Gastric Cancer in the Era of Precision Medicine

A clinical study of traditional Chinese medicine prolonging the survival of advanced gastric cancer patients by regulating the immunosuppressive cell population: A study protocol for a multicenter, randomized controlled trail

BACKGROUND

Gastric cancer (GC) is a common high-mortality disease, causing a serious social burden. Traditional Chinese medicine has been utilized to prevent and treat GC for many years but its effects remain unclear. The aim of our study is to elucidate the anti-tumor effects and the possible mechanism of Jianpi Yangzheng Xiaozheng decoction.

METHODS/DESIGN

This is a prospective, multicenter, randomized controlled trial continuing 1.5 years. Two hundred ten eligible patients will be randomly divided into 2 groups, the chemotherapy alone and the chemotherapy combined with JPYZXZ group at a ratio of 1:2. All patients will receive the treatment for 24 weeks and follow up for 1.5 years. The primary outcomes are one-year survival rate, progression-free survival, and overall survival (OS), while the secondary outcomes are immune related hematology test, objective response rate, tumor makers, traditional Chinese medicine syndrome points, fatigue scale, and quality of life scale. All of these outcomes will be analyzed at the end of the trail.

DISCUSSION

This study will provide the objective evidence for the efficacy and safety of Jianpi Yangzheng Xiaozheng decoction in advanced GC. Furthermore, it will be helpful to form a therapeutic regimen in advanced GC by the combination of traditional medicine and western medicine.Trail registration: ChiCTR1900028147.

Global updates in the treatment of gastric cancer: a systematic review. Part 1: staging, classification and surgical treatment

Gastric cancer (GC) is the fifth malignancy and the third cause of cancer death worldwide, according to the global cancer statistics presented in 2018. Its definition and staging have been revised in the eight edition of the AJCC/TNM classification, which took effect in 2018. Novel molecular classifications for GC have been recently established and the process of translating these classifications into clinical practice is ongoing. The cornerstone of GC treatment is surgical, in a context of multimodal therapy. Surgical treatment is being standardized, and is evolving according to new anatomical concepts and to the recent technological developments. This is leading to a massive improvement in the use of mini-invasive techniques. Mini-invasive techniques aim to be equivalent to open surgery from an oncologic point of view, with better short-term outcomes. The persecution of better short-term outcomes also includes the optimization of the perioperative management, which is being implemented on large scale according to the enhanced recovery after surgery principles. In the era of precision medicine, multimodal treatment is also evolving. The long-time-awaited results of many trials investigating the role for preoperative and postoperative management have been published, changing the clinical practice. Novel investigations focused both on traditional chemotherapeutic regimens and targeted therapies are currently ongoing. Modern platforms increase the possibility for further standardization of the different treatments, promote the use of big data, and open new possibilities for surgical learning. This systematic review in two parts assesses all the current updates in GC treatment.

Human adipose-derived mesenchymal stem cells inhibit proliferation and induce apoptosis of human gastric cancer HGC-27 cells

The aim of this study was to explore the effects of human adipose-derived mesenchymal stem cells (ASCs) on the growth of gastric cancer cells in vivo and vitro and its mechanism. ASCs were isolated from abandoned adipose tissues, and the surface markers were identified by flow cytometry. In vitro experiments, HGC-27 cells cultured in ASCs-conditioned medium (CM) were assigned as the experimental group, while HGC-27 cells cultured in normal medium were as the control group. MTT and colony formation assays were performed to detect cell viability and colony formatting ability, respectively. Annexin-V/PI assay, Western blot, and caspase-3 enzyme activity assay were performed to detect cells apoptosis. The isolated ASCs could be differentiated into adipocytes and osteoblasts in vitro. Flow cytometry showed that CD73 and CD105 were positively expressed in HGC-27 cells. Compared with the mice injected HGC-27 cells only, the tumor formation in mice injected both ASCs and HGC-27 cells was significantly smaller (P < 0.05). The colony formation ability in experimental group was 40.09% smaller than control group (P < 0.05) and the cell apoptosis rate in experimental group was higher than the control group (P < 0.05). Furthermore, the expressions of cleaved PARP, cleaved caspase-3 proteins, and caspase-3 enzyme viability in experimental group were significantly higher than those of control group (P < 0.05). In conclusion, ASCs can effectively inhibit the growth of HGC-27 cells by inducing apoptosis.

Identification of a novel oncogenic mutation of FGFR4 in gastric cancer

Gastric cancer remains one of the leading causes of cancer death worldwide. Despite intensive investigations of treatments over the past three decades, the poor prognosis of patients with unresectable advanced or recurrent gastric cancer has not significantly changed, and improved therapies are required. Here, we report the identification of an oncogenic mutation in FGFR4 in a human gastric tumour that leads to constitutive activation of its product, FGFR4. The G636C-FGFR4 tyrosine kinase domain mutation was found in 1 of 83 primary human gastric tumours. The G636C mutation increased FGFR4 autophosphorylation, and activated FGFR4 downstream signalling molecules and enhanced anchorage-independent cell growth when expressed in NIH/3T3 cells. 3D-structural analysis and modelling of FGFR4 suggest that G636C destabilizes an auto-inhibitory conformation and stabilizes an active conformation, leading to increased kinase activation. Ba/F3 cell lines expressing the G636C-FGFR4 mutant were significantly more sensitive to ASP5878, a selective FGFR inhibitor, than the control. Oral administration of ASP5878 significantly inhibited the growth of tumours in mice engrafted with G636C-FGFR4/3T3 cells. Together, our results demonstrate that mutationally activated FGFR4 acts as an oncoprotein. These findings support the therapeutic targeting of FGFR4 in gastric cancer.

Association of intron microsatellite status and exon mutational profiles of TP53 in human colorectal cancer

Microsatellite instability (MSI) and loss of heterozygosity (LOH), which cause genomic instability, contribute to cancer pathogenesis. However, only few studies have evaluated the association of a single microsatellite locus of the TP53 gene with the mutation spectra of TP53 exons. A total of 256 patients with colorectal cancer were enrolled in the present study. MSI/LOH alterations of a microsatellite in the TP53 intron (TP53ALU) were assessed via short tandem repeat scanning. The exon mutation profile was evaluated by direct sequencing. The mutation rate of TP53 exons was significantly higher in tumors with LOH alterations of TP53 introns compared with those in tumors with a microsatellite-stable status in the TP53 intron (P=0.0047). TNM stage II was significantly more frequent in MSI vs. LOH or MSS of the TP53 intron (P=0.027 and P=0.048, respectively). Thus, microsatellite alterations may be valuable predictors of TP53 exon mutation and the TNM stage of colorectal cancers.

DNA methylation silencing of microRNA gene methylator in the precancerous background mucosa with and without gastric cancer: Analysis of the effects of H. pylori eradication and long-term aspirin use

The risk of gastric cancer (GC) declines after Helicobacter pylori (H. pylori) eradication and long-term aspirin use. We evaluated the effects of H. pylori eradication (Cohort 1) and aspirin use (Cohort 2) on the methylation of microRNAs (miRNAs), such as miR-34c, miR-124a-3, miR-129-2, and miR-137, in the gastric mucosa with and without GC, i.e., in atrophic mucosal glands without intestinal metaplasia (non-IM) and intestinal metaplastic glands (IM). DNA was isolated from non-IM and IM separately using laser caption microdissection. In Cohort 1, H. pylori eradication was associated with a significant reduction of miR-124a-3 methylation only in non-IM, but not in IM. miR-129-2 methylation in non-IM may be a surrogate marker of GC in H. pylori-infected patients. In Cohort 2, aspirin did not reverse miRNA methylation in either non-IM or IM, irrespective of H. pylori infection. miR-129-2 methylation in non-IM was an independent predictive marker of GC in H. pylori-infected but not -eradicated patients. These results indicate that H. pylori eradication and aspirin use were less effective for improving methylation in IM than in non-IM; thus, these interventions are recommended at an early stage prior to the development of IM to prevent GC development. In addition, the effects of the interventions were not uniform for each miRNA gene.

Clinical Implementation of Precision Medicine in Gastric Cancer

Gastric cancer (GC) is one of the deadliest malignancies in the world. Currently, clinical treatment decisions are mostly made based on the extent of the tumor and its anatomy, such as tumor-node-metastasis staging. Recent advances in genome-wide molecular technology have enabled delineation of the molecular characteristics of GC. Based on this, efforts have been made to classify GC into molecular subtypes with distinct prognosis and therapeutic response. Simplified algorithms based on protein and RNA expressions have been proposed to reproduce the GC classification in the clinical field. Furthermore, a recent study established a single patient classifier (SPC) predicting the prognosis and chemotherapy response of resectable GC patients based on a 4-gene real-time polymerase chain reaction assay. GC patient stratification according to SPC will enable personalized therapeutic strategies in adjuvant settings. At the same time, patient-derived xenografts and patient-derived organoids are now emerging as novel preclinical models for the treatment of GC. These models recapitulate the complex features of the primary tumor, which is expected to facilitate both drug development and clinical therapeutic decision making. An integrated approach applying molecular patient stratification and patient-derived models in the clinical realm is considered a turning point in precision medicine in GC.

Detecting genetic hypermutability of gastrointestinal tumor by using a forensic STR kit

Growing evidence suggests that somatic hypermutational status and programmed cell death-1 overexpression are potential predictive biomarkers indicating treatment benefits from immunotherapy using immune checkpoint inhibitors. However, biomarker-matched trials are still limited, and many of the genomic alterations remain difficult to target. To isolate the potential somatic hypermutational tumor from microsatellite instability low/microsatellite stability (MSI-L/MSS) cases, we employed two commercial kits to determine MSI and forensic short tandem repeat (STR) alternations in 250 gastrointestinal (GI) tumors. Three types of forensic STR alternations, namely, allelic loss, Aadd, and Anew, were identified. 62.4% (156/250) of the patients with GI exhibited STR alternation, including 100% (15/15) and 60% (141/235) of the microsatellite high instability and MSI-L/MSS cases, respectively. 30% (75/250) of the patients exhibited STR instability with more than 26.32% (26.32%-84.21%) STR alternation. The cutoff with 26.32% of the STR alternations covered all 15 MSI cases and suggested that it might be a potential threshold. Given the similar mechanism of the mutations of MSI and forensic STR, the widely used forensic identifier STR kit might provide potential usage for identifying hypermutational status in GI cancers.

Crosstalk Between DNA Damage and Inflammation in the Multiple Steps of Gastric Carcinogenesis

Over the last years, intensive investigations in molecular biology and cell physiology extended tremendously the knowledge about the association of inflammation and cancer. In frame of this paradigm, the human pathogen Helicobacter pylori triggers gastritis and gastric ulcer disease, and contributes to the development of gastric cancer. Mechanisms, by which the bacteria-induced inflammation in gastric mucosa leads to intestinal metaplasia and carcinoma, are represented in this review. An altered cell-signaling response and increased production of free radicals by epithelial and immune cells account for the accumulation of DNA damage in gastric mucosa, if infection stays untreated. Host genetics and environmental factors, especially diet, can accelerate the process, which offers the opportunity of intervention based on a balanced nutrition. It is supposed that inflammation might influence stem- or progenitor cells in gastric tissue predisposing for metaplasia or tumor relapse. Herein, DNA is strongly mutated and labile, which restricts therapy options. Thus, the understanding of the mechanisms that underlie gastric carcinogenesis will be of preeminent importance for the development of strategies for screening and early detection. As most gastric cancer patients face late-stage disease with a poor overall survival, the development of multi-targeted therapeutic intervention strategies is a major challenge for the future.

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.

Establishment of Novel Gastric Cancer Patient-Derived Xenografts and Cell Lines: Pathological Comparison between Primary Tumor, Patient-Derived, and Cell-Line Derived Xenografts

Patient-derived xenograft (PDX) models have been recognized as being more suitable for predicting therapeutic efficacy than cell-culture models. However, there are several limitations in applying PDX models in preclinical studies, including their availability—especially for cancers such as gastric cancer—that are not frequently encountered in Western countries. In addition, the differences in morphology between primary, PDX, and tumor cell line-derived xenograft (CDX) models have not been well established. In this study, we aimed to establish a series of gastric cancer PDXs and cell-lines from a relatively large number of gastric cancer patients. We also investigated the clinicopathological factors associated with the establishment of PDX and CDX models, and compared the histology between the primary tumor, PDX, and CDX that originated from the same patient. We engrafted 232 gastric cancer tissues into immune-deficient mice subcutaneously and successfully established 35 gastric cancer PDX models (15.1% success rate). Differentiated type adenocarcinomas (DAs, 19.4%) were more effectively established than poorly differentiated type adenocarcinomas (PDAs, 10.8%). For establishing CDXs, the success rate was less influenced by histological differentiation grade (DA vs. PDA, 12.1% vs. 9.8%). In addition, concordance of histological differentiation grade between primary tumors and PDXs was significant (p < 0.01), while concordance between primary tumors and CDXs was not. Among clinicopathological factors investigated, pathological nodal metastasis status (pN) was significantly associated with the success rate of PDX establishment. Although establishing cell lines from ascites fluid was more efficient (41.2%, 7/17) than resected tissues, it should be noted that all CDXs from ascites fluid had the PDA phenotype. In conclusion, we established 35 PDX and 32 CDX models from 249 gastric cancer patients; among them, 21 PDX/CDX models were established from the same patients. Our findings may provide helpful insights for establishing PDX and CDX models not only from gastric but from other cancer types, as well as select preclinical models for developing new therapeutics.

CircPCMTD1 Acts as the Sponge of miR-224-5p to Promote Glioma Progression

Glioma is the most common malignant tumor of the central nervous system with high morbidity and mortality. Circular RNAs (circRNAs) are abundant non-coding RNAs, which contribute to tumor progression by competing with other endogenous RNAs such as microRNA (miRNA). MiRNA are a class of small non-coding RNAs, which interrupt the translation of target mRNAs. CircPCMTD1 (hsa-circ-0001801) is a newly discovered circRNA that was found to be significantly upregulated in glioma. However, its function is unclear. In this study, circPCMTD1 upregulation promoted the cell viability, migration and invasion dramatically, while the inhibition of circPCMTD1 led to a significant reduction of tumor growth in vivo. MiRNAs microarray analyses on circPCMTD1 silencing models in U251 and U118MG cells were performed, and the results suggested that circPCMTD1 knockdown could upregulate the expression of miR-224-5p and downregulate the expression of mTOR, one of miR-224-5p targets, in both cell lines. According to the prediction from circular RNA interactome and Targetscan, there was a complementary sequence in circPCMTD1 for miR-224-5p. Dual-luciferase reporter assay demonstrated that circPCMTD1 were targets of miR-224-5p. RIP assay was also performed to further confirm their directly interaction. Overexpression of miR-224-5p inhibited the viability and proliferation, migration, and invasion of U251 and U118MG glioma cells. In conclusion, circPCMTD1 could contribute to the promotion of glioma progression, and it may serve as the sponge of miR-224-5p to exert its function.

A subset of diffuse-type gastric cancer is susceptible to mTOR inhibitors and checkpoint inhibitors

Background

Mechanistic target of rapamycin (mTOR) pathway is essential for the growth of gastric cancer (GC), but mTOR inhibitor everolimus was not effective for the treatment of GCs. The Cancer Genome Atlas (TCGA) researchers reported that most diffuse-type GCs were genomically stable (GS). Pathological analysis suggested that some diffuse-type GCs developed from intestinal-type GCs.

Methods

We established patient-derived xenograft (PDX) lines from diffuse-type GCs, and searched for drugs that suppressed their growth. Diffuse-type GCs were classified into subtypes by their gene expression profiles.

Results

mTOR inhibitor temsirolimus strongly suppressed the growth of PDX-derived diffuse-type GC-initiating cells, which was regulated via Wnt-mTOR axis. These cells were microsatellite unstable (MSI) or chromosomally unstable (CIN), inconsistent with TCGA report. Diffuse-type GCs in TCGA cohort could be classified into two clusters, and GS subtype was major in cluster I while CIN and MSI subtypes were predominant in cluster II where PDX-derived diffuse-type GC cells were included. We estimated that about 9 and 55% of the diffuse-type GCs in cluster II were responders to mTOR inhibitors and checkpoint inhibitors, respectively, by identifying PIK3CA mutations and MSI condition in TCGA cohort. These ratios were far greater than those of diffuse-type GCs in cluster I or intestinal-type GCs. Further analysis suggested that diffuse-type GCs in cluster II developed from intestinal-type GCs while those in cluster I from normal gastric epithelial cells.

Conclusion

mTOR inhibitors and checkpoint inhibitors might be useful for the treatment of a subset of diffuse-type GCs which may develop from intestinal-type GCs.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1121-3) contains supplementary material, which is available to authorized users.

Three-Dimensional Organoids in Cancer Research: The Search for the Holy Grail of Preclinical Cancer Modeling

Most solid tumors become therapy resistant and will relapse, with no durable treatment option available. One major impediment to our understanding of cancer biology and finding innovative approaches to cancer treatment stems from the lack of better preclinical tumor models that address and explain tumor heterogeneity and person-to-person differences in therapeutic and toxic responses. Past cancer research has been driven by inadequate in vitro assays utilizing two-dimensional monolayers of cancer cells and animal models. Additionally, animal models do not truly mimic the original human tumor, are time consuming, and usually costly. New preclinical models are needed for innovation in cancer translational research. Hence, it is time to welcome the three-dimensional (3D) organoids: self-organizing cells grown in 3D culture systems mimicking the parent tissues from which the primary cells originate. The 3D organoids offer deeper insights into the crucial cellular processes in tissue and organ formation and pathological processes. Generation of near-perfect physiological microenvironments allow 3D organoids to couple with gene editing tools, such as the clustered regularly interspersed short palindromic repeat (CRISPR)/CRISPR-associated 9 and the transcription activator-like effector nucleases to model human diseases, offering distinct advantages over current models. We explain in this expert review that through recapitulating patients' normal and tumor tissues, organoid technology can markedly advance personalized medicine and help reveal once hidden aspects of cancers. The use of defined tissue- or organ-specific matrices, among other factors, will likely allow organoid technology to realize its potential in innovating many fields of life sciences.

Ratio-based staging systems are better than the 7th and 8th editions of the TNM in stratifying the prognosis of gastric cancer patients: A multicenter retrospective study

BACKGROUND

The current and the previous editions of the tumor-node-metastasis (TNM) system for gastric cancer (GC; TNM8 and TNM7) have a high risk of stage-migration bias when the node count after gastrectomy is suboptimal. Hence, they are possibly not the optimal staging systems for GC patients. This study aims to compare the TNM with two systems less affected by the stage-migration bias, namely, the lymph nodes ratio (LNR) and the log odds of positive lymph nodes (LODDS), to assess which one is the best in stratifying the prognosis of GC patients.

METHODS

The sample study included 1221 GC patients. Two 7-cluster staging systems based on the combination of pT categories and LNR and LODDS categories (TLNR and TLODDS) were compared with the two last editions of TNM, using the Akaike information criteria, the Bayesian information criteria, and the receiver operating characteristic (ROC) curve graphs. Further validation on an independent sample of 251 patients was carried out.

RESULTS

The univariable and multivariable analyses and the ROC curves detected an advantage of the TLNR and TLODDS systems over the TNM. The TLNR and TLODDS showed the best accuracy both in the subgroup of patients with ≥16 nodes examined. The results were confirmed in the validation analysis.

CONCLUSIONS

TLNR and TLODDS staging systems should be considered a valid implementation of the TNM for the prognostic stratification of GC patients. If these results are confirmed in further studies, the future implementation of the TNM should consider the introduction of the LNR or the LODDS along with the number of metastatic nodes.

Podocalyxin-like protein promotes gastric cancer progression through interacting with RUN and FYVE domain containing 1 protein

Podocalyxin‐like protein (PODXL), a transmembrane glycoprotein with anti‐adhesive properties, is associated with an aggressive tumor phenotype and poor prognosis of several cancers. To elucidate the biological significance of PODXL and its molecular mechanism in gastric cancer (GC), we investigated the expression of PODXL in GC samples and assessed its effects on biological behaviors and the related signaling pathways in vitro and in vivo. Moreover, the possible and closely interacted partners of PODXL were identified. Our data showed that the protein or mRNA level of PODXL was significantly upregulated in tissues or serum of GC patients compared with normal‐appearing tissues (NAT) or those of healthy volunteers. Overall survival (OS) curves showed that patients with high PODXL levels in tissues or serum had a worse 5‐year OS. In vitro, restoring PODXL expression promoted tumor progression by increasing cell proliferation, colony formation, wound healing, migration and invasion, as well as suppressing the apoptosis. Furthermore, the PI3K/AKT, NF‐κB and MAPK/ERK signaling pathways were activated. There was a significant positive correlation between PODXL and RUN and FYVE domain containing 1 (RUFY1) expression in tissues or serum. Subsequent mass spectrometry analysis, co‐immunoprecipitation assays and western blot analysis identified PODXL/RUFY1 complexes in GC cells, and silencing RUFY1 expression in GC cells significantly attenuated PODXL‐induced phenotypes and their underlying signaling pathways. Our results suggested that PODXL promoted GC progression via a RUFY1‐dependent signaling mechanism. New GC therapeutic opportunities through PODXL and targeting the PODXL/RUFY1 complex might improve cancer therapy.

Synthetic Circular RNA Functions as a miR-21 Sponge to Suppress Gastric Carcinoma Cell Proliferation

MicroRNA (miR) sponges containing miR binding sequences constitute a potentially powerful molecular therapeutic strategy. Recently, naturally occurring circular RNAs (circRNAs) were shown to function as efficient miR sponges in cancer cells. We hypothesized that synthetic circRNA sponges could achieve therapeutic loss-of-function targeted against specific miRs. Linear RNA molecules containing miR-21 binding sites were transcribed in vitro; after dephosphorylation and phosphorylation, circularization was achieved using 5'-3' end-ligation by T4 RNA ligase 1. circRNA stability was assessed using RNase R and fetal bovine serum. Competitive inhibition of miR-21 activity by a synthetic circRNA sponge was assessed using luciferase reporter, cell proliferation, and cell apoptosis assays in three gastric cancer cell lines. circRNA effects on downstream proteins were also delineated by Tandem Mass Tag (TMT) labeling (data available via ProteomeXchange identifier PRIDE: PXD008584), followed by western blotting. We conclude that artificial circRNA sponges resistant to nuclease digestion can be synthesized using simple enzymatic ligation steps. These sponges inhibit cancer cell proliferation and suppress the activity of miR-21 on downstream protein targets, including the cancer protein DAXX. In summary, synthetic circRNA sponges represent a simple, effective, convenient strategy for achieving targeted loss of miR function in vitro, with potential future therapeutic application in human patients.

Resolving gastric cancer aetiology: an update in genetic predisposition

Every year gastric cancer accounts for nearly 1 million new cases and more than 720 000 deaths worldwide. Prognosis is dismal because most patients are diagnosed with advanced disease; as such, gastric cancer outcomes will benefit from better methods for identification of at-risk individuals that can be targeted for early detection. One approach to targeting high-risk populations is to identify individuals who are genetically predisposed to gastric cancer, as up to 15% of all patients report family history of the disease. On the basis of clinical manifestations, three gastric cancer syndromes have been described, but the diagnosis of some of these syndromes is suboptimal and could benefit from genetic information. Over the past decade, genome-wide association and next-generation sequencing studies have identified several low penetrance variants and high-risk genes, considerably increasing our understanding of inherited gastric cancer predisposition. From these studies, PALB2 has emerged as a new familial gastric cancer gene. Furthermore, genetic analyses in patients with sporadic gastric cancer suggest that more than 10% of all cases have pathogenic mutations, a finding of great importance for cancer aetiology. In this Review, we summarise the role of genetics in gastric cancer aetiology and the implications of genetics findings for the prevention of this malignancy.

Jinlong Capsule (JLC) inhibits proliferation and induces apoptosis in human gastric cancer cells in vivo and in vitro

BACKGROUND

As a representative traditional Chinese medicine made by modern pharmaceutical technology, Jinlong Capsule (JLC) has been used for several decades to treat liver cancer with significantly improved clinical outcomes as adjuvant therapy. JLC consists of three medicinal animals including freshly prepared Bungarus, Agkistrodon and Gecko. The active components were extracted by the process of modern cryogenic and biochemical separation from raw animals. However, the specific molecular mechanisms underlying the antitumor activities of JLC were not fully investigated. In the current study, experiments were carried out to examine the effect of JLC on anti-proliferative, pro-apoptotic activities of human gastric cancer (GC) cell lines in vivo and in vitro.

METHODS

MTT assay was used to observe the viability of MGC-803 and BGC-823 cells treated with JLC. Apoptosis and cell cycle distribution of MGC-803 and BGC-823 cells induced by JLC were analyzed by flow cytometry. Western blot assay was used to detect the effect of JLC on apoptosis-related proteins, including Bax, Bcl-2, survivin and caspase-3. Transmission electron microscopy (TEM) was used to evaluate the microstructure of apoptotic GC cells. Tumor growth in vivo was monitored using live-imaging system. Immunohistochemical staining (IHC) was used to examine the expression of apoptosis-related proteins in tumor tissues.

RESULTS

Our data indicated that JLC inhibited proliferation and induced apoptosis of MGC-803 and BGC-823 cells in a concentration-dependent manner. JLC significantly inhibited tumor growth in nude mice. Both in vivo and in vitro studies showed that JLC could downregulate the expression of Bcl-2 and survivin, whereas upregulate the levels of bax and caspase-3. JLC had significant antitumor effects in human GC through cell cycle arresting. Besides, JLC altered the microstructure of GC cells.

CONCLUSION

These findings demonstrate that JLC can be considered as a promising candidate in GC treatment.

Transcription Factor Myeloid Zinc-Finger 1 Suppresses Human Gastric Carcinogenesis by Interacting with Metallothionein 2A

PURPOSE

Metallothionein 2A (MT2A) suppresses the progression of human gastric cancer potentially through an "MT2A-NF-κB pathway" with unclear mechanisms. This study explored the role of a transcription factor, myeloid zinc-finger 1 (MZF1), in MT2A-NF-κB pathway and its clinical significance in gastric cancer.

EXPERIMENTAL DESIGN

MZF1 expression and function in gastric cancer were investigated in vitro and in vivo. The relationship between MZF1 and MT2A was determined by gain-of-function and loss-of-function assays in gastric cancer cells and an immortalized gastric cell line GES-1. The prognostic value of MZF1 expression in association with MT2A was evaluated using IHC in two cohorts.

RESULTS

MZF1 was epigenetically silenced in human gastric cancer cell lines and primary tumors. Overexpression of MZF1 in gastric cancer cells suppressed cell proliferation and migration, as well as the growth of xenograft tumors in nude mice. Knocking-down of MZF1 transformed GES-1 cells into a malignant phenotype characterized by increased cell growth and migration. Mechanistically, MZF1 was upregulated in both GC and GES-1 cells by MT2A ectopically expressed or induced upon treatment with a garlic-derived compound, diallyl trisulfide (DATS). MZF1 associated with MT2A was colocalized in the nuclei of GES-1 cells to target the promoter of NF-κB inhibitor alpha (NFKBIA). Clinically, MT2A and MZF1 were progressively downregulated in clinical specimens undergoing gastric malignant transformation. Downregulation of MT2A and MZF1 was significantly correlated with poorer patient prognosis.

CONCLUSIONS

MT2A exerts its anti-gastric cancer effects by complexing with MZF1 to target NFKBIA. MT2A/MZF1 may serve as a valuable prognostic marker and a novel therapeutic target for human gastric cancer.

Long-term effects of H. pylori eradication on epigenetic alterations related to gastric carcinogenesis

The risk of gastric cancer (GC) remains in precancerous conditions, including atrophic mucosa and intestinal mucosa (IM), even after H. pylori treatment. To define the molecular changes following H. pylori eradication, molecular alterations in the gastric mucosa with and without GC were evaluated in a long-term follow-up study. A total of 232 biopsy specimens from 78 consecutive patients, including atrophic gastritis patients with follow-up ≥3 y after successful H. pylori eradication (AG group), patients who developed early GC after successful eradication (≥3 y) (GC group), and patients with H. pylori-positive atrophic gastritis (Hp group), were analyzed. H. pylori eradication was associated with significant reductions of methylation of several genes/loci in atrophic mucosa (non-IM), but not in IM. In contrast, the incidence of CpG island methylator phenotype (CIMP) in IM was significantly higher in the GC group than in the AG group. miR-124a-3 methylation and miR-34c methylation were more frequently identified in IM, with very few in non-IM mucosa among the three groups. H. pylori eradication can reverse methylation only in non-IM mucosa. CIMP in IM may have potential as a surrogate maker of GC development, and methylation of miR-124a-3 and miR-34c is a molecular event in IM that may not be associated with GC development.

[Study of the evolution in the activity of a Department of Pathology from a third level hospital in the last decade (2007-2016)]

OBJECTIVE

To study the evolution of variables of interest in a department of pathology from a third level hospital during the last decade and to evaluate the impact on these of the hospital relocation in 2014.

MATERIAL AND METHOD

Retrospective observational study in which the recorded samples (biopsies, cytology specimens, FNA, autopsies, intraoperative) as well as the complementary techniques (IHC, Histochemistry, IF and FISH) and portfolio of services were analyzed during the years 2007-2016 inclusive. For the statistical analysis, the five-year periods 2007-2011 and 2012-2016 were compared.

RESULTS

The following variables were statistically significant: cytology (34055.8±1994.0 vs 26590.4±2938.3, p=0.002), autopsies (156.2±27.3 vs 122.0±14.78, p=0.039), immunohistochemistry (17855.4±3424.2 vs 28559.2±4734.7, p=0.003), histochemistry (11117.8±2300.9 vs 6225.0±1330.5, p=0.003) and immunofluorescence (610.2±185.3 vs. 1205.4±154.0, p=0.001). Statistical correlations of interest among variables have been identified. In 2014, it was observed that the variables of greater specific weight (biopsies, cytology, IHQ and histochemistry) in the work load of the Department showed an average decrease of 12.5%. A generalized increase in the panel of available samples has been identified, the largest increase being seen in the number of antibodies (78.7%), histochemistry (38.7%) and FISH (400%).

CONCLUSION

Relevant variations in work volume, as well as the service portfolio, have been identified, especially in the techniques aimed at improving diagnostic accuracy (IHQ and FI), and a significant decrease in the number of cytology specimens, autopsies and histochemistry. In the year 2014 a decrease of more than 12% in the main variables of the study was observed.

Long non-coding RNA UFC1 promotes gastric cancer progression by regulating miR-498/Lin28b

BACKGROUND

Long non-coding RNAs (lncRNAs) have emerged as important regulators of human cancers. However, the functional roles of lncRNAs and the mechanisms responsible for their aberrant expression in gastric cancer (GC) have not been well characterized.

METHODS

In this study, we examined the expression of lncRNA UFC1 in GC by qRT-PCR and explored its correlation with clinicopathological parameters. In vitro cell functional assays and in vivo animal studies were performed to determine the roles of UFC1 in GC progression.

RESULTS

UFC1 was elevated and predicted poorer prognosis in GC. UFC1 knockdown inhibited while UFC1 overexpression promoted GC cell proliferation, migration, and invasion. UFC1 bound to miR-498 to antagonize its tumor suppressive effect on Lin28b. Suppression of Lin28b by miR-498 could be rescued by UFC1 overexpression, whereas Lin28b overexpression partially rescued UFC1 knockdown-mediated inhibition of GC cell function. Lin28b expression was increased in GC and suggested a co-expression pattern with UFC1.

CONCLUSIONS

UFC1 has a promoting role in GC progression, at least in part, by acting as a miR-498 sponge and derepressing Lin28b expression, which would provide a novel biomarker for GC diagnosis and prognosis and offer a potential target for GC therapy.

Long intergenic non-coding RNA 00324 promotes gastric cancer cell proliferation via binding with HuR and stabilizing FAM83B expression

Substantial evidence shows that long non-coding RNAs (lncRNAs) participate in many biological mechanisms, and their dysregulation are also involved in the development and progression of cancers, including gastric cancer (GC). Long intergenic non-coding RNA 00324 (LINC00324), a 2115 bp ncRNA, is located on chromosome 17p13.1. The biological function and molecular mechanisms of LINC00324 in GC remains undiscovered. In this paper, we found that the expression level of LINC00324 was significantly upregulated in GC tissues compared with the corresponding normal tissues. The overexpression of LINC00324 was correlated with advanced TNM stage, larger tumor size, and lymph node metastasis as well as poor prognosis. Further experiments revealed that knockdown of LINC00324 could suppress the proliferation of GC cells. RNA transcriptome sequencing technology revealed that FAM83B may be a significant downstream target gene of LINC00324. LINC00324 could combine with the RNA-binding protein (RBP) human antigen R (HuR) and thus stabilize the expression of FAM83B. Moreover, rescue assays showed that the reduced FAM83B expression partially reversed the promotion of cell growth in GC induced by the overexpression of LINC00324. In conclusion, our study revealed that LINC00324 acted as an oncogene in tumorigenesis and progression, suggesting that it could be a new biomarker in diagnosis and prognosis of GC.

Detection of Gastric Cancer with Novel Methylated DNA Markers: Discovery, Tissue Validation, and Pilot Testing in Plasma

Purpose: Gastric adenocarcinoma is the third most common cause of cancer mortality worldwide. Accurate and affordable noninvasive detection methods have potential value for screening and surveillance. Herein, we identify novel methylated DNA markers (MDM) for gastric adenocarcinoma, validate their discrimination for gastric adenocarcinoma in tissues from geographically separate cohorts, explore marker acquisition through the oncogenic cascade, and describe distributions of candidate MDMs in plasma from gastric adenocarcinoma cases and normal controls.Experimental Design: Following discovery by unbiased whole-methylome sequencing, candidate MDMs were validated by blinded methylation-specific PCR in archival case-control tissues from U.S. and South Korean patients. Top MDMs were then assayed by an analytically sensitive method (quantitative real-time allele-specific target and signal amplification) in a blinded pilot study on archival plasma from gastric adenocarcinoma cases and normal controls.Results: Whole-methylome discovery yielded novel and highly discriminant candidate MDMs. In tissue, a panel of candidate MDMs detected gastric adenocarcinoma in 92% to 100% of U.S. and South Korean cohorts at 100% specificity. Levels of most MDMs increased progressively from normal mucosa through metaplasia, adenoma, and gastric adenocarcinoma with variation in points of greatest marker acquisition. In plasma, a 3-marker panel (ELMO1, ZNF569, C13orf18) detected 86% (95% CI, 71-95) of gastric adenocarcinomas at 95% specificity.Conclusions: Novel MDMs appear to accurately discriminate gastric adenocarcinoma from normal controls in both tissue and plasma. The point of aberrant methylation during oncogenesis varies by MDM, which may have relevance to marker selection in clinical applications. Further exploration of these MDMs for gastric adenocarcinoma screening and surveillance is warranted. Clin Cancer Res; 24(22); 5724-34. ©2018 AACR.

Long non-coding RNA-mediated regulation of signaling pathways in gastric cancer

Gastric cancer (GC) is one of the most common cancers globally. Because of the high frequency of tumor recurrence, or metastasis, after surgical resection, the prognosis of patients with GC is poor. Therefore, exploring the mechanisms underlying GC is of great importance. Recently, accumulating evidence has begun to show that dysregulated long non-coding RNAs (lncRNAs) participate in the progression of GC via several typical signaling pathways, such as the AKT and MAPK signaling pathways. Moreover, the interactions between lncRNAs and microRNAs appear to represent a novel mechanism in the pathogenesis of GC. This review provides a synopsis of the latest research relating to lncRNAs and associated signaling pathways in GC.

Patient-derived organoid models help define personalized management of gastrointestinal cancer

BACKGROUND

The prognosis of patients with different gastrointestinal cancers varies widely. Despite advances in treatment strategies, such as extensive resections and the addition of new drugs to chemotherapy regimens, conventional treatment strategies have failed to improve survival for many tumours. Although promising, the clinical application of molecularly guided personalized treatment has proven to be challenging. This narrative review focuses on the personalization of cancer therapy using patient-derived three-dimensional 'organoid' models.

METHODS

A PubMed search was conducted to identify relevant articles. An overview of the literature and published protocols is presented, and the implications of these models for patients with cancer, surgeons and oncologists are explained.

RESULTS

Organoid culture methods have been established for healthy and diseased tissues from oesophagus, stomach, intestine, pancreas, bile duct and liver. Because organoids can be generated with high efficiency and speed from fine-needle aspirations, biopsies or resection specimens, they can serve as a personal cancer model. Personalized treatment could become a more standard practice by using these cell cultures for extensive molecular diagnosis and drug screening. Drug sensitivity assays can give a clinically actionable sensitivity profile of a patient's tumour. However, the predictive capability of organoid drug screening has not been evaluated in prospective clinical trials.

CONCLUSION

High-throughput drug screening on organoids, combined with next-generation sequencing, proteomic analysis and other state-of-the-art molecular diagnostic methods, can shape cancer treatment to become more effective with fewer side-effects.

Clinical multi-omics strategies for the effective cancer management

Cancer is a global health issue as a multi-factorial complex disease, and early detection and novel therapeutic strategies are required for more effective cancer management. With the development of systemic analytical -omics strategies, the therapeutic approach and study of the molecular mechanisms of carcinogenesis and cancer progression have moved from hypothesis-driven targeted investigations to data-driven untargeted investigations focusing on the integrated diagnosis, treatment, and prevention of cancer in individual patients. Predictive, preventive, and personalized medicine (PPPM) is a promising new approach to reduce the burden of cancer and facilitate more accurate prognosis, diagnosis, as well as effective treatment. Here we review the fundamentals of, and new developments in, -omics technologies, together with the key role of a variety of practical -omics strategies in PPPM for cancer treatment and diagnosis.

BIOLOGICAL SIGNIFICANCE

In this review, a comprehensive and critical overview of the systematic strategy for predictive, preventive, and personalized medicine (PPPM) for cancer disease was described in a view of cancer prognostic prediction, diagnostics, and prevention as well as cancer therapy and drug responses. We have discussed multi-dimensional data obtained from various resources and integration of multisciplinary -omics strategies with computational method which could contribute the more effective PPPM for cancer. This review has provided the novel insights of the current applications of each and combined -omics technologies, which showed their powerful potential for the establishment of PPPM for cancer.

Mitochondrial biomarkers predict tumor progression and poor overall survival in gastric cancers: Companion diagnostics for personalized medicine

Here, we employed a bioinformatics approach to identify novel molecular determinants to predict tumor progression and overall survival in gastric cancer patients. In particular, we directly assessed whether nuclear-derived mRNA species encoding proteins involved in mitochondrial protein translation and OXPHOS are able to successfully predict clinical outcome in gastric cancer. As such, using in silico validation, we have now established the prognostic value of these mitochondrial biomarkers, in a defined population of gastric cancer patients. In this context, we interrogated 5 year follow-up data collected from a group of N = 359 gastric cancer patients. Importantly, in this group of cancer patients, Ki67 and PCNA (conventional markers of cell proliferation) were associated with tumor progression, as might be expected. Using this simplified informatics approach, we identified ∼75 new individual mitochondrial gene probes that effectively predicted tumor progression, with hazard-ratios (HR) of up to 2.22 (p < 2.1e-10). These mitochondrial mRNA transcripts included heat shock proteins/chaperones, membrane proteins, anti-oxidants, enzymes involved in genome maintenance, as well as mitochondrial ribosomal proteins (MRPs) and numerous members of the OXPHOS complexes. In addition, we combined 8 mitochondrial protein transcripts (NDUFS5, VDAC3, ATP5O, IMMT, MRPL28, COX5B, MRPL52, PRKDC), to generate a compact gastric mitochondrial gene signature, associated with a HR of 2.77 (p = 1.4e-14). As a result of this analysis and validation, we strongly suggest that proteins involved in mitochondrial protein translation and OXPHOS should be considered as targets for new drug discovery, for the treatment of gastric cancers. The mitochondrial markers we identified here could also be used as companion diagnostics, to predict clinical outcomes, as well as the patient response to therapy. This should allow a more successful and personalized approach to gastric cancer diagnosis and therapy.

The Role of Epigenetic Regulation in Epstein-Barr Virus-Associated Gastric Cancer

The Epstein–Barr virus (EBV) is detected in about 10% of gastric carcinoma cases throughout the world. In EBV-associated gastric carcinoma (EBVaGC), all tumor cells harbor the clonal EBV genome. The expression of latent EBV genes is strictly regulated through the methylation of EBV DNA. The methylation of viral DNA regulates the type of EBV latency, and methylation of the tumor suppressor genes is a key abnormality in EBVaGC. The methylation frequencies of several tumor suppressor genes and cell adhesion molecules are significantly higher in EBVaGC than in control cases. EBV-derived microRNAs repress translation from viral and host mRNAs. EBV regulates the expression of non-coding RNA in gastric carcinoma. With regard to the clinical application of demethylating agents against EBVaGC, we investigated the effects of decitabine against the EBVaGC cell lines. Decitabine inhibited the cell growth of EBVaGC cells. The promoter regions of p73 and Runt-related transcription factor 3(RUNX3) were demethylated, and their expression was upregulated by the treatment. We review the role of epigenetic regulation in the development and maintenance of EBVaGC and discuss the therapeutic application of DNA demethylating agents for EBVaGC.

Expression and function of transforming growth factor‑β‑activated protein kinase 1 in gastric cancer

The present study aimed to investigate the expression and role of transforming growth factor (TGF) ‑β‑activated protein kinase 1 (TAK1) in human gastric cancer. Immunohistochemistry was performed to investigate the expression of TAK1 in surgical specimens of human gastric cancer tissue and adjacent normal tissue. The association between TAK1 and clinicopathologic factors was analyzed and the association between TAK1 expression and the overall survival rates was evaluated using Kaplan‑Meier curves. In addition, the effect of the TAK1 selective inhibitor 5Z‑7‑oxozeaenol (OZ) on the biological characteristics of MGC803 human gastric cancer cells in vitro were investigated. The role of TAK1 in gastric cancer cell proliferation, apoptosis and invasion were determined by cell proliferation assays, flow cytometry analysis and transwell invasion assays, respectively. The findings of the present study demonstrated that the positive expression rate of TAK1 in gastric cancer and adjacent normal tissues was 70.5 and 25.9%, respectively. Furthermore, TAK1 expression was significantly associated with advanced N stage and pathological stage (P<0.05). Survival analysis of 139 patients with gastric cancer indicated a lower overall survival rate of patients in the TAK1‑positive group compared with the TAK1‑negative group (P<0.05). In addition, treatment with the TAK1 selective inhibitor OZ reduced the proliferation and invasion abilities of MGC803 cells and significantly reduced the expression levels of phosphorylated‑TAK1 (Thr187), nuclear p65, cyclin D1, Bcl‑2 apoptosis regulator and matrix metallopeptidase (MMP)9 (P<0.05). OZ treatment significantly increased the expression levels of cytosolic cytochrome c and cleaved caspase 3 and the apoptosis rate in MGC803 cells (P<0.05). In conclusion, these findings suggest that increased TAK1 expression may be involved in the progression of gastric cancer; therefore, TAK1 may be used as a future therapeutic target for gastric cancer treatment.