Fingolimod sensitizes EGFR wild‑type non‑small cell lung cancer cells to lapatinib or sorafenib and induces cell cycle arrest

Abstract

Epidermal growth factor receptor (EGFR) is a receptor tyrosine kinase and mutations in this gene are major drivers of lung cancer development. EGFR tyrosine kinase inhibitors (TKIs) are standard first-line therapies for patients with advanced non-small cell lung cancer (NSCLC) with activating EGFR mutations, but are not effective in patients with wild-type EGFR. In the present study, the cytotoxic effects of various TKIs against EGFR were investigated in wild-type NSCLC cells as single treatments or in combination with Fingolimod (FTY720), which has been approved for treating multiple sclerosis and has cytotoxic effects against several tumor cell lines. It was found that the combined treatment with TKIs lapatinib (Lap) or sorafenib (Sor) and FTY720 synergistically suppressed the viability of the NSCLC cell lines A549 and H596. Additionally, FTY720 inhibited lysosomal acidification and suppressed autophagy flux. Immunoblotting and reverse transcription-quantitative polymerase chain reaction showed that FTY720 combined with Lap or Sor, enhanced endoplasmic reticulum (ER) stress loading and cell cycle arrest in A549 cells. The enhancement of ER stress loading and cell cycle arrest induced by combined treatment with Lap or Sor and FTY720, which was associated with the cytotoxicity induced by the combination of these drugs. These findings suggested that FTY720 improved TKI therapy in NSCLC patients with wild-type EGFR, by sensitizing NSCLC cells to TKIs.

Targeting Sphingolipids for Cancer Therapy

“…Fingolimod also shifts macrophages to an anti-inflammatory M2 phenotype and modulates their proliferation, morphology, and cytokine release ( 233 ). Preclinical studies of fingolimod have indicated that this drug is safe, potentiates the effect of chemotherapy ( 192 , 195 , 196 , 200 , 201 , 234 ), and suppresses tumor growth by inducing apoptosis (increased cleavage of PARP and caspases, decreased Bcl-2 and Mcl-1 levels, and increased Bax levels) ( 176 , 177 , 179 , 181 , 182 , 187 , 189 , 194 – 199 , 203 , 204 , 206 ), autophagy (increased LC3-II, beclin-1, and Atg7 levels, and decreased p62 expression) ( 197 , 203 , 208 , 209 ), necrosis ( 183 , 210 ), cell cycle arrest (increased levels of cell cycle inhibitory proteins [p27 and p21]); and decreased expression of cyclin D1 and C-X-C motif chemokine receptor 4 [CXCR4]) ( 186 , 187 , 197 , 204 , 209 ). Fingolimod also increases ceramide levels ( 181 , 204 ), the proteasomal degradation of SPHK1 ( 182 ), inactivation of RhoA-GTPase ( 178 ), histone deacetylase (HDAC) activity ( 185 ), multidrug resistance protein 1 (ABCB1) levels ( 195 ), protein phosphatase 2A (PP2A) reactivation ( 196 , 205 , 206 ), and modulation of signaling pathways (VEGF ( 176 , 186 , 199 ), MMP2, MMP9, CD31, E-cadherin, β-catenin ( 176 ), estrogens ( 187 ), JNK ( 191 ), NF-κB ( 206 ), STAT3 ( 201 , 206 ), AMP-activated protein kinase (AMPK) ( 208 ), mTOR ( 208 ), Erk1/2 ( 182 , 186 , 189 , 191 , ...…”

Induction of Lysosomal Membrane Permeabilization Is a Major Event of FTY720-Mediated Non-Apoptotic Cell Death in Human Glioma Cells

“…FTY720 is a synthetic compound produced by modification of a metabolite from I. sinclairii and has strong anti-cancer activity. For example, FTY720 induces cell death in multiple cancer cells [ 1 , 2 , 3 , 4 ] and sensitizes cancer cells to chemotherapy and radiotherapy [ 5 , 6 , 7 , 8 ]. Interestingly, FTY720 has also been seen to increase non-apoptotic cell death.…”

Lysosome‑targeted drug combination induces multiple organelle dysfunctions and non‑canonical death in pancreatic cancer cells

“…Combination treatment with lapatinib and FTY720 enhances growth inhibition in PDAC cells. Previously, we reported that combination treatment with FTY720 and the EGFR/HER2 inhibitor lapatinib or multikinase inhibitor sorafenib can show prominent growth inhibitory activity in NSCLC cells (18). In the present study, we focused on lysosomotropic drugs (36).…”

“…Although some studies have documented the induction of autophagy by FTY720 (19)(20)(21)(22), others have reported autophagy suppression (23)(24)(25)(26)(27). In our previous study, we reported that FTY720 could inhibit lysosomal function and autophagic flux in NSCLC cells (18). Additionally, FTY720 has been reported to induce lysosomal membrane permeabilization (LMP) and non-apoptotic death in human glioma cells (28).…”

“…We have previously reported that fingolimod (FTY720), a sphingosine analog and Food and Drug Administration (FDA)-approved drug for multiple sclerosis, sensitizes non-small cell lung cancer (NSCLC) cells to molecular-targeted drugs, such as lapatinib and sorafenib, and induces cell cycle arrest (18). In addition, FTY720 can reportedly modulate autophagy.…”