Anti-EGFR-Targeted Therapy for Esophageal and Gastric Cancers: An Evolving Concept. J Oncol. 2009;2009:804108. [PMID: 19636422 PMCID: PMC2712675 DOI: 10.1155/2009/804108]

High-throughput computational screening and in vitro evaluation identifies 5-(4-oxo-4H-3,1-benzoxazin-2-yl)-2-[3-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]-1H-isoindole-1,3(2H)-dione (C3), as a novel EGFR-HER2 dual inhibitor in gastric tumors

Gastric cancers are caused primarily due to the activation and amplification of the EGFR or HER2 kinases resulting in cell proliferation, adhesion, angiogenesis, and metastasis. Conventional therapies are ineffective due to the intra-tumoral heterogeneity and concomitant genetic mutations. Hence, dual inhibition strategies are recommended to increase potency and reduce cytotoxicity. In this study, we have conducted computational high-throughput screening of the ChemBridge library followed by in vitro assays and identified novel selective inhibitors that have a dual impediment of EGFR/HER2 kinase activities. Diversity-based High-throughput Virtual Screening (D-HTVS) was used to screen the whole ChemBridge small molecular library against EGFR and HER2. The atomistic molecular dynamic simulation was conducted to understand the dynamics and stability of the protein-ligand complexes. EGFR/HER2 kinase enzymes, KATOIII, and Snu-5 cells were used for in vitro validations. The atomistic Molecular Dynamics simulations followed by solvent-based Gibbs binding free energy calculation of top molecules, identified compound C3 (5-(4-oxo-4H-3,1-benzoxazin-2-yl)-2-[3-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]-1H-isoindole-1,3(2H)-dione) to have a good affinity for both EGFR and HER2. The predicted compound, C3, was promising with better binding energy, good binding pose, and optimum interactions with the EGFR and HER2 residues. C3 inhibited EGFR and HER2 kinases with IC50 values of 37.24 and 45.83 nM, respectively. The GI50 values of C3 to inhibit KATOIII and Snu-5 cells were 84.76 and 48.26 nM, respectively. Based on these findings, we conclude that the identified compound C3 showed a conceivable dual inhibitory activity on EGFR/HER2 kinase, and therefore can be considered as a plausible lead-like molecule for treating gastric cancers with minimal side effects, though testing in higher models with pharmacokinetic approach is required.

Investigations into the impact of non-coding RNA on the sensitivity of gastric cancer to radiotherapy

Non-coding RNAs (ncRNAs) are a newly discovered functional RNA different from messenger RNA, which can participate in regulating the occurrence and development of tumors. More and more research results show that ncRNAs can participate in the regulation of gastric cancer (GC) radiotherapy response, and its mechanism may be related to its effect on DNA damage repair, gastric cancer cell stemness, cell apoptosis, activation of epidermal growth factor receptor signaling pathway, etc. This article summarizes the relevant mechanisms of ncRNAs regulating the response to radiotherapy in gastric cancer, which will be directly important for the introduction of ncRNAs particularly microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) into clinical medicine as biomarkers and therapeutic targets.

A context-aware deconfounding autoencoder for robust prediction of personalized clinical drug response from cell-line compound screening

Accurate and robust prediction of patient-specific responses to a new compound is critical to personalized drug discovery and development. However, patient data are often too scarce to train a generalized machine learning model. Although many methods have been developed to utilize cell-line screens for predicting clinical responses, their performances are unreliable owing to data heterogeneity and distribution shift. Here we have developed a novel context-aware deconfounding autoencoder (CODE-AE) that can extract intrinsic biological signals masked by context-specific patterns and confounding factors. Extensive comparative studies demonstrated that CODE-AE effectively alleviated the out-of-distribution problem for the model generalization and significantly improved accuracy and robustness over state-of-the-art methods in predicting patient-specific clinical drug responses purely from cell-line compound screens. Using CODE-AE, we screened 59 drugs for 9,808 patients with cancer. Our results are consistent with existing clinical observations, suggesting the potential of CODE-AE in developing personalized therapies and drug response biomarkers.

SMMDA: Predicting miRNA-Disease Associations by Incorporating Multiple Similarity Profiles and a Novel Disease Representation

Simple Summary

Predicting possible associations between miRNAs and diseases would provide new perspectives on disease diagnosis, pathogenesis, and gene therapy. In this work, considering the limited accessibility, high time consumption and high cost in traditional biological researches, we presented a novel computational method called SMMDA by incorporating multiple similarity profiles and a novel disease rep-resentation to accelerate the identification of potential miRNA-disease associations. SMMDA was intended to be useful for the prediction of associations between miRNAs and diseases, and to be effective for prevention, diagnosis, treatment and prognosis of Human diseases.

Abstract

Increasing evidence has suggested that microRNAs (miRNAs) are significant in research on human diseases. Predicting possible associations between miRNAs and diseases would provide new perspectives on disease diagnosis, pathogenesis, and gene therapy. However, considering the intrinsic time-consuming and expensive cost of traditional Vitro studies, there is an urgent need for a computational approach that would allow researchers to identify potential associations between miRNAs and diseases for further research. In this paper, we presented a novel computational method called SMMDA to predict potential miRNA-disease associations. In particular, SMMDA first utilized a new disease representation method (MeSHHeading2vec) based on the network embedding algorithm and then fused it with Gaussian interaction profile kernel similarity information of miRNAs and diseases, disease semantic similarity, and miRNA functional similarity. Secondly, SMMDA utilized a deep auto-coder network to transform the original features further to achieve a better feature representation. Finally, the ensemble learning model, XGBoost, was used as the underlying training and prediction method for SMMDA. In the results, SMMDA acquired a mean accuracy of 86.68% with a standard deviation of 0.42% and a mean AUC of 94.07% with a standard deviation of 0.23%, outperforming many previous works. Moreover, we also compared the predictive ability of SMMDA with different classifiers and different feature descriptors. In the case studies of three common Human diseases, the top 50 candidate miRNAs have 47 (esophageal neoplasms), 48 (breast neoplasms), and 48 (colon neoplasms) are successfully verified by two other databases. The experimental results proved that SMMDA has a reliable prediction ability in predicting potential miRNA-disease associations. Therefore, it is anticipated that SMMDA could be an effective tool for biomedical researchers.

Antibody drug conjugates in gastrointestinal cancer: From lab to clinical development

The antibody-drug conjugates (ADCs) are one the fastest growing biotherapeutics in oncology and are still in their infancy in gastrointestinal (GI) cancer for clinical applications to improve patient survival. The ADC based approach is developed with tumor specific antigen, antibody carrying cytotoxic agents to precisely target and deliver chemotherapeutics at the tumor site. To date, 11 ADCs have been approved by US-FDA, and more than 80 are in the clinical development phase for different oncological indications. However, The ADCs based therapies in GI cancers are still far from having high-efficient clinical outcomes. The limited success of these ADCs and lessons learned from the past are now being used to develop a newer generation of ADC against GI cancers. In this review, we did a comprehensive assessment of the key components of ADCs, including tumor marker, antibody, cytotoxic payload, and linkage strategy, with a focus on technical improvement and some future trends in the pipeline for clinical translation. The various preclinical and clinical ADCs used in gastrointestinal malignancies, their target, composition and bioconjugation, along with preclinical and clinical outcomes, are discussed. The emphasis is also given to new generation ADCs employing novel mAb, payload, linker, and bioconjugation methods are also included.

The Correlation between EGFR and Androgen Receptor Pathways: A Novel Potential Prognostic Marker in Gastric Cancer

BACKGROUND

Despite worthy biologic rationale and numerous studies introducing therapeutic strategies targeting Epidermal Growth Factor Receptor (EGFR), phase III clinical trials have claimed that these current anti-EGFR agents did not significantly improve overall survival of Gastric Cancer (GC) patients. Therefore, to discover flawless candidates of anti-EGFR therapy and ideal prognostic markers, innovative studies are warranted.

METHODS

The aim of this study was to assess the expression profile of EGFR in GC, adjacent non-tumor and normal gastric tissues by qRT-PCR, investigating the association of EGFR expression with clinicopathological features, evaluating possible molecular interaction between EGFR and Androgen Receptor (AR), and elucidating novel prognostic marker using Cox regression model.

RESULTS

Among 60 GC patients, 70% (42/60) overexpressed EGFR relative to normal gastric tissues. EGFR overexpression was significantly correlated with the AR overexpression in GC patients. Although EGFR overexpression was remarkably associated with unfavorable outcomes (HR= 4.067, 95% CI= 1.228-13.467, p= 0.022), it was not an independent prognostic factor adjusted for other variables. However, we provided evidences that simultaneous evaluation of EGFR and AR expression, could independently predict the outcome of GC patients and could use as a precise prognostic marker. Moreover, it was revealed that induction or inhibition of AR signaling could alter the mRNA expression of EGFR in GC cell lines.

CONCLUSION

By targeting AR and EGFR using a potent AR inhibitor such as Enzalutamide, we postulate the possible crosstalk between EGFR and AR pathways in GC. Moreover, our study provided evidences elucidating a novel promising marker, simultaneous evaluation of EGFR and AR expression, which could properly predict prognosis of gastric cancer patients.

Rethink of EGFR in Cancer With Its Kinase Independent Function on Board

The epidermal growth factor receptor (EGFR) is one of most potent oncogenes that are commonly altered in cancers. As a receptor tyrosine kinase, EGFR's kinase activity has been serving as the primary target for developing cancer therapeutics, namely the EGFR inhibitors including small molecules targeting its ATP binding pocket and monoclonal antibodies targeting its ligand binding domains. EGFR inhibitors have produced impressive therapeutic benefits to responsive types of cancers. However, acquired and innate resistances have precluded current anti-EGFR agents from offering sustainable benefits to initially responsive cancers and benefits to EGFR-positive cancers that are innately resistant. Recent years have witnessed a realization that EGFR possesses kinase-independent (KID) pro-survival functions in cancer cells. This new knowledge has offered a different angle of understanding of EGFR in cancer and opened a new avenue of targeting EGFR for cancer therapy. There are already many excellent reviews on the role of EGFR with a focus on its kinase-dependent functions and mechanisms of resistance to EGFR targeted therapies. The present opinion aims to initiate a fresh discussion about the function of EGFR in cancer cells by laying out some unanswered questions pertaining to EGFR in cancer cells, by rethinking the unmet therapeutic challenges from a view of EGFR's KID function, and by proposing novel approaches to target the KID functions of EGFR for cancer treatment.

DpdtbA-Induced Growth Inhibition in Human Esophageal Cancer Cells Involved Inactivation of the p53/EGFR/AKT Pathway

Esophageal cancer (ESC) is one of the most deadly diseases for human. p53 in most cancers, including ESC cell, is mutated, and the mutated p53 losses its original function and acquires “gain of function” that allows for promoting the hallmarks of cancer, such as antiapoptosis, metastasis, invasion, angiogenesis, and resistance to chemotherapy. Targeting p53 through either introducing wild-type or degrading mutated p53 is an important strategy in cancer therapy. Di-2,2′-pyridine ketone dithiocarbamate s-butyric acid (DpdtbA) has significant growth inhibition against gastric cancer lines in previous study. Similar action in ESC cell lines but a novel molecular mechanism was observed in the present study. The results showed that DpdtbA exhibited an excellent antiproliferative effect for ESC cell lines (IC₅₀ ≤ 4.5 ± 0.4 μM for Kyse 450, 3.2 ± 0.6 μM for Kyse 510 cell, and 10.0 ± 0.6 μM for Kyse 150) and led to cell cycle arrest at the S phase which correlated to CDK2 downregulation. The mechanistic study suggested that growth inhibition was related to ROS-mediated apoptosis, and ROS production was due to SOD inhibition initiated by DpdtbA rather than occurrence of ferritinophagy. In addition, DpdtbA also induced a downregulation of EGFR, p53, and AKT, which hinted that mutant p53 still played a role in the regulation of its downstream targets. Further study revealed that the downregulation of p53 was through stub1- (chip-) mediated autophagic degradation rather than MDM2-mediated ubiquitination. Taken together, the DpdtbA-induced growth inhibition in a mechanism was through inactivating the p53/EGFR/AKT signal pathway.

Assessment of EGFR and ERBB2 (HER2) in Gastric and Gastroesophageal Carcinomas: EGFR Amplification is Associated With a Worse Prognosis in Early Stage and Well to Moderately Differentiated Carcinoma

Epidermal growth factor receptor 1 (EGFR) and erb-b2 receptor tyrosine kinase 2 (ERBB2/HER2) are frequently dysregulated in human cancers. We analyzed EGFR and ERBB2 status in 105 gastric and gastroesophageal junction carcinoma and their clinicopathologic features. For EGFR, 92 (88%) tumors were scored as 0, 2 (2%) as 1+, 7 (7%) as 2+, and 4 (3%) as 3+ by immunohistochemistry (IHC) and 4 (4%) tumors showed EGFR amplification by fluorescence in situ hybridization (FISH). For ERBB2, 90 (86%) tumors were scored as 0, 4 (4%) as 1+, 6 (6%) as 2+, and 5 (5%) as 3+ by IHC and 12 (12%) showed ERBB2 amplification by FISH. The concordance rate between IHC and FISH of EGFR was 98.1% (P<0.001) and of ERBB2 was 93.3% (P<0.001). Most tumors with ERBB2 amplification were tubular adenocarcinoma (N=11, P=0.02) and Lauren intestinal type (N=12, P=0.016). There was no statistically significant difference between EGFR amplification and tumor classification. EGFR amplification had significant impact on overall survival in certain subgroups: early stages (stages I and II) (P<0.001), well to moderately differentiated tumors (P=0.001), and fewer regional lymph node metastasis (pN1) (P=0.001). ERBB2 status had little predictive value on overall survival. In conclusion, this study showed ERBB2 amplification was significantly observed in tubular adenocarcinoma and Lauren intestinal-type carcinoma. The IHC scoring criteria for ERBB2 can be applied to EGFR. EGFR amplification had associated with poor prognosis in early, well to moderately differentiated carcinoma.

Sensitive and easy screening for circulating tumor cells by flow cytometry

Circulating Tumor Cells (CTCs) represent an easy, repeatable and representative access to information regarding solid tumors. However, their detection remains difficult because of their paucity, their short half-life, and the lack of reliable surface biomarkers. Flow cytometry (FC) is a fast, sensitive and affordable technique, ideal for rare cells detection. Adapted to CTCs detection (i.e. extremely rare cells), most FC-based techniques require a time-consuming pre-enrichment step, followed by a 2-hours staining procedure, impeding on the efficiency of CTCs detection. We overcame these caveats and reduced the procedure to less than one hour, with minimal manipulation. First, cells were simultaneously fixed, permeabilized, then stained. Second, using low-speed FC acquisition conditions and two discriminators (cell size and pan-cytokeratin expression), we suppressed the pre-enrichment step. Applied to blood from donors with or without known malignant diseases, this protocol ensures a high recovery of the cells of interest independently of their epithelial-mesenchymal plasticity and can predict which samples are derived from cancer donors. This proof-of-concept study lays the bases of a sensitive tool to detect CTCs from a small amount of blood upstream of in-depth analyses.

Laparoscopic fluorescence image-guided photothermal therapy enhances cancer diagnosis and treatment

Endoscopy is the gold standard investigation in the diagnosis of gastrointestinal cancers and the management of early and pre-malignant lesions either by resection or ablation. Recently gold nanoparticles have shown promise in cancer diagnosis and therapeutics (theranostics). The combination of multifunctional gold nanoparticles with near infrared fluorescence endoscopy for accurate mapping of early or pre-malignant lesions can potentially enhance diagnostic efficiency while precisely directing endoscopic near infrared photothermal therapy for established cancers. The integration of endoscopy with near infrared fluorescence imaging and photothermal therapy was aided by the accumulation of our multifunctionalized PEG-GNR-Cy5.5-anti-EGFR-antibody gold nanorods within gastrointestinal tumor xenografts in BALB/c mice. Control mice (with tumors) received either gold nanorods or photothermal therapy, while study mice received both treatment modalities. Local (tumor-centric) and systemic effects were examined for 30 days. Clear endoscopic near infrared fluorescence signals were observed emanating specifically from tumor sites and these corresponded precisely to the tumor margins. Endoscopic fluorescence-guided near infrared photothermal therapy successfully induced tumor ablations in all 20 mice studied, with complete histological clearance and minimal collateral damage. Multi-source analysis from histology, electron microscopy, mass spectrometry, blood, clinical evaluation, psychosocial and weight monitoring demonstrated the inherent safety of this technology. The combination of this innovative nanotechnology with gold standard clinical practice will be of value in enhancing the early optical detection of gastrointestinal cancers and a useful adjunct for its therapy.

Neoadjuvant Therapy for Esophageal Adenocarcinoma in the Community Setting-Practice and Outcomes

There has been an alarming rise in the incidence of esophageal adenocarcinoma which continues to have poor survival rates primarily due to lack of effective chemotherapy and presentation at advanced stages. Over a dozen chemotherapeutic agents are FDA approved for esophageal cancer (EC), and a two or three-drug combination is typically prescribed as first-line therapy for the majority of EC patients, administered either pre or post-operatively with esophageal resection. We have noticed significant variability in adjuvant and neoadjuvant regimens used in the community setting. The aim of this study was to review the various drug regimens used in the neoadjuvant setting for EC patients with adenocarcinoma undergoing resection at a single tertiary referral center in the Midwest. A total of 123 patients (stage II–III) underwent esophageal resection after neoadjuvant treatment at the center. Overall, 18 distinct drug regimens were used in 123 patients including two patients who received targeted therapy. Median survival post-surgery for this group was 11.2 months with no single regimen offering a survival advantage. These results reveal an unclear algorithm of how accepted regimens are prescribed in the community setting as well as a dire need for agents that are more effective. Additionally, it was noted that although proteomic markers have been found to predict drug response to 92% of the FDA-approved drugs in EC (12 of 13), according to pathology reports, molecular diagnostic testing was not used to direct treatment in this cohort. We therefore propose potential strategies to improve clinical outcomes including the use of a robust molecular oncology diagnostic panel and discuss the potential role for targeted chemotherapy and/or immunotherapy in the management of EC patients.

Translating gastric cancer genomics into targeted therapies

Gastric cancer is a common disease with limited treatment options and a poor prognosis. Many gastric cancers harbour potentially actionable targets, including over-expression and mutations in tyrosine kinase pathways. Agents have been developed against these targets with varying success- in particular, the use of trastuzumab in HER2-overexpressing gastric cancers has resulted in overall survival benefits. Gastric cancers also have high levels of somatic mutations, making them candidates for immunotherapy; early work in this field has been promising. Recent advances in whole genome and multi-platform sequencing have driven the development of molecular classification systems, which may in turn guide the selection of patients for targeted treatment. Moving forward, challenges will include the development of appropriate biomarkers to predict responses to targeted therapy, and the application of new molecular classifications into trial development and clinical practice.

Targeted therapy for advanced gastric cancer: A review of current status and future prospects

In the West in particular, the vast majority of gastric cancer (GC) patients present with advanced-stage disease. Although combination chemotherapy is still the most important component of treatment for these patients, it confers a modest survival advantage. Recently, increased knowledge of the key molecular signaling pathways involved in gastric carcinogenesis has led to the discovery of specific molecular-targeted therapeutic agents. Some of these agents such as trastuzumab and ramucirumab have changed the treatment paradigm for this disease. In this paper, we will summarize the current clinical status of targeted drug therapy in the management of GC.

The relation of EGFR expression by immunohistochemical staining and clinical response of combination treatment of nimotuzumab and chemotherapy in esophageal squamous cell carcinoma

INTRODUCTION

The esophageal squamous cell carcinoma (ESCC) is the predominant pathological type and accounts for more than 80 % of esophageal cancer in China. The successful use of anti-epidermal growth factor receptor (EGFR) treatment in head and neck squamous cell carcinoma provides the rationale for introducing anti-EGFR targeting treatment in ESCC. One of our prospective phase II clinical trials analyzed the efficacy of nimotuzumab, an anti-EGFR agent, combined with chemotherapy (paclitaxel and cisplatin) to treat unresectable ESCC.

MATERIALS AND METHODS

We analyzed the correlation of the clinical response with EGFR expression by immunohistochemical staining (IHC).

RESULTS

Totally 55 tumor samples were analyzed. 18/55 (32.7 %) cases were with high EGFR expression while the other 37/55 (67.3 %) cases were with low to moderate EGFR expression. The expression of EGFR was not related to gender, age, tumor location, tumor differentiation and clinical stage of disease. The objective response rate (ORR) in high EGFR expression group was 55.6 % (10/18) while that in low to moderate EGFR expression group was 54.1 % (20/37) (P = 0.57). Both the progression-free survival (PFS) and overall survival (OS) in high EGFR expression group were much shorter than those in low to moderate EGFR expression group (PFS: 5.8 ± 0.5 vs. 11.0 ± 2.8 months, P = 0.007; OS: 9.7 ± 0.5 vs. 21.5 ± 1.5 months, P = 0.03).

CONCLUSIONS

The results showed that over-expression of EGFR was related to poor survival of ESCC. The over-expression of EGFR by IHC might not be an ideal predictive biomarker of nimotuzumab treatment. Other EGFR pathway-associated molecules should be analyzed in further studies.

Advancing pharmacological treatment options for advanced gastric cancer

INTRODUCTION

Gastric cancer is the third most common cause of cancer-related deaths worldwide. Improvement of conventional chemotherapy has been modest in the past decades.

AREAS COVERED

We review recent important studies of metastatic or recurrent gastric cancer. For human epidermal growth factor receptors 2 (HER2) negative cancer, standard treatments are combinations of fluoropyrimidine and platinum with or without epirubicin or docetaxel in first-line therapy. Controversy exists regarding the use of triplet chemotherapies due to their toxicity. For HER2 positive cancer, standard treatments are combinations of fluoropyrimidine and cisplatin with trastuzumab. As second- or third-line treatment, taxanes or irinotecan prolonged survival compared with best supportive care alone, but the extension of overall survival was only 1 - 2 months. A recent study demonstrated that ramucirumab plus paclitaxel improved survival as a second-line therapy.

EXPERT OPINION

Most trials have failed to demonstrate a benefit of targeted agents. It is important to identify predictive biomarkers to enrich an appropriate patient population for targeted agents such as HER2 status for trastuzumab.

Three-gene immunohistochemical panel adds to clinical staging algorithms to predict prognosis for patients with esophageal adenocarcinoma

PURPOSE

Esophageal adenocarcinoma (EAC) is a highly aggressive disease with poor long-term survival. Despite growing knowledge of its biology, no molecular biomarkers are currently used in routine clinical practice to determine prognosis or aid clinical decision making. Hence, this study set out to identify and validate a small, clinically applicable immunohistochemistry (IHC) panel for prognostication in patients with EAC.

PATIENTS AND METHODS

We recently identified eight molecular prognostic biomarkers using two different genomic platforms. IHC scores of these biomarkers from a UK multicenter cohort (N = 374) were used in univariate Cox regression analysis to determine the smallest biomarker panel with the greatest prognostic power with potential therapeutic relevance. This new panel was validated in two independent cohorts of patients with EAC who had undergone curative esophagectomy from the United States and Europe (N = 666).

RESULTS

Three of the eight previously identified prognostic molecular biomarkers (epidermal growth factor receptor [EGFR], tripartite motif-containing 44 [TRIM44], and sirtuin 2 [SIRT2]) had the strongest correlation with long-term survival in patients with EAC. Applying these three biomarkers as an IHC panel to the validation cohort segregated patients into two different prognostic groups (P < .01). Adjusting for known survival covariates, including clinical staging criteria, the IHC panel remained an independent predictor, with incremental adverse overall survival (OS) for each positive biomarker (hazard ratio, 1.20; 95% CI, 1.03 to 1.40 per biomarker; P = .02).

CONCLUSION

We identified and validated a clinically applicable IHC biomarker panel, consisting of EGFR, TRIM44, and SIRT2, that is independently associated with OS and provides additional prognostic information to current survival predictors such as stage.

EGFR intron-1 CA repeat polymorphism is a predictor of relapse and survival in complete resected only surgically treated esophageal cancer

Basal transcription regulation of the epidermal growth factor receptor is dependent upon a CA simple sequence repeat polymorphism in the intron-1 (CA-SSR-1). Here, we evaluate the role of CA-SSR-1 in complete resected esophageal cancer (EC) patients without neoadjuvant or adjuvant treatment. Genomic DNA was extracted from peripheral blood leukocytes of 241 patients. To determine the number of the CA repeats in the CA-SSR-1, DNA was amplified by polymerase chain reaction and sequenced. The results were correlated with clinicopathological parameters and clinical outcome. Three genotypes were defined based on cut-off points for short allele (S) with ≤18 and long allele (L) >18 CA repeats. A steadily increasing risk was evident between LL, SL, and SS genotype for larger tumor size, presence of lymph node metastases, and disseminated tumor cells in bone marrow as well as tumor recurrence (P < 0.001, chi-square test). A gradual decrease in disease-free and overall survival (OS) was present among LL, SL, and SS patients (P < 0.001, log-rank test). The different outcomes were also evident in nodal status and histological type adjusted subgroup analyses. CA-SSR-1 was identified as the strongest independent prognosticator of tumor recurrence and OS (P < 0.001, Cox regression analysis). CA-SSR-1 is a strong predictive factor for tumor recurrence and overall survival in patients with complete resected esophageal cancer without neoadjuvant or adjuvant therapy.

Estrogen receptor α and β in esophageal squamous cell carcinoma

A gender difference has been reported in the morbidity of esophageal squamous cell carcinoma (ESCC). Estrogens have been proposed to play a role in this difference but the details have not yet been clarified. Therefore, in the present study, we examined the status of estrogen receptor (ER)α and ERβ in 90 Japanese ESCC patients. ERα and ERβ immunoreactivity was detected in the nuclei of ESCC cells (41.1 and 97.8%, respectively). There was a significant positive association between the ERβ H score and histological differentiation (P = 0.0403), TNM-pM (LYM) (P = 0.00164) and Ki67/MIB1 LI of carcinoma cells (P = 0.0497, r = 0.207). In addition, the ERβ status of carcinoma cells was significantly correlated with unfavorable clinical outcome of the patients. Multivariate analysis further revealed the ERβ status in carcinoma cells as an independent unfavorable prognostic factor of these patients. We further examined the effects of estrogen treatment on ESCC cell line (ECGI-10) transfected with ERα or ERβ in vitro. The number of ECGI-10 transfected with ERβ was increased by estradiol or ERβ specific agonist but estradiol did not exert any effect upon the cell number of ECGI-10 transfected with ERα. In summary, the results of the present study clearly demonstrate that the status of ERβ in ESCC was closely associated with the unfavorable prognosis, possibly through altering cell proliferation of carcinoma cells.

Combined effects of EGFR and Hedgehog signaling pathway inhibition on the proliferation and apoptosis of pancreatic cancer cells

In the present study, we established a new experimental model to investigate the effects of EGFR targeting by RNAi, and the synergistic actions between the hedgehog (Hh) and EGFR signaling pathways on the proliferation and apoptosis in pancreatic cancer cells. Three human pancreatic cancer cell lines expressing EGFR shRNA were established, and gene expression inhibition was assessed in these lines using RT-PCR and western blot analysis. The effects of EGFR RNAi and Hh inhibition on cell proliferation and apoptosis were explored in vitro and in vivo. We observed that EGFR RNAi notably inhibited cell proliferation and colony formation, induced apoptosis and markedly decreased xenograft tumor growth. Furthermore, EGFR RNAi significantly enhanced cyclopamine sensitivity both in vitro and in vivo, and a synergistic decrease of both AKT and ERK phosphorylation was observed. The present study demonstrates that combined inhibition of both EGFR and Hh signaling pathways could establish a more promising antitumor approach than inhibiting each singly, and that there is a possible synergistic effect for Hh and EGFR signaling pathways on ERK and AKT phosphorylation.

Prognostic significance of cyclooxygenase-2, epidermal growth factor receptor 1, and microvascular density in gastric cancer

Gastric cancer remains a significant global health burden with poor treatment outcome. New treatment modalities that target inflammation, proliferation, and angiogenesis have been used in various cancers, including gastric cancer. We sought to study the pattern of expression of two important proteins, cyclooxygenase-2 and epidermal growth factor receptor, and their association with microvascular density, clinicopathological features, and survival in Arab Omani patients with gastric cancer. Formalin-fixed, paraffin-embedded tumors were studied by immunohistochemistry using monoclonal antibodies to cyclooxygenase-2, epidermal growth factor receptor, and CD34. The immunohistochemical results were correlated with clinicopathological features and survival. In our study population, we found a male/female ratio of 72:43, a median age of 59 years, stage III and IV incidence of 66.9%, and a median follow-up of 96 months. Positive expression rates of cyclooxygenase-2 and epidermal growth factor receptor were 89.6 and 23.5%, respectively. The median microvascular density value was 52.5. When this value was determined as the cut-off point, 50% of patients were found to have high microvascular density. Epidermal growth factor receptor over-expression correlated with high microvascular density values, advanced lymph node involvement (N3), and TNM stage presentation (III and IV). Similarly, lymph node involvement was associated with cyclooxygenase-2 over-expression and high microvascular density. Univariate analysis showed that epidermal growth factor receptor over-expression, pathological T3 and T4 disease, and overall stage III and IV disease were adverse prognostic factors. On multivariate analysis using a Cox regression model, expression of epidermal growth factor receptor, and advanced TNM stage were significant adverse prognostic factors for overall survival. Expression of epidermal growth factor receptor in Arab Omani patients with gastric cancer correlates with aggressive tumor characteristics and is an independent prognostic factor. Further clinical studies are needed to evaluate the utility of epidermal growth factor receptor immunohistochemistry as a tool for gastric cancer treatment.

Barrett's esophagus: treatments of adenocarcinomas II

The following topics are explored in this collection of commentaries on treatments of adenocarcinomas related to Barrett's esophagus: the importance of intraoperative frozen sections of the margins for the detection of high dysplasia; the preferable way for sentinel node dissection; the current role of robotic surgery and of video-endoscopic approach; the value of the Siewert's classification of adenocarcinomas; the indications of two-step esophagectomy; the evaluation of pathological complete response; the role of PET scan in staging and response assessment; the role of p53 in the selection of adenocarcinomas patients; chemotherapy regimens for adenocarcinomas; the use of monoclonal antibodies in the control of cell proliferation; he attempt to define a stage-specific strategy, and the possible indications of selective therapy; and changes in mortality rates from esophageal cancer.

A phase I dose escalation study of Nimotuzumab in combination with concurrent chemoradiation for patients with locally advanced squamous cell carcinoma of esophagus

Nimotuzumab (h-R3) is a humanized anti-epidermal growth factor receptor monoclonal antibody. We conducted a phase I study to assess the safety, tolerance, maximal tolerance dose (MTD) and efficacy of h-R3 in combination with concurrent chemoradiation in patient with locally advanced esophageal carcinoma. Patients with locally advanced squamous cell carcinoma of esophagus were eligible. A total dose of 61.2 Gy was delivered by conventional fractionation. Chemotherapy was concurrently administered with irradiation every 4 weeks with PF regimen (cis-platinum of 25 mg/m(2)/d, d1-3; 5-Fu of 1,800 mg/m(2), intravenously infusion in 72 h) for 4 cycles. h-R3 was administrated weekly during irradiation for 6 weeks. h-R3 dose escalation started with 100 mg/week, and followed by 200 mg/week and 400 mg/week. Three patients were enrolled in of each dose cohort. 11 patients were enrolled in the trial with 3, 4 and 4 in 100 mg/week, 200 mg/week and 400 mg/week cohort, respectively. 2 patients in 200 mg/week and 400 mg/week cohort were withdrawn due to patients' own decisions. No dose limiting toxicity was observed. Grade 3-4 of esophagitis, Grade 3 of leucocytopenia and neutrocytopenia occurred in 18% (2/11), 18% (2/11) and 9% (1/11) of patients, respectively. For nimotuzumab-related toxicity only one patient experienced Grade 1 skin rash, and no Grade ≥ 3 of toxicity was noticed. In 9 patients, who completed planned treatments, 6-month and 1-year overall survival were 78% and 67%, respectively, and 1 year local progression-free survival, 100%. h-R3 of 400 mg/week administered concurrently with chemoradiation was well-tolerant. MTD has not been reached yet.

Global molecular dysfunctions in gastric cancer revealed by an integrated analysis of the phosphoproteome and transcriptome

We integrated LC-MS/MS-based and protein antibody array-based proteomics with genomics approaches to investigate the phosphoproteome and transcriptome of gastric cancer cell lines and endoscopic gastric biopsies from normal subjects and patients with benign gastritis or gastric cancer. More than 3,000 non-redundant phosphorylation sites in over 1,200 proteins were identified in gastric cancer cells. We correlated phosphoproteome data with transcriptome data sets and reported the expression of 41 protein kinases, 5 phosphatases and 65 phosphorylated mitochondrial proteins in gastric cancer cells. Transcriptional expression levels of 190 phosphorylated proteins were >2-fold higher in gastric cancer cells compared to normal stomach tissue. Pathway analysis demonstrated over-presentation of DNA damage response pathway and underscored critical roles of phosphorylated p53 in gastric cancer. This is the first study to comprehensively report the gastric cancer phosphoproteome. Integrative analysis of the phosphoproteome and transcriptome provided an expansive view of molecular signaling pathways in gastric cancer.

Baseline ¹⁸F-FDG PET image-derived parameters for therapy response prediction in oesophageal cancer

PURPOSE

The objectives of this study were to investigate the predictive value of tumour measurements on 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) positron emission tomography (PET) pretreatment scan regarding therapy response in oesophageal cancer and to evaluate the impact of tumour delineation strategies.

METHODS

Fifty patients with oesophageal cancer treated with concomitant radiochemotherapy between 2004 and 2008 were retrospectively considered and classified as complete, partial or non-responders (including stable and progressive disease) according to Response Evaluation Criteria in Solid Tumors (RECIST). The classification of partial and complete responders was confirmed by biopsy. Tumours were delineated on the (18)F-FDG pretreatment scan using an adaptive threshold and the automatic fuzzy locally adaptive Bayesian (FLAB) methodologies. Several parameters were then extracted: maximum and peak standardized uptake value (SUV), tumour longitudinal length (TL) and volume (TV), SUV(mean), and total lesion glycolysis (TLG = TV × SUV(mean)). The correlation between each parameter and response was investigated using Kruskal-Wallis tests, and receiver-operating characteristic methodology was used to assess performance of the parameters to differentiate patients.

RESULTS

Whereas commonly used parameters such as SUV measurements were not significant predictive factors of the response, parameters related to tumour functional spatial extent (TL, TV, TLG) allowed significant differentiation of all three groups of patients, independently of the delineation strategy, and could identify complete and non-responders with sensitivity above 75% and specificity above 85%. A systematic although not statistically significant trend was observed regarding the hierarchy of the delineation methodologies and the parameters considered, with slightly higher predictive value obtained with FLAB over adaptive thresholding, and TLG over TV and TL.

CONCLUSION

TLG is a promising predictive factor of concomitant radiochemotherapy response with statistically higher predictive value than SUV measurements in advanced oesophageal cancer.

Biomarkers in Barrett's oesophagus

Biomarkers are needed to screen multiple stages in the clinical pathway of Barrett's oesophagus patients; from disease diagnosis to risk stratification and predicting response to therapy. Routes to the identification of biomarkers have been recognized by known molecular features of the disease and more recently through transcriptomic, methylation and proteomic screening approaches. The majority of Barrett's oesophagus patients remain undiagnosed in the general population. In order to develop a tool to screen for Barrett's oesophagus in the primary care setting, minimally invasive sampling methods coupled with immunocytology-based biomarkers are currently being assessed. Biomarkers may also have utility in surveillance programmes by allowing endoscopic interval to be adjusted according to individual neoplastic risk. Many individual biomarkers have been proposed in this regard, but have frequently been assessed in studies of limited power, or have lacked sufficient sensitivity or specificity when assessed in wider population-based studies. Biomarker panels may provide a route forward. In this regard, a panel of methylation markers has shown promise in a multicentre, double-blind, validation study. Biomarkers are also being developed to improve detection of high-grade dysplasia and oesophageal adenocarcinoma, utilizing brush cytology combined with FISH (fluorescence in situ hybridization), and to assess therapeutic success and risk of complication during photodynamic therapy. Finally, we outline progress in identifying alternative sources of biomarkers for this condition.