EGFR Inhibition Induces Proinflammatory Cytokines via NOX4 in HNSCC

Abstract

Chronic inflammation plays a significant role in tumor promotion, migration and invasion. Using microarray analysis, we observed a profound increase in genes involved in pro-inflammatory pathways in epidermal growth factor receptor inhibitor (EGFRI)-treated head and neck squamous cell carcinoma (HNSCC) cell lines compared to their respective vehicle-treated cell lines. We hypothesized that the efficacy of EGFRIs may be offset by the pro-inflammatory response that these drugs produce in HNSCC tumor cells. We found that clinical EGFRIs such as erlotinib, cetuximab, lapatinib and panitumumab induced the secretion of pro-inflammatory cytokines such as IL-2, IL-4, IL-6, IL-8, GM-CSF, TNFα and IFNγ. Focusing on IL-6, we found that erlotinib induced a time-dependent increase in IL-6 mRNA and protein expression and exogenous IL-6 was able to protect HNSCC cells from erlotinib-induced cytotoxicity. Conversely, an IL-6 receptor antagonist tocilizumab, sensitized HNSCC cells to erlotinib in vitro and in vivo. Inhibitors of NFκB, p38 and JNK suppressed erlotinib-induced IL-6 expression, suggesting an important role of NFκB and MAPK pathways in IL-6 expression. Furthermore, knockdown of NADPH oxidase 4 (NOX4) suppressed erlotinib-induced pro-inflammatory cytokines expression. Taken together, these results suggest that clinical EGFRIs induce the expression of pro-inflammatory cytokines via NOX4. Therefore, the anti-tumor activity of EGFRIs may be partially reduced by activation of NOX4-mediated pro-inflammatory pathways in HNSCC.

Xilonix, a novel true human antibody targeting the inflammatory cytokine interleukin-1 alpha, in non-small cell lung cancer

“…In diseases characterized by sterile inflammation, such as cancer, elevated serum IL-6 levels indeed may be a surrogate for increased IL-1 signaling(31). At the level of the tumor microenvironment, increases in IL-6 production also occur secondary to EGFR blockade(32,33), which further feeds the cycle of immunosuppression due to inflammation.…”

STAT1-Induced HLA Class I Upregulation Enhances Immunogenicity and Clinical Response to Anti-EGFR mAb Cetuximab Therapy in HNC Patients

“…Previously, we demonstrated the reversal of HLA class I and APM component deficiency in HNC using the STAT1 agonist IFNγ, which enhanced CTL-mediated lysis and induced a higher level of peptide:HLA class I complexes (6,11–14). EGFR antagonism can also increase expression of HLA class I expression (14,15) and pro-inflammatory cytokines (16). We have recently shown that SHP2, which operates downstream of EGFR and dephosphorylates p-STAT1, plays an important role in HLA-induced immune escape in HNC (17).…”

EGFR-TKI, Erlotinib, Causes Hypomagnesemia, Oxidative Stress, and Cardiac Dysfunction

“…However, the fact that erlotinib caused only minimal effects on the plasma Mg levels during earlier weeks of exposure (< 3 weeks) suggested that EGFR inhibition by erlotinib may not be the only mechanism causing Mg wasting in later weeks. Erlotinib is also known to activate NOX4 (8,9), the NADPH oxidase that is highly enriched in the kidney (23, 24). Thus, chronic erlotinib treatment may lead to activation of kidney NOX4 to generate H 2 O 2 ; it was previously demonstrated that H 2 O 2 alone can cause dose-dependent inhibition of TRPM6 channel activity and subsequently decreased re-absorption of Mg (25).…”

“…However, preclinical in vitro patch clamp analyses in TRPM6-expressing renal cells showed that a physiological concentration (0.3 μM) of erlotinib did not inhibit EGF-induced changes in TRPM6 current density and tyrosine phosphorylation of EGFR (7). Erlotinib can provoke cellular oxidative stress in cancer cells through NOX-4 up-regulation (8 9…”