Carotenoids in Cancer Metastasis—Status Quo and Outlook

Abstract

Metastasis represents a major obstacle in cancer treatment and the leading cause of cancer-related deaths. Therefore, the identification of compounds targeting the multi-step and complex process of metastasis could improve outcomes in the management of cancer patients. Carotenoids are naturally occurring pigments with a plethora of biological activities. Carotenoids exert a potent anti-cancer capacity in various cancer models in vitro and in vivo, mediated by the modulation of signaling pathways involved in the migration and invasion of cancer cells and metastatic progression, including key regulators of the epithelial–mesenchymal transition and regulatory molecules, such as matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), urokinase plasminogen activator (uPA) and its receptor (uPAR), hypoxia-inducible factor-1α (HIF-1α), and others. Moreover, carotenoids modulate the expression of genes associated with cancer progression and inflammatory processes as key mediators of the complex process involved in metastasis. Nevertheless, due to the predominantly preclinical nature of the known anti-tumor effects of carotenoids, and unclear results from certain carotenoids in specific cancer types and/or specific parts of the population, a precise analysis of the anti-cancer effects of carotenoids is essential. The identification of carotenoids as effective compounds targeting the complex process of cancer progression could improve the outcomes of advanced cancer patients.

Enzymatic Metabolism of Flavonoids by Gut Microbiota and Its Impact on Gastrointestinal Cancer

“…The positive impact of flavonoids consumption on breast and colorectal cancer was described in our previous publications, supporting the potential role of flavonoids on GI cancer [2,[104][105][106]. To evaluate this further, we looked up the effects of flavonoids on general pathways impaired by GI cancers, such as apoptosis, cellular proliferation, inflammation and invasion (Section 4.1).…”

Natural Compounds in Glioblastoma Therapy: Preclinical Insights, Mechanistic Pathways, and Outlook

“…These pigments exert oncologic effects by upregulating the extrinsic and intrinsic apoptotic pathways in tumor cells [13]. They also disrupt tumor cell migration and invasion and thereby hinder metastasis [14]. Carotenoids discussed in this review include astaxanthin, a xanthophyll derived from chlorophyte; adonixanthin, a carotenone and derivative of astaxanthin; and crocetin, an apocarotenoid from saffron.…”

Halophilic Carotenoids and Breast Cancer: From Salt Marshes to Biomedicine

“…Metastasis and cell migration can also be inhibited by carotenoids [143]. The migration of MCF-7 and MDA-MB-231 cell lines was reduced after the treatment with astaxanthin [144].…”