A Cost-Effective and Labor-Saving Method for Detecting Human Leukocyte Antigen B27 Status via Sequence-Encoded Fluorescence Amplification Assay.

Identification of human leukocyte antigen B27 (HLA-B27) by flow cytometry (FCM) has been widely applied in clinical practice for auxiliary diagnosis of ankylosing spondylitis (AS). However, FCM requires freshly prepared samples and relies on expensive equipment, reagents, and an experienced operator. To provide a cheaper and more convenient method for HLA-B27 detection, we proposed a new method termed sequence-encoded fluorescence amplification assay (SEFA), which specially recognized sequences of HLA-B27 gene (HLA-B∗27) covering current common subtypes in a single closed tube. SEFA could detect as low as 10 pg (equal to 3 copies) genomic DNA per reaction and distinguish HLA-B∗27 from other HLA-B alleles with highly similar sequences. A total of 288 clinical samples were tested by SEFA, including 181 patients with AS and 107 healthy controls. Compared with the detection results from FCM, two controversial samples of patients with AS were obtained and further confirmed to be consistent with SEFA by Sanger sequencing, indicating that our method was more accurate than FCM. Moreover, SEFA could detect HLA-B27 status by using supernatant from crude extract of 10-µL blood without commercial reagents. Overall, SEFA has the potential to be an alternative for HLA-B27 identification with the advantage of convenience and low cost, especially suitable for early diagnosis of AS in areas with limited medical resources.

Molecular profiles of single circulating tumor cells from early breast cancer patients with different lymph node statuses.

BACKGROUND: Characterization of early breast cancer circulating tumor cells (CTCs) may provide valuable information on tumor metastasis. METHODS: We used immunomagnetic nanospheres to capture CTCs from the peripheral blood of eight early breast cancer patients and then performed single-cell RNA sequencing using our proposed bead-dd-seq method. RESULTS: CTCs displayed obvious tumor cell characteristics, such as the activation of oxidative stress, proliferation, and promotion of metastasis. CTCs were clustered into two subtypes significantly correlated with the lymph node metastasis status of patients. CTCs in subtype 1 showed a strong metastatic ability because these CTCs have the phenotype of partial epithelial-mesenchymal transition and enriched transcripts, indicating breast cancer responsiveness and proliferation. Furthermore, DNA damage repair pathways were significantly upregulated in subtype 1. We performed in vitro and in vivo investigations, and found that cellular oxidative stress and further DNA damage existed in CTCs. The activated DNA damage repair pathway in CTCs favors resistance to cisplatin. A checkpoint kinase 1 inhibitor sensitized CTCs to cisplatin in mouse models of breast cancer metastasis. CONCLUSION: The present study dissects the molecular characteristics of CTCs from early-stage breast cancer, providing novel insight into the understanding of CTC behavior in breast cancer metastasis.

Multiplexed and Rapid AST for Escherichia coli Infection by Simultaneously Pyrosequencing Multiple Barcodes Each Specific to an Antibiotic Exposed to a Sample.

Antimicrobial susceptibility testing (AST) is an effective way to guide antibiotic selection. However, conventional culture-based phenotypic AST is time-consuming. The key point to shorten the test is to quantify the small change in the bacterial number after the antibiotic exposure. To achieve rapid AST, we proposed a combination of multiplexed PCR with barcoded pyrosequencing to significantly shorten the time for antibiotic exposure. First, bacteria exposed to each antibiotic were labeled with a unique barcode. Then, the pool of the barcoded products was amplified by PCR with a universal primer pair. Finally, barcodes in the amplicons were individually and quantitatively decoded by pyrosequencing. As pyrosequencing is able to discriminate as low as 5% variation in target concentrations, as short as 7.5 min was enough for cultivation to detect the susceptibility of Escherichia coli to an antibiotic. The barcodes enable more than six kinds of drugs or six kinds of concentrations of a drug to be tested at a time. The susceptibility of 6 antibiotics to 43 E. coli-positive samples from 482 clinical urine samples showed a consistency of 99.3% for drug-resistant samples and of 95.7% for drug-sensitive samples in comparison with the conventional method. In addition, the minimum inhibitory concentration (MIC) of 29 E. coli samples was successfully measured. The proposed AST is dye free (pyrosequencing), multiplexed (six antibiotics), fast (a half-working day for reporting the results), and able to detect the MIC, thus having a great potential for clinical use in quick antibiotic selection.

Galectin-3 enhances trastuzumab resistance by regulating cancer malignancy and stemness in HER2-positive breast cancer cells.

PURPOSE: The aim of this study was to explore the role of galectin-3 in human epidermal growth factor receptor 2 (HER2)-positive breast cancer cells and the potential mechanism. METHODS: Kaplan-Meier (KM)-plot and The Cancer Genome Atlas (TCGA) databases were used to study the role of galectin-3 in the prognosis of HER2-positive breast cancer. The effects of galectin-3 on cell proliferation, migration, invasion, and colony formation ability in HER2-positive breast cancer cells were examined. The relationship between galectin-3 and important components in the HER2 pathways, including HER2, epidermal growth factor receptor (EGFR), protein kinase B (AKT), and phosphatase and tensin homolog (PTEN), was further studied. Lentivirus and CRISPR/Cas9 were used to construct stable cell lines. Cell counting kit-8 (CCK-8) and apoptosis assays were used to study the relationship between galectin-3 and trastuzumab. The effect of galectin-3 on cell stemness was studied by mammosphere formation assay. The effects of galectin-3 on stemness biomarkers and the Notch1 pathway were examined. Tumorigenic models were used to evaluate the effects of galectin-3 on tumorigenesis and the therapeutic effect of trastuzumab in vivo. RESULTS: HER2-positive breast cancer patients with a high expression level of LGALS3 (the gene encoding galectin-3) messenger RNA (mRNA) showed a poor prognosis. Galectin-3 promoted cancer malignancy through phosphoinositide 3-kinase (PI3K)/AKT signaling pathway activation and upregulated stemness by activating the Notch1 signaling pathway in HER2-positive breast cancer cells. These two factors contributed to the enhancement of trastuzumab resistance in cells. Knockout of LGALS3 had a synergistic therapeutic effect with trastuzumab both in vitro and in vivo. CONCLUSIONS: Galectin-3 may represent a prognostic predictor and therapeutic target for HER2-positive breast cancer.

Lipid membrane anchoring and highly specific fluorescence detection of cancer-derived exosomes based on postfunctionalized zirconium-metal-organic frameworks.

Cancer-derived exosomes carry a variety of important biomarkers specific to the formation, invasion and metastasis of tumor tissue. Dynamic monitoring of exosomes originated from cancer cells has clinical significance. Here we proposed a novel method to employ zirconium-metal-organic frameworks (Zr-MOFs) for extracting and identifying exosomes from blood. At first UiO-66 was magnetically modified as the adsorbent to anchor exosomes by forming Zr-O-P bonds. Then UiO-66-NH2 modified with anti-EpCAM was used to construct the fluorescent probe to recognize the extracted EpCAM-positive exosomes by forming a "MOF-exosome-MOF" structure. The proposed fluorescence detection method was evaluated by quantifying MCF-7 cell-derived exosomes at the concentration as low as 16.72 particles/µl. This method was successfully applied to analyze exosomes in the plasma samples from healthy donors and breast cancer patients, demonstrating that our method might have a great potential in assisting the early diagnosis and in dynamically monitoring the efficacy of cancer treatment. We believe that the method could be extended to the detection of other biomarkers in exosomes derived from cancer cell.

Postsynthetic Modification of the Magnetic Zirconium-Organic Framework for Efficient and Rapid Solid-Phase Extraction of DNA.

In recent years, several approaches have been applied to modify metal-organic frameworks (MOFs) owing to their excellent structural tunability such as higher extraction efficiency than that of primitive crystals. Herein, Zr-based MOFs (UiO-66-NH2) with a suitable size modulated by acetic acid were successfully synthesized for effective DNA extraction. The bonding conformations and adsorption mechanism indicated a high affinity between UiO-66-NH2 and the DNA molecules. Furthermore, Fe3O4 nanoparticles were immobilized on the UiO-66-NH2 surface to allow MOFs with magnetism. The magnetic zirconium-organic framework (MZMOF) retained the intact structure of MOFs and simplified subsequent extraction operations. In the DNA recovery investigation, MZMOF showed high recovery efficiency for both short-stranded DNA (90.4%) and pseudovirus DNA (95.1%). In addition, it showed superior DNA extraction efficiency from plasma (57.6%) and swab preservation solution (86.5%). The prepared MZMOF was employed for highly specific extraction of viral DNA and cfDNA from samples. To further simplify the extraction process, MZMOF was applied to immiscible phase filtration assisted by a surface tension (IFAST) chip for facilitating rapid DNA extraction with sensitive point-of-care testing. The developed MZMOF-based extraction method has significant potential for increasing the demand for rapid and efficient nucleic acid extraction.

Circulating tumour cells at baseline and late phase of treatment provide prognostic value in breast cancer.

To determine the prognostic value of the timing of circulating breast tumour cell measurement during treatment, peripheral blood from 164 patients with breast disease was collected. Circulating tumour cells (CTCs) were enriched by using immunomagnetic nanospheres (IMNs) and were identified by using immunofluorescent staining. The CTC shows nuclear-positive, EpCAM-positive, CK19-positive, and CD45-negative. Patients with CTC positivity (> 19/7.5 mL blood) had shorter progression-free survival (PFS) and overall survival (OS) than those with negative results (≤ 19/7.5 mL blood) at baseline. Surgery caused an increase in the number and prevalence of CTCs, and the effect disappeared on day 14 after surgery. During adjuvant chemotherapy, CTCs detected before therapy was only correlated with PFS; however, CTCs at the end of adjuvant chemotherapy were correlated with both PFS and OS. The PFS and OS of the CTC-positive group were significantly shorter than those of the CTC-negative group at the end-point follow-up visit. The prognostic value of CTCs at different measurement time points was demonstrated during breast cancer treatment. Surgery and chemotherapy affected the prevalence of CTCs, leading to different prognostic relevance of CTCs at different treatment stages. CTCs detected at baseline or in the late phase of treatment are preferable for prognosis.