Tumor angiogenesis genotyping and efficacy of first-line chemotherapy in metastatic gastric cancer patients

An observational retrospective analysis of the main metastatic site and corresponding locoregional treatment as a prognostic factor in metastatic gastric cancer

Despite novel drugs, the prognosis for patients with metastatic gastric cancer remains poor. In rare instances, locoregional therapies are used in addition to standard chemotherapy in patients with oligometastatic involvement. This type of approach has not been supported by solid published evidence. The aim of the present retrospective study was to assess the prognostic impact of factors such as metastatic site, tumour histology and locoregional treatment in patients with metastatic gastric cancer. A total of 184 patients with metastatic gastric or gastroesophageal junction adenocarcinoma who received at least one line of palliative therapy with doublet or triplet chemotherapy were enrolled in the current analysis. Median overall survival (OS) was 8.32 months (95% CI, 7.02–9.41) and median progression-free survival (PFS) was 4.16 months (95% CI, 3.24–5.08). Lung metastases vs. other sites of metastatic involvement [hazard ratio (HR), 0.27; P=0.0133] and intestinal histology (HR, 0.48; P=0.08) were significantly associated with an improved OS. Improved PFS was also observed (HR, 0.49; P=0.10 and HR, 0.72; P=0.08 for lung metastases and intestinal histology, respectively). Second line chemotherapy and locoregional treatment of metastases (surgery or radiotherapy) were associated with improved OS (HR, 0.52; P<0.0001 and HR, 0.35; P<0.0001, respectively). Multivariate analysis confirmed an independent prognostic role for OS only for locoregional treatment, second line treatment and intestinal histology. The present results suggested that the presence of lung metastases alone was not a relevant prognostic factor and was influenced by the availability of further lines of treatment or by locoregional treatments. Locoregional treatments in patients with oligometastatic disease should be offered as they allow prolonged survival in patients with otherwise relatively short life expectancy.

Chemotherapy-Induced Distal Enhancers Drive Transcriptional Programs to Maintain the Chemoresistant State in Ovarian Cancer

Chemoresistance is driven by unique regulatory networks in the genome that are distinct from those necessary for cancer development. Here, we investigate the contribution of enhancer elements to cisplatin resistance in ovarian cancers. Epigenome profiling of multiple cellular models of chemoresistance identified unique sets of distal enhancers, super-enhancers (SE), and their gene targets that coordinate and maintain the transcriptional program of the platinum-resistant state in ovarian cancer. Pharmacologic inhibition of distal enhancers through small-molecule epigenetic inhibitors suppressed the expression of their target genes and restored cisplatin sensitivity in vitro and in vivo. In addition to known drivers of chemoresistance, our findings identified SOX9 as a critical SE-regulated transcription factor that plays a critical role in acquiring and maintaining the chemoresistant state in ovarian cancer. The approach and findings presented here suggest that integrative analysis of epigenome and transcriptional programs could identify targetable key drivers of chemoresistance in cancers. SIGNIFICANCE: Integrative genome-wide epigenomic and transcriptomic analyses of platinum-sensitive and -resistant ovarian lines identify key distal regulatory regions and associated master regulator transcription factors that can be targeted by small-molecule epigenetic inhibitors.

Predictive Significance of Serum Level of Vascular Endothelial Growth Factor in Gastric Cancer Patients

The study aims to evaluate serum VEGF expression in gastric cancer patients and investigate its relationship with clinicopathological parameters. We also examined the serum VEGF levels in GC patients having received surgery or chemotherapy treatment to assess its predictive and prognostic value as a biomarker. We enrolled 154 GC patients having not received neoadjuvant treatment and 100 healthy controls. In the treatment groups, 13 surgery patients and 15 chemotherapy patients were investigated. 42 chemotherapy patients with different chemotherapy efficacy were recruited as well. The serum VEGF was examined by ELISA. Serum VEGF level was remarkably upregulated in GC group compared with healthy group (p < 0.001). The serum VEGF level of GC group was significantly correlated with tumor cells differentiation degree, clinical stages, tumor infiltration depth, lymph node metastasis, and tumor size. The serum VEGF level of the 1 to 3 days after operation group was much lower than that of the preoperative group (p < 0.001) and the 7 days after operation group (p < 0.001). By contrast, serum VEGF level was decreased significantly after chemotherapy (p = 0.001). Importantly, serum VEGF level in PD+SD group was significantly higher compared to the PR+CR group (p = 0.011). Therefore, serum VEGF was a valuable biomarker in clinically monitoring the condition of GC patients.

The correlation between LDH serum levels and clinical outcome in advanced biliary tract cancer patients treated with first line chemotherapy

LDH may represent an indirect marker of neo-angiogenesis and worse prognosis in many tumour types. We assessed the correlation between LDH and clinical outcome for biliary tract cancer (BTC) patients treated with first-line chemotherapy. Overall, 114 advanced BTC patients treated with first-line gemcitabine and cisplatin were included. Patients were divided into two groups (low vs. high LDH), according to pre-treatment LDH values. Patients were also classified according to pre- and post-treatment variation in LDH serum levels (increased vs. decreased). Median progression free survival (PFS) was 5.0 and 2.6 months respectively in patients with low and high pre-treatment LDH levels (p = 0.0042, HR = 0.56, 95% CI: 0.37–0.87). Median overall survival (OS) was 7.7 and 5.6 months (low vs. high LDH) (p = 0.324, HR = 0.81, 95% CI: 0.54–1.24). DCR was 71% vs. 43% (low vs. high LDH) (p = 0.002). In 38 patients with decreased LDH values after treatment, PFS and OS were respectively 6.2 and 12.1 months, whereas in 76 patients with post-treatment increased LDH levels, PFS and OS were respectively 3.0 and 5.1 months (PFS: p = 0.0009; HR = 0.49; 95% IC: 0.33–0.74; OS: p < 0.0001; HR = 0.42; 95% IC: 0.27–0.63). Our data seem to suggest that LDH serum level may predict clinical outcome in BTC patients receiving first-line chemotherapy.

Targeted therapies in gastric cancer treatment: where we are and where we are going

Gastric cancer (GC) is one of the most common malignancies and a major cause of cancer-related deaths worldwide. Its incidence has significantly declined over the last few decades, probably due to the identification of specific etiologic agents such as Helicobacter pylori and other dietary and environmental risk factors. Nevertheless, most of the cases are unfortunately diagnosed at an advanced stage justifying median overall survival rates frequently not exceeding one year. Palliative combination chemotherapy usually represented by a platinum-based doublet is the mainstay of treatment in the metastatic setting. Adding a third drug such as an anthracycline or a taxane has been shown to improve response rate and provide limited survival benefits in fit selected patients. Unlike other tumors, the introduction of molecularly targeted drugs in the medical armamentarium for GC is relatively recent with trastuzumab and ultimately ramucirumab constituting the only agents approved to date. Recent advances in the understanding of GC biology have led to the development of novel targeted therapies holding the promise to further improve treatment outcomes. The aim of this paper is to review the main available data coming from clinical trials of targeted drugs and to describe some of the most interesting molecules in clinical development in GC. These include drugs targeting EGFR, angiogenesis, c-MET, FGFR2, mTOR and immune checkpoints.

Thyroid carcinoma cells produce PLGF to enhance metastasis

Cancer neovascularization is essential for metastasis of thyroid carcinoma. However, the underlying molecular mechanisms are ill-defined. Recently, placental growth factor (PLGF) has been shown to play critical roles in the pathological angiogenesis through regulating matrix metalloproteinases (MMPs); here, we were prompted to examine the role of PLGF in the metastasis of thyroid carcinoma. We found that the PLGF and MMP9 levels strongly correlated in the thyroid carcinoma specimen. Higher PLGF and MMP9 levels were detected in the thyroid carcinoma with metastasis. Using a human thyroid carcinoma cell line, TT, we found that overexpression of PLGF in TT cells increased expression of MMP9, while inhibition of PLGF in TT cells decreased expression of MMP9. However, modification of MMP9 levels in TT cells did not affect PLGF levels, suggesting that PLGF may regulate MMP9 in thyroid carcinoma cells. Moreover, application of a specific MAPK p42/p44 inhibitor, but not the application of a specific MAPK p38 inhibitor or specific Akt or JNK inhibitors, substantially abolished the effect of PLGF on MMP9 activation, suggesting that PLGF may increase expression of MMP9 via p42/p44 signaling pathway. Together, these data suggest that antagonizing PLGF in thyroid carcinoma cells may be a promising therapy to suppress cancer metastasis.

The unbinding studies of vascular endothelial growth factor receptor-2 protein tyrosine kinase type II inhibitors

Vascular endothelial growth factor receptor-2 (VEGFR-2) tyrosine kinase has two conformations, active and inactive conformations. Type II inhibitors bind to inactive conformation. It has two possible binding/unbinding paths. To explore the unbinding path of inhibitor 01-435 that was generated by fragment build in the binding pocket of VEGFR-2, molecular dynamics (MD) simulation was performed on the crystal structure of VEGFR-2 in complex with 01-435, then steered molecular dynamics (SMD) simulation was executed on the crystal structure of VEGFR-2 in complex with 01-435. Pull force, van der Waals and electrostatic interaction along the two paths were calculated by using SMD simulation. The SMD simulation results indicate that the more favorable path for inhibitor dissociation is along with the traditional ATP-channel rather than the allosteric-pocket-channel, which is mainly due to the less electrostatic interaction that the ligand suffers during dissociation process along the traditional ATP-channel.

Linking the future of anticancer metal-complexes to the therapy of tumour metastases

Cancer chemotherapy is almost always applied to patients with one or more diagnosed metastases and is expected to impact these lesions, thus providing significant benefits to the patient.

Targeting vascular endothelial growth factor (VEGF) pathway in gastric cancer: preclinical and clinical aspects

The prognosis of advanced gastric cancer has been dreadful with the majority of patients dying of their disease within 1 year of the diagnosis. In the advanced stage several therapeutic options can be discussed, including molecular targeted agents, but biological predicting factors are lacking. A number of molecular targets have been studied over the last decade bringing to several phase II studies; however very few agents moved into phase III clinical trials. The VEGFR-2 inhibitor monoclonal antibody ramucirumab has been recently approved in advanced progressing gastric cancer. This article reviews the basic science as well as clinical data of VEGF signaling in advanced gastric cancer with special emphasis on the different VEGF targeting agents tested previously in this disease.

Molecular regulation of cervical cancer growth and invasion by VEGFa

Although antivascular endothelial growth factor a (VEGFa) treatment has been well applied in cervical cancer therapy, the underlying molecular basis has not been precisely identified. Here, we examined the levels of VEGFa on the tumor growth and invasion in four commonly used human cervical cancer cell lines. We found that overexpression of VEGFa in these lines increased the tumor growth and invasiveness, while inhibition of VEGFa decreased the tumor growth and invasiveness. To figure out the involved signaling pathways, we applied specific inhibitors for ERK/MAPK, JNK, and PI3K/Akt signaling pathways, respectively, to VEGFa-overexpressing cervical cancer lines and found that only inhibition of PI3K/Akt signal transduction abolished VEGFa-induced increases in cell growth and invasiveness. Inhibition of Akt downstream mTor signaling similarly inhibited cell growth and invasion in VEGFa-overexpressing cervical cancer cells, suggesting that VEGFa may activate PI3K/Akt, and subsequently its downstream mTor signaling pathway, to promote cervical cancer cell growth and invasion. Furthermore, the effects of VEGFa-induced activation of mTor signaling cascades appeared to promote cancer cell growth through cyclinD1 and CDK4 activation and promote cancer cell invasion through MMP2 and MMP3. Taken together, our data suggest that anti-VEGFa treatment in cervical cancer may inhibit both tumor cell growth and invasion through PI3k/Akt/mTor signaling pathway.

Novel findings about management of gastric cancer: A summary from 10th IGCC

The Tenth International Gastric Cancer Congress (IGCC) was held in Verona, Italy, from June 19 to 22, 2013. The meeting enclosed various aspects of stomach tumor management, including both tightly clinical approaches, and topics more related to basic research. Moreover, an overview on gastrointestinal stromal tumors was provided too, although here not discussed. Here we will discuss some topics related to molecular biology of gastric cancer (GC), inherent to prognostic, diagnostic and therapeutic tools shown at the conference. Results about well known subjects, such as E-cadherin loss of expression/function, were presented. They revealed that other mutations of the gene were identified, showing a continuous research to improve diagnosis and prognosis of stomach tumor. Simultaneously, new possible molecular markers with an established role for other neoplasms, were discussed, such as mesothelin, stomatin-like protein 2 and Notch-1. Hence, a wide overview including both old and new diagnostic/prognostic tools was offered. Great attention was also dedicated to possible drugs to be used against GC. They included monoclonal antibodies, such as MS57-2.1, drugs used in other pathologies, such as maraviroc, and natural extracts from plants such as biflorin. We would like to contribute to summarize the most impressive studies presented at the IGCC, concerning novel findings about molecular biology of gastric cancer. Although further investigations will be necessary, it can be inferred that more and more tools were developed, so as to better face stomach neoplasms.

PLGF inhibition impairs metastasis of larynx carcinoma through MMP3 downregulation

Cancer neovascularization plays a key role in the metastasis of larynx carcinoma. However, the molecular mechanism for the neovascularization control in larynx carcinoma is poorly understood. Since placental growth factor (PLGF) has been reported to be involved in pathological angiogenesis, and since matrix metalloproteinases (MMPs) are essential for extracellular matrix degradation during neovascularization, here we were prompted to examine whether PLGF and MMPs may play a coordinate role in the metastasis of larynx carcinoma. Our data showed that the expression of PLGF and MMP3 strongly correlated in the larynx carcinoma in the patients, and significant higher levels of PLGF and MMP3 were detected in the larynx carcinoma from the patients with metastasis of the primary cancer. Thus, we used a human larynx carcinoma cell line, Hep-2, to examine whether expression of PLGF and MMP3 may affect each other. We found that overexpression of PLGF in Hep-2 cells increased expression of MMP3, while inhibition of PLGF in Hep-2 cells decreased expression of MMP3. However, neither overexpression, nor inhibition of MMP3 in Hep-2 cells affected the expression level of PLGF. These data suggest that PLGF may function upstream of MMP3 in larynx carcinoma cells. We then analyzed how PLGF affected MMP3. Application of a specific ERK1/2 inhibitor to PLGF-overexpressing Hep-2 cells substantially abolished the effect of PLGF on MMP3 activation, suggesting that PLGF may increase expression of MMP3 via ERK/MAPK signaling pathway. Since anti-PLGF was recently applied in clinical trials to inhibit cancer-related angiogenesis, here our data further demonstrate that inhibition of cancer neovascularization by anti-PLGF is mediated not only by direct effect on endothelial growth and capillary permeability, but also by indirect effect via MMP3 on the extracellular matrix degradation in larynx carcinoma.

Molecular basis underlying inhibition of metastasis of gastric cancer by anti-VEGFa treatment

Neovascularization plays a substantial role in the invasiveness and metastasis of gastric cancer. However, the molecular mechanism underlying the control of neovascularization of gastric cancer remains undefined. Both vascular endothelial growth factor a (VEGFa) and matrix metalloproteinases 2 (MMP2) are essential for neovascularization by promoting endothelial mitogenesis and permeability and by promoting extracellular matrix degradation, respectively. Therefore, we were prompted to examine whether VEGFa and MMP2 may affect expression of each other to coordinate the neovascularization process. We found strong positive correlation of VEGFa and MMP2 levels in the gastric patients. Moreover, patients with metastasis of the original cancer had significantly higher levels of VEGFa and MMP2. Thus, we used a human gastric cancer cell line, SNU-5, to examine whether expression of VEGFa and MMP2 may affect each other. We found that overexpression of VEGFa in SNU-5 cells increased expression of MMP2, while inhibition of VEGFa in SNU-5 cells decreased expression of MMP2. On the other hand, overexpression of MMP2 in SNU-5 cells increased expression of VEGFa, while inhibition of MMP2 in SNU-5 cells decreased expression of VEGFa. These data suggest that expression of VEGFa and MMP2 may activate each other to reinforce a promoting effect on neovascularization. We then analyzed how VEGFa expression affects MMP2 level. Application of a specific Akt inhibitor to VEGFa-overexpressing SNU-5 cells substantially abolished the effect of VEGFa on MMP2 activation, suggesting that VEGFa may increase expression of MMP2 via PI3K/Akt signaling pathway. Since anti-VEGFa is a well-established therapy for many cancers, our data suggest that anti-VEGFa may not only inhibit neovascularization by prohibiting VEGFa-dependent endothelial mitogenesis and permeability increase but also by downregulating MMP2 to abolish the extracellular matrix degradation in gastric cancer.

Ramucirumab for metastatic gastric or gastroesophageal junction cancer: results and implications of the REGARD trial

Gastric cancer is a highly aggressive disease. In metastatic setting, median overall survival, even with modern chemotherapy regimens, generally does not exceed 1 year and toxicity is a major concern. Angiogenesis plays a crucial role in cancer development and progression, and VEGF is one of the most important mediators of this process. Ramucirumab, an anti-VEGFR-2 antibody, has been recently evaluated in the large Phase III REGARD trial, demonstrating a significant survival benefit in second-line treatment of patients with advanced gastric or gastro-eosophageal junction adenocarcinoma. Unlike traditional chemotherapy, treatment with ramucirumab was associated with very few toxic effects. This article will review the main findings of the REGARD trial and discuss their potential impact on future treatment of metastatic gastric cancer.