Human small cell lung cancer cells express functional VEGF receptors, VEGFR-2 and VEGFR-3

Recent advances and future directions on small molecule VEGFR inhibitors in oncological conditions

"A journey of mixed emotions" is a quote that best describes the progress chart of vascular endothelial growth factor receptor (VEGFR) inhibitors as cancer therapeutics in the last decade. Exhilarated with the Food and Drug Administration (FDA) approvals of numerous VEGFR inhibitors coupled with the annoyance of encountering the complications associated with their use, drug discovery enthusiasts are on their toes with an unswerving determination to enhance the rate of translation of VEGFR inhibitors from preclinical to clinical stage. The recently crafted armory of VEGFR inhibitors is a testament to their growing dominance over other antiangiogenic therapies for cancer treatment. This review perspicuously underscores the earnest attempts of the researchers to extract the antiproliferative potential of VEGFR inhibitors through the design of mechanistically diverse structural assemblages. Moreover, this review encompasses sections on structural/molecular properties and physiological functions of VEGFR, FDA-approved VEGFR inhibitors, and hurdles restricting the activity range/clinical applicability of VEGFR targeting antitumor agents. In addition, tactics to overcome the limitations of VEGFR inhibitors are discussed. A clear-cut viewpoint transmitted through this compilation can provide practical directions to push the cart of VEGFR inhibitors to advanced-stage clinical investigations in diverse malignancies.

Recent development of VEGFR small molecule inhibitors as anticancer agents: A patent review (2021-2023)

VEGFR, a receptor tyrosine kinase inhibitor (TKI), is an important regulatory factor that promotes angiogenesis and vascular permeability. It plays a significant role in processes such as tumor angiogenesis, tumor cell invasion, and metastasis. VEGFR is mainly composed of three subtypes: VEGFR-1, VEGFR-2, and VEGFR-3. Among them, VEGFR-2 is the crucial signaling receptor for VEGF, which is involved in various pathological and physiological functions. At present, VEGFR-2 is closely related to a variety of cancers, such as non-small cell lung cancer (NSCLC), Hepatocellular carcinoma, Renal cell carcinoma, breast cancer, gastric cancer, glioma, etc. Consequently, VEGFR-2 serves as a crucial target for various cancer treatments. An increasing number of VEGFR inhibitors have been discovered to treat cancer, and they have achieved tremendous success in the clinic. Nevertheless, VEGFR inhibitors often exhibit severe cytotoxicity, resistance, and limitations in indications, which weaken the clinical therapeutic effect. In recent years, many small molecule inhibitors targeting VEGFR have been identified with anti-drug resistance, lower cytotoxicity, and better affinity. Here, we provide an overview of the structure and physiological functions of VEGFR, as well as some VEGFR inhibitors currently in clinical use. Also, we summarize the in vivo and in vitro activities, selectivity, structure-activity relationship, and therapeutic or preventive use of VEGFR small molecule inhibitors reported in patents in the past three years (2021-2023), thereby presenting the prospects and insights for the future development of targeted VEGFR inhibitors.

The interaction of platelet-related factors with tumor cells promotes tumor metastasis

Platelets not only participate in thrombosis and hemostasis but also interact with tumor cells and protect them from mechanical damage caused by hemodynamic shear stress and natural killer cell lysis, thereby promoting their colonization and metastasis to distant organs. Platelets can affect the tumor microenvironment via interactions between platelet-related factors and tumor cells. Metastasis is a key event in cancer-related death and is associated with platelet-related factors in lung, breast, and colorectal cancers. Although the factors that promote platelet expression vary slightly in terms of their type and mode of action, they all contribute to the overall process. Recognizing the correlation and mechanisms between these factors is crucial for studying the colonization of distant target organs and developing targeted therapies for these three types of tumors. This paper reviews studies on major platelet-related factors closely associated with metastasis in lung, breast, and colorectal cancers.

Therapeutic effectiveness of anlotinib combined with etoposide in extensive-stage small-cell lung cancer: a single-arm, phase II trial

BACKGROUND

Anlotinib plus chemotherapy as first-line treatment for extensive-stage small-cell lung cancer (ES-SCLC) achieves good efficacy, but there is still room for improvement. This clinical study examined the effectiveness of anlotinib plus etoposide for maintenance therapy in ES-SCLC.

METHODS

The current single-arm, prospective phase II study was performed at Jiangsu Cancer Hospital (March 2019 to March 2022). After successful primary etoposide-based therapy, anlotinib was administered at 12 mg/day on days 1 to 14 of 21-day cycles until disease progression or consent withdrawal. All patients also received etoposide at 50 mg/day on days 1 to 14 of 21-day cycles for a maximum of six cycles. Progression-free survival (PFS) constituted the primary study endpoint. Secondary endpoints were overall survival (OS), objective remission rate (ORR), disease control rate (DCR), and safety. In addition, adverse events (AEs) were assessed.

RESULTS

Twenty-eight patients were treated. Median PFS and OS were 8.02 (95%CI 5.36-10.67) and 11.04 (95%CI 10.37-11.68) months, respectively. Totally 9 and 18 participants showed a partial response and stable disease, respectively; ORR and DCR were 32.14% and 96.43%, respectively. The commonest all-grade AEs were fatigue (n = 11, 39.28%), hypertension (n = 11, 39.28%), loss of appetite (n = 9, 32.14%), oral mucositis (n = 7, 25.00%) and proteinuria (n = 6, 21.40%). Grade 3-4 AEs included fatigue (n = 4, 14.28%), hypertension (n = 2, 7.14%), hand and foot syndrome (n = 2, 7.14%), oral mucositis (n = 1, 3.57%), hemoptysis (n = 1, 3.57%), proteinuria (n = 1, 3.57%), gingival bleeding (n = 1, 3.57%), and serum creatinine elevation (n = 1, 3.57%).

CONCLUSION

Maintenance anlotinib plus etoposide achieves promising PFS and OS in clinical ES-SCLC.

REGISTRATION NUMBER

ChiCTR1800019421.

In Silico Evaluation of HN-N07 Small Molecule as an Inhibitor of Angiogenesis and Lymphangiogenesis Oncogenic Signatures in Non-Small Cell Lung Cancer

Tumor angiogenesis and lymphangiogenesis pathways have been identified as important therapeutic targets in non-small cell lung cancer (NSCLC). Bevacizumab, which is a monoclonal antibody, was the initial inhibitor of angiogenesis and lymphangiogenesis that received approval for use in the treatment of advanced non-small cell lung cancer (NSCLC) in combination with chemotherapy. Despite its usage, patients may still develop resistance to the treatment, which can be attributed to various histological subtypes and the initiation of treatment at advanced stages of cancer. Due to their better specificity, selectivity, and safety compared to chemotherapy, small molecules have been approved for treating advanced NSCLC. Based on the development of multiple small-molecule antiangiogenic drugs either in house and abroad or in other laboratories to treat NSCLC, we used a quinoline-derived small molecule-HN-N07-as a potential target drug for NSCLC. Accordingly, we used computational simulation tools and evaluated the drug-likeness properties of HN-N07. Moreover, we identified target genes, resulting in the discovery of the target BIRC5/HIF1A/FLT4 pro-angiogenic genes. Furthermore, we used in silico molecular docking analysis to determine whether HN-N07 could potentially inhibit BIRC5/HIF1A/FLT4. Interestingly, the results of docking HN-N07 with the BIRC5, FLT4, and HIF1A oncogenes revealed unique binding affinities, which were significantly higher than those of standard inhibitors. In summary, these results indicate that HN-N07 shows promise as a potential inhibitor of oncogenic signaling pathways in NSCLC. Ongoing studies that involve in vitro experiments and in vivo investigations using tumor-bearing mice are in progress, aiming to evaluate the therapeutic effectiveness of the HN-N07 small molecule.

Catalytic response and molecular simulation studies in the development of synthetic routes in trimeric triaryl pyridinium type ionic liquids

Under conventional and silica-supported Muffle furnace methods, water-soluble substituted trimeric triaryl pyridinium cations with various inorganic counter anions are synthesized. The solvent-free synthesis method is superior to the conventional method in terms of non-toxicity, quicker reaction times, ease of workup, and higher yields. Trimeric substituted pyridinium salts acted as excellent catalytic responses for the preparation of Gem-bisamide derivatives compared with available literature. To evaluate the molecular docking, benzyl/4-nitrobenzyl substituted triaryl pyridinium salt compounds with VEGFR-2 kinase were used with H-bonds, π-π stacking, salt bridges, and hydrophobic contacts. The results showed that the VEGFR-2 kinase protein had the most potent inhibitory activity. Intriguingly, the compound [NBTAPy]PF₆^- had a strongly binds to VEGFR-2 kinase and controlled its activity in cancer treatment and prevention.

Association of Kinase-Insert-Domain-Containing Receptor Polymorphisms with Glioma Susceptibility in a Chinese Population: A Hospital-Based Case-Control Study

Background

Gliomas are the most common malignant tumors of the central nervous system. However, the inherited genetic variation in gliomas is presently unclear. Therefore, this study investigated the association of the rs2071559 and rs2239702 gene polymorphisms with glioma susceptibility in Chinese patients.

Methods

In this study, a case-control approach was used to compare and analyze whether two genes, rs2071559 and rs2239702, were associated with the risk of glioma formation.

Results

The cases and controls were matched for sex, smoking status, and family history of cancer using single nucleotide polymorphisms. Specific rs2071559 and rs2239702 alleles were found much more frequently in the glioma group than in the control group (P < 0.001 and P = 0.014, respectively).

Conclusions

These findings suggest that specific rs2071559 and rs2239702 polymorphisms are associated with a higher risk of glioma development; the risk allele is C in rs2071559 or A in rs2239702. Moreover, the kinase-insert-domain-containing receptor may act as a suppressor of tumor progression.

A reverse phase protein array based phospho-antibody characterization approach and its applicability for clinical derived tissue specimens

Systematic quantification of phosphoprotein within cell signaling networks in solid tissues remains challenging and precise quantification in large scale samples has great potential for biomarker identification and validation. We developed a reverse phase protein array (RPPA) based phosphor-antibody characterization approach by taking advantage of the lysis buffer compatible with alkaline phosphatase (AP) treatment that differs from the conventional RPPA antibody validation procedure and applied it onto fresh frozen (FF) and formalin-fixed and paraffin-embedded tissue (FFPE) to test its applicability. By screening 106 phospho-antibodies using RPPA, we demonstrated that AP treatment could serve as an independent factor to be adopted for rapid phospho-antibody selection. We also showed desirable reproducibility and specificity in clincical specimens indicating its potential for tissue-based phospho-protein profiling. Of further clinical significance, using the same approach, based on melanoma and lung cancer FFPE samples, we showed great interexperimental reproducibility and significant correlation with pathological markers in both tissues generating meaningful data that match clinical features. Our findings set a benchmark of an efficient workflow for phospho-antibody characterization that is compatible with high-plex clinical proteomics in precison oncology.

Novel therapeutic combinations with PARP inhibitors for small cell lung cancer: A bench-to-bedside review

Small cell lung cancer (SCLC) is treated as a monolithic disease despite the evident intra- and intertumoral heterogeneity. Non-specific DNA-damaging agents have remained the first-line treatment for decades. Recently, emerging transcriptomic and genomic profiling of SCLC tumors identified distinct SCLC subtypes and vulnerabilities towards targeted therapeutics, including inhibitors of the nuclear enzyme poly (ADP-ribose) polymerase (PARPi). SCLC cell lines and tumors exhibited an elevated level of PARP1 protein and mRNA compared to healthy lung tissues and other subtypes of lung tumors. Notable responses to PARPi were also observed in preclinical SCLC models. Clinically, PARPi monotherapy exerted variable benefits for SCLC patients. To date, research is being vigorously conducted to examine predictive biomarkers of PARPi response and various PARPi combination strategies to maximize the clinical utility of PARPi. This narrative review summarizes existing preclinical evidence supporting PARPi monotherapy, combination therapy, and respective translation to the clinic. Specifically, we covered the combination of PARPi with DNA-damaging chemotherapy (cisplatin, etoposide, temozolomide), thoracic radiotherapy, immunotherapy (immune checkpoint inhibitors), and many other novel therapeutic agents that target DNA damage response, tumor microenvironment, epigenetic modulation, angiogenesis, the ubiquitin-proteasome system, or autophagy. Putative biomarkers, such as SLFN11 expression, MGMT methylation, E2F1 expression, and platinum sensitivity, which may be predictive of response to distinct therapeutic combinations, were also discussed. The future of SCLC treatment is undergoing rapid change with a focus on tailored and personalized treatment strategies. Further development of cancer therapy with PARPi will immensely benefit at least a subset of biomarker-defined SCLC patients.

First-Line Treatment for Advanced SCLC: What Is Left Behind and Beyond Chemoimmunotherapy

Small cell lung cancer (SCLC) is still a lethal disease. Three phase III randomized clinical trials (IMpower133, CASPIAN, and KEYNOTE-604) have highlighted the survival gain of adding immune checkpoint inhibitors to first-line standard chemotherapy in advanced SCLC patients. In this review, we discuss the data from the three trials above. Furtherly, we analyze issues that still need to be elucidated, like the role of biomarkers, poor performance status at baseline, the presence of brain metastases, and the platinum compound's choice. Moreover, we depict the future of SCLC first-line therapy management, focusing on new therapeutic strategies currently under investigation.

A phase II study of anlotinib combined with etoposide and platinum-based regimens in the first-line treatment of extensive-stage small cell lung cancer

BACKGROUND

The aim of this prospective, pilot, single-arm phase II trial was to evaluate the safety and efficacy of anlotinib combined with etoposide and platinum-based regimens in the first-line treatment of extensive-stage small cell lung cancer (ES-SCLC).

METHODS

This phase II study was conducted at Fudan University Shanghai Cancer Center between December 2018 and December 2020. All patients received standard chemotherapy (etoposide plus cisplatin/carboplatin) consisting of four courses and anlotinib at 12 mg once per day for 2 weeks followed by a one-week rest. Anlotinib administration was continued until disease progression, intolerable adverse events (AEs) or patient withdrawal from the study. The primary outcome measure was progression-free survival (PFS). The secondary outcome measures were overall survival (OS), objective control rate (ORR), disease control rate (DCR) and AEs.

RESULTS

Thirty-seven patients were included in this study, and 30 patients were eligible for efficacy analysis. ORR and DCR were 90.0% and 96.7%, respectively. The estimated PFS and OS were 6.0 months (95% CI: 1.1-11.9 months) and 14.0 months (95% CI: 8.6-19.4 months), respectively. No unexpected adverse effects were reported. Hypertension (20/37, 54.1%), anemia (16/37, 43.2%), alopecia (15/37, 40.5%), elevated transaminases (9/37, 24.3%) and alkaline phosphatase (9/37, 24.3%) were the most commonly reported AEs. Thirteen patients (35.1%) reported grade 3-5 AEs. No treatment-related deaths occurred during this study.

CONCLUSION

The addition of anlotinib to standard etoposide/platinum chemotherapy achieved encouraging PFS and OS in previously untreated ES-SCLC patients, with an acceptable tolerability profile and no new safety signals observed.

CAR-T Cells for the Treatment of Lung Cancer

Adoptive cell therapy with genetically modified T lymphocytes that express chimeric antigen receptors (CAR-T) is one of the most promising advanced therapies for the treatment of cancer, with unprecedented outcomes in hematological malignancies. However, the efficacy of CAR-T cells in solid tumors is still very unsatisfactory, because of the strong immunosuppressive tumor microenvironment that hinders immune responses. The development of next-generation personalized CAR-T cells against solid tumors is a clinical necessity. The identification of therapeutic targets for new CAR-T therapies to increase the efficacy, survival, persistence, and safety in solid tumors remains a critical frontier in cancer immunotherapy. Here, we summarize basic, translational, and clinical results of CAR-T cell immunotherapies in lung cancer, from their molecular engineering and mechanistic studies to preclinical and clinical development.

Infiltrating T lymphocytes in the tumor microenvironment of small cell lung cancer: a state of knowledge review

Immune checkpoint inhibitors (ICIs) have brought new hope for the treatment of patients with small cell lung cancer (SCLC) over the past decades. However, the overall response rate is limited, and is lower than that in non-small cell lung cancer (NSCLC). This is in part because of the lack of pre-existing tumor-infiltrating T lymphocytes (TITLs), especially cytotoxic T cells (CTLs), in the SCLC tumor microenvironment (TME), resulting in insufficient anti-tumor immune response. To unleash the full potential of ICIs, the trafficking and infiltration of TITLs to the tumor is necessary and tightly regulated, the highly immunosuppressive tumor microenvironment blunts the infiltration and function of TITLs that reach the tumor in SCLC. Here, we review the characteristics of TITLs, the effects of various factors on T cell infiltration, and possible strategies to restore or promote T cell infiltration in the TME of SCLC.

Association of the VEGFR2 single nucleotide polymorphism rs2305948 with glioma risk

BACKGROUND

Many studies have reported a relationship between the vascular endothelial growth factor receptor 2 single nucleotide polymorphism (SNP) rs2305948 and glioma, but their conclusions have been controversial. A meta-analysis was performed to assess the association between rs2305948 and glioma susceptibility.

METHODS

Inclusion criteria and a strategy for screening of original literature were created. Eligible articles on the correlation between the SNP rs2305948 and glioma were identified in the PubMed, Embase, Web of Science, Cochrane Library, CNKI and Wanfang databases. After extracting the data, Stata 12. 0 software was used to perform statistical analysis under 5 genetic models and to calculate the combined odds ratio (OR) value and its 95% confidence interval (CI).

RESULTS

Four case-control studies including 1595 cases and 1657 controls were entered into the study. The overall analysis showed that no obvious association existed between rs2305948 and glioma risk (allele: OR = 1.20, 95% CI = 0.93-1.54, P = .162; dominant: OR = 1.17, 95% CI = 0.93-1.46, P = .174; recessive: OR = 1.72, 95% CI = 0.94-3.15, P = .076; heterozygous: OR = 1.11, 95% CI = 0.94-1.30, P = .226; homozygous: OR = 1.74, 95% CI = 0.92-3.29, P = .088). The subgroup analysis suggested that the SNP rs2305948 was related to glioma susceptibility under allele, dominant, recessive and homozygote models in the Asian population (allele: OR = 1.34, 95% CI = 1.16-1.55, P < .001; recessive: OR = 2.24, 95% CI = 1.49-3.36, P < .001; homozygous: OR = 2.32, 95% CI = 1.54-3.50, P < .001).

CONCLUSION

The vascular endothelial growth factor receptor 2 rs2305948 gene polymorphism may be related to glioma susceptibility in the Asian population. However, the association is not clear in non-Asian populations, for which there has been less research.

Receptor Tyrosine Kinases and Their Signaling Pathways as Therapeutic Targets of Curcumin in Cancer

Receptor tyrosine kinases (RTKs) are transmembrane cell-surface proteins that act as signal transducers. They regulate essential cellular processes like proliferation, apoptosis, differentiation and metabolism. RTK alteration occurs in a broad spectrum of cancers, emphasising its crucial role in cancer progression and as a suitable therapeutic target. The use of small molecule RTK inhibitors however, has been crippled by the emergence of resistance, highlighting the need for a pleiotropic anti-cancer agent that can replace or be used in combination with existing pharmacological agents to enhance treatment efficacy. Curcumin is an attractive therapeutic agent mainly due to its potent anti-cancer effects, extensive range of targets and minimal toxicity. Out of the numerous documented targets of curcumin, RTKs appear to be one of the main nodes of curcumin-mediated inhibition. Many studies have found that curcumin influences RTK activation and their downstream signaling pathways resulting in increased apoptosis, decreased proliferation and decreased migration in cancer both in vitro and in vivo. This review focused on how curcumin exhibits anti-cancer effects through inhibition of RTKs and downstream signaling pathways like the MAPK, PI3K/Akt, JAK/STAT, and NF-κB pathways. Combination studies of curcumin and RTK inhibitors were also analysed with emphasis on their common molecular targets.

Effectiveness and safety of bevacizumab in extensive-disease small cell lung cancer: a systemic review and meta-analysis

Background

Small cell lung cancer (SCLC) is highly invasive and poorly prognostic. The effects of chemotherapy with bevacizumab are promising on other tumors but unclear in extensive-disease SCLC (ED-SCLC). A systemic review and meta-analysis were performed to investigate the efficacy and toxicity in ED-SCLC patients.

Methods

A review of current studies was performed on electronic databases and other sources to identify publications of ED-SCLC patients who received bevacizumab. Endpoints included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and complications.

Results

Nine relevant articles with six single-arm and three two-arm studies were identified. Four hundred seventy-six patients were included, of which 368 and 108 were untreated and relapse patients. Most patients were performance status 0–1 (71.6%) and male (58.1%). The comparisons showed CT/bevacizumab slightly prolonged OS (HR =0.84) but significantly improved PFS (HR =0.74). The ORRs of untreated and relapse patients were 71% and 19%, though no significant difference was observed than CT/placebo. The most grade 3–4 complication and bevacizumab-associated complications were neutropenia and hypertension, whose rates were 33% and 6%. Patients who received CT/bevacizumab had a higher hypertension rate than CT/placebo (6% vs. 2%). No different complication rate was observed between high and lose dose groups.

Discussion

The present study suggests that bevacizumab in the combination of standard chemotherapy provides better PFS than chemotherapy alone. Although the combined regimen is well-tolerated, no superiority in OS or response rate is observed.

Anlotinib vs placebo as third- or further-line treatment for patients with small cell lung cancer: a randomised, double-blind, placebo-controlled Phase 2 study

BACKGROUND

This study aimed to evaluate the efficacy and safety of anlotinib as a third-line and subsequent treatment for patients with small cell lung cancer (SCLC).

METHODS

We conducted this Phase 2 trial at 11 institutions in China. Patients with pathologically confirmed SCLC who failed at least two lines of chemotherapy were enrolled. Subjects were randomly assigned in a 2:1 ratio to receive either anlotinib 12 mg orally once daily for 14 days every 3 weeks or placebo. The primary endpoint was progression-free survival (PFS).

RESULTS

Between March 30, 2017 and June 8, 2018, a total of 82 and 38 patients were randomly assigned to receive anlotinib and placebo. The median PFS was significantly longer in the anlotinib group compared with the placebo group (4.1 months [95% confidence interval (CI), 2.8-4.2] vs 0.7 months [95% CI, 0.7-0.8]; hazard ratio (HR) 0.19 [95% CI, 0.12-0.32], p < 0.0001). Overall survival (OS) was significantly longer with anlotinib than placebo (7.3 months [95% CI, 6.1-10.3] vs 4.9 months [95% CI, 2.7-6.0]; HR 0.53 [95% CI, 0.34-0.81], p = 0.0029).

CONCLUSIONS

Anlotinib as a third-line or subsequent treatment for Chinese patients with SCLC showed improved PFS and OS than placebo with favourable safety profile.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, number NCT03059797.

VEGFR-Mediated Cytotoxic Activity of Pulicaria undulata Isolated Metabolites: A Biological Evaluation and In Silico Study

Natural products play a remarkable role not only in the synthesis, design, and discovery of new drugs but also as the most prominent source of drugs and bioactive substances. Adding to the search for new sources of safe innovative antitumor drugs, here we reported a phytochemical study on Pulicaria undulata which revealed promising antiangiogenic agents. Six compounds were isolated and identified as xanthoxyline (1), stigmasterol (2), oleanolic acid (3), salvigenin (4), rhamnetin (5) and dihydroquercetin-4′-methyl ether (6) using nuclear magnetic resonance (NMR) spectroscopic techniques. Compound 3 and 4 are first reported in Pulicaria genus. Both the extract and isolated compounds were evaluated for in vitro antiproliferative activity against breast cancer cell line (MCF-7). In vivo antiproliferative activity against Ehrlich’s ascites carcinoma (EAC) were also assessed. The P. undulata extract and isolates showed significant reduction in tumor weight, decreased both serum vascular endothelial growth factor B (VEGF-B) levels and vascular endothelial growth factor receptor 2 (VEGFR-2) expression significantly compared to the control EAC group, suggesting an antiangiogenic activity through the inhibition of VEGF signaling. Besides, they displayed reduction in CD34 expression, confirming their antiangiogenic effect. Moreover, the potential affinity of isolated compounds to human estrogen nuclear receptor-alpha (hER-α), the most recognized modulator of VEGFR-2 expression, was virtually estimated through molecular modeling studies. The most promising activity profiles were assigned to the investigated flavonoids, compounds 4–6, as well as the alkyl-phenylketone, compound 1. Additionally, these four top active compounds showed respective high to intermediate docking scores while possessing preferential binding with hER-α critical pocket residues. Based on the provided data, these isolated compounds illustrated promising inhibitors of VEGF-stimulated angiogenesis, which could be a possible mechanism for their anticancer activity.

Inhibitory effects of terrein on lung cancer cell metastasis and angiogenesis

Cancer metastasis is the leading cause of mortality in cancer patients. Over 70% of lung cancer patients are diagnosed at advanced or metastatic stages, and this results in an increased incidence of mortality. Terrein is a secondary bioactive fungal metabolite isolated from Aspergillus terreus. Numerous studies have demonstrated that terrein has anticancer properties, but in the present study, the cellular mechanisms underlying the inhibition of lung cancer cell metastasis by terrein was investigated for the first time. Using MTT assays, the cytotoxic effects of terrein were first examined in human lung cancer cells (A549 cells) and then compared with its cytotoxic effects in three noncancer control cell lines (Vero kidney, L6 skeletal muscle and H9C2 cardiomyoblast cells). The results indicated that terrein significantly reduced the viability of all these cells but exhibited a different level of toxicity in each cell type; these results revealed a specific concentration range in which the effect of terrein was specific to A549 cells. This significant cytotoxic effect of terrein in A549 cells was verified using LDH assays. It was then demonstrated that terrein attenuated the proliferation of A549 cells using IncuCyte image analysis. Regarding its antimetastatic effects, terrein significantly inhibited A549 cell adhesion, migration and invasion. In addition, terrein suppressed the angiogenic processes of A549 cells, including vascular endothelial growth factor (VEGF) secretion, capillary-like tube formation and VEGF/VEGFR2 interaction. These phenomena were accompanied by reduced protein levels of integrins, FAK, and their downstream mediators (e.g., PI3K, AKT, mTORC1 and P70S6K). All these data indicated that terrein was able to inhibit all the major metastatic processes in human lung cancer cells, which is crucial for cancer treatment.

Bevacizumab regulates inflammatory cytokines and inhibits VEGFR2 signaling pathway in an ovalbumin-induced rat model of airway hypersensitivity

BACKGROUND

Bevacizumab with anti-angiogenesis properties reduces the vascular endothelial growth factor (VEGF) level and has widely been used to treat various diseases such as lung diseases and chronic obstructive pulmonary disease (COPD). This study, therefore, aimed to consider the effects of bevacizumab on VEGF receptor 2 (VEGFR2) and lung inflammation of the ovalbumin-induced rat model of airway hypersensitivity.

MATERIALS AND METHODS

Twenty-one male Wistar rats were randomly divided into 3 groups (n = 7 in each group): (1) control, (2) ovalbumin (OVA)-sensitized, and (3) OVA-sensitized with bevacizumab (OVA + Bmab). Groups 2 and 3 were sensitized with ovalbumin (OVA) and aluminum hydroxide on days 1, 8 and challenged with OVA on day 15 by atomization for 10 days (inhalation). After OVA sensitization, the OVA + Bmab was treated with bevacizumab for 2 weeks. VEGFR2 was semiquantitatively analyzed in the lungs by immunohistochemistry. VEGF was measured in the lung tissue by ELISA method. The mRNA of IL-10 and IL-6 lung tissue were measured by real-time PCR.

RESULTS

Ovalbumin exposure promoted the expression of VEGF and resulted in inflammatory factors overexpression (p ≤ 0.05). However, rats in OVA + Bmab group showed significantly a decrease in VEGFR2 and IL-1β, IL-6, TNFα, and an increase in IL-10 (p ≤ 0.05).

CONCLUSION

The results show that bevacizumab efficiently diminishes bronchial inflammation via reducing the expression of VEGFR2, and IL-6 genes and enhancing the expression of IL-10 gene. Hence, bevacizumab could be considered as a potential candidate drug to control pathological conditions relevant to airway hypersensitivity.

The CXCL2/IL8/CXCR2 Pathway Is Relevant for Brain Tumor Malignancy and Endothelial Cell Function

We aimed to evaluate the angiogenic capacity of CXCL2 and IL8 affecting human endothelial cells to clarify their potential role in glioblastoma (GBM) angiogenesis. Human GBM samples and controls were stained for proangiogenic factors. Survival curves and molecule correlations were obtained from the TCGA (The Cancer Genome Atlas) database. Moreover, proliferative, migratory and angiogenic activity of peripheral (HUVEC) and brain specific (HBMEC) primary human endothelial cells were investigated including blockage of CXCR2 signaling with SB225502. Gene expression analyses of angiogenic molecules from endothelial cells were performed. Overexpression of VEGF and CXCL2 was observed in GBM patients and associated with a survival disadvantage. Molecules of the VEGF pathway correlated but no relation for CXCR1/2 and CXCL2/IL8 was found. Interestingly, receptors of endothelial cells were not induced by addition of proangiogenic factors in vitro. Proliferation and migration of HUVEC were increased by VEGF, CXCL2 as well as IL8. Their sprouting was enhanced through VEGF and CXCL2, while IL8 showed no effect. In contrast, brain endothelial cells reacted to all proangiogenic molecules. Additionally, treatment with a CXCR2 antagonist led to reduced chemokinesis and sprouting of endothelial cells. We demonstrate the impact of CXCR2 signaling on endothelial cells supporting an impact of this pathway in angiogenesis of glioblastoma.

Old but gold: the role of drug combinations in improving response to immune check-point inhibitors in thoracic malignancies beyond NSCLC

The introduction of immune checkpoint inhibitors (ICIs) in non-oncogene addicted non-small cell lung cancer (NSCLC) has revolutionized the treatment scenario and led to a meaningful improvement in patient prognosis. Disappointingly, the success of ICI therapy in NSCLC has not been fully replicated in other thoracic malignancies as small cell lung cancer (SCLC), malignant pleural mesothelioma (MPM), and thymic epithelial tumors (TETs), due to the peculiar biological features of these disease and to the difficulties in the conduction of well-designed, biomarker-driven clinical trials. Therefore, combination strategies of ICIs plus conventional therapies (either chemotherapy, alternative ICIs or targeted agents) have been implemented. Although first approvals of ICI therapy have been recently granted in SCLC and MPM (in combination with chemotherapy and different ICIs), results remain somewhat modest and limited to a small proportion of patients. This work reviews the trial results of ICI therapy in mesothelioma, SCLC, and TETs and discusses the potential of combining ICIs with old drugs.

Old Player-New Tricks: Non Angiogenic Effects of the VEGF/VEGFR Pathway in Cancer

Angiogenesis has long been considered to facilitate and sustain cancer growth, making the introduction of anti-angiogenic agents that disrupt the vascular endothelial growth factor/receptor (VEGF/VEGFR) pathway an important milestone at the beginning of the 21st century. Originally research on VEGF signaling focused on its survival and mitogenic effects towards endothelial cells, with moderate so far success of anti-angiogenic therapy. However, VEGF can have multiple effects on additional cell types including immune and tumor cells, by directly influencing and promoting tumor cell survival, proliferation and invasion and contributing to an immunosuppressive microenvironment. In this review, we summarize the effects of the VEGF/VEGFR pathway on non-endothelial cells and the resulting implications of anti-angiogenic agents that include direct inhibition of tumor cell growth and immunostimulatory functions. Finally, we present how previously unappreciated studies on VEGF biology, that have demonstrated immunomodulatory properties and tumor regression by disrupting the VEGF/VEGFR pathway, now provide the scientific basis for new combinational treatments of immunotherapy with anti-angiogenic agents.

[Apatinib Combined with CCI-779 Inhibits the Proliferation and Migration of Small Cell Lung Cancer NCI-H446 Cells In Vitro]

背景与目的

肺癌是世界上最常见的恶性肿瘤，其中小细胞肺癌是恶性程度最高的亚型，具有生长迅速、早期转移和高度血管化等特点。阿帕替尼（Apatinib）是我国自主研发的血管内皮生长因子受体2抑制剂，在多种实体瘤中疗效显著。本研究旨在探讨Apatinib对小细胞肺癌细胞株NCI-H446的体外作用以及联合哺乳动物雷帕霉素靶蛋白（mammalian target of rapamycin, mTOR）抑制剂CCI-779对小细胞肺癌的体外作用。

方法

体外培养小细胞肺癌细胞株NCI-H446，CCK8法、细胞凋亡实验、细胞周期实验及Transwell实验检测Apatinib及联合mTOR抑制剂CCI-779对NCI-H446细胞增殖、凋亡、周期及迁移的影响；Western blot实验检测血管内皮生长因子受体和细胞周期相关蛋白的表达。

结果

CCK8实验结果显示高浓度Apatinib能抑制NCI-H446细胞增殖；细胞凋亡实验结果显示高浓度Apatinib诱导NCI-H446细胞凋亡；Transwell实验结果显示高浓度Apatinib抑制NCI-H446细胞迁移；联合mTOR抑制剂CCI-779后，低浓度Apatinib便能抑制NCI-H446细胞增殖和迁移，诱导细胞凋亡。

结论

Apatinib对小细胞肺癌细胞株NCI-H446的作用具有浓度依赖性特征，高浓度Apatinib能够抑制NCI-H446细胞增殖和迁移，诱导细胞凋亡，与mTOR抑制剂CCI-779联用能增加NCI-H446细胞对Apatinib的敏感性。

[Thoracic lymphatic system-principles, characteristics and advice for the practice]

The lymphatic system of the lungs is complex. To maintain an effective gas exchange there is a need for a dense lymphatic network. The alveolae have no lymphatic vessels. There is no segment-specific lymph drainage. For both lungs there are fixed bronchopulmonary lymph nodes but the number and size of the lymph nodes are variable. There are seven mediastinal lymph node chains that vary in extent, each of which acts as an independent functional unit. The accurate assessment of the nodal status needs a simple reproducible nodal map. The division into compartments or zones makes this easier. Mediastinal lymph node metastases without involvement of bronchopulmonary lymph nodes are possible. The development mechanism of this skip metastasizing is multifactorial.

Apatinib in patients with extensive-stage small-cell lung cancer after second-line or third-line chemotherapy: a phase II, single-arm, multicentre, prospective study

BACKGROUND

Small-cell lung cancer (SCLC) remains an aggressive cancer with short-term survival due to limited therapeutic options. Apatinib is a small-molecule tyrosine kinase inhibitor that selectively inhibits vascular endothelial growth factor receptor-2. This study aimed to investigate the efficacy and safety of apatinib in patients with extensive-stage (EC) SCLC who had progressed after two or three previous therapies.

METHODS

Eligible patients were histologically confirmed ES-SCLC after two or three previous treatments, including a platinum-based regimen. Patients received apatinib at an initial dose of 500 mg once daily. The primary endpoint was the objective response rate.

RESULTS

Forty patients were enrolled. At the data cut-off time (November 15, 2018), the median follow-up was 7.4 months; no patients remained on treatment, and five were still in follow-up. An objective response was achieved in 7 of 40 patients (17.5%) in the intention-to-treat population, and 7 of 38 patients (18.4%) in the per-protocol population. The median progression-free survival and overall survival were 3.0 months and 5·8 months, respectively. The most commonly observed grade 3 or greater treatment-related adverse events were hypertension, hand-foot syndrome, increased L-gamma-glutamyltransferase.

CONCLUSIONS

Apatinib exhibited efficacy and an acceptable safety profile in previously heavily-treated ES-SCLC patients. Further exploration of apatinib in phase III trials is warranted.

TRIAL REGISTRATION

NCT02945852.

Apatinib for chemotherapy-refractory extensive-stage SCLC: a retrospective study

PURPOSE

There is no standard treatment strategy for patients with extensive-stage small cell lung cancer (SCLC) who have failed two or more prior chemotherapeutic regimens. In this study, we retrospectively evaluated the efficacy and safety of apatinib in patients with extensive-stage SCLC after failure of more than second-line chemotherapy.

METHODS

A study group comprised of 22 patients with extensive-stage SCLC after failure of more than two prior chemotherapeutic regimens was given apatinib orally at an initial dose of 500 mg daily until disease progression or unacceptable toxicity. This study was analyzed according to the National Cancer Institute Common Toxicity Criteria for adverse events (AEs) and Response Evaluation Criteria in Solid Tumors (RECIST) for response assessment.

RESULTS

Between August 30, 2015, and May 26, 2017, 22 patients were enrolled for evaluating the efficacy and safety of apatinib. Among them, 12/22 (54.5%) underwent dose reduction during treatment. Up to July 31, 2018, the median progression-free survival rate was 135.0 days [95% confidence interval (CI) 63.8-206.2]. According to the RECIST criteria, the disease control rate (DCR) was 86.4%, 19/22 [comprised of partial response (PR) 18.2%, 4/22; and stable disease (SD) 68.2%, 15/22 patients]. The most frequent AEs were hand-foot syndrome (45.5%, 10/22), secondary hypertension (45.5%, 10/22) and fatigue (40.9%, 9/22). The primary grade 3 or 4 toxicities were hypertension (22.7%, 5/22), hand-foot syndrome (13.6%, 3/22), and proteinuria (9.1%, 2/22).

CONCLUSIONS

Apatinib exhibits modest activity and acceptable toxicity for patients with heavily pretreated extensive-stage SCLC.

The Effect of Venous Thromboembolism on Survival of Cancer Patients and its Relationship with Serum Levels of Factor VIII and Vascular Endothelial Growth Factor: A Prospective Matched-Paired Study

Background

Venous thromboembolism (VT) increases mortality and morbidity in cancer patients. The primary aim of this study was to evaluate the effect of VT on the survival of cancer patients and its relationship with serum vascular endothelial growth factor (VEGF) and plasma factor VIII levels.

Patients and methods

Eighty-two patients with locally advanced or metastatic cancer were included in this study between September 2001 and March 2004, and 31 of them had VT. Fifty-one matched-paired cancer patients without VT were prospectively selected as a control group in the same period. Criteria for the selection of control group patients were having the same malignancy, stage, metastatic site, performance status and age (±5 years) as patients in the VT group.

Results

Plasma factor VIII and serum D-dimer levels in the VT group were significantly higher than those in the control group (p=0.030 and p=0.016, respectively). However, mean serum VEGF levels were similar in both groups (p=0.199). In the VT group, the median survival of patients who had higher serum VEGF levels (>150 pg/mL) was significantly shorter than that of patients in the same group with lower serum VEGF levels (p=0.005). The median survival of the VT group was 14 months, whereas it was 25 months in the control group (p=0.199).

Conclusion

There was a worse prognostic trend for cancer patients with VT. Nevertheless, the difference in survival was not statistically significant between the groups. Plasma factor VIII and serum D-dimer levels might have prognostic value in cancer patients with VT. Cancer patients with VT and higher serum VEGF levels had a significantly poorer prognosis.

VEGF as a potential target in lung cancer

Introduction The vascular endothelial growth factor A (VEGF) is the main mediator of angiogenesis. In addition, VEGF contributes to cancer growth and metastasis directly targeting tumor cells. VEGF overexpression and/or high VEGF serum levels have been reported in lung cancer. Areas covered We searched Pubmed for relevant preclinical studies with the terms 'lung cancer' 'VEGF' and 'in vivo'. We also searched the Clinicaltrials.gov database, the FDA and the EMA websites for the most recent updates on clinical development of anti-VEGF agents. Expert opinion VEGF plays an important role in sustaining the development and progression of lung cancer and it might represent an attractive target for therapeutic strategies. Nevertheless, clinical trials failed to attend the promising expectations deriving from preclinical studies with anti-VEGF agents. To improve the efficacy of anti-VEGF therapies in lung cancer, potential strategies might be the employment of combinatory therapies with immune checkpoint inhibitors or agents that inhibit signaling pathways and proangiogenic factors activated in response to VEGF blockade, and the identification of novel targets in the VEGF cascade. Finally, the identification of predictive markers might help to select patients who are more likely to respond to anti-angiogenic drugs.

Development and Characterization of a Camelid Single Domain Antibody-Urease Conjugate That Targets Vascular Endothelial Growth Factor Receptor 2

Angiogenesis is the process of new blood vessel formation and is essential for a tumor to grow beyond a certain size. Tumors secrete the pro-angiogenic factor vascular endothelial growth factor, which acts upon local endothelial cells by binding to vascular endothelial growth factor receptors (VEGFRs). In this study, we describe the development and characterization of V21-DOS47, an immunoconjugate that targets VEGFR2. V21-DOS47 is composed of a camelid single domain anti-VEGFR2 antibody (V21) and the enzyme urease. The conjugate specifically binds to VEGFR2 and urease converts endogenous urea into ammonia, which is toxic to tumor cells. Previously, we developed a similar antibody-urease conjugate, L-DOS47, which is currently in clinical trials for non-small cell lung cancer. Although V21-DOS47 was designed from parameters learned from the generation of L-DOS47, additional optimization was required to produce V21-DOS47. In this study, we describe the expression and purification of two versions of the V21 antibody: V21H1 and V21H4. Each was conjugated to urease using a different chemical cross-linker. The conjugates were characterized by a panel of analytical techniques, including SDS-PAGE, size exclusion chromatography, Western blotting, and LC-MS^E peptide mapping. Binding characteristics were determined by ELISA and flow cytometry assays. To improve the stability of the conjugates at physiologic pH, the pIs of the V21 antibodies were adjusted by adding several amino acid residues to the C-terminus. For V21H4, a terminal cysteine was also added for use in the conjugation chemistry. The modified V21 antibodies were expressed in the E. coli BL21 (DE3) pT7 system. V21H1 was conjugated to urease using the heterobifunctional cross-linker succinimidyl-[(N-maleimidopropionamido)-diethyleneglycol] ester (SM(PEG)₂), which targets lysine resides in the antibody. V21H4 was conjugated to urease using the homobifunctional cross-linker, 1,8-bis(maleimido)diethylene glycol (BM(PEG)₂), which targets the cysteine added to the antibody C-terminus. V21H4-DOS47 was determined to be the superior conjugate as the antibody is easily produced and purified at high levels, and the conjugate can be efficiently generated and purified using methods easily transferrable for cGMP production. In addition, V21H4-DOS47 retains higher binding activity than V21H1-DOS47, as the native lysine residues are unmodified.

Angiogenesis inhibitors for the treatment of small cell lung cancer (SCLC): A meta-analysis of 7 randomized controlled trials

BACKGROUND

This study aimed to assess the effectiveness and safety of angiogenesis inhibitors for the treatment of patients with small cell lung cancer (SCLC) via meta-analysis.

METHODS

Electronic databases including PubMed, Embase, and Cochrane Library were searched to look for eligible studies through February 1, 2016. RCTs comprising angiogenesis inhibitors and nonangiogenesis inhibitors for SCLC patients were investigated. The extracted data including overall survival (OS), progression-free survival (PFS), and objective response rate (ORR) were summarized. In addition, the common adverse events (AEs) were also explored.

RESULTS

There were 7 phase II/III RCTs, encompassing 1322 SCLC patients eligible for meta-analysis. In comparison to nonangiogenesis inhibitors, angiogenesis inhibitors treatment was not associated with improvement of PFS [HR = 0.87, 95% CI (0.74-1.02), P = 0.09), OS [HR = 0.99, 95% CI (0.88-1.12), P = 0.91], or ORR [OR = 1.12, 95% CI (0.85-1.47), P = 0.41). Also, there was no improvement in 1-year survival rate [OR = 0.96, 95% CI (0.74-1.19), P = 0.63)], 2-year survival rate [OR = 1.00, 95% CI (0.66-1.51), P = 1.00)] or 1-year progression-free survival rates [OR = 0.95, 95% CI (0.69-1.31), P = 0.76)]. However, from subgroup analyses, it was observed that angiogenesis inhibitors improved ORR [HR = 1.66 (95% CI 1.02-2.71), P = 0.04] in phase II studies and bevacizumab improved PFS [HR = 0.73 (95% CI 0.42-0.97), P = 0.04]. It is important to note that angiogenesis inhibitors reduced emesis [OR = 0.38, 95% CI (0.17-0.85), P = 0.02], but increased incidence of constipation [OR = 4.02, 95% CI (2.14-7.55), P < 0.0001) and embolism [OR = 2.24, 95% CI (1.45-3.47), P = 0.0003).

CONCLUSION

Adding angiogenesis inhibitors to chemotherapy did not improve PFS, OS, ORR, 1-year survival rate, 2-year survival rate or 1-year progression-free survival rate for SCLC. However, subgroup analysis revealed that bevacizumab enhanced PFS. Angiogenesis inhibitors also had a high incidence of constipation and embolism.

Targeting angiogenesis in small cell lung cancer

Small cell lung cancer (SCLC) is a highly aggressive and lethal malignancy. Despite high initial response rates to systemic chemotherapy, the disease eventually relapses; further treatment only modestly improves outcomes and overall survival (OS) for patients with extensive stage disease is less than one year. Little progress has been made during the past decades, with no new drugs approved. Consequently, the development of novel strategies is an unmet need. The inhibition of angiogenesis, a defining characteristic of cancer, has demonstrated modest efficacy in several human malignancies, including non-small cell lung cancer (NSCLC). However, results from clinical trials in SCLC have been disappointing, and no anti-angiogenic agent has received regulatory approval due to lack of clinical efficacy. The elucidation of underlying mechanisms responsible for tumor resistance to angiogenic therapy and the simultaneous blockade of multiple elements that play a role in angiogenesis need to be further explored.

Proteomic-Based Approaches for the Study of Cytokines in Lung Cancer

Proteomic techniques are currently used to understand the biology of different human diseases, including studies of the cell signaling pathways implicated in cancer progression, which is important in knowing the roles of different proteins in tumor development. Due to its poor prognosis, proteomic approaches are focused on the identification of new biomarkers for the early diagnosis, prognosis, and targeted treatment of lung cancer. Cytokines are proteins involved in inflammatory processes and have been proposed as lung cancer biomarkers and therapeutic targets because it has been reported that some cytokines play important roles in tumor development, invasion, and metastasis. In this review, we aim to summarize the different proteomic techniques used to discover new lung cancer biomarkers and therapeutic targets. Several cytokines have been identified as important players in lung cancer using these techniques. We underline the most important cytokines that are useful as biomarkers and therapeutic targets. We also summarize some of the therapeutic strategies targeted for these cytokines in lung cancer.

Autocrine VEGFR1 and VEGFR2 signaling promotes survival in human glioblastoma models in vitro and in vivo

Background

Although the vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR) system has become a prime target for antiangiogenic treatment, its biological role in glioblastoma beyond angiogenesis has remained controversial.

Methods

Using neutralizing antibodies to VEGF or placental growth factor (PlGF) or the tyrosine kinase inhibitor, cediranib, or lentiviral gene silencing, we delineated autocrine signaling in glioma cell lines. The in vivo effects of VEGFR1 and VEGFR2 depletion were evaluated in orthotopic glioma xenograft models.

Results

VEGFR1 and VEGFR2 modulated glioma cell clonogenicity, viability, and invasiveness in vitro in an autocrine, cell–line-specific manner. VEGFR1 silencing promoted mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) signaling, whereas VEGFR2 silencing resulted in cell-type dependent activation of the protein kinase B (PKB)/AKT and MAPK/ERK pathways. These responses may represent specific escape mechanisms from VEGFR inhibition. The survival of orthotopic glioma-bearing mice was prolonged upon VEGFR1 silencing in the LNT-229, LN-308, and U87MG models and upon VEGFR2 silencing in LN-308 and U87MG. Disruption of VEGFR1 and VEGFR2 signaling was associated with decreased tumor size, increased tumor necrosis, or loss of matrix metalloproteinase 9 (MMP9) immunoreactivity. Neutralizing VEGF and PlGF by specific antibodies was superior to either antibody treatment alone in the VEGFR1-dependent LNT-229 model.

Conclusions

Differential dependence on autocrine signaling through VEGFR1 and VEGFR2 suggests a need for biomarker–stratified VEGF(R)-based therapeutic approaches to glioblastoma.

Targeted drugs in small-cell lung cancer

In contrast to non-small-cell lung cancer (NSCLC), few advances have been made in systemic treatment of small-cell lung cancer (SCLC) in recent years. Most patients are diagnosed with extensive stage disease and are commonly treated with platinum-based chemotherapy which, although attaining high initial objective responses, has a limited impact on survival. Due to the dismal prognosis of SCLC, novel and more effective treatment strategies are urgently needed. A deeper characterization of the genomic landscape of SCLC has led to the development of rational and promising targeted agents. However, despite a large number of clinical trials, results have been disappointing and there are still no approved targeted drugs for SCLC. Recent comprehensive genomic studies suggest SCLC is a heterogeneous disease, characterized by genomic alterations targeting a broad variety of genes, including those involved in transcription regulation and chromatin modification which seem to be a hallmark of this specific lung cancer subtype. Current research efforts are focusing on further understanding of the cellular and molecular abnormalities underlying SCLC development, progression and resistance to chemotherapy. Unraveling the genomic complexity of SCLC could be the key to optimize existing treatments, including chemotherapy and radiotherapy, and for identifying those patients most likely to benefit from selected targeted therapeutic approaches.

Personalized Therapy of Small Cell Lung Cancer

Small cell lung cancer (SCLC) is an aggressive, poorly differentiated neuroendocrine carcinoma with distinct clinical, pathological and molecular characteristics. Despite robust responses to initial chemotherapy and radiation, the prognosis of patients with SCLC remains poor with an overall 5-year survival rate of less than 10 %. Despite the fact that numerous molecularly targeted approaches have thus far failed to demonstrate clinical utility in SCLC, further advances will rely on better definition of the biological pathways that drive survival, proliferation and metastasis. Recent next-generation, molecular profiling studies have identified many new therapeutic targets in SCLC, as well as extreme genomic instability which explains the high degree of resistance. A wide variety of anti-angiogenic agents, growth factor inhibitors, pro-apoptotic agents, and epigenetic modulators have been evaluated in SCLC and many studies of these strategies are on-going. Perhaps the most promising approaches involve agents targeting cancer stem cell pathways and immunomodulatory drugs that interfere with the PD1 and CTLA-4 pathways. SCLC offers many barriers to the development of successful therapy, including limited tumor samples, inadequate preclinical models, high mutational burden, and aggressive tumor growth which impairs functional status and hampers enrollment on clinical trials.

Positive Interaction between Prophylactic Cranial Irradiation and Maintenance Sunitinib for Untreated Extensive-Stage Small Cell Lung Cancer Patients After Standard Chemotherapy: A Secondary Analysis of CALGB 30504 (ALLIANCE)

BACKGROUND

Prophylactic cranial irradiation (PCI) has become a standard option for patients with extensive-stage small cell lung cancer (ES-SCLC). The Cancer and Leukemia Group B 30504 trial was a randomized phase II study of the effect of sunitinib versus placebo in ES-SCLC patients responding to platinum-based systemic therapy. The study required preenrollment brain imaging. PCI was provided at the discretion of treating physicians. We performed a secondary analysis of the Cancer and Leukemia Group B trial to determine the impact of PCI on patients with ES-SCLC.

METHODS

Fisher's exact test and the Wilcoxon rank-sum test were conducted to identify the differences between patients receiving PCI and patients not receiving PCI. Kaplan-Meier analyses described progression-free survival (PFS) and overall survival (OS) for patients in the PCI and non-PCI groups.

RESULTS

A total of 85 patients received maintenance therapy (41 received placebo and 44 received sunitinib). Patient characteristics were balanced between the PCI and non-PCI groups. The patients receiving PCI plus sunitinib had a nonsignificant 2.7-month improvement in PFS (5.0 months versus 2.3 months, p = 0.14, hazard risk [HR] = 0.62, 95% confidence interval [CI]: 0.33-1.18) trending toward improved OS (8.9 months versus 5.4 months, p = 0.053, HR = 0.47, 95% CI: 0.22-1.03). PCI was associated with a trend toward improved median PFS (2.9 months versus 2.2 months, p = 0.096, HR = 0.69, 95% CI: 0.45-1.07) but not median OS (8.3 months in the PCI group versus 8.7 months in the non-PCI group, p = 0.76, HR = 1.07, 95% CI: 0.67-1.71). The patients receiving placebo had no improvement in PFS or OS with PCI.

CONCLUSIONS

Trends toward improved PFS and OS were seen in patients receiving PCI and sunitinib, thus supporting the need for further prospective research evaluating the integration of maintenance systemic therapy and PCI for patients with ES-SCLC. Improved outcomes for patients with ES-SCLC after induction chemotherapy may require PCI, thoracic radiotherapy, and maintenance systemic therapy to achieve control of both intracranial and extracranial disease.

A human IgG-like bispecific antibody co-targeting epidermal growth factor receptor and the vascular endothelial growth factor receptor 2 for enhanced antitumor activity

Both Epidermal Growth Factor Receptor (EGFR) and the Vascular Endothelial Growth Factor Receptor 2 (VEGFR2) play critical roles in tumorigenesis. We hypothesized co-targeting EGFR and VEGFR2 using a bispecific antibody might have significant therapeutic potential. Here,we designed and produced a human IgG-like bispecific antibody (Bi-Ab) based on the variable regions of cetuximab (an anti-EGFR antibody) and mAb-04 (an anti-VEGFR2 antibody developed in our lab) . The Bi-Ab was found to inhibit the proliferation, survival and invasion of cancer cells via ablating phosphorylation of receptor and downstream signaling. In vivo efficacy was demonstrated against established HT-29 and SKOV-3 xenografts grown in nude mice. Studies revealed our Bi-Ab was able to restrain xenografted tumor growth and prolong survival of mice through inhibiting cell proliferation,promoting apoptosis and anti-angiogenesis. In contrast to cetuximab or mAb-04 alone, our Bi-Ab exhibits enhanced antitumor activity and has equal or slightly superior activity to their combination (Combi). It shows promise as a therapeutic agent, especially for use against tumors EGFR and/or VEGFR2 over-expressing malignancies.

Maintenance sunitinib for extensive-stage small cell lung cancer: a new standard, an option or a step in the right direction?

Systemic treatment for extensive-stage small cell lung cancer (ES-SCLC) has been stagnant for several decades. Sunitinib is a small molecule that inhibits a variety of receptor tyrosine kinases relevant in tumor biology. CALGB (Alliance) 30504 is a phase II study that investigated the use of maintenance sunitinib vs. placebo in patients with ES-SCLC after treatment with induction platinum/etoposide chemotherapy. The trial met its primary endpoint with an improvement in median progression free survival (PFS) of 1.6 months over placebo. Toxicity included grade 3 fatigue in 19% of patients. Although PFS may be a meaningful endpoint in this patient population, the modest improvement in PFS identified with maintenance sunitinib combined with the toxicity profile would not change the current standard of care. Changes in future trial design may enhance the ability to identify agents that will preserve patient functionality and prolong survival.

The Emerging Regulation of VEGFR-2 in Triple-Negative Breast Cancer

Vascular endothelial growth factor-A (VEGF) signals vascular development and angiogenesis mainly by binding to VEGF receptor family member 2 (VEGFR-2). Adaptor proteins mediate many VEGFR-2's functions in the development of blood vessels. Cancer cells secrete VEGF to activate VEGFR-2 pathway in their neighboring endothelial cells in the process of cancer-related angiogenesis. Interestingly, activation of VEGFR-2 signaling is found in breast cancer cells, but its role and regulation are not clear. We highlighted research advances of VEGFR-2, with a focus on VEGFR-2's regulation by mutant p53 in breast cancer. In addition, we reviewed recent Food and Drug Administration-approved tyrosine kinase inhibitor drugs that can inhibit the function of VEGFR-2. Ongoing preclinical and clinical studies might prove that pharmaceutically targeting VEGFR-2 could be an effective therapeutic strategy in treating triple-negative breast cancer.

Vascular endothelial growth factor directly stimulates tumour cell proliferation in non-small cell lung cancer

Vascular endothelial growth factor (VEGF) is a key stimulator of physiological and pathological angiogenesis. VEGF signals primarily through VEGF receptor 2 (VEGFR2), a receptor tyrosine kinase whose expression is found predominantly on endothelial cells. The purpose of this study was to determine the role of VEGFR2 expression in NSCLC cells. NSCLC cells and tissue sections were stained for VEGFR2 expression by immunohistochemistry (IHC). Immunoblotting and ELISA were used to determine the activation and inhibition of VEGFR2 and its downstream signalling pathways. Five-day proliferation assays were carried out in the presence or absence of VEGF. IHC analysis of NSCLC demonstrated tumour cell VEGFR2 expression in 20% of samples. Immunoblot analysis showed expression of VEGFR2 protein in 3/8 NSCLC cell lines that correlated with VEGFR2 mRNA expression levels. VEGF-dependent VEGFR2 activation was apparent in NSCLC cells, and was associated with increased tumor cell proliferation. Cediranib treatment or siRNA against VEGFR2 inhibited VEGF-dependent increases in cell proliferation. Inhibition of VEGFR2 tyrosine kinase activity using cediranib was more effective than inhibition of AKT (MK2206) or MEK (AZD6244) for overcoming VEGFR2-driven cell proliferation. VEGF treatment did not affect cell survival following treatment with radiation, cisplatin, docetaxel or gemcitabine. Our data suggest that a subset of NSCLC tumour cells express functional VEGFR2 which can act to promote VEGF-dependent tumour cell growth. In this tumour subset, therapies targeting VEGFR2 signalling, such as cediranib, have the potential to inhibit both tumour cell proliferation and angiogenesis.

Expression and prognostic significance of VEGFR-2 in breast cancer

Breast cancer is one of the most common cancers among women in the world. Vascular endothelial growth factor receptor 2 (VEGFR-2) was not only found to play a key role in the development of tumor angiogenesis, but has also been located in tumor cells of a variety of tumors. This study investigated the expression pattern of VEGFR-2 in breast cancer tissue specimens in order to evaluate the role of VEGFR-2 in the prognosis of breast cancer. Expression and localization of VEGFR-2 in tumor cells of breast cancer specimens from 98 invasive breast cancer patients were determined by immunohistochemistry. The relationships between VEGFR-2 expression and clinicopathological features were also analyzed. The results showed that VEGFR-2 expression correlated positively with lymph node (LN) metastasis of breast cancer. Patients with high expression of VEGFR-2 had a significantly worse OS. It was also observed that the expression of epithelial-mesenchymal transition (EMT) marker, including Twist1 and Vimentin, was higher in the tumors with higher VEGFR-2 expression, while the E-cadherin expression was lower in the same tumors, suggesting that VEGFR-2 may serve as a possible mediator of EMT in breast cancer.

Targeted therapies for small cell lung cancer: Where do we stand?

Small cell lung cancer (SCLC) accounts for 15% of lung cancer cases and is associated with a dismal prognosis. Standard therapeutic regimens have been improved over the past decades, but without a major impact on patient survival. The development of targeted therapies based on a better understanding of the molecular basis of the disease is urgently needed. At the genetic level, SCLC appears very heterogenous, although somatic mutations targeting classical oncogenes and tumor suppressors have been reported. SCLC also possesses somatic mutations in many other cancer genes, including transcription factors, enzymes involved in chromatin modification, receptor tyrosine kinases and their downstream signaling components. Several avenues have been explored to develop targeted therapies for SCLC. So far, however, there has been limited success with these targeted approaches in clinical trials. Further progress in the optimization of targeted therapies for SCLC will require the development of more personalized approaches for the patients.