Details

Autor(en) / Beteiligte

• Sakai, Akiko
• Otani, Mieko
• Miyamoto, Akiko
• Yoshida, Hideji
• Furuya, Eisuke
• Tanigawa, Nobuhiko

Titel

Identification of phosphorylated serine-15 and -82 residues of HSPB1 in 5-fluorouracil-resistant colorectal cancer cells by proteomics

Ist Teil von

• Journal of proteomics, 2012-01, Vol.75 (3), p.806-818

Ort / Verlag

Kidlington: Elsevier B.V

Erscheinungsjahr

2012

Quelle

MEDLINE

Beschreibungen/Notizen

• To identify the proteins involved in 5-fluorouracil (5-FU) resistance, a comparison of the total and phosphorylated proteins between the human colorectal cancer (CRC) cell line DLD-1 and its 5-FU-resistant subclone DLD-1/5-FU was performed. Using 2-DE and MALDI-TOF/TOF-based proteomics, 17 up-regulated and 19 down-regulated protein spots were identified in the 5-FU-resistant DLD-1/5-FU cells compared with the parent cell lines. In DLD-1/5-FU cells, 7 anti-apoptotic proteins (HSPB1, proteasome subunit α-5, transitional endoplasmic reticulum ATPase, 14-3-3 β, 14-3-3 γ, 14-3-3 σ, and phosphoglycerate kinase 1) were up-regulated and 4 proapoptotic proteins (cofilin-1, pyruvate kinase M2, glyceraldehyde-3-phosphate dehydrogenase, and nucleophosmin) were down-regulated. The results show that the acquired drug resistance of DLD-1/5-FU cells is caused by the prevention of drug-induced apoptosis, in particular through the enhanced constitutive expression of HSPB1 and its phosphorylated form. Short interfering RNA knockdown of endogenous HSPB1 in DLD-1/5-FU cells restored the sensitivity to 5-FU. Furthermore, MALDI-TOF/TOF and 2-DE Western blot analysis identified the phosphorylated residues of HSPB1 as Ser-15 and Ser-82 in the main (diphosphorylated) form and Ser-15, Ser-78, and Ser-82 in the minor (triphosphorylated) form. The current findings indicate that phosphorylated HSPB1 may play an important role in 5-FU resistance. [Display omitted] ► We identify the proteins involved in 5-fluorouracil resistance. ► Up-regulation of 7 anti-apoptotic proteins. ► Down-regulation of 4 proapoptotic proteins. ► Phosphorylated HSPB1 may play an important role in 5-FU resistance. ► We identify phosphorylated residues as Ser-15 and Ser-82 using 2-DE and MALDI-TOF/TOF.