Targeting Colorectal Cancer Proliferation, Stemness and Metastatic Potential Using Brassicaceae Extracts Enriched in Isothiocyanates: A 3D Cell Model-Based Study

• Published in: Nutrients Vol. 9; no. 4; p. 368
• Main Authors: Pereira, Lucília P, Silva, Patrícia, Duarte, Marlene, Rodrigues, Liliana, Duarte, Catarina M M, Albuquerque, Cristina, Serra, Ana Teresa
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.04.2017; MDPI
• Subjects: Agar; Anoikis; Anticarcinogenic Agents - analysis; Anticarcinogenic Agents - chemistry; Anticarcinogenic Agents - isolation & purification; Anticarcinogenic Agents - metabolism; Antineoplastic Agents, Phytogenic - analysis; Antineoplastic Agents, Phytogenic - chemistry; Antineoplastic Agents, Phytogenic - isolation & purification; Antineoplastic Agents, Phytogenic - metabolism; Biomarkers, Tumor - genetics; Biomarkers, Tumor - metabolism; Brassica - chemistry; Brassica - economics; Brassicaceae; Brassicaceae extracts; broccoli; Caco-2 Cells; cancer stem cells; Carbon Dioxide - chemistry; Cell cycle; Cell Differentiation; Cell growth; Cell Proliferation; Cell self-renewal; Colorectal cancer; Colorectal carcinoma; Colorectal Neoplasms - diet therapy; Colorectal Neoplasms - metabolism; Colorectal Neoplasms - pathology; Colorectal Neoplasms - prevention & control; Dietary Supplements - analysis; DNA damage; Drug Resistance, Neoplasm; Flow cytometry; Gene Expression Regulation, Neoplastic; HT29 Cells; Humans; Isothiocyanate; Isothiocyanates - analysis; Isothiocyanates - isolation & purification; Isothiocyanates - metabolism; Metastases; Metastasis; Nasturtium - chemistry; Neoplasm Metastasis - pathology; Neoplasm Metastasis - prevention & control; Neoplasm Metastasis - therapy; Phenethyl isothiocyanate; Plant Extracts - chemistry; Plant Extracts - isolation & purification; Plant Extracts - metabolism; Solvents - chemistry; Spheroids; Spheroids, Cellular; Stem cells; Sulforaphane; Tumor cells; Vegetables; watercress; Wnt protein; β-Catenin; sulforaphane; colorectal cancer; phenethyl isothiocyanate; metastasis; broccoli; cancer stem cells; Brassicaceae extracts; watercress
• ISSN: 2072-6643; 2072-6643
• DOI: 10.3390/nu9040368

Colorectal cancer (CRC) recurrence is often attributable to circulating tumor cells and/or cancer stem cells (CSCs) that resist to conventional therapies and foster tumor progression. Isothiocyanates (ITCs) derived from vegetables have demonstrated anticancer effects in CRC, however little is known about their effect in CSCs and tumor initiation properties. Here we examined the effect of ITCs-enriched extracts derived from watercress and broccoli in cell proliferation, CSC phenotype and metastasis using a previously developed three-dimensional HT29 cell model with CSC-like traits. Both extracts were phytochemically characterized and their antiproliferative effect in HT29 monolayers was explored. Next, we performed cell proliferation assays and flow cytometry analysis in HT29 spheroids treated with watercress and broccoli extracts and respective main ITCs, phenethyl isothiocyanate (PEITC) and sulforaphane (SFN). Soft agar assays and relative quantitative expression analysis of stemness markers and Wnt/β-catenin signaling players were performed to evaluate the effect of these phytochemicals in stemness and metastasis. Our results showed that both extracts and ITCs exert antiproliferative effects in HT29 spheroids, arresting cell cycle at G₂/M, possibly due to ITC-induced DNA damage. Colony formation and expression of LGR5 and CD133 cancer stemness markers were significantly reduced. Only watercress extract and PEITC decreased ALDH1 activity in a dose-dependent manner, as well as β-catenin expression. Our research provides new insights on CRC therapy using ITC-enriched extracts, specially watercress extract, to target CSCs and circulating tumor cells by impairing cell proliferation, ALDH1-mediated chemo-resistance, anoikis evasion, self-renewal and metastatic potential.