Rapid detection of EGFR mutation in CTCs based on a double spiral microfluidic chip and the real-time RPA method.

Circulating tumor cells (CTCs) are cells shed from primary or metastatic tumors and spread into the peripheral bloodstream. Mutation detection in CTCs can reveal vital genetic information about the tumors and can be used for "liquid biopsy" to indicate cancer treatment and targeted medication. However, current methods to measure the mutations in CTCs are based on PCR or DNA sequencing which are cumbersome and time-consuming and require sophisticated equipment. These largely limited their applications especially in areas with poor healthcare infrastructure. Here we report a simple, convenient, and rapid method for mutation detection in CTCs, including an example of a deletion at exon 19 (Del19) of the epidermal growth factor receptor (EGFR). CTCs in the peripheral blood of NSCLC patients were first sorted by a double spiral microfluidic chip with high sorting efficiency and purity. The sorted cells were then lysed by proteinase K, and the E19del mutation was detected via real-time recombinase polymerase amplification (RPA). Combining the advantages of microfluidic sorting and real-time RPA, an accurate mutation determination was realized within 2 h without professional operation or complex data interpretation. The method detected as few as 3 cells and 1% target variants under a strongly interfering background, thus, indicating its great potential in the non-invasive diagnosis of E19del mutation for NSCLC patients. The method can be further extended by redesigning the primers and probes to detect other deletion mutations, insertion mutations, and fusion genes. It is expected to be a universal molecular diagnostic tool for real-time assessment of relevant mutations and precise adjustments in the care of oncology patients.

Enhanced Separation Efficiency and Purity of Circulating Tumor Cells Based on the Combined Effects of Double Sheath Fluids and Inertial Focusing.

Circulating tumor cells (CTCs) play a crucial role in solid tumor metastasis, but obtaining high purity and viability CTCs is a challenging task due to their rarity. Although various works using spiral microchannels to isolate CTCs have been reported, the sorting purity of CTCs has not been significantly improved. Herein, we developed a novel double spiral microchannel for efficient separation and enrichment of intact and high-purity CTCs based on the combined effects of two-stage inertial focusing and particle deflection. Particle deflection relies on the second sheath to produce a deflection of the focused sample flow segment at the end of the first-stage microchannel, allowing larger particles to remain focused and entered the second-stage microchannel while smaller particles moved into the first waste channel. The deflection of the focused sample flow segment was visualized. Testing by a binary mixture of 10.4 and 16.5 µm fluorescent microspheres, it showed 16.5 µm with separation efficiency of 98% and purity of 90% under the second sheath flow rate of 700 µl min-1. In biological experiments, the average purity of spiked CTCs was 74% at a high throughput of 1.5 × 108 cells min-1, and the recovery was more than 91%. Compared to the control group, the viability of separated cells was 99%. Finally, we validated the performance of the double spiral microchannel using clinical cancer blood samples. CTCs with a concentration of 2-28 counts ml-1 were separated from all 12 patients' peripheral blood. Thus, our device could be a robust and label-free liquid biopsy platform in inertial microfluidics for successful application in clinical trials.

Establishment of reference intervals for serum [-2]proPSA (p2PSA), %p2PSA and prostate health index in healthy men.

BACKGROUND: Prostate cancer (PCa) is the second most common cancer among men worldwide. Recent research has identified [-2]proPSA (p2PSA), %p2PSA and prostate health index (phi) as new biomarkers for the early diagnosis and grading of PCa. However, few studies have used these parameters in a healthy population. In this study, we aimed to establish reference intervals (RIs) for p2PSA, %p2PSA and phi in healthy men based on age stratification. METHODS: Between April 2016 and March 2018, healthy subjects were recruited. Healthy men were then stratified into four age groups: <40 years, 40-49 years, 50-59 years and ≥60 years. Total PSA (tPSA), free PSA (fPSA), %fPSA, p2PSA, %p2PSA and phi were measured and RIs were established for p2PSA, %p2PSA and phi. RESULTS: In total, 732 healthy men were used for analysis. The RIs of phi were 9.77-48.44 for <40 years of age, 9.85-65.28 for 40-49 years of age, 9.98-39.72 for 50-59 years of age and 8.16-40.76 for ≥60 years of age. The reference values at the age of 40-49 years were generally higher than those at ≥60 years of age. CONCLUSIONS: Age-specific RIs for p2PSA, %p2PSA and phi were established in this study. This first set of established RIs will be invaluable for physicians to make precise medical decisions and carry out appropriate medical interventions.

The effects of SP110's associated genes on fresh cavitary pulmonary tuberculosis in Han Chinese population.

SP110 is a promising anti-Mycobacterium tuberculosis (MTB) gene. To investigate the effects of SP110 and its associated genes, i.e., MYBBP1A and RELA, on pathological progression of MTB infection, an association study with 424 patients of fresh pulmonary tuberculosis (PTB) and 424 healthy controls was performed. Moreover, classification and regression tree and multifactor dimensionality reduction were employed to explore the effects of gene-gene interactions on cavitary PTB. The results indicated that both the heterozygous genotype GC and homozygous genotype CC in rs3809849 had significant effects on the risk of PTB (OR 1.42, 95 % CI 1.06-1.92, p 0.019; OR 1.55, 95 % CI 1.04-2.33, p = 0.033, respectively), and heterozygous genotype CT in rs9061 also had similar effects (OR 1.43, 95 % CI 1.07-1.90, p = 0.014). The rs3809849 and rs9905742 in MYBBP1A were also significantly associated with cavitary PTB (p = 0.00046 and 0.039, respectively), while rs9061 in SP110 had no such association (p = 0.06931) except its significant association with non-cavitary PTB (p = 0.0093). The interaction of MYBBP1A and RELA had significant effect on cavitary PTB (OR 4.24, 95 % CI 1.44-12.49, p = 0.005). These suggest that MYBBP1A instead of SP110 may be a genetic risk factor for cavitary PTB and play important effects on its whole progress.

Identification of genetic associations of SP110/MYBBP1A/RELA with pulmonary tuberculosis in the Chinese Han population.

Genetic factors play important roles in the development of tuberculosis (TB). SP110 is a promising candidate target for controlling TB infections. However, several studies associating SP110 single nucleotide polymorphisms (SNPs) with TB have yielded conflicting results. This may be partly resolved by studying other genes associated with SP110, such as MYBBP1A and RELA. Here, we genotyped 6 SP110 SNPs, 8 MYBBP1A SNPs and 5 RELA SNPs in 702 Chinese pulmonary TB patients and 425 healthy subjects using MassARRAY and SNaPshot methods. Using SNP-based analysis with Bonferroni correction, rs3809849 in MYBBP1A [Pcorrected (cor) = 0.0038] and rs9061 in SP110 (Pcor = 0.019) were found to be significantly associated with TB. Furthermore, meta-analysis of rs9061 in East Asian populations showed that the rs9061 T allele conferred significant risk for TB [P = 0.002, pooled odds ratio (OR), 1.24, 95% confidence interval (CI) = 1.08-1.43]. The MYBBP1A GTCTTGGG haplotype and haplotypes CGACCG/TGATTG within SP110 were found to be markedly and significantly associated with TB (P = 2.00E-06, 5.00E-6 and 2.59E-4, respectively). Gene-based analysis also demonstrated that SP110 and MYBBP1A were each associated with TB (Pcor = 0.011 and 0.035, respectively). The logistic regression analysis results supported interactions between SP110 and MYBBP1A, indicating that subjects carrying a GC/CC genotype in MYBBP1A and CC genotype in SP110 possessed the high risk of developing TB (P = 1.74E-12). Our study suggests that a combination of SP110 and MYBBP1A gene polymorphisms may serve as a novel marker for identifying the risk of developing TB in the Chinese Han population.

[Promoter activity of B-cell maturation antigen gene in mice].

AIM: To investigate the promoter activity of BCMA gene 5'-flanking regionfor the study the regulation mechanism of BCMA expression. METHODS: Luciferase reporter plasmids containing 5'-flanking region of BCMA gene and serial deletions of the fragment were constructed. The luciferase expression was observed after these reporters were transfected into J558L, 293T and Hela cells. RESULTS: The highest transcriptional activation was expressed in pGL3-B157 reporter, followed by pGL3-B607, pGL3-B359, pGL3-B93, and pGL3-B820 in sequence. The highest transcriptional activation was in J558L cell. CONCLUSION: The 5'-flanking sequence from -820 to +145 bp of BCMA is of promoter activity. Serial deletion analysis of the promoter region of BCMA gene suggests the sequence from -93 to +145 could be a core promoter region.