Greater Clarity Brings a Better Vue of Tumor Biology
Greater Clarity Brings a Better Vue of Tumor Biology
Kirsty Maclean, Ph.D.
Senior Director, Biomarker and Translational Strategy
8-plex panel staining DCIS tissue
For Research Use Only. Not for use in diagnostic procedures.
It’s hard to travel in the pouring rain, because your view is limited. Not being able to see what’s happening ahead of you and not knowing all the factors at play can make navigating any situation difficult if not impossible. You slowly make your way forward with the information at hand, but as new information comes to light, decisions about how best to move forward become clear, opening paths previously unseen. New avenues of exploration often lead to a new views and perspectives, and like any tough situation to navigate, cancer treatment also benefits from new information to improve outcomes.
Today, changes in the immune composition of tumor cells can be used to predict treatment response and prognosis in breast cancer. Recently, though, the diverse components within the tumor microenvironment (TME) have been shown to play a significant role in tumor development, recurrence, metastasis, and response to treatment. The TME is a complex intersection of cancer and non-cancer cells, including stromal cells, vascular cells, tumor-infiltrating lymphocytes (TILs), immune-modulating molecules, and cytokines. Collectively, these components work in concert to influence either the progression or clearance of cancer. Further exploration of this new frontier may yield clues to successfully navigating this journey.
Although many functions of non-cancer cells within the TME are unclear, TIL patterns are reported to correlate with pathologically complete response (pCR) and overall survival (OS) in breast cancer patients. The role of each immune cell type might influence cancer progression in estrogen receptor (ER)-negative breast cancer. Through better understanding of this cellular intersection, a study conducted by Ji et al (2021)1 sought to formulate an immune algorithm that could be applied to tumor samples and predict responses to neoadjuvant chemotherapy. Normalized gene expression data from ER-negative breast cancers from public databases was used to infer the proportions of 22 types of infiltrating immune cells
within the TME. Five types of immune cells were further correlated with survival outcome: CD4+ (T helper), CD8+ (cytotoxic T cell), CD20 (B cell), CD80 (M1 macrophage) and FoxP3 (Treg or regulatory T cell). Manual IHC tissue staining by immunohistochemistry (IHC) was conducted one cellular marker at a time and imaged to define quantity and spatial distribution of these cell types within the tissue.
Findings from the IHC observations were used to formulate an algorithm based on the volumes of specific immune cells within the TME. High numbers of CD4+, CD8+, B cells and M1 macrophages with low numbers of Treg cells (termed immunotype A) were associated with a favorable outcome. High numbers of Treg cells with low numbers of CD4+, CD8+, B cells and M1 macrophages (termed immunotype B) were strongly indicative of a poor outcome. Immune cell stromal infiltration was significantly associated with overall survival of ER-negative breast cancer. Patients associated with an immunotype B profile had significantly shorter OS and disease-free survival (DFS) than those in the immunotype A group.
Insights gained through further TME profiling will define the importance of TILs not only in monitoring the immune response within the tumor but might also predict treatment response to many cancers. As performed in this study, IHC technology has historically been used to characterize the cellular context of tumor tissues. However, limitations to IHC-associated cellular resolution and the need for multiplexed approaches are apparent. IHC protocols are labor-intensive and require multiple experiments to yield a comprehensive picture of cell localization. Serial experiments also limit the ability to view interactions among cell types within a tissue in parallel. Much like how clarity widens your field of view, understanding the complexity of these interactions will uncover new pathways that will broaden our ability to develop novel cancer treatment.
Enhanced multiplex protein detection technologies deliver high-resolution details of cells and cellular interaction within the context of the tumor, providing a holistic view of the tumor microenvironment. Ultivue’s InSituPlex® multiplex immunofluorescent (mIF) technology outperforms traditional IHC for simultaneous multi-target characterization of tissues. InSituPlex technology uses proprietary antibody- DNA barcoding with signal amplification to enable industry-leading biomarker detection and tissue analysis. The workflow begins by incubating a tissue slide with a mixture of barcoded antibodies for multiplex target labeling. Bound antibody barcodes are then amplified to increase the sensitivity of complimentary fluorescent probe hybridization. Bound probes are then imaged to provide a view of targeted cells and cellular interactions within a spatially-preserved tumor microenvironment.
Investigators will benefit from the simplified workflow and availability of Ultivue’s flexible options for off-the-shelf panels or custom panels that include up to 8 targets. Panels are compatible with most scanning instruments and digital imaging software.
The tumor microenvironment remains an area for great discovery. Additional insight into cellular function and diversity, cellular interactions, and stromal changes can be achieved using multiplex target detection in tissues. Keys to inform treatment and management decisions and positively impact patient cancer survival might lie within the tumor microenvironment. Contact Ultivue today to see how InSituPlex mIF technology can drive discovery in your application.
Ji, et al. Tumor microenvironment characterization in breast cancer identifies prognostic and neoadjuvant chemotherapy relevant signatures. Frontiers in Molecular Biosciences. 11 October 2021. https://doi.org/10.3389/fmolb.2021.759495