Members of the heat-shock protein 70 family promote cancer cell growth by distinct mechanisms.

TY - JOUR

T1 - Members of the heat-shock protein 70 family promote cancer cell growth by distinct mechanisms.

AU - Rohde, Mikkel

AU - Daugaard, Mads

AU - Jensen, Mette Hartvig

AU - Helin, Kristian

AU - Nylandsted, Jesper

AU - Jäättelä, Marja

N1 - Keywords: Cell Division; Cell Survival; Cytokines; G1 Phase; G2 Phase; Gene Expression Regulation, Neoplastic; HSC70 Heat-Shock Proteins; HSP70 Heat-Shock Proteins; Hela Cells; Humans; Neoplasms; RNA, Small Interfering; Spermatogenesis; Tumor Suppressor Protein p53

PY - 2005

Y1 - 2005

N2 - Whereas the stress-inducible heat-shock protein 70 (Hsp70) has gained plenty of attention as a putative target for tumor therapy, little is known about the role of other Hsp70 proteins in cancer. Here we present the first thorough analysis of the expression and function of the cytosolic Hsp70 proteins in human cancer cells and identify Hsp70-2, a protein essential for spermatogenesis, as an important regulator of cancer cell growth. Targeted knock-down of the individual family members by RNA interference revealed that both Hsp70 and Hsp70-2 were required for cancer cell growth, whereas the survival of tumorigenic as well as nontumorigenic cells depended on Hsc70. Cancer cells depleted for Hsp70 and Hsp70-2 displayed strikingly different morphologies (detached and round vs. flat senescent-like), cell cycle distributions (G2/M vs. G1 arrest) and gene expression profiles. Only Hsp70-2 depletion induced the expression of macrophage inhibitory cytokine-1 that was identified as a target of P53 tumor-suppressor protein and a mediator of the G1 arrest and the senescent phenotype. Importantly, concomitant depletion of Hsp70 and Hsp70-2 had a synergistic antiproliferative effect on cancer cells. Thus, highly homologous Hsp70 proteins bring about nonoverlapping functions essential for cell growth and survival.

AB - Whereas the stress-inducible heat-shock protein 70 (Hsp70) has gained plenty of attention as a putative target for tumor therapy, little is known about the role of other Hsp70 proteins in cancer. Here we present the first thorough analysis of the expression and function of the cytosolic Hsp70 proteins in human cancer cells and identify Hsp70-2, a protein essential for spermatogenesis, as an important regulator of cancer cell growth. Targeted knock-down of the individual family members by RNA interference revealed that both Hsp70 and Hsp70-2 were required for cancer cell growth, whereas the survival of tumorigenic as well as nontumorigenic cells depended on Hsc70. Cancer cells depleted for Hsp70 and Hsp70-2 displayed strikingly different morphologies (detached and round vs. flat senescent-like), cell cycle distributions (G2/M vs. G1 arrest) and gene expression profiles. Only Hsp70-2 depletion induced the expression of macrophage inhibitory cytokine-1 that was identified as a target of P53 tumor-suppressor protein and a mediator of the G1 arrest and the senescent phenotype. Importantly, concomitant depletion of Hsp70 and Hsp70-2 had a synergistic antiproliferative effect on cancer cells. Thus, highly homologous Hsp70 proteins bring about nonoverlapping functions essential for cell growth and survival.

U2 - 10.1101/gad.305405

DO - 10.1101/gad.305405

M3 - Journal article

C2 - 15741319

SN - 0890-9369

VL - 19

SP - 570

EP - 582

JO - Genes & Development

JF - Genes & Development

IS - 5

ER -