RESUMO
Microtubule-depolymerizing agents can selectively disrupt tumor vessels via inducing endothelial membrane blebbing. However, the mechanism regulating blebbing is largely unknown. IMB5046 is a newly discovered microtubule-depolymerizing agent. Here, the functions of focal adhesion kinase (FAK) during IMB5046-induced blebbing and the relevant mechanism are studied. We found that IMB5046 induced membrane blebbing and reassembly of focal adhesions in human vascular endothelial cells. Both FAK inhibitor and knock-down expression of FAK inhibited IMB5046-induced blebbing. Mechanism study revealed that IMB5046 induced the activation of FAK via GEF-H1/ Rho/ ROCK/ MLC2 pathway. cRGD peptide, a ligand of integrin, also blocked IMB5046-induced blebbing. After activation, FAK further promoted the phosphorylation of MLC2. This positive feedback loop caused more intensive actomyosin contraction and continuous membrane blebbing. FAK inhibitor blocked membrane blebbing via inhibiting actomyosin contraction, and stimulated stress fibre formation via promoting the phosphorylation of HSP27. Conclusively, these results demonstrate that FAK is a molecular switch controlling endothelial blebbing and stress fibre formation. Our study provides a new molecular mechanism for microtubule-depolymerizing agents to be used as vascular disrupting agents.
Assuntos
Benzoatos/farmacologia , Extensões da Superfície Celular/metabolismo , Células Endoteliais/metabolismo , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Microtúbulos/metabolismo , Morfolinas/farmacologia , Miosinas Cardíacas/metabolismo , Extensões da Superfície Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Citoesqueleto/metabolismo , Células Endoteliais/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Adesões Focais/efeitos dos fármacos , Adesões Focais/metabolismo , Proteínas de Choque Térmico/metabolismo , Humanos , Integrinas/metabolismo , Modelos Biológicos , Chaperonas Moleculares/metabolismo , Cadeias Leves de Miosina/metabolismo , Fosforilação/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Quinolonas/farmacologia , Fatores de Troca de Nucleotídeo Guanina Rho/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fibras de Estresse/efeitos dos fármacos , Fibras de Estresse/metabolismo , Sulfonas/farmacologia , Proteínas rho de Ligação ao GTP/metabolismo , Quinases Associadas a rho/metabolismoRESUMO
BACKGROUND: Pancreatic cancer stem cells (CSCs), a special population of cells, renew themselves infinitely and resist to various treatment. Gramicidin A (GrA), an ionophore antibiotic derived from microorganism, can form channels across the cell membrane and disrupt cellular ionic homeostasis, leading to cell dysfunction and death. As reported, the ionophore antibiotic salinomycin (Sal) has been proved to kill CSCs effectively. Whether GrA owns the potential as a therapeutic drug for CSCs still remains unknown. This study investigated the effect of GrA on pancreatic CSCs and the mechanism. METHODS: Tumorsphere formation assay was performed to assess pancreatic CSCs self-renewal potential. In vitro hemolysis assay was determined to test the borderline concentration of GrA. CCK-8 assay was used to detect pancreatic cancer cell proliferation capability. Flow cytometry was performed to detect cell apoptosis and mitochondrial membrane potential. Scanning and transmission electron microscopy was used to observe ultrastructural morphological changes on cell membrane surface and mitochondria, respectively. Western blot analysis was used to determine relative protein expression levels. Immunofluorescence staining was performed to observe CD47 re-distribution. RESULTS: GrA at 0.05 µM caused tumorspheres disintegration and decrease in number of pancreatic cancer BxPC-3 and MIA PaCa-2 cells. GrA and Sal both inhibited cancer cell proliferation. The IC50 values of GrA and Sal for BxPC-3 cells were 0.025 µM and 0.363 µM; while for MIA PaCa-2 cells were 0.032 µM and 0.163 µM, respectively. Compared on equal concentrations, the efficacy of GrA was stronger than that of Sal. GrA at 0.1 µM or lower did not cause hemolysis. GrA induced ultrastructural changes, such as the decrease of microvilli-like protrusions on cell surface membrane and the swelling of mitochondria. GrA down-regulated the expression levels of CD133, CD44, and CD47; in addition, CD47 re-distribution was observed on cell surface. Moreover, GrA showed synergism with gemcitabine in suppressing cancer cell proliferation. CONCLUSIONS: The study found that GrA was highly active against pancreatic CSCs. It indicates that GrA exerts inhibitory effects against pancreatic CSCs associated with CD47 down-regulation, implying that GrA might play a positive role in modulating the interaction between macrophages and tumor cells.
RESUMO
Depending on increasing extracellular protein utilization and altering metabolic programs, cancer cells could proliferate and survive without restricion by ingesting human serum albumin (HSA) to serve as nutritional amino acids. Here, we hypothesize that the consumption of albumin by cancer cells could be utilized as an efficient approach to targeted drug delivery. Lidamycin (LDM), an antitumor antibiotic with extremely potent cytotoxicity to cultured cancer cells, consists of an apoprotein (LDP) and an active enediyne chromophore (AE). In the present study, a novel albumin-lidamycin conjugate was prepared by DNA recombination and molecular reconstitution. Results show that the IC50 values of albumin-lidamycin conjugate (HSA-LDP-AE) for a variety of tested cancer cells were at subnanomolar levels. At tolerated doses, the albumin-lidamycin conjugate significantly inhibited the growth of lung carcinoma PG-BE1 xenografts by 97.8%. The therapeutic efficacy of the albumin-lidamycin conjugate was much stronger than that of free lidamycin. Meanwhile, the images of albumin-lidamycin conjugate showed obvious and lasting tumor localization and fluorescence enrichment and there was no detectable signal in nontumor locations. Taken together, albumin-lidamycin conjugate, a new format of lidamycin, could be a promising antitumor therapeutic agent and albumin-integration might be a feasible approach to targeted antitumor drug delivery.
Assuntos
Albuminas/química , Aminoglicosídeos/química , Aminoglicosídeos/uso terapêutico , Antibióticos Antineoplásicos/uso terapêutico , Enedi-Inos/química , Enedi-Inos/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Antibióticos Antineoplásicos/química , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Imagem Óptica , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Defensins play an essential role in innate immunity. In this study, a novel recombinant ß-defensin that targets the epidermal growth factor receptor (EGFR) was designed and prepared. The EGFR-targeting ß-defensin consists of an EGF-derived oligopeptide (Ec), a ß-defensin-1 peptide (hBD1) and a lidamycin-derived apoprotein (LDP), which serves as the "scaffold" for the fusion protein (Ec-LDP-hBD1). Ec-LDP-hBD1 effectively bound to EGFR highly expressed human epidermoid carcinoma A431 cells. The cytotoxicity of Ec-LDP-hBD1 to EGFR highly expressed A431 cells was more potent than that to EGFR low-expressed human lung carcinoma A549 and H460 cells (the IC50 values in A431, A549, and H460 cells were 1.8 ± 0.55, 11.9 ± 0.51, and 5.19 ± 1.21 µmol/L, respectively); in addition, the cytotoxicity of Ec-LDP-hBD1 was much stronger than that of Ec-LDP and hBD1. Moreover, Ec-LDP-hBD1 suppressed cancer cell proliferation and induced mitochondria-mediated apoptosis. Its in vivo anticancer action was evaluated in athymic mice with A431 and H460 xenografts. The mice were administered Ec-LDP-hBD1 (5, 10 mg/kg, i.v.) two times with a weekly interval. Administration of Ec-LDP-hBD1 markedly inhibited the tumor growth without significant body weight changes. The in vivo imaging further revealed that Ec-LDP-hBD1 had a tumor-specific distribution with a clear image of localization. The results demonstrate that the novel recombinant EGFR-targeting ß-defensin Ec-LDP-hBD1 displays both selectivity and enhanced cytotoxicity against relevant cancer cells by inducing mitochondria-mediated apoptosis and exhibits high therapeutic efficacy against the EGFR-expressed carcinoma xenograft. This novel format of ß-defensin, which induces mitochondrial-mediated apoptosis, may play an active role in EGFR-targeting cancer therapy.
Assuntos
Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/tratamento farmacológico , Mitocôndrias/metabolismo , Proteínas Recombinantes de Fusão/uso terapêutico , beta-Defensinas/uso terapêutico , Aminoglicosídeos/metabolismo , Aminoglicosídeos/uso terapêutico , Animais , Antineoplásicos/metabolismo , Apoproteínas/metabolismo , Apoproteínas/uso terapêutico , Linhagem Celular Tumoral , Enedi-Inos/metabolismo , Enedi-Inos/uso terapêutico , Receptores ErbB/metabolismo , Feminino , Humanos , Camundongos Nus , Mitocôndrias/patologia , Ligação Proteica , Proteínas Recombinantes de Fusão/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , beta-Defensinas/metabolismoRESUMO
CD13 is a marker of angiogenic endothelial cells, and recently it is proved to be a biomarker of human liver cancer stem cells (CSCs). Herein, the therapeutic effects of NGR-LDP-AE, a fusion protein composed of CD13-targeting peptide NGR and antitumor antibiotic lidamycin, on human liver cancer and its mechanism were studied. Western blot and immunofluorescence assay demonstrated that CD13 (WM15 epitope) was expressed in both human liver cancer cell lines and vascular endothelial cells, while absent in normal liver cells. MTT assay showed that NGR-LDP-AE displayed potent cytotoxicity to cultured tumor cell lines with IC50 values at low nanomolar level. NGR-LDP-AE inhibited tumorsphere formation of liver cancer cells, and the IC50 values were much lower than that in MTT assay, indicating selectively killing of CSCs. In endothelial tube formation assay, NGR-LDP-AE at low cytotoxic dose significantly inhibited the formation of intact tube networks. Animal experiment demonstrated that NGR-LDP-AE inhibited the growth of human liver cancer xenograft. Immunohistochemical analysis showed that NGR-LDP-AE induced the down-regulation of CD13. In vitro experiment using cultured tumor cells also confirmed this result. NGR-LDP-AE activated both apoptotic and autophagic pathways in cultured tumor cells, while the induced autophagy protected cells from death. Conclusively, NGR-LDP-AE exerts its antitumor activity via killing liver CSCs and inhibiting angiogenesis. With one targeting motif, NGR-LDP-AE acts on both liver CSCs and angiogenic endothelial cells. It is a promising dual targeting fusion protein for liver cancer therapy, especially for advanced or relapsed cancers.
Assuntos
Antineoplásicos/farmacologia , Antígenos CD13/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Neovascularização Patológica/tratamento farmacológico , Proteínas Recombinantes/farmacologia , Animais , Autofagia/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Humanos , Fígado/irrigação sanguínea , Fígado/efeitos dos fármacos , Fígado/patologia , Neoplasias Hepáticas/patologia , Camundongos Nus , Terapia de Alvo Molecular/métodos , Oligopeptídeos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Overexpression of EGFR and MMP-2 plays an essential role in the initiation and progression of non-small-cell lung carcinoma (NSCLC). In this study, a novel format of EGFR/MMP-2 bi-targeted fusion protein Ec-LDP-TIMP2 and its enediyne-integrated analogue Ec-LDP(AE)-TIMP2 have been prepared by genetic engineering and molecular reconstitution. The Ec-LDP(AE)-TIMP2 comprises endogenous inhibitor of matrix metalloproteinase 2 (TIMP2), EGF-derived oligopeptide (Ec), lidamycin apoprotein (LDP), and the extremely potent cytotoxic enediyne (AE). By tissue microarray, Ec-LDP-TIMP2 showed high binding intensity and selectivity to human NSCLC specimens as compared with the matched non-cancerous tissues. By in vivo imaging, Ec-LDP-TIMP2 displayed prominent tumor-specific distribution in human NSCLC H460 xenograft. Particularly, Ec-LDP(AE)-TIMP2 inhibited tumor growth of H460 xenograft in athymic mice more striking. At doses of 0.2 and 0.4mg/kg, Ec-LDP(AE)-TIMP2 suppressed tumor growth by 74% and 89%, respectively. No histopathological changes were found in various organs of treated animals, suggesting that the effective dosage was tolerated. In summary, the ligand-based and enediyne-integrated fusion protein displaying extremely potent cytotoxicity might be highly effective for NSCLC therapy and useful as a carrier for drug delivery.
Assuntos
Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptores ErbB/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Metaloproteinase 2 da Matriz/metabolismo , Proteínas Recombinantes de Fusão/farmacologia , Inibidor Tecidual de Metaloproteinase-2/farmacologia , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Feminino , Humanos , Ligantes , Neoplasias Pulmonares/metabolismo , Inibidores de Metaloproteinases de Matriz/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Oligopeptídeos/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodosRESUMO
Tuftsin (TF) is an immunomodulator tetrapeptide (Thr-Lys-Pro-Arg) that binds to the receptor neuropilin-1 (Nrp1) on the surface of cells. Many reports have described anti-tumor activity of tuftsin to relate with nonspecific activation of the host immune system. Lidamycin (LDM) that displays extremely potent cytotoxicity to cancer cells is composed of an apoprotein (LDP) and an enediyne chromophore (AE). In addition, Ec is an EGFR-targeting oligopeptide. In the present study, LDP was used as protein scaffold and the specific carrier for the highly potent AE. Genetically engineered fusion proteins LDP-TF and Ec-LDP-TF were prepared; then, the enediyne-energized fusion protein Ec-LDM-TF was generated by integration of AE into Ec-LDP-TF. The tuftsin-based fusion proteins LDP-TF and Ec-LDP-TF significantly enhanced the phagocytotic activity of macrophages as compared with LDP (P < 0.05). Ec-LDP-TF effectively bound to tumor cells and macrophages; furthermore, it markedly suppressed the growth of human epidermoid carcinoma A431 xenograft in athymic mice by 84.2 % (P < 0.05) with up-regulated expression of TNF-α and IFN-γ. Ec-LDM-TF further augmented the therapeutic efficacy, inhibiting the growth of A431 xenograft by 90.9 % (P < 0.05); notably, the Ec-LDM-TF caused marked down-regulation of CD47 in A431 cells. Moreover, the best therapeutic effect was recorded in the group of animals treated with the combination of Ec-LDP-TF with Ec-LDM-TF. The results suggest that tuftsin-based, enediyne-energized, and EGFR-targeting fusion proteins exert highly antitumor efficacy with CD47 modulation. Tuftsin-based fusion proteins are potentially useful for treatment of EGFR- and CD47-overexpressing cancers.
Assuntos
Antígeno CD47/imunologia , Enedi-Inos/farmacologia , Receptores ErbB/imunologia , Imunotoxinas/farmacologia , Proteínas Recombinantes de Fusão/farmacologia , Tuftsina/farmacologia , Animais , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/terapia , Comunicação Celular , Linhagem Celular Tumoral , Regulação para Baixo , Enedi-Inos/química , Feminino , Humanos , Imunotoxinas/química , Imunotoxinas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Vírus da Pneumonia Murina , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/imunologia , Tuftsina/química , Tuftsina/imunologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The present work evaluated the synergistic efficacy of an enediyne antibiotic lidamycin (LDM) plus temozolomide (TMZ) against glioma in vitro and in vivo. LDM plus TMZ inhibited the proliferations of rat glioma C6 cells and human glioma U87 cells more efficiently than the single usage of LDM or TMZ. In addition, LDM also potentiated the apoptosis inductions by TMZ in rat C6 cells and human U87 cells. Meanwhile, the results of TdT-mediated dUTP Nick End Labeling assay for subcutaneous U87 tumor sections indicated an enhanced apoptosis induction in vivo by LDM plus TMZ, which confirmed the high potency of the combination for glioma therapy. As determined by Western blot, apoptosis signal pathways in C6 cells and U87 cells were markedly affected by the synergistic alteration of P53, bax, procaspase 3, and bcd-2 expression. In both subcutaneous U87 xenograft and C6 intracerebral orthotopic implant model, TMZ-induced glioma growth suppression was dramatically potentiated by LDM. As shown, the combination therapy efficiently reduced the tumor volumes and tumor weights of the human glioma U87 xenograft. Kaplan-Meier assay revealed that LDM plus TMZ dramatically prolonged the life span of C6 intracerebral tumor-bearing rats with decreased tumor size. This study indicates that the combination of LDM with TMZ might be a promising strategy for glioma therapy.
Assuntos
Aminoglicosídeos/uso terapêutico , Antibióticos Antineoplásicos/uso terapêutico , Antineoplásicos Alquilantes/uso terapêutico , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Dacarbazina/análogos & derivados , Enedi-Inos/uso terapêutico , Glioma/tratamento farmacológico , Aminoglicosídeos/farmacologia , Animais , Antibióticos Antineoplásicos/farmacologia , Antineoplásicos Alquilantes/farmacologia , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Dacarbazina/farmacologia , Dacarbazina/uso terapêutico , Sinergismo Farmacológico , Enedi-Inos/farmacologia , Glioma/patologia , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Ratos , Transdução de Sinais/efeitos dos fármacos , TemozolomidaRESUMO
Telomere is a protective structure located at the end of chromosomes of eukaryotes, involved in maintaining the integrity and stability of the genome. Telomeres play an essential role in cancer progression; accordingly, targeting telomere dynamics emerges as an effective approach for the development of cancer therapeutics. Targeting telomere dynamics may work through multifaceted molecular mechanisms; those include the activation of anti-telomerase immune responses, shortening of telomere lengths, induction of telomere dysfunction and constitution of telomerase-responsive drug release systems. In this review, we summarize a wide variety of telomere dynamics-targeted agents in preclinical studies and clinical trials, and reveal their promising therapeutic potential in cancer therapy. As shown, telomere dynamics-active agents are effective as anti-cancer chemotherapeutics and immunotherapeutics. Notably, these agents may display efficacy against cancer stem cells, reducing cancer stem levels. Furthermore, these agents can be integrated with the capability of tumor-specific drug delivery by the constitution of related nanoparticles, antibody drug conjugates and HSA-based drugs.
Assuntos
Antineoplásicos , Neoplasias , Telomerase , Telômero , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/terapia , Telômero/efeitos dos fármacos , Antineoplásicos/farmacologia , Antineoplásicos/química , Telomerase/antagonistas & inibidores , Animais , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Imunoterapia/métodos , Células-Tronco Neoplásicas/efeitos dos fármacosRESUMO
Trophoblast cell surface antigen 2 (Trop2) is considered to be an attractive therapeutic target in cancer treatments. We previously generated a new humanized anti-Trop2 antibody named hIMB1636, and designated it as an ideal targeting carrier for cancer therapy. Lidamycin (LDM) is a new antitumor antibiotic, containing an active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). AE and LDP can be separated and reassembled, and the reassembled LDM possesses cytotoxicity similar to that of native LDM; this has made LDM attractive in the preparation of gene-engineering drugs. We herein firstly prepared a new fusion protein hIMB1636-LDP composed of hIMB1636 and LDP by genetic engineering. This construct showed potent binding activities to recombinant antigen with a KD value of 4.57 nM, exhibited binding to Trop2-positive cancer cells and internalization and transport to lysosomes, and demonstrated powerful tumor-targeting ability in vivo. We then obtained the antibody-drug conjugate (ADC) hIMB1636-LDP-AE by molecular reconstitution. In vitro, hIMB1636-LDP-AE inhibited the proliferation, migration, and tumorsphere formation of tumor cells with half-maximal inhibitory concentration (IC50) values at the sub-nanomolar level. Mechanistically, hIMB1636-LDP-AE induced apoptosis and cell-cycle arrest. In vivo, hIMB1636-LDP-AE also inhibited the growth of breast and lung cancers in xenograft models. Moreover, compared to sacituzumab govitecan, hIMB1636-LDP-AE showed more potent antitumor activity and significantly lower myelotoxicity in tumors with moderate Trop2 expression. This study fully revealed the potent antitumor efficacy of hIMB1636-LDP-AE, and also provided a new preparation method for LDM-based ADC, as well as a promising candidate for breast cancer and lung cancer therapeutics.
RESUMO
BACKGROUND: Endostatin (ES) inhibits endothelial cell proliferation, migration, invasion, and tube formation. It also shows antiangiogenesis and antitumor activities in several animal models. Endostatin specifically targets tumor vasculature to block tumor growth. Lidamycin (LDM), which consists of an active enediyne chromophore (AE) and a non-covalently bound apo-protein (LDP), is a member of chromoprotein family of antitumor antibiotics with extremely potent cytotoxicity to cancer cells. Therefore, we reasoned that endostatin-lidamycin (ES-LDM) fusion proteins upon energizing with enediyne chromophore may obtain the combined capability targeting tumor vasculature and tumor cell by respective ES and LDM moiety. METHODS: In this study, we designed and obtained two new endostatin-based fusion proteins, endostatin-LDP (ES-LDP) and LDP-endostatin (LDP-ES). In vitro, the antiangiogenic effect of fusion proteins was determined by the wound healing assay and tube formation assay and the cytotoxicity of their enediyne-energized analogs was evaluated by CCK-8 assay. Tissue microarray was used to analyze the binding affinity of LDP, ES or ES-LDP with specimens of human lung tissue and lung tumor. The in vivo efficacy of the fusion proteins was evaluated with human lung carcinoma PG-BE1 xenograft and the experimental metastasis model of 4T1-luc breast cancer. RESULTS: ES-LDP and LDP-ES disrupted the formation of endothelial tube structures and inhibited endothelial cell migration. Evidently, ES-LDP accumulated in the tumor and suppressed tumor growth and metastasis. ES-LDP and ES show higher binding capability than LDP to lung carcinoma; in addition, ES-LDP and ES share similar binding capability. Furthermore, the enediyne-energized fusion protein ES-LDP-AE demonstrated significant efficacy against lung carcinoma xenograft in athymic mice. CONCLUSIONS: The ES-based fusion protein therapy provides some fundamental information for further drug development. Targeting both tumor vasculature and tumor cells by endostatin-based fusion proteins and their enediyne-energized analogs probably provides a promising modality in cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Endostatinas/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Recombinantes de Fusão/farmacologia , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Endostatinas/farmacocinética , Endostatinas/uso terapêutico , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/fisiologia , Feminino , Humanos , Pulmão/metabolismo , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas Recombinantes de Fusão/farmacocinética , Proteínas Recombinantes de Fusão/uso terapêutico , Análise Serial de Tecidos , Distribuição Tecidual , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The proteasome inhibitor bortezomib has been applied successfully to treat multiple myeloma (MM). Its synergistic effects with other anticancer drugs have been studied widely. In the present study, it was found that lidamycin (LDM), a member of the enediyne antibiotic family, showed much more potent cytotoxicity than bortezomib to MM cell lines: U266 and SKO-007. Here, we investigated the potential synergy of bortezomib and LDM on MM cells. The results showed that cotreatment of bortezomib and LDM synergistically induced cytotoxicity and apoptosis in MM cell lines, followed by enhanced caspase-3 cleavage and degradation of poly-ADP-ribose polymerase together with the decreased nuclear factor-κB protein. These two drugs synergistically induced apoptosis, which was associated with enhanced activation of two mitogen-activated protein kinases: p38 mitogen-activated protein kinase and c-Jun NH(2)-terminal kinase. Moreover, bortezomib plus LDM synergistically induced apoptosis was also associated with downregulation of extracellular signal-regulated kinase, and induction of endoplasmic reticulum stress response. Overall, our results indicate that the combined regimen of bortezomib and LDM might be a potential therapeutic remedy for the treatment of MM.
Assuntos
Aminoglicosídeos/farmacologia , Antineoplásicos/farmacologia , Ácidos Borônicos/farmacologia , Enedi-Inos/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Pirazinas/farmacologia , Aminoglicosídeos/administração & dosagem , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Ácidos Borônicos/administração & dosagem , Bortezomib , Caspase 3/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Enedi-Inos/administração & dosagem , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Pirazinas/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Tea polyphenols (TPs), major biological active constituents of green tea, exert moderate and selective anticancer effects. Molecular mechanisms of TPs in cancer prevention and treatment involve multiple potential molecular targets. TPs inhibit growth factor receptor-mediated signal transduction pathway, decrease the activities of mitogen activated protein kinases and activator protein transcription factor-1, block nuclear factor-kappaB signaling pathway, reduce proteasome activity, lower overexpression of COX-2, subside dihydrofolate reductase and telomerase, and inhibit DNA methylation and matrix metalloproteinases. Furthermore, TPs enhance the inhibitory effect on the growth of cancers by traditional anticancer drugs or targeted antitumor drugs in vitro and in vivo and reverse multidrug resistances of cancer cells to vincristine, doxorubicin, and 5-fluorouracil. Besides, TPs reduce the nephrotoxicity induced by cisplatin, ameliorate irinotecan-induced side effects in the small intestine of mice, and decrease bleomycin-caused DNA damage in human leukocytes. TPs also increase antitumor activity of vaccine through immunological modulation. TPs play roles of the augmentation of antitumor effects, the reversal of multidrug resistance, and the reduction of side effects of chemotherapeutic drugs. TPs could be used as biochemical modulators in cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Terapia de Alvo Molecular/métodos , Neoplasias/tratamento farmacológico , Polifenóis/farmacologia , Chá/química , Animais , Antineoplásicos/isolamento & purificação , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Polifenóis/isolamento & purificação , Transdução de Sinais/efeitos dos fármacos , Terapias em EstudoRESUMO
This study is to optimize the preparation process of fusion protein Fv-LDP which was expressed in the form of inclusion body and consisted of lidamycin apoprotein LDP and single-chain Fv antibody (scFv) directed against type IV collagenase. The preparation and the dissolution of inclusion body, the immobilized metal affinity chromatography of the target protein and the renaturization by stepwise dialysis were optimized by single-factor analysis or orthogonal design. In addition, the refolded fusion protein Fv-LDP was refined by Sephadex G-75 chromatography followed by fluorescence-activated cell sorter (FACS)-based saturation binding assay to measure its antigen-binding activity. After optimization of the process, the purity of fusion protein Fv-LDP existed in the inclusion body was 63.9% and the corresponding solubility was 95.7%; Under denaturing conditions, the purity of fusion protein Fv-LDP was more than 95% after the purification process. The percentage of monomeric fusion protein Fv-LDP was 60% after the refolding process, while it was further refined to 85% which was 5.6-fold higher than that of the initial refolding condition. The refined fusion protein Fv-LDP could bind to human lung adenocarcinoma PAa cells and human hepatoma BEL-7402 cells with the dissociation constants (Kd) of 0.176 micromol x L(-1) and 0.904 micromol x L(-1), respectively. The preparation process of fusion protein Fv-LDP has been successfully optimized, which provides the experimental basis for the production and future development of fusion protein Fv-LDP, and might serve as a relatively practical system for the preparation of other scFv-based proteins expressed in the form of inclusion body.
Assuntos
Aminoglicosídeos , Apoproteínas , Enedi-Inos , Proteínas Recombinantes de Fusão , Anticorpos de Cadeia Única , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Aminoglicosídeos/química , Aminoglicosídeos/metabolismo , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/metabolismo , Apoproteínas/química , Apoproteínas/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Colagenases/imunologia , Enedi-Inos/química , Enedi-Inos/metabolismo , Escherichia coli/química , Escherichia coli/metabolismo , Humanos , Corpos de Inclusão/química , Corpos de Inclusão/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Ligação Proteica , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismoRESUMO
In the present study, a new compound named 17-(6-cinnamamido-hexylamino-)-17-demethoxygeldanamycin (CDG) was obtained by introducing the cinnamic acid (CA) group into the 17-site of geldanamycin (GDM). The anti-cancer effects of CDG in vitro and in vivo were evaluated. MTT assay was used to examine the inhibitory effect of CDG on the proliferation of MCF-7, HepG2, H460 and SW1990 cells. Immunofluorescent staining flow cytometry combined with Annexin V-FITC/PI staining were used to detect apoptotic cells. Transwell assay was used to analyze the effect of CDG on cell invasion and migration ability. Western blotting was used to detect the expression levels of RAF-1, EGFR, AKT, CDK4 and HER-2 of MCF-7, HepG2 and H460 cells. The toxicities of CDG and GDM were evaluated in mice. Using the subcutaneously transplanted MCF-7 xenograft in nude mice, inhibitory effect was evaluated in vivo. The results showed that CDG inhibited the proliferation of cancer cells (IC50: 13.6-67.4 microg.mL-1). After exposure to CDG for 48 h, most cells presented typical morphologic changes of apoptosis such as chromatin condensation or shrunken nucleus. The rates of apoptosis of MCF-7, HepG2, H460 and SW1990 cells incubated with 10 microg.mL-1 CDG were 23.16%, 27.55%, 22.21%, 20.47%, respectively. A dose-dependent reduction of migration of four cell lines was found after exposure to CDG. The decreased levels of RAF-1, EGFR, AKT, CDK4 and HER-2 showed that CDG possessed HSP90 inhibitory effect. The result of animal toxicity test on the mice suggested that CDG had lower toxicity than GDM. Meanwhile, CDG inhibited the growth of MCF-7 xenografts of athymic mice.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Benzoquinonas/farmacologia , Lactamas Macrocíclicas/farmacologia , Carga Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Benzoquinonas/síntese química , Benzoquinonas/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Quinase 4 Dependente de Ciclina/metabolismo , Receptores ErbB/metabolismo , Feminino , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Humanos , Lactamas Macrocíclicas/síntese química , Lactamas Macrocíclicas/química , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , Proteínas Proto-Oncogênicas A-raf/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Distribuição Aleatória , Receptor ErbB-2/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: To establish a simple and highly effective isolation and culture system of mouse spermatogonial stem cells(SSCs)and detect the expression of stem cell-related markers in the isolated cells. METHODS: The structures of seminiferous tubules of neonatal(6-8 days of age)and adult(26-28 weeks)DBA/2 mice were compared using histochemical examination. Testes of neonatal mice were selected for preparing primary cells. The digestive efficiency of different enzymes was compared. SSCs were isolated according to the different binding abilities of testicle somatic cells and SSCs to gelatin matrix. The effects of different base culture media such as StemPro34 and α-MEM,gelatin,and serum on the SSCs binding activity and growth were studied. The cell morphology was observed during the culture process. Immunofluorescence was used to detect the expression of SSCs and cancer stem cells(CSCs)-related markers in SSCs. RESULTS: The content of SSCs in the testes of neonatal mice was relatively higher than that in adult mice. Trypsin showed the highest digestive efficiency. In StemPro34 supplemented with 1% fetal bovine serum and on the gelatin matrix,testicular somatic cells could bind with the plate efficiently. Spermatogonial cells grew well when using mitomycin C-treated testicular somatic cells as feeder cells and showed typical characteristic of SSCs. After 13 days of culture,spermatogonial cells formed cell clusters. Immunofluorescence assay showed that SSCs markers glial cell line-derived neurotrophic factor(GDNF)family receptor α1(GFRα1)and VASA protein were highly expressed in the cell clusters. CSCs marker CD44 was expressed in the As,Apr,Aal and the inner cells of the cell clusters,while seldom expressed in the somatic cells. CONCLUSIONS: An isolation and culture system of SSCs derived from DBA/2 mice was established. CD44 is highly expressed in the early stage of spermatogonial cell development.
Assuntos
Técnicas de Cultura de Células , Receptores de Hialuronatos/metabolismo , Espermatogônias/citologia , Células-Tronco/citologia , Animais , Biomarcadores/metabolismo , Diferenciação Celular , Células Cultivadas , Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos DBARESUMO
OBJECTIVE: To prepare a recombinant EGFR-targeted fusion protein drug conjugate acting on telomere and telomerase; and evaluate its antitumor efficacy. METHODS: We prepared a recombinant fusion protein Fv-LDP-D3 which consists of the Fv fragment of an anti-EGFR monoclonal antibody (MAb), the apoprotein of lidamycin (LDP), and the third domain (D3) of human serum albumin (HSA); then generated the conjugate Fv-LDP-D3â¼AE by integrating the active enediyne chomophore (AE) of lidamycin. Accordingly, in vitro and in vivo experiments were performed. RESULTS: As shown, Fv-LDP-D3 specifically bound to EGFR highly-expressing cancer cells and intensely entered K-Ras mutant cells via enhanced macropinocytosis. By in vivo imaging, Fv-LDP-D3 displayed intense accumulation and persistent retention in tumor-site. Furthermore, the conjugate Fv-LDP-D3â¼AE displayed highly potent cytotoxicity to cancer cells with IC50 at 0.1 nM level. The conjugate induced telomere shortening and downregulation of telomerase and EGFR pathway related proteins. Fv-LDP-D3â¼AE exhibited prominent antitumor efficacy against human colorectal cancer xenograft accompanying with significant increase of serum IFN-ß in athymic mice. CONCLUSION: The recombinant fusion protein conjugate that exhibits the capability of tumor-targeting drug delivery can induce telomere shortening and telomerase downregulation. The investigation may lay the foundation for the development of MAb-HSA domain-based fusion protein drug conjugates.
Assuntos
Imunoconjugados , Telomerase , Animais , Camundongos , Humanos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , Proteínas Recombinantes de Fusão/metabolismo , Telomerase/genética , Telomerase/metabolismo , Receptores ErbB/metabolismo , Regulação para Baixo , Encurtamento do Telômero , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de Xenoenxerto , Imunoconjugados/farmacologia , Telômero/metabolismoRESUMO
Trophoblast cell surface antigen 2 (Trop2) has emerged as a potential target for effective cancer therapy. In this study, we report a novel anti-Trop2 antibody IMB1636, developed using hybridoma technology. It exhibited high affinity and specificity (KD = 0.483 nM) in binding both antigens and cancer cells, as well as human tumor tissues. hIMB1636 could induce endocytosis, and enabled targeted delivery to the tumor site with an in vivo retention time of 264 h. The humanized antibody hIMB1636, acquired using CDR grafting, exhibited the potential to directly inhibit cancer cell proliferation and migration, and to induce ADCC effects. Moreover, hIMB1636 significantly inhibited the growth of MDA-MB-468 xenograft tumors in vivo. Mechanistically, hIMB1636 induced cell cycle arrest and apoptosis by regulating cyclin-related proteins and the caspase cascade. In comparison to commercialized sacituzumab, hIMB1636 recognized a conformational epitope instead of a linear one, bound to antigen and cancer cells with similar binding affinity, induced significantly more potent ADCC effects against cancer cells, and displayed superior antitumor activities both in vitro and in vivo. The data presented in this study highlights the potential of hIMB1636 as a carrier for the formulation of antibody-based conjugates, or as a promising candidate for anticancer therapy.
Assuntos
Imunoconjugados , Neoplasias , Humanos , Moléculas de Adesão Celular , Anticorpos Monoclonais , Neoplasias/tratamento farmacológico , Imunoconjugados/farmacologia , Proliferação de Células , Linhagem Celular Tumoral , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Herein, we first prepared a novel anti-TROP2 antibody-drug conjugate (ADC) hIMB1636-MMAE using hIMB1636 antibody chemically coupled to monomethyl auristatin E (MMAE) via a Valine-Citrulline linker and then reported its characteristics and antitumor activity. With a DAR of 3.92, it binds specifically to both recombinant antigen (KD â¼ 0.687 nM) and cancer cells and could be internalized by target cells and selectively kill them with IC50 values at nanomolar/subnanomolar levels by inducing apoptosis and G2/M phase arrest. hIMB1636-MMAE also inhibited cell migration, induced ADCC effects, and had bystander effects. It displayed significant tumor-targeting ability and excellent tumor-suppressive effects in vivo, resulting in 5/8 tumor elimination at 12 mg/kg in the T3M4 xenograft model or complete tumor disappearance at 10 mg/kg in BxPc-3 xenografts in nude mice. Its half-life in mice was about 87 h. These data suggested that hIMB1636-MMAE was a promising candidate for the treatment of pancreatic cancer with TROP2 overexpression.
Assuntos
Imunoconjugados , Neoplasias Pancreáticas , Humanos , Animais , Camundongos , Imunoconjugados/farmacologia , Imunoconjugados/uso terapêutico , Linhagem Celular Tumoral , Camundongos Nus , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias PancreáticasRESUMO
The use of monoclonal antibodies (mAbs) for cancer therapy has achieved considerable success in recent years. Approximate 17 monoclonal antibodies have been approved as cancer therapeutics since 1997. Antibody-drug conjugates (ADC) are powerful new treatment options for cancer, and naked antibodies have recently achieved remarkable success. The safety and effectiveness of therapeutic mAbs in oncology vary depending on the nature of the target antigen and the mechanisms of tumor cell killing. This review provides a summary of the current state of antibody-based cancer therapy, including the mechanisms of tumor cell killing by antibodies, tumor antigens as antibody targets, clinical effectiveness of antibodies in cancer patients and nanoparticles-based ADCs.