Table 2.
Expression of PcG Genes in Hodgkin’s Lymphoma and HL-Derived Cell Lines
| PcG gene | Hodgkin lymphoma RS cells (n = 54) | Hodgkin lymphoma reactive lymphocytes (n = 54) | HL cell lines* (n = 2) |
|---|---|---|---|
| BMI-1 | 54/54 | 54/54 (30–80% positive cells) | Positive |
| HPH1 | 54/54 | 54/54 (30–80% positive cells) | Positive |
| HPC1 | 7/54** | 0/54 | Positive |
| HPC2 | 54/54 | 54/54 (30–80% positive cells) | Positive |
| RING1 | 54/54 | 54/54 (30–80% positive cells) | Positive |
| MEL-18 | 54/54 | 8/54 (∼5% positive cells) | Positive |
| 46/54 (∼90% positive cells) | |||
| EZH2 | 54/54 | 54/54 (<5% positive cells) | Positive |
| EED | 54/54 | 54/54 (<5% positive cells) | Positive |
| YY1 | 52/54† | 54/54 (>95% positive cells) | Positive |
| CtBP | 53/54‡ | 54/54 (>95% positive cells) | Positive |
*
Expression of PcG proteins was investigated in HL-derived cell lines L428 and L1236.
**
HPC1 expression in neoplastic H/RS cells is only observed using immunofluorescence on frozen tissue sections (7 individual cases were studied). In paraffin-embedded HL tissue, HPC1 is not detected, most likely due to low expression in tumor cells.
†
In 2 of 54 cases YY1 expression was absent from the neoplastic H/RS cells but present in the reactive lymphocytes.
‡
In 1 of 54 cases CtBP expression was absent from the neoplastic H/RS cells but present in the reactive lymphocytes. CtBP-/YY1- cases were not observed.