HER2

Combination of NVP-AEW541 and lapatinib cooperatively inhibits the growth of NVP-AEW541 resistant murine rhabdomyosarcoma primary cell cultures with Igf1r/Her2 complexes. Cell viability assay for Naïve, untreated (U20325; A) and NVP-AEW541 innately resistant mouse rhabdomyosarcoma primary culture (U44676; B) treated with varying concentrations of NVP-AEW541, lapatinib, or a combination of both. Naïve cells (U20325) were sensitive to NVP-AEW541, but lapatinib had no cooperativity. In contrast, NVP-AEW541 at moderate doses increased cell growth in resistant cell cultures (U44676). However, this paradoxical effect was reduced by the addition of lapatinib, although lapatinib treatment alone had very little effect. C, the NVP-AEW541 resistant primary tumor cell line (U44676) was treated with DMSO, 5 μmol/L lapatinib, 5 μmol/L NVP-AEW541, and a combination of 5 μmol/L NVP-AEW541+lapatinib for 25 minutes and Western blot analysis was done on lysates for p-Igf1r and p-Her2.

Inhibition of signaling pathway activation in lung tumor cell lines by kinase inhibitors. Lung tumor cells were cultured in 10% FBS until reaching ∼80% confluence and then the cells were starved in serum-free medium for overnight, followed by 4-hour treatment with the inhibitors. Cell lysates were then prepared and used for determination of the pathway activation signals by the CEER assay.

HER2 mutations V777L, D769H, V842I, G309A induce gain-of-function over HER2 WT in MCF10A mammary epithelial cells. B, HER2 WT, L755S, and del.755–759 cells were grown in Matrigel in the presence of DMSO vehicle (0.5%), neratinib (0.5  μmol/L) or gefitinib (0.5  μmol/L). Phase contrast images were obtained as in A. C,  MCF10A-HER2 WT or mutants were seeded in soft agar. After 7 days of growth, they were treated with DMSO vehicle (0.5%), lapatinib (0.5 μmol/L) or neratinib (0.5 μmol/L) for an additional week. Error bars represent 95% highest posterior density intervals. *, Significant difference between the HER2 mutant and HER2 WT; #, the effect of inhibitor treatment was significant (95% highest posterior density interval did not contain 0 for both).  D, photomicrographs of the colonies in soft agar on day 12, magnification ×40. 

(B–C) LNCaP (B) and LNCaP-AI (C) cells were transiently transfected with sPLA2-IIa(-800)-Luc (0.5 lg). The cells were then treated with Erlotinib (20 lM), Gefitinib (20 lM), Lapatinib (20 lM), CI-1033 (8 lM), LY294002 (20 lM) and Bortezomib (20 lM) without or with EGF (100 ng/ml) for 24 h. Luciferase assay was performed according to a standard protocol with Renilla luciferase as an internal control. Data are presented as the mean (±SD) of duplicate values of a representative experiment that was independently repeated for five times.

Aberrantly activated PI3K/AKT pathway mediates lapatinib resistance in SK-BR-3-LR cells. (A and B) After drug treatment, phosphorylation of HER2, EGFR, AKT, and ERK1/2 was determined by Western blotting using specific antibodies.

(A) Cell proliferationanalysis of NB4 cells 24 h post-Mubritinib treatments(0–1 uM) as measured by MTT proliferation assay. (B) Representative images of cell cycle progression analysis of NB4 cells 24 h post 0.25 uM and 0.5 uM Mubritinib Treatment measured by BrdU flow cytometry.

Co-treatments of PI-103 and EGFR inhibitors enhance cytotoxicity in SUM149PT cells. Cells were treated with 0.3 uM of PI-103 in combination with different concentrations (0.1 and 1 uM) of EGFR inhibitors (BMS-599626) for -72 hrs. Cell viability was measured by MTT assay as described in Materials and methods. Data from two independent experiments performed in triplicate are shown as mean+SEM. *P < 0.05; **P < 0.01; ***P < 0.001.

EGFR-SGLT1 interaction is irresponsive to modulators of EGFR’s tyrosine kinase. A: Immunoprecipitation coupled Western blot analysis ofinteractionsbetween EGFR-HA and SGLT1-FlaginHEK293 cells treatedwith EGF or AEE788. EGFR, total EGFR; pEGFR, phosphorylated EGFR; IP, immunoprecipitation; IB, immunoblot. Input, expression levels of indicated exogenous proteinsin HEK293 whole celllysates used for the IP.

confluent 10cm plates, 24hour FBS starvation,  then treatment with compounds at 10nM for 30mins, followed by 5 minutes of 0.05ug/ml of EGF.  Pellet was sonicated (setting 5, 5 seconds, twice), then quenched with 2XGSB.  Loaded 10ul on AnyKD BioRad gel (20mins at 250V), transfered with BioRad Turbo system for 15 minutes (1.5A, 25V).  Blocked with 5% milk for 1 hour at RT.  Rocked overnight at 1:1000 in 5% BSA with primary Abs; Anti-rabbit secondary Ab at 1:2000 in 5% milk for 1 hour, developed with Thermo Femto Kit.

Identification of tyrphostin AG879 as a Kv4.2 channel inhibitor. (A) Chemical structure of AG879. (B) Effect of AG879 on Kv4.2 channels in CHO-K1 cells. AG879 10 μM reduced the Kv4.2-mediated peak current by 31.27 ± 2.4%. The Kv4.2 channel currents were recorded by a depolarization to +40 mV for 300 ms from a holding potential −80 mV. (C) Inhibition by AG879 3, 10 and 20 μM of Kv4.2/KChIP2 co-expressed channels. (D) Concentration-dependent inhibition by AG879 of Kv4.2/KChIP2 channel shown by measuring peak and integral currents. Concentration–response curves for AG879 were fitted to the Hill equation. (E) Reversible inhibition of Kv4.2 by AG879. Maximal inhibition occurred ∼5 min after drug application. (F) Concentration-dependent inhibition by AG879 of Kv4.3 channels.

Inhibition of signaling pathway activation in lung tumor cell lines by kinase inhibitors. Lung tumor cells were cultured in 10% FBS until reaching ∼80% confluence and then the cells were starved in serum-free medium for overnight, followed by 4-hour treatment with the inhibitors. Cell lysates were then prepared and used for determination of the pathway activation signals by the CEER assay.

Combination of NVP-AEW541 and lapatinib cooperatively inhibits the growth of NVP-AEW541 resistant murine rhabdomyosarcoma primary cell cultures with Igf1r/Her2 complexes. Cell viability assay for Naïve, untreated (U20325; A) and NVP-AEW541 innately resistant mouse rhabdomyosarcoma primary culture (U44676; B) treated with varying concentrations of NVP-AEW541, lapatinib, or a combination of both. Naïve cells (U20325) were sensitive to NVP-AEW541, but lapatinib had no cooperativity. In contrast, NVP-AEW541 at moderate doses increased cell growth in resistant cell cultures (U44676). However, this paradoxical effect was reduced by the addition of lapatinib, although lapatinib treatment alone had very little effect. C, the NVP-AEW541 resistant primary tumor cell line (U44676) was treated with DMSO, 5 μmol/L lapatinib, 5 μmol/L NVP-AEW541, and a combination of 5 μmol/L NVP-AEW541+lapatinib for 25 minutes and Western blot analysis was done on lysates for p-Igf1r and p-Her2.

Inhibition of signaling pathway activation in lung tumor cell lines by kinase inhibitors. Lung tumor cells were cultured in 10% FBS until reaching ∼80% confluence and then the cells were starved in serum-free medium for overnight, followed by 4-hour treatment with the inhibitors. Cell lysates were then prepared and used for determination of the pathway activation signals by the CEER assay.

HER2 mutations V777L, D769H, V842I, G309A induce gain-of-function over HER2 WT in MCF10A mammary epithelial cells. B, HER2 WT, L755S, and del.755–759 cells were grown in Matrigel in the presence of DMSO vehicle (0.5%), neratinib (0.5  μmol/L) or gefitinib (0.5  μmol/L). Phase contrast images were obtained as in A. C,  MCF10A-HER2 WT or mutants were seeded in soft agar. After 7 days of growth, they were treated with DMSO vehicle (0.5%), lapatinib (0.5 μmol/L) or neratinib (0.5 μmol/L) for an additional week. Error bars represent 95% highest posterior density intervals. *, Significant difference between the HER2 mutant and HER2 WT; #, the effect of inhibitor treatment was significant (95% highest posterior density interval did not contain 0 for both).  D, photomicrographs of the colonies in soft agar on day 12, magnification ×40. 

(B–C) LNCaP (B) and LNCaP-AI (C) cells were transiently transfected with sPLA2-IIa(-800)-Luc (0.5 lg). The cells were then treated with Erlotinib (20 lM), Gefitinib (20 lM), Lapatinib (20 lM), CI-1033 (8 lM), LY294002 (20 lM) and Bortezomib (20 lM) without or with EGF (100 ng/ml) for 24 h. Luciferase assay was performed according to a standard protocol with Renilla luciferase as an internal control. Data are presented as the mean (±SD) of duplicate values of a representative experiment that was independently repeated for five times.

Aberrantly activated PI3K/AKT pathway mediates lapatinib resistance in SK-BR-3-LR cells. (A and B) After drug treatment, phosphorylation of HER2, EGFR, AKT, and ERK1/2 was determined by Western blotting using specific antibodies.

(A) Cell proliferationanalysis of NB4 cells 24 h post-Mubritinib treatments(0–1 uM) as measured by MTT proliferation assay. (B) Representative images of cell cycle progression analysis of NB4 cells 24 h post 0.25 uM and 0.5 uM Mubritinib Treatment measured by BrdU flow cytometry.

Co-treatments of PI-103 and EGFR inhibitors enhance cytotoxicity in SUM149PT cells. Cells were treated with 0.3 uM of PI-103 in combination with different concentrations (0.1 and 1 uM) of EGFR inhibitors (BMS-599626) for -72 hrs. Cell viability was measured by MTT assay as described in Materials and methods. Data from two independent experiments performed in triplicate are shown as mean+SEM. *P < 0.05; **P < 0.01; ***P < 0.001.

EGFR-SGLT1 interaction is irresponsive to modulators of EGFR’s tyrosine kinase. A: Immunoprecipitation coupled Western blot analysis ofinteractionsbetween EGFR-HA and SGLT1-FlaginHEK293 cells treatedwith EGF or AEE788. EGFR, total EGFR; pEGFR, phosphorylated EGFR; IP, immunoprecipitation; IB, immunoblot. Input, expression levels of indicated exogenous proteinsin HEK293 whole celllysates used for the IP.

confluent 10cm plates, 24hour FBS starvation,  then treatment with compounds at 10nM for 30mins, followed by 5 minutes of 0.05ug/ml of EGF.  Pellet was sonicated (setting 5, 5 seconds, twice), then quenched with 2XGSB.  Loaded 10ul on AnyKD BioRad gel (20mins at 250V), transfered with BioRad Turbo system for 15 minutes (1.5A, 25V).  Blocked with 5% milk for 1 hour at RT.  Rocked overnight at 1:1000 in 5% BSA with primary Abs; Anti-rabbit secondary Ab at 1:2000 in 5% milk for 1 hour, developed with Thermo Femto Kit.

Identification of tyrphostin AG879 as a Kv4.2 channel inhibitor. (A) Chemical structure of AG879. (B) Effect of AG879 on Kv4.2 channels in CHO-K1 cells. AG879 10 μM reduced the Kv4.2-mediated peak current by 31.27 ± 2.4%. The Kv4.2 channel currents were recorded by a depolarization to +40 mV for 300 ms from a holding potential −80 mV. (C) Inhibition by AG879 3, 10 and 20 μM of Kv4.2/KChIP2 co-expressed channels. (D) Concentration-dependent inhibition by AG879 of Kv4.2/KChIP2 channel shown by measuring peak and integral currents. Concentration–response curves for AG879 were fitted to the Hill equation. (E) Reversible inhibition of Kv4.2 by AG879. Maximal inhibition occurred ∼5 min after drug application. (F) Concentration-dependent inhibition by AG879 of Kv4.3 channels.

Inhibition of signaling pathway activation in lung tumor cell lines by kinase inhibitors. Lung tumor cells were cultured in 10% FBS until reaching ∼80% confluence and then the cells were starved in serum-free medium for overnight, followed by 4-hour treatment with the inhibitors. Cell lysates were then prepared and used for determination of the pathway activation signals by the CEER assay.