Background & objective: Nasopharyngeal carcinoma (NPC) patients commonly have neck regional lymph node metastases. However, patients with NPC of stage T3-4N0 have no lymph node metastases, even the tumors grow over the nasopharyngeal cavities. This study was to explore immune factors related to such a situation by detecting gene expression profile of immune cells from patients with NPC of stage T3-4N0.
Methods: Peripheral blood lymphocytes were isolated from 28 patients with NPC of stage T1-2N2-3, 28 patients with NPC of stage T3-4N0 before treatment, and 56 healthy donors. mRNA of the isolated lymphocytes was extracted, and reverse-transcribed into cDNA probes labeled with Cy5 or Cy3 fluorescent dyes. The Cy5-cDNA probes of T1-2N2-3 group and T3-4N0 group were separately mixed with Cy3-cDNA probes of healthy group, and hybridized with 480 dots of immune genechips. Genes were considered to be differently expressed in NPC patients if the Cy5/Cy3 was >2.0 (up-regulated), or <0.5 (down-regulated). The genes with Cy5/Cy3 of <0.25 or >4.0 were amplified by real time quantitative reverse transcription-polymerase chain reaction (RT-PCR) with RNA templates of T1-2N2-3 group, and T3-4N0 group, respectively.
Results: Of 157 genes showed different expressions, 106 down-regulated, 51 up-regulated. Real time quantitative RT-PCR revealed that among the 4 genes with Cy5/Cy3 of >4.0, and the 3 genes with Cy5/Cy3 of <0.25, expressions of the genes encoding CD86, CD69, NFKB were higher in sample from T3-4N0 group than in sample from T1-2N2-3 group.
Conclusions: More genes are down-regulated in immune cells from patients with NPC of stage T1-2N2-3 or T3-4N0 than those from healthy donors. Whether the different expressions of genes encoding CD86, CD69, and NFKB in immune cells of patients with NPC of stage T1-2N2-3 and stage T3-4N0 related to neck regional lymph node metastasis is worthy of further study.