Antiangiogenic agents in the management of non-small cell lung cancer: where do we stand now and where are we headed?

Design, synthesis and biological evaluation of novel podophyllotoxin derivatives as tubulin-targeting anticancer agents

CONTEXT

Podophyllotoxin (PPT) derivatives, used in cancer therapy, require development toward enhanced efficacy and reduced toxicity.

OBJECTIVE

This study synthesizes PPT derivatives to assess their anticancer activities.

MATERIALS AND METHODS

Compounds E1-E16 antiproliferative activity was tested against four human cancer cell lines (H446, MCF-7, HeLa, A549) and two normal cell lines (L02, BEAS-2B) using the CCK-8 assay. The effects of compound E5 on A549 cell growth were evaluated through molecular docking, in vitro assays (flow cytometry, wound healing, Transwell, colony formation, Western blot), and in vivo tests in female BALB/c nude mice treated with E5 (2 and 4 mg/kg). E5 (4 mg/kg) significantly reduced xenograft tumor growth compared to the DMSO control group.

RESULTS

Among the 16 PPT derivatives tested for cytotoxicity, E5 exhibited potent effects against A549 cells (IC50: 0.35 ± 0.13 µM) and exceeded the reference drugs PPT and etoposide to inhibit the growth of xenograft tumours. E5-induced cell cycle arrest in the S and G2/M phases accelerated tubulin depolymerization and triggered apoptosis and mitochondrial depolarization while regulating the expression of apoptosis-related proteins and effectively inhibited cell migration and invasion, suggesting a potential to limit metastasis. Molecular docking showed binding of E5 to tubulin at the colchicine site and to Akt, with a consequent down-regulation of PI3K/Akt pathway proteins.

DISCUSSION AND CONCLUSIONS

This research lays the groundwork for advancing cancer treatment through developing and using PPT derivatives. The encouraging results associated with E5 call for extended research and clinical validation, leading to novel and more effective cancer therapies.

Role of the STING pathway in myeloid neoplasms: a prospero-registered systematic review of principal hurdles of STING on the road to the clinical practice

Myeloid neoplasms are a group of bone marrow diseases distinguished by disruptions in the molecular pathways that regulate the balance between hematopoietic stem cell (HSC) self-renewal and the generation of specialized cells. Cytokines and chemokines, two important components of the inflammatory process, also influence hematological differentiation. In this scenario, immunological dysregulation plays a pivotal role in the pathogenesis of bone marrow neoplasms. The STING pathway recognizes DNA fragments in the cell cytoplasm and triggers an immune response by type I interferons. The role of STING in cancer has not yet been established; however, both actions, as an oncogene or tumor suppressor, have been documented in other types of cancer. Therefore, we performed a systematic review (registered in PROSPERO database #CRD42023407512) to discuss the role of STING pathway in the advancement of pathogenesis and/or prognosis for different myeloid neoplasms. In brief, scientific evidence supports investigations that primarily use cell lines from myeloid neoplasms, such as leukemia. More high-quality research and clinical trials are needed to understand the role of the STING pathway in the pathology of hematological malignancies. Finally, the STING pathway suggests being a promising therapeutic molecular target, particularly when combined with current drug therapies.

At the Crossroads of the cGAS-cGAMP-STING Pathway and the DNA Damage Response: Implications for Cancer Progression and Treatment

The evolutionary conserved DNA-sensing cGAS-STING innate immunity pathway represents one of the most important cytosolic DNA-sensing systems that is activated in response to viral invasion and/or damage to the integrity of the nuclear envelope. The key outcome of this pathway is the production of interferon, which subsequently stimulates the transcription of hundreds of genes. In oncology, the situation is complex because this pathway may serve either anti- or pro-oncogenic roles, depending on context. The prevailing understanding is that when the innate immune response is activated by sensing cytosolic DNA, such as DNA released from ruptured micronuclei, it results in the production of interferon, which attracts cytotoxic cells to destroy tumors. However, in tumor cells that have adjusted to significant chromosomal instability, particularly in relapsed, treatment-resistant cancers, the cGAS-STING pathway often supports cancer progression, fostering the epithelial-to-mesenchymal transition (EMT). Here, we review this intricate pathway in terms of its association with cancer progression, giving special attention to pancreatic ductal adenocarcinoma and gliomas. As the development of new cGAS-STING-modulating small molecules and immunotherapies such as oncolytic viruses involves serious challenges, we highlight several recent fundamental discoveries, such as the proton-channeling function of STING. These discoveries may serve as guiding lights for potential pharmacological advancements.

Comprehensive analysis of the oncogenic roles of vascular endothelial growth factors and their receptors in stomach adenocarcinoma

Background

Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) play complicated oncogenic roles in multiple tumors by initiating and promoting tumor angiogenesis and lymphangiogenesis. The main goal of our study was to comprehensively investigate the oncogenic roles of VEGFs and VEGFRs in stomach adenocarcinoma (STAD).

Methods

The present study applied multiple bioinformatic tools to comprehensively explore the expression levels, prognostic values, genetic alterations and immune infiltrations of VEGFs and VEGFRs in STAD patients.

Results

We found that VEGFA, VEGFC, placenta growth factor, FLT1, KDR, FLT4, and Neuropilin 1 were overexpressed in STAD, while the expression of VEGFB and VEGFD were decreased. Survival analysis revealed that higher transcription levels of VEGF/VEGFRs were obviously correlated with worse clinical outcome in STAD patients. Additionally, high alteration frequencies of VEGFs and VEGFRs (27%) were observed in STAD patients, and alterations of VEGFs and VEGFRs improved their prognosis. The expression of VEGFs and VEGFRs was remarkably associated with immune cell infiltration and immune checkpoint expression in STAD patients.

Conclusion

Our study systematically explored the transcriptome profiles and distinct prognostic values of VEGFs and their receptors in STAD and contributed to a better understanding of the oncogenic roles of VEGF/VEGFR members in STAD.

Recent Developments and Challenges in Molecular-Targeted Therapy of Non-Small-Cell Lung Cancer

Treatment of lung cancer with conventional therapies, which include radiation, surgery, and chemotherapy results in multiple undesirable adverse or side effects. The major clinical challenge in developing new drug therapies for lung cancer is resistance, which involves mutations and disturbance in various signaling pathways. Molecular abnormalities related to epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B1 (B-RAF) Kirsten rat sarcoma virus (KRAS) mutations, translocation of the anaplastic lymphoma kinase (ALK) gene, mesenchymal-epithelial transition factor (MET) amplification have been studied to overcome the resistance and to develop new therapies for non-small cell lung cancer (NSCLC). But, inevitable development of resistance presents limits the clinical benefits of various new drugs. Here, we review current progress in the development of molecularly targeted therapies, concerning six clinical biomarkers: EGFR, ALK, MET, ROS-1, KRAS, and B-RAF for NSCLC treatment.

125I seed implantation enhances arsenic trioxide-induced apoptosis and anti-angiogenesis in lung cancer xenograft mice

BACKGROUND AND PURPOSE

Arsenic trioxide (ATO) exerts anticancer effects on lung cancer. However, the clinical use of ATO is limited due to its systemic toxicity and resistance of lung cancer cells. The present study aimed to investigate the effects of ATO, alone and in combination with ¹²⁵I seed implantation on tumor growth and proliferation in lung cancer xenograft mice, and investigate the possible molecular mechanisms.

METHODS

The transmission electron microscope observed the tumor ultrastructure of lung cancer xenograft mice. The proliferation index of Ki-67 and the number and morphology of tumor microvessels were detected with immunohistochemical staining. The protein and mRNA expression were examined by western blot and real-time PCR assay.

RESULTS

The in vivo results demonstrated that ATO combined with ¹²⁵I seed significantly inhibited tumor growth and proliferation, as well as promoted apoptosis, and decreased the Ki-67 index and microvessel density in lung cancer xenograft mice. Moreover, ATO combined with ¹²⁵I seed decreased the protein and mRNA expression levels of HIF-1α, VEGF, and BCL-2, and increased those of BAX and P53.

CONCLUSIONS

ATO combined with ¹²⁵I seed significantly inhibited tumor growth and proliferation in lung cancer, which may be accomplished by inhibiting tumor angiogenesis and inducing apoptosis.

Immune checkpoint inhibitors combined with angiogenic inhibitors in the treatment of locally advanced or metastatic lung adenocarcinoma patients

BACKGROUND

To report the efficacy and safety data of immunotherapy plus angiogenic inhibitors treatment in lung adenocarcinoma patients.

METHODS

Eligible patients with pathological or cytological confirmed locally advanced or metastatic lung adenocarcinoma and treated with immune checkpoint inhibitors (ICI) plus angiogenic inhibitors were enrolled. The primary endpoints were progressive free survival (PFS). The secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety.

RESULTS

A total of 46 consecutive enrolled patients received ICI plus angiogenic inhibitor, and the median follow-up was 9.6 months (range 1.5-32.5). The ORR and DCR were 8.7% (n = 4) and 50% (n = 23), respectively. Median PFS and OS were 2.9 months (95% CI 2.1-3.7) and 12.3 months (95% CI 7.6-17.0), respectively. Patients at stage IVB had an inferior PFS than stage IIIC or IVA (2.8 months vs 4.4 months, P = 0.003). The median PFS of patients who were treated with ICI plus bevacizumab was shorter than ICI plus anlotinib or apatinib (1.2 months vs 3.3 months, P = 0.005). The occurrence of hypertension during the combination treatment has been related to a tendency for prolonged PFS (5.5 months vs 2.6 months; P = 0.05). The overall incidence of treatment-related adverse events (TRAE) was 89.1% (n = 41), and grade 3-4 TRAE was occupied 21.4% (n = 10).

CONCLUSION

This study objectively demonstrated that the treatment of ICI and antiangiogenic agents in lung adenocarcinoma could be a promising alternative therapeutic regimen, and the toxic effects were manageable. Subgroup analysis revealed that small molecular angiogenic inhibitors plus ICI and low tumor burden during treatment were better prognostic factors.

Current Landscape of Therapeutic Resistance in Lung Cancer and Promising Strategies to Overcome Resistance

Simple Summary

Despite an initial response to therapy, many lung cancer patients inevitably develop resistance to therapy leading to decreased duration of response and success of treatment. Recent research aims to elucidate mechanisms of resistance in order to improve drug response and treatment outcomes. By utilizing multidisciplinary approaches that target various resistance mechanism, it may be possible to delay development of treatment resistance or even resensitize cancers. This review aims to discuss novel approaches to improve clinical outcomes, delay the occurrence of resistance, and overcome resistance.

Abstract

Lung cancer is one of the leading causes of cancer-related deaths worldwide with a 5-year survival rate of less than 18%. Current treatment modalities include surgery, chemotherapy, radiation therapy, targeted therapy, and immunotherapy. Despite advances in therapeutic options, resistance to therapy remains a major obstacle to the effectiveness of long-term treatment, eventually leading to therapeutic insensitivity, poor progression-free survival, and disease relapse. Resistance mechanisms stem from genetic mutations and/or epigenetic changes, unregulated drug efflux, tumor hypoxia, alterations in the tumor microenvironment, and several other cellular and molecular alterations. A better understanding of these mechanisms is crucial for targeting factors involved in therapeutic resistance, establishing novel antitumor targets, and developing therapeutic strategies to resensitize cancer cells towards treatment. In this review, we summarize diverse mechanisms driving resistance to chemotherapy, radiotherapy, targeted therapy, and immunotherapy, and promising strategies to help overcome this therapeutic resistance.

Host-Related Factors as Targetable Drivers of Immunotherapy Response in Non-Small Cell Lung Cancer Patients

Despite some significant therapeutic breakthroughs leading to immunotherapy, a high percentage of patients with non-small cell lung cancer (NSCLC) do not respond to treatment on relapse, thus experiencing poor prognosis and survival. The unsatisfying results could be related to the features of the tumor immune microenvironment and the dynamic interactions between a tumor and immune infiltrate. Host-tumor interactions strongly influence the course of disease and response to therapies. Thus, targeting host-associated factors by restoring their physiologic functions altered by the presence of a tumor represents a new therapeutic approach to control tumor development and progression. In NSCLC, the immunogenic tumor balance is shifted negatively toward immunosuppression due to the release of inhibitory factors as well as the presence of immunosuppressive cells. Among these cells, there are myeloid-derived suppressor cells, regulatory T cells that can generate a tumor-permissive milieu by reprogramming the cells of the hosts such as tumor-associated macrophages, tumor-associated neutrophils, natural killer cells, dendritic cells, and mast cells that acquire tumor-supporting phenotypes and functions. This review highlights the current knowledge of the involvement of host-related factors, including innate and adaptive immunity in orchestrating the tumor cell fate and the primary resistance mechanisms to immunotherapy in NSCLC. Finally, we discuss combinational therapeutic strategies targeting different aspects of the tumor immune microenvironment (TIME) to prime the host response. Further research dissecting the characteristics and dynamic interactions within the interface host-tumor is necessary to improve a patient fitness immune response and provide answers regarding the immunotherapy efficacy, with the aim to develop more successful treatments for NSCLC.

Crosstalk between H1975 tumor cells and platelets to induce the proliferation, migration and tube formation of vascular endothelial cells

Activated platelets (PLTs) participate in the regulation of tumor angiogenesis, and tumors can activate PLTs. Whether co-culture of lung carcinoma with PLTs improves the function of human umbilical vein endothelial cells (HUVECs) requires further investigation. The present study aimed to investigate the impact of H1975 cell crosstalk with PLTs on the proliferation, migration and tube formation of HUVECs. Following generation of cell-derived supernatants and construction of the co-culture system, Cell Counting Kit-8, flow cytometry, transmission electron microscopy and a meter for epithelial measurement were performed to detect the proliferative ability of HUVECs. Furthermore, the wound healing and Transwell migration assays were performed to detect the migratory ability of HUVECs. A tube formation assay was performed to assess angiogenesis, ELISA was applied to detect the content of vascular endothelial growth factor (VEGF) and western blotting was carried out to measure the expression levels of VEGF receptor 2 (VEGFR2) in HUVECs. Compared with single-cultured HUVECs (control), co-culture with H1975 cells and PLTs (Exp_HP) improved cell proliferation, increased the proportion of cells in the S-phase, destroyed the cell ultrastructure and decreased transepithelial electrical resistance in HUVECs. In addition, a higher relative migration rate, greater number of migrated cells, stronger tube-forming ability and increased expression of VEGF and VEGFR2 were detected in the Exp_HP group compared with the control group. The properties of HUVECs in Exp_H (co-cultured with H1975 cells) were similar to those in Exp_HP, but significantly weaker. Taken together, the results of the present study suggest that tumor cells interacting with PLTs may play an important role in tumor angiogenesis by affecting or mediating changes in the properties of vascular endothelial cells (VECs).

Third-generation EGFR inhibitor HS-10296 in combination with famitinib, a multi-targeted tyrosine kinase inhibitor, exerts synergistic antitumor effects through enhanced inhibition of downstream signaling in EGFR-mutant non-small cell lung cancer cells

BACKGROUND

As a highly heterogeneous disease, lung cancer has a multitude of cellular components and patterns of gene expression which are not dependent on a single mutation or signaling pathway. Thus, using combined drugs to treat lung cancer may be a practical strategy.

METHODS

The combined antitumor effects of HS-10296, a third-generation EGFR inhibitor targeting EGFR T790M mutation, with the multitargeted tyrosine kinase inhibitor (TKI) famitinib in non-small cell lung cancer (NSCLC) were evaluated by in vitro methods such as cell proliferation, apoptosis, angiogenesis assays, and in vivo animal efficacy studies.

RESULTS

Famitinib strengthened the effects of HS-10296 on inhibiting proliferation and inducing apoptosis of NSCLC cells, possibly by synergistic inhibition of AKT and ERK phosphorylation. Meanwhile, HS-10296 significantly potentiated the effects of famitinib on inhibiting the proliferation and migration of HUVEC, which may be through synergistic inhibition of ERK phosphorylation in HUVEC, suggesting that HS-10296 may improve the inhibition of angiogenesis by famitinib. Moreover, combination of HS-10296 and famitinib exerted synergistic antitumor activity in NCI-H1975 and PC-9 xenograft models, and this effect may be accomplished by synergistic inhibition of phosphorylation of AKT and ERK and tumor angiogenesis in tumor tissues.

CONCLUSIONS

Collectively, our results indicate that HS-10296 and famitinib exhibit significant synergistic antitumor activity, suggesting that the third-generation EGFR inhibitor combined with VEGFR inhibitor provides a promising strategy in the treatment of EGFR-mutant NSCLC.

Trial watch: STING agonists in cancer therapy

Stimulator of interferon response cGAMP interactor 1 (STING1, best known as STING) is an endoplasmic reticulum-sessile protein that serves as a signaling hub, receiving input from several pattern recognition receptors, most of which sense ectopic DNA species in the cytosol. In particular, STING ensures the production of type I interferon (IFN) in response to invading DNA viruses, bacterial pathogens, as well as DNA leaking from mitochondria or the nucleus (e.g., in cells exposed to chemotherapy or radiotherapy). As a type I IFN is critical for the initiation of anticancer immune responses, the pharmaceutical industry has generated molecules that directly activate STING for use in oncological indications. Such STING agonists are being tested in clinical trials with the rationale of activating STING in tumor cells or tumor-infiltrating immune cells (including dendritic cells) to elicit immunostimulatory effects, alone or in combination with a range of established chemotherapeutic and immunotherapeutic regimens. In this Trial Watch, we discuss preclinical evidence and accumulating clinical experience shaping the design of Phase I and Phase II trials that evaluate the safety and preliminary efficacy of STING agonists in cancer patients.

Modification of the tumor response threshold in patients of advanced non-small cell lung cancer treated with chemotherapy plus targeted agents: a pooled study from five clinical trials in one institution

Background

Chemotherapy with targeted therapy is a promising therapeutic option for advanced non-small cell lung cancer (NSCLC) patients. Response Evaluation Criteria in Solid Tumors (RECIST) criteria were used in tumor response evaluation. We assumed an optimal threshold for this therapeutic setting and tried to seek a new tumor shrinkage cutoff with the data from five clinical trials in one institution.

Methods

The X-tile program was used to identify the optimal cut-off value of tumor shrinkage. PFS and OS were compared in the current study. Kaplan-Meier method was used to describe PFS and OS. 95% CI was calculated for PFS and OS outcomes to assess the treatment efficacy. A P value of less than 0.05 was considered statistically significant. SPSS 23.0 was used for all statistical analysis.

Results

X-tile analysis yielded -10% in the ∆SLD of the target lesions as the optimal threshold for response/non-response. The 10% tumor shrinkage could discriminate responders from non-responders in PFS (10.1 vs. 2.50 months, P=0.0007) and OS (23.00 vs. 7.66 months, P<0.0001). Univariate and multivariable analysis showed that 10% tumor shrinkage was a valid prognostic factor for PFS (P=0.018) and OS outcome (P<0.0001).

Conclusions

A 10.0% tumor shrinkage in the SLD indicated an indicative efficacy evaluation threshold for NSCLC patients treated with chemotherapy plus targeted agents.

Discovery of Dioxino[2,3-f]quinazoline derivative VEGFR-2 inhibitors exerting significant antipro-liferative activity in HUVECs and mice

Twelve 2,3-dihydro-[1,4]-dioxino[2,3-f]quinazoline derivatives were designed and evaluated as vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitors. The most half-maximal inhibitory concentration (IC₅₀) values of them were less than 10 nM. Among these compounds, 13d displayed highly effective inhibitory activity against VEGFR-2 (IC₅₀ = 2.4 nM) and excellent antiproliferative activities against human umbilical vein endothelial cells (HUVECs) (IC₅₀ = 1.2 nM). When anti-tumor animal experiments were carried out in mice, the tumor almost disappeared (TGI = 133.0%) after six days of administration of 13d. Therefore, 13d was a potential and effective anticancer agent. The binding conformations were respectively compared between VEGFR-2 with 13d and leading compound lenvatinib, and shows that they have similar binding modes.

A phase I study of the vascular endothelial growth factor inhibitor Vatalanib in combination with Pemetrexed disodium in patients with advanced solid tumors

Introduction Vatalanib is an oral receptor tyrosine kinase inhibitor that blocks all known VEGF, PDGF, and c-Kit receptors. This phase I study evaluated the safety, tolerability, and biologic activity of the combination of vatalanib with pemetrexed disodium in patients with advanced solid tumors. Methods Patients were administered escalating twice daily doses of vatalanib in combination with pemetrexed disodium in 21-day cycles. A dose expansion cohort was enrolled to further define the maximum tolerated dose (MTD) and further evaluate efficacy. Results A total of 29 patients were enrolled in the study (dose escalation, 9; dose expansion, 20). Dose-limiting toxicities included grade 4 thrombocytopenia (6.9%) and febrile neutropenia, anorexia, constipation, and dehydration. Other common adverse events were fatigue (75%), nausea (66%), vomiting (48%), oral mucositis (31%) and diarrhea (28%). The majority of these toxicities were Grade 1-2. The MTD was reached at vatalanib 250 mg twice daily continuously combined with pemetrexed disodium 500 mg/m² day 1. Overall, 2 patients (6.9%) had partial responses, 8 (27.6%) had stable disease for at least 4 cycles, 5 had progressive disease (17.2%) and 5 went off study before disease assessment. Conclusion The combination of vatalanib with pemetrexed disodium was feasible, but not well tolerated. The modest efficacy results are consistent with other results obtained from combinations of chemotherapy and a large number of VEGF tyrosine kinase inhibitors. This combination should not be developed further unless predictive biomarkers can be identified.

Angiogenesis in NSCLC: is vessel co-option the trunk that sustains the branches?

The critical role of angiogenesis in tumor development makes its inhibition a valuable new approach in therapy, rapidly making anti-angiogenesis a major focus in research. While the VEGF/VEGFR pathway is the main target of the approved anti-angiogenic molecules in NSCLC treatment, the results obtained are still modest, especially due to resistance mechanisms. Accumulating scientific data show that vessel co-option is an alternative mechanism to angiogenesis during tumor development in well-vascularized organs such as the lungs, where tumor cells highjack the existing vasculature to obtain its blood supply in a non-angiogenic fashion. This can explain the low/lack of response to current anti-angiogenic strategies. The same principle applies to lung metastases of other primary tumors. The exact mechanisms of vessel co-option need to be further elucidated, but it is known that the co-opted vessels regress by the action of Angiopoietin-2 (Ang-2), a vessel destabilizing cytokine expressed by the endothelial cells of the pre-existing mature vessels. In the absence of VEGF, vessel regression leads to tumor cell loss and hypoxia, with a subsequent switch to a neoangiogenic phenotype by the remaining tumor cells. Unravelling the vessel co-option mechanisms and involved players may be fruitful for numerous reasons, and the particularities of this form of vascularization should be carefully considered when planning anti-angiogenic interventions or designing clinical trials for this purpose. In view of the current knowledge, rationale for therapeutic approaches of dual inhibition of Ang-2 and VEGF are swiftly gaining strength and may serve as a launchpad to more successful NSCLC anti-vascular treatments.

Targeted drugs for systemic therapy of lung cancer with brain metastases

Brain metastases are very common in lung cancer patients. The condition of these patients is complicated and difficult to treat, and adverse reactions following treatment can affect the nervous system, which severely reduces quality of life. Lung cancers are categorized as small cell lung cancers and non-small cell lung cancers. Patients with brain metastasis of small cell lung cancers are generally treated with brain radiotherapy and systemic chemotherapy, but stage III/IV patients with brain metastasis of non-small cell lung cancers are generally not responsive to radiotherapy or chemotherapy. With the recent development of targeted drugs, tumor molecular profile detection allows the selection of appropriate targeted drugs for adjuvant pharmacological treatment of brain metastasis in lung cancer patients. In recent years, immune checkpoint inhibitors have emerged and have been approved by the Food and Drug Administration (FDA) for the treatment of certain cancers, but their efficacy in lung cancer patients with brain metastases still needs to be confirmed. This paper focuses on highlighting drugs for targeted therapy of brain metastasis in lung cancer patients and their molecular targets and mechanisms of drug resistance.

Vitamin D derivatives potentiate the anticancer and anti-angiogenic activity of tyrosine kinase inhibitors in combination with cytostatic drugs in an A549 non-small cell lung cancer model

Numerous in vitro and in vivo studies have demonstrated that calcitriol [1,25(OH)₂D₃] and different vitamin D analogs possess antineoplastic activity, regulating proliferation, differentiation and apoptosis, as well as angiogenesis. Vitamin D compounds have been shown to exert synergistic effects when used in combination with different agents used in anticancer therapies in different cancer models. The aim of this study was to evaluate the mechanisms of the cooperation of the vitamin D compounds [1,24(OH)₂D₃ (PRI-2191) and 1,25(OH)₂D₃] with tyrosine kinase inhibitors (imatinib and sunitinib) together with cytostatics (cisplatin and docetaxel) in an A549 non-small cell lung cancer model. The cytotoxic effects of the test compounds used in different combinations were evaluated on A549 lung cancer cells, as well as on human lung microvascular endothelial cells (HLMECs). The effects of such combinations on the cell cycle and cell death were also determined. In addition, changes in the expression of proteins involved in cell cycle regulation, angiogenesis and the action of vitamin D were analyzed. Moreover, the effects of 1,24(OH)₂D₃ on the anticancer activity of sunitinib and sunitinib in combination with docetaxel were examined in an A549 lung cancer model in vivo. Experiments aiming at evaluating the cytotoxicity of the combinations of the test agents revealed that imatinib and sunitinib together with cisplatin or docetaxel exerted potent anti-proliferative effects in vitro on A549 lung cancer cells and in HLMECs; however, 1,24(OH)₂D₃ and 1,25(OH)₂D₃ enhanced the cytotoxic effects only in the endothelial cells. Among the test agents, sunitinib and cisplatin decreased the secretion of vascular endothelial growth factor (VEGF)-A from the A549 lung cancer cells. The decrease in the VEGF-A level following incubation with cisplatin correlated with a higher p53 protein expression, while no such correlation was observed following treatment of the A549 cells with sunitinib. Sunitinib together with docetaxel and 1,24(OH)₂D₃ exhibited a more potent anticancer activity in the A549 lung cancer model compared to double combinations and to treatment with the compounds alone. The observed anticancer activity may be the result of the influence of the test agents on the process of tumor angiogenesis, for example, through the downregulation of VEGF-A expression in tumor and also on the induction of cell death inside the tumor.

The role of pazopanib on tumour angiogenesis and in the management of cancers: A review

Pazopanib is a relatively new compound to be introduced into the chemotherapy field. It is thought to have decent anti-angiogenic properties, which gives an additional hope for the treatment of certain types of cancers. A systematic review solely discussing about pazopanib and its anti-angiogenic effect is yet to be published to date, despite several relevant clinical trials being conducted over the recent years. In this review, we aim to investigate the mechanism of pazopanib's anti-angiogenic effect and its effectiveness in treating several cancers. We have included, in this study, findings from electronically searchable data from randomized clinical trials, clinical studies, cohort studies and other relevant articles. A total of 352 studies were included in this review. From the studies, the effect of pazopanib in various cancers or models was observed and recorded. Study quality is indefinite, with a few decent quality articles. The most elaborately studied cancers include renal cell carcinoma, solid tumors, advanced solid tumors, soft tissue sarcoma, breast cancer and gynecological cancers. In addition, several less commonly studied cancers are included in the studies as well. Pazopanib had demonstrated its anti-angiogenic effect based on favorable results observed in cancers, which are caused by angiogenesis-related mechanisms, such as renal cell carcinoma, solid tumors, advanced solid tumors and soft tissue sarcoma. This review was conducted to study, analyze and review the anti-angiogenic properties of pazopanib in various cancers. The results obtained can provide a decent reference when considering treatment options for angiogenesis-related malignancies. Furthermore, the definite observations of the anti-angiogenic effects of pazopanib could provide newer insights leading to the future development of drugs of the same mechanism with increased efficiency and reduced adverse effects.

Artesunate inhibits proliferation and invasion of mouse hemangioendothelioma cells in vitro and of tumor growth in vivo

Artesunate has been demonstrated to be a novel potential antitumor agent in numerous studies. However, its efficacy in infantile hemangioma is unknown. The aim of the present study was to investigate the role of artesunate in the control of vascular tumor biological behavior and molecular mechanism using mouse hemangioendothelioma endothelial (EOMA) cells and a nude mouse model. Cell viability, apoptosis and invasion were determined by an MTT assay, flow cytometric analysis and Transwell invasion assay, respectively. Reverse transcription-quantitative polymerase chain reaction and western blotting were utilized to examine the expression of genes and proteins. Inoculated EOMA cells were injected into the subcutaneous tissues of nude mice to observe the effect of artesunate therapy on the vascular tumor, an effect that was similar to that of pingyangmycin (PYM). It was identified that artesunate treatment (0-600 µg/ml) inhibited cell growth in a time- and dose-dependent manner. Artesunate at 300 µg/ml significantly reduced the proliferation and invasion of EOMA cells, and significantly decreased the expression of vascular endothelial growth factor (VEGF)-A, VEGFR-1, VEGFR-2 and hypoxia inducible factor-1α over time; caspase-3 was simultaneously upregulated in vitro. Artesunate significantly inhibited tumor growth, and the curative effect was similar to that observed with PYM in vivo. It was concluded that artesunate could effectively inhibit the growth of vascular tumors, and thus could be a novel drug candidate for the treatment of infantile hemangioma.

Anti-angiogenic effect of arsenic trioxide in lung cancer via inhibition of endothelial cell migration, proliferation and tube formation

Arsenic trioxide (As₂O₃) exhibits a remarkable effect on leukemia treatment; however, its effect on solid tumors remains poorly explored. The present study demonstrated the inhibitory effect of As₂O₃ on lung cancer and explored its possible mechanism. It was observed that As₂O₃ significantly inhibited the growth of lung cancer xenografts and tumor angiogenesis in vivo. The inhibitory effect of As₂O₃ on cell proliferation in vitro was more remarkable in vascular endothelial cells than in lung cancer cells. It was also observed that As₂O₃ inhibited the migration of vascular endothelial cells and disrupted vascular tube formation on Matrigel assays. In addition, a series of key signaling factors involved in multiple stages of angiogenesis, including matrix metalloproteinase (MMP)-2, MMP-9, platelet-derived growth factor (PDGF)-BB/PDGF receptor-β, vascular endothelial growth factor (VEGF)-A/VEGF receptor-2, basic fibroblast growth factor (FGF)/FGF receptor-1 and delta like canonical Notch ligand 4/Notch-1, were regulated by As₂O₃. These findings suggested that anti-angiogenesis may be an underlying mechanism of As₂O₃ anticancer activity in lung cancer.

Strategies targeting angiogenesis in advanced non-small cell lung cancer

Tumor angiogenesis is a frequent event in the development and progression of non-small cell lung cancer (NSCLC) and has been identified as a promising therapeutic target. The vascular endothelial growth factor (VEGF) family and other angiogenic factors, including fibroblast growth factor and platelet-derived growth factor, promote the growth of newly formed vessels from preexisting vessels and change the tumor microenvironment. To date, two antiangiogenic monoclonal antibodies, bevacizumab and ramucirumab, which target VEGF-A and its receptor VEGF receptor-2, respectively, have been approved for the treatment of locally advanced or metastatic NSCLC when added to first-line standard chemotherapy. Numerous oral multitargeting angiogenic small molecule tyrosine kinase inhibitors (TKIs) have been widely evaluated in advanced NSCLC, but only nintedanib in combination with platinum-based doublet chemotherapy has demonstrated a survival benefit in the second-line setting. Additionally, small-molecule TKIs remain the standard of care for patients with mutated EGFR, ALK or ROS1. Moreover, immune checkpoint inhibitors that target the programmed cell death protein 1 (PD-1) and programmed cell death protein ligand 1 (PD-L1) are changing the current strategy in the treatment of advanced NSCLC without driver gene mutations. The potential synergistic activity of antiangiogenic agents and TKIs or immunotherapy is an interesting topic of research. This review will summarize the novel antiangiogenic agents, antiangiogenic monotherapy, as well as potential combination therapeutic strategies for the clinical management of advanced NSCLC.

Delivery of curcumin by directed self-assembled micelles enhances therapeutic treatment of non-small-cell lung cancer

BACKGROUND

It has been widely reported that curcumin (CUR) exhibits anticancer activity and triggers the apoptosis of human A549 non-small-cell lung cancer (NSCLC) cells. However, its application is limited owing to its poor solubility and bioavailability. Therefore, there is an urgent need to develop a new CUR formulation with higher water solubility and better biocompatibility for clinical application in the future.

MATERIALS AND METHODS

In this study, CUR-loaded methoxy polyethylene glycol-polylactide (CUR/mPEG-PLA) polymeric micelles were prepared by a thin-film hydration method. Their characteristics and antitumor effects were evaluated subsequently.

RESULTS

The average size of CUR/mPEG-PLA micelles was 34.9±2.1 nm with its polydispersity index (PDI) in the range of 0.067-0.168. The encapsulation efficiency and drug loading were 90.2%±0.78% and 9.1%±0.07%, respectively. CUR was constantly released from the CUR/mPEG-PLA micelles, and its cellular uptake in A549 cells was significantly increased. It was also found that CUR/mPEG-PLA micelles inhibited A549 cell proliferation, increased the cell cytotoxicity, induced G2/M stage arrest and promoted cell apoptosis. Moreover, the CUR/mPEG-PLA micelles suppressed the migration and invasion of A549 cells more obviously than free CUR. Additionally, CUR/mPEG-PLA micelles inhibited human umbilical vein endothelial cells migration, invasion and corresponding tube formation, implying the antiangiogenesis ability. Its enhanced antitumor mechanism may be related to the reduced expression of vascular endothelial growth factor, matrix metalloproteinase (MMP)-2, MMP-9 and Bcl-2 as well as the increased expression of Bax.

CONCLUSION

The mPEG-PLA copolymer micelles can serve as an efficient carrier for CUR. The CUR/mPEG-PLA micelles have promising clinical potential in treating NSCLC.

Vascular endothelial growth factor promoter-based conditionally replicative adenoviruses effectively suppress growth of malignant pleural mesothelioma

Malignant mesothelioma (MM) incidence is increasing drastically worldwide as an occupational disease resulting from asbestos exposure. However, no curative treatment for MM of advanced stage is available. Thus, new therapeutic approaches for MM are required. Because malignant pleural mesothelioma (MPM) cells spread along the pleural surface in most patients, MPM can be targeted using intrapleural therapeutic approaches. In this study, we investigated the effectiveness of the intrapleural instillation of a replication‐competent adenovirus as an oncolytic agent against MPM. We constructed a vascular endothelial growth factor promoter‐based conditionally replicative adenovirus (VEGF‐CRAd) that replicates exclusively in VEGF‐expressing cells. All of the MM cell lines that we tested expressed VEGF mRNA, and VEGF‐CRAd selectively replicated in these MM cells and exerted a direct concentration‐dependent oncolytic effect in vitro. Furthermore, our in vivo studies showed that pre‐infection of MM cells with VEGF‐CRAd potently suppressed MPM tumor formation in nude mice, and that intrapleural instillation of VEGF‐CRAd prolonged the survival time of tumor‐bearing mice. Our results indicate that VEGF‐CRAd exerts an oncolytic effect on MM cells and that intrapleural instillation of VEGF‐CRAd is safe and might represent a promising therapeutic strategy for MPM.

Lung cancer in 2013: state of the art therapy for metastatic disease

Lung cancer is the leading worldwide cause of cancer death and the majority of patients present with metastatic stage IV disease. At diagnosis, clinical, histologic, and molecular features must be considered in therapeutic decision-making for systemic therapy. Molecular testing for at least epidermal growth factor receptor (EGFR) and ALK should be performed in all patients before therapy. Platinum doublet chemotherapy may be considered for "fit" patients who do not have a molecular driver genetic abnormality. Bevacizumab can be considered for addition to the doublet in patients with nonsquamous cancers who have no contraindications. A pemetrexed combination is considered only in nonsquamous histology. Patients with EGFR mutations or ALK fusions should be treated with erlotinib or crizotinib, respectively, even in patients with tumor-related poor performance. The tyrosine-kinase inhibitors (TKIs) may be continued until multisite, symptomatic progression. For patients initially treated with a platinum doublet, maintenance chemotherapy with pemetrexed, erlotinib, gemcitabine, or possibly docetaxel is an option with selection based on clinical features, histology, type of initial therapy, and response to first-line therapy.

Novel investigational vascular endothelial growth factor (VEGF) receptor antagonists for psoriasis

INTRODUCTION

Affecting 1 million people in the UK, psoriasis is a commonly diagnosed inflammatory disease arising from autoimmune processes that are triggered by environmental factors in genetically susceptible individuals. The pathophysiology of psoriasis has been widely studied and there is evidence that angiogenesis is a key component.

AREAS COVERED

In this review the role of vascular endothelial growth factor-A (VEGF), as a key angiogenic mediator in psoriasis pathogenesis is discussed. VEGF is found in higher levels in plaques, normal skin and plasma of patients with psoriasis. The level of VEGF also fluctuates in accordance with disease activity and in response to conventional treatments. There are several VEGF inhibitors currently licenced for use; primarily in the fields of oncology and there are case reports of patients being treated with these therapies for metastatic cancer who have demonstrated significant improvement in their psoriasis. VEGF inhibitory agents have suggested promising utility for the treatment of psoriasis following animal studies.

EXPERT OPINION

VEGF may represent a novel treatment target in psoriasis. However, VEGF inhibitors can cause significant side effects such as hypertension and left ventricular dysfunction. The risks of treatment must be carefully evaluated before VEGF inhibitors are trialled or advocated for psoriasis.

The Microenvironment of Lung Cancer and Therapeutic Implications

The tumor microenvironment (TME) represents a milieu that enables tumor cells to acquire the hallmarks of cancer. The TME is heterogeneous in composition and consists of cellular components, growth factors, proteases, and extracellular matrix. Concerted interactions between genetically altered tumor cells and genetically stable intratumoral stromal cells result in an "activated/reprogramed" stroma that promotes carcinogenesis by contributing to inflammation, immune suppression, therapeutic resistance, and generating premetastatic niches that support the initiation and establishment of distant metastasis. The lungs present a unique milieu in which tumors progress in collusion with the TME, as evidenced by regions of aberrant angiogenesis, acidosis and hypoxia. Inflammation plays an important role in the pathogenesis of lung cancer, and pulmonary disorders in lung cancer patients such as chronic obstructive pulmonary disease (COPD) and emphysema, constitute comorbid conditions and are independent risk factors for lung cancer. The TME also contributes to immune suppression, induces epithelial-to-mesenchymal transition (EMT) and diminishes efficacy of chemotherapies. Thus, the TME has begun to emerge as the "Achilles heel" of the disease, and constitutes an attractive target for anti-cancer therapy. Drugs targeting the components of the TME are making their way into clinical trials. Here, we will focus on recent advances and emerging concepts regarding the intriguing role of the TME in lung cancer progression, and discuss future directions in the context of novel diagnostic and therapeutic opportunities.

Angiogenesis inhibition as a therapeutic strategy in non-small cell lung cancer (NSCLC)

In many cancers, including non-small cell lung cancer (NSCLC), tumor angiogenesis pathways have been identified as important therapeutic targets. Angiogenesis is essential in the process of primary tumor growth, proliferation and metastasis. One of the best characterized group of protein factors for angiogenesis include the members of the vascular endothelial growth factor (VEGF) family, consisting of VEGF-(A-D), and placenta growth factor (PIGF). Targeting tumor angiogenesis has been approached through two primary methods, monoclonal antibodies that block VEGF-vascular endothelial growth factor receptor (VEGFR) binding or small molecule tyrosine kinase inhibitors (TKIs) that inhibit the downstream VEGFR mediated signaling. Many TKIs inhibit multiple pro-angiogenic and pro-proliferative pathways such as the mitogen activated protein (MAP) kinase pathway. Bevacizumab and ramucirumab, monoclonal antibodies targeting VEGF and the VEGFR, respectively, have each led to improvements in overall survival (OS) for NSCLC when added to standard first and second line chemotherapy, respectively. Small incremental gains seen with both bevacizumab and ramucirumab may be further improved upon by incorporating novel agents and treatment strategies, and many additional trials are ongoing.

Structure-Activity Relationship of Indole-Tethered Pyrimidine Derivatives that Concurrently Inhibit Epidermal Growth Factor Receptor and Other Angiokinases

Antiangiogenic agents have been widely investigated in combination with standard chemotherapy or targeted cancer agents for better management of advanced cancers. Therapeutic agents that concurrently inhibit epidermal growth factor receptor and other angiokinases could be useful alternatives to combination therapies for epidermal growth factor receptor-dependent cancers. Here, we report the synthesis of an indole derivative of pazopanib using a bioisosteric replacement strategy, which was designated MKP101. MKP101 inhibited not only the epidermal growth factor receptor with an IC50 value of 43 nM but also inhibited angiokinases as potently as pazopanib. In addition, MKP101 effectively inhibited vascular endothelial growth factor-induced endothelial proliferation, tube formation, migration of human umbilical vein endothelial cells and proliferation of HCC827, an epidermal growth factor receptor-addicted cancer cell line. A docking model of MKP101 and the kinase domain of the epidermal growth factor receptor was generated to predict its binding mode, and validated by synthesizing and evaluating MKP101 derivatives. Additionally, a study of structure-activity relationships of indolylamino or indolyloxy pyrimidine analogues derived from MKP101 demonstrated that selectivity for epidermal growth factor receptor and other angiokinases, especially vascular endothelial growth factor receptor 2 depends on the position of substituents on pyrimidine and the type of link between pyrimidine and the indole moiety. We believe that this study could provide a basis for developing angiokinase inhibitors having high affinity for the epidermal growth factor receptor, from the pyrimidine scaffold.

The pan-deacetylase inhibitor panobinostat affects angiogenesis in hepatocellular carcinoma models via modulation of CTGF expression

Post-translational modifications of chromatin components are significantly involved in the regulation of tumor suppressor gene and oncogene expression. Connective tissue growth factor (CTGF) is an epigenetically regulated growth factor with functions in angiogenesis and cell-matrix interactions and plays a pivotal role in hepatocellular carcinoma (HCC). The pharmacologic inhibition of histone and protein deacetylases represents a new approach to interfere with pathways of apoptosis and angiogenesis. We investigated the effect of the pan-deacetylase inhibitor panobinostat (LBH589) on human HCC cell lines HepG2 (p53wt) and Hep3B (p53null) and in a subcutaneous xenograft model and explored the influence on angiogenesis. Specimens were characterized by quantitative real-time PCR. Protein was separated for western blotting against CTGF, VEGF, VEGF receptor-1 (VEGFR-1/FLT-1), VEGF receptor-2 (VEGFR-2/KDR), MAPK and phospho-MAPK. In vivo, HepG2 cells were xenografted to NMRI mice and treated with daily i.p. injections of 10 mg/kg panobinostat. After 1, 7 and 28 days, real-time PCR was performed. Immunohistochemistry and western blotting were examined after 28 days. An increased significant expression of CTGF was only seen after 24 h treatment with 0.1 µM panobinostat in HepG2 cells and Hep3B cells, whereas after 72 h treatment CTGF expression clearly decreased. In the xenografts, treatment with panobinostat showed a minimal CTGF expression after 1 day and 4 weeks, respectively. In vitro as well as in vivo, VEGF was not affected by panobinostat treatment at any time. In conclusion, panobinostat influences extracellular signaling cascades via CTGF-dependent pathways.

Improved overall survival following tyrosine kinase inhibitor treatment in advanced or metastatic non-small-cell lung cancer-the Holy Grail in cancer treatment?

Advanced or metastatic non-small-cell lung cancer (NSCLC) is characterized by a poor prognosis and few second- or third-line treatments. First-generation epidermal growth factor receptor tyrosine kinase inhibition has paved the way for targeted therapies in lung cancer. Although these drugs result in excellent responses [and significantly improved progression-free survival (PFS)] in patients with activating EGFR mutations, none of these randomized studies has yet demonstrated a statistically significant improvement of overall survival (OS). PFS is often used as a predictor for improved OS since it is independent of subsequent treatment, but OS is acknowledged as the key clinical outcome in the treatment of advanced NSCLC. When effective treatment is given as post therapy, it will be difficult to distinguish the treatment effect of original and subsequent treatments because differences in OS are potentially confounded by crossover, and a relevant number of patients assigned to chemotherapy arms received tyrosine kinase inhibitors (TKIs) as second- or third-line treatment after disease progression. The high proportion of crossover may extend the benefit associated with the administration of TKIs to patients assigned to the control arm, and its "salvage"-effect may compensate for the relevant differences in PFS of first-line treatment consistently demonstrated in all TKI trials. Results for the INFORM trial (maintenance therapy with gefitinib following platinum-based chemotherapy) provided evidence that maintenance therapy with gefitinib significantly improved PFS, with greatest benefit in patients harboring EGFR mutation. Despite a high crossover rate (53%) final OS results of this study have now demonstrated a significant survival benefit for the gefitinib-treated EGFR mutation-positive patients (46.9 vs. 21.0 months, P=0.036). This is the first randomized clinical trial that showed a significant and clinical meaningful OS benefit in EGFR mutation-positive NSCLC patients following maintenance therapy with gefitinib as compared to placebo. It remains to be seen whether further exploration of this treatment strategy will confirm these promising results.

Emerging treatments and combinations in the management of NSCLC: clinical potential of nintedanib

There remains an unmet need for effective, well-tolerated treatment options in advanced non-small cell lung cancer (NSCLC) to alleviate the disease burden for a broad selection of patients. Nintedanib is a potent, oral, triple angiokinase inhibitor of vascular endothelial growth factor, fibroblast growth factor, and platelet-derived growth factor, and was recently approved in Europe for use in combination with docetaxel for the treatment of adults with locally advanced, metastatic, or locally recurrent NSCLC of adenocarcinoma tumor histology, following first-line chemotherapy. Nintedanib has been investigated extensively in preclinical research and in a number of clinical studies, the most important of which was the Phase III LUME-Lung 1 study, which investigated nintedanib in combination with docetaxel in patients with advanced NSCLC after failure of first-line chemotherapy. In this study, which led to the approval of nintedanib, addition of nintedanib to docetaxel significantly improved overall survival in patients with adenocarcinoma histology. Nintedanib demonstrated a manageable safety profile in combination with docetaxel. This review focuses on the clinical experience with nintedanib in NSCLC and discusses the clinical potential of this agent for use in combination with chemotherapy.

DIRAS3 regulates the autophagosome initiation complex in dormant ovarian cancer cells

DIRAS3 is an imprinted tumor suppressor gene that is downregulated in 60% of human ovarian cancers. Re-expression of DIRAS3 at physiological levels inhibits proliferation, decreases motility, induces autophagy, and regulates tumor dormancy. Functional inhibition of autophagy with choroquine in dormant xenografts that express DIRAS3 significantly delays tumor regrowth after DIRAS3 levels are reduced, suggesting that autophagy sustains dormant ovarian cancer cells. This study documents a newly discovered role for DIRAS3 in forming the autophagosome initiation complex (AIC) that contains BECN1, PIK3C3, PIK3R4, ATG14, and DIRAS3. Participation of BECN1 in the AIC is inhibited by binding of BECN1 homodimers to BCL2. DIRAS3 binds BECN1, disrupting BECN1 homodimers and displacing BCL2. Binding of DIRAS3 to BECN1 increases the association of BECN1 with PIK3C3 and ATG14, facilitating AIC activation. Amino acid starvation of cells induces DIRAS3 expression, reduces BECN1-BCL2 interaction and promotes autophagy, whereas DIRAS3 depletion blocks amino acid starvation-induced autophagy. In primary ovarian cancers, punctate expression of DIRAS3, BECN1, and the autophagic biomarker MAP1LC3 are highly correlated (P<0.0001), underlining the clinical relevance of these mechanistic studies. Punctate expression of DIRAS3 and MAP1LC3 was detected in only 21-23% of primary ovarian cancers but in 81-84% of tumor nodules found on the peritoneal surface at second-look operations following primary chemotherapy. This reflects a 4-fold increase (P<0.0001) in autophagy between primary disease and post-treatment recurrence. We suggest that DIRAS3 not only regulates the AIC, but induces autophagy in dormant, nutrient-deprived ovarian cancer cells that remain after conventional chemotherapy, facilitating their survival.

The effectiveness of RECIST on survival in patients with NSCLC receiving chemotherapy with or without target agents as first-line treatment

We analyzed the correlation between survival and antitumor effect evaluated by RECIST in advanced NSCLC patients with chemotherapy plus target therapy or not as first-line treatment, to examine the applicability of RECIST in this population. The patients were screened from 4 clinical trials (12621, 12006, FASTACT-I, and FASTACT-II), and those who received chemotherapy plus target therapy or chemotherapy alone were eligible. Among the 59 enrolled patients, 29 received combination therapy, while the other 30 received chemotherapy only. In the combination therapy group, patients with PR or SD had longer overall survival (OS) than those with PD (P < 0.001 and P = 0.002, respectively). However, in the chemotherapy alone group, compared with PD patients, either PR or SD group had no significant overall survival benefit (P = 0.690 and P = 0.528, respectively). In summary, for advanced NSCLC patients receiving chemotherapy plus target therapy as first-line treatment and evaluated by RECIST criteria, SD has the same overall survival benefit as PR, suggesting that antitumor effective evaluation by RECIST criteria cannot be translated to overall survival benefit especially for this kind of patients. Therefore, developing a more comprehensive evaluation method to perfect RECIST criteria is thus warranted for patients received target therapy in NSCLC.

Efficacy of motesanib diphosphate in non-small-cell lung cancer

INTRODUCTION

Angiogenesis plays a crucial role in the proliferation and in the metastatic spread of tumour cells. Several agents with anti-angiogenic activity have been tested in advanced non-small-cell lung cancer (NSCLC) patients. Motesanib (AMG 706) is a promising anti-angiogenic multi-targeted tyrosine kinase inhibitor (TKI), which has been investigated as a monotherapy or in combination with chemotherapy, in several types of cancer.

AREAS COVERED

We have reviewed the literature, and we have presented the results of clinical trials that have investigated the administration of motesanib in advanced NSCLC patients.

EXPERT OPINION

Encouraging results have been described with the administration of motesanib as first-line treatment in combination with carboplatin and paclitaxel in Asian patients with non-squamous advanced NSCLC. Further studies are needed in order to identify the predictive biomarkers of response and to select patients who may benefit from this anti-angiogenic treatment.

Imbalance between vascular endothelial growth factor and endostatin correlates with the prognosis of operable non-small cell lung cancer

BACKGROUND

Angiogenesis is regulated by a balance of pro-angiogenic and anti-angiogenic factors. Vascular endothelial growth factor (VEGF) and endostatin respectively represents a frequent component of inducers and inhibitors in the process of angiogenesis. The ratio of VEGF/endostatin may reflect the balance of angiogenic switch. This study aimed to determine whether an imbalance between VEGF/endostatin exists in operable non-small cell lung cancer (NSCLC) patients and to assess the correlation, if any, between the imbalance and the prognosis.

METHODS

Preoperative serum levels of VEGF and endostatin were simultaneously determined by quantitiative enzyme-linked immunosorbent assay (ELISA) and the ratio of them was calculated among 98 NSCLC patients and 51 healthy controls. The relationship between these factors and clinicopathological features, including prognosis, was examined.

RESULTS

The ratio of VEGF/endostatin levels was significantly higher in operable NSCLC patients [median, 10.4; interquartile range (IQR), 5.9-19.8] than in normal controls [median, 5.1; IQR, 3.3-9.7] (P = 0.002). While the ratio in patients who were still alive for more than 60 months was 8.3 (IQR, 4.3-17.9), the ratio in those who died was 12.9 (IQR, 8.0-22.1) (p = 0.017). In subgroup analysis of patients with pathological stage N0, there was a statistically significant increase of the survival time in the group with a lower ratio than in the group with a higher ratio (p = 0.032). Multivariate analysis confirmed that the VEGF/endostatin ratio was an independent prognostic factor (p = 0.018).

CONCLUSION

There was an imbalance between VEGF and endostatin in serum of operable NSCLC patients. The imbalance correlated with the prognosis of operable NSCLC.

Axitinib Improves Radiotherapy in Murine Xenograft Lung Tumors

A third of patients with non-small cell lung cancer (NSCLC) present with un-resectable stage III locally advanced disease and are currently treated by chemo-radiotherapy but the median survival is only about 21months. Using an orthotopic xenograft model of lung carcinoma, we have investigated the combination of radiotherapy with the anti-angiogenic drug axitinib (AG-013736, Pfizer), which is a small molecule receptor tyrosine kinase inhibitor that selectively targets the signal transduction induced by VEGF binding to VEGFR receptors. We have tested the combination of axitinib with radiotherapy in nude mice bearing human NSCLC A549 lung tumors. The therapy effect was quantitatively evaluated in lung tumor nodules. The modulation of radiation-induced pneumonitis, vascular damage and fibrosis by axitinib was assessed in lung tissue. Lung irradiation combined with long-term axitinib treatment was safe resulting in minimal weight loss and no vascular injury in heart, liver and kidney tissues. A significant decrease in the size of lung tumor nodules was observed with either axitinib or radiation, associated with a decrease in Ki-67 staining and a heavy infiltration of inflammatory cells in tumor nodules. The lungs of mice treated with radiation and axitinib showed a complete response with no detectable residual tumor nodules. A decrease in pneumonitis, vascular damage and fibrosis were observed in lung tissues from mice treated with radiation and axitinib. Our studies suggest that axitinib is a potent and safe drug to use in conjunction with radiotherapy for lung cancer that could also act as a radioprotector for lung tissue by reducing pneumonitis and fibrosis.

Lower Ras expression as an independent predictor of patient outcomes in lung cancer treated with bevacizumab plus chemotherapy

The objective of this study was to analyze the predictive roles of VEGF/KDR/Ras/MAPK gene expression in patients with advanced non-small-cell lung cancer (NSCLC) treated with bevacizumab plus chemotherapy. Twenty-five patients participating in an open-label phase IV trial (SAiL, MO19390) with available tumor tissues were analyzed. The mRNA expression levels of VEGF, kinase insert domain receptor (KDR), Ras, and mitogen-activated protein kinase (MAPK) in tumor tissues were detected using real-time quantitative PCR methods. The relationships between gene expression and disease control rate (DCR), progression-free survival (PFS), and overall survival (OS) were assessed. Patients with lower Ras expression had a longer PFS and OS than patients with higher expression (median PFS, 9.9 vs 5.5 months, χ(2)=3.944, P=0.047; OS, 19.3 vs 7.1 months, χ(2)=9.384, P=0.002). The PFS and OS of patients with lower and higher MAPK expression exhibited a marginal and significant difference (median PFS, 9.9 vs 5.5 months, χ(2)=3.464, P=0.063; OS, 19.3 vs 9.7 months, χ(2)=5.298, P=0.021), respectively. Multivariate analyses using Cox's proportional hazards model showed that Ras is an independent predictor of OS (χ(2)=9.384, P=0.002). No differences in DCR were found according to Ras expression level. The results indicate that Ras is an independent predictor of OS. Thus, patients with lower Ras expression are most likely to benefit from bevacizumab plus chemotherapy treatment regimen. Patients with higher levels of Ras should receive other inhibitors that target Ras. The results also suggest that gene therapies that decrease RAS expression combined with bevacizumab may improve lung cancer treatment. Although there is a very important implication to patient selection in the target therapy, the data in this study are very preliminary owing to the too small sample size. Therefore, further research involving large numbers of patients and a prospective assessment of low and high RAS mRNA expressions getting the same treatments need to be done before conclusions can be made.

Multiparametric PET/CT-perfusion does not add significant additional information for initial staging in lung cancer compared with standard PET/CT

BACKGROUND

The purpose of this study was to assess the relationship of CT-perfusion (CTP), 18F-FDG-PET/CT and histological parameters, and the possible added value of CTP to FDG-PET/CT in the initial staging of lung cancer.

METHODS

Fifty-four consecutive patients (median age 65 years, 15 females, 39 males) with suspected lung cancer were evaluated prospectively by CT-perfusion scan and 18F-FDG-PET/CT scan. Overall, 46 tumors were identified. CTP parameters blood flow (BF), blood volume (BV), and mean transit time (MTT) of the tumor tissue were calculated. Intratumoral microvessel density (MVD) was assessed quantitatively. Differences in CTP parameters concerning tumor type, location, PET positivity of lymph nodes, TNM status, and UICC stage were analyzed. Spearman correlation analyses between CTP and 18F-FDG-PET/CT parameters (SUVmax, SUVmean, PETvol, and TLG), MVD, tumor size, and tumor stage were performed.

RESULTS

The mean BF (mL/100 mL min-1), BV (mL/100 mL), and MTT (s) was 35.5, 8.4, and 14.2, respectively. The BF and BV were lower in tumors with PET-positive lymph nodes (p = 0.02). However, the CTP values were not significantly different among the N stages. The CTP values were not different, depending on tumor size and location. No significant correlation was found between CTP parameters and MVD.

CONCLUSIONS

Overall, the CTP information showed only little additional information for the initial staging compared with standard FDG-PET/CT. Low perfusion in lung tumors might possibly be associated with metabolically active regional lymph nodes. Apart from that, both CTP and 18F-FDG-PET/CT parameter sets may reflect different pathophysiological mechanisms in lung cancer.

Synergistic inhibition of angiogenesis and glioma cell-induced angiogenesis by the combination of temozolomide and enediyne antibiotic lidamycin

Present work mainly evaluated the inhibitory effects of lidamycin (LDM), an enediyne antibiotic, on angiogenesis or glioma-induced angiogenesis in vitro and in vivo, especially its synergistic anti-angiogenesis with temozolomide (TMZ). LDM alone efficiently inhibited proliferations and induced apoptosis of rat brain microvessel endothelial cells (rBMEC). LDM also interrupted the tube formation of rat brain microvessel endothelial cells (rBMEC) and rat aortic ring spreading. The blockade of rBMEC invasion and C6 cell-induced rBMEC migration by LDM was associated with decrease of VEGF secretion in a co-culture system. TMZ dramatically potentiated the effects of LDM on anti-proliferation, apoptosis induction, and synergistically inhibited angiogenesis events. As determined by western blot and ELISA, the interaction of tumor cells and the rBMEC was markedly interrupted by LDM plus TMZ with synergistic regulations of VEGF induced angiogenesis signal pathway, tumor cell invasion/migration, and apoptosis signal pathway. Immunofluorohistochemistry of CD31 and VEGF showed that LDM plus TMZ resulted in synergistic decrease of microvessel density (MVD) and VEGF expression in human glioma U87 cell subcutaneous xenograft. This study indicates that the high efficacy of LDM and the synergistic effects of LDM plus TMZ against glioma are mediated, at least in part, by the potentiated anti-angiogenesis.

Membrane phospholipids, EML4-ALK, and Hsp90 as novel targets in lung cancer treatment

Approximately one third of patients with non-small cell lung cancer have unresectable stage IIIA or stage IIIB disease; combined cytotoxic chemotherapy and radiation therapy delivered concurrently has been established as the standard treatment for such patients. Despite many clinical trials that tested several different radiochemotherapy combinations, it seems that a plateau of efficiencies at the acceptable risk of complications has been reached. Clinical studies indicate that the improved efficacy of radiochemotherapy is associated with the radiosensitizing effects of chemotherapy. Improvement of outcomes of this combined modality by developing novel radiosensitizers is a viable therapeutic strategy. In addition to causing cell death, ionizing radiation also induces a many-faceted signaling response, which activates numerous prosurvival pathways that lead to enhanced proliferation in the endothelial cells and increased vascularization in tumors. Radiation at doses used in the clinic activates cytoplasmic phospholipase A2, leading to increased production of arachidonic acid and lysophosphatidylcholine. The former is the initial step in the generation of eicosanoids, while the later is the initial step in the formation of lysophosphatidic acid, leading to the activation of inflammatory pathways. The echinoderm microtubule-associated protein-like 4 anaplastic lymphoma kinase (EML4-ALK) is member of the insulin superfamily of receptor tyrosine kinases. The EML4-ALK fusion gene appears unique to lung cancer and signals through extracellular signal regulated kinase and phosphoinositide 3-kinase. Heat shock protein 90 (Hsp90) is often overexpressed and present in an activated multichaperone complex in cancer cells, and it is now regarded as essential for malignant transformation and progression. In this review we focus on radiosensitizing strategies involving the targeting of membrane phospholipids, EML4-ALK, and Hsp90 with specific inhibitors and briefly discuss the combination of radiation with antivascular agents.

New treatment options for lung adenocarcinoma--in view of molecular background

Lung cancer is the leading cause of cancer related mortality all over the world, and a number of developments have indicated future clinical benefit recently. The development of molecular pathology methods has become increasingly important in the prediction of chemotherapy sensitivity and mutation analysis to identify driver mutations as important targets of new therapeutic agents. The most significant changes in the treatment of NSCLC revealed in new pathologic classification and in the introduction of molecularly targeted therapies, which include monoclonal antibodies and small molecule tyrosine kinase inhibitors. The side effects of these agents are generally better tolerated than those of conventional chemotherapy and show higher efficacy. The most important factor follows: histology subtypes, gene mutation status, patients' selection, drug toxicities and occurence of drug resistance. In the advanced disease, the hope of cure is less than 3%, but improvements in survival have been clearly achieved. Some years ago the median lung cancer survival rate was 10-12 months, now in case of available specific molecular targets, a significant increase in median survival rates to 24-36 months has been achieved. These agents give an opportunity to provide a new standard of care. Therefore testing EGFR mutations and ALK rearrangements in patients with advanced lung adenocarcinoma should be incorporated into routine clinical practice. This review focuses on the rationale for targeted agents and new treatment possibilities in case of advanced lung adenocarcinoma.

Novel compound 1,3-bis (3,5-dichlorophenyl) urea inhibits lung cancer progression

The successful clinical management of lung cancer is limited by frequent loss-of-function mutations in p53 which cooperates with chronic oxidant-stress induced adaptations in mercapturic acid pathway (MAP) which in turn regulates critical intracellular signaling cascades that determine therapeutic refractoriness. Hence, we investigated the anti-cancer effects and mechanisms of action of a novel compound called 1,3-bis(3,5-dichlorophenyl) urea (COH-SR4) in lung cancer. Treatment with COH-SR4 effectively inhibited the survival and clonogenic potential along with inducing apoptosis in lung cancer cells. COH-SR4 treatment caused the inhibition of GST activity and G0/G1 cell cycle arrest and inhibited the expression of cell cycle regulatory proteins CDK2, CDK4, cyclin A, cyclin B1, cyclin E1, and p27. The COH-SR4 activated AMPK pathway and knock-down of AMPK partially reversed the cytotoxic effects of COH-SR4 in lung cancer. COH-SR4 treatment lead to regression of established xenografts of H358 lung cancer cells without any overt toxicity. The histopathology of resected tumor sections revealed an increase in pAMPK, a decrease in the nuclear proliferative marker Ki67 and angiogenesis marker CD31. Western-blot analyses of resected tumor lysates revealed a decrease in pAkt and anti-apoptotic protein Bcl2 along with an increase in pAMPK, pro-apoptotic protein Bax and cleaved PARP levels. Importantly, COH-SR4 lead to decrease in the mesenchymal marker vimentin and increase in the normal epithelial marker E-cadherin. The results from our in-vitro and in-vivo studies reveal that COH-SR4 represents a novel candidate with strong mechanistic relevance to target aggressive and drug-resistant lung tumors.

Vascular endothelial growth factor inhibitors: investigational therapies for the treatment of psoriasis

Psoriasis is a common inflammatory autoimmune condition in which environmental factors and genetic predisposition contribute to the development of disease in susceptible individuals. Angiogenesis is known to be a key pathogenic feature of psoriasis. Local and systemic elevation of vascular endothelial growth factor (VEGF)-A has been demonstrated in the skin and plasma of patients with psoriasis and is known to correlate with improvement following some traditional psoriasis treatments. A number of VEGF inhibitors are licensed for the treatment of malignancies and eye disease and isolated case reports suggest that some individuals with psoriasis may improve when exposed to these agents. The small number of cases and lack of unified reporting measures makes it difficult to draw generalizations and underline the heterogeneity of psoriasis as a disease entity. Though not yet licensed for the treatment of psoriasis in humans, experimental data supports the potential of VEGF inhibitors to influence relevant aspects of human cell biology (such as endothelial cell differentiation) and to improve animal models of skin disease. Given the multi-factorial nature of psoriasis it is unlikely that VEGF inhibitors will be effective in all patients, however they have the potential to be a valuable addition to the therapeutic arsenal in selected cases. Current VEGF inhibitors in clinical use are associated with a number of potentially serious side effects including hypertension, left ventricular dysfunction, and gastrointestinal perforation. Such risks require careful consideration in psoriasis populations particularly in light of growing concerns linking psoriasis to increased cardiovascular risk.

Sanguinarine is a novel VEGF inhibitor involved in the suppression of angiogenesis and cell migration

Vascular endothelial growth factor (VEGF) is a main angiogenic factor which is known to be upregulated in lung cancer. In the present study, it was demonstrated that sanguinarine, an alkaloid obtained from the bloodroot plant, markedly repressed the VEGF-induced tube formation of human microvascular endothelial cells (HMVECs) and the migration of human A549 lung cancer cells. Furthermore, sanguinarine decreased VEGF secretion and expression in HMVECs and A549 lung cancer cells in a dose- and time-dependent manner. Additionally, sanguinarine inhibited the activation of serum starvation- and hypoxia-induced VEGF promoter activity. Sanguinarine also inhibited the VEGF-mediated Akt and p38 activation, as well as VE-cadherin protein phosphorylation. To the best of our knowledge, this is the first study demonstrating that VEGF inhibition appears to be an important mechanism involved in the antiangiogenic and anti-invasive activities of sanguinarine in lung cancer treatment.

The impact of tumor size change after target therapy on survival: analysis of patients enrolled onto three clinical trials of advanced NSCLC from one institution

Purpose

To explore whether changes in tumor size impact survival in advanced non-small-cell lung cancer (NSCLC) after target therapy, especially in patients with evaluation of stable disease (SD), and to review the applicability of the Response Evaluation Criteria in Solid Tumors (RECIST) criteria in target therapy.

Patients and methods

Data from 88 NSCLC patients receiving gefitinib (250 mg, daily [qd]), erlotinib (150 mg, qd), and ZD6474 (100 mg, qd) in three clinical trials (IRESSA registration clinical trial, TRUST study, ZD6474 study) during November 2003 to June 2005 were retrospectively analyzed. The treatment effect (complete response, partial response, stable disease [SD], or progressive disease) was evaluated with radiologic assessment according to the RECIST criteria. SD patients were divided into two groups: SD−/0, in which the sum of the longest diameter of target lesions decreased by less than 30% or did not change; and SD+, in which the sum of the longest diameter of target lesions increased by less than 20%. The differences of progression-free survival (PFS) and overall survival (OS) between these groups were analyzed.

Results

In the whole group, 27 patients achieved complete response or partial response as best response, 40 achieved SD, and 22 had progressive disease. The median PFS and OS were 4 months and 11.1 months, respectively. In SD patients, 27 were SD−/0 and 13 patients were SD+. The PFS and OS of SD+ patients was shorter than that of SD−/0 patients (5.65 months vs 2.03 days, P < 0.001 and 12.2 months vs 7.1 months, P < 0.001).

Conclusion

The applicability of RECIST criteria was called into question in the evaluation of target therapy. Change in tumor size might predict survival in advanced NSCLC patients with target therapy and may be a surrogate endpoint for efficacy in target therapy.