NKD1 promotes glucose uptake in colon cancer cells by activating YWHAE transcription / 南方医科大学学报

OBJECTIVE@#Bo investigate the regulatory relationship between NKD1 and YWHAE and the mechanism of NKD1 for promoting tumor cell proliferation.@*METHODS@#HCT116 cells transfected with pcDNA3.0-NKD1 plasmid, SW620 cells transfected with NKD1 siRNA, HCT116 cells with stable NKD1 overexpression (HCT116-NKD1 cells), SW620 cells with nkd1knockout (SW620-nkd1-/- cells), and SW620-nkd1-/- cells transfected with pcDNA3.0-YWHAE plasmid were examined for changes in mRNA and protein expression levels of YWHAE using qRT-PCR and Western blotting. Chromatin immunoprecipitation (ChIP) assay was used to detect the binding of NKD1 to the promoter region of YWHAE gene. The regulatory effect of NKD1 on YWHAE gene promoter activity was analyzed by dual-luciferase reporter gene assay, and the interaction between NKD1 and YWHAE was analyzed with immunofluorescence assay. The regulatory effect of NKD1 on glucose uptake was examined in the tumor cells.@*RESULTS@#In HCT116 cells, overexpression of NKD1 significantly enhanced the expression of YWHAE at both the mRNA and protein levels, while NKD1 knockout decreased its expression in SW620 cells (P < 0.001). ChIP assay showed that NKD1 protein was capable of binding to the YWHAE promoter sequence; dual luciferase reporter gene assay showed that NKD1 overexpression (or knockdown) in the colon cancer cells significantly enhanced (or reduced) the transcriptional activity of YWHAE promoter (P < 0.05). Immunofluorescence assay demonstrated the binding of NKD1 and YWHAE proteins in colon cancer cells. NKD1 knockout significantly reduced glucose uptake in colon cancer cells (P < 0.01), while YWHAE overexpression restored the glucose uptake in NKD1-knockout cells (P < 0.05).@*CONCLUSION@#NKD1 protein activates the transcriptional activity of YWHAE gene to promote glucose uptake in colon cancer cells.

Naked Cuticle Drosophila 1 Expression in Histologic Subtypes of Small Adenocarcinoma of the Lung

BACKGROUND: Naked cuticle Drosophila 1 (NKD1) has been related to non-small cell lung cancer in that decreased NKD1 levels have been associated with both poor prognosis and increased invasive quality. METHODS: Forty cases of lung adenocarcinoma staged as Tis or T1a were selected. Cases were subclassified into adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and small adenocarcinoma (SAD). Immunohistochemical studies for NKD1 were performed. RESULTS: Forty samples comprised five cases of AIS (12.5%), eight of MIA (20.0%), and 27 of SAD (67.5%). AIS and MIA showed no lymph node metastasis and 100% disease-free survival, whereas among 27 patients with SAD, 2 (7.4%) had lymph node metastasis, and 3 (11.1%) died from the disease. Among the 40 cases, NKD1-reduced expression was detected in 8 (20%) samples, whereas normal expression was found in 15 (37.5%) and overexpression in 17 (42.5%). Loss of NKD1 expression was significantly associated with lymph node metastasis (p=0.001). All cases with predominant papillary pattern showed overexpression of NKD1 (p=0.026). CONCLUSIONS: Among MIA and SAD, MIA had better outcomes than SAD. Down-regulated NKD1 expression was closely associated with nodal metastasis, and overexpression was associated with papillary predominant adenocarcinoma.