Activation of FXR and inhibition of EZH2 synergistically inhibit colorectal cancer through cooperatively accelerating FXR nuclear location and upregulating CDX2 expression

Development and validation of nomograms for predicting overall survival and cancer-specific survival in unresected colorectal cancer patients undergoing chemotherapy

This study aims to develop nomograms for predicting overall survival (OS) and cancer-specific survival (CSS) in colorectal cancer (CRC) patients who did not receive primary site surgery but underwent chemotherapy. We analyzed data from 3,050 patients treated with chemotherapy without primary site surgery from 2010 to 2015, sourced from the Surveillance, Epidemiology, and End Results (SEER) database. The data were randomly divided into training and validation sets. Initial variable selection was performed using the least absolute shrinkage and selection operator (LASSO), and multivariate Cox regression analysis was used to identify independent prognostic factors. Two nomograms were subsequently constructed based on these factors. Survival analysis was conducted using Kaplan-Meier plots and the log-rank test. We identified nine significant predictors of OS and CSS: age, marital status, primary site, grade, histology, T stage, M stage, tumor size, and CEA levels. The models for OS and CSS exhibited excellent predictability, with time-dependent area under the receiver operating characteristic curves (AUCs) exceeding 0.7. Calibration curves confirmed the accuracy of these predictions in the training and validation sets. Additionally, decision curve analysis (DCA) indicated that our models provide greater clinical benefit than traditional TNM staging. Notably, survival outcomes varied significantly across risk categories, affirming the models' effective discrimination. For CRC patients who did not receive primary site surgery but underwent chemotherapy, this validated nomogram enables precision prognostication fundamentally shifting the paradigm from population-level TNM estimates to individualized risk-adaptive management.

The Status of SOX2 Expression in Gastric Cancers with Induction of CDX2 Defines Groups with Different Genomic Landscapes

BACKGROUND

Gastric adenocarcinoma is a highly lethal neoplasm with a short survival especially when metastatic. Few effective treatments are available for the control of the disease and palliation of patients with metastatic gastric cancer. Although progress has been made in the elucidation of molecular pathways invoked in gastric carcinogenesis, this knowledge has not yet led to major breakthroughs, in contrast to several other types of cancer. The role of stem cell transcription factors SOX2 and CDX2 is of particular interest in the pathogenesis of gastric cancer.

METHODS

The cohort of gastric adenocarcinomas from The Cancer Genome Atlas (TCGA) was interrogated and two groups of gastric cancers, with CDX2 induction and SOX2 suppression on the one hand and with CDX2 induction and SOX2 maintained expression on the other hand were retained. The induction of expression of the two transcription factors was defined as a mRNA expression z score compared with normal samples above zero. The two groups were compared for clinical-pathologic and genomic differences.

RESULTS

Among gastric cancers with up-regulated CDX2 mRNA, cancers with suppressed SOX2 mRNA were slightly more numerous (55.9%) than those with a maintained SOX2 expression. The SOX2 suppressed group had a higher prevalence of MSI high cancers (30.9% versus 10%) and of cases with high tumor mutation burden (35% versus 12.4%) than cancers with a SOX2 maintained expression, which presented more frequently high Chromosomal Instability (CIN). The group with SOX2 suppression had higher rates of mutations in many gastric cancer-associated genes such as epigenetic modifiers ARID1A, KMT2D, KMT2C, and KMT2B, as well as higher rates of mutations in genes encoding for receptor tyrosine kinases ERBB4 and FGFR1. On the other hand, TP53 mutations and amplifications in MYC, ERBB2, and CCNE1 were more common in the group with a maintained expression of SOX2, approaching significance for MYC.

CONCLUSIONS

Notable differences are present in the genomic landscape of CDX2-induced gastric cancer depending on the level of expression of SOX2 mRNA. Despite this, SOX2 mRNA expression levels were not prognostic.

Hyodeoxycholic acid inhibits colorectal cancer proliferation through the FXR/EREG/EGFR axis

Background

The high morbidity and mortality rates of colorectal cancer (CRC) have been a public health concern globally, and the search for additional therapeutic options is imminent. Hyodeoxycholic acid (HDCA) has been receiving attention in recent years and has demonstrated potent efficacy in several diseases. Nonetheless, the antitumor effects and molecular pathways of HDCA in CRC remain largely unexplored.

Methods

In this study, we investigated how HDCA influences the growth potential of CRC cells using techniques such as flow cytometry, Edu assay, CCK-8, colony formation assay, Western blot analysis, and animal experiments.

Results

It was found that HDCA treatment of CRC cells was able to significantly inhibit the proliferative capacity of the cells. Furthermore, it was discovered that HDCA primarily stimulated Farnesoid X Receptor (FXR) rather than Takeda G protein coupled receptor 5 (TGR5) to suppress CRC growth. It was also confirmed that HDCA inhibited the Epiregulin (EREG)/Epidermal Growth Factor Receptor (EGFR) pathway by activating FXR, and a negative correlation between FXR and EREG was analyzed in CRC tissue samples. Finally, in vivo animal studies confirmed that HDCA inhibited CRC proliferation without hepatotoxicity.

Conclusion

Our findings indicate that HDCA suppresses the EREG/EGFR signaling route by activating FXR, thereby hindering the growth of CRC cells and demonstrating a tumor-inhibiting effect in CRC. This study may provide a new therapeutic strategy to improve the prognosis of CRC.

Trametinib and M17, a novel small molecule inhibitor of AKT, display a synergistic antitumor effect in triple negative breast cancer cells through the AKT/mTOR and MEK/ERK pathways

Triple negative breast cancer (TNBC) is associated with a poor prognosis and limited response to traditional chemotherapy, necessitating the exploration of novel treatment approaches. Recent researches have highlighted the interconnected roles of the PI3K/AKT pathway and MAPK pathway in TNBC cells, contributing to the efficacy of treatments. Therefore, the concurrent inhibition of both pathways presents a potential new therapeutic strategy for TNBC patients. This study aimed to evaluate the antitumor efficacy of M17, an AKT allosteric inhibitor and a new synthesized shikonin derivative, both alone and in combination with the MEK inhibitor trametinib. We applied various cellular assays and a subcutaneous 4T1 tumor bearing BALB/c mice model were utilized to assess the in vitro and in vivo antitumor effects. Computational docking and Bio-Layer Interferometry (BLI) were employed to investigate the binding of M17 with AKT. Additionally, flow cytometry, transwell assays, western blotting, and tumor xenograft assays were conducted to explore the potential synergistic mechanisms of the combined therapy. The results demonstrated that M17 exhibited moderate antitumor activity against TNBC cells, but significantly enhanced the apoptotic effects and inhibited proliferation and migration when combined with trametinib. Furthermore, the combination of M17 and trametinib showed even more pronounced antitumor activity in vivo. Mechanistically, the dual therapy synergistically suppressed TNBC by targeting the AKT/mTOR and MEK/ERK signaling pathways and inhibiting epithelial-mesenchymal transition. In conclusion, the findings suggested that the combination of M17 and trametinib holds promise as a synergistic treatment option for TNBC patients.

FXR promotes clear cell renal cell carcinoma carcinogenesis via MMP-7-regulated EMT pathway

Renal cell carcinoma (RCC) ranks as a prevalent malignant neoplasm, with clear cell renal cell carcinoma (ccRCC, also known as KIRC) accounting for approximately 75% of all RCC cases. The farnesoid X receptor (FXR, encoded by NR1H4), functioning as a nuclear receptor, plays a crucial role in regulating gene transcription. Although the involvement of FXR in tumors of the digestive system and in acute kidney injury has been extensively studied, its specific role in the pathogenesis of ccRCC has yet to be thoroughly investigated. Consequently, the objective of our current investigation is to uncover the functional roles of FXR in ccRCC. In this study, plasmids for the overexpression of FXR were constructed, and small interfering RNA (siRNA) constructs were designed. Dual-luciferase reporter assays confirmed a direct binding interaction between FXR and the promoter of the matrix metalloproteinase 7 (MMP-7) gene. Additionally, a mouse xenograft model elucidated the regulatory effect of FXR on MMP-7 in the context of tumor growth. This study elucidates how FXR regulates the promotion of ccRCC through the MMP-7-mediated EMT pathway. Interestingly, FXR is typically regarded as a tumor suppressor gene that affects gastrointestinal tumors, providing a potential new therapeutic direction for ccRCC.

Homeobox B9 promotes the invasion and metastasis of hepatocellular carcinoma cells via the EZH2-MIR203A-SNAI2 axis

BACKGROUND

Research has elucidated that homeobox B9 (HOXB9), an important transcriptional activator, plays a pivotal role in promoting the invasion and metastasis of hepatocellular carcinoma (HCC) cells. However, the mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells is incompletely understood and needs further exploration.

METHODS

HOXB9 and snail family transcriptional repressor 2 (SNAI2) expression were analyzed using qRT-PCR and western blotting. The invasion and metastasis of hepatocellular carcinoma (HCC) cells were investigated using in vitro and in vivo assays. The H3K27me3 enrichment and HOXB9 interaction with microRNA 203a (MIR203A) or SNAI2 were detected using ChIP-qPCR. Transcriptional activities of SNAI2 and MIR203A promoter were detected using dual-luciferase reporter assays. Co-IP and GST pull-down assays were performed to confirm the binding between HOXB9 and EZH2.

RESULTS

HOXB9 and SNAI2 were highly expressed in HCC tissues and their expression was positively intercorrelated and associated with poor prognosis in patients with HCC. In vitro and in vivo experiments confirmed that HOXB9 can upregulate the expression of SNAI2 to promote the invasion and metastasis of HCC cells. Furthermore, HOXB9 elevated SNAI2 expression by inhibiting MIR203A expression, a tumor suppressor gene, in HCC cells. Mechanistically, HOXB9 recruited enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) through interaction with its WD-binding domain, which increased EZH2-mediated histone H3 lysine 27 trimethylation (H3K27me3) at the MIR203A promoter region, in turn repressing the transcriptional activity and expression of MIR203A and consequently increasing the SNAI2 level in HCC cells. Finally, empirical evidence from in vitro and in vivo studies confirmed that mitigation of the HOXB9-mediated enhancement of epigenetic silencing of MIR203A inhibited SNAI2 expression, impeding the invasion and metastasis of HCC cells.

CONCLUSIONS

Our study reveals a novel mechanism by which HOXB9 promotes the invasion and metastasis of HCC cells and expands the understanding of the function of HOXB9 in tumor progression and provides a novel therapeutic strategy for curtailing HCC invasion and metastasis.

Anti-Glioma Effects of Ligustilide or n-Butylphthalide on Their Own and the Synergistic Effects with Temozolomide via PI3K/Akt Signaling Pathway

Background

Ligustilide (LIG) and n-butylphthalide (NBP) have neuroprotective effects in cerebral ischemia; however, their roles in gliomas are not well-known.This study aimed to explore the anti-glioma effects of LIG and NBP individually and the synergistic effects of temozolomide (TMZ) via the PI3K/Akt Signaling Pathway.

Materials and Methods

Cytotoxicity of LIG and NBP alone and in combination with TMZ in U251 cells was determined using the CCk-8. The effect of compounds alone or in combination on cell migration was detected using the wound healing assay, and the invasion was evaluated by transwell assays, respectively. Cell apoptosis was quantified by flow cytometry and the changed expressions of proteins were detected by Western blotting.

Results

The results showed that LIG and NBP significantly inhibited the growth of U251 cells at concentrations of 4-10 µg/mL and 1.5-6 µg/mL in a dose-dependent manner (p<0.05, p<0.01). The combination of 20 µg/mL TMZ with LIG in the concentration range of 4-10 µg/mL or with NBP of 0.5-6 µg/mlachieved synergistic effect towardsU251 cells. LIG and NBP, alone or in combination with TMZ, markedly inhibited cell invasion (p< 0.001) and enhanced apoptosis (p< 0.05). The combination of TMZ with LIG or NBP markedly inhibited cell migration (p< 0.001). Western blot analysis showed that LIG, NBP, and TMZ, alone and in combination, significantly decreased the expression of Bcl-2, p-PI3K, and p-Akt, and increased the expression of Bax.

Conclusion

Both LIG and NBP exert anti-glioma effects on their own through the PI3K/Akt pathway and enhance TMZ-mediated anti-glioma efficiency via the same pathway.

Bile Acids, Intestinal Barrier Dysfunction, and Related Diseases

The intestinal barrier is a precisely regulated semi-permeable physiological structure that absorbs nutrients and protects the internal environment from infiltration of pathological molecules and microorganisms. Bile acids are small molecules synthesized from cholesterol in the liver, secreted into the duodenum, and transformed to secondary or tertiary bile acids by the gut microbiota. Bile acids interact with bile acid receptors (BARs) or gut microbiota, which plays a key role in maintaining the homeostasis of the intestinal barrier. In this review, we summarize and discuss the recent studies on bile acid disorder associated with intestinal barrier dysfunction and related diseases. We focus on the roles of bile acids, BARs, and gut microbiota in triggering intestinal barrier dysfunction. Insights for the future prevention and treatment of intestinal barrier dysfunction and related diseases are provided.

FXR agonist GW4064 enhances anti-PD-L1 immunotherapy in colorectal cancer

Colorectal cancer (CRC) is one of the top three malignant tumors in terms of morbidity, and the limited efficacy of existing therapies urges the discovery of potential treatment strategies. Immunotherapy gradually becomes a promising cancer treatment method in recent decades; however, less than 10% of CRC patients could really benefit from immunotherapy. It is pressing to explore the potential combination therapy to improve the immunotherapy efficacy in CRC patients. It is reported that Farnesoid X receptor (FXR) is deficiency in CRC and associated with immunity. Herein, we found that GW4064, a FXR agonist, could induce apoptosis, block cell cycle, and mediate immunogenic cell death (ICD) of CRC cells in vitro. Disappointingly, GW4064 could not suppress the growth of CRC tumors in vivo. Further studies revealed that GW4064 upregulated PD-L1 expression in CRC cells via activating FXR and MAPK signaling pathways. Gratifyingly, the combination of PD-L1 antibody with GW4064 exhibited excellent anti-tumor effects in CT26 xenograft models and increased CD8+ T cells infiltration, with 33% tumor bearing mice cured. This paper illustrates the potential mechanisms of GW4064 to upregulate PD-L1 expression in CRC cells and provides important data to support the combination therapy of PD-L1 immune checkpoint blockade with FXR agonist for CRC patients.

FXR agonists for colorectal and liver cancers, as a stand-alone or in combination therapy

Farnesoid X receptor (FXR, NR1H4) is generally considered as a tumor suppressor of colorectal and liver cancers. The interaction between FXR, bile acids (BAs) and gut microbiota is closely associated with an increased risk of colorectal and liver cancers. Increasing evidence shows that FXR agonists may be potential therapeutic agents for colorectal and liver cancers. However, FXR agonists alone do not produce the desired results due to the complicated pathogenesis and single therapeutic mechanism, which suggests that effective treatments will require a multimodal approach. Based on the principle of improvingefficacy andreducingside effects, combination therapy is currently receiving considerable attention. In this review, colorectal and liver cancers are grouped together to discuss the effects of FXR agonists alone or in combination for combating the two cancers. We hope that this review will provide a theoretical basis for the clinical application of novel FXR agonists or combination with FXR agonists against colorectal and liver cancers.

Promotion of Deoxycholic Acid Effect on Colonic Cancer Cell Lines In Vitro by Altering the Mucosal Microbiota

Colorectal cancer (CRC) is the third most prevalent neoplasm and the second leading cause of cancer death worldwide. Microbiota and their products, such as bile acids (BAs), are important causal factors for the occurrence and development of CRC. Therefore, we performed 16S ribosomal RNA (16S rRNA) and liquid chromatography/mass spectrometry (LC-MS) to measure mucosal microbiota and BA composition in paired cancerous and noncancerous gut tissue samples from 33 patients with CRC at a hospital in Beijing. In cancerous tissues, we detected altered mucosal microbiota with increased levels of the genera Bacteroides, Curtobacterium, and Campylobacter and an increase in deoxycholic acid (DCA), which was the only BA elevated in cancerous tissues. Ex vivo coculture showed that the mucosal microbiota in cancerous tissues indeed had a stronger DCA production ability, indicating that DCA-producing bacteria are enriched in tumors. Results from the CCK8 and Transwell assays indicated that DCA enhances the overgrowth, migration, and invasion of CRC cell lines, and, through qPCR and Western blot analyses, downregulation of FXR was observed in CRC cell lines after DCA culture. We then verified the downregulation of FXR expression in cancerous tissues using our data and the TCGA database, and we found that FXR downregulation plays an important role in the development of CRC. In conclusion, differing mucosal microbiota, increased amounts of mucosal DCA, and lower FXR expression were demonstrated in cancerous tissues compared to normal tissue samples. The results of this study can be applied to the development of potential therapeutic targets for CRC prevention, such as altering mucosal microbiota, DCA, or FXR.

EZH2 as a Prognostic Factor and Its Immune Implication with Molecular Characterization in Prostate Cancer: An Integrated Multi-Omics in Silico Analysis

Prostate cancer (PCa) is a type of potentially fatal malignant tumor. Immunotherapy has shown a lot of potential for various types of solid tumors, but the benefits have been less impressive in PCa. Enhancer of zeste homolog 2 (EZH2) is one of the three core subunits of the polycomb repressive complex 2 that has histone methyltransferase activity, and the immune effects of EZH2 in PCa are still unclear. The purpose of this study was to explore the potential of EZH2 as a prognostic factor and an immune therapeutic biomarker for PCa, as well as the expression pattern and biological functions. All analyses in this study were based on publicly available databases, mainly containing Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), UCSCXenaShiny, and TISIDB. We performed differential expression analysis, developed a prognostic model, and explored potential associations between EZH2 and DNA methylation modifications, tumor microenvironment (TME), immune-related genes, tumor mutation burden (TMB), tumor neoantigen burden (TNB), and representative mismatch repair (MMR) genes. We also investigated the molecular and immunological characterizations of EZH2. Finally, we predicted immunotherapeutic responses based on EZH2 expression levels. We found that EZH2 was highly expressed in PCa, was associated with a poor prognosis, and may serve as an independent prognostic factor. EZH2 expression in PCa was associated with DNA methylation modifications, TME, immune-related genes, TMB, TNB, and MMR. By gene set enrichment analysis and gene set variation analysis, we found that multiple functions and pathways related to tumorigenesis, progression, and immune activation were enriched. Finally, we inferred that immunotherapy may be more effective for PCa patients with low EZH2 expression. In conclusion, our study showed that EZH2 could be a potentially efficient predictor of prognosis and immune response in PCa patients.

Combining EZH2 inhibitors with other therapies for solid tumors: more choices for better effects

EZH2 is an epigenetic regulator that methylates lysine 27 on histone H3 (H3K27) and is closely related to the development and metastasis of tumors. It often shows gain-of-function mutations in hematological tumors, while it is often overexpressed in solid tumors. EZH2 inhibitors have shown good efficacy in hematological tumors in clinical trials but poor efficacy in solid tumors. Therefore, current research on EZH2 inhibitors has focused on exploring additional combination strategies in solid tumors. Herein we summarize the combinations and mechanisms of EZH2 inhibitors and other therapies, including immunotherapy, targeted therapy, chemotherapy, radiotherapy, hormone therapy and epigenetic therapy, both in clinical trials and preclinical studies, aiming to provide a reference for better antitumor effects.