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Targeting a cell state common to triple-negative breast cancers.

Muellner MK, Mair B, Ibrahim Y, Kerzendorfer C, Lechtermann H, Trefzer C, Klepsch F, Müller AC, Leitner E, Macho-Maschler S, Superti-Furga G, Bennett KL, Baselga J, Rix U, Kubicek S, Colinge J, Serra V, Nijman SM - Mol. Syst. Biol. (2015)

Bottom Line: We employed a multi-omics approach and computational modeling to address the mechanism of action and identified spleen tyrosine kinase (SYK) as a novel and unexpected target in TNBC.Quantitative phosphoproteomics revealed that SYK inhibition abrogates signaling to STAT3, explaining the selectivity for basal-like breast cancer cells.This non-oncogene addiction suggests that chemical SYK inhibition may be beneficial for a specific subset of TNBC patients and demonstrates that targeting cell states could be a viable strategy to discover novel treatment strategies.

View Article: PubMed Central - PubMed

Affiliation: CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.

No MeSH data available.


Related in: MedlinePlus

Structure–activity relationship between PKC412 analogs and SYK inhibitionA MDA-MD-468 (basal-like) or HCC1419 (luminal) cells were infected with two independent SYK-shRNA or control vectors and plated at equal cell numbers. Plates were stained with crystal violet after 10 days.B Structural representation of in silico docking poses of staurosporine aglycon (cyan) or a derivative lacking the closed central benzene ring (red) into the SYK kinase ATP binding pocket.C Quantification of docking scores from (B). *P < 0.05, Mann–Whitney U-test.D In vitro kinase assay with recombinant SYK kinase incubated with vehicle (DMSO), staurosporine aglycon, staurosporine aglycon derivative or PKC412. The SYK inhibitor R406 was used as a positive control. n = 4; error bars indicate standard deviation. ***P < 0.001, Mann–Whitney U-test. n.s. = not significant.E EC50 values of a cell line panel treated with the compounds from (C). **P < 0.01. n.s. = not significant.
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fig04: Structure–activity relationship between PKC412 analogs and SYK inhibitionA MDA-MD-468 (basal-like) or HCC1419 (luminal) cells were infected with two independent SYK-shRNA or control vectors and plated at equal cell numbers. Plates were stained with crystal violet after 10 days.B Structural representation of in silico docking poses of staurosporine aglycon (cyan) or a derivative lacking the closed central benzene ring (red) into the SYK kinase ATP binding pocket.C Quantification of docking scores from (B). *P < 0.05, Mann–Whitney U-test.D In vitro kinase assay with recombinant SYK kinase incubated with vehicle (DMSO), staurosporine aglycon, staurosporine aglycon derivative or PKC412. The SYK inhibitor R406 was used as a positive control. n = 4; error bars indicate standard deviation. ***P < 0.001, Mann–Whitney U-test. n.s. = not significant.E EC50 values of a cell line panel treated with the compounds from (C). **P < 0.01. n.s. = not significant.

Mentions: In agreement with the chemical proteomics data, PKC412 inhibited SYK autophosphorylation in MDA-MB-468 cells (Supplementary Fig S10). This allows the possibility that SYK inhibition contributes to the mechanism of action of the drug. Indeed, RNAi-mediated depletion of SYK resulted in a pronounced and specific effect (Fig 4A and Supplementary Fig S11). SYK depletion was highly cytotoxic to the basal-like and PKC412-sensitive MDA-MB-468 cells while having a negligible effect on the resistant HCC1419 cell line (Fig 4A). Similar results were obtained in two additional basal-like and luminal cell lines (Supplementary Fig S12). Given that SYK has never been implicated as a drug target in solid tumors and has not been found mutated in breast cancer, we decided to study this interaction further.


Targeting a cell state common to triple-negative breast cancers.

Muellner MK, Mair B, Ibrahim Y, Kerzendorfer C, Lechtermann H, Trefzer C, Klepsch F, Müller AC, Leitner E, Macho-Maschler S, Superti-Furga G, Bennett KL, Baselga J, Rix U, Kubicek S, Colinge J, Serra V, Nijman SM - Mol. Syst. Biol. (2015)

Structure–activity relationship between PKC412 analogs and SYK inhibitionA MDA-MD-468 (basal-like) or HCC1419 (luminal) cells were infected with two independent SYK-shRNA or control vectors and plated at equal cell numbers. Plates were stained with crystal violet after 10 days.B Structural representation of in silico docking poses of staurosporine aglycon (cyan) or a derivative lacking the closed central benzene ring (red) into the SYK kinase ATP binding pocket.C Quantification of docking scores from (B). *P < 0.05, Mann–Whitney U-test.D In vitro kinase assay with recombinant SYK kinase incubated with vehicle (DMSO), staurosporine aglycon, staurosporine aglycon derivative or PKC412. The SYK inhibitor R406 was used as a positive control. n = 4; error bars indicate standard deviation. ***P < 0.001, Mann–Whitney U-test. n.s. = not significant.E EC50 values of a cell line panel treated with the compounds from (C). **P < 0.01. n.s. = not significant.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4358660&req=5

fig04: Structure–activity relationship between PKC412 analogs and SYK inhibitionA MDA-MD-468 (basal-like) or HCC1419 (luminal) cells were infected with two independent SYK-shRNA or control vectors and plated at equal cell numbers. Plates were stained with crystal violet after 10 days.B Structural representation of in silico docking poses of staurosporine aglycon (cyan) or a derivative lacking the closed central benzene ring (red) into the SYK kinase ATP binding pocket.C Quantification of docking scores from (B). *P < 0.05, Mann–Whitney U-test.D In vitro kinase assay with recombinant SYK kinase incubated with vehicle (DMSO), staurosporine aglycon, staurosporine aglycon derivative or PKC412. The SYK inhibitor R406 was used as a positive control. n = 4; error bars indicate standard deviation. ***P < 0.001, Mann–Whitney U-test. n.s. = not significant.E EC50 values of a cell line panel treated with the compounds from (C). **P < 0.01. n.s. = not significant.
Mentions: In agreement with the chemical proteomics data, PKC412 inhibited SYK autophosphorylation in MDA-MB-468 cells (Supplementary Fig S10). This allows the possibility that SYK inhibition contributes to the mechanism of action of the drug. Indeed, RNAi-mediated depletion of SYK resulted in a pronounced and specific effect (Fig 4A and Supplementary Fig S11). SYK depletion was highly cytotoxic to the basal-like and PKC412-sensitive MDA-MB-468 cells while having a negligible effect on the resistant HCC1419 cell line (Fig 4A). Similar results were obtained in two additional basal-like and luminal cell lines (Supplementary Fig S12). Given that SYK has never been implicated as a drug target in solid tumors and has not been found mutated in breast cancer, we decided to study this interaction further.

Bottom Line: We employed a multi-omics approach and computational modeling to address the mechanism of action and identified spleen tyrosine kinase (SYK) as a novel and unexpected target in TNBC.Quantitative phosphoproteomics revealed that SYK inhibition abrogates signaling to STAT3, explaining the selectivity for basal-like breast cancer cells.This non-oncogene addiction suggests that chemical SYK inhibition may be beneficial for a specific subset of TNBC patients and demonstrates that targeting cell states could be a viable strategy to discover novel treatment strategies.

View Article: PubMed Central - PubMed

Affiliation: CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria.

No MeSH data available.


Related in: MedlinePlus