Endothelin-1 as a Mediator of Heme Oxygenase-1-Induced Stemness in Colorectal Cancer: Influence of p53

Abstract

Heme oxygenase-1 (HO-1) is an antioxidant protein implicated in tumor progression, metastasis, and resistance to therapy. Elevated HO-1 expression is associated with stemness in several types of cancer, although this aspect has not yet been studied in colorectal cancer (CRC). Using an in vitro model, we demonstrated that HO-1 overexpression regulates stemness and resistance to 5-FU treatment, regardless of p53. In samples from CRC patients, HO-1 and endothelin converting enzyme-1 (ECE-1) expression correlated significantly, and p53 had no influence on this result. Carbon monoxide (CO) activated the ECE-1/endothelin-1 (ET-1) pathway, which could account for the protumoral effects of HO-1 in p53 wild-type cells, as demonstrated after treatment with bosentan (an antagonist of both ETRA and ETRB endothelin-1 receptors). Surprisingly, in cells with a non-active p53 or a mutated p53 with gain-of-function, ECE-1-produced ET-1 acted as a protective molecule, since treatment with bosentan led to increased efficiency for spheres formation and percentage of cancer stem cells (CSCs) markers. In these cells, HO-1 could activate or inactivate certain unknown routes that could induce these contrary responses after treatment with bosentan in our cell model. However more research is warranted to confirm these results. Patients carrying tumors with a high expression of both HO-1 and ECE-1 and a non-wild-type p53 should be considered for HO-1 based-therapies instead of ET-1 antagonists-based ones.

Narrow Leafed Lupin (Lupinus angustifolius L.) β-Conglutin Seed Proteins as a New Natural Cytotoxic Agents against Breast Cancer Cells

“…MTT viability assay was accomplished by seeding 4 × 10 3 cells per well in 96-well plates, following [ 34 ]. Cells were allowed to grow overnight and treated with different concentrations of β-conglutins 1, 3, and 6 for 24, 48, and 72 h.…”

“…To detect aldehyde dehydrogenase 1 (ALDH1) activity (directly related to the number of CSCs) in cell culture with and without treatments, the Aldefluor kit (Stem Cell Technologies) was used according to the protocol proposed by the manufacturer [ 34 ]. After the treatments, cells were incubated with BODIPY-amino acetaldehyde (BAAA), a fluorescent non-toxic substrate for ALDH, which was converted into BODIPY-aminoacate (BAA) and retained inside the cells.…”

“…The characterization of CSCs was performed according to cell surface markers using CD44-PE and CD24-FITC antibodies (Biolegend, San Diego, CA, USA) [ 34 ]. After 30 min of incubation in darkness and at 4 °C, the samples were analyzed using a BD FACSAria IIIu flow cytometry (Becton Dickinson, BD Biosciences) from the Cytometry and Microscopy Research Service of the Biosanitary Research Institute of Granada (ibs.GRANADA).…”

“…Cells were seeded with culture medium in 6 well-plate 2 days before starting the sphere formation assay and then treated for 24 h with the β-conglutins 1, 3, and 6 as previously described. Then, cells were trypsinized and, from each condition, a 12-well triplicate with 1 × 10 2 cells/well was seeded in ultra-low attachment plates (Corning) in sphere culture medium prepared following [ 34 ]: DMEM/F12 supplemented with 1% penicillin/streptomycin, B27 10 µg/mL, 1 µg/mL Hydrocortisone, 4 ng/mL Heparin, 10 ng/mL EGF, and 20 ng/mL FGF, and let grow for 5–8 days. All reagents were purchased from Gibco (Carlsbad, CA, USA).…”

Personalized Medicine in Oncology; a Special Issue of the Journal of Personalized Medicine

“…Two of the original research pieces look specifically at novel biomarkers in gastrointestinal cancers. Rios-Arrabal and colleagues present the role of heme oxygenase-1 (HO-1) as a marker of “stemness” in colorectal cancer [ 6 ]. The authors found that HO-1 overexpression is commonly co-expressed with endothelin converting enzyme-1, and that resistance was unrelated to the presence or absence of p53 (a poor prognosis tumor marker).…”