Defining COMMD4 as an anti-cancer therapeutic target and prognostic factor in non-small cell lung cancer

Abstract

BACKGROUND: Non-small cell lung cancers (NSCLC) account for 85-90% of all lung cancers. As drug resistance critically impairs chemotherapy effectiveness, there is great need to identify new therapeutic targets. The aims of this study were to investigate the prognostic and therapeutic potential of the copper-metabolism-domain-protein, COMMD4, in NSCLC. METHODS: The expression of COMMD4 in NSCLC was investigated using bioinformatic analysis, immunoblotting of immortalised human bronchial epithelial (HBEC) and NSCLC cell lines, qRT-PCR and immunohistochemistry of tissue microarrays. COMMD4 function was additionally investigated in HBEC and NSCLC cells depleted of COMMD4, using small interfering RNA sequences. RESULTS: Bioinformatic analysis and in vitro analysis of COMMD4 transcripts showed that COMMD4 levels were upregulated in NSCLC and elevated COMMD4 was associated with poor prognosis in adenocarcinoma (ADC). Immunoblotting demonstrated that COMMD4 expression was upregulated in NSCLC cells and siRNA-depletion of COMMD4, decreased cell proliferation and reduced cell viability. Cell death was further enhanced after exposure to DNA damaging agents. COMMD4 depletion caused NSCLC cells to undergo mitotic catastrophe and apoptosis. CONCLUSIONS: Our data indicate that COMMD4 may function as a prognostic factor in ADC NSCLC. Additionally, COMMD4 is a potential therapeutic target for NSCLC, as its depletion induces cancer cell death.

COMMD1, from the Repair of DNA Double Strand Breaks, to a Novel Anti-Cancer Therapeutic Target

“…A single unrepaired DSB in a cell can be cytotoxic [22,47], additionally mutations or down-regulation of DNA repair proteins, associated with the repair of DSBs, are strongly linked with inherited cancer risk (BRCA1, BRCA2, ATM) [48][49][50][51]. Here, as we confirmed a role for COMMD1 in the repair of DSBs and as COMMD4 was previously shown to function in the repair of DSBs [35] and additionally a potential therapeutic target and prognostic factor in NSCLC [36], we investigated a similar role for COMMD1 in NSCLC. Initially, the expression of COMMD1 transcripts were evaluated using bioinformatic analysis of The Cancer Genome Atlas (TCGA) datasets (Figure 2A-E).…”

“…HBEC3-KT and NSCLC cells were cultured in a humidified incubator at 37 °C/5% CO 2 atmosphere. The histologic features and origin of all cell lines used in this study have been previously described [ 36 ]. Hoechst 33342 was purchased from Life Technologies (H3570) and irradiations were performed at room temperature using a 137 Cs source (Gammacell 40 Exactor [MDS Nordion]; dose rate 1.1 Gy/min).…”

“…Lysates were collected and immunoblotted as previously described [ 36 , 41 ]. Briefly, total cell lysates were washed with phosphate-buffered saline and lysed in ice-cold NP40 buffer (20 mM HEPES pH 8, 10 mM MgCl 2 , 150 mM KCl, 0.5 mM EDTA, 0.2% NP40, 5% glycerol, 0.5 mM DTT, 1× protease and phosphatase inhibitor cocktail (Thermo Scientific, 78444) and 1× Pierce Universal Nuclease for cell lysis (Thermo Fisher Scientific, PIE88702)).…”

“…COMMD4-depleted cells were hypersensitive to DNA damaging agents and were unable to repair DSBs efficiently. In a separate publication, the authors additionally showed that COMMD4 transcripts are upregulated in NSCLC and elevated COMMD4 was associated with poor prognosis for the ADC subtype of NSCLC [ 36 ]. Furthermore, COMMD4 protein expression was also elevated in the NSCLC cell lines.…”

Bioinformatics Analysis and Insights for the Role of COMMD7 in Hepatocellular Carcinoma

“…COMMD3/8 complex selectively recruited GRK6 and induced GRK6-mediated phosphorylation of the receptor and activation of β-arrestin-mediated signaling thus regulates immune response [21]. COMMD4 was de ned as an anti-cancer therapeutic target and prognostic factor in nonsmall cell lung cancer [22]. COMMD5 acts as an adaptor protein to coordinate endosomal tra cking and plays an important role inEGFR transporting and activity in renal cell carcinoma [23].…”