EVs are released by all cells and carry molecular cargo that can be used to assess the identity and state of their cell of origin, making them attractive targets for liquid biopsy. However, EVs are also very small, heterogeneous, and difficult to measure, posing challenges to their rigorous and reproducible measurement. Recent advances in instruments, reagents, and assays are enabling the quantitative analysis of EVs and their cargo with high throughput, sensitivity, and molecular resolution.

Urinary extracellular vesicles (EVs) are great resources for multi-omic investigation on specific biomarkers for diagnostic and prognostic analysis of MIBC. We identified urinary EV-based molecular fingerprints for detection of MIBC and predicting their therapeutic response. The ability to predict best responses to NAC could significantly improve oncological outcomes and decreased effects on patients’ quality of life.

In this talk, I summarize our lab’s recent progress in this exciting field and highlight the versatility of acoustofluidic tools for biomedical applications through many unique examples, ranging from the development of high-purity, high-yield methods for the separation of circulating biomarkers such as small extracellular vesicles (sEVs) and circulating tumor cells (CTCs), to our newly developed harmonic acoustics for a non-contact, dynamic, selective (HANDS) particle manipulation platform, which enables the reversible assembly and disassembly of cells. These acoustofluidic devices can precisely manipulate objects across 7 orders of magnitude (from a few nanometers to a few centimeters). Thanks to these favorable attributes (e.g., versatility, precision, and biocompatibility), acoustofluidic devices harbor enormous potential in becoming a leading technology for a broad range of applications, playing a critical role for translating innovations in technology into advances in biology and medicine.

The UCLA Liquid Biopsy Laboratory has developed an IVD test that utilizes extracellular vesicles (EVs) to detect systemic disease burden with great sensitivity. This novel test can quantify tumor EVs using less than 1mL plasma and a 2-hour workflow, by utilizing a proprietary Click Chemistry-mediated EV enrichment followed by downstream EV quantification using PCR. Our first clinical test is specifically designed to distinguish hepatocellular carcinoma (HCC) from at-risk liver cirrhosis, and has been validated through a phase II biomarker study.

The metastatic spread of cancer is achieved by the haematogenous dissemination of CTCs. However, the temporal dynamics dictating the generation of metastasis-competent CTCs are largely uncharacterised and it is often assumed that CTCs are constantly shed from growing tumours. Here I will present data showing a striking and unexpected pattern of CTC generation dynamics, highlighting that most spontaneous CTC intravasation events occur during sleep.

• Breast cancer spreads during sleep
• Timing of biopsy collection can be critical for an accurate cancer diagnosis
  
• Chronotherapy could lead to more effective disease management in cancer patients?
  

Using a plasma-based BRAF mutation detection system allowed for rapid detection of BRAF mutation in a case of metastatic melanoma, enabling same-day initiation of targeted therapy without the need for invasive biopsy. This case involved a hospitalized 53-year-old male with rapidly deteriorating clinical status due to extensive melanoma metastases, and BRAF mutation status was unknown. Targeted treatment with dabrafenib and trametinib resulted in swift improvement, allowing for discharge within a week and significant clinical improvement over the following weeks. Harnessing this type of technology can improve outcomes in urgent clinical situations where timely decision-making is critical.

Our laboratory has found that colorectal cancer (CRC) cells resistant to oxaliplatin chemotherapy become more sensitive to TRAIL-mediated cell death. This increased sensitivity is due to augmented death receptor 4 (DR4) localization within tightly packed, cholesterol-enriched regions in the cell membrane known as lipid rafts. This mechanism of DR4 translocation into lipid rafts within oxaliplatin-resistant cells is found to be through increased palmitoylation of DR4. In the circulation, these cells experience activation of the mechanosensitive ion channel Piezo1, causing an influx of calcium that can be exploited with novel therapies.

Circulating tumor cell clusters (CTCs) are significantly associated with poor prognosis due to enhanced seeding of metastases compared to single cells, suggesting that cell-cell adhesion mechanisms are potential targets for the prevention and treatment of metastases. Using preclinical mouse models and a liquid 3D cell culture paradigm, we recently discovered that the pro-inflammatory prostaglandin signaling pathway stabilizes epithelial cadherin adhesion proteins and can be targeted with several clinically approved pharmacological agents.

We developed a novel microfluidic device for not only efficient capture but also controlled release of heterogenous circulating tumor cells (CTCs) with high viability. Capturing the CTC heterogeneity was found to greatly enhance the CTC culturability in vitro for their further use and analysis. Moreover, we developed a novel one-cell culture technology to isolate and culture the rare metastatic subpopulation of CTCs as a potential target to combat cancer metastasis.

• Cost-effectiveness
• Post-test decision-making  
• Patient compliance    
• Rare cancer detections

Circulating tumor cells (CTCs) and cell free DNA (cfDNA) are considered types of liquid biopsy for cancer diagnosis and monitoring. In this study, we analyzed both CTCs and cfDNA from a small cohort of cancer patients with brain metastasis and also compared with the single cell transcriptome from the brain metastasis. The goal is to evaluate whether CTCs or cfDNA can be used to infer brain metastasis prediction or signature.

Circulating tumor cells (CTCs) represent an especially aggressive subset of cancer cells, capable of causing metastasis and progressing the disease. Due to the genetic instability and dynamic changes a tumor undergoes throughout treatment, real-time CTC monitoring of tumor evolution could help continually optimize a patient’s treatment plan, improving patient outcome. A workflow for rapid single cell profiling of CTCs for simultaneous gene expression and mutation detection will be presented. The single-cell resolution enables the early detection of emerging rare clones that could lead to therapeutic resistance from a routine blood draw, allowing for more predictive analysis of targeted therapy response.