Fig 1.
SIAH2 mRNA expression levels in NSCLC.
Total RNA was extracted from tissues, integrity evaluated (all the samples included showed a RIN above 9) and changes in expression of SIAH2 in tumor samples compared to normal lung samples from the same patient analyzed by qPCR and expressed as a fold-change. Amplification efficiencies were validated and normalized against β-actin and HPRT, and fold change in gene expression was calculated using the 2−ΔΔCt method. Results represent the mean ± SD.
Table 1.
Patient characteristics.
Fig 2.
SIAH2 protein expression in human lung cancer compared to surrounding healthy tissue.
(A, B) Total proteins were extracted from ADC or SDC specimens and the corresponding normal lung tissue, SIAH2 protein expression analyzed by western blot and the bands quantified by densitometry after normalization to actin signal intensities. The results are expressed as relative OD expression and represent the mean ± SD. ** p < 0.001. (C) Fold induction representation of SIAH2 in tumor samples compared to normal lung samples from the same patient. Results represent the mean ± SD. (D) Results from 16 patients (8 ADC and 8 SCC) selected to represent a range of differential mRNA expression between normal lung tissue (N) and tumor (T). SIAH2 protein expression was analyzed by immunoblots (upper panel) and mRNA expression by qPCR (lower panel). Data are mean ± SD of n = 3 experiments. ** p < 0.001 and *** p < 0.0001.
Fig 3.
Expression of SIAH2 in ADC and SCC analyzed by immunohistochemistry.
Representative images of lung tumor and adjacent normal tissue stained with SIAH2 antibody and hematoxylin–eosin (HE)(x100).
Fig 4.
Correlation between SIAH2 expression and tumor grade.
Representative images of immunohistochemical analysis of SIAH2 in normal lung, well and poorly differentiated adenocarcinoma and squamous cell carcinoma. Occasional nuclear positivity in normal lung, moderate staining in well differentiated adenocarcinoma and strong staining in poorly differentiated adenocarcinoma and squamous cell carcinoma (HE: hematoxylin–eosin)(x100).
Fig 5.
Scatter plot showing results of Pearson´s correlation analysis.
(A) Positive correlation between SIAH2 protein expression and 18FDG uptake (measured as maximum standardized uptake value-SUVmax) in primary NSCLC (p = 0.014), r2 = 0.13). (B) Positive correlation between increasing tumor size and 18FDG uptake on PET/CT scans (p = 0.012, r2 = 0.12).
Fig 6.
SIAH2 protein expression correlates with expression of DYRK2.
(A) Representative images of adenocarcinoma or squamous cell carcinoma, and adjacent normal tissue stained with DYRK2 antibody (x100). (B) BEAS-2B cells were cultured with or without serum during 7 days, lysed and protein expression was evaluated by immunoblot with the indicated antibodies (upper panel) and mRNA expression by qPCR (lower panel). Representative blot out of three independent experiments and the positions and molecular weights (in kDa) are indicated.