Combined targeting of EGFR-dependent and VEGF-dependent pathways: rationale, preclinical studies and clinical applications

3,5-Disubstituted pyrazoline as a promising core for anticancer agents: mechanisms of action and therapeutic potentials

The rapidly growing interest in the literature about the anticancer activity of 3,5-disubstituted pyrazolines and their promising therapeutic potentials/pharmacological properties, supported by the number of pyrazoline derivatives currently in clinical use or clinical trials, encouraged us to review the in vitro antiproliferative effects and biochemical investigations of probable mechanisms of action. Nevertheless, many reported pyrazoline-bearing compounds have anticancer activity without an explored mode of action, which opens new research avenues to examine their biochemical profiles further. Therefore, 3,5-disubstituted pyrazoline is a promising core that can be used to design new derivatives with anticancer activity based on the structure-activity relationship summarized in this review to obtain higher potency and selectivity.

ctDNA Dynamics and Mechanisms of Acquired Resistance in Patients Treated with Osimertinib with or without Bevacizumab from the Randomized Phase II ETOP-BOOSTER Trial

PURPOSE

The ETOP 10-16 BOOSTER study was a randomized phase II trial of osimertinib and bevacizumab therapy versus osimertinib therapy in patients with an acquired EGFR T790M mutation. The mechanisms of acquired resistance to osimertinib and bevacizumab have not been described previously.

EXPERIMENTAL DESIGN

Next-generation sequencing (Guardant360) was conducted in serial plasma samples. The association between ctDNA and efficacy outcomes was explored, and molecular alterations at progression were described.

RESULTS

A total of 136 patients (88% of 155 randomized) had plasma samples at baseline (68 per arm), 110 (71%) at week 9, and 65 (42%) at progression. In a multivariable model for progression-free survival (PFS), the treatment effect was found to differ by smoking status (interaction P = 0.046), with the effect of smoking also differing by baseline EGFR T790M (interaction P = 0.033), whereas both TP53 at baseline and the tissue EGFR exon 21 L858R mutation were significantly associated with worse PFS outcome. Smokers (current/former) without baseline EGFR T790M showed a significant improvement in PFS under combination treatment, albeit with small numbers (P = 0.015). Week-9 EGFR T790M clearance was associated with improved PFS in the osimertinib arm (P = 0.0097). Acquired EGFR C797S mutations were detected in 22% and 13% of patients in the combination and osimertinib arms, respectively.

CONCLUSIONS

The differential effect of treatment by smoking was not explained by TP53 mutations or other molecular alterations examined. Molecular mechanisms of acquired resistance were detected, but no novel molecular alterations were identified in the combination arm.

Pharmacophore-Based Virtual Screening and In-Silico Explorations of Biomolecules (Curcumin Derivatives) of Curcuma longa as Potential Lead Inhibitors of ERBB and VEGFR-2 for the Treatment of Colorectal Cancer

The newly FDA-approved drug, Axitinib, is an effective therapy against RTKs, but it possesses severe adverse effects like hypertension, stomatitis, and dose-dependent toxicity. In order to ameliorate Axitinib's downsides, the current study is expedited to search for energetically stable and optimized pharmacophore features of 14 curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,6-diene-3,5-dione) derivatives. The rationale behind the selection of curcumin derivatives is their reported anti-angiogenic and anti-cancer properties. Furthermore, they possessed a low molecular weight and a low toxicity profile. In the current investigation, the pharmacophore model-based drug design, facilitates the filtering of curcumin derivatives as VEGFR2 interfacial inhibitors. Initially, the Axitinib scaffold was used to build a pharmacophore query model against which curcumin derivatives were screened. Then, top hits from pharmacophore virtual screening were subjected to in-depth computational studies such as molecular docking, density functional theory (DFT) studies, molecular dynamics (MD) simulations, and ADMET property prediction. The findings of the current investigation revealed the substantial chemical reactivity of the compounds. Specifically, compounds S8, S11, and S14 produced potential molecular interactions against all four selected protein kinases. Docking scores of -41.48 and -29.88 kJ/mol for compounds S8 against VEGFR1 and VEGFR3, respectively, were excellent. Whereas compounds S11 and S14 demonstrated the highest inhibitory potential against ERBB and VEGFR2, with docking scores of -37.92 and -38.5 kJ/mol against ERBB and -41.2 and -46.5 kJ/mol against VEGFR-2, respectively. The results of the molecular docking studies were further correlated with the molecular dynamics simulation studies. Moreover, HYDE energy was calculated through SeeSAR analysis, and the safety profile of the compounds was predicted through ADME studies.

An ultra-small bispecific protein augments tumor penetration and treatment for pancreatic cancer

PURPOSE

The once highly anticipated antibody-based pathway-targeted therapies have not achieved promising outcomes for deadly pancreatic ductal adenocarcinoma (PDAC), mainly due to drugs' low intrinsic anticancer activity and poor penetration across the dense physiological barrier. This study aims to develop an ultra-small-sized, EGFR/VEGF bispecific therapeutic protein to largely penetrate deep tumor tissue and effectively inhibit PDAC tumor growth in vivo.

METHODS

The bispecific protein, Bi-fp50, was constructed by a typical synthetic biology method and labeled with fluorescent dyes for in vitro and in vivo imaging. Physicochemical properties, protein dual-binding affinity, and specificity of the Bi-fp50 were evaluated in several PDAC cell lines. In vitro quantitatively and qualitatively anticancer activity of Bi-fp50 was assessed by live/dead staining, MTT assay, and flow cytometry. In vivo pharmacokinetic and biodistribution were evaluated using blood biopsy samples and near-infrared fluorescence imaging. In vivo real-time tracking of Bi-fp50 in the local tumor was conducted by fibered confocal fluorescence microscopy. The subcutaneous PDAC tumor model was used to assess the in vivo antitumor effect of Bi-fp50.

RESULTS

Bi-fp50 with an ultra-small size of 50 kDa (5 ~ 6 nm) showed an excellent binding ability to VEGF and EGFR simultaneously and had enhanced, accumulated binding capability for Bxpc3 PDAC cells compared with anti-VEGF scFv and anti-EGFR scFv alone. Additionally, bi-fp50 significantly inhibited the proliferation and growth of Bxpc3 and Aspc1 PDAC cells even under a relatively low concentration (0.3 µM). It showed synergistically enhanced therapeutic effects relative to two individual scFv and Bi-fp50x control in vitro. The half-life of blood clearance of Bi-fp50 was 4.33 ± 0.23 h. After intravenous injection, Bi-fp50 gradually penetrated the deep tumor, widely distributed throughout the whole tissue, and primarily enriched in the tumor with nearly twice the accumulation than scFv2 in the orthotopic PDAC tumor model. Furthermore, the Bi-fp50 protein could induce broad apoptosis in the whole tumor and significantly inhibited tumor growth 3 weeks after injection in vivo without other noticeable side effects.

CONCLUSION

The proof-of-concept study demonstrated that the ultra-small-sized, bispecific protein Bi-fp50 could be a potential tumor suppressor and an efficient, safe theranostic tool for treating PDAC tumors.

Discovery of novel thiazolyl-pyrazolines as dual EGFR and VEGFR-2 inhibitors endowed with in vitro antitumor activity towards non-small lung cancer

New series of thiazolyl-pyrazoline derivatives (7a–7d, 10a–10d and 13a–13f) have been synthesised and assessed for their potential EGFR and VEGFR-2 inhibitory activities. Compounds 10b and 10d exerted potent and selective inhibitory activity towards the two receptor tyrosine kinases; EGFR (IC₅₀ = 40.7 ± 1.0 and 32.5 ± 2.2 nM, respectively) and VEGFR-2 (IC₅₀ = 78.4 ± 1.5 and 43.0 ± 2.4 nM, respectively). The best anti-proliferative activity for the examined thiazolyl-pyrazolines was observed against the non-small lung cancer cells (NSCLC). Compounds 10b and 10d displayed pronounced efficacy against A549 (IC₅₀ = 4.2 and 2.9 µM, respectively) and H441 cell lines (IC₅₀ = 4.8 and 3.8 µM, respectively). Moreover, our results indicated that 10b and 10d were much more effective towards EGFR-mutated NSCLC cell lines (NCI-H1650 and NCI-H1975 cells) than gefitinib. Finally, compounds 10b and 10d induce G2/M cell cycle arrest and apoptosis and inhibit migration in A549 cancerous cells.

A new era: tumor microenvironment in chemoresistance of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is a solid malignant tumor with an extremely poor prognosis. Gemcitabine (GEM)-based chemotherapy remains one of the most important treatment choices for PDAC. However, either as monotherapy or as a part of the combination chemotherapy, GEM achieved only limited success in improving the survival of patients with advanced PDAC, primarily due to GEM resistance. PDAC is characterized by an extensive desmoplasia in the tumor microenvironment (TME). Increasing evidence indicates that this fibrotic TME not only actively participates in the tumor growth and spread of PDAC but also contributes to the induction of GEM resistance. Here we review the current advances of how TME components are involved in the induction of GEM resistance.

Ethoxy-erianin phosphate and afatinib synergistically inhibit liver tumor growth and angiogenesis via regulating VEGF and EGFR signaling pathways

The therapeutic efficacy of tyrosine kinase inhibitors (TKIs) on solid tumors is limited by drug resistance and side effects. Currently, the combination therapy comprises of TKIs and angiogenesis inhibitors have been corroborated as an effective approach in cancer therapy. Ethoxy-erianin phosphate (EBTP) is an anti-angiogenic compound with low toxicity obtained by structural modification of the natural product erianin. Here, we aimed to evaluate whether EBTP can cooperate with TKIs to inhibit the proliferation and angiogenesis of tumor cells and reduce toxic effects. First, CCK-8 results showed that EBTP can effectively inhibit the proliferation of liver cancer cell line HepG2. We combined EBTP with four TKIs (Bosutinib, Apatinib, Afatinib and Erlotinib) to treat HepG2 cells and CompuSyn software analysis suggested that EBTP/Afatinib(Afa)shows the best synergistic inhibitory effect. Meanwhile, EBTP/Afa can significantly suppress the proliferation, invasion, migration and angiogenesis of HepG2 and HUVECs. ELISA results revealed that EBTP/Afa inhibits the secretion of VEGF in HepG2. EBTP/Afa down-regulates the expression of VEGF, p-VEGFR1, p-VEGFR2 and p-EGFR in both HepG2 and HUVECs. Further, the supernatant of HepG2 cells treated with EBTP/Afa blocks the intracellular downstream signal transduction shared by VEGF and EGFR in HUVECs. Finally, EBTP/Afa significantly inhibits tumor growth and angiogenesis in vivo. To conclude, EBTP/Afa targets VEGF and EGFR signaling pathways in liver cancer cells and tumor vasculature, thereby inhibiting the proliferation, motion and angiogenesis of liver cancer cells. Overall, this study provides a new combined strategy for the clinical treatment of hepatocellular carcinoma.

Opportunities and challenges in targeted therapy and immunotherapy for pancreatic cancer

Pancreatic cancer is one of the most malignant tumours with a poor prognosis. In recent years, the incidence of pancreatic cancer is on the rise. Traditional chemotherapy and radiotherapy for pancreatic cancer have been improved, first-line and second-line palliative treatments have been developed, and adjuvant treatments have also been used in clinical. However, the 5-year survival rate is still less than 10% and new treatment methods such as targeted therapy and immunotherapy need to be investigated. In the past decades, many clinical trials of targeted therapies and immunotherapies for pancreatic cancer were launched and some of them showed an ideal prospect in a subgroup of pancreatic cancer patients. The experience of both success and failure of these clinical trials will be helpful to improve these therapies in the future. Therefore, the current research progress and challenges of selected targeted therapies and immunotherapies for pancreatic cancer are reviewed.

Drug combination screening as a translational approach toward an improved drug therapy for chordoma

PURPOSE

Drug screening programmes have revealed epidermal growth factor receptor inhibitors (EGFRis) as promising therapeutics for chordoma, an orphan malignant bone tumour, in the absence of a known genetic driver. Concurrently, the irreversible EGFRi afatinib (Giotrif®) is being evaluated in a multicentric Phase II trial. As tyrosine kinase inhibitor (TKI) monotherapies are invariably followed by resistance, we aimed to evaluate potential therapeutic combinations with EGFRis.

METHODS

We screened 133 clinically approved anticancer drugs as single agents and in combination with two EGFRis (afatinib and erlotinib) in the clival chordoma cell line UM-Chor1. Synergistic combinations were analysed in a 7 × 7 matrix format. The most promising combination was further explored in clival (UM-Chor1, MUG-CC1) and sacral (MUG-Chor1, U-CH1) chordoma cell lines. Secretomes were analysed for receptor tyrosine kinase ligands (EGF, TGF-α, FGF-2 and VEGF-A) upon drug treatment.

RESULTS

Drugs that were active as single agents (n = 45) included TKIs, HDAC and proteasome inhibitors, and cytostatic drugs. Six combinations were analysed in a matrix format: n = 4 resulted in a significantly increased cell killing (crizotinib, dabrafenib, panobinostat and doxorubicin), and n = 2 exhibited no or negligible effects (regorafenib, venetoclax). Clival chordoma cell lines were more responsive to combined EGFR-MET inhibition. EGFR-MET cross-talk (e.g. via TGF-α secretion) likely accounts for the synergistic effects of EGFR-MET inhibition.

CONCLUSION

Our screen revealed promising combinations with EGFRis, such as the ALK/MET-inhibitor crizotinib, the HDAC-inhibitor panobinostat or the topoisomerase-II-inhibitor doxorubicin, which are part of standard chemotherapy regimens for various bone and soft-tissue sarcomas.

Advances in research of extracellular mechanisms underlying gemcitabine resistance in pancreatic cancer

Pancreatic cancer is a solid malignant tumor with the worst prognosis worldwide, and about 90% of cases are pancreatic ductal adenocarcinoma (PDAC). Although surgical resection is the only potential way to cure PDAC, the overall survival rate after surgery is still not optimistic. Consequently, gemcitabine (GEM)-based chemotherapy is still one of the most important treatment options for PDAC. However, the survival improvement by GEM monotherapy for advanced PDAC is very limited, and GEM resistance is the key reason. The mechanism underlying gemcitabine resistance is complex and still unclear in PDAC. The extensive and dense fibrous mesenchyme in the tumor microenvironment (TME) is an important feature of PDAC. More and more evidence has shown that TME is not only an active participant in tumor growth and spread, but also a contributor to the induction of GEM resistance. This article will review the recent advances in the understanding of the cellular and molecular mechanisms underlying GEM resistance in PDAC, and discuss potential GEM chemosensitization strategies, in order to improve the effective rate of chemotherapy and the outcome.

The Multifaceted Roles of EGFL7 in Cancer and Drug Resistance

Simple Summary

Cancer growth and metastasis require interactions with the extracellular matrix (ECM), which is home to many biomolecules that support the formation of new vessels and cancer growth. One of these biomolecules is epidermal growth factor-like protein-7 (EGFL7). EGFL7 alters cellular adhesion to the ECM and migratory behavior of tumor and immune cells contributing to tumor metastasis. EGFL7 is engaged in the formation of new vessels and changes in ECM stiffness. One of its binding partners on the endothelial and cancer cell surface is beta 3 integrin. Beta 3 integrin pathways are under intense investigation in search of new therapies to kill cancer cells. All these properties enable EGFL7 to contribute to drug resistance. In this review, we give insight into recent studies on EGFL7 and its engagement with beta3 integrin, a marker predicting cancer stem cells and drug resistance.

Abstract

Invasion of cancer cells into surrounding tissue and the vasculature is an important step for tumor progression and the establishment of distant metastasis. The extracellular matrix (ECM) is home to many biomolecules that support new vessel formation and cancer growth. Endothelial cells release growth factors such as epidermal growth factor-like protein-7 (EGFL7), which contributes to the formation of the tumor vasculature. The signaling axis formed by EGFL7 and one of its receptors, beta 3 integrin, has emerged as a key mediator in the regulation of tumor metastasis and drug resistance. Here we summarize recent studies on the role of the ECM-linked angiocrine factor EGFL7 in primary tumor growth, neoangiogenesis, tumor metastasis by enhancing epithelial-mesenchymal transition, alterations in ECM rigidity, and drug resistance. We discuss its role in cellular adhesion and migration, vascular leakiness, and the anti-cancer response and provide background on its transcriptional regulation. Finally, we discuss its potential as a drug target as an anti-cancer strategy.

Predicting the Molecular Mechanism of EGFR Domain II Dimer Binding Interface by Machine Learning to Identify Potent Small Molecule Inhibitor for Treatment of Cancer

Epidermal growth factor receptor (EGFR) is a transmembrane druggable target controlling cellular differentiation, proliferation, migration, survival and invasion. EGFR activation mainly occurs by its homo/hetro dimerization molecular phenomenon leading to tumor development and invasion. Several tyrosine kinase based inhibitors were discovered as potent anti-cancer drugs. However, mutations in its kinase domain confer resistance to most of these drugs. To overcome this drug resistance, development of small molecule inhibitors disrupting the EGFR Domain II dimer binding by machine learning methods are promising. Based on this insight, a structure-based drug repurposing strategy was adopted to repurpose the existing FDA approved drugs in blocking the EGFR Domain II mediated dimerization. We identified five best repurposed drug molecules showing good binding affinity at its key arm-cavity dimer interface residues by different machine learning methods. The molecular mechanisms of action of these repurposed drugs were computationally validated by molecular electrostatics potential mapping, point mutations at the dimer arm-cavity binding interface, molecular docking and receptor interaction studies. The present machine learning strategy thus forms the basis of identifying potent and putative small molecule drugs for the treatment of different types of cancer.

Immune Checkpoint Blockade in Oncogene-Driven Non-Small-Cell Lung Cancer

Patients with oncogene-driven lung cancer have limited therapeutic options after progressing on their targeted tyrosine kinase inhibitor (TKI) therapy. Given the growing role of immune checkpoint inhibitor (ICI) therapy in the treatment of lung cancer, oncogene-driven cancer has warranted further evaluation regarding ICI therapy. However, initial ICI studies have suggested that ICI monotherapy is not only lacking in efficacy, but that it may be less tolerable in oncogene-driven non-small-cell lung cancer (NSCLC). We performed a detailed review of the literature using Pubmed, and present the current and impactful findings here. Studies evaluating the use of concurrent ICI therapy and TKI therapy have also suggested increased toxicity and lack of increased activity in these patients. Larger studies have suggested that the sequence of ICI therapy and TKI, such as utilizing ICI therapy after TKI as opposed to before TKI, may play a role in reducing toxicity (hepatotoxicity, pneumonitis); however, these studies are limited in number. Novel methods of patient selection, including low tumor mutational burden, inflamed phenotyping, and  high CD8 + tumor infiltrating lymphocytes, may aid in determining ideal patients to give ICI therapy. Novel therapeutic combinations including the addition of anti-VEGF (vascular endothelial growth factor) therapy or radiotherapy show promising findings for these patients. Given the growing unmet need for therapeutic options in patients with oncogene-driven NSCLC who have failed TKI therapy, further research is warranted.

Genomic profiling of sporadic liver metastatic colorectal cancer

Sporadic colorectal cancer (sCRC) is the third leading cause of cancer death in the Western world. Approximately, a quarter of sCRC patients present metastatic dissemination at the moment of diagnosis, the liver being the most frequently affected organ. Additionally, this group of CRC patients is characterized by a worse prognosis. In the last decades, significant technological developments for genome analysis have fostered the identification and characterization of genetic alterations involved in the pathogenesis of sCRC. However, genetic alterations involved in the metastatic process through which tumor cells are able to colonize other tissues with a different microenvironment, still remain to be fully identified. Here, we review current knowledge about the most relevant genomic alterations involved in the liver metastatic process of sCRC, including detailed information about the genetic profile of primary colorectal tumors vs. their paired liver metastases.

CM082, a novel angiogenesis inhibitor, enhances the antitumor activity of gefitinib on epidermal growth factor receptor mutant non-small cell lung cancer in vitro and in vivo

Background

CM082 is a novel angiogenesis inhibitor targeting vascular endothelial growth factor receptor (VEGFR) and platelet‐derived growth factor receptor (PDGFR). The purpose of this research was to evaluate the antitumor activity of CM082 combined with gefitinib on epidermal growth factor receptor (EGFR) mutant non‐small cell lung cancer (NSCLC) in vitro and in vivo.

Methods

The effect of CM082 on human umbilical vein endothelial cells (HUVECs) was assessed. In vitro and in vivo efficacy of CM082 combined with gefitinib on EGFR NSCLC cell lines (HCC827 harboring E746_A750 deletion and H3255 harboring L858R) and a xenograft model was evaluated.

Results

CM082 inhibited VEGF‐induced cell growth, phosphorylation of VEGFR and downstream signaling molecules, tube formation, and cell migration of HUVECs. Furthermore, CM082 combined with gefitinib was more effective in inhibiting growth and colony formation and inducing apoptosis of H3255 and HCC827 cells in vitro than monotherapy. Moreover, tumor growth inhibition by the combination in a H3255 xenograft model was 107.7% more than that by gefitinib (93.6%) (P < 0.0001) and CM082 (51.4%) (P < 0.0001) alone. In addition, coadministration had a better effect on inhibiting cell proliferation, inducing apoptosis, and inhibiting the expression of CD31 and VEGF‐A. The combination therapy had a stronger inhibition effect on STAT3 phosphorylation than monotherapy.

Conclusions

CM082, a novel angiogenesis inhibitor, enhances the antitumor activity of gefitinib on EGFR mutant NSCLC by inhibiting proliferation and angiogenesis and promoting apoptosis of tumor cells.

Key points

Significant findings of the study CM082, a novel angiogenesis inhibitor, enhances the antitumor activity of gefitinib on EGFR mutant NSCLC by inhibiting proliferation and angiogenesis and promoting apoptosis of tumor cells. What this study adds These findings justify evaluation of the efficacy of CM082 combined with gefitinib in patients with EGFR mutant advanced NSCLC in clinical trials.

Dual EGFR blockade with cetuximab and erlotinib combined with anti-VEGF antibody bevacizumab in advanced solid tumors: a phase 1 dose escalation triplet combination trial

Background

Angiogenesis and activation of the epidermal growth factor (EGFR) pathway play an essential role in tumor proliferation and metastasis. Targeting angiogenesis or EGFR alone does not yield adequate tumor control in most solid tumors. Overcoming intrinsic and/or acquired resistance may need a doublet or triplet therapy strategy. Herein, we report the safety and feasibility of dual EGFR blockade with EGFR monoclonal antibody and EGFR tyrosine kinase inhibitor combined with anti-VEGF antibody in advanced solid tumors.

Methods

We conducted a phase I study combining erlotinib, cetuximab, and bevacizumab. Patients with advanced or metastatic solid tumors (excluding colorectal and non-small cell lung cancers) were analyzed for safety, toxicity profile, and response. Anti-tumor activity was evaluated per response evaluation criteria in solid tumors (RECIST 1.0).

Results

Thirty-six patients received treatment on a range of dose-levels. The most frequent tumor types enrolled were cervical (n = 10), head and neck squamous cell (n = 10), and follicular thyroid (n = 4) cancers. The most common treatment-related grade ≥ 2 adverse events were rash (56%), hypomagnesemia (17%), pruritus (11%), diarrhea (8%), and tumor-related bleeding (8%). Seventeen of 19 patients (89%) treated at the maximum tolerated dose did not present treatment-related dose-limiting toxicity. Fifteen (63%) of the 24 evaluable patients achieved a disease control (stable disease ≥ 4 months (n = 14) and partial response (n = 1). The median number of prior lines of therapies was 3 (range 1–10).

Conclusions

The triplet combination of erlotinib, cetuximab, and bevacizumab was well tolerated, conferring clinical benefit in heavily pretreated patients. Future studies are warranted with second or third-generation EGFR tyrosine kinase triplet combinations in the EGFR pathway aberrant patients.

Trial Registration: ClinicalTrials.gov Identifier: NCT00543504. Sponsor(s): National Cancer Institute (NCI), MD Anderson Cancer Center

Peripheral blood mononuclear cells extracts VEGF protein levels and VEGF mRNA: Associations with inflammatory molecules in a healthy population

Background

Vascular endothelial growth factor (VEGF) is a signal protein, implicated in various physiological and pathophysiological processes together with other common inflammatory biomarkers. However, their associations have not yet been fully elucidated. In the present study, we investigated associations between VEGF and four specific VEGF mRNA isoforms with levels of 11 inflammation molecules, derived from peripheral blood mononuclear cells (PBMCs) extracts.

Methods

Healthy participants from the STANISLAS Family Study (n = 285) were included. Levels of VEGF (four mRNA isoforms and protein levels) and inflammatory molecules (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, INF-γ, TNF-α, MCP-1, EGF) were measured in PBMCs extracts. Multiple regression analyses were performed, adjusted for age and gender.

Results

The analyses revealed significant associations between VEGF protein levels and levels of IL-4 (β = 0.028, P = 0.013), MCP-1 (β = 0.015, P<0.0001) and EGF (β = 0.017, P<0.0001). Furthermore, mRNA isoform VEGF₁₆₅ was associated with MCP-1 and IL-1α (P = 0.002 and P = 0.008, respectively); and mRNA isoform VEGF₁₈₉ was associated with IL-4 and IL-6 (P = 0.019 and P = 0.034, respectively).

Conclusions

To our knowledge, the present study represents the first investigation that successfully demonstrates links between VEGF protein levels and inflammatory molecules levels derived from PBMCs extracts and identifies associations between specific VEGF mRNA isoforms and inflammatory molecules.

Impact

These findings provide novel insights that may assist in the development of new tissue and mRNA isoform specific measurements of VEGF levels, which may positively contribute to predicting the risk of common complex diseases and response of currently used anti-VEGF agents, and developing of novel targeted therapies for VEGF-related pathophysiology.

Combination therapy of apatinib with icotinib for primary acquired icotinib resistance in patients with advanced pulmonary adenocarcinoma with EGFR mutation

Multi-targeted agents represent the next generation of targeted therapies for solid tumors, and patients with acquired resistance to EGFR-tyrosine kinase inhibitors (TKIs) may also benefit from their combination with TKI therapy. Third-generation targeted drugs, such as osimertinib, are very expensive, thus a more economical solution is required. The aim of this study was to explore the use of apatinib combined with icotinib therapy for primary acquired resistance to icotinib in three patients with advanced pulmonary adenocarcinoma with EGFR mutations. We achieved favorable oncologic outcomes in all three patients, with progression-free survival of four to six months. Unfortunately, the patients ultimately had to cease combination therapy because of intolerable adverse effects of hand and foot syndrome and oral ulcers. Combination therapy of apatinib with icotinib for primary acquired resistance to icotinib may be an option for patients with advanced pulmonary adenocarcinoma with EGFR mutations, but physicians must also be aware of the side effects caused by such therapy.

Antiangiogenesis for Advanced Non-Small-Cell Lung Cancer in the Era of Immunotherapy and Personalized Medicine

Over the past decade, patients with advanced non-small-cell lung cancer (NSCLC) have witnessed substantial advances in regards to therapeutic alternatives. Among newly developed agents, angiogenesis inhibitors were extensively tested in different settings and have produced some favorable outcomes despite several shortcomings. Bevacizumab is the most examined agent in this context and has demonstrated significant survival benefits when combined with standard chemotherapy in eligible patients. Preliminary results on the addition of bevacizumab to erlotinib in patients with EGFR-mutated NSCLC seem promising. Other antiangiogenic agents were also tested, but ramucirumab and nintedanib are the only agents with a positive impact on survival. More recently, immune checkpoint inhibitors (ICIs) have had considerable success due to their prolonged durations of response, yet response rates are still deemed suboptimal, and various combination therapies are being tested in an effort to improve efficacy. Preclinical evidence suggests an immunosuppressive effect of pro-angiogenic factors, which sets up a plausible rationale for combining ICIs and antiangiogenic agents. Herein, we review the landmark data supporting the success of angiogenesis inhibitors, and we discuss the potential for combination with immunotherapy and targeted agents.

Predictive model of thrombospondin-1 and vascular endothelial growth factor in breast tumor tissue

Angiogenesis, the formation of new blood capillaries from pre-existing vessels, is a hallmark of cancer. Thus far, strategies for reducing tumor angiogenesis have focused on inhibiting pro-angiogenic factors, and less is known about the therapeutic effects of mimicking the actions of angiogenesis inhibitors. Thrombospondin-1 (TSP1) is an important endogenous inhibitor of angiogenesis that has been investigated as an anti-angiogenic agent. TSP1 impedes the growth of new blood vessels in many ways, including crosstalk with pro-angiogenic factors. Owing to the complexity of TSP1 signaling, a predictive systems biology model would provide quantitative understanding of the angiogenic balance in tumor tissue. Therefore, we have developed a molecular-detailed, mechanistic model of TSP1 and vascular endothelial growth factor (VEGF), a promoter of angiogenesis, in breast tumor tissue. The model predicts the distribution of the angiogenic factors in tumor tissue, revealing that TSP1 is primarily in an inactive, cleaved form owing to the action of proteases, rather than bound to its cellular receptors or to VEGF. The model also predicts the effects of enhancing TSP1’s interactions with its receptors and with VEGF. To provide additional predictions that can guide the development of new anti-angiogenic drugs, we simulate administration of exogenous TSP1 mimetics that bind specific targets. The model predicts that the CD47-binding TSP1 mimetic markedly decreases the ratio of receptor-bound VEGF to receptor-bound TSP1, in favor of anti-angiogenesis. Thus, we have established a model that provides a quantitative framework to study the response to TSP1 mimetics.

Combined application of anti-VEGF and anti-EGFR attenuates the growth and angiogenesis of colorectal cancer mainly through suppressing AKT and ERK signaling in mice model

BACKGROUND

Angiogenesis is generally involved during the cancer development and hematogenous metastasis. Vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) are considered to have an important role in tumor-associated angiogenesis. However, the effects of simultaneously targeting on VEGF and EGFR on the growth and angiogenesis of colorectal cancer (CRC), and its underlying mechanisms remain unknown.

METHODS

Immunohistochemical staining was used to detect the VEGF and EGFR expression in different CRC tissue specimens, and the correlation between VEGF/EGFR expression with the clinicopathologic features was analyzed. Cell counting kit‑8 (CCK-8) and transwell assays were used to assess the cellular proliferation and invasion of CRC cells after treated with anti-VEGF antibody and/or anti-EGFR antibody in vitro, respectively. Moreover, in vivo tumor formation was performed on nude mice model, and the tumor microvessel density (MVD) was determined by anti-CD34 staining in different groups. Finally, we evaluated the impact of anti-VEGF antibody and/or anti-EGFR antibody on the activation of downstream signaling effectors using western blot.

RESULTS

VEGF and EGFR were upregulated in CRC tissues, and their expression levels were correlated with hepatic metastasis. Blockage on VEGF or EGFR alone could inhibit the cellular proliferation and metastasis while their combination could reach a good synergism in vitro. In addition, in vivo xenograft mice model demonstrated that the tumor formation and angiogenesis were strongly suppressed by combination treatment of anti-VEGF and anti-EGFR antibodies. Besides, the combination treatment significantly reduced the activation of AKT and ERK1/2, but barely affected the activation of c-Myc, NF-κB/p65 and IκBα in CRC cells tumors. Interestingly, anti-VEGF antibody or anti-EGFR antibody alone could attenuate the phosphorylation of STAT3 as compared with negative control group, whereas the combined application not further suppressed but at least partially restored the activation of STAT3 in vivo.

CONCLUSIONS

Simultaneous targeting on VEGF and EGFR does show significant inhibition on CRC tumor growth and angiogenesis in mice model, and these effects are mainly attributed to suppression of the AKT and ERK signaling pathways.

Preclinical PK/PD model for combined administration of erlotinib and sunitinib in the treatment of A549 human NSCLC xenograft mice

AIM

Combined therapy of EGFR TKI and VEGFR TKI may produce a greater therapeutic benefit and overcome EGFR TKI-induced resistance. However, a previous study shows that a combination of EGFR TKI erlotinib (ER) with VEGFR TKI sunitinib (SU) did not improve the overall survival in patients with non-small-cell lung cancer (NSCLC). In this study we examined the anticancer effect of ER, SU and their combination in the treatment of A549 human NSCLC xenograft mice, and conducted PK/PD modeling and simulations to optimize the dose regimen.

METHODS

ER (20, 50 mg·kg(-1)·d(-1)) or SU (5, 10, 20 mg·kg(-1)·d(-1)) alone, or their combination were administered to BALB/c nude mice bearing A549 tumors for 22 days. The tumor size and body weight were recorded daily. The experimental data were used to develop PK/PD models describing the quantitative relationship between the plasma concentrations and tumor suppression in different dose regimens. The models were further evaluated and validated, and used to predict the efficacy of different combination regimens and to select the optimal regimen.

RESULTS

The in vivo anticancer efficacy of the combination groups was much stronger than that of either drug administered alone. A PK/PD model was developed with a combination index (φ) of 4.4, revealing a strong synergistic effect between ER and SU. The model simulation predicted the tumor growth in different dosage regimens, and showed that the dose of SU played a decisive role in the combination treatment, and suggested that a lower dose of ER (≤5 mg·kg(-1)·d(-1)) and adjusting the dose of SU might yield a better dosage regimen for clinical research.

CONCLUSION

The experimental data and modeling confirm synergistic anticancer effect of ER and SU in the treatment of A549 xenograft mice. The optimal dosage regimen determined by the PK/PD modeling and simulation can be used in future preclinical study and provide a reference for clinical application.

Efficacy and safety of bevacizumab plus erlotinib versus bevacizumab or erlotinib alone in the treatment of non-small-cell lung cancer: a systematic review and meta-analysis

OBJECTIVES

Bevacizumab and erlotinib inhibit different tumour growth pathways, and both exhibit beneficial effects in the treatment of non-small-cell lung cancer (NSCLC). However, the efficacy of bevacizumab in combination with erlotinib remains controversial. Therefore, we conducted a meta-analysis to compare combination treatment with bevacizumab and erlotinib to bevacizumab or erlotinib monotherapy in the treatment of NSCLC.

METHODS

Randomised controlled trials (RCTs) published in PubMed, Web of Science and EMBASE were systematically reviewed. The main outcome measures included overall survival (OS), progression-free survival (PFS), overall response rate (ORR) and adverse events. Results were expressed as HRs or risk ratios (RRs) with 95% CIs.

RESULTS

5 RCTs involving a total of 1736 patients were included in this meta-analysis. The combination of bevacizumab and erlotinib significantly improved PFS (HR=0.63, 95% CI 0.53 to 0.75; p=0.000) and the ORR (RR=1.91, 95% CI 1.19 to 3.06; p=0.007) in the second-line treatment of NSCLC compared with bevacizumab or erlotinib alone. However, no significant difference in OS was observed between the combination and monotherapy groups (HR=0.96, 95% CI 0.83 to 1.11; p=0.573). A subgroup analysis has shown that the greatest PFS benefit was associated with an age of <65 years(HR=0.74, 95% CI 0.57 to 0.96; p=0.026), Asian/Pacific Islander ethnicity (HR=0.23, 95% CI 0.10 to 0.54; p=0.001), Eastern Cooperative Oncology Group performance status (ECOG PS) 1 (HR=0.82, 95% CI 0.68 to 0.98; p=0.033), stage IIIB or IV disease (HR=0.68, 95% CI 0.57 to 0.82; p=0.000) and no history of smoking (HR=0.48, 95% CI 0.32 to 0.71; p=0.000). The incidence of grade 3/4 adverse events such as rash and diarrhoea was higher in the combination group than in the monotherapy group.

CONCLUSIONS

The addition of bevacizumab to erlotinib can significantly improve PFS and the ORR in the second-line treatment of NSCLC with an acceptable and manageable risk of rash and diarrhoea. Further well-conducted, large-scale trials are needed to validate these findings.

Phase I Trial of Consolidative Radiotherapy with Concurrent Bevacizumab, Erlotinib and Capecitabine for Unresectable Pancreatic Cancer

Purpose

To determine the safety, tolerability and maximum tolerated dose (MTD) of addition of erlotinib to bevacizumab and capecitabine-based definitive chemoradiation (CRT) in unresectable pancreatic cancer.

Methods

Seventeen patients with CT-staged, biopsy-proven unresectable pancreatic cancer were enrolled between 3/2008 and 10/2010. Prior chemotherapy was permitted. Two patients each were enrolled at dose levels (DLs) 1–4 and 9 patients at DL 5. All patients received 50.4 Gy (GTV only) in 28 fractions with concurrent capecitabine, bevacizumab and erlotinib. Dose of each drug was escalated in 5 DLs using the continual reassessment method. Bevacizumab was escalated from 5mg/Kg q2weeks (DLs 1–4) to 10mg/Kg q2weeks (DL 5); daily erlotinib from 100mg/day (DLs 1–2) to 150 mg/Kg (DLs 3–5); and capecitabine from 400mg/m² twice daily on days of radiation (DL 1) to 650mg/m² (DLs 2–3) to 825 mg/m² (DLs 4–5). Reassessment for potential resection was performed 6–8 weeks later.

Results

Sixteen patients received gemcitabine-based chemotherapy prior to CRT. With a median clinical follow-up of 10 months, no grade 3 toxicities were observed in DLs 1–4. Three (33%) patients at DL 5 developed a grade 3 acute toxicity (2 diarrhea, 1 rash). No grade 4 or 5 toxicities were seen. DL 4 was selected as the MTD; therefore, the recommended doses in combination with radiation are: bevacizumab, 5mg/Kg q2weeks; erlotinib, 150 mg/Kg daily; and capecitabine, 825mg/m² BID. Median survival was 17.4 months. Of the five patients who underwent resection, 4 were originally deemed locally advanced and 1 was borderline resectable. Three patients had excellent pathological response (2 complete response and 20% viable tumor) at surgery, and the 2 patients with complete response are still alive at 61 and 67 months of follow up with no local or distant failures.

Conclusions

This chemoradiation regimen at the recommended dose levels is safe and tolerable for patients with unresectable pancreatic cancer and merits further evaluation.

Current targeted therapies in the treatment of advanced colorectal cancer: a review

Treatment strategies for metastatic colorectal cancer (mCRC) patients have undergone dramatic changes in the past decade and despite improved patient outcomes, there still exist areas for continued development. The introduction of targeted agents has provided clinicians with additional treatment options in mCRC, however, results have been mixed at best. These novel therapies were designed to interfere with specific molecules involved in the cellular carcinogenesis pathway and ultimately deliver a more focused treatment. Currently, their use in mCRC has been limited primarily as an adjunct to conventional chemotherapy regimens. This review explores the relevant cell-signaling networks in colorectal cancer, provides focus on the current targeted agent armamentarium approved for use in mCRC and explores the usefulness of predictive mCRC biomarkers.

A multicenter phase II study of sorafenib in combination with erlotinib in patients with advanced non-small cell lung cancer (KCSG-0806)

OBJECTIVES

Sorafenib and erlotinib are potent, orally administered receptor tyrosine kinase inhibitors with antiproliferative and antiangiogenic activities. Given their synergistic activity in combination, we conducted a phase II study to determine the clinical activity of sorafenib in combination with erlotinib in patients with advanced non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Patients with advanced NSCLC who have received one or two prior chemotherapy regimens for metastatic disease, ECOG 0-2, and adequate organ function were eligible. Patients received 400mg twice daily sorafenib and 150 mg daily erlotinib in 28-day cycles. Epidermal growth factor receptor mutation and its downstream pathways were analyzed from available tumor samples. Changes in plasma cytokine and angiogenic factors were correlated with clinical outcomes.

RESULTS

A total of 46 patients were enrolled. Twenty patients (43%) were never smokers and 35 patients (75%) had adenocarcinoma histology. The overall response rate was 30.4%. Response to sorafenib/erlotinib was observed more commonly in patients with EGFR mutation than in those with EGFR wild type (WT) or EGFR unknown tumors (62.5% vs. 6.7% vs. 34.8%; P=0.013). Likewise, DCR was higher among patients with EGFR mutation than in those with EGFR WT or EGFR unknown tumors (87.5% vs. 46.7% vs. 60.9%; P=0.161). The most frequent adverse events (AEs) of all grades were hand-foot skin reaction (67.4%) followed by acneiform rash (58.7%).

CONCLUSION

Sorafenib combined with erlotinib is well-tolerated with manageable toxicity and appears to be effective against advanced NSCLC with one or two prior line of systemic treatment (NCT00801385).

DCLAK11, a multi-tyrosine kinase inhibitor, exhibits potent antitumor and antiangiogenic activity in vitro

AIM

To investigate the molecular targets of DCLAK11, a novel compound discovered from a series of substituted pyridin-3-amine derivatives, and to characterize its anti-tumor properties in vitro.

METHODS

Kinase inhibition was measured by an ELISA assay. Cell viability was assessed with an SRB or a CCK8 assay. The alterations induced by kinase signaling proteins in cancer cells were detected by Western blot. Apoptosis was determined by an Annexin V-PI assay. The following assays were used to evaluate the impact on angiogenesis: wound-healing, Transwell, tube formation and microvessel outgrowth from rat aortic rings.

RESULTS

DCLAK11 was a multi-targeted kinase inhibitor that primarily inhibited the EGFR, HER2, and VEGFR2 tyrosine kinases with IC50 value of 6.5, 18, and 31 nmol/L, respectively. DCLAK11 potently inhibited the proliferation of EGFR- and HER2-driven cancer cells: its IC50 value was 12 and 22 nmol/L, respectively, in HCC827 and HCC4006 cells with EGFR exon deletions, and 19 and 81 nmol/L, respectively, in NCI-N87 and BT474 cells with HER2 amplification. Consistently, DCLAK11 blocked the EGFR and HER2 signaling in cancer cells with either an EGFR or a HER2 aberration. Furthermore, DCLAK11 effectively induced EGFR/HER2-driven cell apoptosis. Moreover, DCLAK11 exhibited anti-angiogenic activity, as shown by its inhibitory effect on the proliferation, migration and tube formation of human umbilical vascular endothelial cells and the microvessel outgrowth of rat aortic rings.

CONCLUSIONS

DCLAK11 is a multi-targeted kinase inhibitor with remarkable potency against tyrosine kinases EGFR, HER2 and VEGFR2, which confirms its potent anti-cancer activity in EGFR- and HER2-addicted cancers and its anti-angiogenic activity.

Cholangiocarcinoma: Correlation between Molecular Profiling and Imaging Phenotypes

PURPOSE

To investigate associations between imaging features of cholangiocarcinoma by visual assessment and texture analysis, which quantifies heterogeneity in tumor enhancement patterns, with molecular profiles based on hypoxia markers.

METHODS

The institutional review board approved this HIPAA-compliant retrospective study of CT images of intrahepatic cholangiocarcinoma, obtained before surgery. Immunostaining for hypoxia markers (EGFR, VEGF, CD24, P53, MDM2, MRP-1, HIF-1α, CA-IX, and GLUT1) was performed on pre-treatment liver biopsies. Quantitative imaging phenotypes were determined by texture analysis with gray level co-occurrence matrixes. The correlations between quantitative imaging phenotypes, qualitative imaging features (measured by radiographic inspection alone), and expression levels of the hypoxia markers from the 25 tumors were assessed.

RESULTS

Twenty-five patients were included with a median age of 62 years (range: 54-84). The median tumor size was 10.2 cm (range: 4-14), 10 (40%) were single tumors, and 90% were moderately differentiated. Positive immunostaining was recorded for VEGF in 67% of the cases, EGFR in 75%, and CD24 in 55%. On multiple linear regression analysis, quantitative imaging phenotypes correlated significantly with EGFR and VEGF expression levels (R2 = 0.4, p<0.05 and R2 = 0.2, p<0.05, respectively), while a trend was demonstrated with CD24 expression (R2 = 0.33, p = 0.1). Three qualitative imaging features correlated with VEGF and CD24 expression (P<0.05), however, none of the qualitative features correlated with the quantitative imaging phenotypes.

CONCLUSION

Quantitative imaging phenotypes, as defined by texture analysis, correlated with expression of specific markers of hypoxia, regardless of conventional imaging features.

Experience with erlotinib in the treatment of non-small cell lung cancer

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related deaths. In the last decade, the epidermal growth factor receptor (EGFR) signalling pathway has emerged as one of the most important molecular aberrations, representing an attractive therapeutic target in NSCLC. Drugs interfering with the tyrosine kinase domain of the EGFR (EGFR TKIs), such as erlotinib and gefitinib, have demonstrated efficacy in patients with advanced NSCLC irrespective of therapy line and particularly in patients harbouring activating mutations in the EGFR gene (EGFR(mut+)). Results of large phase III randomized trials clearly established that EGFR TKIs are superior to chemotherapy as frontline treatment in patients with EGFR(mut+), whereas in the EGFR wild-type (EGFR(WT)) or EGFR unknown population, platinum-based chemotherapy remains the standard of care, with no consistent benefit produced by the addition of EGFR TKI. In pretreated NSCLC, EGFR TKIs are considered more effective than standard monotherapy with cytotoxics in the presence of classical EGFR mutations, whereas in the EGFR(WT) population, a similar efficacy to docetaxel or pemetrexed in terms of survival has been demonstrated. Unfortunately, patients who initially responded to EGFR TKIs invariably develop acquired resistance. For such patients there is an urgent need for more effective strategies able to delay or possibly overcome resistance. In the present review we analysed the available data on erlotinib in the treatment of advanced NSCLC.

Efficacy and safety of chemotherapy or tyrosine kinase inhibitors combined with bevacizumab versus chemotherapy or tyrosine kinase inhibitors alone in the treatment of non-small cell lung cancer: a systematic review and meta-analysis

The meta-analysis evaluated the efficacy and safety of chemotherapy or tyrosine kinase inhibitors combined with bevacizumab versus chemotherapy or tyrosine kinase inhibitors alone in the treatment of non-small cell lung cancer (NSCLC). The PubMed/MEDLINE, Ovid, Web of Science, CNKI, and the Cochrane Library database were searched for eligible randomized controlled trials comparing the combination of chemotherapy or epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) with bevacizumab to chemotherapy or EGFR-TKI alone. Main outcome measures were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), and adverse effects. The pooled data were analyzed by STATA 12.0 and expressed as hazard ratio (HR) or risk ratio (RR), with their corresponding 95 % confidence intervals (95 % CI). Nine eligible trials comprising 3,547 patients (1,779 for bevacizumab and 1,768 for controls) were included in the study. Chemotherapy or TKIs in combination with bevacizumab significantly prolonged PFS (HRpfs 0.72, 95 % CIpfs 0.66-0.79, P pfs < 0.001) and OS (HRos 0.90, 95 % CIos 0.82-0.99, P os = 0.029) as first-line treatment for NSCLC compared with chemotherapy or TKIs alone. Bevacizumab combination regimens significantly prolonged PFS (HR 0.62, 95 % CI 0.52-0.74, P < 0.001) as second-line treatment; however, no benefit regarding OS was observed with the addition of bevacizumab (HR 0.94, 95 % CI 0.78-1.12, P = 0.479). The bevacizumab group showed increased ORR in both first- and second-line treatments. The high-dose bevacizumab subgroup in combination with chemotherapy showed a statistically significant improvement in OS, PFS, and ORR (HRos 0.89, 95 % CIos 0.80-0.99, P os 0.037; HRpfs 0.71, 95 % CIpfs 0.64-0.79, P pfs < 0.01, RRorr 1.85, 95 % CIorr 1.59-2.15, P orr < 0.001, respectively); however, the low-dose bevacizumab subgroup did not show enhanced OS (HRos 0.91, 95 % CIos 0.77-1.07, P os = 0.263), and a moderate improvement of PFS and ORR (HRpfs 0.85, 95 % CIpfs 0.72-1.00, P pfs = 0.049; RRorr 1.60, 95 % CIorr 1.28-2.0, P orr < 0.001). Erlotinib in combination with bevacizumab significantly prolonged PFS (HR 0.60, P < 0.001, 95 % CI 0.51-0.71) and increased ORR (RR 1.21, 95 % CI 0.98-1.49, P = 0.067) compared with erlotinib alone. A higher incidence of grade ≥3 adverse events such as proteinuria, hypertension, and hemorrhage was observed in the bevacizumab combination group than in the control group without bevacizumab (P all < 0.05). The addition of bevacizumab to chemotherapy or erlotinib can significantly improve PFS and ORR both in first- and second-line treatments of advanced NSCLC, with an acceptable risk of bleeding events, hypertension, proteinuria, and rash. Combination therapy with bevacizumab and chemotherapy is beneficial regarding OS; however, whether bevacizumab plus erlotinib can prolong OS need further validation.

mTOR pathway: A current, up-to-date mini-review (Review)

Mammalian target of rapamycin (mTOR) is a protein serine/threonine kinase that was initially identified as the cellular target of rapamycin. This kinase regulates cell growth, proliferation, motility and survival, as well as the gene transcription and protein synthesis that are activated in response to hormones, growth factors and nutrients. Results from preclinical studies have indicated that factors antagonizing the mTOR pathway exert an antitumor effect on lung cancer. Furthermore, primary clinical trials of mTOR inhibitors have demonstrated that the inhibitors may be effective against lung carcinoma. The present study explores the association between mTOR and lung carcinogenesis and describes the clinical trials of mTOR inhibitors.

Antineoplastic activity of the multitarget tyrosine kinase inhibitors CLM3 and CLM94 in medullary thyroid cancer in vitro

BACKGROUND

We report the antineoplastic and anti-angiogenic activity of the pyrazolo[3,4-d]pyrimidine derivative CLM3 and the cyclic amide CLM94, both multiple tyrosine kinase inhibitors (TKIs), in human primary medullary thyroid cancer (P-MTC) cells, and in vitro in the medullary thyroid cancer (MTC) cell lines TT (harboring a RET C634W activating mutation) and MZ-CRC-1 (carrying the MEN2B RET mutation Met891Thr).

METHODS

The antiproliferative and proapoptotic effects of CLM3 and CLM94 (1, 5, 10, 30, and 50 μmol/L) were tested in P-MTC cells obtained at operation, and in TT cells. In addition, the antiproliferative effects of CLM3 and CLM94 (0.005, 0.05, 0.5, and 5 μmol/L) were tested in TT and MZ-CRC-1 cells after 7 days of treatment to compare the results with those previously reported in the literature.

RESULTS

CLM3 and CLM94 (30 or 50 μmol/L) inhibited (P < .01) the proliferation of the P-MTC cells, TT cells, and MZ-CRC-1 cells and increased the level of apoptosis in a dose-dependent manner at 10, 30, and 50 μmol/L (P < .001), while having no effect on migration or invasion. The inhibition of proliferation by CLM3 and CLM94 was similar among P-MTC cells with/without RET mutations, and similar effects were observed regarding the increased level of apoptosis. Furthermore, CLM3 and CLM94 significantly decreased vascular endothelial growth factor-A expression in TT cells.

CONCLUSION

The antitumor activities of the multiple TKIs CLM3 and CLM94 were demonstrated in both primary MTC cultures as well as 2 established MTC cell lines in vitro, opening an avenue for future clinical evaluations.

Dual EGFR inhibition in combination with anti-VEGF treatment in colorectal cancer

Preclinical studies demonstrate that epidermal growth factor receptor (EGFR) signals through both kinase-dependent and independent pathways and that combining a small-molecule EGFR inhibitor, EGFR antibody, and/or anti-angiogenic agent is synergistic. We conducted a dose-escalation, phase I study combining erlotinib, cetuximab, and bevacizumab. The subset of patients with metastatic colorectal cancer was analyzed for safety and antitumor activity. Forty-one patients with heavily pretreated metastatic colorectal cancer received treatment on a range of dose levels. The most common treatment-related grade ≥2 adverse events were rash (68%), hypomagnesemia (37%), and fatigue (15%). Thirty of 34 patients (88%) treated at the full FDA-approved doses of all three drugs tolerated treatment without drug-related dose-limiting effects. Eleven patients (27%) achieved stable disease (SD) ≥6 months and three (7%) achieved a partial response (PR) (total SD>6 months/PR= 14 (34%)). Of the 14 patients with SD≥6 months/PR, eight (57%) had received prior sequential bevacizumab and cetuximab, two (5%) had received bevacizumab and cetuximab concurrently, and four (29%) had received prior bevacizumab but not cetuximab or erlotinib (though three had received prior panitumumab). The combination of bevacizumab, cetuximab, and erlotinib was well tolerated and demonstrated antitumor activity in heavily pretreated patients with metastatic colorectal cancer.

A microfluidic device to select for cells based on chemotactic phenotype

In the search for biomarkers of metastasis, attention has been largely placed on ensemble-averaged measurements that screen for molecules or genes. However, individual molecular changes do not always result in disease, and population-based measurements can mask the molecular signatures of the cells responsible for disease. Here, we describe a device that selects for cells based on chemotactic behavior rather than based on molecular differences, enabling the most aggressive cells to be studied independently from the heterogeneous population.

Analysis of chemotherapeutic response in ovarian cancers using publicly available high-throughput data

A third of patients with epithelial ovarian cancer (OVCA) will not respond to standard treatment. The determination of a robust signature that predicts chemoresponse could lead to the identification of molecular markers for response as well as possible clinical implementation in the future to identify patients at risk of failing therapy. This pilot study was designed to identify biologic processes affecting candidate pathways associated with chemoresponse and to create a robust gene signature for follow-up studies. After identifying common pathways associated with chemoresponse in serous OVCA in three independent gene-expression experiments, we assessed the biologic processes associated with them using The Cancer Genome Atlas (TCGA) dataset for serous OVCA. We identified differential copy-number alterations (CNA), mutations, DNA methylation, and miRNA expression between patients that responded to standard treatment and those who did not or recurred prematurely. We correlated these significant parameters with gene expression to create a signature of 422 genes associated with chemoresponse. A consensus clustering of this signature identified two differentiated clusters with unique molecular patterns: cluster 1 was significant for cellular signaling and immune response (mainly cell-mediated); and cluster 2 was significant for pathways involving DNA-damage repair and replication, cell cycle, and apoptosis. Validation through consensus clustering was performed in five independent OVCA gene-expression experiments. Genes were located in the same cluster with consistent agreement in all five studies (κ coefficient ≥ 0.6 in 4). Integrating high-throughput biologic data have created a robust molecular signature that predicts chemoresponse in OVCA.

Emerging combination therapies to overcome resistance in EGFR-driven tumors

The epidermal growth factor receptor (EGFR) is responsible for the growth and progression of tumor cells; its overexpression and deregulation of its downstream signaling pathway have been found in many different neoplasms. These characteristics make it an ideal target for cancer treatment. Two classes of EGFR inhibitors, which bind to different parts of this molecule, have been developed and studied: monoclonal antibodies, such as cetuximab and panitumumab and tyrosine kinase inhibitors, including erlotinib and gefitinib. The effectiveness of these new drugs is considerably reduced by a number of mechanisms of resistance developed by tumor cells. Hence, there is a clear need for better characterization of these processes and finding new therapeutic strategies to make the action of these drugs more incisive. Here, we describe some of the mechanisms of resistance to EGFR inhibitors and review the main innovations attempting to overcome these drawbacks.

Cetuximab: still an option in the treatment of pancreatic cancer?

INTRODUCTION

In this review, we analyzed the current literature about cetuximab to clarify its role in the treatment of pancreatic cancer. Using single-agent gemcitabine has been the standard treatment for more than 15 years for advanced pancreatic cancer. The attempts at improving the results by combining it with several other drugs, such as fluorouracil, cisplatin, irinotecan, oxaliplatin, or pemetrexed produced no clear survival benefit. Recently, however, new combination chemotherapy regimens (e.g., FOLFIRINOX, nab-paclitaxel plus gemcitabine) achieved a significant survival benefit compared to gemcitabine alone.

AREAS COVERED

Epidermal growth factor receptor (EGFR) transmembrane glycoprotein has been demonstrated to be overexpressed in pancreatic cancer, and it correlates with more advanced disease, poor survival, and the presence of metastases. Therefore, inhibition of the EGFR signaling pathway could be an attractive therapeutic target in this tumor. Although several combinations of EGFR inhibitors with chemotherapy demonstrate inhibition of tumor-induced angiogenesis, tumor cell apoptosis, and regression in xenograft models, these benefits remain to be confirmed.

EXPERT OPINION

The encouraging results from preclinical and early clinical studies with cetuximab in pancreatic cancer were not confirmed in a Phase III trial. Cetuximab failed to demonstrate improved patient outcome when paired with various chemotherapeutic regimens and/or other biological agents.

Dual EGFR inhibition in combination with anti-VEGF treatment: a phase I clinical trial in non-small cell lung cancer

BACKGROUND

Preclinical data indicate EGFR signals through both kinase-dependent and independent pathways and that combining a small-molecule EGFR inhibitor, EGFR antibody, and/or anti-angiogenic agent is synergistic in animal models.

METHODS

We conducted a dose-escalation, phase I study combining erlotinib, cetuximab, and bevacizumab. The subset of patients with non-small cell lung cancer (NSCLC) was analyzed for safety and response.

RESULTS

Thirty-four patients with NSCLC (median four prior therapies) received treatment on a range of dose levels. The most common treatment-related grade ≥2 adverse events were rash (n=14, 41%), hypomagnesemia (n=9, 27%), and fatigue (n=5, 15%). Seven patients (21%) achieved stable disease (SD) ≥6 months, two achieved a partial response (PR) (6%), and two achieved an unconfirmed partial response (uPR) (6%) (total=32%). We observed SD≥6 months/PR/uPR in patients who had received prior erlotinib and/or bevacizumab, those with brain metastases, smokers, and patients treated at lower dose levels. Five of 16 patients (31%) with wild-type EGFR experienced SD≥6 months or uPR. Correlation between grade of rash and rate of SD≥6 months/PR was observed (p less than 0.01).

CONCLUSION

The combination of erlotinib, cetuximab, and bevacizumab was well-tolerated and demonstrated antitumor activity in heavily pretreated patients with NSCLC.

HSP90 Inhibitor SNX5422/2112 Targets the Dysregulated Signal and Transcription Factor Network and Malignant Phenotype of Head and Neck Squamous Cell Carcinoma

Heat shock protein 90 (HSP90) is a chaperone protein that stabilizes proteins involved in oncogenic and therapeutic resistance pathways of epithelial cancers, including head and neck squamous cell carcinomas (HNSCCs). Here, we characterized the molecular, cellular, and preclinical activity of HSP90 inhibitor SNX5422/2112 in HNSCC overexpressing HSP90. SNX2112 inhibited proliferation, induced G2/M block, and enhanced cytotoxicity, chemosensitivity, and radiosensitivity between 25 and 250 nM in vitro. SNX2112 showed combinatorial activity with paclitaxel in wild-type (wt) TP53-deficient and cisplatin in mutant (mt) TP53 HNSCC lines. SNX2112 decreased expression or phosphorylation of epidermal growth factor receptor (EGFR), c-MET, v-akt murine thymoma viral oncogene homolog 1 (AKT), extracellular signal-regulated kinases (ERK) 1 and 2, inhibitor κB kinase, and signal transducer and transcription factor 3 (STAT3), corresponding downstream nuclear factor κB, activator protein-1, and STAT3 reporter genes, and target oncogenes and angiogenic cytokines. Furthermore, SNX2112 enhanced re-expression of TP53 and targets p21WAF1 and PUMA, while TP53 inhibitor Pifithrin or siRNA attenuated the antiproliferative activity of SNX2112 in wtTP53 HNSCC in vitro. Prodrug SNX5422 similarly down-modulated key signal targets, enhanced TP53 expression and apoptosis, and inhibited proliferation, angiogenesis, and tumorigenesis in a wtTP53-deficient HNSCC xenograft model. Thus, HSP90 inhibitor SNX5422/2112 broadly modulates multiple key nodes within the dysregulated signaling network, with corresponding effects upon the malignant phenotype. Our data support investigation of SNX5422/2112 in combination with paclitaxel, cisplatin, and radiotherapy in HNSCC with different TP53 status.

Second-line therapy in advanced biliary tract cancer: what should be the standard?

Biliary tract cancer is a rare malignant tumor. Accordingly, to perform prospective and randomized trials is difficult and the knowledge of its natural history and optimal management remains limited. Chemotherapy is commonly used to improve the outcome and to delay tumor progression in advanced disease. Only recently, cisplatin-gemcitabine combination was identified as the new standard first-line therapy. Despite the outcome improvement, disease progression is a constant and approximately half of patients failing upfront treatment maintain a good performance status and are willing to undergo further treatment. No standard salvage chemotherapy regimen has been identified yet. Experiences of salvage therapy in advanced biliary tract cancer are sparse and yielded disappointing results. Well designed multi-institutional randomized trials are warranted to clarify the role and the activity of a second-line therapy.

FGF receptors: cancer biology and therapeutics

Fibroblast growth factors (FGFs) are involved in a variety of cellular processes, such as stemness, proliferation, anti-apoptosis, drug resistance, and angiogenesis. Here, FGF signaling network, cancer genetics/genomics of FGF receptors (FGFRs), and FGFR-targeted therapeutics will be reviewed. FGF signaling to RAS-MAPK branch and canonical WNT signaling cascade mutually regulate transcription programming. FGF signaling to PI3K-AKT branch and Hedgehog, Notch, TGFβ, and noncanonical WNT signaling cascades regulate epithelial-to-mesenchymal transition (EMT) and invasion. Gene amplification of FGFR1 occurs in lung cancer and estrogen receptor (ER)-positive breast cancer, and that of FGFR2 in diffuse-type gastric cancer and triple-negative breast cancer. Chromosomal translocation of FGFR1 occurs in the 8p11 myeloproliferative syndrome and alveolar rhabdomyosarcoma, as with FGFR3 in multiple myeloma and peripheral T-cell lymphoma. FGFR1 and FGFR3 genes are fused to neighboring TACC1 and TACC3 genes, respectively, due to interstitial deletions in glioblastoma multiforme. Missense mutations of FGFR2 are found in endometrial uterine cancer and melanoma, and similar FGFR3 mutations in invasive bladder tumors, and FGFR4 mutations in rhabdomyosarcoma. Dovitinib, Ki23057, ponatinib, and AZD4547 are orally bioavailable FGFR inhibitors, which have demonstrated striking effects in preclinical model experiments. Dovitinib, ponatinib, and AZD4547 are currently in clinical trial as anticancer drugs. Because there are multiple mechanisms of actions for FGFR inhibitors to overcome drug resistance, FGFR-targeted therapy is a promising strategy for the treatment of refractory cancer. Whole exome/transcriptome sequencing will be introduced to the clinical laboratory as the companion diagnostic platform facilitating patient selection for FGFR-targeted therapeutics in the era of personalized medicine.

Safety and feasibility of targeted agent combinations in solid tumours

The plethora of novel molecular-targeted agents (MTAs) has provided an opportunity to selectively target pathways involved in carcinogenesis and tumour progression. Combination strategies of MTAs are being used to inhibit multiple aberrant pathways in the hope of optimizing antitumour efficacy and to prevent development of resistance. While the selection of specific agents in a given combination has been based on biological considerations (including the role of the putative targets in cancer) and the interactions of the agents used in combination, there has been little exploration of the possible enhanced toxicity of combinations resulting from alterations in multiple signalling pathways in normal cell biology. Owing to the complex networks and crosstalk that govern normal and tumour cell proliferation, inhibiting multiple pathways with MTA combinations can result in unpredictable disturbances in normal physiology. This Review focuses on the main toxicities and the lack of tolerability of some common MTA combinations, particularly where evidence of enhanced toxicity compared to either agent alone is documented or there is development of unexpected toxicity. Toxicities caused by MTA combinations highlight the need to introduce new preclinical testing paradigms early in the drug development process for the assessment of chronic toxicities resulting from such combinations.

Recent advances in novel targeted therapies for HER2-positive breast cancer

The monoclonal antibody trastuzumab has improved the outcomes of patients with breast cancer that overexpresses the human epidermal growth factor receptor 2 (HER2). However, despite this advancement, many tumors develop resistance and novel approaches are needed. Recently, a greater understanding of cellular biology has translated into the development of novel anti-HER2 agents with varying mechanisms of action. The small molecule tyrosine kinase inhibitor lapatinib has demonstrated activity in HER2-positive metastatic breast cancer (MBC) and in the preoperative setting. Pertuzumab is a monoclonal antibody with a distinct binding site from trastuzumab, which inhibits receptor dimerization. In recent studies, the addition of pertuzumab to combination therapy has led to improvements in progression-free survival in patients with HER2-positive MBC and higher response rates in the preoperative setting. An alternative approach is the use of novel antibody-drug conjugates such as trastuzumab-emtansine, which recently demonstrated activity in MBC. Neratinib, a pan-HER tyrosine kinase inhibitor, which irreversibly inhibits HER1 and HER2, also has proven activity in MBC. A range of compounds is being developed to attempt to overcome trastuzumab resistance by targeting heat shock protein 90, a molecular chaperone required for the stabilization of cellular proteins. Furthermore, agents are being developed to inhibit the mammalian target of rapamycin, a downstream component of the PTEN/PI3K pathway, which has been implicated in trastuzumab resistance. Finally, there are emerging data indicating that combinations of anti-HER2 agents may circumvent resistance mechanisms and improve patient outcomes. In this review, recent data on these emerging agents and novel combinations for HER2-positive breast cancer are discussed.

Phase II trial of lapatinib in adult and pediatric patients with neurofibromatosis type 2 and progressive vestibular schwannomas

This single-institution phase II study was performed to estimate the response rate to lapatinib in neurofibromatosis type 2 (NF2) patients with progressive vestibular schwannoma (VS). Twenty-one eligible patients were enrolled. Brain and spine MRIs, including 3-dimensional volumetric tumor analysis, and audiograms were performed once at baseline and again every 12 weeks. The primary response end point was evaluable in 17 patients and defined as ≥15% decrease in VS volume. Hearing was evaluable as a secondary end point in 13 patients, with responses defined as an improvement in the pure tone average of at least 10 dB  or a statistically significant increase in word recognition scores. Four of 17 evaluable patients experienced an objective volumetric response (23.5%; 95% confidence interval [CI], 10%-47%), with median time to response of 4.5 months (range, 3-12). In responders, reduction in VS volumes ranged from -15.7% to -23.9%. Four of 13 patients evaluable for hearing met hearing criteria for response (30.8%; 95% CI, 13%-58%). One sustained response exceeded 9 months in duration. Median time to overall progression (ie, volumetric progression or hearing loss) was 14 months. The estimated overall progression-free survival and volumetric progression-free survival at 12 months were 64.2% (95% CI, 36.9%-82.1%) and 70.6% (95% CI, 43.1%-86.6%), respectively. Toxicity was generally minor, and no permanent dose modifications were required. Lapatinib carries minor toxicity and has objective activity in NF2 patients with progressive VS, including volumetric and hearing responses. Future studies could explore combination therapy with other molecular targeted agents such as bevacizumab.