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Novel receptor tyrosine kinase targeted combination therapies for imatinib-resistant gastrointestinal stromal tumors (GIST).

Mahadevan D, Theiss N, Morales C, Stejskal AE, Cooke LS, Zhu M, Kurtzman D, Swart R, Ong E, Qi W - Oncotarget (2015)

Bottom Line: GIST882 and GIST430/654 cells have an IC50 0.077 and 0.59 µM to IM respectively.GIST48 have an IC50 0.66 µM to IM, 0.91 µM to amuvatinib [AMU] and 0.67 µM to erlotinib (Erl).Synergistic combinations: GIST882, AMU + Erl (CI 0.20); IM + AMU (CI 0.50), GIST430/654, IM + afatinib (CI 0.39); IM + AMU (CI 0.42), GIST48, IM + afatinib (CI 0.03); IM + AMU (CI 0.04); AMU + afatinib (CI 0.36); IM + Erl (CI 0.63).

View Article: PubMed Central - PubMed

Affiliation: West Cancer Center/University of Tennessee Health Science Center (UTHSC), Memphis, TN.

ABSTRACT

Background: c-Kit/α-PDGFR targeted therapies are effective for gastrointestinal stromal tumors (GIST), but, >50% develop drug resistance.

Methods: RTK expression (c-Kit, c-Met, AXL, HER-1, HER-2, IGF-1R) in pre-/post-imatinib (IM) GIST patient samples (n=16) and 4 GIST cell lines were examined for RTK inhibitor activity. GIST-882 cells were cultured in IM every other day, cells collected (1 week to 6 months) and analyzed by qRT-PCR and Western blotting.

Results: Immunohistochemistry pre-/post-IM demonstrated continued expression of c-Kit and HER1, while a subset expressed IGF-1R, c-Met and AXL. In GIST cells (GIST-882, GIST430/654, GIST48) c-Kit, HER1 and c-Met are co-expressed. Acute IM over-express c-Kit while chronic IM, lose c-Kit and HER-1 in GIST882 cells. GIST882 and GIST430/654 cells have an IC50 0.077 and 0.59 µM to IM respectively. GIST48 have an IC50 0.66 µM to IM, 0.91 µM to amuvatinib [AMU] and 0.67 µM to erlotinib (Erl). Synergistic combinations: GIST882, AMU + Erl (CI 0.20); IM + AMU (CI 0.50), GIST430/654, IM + afatinib (CI 0.39); IM + AMU (CI 0.42), GIST48, IM + afatinib (CI 0.03); IM + AMU (CI 0.04); AMU + afatinib (CI 0.36); IM + Erl (CI 0.63).

Conclusion: Targeting c-Kit plus HER1 or AXL/c-Met abrogates IM resistance in GIST.

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Related in: MedlinePlus

Immunohistochemistry Analysis(A). Immunohistochemistry Analysis of Receptor Tyrosine Kinases (c-Kit, HER-1, IGF-1R, HER-2, AXL and c-Met) with H/E staining, PTEN (positive control) and diluent (negative control), in GIST Specimens. Representative photomicrographs of patient 1 with H-Score (scale 0-300) and magnification = 20x. (B). Western blotting analysis for c-Kit, HER-1 and c-Met expression in GIST882, GIST48 and GIST430/654 cells.
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Figure 1: Immunohistochemistry Analysis(A). Immunohistochemistry Analysis of Receptor Tyrosine Kinases (c-Kit, HER-1, IGF-1R, HER-2, AXL and c-Met) with H/E staining, PTEN (positive control) and diluent (negative control), in GIST Specimens. Representative photomicrographs of patient 1 with H-Score (scale 0-300) and magnification = 20x. (B). Western blotting analysis for c-Kit, HER-1 and c-Met expression in GIST882, GIST48 and GIST430/654 cells.

Mentions: A panel of 6 receptor tyrosine kinases (RTKs) by IHC assays was used to characterize 15 GIST samples. Representative images of patient 1 are shown in Figure 1A. Positivity across all samples was defined as the tumor displaying at least 10% of tumor cells staining (Table 3). An H-score was used to assess staining intensity (Table S2). As expected, c-Kit expression was seen in 14 of 15 tumors (93%) with a mean intensity of an H-score of 165 (range of 0-259). Protein expression was observed for the other RTKs: HER1 - 14/15 (93%), mean H-score of 73 (range 0-179); IGF-1R - 3/15 (20%), mean H-score 93 (range 0-137); AXL - 15/15 (100%), mean H-score of 111 (range 14-220). All samples were negative for c-Met and HER-2. One patient (9) had negative staining across all markers except for low AXL staining.


Novel receptor tyrosine kinase targeted combination therapies for imatinib-resistant gastrointestinal stromal tumors (GIST).

Mahadevan D, Theiss N, Morales C, Stejskal AE, Cooke LS, Zhu M, Kurtzman D, Swart R, Ong E, Qi W - Oncotarget (2015)

Immunohistochemistry Analysis(A). Immunohistochemistry Analysis of Receptor Tyrosine Kinases (c-Kit, HER-1, IGF-1R, HER-2, AXL and c-Met) with H/E staining, PTEN (positive control) and diluent (negative control), in GIST Specimens. Representative photomicrographs of patient 1 with H-Score (scale 0-300) and magnification = 20x. (B). Western blotting analysis for c-Kit, HER-1 and c-Met expression in GIST882, GIST48 and GIST430/654 cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4385828&req=5

Figure 1: Immunohistochemistry Analysis(A). Immunohistochemistry Analysis of Receptor Tyrosine Kinases (c-Kit, HER-1, IGF-1R, HER-2, AXL and c-Met) with H/E staining, PTEN (positive control) and diluent (negative control), in GIST Specimens. Representative photomicrographs of patient 1 with H-Score (scale 0-300) and magnification = 20x. (B). Western blotting analysis for c-Kit, HER-1 and c-Met expression in GIST882, GIST48 and GIST430/654 cells.
Mentions: A panel of 6 receptor tyrosine kinases (RTKs) by IHC assays was used to characterize 15 GIST samples. Representative images of patient 1 are shown in Figure 1A. Positivity across all samples was defined as the tumor displaying at least 10% of tumor cells staining (Table 3). An H-score was used to assess staining intensity (Table S2). As expected, c-Kit expression was seen in 14 of 15 tumors (93%) with a mean intensity of an H-score of 165 (range of 0-259). Protein expression was observed for the other RTKs: HER1 - 14/15 (93%), mean H-score of 73 (range 0-179); IGF-1R - 3/15 (20%), mean H-score 93 (range 0-137); AXL - 15/15 (100%), mean H-score of 111 (range 14-220). All samples were negative for c-Met and HER-2. One patient (9) had negative staining across all markers except for low AXL staining.

Bottom Line: GIST882 and GIST430/654 cells have an IC50 0.077 and 0.59 µM to IM respectively.GIST48 have an IC50 0.66 µM to IM, 0.91 µM to amuvatinib [AMU] and 0.67 µM to erlotinib (Erl).Synergistic combinations: GIST882, AMU + Erl (CI 0.20); IM + AMU (CI 0.50), GIST430/654, IM + afatinib (CI 0.39); IM + AMU (CI 0.42), GIST48, IM + afatinib (CI 0.03); IM + AMU (CI 0.04); AMU + afatinib (CI 0.36); IM + Erl (CI 0.63).

View Article: PubMed Central - PubMed

Affiliation: West Cancer Center/University of Tennessee Health Science Center (UTHSC), Memphis, TN.

ABSTRACT

Background: c-Kit/α-PDGFR targeted therapies are effective for gastrointestinal stromal tumors (GIST), but, >50% develop drug resistance.

Methods: RTK expression (c-Kit, c-Met, AXL, HER-1, HER-2, IGF-1R) in pre-/post-imatinib (IM) GIST patient samples (n=16) and 4 GIST cell lines were examined for RTK inhibitor activity. GIST-882 cells were cultured in IM every other day, cells collected (1 week to 6 months) and analyzed by qRT-PCR and Western blotting.

Results: Immunohistochemistry pre-/post-IM demonstrated continued expression of c-Kit and HER1, while a subset expressed IGF-1R, c-Met and AXL. In GIST cells (GIST-882, GIST430/654, GIST48) c-Kit, HER1 and c-Met are co-expressed. Acute IM over-express c-Kit while chronic IM, lose c-Kit and HER-1 in GIST882 cells. GIST882 and GIST430/654 cells have an IC50 0.077 and 0.59 µM to IM respectively. GIST48 have an IC50 0.66 µM to IM, 0.91 µM to amuvatinib [AMU] and 0.67 µM to erlotinib (Erl). Synergistic combinations: GIST882, AMU + Erl (CI 0.20); IM + AMU (CI 0.50), GIST430/654, IM + afatinib (CI 0.39); IM + AMU (CI 0.42), GIST48, IM + afatinib (CI 0.03); IM + AMU (CI 0.04); AMU + afatinib (CI 0.36); IM + Erl (CI 0.63).

Conclusion: Targeting c-Kit plus HER1 or AXL/c-Met abrogates IM resistance in GIST.

Show MeSH
Related in: MedlinePlus