DARPP-32 increases interactions between epidermal growth factor receptor and ERBB3 to promote tumor resistance to gefitinib

Shoumin Zhu, Abbes Belkhiri, Wael El-Rifai

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Background & Aims: Dopamine and adenosine 3′,5′-cyclic monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32), is overexpressed during gastric carcinogenesis. Gastric tumors can become resistant to gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR). We investigated the role of DARPP-32 in gastric tumor resistance to gefitinib. Methods: Cell survival was determined by clonogenic survival and ATP-Glo Viability Assays. Apoptosis was assessed by Annexin-V and immunoblot analyses. The association between DARPP-32 and EGFR was evaluated by immunofluorescence and co-immunoprecipitation assays. Findings were validated in mice with gastric xenograft tumors. DARPP-32 expression was reduced using small hairpin RNAs in the human gastric cancer cell lines SNU-16 and MKN-45 cells. Results: Overexpression of DARPP-32 in MKN-28 cells, which do not normally express DARPP-32, blocked gefitinib-induced apoptosis and increased the drug's IC 50 10-fold, compared to that of control cells (P < .01). Reduced expression of DARPP-32 in SNU-16 cells increased the sensitivity to gefitinib (P < .01). DARPP-32 activated phosphatidylinositol-3-kinase-AKT signaling, increased stability of the EGFR, and suppressed EGF- or gefitinib-induced degradation of the EGFR. DARPP-32 colocalized with EGFR on the cell membrane in a complex with EGFR and the EGF receptor ERBB3. DARPP-32-mediated resistance to gefitinib resulted from increased phosphorylation of and interaction between EGFR and ERBB3, which led to phosphorylation of AKT (at serine 473). Knockdown of DARPP-32 in gastric cancer cells reduced the mean size of tumors in mice and increased their response to gefitinib. Conclusions: DARPP-32 promotes resistance of gastric cancer cells to gefitinib by promoting interaction between EGFR and ERBB3 and activating phosphatidylinositol-3-kinase-AKT signaling.

Original languageEnglish (US)
Pages (from-to)1738-1748.e2
JournalGastroenterology
Volume141
Issue number5
DOIs
StatePublished - Jan 1 2011
Externally publishedYes

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Epidermal Growth Factor Receptor
Neoplasms
Stomach
Phosphatidylinositol 3-Kinase
Stomach Neoplasms
Phosphorylation
Apoptosis
gefitinib
Annexin A5
Phosphoproteins
Immunoprecipitation
Epidermal Growth Factor
Heterografts
Adenosine
Serine
Small Interfering RNA
Fluorescent Antibody Technique
Dopamine
Cell Survival
Carcinogenesis

Keywords

  • AKT
  • Dopamine Signaling
  • Drug Resistance
  • PI3K
  • PPP1R1B
  • Stomach Cancer
  • Treatment

ASJC Scopus subject areas

  • Hepatology
  • Gastroenterology

Cite this

DARPP-32 increases interactions between epidermal growth factor receptor and ERBB3 to promote tumor resistance to gefitinib. / Zhu, Shoumin; Belkhiri, Abbes; El-Rifai, Wael.

In: Gastroenterology, Vol. 141, No. 5, 01.01.2011, p. 1738-1748.e2.

Research output: Contribution to journalArticle

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abstract = "Background & Aims: Dopamine and adenosine 3′,5′-cyclic monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32), is overexpressed during gastric carcinogenesis. Gastric tumors can become resistant to gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR). We investigated the role of DARPP-32 in gastric tumor resistance to gefitinib. Methods: Cell survival was determined by clonogenic survival and ATP-Glo Viability Assays. Apoptosis was assessed by Annexin-V and immunoblot analyses. The association between DARPP-32 and EGFR was evaluated by immunofluorescence and co-immunoprecipitation assays. Findings were validated in mice with gastric xenograft tumors. DARPP-32 expression was reduced using small hairpin RNAs in the human gastric cancer cell lines SNU-16 and MKN-45 cells. Results: Overexpression of DARPP-32 in MKN-28 cells, which do not normally express DARPP-32, blocked gefitinib-induced apoptosis and increased the drug's IC 50 10-fold, compared to that of control cells (P < .01). Reduced expression of DARPP-32 in SNU-16 cells increased the sensitivity to gefitinib (P < .01). DARPP-32 activated phosphatidylinositol-3-kinase-AKT signaling, increased stability of the EGFR, and suppressed EGF- or gefitinib-induced degradation of the EGFR. DARPP-32 colocalized with EGFR on the cell membrane in a complex with EGFR and the EGF receptor ERBB3. DARPP-32-mediated resistance to gefitinib resulted from increased phosphorylation of and interaction between EGFR and ERBB3, which led to phosphorylation of AKT (at serine 473). Knockdown of DARPP-32 in gastric cancer cells reduced the mean size of tumors in mice and increased their response to gefitinib. Conclusions: DARPP-32 promotes resistance of gastric cancer cells to gefitinib by promoting interaction between EGFR and ERBB3 and activating phosphatidylinositol-3-kinase-AKT signaling.",
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author = "Shoumin Zhu and Abbes Belkhiri and Wael El-Rifai",
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T1 - DARPP-32 increases interactions between epidermal growth factor receptor and ERBB3 to promote tumor resistance to gefitinib

AU - Zhu, Shoumin

AU - Belkhiri, Abbes

AU - El-Rifai, Wael

PY - 2011/1/1

Y1 - 2011/1/1

N2 - Background & Aims: Dopamine and adenosine 3′,5′-cyclic monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32), is overexpressed during gastric carcinogenesis. Gastric tumors can become resistant to gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR). We investigated the role of DARPP-32 in gastric tumor resistance to gefitinib. Methods: Cell survival was determined by clonogenic survival and ATP-Glo Viability Assays. Apoptosis was assessed by Annexin-V and immunoblot analyses. The association between DARPP-32 and EGFR was evaluated by immunofluorescence and co-immunoprecipitation assays. Findings were validated in mice with gastric xenograft tumors. DARPP-32 expression was reduced using small hairpin RNAs in the human gastric cancer cell lines SNU-16 and MKN-45 cells. Results: Overexpression of DARPP-32 in MKN-28 cells, which do not normally express DARPP-32, blocked gefitinib-induced apoptosis and increased the drug's IC 50 10-fold, compared to that of control cells (P < .01). Reduced expression of DARPP-32 in SNU-16 cells increased the sensitivity to gefitinib (P < .01). DARPP-32 activated phosphatidylinositol-3-kinase-AKT signaling, increased stability of the EGFR, and suppressed EGF- or gefitinib-induced degradation of the EGFR. DARPP-32 colocalized with EGFR on the cell membrane in a complex with EGFR and the EGF receptor ERBB3. DARPP-32-mediated resistance to gefitinib resulted from increased phosphorylation of and interaction between EGFR and ERBB3, which led to phosphorylation of AKT (at serine 473). Knockdown of DARPP-32 in gastric cancer cells reduced the mean size of tumors in mice and increased their response to gefitinib. Conclusions: DARPP-32 promotes resistance of gastric cancer cells to gefitinib by promoting interaction between EGFR and ERBB3 and activating phosphatidylinositol-3-kinase-AKT signaling.

AB - Background & Aims: Dopamine and adenosine 3′,5′-cyclic monophosphate-regulated phosphoprotein, Mr 32000 (DARPP-32), is overexpressed during gastric carcinogenesis. Gastric tumors can become resistant to gefitinib, an inhibitor of the epidermal growth factor receptor (EGFR). We investigated the role of DARPP-32 in gastric tumor resistance to gefitinib. Methods: Cell survival was determined by clonogenic survival and ATP-Glo Viability Assays. Apoptosis was assessed by Annexin-V and immunoblot analyses. The association between DARPP-32 and EGFR was evaluated by immunofluorescence and co-immunoprecipitation assays. Findings were validated in mice with gastric xenograft tumors. DARPP-32 expression was reduced using small hairpin RNAs in the human gastric cancer cell lines SNU-16 and MKN-45 cells. Results: Overexpression of DARPP-32 in MKN-28 cells, which do not normally express DARPP-32, blocked gefitinib-induced apoptosis and increased the drug's IC 50 10-fold, compared to that of control cells (P < .01). Reduced expression of DARPP-32 in SNU-16 cells increased the sensitivity to gefitinib (P < .01). DARPP-32 activated phosphatidylinositol-3-kinase-AKT signaling, increased stability of the EGFR, and suppressed EGF- or gefitinib-induced degradation of the EGFR. DARPP-32 colocalized with EGFR on the cell membrane in a complex with EGFR and the EGF receptor ERBB3. DARPP-32-mediated resistance to gefitinib resulted from increased phosphorylation of and interaction between EGFR and ERBB3, which led to phosphorylation of AKT (at serine 473). Knockdown of DARPP-32 in gastric cancer cells reduced the mean size of tumors in mice and increased their response to gefitinib. Conclusions: DARPP-32 promotes resistance of gastric cancer cells to gefitinib by promoting interaction between EGFR and ERBB3 and activating phosphatidylinositol-3-kinase-AKT signaling.

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KW - Dopamine Signaling

KW - Drug Resistance

KW - PI3K

KW - PPP1R1B

KW - Stomach Cancer

KW - Treatment

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