Combination of multiple gene markers to detect circulating tumor cells in the peripheral blood of patients with non-small cell lung cancer using real-time PCR.

Our study aims to determine the clinical significance of human telomerase reverse transcriptase (hTERT), S-phase kinase-associated protein 2 (Skp2) and thyroid transcription factor-1 (TTF-1) mRNA expressions in peripheral blood (PB) of patients with non-small cell lung cancer (NSCLC). Real-time polymerase chain reaction was used to investigate the gene expressions of hTERT, Skp2, TTF-1 as in the PB of 60 patients with NSCLC and 20 benign lung diseases. Statistical analyses were performed to examine the correlation between the expression of these mRNA markers and the clinical pathological features of NSCLC. We found that hTERT, Skp2, and TTF-1 were overexpressed in the PB of NSCLC patients, and demonstrated high specificity as well as sensitivity when used for NSCLC diagnosis. Significant correlation was observed between disease stage and the three markers (P < 0.05). This study suggests that the genes hTERT, Skp2, and TTF-1 play important roles in tumor genesis and development, and can be used as diagnosis markers in NSCLC patients. The expression of three markers in combination can significantly improve the sensitivity and accuracy of diagnosis relative to single marker diagnosis, and provides a reliable method to detect CTCs in the PB. Additionally, these markers can also be used as diagnostic markers for clinical stages of NSCLC.

S-phase kinase-associated protein 2 expression interference inhibits breast cancer cell proliferation.

We investigated the expression of S-phase kinase-associated protein 2 (SKP2) in breast cancer tissues, and the effects of SKP2-specific small interfering RNA (siRNA) interference on breast cancer cell proliferation. Thirty subjects provided breast cancer tissue samples and 18 subjects provided normal breast specimens for this study. The expression of SKP2 in breast cancer patient tissues and normal breast tissues was detected by western blotting analysis and reverse transcription-polymerase chain reaction. SKP2-specific siRNA was used to decrease SKP2 expression in breast cancer cell line MDA-MB-231. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell proliferation. SKP2 expression in breast cancer tissues was significantly higher than in normal breast tissues (P < 0.05). Two pairs of siRNA specific to SKP2 were required to downregulate SKP2 expression in the breast cancer cell line MDA-MB-231. The MTT assay showed that MDA-MB-231 growth significantly slowed after SKP2 interference. Patients with breast cancer have an increased SKP2 level. Interference in SKP2 gene expression can inhibit breast cancer cell growth, suggesting that SKP2 is potentially a new target for breast cancer therapy.

Identifying differentially expressed genes and pathways in two types of non-small cell lung cancer: adenocarcinoma and squamous cell carcinoma.

Non-small cell lung carcinoma, NSCLC, accounts for 80-85% of lung cancers. NSCLC can be mainly divided into two types: adenocarcinoma (ADC) and squamous cell carcinoma (SCC). The purpose of our study was to identify and differentiate the pathogenesis of ADC and SCC at the molecular level. The gene expression profiles of ADC and SCC were downloaded from Gene Expression Omnibus under accession No. GSE10245. Accordingly, differentially expressed genes (DEGs) were identified by the limma package in R language. In addition, DEGs were functionally analyzed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. A total of 4124 DEGs were identified, including CDK1, CDK2, CDK4, and SKP2. The DEGs were mainly involved in 16 pathways related to cell proliferation, cell signal transduction and metabolism. We conclude that the molecular mechanisms of ADC and SCC are considerably different, and that they are involved in immune response, cell signal transduction, metabolism, cell division, and cell proliferation. Therefore, the two diseases should be treated differently. This study offers new insight into the diagnosis and therapy of these two types of lung cancer.

Molecular characterization of the Aspergillus nidulans fbxA encoding an F-box protein involved in xylanase induction.

The filamentous fungus Aspergillus nidulans has been used as a fungal model system to study the regulation of xylanase production. These genes are activated at transcriptional level by the master regulator the transcriptional factor XlnR and repressed by carbon catabolite repression (CCR) mediated by the wide-domain repressor CreA. Here, we screened a collection of 42 A. nidulans F-box deletion mutants grown either in xylose or xylan as the single carbon source in the presence of the glucose analog 2-deoxy-D-glucose, aiming to identify mutants that have deregulated xylanase induction. We were able to recognize a null mutant in a gene (fbxA) that has decreased xylanase activity and reduced xlnA and xlnD mRNA accumulation. The ΔfbxA mutant interacts genetically with creAd-30, creB15, and creC27 mutants. FbxA is a novel protein containing a functional F-box domain that binds to Skp1 from the SCF-type ligase. Blastp analysis suggested that FbxA is a protein exclusive from fungi, without any apparent homologs in higher eukaryotes. Our work emphasizes the importance of the ubiquitination in the A. nidulans xylanase induction and CCR. The identification of FbxA provides another layer of complexity to xylanase induction and CCR phenomena in filamentous fungi.