Hodgkin Lymphoma : Cytogenetics
Hodgkin Lymphoma - Cytogenetics: Hodgkin and Reed-Sternberg (HRS) cells show multiple chromosomal abnormalities and are aneuploid. Chromosomal translocations involving Ig loci are seen in about 20% of classic Hodgkin lymphomas (cHL). Some translocations involve known oncogenes such as BCL1, BCL2, BCL3, BCL6, REL, and MYC, but partner genes are unknown in most cases. Comparative genomic hybridization has shown recurrent gains in chromosomes 2p, 7p, 9p, and 11q, and losses in 4q and 11q. The gains in 2p occur in the 2p16 region containing the REL oncogene, a component of NF-κB pathway which is known to be constitutively activated in cHL. Another region that is frequently amplified in HRS cells is the 9p24 which contains JAK2, PD1L1 and PD1L2 genes. These events result in constitutive activation of JAK/STAT pathway in cHL.