Clinical application and research progress of antibody drugs conjugation in breast cancer / 中国临床药理学与治疗学

Antibody drug conjugations (ADCs) are a new class of drugs with both targeted specificity and high activity of chemotherapy drugs, which has gradually become a novel generation of therapeutic models with great clinical application prospects. In recent years, ADCs composed of monoclonal antibodies against different tumor cell surface antigens and small molecule potent cytotoxic drugs have shown superior therapeutic effects on recurrent / metastatic breast cancer. This article reviews the clinical application and research progress of ADCs with different molecular targets in the field of breast cancer.

Antitumor activity of a novel HER3-targeting antibody-drug-conjugate / 药学学报

As a member of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases, HER3 is an aberrantly activator of the PI3K/AKT pathway. Studies have indicated that HER3 is related to the progression of a variety of tumor types such as breast cancer, non-small cell lung cancer (NSCLC), ovary cancer and colon cancer, and in acquired resistance to EGFR and HER2 therapies. However, the attempts to target HER3 with neutralizing antibodies are not ideal previously. This is most likely due to the fact that the antibodies targeting HER3 fail to completely block the heterodimerization of HER3 and other receptors. Antibody-drug conjugates (ADCs) can specifically bind to target cells and exert the highly cytotoxicity effect on cancer cells through chemical drugs. ADCs have been widely used in clinical cancer therapies. We analyzed and optimized the structure of the antigen-antibody complex between HER3 and antibody LmAb3 by computer-aided molecular simulation technology, and the key sites involved in antigen binding in LmAb3 were predicted by distance geometry and computer graphics technology. Then a novel anti-HER3 antibody FD001 was obtained by point mutation technology. The affinity measurement by ForteBio results showed that the affinity of FD001 is much higher than LmAb3, the KD values of FD001 and LmAb3 with HER3 were 1.48E-11 and 2.46E-10, respectively. Antibody drug conjugate FD001-DM1 is obtained by coupling FD001 to DM1 [emtansine, N2'-deacetyl-N2'-(3-mercapto-1-oxopropyl)-maytansine] by lysine coupling technology. The results of cell cytotoxicity experiments showed that FD001-DM1 could effectively inhibit the proliferation of HER3-positive HT-29 colon cancer cells, with EC50 value of 33.62 nmol·L-1. The in vivo xenografts therapy results showed that the tumor volume of the FD001-DM1 treatment group was about 25% of that of the control group, and there was no significant weight reduction of the mice. These results reveal that FD001-DM1 had good in vivo and in vitro anti-tumor activity with high safety, which may provide effective help for further exploration of HER3-targeted ADCs drugs. The mice in this study were used and treated in accordance with international laboratory animal care and use guidelines and approved by the Animal Ethics Committee of the Military Cognitive and Brain Science Institute of the Military Medical Research Institute.

Bacterial expression of 183-227aa region of HER3 extracellular domain I and preparation and identification of its polyclonal antibodies / 南方医科大学学报

OBJECTIVE@#To prepare the recombinant peptide MVF-HER3 I composed of the 183-227aa peptide segment of human epidermal growth factor receptor 3 (HER3 I) and the measles virus protein 288-302 peptide segment (MVF), and prepare polyclonal antibodies (PcAb) against this recombinant peptide.@*METHODS@#The MVF-HER3 I gene was synthesized chemically and subcloned into pET21b or pET32a plasmid containing Thioredoxin (Trx) tag gene. The recombinant plasmids were identified by endonuclease digestion. MVF-HER3 I was expressed in BL21(DE3) cells under an optimal bacterial expression condition. The fusion protein Trx-MVF-HER3 I was purified using nickel ion affinity chromatography, and the purified protein was digested by enterokinase to remove Trx tag. The digested mixture underwent further nickel ion affinity chromatography to obtain purified MVF-HER3 I. The purified MVF-HER3 I was used to immunize SD rats subcutaneously for preparing anti-MVF-HER3 I PcAb. The titer of PcAb was determined using ELISA. The bindings of anti-MVF-HER3 I PcAb to MVF-HER3 I, native HER3 and MCF7 cells were analyzed using immunoblotting, immunoprecipitation and laser confocal microscopy. The growth inhibition effect of the antibodies on MCF7 cells cultured in the absence or presence of NRG was assessed using sulforhodamine B.@*RESULTS@#The recombinant peptide gene could not be expressed alone, but could be efficiently expressed after fusion with Trx gene under optimized conditions. The fusion peptide MVF-HER3 I was successfully prepared from Trx-MVF-HER3 I. The anti-MVF-HER3 I PcAb, with a titer reaching 1: 512 000, specifically bound to MVF-HER3 I, recognized native HER3 and bound to the membrane of MCF7 cells. The obtained PcAb could dose-dependently inhibit the growth of MCF7 cells irrespective of the presence or absence of NRG.@*CONCLUSIONS@#We successfully obtained the recombinant peptide MVF-HER3 I and prepared its PcAb, which can facilitate further functional analysis of HER3 signaling pathway.

ErbB1 and ErbB3 co-over expression as a prognostic factor in gastric cancer

BACKGROUND: Epidermal growth factor receptor family members such as ErbB1 and ErbB3 are involved in tumor progression and metastasis. Although, there are various reports about the prognostic value of EGFR members separately in gastric cancer, there is not any report about the probable correlation between ErbB1 and ErbB3 co-expression and gastric cancer prognosis. In present study, we assessed the correlation between ErbB1 and ErbB3 co-overexpression (in the level of mRNA and protein expression) and gastric cancer prognosis for the first time. METHODS: ErbB1 and ErbB3 expressions were analyzed by immunohistochemistry and real-time PCR in 50 patients with gastric cancer. Parametric correlations were done between the ErbB1 and ErbB3 expression and clinicopathological features. Multivariate and logistic regression analyses were also done to assess the roles of ErbB1 and ErbB3 in tumor prognosis and survival. RESULTS: There were significant correlations between ErbB1/ErbB3 co-overexpression and tumor size (p = 0.026), macroscopic features (p < 0.05), tumor differentiation (p < 0.05), stage of tumor (p < 0.05), and recurrence (p < 0.05). Moreover, ErbB1/ErbB3 co-overexpression may predict the survival status of patients (p < 0.05). CONCLUSION: ErbB1 and ErbB3 co-overexpression is accompanied with the poor prognosis and can be used efficiently in targeted therapy of gastric cancer patients.

Expression of HER3 in HER2-positive breast cancer and its relationship with clinical prognosis / 中华内分泌外科杂志

Objective To explore the expression of human epidermal growth factor receptor -3( HER3) in human epidermal growth factor receptor-2(HER2)-positive breast cancer and its relationship with the therapeutic effect of trastuzumab and clinical prognosis .Methods Clinicopathological characteristics of 235 HER2-positive breast cancer patients undergoing surgery in Jiangsu Cancer Hospital from Jan .2007 to Jun.2012 were analyzed retrospectively.The expression of HER3 was detected using immunohistochemisty staining .The expression of HER3 and its correlation with the clinicopathological characteristics were analyzed .All patients were followed-up to find out the impact of HER3 on the disease free survival and the therapeutic effect of trastuzumab .Results The positive rate of HER3 in Luminal B ( HER2 +) and HER2-overexpressing breast cancer was 100/135 (74.1%), and 85/100(85%)respectively.The difference had statistical significance (P<0.05).The histolog-ical grading and the lymph node metastasis were significantly different in Luminal B ( HER2+) breast cancer .The tumor volume , histological grading and lymph node metastasis were significantly different in HER 2-overexpressing breast cancer .The 5-year disease free survival of HER 2-positive breast cancer patients with negative HER 3 was higher than that with positive HER3.The non-relapse survival time was not significantly different between the pos-itive and negative HER 3 expression in Luminal B ( HER2+) breast cancer patients receiving trastuzumab treat-ment , but was significantly different in HER 2-overexpressing breast cancer patients .Conclusions HER3 is cor-related with unfavourable prognosis in HER 2-positive breast cancer .The treatment targeting HER3 may improve the clinical prognosis of both HER 2-positive and HER3-positive breast cancer patients .The HER2-overexpressing breast cancer patients with negative HER 3 may benefit more from trastuzumab treatment .

Expression of HER-3 in breast cancer tissues and its relationship with ER, PR and HER-2 / 中华内分泌外科杂志

Objective To study the expression of HER-3 in breast cancer patients and analyze its relationship with the clinical pathology and prognosis of breast cancer,ER,PR and HER-2.Methods Data of 139 female breast cancer patients undergoing operations at the Second Hospital of Dalian Medical University from Jan.2006 to Oct.2006 were collected.These 139 patients didn't have preoperative chemotherapy or radiation therapy,but had postoperative endocrine therapies.Immunohistochemisty was used to detect the expression of HER-3 in the 139 patients.Data like the expression of ER,PR and HER-2,histological grading,tumor size and lymph node metastasis were obtained from their medical records.The relationship between indicators and breast cancer was analyzed.Results ①The positive expression rate of HER-3,HER-2,ER,and PR was 30.2％ (42/139),42.5％ (59/139),66.9％ (93/139),and 59.7％ (83/139) respectively.(②)The statistical items had no relation with patients' age(P ＞0.05).③HER-3 expression was correlated with tumor sizes,lymph node metastasis,histological grading,5 year survival rate and HER-2 expression(P ＜ 0.05),and had no relation with ER or PR(P ＞0.05).④)The combined expression of HER-3 & HER-2 was correlated with tumor sizes,axillary lymph node metastasis,histological grading,ER and PR.(P ＜ 0.05).Conclusions HER-3 detection is of great significance for the diagnosis and prognosis of breast cancer.The combined examination of HER-3,HER-2,ER,and PR in breast cancer tissues is of clinical significance for early diagnosis/treatment,medication and prognosis of the tumor,as well as for new drug research and development.

Role of Shc and phosphoinositide 3-kinase in heregulin-induced mitogenic signaling via ErbB3

ErbB3/HER3 is a cell surface receptor which belongs to the ErbB/HER subfamily of receptor protein tyrosine kinases. When expressed in NIH/3T3 cells, ErbB3 can form heterodimeric coreceptor with endogenous ErbB2. Among known intracellular effectors of the ErbB2/ErbB3 are mitogen-activated protein kinase (MAPK) and phosphoinositide (PI) 3-kinase. In the present study, we studied relative contributions of above two distinct signaling pathways to the heregulin-induced mitogenic response via activated ErbB3. For this, clonal NIH-3T3 cell lines expressing wild-type ErbB3 and ErbB3 mutants were stimulated with heregulin beta1. While cyclin D1 level was markedly high and further increased by treatment of heregulin in cells expressing wild-type ErbB3, the elimination of either Shc binding or PI 3-kinase binding lowered both levels. This result was supported by the reduction of cyclin D1 expression by preteatment with MAPK kinase inhibitor or PI 3-kinase inhibitor before stimulation with heregulin. In accordance with the cyclin D1 expression, elimination of either Shc binding or PI 3-kinase binding reduced the heregulin-induced DNA synthesis and cell growth rate. Our results obtained by the comparison of wild-type and ErbB3 mutants indicate that the full induction of the cell cycle progression through G1/S phase by ErbB3 activation is dependent on both Shc/MAPK and PI 3-kinase signal transduction pathways.