P cumaric acid

All chemicals were analytical-reagent grade. Ultra-pure (MilliQ) water was used for the preparation of aqueous solutions. All chemicals, that is acetone, acetic acid, Folin–Ciocalteu reagent, 2,2-Diphenyl-1-picrylhydrazyl, sodium carbonate, sodium bisulfite, gallic acid, quercetin, rutin, caffeic acid, p-cumaric acid, and malvidin-3-glucoside were purchased from Sigma-Aldrich (St. Louis, MO, USA). Red grape pomace were purchased from a local winery producer (grape Nebbiolo, from Producers of Barabresco, CN, Italy).

Total protein was extracted from cells using RIPA buffer containing 10% protease inhibitor cocktail (Sigma, St. Louis, MO). Protein concentration was determined using Bradford (Bio-Rad Laboratories, Hercules, CA), and 40 μg of each sample was fractionated by 10–12% SDS-PAGE and blotted onto a nitrocellulose membrane (Hybond-ECL; Amersham Biosciences, Little Chalfont, UK). Non-specific binding sites were blocked with 5% non-fat dry milk in PBS−0.1% Tween-20. The following primary antibodies were used: anti-FAM83F (N17) (sc-102517), anti-p-ERK1/2 (sc-7393), anti-ERK1(sc-94), anti-BRAF (sc-166), anti-RAF-1 (sc-133), anti-Vimentin (sc-32322), anti-TTF-1 (sc-13040), anti PAX-8 (sc-81353), anti-β-actin (sc-47778) (Santa Cruz, Santa Cruz, CA, USA), anti-Myc-tag (TA100010) (OriGene Technologies), and anti-LIN28B (Cell Signaling). The anti-Nis antibody was kindly donated by Dr. Sissy Jhiang.
Immunoexpression was detected with horseradish peroxidase-conjugated secondary antibodies (GeHealthcare) and developed with luminol and p-cumaric acid (Sigma) reagents in the presence of H₂O₂. Chemoluminescence emission was visualized in an ImageQuant LAS4000 imaging system (GE Healthcare, Little Chalfont, UK).

Folin−Ciocalteu reagent was purchased from Kemika (Zagreb, Croatia); 2,2-diphenyl-1-picrylhydrazyl, catechin (CAS: 154–23–4, ≥99.0%), epicatechin (CAS: 490–46–0; ≥98%), gallic acid (CAS: 149–91–7, ≥97.5), p-cumaric acid (CAS: 501–98–4, ≥98.0%), phloretin (CAS: 60–82–2, ≥99.0%), phloridzin (CAS: 60–81–1, ≥98%), chlorogenic acid (CAS: 327–97–9, ≥95%) and caffeic acid (CAS: 331–39–5, ≥98.0%) were obtained from Sigma Chemical Co. (St. Louis, MO, USA). Methanol (HPLC grade) and orthophosphoric acid (85%) were obtained from Panareac (Barcelona, Spain). Certified standard of patulin and MycoSep^® 228 AflaPat columns were obtained from Romer Labs Biopure (Romer Labs, Tulln, Austria). Certified pesticide standard solutions were obtained from CPAchem (CPAchem, Stara Zagora, Bulgaria). LC-MS and HPLC grade acetonitrile was purchased from J.T. Baker (J.T. Baker, Deventer, The Netherlands), while LC-MS grade formic acid and LC-MS ammonium formate were produced by Sigma–Aldrich (Sigma-Aldrich, St. Louis, MO, USA). Ammonium hydroxide solution, ≥25% NH₃ in H₂O, was purchased from Honeywell (Offenbach, Germany). Nylon syringe filters, 0.2 µm pore size and 13 mm diameter, were obtained from Agilent (Santa Clara, CA, USA). Ultrapure water was generated by Niro VV system (Nirosta d.o.o., Osijek, Croatia).