Matches in SemOpenAlex for { <https://semopenalex.org/work/W2743288911> ?p ?o ?g. }
Showing items 1 to 72 of
72
with 100 items per page.
- W2743288911 abstract "C46 Epidemiological studies have implicated high circulating IGF-I and low circulating IGFBP-3 levels with increased risk of developing prostate cancer. IGFBP-3 promotes apoptosis by both IGF-dependent and -independent mechanisms in many cancer models, including prostate. In cultured prostate cancer cells, IGFBP-3 is rapidly internalized and localized to the nucleus, where its interactions with the nuclear receptor RXR alpha are important in apoptosis induction. However, little is known about the intrinsic mechanisms regulating the apoptotic actions of IGFBP-3. Proteomic and bioinformatic analysis of IGFBP-3 reveals multiple consensus phosphorylation sites for kinases including CK2, PKA, PKC and cdc2. We have previously reported that phosphorylation of IGFBP-3 at Ser-156 by DNA-PK enhances its nuclear accumulation, and is essential for its ability to interact with RXR and induce apoptosis in 22RV1 and LAPC4 prostate cancer cells. Indeed, IGFBP-3-S156A is completely unable to induce apoptosis in our cell system. Using specific chemical inhibitors and siRNA, we now investigated the contribution of other protein kinases to the regulation of IGFBP-3-induced apoptosis. Importantly, preventing the activation of CK2 enhanced the apoptotic potential of IGFBP-3. We mapped two potential CK2 phosphorylation sites to the central region of IGFBP-3: S167 and S175. These sites were mutated to Ala, and the resulting constructs were transfected in to 22RV1 and LAPC4 cells. Wt-IGFBP-3 and IGFBP-3-S175A induced apoptosis to a comparable extent, however, overexpression of IGFBP-3-S167A was significantly more apoptotic. These effects were specific to apoptosis-induction, however, since wtIGFBP-3 and IGFBP-3/S167A had comparable effects on cell growth and proliferation, assessed by MTT and BrdU incorporation assays. Interestingly, IGFBP-3-S167A was able to induce apoptosis even in the absence of active DNA-PK, while the DNA-PK inactive IGFBP-3-S156A mutant regained the ability to induce apoptosis when CK2 activity was inhibited chemically or by using siRNA. Together, these data reveal two key regulatory phosphorylation sites in the central region of IGFBP-3. Phosphorylation of S156 by DNA-PK promotes apoptosis, whilst phosphorylation of S167 by CK2 limits the ability of IGFBP-3 to induce apoptosis. Interestingly, our data suggest that the anti-apoptotic phosphorylation event induced by CK2 is dominant. Pre-treatment of 22RV1 cells with IGFBP-3-siRNA also limits the ability of high doses of CK2 inhibitor to induce apoptosis. These effects can be reversed by the addition of exogenous IGFBP-3 protein, suggesting that inhibition of IGFBP-3 action by CK2 may be a key mechanism through which CK2 induces cell survival. IGFBP-3-S167A, but not wild type IGFBP-3, can partially antagonize the survival effects of overexpressing CK2, suggesting a potentially important relationship between IGFBP-3 and CK2 in regulating cell survival and apoptosis in prostate cancer. IGFBP-3 infusion into SCID mice with 22RV1 xenograts reduced tumor size by 40%, dramatically enhanced apoptosis, and suppressed angiogenesis. IMPACT: IGFBP-3 is currently being explored as a potential therapy for many cancers, including prostate. Regulation of IGFBP-3 by kinases and phosphatases may modulate the development and effectiveness of IGFBP-3 as an anti-cancer therapy." @default.
- W2743288911 created "2017-08-17" @default.
- W2743288911 creator A5005801351 @default.
- W2743288911 creator A5009090661 @default.
- W2743288911 creator A5029757725 @default.
- W2743288911 creator A5041133639 @default.
- W2743288911 creator A5084207564 @default.
- W2743288911 date "2007-11-15" @default.
- W2743288911 modified "2023-10-01" @default.
- W2743288911 title "IGFBP-3 therapy inhibits prostate cancer growth by enhancing apoptosis and suppressing angiogensis: role of phosphorylation" @default.
- W2743288911 hasPublicationYear "2007" @default.
- W2743288911 type Work @default.
- W2743288911 sameAs 2743288911 @default.
- W2743288911 citedByCount "0" @default.
- W2743288911 crossrefType "journal-article" @default.
- W2743288911 hasAuthorship W2743288911A5005801351 @default.
- W2743288911 hasAuthorship W2743288911A5009090661 @default.
- W2743288911 hasAuthorship W2743288911A5029757725 @default.
- W2743288911 hasAuthorship W2743288911A5041133639 @default.
- W2743288911 hasAuthorship W2743288911A5084207564 @default.
- W2743288911 hasConcept C11960822 @default.
- W2743288911 hasConcept C121608353 @default.
- W2743288911 hasConcept C184235292 @default.
- W2743288911 hasConcept C185592680 @default.
- W2743288911 hasConcept C190283241 @default.
- W2743288911 hasConcept C2780192828 @default.
- W2743288911 hasConcept C502942594 @default.
- W2743288911 hasConcept C54355233 @default.
- W2743288911 hasConcept C55493867 @default.
- W2743288911 hasConcept C86803240 @default.
- W2743288911 hasConcept C95444343 @default.
- W2743288911 hasConcept C96232424 @default.
- W2743288911 hasConceptScore W2743288911C11960822 @default.
- W2743288911 hasConceptScore W2743288911C121608353 @default.
- W2743288911 hasConceptScore W2743288911C184235292 @default.
- W2743288911 hasConceptScore W2743288911C185592680 @default.
- W2743288911 hasConceptScore W2743288911C190283241 @default.
- W2743288911 hasConceptScore W2743288911C2780192828 @default.
- W2743288911 hasConceptScore W2743288911C502942594 @default.
- W2743288911 hasConceptScore W2743288911C54355233 @default.
- W2743288911 hasConceptScore W2743288911C55493867 @default.
- W2743288911 hasConceptScore W2743288911C86803240 @default.
- W2743288911 hasConceptScore W2743288911C95444343 @default.
- W2743288911 hasConceptScore W2743288911C96232424 @default.
- W2743288911 hasLocation W27432889111 @default.
- W2743288911 hasOpenAccess W2743288911 @default.
- W2743288911 hasPrimaryLocation W27432889111 @default.
- W2743288911 hasRelatedWork W1196157949 @default.
- W2743288911 hasRelatedWork W1491177143 @default.
- W2743288911 hasRelatedWork W1509454442 @default.
- W2743288911 hasRelatedWork W1529830323 @default.
- W2743288911 hasRelatedWork W1972618039 @default.
- W2743288911 hasRelatedWork W1983097445 @default.
- W2743288911 hasRelatedWork W1989779077 @default.
- W2743288911 hasRelatedWork W1998405951 @default.
- W2743288911 hasRelatedWork W1999534242 @default.
- W2743288911 hasRelatedWork W2007891088 @default.
- W2743288911 hasRelatedWork W2008420298 @default.
- W2743288911 hasRelatedWork W2012612470 @default.
- W2743288911 hasRelatedWork W2023954953 @default.
- W2743288911 hasRelatedWork W2112027843 @default.
- W2743288911 hasRelatedWork W2169447118 @default.
- W2743288911 hasRelatedWork W2192158764 @default.
- W2743288911 hasRelatedWork W2317437890 @default.
- W2743288911 hasRelatedWork W2323173246 @default.
- W2743288911 hasRelatedWork W2560877231 @default.
- W2743288911 hasRelatedWork W348921385 @default.
- W2743288911 hasVolume "13" @default.
- W2743288911 isParatext "false" @default.
- W2743288911 isRetracted "false" @default.
- W2743288911 magId "2743288911" @default.
- W2743288911 workType "article" @default.