Emerging drugs for esophageal cancer

Epidermal growth factor receptor protein overexpression and gene amplification are associated with aggressive biological behaviors of esophageal squamous cell carcinoma

Alterations of the epidermal growth factor receptor (EGFR), including overexpression or gene mutations, contribute to the malignant transformation of human epithelial cells. The aim of this study was to assess EGFR overexpression or gene amplification in esophageal squamous cell carcinoma (ESCC) tissue samples and investigate their correlations with biological behaviors. Tissue specimens from 56 patients with surgically resected ESCC were obtained for immunohistochemical analysis of EGFR expression and fluorescence in situ hybridization analysis of EGFR amplification. The data were statistically analyzed to determine the associations with patient clinicopathological and survival data. EGFR was overexpressed in 30 of the 56 (53.6%) ESCC samples and was associated with poor tumor differentiation (P=0.047). EGFR amplification was detected in 13 cases (23.2%) and was associated with advanced pathological stage (P=0.042) and tumor lymph node metastasis (P=0.002). The univariate analysis identified no association between EGFR overexpression and the overall survival (OS) of the patients. By contrast, EGFR amplification predicted ESCC prognosis (P=0.031), while the multivariate analysis revealed a marginal statistical significance for the association between EGFR amplification and OS (P=0.056). EGFR overexpression and increased EGFR copy number were common events in ESCC and contributed to malignant biological behaviors, including tumor dedifferentiation and lymph node metastasis. EGFR amplification may therefore be useful in predicting OS in patients with ESCC.

Myricetin enhance chemosensitivity of 5-fluorouracil on esophageal carcinoma in vitro and in vivo

BACKGROUND

Flavonoids are structurally heterogeneous, polyphenolic compounds present in high concentrations in fruits, vegetables, and other plant-derived foods. Currently, there is growing interest in the therapeutic applications of bioflavonoids for the treatment and prevention of diseases in humans. Myricetin is a naturally occurring flavonoid that is commonly found in tea, berries, fruits, vegetables, and medicinal herbs. Previous studies have shown that myricetin has antioxidant, anti-inflammatory and potent anticancer effects. It was interesting to investigate whether myricetin has the cooperative inhibitory effect combined with 5-fluorouracil on esophageal cancer cells.

METHODS

EC9706 cells were treated with 5-fluorouracil combination with or without myricetin. Colony formation assays, CCK-8 assay and flow cytometry were used to evaluate the chemosensitization activity of myricetin combine with 5-fluorouracil on the cell growth and viability, cell proliferation and apoptosis in vitro. Western blot was engaged to detect changes of Survivin, Cyclin D, Bcl-2, Caspase-3 and P53 protein expression level, which were associated with cells proliferation and apoptosis. Nude mouse tumor xenograft model was built to assessed chemosensitization effect of myricetin combine with 5-fluorouracil in vivo.

RESULTS

Compared with the 5-fluorouracil group without myricetin treatment, the groups treated with 5-fluorouracil combine with myricetin showed significantly suppressed cell survival fraction and proliferation, increased the cell apoptosis. Decreased Survivin, Cyclin D, Bcl-2, and increased Caspase-3, P53 expression level were aslo confirmed by western blot in 5-fluorouracil combine with myricetin groups in vitro. And in vivo assay, growth speed of tumor xenografts was significantly decreased in the mice treated with 5-fluorouracil + myricetin combiantion group.

CONCLUSIONS

The study demonstrated both in vitro and in vivo evidence that combination of myricetin with 5-fluorouracil chemotherapy can enhance tumor chemosensitivity of esophageal cancer EC9706 cells, and myricetin could be a potential chemosensitizer for esophageal cancer therapy.

An EGFR/HER2-Bispecific and enediyne-energized fusion protein shows high efficacy against esophageal cancer

Esophageal cancer is one of the most common cancers, and the 5-year survival rate is less than 10% due to lack of effective therapeutic agents. This study was to evaluate antitumor activity of Ec-LDP-Hr-AE, a recently developed bispecific enediyne-energized fusion protein targeting both epidermal growth factor receptor (EGFR) and epidermal growth factor receptor 2 (HER2), on esophageal cancer. The fusion protein Ec-LDP-Hr-AE consists of two oligopeptide ligands and an enediyne antibiotic lidamycin (LDM) for receptor binding and cell killing, respectively. The current study demonstrated that Ec-LDP-Hr had high affinity to bind to esophageal squamous cell carcinoma (ESCC) cells, and enediyne-energized fusion protein Ec-LDP-Hr-AE showed potent cytotoxicity to ESCC cells with differential expression of EGFR and HER2. Ec-LDP-Hr-AE could cause significant G2-M arrest in EC9706 and KYSE150 cells, and it also induced apoptosis in ESCC cells in a dosage-dependent manner. Western blot assays showed that Ec-LDP-Hr-AE promoted caspase-3 and caspase-7 activities as well as PARP cleavage. Moreover, Ec-LDP-Hr-AE inhibited cell proliferation via decreasing phosphorylation of EGFR and HER2, and further exerted inhibition of the activation of their downstream signaling molecules. In vivo, at a tolerated dose, Ec-LDP-Hr-AE inhibited tumor growth by 88% when it was administered to nude mice bearing human ESCC cell KYSE150 xenografts. These results indicated that Ec-LDP-Hr-AE exhibited potent anti-caner efficacy on ESCC, suggesting it could be a promising candidate for targeted therapy of esophageal cancer.

Epidermal growth factor receptor: an important target in esophageal cancer

INTRODUCTION

Even after complete tumor removal by surgery, the clinical outcomes remain poor in patients with advanced esophageal cancer, justifying the need for new treatment options. Epidermal growth factor receptor (EGFR) is a molecular target for antibody-based therapy in various cancer types, and it may play important roles in the development of esophageal cancer.

AREAS COVERED

This review evaluates the expression, function, and mechanism of EGFR in esophageal cancer and analyzes its value for the prognosis and therapy of esophageal cancer. Future developments toward the clinical applications of EGFR to cancer treatment are also envisaged.

EXPERT OPINION

EGFR may function as an ideal therapeutic target for esophageal cancer. Further investigation of epidermal growth-factor-receptor-mediated pathways will push insight into the novel strategies of target therapy for esophageal cancer. More clinical trials should be performed to promote the success of therapeutic-clinical use of EGFR and its targets in esophageal cancer.

Lapatinib, a dual inhibitor of epidermal growth factor receptor and human epidermal growth factor receptor 2, potentiates the antitumor effects of cisplatin on esophageal carcinoma

Epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) overexpression occurs in over 30% of esophageal carcinomas. Combination therapies of EGFR- and HER2-targeting agents with cytotoxic agents are considered a potential therapeutic strategy for esophageal cancer. The antitumor effects of lapatinib, a dual tyrosine kinase inhibitor of EGFR and HER2, cisplatin alone, and the combination of the two drugs on esophageal cancer cells were evaluated. The growth inhibition activity of lapatinib, cisplatin, and lapatinib plus cisplatin was measured by 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide (MTT) assays, and the combination index values were calculated. Additionally, cell cycle distribution and cell apoptosis treated with lapatinib or cisplatin alone and the combination of the two drugs were detected by flow cytometry analysis. The activation of EGFR and HER2 signaling pathways was monitored by Western blot analysis. These experimental data showed that the combination of lapatinib and cisplatin synergistically inhibited cell proliferation and exhibited an enhanced pro-apoptotic effect on esophageal cancer cells. The underlying mechanisms of potentiated effects of combined treatment were associated with reduced phosphorylation of EGFR and HER2, and the downstream signaling molecules AKT and extracellular regulated protein kinases (ERK). Our findings indicated that the combination of lapatinib and cisplatin is one of the promising treatment strategies for esophageal carcinomas with EGFR and HER2 overexpression.

Progress in medication treatment of esophageal cancer

Esophageal cancer is one of the common malignant tumors. Multimodality treatment (including surgery, chemotherapy and radiotherapy) of esophageal cancer has become a consensus. Although there is currently no standard treatment, neoadjuvant chemoradiotherapy followed by surgery and postoperative adjuvant radiotherapy or chemotherapy based on risk factors, such as positive surgical margin and lymph node metastasis, and definitive chemoradiotherapy when inoperable, has been recommended by the NCCN Guidelines. In recent years, clinical trials show that targeted drugs can further improve the prognosis of esophageal cancer. How to choose chemotherapy drugs and develop reasonable treatment modality has become a hotspot of clinical research. This article aims to review recent progress in medication treatment of esophageal cancer.

Multidisciplinary approach for patients with esophageal cancer

Patients with esophageal cancer have a poor prognosis because they often have no symptoms until their disease is advanced. There are no screening recommendations for patients unless they have Barrett's esophagitis or a significant family history of this disease. Often, esophageal cancer is not diagnosed until patients present with dysphagia, odynophagia, anemia or weight loss. When symptoms occur, the stage is often stage III or greater. Treatment of patients with very early stage disease is fairly straight forward using only local treatment with surgical resection or endoscopic mucosal resection. The treatment of patients who have locally advanced esophageal cancer is more complex and controversial. Despite multiple trials, treatment recommendations are still unclear due to conflicting data. Sadly, much of our data is difficult to interpret due to many of the trials done have included very heterogeneous groups of patients both histologically as well as anatomically. Additionally, studies have been underpowered or stopped early due to poor accrual. In the United States, concurrent chemoradiotherapy prior to surgical resection has been accepted by many as standard of care in the locally advanced patient. Patients who have metastatic disease are treated palliatively. The aim of this article is to describe the multidisciplinary approach used by an established team at a single high volume center for esophageal cancer, and to review the literature which guides our treatment recommendations.

Pingyangmycin downregulates the expression of EGFR and enhances the effects of cetuximab on esophageal cancer cells and the xenograft in athymic mice

PURPOSE

As reported, epidermal growth factor receptor (EGFR) is over expressed in a variety of cancers including esophageal squamous cell carcinoma. Therefore, it becomes one of the potential targets for treating esophageal cancer. Pingyangmycin (PYM), a single A5 component of bleomycin, is currently used for the treatment of different types of cancers of epidermal origin, especially for head and neck cancers. In this report, the effect of PYM on EGFR expression in human esophageal cancer cells and the therapeutic efficacy of the combination of PYM and cetuximab on esophageal cancer xenograft were investigated.

METHODS

The effects of PYM, cetuximab and the combination on EGFR signaling, proliferation, cell cycle, apoptosis were evaluated by using MTT, Western blotting, RT-PCR assays and flow cytometry assays, respectively, in vitro and the therapeutic efficacy by a xenograft model in athymic mice.

RESULTS

Cell volume and nucleus were enlarged after PYM treatment. PYM showed potent cytotoxicity in both cell lines of Kyse-150 and Eca-109 in time and dosage-depended manner in MTT assay. PYM treatment induced G(2)/M phase arrest and apoptosis. Notably, the expression of EGFR was down-regulated by PYM in EGFR highly expression esophageal cancer cells. PYM plus cetuximab resulted in a potentiation of antiproliferative activity. PYM combined with cetuximab displayed a much higher therapeutic effect than that of the single agent on esophageal cancer xenograft in athymic mice.

CONCLUSIONS

PYM could down-regulate the expression of EGFR in esophageal cancer cells and potentiate the effects of cetuximab on esophageal cancer xenograft in nude mice. The combination of PYM and cetuximab, the EGFR-targeted combination of a chemotherapeutic agent and an antibody-based drug, might be useful in cancer therapy.

Assessment of ErbB2 (Her2) in oesophageal adenocarcinomas: summary of a revised immunohistochemical evaluation system, bright field double in situ hybridisation and fluorescence in situ hybridisation

Amplification and overexpression of ErbB2 (Her2) is a frequent event in oesophageal adenocarcinomas. Assessment of ErbB2 status is crucial for identifying patients who are likely to benefit from treatment with trastuzumab. In this study, we performed a comprehensive analysis of ErbB2 amplification and expression in 142 oesophageal adenocarcinomas by comparing the most commonly used methods for ErbB2 assessment: ErbB2 expression was determined by immunohistochemistry and was scored (0, 1+, 2+ and 3+) according to a recently described modified scoring system for gastric cancer. ErbB2 amplification was evaluated by bright field double in situ hybridisation. The results were compared with pathologic features, patients' survival and previously published data from fluorescence in situ hybridisation analysis. On the basis of immunohistochemistry, which was applicable in 110 cores of the cases, 83 tumours (75%) had a score of 0 or 1+ (immunohistochemistry negative), 13 tumours (12%) were scored as 2+ and 14 tumours (13%) were scored as 3+. In situ hybridisation data were obtained from 142 cases. There was a highly significant correlation of immunohistochemistry, bright field in situ hybridisation and fluorescent in situ hybridisation (P<0.001 each). In total, 41 tumours (29%) were categorised as ErbB2 positive, which was defined as immunohistochemistry 3+ and/or an ErbB2/Chr17 quotient of ≥2 as assessed by either bright field double in situ hybridisation or fluorescence in situ hybridisation. ErbB2 positivity was observed more frequently in tumours with lower differentiation grades (P=0.029). Patients with ErbB2-positive tumours had a significantly worse prognosis, both in univariate analysis (P=0.004) and in multivariate analysis (P=0.03). In conclusion, we demonstrate that a significant number of oesophageal adenocarcinomas are positive for ErbB2. Assessment of ErbB2 amplification can be equivalently performed by conventional fluorescence in situ hybridisation or other light-microscopy-based methods, such as the novel bright field double in situ hybridisation technique.

Neoadjuvant treatment of esophageal cancer

The management of esophageal cancer has been evolving over the past 30 years. In the United States, multimodality treatment combining chemotherapy and radiotherapy (RT) prior to surgical resection has come to be accepted by many as the standard of care, although debate about its overall effect on survival still exists, and rightfully so. Despite recent improvements in detection and treatment, the overall survival of patients with esophageal cancer remains lower than most solid tumors, which highlights why further advances are so desperately needed. The aim of this article is to provide a complete review of the history of esophageal cancer treatment with the addition of chemotherapy, RT, and more recently, targeted agents to the surgical management of resectable disease.