Copy number gains of the putative CRKL oncogene in laryngeal squamous cell carcinoma result in strong nuclear expression of the protein and influence cell proliferation and migration

Abstract

Laryngeal squamous cell carcinoma is a major medical problem worldwide. Although our understanding of genetic changes and their consequences in laryngeal cancer has opened new therapeutic pathways over the years, the diagnostic as well as treatment options still need to be improved. in our previous study, we identified CRKL (22q11) as a novel putative oncogene overexpressed and amplified in a subset of LScc tumors and cell lines. Here we analyze to what extent CRKL DnA copy number gains correlate with the higher expression of cRKL protein by performing iHc staining of the respective protein in LScc cell lines (n = 3) and primary tumors (n = 40). Moreover, the importance of CRKL gene in regard to proliferation and motility of LSCC cells was analyzed with the application of RNA interference (siRNA). Beside the physiological cytoplasmic expression, the analysis of LScc tumor samples revealed also nuclear expression of CRKL protein in 10/40 (25%) cases, of which three (7.5%), presented moderate or strong nuclear expression. Similarly, we observed a shift towards aberrantly strong nuclear abundance of the CRKL protein in LSCC cell lines with gene copy number amplifications. Moreover, siRNA mediated silencing of CRKL gene in the cell lines showing its overexpression, significantly reduced proliferation (p < 0.01) as well as cell migration (p < 0.05) rates. Altogether, these results show that the aberrantly strong nuclear localization of cRKL is a seldom but recurrent phenomenon in LScc resulting from the increased DnA copy number and overexpression of the gene. Moreover, functional analyses suggest that proliferation and migration of the tumor cells depend on CRKL expression. Laryngeal squamous cell carcinoma (LSCC) belongs to the highly heterogeneous group of head and neck squamous cell carcinomas (HNSCC). HNSCC is the sixth most common cancer worldwide affecting annually more than 600,000 new patients with mortality rate of approximately 50% 1-3. Hitherto, there are only two targeted therapies approved for HNSCC patients. The first, Cetuximab is based on a monoclonal antibody directed against the epidermal growth factor receptor (EGFR) found recurrently amplified in head and neck cancer cells 4. The

Integrative molecular and clinical profiling of acral melanoma links focal amplification of 22q11.21 to metastasis

“…6b–d , Methods). Beyond LZTR1 , we noted that CRKL (CRK like proto-oncogene, adapter protein), a recurrently amplified gene in multiple carcinomas 50 – 53 , including non-small cell lung cancer (3–13% of cases) 50 – 52 , was also present in the minimal common region of focal amplification (Fig. 2h ).…”

Integrative molecular and clinical profiling of acral melanoma identifies LZTR1 as a key tumor promoter and therapeutic target

“…5, Methods). Beyond LZTR1, we noted that ZNF74, a zinc finger protein, and CRKL (CRK like proto-oncogene, adaptor protein), a recurrently amplified gene in multiple carcinomas [47][48][49][50] , including nonsmall cell lung cancer (3% -13% of cases) [47][48][49] , were ranked 2 nd and 3 rd in our analysis, respectively. Given these results, we set out to characterize the biological functions of these genes to determine which, if any, underlie the observed clinical phenotype of 22q11.21 amplification.…”

Clinical, genomic, and transcriptomic correlates of response to immune checkpoint blockade-based therapy in a cohort of patients with angiosarcoma treated at a single center

“… 51 52 In laryngeal squamous cell carcinoma, CRKL amplification is associated with increased nuclear expression of CRKL, a requirement for tumor cell viability. 53 In non-small cell lung cancer, CRKL amplification is a noted oncogene that activates the RAS and SRC pathways and is associated with resistance to EGFR inhibition. 54 Although our analysis did not show an impact of CRKL amplification on outcome of ICB-based treatment, it may be prognostic of outcome in a larger dataset of angiosarcoma.…”