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The HER2 gene belongs to the human epidermal growth factor receptor family (ErbB family), which consists of four highly homologous protein members—EGFR, HER2, HER3, and HER4—that regulate cell growth, survival, differentiation, and migration. Unlike the other three members, the HER2 protein is essentially an orphan receptor that lacks a specific ligand and is the only receptor capable of binding to other family members to form a dimeric structure. ErbB2 is a ligand-independent receptor, while ErbB3 lacks tyrosine kinase activity. Therefore, ErbB2 and ErbB3 are active only in the context of ErbB heterodimers, and the ErbB2-ErbB3 heterodimer driven by the Nrg (neural regulatory protein) ligand is the most common and potent complex involved in cell growth and transformation. The basis for the signaling efficacy of the ligand-activated ErbB2-ErbB3 heterodimer lies in the fact that this dimer can signal very effectively, promoting proliferation via the Ras-ERK (extracellular signal-regulated kinase) pathway and survival via the PI3K-Akt/PKB (phosphoinositide 3-kinase-Akt/protein kinase B) pathway. Furthermore, this receptor dimer can evade downregulation mechanisms, thereby prolonging the duration of signal transduction.

The ERBB2 & ERBB3 Dimerization CHO Reporter Gene Drug Target Model effectively mimics the in vivo signal transduction process of ERBB2 and ERBB3; the mechanism is illustrated in the figure.

Figure 1. Schematic diagram of the CHO cell model for ERBB2 and ERBB3 dimerization

Figure 2. Recombinant ERBB2&ERBB3 Dimerization CHO stably expressing ERBB2&ERBB3.


Figure 3. Dose Response of Ligands in ERBB2&ERRB3 Dimerization CHO( C14).



Figure 4. Inhibition of Human NRG1-β1 induced ERBB2&ERBB3 Dimerization by ERBB3 or ERBB3 Abs in ERBB2&ERBB3 Dimerization CHO( C14).


Figure 5. Inhibition of Human NRG1-β2 induced ERBB2&ERBB3 Dimerization by ERBB3 or ERBB3 Abs in ERBB2&ERBB3 Dimerization CHO(C14).

Cell Resuscitation
1)Rapidly thaw the frozen cells in a 37 °C water bath for approximately 60 seconds. Once thawed (which may take slightly less or more than 60 seconds), immediately transfer the cell suspension from the cryovial into a 15 mL centrifuge tube containing 10 mL of pre-warmed  CHO-K1 Human ERBB2&ERBB3 Dimerization Cell complete culture medium.
2)Centrifuge cells at 1000 rpm for 5 min to remove medium, then resuspend cells in 5 mL of pre-warmed complete medium.
3)Transfer the cell suspension into a T25 culture flask and incubate at 37 °C with 5% CO₂.
4)After approximately 24–36 hours, replace the medium or passage the cells to remove non-adherent dead cells.

Subculturing procedure
1)When the cell density reaches the appropriate confluency for passaging, wash the cells with PBS, then add 1 mL trypsin to detach the cells. When more than 80% of the cells detach upon gently tapping the culture flask, add complete culture medium to terminate digestion. Gently pipette to obtain a single-cell suspension, transfer to a 15 mL centrifuge tube, and centrifuge at 1000 rpm for 5 minutes.

2)Discard supernatant after centrifugation. Resuspend cells in fresh medium to a single-cell suspension and transfer to a new culture flask for continued growth.

Cell Freezing
After trypsinization and centrifugation of cells from each T75 flask or 10 cm culture dish, discard the supernatant. Add 2 mL of cryopreservation medium (90% FBS + 10% DMSO), gently resuspend thoroughly, and aliquot into two cryovials. Immediately place the cryovials into a controlled-rate freezing container (e.g., Nalgene 5100-0001), fill with isopropanol to the indicated level, and store at −80 °C. After 24 hours, transfer the cryovials to liquid nitrogen for long-term storage.