Molecular Profiling of Cancer Testis Antigens in Chronic Lymphocytic Leukemia.

Chronic Lymphocytic Leukemia (CLL) is characterized by the progressive accretion of long-lived mature B-lymphocytes. Although the classical Rai and Binet staging is still commonly used, a new molecular understanding has identified specific signatures which could help predict disease progression and survival. Given the recent success of immunotherapeutic strategies and immunomodulatory drugs in the treatment of CLL we sought to identify potentially immunologically relevant targets and their relation to well known disease criterion.

Our study characterized the mRNA expression of 29 known cancer-testis antigens (CTAs) in 66 patients with CLL at varying stages of disease using a RT-PCR based expression panel. Relevant clinical criterion such as RAI stage, B2m, ZAP-70, IGVH mutational status, CD38, cytogenetics by FISH analysis, WBC count, age, gender, and treatment among others were then taken into account. The binary RNA expression data associated with the clinical and demographic factors were evaluated using chi-square or Wilcoxon rank sum analysis.

Of the cancer-testis antigens tested, the MAGE family of CTAs revealed statistically significant correlations with multiple clinical criteria. Our analysis reveals a correlation between previous chemo-immunotherapy treatment and MAGE-A1, B2, E1, MAD-CT-2, SPA-17, and PAGE-5 expression. Beyond treatment, total white blood cell count was shown to have a significant association with MAGE family members A1, A3, and B2 expression. In addition, MAD-CT-2 and MAGE-B2 were significantly correlated with the expression of FMC-7 and SSX-4 and LAGE-1 correlated with the presence of B-cell symptomatology.

Preliminary RT-PCR based CTA phenotyping has unveiled interesting correlations to clinical criteria, opening multiple avenues for future immunotherapeutic interventions as well as possible prognostic value in CLL. Further investigation to better understand the biological value of this information in warranted.

Pinilla:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Bristol-Myers Squibb: Research Funding; exelixis: Research Funding.