MeSH Terms

3' Untranslated Regions
Adenosine
Blotting, Southern
Blotting, Western
Carcinogenesis
Cell Line
Cyclin-Dependent Kinase Inhibitor p16
Drug Therapy
Exons
Gentian Violet
Methionine
Methylation
Polymerase Chain Reaction
Promoter Regions, Genetic
Sequence Analysis, DNA
Pemetrexed
3' Untranslated Regions
Adenosine
Cyclin-Dependent Kinase Inhibitor p16
Gentian Violet
Methionine