A critical review of HER2-positive gastric cancer evaluation and treatment: from trastuzumab, and beyond

Thioridazine reverses trastuzumab resistance in gastric cancer by inhibiting S-phase kinase associated protein 2-mediated aerobic glycolysis

BACKGROUND

Trastuzumab constitutes the fundamental component of initial therapy for patients with advanced human epidermal growth factor receptor 2 (HER-2)-positive gastric cancer (GC). However, the efficacy of this treatment is hindered by substantial challenges associated with both primary and acquired drug resistance. While S-phase kinase associated protein 2 (Skp2) overexpression has been implicated in the malignant progression of GC, its role in regulating trastuzumab resistance in this context remains uncertain. Despite the numerous studies investigating Skp2 inhibitors among small molecule compounds and natural products, there has been a lack of successful commercialization of drugs specifically targeting Skp2.

AIM

To discover a Skp2 blocker among currently available medications and develop a therapeutic strategy for HER2-positive GC patients who have experienced progression following trastuzumab-based treatment.

METHODS

Skp2 exogenous overexpression plasmids and small interfering RNA vectors were utilized to investigate the correlation between Skp2 expression and trastuzumab resistance in GC cells. Q-PCR, western blot, and immunohistochemical analyses were conducted to evaluate the regulatory effect of thioridazine on Skp2 expression. A cell counting kit-8 assay, flow cytometry, a amplex red glucose/glucose oxidase assay kit, and a lactate assay kit were utilized to measure the proliferation, apoptosis, and glycolytic activity of GC cells in vitro. A xenograft model established with human GC in nude mice was used to assess thioridazine's effectiveness in vivo.

RESULTS

The expression of Skp2 exhibited a negative correlation with the sensitivity of HER2-positive GC cells to trastuzumab. Thioridazine demonstrated the ability to directly bind to Skp2, resulting in a reduction in Skp2 expression at both the transcriptional and translational levels. Moreover, thioridazine effectively inhibited cell proliferation, exhibited antiapoptotic properties, and decreased the glucose uptake rate and lactate production by suppressing Skp2/protein kinase B/mammalian target of rapamycin/glucose transporter type 1 signaling pathways. The combination of thioridazine with either trastuzumab or lapatinib exhibited a more pronounced anticancer effect in vivo, surpassing the efficacy of either monotherapy.

CONCLUSION

Thioridazine demonstrates promising outcomes in preclinical GC models and offers a novel therapeutic approach for addressing trastuzumab resistance, particularly when used in conjunction with lapatinib. This compound has potential benefits for patients with Skp2-proficient tumors.

Dual block HER2 assessment increased HER2 immunohistochemistry positive rate in resected specimens of gastric cancer: a prospective multicenter clinical trial from China

Background

Former single center studies indicated that HER2 assessment with two primary tumor blocks (dual block HER2 assessment) could be an efficient and practical approach to overcome the adverse impact of heterogeneity and acquire a HER2 positive rate in gastric cancer (GC). This multicenter prospective clinical trial (NCT 02843412) was launched to verify its value and generality.

Methods

A total of 3806 participants with primary GCs have been enrolled from 8 hospitals in China. Two primary tumor blocks were selected and recorded as block 1 and block 2 after histological evaluation. An HER2 (4B5) rabbit monoclonal antibody was used for the immunohistochemistry (IHC) analysis.

Results

In total patients, HER2 IHC positive (3+) rate with dual block assessment (9.4%) was higher than that with single block assessment (block 1: 7.8%, block 2: 7.8%) (P < 0.001). Compared with single-block assessment, dual-block assessment increased the positive rate by approximate 20%. Similarly, HER2 equivocal (2+) rate was increased in dual block assessment (25.8%), which was higher than that in single block assessment (block 1: 20.3%, block 2: 20.9%) (P < 0.001). Conversely, dual block assessment demonstrated a lower HER2 negative (0/1+) rate (64.8%) than single block assessment (block1: 71.9%, block 2: 71.3%) (P < 0.001). These findings were also confirmed in individual hospitals.

Conclusions

Dual block HER2 assessment effectively increased HER2 IHC positive rate in resected specimens of GC. We recommended dual block HER2 assessment be promoted in routine clinical practice in GC.

Trial registration

ClinicalTrials.gov, NCT 02843412. Registered 1 July 2016 - Retrospectively registered.

Meta-Analysis of HER2-Enriched Subtype Predicting the Pathological Complete Response Within HER2-Positive Breast Cancer in Patients Who Received Neoadjuvant Treatment

Background

This meta-analysis aimed to better elucidate the predictive value of human epidermal growth factor receptor 2 (HER2)-enriched subtype of pathological complete response (pCR) rate within HER2-positive breast cancer patients receiving neoadjuvant treatment.

Methods

We identified prospective trials that evaluated the correlation between an HER2-enriched subtype and pCR rate in HER2-positive breast cancer. Pooled odds ratio (OR) values with 95% confidence intervals (CIs) were computed.

Results

Fifteen studies comprising 2,190 patients met the inclusion criteria. The HER2-enriched subtype was associated with increased odds of achieving a pCR (OR = 4.12, 95% CI = 3.38 to 5.03, P < 0.001) in patients overall. Moreover, it was correlated with improved pCR when single or dual HER2-targeted agent-based therapy was employed (OR = 3.36, 95% CI = 2.25 to 5.02, P < 0.001; OR = 4.66, 95% CI = 3.56 to 6.10, P < 0.001, respectively), but not when HER2-targeted agent-free chemotherapy was used (OR = 2.52, 95% CI = 0.98 to 6.49, P = 0.05). Moreover, an HER2-enriched subtype predicted higher pCR rates irrespective of HER2-targeted agents (trastuzumab, lapatinib, pertuzumab, or T-DM1); chemotherapy agents (taxane-based, or anthracyclines plus taxane-based); endocrine therapy and hormone receptor [all the differences were statistically significant (P all ≤ 0.001)].

Conclusions

The HER2-enriched subtype can more effectively and specifically predict pCR for HER2-targeted agent-based neoadjuvant treatment, irrespective of the number (single or dual) or category of HER2-targeted agent, including chemotherapy and endocrine therapy, or hormone receptor in cases of HER2-positive breast cancer.

LncRNA HOTAIR promotes the growth and metastasis of gastric cancer by sponging miR-1277-5p and upregulating COL5A1

BACKGROUND

Emerging studies have shown that HOTAIR acts as an oncogene in gastric cancer (GC). However, its role in the extracellular matrix and in tumor immune infiltration remains unknown.

METHODS

HOTAIR and COL5A1 levels were analyzed by bioinformatics analysis and validated by qRT-PCR, western blotting and immunohistochemistry assays. The regulatory relationships between components of the HOTAIR/miR-1277-5p/COL5A1 axis and the role of this axis in GC were predicted by bioinformatics analysis, and validated by in vitro and in vivo experiments. The correlation between COL5A1 and GC immune infiltration was assessed by bioinformatics analysis and a COL5A1-based predictive nomogram was established using the Stomach Adenocarcinoma dataset from The Cancer Genome Atlas.

RESULTS

We found that HOTAIR and COL5A1 were overexpressed in GC compared to normal controls, which predicted poor prognosis. The regulatory relationship of the HOTAIR/miR-1277-5p/COL5A1 axis in GC was demonstrated, and HOTAIR and COL5A1 were found to promote GC growth while miR-1277-5p exerted the reverse effects. In addition, COL5A1 was negatively associated with tumor purity but positively associated with immune infiltration, which suggested that COL5A1-mediated GC growth may be partially mediated by the regulation of immune infiltration. Additionally, the established COL5A1-based nomogram showed that COL5A1 can serve as a prognostic biomarker in GC.

CONCLUSIONS

HOTAIR regulates GC growth by sponging miR-1277-5p and upregulating COL5A1, and COL5A1-mediated GC cell proliferation may be mediated by effects on the tumor microenvironment, which provides novel targets for GC treatment.

HGF/c-Met Axis: The Advanced Development in Digestive System Cancer

Numerous studies have indicated that abnormal activation of the HGF/c-Met signaling pathway can lead to cell proliferation, invasiveness, and metastasis of cancers of the digestive system. Moreover, overexpression of c-Met has been implicated in poor prognosis of patients with these forms of cancer, suggesting the possibility for HGF/c-Met axis as a potential therapeutic target. Despite the large number of clinical and preclinical trials worldwide, no significant positive success in the use of anti-HGF/c-Met treatments on cancers of the digestive system has been achieved. In this review, we summarize advanced development of clinical research on HGF/c-Met antibody and small-molecule c-Met inhibitors of cancers of the digestive system and provide a possible direction for future research.

Identifying multiple collagen gene family members as potential gastric cancer biomarkers using integrated bioinformatics analysis

Background

Gastric cancer is one of the most common malignant cancers worldwide. Despite substantial developments in therapeutic strategies, the five-year survival rate remains low. Therefore, novel biomarkers and therapeutic targets involved in the progression of gastric tumors need to be identified.

Methods

We obtained the mRNA microarray datasets GSE65801, GSE54129 and GSE79973 from the Gene Expression Omnibus database to acquire differentially expressed genes (DEGs). We used the Database for Annotation, Visualization, and Integrated Discovery (DAVID) to analyze DEG pathways and functions, and the Search Tool for the Retrieval of Interacting Genes (STRING) and Cytoscape to obtain the protein-protein interaction (PPI) network. Next, we validated the hub gene expression levels using the Oncomine database and Gene Expression Profiling Interactive Analysis (GEPIA), and conducted stage expression and survival analysis.

Results

From the three microarray datasets, we identified nine major hub genes: COL1A1, COL1A2, COL3A1, COL5A2, COL4A1, FN1, COL5A1, COL4A2, and COL6A3.

Conclusion

Our study identified COL1A1 and COL1A2 as potential gastric cancer prognostic biomarkers.

The Quest for Improving Treatment of Cancer of Unknown Primary (CUP) Through Molecularly-Driven Treatments: A Systematic Review

Background: Carcinomas of unknown primary (CUP) account for 3–5% of all malignancy and, despite a reduction in incidence, the overall survival has not improved over the last decade. Chemotherapy regimens have not provided encouraging results. New diagnostic technologies, such as next generation sequencing (NGS), could represent a chance to identify potentially targetable genomic alterations in order to personalize treatment of CUP and provide insights into tumor biology.

Methods: A systematic review of studies of patients with CUP, whose tumor specimen was evaluated through a NGS panel, has been performed on June 10th, 2019 according to PRISMA criteria from PubMed, ASCO meeting library and Clinicaltrial.gov. We have identified potentially targetable alterations for which approved/off-label/in clinical trials drugs are available. Moreover, we have included case reports about CUP patients treated with targeted therapies driven by NGS results in order to explore the clinical role of NGS in this setting.

Results: We have evaluated 15 publications of which eleven studies (9 full-text articles and 2 abstracts) have analyzed the genomic profiling of CUPs through NGS technology, with different platforms and with different patients cohorts, ranging from 16 to 1,806 patients. Among all these studies, 85% of patients demonstrated at least one molecular alteration, the most frequent involving TP53 (41.88%), KRAS (18.81%), CDKN2A (8.8%), and PIK3CA (9.3%). A mean of 47.3% of patients harbored a potentially targetable alteration for which approved/off-label/in clinical trials drugs were available. Furthermore, we have identified 4 case reports in order to evaluate the clinical relevance of a specific targeted therapy identified through NGS.

Conclusions: NGS may represent a tool to improve diagnosis and treatment of CUP by identifying therapeutically actionable alterations and providing insights into tumor biology.

A novel anti-HER2 antibody GB235 reverses Trastuzumab resistance in HER2-expressing tumor cells in vitro and in vivo

HER2 overexpression is frequently associated with tumor metastasis and poor prognosis of breast cancer. More evidence indicates that HER3 is involved in HER2-resistant therapies. Combination treatments with two or more different monoclonal antibodies are a promising strategy to overcome resistance to HER2 therapies. We presented a novel fully human HER2-targeted monoclonal antibody, GB235, screened from a phage-display library against the HER2 antigen. GB235 in combination with Trastuzumab overcomes resistance in HER2-positive tumors and results in more sustained inhibition of tumor growth over time. The competition binding assay showed that the epitopes of GB235 do not overlap with those of Pertuzumab and Trastuzumab on HER2. Further HER2 mutagenesis results revealed that the binding epitopes of GB235 were located in the domain III of HER2. The mechanism of action of GB235 in blocking HER2-driven tumors is different from the mechanisms of Trastuzumab or Pertuzumab. GB235 does not affect the heterodimerization of HER2 and HER3, whereas the GB235 combined treatment with Trastuzumab significantly inhibited heregulin-induced HER3 phosphorylation and downstream signaling. Moreover, GB235 in combination with Trastuzumab reversed the resistance to heregulin-induced proliferation in HER2-overexpressing cancer cell lines. GB235 combined with Trastuzumab treatment in xenograft models resulted in improved antitumor activity. Complete tumor suppression was observed in the HER2-positive NCI-N87 xenograft model treated with the combination treatment with GB235 and Trastuzumab. In a Trastuzumab-resistant patient-derived tumor xenograft model GA0060, GB235 plus Trastuzumab reversed the resistance to Trastuzumab monotherapy. Because GB235 showed a different working mechanism with Pertuzumab and Trastuzumab, these agents can be considered complementary therapy against HER2 overexpression tumors.

The age variation of HER2 immunohistochemistry positive rate in biopsy specimens of gastric cancer

AIMS

The aim of this study was to explore HER2 status and characteristics in biopsy specimens of gastric cancer (GC) in Chinese population.

METHODS AND RESULTS

A total of 27,787 biopsy specimens of GC from 103 hospitals were obtained. Immunohistochemistry (IHC) staining of HER2 was performed. Overall HER2 IHC positive rate was 11.2 %. HER2 positive rate elevated with the increase of age in total patients and both genders. The rates were 7.1 %, 8.1 %, 9.0 %, 10.9 %, 11.8 %, 12.6 %, and 12.1 % when patient age was ≤30, 31-40, 41-50, 51-60, 61-70, 71-80, and >80, respectively (P < 0.001). In male, the rates were 6.5 %, 8.4 %, 9.6 %, 11.5 %, 12.4 %, 13.3 %, and 12.1 % (P < 0.001). In female, the rates were 7.4 %, 7.9 %, 8.0 %, 9.0 %, 9.6 %, 10.6 %, and 11.9 % (P = 0.128). The changes in male were more dramatic than in female (P < 0.001). Furthermore, the proportion of the intestinal type GCs increased with age in total patients and both genders (P < 0.001), and in male the changes were more dramatic (P < 0.001). While the proportion of the diffuse type showed the opposite tendency to that of the intestinal type (P < 0.001). HER2 IHC positive rate showed a positive correlation with the proportion of the intestinal type (r=0.986, P < 0.001), and a negative correlation with the proportion of the diffuse type (r=0.984, P < 0.001).

CONCLUSIONS

The HER2 IHC positive rate showed age variation in biopsy specimens of GC. In male the variation was more dramatic than in female. The variation of HER2 positive rate can be attributed to the age variation of the Lauren subtypes.

A prospective observational study on the optimal maintenance strategy in HER2-positive advanced gastric cancer treated with trastuzumab-based therapy

PURPOSE

Trastuzumab plus chemotherapy is an effective therapy in HER2 positive advanced gastric cancer (AGC). However, the optimal maintenance treatment in patients benefited from the first line therapy remains unclear.

METHODS

In this prospective observational study, patients with HER2 positive AGC who received six cycles of trastuzumab-based first line chemotherapy were divided into two arms according to the maintenance strategy: trastuzumab monotherapy (arm A) and trastuzumab plus mono-chemo-agent derived from the initial chemotherapy (arm B). The primary end point was overall survival (OS), the secondary end points were first line progression free survival (PFS), maintenance PFS, cost-effectiveness ratios (CERs), incremental cost-effectiveness ratios (ICERs) and safety.

RESULTS

30 patients were in arm A received trastuzumab monotherapy and 48 were in arm B. The clinical and pathological characteristics of two arms were well balanced. There was no significant difference of median OS (16.5 vs 20.0 months, HR 0.71 P = 0.169) or PFS (7.9 vs 11.0, HR 1.06, P = 0.892) between two arms, however, adding chemo-agent could lead to a 29% reduction in mortality risk. Adverse effects including cardiac safety were also similar. Subgroup analysis showed chemotherapy additional to trastuzumab benefited on OS in patients who had stable disease (SD) of response (HR: 0.084, P = 0.004), elder than 65 years old (HR: 0.4, P = 0.015), without liver metastasis (HR: 0.271, P = 0.008) or less than two organs of distance metastasis (HR: 0.263, P = 0.005). The average cost per patients in arm A was 153,137 RMB and 165,195 RMB in arm B. While, ICER in arm A was 1.29 times higher than arm B (CERs of two arms were 19,384 vs 15,018 RMB).

CONCLUSION

Mono-chemo-agent combined with trastuzumab showed an advantage of absolute value and hazard ratio on OS, in addition to ICER of PFS for patients who benefit from the initial six cycles of trastuzumab-based first line therapy, especially in patients with certain clinical or treatment-related characterisitics. A large sample randomized trial is warranted.

Multimodal analysis of formalin-fixed and paraffin-embedded tissue by MALDI imaging and fluorescence in situ hybridization for combined genetic and metabolic analysis

Multimodal tissue analyses that combine two or more detection technologies provide synergistic value compared to single methods and are employed increasingly in the field of tissue-based diagnostics and research. Here, we report a technical pipeline that describes a combined approach of HER2/CEP17 fluorescence in situ hybridization (FISH) analysis with MALDI imaging on the very same section of formalin-fixed and paraffin-embedded (FFPE) tissue. FFPE biopsies and a tissue microarray of human gastroesophageal adenocarcinoma were analyzed by MALDI imaging. Subsequently, the very same section was hybridized by HER2/CEP17 FISH. We found that tissue morphology of both, the biopsies and the tissue microarray, was unaffected by MALDI imaging and the HER2 and CEP17 FISH signals were analyzable. In comparison with FISH analysis of samples without MALDI imaging, we observed no difference in terms of fluorescence signal intensity and gene copy number. Our combined approach revealed adenosine monophosphate, measured by MALDI imaging, as a prognostic marker. HER2 amplification, which was detected by FISH, is a stratifier between good and poor patient prognosis. By integrating both stratification parameters on the basis of our combined approach, we were able to strikingly improve the prognostic effect. Combining molecules detected by MALDI imaging with the gene copy number detected by HER2/CEP17 FISH, we found a synergistic effect, which enhances patient prognosis. This study shows that our combined approach allows the detection of genetic and metabolic properties from one very same FFPE tissue section, which are specific for HER2 and hence suitable for prognosis. Furthermore, this synergism might be useful for response prediction in tumors.

Towards Circulating-Tumor DNA-Based Precision Medicine

In the era of precision medicine, targeted therapies have been implemented for various diseases. Genomic information guides decision-making in cancer treatment. The improvements in next-generation sequencing and polymerase chain reaction have made it possible to access the genetic information using circulating-tumor DNAs (ctDNAs). Molecular characteristics of individual tumors can be obtained by analysis of ctDNAs, thus making them excellent tools to guide decision-making during treatment. In oncology, the use of ctDNAs in clinical practice is now gaining importance. Molecular analysis of ctDNAs has potential for multiple clinical applications, including early diagnosis, prognosis of disease, prognostic and/or predictive biomarkers, and monitoring response to therapy and clonal evolution. In this paper, we highlight the applications of ctDNAs in cancer management, especially in metastatic setting, and summarize recent studies about the use of ctDNAs as predictive biomarkers for the therapeutic adaptation/response in lung cancer, breast cancer, and colorectal cancer. These studies offer the evidence to use ctDNAs as a promising approach to solve unmet clinical needs.

Somatic mutation of DNAH genes implicated higher chemotherapy response rate in gastric adenocarcinoma patients

Background

The dynein axonemal heavy chain (DNAH) family of genes encode the dynein axonemal heavy chain, which is involved in cell motility. Genomic variations of DNAH family members have been frequently reported in diverse kinds of malignant tumors. In this study, we analyzed the genomic database to evaluate the mutation status of DNAH genes in gastric adenocarcinoma and further identified the significance of mutant DNAH genes as effective molecular biomarkers for predicting chemotherapy response in gastric cancer patients.

Methods

We analyzed the clinical and genomic data of gastric cancer patients published in The Cancer Genome Atlas (TCGA) project. Data on chemotherapy response, overall survival (OS) and chemotherapy-free survival were retrieved. Then, we verified the results via targeted sequencing of gastric cancer patients with similar clinical characteristics but different chemotherapeutic outcomes.

Results

In total, 132 gastric adenocarcinoma patients undergoing chemotherapy treatment from TCGA were included in our study. Somatic mutations in all 13 members of the DNAH family of genes were associated with different chemotherapy responses. Compared with patients with wild-type DNAH genes (n = 59), a significantly higher proportion of those with mutations in DNAH genes (n = 73) (55.9% vs 80.8%) responded to chemotherapy (P = 0.002). Moreover, DNAH mutations were correlated with significantly better OS (P = 0.027), chemotherapy-free survival (P = 0.027), fluoropyrimidine-free survival (P = 0.048) and platinum-free survival (P = 0.014). DNAH mutation status was an independent risk factor for OS (P = 0.015), chemotherapy-free survival (P = 0.015) and platinum-free survival (P = 0.011). We identified somatic mutations in 27 (42.2%) of the 64 stage III gastric adenocarcinoma patients receiving fluoropyrimidine-based chemotherapy by targeted exon sequencing with strict screening conditions. In our own cohort, a significantly higher proportion of patients (n = 32) with DNAH mutations than patients with wild-type DNAH genes (n = 32) had a good prognosis (OS > 48 months) (70.4% vs 35.1%) (P = 0.005).

Conclusions

Dynein axonemal heavy chain gene mutations contribute positively to chemotherapy sensitivity in gastric cancer patients.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1867-6) contains supplementary material, which is available to authorized users.

Genomic markers of resistance to targeted treatments in gastric cancer: potential new treatment strategies

Gastric cancer is a highly heterogeneous disease, displaying a complex genomic landscape and an unfavorable outcome with standard therapies. Based on distinctive genomic alterations, novel targeted agents have been developed with the aim of personalizing treatments and improving patient outcome. However, a subgroup of patients is primarily treatment-resistant, and even in the initially sensitive population, secondary resistance emerges, thus limiting therapeutic benefit. In this review, we summarize the clinical data about standard targeted agents in gastric cancer, specifically anti-HER2 treatments and antivascular therapies. We also illustrate the available evidence regarding molecular mechanisms of resistance to these agents and we discuss potential strategies for new targeted treatments that could overcome such resistance.

Label-Free Quantitative Proteomics Combined with Biological Validation Reveals Activation of Wnt/β-Catenin Pathway Contributing to Trastuzumab Resistance in Gastric Cancer

Resistance to trastuzumab, which specifically target HER2-positive breast and gastric cancer, can develop ultimately in cancer patients. However, the underlying mechanisms of resistance in gastric cancer have not been fully elucidated. Here, we established trastuzumab-resistant MKN45 and NCI N87 gastric cancer sublines from their parental cells. The resistant cells exhibited characteristics of epithelial-mesenchymal transition (EMT) and acquired higher migratory and invasive capacities. To exploit the activated pathways and develop new strategies to overcome trastuzumab resistance, we investigated MKN45 and MKN45/R cells via label-free quantitative proteomics, and found pathways that were altered significantly in MKN45/R cells, with the Wnt/β-catenin pathway being the most significant. We further confirmed the activation of this pathway by detecting its key molecules in MKN45/R and NCI N87/R cells via Western blot, in which Wnt3A, FZD6, and CTNNB1 increased, whereas GSK-3β decreased, manifesting the activation of the Wnt/β-catenin pathway. Correspondingly, inhibition of Wnt/β-catenin pathway by ICG-001, a specific Wnt/β-catenin inhibitor, preferentially reduced proliferation and invasion of trastuzumab-resistant cells and reversed EMT. Concurringly, CTNNB1 knockdown in stable cell lines potently sensitized cells to trastuzumab and induced more apoptosis. Taken together, our study demonstrates that the Wnt/β-catenin pathway mediates trastuzumab resistance, and the combination of Wnt/β-catenin inhibitors with trastuzumab may be an effective treatment option.

Efficacy prediction of targeted therapy for gastric cancer: The current status (Review)

Despite significant progress in the treatment of gastric cancer (GC), the prognosis remains poor and the mortality is high. Targeted drugs have been incorporated into routine treatment to improve treatment efficacy. However, the therapy response is still below 50%. Therefore, there is a need to identify predictive factors for patient response to a specific drug in order to improve the efficacy of drug therapy. The present article reviewed the predictive factors for target therapy in GC, including epidermal growth factor receptor, human epidermal receptor 2, vascular endothelial growth factor family, molecules in the mesenchymal‑epithelial transition pathway and the mammalian target of rapamycin. Additionally, the present review described the interactions between these molecules and signaling pathways.

RUNX1 positively regulates the ErbB2/HER2 signaling pathway through modulating SOS1 expression in gastric cancer cells

The dual function of runt-related transcriptional factor 1 (RUNX1) as an oncogene or oncosuppressor has been extensively studied in various malignancies, yet its role in gastric cancer remains elusive. Up-regulation of the ErbB2/HER2 signaling pathway is frequently-encountered in gastric cancer and contributes to the maintenance of these cancer cells. This signaling cascade is partly mediated by son of sevenless homolog (SOS) family, which function as adaptor proteins in the RTK cascades. Herein we report that RUNX1 regulates the ErbB2/HER2 signaling pathway in gastric cancer cells through transactivating SOS1 expression, rendering itself an ideal target in anti-tumor strategy toward this cancer. Mechanistically, RUNX1 interacts with the RUNX1 binding DNA sequence located in SOS1 promoter and positively regulates it. Knockdown of RUNX1 led to the decreased expression of SOS1 as well as dephosphorylation of ErbB2/HER2, subsequently suppressed the proliferation of gastric cancer cells. We also found that our novel RUNX inhibitor (Chb-M’) consistently led to the deactivation of the ErbB2/HER2 signaling pathway and was effective against several gastric cancer cell lines. Taken together, our work identified a novel interaction of RUNX1 and the ErbB2/HER2 signaling pathway in gastric cancer, which can potentially be exploited in the management of this malignancy.

Efficacy of trastuzumab beyond progression in HER2 positive advanced gastric cancer: a multicenter prospective observational cohort study

Introduction

Trastuzumab plus chemotherapy is the standard first-line regimen in HER2 positive advanced gastric cancer (AGC), but lack of data in post-progression treatment. So, it is worth evaluating the efficacy of continuing trastuzumab after failure of the first-line trastuzumab based treatment.

Methods

59 patients were enrolled from Zhongshan Hospital Fudan University, Sun Yat-sen University Cancer Center and Peking University Cancer Hospital between September 2012 and Oct 2015. Patients were divided into two groups according to the second line regimens: with or without trastuzumab. The primary endpoint was progression free survival of second line therapy (PFS2). Secondary end points included overall survival (OS), response rate, and adverse events (AEs).

Results

Baseline factors were well balanced between two groups. 32 patients treated with trastuzumab plus second line chemotherapy (group A) and 27 patients received chemotherapy alone (group B). The median follow-up time was 7.60 months (range 1.50-32.50). Longer median PFS2 was observed in group A than in group B (3.1 vs 2.0 months, P=0.008). There was no significant differences of median OS2 calculating from the second line therapy (10.5 vs 6.5 months, P=0.172) between two groups. Response rate was 9.3% in group A compared with 3.7% in group B (P=0.617). AEs were similar in two groups including cardiac safety. Subgroup analysis showed that factors of male, age<65, good performance status, HER2 immunohistochemical (IHC) 2+ and poor response to first line indicated superior PFS2 in patients continuing trastuzumab to those treated with chemotherapy alone.

Conclusion

Continuing treatment of trastuzumab beyond first line therapy progression showed effective and safe in AGC.

PTEN loss and level of HER2 amplification is associated with trastuzumab resistance and prognosis in HER2-positive gastric cancer

Background

Trastuzumab is an active agent against human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). This study aimed to characterize resistance to trastuzumab-based front-line chemotherapy in HER2+ GC patients and to establish factors predictive of this resistance.

Results

Among 129 HER2+ GC patients, 25% displayed rapid disease progression within 4 months from initiation of therapy. These patients showed a higher rate of signet ring cell histology, bone metastasis, poor performance status, frequent loss of PTEN expression, and low HER2 amplification index compared with patients who were progression-free for at least 4 months. In contrast, there was no significant difference in the frequency of the PIK3R1 variant. Multivariate analyses confirmed two independent molecular predictors for trastuzumab resistance: loss of PTEN expression and low HER2 amplification index (<5). Patients with one or both molecular predictors at diagnosis exhibited worse progression-free and overall survival compared to those without risk factors (p < 0.001 and p = 0.001, respectively).

Conclusion

In HER2+ GC patients, loss of PTEN expression and low HER2 AI correlated with resistance to trastuzumab-based therapy and dismal prognosis. Since patients harboring these molecular predictors are unlikely to respond to trastuzumab-based therapy, other novel therapeutic targets needed to be considered.

Methods

HER2+ GC patients who were treated with trastuzumab in combination with either 5-fluorouracil/cisplatin or capecitabine/cisplatin were enrolled. Clinicopathologic features and molecular alterations of HER2, phosphoinositide 3-kinase regulatory subunit 1 (PIK3R1), and phosphatase and tensin homolog (PTEN) were correlated with treatment outcome. Factors predictive of resistance were also explored.

Pharmacological inhibition of DUSP6 suppresses gastric cancer growth and metastasis and overcomes cisplatin resistance

Gastric cancer (GC) is the second cause of cancer-related death. Cisplatin (CDDP) is widely used as the standard GC treatment, but relapse and metastasis are common because of intrinsic or acquired drug resistance. The mitogen-activated protein kinase phosphatases (MAPK)-extracellular signal regulated kinases (ERK) pathway contributes to GC progression and drug resistance, but targeting the MAPK-ERK pathway is challenging in GC therapy. Here, we demonstrated that dual-specificity phosphatases 6 (DUSP6) was overexpressed in GC and predicted poor overall survival and progression-free survival. Knockdown DUSP6 inhibited GC proliferation, migration, invasion and induced apoptosis. (E/Z)-BCI hydrochloride (BCI), a DUSP6 small molecule inhibitor, increased the activity of ERK but interestingly decreased the expression of ERK response genes in BGC823, SGC7901 and CDDP-resistant SGC7901/DDP cells. BCI also caused cell death through the DNA damage response (DDR) pathway. Moreover, BCI inhibited cell proliferation, migration and invasion in a receptor-independent manner and enhanced CDDP cytotoxicity at pharmacological concentrations in the GC cells. In vivo experiments further showed that BCI enhances the antitumor effects of CDDP in cell-based xenografts and PDX models. In summary, our findings indicated that disruption of DUSP6 by BCI enhanced CDDP-induced cell death and apoptosis in GC may partly through ERK and DDR pathways. Thus, this study suggests that DUSP6 is a potential prognostic biomarker and a promising target for GC therapy.

Down-regulation of HECTD3 by HER2 inhibition makes serous ovarian cancer cells sensitive to platinum treatment

Resistance to platinum-based chemotherapy is a major cause of treatment failure in patients with epithelial ovarian cancer and predicts a poor prognosis. Previously, we found that HECTD3 confers cancer cell resistance to apoptosis. However, the significance of HECTD3 expression in ovarian cancer and its regulatory mechanisms were unknown. Here, we found that HECTD3 depletion promotes carboplatin-induced apoptosis in both an ovarian cancer cell model and a xenograft mouse model. Moreover, high HECTD3 expression is significantly associated with poor platinum response and prognosis in ovarian cancer patients. We further demonstrated that HER2 can up-regulate HECTD3 expression through activating STAT3. Furthermore, HER2 inhibitors, such as lapatinib, down-regulate HECTD3 expression and thus promote the chemosensitivity of ovarian cancer cells to carboplatin. Lapatinib combined with carboplatin also significantly inhibits serous ovarian carcinoma growth compared with each drug alone in a xenograft mouse model. HECTD3 may be considered a promising molecular predictor of platinum chemosensitivity and prognosis for serous ovarian cancer. Through decreasing HECTD3, lapatinib possesses significantly increased anti-tumor activity when combined with carboplatin compared with each agent alone, which provides an optional therapeutic regimen for serous ovarian cancer.

Diagnostic, Predictive, Prognostic, and Therapeutic Molecular Biomarkers in Third Millennium: A Breakthrough in Gastric Cancer

Introduction

Gastric cancer is the fifth most common cancer and the third cause of cancer death. The clinical outcomes of the patients are still not encouraging with a low rate of 5 years' survival. Often the disease is diagnosed at advanced stages and this obviously negatively affects patients outcomes. A deep understanding of molecular basis of gastric cancer can lead to the identification of diagnostic, predictive, prognostic, and therapeutic biomarkers.

Main Body

This paper aims to give a global view on the molecular classification and mechanisms involved in the development of the tumour and on the biomarkers for gastric cancer. We discuss the role of E-cadherin, HER2, fibroblast growth factor receptor (FGFR), MET, human epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (HGFR), mammalian target of rapamycin (mTOR), microsatellite instability (MSI), PD-L1, and TP53. We have also considered in this manuscript new emerging biomarkers as matrix metalloproteases (MMPs), microRNAs, and long noncoding RNAs (lncRNAs).

Conclusions

Identifying and validating diagnostic, prognostic, predictive, and therapeutic biomarkers will have a huge impact on patients outcomes as they will allow early detection of tumours and also guide the choice of a targeted therapy based on specific molecular features of the cancer.

Quantitative proteomics profiling reveals activation of mTOR pathway in trastuzumab resistance

Trastuzumab is an antibody-based therapy drug targeting HER2-overexpressing tumors. While it has been proven to be very successful initially, most patients eventually develop resistance to trastuzumab. The mechanism of drug resistance is not well understood. Identifying pathways that mediate trastuzumab resistance will improve our understanding of the underlying mechanism and is crucial for the development of therapeutic strategies to overcome resistance.Here we report a quantitative proteomics profiling of a trastuzumab-sensitive (T-S) gastric cancer cell line NCI N87 and a trastuzumab-resistant NCI N87 (T-R) subline generated by low-dose, continuous trastuzumab treatment. By identifying proteins differentially expressed in these two cell lines, we show that multiple pathways including mTOR, Wnt, DNA damage response and metabolic pathways are significantly altered. We further confirm by western blotting that protein levels of multiple components of the mTOR pathway, including mTOR, AKT and RPS6KB1, are increased, whereas AKT1S1 is decreased, suggesting the activation of mTOR pathway. Importantly, treatment of AZD8055, an mTOR inhibitor, leads to the decreased phosphorylation levels of mTOR downstream molecules RPS6KB1 at Thr421/Ser424 and AKT at Ser473. Furthermore, AZD8055 also preferentially reduces viability, and inhibits migration and invasion abilities of the T-R cells. Together, our findings indicate that mTOR pathway is among multiple signaling pathways that mediate trastuzumab resistance in NCI N87 T-R cells, and that mTOR inhibitors may be used to treat trastuzumab resistant, HER2-positive gastric cancer tumors.

Targeting c-MET in gastrointestinal tumours: rationale, opportunities and challenges

Data from many preclinical studies, including those using cellular models of colorectal, gastric, gastro-oesophageal and gastro-oesophageal junction cancers, indicate that the hepatocyte growth factor (HGF)-hepatocyte growth factor receptor (c-MET) pathway is vital for the growth, survival and invasive potential of gastrointestinal cancers. Following the availability of data from these various studies, and data on c-MET expression as a biomarker that indicates a poor prognosis in patients with gastrointestinal cancer and increased c-MET expression, inhibitors targeting this pathway have entered the clinic in the past decade. However, the design of clinical trials that incorporate the use of HGF/c-MET inhibitors in their most appropriate genetic and molecular context remains crucial. Recognizing and responding to this challenge, the European Commission funded Framework 7 MErCuRIC programme is running a biomarker-enriched clinical trial investigating the efficacy of combined c-MET/MEK inhibition in patients with RAS-mutant or RAS-wild-type metastatic colorectal cancer with aberrant c-MET expression. The design of this trial enables the continued refinement of the predictive biomarker and co-development of companion diagnostics. In this Review, we focus on advances in our understanding of inhibition of the HGF/c-MET pathway in patients with gastro-intestinal cancers, the prominent challenges facing the clinical translation and implementation of agents targeting HGF/c-MET, and discuss the various efforts, and associated obstacles to the discovery and validation of biomarkers that will enable patient stratification in this context.

DDX5 promotes gastric cancer cell proliferation in vitro and in vivo through mTOR signaling pathway

DEAD (Asp-Glu-Ala-Asp) box helicase 5 (DDX5) is an ATP-dependent RNA helicase that is overexpressed in various malignancies. Increasing evidence suggests that DDX5 participates in carcinogenesis and cancer progression via promoting cell proliferation and metastasis. However, the functional role of DDX5 in gastric cancer is largely unknown. In this study, we observed that DDX5 was significantly up-regulated in gastric cancer tissues compared with the paired adjacent normal tissues. The expression of DDX5 correlated strongly with Ki67 index and pathological stage of gastric cancer. In vitro and in vivo studies suggested that knockdown of DDX5 inhibited gastric cancer cell proliferation, colony formation and xenografts growth, whereas ectopic expression of DDX5 promoted these cellular functions. Mechanically, DDX5 induced gastric cancer cell growth by activating mTOR/S6K1. Treatment of everolimus, the specific mTOR inhibitor, significantly attenuated DDX5-mediated cell proliferation. Interestingly, the expression of DDX5 and p-mTOR in gastric cancer tissues demonstrated a positive correlation. Taken together, these results revealed a novel role of DDX5 in gastric cancer cell proliferation via the mTOR pathway. Therefore, DDX5 may serve as a therapeutic target in gastric cancer.

Molecular Mechanisms and Translational Therapies for Human Epidermal Receptor 2 Positive Breast Cancer

Breast cancer is the second leading cause of cancer death among women. Human epidermal receptor 2 (HER2) positive breast cancer (HER2+ BC) is the most aggressive subtype of breast cancer, with poor prognosis and a high rate of recurrence. About one third of breast cancer is HER2+ BC with significantly high expression level of HER2 protein compared to other subtypes. Therefore, HER2 is an important biomarker and an ideal target for developing therapeutic strategies for the treatment HER2+ BC. In this review, HER2 structure and physiological and pathological roles in HER2+ BC are discussed. Two diagnostic tests, immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH), for evaluating HER2 expression levels are briefly introduced. The current mainstay targeted therapies for HER2+ BC include monoclonal antibodies, small molecule tyrosine kinase inhibitors, antibody-drug conjugates (ADC) and other emerging anti-HER2 agents. In clinical practice, combination therapies are commonly adopted in order to achieve synergistic drug response. This review will help to better understand the molecular mechanism of HER2+ BC and further facilitate the development of more effective therapeutic strategies against HER2+ BC.

MiR-16 mediates trastuzumab and lapatinib response in ErbB-2-positive breast and gastric cancer via its novel targets CCNJ and FUBP1

ErbB-2 amplification/overexpression accounts for an aggressive breast cancer (BC) subtype (ErbB-2-positive). Enhanced ErbB-2 expression was also found in gastric cancer (GC) and has been correlated with poor clinical outcome. The ErbB-2-targeted therapies trastuzumab (TZ), a monoclonal antibody, and lapatinib, a tyrosine kinase inhibitor, have proved highly beneficial. However, resistance to such therapies remains a major clinical challenge. We here revealed a novel mechanism underlying the antiproliferative effects of both agents in ErbB-2-positive BC and GC. TZ and lapatinib ability to block extracellular signal-regulated kinases 1/2 and phosphatidylinositol-3 kinase (PI3K)/AKT in sensitive cells inhibits c-Myc activation, which results in upregulation of miR-16. Forced expression of miR-16 inhibited in vitro proliferation in BC and GC cells, both sensitive and resistant to TZ and lapatinib, as well as in a preclinical BC model resistant to these agents. This reveals miR-16 role as tumor suppressor in ErbB-2-positive BC and GC. Using genome-wide expression studies and miRNA target prediction algorithms, we identified cyclin J and far upstream element-binding protein 1 (FUBP1) as novel miR-16 targets, which mediate miR-16 antiproliferative effects. Supporting the clinical relevance of our results, we found that high levels of miR-16 and low or null FUBP1 expression correlate with TZ response in ErbB-2-positive primary BCs. These findings highlight a potential role of miR-16 and FUBP1 as biomarkers of sensitivity to TZ therapy. Furthermore, we revealed miR-16 as an innovative therapeutic agent for TZ- and lapatinib-resistant ErbB-2-positive BC and GC.

Gastric biomarkers: a global review

BACKGROUND

Gastric cancer is an aggressive disease with a poor 5-year survival and large global burden of disease. The disease is biologically and genetically heterogeneous with a poorly understood carcinogenesis at the molecular level. Despite the many prognostic, predictive, and therapeutic biomarkers investigated to date, gastric cancer continues to be detected at an advanced stage with resultant poor clinical outcomes.

MAIN BODY

This is a global review of gastric biomarkers with an emphasis on HER2, E-cadherin, fibroblast growth factor receptor, mammalian target of rapamycin, and hepatocyte growth factor receptor as well as sections on microRNAs, long noncoding RNAs, matrix metalloproteinases, PD-L1, TP53, and microsatellite instability.

CONCLUSION

A deeper understanding of the pathogenesis and biological features of gastric cancer, including the identification and characterization of diagnostic, prognostic, predictive, and therapeutic biomarkers, hopefully will provide improved clinical outcomes.

Evaluation of a trastuzumab-containing treatment regimen for patients with unresectable advanced or recurrent gastric cancer

The present study aimed to evaluate the efficacy and safety of trastuzumab plus chemotherapy for patients with unresectable advanced or recurrent gastric cancer. A retrospective analysis of 213 patients with unresectable advanced or recurrent gastric cancer who received systemic chemotherapy, including 15 patients who were also administered trastuzumab, at Kochi Medical School between 2007 and 2013 was performed. The overall survival was compared between patients who received trastuzumab plus chemotherapy and patients who received chemotherapy alone, and the safety and efficacy of the trastuzumab-containing regimen was evaluated. Human epidermal growth factor receptor (HER)2 status was examined in 86 patients, of whom 15 (17.4%) exhibited strong positive HER2 expression. The rate of strong positive HER2 expression was significantly higher for intestinal type tumors compared with diffuse type tumors [23.6 (13/55) vs. 6.5% (2/31); P=0.044]. The median overall survival of the patients treated with trastuzumab was significantly longer compared with that for patients who were not treated with trastuzumab (22.9 vs. 11.6 months; P=0.014). The objective response rate and disease control rate for trastuzumab plus chemotherapy were 46.7 and 86.7%, respectively. Frequently encountered grade 3-4 toxicities included neutropenia (26.7%; 4/15), anemia (13.3%; 2/15) and fatigue (13.3%; 2/15). Trastuzumab plus chemotherapy is effective for patients with HER2-positive advanced or recurrent gastric cancer, and the frequencies of hematological and non-hematological toxicities experienced by patients in the present study indicated that it can be safely administered clinically.

Stat3 regulates ErbB-2 expression and co-opts ErbB-2 nuclear function to induce miR-21 expression, PDCD4 downregulation and breast cancer metastasis

Membrane overexpression of the receptor tyrosine kinase ErbB-2 (MErbB-2) accounts for a clinically aggressive breast cancer (BC) subtype (ErbB-2-positive) with increased incidence of metastases. We and others demonstrated that nuclear ErbB-2 (NErbB-2) also plays a key role in BC and is a poor prognostic factor in ErbB-2-positive tumors. The signal transducer and activator of transcription 3 (Stat3), another player in BC, has been recognized as a downstream mediator of MErbB-2 action in BC metastasis. Here, we revealed an unanticipated novel direction of the ErbB-2 and Stat3 interaction underlying BC metastasis. We found that Stat3 binds to its response elements (GAS) at the ErbB-2 promoter to upregulate ErbB-2 transcription in metastatic, ErbB-2-positive BC. We validated these results in several BC subtypes displaying metastatic and non-metastatic ability, highlighting Stat3 general role as upstream regulator of ErbB-2 expression in BC. Moreover, we showed that Stat3 co-opts NErbB-2 function by recruiting ErbB-2 as its coactivator at the GAS sites in the promoter of microRNA-21 (miR-21), a metastasis-promoting microRNA (miRNA). Using an ErbB-2 nuclear localization domain mutant and a constitutively activated ErbB-2 variant, we found that NErbB-2 role as a Stat3 coactivator and also its direct role as transcription factor upregulate miR-21 in BC. This reveals a novel function of NErbB-2 as a regulator of miRNAs expression. Increased levels of miR-21, in turn, downregulate the expression of the metastasis-suppressor protein programmed cell death 4 (PDCD4), a validated miR-21 target. Using an in vivo model of metastatic ErbB-2-postive BC, in which we silenced Stat3 and reconstituted ErbB-2 or miR-21 expression, we showed that both are downstream mediators of Stat3-driven metastasis. Supporting the clinical relevance of our results, we found an inverse correlation between ErbB-2/Stat3 nuclear co-expression and PDCD4 expression in ErbB-2-positive primary invasive BCs. Our findings identify Stat3 and NErbB-2 as novel therapeutic targets to inhibit ErbB-2-positive BC metastasis.

Septin oligomerization regulates persistent expression of ErbB2/HER2 in gastric cancer cells

Septins are a family of cytoskeletal GTP-binding proteins that assemble into membrane-associated hetero-oligomers and organize scaffolds for recruitment of cytosolic proteins or stabilization of membrane proteins. Septins have been implicated in a diverse range of cancers, including gastric cancer, but the underlying mechanisms remain unclear. The hypothesis tested here is that septins contribute to cancer by stabilizing the receptor tyrosine kinase ErbB2, an important target for cancer treatment. Septins and ErbB2 were highly over-expressed in gastric cancer cells. Immunoprecipitation followed by MS analysis identified ErbB2 as a septin-interacting protein. Knockdown of septin-2 or cell exposure to forchlorfenuron (FCF), a well-established inhibitor of septin oligomerization, decreased surface and total levels of ErbB2. These treatments had no effect on epidermal growth factor receptor (EGFR), emphasizing the specificity and functionality of the septin-ErbB2 interaction. The level of ubiquitylated ErbB2 at the plasma membrane was elevated in cells treated with FCF, which was accompanied by a decrease in co-localization of ErbB2 with septins at the membrane. Cathepsin B inhibitor, but not bafilomycin or lactacystin, prevented FCF-induced decrease in total ErbB2 by increasing accumulation of ubiquitylated ErbB2 in lysosomes. Therefore, septins protect ErbB2 from ubiquitylation, endocytosis and lysosomal degradation. The FCF-induced degradation pathway is distinct from and additive with the degradation induced by inhibiting ErbB2 chaperone Hsp90. These results identify septins as novel regulators of ErbB2 expression that contribute to the remarkable stabilization of the receptor at the plasma membrane of cancer cells and may provide a basis for the development of new ErbB2-targeting anti-cancer therapies.

Acquisition of resistance to trastuzumab in gastric cancer cells is associated with activation of IL-6/STAT3/Jagged-1/Notch positive feedback loop

In the present study, we demonstrate that prolonged treatment by trastuzumab induced resistance of NCI-N87 gastric cancer cells to trastuzumab. The resistant cells possessed typical characteristics of epithelial to mesenchymal transition (EMT)/cancer stem cells and acquired more invasive and metastatic potentials both in vitro and in vivo. Long term treatment with trastuzumab dramatically inhibited the phosphorylation of Akt, but triggered the activation of STAT3. The level of IL-6 was remarkably increased, implicating that the release of IL-6 that drives the STAT3 activation initiates the survival signaling transition. Furthermore, the Notch activities were significantly enhanced in the resistant cells, companied by upregulation of the Notch ligand Jagged-1 and the Notch responsive genes Hey1 and Hey2. Inhibiting the endogenous Notch pathway reduced the IL-6 expression and restored the sensitivities of the resistant cells to trastuzumab. Blocking of the STAT3 signaling abrogated IL-6-induced Jagged-1 expression, effectively inhibited the growth of the trastuzumab resistant cells, and enhanced the anti-tumor activities of trastuzumab in the resistant cells. These findings implicate that the IL-6/STAT3/Jagged-1/Notch axis may be a useful target and that combination of the Notch or STAT3 inhibitors with trastuzumab may prevent or delay clinical resistance and improve the efficacy of trastuzumab in gastric cancer.

WASF3 provides the conduit to facilitate invasion and metastasis in breast cancer cells through HER2/HER3 signaling

The WASF3 gene is overexpressed in high-grade breast cancer and promotes invasion and metastasis but does not affect proliferation. The HER2/ERBB2/NEU gene is also frequently overexpressed in breast cancer and has been shown to promote invasion and metastasis in these tumors. Here we show that WASF3 in present in the HER2 immunocomplex and suppression of WASF3 function leads to suppression of invasion even in the presence of HER2 expression. Overexpression of both HER2 and WASF3 in non-metastatic MCF7 breast cancer cells promotes invasion and metastasis more significantly than either gene alone. HER2 forms homodimers as well as heterodimers with other HER family members and we now show that the ability of WASF3 to promote invasion is highly dependent on the HER2/HER3 heterodimer. The engagement of WASF3 with the HER2/HER3 complex facilitates its phospho-activation and transcriptional upregulation, which is facilitated by HER2/HER3 activation of JAK/STAT signaling. In breast cancer cells overexpressing HER2, therefore, WASF3 is specifically required to facilitate the invasion/metastasis response. Targeting WASF3, therefore, could be a potential therapeutic approach to suppress metastasis of HER2-overexpressing breast tumors.

A Novel Scoring System Based on Fibrinogen and the Neutrophil-Lymphocyte Ratio as a Predictor of Chemotherapy Response and Prognosis in Patients with Advanced Gastric Cancer

<b><i>Objective:</i></b> We assessed the clinical applicability of the F-NLR score, which is based on fibrinogen (F) and the neutrophil-lymphocyte ratio (NLR), and the Glasgow Prognostic Score (GPS) to predict the therapeutic effects of chemotherapy or chemoradiotherapy on advanced gastric cancer and the prognoses of patients. <b><i>Methods:</i></b> Sixty-eight patients with advanced gastric cancer treated with first-line chemotherapy or chemoradiotherapy were classified into two groups based on tumor response. Furthermore, we categorized patients according to cutoff F-NLR scores of 2 [hyperfibrinogenemia (>400 mg/dl) and high NLR (>3.0)], 1 [one of these hematological abnormalities], and 0 [neither hyperfibrinogenemia nor high NLR]. <b><i>Results:</i></b> A total of 27 patients had progressive disease (PD) and 41 did not. The F-NLR scores were significantly higher in the PD than in the non-PD group (p = 0.003). Survival was significantly shorter for patients with high F-NLR scores and GPS (p = 0.0071 and p = 0.0065, respectively). Multivariate analysis selected the F-NLR score as an independent prognostic factor (p = 0.017). <b><i>Conclusion:</i></b> A novel grading system based on F-NLR scores, as well as the GPS, appears to have value as a clinical predictor of the therapeutic response of advanced gastric cancer to chemotherapy or chemoradiotherapy and the prognoses of patients.

Clinical Perspectives on Targeting Therapies for Personalized Medicine

Expected benefits from new technology include more efficient patient selection for clinical trials, more cost-effective treatment pathways for patients and health services and a more profitable accelerated approach for drug developers. Regulatory authorities expect the pharmaceutical and biotechnology industries to accelerate their development of companion diagnostics and companion therapeutics toward the goal of safer and more effective personalized medicine, and expect health services to fund and prescribers to adopt these new therapeutic technologies.

This review discusses the importance of a range of new approaches to developing new and reprofiled medicines to treat common and serious diseases, and rare diseases: new network pharmacology approaches, adaptive trial designs with enriched populations more likely to respond safely to treatment, as assessed by companion diagnostics for response and toxicity risk and use of “real world” data.

Case studies are described of single and multiple protein drug targets in several important therapeutic areas. These case studies also illustrate the value and complexity of use of selective biomarkers of clinical response and risk of adverse drug effects, either singly or in combination.

Trastuzumab Inhibits Growth of HER2-Negative Gastric Cancer Cells Through Gastrin-Initialized CCKBR Signaling

BACKGROUND

Administration of trastuzumab, a fully humanized monoclonal antibody targeted to the human epidermal growth factor receptor 2 (HER2, p185), has improved outcomes for patients with HER2-positive gastric cancer (GC), but some relevant issues remain to be investigated and will emerge with new anti-GC drugs. Gastrin is a major gastrointestinal hormone proven to have an inhibitory effect on GC in vitro and in vivo.

AIM

To explore the sympathetic role of trastuzumab and gastrin on inhibition of GC.

METHODS

The HER2-positive and HER2-negative GC cell lines were treated with trastuzumab, gastrin, or their combination in vitro and in xenograft model. The synergistical role of trastuzumab and gastrin and related mechanisms were investigated.

RESULTS

We found the synergistic inhibitory effects of trastuzumab and gastrin on HER2-negative GC cells through the gastrin/cholecystokinin B receptor (CCKBR) pathway. Trastuzumab upregulated CCKBR protein levels but could not initiate its signal transduction, whereas gastrin increased the levels and activation of CCKBR. Molecular experiments indicated that trastuzumab and gastrin co-treatment synergistically enhanced the stability of CCKBR. Moreover, their combined treatment synergistically arrested GC cells at G0/G1 phase, down-regulated levels of GC-related proteins, including anion exchanger 1 (AE1), cyclin D1, β-catenin, and cytoplasmic p16, and promoted nuclear translocation of p16. In addition, combination treatment upregulated AE2 levels, which are reduced in GC tissues. The in vivo synergistic anti-GC effect of combined treatment was confirmed in xenograft experiments.

CONCLUSIONS

Trastuzumab plus gastrin inhibit growth of Her2-negative GC by targeting cytoplasmic AE1 and p16.

Droplet digital polymerase chain reaction detection of HER2 amplification in formalin fixed paraffin embedded breast and gastric carcinoma samples

RATIONALE

Human epidermal growth factor receptor 2 (HER2) is a key driver of tumorigenesis, and over-expression as a result of HER2 gene amplification has been observed in a number of solid tumors. Recently HER2 has become an important biomarker for the monoclonal antibody treatment of HER2-positive metastatic breast and advanced gastric cancer. The HER2 targeting antibody trastuzumab treatment requires accurate measurement of HER2 levels for proper diagnosis. Droplet digital PCR (ddPCR) with highly direct, precise and absolute nucleic acid quantification could be used to detect HER2 amplification levels.

OBJECTIVES

Our objective was to evaluate a robust, accurate and less subjective application of ddPCR for HER2 amplification levels and test the assay performance in clinical formalin-fixed paraffin-embedded (FFPE) breast and gastric carcinoma samples.

METHODS

Genomic DNA from HER2 amplified cell line SK-BR-3 was used to set up the ddPCR assays. The copy number of HER2 was compared to the chromosome 17 centromere reference gene (CEP17), expressed as HER2:CEP17 ratio. Genomic DNAs of FFPE specimens from 145 Asian patients with breast and gastric carcinomas were assayed using both standard methods, immunohistochemistry (IHC) and/or fluorescence in situ hybridization (FISH), and ddPCR.

RESULTS

Based on 145 clinical breast and gastric carcinoma cases, our study demonstrated a high concordance of ddPCR results to FISH and IHC. In breast cancer specimens, the ddPCR results had high concordance with FISH and IHC defined HER2 status with a sensitivity of 90.9% (30/33) and a specificity of 100% (77/77). In gastric cancer specimens that were concordant in both FISH and IHC, our assay was 95.5% concordant with FISH and IHC (21/22).

CONCLUSIONS

ddPCR has the advantage of automation and also allows levels of HER2 amplification to be easily evaluated in large numbers of samples, and presents a potential option to define HER2 status.

Predictive value of serum HER2 ECD in patients with HER2-positive advanced gastric cancer treated with trastuzumab plus chemotherapy

BACKGROUND

The levels of serum HER2 extracellular domain (ECD) are highly correlated with tissue HER2 status in metastatic gastric cancer (AGC). We sought to explore whether serum HER2 ECD could predict the efficacy of trastuzumab-treated HER2-positive AGC.

MATERIALS AND METHODS

From 2011 to 2013, trastuzumab-treated AGC patients were enrolled. Serum HER2 ECD was centrally measured by chemiluminescence immunoassays (CLIA) method in available samples at baseline and after two cycles of trastuzumab combined with chemotherapy. The correlation between serum HER2 ECD and overall response rate (ORR) and progression-free survival (PFS) was analyzed.

RESULTS

Sixty-five patients were analyzed with a median age of 58 years (range, 27-80 years). A significant difference of serum HER2 ECD levels was found between patients with HER2 IHC 3+ and those with HER2 IHC 2+ and FISH positive (p = 0.014). There was a significantly better ORR (80.00 vs. 50.00 %, p = 0.017) and PFS (median PFS, 268 vs. 139 days, p = 0.039) for patients with abnormal baseline serum HER2 ECD than for patients with normal serum HER2 ECD. Change in serum HER2 ECD during chemotherapy was significantly correlated with response to chemotherapy (79.17 vs. 51.52 %, p = 0.033) and PFS (median PFS, 303 vs. 147 days, p = 0.005) in patients with HER2-positive tumor tissue.

CONCLUSIONS

Our results support the clinical utility of measuring serum HER2 ECD levels in patients with advanced gastric cancer. Baseline and early changes in serum HER2 ECD could be useful for monitoring clinical outcome in HER2-positive AGC patients receiving trastuzumab-combined chemotherapy.

Nanobodies for targeted treatment of gastric cancer

With the development and application of monoclonal antibody-based targeted therapy drugs in recent years, some achievements have been made in the treatment of gastric cancer; however, because their preparation is relatively complex and expensive, their application is limited. Nanobodies have some advantages over conventional molecular targeted drugs, such as small molecular weight and unique structural features, and provide a new treatment strategy for targeted therapy of gastric cancer. In this paper, we review the nanobodies that have the potential for targeted treatment of gastric cancer.

Review on the Applications and Molecular Mechanisms of Xihuang Pill in Tumor Treatment

Xihuang pill (XH) is a complementary and alternative medicine that has been used in traditional Chinese medicine (TCM) for the treatment of tumors since the 18th century. XH has clinical effects on non-Hodgkin lymphoma, breast cancer, gastric cancer, liver cancer, and bone metastasis. XH can also inhibit the growth of tumor cells and cancer stem cells, prevent tumor invasion and angiogenesis, and regulate the tumor microenvironment. XH is composed of Ru Xiang (olibanum), Mo Yao (Commiphora myrrha), She Xiang (Moschus), and Niu Huang (Calculus bovis). Some of the compounds found in these ingredients exert multiple antitumor effects and may synergize with the other ingredients. We aimed to summarize the clinical applications and molecular mechanisms of XH and its chemical composition. This review will provide potential new strategies and alternative perspectives for tumor treatments and basic research into complementary and alternative medicine.

Engineering of lipid prodrug-based, hyaluronic acid-decorated nanostructured lipid carriers platform for 5-fluorouracil and cisplatin combination gastric cancer therapy

PURPOSE

The first-line chemotherapy treatment protocol for gastric cancer is combination chemotherapy of 5-fluorouracil (5-FU) and cisplatin (CDDP). The aim of this study was to engineer prodrug-based nanostructured lipid carriers (NLC) platform for codelivery of 5-FU and CDDP to enhance therapy and decrease toxicity.

METHODS

First, 5-FU-stearic acid lipid conjugate was synthesized by two steps. Second, 5-FU-stearic acid prodrug and CDDP were loaded in NLC. Finally, hyaluronic acid (HA) was coated onto NLC surface. Average size, zeta potential, and drug loading capacity of NLC were evaluated. Human gastric cancer cell line BGC823 (BGC823 cells) was used for the testing of in vitro cytotoxicity assays. In vivo antitumor activity of NLC was evaluated in mice bearing BGC823 cells model.

RESULTS

HA-coated 5-FU-stearic acid prodrug and CDDP-loaded NLC (HA-FU/C-NLC) showed a synergistic effect in combination therapy and displayed the greatest antitumor activity than all of the free drugs or uncoated NLC in vitro and in vivo.

CONCLUSION

This work reveals that HA-coated NLC could be used as a novel carrier to code-liver 5-FU and CDDP for gastric cancer therapy. HA-FU/C-NLC could be a promising targeted and combinational therapy in nanomedicine.

Immune Therapy in GI Malignancies: A Review

The balance between tumor-promoting and tumor-suppressing immune responses and the difference between them ultimately determine whether a cancer escapes immune recognition mechanisms. Defining the complex relationships between the tumor itself, the tumor environment, and the immune system has been critical in facilitating the development of successful immunotherapies. This review explores the role of oncogenes in inducing cancer-associated inflammation, the local and systemic factors that lead to immune suppression, and immunotherapy approaches to overcome immune privilege.

The advent of precision therapy in gastrointestinal malignancies: Targeting the human epidermal growth factor receptor family in colorectal and esophagogastric cancer

Until recently, systemic therapy for gastrointestinal malignancies was restricted to relatively noncancer-specific cytotoxic chemotherapy. Over the last 15 years targeted therapies have become available, most notably bevacizumab in the case of advanced colorectal cancer. Unfortunately, there are no predictive biomarkers to guide the use of this agent. In this review article, we describe the advent of “Precision Medicine” (in part, the use of patient-specific molecular markers to inform treatment) in gastrointestinal cancers: The use of monoclonal antibodies targeting epidermal growth factor receptor in advanced colorectal cancer, and human epidermal growth factor receptor 2-neu in advanced esophagogastric cancer. In both instances, biomarkers help in selecting appropriate patients for such treatment.

AFP (alpha fetoprotein): who are you in gastrology?

AFP-producing (hepatoid differentiation) gastric cancer (GC) initially reported in 1970 plays an important role in the field of gastrology, which should be distinguished from other solid-type GCs owing to their different biological behavior. This review article aims to summarize the literature related to the role of AFP in gastric cancer and to unveil the underlying mechanism by which AFP-production impacts prognosis of GC patients. The prima facie evidence demonstrated that AFP-producing GC is more aggressive and characterized by a high incidence of venous invasion, lymphatic invasion, and metachronous and synchronous liver metastasis compared with AFP-non producing GC. Furthermore, distant metastasis was frequently observed, leading to a poorer overall prognosis. The underlying molecular mechanism is still obscure and optimal regimen remains undefined well. Nevertheless, our present study advances the knowledge of AFP-producing GC in the field of gastrology. AFP-positivity should be highlighted and an a priori enhancive intervention is needed to improve prognosis in future clinical practice. Personalized medication is strongly suggested.