Fish oil (FO) and selenium (Se) possess antiangiogenic potential in malignant tumors. This study aimed to determine whether combination of FO and Se enhanced treatment efficacy of low-dose antiangiogenic agent Avastin (bevacizumab) in a dose-dependent manner and targeted multiple signaling pathways in triple-negative breast cancer (TNBC)-bearing mice. Randomized into five groups, mice received treatment with either physiological saline (control), Avastin alone, or Avastin in combination with low, medium, and high doses of FO/Se. The target signaling molecules for anticancer were determined either by measuring protein or mRNA expression. Avastin-treated mice receiving FO/Se showed lower tumor growth and metastasis than did mice treated with Avastin alone. Combination-treated mice exhibited lower expressions in multiple proangiogenic (growth) factors and their membrane receptors, and altered cytoplasmic signaling molecules (PI3K-PTEN-AKT-TSC-mTOR-p70S6K-4EBP1, Ras-Raf-MEK-ERK, c-Src-JAK2-STAT3-TMEPAI-Smad, LKB1-AMPK, and GSK3β/β-catenin). Dose-dependent inhibition of down-stream targets including epithelial-to-mesenchymal transition transcription factors, nuclear cyclin and cyclin-dependent kinases, cancer stem cell markers, heat shock protein (HSP-90), hypoxia-inducible factors (HIF-1α/-2α), matrix metalloprotease (MMP-9), and increased apoptosis were observed. These results suggest that combination treatment with FO and Se increases the therapeutic efficacy of Avastin against TNBC in a dose-dependent manner through multiple signaling pathways in membrane, cytoplasmic, and nucleic targets.

Selenium (Se) and fish oil (FO) exert anti-epidermal growth factor receptor (EGFR) action on tumors. This study aimed to compare the anti-cancer efficacy of EGFR inhibitors (gefitinib and erlotinib) alone and in combination with nutritional supplements of Se/FO in treating lung cancer. Lewis LLC1 tumor-bearing mice were treated with a vehicle or Se/FO, gefitinib or gefitinib plus Se/FO, and erlotinib or erlotinib plus Se/FO. The tumors were assessed for mRNA and protein expressions of relevant signaling molecules. Untreated tumor-bearing mice had the lowest body weight and highest tumor weight and volume of all the mice. Mice receiving the combination treatment with Se/FO and gefitinib or erlotinib had a lower tumor volume and weight and fewer metastases than did those treated with gefitinib or erlotinib alone. The combination treatment exhibited greater alterations in receptor signaling molecules (lower EGFR/TGF-β/TβR/AXL/Wnt3a/Wnt5a/FZD7/β-catenin; higher GSK-3β) and immune checkpoint molecules (lower PD-1/PD-L1/CD80/CTLA-4/IL-6; higher NKp46/CD16/CD28/IL-2). These mouse tumors also had lower angiogenesis, cancer stemness, epithelial to mesenchymal transitions, metastases, and proliferation of Ki-67, as well as higher cell cycle arrest and apoptosis. These preliminary results showed the Se/FO treatment enhanced the therapeutic efficacies of gefitinib and erlotinib via modulating multiple signaling pathways in an LLC1-bearing mouse model.