Eribulin

IC₅₀ concentrations, which induced 50% cell death, were calculated for eribulin (kindly provided by Eisai Inc. (Tokyo, Japan)) and gemcitabine hydrochloride (Sigma Aldrich) in all cell lines. DMSO was used as a drug vehicle and negative control. SK-UT-1 (2 × 10³), CP0024 (2.5 × 10³), 93T449, and 94T778 (3 × 10³) cells were seeded in 96-well plates and treated for 72 h (h) with drug concentrations ranging from 10⁻⁷ to 10⁻¹¹M for eribulin and from 10⁻⁶ to 10⁻¹⁰M for gemcitabine. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) method (Promega; Madison, WI, USA), recording absorbance at 490 nm in an iMarkTM microplate absorbance reader (Bio-Rad, Hercules, CA, USA) spectrophotometer. Data were analysed using Prism 6.0 (GraphPad; San Diego, CA, USA).

The human gastric cancer cell lines MKN1 (RRID, CVCL_1415), MKN74 (CVCL_2791), MKN45 (CVCL_0434), and NUGC3 (CVCL_1612), as well as HeLa cervical carcinoma cells (CVCL_0030), were obtained from the JCRB cell bank. The human gastric cancer cell lines SNU1 (CVCL_0099), Hs746T (CVCL_0333), and NCI‐N87 (CVCL_1603) were from American Type Culture Collection and SNU216 (CVCL_3946) was from the Korean Cell Line Bank. The cells were maintained under a humidified atmosphere of 5% CO₂ at 37°C in RPMI 1640 medium (Sigma‐Aldrich) supplemented with 10% heat‐inactivated fetal bovine serum (FBS) (Biowest) and 1% penicillin‐streptomycin‐amphotericin B (Wako). Cells were tested for mycoplasma contamination using MycoAlert (LT07, Lonza) and were confirmed negative. Eribulin was obtained from Eisai Co. Ltd and Oxaliplatin from Yakult. MORAb‐202 and farletuzumab were provided by Eisai Co. Ltd. MG132 was obtained from Funakoshi.

MCF7 and T47D cells were purchased from the American Type Cell Collection (Manassas, VA, USA). Palbociclib-resistant sublines were established via continuous exposure to a constant concentration of Palbociclib for more than 6 months as described in the Supplementary Methods. Three representative clones (MCF7-P1, MCF7-P2, and T47D-PR) were used in this study. Eribulin was provided by Eisai Co., Ltd. (Tokyo, Japan). Abemaciclib, dinaciclib, and everolimus were purchased from Selleck Biotech Co., Ltd. (Tokyo, Japan). Palbociclib, paclitaxel, doxorubicin, and fluorouracil were purchased from Sigma-Aldrich (Saint Louis, MO, USA). This study was approved by the Medical Ethics Committee on Clinical Investigation of Shinshu University (No. 341).

Eribulin was obtained from Eisai Co. Ltd. (Tokyo, Japan) through a Material Transfer Agreement. Anti-α-tubulin (DM1A, ab7291), anti-pericentrin (ab4448), and anti-Tyr397-phosphorylated FAK (p-FAK, EP2160Y, ab81298), Goat Anti-Mouse IgG (Alexa Fluor^® 488, ab150113), Donkey Anti-Rabbit IgG (Alexa Fluor^® 555, ab150062), and Donkey Anti-Mouse IgG (Alexa Fluor^® 555, ab150110) were purchased from Abcam (Cambridge, UK). Anti-Vinculin (hVIN-1, NB600-1293) was purchased from Novus Biologicals (Littleton, CO, USA). Anti-APC (F-3, sc-9998) and anti-GAPDH (sc-32233) were purchased from Santa Cruz Biotechnology, Inc. (Dallas, TX, USA). Anti-FAK (#3285) was purchased from Cell Signaling Technology, Inc. (Danvers, MA, USA). Hoechst33342 was purchased from Invitrogen (Carlsbad, CA, USA). Rhodamine-Phalloidin (PHDR1) was purchased from Cytoskeleton, Inc. (Denver, CO, USA). Fibronectin solution (C-43050) was purchased from PromoCell GmbH (Heidelberg, Germany). Horseradish peroxidase (HRP)-anti-mouse IgG and HRP-anti-rabbit IgG were purchased from Jackson ImmunoResearch (West Grove, PA, USA).