Megakaryocytic leukemia 1 (MKL1) is a key transcription factor involved in non-small cell lung cancer (NSCLC) growth and metastasis. Yet, its downstream target genes, especially long non-coding RNA ...(lncRNA) targets, are poorly investigated. In this study, we employed lncRNA array technology to identify differentially expressed lncRNAs in NSCLC cells with or without overexpression of MKL1. Candidate lncRNAs were further explored for their clinical significance and function in NSCLC. The results showed that MKL1 promoted the expression of lncRNA SNHG18 in NSCLC cells. SNHG18 upregulation in NSCLC specimens correlated with lymph node metastasis and reduced overall survival of NSCLC patients. SNHG18 expression served as an independent prognostic factor for NSCLC. Knockdown of SNHG18 blocked MKL1-induced growth and invasion of NSCLC cells in vitro. Animal studies validated the requirement for SNHG18 in NSCLC growth and metastasis. Moreover, overexpression of SNHG18 promoted NSCLC cell proliferation and invasion. Mechanically, SNHG18 exerted its prometastatic effects on NSCLC cells through repression of miR-211-5p and induction of BRD4. Clinical evidence indicated that SNHG18 expression was negatively correlated with miR-211-5p expression in NSCLC tissues. Altogether, SNHG18 acts as a lncRNA mediator of MKL1 in NSCLC. SNHG18 facilitates NSCLC growth and metastasis by modulating the miR-211-5p/BRD4 axis. Therefore, SNHG18 may be a potential therapeutic target for the treatment of NSCLC.
Poorly differentiated tumors usually exhibit phenotypes similar to that of their developmental precursor cells. Tumor cells that acquire the lineage progenitor cells feature usually exploit ...developmental signaling to potentiate cancer progression. However, the underlying molecular events remain elusive. In this study, based on analysis of an in vitro hepatocyte differentiation model, the maternal factor PGC7 (also known as DPPA3, STELLA) was found closely associated with liver development and tumor differentiation in hepatocellular carcinoma (HCC). Expression of PGC7 decreased during hepatocyte maturation and increased progressively from well-differentiated HCCs to poorly differentiated HCCs. Whole-genome methylation sequencing found that PGC7 could induce promoter demethylation of genes related to development. Pathway-based network analysis indicated that downstream targets of PGC7 might form networks associated with developmental transcription factor activation. Overexpression of PGC7 conferred progenitor-like features of HCC cells both in vitro and in vivo. Mechanism studies revealed that PGC7 could impede nuclear translocation of UHRF1, and thus facilitate promoter demethylation of GLI1 and MYCN, both of which are important regulators of HCC self-renewal and differentiation. Depletion or inhibition of GLI1 effectively downregulated MYCN, abolished the effect of PGC7, and sensitized HCC cells to sorafenib treatment. In addition, we found a significant correlation of PGC7 with GLI1/MYCN and lineage differentiation markers in clinical HCC patients. PGC7 expression might drive HCC toward a "dedifferentiated" progenitor lineage through facilitating promoter demethylation of key developmental transcription factors; further inhibition of PGC7/GLI1/MYCN might reverse poorly differentiated HCCs and provide novel therapeutic strategies.
Multiple myeloma (MM) is a malignant plasma cell disorder that remains incurable for most patients, as persistent clonal evolution drives new mutations which confer MM high-risk signatures and ...resistance to standard care. The past two decades have significantly refashioned the therapeutic options for MM, especially adoptive T cell therapy contributing to impressive response rate and clinical efficacy. Despite great promises achieved from chimeric antigen receptor T-cell (CAR-T) therapy, the poor durability and severe toxicity (cytokine release syndrome and neurotoxicity) are still huge challenges. Therefore, relapsed/refractory multiple myeloma (RRMM), characterized by the nature of clinicopathologic and molecular heterogeneity, is frequently associated with poor prognosis. B Cell Maturation Antigen (BCMA) is the most successful target for CAR-T therapy, and other potential targets either for single-target or dual-target CAR-T are actively being studied in numerous clinical trials. Moreover, mechanisms driving resistance or relapse after CAR-T therapy remain uncharacterized, which might refer to T-cell clearance, antigen escape, and immunosuppressive tumor microenvironment. Engineering CAR T-cell to improve both efficacy and safety continues to be a promising area for investigation. In this review, we aim to describe novel tumor-associated neoantigens for MM, summarize the data from current MM CAR-T clinical trials, introduce the mechanism of disease resistance/relapse after CAR-T infusion, highlight innovations capable of enhanced efficacy and reduced toxicity, and provide potential directions to optimize manufacturing processes.
To investigate the therapeutic effects of concurrent preoperative β-elemene treatment in patients with esophageal squamous cell carcinoma who received concurrent chemoradiotherpay followed by ...surgery.
The clinicopathological parameters and outcomes of 102 patients with esophageal squamous cell carcinoma were studied and compared between patients treated with and without β-elemene.
β-elemene treatment could prolong the overall survival and progression-free survival. The 3-year overall survival rate was also increased by β-elemene treatment. β-elemene treatment was an independent prognostic factor for both overall survival and progression-free survival. Occurrence of toxicities associated with chemoradiotherapy was decreased by β-elemene treatment.
Findings in this study suggested that β-elemene treatment provided survival benefits and reduced chemoradiotherapy-associated toxicities in patients with esophageal squamous cell carcinoma.
•β-elemene were first studied in patients with esophageal cancer.•β-elemene provided survival benefits in patients with esophageal cancer.•β-elemene reduced toxicities associated with chemoradiotherapy.•β-elemene was an independent prognostic factor in patients with esophageal cancer.
Background Lymph node metastasis is one of most common determinants of the stage and prognosis of gastric cancer (GC). However, the key molecular events and mechanisms mediating lymph node metastasis ...remain elusive. Methods RNA sequencing was used to identify driver genes responsible for lymph node metastasis in four cases of gastric primary tumors, metastatic lesions of lymph nodes and matched normal gastric epithelial tissue. qRT-PCR and IHC were applied to examine RPRD1B expression. Metastatic functions were evaluated in vitro and in vivo. RNA-seq was used to identify target genes. ChIP, EMSA and dual luciferase reporter assays were conducted to identify the binding sites of target genes. Co-IP, RIP, MeRIP, RNA-FISH and ubiquitin assays were applied to explore the underlying mechanisms. Results The top 8 target genes (RPRD1B, MAP4K4, MCM2, TOPBP1, FRMD8, KBTBD2, ADAM10 and CXCR4) that were significantly upregulated in metastatic lymph nodes of individuals with GC were screened. The transcriptional cofactor RPRD1B (regulation of nuclear pre-mRNA domain containing 1B) was selected for further characterization. The clinical analysis showed that RPRD1B was significantly overexpressed in metastatic lymph nodes and associated with poor outcomes in patients with GC. The Mettl3-induced m.sup.6A modification was involved in the upregulation of RPRD1B. Functionally, RPRD1B promoted lymph node metastasis capabilities in vitro and in vivo. Mechanistic studies indicated that RPRD1B increased fatty acid uptake and synthesis by transcriptionally upregulating c-Jun/c-Fos and activating the c-Jun/c-Fos/SREBP1 axis. In addition, NEAT1 was upregulated significantly by c-Jun/c-Fos in RPRD1B-overexpressing cells. NEAT1, in turn, increased the stability of the RPRD1B mRNA by recruiting the m.sup.6A "reader" protein hnRNPA2B1 and reduced the degradation of the RPRD1B protein by inhibiting TRIM25-mediated ubiquitination. Notably, this functional circuitry was disrupted by an inhibitor of c-Jun/c-Fos/AP1 proteins (SR11302) and small interfering RNAs targeting NEAT1, leading to a preferential impairment of lymph node metastasis. Conclusions Based on these findings, RPRD1B facilitated FA metabolism and assisted primary tumor implantation in lymph nodes via the c-Jun/c-Fos/SREBP1 axis, which was enhanced by a NEAT1-mediated positive feedback loop, serving as a potential therapeutic target for GC treatment. Keywords: RPRD1B, Lymph node metastasis, Fatty acid metabolism, c-Jun/c-Fos/SREBP1 axis, NEAT1, hnRNPA2B1, TRIM25
The transcription factor forkhead box protein O1 (FOXO1) is critical for regulating cytokine and chemokine secretion. However, its function in the tumor microenvironment (TME) remains largely ...unexplored. In this study, we characterized the prognostic value of FOXO1 and the interaction between tumor-derived FOXO1 and M2 macrophages in esophageal squamous cell carcinoma (ESCC).
FOXO1 expression and macrophage infiltration in clinical samples and mouse models were quantified using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemistry staining. Western blotting, qRT-PCR, and enzyme-linked immunosorbent assay were used to evaluate chemokine ligand 20 (CCL20) and colony stimulating factor 1 (CSF-1) expression in FOXO1(+) and FOXO1(-) tumor cells. Macrophage phenotypes were determined using qRT-PCR, flow cytometry, and RNA sequencing. Transcriptional activity was measured using chromatin immunoprecipitation (ChIP)-qPCR. Tumor viability was investigated using XTT proliferation and foci formation assays.
FOXO1 upregulation in tumor tissues was found to drive the polarization of M0 macrophages and infiltration of M2 macrophages into the TME, resulting in worse prognosis in ESCC patients. CSF-1, a vital factor inducing M0-to-M2 polarization, was upregulated via a FOXO1-mediated mechanism. RNA sequencing results corroborated that the FOXO1-induced macrophages exhibited similar molecular signatures to the IL4-stimulated M2 macrophages. The transwell assays showed that FOXO1 promoted the migration of M2 macrophages via CCL20 secretion, which could be inhibited using an anti-CCL20 antibody. FOXO1(+) tumor-induced M2 macrophages promoted tumor proliferation via the FAK-PI3K-AKT pathway and the PI3K inhibitor could effectively impede the oncogenical process.
FOXO1 facilitated M0-to-M2 polarization and the recruitment of M2 macrophages in the TME via the transcriptional modulation of CCL20 and CSF-1. Our data deciphered the FOXO1-dependent mechanism in M2 macrophage infiltration in the TME of ESCC, which has implications for the development of novel prognostic and therapeutic targets to optimize the current treatment against ESCC.
Gastric carcinoma (GC) is the fourth leading cause of cancer-related mortality worldwide. Patients with advanced GC tend to have poor prognoses and shortened survival. Finding novel predictive ...biomarkers for GC prognosis is an urgent need. Mitophagy is the selection degradation of damaged mitochondria to maintain cellular homeostasis, which has been shown to play both pro- and anti-tumor effects. This study combined single-cell sequencing data and transcriptomics to screen mitophagy-related genes (MRGs) associated with GC progression and analyze their clinical values. Reverse transcription-quantitative PCR (RT-qPCR) and immunochemistry (IHC) further verified gene expression profiles. A total of 18 DE-MRGs were identified after taking an intersection of single-cell sequencing data and MRGs. Cells with a higher MRG score were mainly distributed in the epithelial cell cluster. Cell-to-cell communications among epithelial cells with other cell types were significantly upregulated. We established and validated a reliable nomogram model based on DE-MRGs (GABARAPL2 and CDC37) and traditional clinicopathological parameters. GABARAPL2 and CDC37 displayed different immune infiltration states. Given the significant correlation between hub genes and immune checkpoints, targeting MRGs in GC may supplement more benefits to patients who received immunotherapy. In conclusion, GABARAPL2 and CDC37 may be prognostic biomarkers and candidate therapeutic targets of GC.
•Combined analysis of single-cell and bulk-RNA sequencing data revealed prognostic values of mitophagy-related genes (MRGs) in GC patients.•Two differentially expressed MRGs (GABARAPL2 and CDC37) displayed distinct immune infiltration states and showed different correlations with immune checkpoint genes.•Targeting MRGs hold the potential to ameliorate the efficacy of immunotherapy in clinical practice.
Abstract
Background
Increasing studies focused on the regulatory roles of circular RNAs (circRNAs) in diverse cancers. This study was to evaluate the function and mechanism of circRNA Scm-like with ...four malignant brain tumor domains 2 (circ-SFMBT2) in esophageal cancer (EC).
Methods
The circ-SFMBT2, microRNA-107 (miR-107) and solute-linked carrier family A1 member 5 (SLC1A5) levels were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). Cell proliferation was evaluated by 3-(4, 5-dimethylthiazol-2-y1)-2, 5-diphenyl tetrazolium bromide (MTT) assay, colony formation assay and EdU assay. Cell apoptosis and invasion were detected by flow cytometry and transwell assay. Glutamine metabolism was assessed by the corresponding kits for glutamine consumption, α-ketoglutarate production and glutamate production. Western blot was used for protein quantification. The binding analysis was performed using dual-luciferase reporter assay, RNA immunoprecipitation (RIP) and pull-down assays. The functional research of circ-SFMBT2 in vivo was performed by xenograft tumor assay. Exosomes were identified by morphological observation and protein detection.
Results
Circ-SFMBT2 was overexpressed in EC samples and cells. Circ-SFMBT2 downregulation inhibited EC cell proliferation, invasion and glutamine metabolism. Circ-SFMBT2 targeted miR-107 and the regulation of circ-SFMBT2 was achieved by sponging miR-107. SLC1A5 was a target of miR-107, and it worked as an oncogene in EC cells. MiR-107 retarded the EC progression by downregulating SLC1A5. Circ-SFMBT2 could affect the SLC1A5 expression by targeting miR-107. Circ-SFMBT2 regulated EC progression in vivo by miR-107/SLC1A5 axis. Circ-SFMBT2 was transferred by exosomes in EC cells.
Conclusion
These results suggested that circ-SFMBT2 upregulated the SLC1A5 expression to promote the malignant development of EC by serving as a miR-107 sponge.
Esophageal squamous cells carcinoma (ESCC) is a major common thoracic tumor characterized by distinctly high incidences and mortality rates. Despite advances in multimodality therapy, the mortality ...rate of ESCC remains high and understanding of molecular alterations leading to the development and progression of ESCC is still very limited. In this study, a new tumor suppressor candidate, cell adhesion molecule with homology to L1CAM (CHL1), located at 3p26 which was frequently deleted in ESCC was identified. Reduced expression of CHL1 correlated with poor differentiation, increased invasion, and lymph-node metastasis, advanced tumor stage, and decreased overall survival. Methylation-specific PCR and FISH assays revealed that down-regulation of CHL1 in both ESCC cell lines and clinical samples were associated with promoter hypermethylation and loss of heterozygosity. Functional studies using lentiviral-based overexpression and knockdown systems provided direct support of CHL1 to function as an important tumor suppressor with both anti-proliferation and anti-metastasis abilities, through Merlin and SEMA3B-Np1-mediated inhibition of AKT signaling pathway. Further characterization of CHL1 may provide a novel therapeutic target in ESCC treatment.
Esophageal squamous cell carcinoma (ESCC) is the main subtype of esophageal cancer. Current therapeutic effect is far from satisfaction. Hence, identifying susceptible genes and potential targets is ...necessary for therapy of ESCC patients.
Plant homeodomain (PHD)-finger domain protein 5 A (PHF5A) expression in ESCC tissues was examined by immunohistochemistry. RNA interference was used for in vitro loss-of-function experiments. In vivo assay was performed using xenograft mice model by subcutaneous injection. Besides, microarray assay and co-immunoprecipitation experiments were used to study the potential downstream molecules of PHF5A in ESCC. The molecular mechanism between PHF5A and vascular endothelial growth factor A (VEGFA) was explored by a series of ubiquitination related assays.
We found that PHF5A was highly expressed in ESCC tissues compared to normal tissues and that was correlated with poor prognosis of ESCC. Loss-of-function experiments revealed that PHF5A silence remarkably inhibited cell proliferation, migration, and induced apoptosis as well as cell cycle arrest. Consistently, in vivo assay demonstrated that PHF5A deficiency was able to attenuate tumor growth. Furthermore, molecular studies showed that PHF5A silencing promoted VEGFA ubiquitination by interacting with MDM2, thereby regulating VEGFA protein expression. Subsequently, in rescue experiments, our data suggested that ESCC cell viability and migration promoted by PHF5A were dependent on intact VEGFA. Finally, PI3K/AKT signaling rescue was able to alleviate shPHF5A-mediated cell apoptosis and cell cycle arrest.
PHF5A is a tumor promoter in ESCC, which is dependent on VEGFA and PI3K/AKT signaling. PHF5A might serve as a potential therapeutic target for ESCC treatment.
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