Comparison of microfluidic platforms for the enrichment of circulating tumor cells in breast cancer patients.

PURPOSE: Circulating tumor cells (CTCs) hold promise to be a non-invasive measurable biomarker in all cancer stages. Because the analysis of CTCs is still a technical challenge, we compared different types of microfluidic enrichment protocols to isolate these rare cells from the blood. METHODS: Blood samples from patients with early and metastatic breast cancer (BC) were processed using the microfluidic Parsortix® technology employing (i) a single-step cell separation using the standard GEN3D6.5 microfluidic cassette, (ii) a two-step separation with an upfront pre-enrichment, and (iii) a two-step separation with a different type of cassette. In the enriched cells, the gene expression levels of CTC-related transcripts were assessed using quantitative real-time PCR (qPCR) by Taqman® and Lightcycler (LC) technology. RESULTS: 23/60 (38.3%) BC samples were assigned as positive due to the presence of at least one gene marker beyond the threshold level. The prevalence of epithelial markers was significantly higher in metastatic compared to early BC (EpCAM: 31.3% vs. 7.3%; CK19: 21.1% vs. 2.4%). A high level of concordance was observed between CK19 assessed by Taqman® and LC technology, and for detection of the BC-specific gene SCGB2A2. An upfront pre-enrichment resulted in lower leukocyte contamination, at the cost of fewer tumor cells captured. CONCLUSION: The Parsortix® system offers both reasonable recovery of tumor cells and depletion of contaminating leukocytes when the single-step separation using the GEN3D6.5 cassette is employed. Careful selection of suitable markers and cut-off thresholds is an essential point for the subsequent molecular analysis of the enriched cells.

Can simvastatin reduce COPD exacerbations? A randomised double-blind controlled study.

BACKGROUND: Several studies have shown that statins have beneficial effects in COPD regarding lung function decline, rates and severity of exacerbation, hospitalisation and need for mechanical ventilation. METHODS: We performed a randomised double-blind placebo-controlled single-centre trial of simvastatin at a daily dose of 40 mg versus placebo in patients with Global Initiative for Chronic Obstructive Lung Disease criteria grades 2-4 at a tertiary care pulmonology department in Austria. Scheduled treatment duration was 12 months and the main outcome parameter was time to first exacerbation. RESULTS: Overall, 209 patients were enrolled. In the 105 patients taking simvastatin, time to first exacerbation was significantly longer compared to the 104 patients taking placebo: median 341 versus 140 days (log-rank test p<0.001). Hazard ratio for risk of first exacerbation for the simvastatin group was 0.51 (95% CI 0.34-0.75; p=0.001). Rate of exacerbations was significantly lower with simvastatin: 103 (41%) versus 147 (59%) (p=0.003). The annualised exacerbation rate was 1.45 events per patient-year in the simvastatin group and 1.9 events per patient-year in the placebo group (incidence rate ratio 0.77, 95% CI 0.60-0.99). We found no effect on quality of life, lung function, 6-min walk test and high-sensitivity C-reactive protein. More patients dropped out in the simvastatin group compared to the placebo group (39 versus 29). CONCLUSION: In our single-centre RCT, simvastatin at a dose of 40 mg daily significantly prolonged time to first COPD exacerbation and reduced exacerbation rate.

Mass spectrometric profiling of low-molecular-weight proteins.

Tracing potential biomarkers through proteomics has been further developed and is nearing realization. The whole sequence of human proteome is becoming better understood with the passage of time. However, it is a long way to go to pinpoint biomarker proteins out of complex biofluids and use them for clinical diagnosis, prognosis, and therapeutic applications. From that point of view, the high hopes put in proteomics have not been fulfilled yet. The key reasons for that is the complexity of the proteome and the limited technologies in terms of specificity and reproducibility. Thus, major focus is put on the development of novel innovative analytical techniques in the field of life science, using high-performance single- and multidimensional separation and enrichment methods, such as solid-phase extraction (SPE), liquid chromatography (HPLC), or capillary electrophoresis (CE) coupled to mass spectrometry (MS). A newly emerged technology, termed as material-enhanced laser desorption/ionization (MELDI) meets basic requirements and is applied to reduce the complexity of proteomic samples while liquid chromatography (LC) is used for separation and fractionation, followed by identification with MS/MS including database searching analysis. Different MELDI carriers are employed as support materials to specifically bind peptides and proteins from biofluids like serum or urine. The MELDI approach supports automated routine analysis by means of liquid handling robots for high-throughput applications leading to higher reproducibility, crucial for a successful identification of disease markers with MALDI-TOF MS. Such promising new methods and further technical developments will be necessary to answer the high-wrought expectations on the field of proteomics.

Genetic polymorphisms in centrobin and Nek2 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome aberrations have been suggested to cause chromosomal instability and aneuploidy, and eventually promote cancer development. The Centrobin and Nek2 proteins interact with each other and both are involved in centrosome duplication and chromosome segregation. This study aimed to investigate whether genetic polymorphisms in these two genes may affect breast cancer susceptibility in Chinese Han population using a haplotype-based analysis. Five single nucleotide polymorphisms (SNPs) in centrobin and four SNPs in Nek2 were genotyped in 1,215 cases of infiltrating ductal breast cancer and 1,215 age-matched cancer-free controls from Chinese Han population. The results showed that CATCG haplotype of centrobin was strongly associated with decreased breast cancer risk (adjusted OR = 0.14, 95 % CI = 0.09-0.22), which was mainly driven by the C allele of SNP rs11650083 (A>C, located in exon 12, resulting in Pro578Gln). None of the individual SNPs in Nek2 was associated with breast cancer risk. However, haplotype GTAT of Nek2 was associated with increased risk of breast cancer (adjusted OR = 1.56, 95 % CI = 1.18-2.06) and its risk was significantly elevated among women with both family history of cancer and a longer menarche-first full-term pregnancy (FFTP) interval (>11 years) (adjusted OR = 5.31, 95 % CI = 1.97-14.32). Furthermore, women harboring both at-risk haplotype GTAT of Nek2 and protective haplotype CATCG of centrobin were linked with decreased breast cancer risk, suggesting that the association between genetic variants of Nek2 and increased breast cancer risk was modified by genetic variants of centrobin. Our results indicate that genetic polymorphisms of centrobin and Nek2 are related to breast cancer susceptibility in Chinese Han women.

Histological and clinical characteristics of malignant giant cell tumor of bone.

Malignant giant cell tumors of bone (MGCTB) are rare, and the diagnosis can be difficult due to the occurrence of a variety of malignant tumors containing giant cells. To better understand its clinicopathological features, we have reviewed our experience with 17 cases of MGCTB. Five cases were primary malignant giant cell tumor of bone (PMGCTB), and 12 cases were giant cell tumors of bone initially diagnosed as benign but malignant in a recurrent lesion (secondary MGCTB, SMGCTB). The patients included six women and 11 men (age ranged from 17 to 52 years; mean, 30.5 years). The tumor arose in the femur (six cases), the tibia (seven cases), the humerus (three cases), and the fibula (one case). Microscopically, PMGCTB showed both conventional giant cell tumor and malignant sarcoma features. SMGCTB were initially diagnosed as conventional giant cell tumor of bone, the recurrent lesion showing malignant features. Histologically, the malignant components included osteosarcoma (11 cases), undifferentiated high-grade pleomorphic sarcoma (two cases), and fibrosarcoma (four cases). SMGCTB cases showed strong expression of p53. Follow-up information revealed that four patients died of lung metastasis, two patients are alive with lung metastases, and 11 patients are alive without tumor. MGCTB should be considered as a high-grade sarcoma. It must be distinguished from GCTB and other malignant tumors containing giant cells. p53 might play a role in the malignant transformation of GCTB.

Genetic polymorphisms in AURKA and BRCA1 are associated with breast cancer susceptibility in a Chinese Han population.

Centrosome defects can result in aneuploidy and genomic instability, and have important implications for breast cancer development. The Aurora-A and BRCA1 proteins interact and both are strongly involved in centrosome regulation. Genetic variants in these two genes may have an effect on breast cancer development. Here, we report a comprehensive single nucleotide polymorphism (SNP) and haplotype-tagging association study on these two genes in 1334 breast cancer cases and 1568 unaffected controls among the Chinese Han population. Apart from a missense SNP, rs2273535 (Phe31Ile), and a probable risk SNP, rs2064863, six htSNPs were analysed in three high-LD blocks of AURKA spanning from 10 kb upstream to 2 kb downstream of AURKA. For BRCA1, six htSNPs were analysed in a large high-LD region covering 98 kb (10 kb was extended to each end of BRCA1). The results showed that four SNPs in AURKA (data in recessive model, rs2273535: OR = 2.19, 95% CI = 1.03-4.66, p = 0.0422; rs2298016: OR = 0.38, 95% CI = 0.18-0.82, p = 0.0141; rs6024836: OR = 1.54, 95% CI = 1.18-2.00, p = 0.0014; rs10485805: OR = 0.68, 95% CI = 0.47-0.98, p = 0.0380) and one SNP in BRCA1 (rs3737559, dominant model OR = 1.35, 95% CI = 1.11-1.64, p = 0.0030) were associated with breast cancer susceptibility. After correction for multiple comparisons (FDR = 0.05), only rs6024836 and rs3737559 remained significant. Two haplotypes (CC of block 2, OR = 20.74, 95% CI = 4.35-98.88, p = 0.0001; GG of block 3, OR = 1.32, 95% CI = 1.12-1.56, p = 0.0010) and one diplotype (AG-GG of block 3, OR = 1.63, 95% CI = 1.18-2.26, p = 0.0031) within AURKA showed strong associations with breast cancer risk. One haplotype of BRCA1 (CTGTTG, OR = 1.30, 95% CI = 1.06-1.59, p = 0.0118) was also associated with breast cancer risk. However, women harbouring both at-risk genotypes of Aurora-A and BRCA1 were at a slightly increased risk compared with those harbouring either at-risk variant alone. Common genetic variants in the AURKA and BRCA1 genes may contribute to breast cancer development.

Expression of cell-cycle regulatory proteins BUBR1, MAD2, Aurora A, cyclin A and cyclin E in invasive ductal breast carcinomas.

Cyclin A, cyclin E, BUBR1, MAD2 and Aurora A are all cell-cycle regulatory proteins and have been proven to play crucial roles in carcinogenesis. However, their expression patterns in invasive ductal breast carcinoma (IDBC) are controversial and unclear. In this study, we examined the expression status of these candidate proteins in a set of 117 invasive ductal carcinomas, and evaluated their associations with known clinicopathological parameters and the expressions of estrogen receptor, progesterone receptor, Ki-67 and Her-2. Univariate and multivariate data analyses both displayed that positive BUBR1 expression was associated with a high Ki-67 labeling index, and negative MAD2 expression was associated with Her-2 overexpression. Positive BUBR1 expression was also associated with a high histological tumor grade in univariate analysis, but not in multivariate analysis. In addition, high Aurora A expression was weakly associated with lymph node metastasis, and cyclin A was strongly associated with the expression of cyclin E in both univariate and multivariate models. In conclusion, this study suggests that evaluation of BUBR1, MAD2 and Aurora A expression levels is likely to improve accuracy of prognostic predictions in IDBC.