Gastric cancer and Hedgehog signaling pathway: emerging new paradigms

The plasticity of epithelial cells and its potential in the induced differentiation of gastric cancer

Cell plasticity refers to the deviation of cells from normal terminal differentiation states when faced with environmental and genetic toxic stresses, resulting in the phenomenon of transforming into other cell or tissue phenotypes. Unlocking phenotype plasticity has been defined as a hallmark of malignant tumors. The stomach is one of the organs in the body with the highest degree of self-renewal and exhibits significant cell plasticity. In this paper, based on the review of the characteristics of normal differentiation of gastric epithelial cells and their markers, the four main phenotypes of gastric epithelial cell remodeling and their relationship with gastric cancer (GC) are drawn. Furthermore, we summarize the regulatory factors and mechanisms that affect gastric epithelial cell plasticity and outline the current status of research and future prospection for the treatment targeting gastric epithelial cell plasticity. This study has important theoretical reference value for the in-depth exploration of epithelial cell plasticity and the tumor heterogeneity caused by it, as well as for the precise treatment of GC.

Identification of gastric cancer stem cells with CD44 and Lgr5 double labelling and their initial roles on gastric cancer malignancy and chemotherapy resistance

Accumulating evidences have indicated that cancer stem cells (CSCs) can initiate tumor progression and cause recurrence after therapy. However, specific markers of gastric CSCs (GCSCs) from different origins have not been comprehensively revealed. Here, we further detected whether cell populations labelled with CD44 and Lgr5, well-recognized stem markers for gastric cancer (GC), can better emphasize cancer initiation, therapeutic resistance and recurrence. Flow cytometry was utilized to sort the CD44 + Lgr5 + and CD44 + Lgr5- cells from GC cell line HGC-27 and primary GC cells. The influences of CD44 and Lgr5 GCSCs on the malignant behaviors and their potential mechanisms was investigated, respectively. In our study, we reported the identification and validation of CD44 + Lgr5 + cells that presented stronger stemness characteristics, as evidenced by increase of sphere forming ability, elevation of stem cell transcriptional activity. Additionally, CD44 + Lgr5 + double positive cells have lower apoptosis, greater chemotherapy resistance, and higher EMT capacity and LC3 density compared with CD44 + Lgr5- cells. Tumor xenograft experiments also verified the faster carcinogenesis of CD44 + Lgr5 + GCSCs. Furthermore, a series of key proteins in the Wnt, Hedgehog, Notch, and TGF-β pathways were elevated in the CD44 + Lgr5 + double positive subpopulation, except for Notch 1 and Smad 1. In conclusion, the binding of CD44 and Lgr5 can serve as a precise GCSCs marker that initiate malignant progression and chemotherapy resistance in GC by activating Wnt, Hedgehog, Notch, TGF-β pathways. Those evidences raise the needs to target both markers simultaneously as a potential approach for the GC treatment.

ANGPTL4 plays a paradoxical role in gastric cancer through the LGALS7 and Hedgehog pathways

Gastric cancer (GC) is a malignant disease worldwide. Angiopoietin-like protein 4 (ANGPTL4) plays a role in pathophysiological processes, including metabolic reprogramming, angiogenesis, proliferation, and metastasis. Current evidence shows conflicting findings regarding the role of ANGPTL4 in the progression of GC. ANGPTL4 in GC was confirmed through bioinformatic analysis and immunofluorescence staining. The impact of ANGPTL4 was subsequently validated in GC cell lines using various assays, including 5-ethynyl-2-deoxyuridine (EdU), 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Flow Cytometry (FCM), wound healing, transwell, tube formation, chorioallantoic membrane model, and nude mouse model assays. RNA-seq analysis, polymerase chain reaction (PCR), western blotting (WB), immunofluorescence (IF) and coimmunoprecipitation (co-IP) were conducted to determine the potential downstream mechanism of ANGPTL4. In SNU5 and MKN7 cells, ANGPTL4 was found to augment proliferation, migration, invasion, evasion of apoptosis, and angiogenesis. Conversely, in the AGS cell line, ANGPTL4 was observed to suppress these processes. Notably, the overexpression of ANGPTL4 in AGS cells led to the upregulation of LGALS7, which has emerged as a pivotal factor contributing to the manifestation of an anticancer phenotype induced by ANGPTL4. LGALS7, which is involved in the regulation of the hedgehog pathway and subsequent promotion of GC progression through various processes, such as proliferation, migration, apoptosis evasion, angiogenesis, and lymphangiogenesis, was found to contribute to the contradictory effects of ANGPTL4.

miR-200c targeting GLI3 inhibits cell proliferation and promotes apoptosis in non-small cell lung cancer cells

Lung cancer is a common malignant tumor with low cure rate. It has an easy recurrence and metastasis. This study explored whether miR-200c could regulate the biological behavior of non-small cell lung cancer cells through targeting GLI3. Luciferase reporter gene analysis was used to verify the interaction between miR-200c-3p and GLI3. miR-200c-3p and GLI3 were transiently overexpressed into A549 cells. The cell viability rate was detected by cell counting kit-8, cell invasion ability was detected with Transwell, cell apoptosis and cell cycle was determined by flow cytometry, and the expression of GLI3 was detected using quantitative polymerase chain reaction and Western blot, to verify the effect of the interaction between miR-200c-3p and GLI3 on the cell activities. miR-200c-3p overexpression could inhibit cell viability and invasion, promote apoptosis, induce G0/G1 arrest, and inhibit cell division. GLI3 overexpression could reverse the miR-200c-3p inhibition on cell cycle, reduce the number of cells in the G0/G1 phase and increase the number of cells in the S phase. miR-200c-3p overexpression in A549 cells could inhibit cell viability and invasion, and promote apoptosis. miR-200c-3p could target GLI3 to regulate cell cycle and inhibit cell proliferation.

DNA methylation profiling identifies epigenetic signatures of early gastric cancer

Research on the DNA methylation status of gastric cancer (GC) has primarily focused on identifying invasive GC to develop biomarkers for diagnostic. However, DNA methylation in noninvasive GC remains unclear. We conducted a comprehensive DNA methylation profiling study of differentiated-type intramucosal GCs (IMCs). Illumina 850K microarrays were utilized to assess the DNA methylation profiles of formalin-fixed paraffin-embedded tissues from eight patients who were Epstein-Barr virus-negative and DNA mismatch repair proficient, including IMCs and paired adjacent nontumor mucosa. Gene expression profiling microarray data from the GEO database were analyzed via bioinformatics to identify candidate methylation genes. The final validation was conducted using quantitative real-time PCR, the TCGA methylation database, and single-sample gene set enrichment analysis (GSEA). Genome-wide DNA methylation profiling revealed a global decrease in methylation in IMCs compared with nontumor tissues. Differential methylation analysis between IMCs and nontumor tissues identified 449 differentially methylated probes, with a majority of sites showing hypomethylation in IMCs compared with nontumor tissues (66.1% vs 33.9%). Integrating two RNA-seq microarray datasets, we found one hypomethylation-upregulated gene: eEF1A2, overlapped with our DNA methylation data. The mRNA expression of eEF1A2 was higher in twenty-four IMC tissues than in their paired adjacent nontumor tissues. GSEA indicated that the functions of eEF1A2 were associated with the development of IMCs. Furthermore, TCGA data indicated that eEF1A2 is hypomethylated in advanced GC. Our study illustrates the implications of DNA methylation alterations in IMCs and suggests that aberrant hypomethylation and high mRNA expression of eEF1A2 might play a role in IMCs development.

Exploring the therapeutic efficacy of crocetin in oncology: an evidence-based review

With cancer being a leading cause of death globally, there is an urgent need to improve therapeutic strategies and identify effective chemotherapeutics. This study aims to highlight the potential of crocetin, a natural product derived from certain plants, as an anticancer agent. It was  conducted an extensive review of the existing literature to gather and analyze the most recent data on the chemical properties of crocetin and its observed effects in various in vitro and in vivo studies. The study  particularly focused on studies that examined crocetin's impact on cell cycle dynamics, apoptosis, caspases and antioxidant enzyme levels, tumor angiogenesis, inflammation, and overall tumor growth. Crocetin exhibited diverse anti-tumorigenic activities including inhibition of tumor cell proliferation, apoptosis induction, angiogenesis suppression, and potentiation of chemotherapy. Multiple cellular and molecular pathways such as the PI3K/Akt, MAPK and NF-κB were modulated by it. Crocetin demonstrates promising anti-cancer properties and offers potential as an adjunctive or alternative therapy in oncology. More large-scale, rigorously designed clinical trials are needed to establish therapeutic protocols and ascertain the comprehensive benefits and safety profile of crocetin in diverse cancer types.

Targeting signaling pathways in cancer stem cells: A potential approach for developing novel anti-cancer therapeutics

Cancer stem cells (CSCs) have emerged as prime players in the intricate landscape of cancer development, progression, and resistance to traditional treatments. These unique cellular subpopulations own the remarkable capability of self-renewal and differentiation, giving rise to the diverse cellular makeup of tumors and fostering their recurrence following conventional therapies. In the quest for developing more effective cancer therapeutics, the focus has now shifted toward targeting the signaling pathways that govern CSCs behavior. This chapter underscores the significance of these signaling pathways in CSC biology and their potential as pivotal targets for the development of novel chemotherapy approaches. We delve into several key signaling pathways essential for maintaining the defining characteristics of CSCs, including the Wnt, Hedgehog, Notch, JAK-STAT, NF-κB pathways, among others, shedding light on their potential crosstalk. Furthermore, we highlight the latest advancements in CSC-targeted therapies, spanning from promising preclinical models to ongoing clinical trials. A comprehensive understanding of the intricate molecular aspects of CSC signaling pathways and their manipulation holds the prospective to revolutionize cancer treatment paradigms. This, in turn, could lead to more efficacious and personalized therapies with the ultimate goal of eradicating CSCs and enhancing overall patient outcomes. The exploration of CSC signaling pathways represents a key step towards a brighter future in the battle against cancer.

Dietary Polyphenols against Oxidative Stress in Head and Neck Cancer: What's New, What's Next

Head and neck cancers (HNC) are a worldwide health problem, accounting for over 5% of all types of cancers. Their varied nature makes it sometimes difficult to find clear explanations for the molecular mechanisms that underline their onset and development. While chemio- and radiotherapy are clearly not to be dismissed, we cannot undervalue the effect that polyphenols - especially dietary polyphenols - can have in helping us to cope with this medical emergency. By influencing several different proteins involved in numerous different metabolic pathways, polyphenols can have a broad spectrum of biological action and can hopefully act synergistically to tackle down head and neck cancer. Moreover, being natural molecules, polyphenols does not present any side effects and can even enhance drugs efficacy, making our clinical therapy against head and neck cancer more and more effective. Certainly, oxidative stress plays an important role, altering several molecular pathways, lowering the body's defenses, and ultimately helping to create a microenvironment conducive to the appearance and development of the tumor. In this regard, the regular and constant intake of foods rich in polyphenols can help counteract the onset of oxidative stress, improving the health of the general population. In this review, we highlight the role of polyphenols in managing oxidative stress, with such positive effects that they can be considered new tools to use in our anti-head and neck cancer strategy.

Diallyl trisulfide inhibits gastric cancer stem cell properties through ΔNp63/sonic hedgehog pathway

Gastric cancer is one of the deadliest malignant tumors, and half of the patients develop recurrences or metastasis within 5 years after eradication therapy. Cancer stem cells (CSCs) are considered to be important in this progress. The sonic hedgehog (SHH) pathway plays an important role in the maintenance of gastric CSCs characteristics. The p63 proteins are vital transcription factors belonging to the p53 family, while their functions in regulating CSCs remain unclear. The preventive effects of dietary diallyl trisulfide (DATS) against human gastric cancer have been verified. However, whether DATS can target gastric CSCs are poorly understood. Here, we investigated the role of ΔNp63/SHH pathway in gastric CSCs and the inhibitory effect of DATS on gastric CSCs via ΔNp63/SHH pathway. We found that ΔNp63 was upregulated in serum-free medium cultured gastric tumorspheres compared with the parental cells. Overexpression of ΔNp63 elevated the self-renewal capacity and CSC markers' levels in gastric sphere-forming cells. Furthermore, we found that ΔNp63 directly bound to the promoter region of Gli1, the key transcriptional factor of SHH pathway, to enhance its expression and to activate SHH pathway. In addition, it was revealed that DATS effectively inhibited gastric CSC properties both in vitro and in vivo settings. Activation of SHH pathway attenuated the suppressive effects of DATS on the stemness of gastric cancer. Moreover, DATS suppression of gastric CSC properties was also diminished by ΔNp63 upregulation through SHH pathway activation. These findings illustrated the role of ΔNp63/SHH pathway in DATS inhibition of gastric cancer stemness. Taken together, the present study suggested for the first time that DATS inhibited gastric CSCs properties by ΔNp63/SHH pathway.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

The impact of the Hedgehog signal pathway on the tumor immune microenvironment of gastric adenocarcinoma by integrated analysis of scRNA-seq and RNA-seq datasets

The Hedgehog signaling is a highly conserved pathway to regulate cell growth and proliferation, and plays an essential role in stomach adenocarcinoma (STAD) and other cancer types. However, previous studies were primarily conducted in terms of mRNA or vitro cell culture. It would be more convincing to integrate single-cell RNA sequencing (scRNA-seq) data because it is a more precise approach for genomic research. The expression profile, genetic alteration, and activity of the Hedgehog signaling pathway were investigated in both scRNA-seq and RNA-seq datasets of STAD. Communications between cancer cells and fibroblasts were determined by the cell-chat algorithm, and the Hedgehog-related gene signature was constructed to predict the survival of STAD. Patients were categorized into high- and low-risk groups according to the median of the signature. Further analysis explored the difference in survival outcome, tumor immune microenvironment (TIME), and drug sensitivity between the two groups, aiming to guide the use of chemotherapy and immunotherapy in STAD patients. Hedgehog signal pathway was over-activated in STAD. GAS1, GLI1, and SCEBU2 were recognized as hub genes in the prognostic signature of STAD, and served as robust risk factors to induce a poor survival outcome. Patients in the high-risk group demonstrated an exhausted TIME pattern, with rather low sensitivity toward molecular-targeted drugs. This study depicted the influence of the Hedgehog pathway on the survival outcome, TIME, and drug sensitivity of STAD, and provides novel insights for the treatment of STAD.

Glutamine metabolism genes prognostic signature for stomach adenocarcinoma and immune infiltration: potential biomarkers for predicting overall survival

Background

Stomach adenocarcinoma (STAD), caused by mutations in stomach cells, is characterized by poor overall survival. Chemotherapy is commonly administered for stomach cancer patients following surgical resection. An imbalance in tumor metabolic pathways is connected to tumor genesis and growth. It has been discovered that glutamine (Gln) metabolism plays a crucial role in cancer. Metabolic reprogramming is associated with clinical prognosis in various cancers. However, the role of glutamine metabolism genes (GlnMgs) in the fight against STAD remains poorly understood.

Methods

GlnMgs were determined in STAD samples from the TCGA and GEO datasets. The TCGA and GEO databases provide information on stemness indices (mRNAsi), gene mutations, copy number variations (CNV), tumor mutation burden (TMB), and clinical characteristics. Lasso regression was performed to build the prediction model. The relationship between gene expression and Gln metabolism was investigated using co-expression analysis.

Results

GlnMgs, found to be overexpressed in the high-risk group even in the absence of any symptomatology, demonstrated strong predictive potential for STAD outcomes. GSEA highlighted immunological and tumor-related pathways in the high-risk group. Immune function and m6a gene expression differed significantly between the low- and high-risk groups. AFP, CST6, CGB5, and ELANE may be linked to the oncology process in STAD patients. The prognostic model, CNVs, single nucleotide polymorphism (SNP), and medication sensitivity all revealed a strong link to the gene.

Conclusion

GlnMgs are connected to the genesis and development of STAD. These corresponding prognostic models aid in predicting the prognosis of STAD GlnMgs and immune cell infiltration in the tumor microenvironment (TME) may be possible therapeutic targets in STAD. Furthermore, the glutamine metabolism gene signature presents a credible alternative for predicting STAD outcomes, suggesting that these GlnMgs could open a new field of study for STAD-focused therapy Additional trials are needed to validate the results of the current study.

Bone Marrow Mesenchymal Stem Cell (BMSC)-Derived Exosomes Regulates Growth of Breast Cancer Cells Mediated by Hedgehog Signaling Pathway

BMSCs promote breast cancer development mainly through tumor microenvironment pathway and secreting exosomes. However, the mechanism is unclear. This study mainly explores whether BMSC-derived exosomes influence breast cancer by mediating Hedgehog signaling pathway. MCF-7 and BMSC were cultured and then assigned into MCF-7 +Vehicle group, MCF-7+ Exosome group, and MCF-7+Exosome+Gant61 (Hedgehog signaling blocker) group followed by analysis of cell proliferation and migration, p-Akt and β-catenin expression. MCF-7+Exosome group had the highest OD450 value compared to other two groups (P >0.05). In addition, migration distance of MCF-7 cells was the highest in MCF-7+Exosome group without difference between other two groups (P >0.05). Gli1 and SMO expression in MCF-7+Exosome group was highest compared to other two groups (P >0.05). In conclusion, exosome from BMSC promotes breast cancer cell proliferation and migration. The mechanism may be through raising GLI1, Smo protein expression, further raising the Hedgehog signaling pathway to some extent.

Constructing and validating of m6a-related genes prognostic signature for stomach adenocarcinoma and immune infiltration: Potential biomarkers for predicting the overall survival

Background

Stomach adenocarcinoma (STAD) arises from the mutations of stomach cells and has poor overall survival. Chemotherapy is commonly indicated for patients with stomach cancer following surgical resection. The most prevalent alteration that affects cancer growth is N6-methyladenosine methylation (m6A), although the possible function of m6A in STAD prognosis is not recognized.

Method

The research measured predictive FRGs in BLCA samples from the TCGA and GEO datasets. Data on the stemness indices (mRNAsi), gene mutations, copy number variations (CNV), tumor mutation burden (TMB), and corresponding clinical characteristics were obtained from TCGA and GEO. STAD from TCGA and GEO at 24 m6A was investigated. Lasso regression was used to construct the prediction model to assess the m6A prognostic signals in STAD. In addition, the correlation between m6a and immune infiltration in STAD patients was discussed using GSVA and ssGSEA analysis. Based on these genes, GO and KEGG analyses were performed to identify key biological functions and key pathways.

Result

A significant relationship was discovered between numerous m6A clusters and the tumor immune microenvironment, as well as three m6A alteration patterns with different clinical outcomes. Furthermore, GSVA and ssGSEA showed that m6A clusters were significantly associated with immune infiltration in the STAD. The low-m6Ascore group had a lower immunotherapeutic response than the high-m6Ascore group. ICIs therapy was more effective in the group with a higher m6Ascore. Three writers (VIRMA, ZC3H13, and METTL3) showed significantly lower expression, whereas five authors (METTL14, METTL16, WTAP, RBM15, and RBM15B) showed considerably higher expression. Three readers (YTHDC2, YTHDF2, and LRPPRC) had higher levels of expression, whereas eleven readers (YTHDC1, YTHDF1, YTHDF3, HNRNPC, FMR1, HNRNPA2B1, IGFBP1, IGFBP2, IGFBP3, and RBMX) had lower levels. As can be observed, the various types of m6 encoders have varied ramifications for STAD control.

Conclusion

STAD occurrence and progression are linked to m6A-genes. Corresponding prognostic models help forecast the prognosis of STAD patients. m6A-genes and associated immune cell infiltration in the tumor microenvironment (TME) may serve as potential therapeutic targets in STAD, which requires further trials. In addition, the m6a-related gene signature offers a viable alternative to predict bladder cancer, and these m6A-genes show a prospective research area for STAD targeted treatment in the future.

Constructing and Validating a Pyroptosis-Related Genes Prognostic Signature for Stomach Adenocarcinoma and Immune Infiltration: Potential Biomarkers for Predicting the Overall Survival

Background

Stomach adenocarcinoma (STAD) is a kind of cancer that begins in the stomach cells and has a poor overall survival rate. Following resection surgery, chemotherapy has been suggested as a curative method for stomach cancer. However, it is ineffective. Pyroptosis, a kind of inflammatory programmed cell death, has been shown to play a significant role in the development and progression of STAD. However, whether pyroptosis-related genes (PRGs) can be utilized to predict the diagnosis and prognosis of gastric cancer remains unknown.

Method

The research measured at predictive PRGs in STAD samples from TCGA and GEO. Lasso regression was used to build the prediction model. Coexpression analysis revealed that gene expression was linked to pyroptosis. PRGs were found to be overexpressed in high-risk individuals, implying that they could be used in a model to predict STAD prognosis.

Result

Immunological and tumor-related pathways were discovered using GSEA. In STAD patients, the genes GPX3, PDGFRL, RGS2, and SERPINE1 may be connected to the cancer process. The levels of expression also differed between the two risk groups.

Conclusion

The purpose of this study is to identify and verify STAD-associated PRGs that can effectively guide prognosis and the immunological milieu in STAD patients as well as offer evidence for the development of pyroptosis-related molecularly targeted therapeutics. Therefore, PRGs and the link between immunological and PRGs in STAD may be therapeutic targets.

RNA-seq and ChIP-seq Identification of Unique and Overlapping Targets of GLI Transcription Factors in Melanoma Cell Lines

BACKGROUND

Despite significant progress in therapy, melanoma still has a rising incidence worldwide, and novel treatment strategies are needed. Recently, researchers have recognized the involvement of the Hedgehog-GLI (HH-GLI) signaling pathway in melanoma and its consistent crosstalk with the MAPK pathway. In order to further investigate the link between the two pathways and to find new target genes that could be considered for combination therapy, we set out to find transcriptional targets of all three GLI proteins in melanoma.

METHODS

We performed RNA sequencing on three melanoma cell lines (CHL-1, A375, and MEL224) with overexpressed GLI1, GLI2, and GLI3 and combined them with the results of ChIP-sequencing on endogenous GLI1, GLI2, and GLI3 proteins. After combining these results, 21 targets were selected for validation by qPCR.

RESULTS

RNA-seq revealed a total of 808 differentially expressed genes (DEGs) for GLI1, 941 DEGs for GLI2, and 58 DEGs for GLI3. ChIP-seq identified 527 genes that contained GLI1 binding sites in their promoters, 1103 for GLI2 and 553 for GLI3. A total of 15 of these targets were validated in the tested cell lines, 6 of which were detected by both RNA-seq and ChIP-seq.

CONCLUSIONS

Our study provides insight into the unique and overlapping transcriptional output of the GLI proteins in melanoma. We suggest that our findings could provide new potential targets to consider while designing melanoma-targeted therapy.

Study on the Mechanism of Sancao Tiaowei Decoction in the Treatment of MNNG-Induced Precancerous Lesions of Gastric Carcinoma Through Hedgehog Signaling Pathway

Sancao Tiaowei Decoction (SCTWD), a traditional Chinese medicine created by Professor Chen Weijian, has been used in the prevention and treatment of precancerous lesions of gastric carcinoma (PLGC). However, its mechanism has not been made clear. This study aimed to evaluate the therapeutic effect of SCTWD on 1-methyl-3-nitro-1-nitrosoguanidine-induced PLGC in rats and the mechanism of this effect. We found that SCTWD effectively repaired gastric mucosal injury, reversed the process of PLGC, and inhibited the occurrence of gastric cancer to some extent. In the results of hematoxylin-eosin (HE) staining, the number and arrangement of mucosal glands and the number of mononuclear cells in the lamina propria were improved in varying degrees; the enzyme-linked immunosorbent assay (ELISA) showed that the PG I and PGR of the medication treatment group were significantly higher; a Reverse Transcription-Polymerase Chain Reaction (RT-PCR) test showed that SCTWD could significantly upregulate the expression levels of Shh, Ptch, and Gli-1 in the gastric tissue of rats. The immunohistochemical method showed that SCTWD could significantly upregulate the protein expressions of Shh, Gli-1, Smo, cyclin D1, CDKN2A/p16INK4a, and NF-κBP65 and could reduce the expression of Ptch at the same time. Through the preliminary analysis of 75 compounds screened by UPLC-Q-TOF-MS, the main components, such as organic acids, esters and anhydrides, flavonoids, phenols, tanshinones, and so on, have anti-inflammatory and anti-tumor pharmacological effects. The results of KEGG enrichment analysis showed that 5 signaling pathways related to this project were found, and 33 differential genes were presented to construct the interaction network. These results suggested that SCTWD had a good regulatory effect on PLGC and thus may have a multi-targeted effect; SCTWD can not only significantly improve the pathological changes of gastric mucosa in rats with PLGC but also exert a strong effect of the regulation of the hedgehog signaling pathway.

Molecular mechanism of therapeutic approaches for human gastric cancer stem cells

Gastric cancer (GC) is a primary cause of cancer-related mortality worldwide, and even after therapeutic gastrectomy, survival rates remain poor. The presence of gastric cancer stem cells (GCSCs) is thought to be the major reason for resistance to anticancer treatment (chemotherapy or radiotherapy), and for the development of tumor recurrence, epithelial-mesenchymal transition, and metastases. Additionally, GCSCs have the capacity for self-renewal, differentiation, and tumor initiation. They also synthesize antiapoptotic factors, demonstrate higher performance of drug efflux pumps, and display cell plasticity abilities. Moreover, the tumor microenvironment (TME; tumor niche) that surrounds GCSCs contains secreted growth factors and supports angiogenesis and is thus responsible for the maintenance of the growing tumor. However, the genesis of GCSCs is unclear and exploration of the source of GCSCs is essential. In this review, we provide up-to-date information about GCSC-surface/intracellular markers and GCSC-mediated pathways and their role in tumor development. This information will support improved diagnosis, novel therapeutic approaches, and better prognosis using GCSC-targeting agents as a potentially effective treatment choice following surgical resection or in combination with chemotherapy and radiotherapy. To date, most anti-GCSC blockers when used alone have been reported as unsatisfactory anticancer agents. However, when used in combination with adjuvant therapy, treatment can improve. By providing insights into the molecular mechanisms of GCSCs associated with tumors in GC, the aim is to optimize anti-GCSCs molecular approaches for GC therapy in combination with chemotherapy, radiotherapy, or other adjuvant treatment.

MicroRNA-214 in Health and Disease

MicroRNAs (miRNAs) are endogenously expressed, non-coding RNA molecules that mediate the post-transcriptional repression and degradation of mRNAs by targeting their 3′ untranslated region (3′-UTR). Thousands of miRNAs have been identified since their first discovery in 1993, and miR-214 was first reported to promote apoptosis in HeLa cells. Presently, miR-214 is implicated in an extensive range of conditions such as cardiovascular diseases, cancers, bone formation and cell differentiation. MiR-214 has shown pleiotropic roles in contributing to the progression of diseases such as gastric and lung cancers but may also confer cardioprotection against excessive fibrosis and oxidative damage. These contrasting functions are achieved through the diverse cast of miR-214 targets. Through silencing or overexpressing miR-214, the detrimental effects can be attenuated, and the beneficial effects promoted in order to improve health outcomes. Therefore, discovering novel miR-214 targets and understanding how miR-214 is dysregulated in human diseases may eventually lead to miRNA-based therapies. MiR-214 has also shown promise as a diagnostic biomarker in identifying breast cancer and coronary artery disease. This review provides an up-to-date discussion of miR-214 literature by describing relevant roles in health and disease, areas of disagreement, and the future direction of the field.

Sulforaphane as a potential remedy against cancer: Comprehensive mechanistic review

Sulforaphane belongs to the active class of isothiocyanates capable of delivering various biological benefits for health promotion and disease prevention. This compound is considered vital to curtail numerous metabolic disorders. Various studies have proven its beneficial effects against cancer prevention and its possible utilization as a therapeutic agent in cancer treatment. Understanding the mechanistic pathways and possible interactions at cellular and subcellular levels is key to design and develop cancer therapeutics for humans. In this respect, a number of mechanisms such as modulation of carcinogen metabolism & phase II enzymatic activities, cell cycle arrest, activation of Nrf2, cytotoxic, proapoptotic and apoptotic pathways have been reported to be involved in cancer prevention. This article provides sufficient information by critical analysis to understand the mechanisms involved in cancer prevention attributed to sulforaphane. Furthermore, various clinical studies have also been included for design and development of novel therapies for cancer prevention and cure. PRACTICAL APPLICATIONS: Diet and dietary components are potential tools to address various lifestyle-related disorders. Due to plenty of environmental and cellular toxicants, the chances of cancer prevalence are quite large which are worsen by adopting unhealthy lifestyles. Cancer can be treated with various therapies but those are acquiring side effects causing the patients to suffer the treatment regime. Nutraceuticals and functional foods provide safer options to prevent or delay the onset of cancer. In this regard, sulforaphane is a pivotal compound to be targeted as a potential agent for cancer treatment both in preventive and therapeutic regimes. This article provides sufficient evidence via discussing the underlying mechanisms of positive effects of sulforaphane to further the research for developing anticancer drugs that will help assuage this lethal morbidity.

Apatinib Suppresses Gastric Cancer Stem Cells Properties by Inhibiting the Sonic Hedgehog Pathway

The presence of gastric cancer stem cells (GCSCs) marks the onset of gastric carcinoma. The sonic hedgehog (SHH) pathway plays a vital role in the maintenance of GCSC characteristics. Apatinib has been approved in China for advanced gastric cancer (GC) treatment. However, whether apatinib can target GCSCs and affect the SHH pathway remains unclear. The present study aimed to investigate the underlying mechanism of apatinib’s antitumor effects on GC. The expression levels of GCSC markers and number of CD133⁺ cells were significantly elevated in the sphere-forming cells. Apatinib effectively suppressed GCSC traits by inhibiting tumorsphere formation and cell proliferation, suppressing GCSC markers expression and CD133⁺ cell number, and inducing apoptosis. Apatinib downregulated the activation of the SHH pathway; while upregulation of the SHH pathway attenuated the inhibitory effects of apatinib on GCSCs. Moreover, apatinib treatment significantly delayed tumor growth and inhibited GCSC characteristics in the xenograft model. Our data suggested that apatinib exhibited inhibitory effects on GCSCs by suppressing SHH pathway both in vitro and in vivo, thus providing new insights into the therapeutic application of apatinib in GCSC suppression and advanced gastric cancer treatment.

Gastric Cancer: Identification of microRNAs Inhibiting Druggable Targets and Mediating Efficacy in Preclinical In Vivo Models

In addition to chemotherapy, targeted therapies have been approved for treatment of locally advanced and metastatic gastric cancer. The therapeutic benefit is significant but more durable responses and improvement of survival should be achieved. Therefore, the identification of new targets and new approaches for clinical treatment are of paramount importance. In this review, we searched the literature for down-regulated microRNAs which interfere with druggable targets and exhibit efficacy in preclinical in vivo efficacy models. As druggable targets, we selected transmembrane receptors, secreted factors and enzymes. We identified 38 microRNAs corresponding to the criteria as outlined. A total of 13 miRs target transmembrane receptors, nine inhibit secreted proteins and 16 attenuate enzymes. These microRNAs are targets for reconstitution therapy of gastric cancer. Further target validation experiments are mandatory for all of the identified microRNAs.

Increased IGFBP7 Expression Correlates with Poor Prognosis and Immune Infiltration in Gastric Cancer

Background: Insulin-like growth factor binding protein-7 (IGFBP7) contributes to multiple biological processes in various tumors. However, the role of IGFBP7 in gastric cancer (GC) is still undetermined. The study aims to explore the role of IGFBP7 in GC via an integrated bioinformatics analysis. Methods: IGFBP7 expression levels in GC and its normal gastric tissues were analyzed using multiple databases, including the Tumor Immune Estimation Resource (TIMER), Oncomine, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, as well as by our clinical gastric specimens. The methylation analysis was conducted with MEXPRESS, UALCAN and Xena online tools. The survival analysis was conducted using the Kaplan-Meier Plotter and Gene Expression Profiling Interactive Analysis (GEPIA) databases. Coexpressed genes of IGFBP7 were selected with the cBioPortal tool and enrichment analysis was conducted with the clusterProfiler package in R software. Gene set enrichment analysis (GSEA) was performed to explore the IGFBP7-related biological processes involved in GC. Correlations between IGFBP7 and immune cell infiltrates were analyzed using the TIMER database. Results: IGFBP7 expression was significantly upregulated in GC and correlated with stage, grade, tumor status and Helicobacter pylori infection. High IGFBP7 expression and low IGFBP7 methylation levels were significantly associated with short survival of patients with GC. Univariate and multivariate analyses revealed that IGFBP7 was an independent risk factor for GC. The coexpressed genes LHFPL6, SEPTIN4, HSPB2, LAYN and GGT5 predicted unfavorable outcomes of GC. Enrichment analysis showed that the coexpressed genes were involved in extracellular matrix (ECM)-related processes. GSEA indicated that IGFBP7 was positively related to ECM and inflammation-related pathways. TIMER analysis indicated that the mRNA level of IGFBP7 was strongly correlated with genes related to various infiltrating immune cells in GC, especially with gene markers of tumor associated macrophages (TAMs). Conclusions: Increased IGFBP7 expression correlates with poor prognosis and immune cell infiltration in GC, which might be a potential biomarker for the diagnosis of GC.

HHIP Overexpression Suppresses Human Gastric Cancer Progression and Metastasis by Reducing Its CpG Island Methylation

Human hedgehog-interacting protein (HHIP), a negative regulator of hedgehog (HH) signaling pathway, has been reported to be dysregulated in many types of cancer, including gastric cancer. However, the inhibitory role of HHIP as well as the underlying molecular mechanism of HHIP regulation in gastric cancer haven't been fully elucidated yet. In this study, we demonstrated that HHIP overexpression significantly suppressed the proliferation and invasion of AGS cells evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays, respectively. Interestingly, methylation-specific polymerase chain reaction (MS-PCR, MSP) showed that HHIP overexpression dramatically decreased its de novo promoter methylation levels in AGS cells. Furthermore, HHIP expression was higher in adjacent non-cancerous tissue compared to matched gastric cancer tissue. High HHIP level was negatively correlated with metastasis (p = 0.035) but not local recurrence (p = 0.58). Taken together, our study suggested that HHIP can modulate gastric cancer progression and metastasis via regulation of its de novo promoter methylation levels in a feedback manner. Lower HHIP levels is positively associated with gastric cancer metastasis, which not only indicates HHIP could be served as a protective marker for gastric cancer, but also suggests restoring HHIP expression might be a potential therapeutic strategy for clinical treatment.

Downregulation of miR-506-3p Facilitates EGFR-TKI Resistance through Induction of Sonic Hedgehog Signaling in Non-Small-Cell Lung Cancer Cell Lines

Non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutation eventually develop resistance to EGFR-targeted tyrosine kinase inhibitors (TKIs). Treatment resistance remains the primary obstacle to the successful treatment of NSCLC. Although drug resistance mechanisms have been studied extensively in NSCLC, the regulation of these mechanisms has not been completely understood. Recently, increasing numbers of microRNAs (miRNAs) are implicated in EGFR-TKI resistance, indicating that miRNAs may serve as novel targets and may hold promise as predictive biomarkers for anti-EGFR therapy. MicroRNA-506 (miR-506) has been identified as a tumor suppressor in many cancers, including lung cancer; however, the role of miR-506 in lung cancer chemoresistance has not yet been addressed. Here we report that miR-506-3p expression was markedly reduced in erlotinib-resistant (ER) cells. We identified Sonic Hedgehog (SHH) as a novel target of miR-506-3p, aberrantly activated in ER cells. The ectopic overexpression of miR-506-3p in ER cells downregulates SHH signaling, increases E-cadherin expression, and inhibits the expression of vimentin, thus counteracting the epithelial-mesenchymal transition (EMT)-mediated chemoresistance. Our results advanced our understanding of the molecular mechanisms underlying EGFR-TKI resistance and indicated that the miR-506/SHH axis might represent a novel therapeutic target for future EGFR mutated lung cancer treatment.

WISP1 indicates poor prognosis and regulates cell proliferation and apoptosis in gastric cancer via targeting AKT/mTOR signaling pathway

PURPOSE

Gastric cancer (GC) is a serious threat to human health. We aimed to explore the effects of Wnt1 induced signaling protein 1 (WISP1) on GC.

METHODS

The WISP1 expressions in GC tissues were detected using immunohistochemistry and qRT-PCR. The connection between GC prognosis and WISP1 expression was analyzed via Pearson's χ² test. The WISP1 expressions were down-regulated in GC cells through siWISP1 transfection. Colony formation assay and cell counting kit-8 assay were carried out to measure cell colony formation and proliferation, respectively. Flow cytometry was operated to examine the cell cycle and apoptosis. The protein expressions in our study were assessed using western blot. The AKT pathway was blocked by LY294002 treatment and then the cell activities were assessed. Furthermore, GC mice models were established to investigate the effects of WISP1 on GC in vivo.

RESULTS

We found that WISP1 was highly expressed in GC cells and tissues. The up-regulation of WISP1 was related to poor prognosis of GC patients. WISP1 down-regulation reduced colony formation and cell proliferation, resulted cell cycle arrest and promoted cell apoptosis in GC. WISP1 knockdown suppressed AKT/mTOR pathway activity. LY294002 treatment recovered the decreases of colony formation and cell proliferation, arrest of cell cycle and increase of cell apoptosis which were induced by WISP1 knockdown. WISP1 down-regulation repressed GC tumor growth and enhanced tumor apoptosis in vivo.

CONCLUSION

WISP1 regulated GC cell proliferation and apoptosis in vivo and in vitro through activating AKT/mTOR pathway. WISP1 might be a target in GC therapy.

Mesenchymal stem cells reverse EMT process through blocking the activation of NF-κB and Hedgehog pathways in LPS-induced acute lung injury

Acute lung injury (ALI) is a pulmonary disorder, which can result in fibrosis of the lung tissues. Recently, mesenchymal stem cell (MSC) has become a novel therapeutic method for ALI. However, the potential mechanism by which MSC regulates the progression of ALI remains blurry. The present study focused on investigating the mechanism underneath MSC-reversed lung injury and fibrosis. At first, we determined that coculture with MSC led to the inactivation of NF-κB signaling and therefore suppressed hedgehog pathway in LPS-treated MLE-12 cells. Besides, we confirmed that MSC-exosomes were responsible for the inhibition of EMT process in LPS-treated MLE-12 cells through transmitting miRNAs. Mechanism investigation revealed that MSC-exosome transmitted miR-182-5p and miR-23a-3p into LPS-treated MLE-12 cells to, respectively, target Ikbkb and Usp5. Of note, Usp5 interacted with IKKβ to hamper IKKβ ubiquitination. Moreover, co-inhibition of miR-182-5p and miR-23a-3p offset the suppression of MSC on EMT process in LPS-treated MLE-12 cells as well as in LPS-injured lungs of mice. Besides, the retarding effect of MSC on p65 nuclear translocation was also counteracted after co-inhibiting miR-182-5p and miR-23a-3p, both in vitro and in vivo. In summary, MSC-exosome transmitted miR-23a-3p and miR-182-5p reversed the progression of LPS-induced lung injury and fibrosis through inhibiting NF-κB and hedgehog pathways via silencing Ikbkb and destabilizing IKKβ.

A Middle-Out Modeling Strategy to Extend a Colon Cancer Logical Model Improves Drug Synergy Predictions in Epithelial-Derived Cancer Cell Lines

Cancer is a heterogeneous and complex disease and one of the leading causes of death worldwide. The high tumor heterogeneity between individuals affected by the same cancer type is accompanied by distinct molecular and phenotypic tumor profiles and variation in drug treatment response. In silico modeling of cancer as an aberrantly regulated system of interacting signaling molecules provides a basis to enhance our biological understanding of disease progression, and it offers the means to use computer simulations to test and optimize drug therapy designs on particular cancer types and subtypes. This sets the stage for precision medicine: the design of treatments tailored to individuals or groups of patients based on their tumor-specific molecular cancer profiles. Here, we show how a relatively large manually curated logical model can be efficiently enhanced further by including components highlighted by a multi-omics data analysis of data from Consensus Molecular Subtypes covering colorectal cancer. The model expansion was performed in a pathway-centric manner, following a partitioning of the model into functional subsystems, named modules. The resulting approach constitutes a middle-out modeling strategy enabling a data-driven expansion of a model from a generic and intermediate level of molecular detail to a model better covering relevant processes that are affected in specific cancer subtypes, comprising 183 biological entities and 603 interactions between them, partitioned in 25 functional modules of varying size and structure. We tested this model for its ability to correctly predict drug combination synergies, against a dataset of experimentally determined cell growth responses with 18 drugs in all combinations, on eight cancer cell lines. The results indicate that the extended model had an improved accuracy for drug synergy prediction for the majority of the experimentally tested cancer cell lines, although significant improvements of the model's predictive performance are still needed. Our study demonstrates how a tumor-data driven middle-out approach toward refining a logical model of a biological system can further customize a computer model to represent specific cancer cell lines and provide a basis for identifying synergistic effects of drugs targeting specific regulatory proteins. This approach bridges between preclinical cancer model data and clinical patient data and may thereby ultimately be of help to develop patient-specific in silico models that can steer treatment decisions in the clinic.

Therapeutic Targeting of Signaling Pathways Related to Cancer Stemness

The theory of cancer stem cells (CSCs) proposes that the different cells within a tumor, as well as metastasis deriving from it, are originated from a single subpopulation of cells with self-renewal and differentiation capacities. These cancer stem cells are supposed to be critical for tumor expansion and metastasis, tumor relapse and resistance to conventional therapies, such as chemo- and radiotherapy. The acquisition of these abilities has been attributed to the activation of alternative pathways, for instance, WNT, NOTCH, SHH, PI3K, Hippo, or NF-κB pathways, that regulate detoxification mechanisms; increase the metabolic rate; induce resistance to apoptotic, autophagic, and senescence pathways; promote the overexpression of drug transporter proteins; and activate specific stem cell transcription factors. The elimination of CSCs is an important goal in cancer therapeutic approaches because it could decrease relapses and metastatic dissemination, which are main causes of mortality in oncology patients. In this work, we discuss the role of these signaling pathways in CSCs along with their therapeutic potential.

Molecular Bases of Mechanisms Accounting for Drug Resistance in Gastric Adenocarcinoma

Gastric adenocarcinoma (GAC) is the most common histological type of gastric cancer, the fifth according to the frequency and the third among the deadliest cancers. GAC high mortality is due to a combination of factors, such as silent evolution, late clinical presentation, underlying genetic heterogeneity, and effective mechanisms of chemoresistance (MOCs) that make the available antitumor drugs scarcely useful. MOCs include reduced drug uptake (MOC-1a), enhanced drug efflux (MOC-1b), low proportion of active agents in tumor cells due to impaired pro-drug activation or active drug inactivation (MOC-2), changes in molecular targets sensitive to anticancer drugs (MOC-3), enhanced ability of cancer cells to repair drug-induced DNA damage (MOC-4), decreased function of pro-apoptotic factors versus up-regulation of anti-apoptotic genes (MOC-5), changes in tumor cell microenvironment altering the response to anticancer agents (MOC-6), and phenotypic transformations, including epithelial-mesenchymal transition (EMT) and the appearance of stemness characteristics (MOC-7). This review summarizes updated information regarding the molecular bases accounting for these mechanisms and their impact on the lack of clinical response to the pharmacological treatment currently used in GAC. This knowledge is required to identify novel biomarkers to predict treatment failure and druggable targets, and to develop sensitizing strategies to overcome drug refractoriness in GAC.

Epigenetics of SFRP1: The Dual Roles in Human Cancers

Secreted frizzled-related protein 1 (SFRP1) is a gene that belongs to the secreted glycoprotein SFRP family. SFRP1 has been classified as a tumor suppressor gene due to the loss of expression in various human cancers, which is mainly attributed by epigenetic inactivation via DNA methylation or transcriptional silencing by microRNAs. Epigenetic silencing of SFRP1 may cause dysregulation of cell proliferation, migration, and invasion, which lead to cancer cells formation, disease progression, poor prognosis, and treatment resistance. Hence, restoration of SFRP1 expression via demethylating drugs or over-expression experiments opens the possibility for new cancer therapy approach. While the role of SFRP1 as a tumor suppressor gene is well-established, some studies also reported the possible oncogenic properties of SFRP1 in cancers. In this review, we discussed in great detail the dual roles of SFRP1 in cancers-as tumor suppressor and tumor promoter. The epigenetic regulation of SFRP1 expression will also be underscored with additional emphasis on the potentials of SFRP1 in modulating responses toward chemotherapeutic and epigenetic-modifying drugs, which may encourage the development of novel drugs for cancer treatment. We also present findings from clinical trials and patents involving SFRP1 to illustrate its clinical utility, extensiveness of each research area, and progression toward commercialization. Lastly, this review provides directions for future research to advance SFRP1 as a promising cancer biomarker.

Sonic hedgehog signaling in epithelial tissue development

The Sonic hedgehog (SHH) signaling pathway is essential for embryonic development and tissue regeneration. The dysfunction of SHH pathway is involved in a variety of diseases, including cancer, birth defects, and other diseases. Here we reviewed recent studies on main molecules involved in the SHH signaling pathway, specifically focused on their function in epithelial tissue and appendages development, including epidermis, touch dome, hair, sebaceous gland, mammary gland, tooth, nail, gastric epithelium, and intestinal epithelium. The advance in understanding the SHH signaling pathway will give us more clues to the mechanisms of tissue repair and regeneration, as well as the development of new treatment for diseases related to dysregulation of SHH signaling pathway.

The role of hedgehog signaling in gastric cancer: molecular mechanisms, clinical potential, and perspective

Patients with advanced gastric cancer usually have a poor prognosis and limited therapeutic options. Overcoming this challenge requires novel targets and effective drugs. The Hedgehog (Hh) signaling pathway plays a crucial role in the development of the gastrointestinal tract and maintenance of the physiologic function of the stomach. Aberrantly activated Hh signaling is implicated in carcinogenesis as well as maintenance of cancer stem cells. Somatic mutations in the components of Hh signaling (PTCH1 and SMO) have been shown to be a major cause of basal cell carcinoma, and dozens of Hh inhibitors have been developed. To date, two inhibitors (GDC-0449 and LDE225) have been approved by the U.S. Food and Drug Administration to treat basal cell carcinoma and medulloblastoma. Here, we review the role of the Hh signaling in the carcinogenesis and progression of gastric cancer and summarize recent findings on Hh inhibitors in gastric cancer. Hedgehog signaling is often aberrantly activated and plays an important role during inflammation and carcinogenesis of gastric epithelial cells. Further study of the precise mechanisms of Hh signaling in this disease is needed for the validation of therapeutic targets and evaluation of the clinical utility of Hh inhibitors for gastric cancer.

Hedgehog Signaling: An Achilles' Heel in Cancer

Hedgehog signaling pathway originally identified in the fruit fly Drosophila is an evolutionarily conserved signaling mechanism with crucial roles in embryogenesis, growth and patterning. It exerts its biological effect through a signaling mechanism that terminates at glioma-associated oncogene (GLI) transcription factors which alternate between activator and repressor forms and mediate various responses. The important components of the pathway include the hedgehog ligands (SHH), the Patched (PTCH) receptor, Smoothened (SMO), Suppressor of Fused (SuFu) and GLI transcription factors. Activating or inactivating mutations in key genes cause uncontrolled activation of the pathway in a ligand independent manner. The ligand-dependent aberrant activation of the hedgehog pathway causing overexpression of hedgehog pathway components and its target genes occurs in autocrine as well as paracrine fashion. In adults, aberrant activation of hedgehog signaling has been linked to birth defects and multiple solid cancers. In this review, we assimilate data from recent studies to understand the mechanism of functioning of the hedgehog signaling pathway, role in cancer, its association in various solid malignancies and the current strategies being used to target this pathway for cancer treatment.

An Update on Clinicopathological and Molecular Features of Plexiform Fibromyxoma

Plexiform fibromyxoma is a rare and newly described gastric mesenchymal tumor with only 121 reported cases in the literature. Our understanding of plexiform fibromyxoma requires updating since the first case has been reported by Takahashi et al. 12 years ago. The present review summarized reported cases in the literature, and both clinical and pathological aspects of plexiform fibromyxoma were comprehensively discussed. Plexiform fibromyxoma usually causes nonspecific or bleeding signs or symptoms, and therefore clinical recognition of the disease is challenging. Plexiform fibromyxoma is of benign nature without any metastasis or recurrence reported, and more conservative surgical treatment should be considered.

Reduced m6A modification predicts malignant phenotypes and augmented Wnt/PI3K-Akt signaling in gastric cancer

Background

As the most abundant epigenetic modification on mRNAs and long non‐coding RNAs, N6‐methyladenosine (m6A) modification extensively exists in mammalian cells. Controlled by writers (methyltransferases), readers (signal transducers), and erasers (demethylases), m6A influences mRNA structure, maturation, and stability, thus negatively regulating protein expression in a post‐translational manner. Nevertheless, current understanding of m6A's roles in tumorigenesis, especially in gastric cancer (GC) remains to be unveiled. In this study, we assessed m6A's clinicopathological relevance to GC and explored the underlying mechanisms.

Methods

By referring to a proteomics‐based GC cohort we previously generated and the TCGA‐GC cohort, we merged expressions of canonical m6A writers (METTL3/METTL14), readers (YTHDF1/YTHDF2/YTHDF3), and erasers (ALKBH5/FTO), respectively, as W, R, and E signatures to represent m6A modification. We stratified patients according to these signatures to decipher m6A's associations with crucial mutations, prognosis, and clinical indexes. m6A's biological functions in GC were predicted by gene set enrichment analysis (GSEA) and validated by in vitro experiments.

Results

We discovered that W and R were potential tumor suppressive signatures, while E was a potential oncogenic signature in GC. According to W/R/E stratifications, patients with low m6A‐indications were accompanied with higher mutations of specific genes (CDH1, AR, GLI3, SETBP1, RHOA, MUC6, and TP53) and also demonstrated adverse clinical outcomes. GSEA suggested that reduced m6A was correlated with oncogenic signaling and phenotypes. Through in vitro experiments, we proved that m6A suppression (represented by METTL14 knockdown) promoted GC cell proliferation and invasiveness through activating Wnt and PI3K‐Akt signaling, while m6A elevation (represented by FTO knockdown) reversed these phenotypical and molecular changes. m6A may also be involved in interferon signaling and immune responses of GC.

Conclusions

Our work demonstrated that low‐m6A signatures predicted adverse clinicopathological features of GC, while the reduction of RNA m6A methylation activated oncogenic Wnt/PI3K‐Akt signaling and promoted malignant phenotypes of GC cells.

Fatty acid 2-hydroxylation inhibits tumor growth and increases sensitivity to cisplatin in gastric cancer

Background

Most gastric cancers are diagnosed at an advanced or metastatic stage with poor prognosis and survival rate. Fatty acid 2-hydroxylase (FA2H) with high expression in stomach generates chiral (R)-2-hydroxy FAs ((R)-2-OHFAs) and regulates glucose utilization which is important for cell proliferation and invasiveness. We hypothesized that FA2H impacts gastric tumor growth and could represent a novel target to improve gastric cancer therapy.

Methods

FA2H level in 117 human gastric tumors and its association with tumor growth, metastasis and overall survival were examined. Its roles and potential mechanisms in regulating tumor growth were studied by genetic and pharmacological manipulation of gastric cancer cells in vitro and in vivo.

Findings

FA2H level was lower in gastric tumor tissues as compared to surrounding tissues and associated with clinicopathologic status of patients, which were confirmed by analyses of multiple published datasets. FA2H depletion decreased tumor chemosensitivity, partially due to inhibition of AMPK and activation of the mTOR/S6K1/Gli1 pathway. Conversely, FA2H overexpression or treatment with (R)-2-OHFAs had the opposite effects. In line with these in vitro observations, FA2H knockdown promoted tumor growth with increased level of tumor Gli1 in vivo. Moreover, (R)-2-OHFA treatment significantly decreased Gli1 level in gastric tumors and enhanced tumor chemosensitivity to cisplatin, while alleviating the chemotherapy-induced weight loss in mice.

Interpretation

Our results demonstrate that FA2H plays an important role in regulating Hh signaling and gastric tumor growth and suggest that (R)-2-OHFAs could be effective as nontoxic wide-spectrum drugs to promote chemosensitivity.

Fund

Grants of NSF, NIH, and PAPD.