HER2 (ERBB2) Chimeric Antigen Receptor (CAR): A Comprehensive Guide and Our Service & Product Introduction

HER2 (ERBB2) is a key target for tumor targeted therapy, and HER2 CAR-T therapy has become one of the most promising research directions in the field of immunotherapy. With the continuous deepening of research, the demand for high-quality HER2 CAR expression plasmid vectors and professional custom services is increasing. RGBiotech provides a full range of standardized HER2 CAR plasmid products and personalized custom services, covering different generations of CAR structures, with strict quality control and competitive advantages.

We are committed to supporting the research and development of HER2-targeted immunotherapy, providing reliable tools and technical support for researchers and pharmaceutical companies, and contributing to the advancement of cancer treatment. We look forward to cooperating with you to promote the development of HER2 CAR technology and bring new hope to patients with HER2-positive tumors.

Our HER2 (ERBB2) CAR Expression Plasmid Vector Products and Custom Services

To support the research and development of HER2 (ERBB2) CAR, RGBiotech provides a full range of HER2 (ERBB2) CAR expression plasmid vector products, covering different generations of HER2 CAR, and offers customized plasmid vector construction services tailored to customers' specific research needs. We adhere to the concept of "quality first, customer-oriented", continuously optimizes product performance and service quality, and strives to become a trusted partner for researchers in the field of HER2-targeted immunotherapy. Whether you are engaged in basic research on HER2 CAR, preclinical evaluation of CAR-T cells, or drug development, we can provide tailored products and services to help you achieve your research goals.

Our HER2 CAR expression plasmid vectors cover different generations, each optimized for specific research purposes, ensuring flexibility and adaptability for different experimental designs:

1) First-Generation HER2 CAR Plasmid: Contains only the CD3ζ intracellular signaling domain, which can activate T cells but has weak proliferation capacity and short persistence, suitable for preliminary research on HER2 CAR function.

2) Second-Generation HER2 CAR Plasmid: Adds one co-stimulatory domain (CD28 or 4-1BB) to the CD3ζ domain, significantly enhancing T cell proliferation, cytotoxicity, and persistence. This is the most widely used generation in current basic and preclinical research.

3) Third-Generation HER2 CAR Plasmid: Contains two co-stimulatory domains (e.g., CD28+4-1BB, CD28+OX40), further improving the anti-tumor activity and long-term persistence of CAR-T cells, suitable for research on overcoming T cell exhaustion.

4) Fourth-Generation HER2 CAR Plasmid (Armored CAR): On the basis of third-generation CAR, adds sequences encoding cytokines (IL-12, IL-15) or immune checkpoint inhibitors (PD-1 scFv), which can remodel the tumor microenvironment, enhance the anti-tumor effect of CAR-T cells, and reduce immunosuppression, suitable for research on solid tumor therapy.

Product Features

1) Promoters: We offer a variety of high-efficiency promoters to meet different expression needs, including CMV (cytomegalovirus promoter, high-efficiency constitutive expression), EF1α (elongation factor 1α promoter, stable expression in various cell types, including primary T cells), Tet/on inducible promoter etc. Customers can choose the appropriate promoter according to their experimental system.

2) Fluorescent Markers: Some of our plasmid vectors are equipped with fluorescent marker genes for easy detection and sorting of CAR-expressing cells, such as GFP (green fluorescent protein), mCherry (red fluorescent protein) etc. The fluorescent marker is either linked to the CAR gene or the selection marker gene via a 2A peptide (P2A or T2A), ensuring co-expression of CAR and fluorescent protein.

3) Antibiotic Selection Markers: Equipped with common antibiotic selection markers to facilitate plasmid screening and amplification, such as Puromycin (Puro), Neomycin (Neo), Hygromycin (Hygro), Blasticidin (Bla) for eukaryotic cell screening. Customers can choose the appropriate selection marker according to their cell type and experimental needs.

4) High Compatibility: The plasmids are compatible with various transfection methods (liposome transfection, electroporation, lentiviral packaging, AAV packaing, retroviral packaging) and can be used in different cell types, including primary T cells, Jurkat cells, and NK cells.

Product Advantages

1) High Expression Efficiency: Optimized vector design (including promoter selection, codon optimization of CAR gene) ensures high and stable expression of HER2 CAR in target cells, improving the efficiency of CAR-T cell preparation.

2) Excellent Performance: The CAR structure is optimized ensuring strong binding ability to HER2 antigen and efficient activation of immune cells.

3) Strict Quality Control: The full length of the CAR gene is verified by Sanger sequencing, ensuring no sequence mutations, deletions, or insertions.

4) Ready-to-Use: The plasmids are provided in a ready-to-use format, with detailed product instructions and experimental protocols, reducing experimental time and operational difficulty for customers.

5) Cost-Effective: We offer competitive pricing and flexible packaging options to meet the needs of different research scales, helping customers reduce research costs.

Product Applications

1) Basic Research: Used for studying the structure and function of HER2 CAR, exploring the mechanism of CAR-T cell activation and anti-tumor effect, and optimizing the CAR structure.

2) Preclinical Research: Used for preparing HER2 CAR-T/NK cells, evaluating their anti-tumor activity in vitro (cytotoxicity assay, cytokine secretion assay) and in vivo (animal tumor models), and supporting preclinical trial applications.

3) Drug Development: Providing tool vectors for the development of HER2 CAR-T drugs, including the screening of lead candidates and the optimization of manufacturing processes.

4) Teaching and Training: Used for teaching experiments in immunology, molecular biology, and oncology, helping students understand the principle and application of CAR-T therapy.

Custom HER2 (ERBB2) CAR Plasmid Vector Construction Services

In addition to standard products, we also provide customized HER2 CAR plasmid vector construction services to meet the personalized needs of customers. Our professional R&D team has rich experience in plasmid vector design and construction, and can provide one-stop services from vector design to plasmid preparation and quality inspection.

1) Custom scFv Sequences: According to the customer's needs, design and insert specific anti-HER2 scFv sequences to improve the specificity and affinity of CAR to HER2 antigen.

2) Custom CAR Structure: Design and construct CAR vectors with custom co-stimulatory domains, signaling domains, or additional functional sequences (cytokines, immune checkpoint inhibitors, suicide genes), tailored to specific research goals.

3) Custom Promoters and Markers: Select appropriate promoters, fluorescent markers, and antibiotic selection markers according to the customer's experimental system and cell type.

4) Lentiviral/Retroviral Vector Construction: Construct HER2 CAR lentiviral or retroviral vectors to facilitate efficient transduction of primary T cells or other immune cells, improving the efficiency of CAR expression.

5) Codon Optimization: Optimize the codon of the CAR gene according to the target cell type to improve the expression efficiency of CAR in target cells.

Service Advantages

Introduction of HER2 (ERBB2)

Human Epidermal Growth Factor Receptor 2 (HER2), also known as ERBB2 (v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2), is a key member of the epidermal growth factor receptor (EGFR) family of transmembrane glycoprotein receptors. Discovered independently by three research teams in the 1980s, HER2 was initially identified as a transforming gene from rat neuroblastoma (named neu gene) and later confirmed to be homologous to the viral ERBB2 gene, hence its dual nomenclature. As a proto-oncogene-encoded protein, HER2 plays a pivotal role in regulating cell proliferation, survival, differentiation, and migration, and its abnormal expression or activation is closely associated with the occurrence and progression of various malignant tumors, making it a core target for cancer diagnosis and targeted therapy. HER2 is also commonly referred to as CD340 or p185, with the latter name derived from its relative molecular mass of 185 kDa.

The HER2 (ERBB2) gene is located on human chromosome 17q21 (17q12 in some annotations), spanning a total length of 29,315 bp and containing 26 exons. Its messenger RNA (mRNA) is 4,530 nt in length, encoding a single-chain transmembrane glycoprotein composed of 1,255 amino acids. The gene is highly conserved across species, and its expression is tightly regulated under normal physiological conditions. Abnormalities in the HER2 gene mainly manifest in three forms: gene amplification (occurring in approximately 20-30% of breast cancers), gene mutation (such as exon 20 insertion mutations in non-small cell lung cancer), and epigenetic dysregulation (including abnormal DNA methylation and histone modification), all of which can lead to overexpression or constitutive activation of the HER2 protein. The HER2 gene ID (NCBI Gene) is 2064, and its UniProt accession number is P04626, providing a clear genetic basis for related research and product development.

The HER2 protein is a transmembrane glycoprotein with tyrosine kinase activity, consisting of three distinct structural domains: an extracellular ligand-binding domain (ECD), a single transmembrane domain, and an intracellular tyrosine kinase domain (TKD) with a C-terminal tail. The extracellular domain contains 8 potential N-glycosylation sites and two cysteine-rich regions (composed of 26 and 21 cysteines, respectively), which are critical for receptor dimerization. The transmembrane domain is composed of 22 highly hydrophobic amino acids, anchoring the protein to the cell membrane. The intracellular cytoplasmic domain (580 amino acids) includes the tyrosine kinase active site and three key tyrosine phosphorylation sites (Tyr1139, Tyr1196, and Tyr1248), which mediate downstream signal transduction upon activation. A unique feature of HER2 is that it has no known direct ligand; instead, it acts as a "preferred partner" to form heterodimers with other EGFR family members (HER1/EGFR, HER3, HER4) to exert its biological functions.

As a key signal transducer, HER2 regulates cell fate by activating downstream signaling pathways, primarily through heterodimerization with other EGFR family members. The most biologically significant heterodimers are HER2/HER1 and HER2/HER3, among which the HER2/HER3 heterodimer is the strongest "oncogenic driver" in many tumors, as HER3, despite weak kinase activity, amplifies signaling through multiple binding sites. Upon dimerization, the intracellular tyrosine kinase domain of HER2 is activated, leading to autophosphorylation of tyrosine residues and subsequent activation of two major downstream signaling pathways: the PI3K/AKT pathway (which inhibits apoptosis and promotes cell survival) and the MAPK pathway (which promotes cell proliferation and migration). Under normal physiological conditions, HER2 is involved in the development and maintenance of epithelial tissues (such as mammary glands), but its abnormal activation disrupts the balance of cell growth, driving normal cells toward malignant transformation.

Under normal physiological conditions, HER2 is weakly expressed in a variety of epithelial tissues, including the mammary gland, ovary, uterus, stomach, and lung, where it participates in tissue development and homeostasis. In the mammary gland, HER2 is involved in ductal development and lactation regulation; in the gastrointestinal tract, it contributes to epithelial barrier maintenance. Notably, HER2 expression is strictly regulated, and its overexpression or abnormal activation is rarely observed in normal tissues. In contrast, in malignant tumors, HER2 is frequently overexpressed or amplified, with high expression levels detected in breast cancer, gastric cancer, gastroesophageal junction adenocarcinoma, non-small cell lung cancer, colorectal cancer, ovarian cancer, and other solid tumors, making it a specific molecular marker for these tumors.

The most well-known disease associated with HER2 abnormality is breast cancer, where 20-30% of cases exhibit HER2 gene amplification or protein overexpression; these patients often have more aggressive tumors, higher metastasis risk, and poorer prognosis compared to HER2-negative patients. HER2 overexpression is also detected in 10-20% of gastric cancers and gastroesophageal junction adenocarcinomas, and it is associated with advanced disease stage and poor treatment response. In non-small cell lung cancer (NSCLC), HER2 exon 20 insertion mutations occur in 2-4% of cases, leading to constitutive activation of the receptor and resistance to traditional chemotherapy. Additionally, HER2 abnormality is involved in the progression of colorectal cancer, ovarian cancer, biliary tract cancer, and prostate cancer, making it a broad-spectrum target for anti-tumor therapy.

Introduction of HER2 (ERBB2) Chimeric Antigen Receptor (CAR)

Chimeric Antigen Receptor (CAR) is a genetically engineered receptor that can redirect immune cells (primarily T cells, known as CAR-T cells) to specifically recognize and kill target cells expressing a specific antigen. HER2 (ERBB2) CAR is designed to target the extracellular domain of the HER2 protein, enabling immune cells to specifically recognize and eliminate HER2-positive tumor cells, thus providing a novel immunotherapeutic strategy for HER2-positive tumors. The structure of HER2 CAR typically includes four core components: an extracellular antigen-binding domain (usually a single-chain variable fragment, scFv, derived from anti-HER2 monoclonal antibodies), a transmembrane domain (ensuring the receptor is anchored to the immune cell membrane), a hinge region (enhancing the flexibility of the extracellular domain), and an intracellular signaling domain (mediating immune cell activation and effector functions). With the continuous advancement of technology, HER2 CAR has evolved through multiple generations, each with improved efficacy and safety.

Since the first report of HER2 CAR-T cells in the 1990s, significant progress has been made in preclinical and clinical research. Preclinically, HER2 CAR-T cells have shown strong anti-tumor activity in various animal models of HER2-positive tumors, including breast cancer, gastric cancer, and NSCLC, effectively inhibiting tumor growth and prolonging animal survival. Clinically, early-phase trials have demonstrated the feasibility and potential efficacy of HER2 CAR-T therapy in patients with advanced HER2-positive solid tumors. For example, a phase I trial in patients with advanced HER2-positive breast cancer showed that HER2 CAR-T therapy achieved partial remission in some patients who had failed multiple lines of treatment. In NSCLC, HER2 CAR-T combined with other therapies has shown promising results in overcoming tumor immunosuppressive microenvironment. Additionally, studies have shown that optimizing the structure of HER2 CAR (such as modifying the scFv, adding co-stimulatory domains, or using armored CAR designs) can significantly improve the anti-tumor activity and persistence of CAR-T cells.

Approved Drugs

While no HER2 CAR-T drugs have been officially approved globally to date, a variety of HER2-targeted drugs have been approved for clinical use, laying a foundation for the development of HER2 CAR therapy.

1) Monoclonal Antibodies: Trastuzumab (Herceptin), the first approved HER2-targeted drug, binds to the extracellular domain of HER2, blocking dimerization and activating antibody-dependent cellular cytotoxicity (ADCC). Pertuzumab (Perjeta) binds to a different epitope of HER2, preventing its interaction with HER3 and enhancing anti-tumor efficacy when combined with trastuzumab.

2) Small Molecule Tyrosine Kinase Inhibitors (TKIs): Lapatinib inhibits the intracellular kinase activity of HER2, blocking downstream signaling pathways; Neratinib irreversibly binds to HER1/HER2/HER4, used for adjuvant treatment of early breast cancer to reduce recurrence risk.

3) Antibody-Drug Conjugates (ADCs): T-DM1 (Kadcyla) conjugates trastuzumab with the cytotoxic drug DM1, delivering toxic agents specifically to HER2-positive cells. T-DXd (Enhertu), an ADC with a more potent topoisomerase inhibitor payload, is effective in patients with advanced HER2-positive tumors who have failed multiple lines of treatment. In China, Rui Kang Trastuzumab (Aivida), an independently developed ADC by Hengrui Medicine, was approved for the treatment of HER2-mutated NSCLC, with an objective response rate (ORR) of 74.5% in clinical trials. Other approved ADCs include Disitamab Vedotin (by Rongchang Bio) and Bodotuximab (by Kelun Botai).

The clinical success of these drugs has confirmed the validity of HER2 as a tumor target, and HER2 CAR-T therapy is expected to provide a new treatment option for patients who are resistant to existing HER2-targeted therapies.

Research Hotspots

Currently, the research hotspots of HER2 (ERBB2) CAR mainly focus on the following aspects, aiming to improve efficacy, reduce toxicity, and expand application scope:

1) Optimization of CAR Structure: Development of next-generation HER2 CAR (third, fourth, and fifth generations) by adding multiple co-stimulatory domains or cytokine-encoding sequences to enhance the proliferation, persistence, and anti-tumor activity of CAR-T cells, while reducing cell exhaustion.

2) Overcoming Tumor Microenvironment (TME) Barriers: The immunosuppressive TME (including immune-inhibitory cells, cytokines, and extracellular matrix) is a major obstacle to CAR-T therapy in solid tumors. Current research focuses on combining HER2 CAR-T with immune checkpoint inhibitors (such as PD-1/PD-L1 inhibitors), small molecule drugs targeting the TME, or local administration (intrapleural, intracerebroventricular) to improve the infiltration and function of CAR-T cells in tumors.

3) Differentiated ADC and CAR Combinations: Development of bispecific HER2 ADCs (targeting non-overlapping epitopes of HER2) to enhance tumor targeting and reduce off-target effects; exploration of combinations of HER2 ADCs and CAR-T therapy to achieve synergistic anti-tumor effects.

4) Treatment of HER2-Targeted Therapy Resistance: Development of CAR-T cells targeting HER2 variants or downstream signaling molecules to overcome resistance to existing HER2-targeted drugs.

5) Application in Pediatric Tumors: HER2 is overexpressed in some pediatric tumors (such as neuroblastoma and osteosarcoma), and research on HER2 CAR-T therapy for pediatric patients is ongoing, aiming to provide new treatment options for children with refractory or relapsed tumors.

Research Challenges

Despite significant progress, HER2 (ERBB2) CAR research still faces several key difficulties and challenges that limit its clinical transformation:

1) Off-Target Toxicity: HER2 is weakly expressed in some normal tissues (such as cardiac myocytes and lung epithelial cells), and HER2 CAR-T cells may recognize and attack these normal cells, leading to severe toxicities (such as cardiotoxicity and pulmonary toxicity). How to improve the specificity of HER2 CAR and reduce off-target effects is a major challenge.

2) Tumor Microenvironment Barriers: Solid tumors have a complex immunosuppressive microenvironment, which inhibits the infiltration, activation, and proliferation of CAR-T cells, resulting in poor efficacy of HER2 CAR-T therapy in solid tumors compared to hematological tumors. Overcoming these barriers remains a key research focus.

3) CAR-T Cell Exhaustion: Long-term exposure to tumor antigens can lead to exhaustion of HER2 CAR-T cells, characterized by reduced proliferation capacity, weakened cytotoxicity, and increased expression of immune checkpoint molecules (such as PD-1), which limits the long-term anti-tumor effect of CAR-T cells.

4) Heterogeneity of HER2 Expression: Tumor heterogeneity leads to inconsistent HER2 expression levels in different parts of the same tumor; some tumor cells may lose HER2 expression, leading to CAR-T therapy resistance. Defining and characterizing HER2 heterogeneity and developing strategies to address it are important challenges.

5) Clinical Transformation Challenges: The translation success rate of CAR-T therapy from preclinical to clinical is less than 10%. Differences in pharmacokinetics and toxicity between animal models and humans, as well as the high cost of CAR-T manufacturing and lack of standardized quality control systems, hinder the widespread clinical application of HER2 CAR-T therapy.

References

Contact Us