A Clinical Application Study of Nanostructured Substrates for the Detection of Circulating Tumor Cells.

BACKGROUND: Circulating tumor cell (CTC) isolation methods based on nanostructured substrates can be used to isolate tumor cells from peripheral blood. This study aimed to validate the clinical application of our method and determine the appropriate diagnostic critical value. METHODS: AFM was used to detect the surface roughness of nanostructured substrates. Cell lines and blood samples were used to verify CTC isolation methods. The ROC curve and AUC were used to evaluate the diagnostic value of CTC numbers. RESULTS: First, AFM, cell binding yields, and tumor cell detection rate from blood showed that NS has a potential for cell adsorption. Then, the CTC detection method was verified by using cell lines and blood samples. The number of CTCs in patients with cancers or metastases were significantly greater than those of patients without cancers. Then, the ROC curves and AUC showed that this method had a medium diagnostic value. CONCLUSIONS: Isolating CTCs based on nanostructured substrates was appropriate for the clinical diagnosis of tumors, and samples with more than 1.5 CTCs/1 mL blood could be identified as CTC-positive.

Loss of function of SWI/SNF chromatin remodeling genes leads to genome instability of human lung cancer.

SWI/SNF chromatin remodeling complexes are frequently mutated in a variety of human cancers. We investigated the mutation incidence and the role of mSWI/SNF (BAF) complexes in human lung cancer. In the present study, we analyzed somatic mutations of BAF complexes and other driver mutated genes of lung carcinoma deposited in the Catalogue of Somatic Mutations in Cancer (COSMIC) database. BAF complexes were mutated in 282 of 803 (35.12%) lung carcinoma samples analyzed, ranking second to TP53. Significantly, BAF-mutated samples exhibited more genomic mutations than BAF wild-type ones. Moreover, a significant positive correlation existed between the BAF mutations and overall genomic mutations in these lung carcinoma samples (P<0.001, Pearson's correlation analysis). Specifically, the mutant-typing of 6 BAF genes, SMARCA4, ARID2, ARID1B, BCL11A, BCL11B and BRD9 was associated with more overall mutations in the lung carcinoma samples. A mutation reporter system was developed by means of the establishment of stable cell sublines with slippage-luciferase transcript in a lung adenocarcinoma cell line, Calu-3. SMARCA4, the most frequently mutated BAF gene in lung cancer, was stably knocked down by pSUPER constructs carrying short hairpin RNA (shRNA). Mutation ratios determined from the mutation reporters of Calu-3 cells were significantly increased upon stable SMARCA4 knockdown. We demonstrated that genetic mutations of BAF complexes lead to genome instability of lung carcinoma. Therefore, BAF complexes play an important role in maintaining genome stability in human lung cancer.