Aptamer-polymer functionalized silicon nanosubstrates for enhanced recovered circulating tumor cell viability and in vitro chemosensitivity testing

Capturing and releasing of hepatocellular carcinoma EpCAM+ and EpCAM- circulating tumor cells based on photosensitive intelligent nanoreactor

Epithelial cell adhesion molecule negative circulating tumor cells (EpCAM- CTCs) and EpCAM positive CTCs (EpCAM + CTCs) have different biological characteristics. Therefore, the isolation of EpCAM + CTCs and EpCAM- CTCs is a new strategy to study the heterogeneity of tumor cells. The azobenzene group (Azo) and cyclodextrin (CD) composite system forms a photosensitive molecular switch based on the effect of external light stimulation. We used the technology of specifically capturing CTCs using anti-EpCAM and aptamers functionalized nanochips. Both anti-EpCAM and aptamers can be connected to Azo through the 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) modification process. Therefore, we assume that a photosensitive intelligent nanoreactor (PSINR) modified with anti-EpCAM can be used to capture EpCAM + CTCs; Utilizing the characteristics of aptamer and ligand binding, a PSINR modified with aptamer is used to capture EpCAM- CTCs; Then, two PSINRs were separated and stimulated with light to release EpCAM + CTCs and EpCAM- CTCs, respectively. Based on the isolation the EpCAM + CTCs and EpCAM- CTCs, we expected to reveal the key biological mechanisms of tumor recurrence, metastasis and drug resistance, and make the individualized treatment of liver cancer more targeted, safe and effective, and provide a new basis for the final realization of accurate and individualized treatment of tumors.

Mini-patient-derived xenograft assay based on microfluidic technology promises to be an effective tool for screening individualized chemotherapy regimens for advanced non-small cell lung cancer

Patient-derived xenograft (PDX) assay has been widely used in preclinical research in patients with multidrug-resistant lung cancer. One hundred patients with non-small cell lung cancer (NSCLC) were divided into MiniPDX group and conventional group, with 50 cases in each group. The MiniPDX assay was established by enriching high-purity tumor cells using microfluidic technology to detect the drug sensitivity of NSCLC cells. All patients underwent conventional computed tomography (CT) scans of lung and mediastinum at baseline and during follow-up. Kaplan-Meier method was used to compare the overall survival and progression-free survival of two groups. The sensitivity of the same drug in different tumor xenograft varied greatly. The overall survival, progression-free survival, and clinical benefit rate of patients in the MiniPDX-guided chemotherapy group were significantly longer than those in the conventional chemotherapy group. MiniPDX assay may be an effective tool for screening chemotherapy regimens in NSCLC patients.

A novel label-free terbium(iii)-aptamer based aptasensor for ultrasensitive and highly specific detection of acute lymphoma leukemia cells

Acute leukemia is a malignant clonal disease of hematopoietic stem cells with a high prevalence and mortality rate. However, there are no efficient tools to facilitate early diagnosis and treatment of leukemia. Therefore, development of new methods for the early diagnosis and prevention of leukemia, especially non-invasive diagnosis at the cellular level, is imperative. Here, a label-free signal-on fluorescence aptasensor based on terbium(iii)-aptamer (Tb³⁺-apt) was applied for the detection of leukemia. The aptamer sensitizes the fluorescence of Tb³⁺ and forms the strong fluorescent Tb³⁺-apt probe. The target cells, the T-cell acute lymphoblastic leukemia cell line (CCRF-CEM) combined with the Tb³⁺-apt probe to form the Tb³⁺-apt-CEM complex, were removed by centrifugation, and the supernatant containing a small amount of the Tb³⁺-apt probe was detected using a fluorescence spectrophotometer. The logarithm of cell concentration showed a good linear relationship (R² = 0.9881) with the fluorescence signal. The linear range for CCRF-CEM detection was 5-5 × 10⁶ cells per ml, while the detection limit was 5 cells per ml of the binding buffer. Clinical samples were collected from 100 cases, and the specificity and positive rates detected by this method were up to 94% and 90%, respectively. Therefore, a single-stranded DNA-sensitized terbium(iii) luminescence method diagnostic was developed which is rapid, sensitive, and economical and can be used for diagnosis of various types of leukemia at the early stage.

Capture and biological release of circulating tumor cells in pancreatic cancer based on peptide-functionalized silicon nanowire substrate

Background

Efficient and precise circulating tumor cells' (CTCs) capture and release with minimal effect on cell viability for CTCs' analysis are general requirements of CTCs' detection device in clinical application. However, these two essential factors are difficult to be achieved simultaneously.

Methods

In order to reach the aforementioned goal, we integrated multiple strategies and technologies of staggered herringbone structure, nanowires' substrate, peptides, enzymatic release, specific cell staining, and gene sequencing into microfluidic device and the sandwich structure peptide-silicon nanowires' substrate was termed as Pe-SiNWS.

Results

The Pe-SiNWS demonstrated excellent capture efficiency (95.6%) and high release efficiency (92.6%). The good purity (28.5%) and cell viability (93.5%) of CTCs could be obtained through specific capture and biological release by using Pe-SiNWS. The good purity of CTCs facilitated precise and quick biological analysis, and five types of KRAS mutation were detected in 16 pancreatic cancer patients but not in healthy donors.

Conclusion

The results proved that the effective capture, minor damage release, and precise analysis of CTCs could be realized simultaneously by our novel strategy. The successful clinical application indicated that our work was anticipated to open up new opportunities for the design of CTC microfluidic device.

Detecting EGFR mutations and ALK/ROS1 rearrangements in non-small cell lung cancer using malignant pleural effusion samples

Background

The study was conducted to evaluate the feasibility of using malignant pleural effusion (MPE) as a substitute specimen for genetic testing and to determine the significance of genetic profiling of MPE tumor cells to monitor non‐small cell lung cancer (NSCLC) progression and therapeutic response.

Methods

We selected 168 NSCLC patients with MPE. We extracted MPE and enriched tumor cells using a custom‐designed device. EGFR mutations and ALK/ROS1 fusions were then detected by quantitative real‐time PCR, and the results were used to guide targeted therapy. We investigated drug responses through imaging.

Results

MPE tumor cells were detected in all patients. EGFR mutations and ALK/ROS1 rearrangements were detected in biopsy samples, treated MPE, and untreated MPE. We found that treated MPE had higher sensitivity and specificity than biopsy or untreated MPE. Among the 26 EGFR inhibitor patients, 13 showed a partial response, 7 had progressive disease, and 6 showed stable disease. Among the 16 patients that received ALK/ROS1 inhibitors, 8 had a partial response, 4 had progressive disease, and 4 showed stable disease.

Conclusion

Our study provides a new, less invasive, and highly repeatable method of analyzing MPE tumor cells in NSCLC that facilitates precision medicine and genetic testing.