NEW METHODS FOR LIQUID BIOPSIES
The Lang Research group in collaboration with Beebe Research Group in the Department of Biomedical Engineering have developed several technologies to isolate and study circulating tumor cells from patients with cancer, including the Versatile Exclusion-based Rare Sample Analysis (VERSA) and Automated VERSA. Using this technology, we have developed a robust, simplified assay for integrated capture and processing of CTCs. Known as Exclusion-based Sample Preparation (ESP), this simplified technology is a non-dilutive, non-destructive process for analysis of rare cell populations with improved sensitivity and retention over tube-based methods. ESP is accomplished through the formation of virtual barriers by leveraging the unique properties of surface tension at the microscale to capture target cell populations which are magnetically pulled between reagents with paramagnetic particles (PMPs). ESP technology has been optimized for high performance CTC extraction through years of collaboration between teams of cancer biologists in the Lang group and biomedical engineers in the Beebe group into a fully automated sample processing system offering multiplexed outputs: from CTC extraction to protein analysis and both mRNA and DNA isolation.
BIOMARKER DEVELOPMENT
The Lang Research group works to develop biomarkers with a goal of better directing patient treatment. The art of medicine often involves decisions about what the best course of treatment may be for a patient. Upon diagnosis with metastatic castrate resistant prostate cancer (CRPC), a patient and their physician often decide whether to treat with Androgen Receptor Signaling Inhibitor (ARSI) targeted therapy or with chemotherapy. To aid in these decisions we have developed an assay using liquid biopsies. We demonstrate that a transcriptional profile that suggests a highly active AR detectable in CTCs can serve as an independent prognostic marker in patients with metastatic prostate cancer and can be used to identify the emergence of multiple ARSI resistance mechanisms. We are currently investigating this assay in additional prospective trials.
Additionally, we are using liquid biopsies to help target and/or monitor treatment with other targeted therapies such as sacituzumab govitecan which is an antibody drug conjugate (ADC) that targets tumors expressing the Trop-2 protein. We are currently assessing the prevalence of Trop-2 in CTCs of patients with prostate cancer and changes to this biomarker after treatment with sacituzumab govitecan. Additionally, we are collaborating with the LeBeau Research group to study additional targets for development of new ADCs.
The Lang Research Group are currently working to broaden this assay to assess multiple aggressive cancer subtypes including neuroendocrine prostate cancer (NEPC). NEPC is a type of fast growing prostate cancer often characterized by a decrease in the AR pathway activity and decreased response to therapy. NEPC is usually diagnosed with a biopsy of a metastatic site. Here we aim to use gene expression analysis from CTCs to identify patients with this aggressive type of prostate cancer without invasive biopsies. Additionally, treatment of CRPC with ARSI has been shown to increase the incidence of NEPC. With liquid biopsies, we are able to monitor changes in methylation of DNA, gene expression, and cell free DNA over time to learn more about changes in the tumor that may lead to the development of NEPC.
TUMOR MICROENVIRONMENT
The Lang Research Group is focusing on the role of tumor microenvironmental interactions in prostate cancer pathogenesis, progression, and therapeutic resistance. To reflect primary prostate cancer heterogeneity and multi-lateral interactions more faithfully within the TME, we have been developing novel model systems including patient-derived cancer organoids (PDCOs) and tissue slice cultures from clinical specimen. Integrated microfluidic platforms such as the Stacks and LumeNEXT systems allow us to reconstitute multi-cellular TME networks and study cellular interactions between prostate cancer cells, stromal components, and immune infiltrates in vitro or ex vivo. These integrated 3D platforms enable orthogonal analysis such as capturing cellular interactions by confocal microscopy, single-cell investigations by multi-parameter flow cytometry, and analysis of the secretome, transcriptomic and epigenomic profiles within the multi-cellular networks.
Our TME studies aim to identify biomarker patterns that associate with tumor progression, invasion, immune evasion, and therapeutic resistance in vivo, in clinical trial settings. The lab-on-chip models allow us to address potential tumor progression mechanisms in the multi-cellular TME models.
Epigenetic regulation within the TME has been identified as a potential driver of immune evasion in primary prostate cancer. We are specifically interested in dissecting potential epigenetic mechanisms that lead to MHC I deficiencies on the tumor cells allowing immune evasion. In our model systems, we study the potential of targeting MHC I deficiency with epigenetic modifying agents to restore surface HLA availability and reinstate CD8 T cell mediated immune surveillance, with a strong focus of translation.