NOTCH3, a crucial target of miR-491-5p/miR-875-5p, promotes gastric carcinogenesis by upregulating PHLDB2 expression and activating Akt pathway

Glycerophosphoinositol modulates FGA and NOTCH3 in exercise-induced muscle adaptation and colon cancer progression

Objectives

Fibroleukin (FGA) and NOTCH3 are vital in both exercise-induced muscle adaptation and colon adenocarcinoma (COAD) progression. This study aims to elucidate the roles of FGA and NOTCH3 in phenotypic variations of striated muscle induced by exercise and in COAD development. Additionally, it seeks to evaluate the prognostic significance of these proteins.

Methods

Gene Set Variation Analysis (GSVA) and protein-protein interaction (PPI) network analysis were employed to identify differentially expressed genes (DEGs). Molecular docking studies were conducted to assess the binding affinities of 39 compounds to the NOTCH3 protein. In vitro assays, including mobileular viability, gene expression, and apoptosis assays, were performed to evaluate the effects of glycerophosphoinositol on FGA and NOTCH3 expression. Additionally, copy number variation (CNV), methylation status, and survival analyses were conducted across multiple cancers types.

Results

The NOTCH signaling pathway was consistently upregulated in exercise-induced muscle samples. High NOTCH3 expression was associated with poor prognosis in COAD, extracellular matrix organization, immune infiltration, and activation of the PI3K-Akt pathway. Molecular docking identified gamma-Glu-Trp, gamma-Glutamyltyrosine, and 17-Deoxycortisol as strong binders to NOTCH3. Glycerophosphoinositol treatment modulated FGA and NOTCH3 expression, influencing cell proliferation and apoptosis. CNV and methylation analyses revealed specific changes in FGA and NOTCH3 across 20 cancers types. Survival analyses showed strong associations between FGA/NOTCH3 expression and survival metrics, with negative correlations for FGA and positive correlations for NOTCH3.

Conclusion

FGA and NOTCH3 play significant roles in exercise-induced muscle adaptation and colon cancer progression. The expression profiles and interactions of these proteins provide promising prognostic markers and therapeutic targets. These findings offer valuable insights into the post-translational modifications (PTMs) in human cancer, highlighting novel pharmacological and therapeutic opportunities.

THBS2 promotes gastric cancer progression and stemness via the Notch signaling pathway

Thrombospondin-2 (THBS2), a secreted extracellular matrix protein, plays a crucial role in various biological processes including angiogenesis, tissue remodeling, and inflammation. Our study focuses on its function in human gastric cancer (GC). Through bioinformatics and tumor tissue analysis, we compared THBS2 expression in GC tissues and adjacent tissues, and predicted regulatory upstream and downstream molecules. The direct regulatory effect of miR-29b-3p on THBS2 was evaluated through dual-luciferase reporter assays, showing that miR-29b-3p targets the 3'-UTR of THBS2 mRNA, reducing its expression in GC cells. The influence of THBS2 on tumorigenesis and stemness was examined on protein expression levels via Western blot. In vivo, THBS2's role was investigated through xenograft and metastasis assays in nude mice, demonstrating that downregulation of THBS2 impairs GC tumorigenesis and liver metastasis. Our study identified THBS2 as a highly expressed prognostic factor in GC patients. Functionally, THBS2 promotes GC progression through the Notch signaling pathway by regulating Notch3, NEY1, and HES1 proteins, and sustains cancer stem cell-like characteristics by Notch3, including the expression of CD44, Nanog, OCT4, and SOX2. In sum, our study reveals that THBS2 promotes GC progression and stemness, modulated negatively by miR-29b-3p. This suggests potential therapeutic targets within the THBS2/Notch signaling axis for combating gastric cancer.

FPR3 reprograms glycolytic metabolism and stemness in gastric cancer via calcium-NFATc1 pathway

Aerobic glycolysis accelerates tumor proliferation and progression, and inhibitors or drugs targeting abnormal cancer metabolism have been developing. Cancer stem-like cells (CSCs) significantly contribute to tumor initiation, metastasis, therapy resistance, and recurrence. Formyl peptide receptor 3 (FPR3), a member of FPR family, involves in inflammation, tissue repair, and angiogenesis. However, studies in exploring the regulatory mechanisms of aerobic glycolysis and CSCs by FPR3 in gastric cancer (GC) remain unknown. Here, we demonstrated that overexpressed FPR3 suppressed glycolytic capacity and stemness of tumor cells, then inhibited GC cells proliferation. Mechanistically, FPR3 impeded cytoplasmic calcium ion flux and hindered nuclear factor of activated T cells 1 (NFATc1) nuclear translocation, leading to the transcriptional inactivation of NFATc1-binding neurogenic locus notch homolog protein 3 (NOTCH3) promoter, subsequently obstructing NOTCH3 expression and the AKT/mTORC1 signaling pathway, and ultimately downregulating glycolysis. Additionally, NFATc1 directly binds to the sex determining region Y-box 2 (SOX2) promoter and modifies stemness in GC. In conclusion, our work illustrated that FPR3 played a negative role in GC progression by modulating NFATc1-mediated glycolysis and stemness in a calcium-dependent manner, providing potential insights into cancer therapy.

MicroRNA-875-5p inhibits the growth and metastasis of cervical cancer cells by promoting autophagy and apoptosis and inhibiting the epithelial-mesenchymal transition

Introduction

MicroRNA-875-5p (miR-875-5p) is a cancer-related microRNA. It has been demonstrated that miR-875-5p participates in the development of various types of cancer such as hepatocellular carcinoma, gastric carcinoma, prostate and bladder cancer. Previous research suggested that miR-875 is implicated in the development of cervical cancer cells. However, the exact role and function of miR-875-5p in cervical cancer remain unexplored. It is important to examine the role and function of miR-875-5p and the associated signaling pathway, as the findings may have diagnostic and therapeutic significance. Thus, in this study, we investigated the effect of miR-875-5p on the growth and metastasis of cervical cancer cells and the possible underlying mechanisms.

Methods

Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the expression of miR-875-5p in cervical cancer cells and normal cervical epithelium. After overexpression or co-expression of miR-875-5p in cells, the changes in cell function were analyzed. Western blot was used to detect the expression changes of epithelial-mesenchymal transition (EMT) -related proteins and autophagy-related proteins.

Results

Functional studies demonstrated that miR-875-5p overexpression significantly inhibited the proliferation, migration, invasion, and EMT, and promotes apoptosis and autophagy of cervical cancer cells., while miR-875-5p knockdown promoted the proliferation, migration, invasion, and EMT, and inhibited apoptosis and autophagy cervical cancer cells. Furthermore, Western blot results showed that overexpression of miR-875-5p downregulated the expressions of N-cadherin, Snail, Vimentin and microtubule-associated protein 1 light chain 3B I (LC3B I). Conversely, miR-875-5p upregulated the expression of E-cadherin.

Conclusion

In conclusion, our findings suggest that miR-875-5p functions as a tumor inhibitor suppressing the growth and metastasis of cervical cancer. Overexpression of miR-875-5p inhibits malignant behavior and promotes autophagy and apoptosis in cervical cancer cells. These findings advance our understanding of the role and function of miR-875-5p in cervical cancer and could facilitate the development of early genetic markers or biomarkers and therapeutic targets for cervical cancer.

Depletion of PHLDB2 Suppresses Epithelial-Mesenchymal Transition and Enhances Anti-Tumor Immunity in Head and Neck Squamous Cell Carcinoma

The role of Pleckstrin homology-like domain family B member 2 (PHLDB2) in the regulation of cell migration has been extensively studied. However, the exploration of PHLDB2 in head and neck squamous cell carcinoma (HNSCC) is still limited in terms of expression, function, and therapeutic potential. In this study, we discovered an upregulation of PHLDB2 expression in HNSCC tissues which was correlated with a negative prognosis in patients with HNSCC. Additionally, we determined that a high level of expression of PHLDB2 is crucial for maintaining cell migration through the regulation of the epithelial-mesenchymal transition (EMT). Furthermore, we demonstrated that the ablation of PHLDB2 in tumor cells inhibited tumorigenicity in a C3H syngeneic tumor-bearing mouse model. Mechanistically, PHLDB2 was found to be involved in the regulation of T cell anti-tumor immunity, primarily by enhancing the activation and infiltration of CD8+ T cells. In light of these findings, PHLDB2 emerges as a promising biomarker and therapeutic target for interventions in HNSCC.

Nebulized inhalation of LPAE-HDAC10 inhibits acetylation-mediated ROS/NF-κB pathway for silicosis treatment

Silicosis is a serious silica-induced respiratory disease for which there is currently no effective treatment. Irreversible pulmonary fibrosis caused by persistent inflammation is the main feature of silicosis. As an underlying mechanism, acetylation regulated by histone deacetylases (HDACs) are believed to be closely associated with persistent inflammation and pulmonary fibrosis. However, details of the mechanisms associated with the regulation of acetylated modification in silicosis have yet to be sufficiently established. Furthermore, studies on the efficient delivery of DNA to lung tissues by nebulized inhalation for the treatment of silicosis are limited. In this study, we established a mouse model of silicosis successfully. Differentially expressed genes (DEGs) between the lung tissues of silicosis and control mice were identified based on transcriptomic analysis, and HDAC10 was the only DEG among the HDACs. Acetylomic and combined acetylomic/proteomic analysis were performed and found that the differentially expressed acetylated proteins have diverse biological functions, among which 12 proteins were identified as the main targets of HDAC10. Subsequently, HDAC10 expression levels were confirmed to increase following nebulized inhalation of linear poly(β-amino ester) (LPAE)-HDAC10 nanocomplexes. The levels of oxidative stress, the phosphorylation of IKKβ, IκBα and p65, as well as inflammation were inhibited by HDAC10. Pulmonary fibrosis, and lung function in silicosis showed significant improvements in response to the upregulation of HDAC10. Similar results were obtained for the silica-treated macrophages in vitro. In conclusion, HDAC10 was identified as the main mediator of acetylation in silicosis. Nebulized inhalation of LPAE-HDAC10 nanocomplexes was confirmed to be a promising treatment option for silicosis. The ROS/NF-κB pathway was identified as an essential signaling pathway through which HDAC10 attenuates oxidative stress, inflammation, and pulmonary fibrosis in silicosis. This study provides a new theoretical basis for the treatment of silicosis.

miR-491-5p regulates the susceptibility of glioblastoma to ferroptosis through TP53

BACKGROUND

Ferroptosis has excellent potential in glioblastoma (GBM) therapy. In this study, we attempted to explore the effect of miR 491-5p on ferroptosis in GBM.

METHODS

In this study, publicly available ferroptosis-related genome maps were used to screen genes upregulated in GBM and their target genes. The Spearman correlation coefficient was applied to analyze the correlation between the tumor protein p53 gene (TP53) and miR-491-5p. The expressions of miR-491-5p and TP53 were determined. The protein abundances of the TP53-encoded factors p53 and p21 were measured. Cell proliferation, migration and invasion were assessed. We pretreated U251MG cells and GBM mice with a ferroptosis inducer (erastin). The mitochondrial state was observed. The contents of reactive oxygen species (ROS), total Fe and Fe²⁺ were calculated.

RESULTS

The level of TP53 was significantly increased in GBM and negatively correlated with miR-491-5p. miR-491-5p overexpression promoted U251MG cell proliferation, migration and invasion and interfered with the p53/p21 pathway. TP53 supplement reversed the effects of miR-491-5p. U251MG cells and GBM mice exhibited significant accumulations of ROS and iron. Erastin promoted the expression of TP53. Inhibition of TP53 reversed erastin-induced physiological phenotypes. Moreover, miR-491-5p overexpression caused a decrease in the number of damaged mitochondria and the contents of ROS, total Fe and Fe²⁺. TP53 supplement disrupted miR-491-5p-repressed ferroptosis. Erastin could inhibit GBM growth, and miR-491-5p overexpression impeded the therapeutic effect of erastin.

CONCLUSIONS

Our findings reveal the functional diversity of miR-491-5p in GBM and suggest that miR-491-5p/TP53 signaling hinders the sensitivity of GBM to ferroptosis through the p53/p21 pathway.

Long Noncoding RNA LINC00909 Induces Epithelial-Mesenchymal Transition and Contributes to Osteosarcoma Tumorigenesis and Metastasis

Background

Osteosarcoma (OS) is a malignant tumor that is highly metastatic with a high mortality rate. Although mounting evidence suggests that LINC00909 is strongly associated with the malignant progression of various tumors, the exact role of LINC00909 in OS remains unknown. Therefore, the current study was designed to investigate the relationship between LINC00909 and the malignant progression of OS.

Methods

LINC00909 expression was measured in OS cell lines and clinical specimens using RT-qPCR assays. The effects of LINC00909 on OS proliferation, invasion, and migration were calculated both in vitro and in vivo. Apart from that, bioinformatics analyses, FISH, RIP, and luciferase reporter assays were carried out to investigate the downstream target of LINC00909. Rescue experiments were also conducted to investigate the potential mechanisms of action of competitive endogenous RNAs (ceRNAs).

Results

In this study, we found that LINC00909 was highly expressed in OS cell lines and clinical specimens. In vivo and in vitro experiments demonstrated that LINC00909 induces epithelial-to-mesenchymal transition (EMT) and contributes to OS tumorigenesis and metastasis. FISH, RIP, and luciferase assays indicated that miR-875-5p is a direct target of LINC00909. Moreover, HOXD9 was validated as the downstream target of miR-875-5p in a luciferase reporter assay and western blotting experiments. Rescue experiments revealed that HOXD9 reversed the effect of LV-sh-LINC00909 on OS cells by positively regulating the PI3K/AKT/mTOR signaling pathway.

Conclusion

Collectively, LINC00909 induces EMT and contributes to OS tumorigenesis and metastasis through the PI3K/AKT/mTOR pathway by binding to miR-875-5p to upregulate HOXD9 expression. Targeting the LINC00909/miR-875-5p/HOXD9 axis may have potential in treating OS.

A nine–consensus–prognostic –gene–based prognostic signature, recognizing the dichotomized subgroups of gastric cancer patients with different clinical outcomes and therapeutic strategies

Background: The increasing prevalence and mortality of gastric cancer (GC) has promoted the urgent need for prognostic signatures to predict the long-term risk and search for therapeutic biomarkers.

Methods and materials: A total of 921 GC patients from three GEO cohorts were enrolled in the current study. The GSE15459 and GSE62254 cohorts were used to select the top prognostic gene via the evaluation of the area under the receiver operating characteristic (ROC) curve (AUC) values. The GSE84437 cohort was used as the external validation cohort. Least absolute shrinkage and selector operation (LASSO) regression analysis was applied to reduce the feature dimension and construct the prognostic signature. Furthermore, a nomogram was constructed by integrating the independent prognostic analysis and validated by calibration plot, decision curve analysis and clinical impact curve. The molecular features and response to chemo-/immunotherapy among risk subgroups were evaluated by the “MOVICS” and “ESTAMATE” R packages and the SubMap algorithm. Lauren classification and ACRG molecular subtype were obtained to compare with the risk model.

Results: Forty-four prognosis-associated genes were identified with a preset cutoff AUC value of 0.65 in both the GSE62254 and GSE15459 cohorts. With the 10-fold cross validation analysis of LASSO, nine genes were selected to construct the nine-consensus-prognostic-gene signature. The signature showed good prognostic value in the GSE62254 (p < 0.001, HR: 3.81, 95% CI: 2.44–5.956) and GSE15459 (p < 0.001, HR: 2.65, 95% CI: 1.892–3.709) cohorts and the external validation GSE84437 cohort (p < 0.001, HR: 2.06, 95% CI: 1.554–2.735). The nomogram constructed based on two independent predictive factors, tumor stage and the signature, predicted events tightly consistent with the actual (Hosmer–Lemeshow p value: 1-year, 0.624; 3-years, 0.795; 5-years, 0.824). For the molecular features, we observed the activation of apical junction, epithelial mesenchymal transition, and immune pathways in the high-risk group, while in the low-risk group, cell cycle associated G2M, E2F and MYC target pathways were activated. Based on the results we obtained, we indicated that gastric patients in the low-risk group are more suitable for 5-fluorouracil therapy, while high-risk group patients are more suitable for anti-CTLA4 immunotherapy, these results need more support in the further studies. After compare with proposed molecular subtypes, we realized that the nine-consensus prognostic gene signature is a powerful addition to identify the gastric patients with poor prognosis.

Conclusion: In summary, we constructed a robust nine-consensus-prognostic-gene signature for the prediction of GC prognosis, which can also predict the personalized treatment of GC patients.

The Tumor Suppressor Roles and Mechanisms of MiR-491 in Human Cancers

MicroRNAs (miRNAs) are short non-coding RNAs that bind to the 3' untranslated region (3'' UTR) of target mRNAs to control gene expression post-transcriptionally. Recent indications have highlighted their important roles in a variety of pathophysiological conditions as well as human malignancies. Dysregulated miRNAs act as tumor suppressor genes or oncogenes in a variety of cancers. MiR-491 has been shown to have a major effect on tumorigenesis in multiple malignancies through binding to specific genes and signaling cascades, thereby preventing cancer progression. This review provides an overview of miR-491 expression in regulatory mechanisms and biological procedures of tumor cells, as well as the prospective possible treatment effects of various types of human cancers.

Hypoxia-inducible factor-1α and poly [ADP ribose] polymerase 1 cooperatively regulate Notch3 expression under hypoxia via a non-canonical mechanism

Upregulation of Notch3 expression has been reported in many cancers and is considered a marker for poor prognosis. Hypoxia is a driving factor of the Notch3 signaling pathway; however, the induction mechanism and role of hypoxia-inducible factor-1α (HIF-1α) in the Notch3 response are still unclear. In this study, we found that HIF-1α and poly [ADP-ribose] polymerase 1 (PARP-1) regulate Notch3 induction under hypoxia via a noncanonical mechanism. In the analyzed cancer cell lines, Notch3 expression was increased during hypoxia at both the mRNA and protein levels. HIF-1α knockdown and Notch3 promoter reporter analyses indicated that the induction of Notch3 by hypoxia requires HIF-1α and also another molecule that binds the Notch3 promoter’s guanine-rich region, which lacks the canonical hypoxia response element. Therefore, using mass spectrometry analysis to identify the binding proteins of the Notch3 promoter, we found that PARP-1 specifically binds to the Notch3 promoter. Interestingly, analyses of the Notch3 promoter reporter and knockdown of PARP-1 revealed that PARP-1 plays an important role in Notch3 regulation. Furthermore, we demonstrate that PARP inhibitors, including an inhibitor specific for PARP-1, attenuated the induction of Notch3 by hypoxia. These results uncover a novel mechanism in which HIF-1α associates with PARP-1 on the Notch3 promoter in a hypoxia response element–independent manner, thereby inducing Notch3 expression during hypoxia. Further studies on this mechanism could facilitate a better understanding of the broader functions of HIF-1α, the roles of Notch3 in cancer formation, and the insights into novel therapeutic strategies.

hsa_circ_0001741 promotes esophageal squamous cell carcinoma stemness, invasion and migration by sponging miR-491-5p to upregulate NOTCH3 expression

Circular RNAs (circRNAs) have been reported to play crucial roles in the progression of various cancers, including esophageal squamous cell carcinoma (ESCC). However, the function of circRNAs in ESCC stemness has not been reported. This study aimed to identify novel circRNAs that regulate ESCC stemness and explore their internal mechanisms in ESCC. We found that hsa_circ_0001741 was upregulated in ESCC tissues and was positively related to lymphatic metastasis, higher TNM stage, and poor prognosis. Functionally, hsa_circ_0001741 promoted ESCC cell stemness, invasion, and migration in vitro. Mechanistically, analysis of the relationship between hsa_circ_0001741 and tumor suppressor miR-491-5p revealed that hsa_circ_0001741 functioned as a miR-491-5p sponge. Specifically, hsa_circ_0001741 bound to miR-491-5p to prevent the microRNA from binding to the 3'-UTR of NOTCH3 mRNA and suppressing NOTCH3 expression. Moreover, the ablation of hsa_circ_0001741 significantly inhibited the tumorigenicity in vivo. In conclusion, hsa_circ_0001741 promotes ESCC stemness, invasion, and migration by sponging tumor suppressor miR-491-5p to upregulate NOTCH3 expression. Our findings identify a novel therapeutic target for ESCC patients and the expression level of hsa_circ_0001741 has the potential to serve as a prognostic biomarker for ESCC.

Components of NOTCH Signaling for Uterine Cancer Patients’ Prognosis

New molecular biomarkers that could have an independent prognostic value in endometrial cancer are currently under investigation. Recently, it was suggested that genetic changes in the Notch signaling pathway could be associated with the development of endometrial carcinoma. This study aimed to determine the expression of the Notch signaling pathway components in tumour and adjacent normal uterine tissue and to evaluate their importance for the survival of uterine cancer patients. The present study was performed on uterine body samples collected from 109 patients and paired adjacent noncancerous endometrial tissue samples. Kaplan–Meier curves and Cox regression were used for survival analyses. Expression alterations of NOTCH2, NOTCH3, NOTCH4, JAG2, and HES1 were evaluated as independent and significant prognostic factors for uterine cancer patients.

A comprehensive multi-omics analysis reveals molecular features associated with cancer via RNA cross-talks in the Notch signaling pathway

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Many Notch genes are identified as cancer-associated genes with an important role in tumorigenesis.

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Dynamic expression patterns are associated with the Notch activity that are largely regulated by multiple ncRNAs.

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Cross-talks among diverse RNAs are crucial in cancers via ceRNA network.

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The Notch pathway shows a robust prognostic ability via integrating multi-omics features as well as their targets.

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The Notch pathway is also correlated with immune infiltration and maybe available cancer treatment drug targets.

The Notch signaling has an important role in multiple cellular processes and is related to carcinogenic process. To understand the potential molecular features of the crucial Notch pathway, a comprehensive multi-omics analysis is performed to explore its contributions in cancer, mainly including analysis of somatic mutation landscape, pan-cancer expression, ncRNA regulation and potential prognostic power. The screened 22 Notch core genes are relative stable in DNA variation. Dynamic expression patterns are associated with the Notch activity, which are mainly regulated by multiple ncRNAs via interactions of ncRNA:mRNA and ceRNA networks. The Notch pathway shows a potential prognostic ability through integrating multi-omics features as well as their targets, and it is correlated with immune infiltration and maybe available drug targets, implying the potential role in individualized treatment. Collectively, all of these findings contribute to exploring crucial role of the key pathway in cancer pathophysiology and gaining mechanistic insights into cross-talks among RNAs and biological pathways, which indicates the possible application of the well-conserved Notch signaling pathway in precision medicine.

PHLDB2 Mediates Cetuximab Resistance via Interacting With EGFR in Latent Metastasis of Colorectal Cancer

BACKGROUND & AIMS

Latent metastasis of colorectal cancer (CRC) frequently develops months or years after primary surgery, followed by adjuvant therapies, and may progress rapidly even with targeted therapy administered, but the underlying mechanism remains unclear. Here, we aim to explore the molecular basis for the aggressive behavior of latent metastasis in CRC.

METHODS

Transcriptional profiling and pathway enrichment analysis of paired primary and metastatic tumor samples were performed. The underlying mechanisms of pleckstrin homology-like domain, family B, member 2 (PHLDB2) in CRC were investigated by RNA immunoprecipitation assay, immunohistochemistry, mass spectrometry analysis, and Duolink in situ proximity ligation assay (Sigma-Aldrich, Shanghai, China). The efficacy of targeting PHLDB2 in cetuximab treatment was elucidated in CRC cell lines and mouse models.

RESULTS

Based on the transcriptional profile of paired primary and metastatic tumor samples, we identified PHLDB2 as a potential regulator in latent liver metastasis. A detailed mechanistic study showed that chemotherapeutic agent-induced oxidative stress promotes methyltransferase-like 14 (METTL14)-mediated N6-methyladenosine modification of PHLDB2 messenger RNA, facilitating its protein expression. Up-regulated PHLDB2 stabilizes epidermal growth factor receptor (EGFR) and promotes its nuclear translocation, which in turn results in EGFR signaling activation and consequent cetuximab resistance. Moreover, Arg1163 (R1163) of PHLDB2 is crucial for interaction with EGFR, and the R1163A mutation abrogates its regulatory function in EGFR signaling.

CONCLUSIONS

PHLDB2 plays a crucial role in cetuximab resistance and is proposed to be a potential target for the treatment of CRC.

NR2F1-AS1/miR-190a/PHLDB2 Induces the Epithelial-Mesenchymal Transformation Process in Gastric Cancer by Promoting Phosphorylation of AKT3

The median survival time of patients with advanced gastric cancer (GC) who received radiotherapy and chemotherapy was <1 year. Epithelial–mesenchymal transformation (EMT) gives GC cells the ability to invade, which is an essential biological mechanism in the progression of GC. The long non-coding RNA (lncRNA)-based competitive endogenous RNA (ceRNA) system has been shown to play a key role in the GC-related EMT process. Although the AKT pathway is essential for EMT in GC, the relationship between AKT3 subtypes and EMT in GC is unclear. Here, we evaluated the underlying mechanism of ceRNA involving NR2F1-AS1/miR-190a/PHLDB2 in inducing EMT by promoting the expression and phosphorylation of AKT3. The results of bioinformatics analysis showed that the expression of NR2F1-AS1/miR-190a/PHLDB2 in GC was positively associated with the pathological features, staging, poor prognosis, and EMT process. We performed cell transfection, qRT-PCR, western blot, cell viability assay, TUNEL assay, Transwell assay, cell morphology observation, and double luciferase assay to confirm the regulation of NR2F1-AS1/miR-190a/PHLDB2 and its effect on EMT transformation. Finally, GSEA and GO/KEGG enrichment analysis identified that PI3K/AKT pathway was positively correlated to NR2F1-AS1/miR-190a/PHLDB2 expression. AKT3 knockout cells were co-transfected with PHLDB2-OE, and the findings revealed that AKT3 expression and phosphorylation were essential for the PHLDB2-mediated EMT process. Thus, our results showed that NR2F1-AS1/miR-190a/PHLDB2 promoted the phosphorylation of AKT3 to induce EMT in GC cells. This study provides a comprehensive understanding of the underlying mechanism involved in the EMT process as well as the identification of new EMT markers.

Identification of the Novel Tumor Suppressor Role of FOCAD/miR-491-5p to Inhibit Cancer Stemness, Drug Resistance and Metastasis via Regulating RABIF/MMP Signaling in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) possesses poor prognosis mainly due to development of chemoresistance and lack of effective endocrine or targeted therapies. MiR-491-5p has been found to play a tumor suppressor role in many cancers including breast cancer. However, the precise role of miR-491-5p in TNBC has never been elucidated. In this study, we reported the novel tumor suppressor function of FOCAD/miR-491-5p in TNBC. High expression of miR-491-5p was found to be associated with better overall survival in breast cancer patients. We found that miR-491-5p could be an intronic microRNA processed form FOCAD gene. We are the first to demonstrate that both miR-491-5p and FOCAD function as tumor suppressors to inhibit cancer stemness, epithelial-mesenchymal transition, drug resistance, cell migration/invasion, and pulmonary metastasis etc. in TNBC. MiR-491-5p was first reported to directly target Rab interacting factor (RABIF) to downregulate RABIF-mediated TNBC cancer stemness, drug resistance, cell invasion, and pulmonary metastasis via matrix metalloproteinase (MMP) signaling. High expression of RABIF was found to be correlated with poor clinical outcomes of breast cancer and TNBC patients. Our data indicated that miR-491-5p and RABIF are potential prognostic biomarkers and targeting the novel FOCAD/miR-491-5p/RABIF/MMP signaling pathway could serve as a promising strategy in TNBC treatment.

The Role of Notch3 Signaling in Cancer Stemness and Chemoresistance: Molecular Mechanisms and Targeting Strategies

Aberrant Notch signaling profoundly affects cancer progression. Especially the Notch3 receptor was found to be dysregulated in cancer, where its expression is correlated with worse clinicopathological features and poor prognosis. The activation of Notch3 signaling is closely related to the activation of cancer stem cells (CSCs), a small subpopulation in cancer that is responsible for cancer progression. In addition, Notch3 signaling also contributes to tumor chemoresistance against several drugs, including doxorubicin, platinum, taxane, epidermal growth factor receptor (EGFR)–tyrosine kinase inhibitors (TKIs) and gemcitabine, through complex mechanisms. In this review, we mainly focus on discussing the molecular mechanisms by which Notch3 modulates cancer stemness and chemoresistance, as well as other cancer behaviors including metastasis and angiogenesis. What’s more, we propose potential treatment strategies to block Notch3 signaling, such as non-coding RNAs, antibodies and antibody-drug conjugates, providing a comprehensive reference for research on precise targeted cancer therapy.

RNA-seq-Based Screening in Coal Dust-Treated Cells Identified PHLDB2 as a Novel Lung Cancer-Related Molecular Marker

Lung cancer is one of the most serious leading cancers with high incidence globally. Identifying molecular markers is key for disease diagnosis and treatment. Coal dust might be important triggering factors in disease development. Here, we first performed RNA-seq-based screening in coal dust treated and nontreated RAW264.7 cell lines. PHLDB2 was found to be the top differentially expressed gene. By retrieving TCGA lung cancer dataset, we observed that PHLDB2 showed upregulations in males and smoker patients. Patients with lower PHLDB2 expression survived longer than those with higher expressions. Furthermore, PHLDB2 was negatively correlated with EMT makers, and a total of 2.74% mutation rate were observed in 1,059 patients. This finding highlights the critical role of PHLDB2 in lung cancer development. PHLDB2 might be a molecular maker for disease diagnosis or treatment.