Protein kinase C β inhibition by enzastaurin leads to mitotic missegregation and preferential cytotoxicity toward colorectal cancer cells with chromosomal instability (CIN)

Ouaret, Djamila; Larsen, Annette K.

doi:10.4161/15384101.2015.945383

Cited by 7 publications

(6 citation statements)

References 61 publications

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“…HeLa cells were incubated with trabectedin or lurbinectedin for 1 hour and post-incubated in drug free medium for up to 6 hours at 37°C. Cells were then washed in PBS and lysed in lysis buffer (0.5% NP40, 20 mM Tris/HCl pH 8, 1 mM EDTA, 150 mM NaCl, 1 mM PMSF, 1 μM leupeptin, 1 μM aprotinin, 1 mM orthovanadate and 1 mM DTT) as described [ 58 ]. Proteins were resolved on SDS/PAGE (10 or 15%) and blotted onto nitrocellulose membranes (Bio-Rad).…”

Section: Methodsmentioning

confidence: 99%

Dual inhibition of ATR and ATM potentiates the activity of trabectedin and lurbinectedin by perturbing the DNA damage response and homologous recombination repair

et al. 2016

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Trabectedin (Yondelis®, ecteinascidin-743, ET-743) is a marine-derived natural product approved for treatment of advanced soft tissue sarcoma and relapsed platinum-sensitive ovarian cancer. Lurbinectedin is a novel anticancer agent structurally related to trabectedin. Both ecteinascidins generate DNA double-strand breaks that are processed through homologous recombination repair (HRR), thereby rendering HRR-deficient cells particularly sensitive. We here characterize the DNA damage response (DDR) to trabectedin and lurbinectedin in HeLa cells. Our results show that both compounds activate the ATM/Chk2 (ataxia-telangiectasia mutated/checkpoint kinase 2) and ATR/Chk1 (ATM and RAD3-related/checkpoint kinase 1) pathways. Interestingly, pharmacological inhibition of Chk1/2, ATR or ATM is not accompanied by any significant improvement of the cytotoxic activity of the ecteinascidins while dual inhibition of ATM and ATR strongly potentiates it. Accordingly, concomitant inhibition of both ATR and ATM is an absolute requirement to efficiently block the formation of γ-H2AX, MDC1, BRCA1 and Rad51 foci following exposure to the ecteinascidins. These results are not restricted to HeLa cells, but are shared by cisplatin-sensitive and -resistant ovarian carcinoma cells. Together, our data identify ATR and ATM as central coordinators of the DDR to ecteinascidins and provide a mechanistic rationale for combining these compounds with ATR and ATM inhibitors.

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Section: Methodsmentioning

confidence: 99%

Dual inhibition of ATR and ATM potentiates the activity of trabectedin and lurbinectedin by perturbing the DNA damage response and homologous recombination repair

et al. 2016

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“…Colorectal cancer cells were maintained in cell culture as described previously (9). SW48, LS174T, and DLD-1 colorectal cancer cells were a kind gift from Richard Hamelin (Saint-Antoine Research Center, Paris, France), while SW480 and LIM1215 cells were purchased from American Type Culture Collection.…”

Section: Tumor Cellsmentioning

confidence: 99%

Combinations of Bevacizumab and Erlotinib Show Activity in Colorectal Cancer Independent of RAS Status

Mésange

Bouygues

Ferrand

et al. 2018

Clinical Cancer Research

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There is extensive cross-talk between VEGF- and EGFR-pathway signaling in colorectal cancer. However, combinations of VEGF- and EGFR-targeted monoclonal antibodies (mAb) show disappointing activity, in particular for patients with mutant Previous results show that tyrosine kinase inhibitors (TKI) can be active in colorectal cancer models resistant to mAbs. This prompted us to examine whether the activity of bevacizumab can be increased by combination with erlotinib. The antitumor activity of bevacizumab, erlotinib, and their combination was determined in colorectal cancer models with different status and bevacizumab sensitivity. EGFR/VEGF pathway activation was characterized by immunohistochemistry, Western blot, and ELISA assays. The influence of cetuximab and erlotinib on EGF-mediated migration and the EGFR-EGF ligand feedback loop was established in colorectal cancer cell lines with different status. The addition of erlotinib increased bevacizumab activity in all models independent of status. Bevacizumab exposure was accompanied by marked EGFR activation in tumor cells as well as in tumor-associated endothelial cells (TECs) and resulted in strong accumulation of intracellular EGFR, which could be attenuated by erlotinib. In cellular models, erlotinib was able to attenuate EGF-mediated functions in all cell lines independent of status while cetuximab only showed activity in wild-type cells. These results should provide a molecular framework to better understand the increased activity of the bevacizumab-erlotinib combination, compared with bevacizumab alone, in the GERCOR DREAM phase III clinical trial. Differential activity of mAbs and TKIs targeting the same signaling pathway is likely applicable for other tumor types. .

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“…PKF 118–310 binds selectively to beta-catenin, thereby disrupting its interaction with TCF-4 [ 40 ]. The growth inhibitory effects of ICG-001 and PKF 118 were determined by the MTT viability assay after 120 hours continuous drug exposure [ 41 ] and is expressed as IC 50 values (drug concentration inhibiting cell growth by 50% compared to untreated controls). The IC 50 values were around 3 μM for ICG-001 and 0.3 μM for PKF 118 (Figure 7 ) in agreement with previous findings [ 39 , 40 ].…”

Section: Resultsmentioning

confidence: 99%

“…The growth inhibitory effects were determined by the MTT (3-(4, 5-dimethyl-thiazol-2yl)-2, 5-diphenyl-tetrazolium bromide) viability test as previously described [ 41 ] with minor modifications. Cells (7,000 cells per well for HCT-116, 10,000 per well for HT-29, SW480 and DLD-1) were seeded in 24-well plates in culture media containing 5% FCS, incubated in drug-free media for 24 hours followed by drug exposure for 120 hours.…”

Section: Methodsmentioning

confidence: 99%

Chronic chemotherapeutic stress promotes evolution of stemness and WNT/beta-catenin signaling in colorectal cancer cells: implications for clinical use of WNT-signaling inhibitors

et al. 2015

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Most solid tumors contain a subfraction of cells with stem/progenitor cell features. Stem cells are naturally chemoresistant suggesting that chronic chemotherapeutic stress may select for cells with increased “stemness”. We carried out a comprehensive molecular and functional analysis of six independently selected colorectal cancer (CRC) cell lines with acquired resistance to three different chemotherapeutic agents derived from two distinct parental cell lines. Chronic drug exposure resulted in complex alterations of stem cell markers that could be classified into three categories: 1) one cell line, HT-29/5-FU, showed increased “stemness” and WNT-signaling, 2) three cell lines showed decreased expression of stem cell markers, decreased aldehyde dehydrogenase activity, attenuated WNT-signaling and lost the capacity to form colonospheres and 3) two cell lines displayed prominent expression of ABC transporters with a heterogeneous response for stem cell markers. While WNT-signaling could be attenuated in the HT-29/5-FU cells by the WNT-signaling inhibitors ICG-001 and PKF-118, this was not accompanied by any selective growth inhibitory effect suggesting that the cytotoxic activity of these compounds is not directly linked to WNT-signaling inhibition. We conclude that classical WNT-signaling inhibitors have toxic off-target activities that need to be addressed for clinical development.

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Protein kinase C β inhibition by enzastaurin leads to mitotic missegregation and preferential cytotoxicity toward colorectal cancer cells with chromosomal instability (CIN)

Cited by 7 publications

References 61 publications

Dual inhibition of ATR and ATM potentiates the activity of trabectedin and lurbinectedin by perturbing the DNA damage response and homologous recombination repair

Dual inhibition of ATR and ATM potentiates the activity of trabectedin and lurbinectedin by perturbing the DNA damage response and homologous recombination repair

Combinations of Bevacizumab and Erlotinib Show Activity in Colorectal Cancer Independent of RAS Status

Chronic chemotherapeutic stress promotes evolution of stemness and WNT/beta-catenin signaling in colorectal cancer cells: implications for clinical use of WNT-signaling inhibitors

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