Insulin-like growth factors are more effective than progastrin in reversing proapoptotic effects of curcumin : critical role of p38MAPK

Progastrin and insulin-like growth factors (IGFs) stimulate hyperproliferation of intestinal epithelial cells (IECs) via endocrine/paracrine routes; hyperproliferation is a known risk factor for colon carcinogenesis. In the present study, inhibitory potency of curcumin in the presence or absence of progastrin and/or IGF-II was examined. Progastrin and IGF-II significantly increased proliferation of an immortalized IEC cell line, IEC-18, whereas curcumin decreased the proliferation in a dose-dependent manner. IGF-II was significantly more effective than progastrin in reversing antiproliferative effects of curcumin and reversed proapoptotic effects of curcumin by >80%; progastrin was relatively ineffective toward reversing proapoptotic effects of curcumin. IEC-18 clones were generated to overexpress either progastrin (IEC-PG) or hIGF-II (IEC-IGF). Proliferation of IEC-PG and IEC-IGF clones was increased, compared with that of control clones. Curcumin significantly reduced proliferation of IEC-PG, but not IEC-IGF, clones. Similarly, a human colon cancer cell line, Caco-2 (which expresses autocrine IGF-II), was relatively resistant to inhibitory effects of curcumin. However, Caco-2 cells treated with anti-IGF-II-antibodies were rendered sensitive to inhibitory effects of curcumin. Significant differences in inhibitory potency of curcumin against PG- vs. IGF-II-stimulated growth of IEC-18 cells were not reflected by differences in curcumin-mediated inhibition of activated (phosphorylated) ERKs/IKK(alpha/beta)/p65NF-kappaB and c-Src in wild-type (wt)IEC-18 cells, in response to the two growth factors. Surprisingly, curcumin was almost ineffective in reducing IGF-II-stimulated activation of p38MAPK but significantly reduced progastrin-stimulated phosphorylation of p38. Treatment with a p38MAPK inhibitor resulted in loss of protective effects of IGF-II against inhibitory effects of curcumin. These novel findings suggest that growth factor profile of patients and tumors may dictate inhibitory potency of curcumin and that combination of curcumin + p38MAPK inhibitor may be required for reducing hyperproliferative or tumorigenic response of IECs to endocrine and autocrine IGFs.

Medienart:

E-Artikel

Erscheinungsjahr:

2010

Erschienen:

2010

Enthalten in:

Zur Gesamtaufnahme - volume:298

Enthalten in:

American journal of physiology. Gastrointestinal and liver physiology - 298(2010), 4 vom: 16. Apr., Seite G551-62

Sprache:

Englisch

Beteiligte Personen:

Singh, Pomila [VerfasserIn]
Sarkar, Shubhashish [VerfasserIn]
Umar, Shahid [VerfasserIn]
Rengifo-Cam, William [VerfasserIn]
Singh, Amar P [VerfasserIn]
Wood, Thomas G [VerfasserIn]

Links:

Volltext

Themen:

3BL184GALN
67763-97-7
Antibodies
Big gastrin
CSK Tyrosine-Protein Kinase
CSK protein, human
Camptothecin
Caspase 3
Caspase 9
Curcumin
EC 2.7.10.1
EC 2.7.10.2
EC 2.7.10.23
EC 2.7.11.10
EC 2.7.11.24
EC 3.4.22.-
Gastrins
I-kappa B Kinase
IT942ZTH98
Imidazoles
Insulin-Like Growth Factor II
Journal Article
Mitogen-Activated Protein Kinase 1
Mitogen-Activated Protein Kinase 3
NF-kappa B
OU13V1EYWQ
P38 Mitogen-Activated Protein Kinases
Protein Kinase Inhibitors
Protein Precursors
Protein-Tyrosine Kinases
Pyridines
Research Support, N.I.H., Extramural
SB 203580
Somatomedins
Src-Family Kinases
Transcription Factor RelA
XT3Z54Z28A

Anmerkungen:

Date Completed 16.04.2010

Date Revised 20.10.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1152/ajpgi.00497.2009

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM194893308