Targeted therapy for gastric cancer: Current status and future directions (Review)

Claudin18.2-Targeted SPECT/CT Imaging for Gastric Cancer: Preclinical Evaluation and Clinical Translation of the 99mTc-Labeled Nanobody (PHG102) Radiotracer

Claudin18.2 (CLDN18.2) has emerged as a significant target in the treatment of advanced gastric cancer. The screening of patients positive for CLDN18.2 is crucial for the effective application of targeted therapies specific to CLND18.2. In this study, we developed a novel nanobody-based probe, [99mTc]Tc-PHG102, for use in nuclear medicine. We analyzed its radiochemical yield and stability to ensure accurate probe characterization. Additionally, we assessed the probe's affinity and specificity toward the CLDN18.2 target and evaluated its efficacy in the BGC82318.2 xenograft model for SPECT/CT imaging of gastric cancer. The binding of [99mTc]Tc-PHG102 to HEK-293T18.2 and BGC82318.2 cells was notably higher than its binding to HEK-293T18.1, HEK-293T, and BGC823 cells, with bound values of 12.87 ± 1.46%, 6.16 ± 0.34%, 1.25 ± 0.22%, 1.14 ± 0.26%, and 1.32 ± 0.07% AD, respectively. The binding ability of [99mTc]Tc-PHG102 was significantly different between CLDN18.2-positive and negative cells (P < 0.001). Imaging results demonstrated a time-dependent tumor accumulation of the radiotracer. Notably, at 0.5 h postinjection, rapid accumulation was observed with an average tumor uptake of 4.63 ± 0.81% ID/cc (n = 3), resulting in clear tumor visualization. By 1 h postinjection, as [99mTc]Tc-PHG102 was rapidly metabolized, a decrease in uptake by other organs was noted. Preliminary clinical imaging trials further confirmed the safety and effectiveness of the probe, indicating specificity for lesions expressing CLDN18.2 in gastric cancer and favorable in vivo metabolic properties. In conclusion, the nanobody-based probe [99mTc]Tc-PHG102 proves to be a safe and effective tool for detecting CLDN18.2 expression levels in gastric cancer tumors and for screening CLDN18.2-positive patients.

Synthesis, preclinical evaluation and pilot clinical translation of [68Ga]Ga-PMD22, a novel nanobody PET probe targeting CLDN18.2 of gastrointestinal cancer

PURPOSE

Claudin18.2 (CLDN18.2) is a novel target for diagnosis and therapy of gastrointestinal cancer. This study aimed to evaluate the safety and feasibility of a novel CLDN18.2-targeted nanobody, PMD22, labeled with gallium-68 ([68Ga]Ga), for detecting CLDN18.2 expression in patients with gastrointestinal cancer using PET/CT imaging.

METHODS

[68Ga]Ga-PMD22 was synthesized based on the nanobody, and its cell binding properties were assayed. Preclinical pharmacokinetics were determined in CLDN18.2-positive xenografts using microPET/CT. Effective dosimetry of [68Ga]Ga-PMD22 was evaluated in 5 gastrointestinal cancer patients, and PET/CT imaging of [68Ga]Ga-PMD22 and [18F]FDG were performed head-to-head in 16 gastrointestinal cancer patients. Pathological tissues were obtained for CLDN18.2 immunohistochemical (IHC) staining and comparative analysis with PET/CT findings.

RESULTS

Cell binding assay showed that [68Ga]Ga-PMD22 had a higher binding ability to AGSCLDN18.2 and BGC823CLDN18.2 cells than to AGS and BGC823 cells (p < 0.001). MicroPET/CT images showed that [68Ga]Ga-PMD22 rapidly accumulated in AGSCLDN18.2 and BGC823CLDN18.2 tumors, and high contrast tumor to background imaging was clearly observed. In the pilot study, the effective dose of [68Ga]Ga-PMD22 was 1.68E-02 ± 1.45E-02 mSv/MBq, and the CLDN18.2 IHC staining result was highly correlated with the SUVmax/BKGstomach of [68Ga]Ga-PMD22 (rs = 0.848, p < 0.01).

CONCLUSION

A novel [68Ga]Ga-labeled nanobody probe targeting CLDN18.2, [68Ga]Ga-PMD22, was established and preliminarily proved to be safe and effective in revealing CLDN18.2-positive gastrointestinal cancer, providing a basis for the clinical translation of the agent.

CLINICAL TRIAL REGISTRATION

This study was registered on the ClinicalTrials.gov (NCT05937919).

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance. Human epidermal growth factor receptor 2 (HER2) is one of the most important targets in targeted therapy for gastric cancer. Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer. The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified. However, monoclonal antibodies, due to their large molecular weight, inability to penetrate the blood-brain barrier, and drug resistance, lead to decreased therapeutic efficacy, so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer. Small-molecule tyrosine kinase inhibitors, such as lapatinib and pyrrotinib, have the advantages of small molecular weight, penetrating the blood-brain barrier and high oral bioavailability, and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future. Antibo-drug conjugate, such as T-DM1 and T-DXd, can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing, and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab. Therefore, after more detailed stratification of gastric cancer patients, various gastric cancer drugs targeting HER2 are expected to play a more significant role.

Glutamate-cysteine ligase catalytic and its modifier function as novel immunotargets in gastric adenocarcinoma

OBJECTIVES

To determine the expression and function of glutamate-cysteine ligase catalytic (GCLC) and glutamate-cysteine ligase catalytic modifier (GCLM) in gastric adenocarcinoma.

METHODS

Bioinformatics was used to analyze the expression of GCLC and GCLM. We download and analyzed the expression of gastric adenocarcinoma patients from TCGA database. Moreover, the method of immunochemistry was used to verify the expression of GCLC and GCLM in gastric adenocarcinoma.

RESULTS

At first, the expression of GCLC and GCLM in gastric adenocarcinoma tissues were both significantly higher compared with normal tissues analyzed via TCGA database. Then, gastric adenocarcinoma tissues were collected and performed with immunochemistry. The gastric adenocarcinoma with positive staining for GCLC and GCLM was 77% and 80%, respectively, which was significantly higher compared with adjacent normal tissues (9% and 11%, respectively).

CONCLUSIONS

The disordered expression of GCLC and GCLM in gastric adenocarcinoma suggested that these factors may induce tumorigenesis and may be a novel target for diagnosis and treatment of gastric adenocarcinoma.

Thermo-Transient Receptor Potential Channels: Therapeutic Potential in Gastric Cancer

Over the last decade, researchers have found abnormal expression of transient receptor potential (TRP) channels. In particular, members of the thermally sensitive subclass (thermo-TRPs) are involved in many disease processes. Moreover, they have a vital role in the occurrence and development of gastric cancer (GC). Accordingly, thermo-TRPs constitute a major pharmacological target, and the elucidation of the mechanisms underlying their response to physiological stimuli or drugs is key for notable advances in GC treatment. Therefore, this paper summarizes the existing literature about thermo-TRP protein expression changes that are linked to the incidence and progression of GC. The review also discusses the implication of such association to pathology and cell physiology and identifies potential thermo-TRP protein targets for diagnosis and treatment of GC.

miR-4735-3p inhibits cell migration and invasion of gastric cancer by downregulating NEDD9

Gastric cancer (GC) comprises the 3rd cause of cancer-related death worldwide. Increased expression of neural precursor cell expressed, developmentally downregulated 9 (NEDD9) is commonly observed in GC, however, its underlying molecular mechanism in GC remains unknown. The potential interaction between miR-4735-3p and NEDD9 was predicted by TargetScan 7.1. Expression profiles of miR-4735-3p and NEDD9 were examined between GC tissues and normal tissues by reverse transcription-quantitative (RT-q) PCR. The relationship between miR-4735-3p and NEDD9 was validated by RT-qPCR, western blotting, dual luciferase reporter assay and RNA immunoprecipitation assay. Biological relationship between miR-4735-3p and NEDD9 was evidenced by the cell invasion and cell migration assays. NEDD9 level was negatively associated with miR-4735-3p level in GC tissues. miR-4735-3p suppressed NEDD9 levels in GC cells. NEDD9 was revealed to be a target gene of miR-4735-3p. miR-4735-3p overexpression suppressed cell migration and invasion of GC cells, which were antagonized by overexpression of NEDD9. Moreover, miR-4735-3p mimic decreased the levels of matrix metalloproteinases 2/9, increased the level of E-cadherin, which were reversed by overexpression of NEDD9. Collectively, the present study provided a potential mechanism for the tumor suppressor role of miR-4735-3p in GC by targeting NEDD9.

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.

FGFR2 overexpression and compromised survival in diffuse-type gastric cancer in a large central European cohort

The significance of fibroblast growth factor receptor 2 (FGFR2) in gastric cancer (GC) has been studied predominantly in Asian patient cohorts. Data on White patients are scarce. Here, we aimed to independently validate the expression and putative tumor biological significance of FGFR2 in a large non-Asian GC cohort. Immunohistochemistry (IHC) was performed on large-area tissue sections from 493 patients with GC and evaluated using the HScore. GCs with moderate and strong FGFR2 expression were studied for Fgfr2 amplification using chromogenic in situ hybridization (CISH). Median overall survival was determined using the Kaplan–Meier method. The majority [240 (99.1%)] of FGFR2-positive GCs showed a variable combination of staining intensities with marked intratumoral heterogeneity, including weak [198 (40.2%) cases], moderate [145 (29.4%)], and strong [108 (21.9%)] staining in diverse combinations. 250 (50.9%) GCs expressed no FGFR2. Fgfr2 gene amplification was found in 40% of selected cases with high protein expression and was also heterogeneous at the cell level. FGFR2 protein expression did not correlate with patient survival in the entire cohort However, using different cutoff values, a negative correlation between FGFR2-expression and patient outcome was found for diffuse-type GC. FGFR2 expression was associated with a lower tumor grade and intestinal phenotype (p≤0.0001). FGFR2–positive diffuse-type GCs classify a small subset of patients with a poor tumor specific survival (5.29±1.3 vs. 14.67±1.9 months; p = 0.004).

NDUFC1 Is Upregulated in Gastric Cancer and Regulates Cell Proliferation, Apoptosis, Cycle and Migration

Gastric cancer is one of the most common primary tumors of the digestive system. NADH: ubiquinone oxidoreductase subunit C1 (NDUFC1), which is an accessory subunit of the NADH dehydrogenase (complex I), is responsible for the transportation of electrons from NADH to the respiratory chain essential for the oxidative phosphorylation. However, little is known about the roles of NDUFC1 in carcinogenesis. In this study, NDUFC1 protein level in NSCLC tissues was tested by immunohistochemistry (IHC) staining. NDUFC1 mRNA level in gastric cancer cell lines was determined by qRT-PCR. MGC-803 and SGC-7901 cells were transfected with shNDUFC1 lentivirus designed to silence NDUFC1. MTT assay, CCK8 assay, wound healing assay and transwell migration assay were conducted. Cell cycle and apoptosis were detected by flow cytometry. In vivo experiments were performed using nude mice. The results indicated that overexpressed NDUFC1 in gastric cancer was related to more serious tumor infiltrates, a higher risk of lymphatic metastasis, a higher proportion of positive lymph nodes, and a more advanced tumor stage. Compared with shCtrl groups, MGC-803 and SGC-7901 of shNDUFC1 groups had lower abilities of proliferation and migration, higher levels of apoptosis. NDUFC1 knockdown also inhibited SGC-7901 cell growth in vivo and suppressed Ki67 expression in xenograft tumors. More importantly, we found that NDUFC1 downregulation made the levels of P-Akt, P-mTOR, CCND1, CDK6, PIK3CA, Bcl-2, Survivin, and XIAP decreased, and that PI3K/AKT signaling pathway agonist SC79 rescued the inhibitory effects on cell proliferation and migration, reversed the promoted effects on cell apoptosis caused by NDUFC1 knockdown. More importantly, compared with NDUFC1 knockdown group, the expression of P-Akt, Bcl-2, Survivin, and XIAP was raised in shNDUFC1 + SC79 group. Thus, our suspicion was that NDUFC1 exacerbates NSCLC progression via PI3K/Akt pathway. Taken together, our study indicated that targeting NDUFC1 could open innovative perspectives for new multi-targeting approaches in the treatment of gastric cancer.

TMSB10, a potential prognosis prediction biomarker, promotes the invasion and angiogenesis of gastric cancer

BACKGROUND AND AIM

The thymosin beta 10 (TMSB10) was originally identified from the thymus, which plays a key role in the development of many cancers. However, the underlying molecular mechanisms of TMSB10 involved in GC have not been understood.

METHODS

We sought to determine the expression of TMSB10 in human GC tissues and illustrate whether it is correlated with the clinical pathologic characteristics and prognosis in GC patients. Its roles and potential mechanisms in regulating tumor growth, invasion, and angiogenesis were evaluated by TMSB10 knockdown/overexpression of GC cells in vitro and ex vivo.

RESULTS

Marked overexpression of TMSB10 protein expression was observed in GC cells and tissues, which was associated with the advanced tumor stage and lymph nodes (LN) metastasis of GC patients. Furthermore, prognostic analysis showed that GC patients with high TMSB10 expression had a remarkably shorter survival and acted as an important factor for predicting poor overall survival in GC patients. Moreover, TMSB10 overexpression promoted, while TMSB10 knockdown the proliferation, EMT process, and angiogenesis of GC cells.

CONCLUSION

The study highlights that TMSB10 may hold promise as potential prognosis prediction biomarker for the diagnosis of GC and a potential therapeutic target, which will facilitate the development of a novel therapeutic strategy against GC.

Circular RNA CDR1as Inhibits the Metastasis of Gastric Cancer through Targeting miR-876-5p/GNG7 Axis

Circular RNA CDR1as has been demonstrated to participate in various cancer progressions as miRNA sponges. The exact underlying mechanisms of CDR1as on gastric cancer (GC) metastasis remain unknown. Here, we found that CDR1as knockdown facilitated GC cell migration and invasion while its overexpression inhibited the migration and invasion abilities of GC cells in vitro and in vivo. Moreover, epithelial-mesenchymal transition- (EMT-) associated proteins and MMP2 and MMP9 were downregulated by CDR1as. Bioinformatics analysis combined with dual-luciferase reporter gene assays, western blot, RT-qPCR analysis, and functional rescue experiments demonstrated that CDR1as served as a miR-876-5p sponge and upregulated the target gene GNG7 expression to suppress GC metastasis. In summary, our findings indicate that CDR1as suppresses GC metastasis through the CDR1as/miR-876-5p/GNG7 axis.

Long Noncoding RNAs: New Regulators of Resistance to Systemic Therapies for Gastric Cancer

Gastric cancer (GC) is the second leading cause of cancer mortality and the fourth most commonly diagnosed malignant disease, with approximately 951,000 new cases diagnosed and approximately 723,000 cases of mortality each year. The highest mortality rate of GC is in East Asia, and the lowest is in North America. A large number of studies have demonstrated that GC patients are characterized by higher morbidity, metastasis rates, and mortality and lower early diagnosis rates, radical resection rates, and 5-year survival rates. All cases of GC can be divided into two important stages, namely, early- and advanced-stage GC, and the stage mainly determines the treatment strategy for and the therapeutic effect in GC patients. Patients with early-stage GC undergo radical surgery followed by chemotherapy, and the 5-year survival rate can be as high as 90%. However, patients with advanced-stage GC cannot undergo radical surgery because they are at risk for metastasis; therefore, they can choose only radiotherapy or chemotherapy and have a poor prognosis. Based on the lack of specific clinical manifestations and detection methods, most GC patients (>70%) are diagnosed in the advanced stage; therefore, continued efforts toward developing treatments have been focused on advanced-stage GC patients and include molecular targeted therapy, immunotherapy, and small molecular therapy. Nevertheless, in recent years, accumulating evidence has indicated that small molecules, especially long noncoding RNAs (lncRNAs), are involved in the occurrence, development, and progression of GC, and their abundantly dysregulated expression has been identified in GC tissues and cell lines. Therefore, lncRNAs are considered easily detectable molecules and ideal biomarkers or target-specific agents for the future diagnosis or treatment of GC. In this review, we primarily discuss the status of GC, the role of lncRNAs in GC, and the emerging systemic treatments for GC.

Intratumoral and intertumoral heterogeneity of HER2 immunohistochemical expression in gastric cancer

BACKGROUND

Given the high heterogeneity of tumor tissue in gastric cancer (GC), inaccurate detection of tumor biomarkers will inevitably hamper a precise diagnosis and selection of patients for targeted therapies. Human epidermal growth factor receptor 2 (HER2) has been widely accepted as an underlying treatment biomarker of GC. The objective of this study is to investigate the heterogeneity (both intratumoral and intertumoral) of HER2 expression in GC, and the relationship between heterogeneity and the clinicopathological features.

METHODS

A total of 618 patients with primary gastric adenocarcinoma were recruited, and two formalin-fixed paraffin-embedded (FFPE) tumor-containing blocks of each patient were selected for HER2 immunohistochemical (IHC) assay. Clinicopathological characteristics were recorded, and intratumoral and intertumoral heterogeneity of HER2 IHC expression was determined.

RESULTS

The results indicated that the dual-block assays significantly increased the HER2 overexpression (IHC 2+ and 3+) rate compared with the single paraffin block detection. Approximately 50 % of the cases showed intratumoral HER2 heterogeneity within a single tissue section, and 30.10 % of cases showed intertumoral heterogeneity between a patient's two blocks. Furthermore, intertumoral heterogeneity was associated with tumors of small size (P = 0.029) and distal location (P = 0.032) characters, while the intratumoral heterogeneity was correlated with poorly differentiated carcinomas. Laurén's diffuse type showed a notably higher intratumoral heterogeneity rate, and the mixed type exhibited higher intertumoral HER2 discordance between the dual-block cohorts (P < 0.001). Besides, HER2 heterogenous overexpression was not associated with age, gender, type of resection, lymphatic or venous invasion, perineural invasion or pTNM (P > 0.05) for both cohorts.

CONCLUSION

The research findings in this paper indicate that the intratumoral and intertumoral heterogeneity of HER2 overexpression is common in GC patients, and these variations are associated with certain clinicopathological features. We highly recommend multi-block HER2 assessment for accurate diagnosis of GC.

Activation of the LINC00242/miR-141/FOXC1 axis underpins the development of gastric cancer

Background

Long non-coding RNAs (LncRNAs) are a class of newly identified transcripts recognized as critical governors of gene expression during human carcinogenesis, whereas their tumor-suppressive or tumor-promoting effects on gastric cancer (GC) are required for further investigation. In the study, we identify the expression pattern of a novel lncRNA LINC00242 in GC and its possible permissive role in the development of GC.

Methods

The study included 68 pairs of GC and adjacent normal gastric tissue samples. The viability, migration, and invasion of cultured human GC cells HGC27 were evaluated by CCK-8 and Transwell chamber assays. In vitro tube formation of human brain microvascular endothelial cells (HBMVECs) in HGC27 cell coculture was detected. The regulatory network of LINC00242/miR-141/FOXC1 was verified using dual luciferase reporter gene assay and RNA immunoprecipitation (RIP) assay. Subcutaneous xenografts of HGC27 cells were performed in nude mice.

Results

LINC00242 was highly expressed in GC tissues and cells and contributed to poor prognosis. LINC00242 knockdown inhibited HGC27 cell viability, migration and invasion, and tube formation of HBMVECs. LINC00242 interacted with miR-141 and positively regulated FOXC1, a target gene of miR-141. LINC00242 knockdown was partially lost in HGC27 cells upon miR-141 inhibition or FOXC1 overexpression. The tumor-promoting effect of LINC00242 on GC was demonstrated in nude mice.

Conclusion

Taken together, the present study demonstrates the oncogenic role of the LINC00242/miR-141/FOXC1 axis in GC, highlighting a theoretical basis for GC treatment.

Identification of UAP1L1 as tumor promotor in gastric cancer through regulation of CDK6

Gastric cancer (GC) is one of the most commonly diagnosed malignancies in digestive tract and its underlying molecular mechanism is still not clear, so we aimed to reveal the relationship between GC and UDP-GlcNAc pyrophosphorylase-1 like 1 (UAP1L1). The detection of UAP1L1 expression in GC tumor and normal tissues was accomplished by immunohistochemistry and demonstrated the upregulation of UAP1L1 in GC, which was statistically associated with tumor grade. GC cell models constructed via transfection of UAP1L1-silencing/overexpressing lentiviruses were employed for evaluating the effects of UAP1L1 knockdown/overexpression on GC in vitro and in vivo. The results indicated that UAP1L1 played important role in development of GC through regulating cell proliferation, colony formation, cell apoptosis and cell migration. Subsequently, CDK6 was identified as a potential target in UAP1L1 induced regulation of GC, downregulation of which exhibited similar inhibition effects on GC with UAP1L1. Moreover, it was demonstrated that the promotion of GC by UAP1L1 overexpression could be significantly attenuated or even reversed by simultaneously silencing CDK6. In conclusion, UAP1L1 was reported to be a tumor promotor in the development and progression of GC which may exert its role through regulating CDK6 and may act as a candidate of therapeutic target in treatment.

PELP1 is a novel oncogene in gastric tumorigenesis and negatively regulated by miR-15 family microRNAs

BACKGROUD

Gastric cancer (GC) is one of the leading causes of cancer-related death in East Asia and some South American countries, but its mechanism has not been clarified clearly. Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1), a co-regulatory molecule of estrogen receptor α (ER α), is up-regulated in series of cancers such as endometrial carcinoma, ovarian cancer, colorectal cancer, breast cancer, and non-small cell lung cancer. However, PELP1's role in GC is still obscure, and its aberrant expression in cancers also remains to be explained.

METHODS

Immunohistochemical staining and Real-time PCR were used to compare the expression level of PELP1 in GC tissues and adjacent tissues. Western blot was used to detect the expression of PELP1 in cell lines. Kaplan-meier analysis and chi-square test were applied to evaluate the potential of PELP1 to function as a cancer biomarker. RNA interference was used to inhibit PELP1 expression in GC cells, followed by detecting cell proliferation, apoptosis, migration and invasion. Luciferase assay was conducted to validate whether miR-15 family members can directly target PELP1.

RESULTS

In this study, we validated that PELP1 was significantly up-regulated in GC samples and cell lines. It was also demonstrated that the up-regulation of PELP1 was associated with several clinicopathologic features such as tumor diameter (P< 0.001), serum CEA level (P= 0.034), and lymphatic metastasis (P= 0.0009) of GC patients, and its high expression was correlated with shorter disease-free survival and overall survival of the patients. Knockdown of PELP1 remarkably arrested the proliferationï¼ migration and invasion, while promoted apoptosis. We also confirmed that miR-15 family microRNAs, most of which were down-regulated and tumor suppressor in cancers, were posttranscriptional regulators of PELP1.

CONCLUSION

In conclusion, we demonstrated that PELP1 was an oncogene of GC associated with patients' prognosis and miR-15 family members contributed to its aberrant expression in cancers.

MFAP2 is overexpressed in gastric cancer and promotes motility via the MFAP2/integrin α5β1/FAK/ERK pathway

Gastric cancer (GC) is one of the most common malignancies and its prognosis is extremely poor. This study identifies a novel oncogene, microfibrillar-associated protein 2 (MFAP2) in GC. With integrative reanalysis of transcriptomic data, we found MFAP2 as a GC prognosis-related gene. And the aberrant expression of MFAP2 was explored in GC samples. Subsequent experiments indicated that silencing and exogenous MFAP2 could affect motility of cancer cells. The inhibition of silencing MFAP2 could be rescued by another FAK activator, fibronectin. This process is probably through affecting the activation of focal adhesion process via modulating ITGB1 and ITGA5. MFAP2 regulated integrin expression through ERK1/2 activation. Silencing MFAP2 by shRNA inhibited tumorigenicity and metastasis in nude mice. We also revealed that MFAP2 is a novel target of microRNA-29, and miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression. In conclusion, our data identified MFAP2 as a novel oncogene in GC and revealed that miR-29/MFAP2/integrin α5β1/FAK/ERK1/2 could be an important oncogenic pathway in GC progression.

Trop2 Promotes Multidrug Resistance by Regulating Notch1 Signaling Pathway in Gastric Cancer Cells

BACKGROUND Chemotherapy is widely used in gastric cancer treatment, but multidrug resistance remains a leading cause of chemotherapy failure. Trop2 is highly expressed in gastric tumor tissues and greatly influences cancer progression. However, little is known about the relationship between Trop2 and drug resistance in gastric cancer. MATERIAL AND METHODS In the present study, Trop2 was knocked down in BGC823 cells and overexpressed in HGC27. CCK-8 assay was performed to explore the relationship of Trop2 expression and cell proliferation treated with anticancer drugs. Flow cytometry was performed to assess the relationship between Trop2 and cell apoptosis after chemotherapy. Subcutaneous xenograft models were generated to explore the curative effect of DDP to GC in vivo. MRP1 and Notch1 expressions were assessed by Western blot. RESULTS Trop2 decreased cell proliferation inhibition and apoptosis after chemotherapeutic treatments. DDP showed stronger therapeutic effects on Trop2-knockdown tumor than control in vivo. MRP1 and Notch1 signaling pathway were confirmed to participate in Trop2-induced drug resistance. CONCLUSIONS Our findings suggest that Trop2 promotes the resistance of gastric cancer to chemotherapy by activating the Notch1 pathway.

Therapeutic Approaches to Gastric Hepatoid Adenocarcinoma: Current Perspectives

Hepatoid adenocarcinoma of the stomach (HAS) is a rare subgroup of gastric cancer (GC). Morphologically, this tumor exhibits both adenocarcinomatous and hepatocellular differentiation, and most tumors show immunohistochemical staining for alpha-fetoprotein (AFP) or elevated AFP serum levels. The diagnosis of HAS is frequently delayed, and at least half of patients have advanced disease at the time of diagnosis. Despite a lack of evidence, treatment approaches have mostly followed principles for the treatment of common gastric cancer (CGC), including radical surgery in eligible patients with curative intent. The indications for and the type of adjuvant systemic treatments remain unclear. Additionally, there is a lack of evidence allowing any firm conclusions to be drawn regarding the best treatment for patients with metastatic HAS (mHAS). Chemotherapy regimens, including cisplatin-based chemotherapy, are considered the most efficient first-line systemic treatment in advanced situations. Their combination with targeted therapy (i.e., trastuzumab) in HER2-positive tumors seems promising. The rarity of these patients and the scarce and heterogeneous literature on this particular subgroup of GC make it difficult to provide any robust evidence for the clinical management of patients with HAS.

Late stage gastric cancer patients with extra gained HER2 positivity by dual block assessment may not show compromised efficacy to trastuzumab treatment

Dual block HER2 assessment can effectively increase the HER2 positive rate in resected specimens of gastric cancer (GC). The aim of this study is to explore whether GC patients with extra gained HER2 positivity by dual block assessment can benefit from trastuzumab therapy. Twenty-eight GC patients receiving gastrectomy prior to trastuzumab treatment were retrospectively analyzed. All the cases routinely accepted dual block HER2 assessment. The cases were divided into 2 cohorts based on HER2 status: cohort A with concordant HER2 results and cohort B with discordant HER2 results between the two blocks (cases with extra gained HER2 positivity). Response rate (RR), progress free survival (PFS) and overall survival (OS) were compared between the two cohorts. The results showed that no significant differences were found between the two cohorts in main clinicopathologic characteristics. No statistical difference was found in response rate (47.6% vs 57.1%) (P=1.0), either. The two cohorts did not demonstrate statistical differences in the PFS (10.5 months (95%CI 6.4-14.6) vs 8.0 months (95%CI 3.2-12.8), P=0.686) and the OS (23.3 months (95%CI 12.1-34.5) vs 20.0 months (95%CI 10.1-29.9), P=0.776). In conclusion, our study suggests that patients with extra gained HER2 positivity may not show compromised efficacy to trastuzumab treatment.

In silico chemical screening identifies epidermal growth factor receptor as a therapeutic target of drug-tolerant CD44v9-positive gastric cancer cells

Background

Tumours consist of heterogeneous cancer cells and are likely to contain drug-tolerant cell subpopulations, causing early relapse. However, treatment strategies to eliminate these cells have not been established.

Methods

We established gastric cancer patient-derived cells (PDCs) to examine the contribution of CD44 splicing variant 9 (CD44v9)-positive cells in gastric cancer drug tolerance. We performed gene expression signature-based in silico screening using JFCR_LinCAGE, our anticancer compound gene expression database and subsequent validation in BALB/c-nu/nu mouse xenograft to identify agents targeting the drug-tolerant cancer cells.

Results

CD44v9-positive cancer cells were enriched among residual cancer cells after treatment with SN-38, an active metabolic of irinotecan. CD44v9 protein was responsible for this drug resistance. We identified epidermal growth factor receptor (EGFR) inhibitors as agents that can target CD44v9-positive cell populations in gastric cancer PDCs. CD44v9 promoted cell proliferation, and EGFR inhibition attenuated CD44v9 protein expression through downregulation of the AKT and the ERK signalling pathways, leading to preferential suppression of CD44v9-positive cells. Importantly, EGFR inhibitors significantly reduced the number of residual cancer cells after cytotoxic anticancer drug treatment and enhanced the antitumor effect of irinotecan in vivo.

Conclusions

EGFR inhibitors could be potential agents to eradicate cytotoxic anticancer drug-tolerant gastric cancer cell populations.

High-Expression HBO1 Predicts Poor Prognosis in Gastric Cancer

OBJECTIVES

Our goal was to assess the expression of histone acetyltransferase binding to origin recognition complex 1 (HBO1) in gastric cancer and the effect on prognosis for the patients.

METHODS

We used quantitative reverse transcription polymerase chain reaction, Western blot, and tissue microarray immunohistochemistry to investigate the expressions of HBO1 messenger RNA (mRNA) and protein in gastric cancer tissues. Online resources, including Oncomine and Kaplan-Meier Plotter, were used to further assess the correlation between HBO1 expression and the prognosis of the patients with gastric cancer.

RESULTS

HBO1 mRNA and protein expressions in gastric cancer tissues were both significantly higher than those in normal tissues. The correlations between high HBO1 expression and differentiation, invasive depth (T), lymph node metastasis (N), distant metastasis (M), TNM staging, and serum carcinoembryonic antigen levels were positive. High HBO1 expression was negatively correlated with survival time in patients with gastric cancer.

CONCLUSIONS

HBO1 might be a valuable biomarker to evaluate the prognosis of patients with gastric cancer.

microRNA-95 knockdown inhibits epithelial-mesenchymal transition and cancer stem cell phenotype in gastric cancer cells through MAPK pathway by upregulating DUSP5

This study investigated the role of microRNA-95 (miR-95) in gastric cancer (GC) and to elucidate the underlying mechanism. Initially, bioinformatic prediction was used to predict the differentially expressed genes and related miRNAs in GC. miR-95 and DUSP5 expression was altered in GC cell line (MGC803) to evaluate their respective effects on the epithelial-mesenchymal transition (EMT) process, cellular processes (cell proliferation, migration, invasion, cell cycle, and apoptosis), cancer stem cell (CSC) phenotype, as well as tumor growth ability. It was further predicted in bioinformatic prediction and verified in GC tissue and cell line experiments that miR-95 was highly expressed in GC. miR-95 negatively regulated DUSP5, which resulted in the MAPK pathway activation. Inhibited miR-95 or overexpressed DUSP5 was observed to inhibit the levels of CSC markers (CD133, CD44, ALDH1, and Lgr5), highlighting the inhibitory role in the CSC phenotype. More important, evidence was obtained demonstrating that miR-95 knockdown or DUSP5 upregulation exerted an inhibitory effect on the EMT process, cellular processes, and tumor growth. Together these results, miR-95 knockdown inhibited GC development via DUSP5-dependent MAPK pathway.

TRP channels in gastric cancer: New hopes and clinical perspectives

Gastric cancer is a multifactorial disease associated with a combination of and environmental factors. Each year, one million new gastric cancer cases are diagnosed worldwide and two-thirds end up losing the battle with this devastating disease. Currently, surgery represents the only effective treatment option for patients with early stage tumors. However, the asymptomatic phenotype of this disease during the early stages poses as a significant limiting factor to diagnosis and often renders treatments ineffective. To address these issues, scientists are focusing on personalized medicine and discovering new ways to treat cancer patients. Emerging therapeutic options include the transient receptor potential (TRP) channels. Since their discovery, TRP channels have been shown to contribute significantly to the pathophysiology of various cancers, including gastric cancer. This review will summarize the current knowledge about gastric cancer and provide a synopsis of recent advancements on the role and involvement of TRP channels in gastric cancer as well as a discussion of the benefits of targeting TPR channel in the clinical management of gastric cancer.

HOXC10 overexpression promotes cell proliferation and migration in gastric cancer

Homeodomain‑containing gene 10 (HOXC10) is a member of the homeobox transcription factors that plays an important role in the development of multicellular organisms. HOXC10 is overexpressed in a variety of human cancers, and recent studies have revealed that HOXC10 is upregulated in gastric cancer as well. However, its mechanism of action is not fully understood, thus, the role of HOXC10 was investigated in the present study in human gastric cancer. First, HOXC10 expression was revealed to be significantly increased in gastric cancer tissues compared to normal tissues (TCGA dataset), and HOXC10 upregulation was associated with decreased recurrence‑free survival in gastric cancer patients in a public gene expression dataset. HOXC10 promoted cell proliferation and metastasis in two gastric cancer cell lines (AGS and MKN74). Analyzing TCGA 450K DNA methylation dataset, it was revealed that HOXC10 CpG sites were hypomethylated in gastric cancer tissues. Bisulfite sequencing revealed that CpG sites in the HOXC10 first intronic region were hypomethylated in three gastric cancer tissues, and HOXC10 expression was increased in gastric cancer cell lines (AGS and SNU620) in response to 5‑azacytidine treatment. By RNA‑sequencing of AGS cells with ectopic HOXC10 expression, it was revealed that many genes were upregulated by HOXC10 overexpression. Among them, CST1 was predicted to be a HOXC10 direct target gene via prediction of HOXC10 binding sites from the JASPAR database. A chromatin immunoprecipitation assay revealed that HOXC10 directly bound to CST1 promoter regions. The present study proposes HOXC10 is a potential prognostic marker or therapeutic target in human gastric cancer.

[Expression of PSMA 7 and its effect on proliferation, invasion, migration and tumorigenesis of gastric cancer]

OBJECTIVE

To study the expression of PSMA7 and its effect on proliferation, invasion and migration of gastric cancer and subcutaneous tumorigenesis in nude mice. >and subcutaneous tumorigenesis in nude mice.

METHODS

Specimens of tumor tissues and paired adjacent tissues were collected from 60 patients with gastric cancer for detecting the expression levels of PSMA7 using immunohistochemical method. Gastric cancer cell line SGC7901 was transfected with a lentiviral vector to inhibit PSMA7 expression, and the changes in cell proliferation and invasion were observed using cell counting kit-8 (CCK-8), clone formation assay and Transwell assay. A BALB/c mouse model bearing subcutaneous gastric cancer xenograft was established using SGC7901 cells with stable PSMA7 knockdown to assess the effect of low expression of PSMA7 on xenograft growth.

RESULTS

Gastric cancer tissues expressed significantly higher levels of PSMA7 than the paired adjacent tissues (P < 0.05). In SGC7901 cells, interference of PSMA7 expression significantly inhibited the cell proliferation and invasion (P < 0.05). In the tumor-bearing BALB/c mice, the xenografts derived from SGC7901 cells with PSMA7 expression interference showed significant growth suppression as compared with the control xenografts (P < 0.05).

CONCLUSIONS

PPSMA 7 is overexpressed in gastric cancer tissues, and PSMA7 knockdown inhibits the proliferation, invasion, migration and subcutaneous tumorigenesis of gastric cancer cells in nude mice.

Serum Inflammatory Cytokines Comparison in Gastric Cancer Therapy

To compare serum inflammatory cytokines between laparoscopic-assisted and open radical gastrectomy in the perioperative period, 80 cases of advanced gastric cancer were chosen for the study. They were divided into laparoscopy group (40 cases) and abdominal open surgery group (40 cases), performed laparoscopic-assisted radical gastrostomy and conventional open radical gastrectomy, respectively. Serum Heme oxygenase-1 (HO-1), TNF-α, IL-6 and CRP were measured by ELISA on preoperative day 1, post-operative day 1 and post-operative day3. Serum HO-1, TNF-α, IL-6 and CRP had no significant difference between the laparoscopy group and the open group on pre-operative day 1. Serum HO-1, IL-6 and CRP of the laparoscopy group were significantly lower than that of the open group on post-operative day 1 and day 3 except for Serum TNF-α which had no significant difference. Laparoscopic-assisted radical gastrectomy was minimally invasive compared with conventional open radical gastrectomy in advanced gastric cancer patients.

Remifentanil regulates proliferation and apoptosis of gastric cancer cells by regulating miR-206/GOLPH3

BACKGROUND

Remifentanil is a commonly used anesthetic in clinical practice. In recent years, its new efficacy has been continuously discovered, especially its anti-cancer function. However, the role and mechanism of remifentanil in gastric cancer (GC) are still not clear.

AIM

To investigate the effect of remifentanil on the expression of miR-206, GOLPH3, cell proliferation, and apoptosis in human GC cell lines AGS and MKN-45.

METHODS

The expression of miR-206 and GOLPH3 and the viability and apoptosis of AGS and MKN-45 cells after treatment with 40 nmol/L remifentanil were detected by qRT-PCR, Western blot, MTT assay, and flow cytometry, respectively. Cell viability and apoptosis of AGS and MKN-45 cells with overexpression of miR-206 or knockdown of GOLPH3 were detected by MTT assay and flow cytometry, respectively. The targeting relationship between miR-206 and GOLPH3 was verified by Targetscan online prediction, dual-luciferase assay, and Western blot. After transfection with miR-206 inhibitor or pcDNA-GOLPH3, AGS and MKN-45 cells were treated with 40 nmol/L remifentanil and then detected for cell viability and apoptosis.

RESULTS

After treatment with remifentanil, the expression of miR-206 and apoptosis rate were increased while the expression of GOLPH3 and cell viability were decreased in AGS and MKN-45 cells. Cell viability was decreased and apoptotic rate was increased in AGS and MKN-45 cells after overexpression of miR-206 or knockdown of GOLPH3. The results of Targetscan online prediction, dual-luciferase assay, and Western blot indicted that miR-206 could regulate the expression of GOLPH3 protein. Down-regulation of miR-206 or overexpression of GOLPH3 could reverse the inhibition of proliferation and apoptosis of AGS and MKN-45 cells by remifentanil.

CONCLUSION

Remifentanil could inhibit the proliferation and induce apoptosis of AGS and MKN-45 cells by regulating the expression of miR-206 and GOLPH3.

Mesothelin is a target of chimeric antigen receptor T cells for treating gastric cancer

BACKGROUND

Gastric cancer (GC) is a common cancer in Asia and currently lacks a targeted therapy approach. Mesothelin (MSLN) has been reported to be expressed in GC tissue and could be targeted by chimeric antigen receptor (CAR) T cells. Mesothelin targeting CAR-T has been reported in mesothelioma, lung cancer, breast cancer, and pancreas cancer. However, the feasibility of using anti-MSLN CAR T cells to treat GC remains to be studied.

METHODS

We verified MSLN expression in primary human GC tissues and GC cell lines and then redirected T cells with a CAR containing the MSLN scFv (single-chain variable fragment), CD3ζ, CD28, and DAP10 intracellular signaling domain (M28z10) to target MSLN. We evaluated the function of these CAR T cells in vitro in terms of cytotoxicity, cytokine secretion, and surface phenotype changes when they encountered MSLN+ GC cells. We also established four different xenograft GC mouse models to assess in vivo antitumor activity.

RESULTS

M28z10 T cells exhibited strong cytotoxicity and cytokine-secreting ability against GC cells in vitro. In addition, cell surface phenotyping suggested significant activation of M28z10 T cells upon target cell stimulation. M28z10 T cells induced GC regression in different xenograft mouse models and prolonged the survival of these mice compared with GFP-transduced T cells in the intraperitoneal and pulmonary metastatic GC models. Importantly, peritumoral delivery strategy can lead to improved CAR-T cells infiltration into tumor tissue and significantly suppress the growth of GC in a subcutaneous GC model.

CONCLUSION

These results demonstrate that M28z10 T cells possess strong antitumor activity and represent a promising therapeutic approach to GC.

Heat Shock Factor 1 Predicts Poor Prognosis of Gastric Cancer

PURPOSE

Heat shock factor 1 (HSF1) is a key regulator of the heat shock response and plays an important role in various cancers. However, the role of HSF1 in gastric cancer is still unknown. The present study evaluated the function of HSF1 and related mechanisms in gastric cancer.

MATERIALS AND METHODS

The expression levels of HSF1 in normal and gastric cancer tissues were compared using cDNA microarray data from the NCBI Gene Expression Omnibus (GEO) dataset. The proliferation of gastric cancer cells was analyzed using the WST assay. Transwell migration and invasion assays were used to evaluate the migration and invasion abilities of gastric cancer cells. Protein levels of HSF1 were analyzed using immunohistochemical staining of tissue microarrays from patients with gastric cancer.

RESULTS

HSF1 expression was significantly higher in gastric cancer tissue than in normal tissue. Knockdown of HSF1 reduced the proliferation, migration, and invasion of gastric cancer cells, while HSF1 overexpression promoted proliferation, migration, and invasion of gastric cancer cells. Furthermore, HSF1 promoted the proliferation of gastric cancer cells in vivo. In Kaplan-Meier analysis, high levels of HSF1 were associated with poor prognosis for patients with gastric cancer (p=0.028).

CONCLUSION

HSF1 may be closely associated with the proliferation and motility of gastric cancer cells and poor prognosis of patients with gastric cancer. Accordingly, HSF1 could serve as a prognostic marker for gastric cancer.

Comparison of Conventional and Advanced Echocardiographic Techniques in Early Detection of Cardiotoxicity in Patients Undergoing Cancer Chemotherapy

Context: The assessment of left ventricular ejection fraction (LVEF) is the most important component in prediction and detection of cardiotoxicity in patients undergoing cancer chemotherapy. LVEF may not be sensitive enough to pick the cardiotoxicity early since drop in LVEF occurs in the last and irreversible stage. A 10%–15% early reduction in global longitudinal strain (GLS) by speckle tracking echocardiography proposed to be the earliest indicator of myocardial dysfunction. Aims: The aim of this study was to compare the early detection of cardiotoxicity (at 0 and 3 months) using drop in LVEF with two-dimensional echocardiography (2DE), three-dimensional echocardiography (3DE), and GLS techniques. Settings and Design: This was a prospective cohort study of patients attending cardiooncology clinic in a tertiary care institute. Subjects and Methods: Newly diagnosed 75 cases of cancer of various etiologies, for whom cardiotoxic chemotherapy drugs has to be used, were included from January 2016 to June 2016. Statistical Analysis Used: Data were analyzed with Pearson’s Chi-square test, mean, standard deviation, and 95% confidence interval. Results: A total of 17 (22.6%) subjects out of 75, had drop in LVEF by GLS (<−18.9%) as compared to 5 (6.6%) in 2DE and 7 (9.3%) in 3DE at 3 months with statistically significant P values (P = 0.0001). In the 17 subjects who had significant fall in GLS at 3 months, the mean GLS was −16.17 ± 1.55% with a significant reduction of 13.48% from baseline. Conclusion: Reduction in GLS preceded decrease in ejection fraction. Early detection allows modification of chemotherapeutic regimens and medical intervention preventing the irreversible cardiac damage.

Paclitaxel reversed trastuzumab resistance via regulating JUN in human gastric cancer cells identified by FAN analysis

AIM

In this study, we aim to use bioinformatics approach to identify paclitaxel-targeted modulators potentially involved in the process of reversing the trastuzumab resistance. Materials & methods: We extracted data from GSE77346 to identify potential trastuzumab resistance-related genes, used bioinformatics analysis and functional/activity network approach to find genes involved in trastuzumab resistance reversal.

RESULTS

We identified hub differentially expressed genes related to trastuzumab resistance, trastuzumab targeting and paclitaxel targeting, respectively. We then found C-Jun may be critical in trastuzumab resistance reversal.  This process may involve transcriptional activation of DUSP1 by JUN, which lead to regulation of DUSP1-related signaling pathways.

CONCLUSION

The present study revealed paclitaxel may reverse the trastuzumab resistance by JUN, which possibly in turn regulated DUSP1 and DUSP1-related signaling pathways.

Expression of transmembrane protein 41A is associated with metastasis via the modulation of E‑cadherin in radically resected gastric cancer

Gastric cancer (GC) is one of the most commonly occurring malignancies worldwide, and metastasis is one of the key processes affecting the prognosis of GC. TMEM41A, which belongs to a group of transmembrane proteins that participate in signaling pathways and tumor development, is a 264‑amino acid protein encoded by a gene mapped to human chromosome The exact role of TMEM41A in GC has not been determined to date. In the present study, the expression of TMEM41A in 147 cases of GC was analyzed with immunohistohemistry and the prognoses of these patients were analyzed. It was revealed that TMEM41A was highly expressed in GC tissues, and may be associated with the progression of GC and poor prognosis. The expression of TMEM41A was observed to be correlated with lymph node metastasis, distant metastasis and advanced tumor, node and metastasis stages. Knockdown of TMEM41A in vitro and in vivo decreased the GC cell migration ability by regulating epithelial‑to‑mesenchymal transition and cell autophagy, via the upregulation of E‑cadherin and downregulating N‑cadherin expression in GC cells by reverse transcription‑quantitative polymerase chain reaction (PCR), semi‑PCR and western blotting. Furthermore, TMEM41A upregulation was associated with the upregulation of p62 and altered the conversion of light chain (LC)3‑1 into LC3‑2 by western blotting. Knockdown of TMEM41A was also observed to affect tumor metastasis in nude mice. Therefore, TMEM41A may be considered as a novel therapeutic target for the treatment of GC‑associated metastasis.

Overexpression of FIBCD1 Is Predictive of Poor Prognosis in Gastric Cancer

OBJECTIVES

Fibrinogen C domain containing 1 (FIBCD1) is a newly identified acetyl group recognition receptor. The aim of this study was to evaluate the prognostic significance of FIBCD1 in gastric cancer.

METHODS

This study included 706 samples, and the clinical data of all patients were recorded in detail. We studied messenger RNA (mRNA) and protein expression of FIBCD1 in cancerous and normal tissues by quantitative real-time polymerase chain reaction (n = 54) and tissue microarray immunohistochemistry analysis (n = 706), respectively.

RESULTS

mRNA and protein expression levels of FIBCD1 were significantly higher in gastric cancer than in normal tissues. High FIBCD1 protein level showed significant correlations with age (P = .011), TNM stage (P < .001), serum carcinoembryonic antigen (CEA) level (P = .002), and the expression of human epidermal growth factor receptor 2 (P < .001). Kaplan-Meier survival analysis revealed that patients with gastric cancer with high levels of FIBCD1 had a significantly shorter survival time than those with low expression levels. In univariate analysis, high FIBCD1 expression, older age, histologic type, differentiation, TNM stage, serum CEA, and serum CA19-9 level correlated with overall survival. Multivariate analysis suggested that FIBCD1 expression was an independent prognostic factor.

CONCLUSIONS

FIBCD1 may be a novel biomarker to evaluate the prognosis of gastric cancer.

Poor efficacy response to trastuzumab therapy in advanced gastric cancer with homogeneous HER2 positive and non-intestinal type

Introduction

Factors affecting trastuzumab efficacy in advanced gastric cancer (GC) are largely unknown. Heterogeneity is a notable feature of HER2 in GC. Whether the heterogeneity influences trastuzumab efficacy is still unknown.

Results

The HER2^homogeneous group and HER2^{heterogeneous} group showed no statistical difference in RR (46.4% vs 55.0%, P = 0.558), PFS (5.80 vs 6.30 months, P = 0.804) and OS (16.00 vs 16.00 months, P = 0.787). The Lauren^intestinal group and Lauren^{non-intestinal} group demonstrated no discrepancy in PFS (6.00 vs 6.00 months, P = 0.912) and OS (16.50 vs 14.00 months, P = 0.227). However, by combining HER2 heterogeneity and Lauren classification, PFS and OS of HER2^homogeneous/Lauren^{non-intestinal} subgroup was the shortest among the 4 subgroups (P = 0.012 and P = 0.037), which was much shorter than the other patients (PFS:3.00 vs 6.30 months, P = 0.003; OS: 4.50 vs 16.50 months, P = 0.004). Univariate and multivariate analysis showed that HER2 heterogeneity combined with Lauren classification was an independent prognostic factor in both PFS (P = 0.031 and P = 0.002) and OS (P = 0.039 and P = 0.013).

Materials and Methods

48 patients with HER2 positive advanced GCs accepting trastuzumab treatment were retrospectively analyzed. Based on HER2 heterogeneity, the patients were divided into a HER2^homogeneous group and a HER2^{heterogeneous} group. Response rate (RR), progression free survival (PFS), and overall survival (OS) were compared. Main clinicopathological factors including Lauren classification were subjected to subgroup analysis.

Conclusions

HER2 heterogeneity alone may not correlate with trastuzumab efficacy in HER2 positive advanced GCs. HER2 heterogeneity combined with Lauren classification may help to identify a subgroup with poor response to trastuzumab which is homogeneous HER2 positive and non-intestinal type.

Epstein-Barr virus-associated gastric cancer reveals intratumoral heterogeneity of PIK3CA mutations

Background

Recent whole-genome sequencing identified four molecular subtypes of gastric cancer (GC), of which the subgroup of Epstein–Barr virus-associated GC (EBVaGC) showed a significant enrichment of PIK3CA mutations. We here aimed to validate independently the enrichment of PIK3CA mutations in EBVaGC of a Central European GC cohort, to correlate EBV status with clinico-pathological patient characteristics and to test for a major issue of GC, intratumoral heterogeneity.

Patients and methods

In a first step, 484 GCs were screened for EBV and PIK3CA hot spot mutations of exon 9/20 using EBER in situ hybridization and pyrosequencing, respectively. Secondly, an extended sequencing of PIK3CA also utilizing next generation sequencing was carried out in all EBVaGCs and 96 corresponding lymph node metastases.

Results

Twenty-two GCs were EBER-positive, all being of latency type I. Intratumoral heterogeneity of EBER-positivity was found in 18% of EBVaGCs. Twenty-three GCs held PIK3CA mutations in hot spot regions of exon 9 or 20, being significantly more common in EBVaGCs (P < 0.001). Subsequent extended sequencing of PIK3CA of EBVaGCs showed that 14% harvested three to five different PIK3CA genotypes (including wildtype) in the same primary tumor, albeit in histologically and spatially distinct tumor areas, and that intratumoral heterogeneity of PIK3CA was also present in the corresponding lymph node metastases.

Conclusions

Our findings unravel issues of tumor heterogeneity and illustrate that the assessment of the EBV status in tissue biopsies might carry the risk of sampling errors, which may significantly hamper adequate molecular tumor classification in a more clinical setting. Moreover, this is the first report of intratumoral heterogeneity of PIK3CA mutations in GC, and our findings lead to the conclusion that PIK3CA mutant and -wildtype tumor subclones are skilled to metastasize independently to different regional lymph nodes.

Inhibition of Topoisomerase IIα and Induction of Apoptosis in Gastric Cancer Cells by 19-Triisopropyl Andrographolide

Gastric cancer is the most common cancer in Eastern Asia. Increasing chemoresistance and general systemic toxicities have complicated the current chemotherapy leading to an urgent need of more effective agents. The present study reported a potent DNA topoisomerase IIα inhibitory activity of an andrographolide analogue (19-triisopropyl andrographolide, analogue-6) in gastric cancer cells; MKN-45, and AGS cells. The analogue was potently cytotoxic to both gastric cancer cell lines with the half maximal inhibitory concentration (IC50 values) of 6.3±0.7 μM, and 1.7±0.05 μM at 48 h for MKN-45, and AGS cells, respectively. It was more potent than the parent andrographolide and the clinically used, etoposide with the IC50 values of >50 μM in MKN-45 and 11.3±2.9 μM in AGS cells for andrographolide and 28.5±4.4 μM in MKN-45 and 4.08±0.5 μM in AGS cells for etoposide. Analogue-6 at 2 μM significantly inhibited DNA topoisomerase IIα enzyme in AGS cells, induced DNA damage, activated cleaved PARP-1, and Caspase3 leading to late cellular apoptosis. Interestingly, the expression of tumor suppressor p53 was not activated. These results show the importance of 19-triisopropyl-andrographolide in its emerging selectivity to primary target on topoisomerase IIα enzyme, inducing DNA damage and apoptosis by p53- independent mechanism. Thereby, the results provide insights of the potential of 19-triisopropyl andrographolide as an anticancer agent for gastric cancer. The chemical transformation of andrographolide is a promising strategy in drug discovery of a novel class of anticancer drugs from bioactive natural products.

Perspective on the dynamics of cancer

BACKGROUND

The genetic diversity of cancer and the dynamic interactions between heterogeneous tumor cells, the stroma and immune cells present daunting challenges to the development of effective cancer therapies. Although cancer biology is more understood than ever, this has not translated into therapies that overcome drug resistance, cancer recurrence and metastasis. The future development of effective therapies will require more understanding of the dynamics of homeostatic dysregulation that drives cancer growth and progression.

RESULTS

Cancer dynamics are explored using a model involving genes mediating the regulatory interactions between the signaling and metabolic pathways. The exploration is informed by a proposed genetic dysregulation measure of cellular processes. The analysis of the interaction dynamics between cancer cells, cancer associated fibroblasts, and tumor associate macrophages suggests that the mutual dependence of these cells promotes cancer growth and proliferation. In particular, MTOR and AMPK are hypothesized to be concurrently activated in cancer cells by amino acids recycled from the stroma. This leads to a proliferative growth supported by an upregulated glycolysis and a tricarboxylic acid cycle driven by glutamine sourced from the stroma. In other words, while genetic aberrations ignite carcinogenesis and lead to the dysregulation of key cellular processes, it is postulated that the dysregulation of metabolism locks cancer cells in a state of mutual dependence with the tumor microenvironment and deepens the tumor's inflammation and immunosuppressive state which perpetuates as a result the growth and proliferation dynamics of cancer.

CONCLUSIONS

Cancer therapies should aim for a progressive disruption of the dynamics of interactions between cancer cells and the tumor microenvironment by targeting metabolic dysregulation and inflammation to partially restore tissue homeostasis and turn on the immune cancer kill switch. One potentially effective cancer therapeutic strategy is to induce the reduction of lactate and steer the tumor microenvironment to a state of reduced inflammation so as to enable an effective intervention of the immune system. The translation of this therapeutic approach into treatment regimens would however require more understanding of the adaptive complexity of cancer resulting from the interactions of cancer cells with the tumor microenvironment and the immune system.

Porphyrin modified trastuzumab improves efficacy of HER2 targeted photodynamic therapy of gastric cancer

Gastric cancer (GC) is the 3rd deadliest cancer worldwide, due to limited treatment options and late diagnosis. Human epidermal growth factor receptor-2 (HER2) is overexpressed in ∼20% of GC cases and anti-HER2 antibody trastuzumab in combination with conventional chemotherapy, is recognized as standard therapy for HER2-positive metastatic GC. This strategy improves GC patients' survival by 2-3 months, however its optimal results in breast cancer indicate that GC survival may be improved. A new photoimmunoconjugate was developed by conjugating a porphyrin with trastuzumab (Trast:Porph) for targeted photodynamic therapy in HER2-positive GC. Using mass spectrometry analysis, the lysine residues in the trastuzumab structure most prone for porphyrin conjugation were mapped. The in vitro data demonstrates that Trast:Porph specifically binds to HER2-positive cells, accumulates intracellularly, co-localizes with lysosomal marker LAMP1, and induces massive HER2-positive cell death upon cellular irradiation. The high selectivity and cytotoxicity of Trast:Porph based photoimmunotherapy is confirmed in vivo in comparison with trastuzumab alone, using nude mice xenografted with a HER2-positive GC cell line. In the setting of human disease, these data suggest that repetitive cycles of Trast:Porph photoimmunotherapy may be used as an improved treatment strategy in HER2-positive GC patients.

PET/Computed Tomography and Precision Medicine: Gastric Cancer

Gastric cancer is a disease with low survival rates and high morbidity, requiring accurate and prompt diagnosis and treatment. Although limited in the evaluation of the primary tumor as such, the metabolic information of primary tumors in an ¹⁸F-FDG PET/CT study can assist in surgical and treatment planning and differentiating gastric cancers. It detects nodal disease with good specificity and positive predictive value, thus enabling appropriate therapy for individual patients. It provides valuable information about distant metastases, altering therapy decisions. It has reasonably good performance in detecting recurrent disease and in the follow-up of patients.

Significant response to ramucirumab monotherapy in chemotherapy-resistant recurrent alpha-fetoprotein-producing gastric cancer: A case report

Alpha-fetoprotein (AFP)-producing gastric cancer (AFPGC) is a relatively rare type of gastric cancer characterized by a high incidence of liver and lymph node metastases, and a poor prognosis. Few advanced AFPGC cases treated successfully with conventional chemotherapy have been reported thus far. Although the development of molecular-targeted therapy has improved the prognosis of various types of cancer, there are currently no tailored therapies for AFPGC. In the present report, the case of a chemotherapy-resistant recurrent AFPGC patient who exhibited a significant response to ramucirumab monotherapy is presented. Following six doses of ramucirumab, a metastatic lymph node displayed central necrosis, and the patient's serum AFP levels decreased from 12,800 to 225 ng/ml. AFPGC is known to have increased vascular endothelial growth factor (VEGF) expression and rich neovascularization. Furthermore, in the present case, tumor cells were positive for VEGF. Ramucirumab is a monoclonal antibody for VEGF receptor-2 and the first anti-angiogenic drug approved for the treatment of advanced gastric cancer. However, the clinical efficacy of ramucirumab in patients with AFPGC has not been reported previously. The present report suggests that AFP production in gastric cancer can be a predictor for the response to anti-angiogenic drugs such as ramucirumab.

High expression of Wls is associated with lymph node metastasis and advanced TNM stage in gastric carcinomas

The roles of Wnt protein in carcinogenesis have been well documented in human cancers. Wls is a key modulator for the secretion of Wnt protein. We previously found that Wls was aberrantly expressed in colorectal carcinomas. Studies have revealed that dysregulation of Wnt signal transduction plays an important role in gastric carcinoma. We hypothesized that Wls may play a role in the development and progression of gastric carcinoma. In this study, three gastric cancer cell lines MGC-803, SGC-7901, and AGS, and a set of gastric carcinoma tissue specimens were subjected to immunohistochemistry. The relationship between the expression of Wls and clinicopathological parameters was analyzed. Wls was negatively detected in MGC-803, positively detected in SGC-7901 and AGS cell lines. Wls was weakly expressed in 9.7% (15/154), moderately in 33.1% (51/154), and strongly in 57.1% (88/154) of tested gastric carcinoma specimens. High expression of Wls was positively associated with well and moderately differentiated tumors (P = 0.035, r_s  = 0.170), lymph node metastasis (P = 0.001, r_s  = 0.276), and advanced TNM stage (P = 0.006, r_s  = 0.219). Our data suggest that Wls protein is related to tumor metastasis and advanced TNM stage, and may be used as a new marker for prognosis of gastric carcinoma.

Role of miR-647 in human gastric cancer suppression

MicroRNAs (miRNAs) regulate various oncogenes concomitantly, resulting in tumor suppression. They regulate proliferation and migration pathways in tumor development, suggesting a potential therapeutic role. In the present study, we found that miR-647 was markedly downregulated in gastric cancer (GC), and was significantly correlated with reduced tumor size and metastasis. In addition, miR-647 was also reduced in GC cell lines. Furthermore, overexpression of miR-647 in the GC cell lines inhibited cell proliferation, promoted cell cycle arrest at the G0/G1 phase and induced cell apoptosis. miR-647 also significantly inhibited tumor growth in vivo. Notably, we found that miR-647 overexpression suppressed the migration and invasion of the cancer cells, particularly liver metastasis in nude mice. miR-647 also reduced the expression levels of genes associated with proliferation and metastasis in tumors, including ANK2, FAK, MMP2, MMP12, CD44 and SNAIL1. Overall, our findings demonstrated that miR-647 exerts powerful antitumorigenic effects in vitro and in vivo, and may represent a promising therapeutic agent against GC.

Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) levels in the cerebrospinal fluid of children with influenza-associated encephalopathy

INTRODUCTION

To search for an index of neurologic prognosis of children with influenza-associated encephalopathy (IAE), involvement of angiogenesis-related growth factors in the pathology was investigated.

PATIENTS AND METHODS

The subjects were 11 IAE patients, 6 patients with bacterial meningitis (BM), and 24 patients with non-central nervous system infection as a control group admitted to our hospital. The correlation between the vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) levels in cerebrospinal fluid and the relationship with an index of inflammatory marker, interleukin (IL)-6, were investigated. Using the Pediatric Cerebral Performance Categories (PCPC) score as a prognostic indicator, we evaluated the association between the biomarkers and neurologic prognosis.

RESULT

PDGF significantly increased in the IAE group compared with that in the BM group. Cerebrospinal fluid VEGF and PDGF increased in all IAE and BM patients compared with that in the control group, and VEGF and PDGF were positively correlated in the 2 groups. No correlation was found between the cerebrospinal fluid VEGF and PDGF levels and IL-6 level in the IAE group, whereas a correlation was found in the BM group. All these factors increased in patients with poor neurologic prognosis.

DISCUSSION

It is possible that the disease state of IAE can be evaluated based on vascular endothelial disorder-related markers.

Ablation of human telomerase reverse transcriptase (hTERT) induces cellular senescence in gastric cancer through a galectin-3 dependent mechanism

The human Telomerase Reverse Transcriptase (hTERT) gene encodes a rate-limiting catalytic subunit of telomerase that maintains genomic integrity. Suppression of hTERT expression could induce cellular senescence and is considered a potent approach for gastric cancer therapy. However, control of hTERT expression and function remains poorly understood in gastric cancer. In this study, we demonstrated that high expression levels of hTERT in malignant tissues are correlated with poor survival probability in gastric cancer patients. Knockdown of hTERT expression retarded cell proliferation and cellular senescence, which was confirmed by increased protein expression levels of p21cip1 and p27kip1, and decreased phosphorylation of Rb. In contrast, overexpression of hTERT increased cell proliferation and decreased cellular senescence. Remarkably, the down-regulation of hTERT expression was detected in lgals3-/- mouse embryo fibroblasts (MEFs). Knockdown of galectin-3 decreased the expression of hTERT in gastric cancer cells. Galectin-3 ablation-induced cellular senescence was rescued by concomitant overexpression of hTERT. hTERT ablation-induced cellular senescence and p21cip1 and p27kip1 expression was rescued by concomitant overexpression of galectin-3. The size of tumor burdens was increased in hTERT-overexpressed gastric cancer cells xenografted mice, whereas it was repressed by concomitant depletion of galectin-3. Additionally, we determined that the N-terminal domain of galectin-3 directly interacted with hTERT. The telomeric activity of hTERT was also decreased by galectin-3 ablation. Taken together, ablation of hTERT induces cellular senescence and inhibits the growth of gastric cancer cells, suggesting that it could be a potent target in gastric cancer therapy. We also propose that galectin-3 is an important regulator of hTERT expression and telomeric activity in gastric tumorigenesis.

Significance of expression of INPP4B in gastric cancer

AIM: To investigate the expression of inositol polyphosphate-4-phosphatase, type II (INPP4B) in gastric cancer, and to analyze its relationship with clinical and pathological characteristics.

METHODS: The expression of INPP4B mRNA and protein in 50 gastric cancer tissues and matched tumor-adjacent normal tissues was detected by quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC), respectively. The relationship between INPP4B expression and clinical and pathological characteristics was then analyzed.

RESULTS: INPP4B mRNA expression was significantly lower in gastric cancer tissue than in adjacent normal tissues (P < 0.01). The expression of INPP4B protein in gastric cancer tissues was also significantly lower compared with adjacent normal tissues (28.0% vs 82.0%, P < 0.01). The expression of INPP4B mRNA and protein was significantly related to tumor differentiation, lymph node metastasis and TNM stage in GC (P < 0.05), but not to gender, age or tumor size (P > 0.05).

CONCLUSION: Both INPP4B protein and mRNA are down-regulated in gastric cancer, and its expression significantly correlates with tumor differentiation, lymph node metastasis and TNM stage. INPP4B may be a tumor suppressor gene for gastric cancer.

Lauren classification and individualized chemotherapy in gastric cancer

Gastric cancer is one of the most common malignancies worldwide. During the last 50 years, the histological classification of gastric carcinoma has been largely based on Lauren's criteria, in which gastric cancer is classified into two major histological subtypes, namely intestinal type and diffuse type adenocarcinoma. This classification was introduced in 1965, and remains currently widely accepted and employed, since it constitutes a simple and robust classification approach. The two histological subtypes of gastric cancer proposed by the Lauren classification exhibit a number of distinct clinical and molecular characteristics, including histogenesis, cell differentiation, epidemiology, etiology, carcinogenesis, biological behaviors and prognosis. Gastric cancer exhibits varied sensitivity to chemotherapy drugs and significant heterogeneity; therefore, the disease may be a target for individualized therapy. The Lauren classification may provide the basis for individualized treatment for advanced gastric cancer, which is increasingly gaining attention in the scientific field. However, few studies have investigated individualized treatment that is guided by pathological classification. The aim of the current review is to analyze the two major histological subtypes of gastric cancer, as proposed by the Lauren classification, and to discuss the implications of this for personalized chemotherapy.

Effects for Sequential Treatment of siAkt and Paclitaxel on Gastric Cancer Cell Lines

Real-time screening of cellular response on the drugs could provide valuable insights for the early detection of therapeutic efficiency and the evaluation of disease progression. Cancer cells have the ability to vary widely in response to stress in a manner to adjust the signaling pathway to promote the survival or having a resistance to stimulation. Cell-based label-free technologies using electronic impedance sensor have strategies for constructing the signature profiles of each cells. To achieve exquisite sensitivity to substantially change of live-cell response have an important role that predict the potential of therapeutic effects. In this study, we use an impedance-based real-time cell analysis system to investigate dynamic phenotypes of cells described as a cellular index value. We show that gastric cancer cells generated characteristic kinetic patterns that corresponded to the treatment order of therapeutics. The kinetic feature of the cells offers insightful information that cannot be acquired from a conventional single end-point assay. Furthermore, we employ a 'sequential treatment strategy' to increase cytotoxic effects with minimizing the use of chemotherapeutics. Specifically, treatment of paclitaxel (PTX) after down-regulating Akt gene expression using RNAi reduces the cell proliferation and increases apoptosis. We propose that the sequential treatment may exhibit more effective approach rather than traditional combination therapy. Moreover, the dynamic monitoring of cell-drug interaction enables us to obtain a better understanding of the temporal effects in vitro.