CD56 Assay Portfolio Service

Overview

CD56, also known as the neural cell adhesion molecule (NCAM), is a membrane glycoprotein of the immunoglobulin superfamily. CD56 is mainly expressed by neurons, glia, skeletal muscle, and natural killer (NK) cells. Functionally, CD56 contributes to cell-cell adhesion or cell-matrix adhesion during embryonic development. CD56 is a neural cell adhesion molecule that plays a role in the cohesiveness of neuroendocrine cells. In addition, CD56 has been detected on lymphoid cells, including NK cells, γδ-T cells, and activated CD8+ T cells, as well as on dendritic cells (DCs), that may have an immunoregulatory function.

Characteristics

At least 27 alternatively spliced CD56 mRNAs produce several isoforms. The human NCAM gene is located on chromosome 11q23. CD56 contains a 689 amino acid extracellular domain which contains 5 Ig-like C2-type domains, 2 fibronectin type-3 domains, and 6 potential N-glycosylation sites. CD56 exists three main isoforms (NCAM-120, NCAM-140, and NCAM-180), all generated by alternative splicing from one single gene. These main isoforms of NCAM vary only in their cytoplasmic domain:

• NCAM-120kDa (GPI anchored)
• NCAM-140kDa (short cytoplasmic domain)
• NCAM-180kDa (long cytoplasmic domain)

Fig.1 Isoforms of CD56. ^{1, 4}

CD56 and NK Cells

The degree of CD56 expression is ubiquitously used to define human NK cell maturation, functional and tissue-specific subsets. The highest CD56 expression is by NKs of the liver and decidua. In the hematopoietic system, CD56 is the prototypic marker of NK cells (80-90%). There are 2 distinct subsets of human NK cells identified by the cell surface density of CD56. Whereas most NK cells in peripheral blood are CD56^dim, CD56^bright NK cells are more abundant in tissues. NK cells acquire motility with progressive maturation, correlated with the expression of CD56 on developing NK cells. Until recently it was widely believed that CD56^bright NK cells were superior at producing pro-inflammatory cytokines, and CD56^dim NK cells were described as the more cytotoxic subset. CD56+ NKs are important in defense against viral infections, tumor remission, and graft rejection.

Fig.2 NK cell subsets based on CD56 expressions. ^{2, 4}

The Expression of CD56 in Cancers

The role of CD56 in cancer is perhaps the most extensively studied one. A 120 kDa NCAM isoform is predominantly expressed in normal and well-differentiated tissues. The 140 and180 kDa isoforms (which contains a transmembrane domain) are found predominantly in less differentiated embryonic or malignant cell types, thereby the expression of NCAM shifts from the NCAM120 isoform to the NCAM140 and NCAM180 isoforms in cancer. Aberrant CD56 expression is seen in a range of hematological malignancies (e.g., multiple myeloma and leukemia) as well as solid tumors (e.g., lung cancer, ovarian cancer, and neuroblastoma). Malignancies expressing CD56 are usually aggressive, with more potential for metastasis and extramedullary/ central nervous system (CNS) involvement, and may respond to new CD56‑linked targeted therapies.

CD56 Assay Portfolio Service for Research

CD56 has roles in cell proliferation, differentiation, motility, trafficking, apoptosis, and tissue architecture. Creative Biolabs' expertise and our commitment to high-quality standards can provide one-stop customized tumor marker assay services. Our experience in custom assay development covers a breadth of research areas to satisfy your demands. Our CD56 assay portfolio services for research include but are not limited to

• NK cell function assays
• Flow cytometric analysis of surface and intracellular markers and cytokine production
• Degranulation assay
• Active caspase 3 apoptosis assay
• Immune synapse formation assay
• Cell migration (transwell) and wound healing assay
• Apoptosis assay
• CD56 blocking
• ELISA
• Immunostain

Published Data

Despite advances in therapy, breast cancer (BC) often resists NK cell immunotherapy. This study identifies CD56 (NCAM-1) as a key regulator of NK cell cytotoxicity. CD56⁺ BC cells (e.g., BT549) and precancerous cells were highly sensitive to NK killing, while CD56^- lines (e.g., MDA-MB-231) resisted. Mechanistically, CD56 enabled homophilic interactions with NK cells, enhancing immunological synapse formation, granzyme B transfer, and caspase-3 activation. Ectopic CD56 expression sensitized resistant BC cells. Clinically, CD56 was expressed in 36% of BC tissues (vs. 80% in normal tissue), suggesting its loss aids immune evasion. These findings position CD56 as both a predictive biomarker and therapeutic target to improve NK cell therapy for BC subsets.

Fig.3 Comparative flow cytometric profiling of CD56 epitopes on live NK and target cells. ^{3, 4}

Why Choose Us?

At Creative Biolabs, we combine cutting-edge science with tailored solutions to advance your CD56 research. As a trusted partner in immuno-oncology, we offer end-to-end support—from biomarker discovery to therapeutic development—backed by rigorous, reproducible data.

CD56 is more than just a cell adhesion marker; emerging studies reveal its active role in anti-tumor immunity. Through homodimerization, CD56 strengthens immune synapse formation, boosting NK cell cytotoxicity. Post-translational modifications like ubiquitination fine-tune its activity, while IL-15 stimulation can elevate CD56 expression, enhancing immune cell function. These insights open new avenues for immunotherapy development.

Our team leverages advanced technologies and deep expertise to help you explore CD56's therapeutic potential. Whether you're investigating its mechanisms, developing targeting strategies, or optimizing cell-based therapies, we provide the tools and collaboration to accelerate your success.

Partner with us to translate CD56 research into impactful therapies—because every breakthrough starts with the right science.

Frequently Asked Questions

Customer Review

• Meticulous Quality Control
  The reproducibility of the data we received from Creative Biolabs was outstanding. Their stringent quality control standards gave us absolute confidence in the results, which is essential for our regulatory submissions. - Dr. Aa** Gr
• Comprehensive Reporting
  The final report was a complete package, not just raw data. It included detailed methodology and publication-ready figures that significantly expedited our internal review and presentation processes. It was a huge time-saver. - Dr. Rr** Hs

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How to Contact Us

Creative Biolabs is dedicated to accelerating your research with our reliable and comprehensive CD56 assay portfolio service. Partner with us to unlock the full potential of your next-generation immunotherapies and scientific discoveries.

For detailed information, to request a quote, or to discuss your project, please contact our team.

References

1. Van Acker, Heleen H., et al. "CD56 in the immune system: more than a marker for cytotoxicity?" Frontiers in immunology 8 (2017): 892. https://doi.org/10.3389/fimmu.2017.00892
2. Homrich, Mirka, et al. "Cell adhesion molecules and ubiquitination—functions and significance." Biology 5.1 (2015): 1. https://doi.org/10.3390/biology5010001
3. Taouk, Ghina, et al. "CD56 expression in breast cancer induces sensitivity to natural killer-mediated cytotoxicity by enhancing the formation of cytotoxic immunological synapse." Scientific reports 9.1 (2019): 8756. https://doi.org/10.1038/s41598-019-45377-8
4. Distributed under Open Access license CC BY 4.0, without modification.

For Research Use Only | Not For Clinical Use