Treatment with DHA Modifies the Response of MDA-MB-231 Breast Cancer Cells and Tumors from nu/nu Mice to Doxorubicin through Apoptosis and Cell Cycle Arrest

Abstract

Background Docosahexaenoic acid (DHA) has been shown to reduce growth of breast cancer cells in vitro and in vivo; it may also benefit the action of cytotoxic cancer drugs. The mechanisms for these observations are not completely understood. Objectives We sought to explore how pretreatment of MDA-MB-231 breast cancer cells with DHA alters gene expression with doxorubicin (DOX) treatment and confirm that feeding DHA to tumor-bearing nu/nu mice improves the efficacy of DOX. Methods MDA-MB-231 cells were subjected to 4 conditions: a control mixture of 40 μM linoleic and 40 μM oleic acid (OALA), DHA (60 μM plus OALA), OALA DOX (0.41 μM), or DHA DOX (plus OALA) and assessed for effects on viability and function. Female nu/nu mice (6 wk old) bearing MDA-MB-231 tumors were randomly assigned to a nutritionally complete diet (20 g ± 2.8 g DHA/100 g diet) containing a polyunsaturated:saturated fat ratio of 0.5, with or without injections 2 times/wk of 5 mg DOX/kg for 4 wk. Results Microarray and protein analysis indicated that DHA DOX cells, compared with OALA DOX, had upregulated expression of apoptosis genes, Caspase-10 (1.3-fold), Caspase-9 (1.4-fold), and Receptor (TNFRSF)-interacting serine-threonine kinase 1 (RIPK1) (1.2-fold), while downregulating cell cycle genes, Cyclin B1 (−2.1-fold), WEE1 (−1.6-fold), and cell division cycle 25 homolog C (CDC25C) (−1.8-fold) (P < 0.05). DHA DOX–treated mice had 50% smaller tumors than control mice (P < 0.05). Analysis of proapoptotic proteins from tumors of DHA DOX mice showed increased Caspase-10 (by 68%) and BH3 interacting domain death agonist (Bid) (by 50%), decreased B-cell CLL/lymphoma 2 (BCL2) (by 24%), and decreased cell cycle proteins Cyclin B1 and Cdc25c (both by 42%), compared with control mice (P < 0.05). Conclusions Supplementation with DHA facilitates the action of DOX in MDA-MB-231 cells and in nu/nu mice, which may occur via amplification of the effect of DOX on apoptosis and cell cycle genes.

Docosahexaenoic Acid Incorporation Is Not Affected by Doxorubicin Chemotherapy in either Whole Cell or Lipid Raft Phospholipids of Breast Cancer Cells in vitro and Tumor Phospholipids in vivo

“…Paraffin-embedded tumor sections were deparaffinized as previously described (Newell et al, 2019a) and stained with Harris Modified Hematoxylin and Eosin Y (H&E, Fisher Scientific, Edmonton, AB, Canada) to assess morphology and regions of necrosis. Slides were scanned with an Aperio Scanner and relative percent of necrosis was determined with Image Scope software.…”

“…MDA-MB-231 cells, representative of TNBC, have more aggressive growth and an intermediate response to chemotherapy (Holliday and Speirs, 2011). The antitumorigenic properties of n-3 long-chain polyunsaturated fatty acids (LCPUFA), specifically docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have been shown in both cell culture and animal studies (Chajes et al, 1995;D'Eliseo and Velotti, 2016;Ewaschuk et al, 2012;Newell et al, 2019a;Newell et al, 2019b;Rose et al, 1995;Schley et al, 2007). DHA has displayed greater cytotoxicity than EPA at the same concentration in MDA-MB-231 and MCF-7 cells (Barascu et al, 2006;Ewaschuk et al, 2012).…”

“…We have previously determined the efficacy of treating MDA-MB-231 and MCF-7 cells with DHA in conjunction with the chemotoxic drug, doxorubicin (DOX) and the modulation of CD95 protein apoptotic activity within lipid rafts (Ewaschuk et al, 2012). Recently, we have also established the efficacy of DHA in conjunction with DOX on reducing tumor size in nu/nu mice implanted with MDA-MB-231 BC cells (Newell et al, 2019a). DOX is an anthracycline commonly used in the treatment of BC.…”

Comparative Transcriptome Analysis Provides Insights into the Polyunsaturated Fatty Acid Synthesis Regulation of Fat-1 Transgenic Sheep

“…In our previous study, ESCs derived from fad3b (has similar functions as Fat-1 [40]) transgenic mice showed a much slower cell cycle with an increased n-3 PUFA content in the cells [41]. In other studies, n-3 PUFAs could also inhibit the proliferation of different kinds of cancer cells by regulating their cell cycle [42][43][44][45]. Therefore, Fat-1 expression cells may also have a lower proliferation rate than Fat-1 silencing cells or cells in wild type sheep.…”

Do Olive and Fish Oils of the Mediterranean Diet Have a Role in Triple Negative Breast Cancer Prevention and Therapy? An Exploration of Evidence in Cells and Animal Models

“…Doxorubicin is another first-line chemotherapy used in TNBC ( 103 ). Studies showed DHA enhanced the efficacy of doxorubicin in TNBC cells and an in vivo mouse model ( 55 ). Single agent treatment with either doxorubicin or DHA (60 μM) decreased MDA-MB-231 cell viability.…”