Table 1

Genetic and epigenetic changes of RASSF1A in the xenografts, cell lines, and primary tumors of NPC

MutationMethylation3p deletionaRNA expression
Xenografts (n = 4)
 xeno-2117−ve (P1)b+ve (PM)b? (gain)c+ve
 xeno-1915−ve (P1)b+ve (PM)b−veNAd
 xeno-8−ve (P1)b+ve+ve−ve
 xeno-666−ve (P1)+ve−ve−ve
Cell lines (n = 4)
 C666-1−ve (P1)b+ve−ve−ve
 CNE-1−ve+ve (PM)b+ve+ve
 CNE-2−ve+ve (PM)b+ve+ve
Primary tumors (n = 21)
 NPC-1−ve−ve+ve (LOH)NAd
 NPC-2−ve (P1, P2)b+ve+ve (LOH)NAd
 NPC-3−ve−ve+ve (LOH)NAd
 NPC-4+ve+ve+ve (LOH)NAd
(Frameshift mutation, 1-bp deletion at nt 829)
 NPC-5−ve−ve+ve (LOH)NAd
 NPC-6−ve+ve+ve (LOH)NAd
 NPC-7−ve+ve+ve (LOH)NAd
 NPC-8−ve−ve+ve (LOH)NAd
 NPC-9−ve+ve+ve (LOH)NAd
 NPC-10−ve+ve+ve (LOH)NAd
 NPC-11−ve+ve+ve (LOH)NAd
 NPC-12−ve+ve+ve (LOH)NAd
 NPC-13−ve+ve+ve (LOH)NAd
 NPC-14−ve+ve+ve (LOH)NAd
 NPC-15−ve−ve+ve (LOH)NAd
 NPC-16−ve−ve+ve (LOH)NAd
 NPC-17−ve+ve+ve (LOH)NAd
 NPC-18+ve−ve+ve (LOH)NAd
(Codon 201 missense mutation, CGC (Arg) to CAC (His))
 NPC-19−ve+ve+ve (LOH)NAd
 NPC-20−ve+ve+ve (LOH)NAd
 NPC-21−ve+ve+ve (LOH)NAd
(2/21 = 9.5%)(14/21 = 66.7%)
  • a Results of 3p deletions in DPC samples were from previous allelotyping, karyotyping, and CGH studies (Refs. 2 3 4 and 11 12 13 ).

  • b P1, rare polymorphism with sequences changes at codon 53, 56, 57, and 60; PM, partial methylation; P2, rare polymorphism with sequence change at codon 133.

  • c Gain, copy number gain detected by CGH analysis.

  • d NA, not available.