Unique characteristics of ARID1A mutation and protein level in gastric and colorectal cancer: A meta-analysis

Potential Regulation of ARID1A by miR-129-5p and miR-3613-3p and Their Prognostic Value in Gastric Cancer

Gastric cancer (GC) remains the most common malignant tumor of the gastrointestinal tract and one of the leading causes of cancer-related deaths worldwide. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), are involved in the pathogenesis and progression of GC and, therefore, may be potential diagnostic and prognostic biomarkers. Our work was aimed at investigating the predicted regulation of ARID1A by miR-129-5p and miR-3613-3p and the clinical value of their aberrant expression in GC. The study included tumor and adjacent non-tumor tissues from 110 GC patients, 38 sectional normal gastric tissue samples, as well as 65 plasma samples of GC patients and 49 plasma samples of healthy donors. Expression levels of ARID1A and both miRNAs were quantified by reverse transcription-polymerase chain reaction (RT-PCR). We have identified significant associations of their expression with the clinical and pathological characteristics of GC patients both in tissues and plasma. To validate predicted target pairs miR-129-5p/ARID1A and miR-3613-3p/ARID1A, in vitro experiments on cancer cell lines were conducted. The obtained results suggest a complex role of ARID1A, miR-129-5p and miR-3613-3p in GC and potential regulation of ARID1A expression by both miRNAs.

Microbiome Differences in Colorectal Cancer Patients and Healthy Individuals: Implications for Vaccine Antigen Discovery

Background

Colorectal cancer (CRC) is the third most prevalent cancer worldwide, with numerous risk factors contributing to its development. Recent research has illuminated the significant role of the gut microbiota in CRC pathogenesis, identifying various microbial antigens as potential targets for vaccine development.

Aim

This review aimed at exploring the potential sources of microbial antigens that could be harnessed to create effective CRC vaccines and understand the role of microbiome-CRC interactions in carcinogenesis.

Methods

A comprehensive search of original research and review articles on the pathological links between key microbial candidates, particularly those more prevalent in CRC tissues, was conducted. This involved extensive use of the PubMed and Medline databases, as well as the Google Scholar search engine, utilizing pertinent keywords. A total of one hundred and forty-three relevant articles in English, mostly published between 2018 and 2024, were selected.

Results

Numerous microbes, particularly bacteria and viruses, are significantly overrepresented in CRC tissues and have been shown to promote tumorigenesis by inducing inflammation and modulating the immune system. This makes them promising candidates for antigens in the development of CRC vaccines.

Conclusion

The selection of microbial antigens focuses on their capacity to trigger a strong immune response and their link to tumor presence and progression. Identifying and validating these antigens through preclinical testing is essential in developing a CRC vaccine.

Identification of the Expression of TIE1 and Its Mediated Immunosuppression in Gastric Cancer

Background: Recently, various evidence has confirmed that Tyrosine Kinase with Immunoglobulin-like and EGF-like domains 1 (TIE1) promotes tumor growth in many cancers. However, the precise mechanism underlying TIE1's involvement in Gastric Cancer (GC) remains elusive. This research aimed to investigate the biological function of TIE1 in regulating GC progression. Methods: The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), GEPIA2.0, Sangerbox3.0 and TIMER databases were used to analyze the TIE1 expression. Immunohistochemistry (IHC) was used to demonstrate the expression of TIE1. TCGA, GEPIA2.0 and Kaplan-Meier were utilized for survival analysis and to explore the association of TIE1 with clinicopathological features. Protein-Protein Interaction (PPI) networks were constructed using Cytoscape. The potential molecular mechanism of TIE1 was investigated by Gene Ontology (GO), Kyoto Encyclopedia of Gene Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). We studied the relationships between TIE1 and mutations, immune checkpoints (ICs), tumor mutational burden (TMB), as well as microsatellite instability (MSI) to explore the underlying mechanism of immunity in GC. Results: Compared with normal tissue, TIE1 was significantly overexpressed in GC tissues (p = 0.0072) and was associated with poor survival (P < 0.05). According to GO and KEGG enrichment analyses, TIE1 was enriched in signal pathways related to the occurrence, invasion, and migration of malignant tumors (i.e., PI3K-Akt signaling pathway, Calcium signaling pathway, etc.). Immune infiltration analysis suggested that TIE1 is positively correlated with macrophages M2 and negatively correlated with Mast cells, naive B cells and Follicular helper T cells (TFH), which may be a contributing factor to tumor progression. Furthermore, the research on the tumor microenvironment (TME) and tumor purity also proved that TIE1 may be an oncogene. Mutation analysis showed that the high expression group of TIE1 had a higher frequency of mutations in TP53 and ARID1, while the TMB score was lower. Conclusion: TIE1 might be an oncogene via regulating dysregulated immune infiltration to cause immunosuppression in GC and could be identified as a biomarker for prognosis and a therapeutic target for GC.

Comparative analysis of ARID1A mutations with mRNA levels and protein expression in gastric carcinoma

The ARID1A gene is pivotal in chromatin remodeling and genomic integrity and is frequently mutated in various cancer types. ARID1A mutation is the second most frequently mutated tumor suppressor gene and has been suggested as a predictor of immunotherapeutic responsiveness in gastric carcinoma (GC). Despite its significance, the relationship among ARID1A somatic mutations, RNA expression levels, and protein expression remains unclear, particularly in GC. For this purpose, we performed comparative study in two cohorts. Cohort 1 used next-generation sequencing (NGS) to identify 112 GC cases with ARID1A mutations. These cases were compared with ARID1A immunohistochemistry (IHC) results. Cohort 2 employed microarray gene expression data to assess ARID1A RNA levels and compare them with ARID1A IHC results. In Cohort 1, 38.4% of ARID1A-mutated GC exhibited a complete loss of ARID1A protein when assessed by IHC, whereas the remaining 61.6% displayed intact ARID1A. Discordance between NGS and IHC results was not associated with specific mutation sites, variant classifications, or variant allele frequencies. In Cohort 2, 24.1% of the patients demonstrated a loss of ARID1A protein, and there was no significant difference in mRNA levels between the ARID1A protein-intact and -loss groups. Our study revealed a substantial discrepancy between ARID1A mutations detected using NGS and protein expression assessed using IHC in GC. Moreover, ARID1A mRNA expression levels did not correlate well with protein expression. These findings highlighted the complexity of ARID1A expression in GC.

Molecular Classifications in Gastric Cancer: A Call for Interdisciplinary Collaboration

Gastric cancer (GC) is a heterogeneous disease, often diagnosed at advanced stages, with a 5-year survival rate of approximately 20%. Despite notable technological advancements in cancer research over the past decades, their impact on GC management and outcomes has been limited. Numerous molecular alterations have been identified in GC, leading to various molecular classifications, such as those developed by The Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG). Other authors have proposed alternative perspectives, including immune, proteomic, or epigenetic-based classifications. However, molecular stratification has not yet transitioned into clinical practice for GC, and little attention has been paid to alternative molecular classifications. In this review, we explore diverse molecular classifications in GC from a practical point of view, emphasizing their relationships with clinicopathological factors, prognosis, and therapeutic approaches. We have focused on classifications beyond those of TCGA and the ACRG, which have been less extensively reviewed previously. Additionally, we discuss the challenges that must be overcome to ensure their impact on patient treatment and prognosis. This review aims to serve as a practical framework to understand the molecular landscape of GC, facilitate the development of consensus molecular categories, and guide the design of innovative molecular studies in the field.

The effects of ARID1A mutation in gastric cancer and its significance for treatment

Gastric cancer (GC) has emerged as a significant issue in public health all worldwide as a result of its high mortality rate and dismal prognosis. AT-rich interactive domain 1 A (ARID1A) is a vital component of the switch/sucrose-non-fermentable (SWI/SNF) chromatin remodeling complex, and ARID1A mutations occur in various tumors, leading to protein loss and decreased expression; it then affects the tumor biological behavior or prognosis. More significantly, ARID1A mutations will likely be biological markers for immune checkpoint blockade (ICB) treatment and selective targeted therapy. To provide theoretical support for future research on the stratification of individuals with gastric cancer with ARID1A as a biomarker to achieve precision therapy, we have focused on the clinical significance, predictive value, underlying mechanisms, and possible treatment strategies for ARID1A mutations in gastric cancer in this review.

The clinicopathological and genetic differences among gastric cancer patients with no recurrence, early recurrence, and late recurrence after curative surgery

BACKGROUND

To date, few reports have investigated the genetic alterations and clinicopathological features among gastric cancer (GC) patients with no tumor recurrence, early recurrence, and late recurrence following curative surgery.

METHODS

A total of 473 GC patients undergoing curative surgery were included. The clinicopathological characteristics, patient prognosis, recurrence patterns, and genetic alterations were compared between GC patients with early recurrence and late recurrence.

RESULTS

Among the 473 GC patients, 119 had early recurrence (<2 years) and 45 had late recurrence (≥2 years). Patients with early recurrence had tumor size larger than 5 cm, fewer superficial-type tumors, more lymphovascular invasion, more advanced pathological T and N categories and Tumor, Node, Metastasis (TNM) stages, and worse 5-year overall survival than patients with late recurrence and no recurrence. For intestinal-type GC, patients with no tumor recurrence had more Helicobacter pylori infection than patients with early recurrence and late recurrence; for diffuse-type GC patients, the frequency of PIK3CA amplification was the highest in early recurrence, followed by late recurrence and no recurrence. GC patients with single-site recurrence had more ARID1A mutations than those with multiple-site recurrence. Multivariate analysis demonstrated that age, tumor recurrence, and pathological N categories were independent prognostic factors.

CONCLUSION

PIK3CA amplifications were more common in diffuse-type GC with early recurrence, whereas ARID1A mutations were more common in patients with single-site recurrence. Targeted therapy and immunotherapy might be helpful for these patients.

Chromatin Dynamics in Digestive System Cancer: Commander and Regulator

Digestive system tumors have a poor prognosis due to complex anatomy, insidious onset, challenges in early diagnosis, and chemoresistance. Epidemiological statistics has verified that digestive system tumors rank first in tumor-related death. Although a great number of studies are devoted to the molecular biological mechanism, early diagnostic markers, and application of new targeted drugs in digestive system tumors, the therapeutic effect is still not satisfactory. Epigenomic alterations including histone modification and chromatin remodeling are present in human cancers and are now known to cooperate with genetic changes to drive the cancer phenotype. Chromatin is the carrier of genetic information and consists of DNA, histones, non-histone proteins, and a small amount of RNA. Chromatin and nucleosomes control the stability of the eukaryotic genome and regulate DNA processes such as transcription, replication, and repair. The dynamic structure of chromatin plays a key role in this regulatory function. Structural fluctuations expose internal DNA and thus provide access to the nuclear machinery. The dynamic changes are affected by various complexes and epigenetic modifications. Variation of chromatin dynamics produces early and superior regulation of the expression of related genes and downstream pathways, thereby controlling tumor development. Intervention at the chromatin level can change the process of cancer earlier and is a feasible option for future tumor diagnosis and treatment. In this review, we introduced chromatin dynamics including chromatin remodeling, histone modifications, and chromatin accessibility, and current research on chromatin regulation in digestive system tumors was also summarized.

ARID1A knockdown enhances carcinogenesis features and aggressiveness of Caco-2 colon cancer cells: An in vitro cellular mechanism study

Loss of ARID1A, a tumor suppressor gene, is associated with the higher grade of colorectal cancer (CRC). However, molecular and cellular mechanisms underlying the progression and aggressiveness of CRC induced by the loss of ARID1A remain poorly understood. Herein, we evaluated cellular mechanisms underlying the effects of ARID1A knockdown on the carcinogenesis features and aggressiveness of CRC cells. A human CRC cell line (Caco-2) was transfected with small interfering RNA (siRNA) specific to ARID1A (siARID1A) or scrambled (non-specific) siRNA (siControl). Cell death, proliferation, senescence, chemoresistance and invasion were then evaluated. In addition, formation of polyploid giant cancer cells (PGCCs), self-aggregation (multicellular spheroid) and secretion of an angiogenic factor, vascular endothelial growth factor (VEGF), were examined. The results showed that ARID1A knockdown led to significant decreases in cell death and senescence. On the other hand, ARID1A knockdown enhanced cell proliferation, chemoresistance and invasion. The siARID1A-transfected cells also had greater number of PGCCs and larger spheroid size and secreted greater level of VEGF compared with the siControl-transfected cells. These data, at least in part, explain the cellular mechanisms of ARID1A deficiency in carcinogenesis and aggressiveness features of CRC.

Epstein-Barr Virus in the Development of Colorectal Cancer (Review)

The study of the influence of the Epstein–Barr virus (EBV) on the development of colorectal cancer is of current interest, particularly in light of the active discussion of the participation of this virus in the carcinogenesis of stomach cancer. In this review, aimed at a fundamental understanding of the processes associated with the impact of EBV on the human body, attention is paid to the issues of the life cycle of the virus, its phases (latent and lytic), as well as proteins that may be detected in each of the phases. The papers reporting on the role of EBV in the development of colorectal cancer have been analyzed. A summary table indicating the population under study, the number of samples, the method, and the result obtained is provided. Given that the primary cells affected by EBV are lymphocytes, it is logical to assume the involvement of this virus in the development of inflammatory bowel diseases. The review cites studies which confirm the presence of virus DNA in tissues in the inflammatory diseases of the colon, including microscopic and ulcerative colitis. To confirm the direct impact of EBV on the development of colorectal cancer, large studies with applying various methods for detecting the virus and the mandatory description of its localization are required. Besides, it is necessary to correlate these data with the clinical and morphological characteristics of EBV.

CD47 expression in gastric cancer clinical correlates and association with macrophage infiltration

BACKGROUND

CD47 has been identified as an innate immune checkpoint and found to be associated with inferior survival in various types of cancer. However, the critical role of CD47 in gastric cancer and its association with tumor associated macrophages remain unclear.

METHODS

Tumor tissues of gastric cancer from Zhongshan Hospital and data from GSE62254, GSE84437 and TCGA datasets were analyzed. Immunohistochemistry was performed to detect the expression of CD47, CD11c, CD163 and CD68 in gastric cancer tissues. Kaplan-Meier curves and Cox model were used for comparing the clinical outcomes of patients belonging to different subgroups.

RESULTS

Gastric cancer patients with high CD47 expression exhibited poor prognosis and inferior therapeutic responsiveness to fluorouracil-based adjuvant chemotherapy (ACT). A positive correlation was found between M1-polarized macrophage infiltration and CD47 expression in gastric cancer; however, the prognostic value of M1-polarized macrophages was attenuated in CD47-high gastric cancer patients. Moreover, we found that CD47 mRNA level was enriched in microsatellite-instable (MSI) subtype of gastric cancer and associated with ARID1A mutation and FGFR2 signaling pathway activation.

CONCLUSIONS

Aberrant CD47 expression represented an independent predictor for adverse survival outcome and ACT resistance in gastric cancer. Targeting CD47 might be a promising strategy for gastric cancer patients.

Cardia Gastric Cancer Is Associated With Increased PIK3CA Amplifications and HER2 Expression Than Noncardia Gastric Cancer According to Lauren Classification

Background

To date, few reports have investigated genetic alterations and clinicopathological features in cardia and noncardia gastric cancer (GC).

Methods

In total, 435 GC patients receiving curative surgery were included. The clinicopathological features, recurrence patterns, prognoses and genetic alterations were compared between cardia and noncardia GC patients.

Results

Among the 435 enrolled patients, 47 (10.8%) had cardia GC. Compared with noncardia GC, cardia GC was associated with more intestinal-type tumors and similar initial recurrence patterns and 5-year overall survival (OS; 50.8% vs. 50.5%, P = 0.480) and disease-free survival (DFS; 48.6% vs. 48.9%, P = 0.392) rates. For both intestinal-type GC and diffuse-type GC, the clinicopathological features and 5-year OS and DFS rates were not significantly different between the cardia and noncardia GC patients. Multivariable analysis showed that cardia GC was not an independent prognostic factor. Compared with noncardia GC, cardia GC was associated with increased PIK3CA amplification than in patients with intestinal-type GC and was associated with increased HER2 expression in patients with diffuse-type GC.

Conclusions

Cardia GC is not an independent prognostic factor. In cardia GC patients with intestinal-type GC, PIK3CA amplification was more common, and in those with diffuse-type GC, HER2 expression was more common. Targeted therapy may be beneficial for these patient subgroups.

The effects of ARID1A mutations on colorectal cancer and associations with PD-L1 expression by stromal cells

Background

ARID1A is a component of the SWI/SNF complex, which controls the accessibility of proteins to DNA. ARID1A mutations are frequently observed in colorectal cancers (CRCs) and have been reported to be associated with high mutational burden and tumor PD‐L1 expression in vitro.

Aim

To clarify the role of ARID1A mutation in CRC.

Method and results

We used next generation sequencing (NGS) and immunohistochemistry on clinically obtained samples. A total of 201 CRC tissues from Niigata University and Niigata Center Hospital were processed by NGS using the CANCERPLEX panel. Immunohistochemistry for ARID1A, PD‐L1, MLH1, and MSH2 was performed on 66 propensity‐matched (33 microsatellite instability‐high [MSI‐H] and 33 microsatellite‐stable [MSS]) cases among 499 cases from Kyushu University. TCGA data were downloaded from cBioPortal. NGS showed significantly more mutations in ARID1A mutated CRCs (p = 0.01), and the trend was stronger for right‐sided CRCs than left‐sided. TCGA data confirmed these findings (p < 0.01). BRAF V600E and ATM mutations were also found at higher frequencies. Immunohistochemistry showed that 30% of MSI‐H CRCs had ARID1A loss, while this was true in only 6% of MSS CRCs. In both MSI‐H and MSS, PD‐L1 expression by stromal cells was enhanced in the ARID1A‐mutant groups (90% vs 39% in MSI‐H, 100% vs 26% in MSS).

Conclusion

We found a higher mutational burden in ARID1A‐mutant CRCs, and IHC study showed that ARID1A loss was correlated with high PD‐L1 expression in stromal cells regardless of MSI status. These data support the idea that mutant ARID1A is a potential biomarker for CRCs.

Molecular Heterogeneity of High Grade Colorectal Adenocarcinoma

Simple Summary

Due to its low frequency, high grade colorectal carcinomas (HG-CRCs) are underrepresented in molecular series. We intended to further characterize the pathological and molecular features of these tumors. In addition, morphologically different areas when present, were analyzed separately to study tumor heterogeneity. We found that most (72.5%) of HG-CRCs showed mismatch repair (MMR) deficiency. MMR status conditioned the frequency and the clonality of the molecular alterations found. Thus, whereas BRAF mutations and gene fusions were observed only in MMR deficient (MMRd) tumors, TP53, KRAS, and gene amplifications predominated in MMR proficient (MMRp) tumors. In MMRp tumors, gene amplification was a mechanism of progression, whereas the accumulation of mutations in genes of different pathways such as NOTCH, MMR or PIK3CA was involved in the clonal diversity of MMRd HG-CRC. In summary, intertumor and intratumor molecular heterogeneity in HG-CRCs is mainly due to MMR status.

Abstract

High grade colorectal carcinomas (HG-CRCs), which comprise 15% of colorectal carcinomas, are underrepresented in reported molecular studies. Clinicopathological, immunohistochemical, and molecular features of 40 HG-CRCs are described. Moreover, glandular and solid areas of 25 tumors were separately analyzed. The expression of MLH1, PMS2, MSH2, MSH6, p53, E-cadherin, CDX2, CK20, CD8, PDL1, PAN-TRK, c-MET, SMARCB1, ARID1A, SMARCA2, and SMARCA4 was analyzed by immunohistochemistry. Promoter MLH1 methylation was analyzed in tumors with MLH1/PMS2 loss. Next-generation sequencing was used to screen 161 genes for hotspot mutations, copy number variations and gene fusions. In this series, 72.5% of HG-CRCs showed mismatch repair deficiency (MMRd). MMR deficient tumor and MMR proficient (MMRp) tumors showed striking molecular differences. Thus, whereas BRAF mutations were only observed in MMRd tumors, mutations in KRAS and TP53 were more frequent in MMR proficient tumors. Moreover, gene fusions (NTRK1 and MET) were detected only in MMRd tumors, whereas gene amplification (MYC, CCND1 and EGFR) predominated in MMRp/TP53-mutated tumors. Loss of expression of proteins involved in chromatin remodeling, such as ARID1A, was observed only in MMRd HG-CRCs, which also showed more frequently PD-L1 expression and a higher number of tumor infiltrating lymphocytes. The separate analysis of glandular and solid areas indicated that the clonal or subclonal nature of the molecular alterations also depended on MMR status. Mutations in genes such as TP53 and KRAS were always clonal in MMRp-CRCs but occurred as subclonal events in MMRd-CRCs. Gene amplification was implicated in the progression of MMRp tumors, but not in MMRd tumors, in which clonal diversity was due to accumulation of mutations in genes of different pathways such as NOTCH, MMR, or PIK3CA. In summary, intertumor and intratumor molecular heterogeneity in HG-CRCs is mainly due to MMR status.

The Role of ARID1A in Tumors: Tumor Initiation or Tumor Suppression?

Genes encoding subunits of SWItch/Sucrose Non-Fermenting (SWI/SNF) chromatin remodeling complexes are collectively mutated in 20% of all human cancers, among which the AT-rich interacting domain-containing protein 1A (ARID1A, also known as BAF250a, B120, C1orf4, Osa1) that encodes protein ARID1A is the most frequently mutated, and mutations in ARID1A have been found in various types of cancer. ARID1A is thought to play a significant role both in tumor initiation and in tumor suppression, which is highly dependent upon context. Recent molecular mechanistic research has revealed that ARID1A participates in tumor progression through its effects on control of cell cycle, modulation of cellular functions such as EMT, and regulation of various signaling pathways. In this review, we synthesize a mechanistic understanding of the role of ARID1A in human tumor initiation as well as in tumor suppression and further discuss the implications of these new discoveries for potential cancer intervention. We also highlight the mechanisms by which mutations affecting the subunits in SWI/SNF complexes promote cancer.

Molecular screening and clinicopathologic characteristics of Lynch-like syndrome in a Chinese colorectal cancer cohort

Colorectal cancers (CRC) with microsatellite instability (MSI) or mismatch repair-deficiency (dMMR), but without detectable MMR germline mutations are termed Lynch-like syndrome (LLS). We assess the clinicopathologic and molecular characteristics of LLS tumors and the proportion in LLS, which remain poorly investigated in China. We enrolled 404 CRC patients with surgery in our institution from 2014 to 2018. LLS tumors were detected by a molecular stratification based on MMR protein expression, MLH1 methylation and MMR gene mutation. LLS tumors were profiled for germline mutations in 425 cancer-relevant genes. Among 42 MMR-deficient tumors, 7 (16.7%) were attributable to MLH1 methylation and 7 (16.7%) to germline mutations, leaving 28 LLS cases (66.6%). LLS tumors were diagnosed at a mean age of 60.7 years, had an almost equivalent ratio among rectum, left colon and right colon, and had high rates of lymph node metastases (50%, 4/28 N2). Most MMR gene mutations (88.2%, 15/17) in LLS tumors were variants of unknown significance (VUS). Two novel frameshift mutations were detected in ATM and ARID1A, which are emerging as candidate responsible genes for LLS. In this study, 28 (66.6%) MMRd tumors were classified as LLS, which were significantly higher than reports of western countries. LLS tumors were more likely to carry lymph node metastases. However, it's hard to differentiated LLS tumors from LS through family history, tumor location, histological type of tumors, immunohistochemistry (IHC) for MMR proteins and MSI analysis.

Remodeling of the ARID1A tumor suppressor

In recent years, AT-rich interactive domain-containing protein 1A (ARID1A) has been widely accepted as a bona fide tumor suppressor due to its essential role in preventing tumorigenesis and tumor progression in both mouse and human contexts. ARID1A shows high mutation frequencies in both cancers and preneoplastic lesions. The loss of ARID1A expression in cancer cells leads to increases in cell proliferation, invasion and migration and reductions in cell apoptosis and chemosensitivity. The tumor-suppressive role of ARID1A is mainly attributed to its regulation of gene transcription, which can be induced either directly by chromatin remodeling or indirectly by affecting histone modifications. ARID1A also acts independently of its cardinal transcription-regulating mechanisms, which include interfering with protein-protein interactions. Interestingly, nonmutational mechanisms, such as regulation by DNA hypermethylation, microRNAs, and ubiquitinases/deubiquitinases, have provided another perspective on ARID1A inactivation in cancer. Since the critical tumor-suppressive role of ARID1A has been revealed, several studies have attempted to identify synthetic lethal targets with ARID1A mutation/inactivation as an alternative strategy for cancer treatment.

The clinicopathological characteristics and genetic alterations between younger and older gastric cancer patients with curative surgery

Few reports have investigated different genetic alterations according to age in various cancers. In total, 1749 GC patients receiving curative surgery were enrolled. The clinicopathological features, and prognoses were compared between younger (<65 years) and older (≥65 years) patients. Genetic mutations were analyzed using mass spectrometric single nucleotide polymorphism genotyping technology, including 68 validated mutations within eight genes (TP53, ARID1A, BRAF, and the PI3K/AKT pathway) previously reported in relation to age. Younger patients were more likely to be female and have poor cell differentiation, diffuse-type tumors, less lymphovascular invasion, fewer liver metastases, and better 5-year overall survival (OS) (68.0% vs. 54.6%, P<0.001) and disease-free survival (DFS) (65.4% vs. 53.0%, P<0.001) rates than older patients. Regarding the genetic alterations, older patients had more microsatellite instability-high (MSI-H) tumors and more ARID1A mutations than younger patients. Younger patients had significantly better OS and DFS rates than older patients for each pathological Tumor, Node, Metastasis (TNM) stage. Older patients had a significantly higher non-cancer related death rate than younger patients (36.2% vs. 12.3%, P<0.001). Age was an independent prognostic factor in GC. In conclusion, age was associated with different clinicopathological features and genetic alterations in GC with curative surgery.

The Clinicopathological Characteristics And Genetic Alterations of Signet-ring Cell Carcinoma in Gastric Cancer

Signet-ring cell carcinoma (SRC) in advanced gastric cancer (GC) is often associated with more invasiveness and a worse prognosis than other cell types. The genetic alterations associated with gastric carcinogenesis in SRC are still unclear. In this study, 441 GC patients receiving curative surgery for GC between 2005 and 2013 were enrolled. The clinicopathological characteristics and genetic alterations of GC patients with and without SRC were compared. Among the 441 GC patients, 181 had SRC. For early GC, patients with SRC had more tumors located in the middle and lower stomach, more infiltrating tumors and better overall survival (OS) rates than those without SRC. For advanced GC, patients with SRC had more scirrhous type tumors, more PIK3CA amplifications, fewer microsatellite instability-high (MSI-H) tumors, more peritoneal recurrences and worse 5-year OS rates than those without SRC. For advanced GC with SRC, patients with peritoneal recurrence tended to have PD-L1 expression. For advanced GC without SRC, patients with liver metastasis tended to have PD-L1 expression, PI3K/AKT pathway mutations, TP53 mutations and MSI-H tumors. For advanced GC, PD-L1 expression was associated with peritoneal recurrence in SRC tumors, while non-SRC tumors with liver metastasis were likely to have PI3K/AKT pathway mutations, TP53 mutations and PD-L1 expression; immunotherapy and targeted therapy may be beneficial for these patients.

Human Papillomaviruses and Epstein-Barr Virus Interactions in Colorectal Cancer: A Brief Review

Human papillomaviruses (HPVs) and the Epstein-Barr virus (EBV) are the most common oncoviruses, contributing to approximately 10%-15% of all malignancies. Oncoproteins of high-risk HPVs (E5 and E6/E7), as well as EBV (LMP1, LMP2A and EBNA1), play a principal role in the onset and progression of several human carcinomas, including head and neck, cervical and colorectal. Oncoproteins of high-risk HPVs and EBV can cooperate to initiate and/or enhance epithelial-mesenchymal transition (EMT) events, which represents one of the hallmarks of cancer progression and metastasis. Although the role of these oncoviruses in several cancers is well established, their role in the pathogenesis of colorectal cancer is still nascent. This review presents an overview of the most recent advances related to the presence and role of high-risk HPVs and EBV in colorectal cancer, with an emphasis on their cooperation in colorectal carcinogenesis.

Actionable Potentials of Less Frequently Mutated Genes in Colorectal Cancer and Their Roles in Precision Medicine

Global statistics have placed colorectal cancer (CRC) as the third most frequently diagnosed cancer and the fourth principal cause of cancer-related deaths worldwide. Improving survival for CRC is as important as early detection. Personalized medicine is important in maximizing an individual's treatment success and minimizing the risk of adverse reactions. Approaches in achieving personalized therapy in CRC have included analyses of specific genes with its clinical implications. Tumour genotyping via next-generation sequencing has become a standard practice to guide clinicians into predicting tumor behaviour, disease prognosis, and treatment response. Nevertheless, better prognostic markers are necessary to further stratify patients for personalized treatment plans. The discovery of new markers remains indispensable in providing the most effective chemotherapy in order to improve the outcomes of treatment and survival in CRC patients. This review aims to compile and discuss newly discovered, less frequently mutated genes in CRC. We also discuss how these mutations are being used to assist therapeutic decisions and their potential prospective clinical utilities. In addition, we will summarize the importance of profiling the large genomic rearrangements, gene amplification, and large deletions and how these alterations may assist in determining the best treatment option for CRC patients.

Prognostic Biomarkers for Gastric Cancer: An Umbrella Review of the Evidence

Introduction: Biomarkers are biological molecules entirely or partially participating in cancerous processes that function as measurable indicators of abnormal changes in the human body microenvironment. Aiming to provide an overview of associations between prognostic biomarkers and gastric cancer (GC), we performed this umbrella review analyzing currently available meta-analyses and grading the evidence depending on the credibility of their associations. Methods: A systematic literature search was conducted by two independent investigators of the PubMed, Embase, Web of Science, and Cochrane Databases to identify meta-analyses investigating associations between prognostic biomarkers and GC. The strength of evidence for prognostic biomarkers for GC were categorized into four grades: strong, highly suggestive, suggestive, and weak. Results: Among 120 associations between prognostic biomarkers and GC survival outcomes, only one association, namely the association between platelet count and GC OS, was supported by strong evidence. Associations between FITC, CEA, NLR, foxp3+ Treg lymphocytes (both 1- and 3-year OS), CA 19-9, or VEGF and GC OS were supported by highly suggestive evidence. Four associations were considered suggestive and the remaining 108 associations were supported by weak or not suggestive evidence. Discussion: The association between platelet count and GC OS was supported by strong evidence. Associations between FITC, CEA, NLR, foxp3+ Treg lymphocytes (both 1- and 3-year OS), CA 19-9, or VEGF and GC OS were supported by highly suggestive evidence, however, the results should be interpreted cautiously due to inadequate methodological quality as deemed by AMSTAR 2.0.

Molecularly annotation of mouse avatar models derived from patients with colorectal cancer liver metastasis

Background: Liver is the most common metastatic site in advanced colorectal cancer. Most patients with colorectal cancer liver metastasis (CRLM) do not benefit from current treatment. Patient-derived xenografts (PDXs) with defined molecular signatures are attractive models for preclinical studies. Methods: Successfully established PDXs were evaluated to elucidate their fidelity of patients' biologic characteristics (pathologic, genetic and protein properties, together with chemosensitivity). The genomic variations of PDXs were analyzed by next-generation sequencing to explore the underlying molecular mechanism of metastasis and potential therapeutic targets. Results: CRLM (N=73) showed a significantly higher successful PDX establishment rate than primary specimens (N=26; 76.7% vs. 57.7%). CRLM PDXs recapitulated the pathologic, genetic and protein properties of parental tumors, as well as chemosensitivity. Frequent altered genes in PDXs showed high consistency compared to patients' genomic alterations and were enriched in MAPK, ErbB, cell cycle, focal adhesion pathways for CRLM PDXs, whereas primary tumor-derived PDXs only exhibited genomic variations involving ErbB and cell cycle. The genetic alterations showed high concordance between paired PDXs from primary and metastatic tissues, except for recurrent gene mutations (ARID1A, CDK8, ETV1, STAT5B and WNK3) and common copy number gains in chromosomes 20q (e.g., SRC/AURKA). Several potential drug targets such as KRAS, HER2, and FGFR2 were validated using corresponding inhibitors. Additionally, PDX models could also be used in screening efficient regimens for patients with no druggable alterations. Conclusion: This study has successfully established and validated a large panel of molecularly annotated platforms from patients with CRLM for preclinical studies.