Crkl Efficiently Mediates Cell Proliferation, Migration, and Invasion Induced by TGF-β Pathway in Glioblastoma

Abstract

Crk-like (CrkL) is an adapter protein that has crucial roles in cell proliferation, adhesion, and migration. However, the expression pattern and potential mechanism of CrkL protein in glioblastoma multiforme (GBM) have not been fully elucidated. To determine roles of CrkL in cell signaling, proliferation, and migration, small interfering RNAs and plasmids transfection were used to suppress or overexpress CrkL in U87 and U251; soft-agar assay and wound-healing assay were used to observe cell invasiveness, migration, and proliferation. Erk1/2, Smad2, and matrix metalloproteinase 9 (MMP9) were also analyzed by western blot. CrkL was expressed in U87 and U251 cell lines and can be activated by transforming growth factor-beta 1 (TGF-β1) in vitro; CrkL knockdown significantly suppressed the expression of phosph-ERK1/2 and MMP9 but enhanced phosph-Smad2 expression compared with control (p <0.001). Overexpression of CrkL against control upregulated phosph-ERK1/2 and MMP9 and, at the same time, downregulated phosph-Smad2 (p <0.01). On the other hand, CrkL knockdown could significantly affect U87 and U251 invasiveness (p <0.01) and wound closure (p <0.01) using soft-agar assay and wound-healing assay. These studies suggest that CrkL efficiently mediates cell proliferation, migration, and invasion induced by TGF-β pathway in glioblastoma. Furthermore, CrkL can be used as a potential and efficient therapeutic target of GBM and may also mediate other signaling pathway.

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

“…CRKL level was reported to be positively correlated with the cell proliferations of lung, colon, gastric, bladder and breast cancers as well as with TGF-b induced cell proliferation of glioblastoma cell [16,20,[31][32][33][34]. While, consistent with our previous work that CRKL overexpression inhibited Hca-P in vitro proliferation [23], CRKL knockdown significantly enhanced the in vitro proliferation of Hca-P (Fig.…”

The Role of CT10 Regulation of Kinase-Like in Cancer

“…CRKL can be activated by TGF-β1 in U87 and U251 cell lines [20]. CRKL knockdown not only significantly decreased U87 and U251 cell migration and proliferation, but also reduced TGF-β-mediated invasiveness [20]. Interestingly, CRKL knockdown significantly suppressed pERK1/2 and MMP9 expressions, while enhanced pSmad2 expression; its overexpression upregulated pERK1/2 and MMP9, while downregulated pSmad2 [20].…”

“…Its diffuse infiltration into normal brain renders complete surgical resection tricky. Additionally, it remains difficult to eradicate tumor cells with radiation or chemotherapy [20]. Thus, it is essential to throw light on the molecular mechanism of GBM.…”

“…CRKL is involved in TGF-β signaling with unclear role in many tumor cells. CRKL can be activated by TGF-β1 in U87 and U251 cell lines [20]. CRKL knockdown not only significantly decreased U87 and U251 cell migration and proliferation, but also reduced TGF-β-mediated invasiveness [20].…”

A Mouse Splice-Site Mutant and Individuals with Atypical Chromosome 22q11.2 Deletions Demonstrate the Crucial Role for Crkl in Craniofacial and Pharyngeal Development

“…Crkl is an SH2-SH3 domain adaptor protein with roles in propagating signalling from growth factor systems including Fgf [Moon et al, 2006], oestrogen [Padmanabhan et al, 2011] and TGFβ [Wurdak et al, 2005;Lv et al, 2013] which mediate a range of cellular activities including proliferation, migration and adhesion. Homozygous deletion of Crkl in mice results in late-gestation lethality and a range of developmental defects that recapitulates many of the features of 22q11DS.…”