General Information of This Peptide-drug Conjugate (PDC)
PDC ID
PDC_00223
PDC Name
I-5 (NPNWGRSWYNQRFKGC=(-SS-COO-CPT)GC=(-SS-COO-CPT)GRIKPRKGYTR)
PDC Status
Investigative
Indication
In total 1 Indication(s)
Breast cancer
Structure
Peptide Name
P1GCGCGT1
 Peptide Info 
Receptor Name
Receptor tyrosine-protein kinase erbB-2 (ERBB2)
 Receptor Info 
Drug Name
Camptothecin
 Drug Info 
Therapeutic Target
DNA topoisomerase 1 (TOP1)
 Target Info 
Linker Name
3-Disulfanylpropanoic Acid
 Linker Info 
Formula
C199H269N57O48S4
#Ro5 Violations (Lipinski): 5 Molecular Weight 4355.96
Lipid-water partition coefficient (xlogp) -11.4735
Hydrogen Bond Donor Count (hbonddonor) 51
Hydrogen Bond Acceptor Count (hbondacc) 64
Rotatable Bond Count (rotbonds) 134
Full List of Activity Data of This Peptide-drug Conjugate
Revealed Based on the Cell Line Data
Click To Hide/Show 5 Activity Data Related to This Level
Experiment 1 Reporting the Activity Data of This PDC [1]
Indication Breast cancer
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
1.49 ± 0.58 µM
Administration Time 48 h
Evaluation Method MTT assay
MOA of PDC
To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

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Description
The cytotoxicity of conjugates was evaluated on cell lines with different expression levels of HER2. The results showed that among all conjugates with a single CPT molecule (I-1 to I-3), I-1 was the most cytotoxic against three HER2-positive cell lines (SK-BR-3, NCI-N87, and SK-OV-3 cells), and the calculated IC50 values for the three cells were 1.47 ± 0.54, 3.29 ± 0.67, and 4.29 ± 1.11 uM, respectively. Similarly, among all conjugates with two CPT molecules (I-4 to I-6), I-4 showed the highest cytotoxicity toward HER2-positive cells, and the IC50 values for SK-BR-3, NCI-N87, and SK-OV-3 cells were 0.12 ± 0.07, 1.78 ± 0.47, and 1.27 ± 0.38 uM, respectively. The activity of I-4 against SK-BR-3 cells was also slightly better than that of the positive control CPT (IC50 = 0.21 ± 0.04 uM). The cytotoxicity of I-1 and I-4 against HER2-negative MDA-MB-231 cells was comparatively lower (calculated IC50s were 7.60 ± 1.23 and 7.72 ± 0.92 uM, respectively). In contrast, CPT itself showed higher cytotoxicity against MDA-MB-231 (IC50 = 1.06 ± 0.42 uM), indicating that conjugates showed higher specificity in cell targeting. Furthermore, the cytotoxicity of I-1 and I-4 against normal cells MCF-10A (IC50 = 23.90 ± 1.58 and 17.14 ± 2.42 uM, respectively) was significantly lower than that of CPT alone (2.58 ± 0.77 uM). Based on these results, I-1 and I-4 were selected for subsequent biological evaluation.

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In Vitro Model Breast adenocarcinoma SK-BR-3 cell CVCL_0033
Experiment 2 Reporting the Activity Data of This PDC [1]
Indication Breast cancer
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
4.12 ± 0.87 µM
Administration Time 48 h
Evaluation Method MTT assay
MOA of PDC
To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

   Click to Show/Hide
Description
The cytotoxicity of conjugates was evaluated on cell lines with different expression levels of HER2. The results showed that among all conjugates with a single CPT molecule (I-1 to I-3), I-1 was the most cytotoxic against three HER2-positive cell lines (SK-BR-3, NCI-N87, and SK-OV-3 cells), and the calculated IC50 values for the three cells were 1.47 ± 0.54, 3.29 ± 0.67, and 4.29 ± 1.11 uM, respectively. Similarly, among all conjugates with two CPT molecules (I-4 to I-6), I-4 showed the highest cytotoxicity toward HER2-positive cells, and the IC50 values for SK-BR-3, NCI-N87, and SK-OV-3 cells were 0.12 ± 0.07, 1.78 ± 0.47, and 1.27 ± 0.38 uM, respectively. The activity of I-4 against SK-BR-3 cells was also slightly better than that of the positive control CPT (IC50 = 0.21 ± 0.04 uM). The cytotoxicity of I-1 and I-4 against HER2-negative MDA-MB-231 cells was comparatively lower (calculated IC50s were 7.60 ± 1.23 and 7.72 ± 0.92 uM, respectively). In contrast, CPT itself showed higher cytotoxicity against MDA-MB-231 (IC50 = 1.06 ± 0.42 uM), indicating that conjugates showed higher specificity in cell targeting. Furthermore, the cytotoxicity of I-1 and I-4 against normal cells MCF-10A (IC50 = 23.90 ± 1.58 and 17.14 ± 2.42 uM, respectively) was significantly lower than that of CPT alone (2.58 ± 0.77 uM). Based on these results, I-1 and I-4 were selected for subsequent biological evaluation.

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In Vitro Model Ovarian serous cystadenocarcinoma SK-OV-3 cell CVCL_0532
Experiment 3 Reporting the Activity Data of This PDC [1]
Indication Breast cancer
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
7.37 ± 1.18 µM
Administration Time 48 h
Evaluation Method MTT assay
MOA of PDC
To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

   Click to Show/Hide
Description
The cytotoxicity of conjugates was evaluated on cell lines with different expression levels of HER2. The results showed that among all conjugates with a single CPT molecule (I-1 to I-3), I-1 was the most cytotoxic against three HER2-positive cell lines (SK-BR-3, NCI-N87, and SK-OV-3 cells), and the calculated IC50 values for the three cells were 1.47 ± 0.54, 3.29 ± 0.67, and 4.29 ± 1.11 uM, respectively. Similarly, among all conjugates with two CPT molecules (I-4 to I-6), I-4 showed the highest cytotoxicity toward HER2-positive cells, and the IC50 values for SK-BR-3, NCI-N87, and SK-OV-3 cells were 0.12 ± 0.07, 1.78 ± 0.47, and 1.27 ± 0.38 uM, respectively. The activity of I-4 against SK-BR-3 cells was also slightly better than that of the positive control CPT (IC50 = 0.21 ± 0.04 uM). The cytotoxicity of I-1 and I-4 against HER2-negative MDA-MB-231 cells was comparatively lower (calculated IC50s were 7.60 ± 1.23 and 7.72 ± 0.92 uM, respectively). In contrast, CPT itself showed higher cytotoxicity against MDA-MB-231 (IC50 = 1.06 ± 0.42 uM), indicating that conjugates showed higher specificity in cell targeting. Furthermore, the cytotoxicity of I-1 and I-4 against normal cells MCF-10A (IC50 = 23.90 ± 1.58 and 17.14 ± 2.42 uM, respectively) was significantly lower than that of CPT alone (2.58 ± 0.77 uM). Based on these results, I-1 and I-4 were selected for subsequent biological evaluation.

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In Vitro Model Gastric tubular adenocarcinoma NCI-N87 cell CVCL_1603
Experiment 4 Reporting the Activity Data of This PDC [1]
Indication Breast cancer
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
11.51 ± 1.37 µM
Administration Time 48 h
Evaluation Method MTT assay
MOA of PDC
To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

   Click to Show/Hide
Description
The cytotoxicity of conjugates was evaluated on cell lines with different expression levels of HER2. The results showed that among all conjugates with a single CPT molecule (I-1 to I-3), I-1 was the most cytotoxic against three HER2-positive cell lines (SK-BR-3, NCI-N87, and SK-OV-3 cells), and the calculated IC50 values for the three cells were 1.47 ± 0.54, 3.29 ± 0.67, and 4.29 ± 1.11 uM, respectively. Similarly, among all conjugates with two CPT molecules (I-4 to I-6), I-4 showed the highest cytotoxicity toward HER2-positive cells, and the IC50 values for SK-BR-3, NCI-N87, and SK-OV-3 cells were 0.12 ± 0.07, 1.78 ± 0.47, and 1.27 ± 0.38 uM, respectively. The activity of I-4 against SK-BR-3 cells was also slightly better than that of the positive control CPT (IC50 = 0.21 ± 0.04 uM). The cytotoxicity of I-1 and I-4 against HER2-negative MDA-MB-231 cells was comparatively lower (calculated IC50s were 7.60 ± 1.23 and 7.72 ± 0.92 uM, respectively). In contrast, CPT itself showed higher cytotoxicity against MDA-MB-231 (IC50 = 1.06 ± 0.42 uM), indicating that conjugates showed higher specificity in cell targeting. Furthermore, the cytotoxicity of I-1 and I-4 against normal cells MCF-10A (IC50 = 23.90 ± 1.58 and 17.14 ± 2.42 uM, respectively) was significantly lower than that of CPT alone (2.58 ± 0.77 uM). Based on these results, I-1 and I-4 were selected for subsequent biological evaluation.

   Click to Show/Hide
In Vitro Model Breast adenocarcinoma MDA-MB-231 cell CVCL_0062
Experiment 5 Reporting the Activity Data of This PDC [1]
Indication Breast cancer
Efficacy Data Half Maximal Inhibitory Concentration (IC50)
18.25 ± 1.76 µM
Administration Time 48 h
Evaluation Method MTT assay
MOA of PDC
To enhance the affinity of the human epidermal growth receptor 2 (HER2) targeted peptide developed previously, bispecific fusion peptidesP1GCGT1andP1GCGCGT1were designed using anin silicoapproach. Molecular dynamic simulation showed that both peptides strongly interacted with HER2 domains II and IV. Compared with peptides targeting each single domain,P1GCGT1andP1GCGCGT1could bind to HER2 more significantly and targeted HER2-positive cells specifically. Additionally, both peptides were used to generate peptide-drug conjugates with camptothecin (CPT), among whichI-1andI-4were screened for enhanced cellular activity and selectivity. Biological evaluation demonstrated thatI-1andI-4induced cell apoptosis, promoted cell cycle arrestin S-phase, and inhibited Topo I activity. The binding affinity assay and confocal analysis revealed thatI-1andI-4were effective at targeting HER2. Moreover,I-1andI-4showed better stability than single targeting peptide and presented enhanced antitumor activity and safety than CPT in tumor-bearing mice.

   Click to Show/Hide
Description
The cytotoxicity of conjugates was evaluated on cell lines with different expression levels of HER2. The results showed that among all conjugates with a single CPT molecule (I-1 to I-3), I-1 was the most cytotoxic against three HER2-positive cell lines (SK-BR-3, NCI-N87, and SK-OV-3 cells), and the calculated IC50 values for the three cells were 1.47 ± 0.54, 3.29 ± 0.67, and 4.29 ± 1.11 uM, respectively. Similarly, among all conjugates with two CPT molecules (I-4 to I-6), I-4 showed the highest cytotoxicity toward HER2-positive cells, and the IC50 values for SK-BR-3, NCI-N87, and SK-OV-3 cells were 0.12 ± 0.07, 1.78 ± 0.47, and 1.27 ± 0.38 uM, respectively. The activity of I-4 against SK-BR-3 cells was also slightly better than that of the positive control CPT (IC50 = 0.21 ± 0.04 uM). The cytotoxicity of I-1 and I-4 against HER2-negative MDA-MB-231 cells was comparatively lower (calculated IC50s were 7.60 ± 1.23 and 7.72 ± 0.92 uM, respectively). In contrast, CPT itself showed higher cytotoxicity against MDA-MB-231 (IC50 = 1.06 ± 0.42 uM), indicating that conjugates showed higher specificity in cell targeting. Furthermore, the cytotoxicity of I-1 and I-4 against normal cells MCF-10A (IC50 = 23.90 ± 1.58 and 17.14 ± 2.42 uM, respectively) was significantly lower than that of CPT alone (2.58 ± 0.77 uM). Based on these results, I-1 and I-4 were selected for subsequent biological evaluation.

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In Vitro Model Normal MCF-10A cell CVCL_0598
References
Ref 1 In Silico Exploration and Biological Evaluation of Bispecific Peptides Derived from Anti-HER2 Antibodies and Peptide-Camptothecin Conjugates for HER2-Positive Breast Cancer. J Med Chem. 2022 Nov 24;65(22):15123-15139. doi: 10.1021/acs.jmedchem.2c00968. Epub 2022 Nov 9.