BRAF Inhibitors and IFNα: Plus, Minus, or Indeterminate?

Oncogenic Mutation BRAF V600E Changes Phenotypic Behavior of THLE-2 Liver Cells through Alteration of Gene Expression

The accumulation of mutations in cancer driver genes, such as tumor suppressors or proto-oncogenes, affects cellular homeostasis. Disturbances in the mechanism controlling proliferation cause significant augmentation of cell growth and division due to the loss of sensitivity to the regulatory signals. Nowadays, an increasing number of cases of liver cancer are observed worldwide. Data provided by the International Cancer Genome Consortium (ICGC) have indicated many alterations within gene sequences, whose roles in tumor development are not well understood. A comprehensive analysis of liver cancer (virus-associated hepatocellular carcinoma) samples has identified new and rare mutations in B-Raf proto-oncogene (BRAF) in Japanese HCC patients, as well as BRAF V600E mutations in French HCC patients. However, their function in liver cancer has never been investigated. Here, using functional analysis and next generation sequencing, we demonstrate the tumorigenic effect of BRAF V600E on hepatocytes (THLE-2 cell line). Moreover, we identified genes such as BMP6, CXCL11, IL1B, TBX21, RSAD2, MMP10, and SERPIND1, which are possibly regulated by the BRAF V600E-mediated, mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK) signaling pathway. Through several functional assays, we demonstrate that BRAF L537M, D594A, and E648G mutations alone are not pathogenic in liver cancer. The investigation of genome mutations and the determination of their impact on cellular processes and functions is crucial to unraveling the molecular mechanisms of liver cancer development.

BRAF mutation status might contribute an effect on both disease-free and overall survival in stage III cutaneous melanomas treated with intermediate dose interferon-alpha

PURPOSE

The interaction between interferon treatment and BRAF mutation status among melanoma patients have yet to be evaluated. The present study aims to assess the intermediate dose interferon (IDI) in stage III melanoma patients with respect to BRAF mutation status.

METHODS

A total of 46 adult lymph node-positive primary skin melanoma patients (23 BRAF-mutant and 23 BRAF-wild) with available information on the mutational status of the oncogene BRAF V600E were included in the analysis. BRAF V600E mutation was detected using the real-time PCR in the formalin-fixed paraffin-embedded samples. All the patients were treated with adjuvant IDI. IFN-alpha-2b was administered 10 MU per day, subcutaneously, three times per week for 1 year.

RESULTS

The distribution of patient numbers between the clinicopathological variables and BRAF mutation status was well balanced. Most of the patients relapsed (83%); however, no significant differences were found between recurrence frequencies and recurrence sites in accordance with BRAF mutation status. BRAF-mutant melanomas were found to be significantly advantageous in disease-free survival (HR 0.464, p = 0.03). More deaths occurred in BRAF-wild-type patients (67%) (p = 0.03), and BRAF mutation was found to be a favorable prognostic factor for overall survival (HR 0.373, p = 0.04).

CONCLUSION

The presence of BRAF mutation in stage III melanoma patients treated with IDI might contribute a favorable effect on both disease-free survival and overall survival.