Dynamics of Chemokine, Cytokine, and Growth Factor Serum Levels in BRAF-Mutant Melanoma Patients during BRAF Inhibitor Treatment

Abstract

The purpose of this study is to profile the changes in the serum levels of a range of chemokines, cytokines, and growth and angiogenic factors in MAPK inhibitor–treated metastatic melanoma patients and to correlate these changes with clinical outcome and changes in melanoma tissue biopsies taken from the same patients. Forty-two chemokine, cytokine, angiogenic, and growth factors were measured in the sera of 20 BRAF inhibitor–treated and four combination BRAF and MEK inhibitor–treated metastatic melanoma patients using a multiplex chemokine assay. The changes were correlated with Ki-67 and CD8+ tumor-infiltrating lymphocytes in the tumor biopsies taken at the same time points, as well as clinical outcome, including response rate, progression-free survival, and overall survival. Serum levels of IFN-γ, CCL4, and TNF-α were significantly increased, whereas CXCL8 significantly decreased from pretreatment (PRE) to early during treatment (EDT) serum samples. The decrease in serum CXCL8 levels from PRE to EDT significantly correlated with decreases in markers of melanoma proliferation (Ki-67) and increases in cytotoxic tumor-infiltrating T cells in corresponding tumor biopsies. In addition, a greater fold reduction in CXCL8 serum levels from PRE to EDT serum samples was associated with decreased overall survival. These results suggest that BRAF inhibition causes decreased CXCL8 secretion from melanoma cells and induce an immune response against the tumor associated with increased IFN-γ, CCL4, and TNF-α. Further studies are needed to determine if CXCL8 is predictive of response and to confirm the functions of these chemokine and cytokine in BRAF-mutant melanoma under BRAF inhibition.

Co-clinical assessment identifies patterns of BRAF inhibitor resistance in melanoma

“…Again supporting these RNA expression findings are the RPPA data showing on-treatment LCK antibody levels (an immune marker) to be among the most highly correlated with RECIST responses ( Figure 6I). Taken together, these observations suggest that tumors with primed immune systems might be better poised for response to treatment, consistent with a recent report on prognostic immune serum markers in a BRAF inhibitor trial (35) and with the observation that microarray-based immune infiltration signatures positively correlate with survival in non-BRAFi-treated melanoma patient populations (36)(37)(38)(39). Additionally, the large-scale TCGA (The Cancer Genome Atlas) study has confirmed that elevated lymphocytic RNA-seq signatures and LCK RPPA signals positively correlate with outcome in over 300 patients (https://tcga-data.…”

The BRAF and MEK Inhibitors Dabrafenib and Trametinib: Effects on Immune Function and in Combination with Immunomodulatory Antibodies Targeting PD-1, PD-L1, and CTLA-4

“…HLA-class I molecules are often downregulated or lost in tumor cells and play a key role in immune escape (30)(31)(32). A study by Carreteto and colleagues (33) showed that higher HLA class I gene expression was observed in regressing but not in progressing metastases from microdissected tumor regions, supporting the idea that the nature of HLA class I alterations in tumor cells may contribute to antitumor effects of therapeutic interventions. Our observation of MAPK inhibition induced apoptosis, increase of MHC class I and/or II along with the decrease of immunosuppression factors in most of the human tumor cell lines, and in CT26 tumors when combined with anti-PD-1 antibody in vivo is intriguing.…”

Blocking Tumor Necrosis Factor α Enhances CD8 T-cell–Dependent Immunity in Experimental Melanoma

“…Evaluating HLA-I expression in melanoma biopsies would help define eligibility of patients for TNF blockade treatment. In addition, emerging therapies for the treatment of melanomas, such as anti-CTLA4 (50), and BRAF V600E inhibitors (7,8), are associated with CD8 þ T-cell immune response and TNF production, even in patients with disease progression. Macrophage-derived TNF is important for BRAF V600E melanoma growth in vivo and confers resistance to MAPK pathway inhibitors (16).…”

“…Injection of high levels of recombinant TNF triggers necrosis of melanoma, not only in mice, but also in humans and is currently used in isolated limb perfusion in the clinic (2). In sharp contrast, it has been recently shown that TNF, which is produced in patients treated with BRAF V600E inhibitors (7,8), may confer treatment resistance of human melanoma by increasing Twist1 levels (9). The role of TNF in melanoma has been further investigated in mice using B16 melanoma cells, which do not express TNF endogenously (10).…”