angiotensin-i and Lung-Neoplasms

Renin-angiotensin system (RAS) signaling has been implicated in the development of cancer. The new RAS ACE2/Ang-(1-7)/Mas axis antagonizes the classical ACE/Ang II/AT1R axis. Ang-(1-7) has pleiotropic roles in lung cancer including suppressing proliferation, angiogenesis, and metastasis. This research was designed to investigate the effect of Ang-(1-7) on tumor-associated angiogenesis in DDP-resistant lung cancer cell lines. We first established acquired DDP-resistant cell lines A549 (A549-DDP) and LLC (LLC-DDP). We next performed RT-qPCR, western blot, ELISA, tube formation, microvessel density detection, immunohistochemistry, and tumor formation assays. The results showed that the mRNA and protein levels of RAS components and vascular endothelial growth factor A (VEGFa) were lessened in the A549/LLC-DDP+Ang-(1-7) group compared with the A549/LLC-DDP group. This effect could be blocked by the MAS receptor antagonist A779. The data revealed that Ang-(1-7) could perform its antiangiogenic function by PI3K/AKT and MAPK pathways. Furthermore, the impact of Ang-(1-7) on tumor-associated angiogenesis has been confirmed in lung cancer xenograft model with acquired DDP resistance. These results provide a theoretical basis for designing therapeutic strategies for targeting Ang-(1-7) in the treatment of NSCLC.

Topics: Angiotensin I; Carcinoma, Non-Small-Cell Lung; Humans; Lung Neoplasms; Peptide Fragments; Phosphatidylinositol 3-Kinases; Platinum; Vascular Endothelial Growth Factor A

The recently reported inhibitory effects of angiotensin 1-7 (Ang-(1-7)) on various cancers indicate its potential use as a therapeutic agent for primary and metastatic cancers. However, its extremely short half-life in the circulation greatly compromises its potential applications. Here, we reported an Ang-(1-7) analogue peptide with the amino and carboxy termini protected by acetylation and amination. The in vitro and in vivo degradation of the resulting analogue, Ang-AA, were determined using high-performance liquid chromatography (HPLC). At the same time, small RNA interference and competition studies were performed to evaluate the specific capacity of Ang-AA to bind to the cell surface Mas receptor. Cell Counting Kit-8 (CCK8), wound-healing, and Boyden chamber assays were performed to investigate the inhibitory effects of Ang-AA on A549 cells. Finally, the synergistic inhibitory effects of Ang-AA and paclitaxel (PTX) on A549 xenografts in mice were observed using animal imaging systems and survival observations. The toxicity of Ang-AA in mice was evaluated. Our results showed that acetylation and amination significantly inhibited the hydrolyzation of Ang-(1-7) in vitro and in vivo. The half-life of Ang-(1-7) in rats was prolonged from 2.4 ± 0.6 min to 238.7 ± 61.3 min ( p < 0.001). The specific binding of Ang-AA to the Mas receptor was well preserved, and Ang-AA exerted significantly greater inhibitory effects on the proliferation, migration, and invasion of A549 cells than Ang-(1-7). The combination of Ang-AA and PTX exhibited a significantly greater synergistic inhibitory effect on A549 xenografts than the combination of Ang-(1-7) and PTX. Ang-AA did not display obvious toxicity in mice. Our findings indicate acetylation and amination is a simple and effective method for producing Ang-(1-7) as a bioactive peptide.

Topics: A549 Cells; Acetylation; Amination; Angiotensin I; Animals; Antineoplastic Agents; Chemistry, Pharmaceutical; Drug Synergism; Half-Life; Humans; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Paclitaxel; Peptide Fragments; Rats; Rats, Sprague-Dawley; Treatment Outcome; Xenograft Model Antitumor Assays

Ang-(1-7) inhibits lung cancer cell growth both in vitro and in vivo. However, the molecular mechanism of action is unclear and also the rapid degradation of Ang-(1-7) in vivo limits its clinical application. Here, we have demonstrated that Ang- (1-7) inhibits lung cancer cell growth by interrupting pre-replicative complex assembly and restrains epithelial-mesenchymal transition via Cdc6 inhibition. Furthermore, we constructed a mutant adeno-associated viral vector AAV8 (Y733F) that produced stable and high efficient Ang-(1-7) expression in a xenograft tumor model. The results show that AAV8-mediated Ang-(1-7) over-expression can remarkably suppress tumor growth in vivo by down-regulating Cdc6 and anti-angiogenesis. Ang-(1-7) over-expression via the AAV8 method may be a promising strategy for lung cancer treatment.

Topics: Angiotensin I; Animals; Carcinoma, Non-Small-Cell Lung; Cell Cycle Proteins; Cell Line, Tumor; Cell Movement; Cell Proliferation; Dependovirus; DNA Replication; Down-Regulation; Epithelial-Mesenchymal Transition; Female; Genetic Vectors; Humans; Immunohistochemistry; Lung; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Multienzyme Complexes; Neovascularization, Pathologic; Nuclear Proteins; Peptide Fragments; Proteolysis; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

The local renin-angiotensin system (RAS) is one of the crucial components in the tumor microenvironment. Recent evidence suggests that the local RAS plays an important role in tumor metabolism, survival, angiogenesis and invasion processes. Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide of the RAS with vasodilator and anti-proliferative properties. Previous studies have demonstrated that Ang-(1-7) inhibits both the growth of human lung cancer cells in vitro and tumor angiogenesis in vivo through activation of the MAS receptor. This study investigated the anti-metastatic effect of Ang-(1-7) in A549 human lung adenocarcinoma cells in vitro. We found that Ang-(1-7) reduced the cell migratory and invasive abilities by reducing the expression and activity of MMP-2 and MMP-9. Furthermore, we demonstrated that the anti-migration and anti-invasion effect of Ang-(1-7) was mediated through inactivation of the PI3K/Akt, P38 and JNK signal pathways. Our results suggest that Ang-(1-7) may have therapeutic potential against advanced lung carcinoma as a new agent.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Angiotensin I; Cell Line, Tumor; Cell Movement; Cell Proliferation; Humans; Lung Neoplasms; MAP Kinase Signaling System; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mitogen-Activated Protein Kinase Kinases; Neoplasm Invasiveness; Neovascularization, Pathologic; Peptide Fragments; Phosphatidylinositol 3-Kinases; Phosphoinositide-3 Kinase Inhibitors; Proto-Oncogene Proteins c-akt; Renin-Angiotensin System; Signal Transduction; Survival

Angiotensin-(1-7) [Ang-(1-7)] is an endogenous seven-amino acid peptide hormone with antiproliferative properties. Our previous studies showed that Ang-(1-7) inhibits the growth of human lung cancer cells in vitro and reduces the size of human lung tumor xenografts in vivo. In the current study, s.c. injection of Ang-(1-7) not only caused a significant reduction in human A549 lung tumor growth but also markedly decreased vessel density, suggesting that the heptapeptide inhibits angiogenesis to reduce tumor size. A decrease in human endothelial cell tubule formation in Matrigel was observed following a 16 h incubation with Ang-(1-7), with a maximal reduction at a 10 nmol/L concentration. Ang-(1-7) had similar antiangiogenic effects in the chick chorioallantoic membrane, causing a >50% decrease in neovascularization. The Ang-(1-7)-induced reduction in both endothelial cell tubule formation and vessel formation in the chick was completely blocked by the specific Ang-(1-7) receptor antagonist [d-proline(7)]-Ang-(1-7), suggesting that these biological actions are mediated by an AT((1-7)) receptor. Ang-(1-7) significantly reduced vascular endothelial growth factor-A protein and mRNA in tumors from mice treated with the heptapeptide compared with saline controls as well as in the parent A549 human lung cancer cells in culture. These results suggest that Ang-(1-7) may attenuate tumor angiogenesis by reducing vascular endothelial growth factor-A, a primary proangiogenic protein. Taken together, this study shows that Ang-(1-7) exhibits significant antiangiogenic activity and may be a novel therapeutic agent for lung cancer treatment targeting a specific AT((1-7)) receptor.

Topics: Angiotensin I; Animals; Blotting, Western; Cell Line, Tumor; Cells, Cultured; Chick Embryo; Chorioallantoic Membrane; Endothelial Cells; Humans; Injections, Subcutaneous; Lung Neoplasms; Mice; Mice, Nude; Neovascularization, Pathologic; Neovascularization, Physiologic; Peptide Fragments; Proto-Oncogene Mas; Proto-Oncogene Proteins; Receptors, G-Protein-Coupled; Reverse Transcriptase Polymerase Chain Reaction; Vascular Endothelial Growth Factor A; Xenograft Model Antitumor Assays

Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide of the renin-angiotensin system with vasodilator and antiproliferative properties. Our previous studies showed that Ang-(1-7) reduced serum-stimulated growth of human lung cancer cells in vitro through activation of a unique AT((1-7)) receptor. The current study investigates the effect of Ang-(1-7) on lung tumor growth in vivo, using a human lung tumor xenograft model. Athymic mice with tumors resulting from injection of A549 human lung cancer cells were treated for 28 days with either i.v. saline or Ang-(1-7), delivered by implanted osmotic mini-pumps. Treatment with Ang-(1-7) reduced tumor volume by 30% compared with the size before treatment; in contrast, tumor size in the saline-treated animals increased 2.5-fold. These results correlate with a reduction in the proliferation marker Ki67 in the Ang-(1-7)-infused tumors when compared with the saline-infused tumor tissues. Treatment with Ang-(1-7) significantly reduced cyclooxygenase-2 (COX-2) mRNA and protein in tumors of Ang-(1-7)-infused mice when compared with mice treated with saline as well as in the parent A549 human lung cancer cells in tissue culture. These results suggest that Ang-(1-7) may decrease COX-2 activity and proinflammatory prostaglandins to inhibit lung tumor growth. In contrast, the heptapeptide had no effect on COX-1 mRNA in xenograft tumors or A549 cells. Because Ang-(1-7), a peptide with antithrombotic properties, reduces growth through activation of a selective AT((1-7)) receptor, our results suggest that the heptapeptide represents a novel treatment for lung cancer by reducing COX-2.

Topics: Adenocarcinoma; Angiotensin I; Animals; Cell Growth Processes; Cell Line, Tumor; Cyclooxygenase 2; Humans; Lung Neoplasms; Male; Mice; Mice, Nude; Peptide Fragments; RNA, Messenger; Xenograft Model Antitumor Assays

Angiotensin-(1-7) [Ang-(1-7)] is an endogenous peptide hormone of the renin-angiotensin system with vasodilator and anti-proliferative properties. Human adenocarcinoma SK-LU-1 and A549 cells as well as non-small lung cancer SK-MES-1 cells were treated with serum in the presence and absence of Ang-(1-7), to determine whether Ang-(1-7) inhibits the growth of lung cancer cells. Ang-(1-7) caused a significant reduction in serum-stimulated growth in all three lung cancer cell lines. Treatment with Ang-(1-7) resulted in both a dose- and time-dependent reduction in serum-stimulated DNA synthesis in all three cell lines, with IC(50)'s in the sub-nanomolar range. The Ang-(1-7) receptor antagonist [D-Ala(7)]-Ang-(1-7) blocked the attenuation of the serum-stimulated DNA synthesis of SK-LU-1 cells by Ang-(1-7), while neither AT(1) nor AT(2) angiotensin receptor subtype antagonists prevented the response to the heptapeptide. MAS mRNA and protein, a receptor for Ang-(1-7), was detected in the three lung cancer cell lines, suggesting that the anti-proliferative effect of Ang-(1-7) in the cancer cells may be mediated by the non-AT(1), non-AT(2), AT((1-7)) receptor MAS. Other angiotensin peptides [Ang I, Ang II, Ang-(2-8), Ang-(3-8) and Ang-(3-7)] did not attenuate mitogen-stimulated DNA synthesis of SK-LU-1 cells, demonstrating that Ang-(1-7) selectively inhibits SK-LU-1 cancer cell growth. Pre-treatment of SK-LU-1 cells with 10 nM Ang-(1-7) reduced serum-stimulated phosphorylation of extracellular signal-regulated kinase (ERK)1 and ERK2, indicating that the anti-proliferative effects may occur, at least in part, through inhibition of the ERK signal transduction pathway. The results of this study suggest that Ang-(1-7) inhibits lung cancer cell growth through the activation of an angiotensin peptide receptor and may represent a novel chemotherapeutic and chemopreventive treatment for lung cancer.

Topics: Angiotensin I; Antineoplastic Agents; Cell Division; Cell Line, Tumor; Culture Media; DNA Replication; Humans; Kinetics; Lung Neoplasms; Mitogen-Activated Protein Kinase 3; Peptide Fragments

A 54-year-old woman was referred to our hospital for the treatment of a tumor of the right chest wall. Clinical examination revealed hypertension, hypokalemia, metabolic alkalosis, hyperaldosteronism and hyperreninemia. Computed tomography and an abdominal echogram indicated a tumor in the right phrenic area and two tumors in the retroperitoneum near the pancreas head. After the surgical resection of these tumors, the primary reninism was diminished. The pathological diagnosis of these tumors was leiomyosarcoma. Plasma active and inactive (trypsin-activated) renin activities (PRA) were 85.7 and 38.9 ng angiotensin I/ml/h, respectively. These PRA did not respond to either postural stimulation or suppression by the volume expansion. Active and inactive renin activities in a right phrenic area tumor were 208 and 32 ng angiotensin I/mg protein /h, respectively. Those of an abdominal tumor were 196 and 30 ng angiotensin I/mg protein/h, respectively. Renin mRNA identical in molecular size to that of the human kidney was identified by northern blot analysis. This is the first case report of renin producing leiomyosarcoma derived from the lung, which is characterized by relatively lower plasma prorenin concentrations.

Topics: Abdomen; Angiotensin I; Blotting, Northern; Female; Humans; Leiomyosarcoma; Lung Neoplasms; Middle Aged; Renin; Retroperitoneal Neoplasms; RNA, Messenger; Tomography, X-Ray Computed