The CRKL gene encoding an adaptor protein is amplified, overexpressed, and a possible therapeutic target in gastric cancer

Abstract

BackgroundGenomic DNA amplification is a genetic factor involved in cancer, and some oncogenes, such as ERBB2, are highly amplified in gastric cancer. We searched for the possible amplification of other genes in gastric cancer.Methods and ResultsA genome-wide single nucleotide polymorphism microarray analysis was performed using three cell lines of differentiated gastric cancers, and 22 genes (including ERBB2) in five highly amplified chromosome regions (with a copy number of more than 6) were identified. Particular attention was paid to the CRKL gene, the product of which is an adaptor protein containing Src homology 2 and 3 (SH2/SH3) domains. An extremely high CRKL copy number was confirmed in the MKN74 gastric cancer cell line using fluorescence in situ hybridization (FISH), and a high level of CRKL expression was also observed in the cells. The RNA-interference-mediated knockdown of CRKL in MKN74 disclosed the ability of CRKL to upregulate gastric cell proliferation. An immunohistochemical analysis revealed that CRKL protein was overexpressed in 24.4% (88/360) of the primary gastric cancers that were analyzed. The CRKL copy number was also examined in 360 primary gastric cancers using a FISH analysis, and CRKL amplification was found to be associated with CRKL overexpression. Finally, we showed that MKN74 cells with CRKL amplification were responsive to the dual Src/BCR-ABL kinase inhibitor BMS354825, likely via the inhibition of CRKL phosphorylation, and that the proliferation of MKN74 cells was suppressed by treatment with a CRKL-targeting peptide.ConclusionThese results suggested that CRKL protein is overexpressed in a subset of gastric cancers and is associated with CRKL amplification in gastric cancer. Furthermore, our results suggested that CRKL protein has the ability to regulate gastric cell proliferation and has the potential to serve as a molecular therapy target for gastric cancer.

The Role of CT10 Regulation of Kinase-Like in Cancer

“…Some oncogenes are highly amplified in GC. CRKL shows an important role in GC development with potential utilization as a molecular therapy target [18] CRKL amplification was found consistent with CRKL overexpression in GC. An extremely high CRKL copy number was detected in MKN74 GC cell line using fluorescence in situ hybridization, which was consistent with a high level of CRKL expression determined by western blotting assay.…”

“…IHC analysis revealed that CRKL was overexpressed in primary GC tissues. Concordantly, CRKL amplification by determining CRKL copy number using fluorescence in situ hybridization was positively correlated with its overexpression in primary GC tissues [18]. Finally, MKN74 cells with CRKL amplification were responsive to dual Src/BCR-ABL kinase inhibitor BMS354825, likely via the inhibition of CRKL phosphorylation, indicating CRKL may be a target of BMS354825-mediated therapy for a subset of GC.…”

“…An extremely high CRKL copy number was detected in MKN74 GC cell line using fluorescence in situ hybridization, which was consistent with a high level of CRKL expression determined by western blotting assay. RNAi knockdown of CRKL suppressed cell proliferation of MKN74 [18]. IHC analysis revealed that CRKL was overexpressed in primary GC tissues.…”

Accumulated phosphatidylcholine (16:0/16:1) in human colorectal cancer; possible involvement of LPCAT4

“…The areas evaluated were a small core of the TMA (2 mm in diameter) and the apparent intratumor heterogeneity was negligible. (24)(25)(26) Western blotting was performed as described previously. (22) btubulin (1:1000) was used as an internal control.…”

CRKL knockdown promotes in vitro proliferation, migration and invasion, in vivo tumor malignancy and lymph node metastasis of murine hepatocarcinoma Hca-P cells

“…CRKL commonly localizes in multiple intracellular compartments mapped at 22q11.21 encoding a protein of 36 kDa [14]. CRKL deregulation is involved in the development and progression of a variety of cancers including gastric cancer (GC), glioblastoma multiforme (GBM), hepatocellular carcinoma (HCC), bladder cancer, lung cancer, colon cancer, ovarian cancer, leukemia, breast cancer, head and neck cancer, rhabdomyosarcoma and neuroblastoma [15][16][17][18][19][20][21][22]. Nevertheless, the role and action mechanism of CRKL in tumor progression are still unclear.…”