Identification of the mitochondrial protein ADCK2 as a therapeutic oncotarget of NSCLC.

The aarF domain containing kinase 2 (ADCK2) is a mitochondria-locating protein, important for fatty acid metabolism and coenzyme Q biosynthesis. The bioinformatics results show that elevated ADCK2 transcripts in NSCLC correlate with poor overall survival and poor anti-PD-1/PD-L1 therapy response. ADCK2 is overexpressed in local human NSCLC tissues and various primary and established NSCLC cells. In NSCLC cells, ADCK2 shRNA or CRISPR/Cas9 knockout remarkably suppressed cell viability, proliferation, cell cycle progression, cell mobility, and provoked cell apoptosis. Moreover, ADCK2 depletion disrupted mitochondrial functions in NSCLC cells, causing cytochrome C release, mitochondrial depolarization, DNA damage and ATP reduction. Contrarily, ectopic ADCK2 overexpression promoted NSCLC cell growth. Further studies revealed that ADCK2 depletion inactivated Akt-mTOR signaling in primary NSCLC cells. NSCLC xenograft growth in nude mice was significantly hindered after ADCK2 silencing or knockout. ADCK2 depletion, apoptosis induction and oxidative injury as well as ATP reduction and Akt-mTOR inactivation were detected in ADCK2-silenced or ADCK2-knockout NSCLC xenograft tissues. Together overexpressed ADCK2 is important for the growth of NSCLC cells, representing an important therapeutic molecular oncotarget.

Enhanced proliferation and defective activation-induced cell death of CD4+ T cells in childhood asthma.

BACKGROUND: Hyperactivation of CD4+ T cells in peripheral blood and airway tissues has been suggested to play a key role in the development and maintenance of chronic inflammation in childhood asthma. However, the underlying mechanisms are not yet clear. OBJECTIVE: To investigate alterations in serum levels of T helper cell-related cytokines, mitogen-stimulated CD4+ T cell proliferation and activation-induced cell death (AICD) in childhood asthma. METHODS: 21 children with untreated asthma and 21 healthy volunteers (age and gender matched) participated in this study. Th1/Th2/Th17 cytokines in serum were analyzed by flow cytometry. CD4+ T cells were isolated from participants by using immuno-magnetic beads and were stimulated by phytohemagglutinin (PHA). Cell proliferation was evaluated with a Cell Counting Kit-8 (CCK-8). Activation induced cell death (AICD) of CD4+ T cells was also induced by PHA and apoptosis was assayed by annexin V/PI staining. Quantitative RT-PCR was carried out to analyze Fas and FasL mRNA expression. FLIPL, caspase-8 and Bcl-2 were detected by western blot analysis. RESULTS: In children with asthma, the proliferative capacity of CD4+ T cells was enhanced and AICD was inhibited significantly, while serum IL-4, IL-10 and TNF were markedly higher compared with the control group. Fas mRNA expression in the asthma group was obviously lower than that in the control group, while no change was detected in FasL mRNA expression. Western blot analysis showed that the levels of the anti-apoptotic proteins, FLIPL and Bcl-2 in CD4+ T cells of the asthma group were significantly higher than in the control group. Spearman's correlation tests showed that only IL-4 correlated positively with FLIPL and Bcl-2 expression, while IL-10 and TNF were unrelated to FLIPL and Bcl-2 expression. CONCLUSIONS: These results indicate that enhanced proliferation and defective AICD of CD4+ T cells influence the T cell-mediated inflammatory reaction in childhood asthma and that increased IL-4, FLIPL and Bcl-2 expression and decreased Fas expression jointly participate in these changes in cell proliferation and apoptosis.ression and decreased Fas expression jointly participate in these changes in cell proliferation and apoptosis.