Specific activation of glycolytic enzyme enolase 2 in BRAF V600E-mutated colorectal cancer

The BRAF V600E mutation occurs in approximately 10% of patients with metastatic colorectal cancer (CRC) and constitutes a distinct subtype of the disease with extremely poor prognosis. To address this refractory disease, we investigated the unique metabolic gene profile of BRAF V600E‐mutated tumors via in silico analysis using a large‐scale clinical database. We found that BRAF V600E‐mutated tumors exhibited a specific metabolic gene expression signature, including some genes that are associated with poor prognosis in CRC. We discovered that BRAF V600E‐mutated tumors expressed high levels of glycolytic enzyme enolase 2 (ENO2), which is mainly expressed in neuronal tissues under physiological conditions. In vitro experiments using CRC cells demonstrated that BRAF V600E‐mutated cells exhibited enhanced dependency on ENO2 compared to BRAF wild‐type cancer cells and that knockdown of ENO2 led to the inhibition of proliferation and migration of BRAF V600E‐mutated cancer cells. Moreover, inhibition of ENO2 resulted in enhanced sensitivity to vemurafenib, a selective inhibitor of BRAF V600E. We identified AP‐1 transcription factor subunit (FOSL1) as being involved in the transcription of ENO2 in CRC cells. In addition, both MAPK and PI3K/Akt signaling were suppressed upon inhibition of ENO2, implying an additional oncogenic role of ENO2. These results suggest the crucial role of ENO2 in the progression of BRAF V600E‐mutated CRC and indicate the therapeutic implications of targeting this gene.

Low absolute peripheral blood CD4+ T-cell count predicts poor prognosis in R-CHOP-treated patients with diffuse large B-cell lymphoma

The absolute peripheral blood lymphocyte count at diagnosis is known to be a strong prognostic factor in patients with diffuse large B-cell lymphoma (DLBCL) treated with rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP), but it remains unclear as to which peripheral blood lymphocyte population is reflective of DLBCL prognosis. In this cohort, 355 patients with DLBCL treated with R-CHOP from 2006 to 2013 were analyzed. The low absolute CD4+ T-cell count (ACD4C) at diagnosis negatively correlated with the overall response rate and the complete response rate significantly (P<0.00001). An ACD4C<343 × 106/l had a significant negative impact on the 5-year progression-free survival and the overall survival as compared with an ACD4C⩾343 × 106/l (73.7% (95% confidence interval (CI)=66.7-79.5) versus 50.3% (95% CI=39.0-60.6), P<0.00001 and 83.3% (95% CI=77.1-88.0) versus 59.0% (95% CI=47.9-68.5), P<0.00000001, respectively). Multivariate analysis revealed that the ACD4C was an independent prognostic marker (hazard ratio=2.2 (95% CI=1.3-3.7), P<0.01). In conclusion, a low ACD4C at diagnosis served as an independent poor prognostic marker in patients with DLBCL.