E2F2 drives glioma progression via PI3K/AKT in a PFKFB4-dependent manner

Transitioning from molecular methods to therapeutic methods: An in‑depth analysis of glioblastoma (Review)

Glioblastoma (GBM) is the most aggressive primary brain tumour, characterised by high heterogeneity, aggressiveness and resistance to conventional therapies, leading to poor prognosis for patients. In recent years, with the rapid development of molecular biology and genomics technologies, significant progress has been made in understanding the molecular mechanisms of GBM. This has revealed a complex molecular network involving aberrant key signalling pathways, epigenetic alterations, interactions in the tumour microenvironment and regulation of non‑coding RNAs. Based on these molecular features, novel therapeutic strategies such as targeted therapies, immunotherapy and gene therapy are rapidly evolving and hold promise for improving the outcome of GBM. This review systematically summarises the advances in molecular mechanisms and therapeutic approaches for GBM. It aims to provide new perspectives for the precise diagnosis and personalised treatment of GBM, and to ultimately improve the prognosis of patients.

LAMB1 downregulation suppresses glioma progression by inhibiting aerobic glycolysis through regulation of the NF-κB/HK2 axis

BACKGROUND

Laminin subunit beta 1 (LAMB1) has regulatory functions on the proliferation, attachment, and migration of tumor cells, with increased levels linked to different cancers.

OBJECTIVE

This study aims at investigating the effects and mechanisms of LAMB1 in glioma.

METHODS AND MATERIAL

Glioma cell models with LAMB1 overexpression or downregulation were constructed. Cell viability, proliferation, and invasion were evaluated. Glucose uptake and lactate production were examined, and Seahorse was used to assess the extracellular acidification rate (ECAR). The EC50 of temozolomide (TMZ) in glioma cells was tested. Western blotting was conducted to monitor the expression of HK1, HK2, PDHA, and PKM. Bioinformatic analysis was employed to investigate the downstream mechanism of LAMB1. In addition, a subcutaneous tumor model was constructed to determine the influence of LAMB1 on GBM cell growth in vivo.

RESULTS

LAMB1 overexpression enhanced cell viability, proliferation, and invasion and promoted glioma cell growth. LAMB1 upregulation enhanced cellular glycolysis and repressed the sensitivity of cells to TMZ. LAMB1 activated the NF-κB pathway. Downregulation of LAMB1 or mitigating of the NF-κB pathway by Bay 11-7082 inhibited glioma cell proliferation, growth, and glycolysis and enhanced TMZ sensitivity.

CONCLUSIONS

LAMB1 downregulation exerted antitumor effects on glioma cells by regulating the NF-κB/HK2 axis.

E2F1 and E2F7 regulate gastric cancer cell proliferation, respectively, through transcriptional activation and transcriptional repression of MYBL2

Gastric cancer (GC) is the most common malignant tumor of the digestive tract. However, the molecular pathogenesis is not well understood. Through bioinformatic analysis and analyzing clinical tissue samples, we found that E2F1 and E2F7 as well as their potential downstream target MYBL2 were all upregulated in GC tissues and that their expressions correlated with patient prognosis. While knockdown of E2F1 or MYBL2 inhibited cell proliferation and promoted apoptosis, knockdown of E2F7 promoted cell proliferation but had no effects on apoptosis. Chromatin immunoprecipitation and dual luciferase reporter assays demonstrated that MYBL2 was transcriptionally activated and repressed by E2F1 and E2F7, respectively. Importantly, in vitro and ex vivo experiments demonstrated that the effects of E2F1 and E2F7 on GC cell proliferation were significantly attenuated by reversely modulating MYBL2 expression, indicating that MYBL2 is a direct and functionally relevant target of E2F1 and E2F7 in GC cells. Furthermore, the effects of E2F1 and E2F7 on GC cell proliferation through transcriptional regulation of MYBL2 can be mediated by the PI3K/AKT signaling pathway. Interestingly, we found differential nucleocytoplasmic distribution of E2F7 in GC cells with functional relevance. Taken together, our data suggest that targeted therapies of GC may be achieved from three different angles, E2F1, E2F7, and MYBL2 themselves, E2F1/E2F7 expression balance, and E2F7 nuclear localization.

Interplay between lncRNAs and the PI3K/AKT signaling pathway in the progression of digestive system neoplasms (Review)

Long non‑coding RNA (lncRNA) is a class of non‑coding RNA molecules located in the cytoplasm or nucleus, which can regulate chromosome structure and function by interacting with DNA, RNA, proteins and other molecules; binding to mRNA bases in a complementary manner, affecting the splicing, stabilization, translation and degradation of mRNA; acting as competing endogenous RNA competitively binds to microRNAs to regulate gene expression and participate in the regulation of various vital activities of the body. The PI3K/AKT signalling pathway plays a key role in numerous biological and cellular processes, such as cell proliferation, invasion, migration and angiogenesis. It has been found that the lncRNA/PI3K/AKT axis regulates the expression of cancer‑related genes and thus tumour progression. The abnormal regulation of lncRNA expression in the lncRNA/PI3K/AKT axis is clearly associated with clinicopathological features and plays an important role in regulating biological functions. In the present review, the expression and biological functions of PI3K/AKT‑related lncRNAs both in vitro and in vivo over recent years, were comprehensively summarized and analyzed. Their correlation with clinicopathological features was also evaluated, with the objective of furnishing a solid theoretical foundation for clinical diagnosis and the monitoring of efficacy in digestive system neoplasms. The present review aimed to provide a comprehensive overview of the expression and biological functions of PI3K/AKT‑related lncRNAs in digestive system neoplasms and to assess their correlation with clinicopathological features. This endeavor seeks to establish a solid theoretical foundation for the clinical diagnosis and efficacy monitoring of digestive system tumors.

Peimine induces apoptosis of glioblastoma cells through regulation of the PI3K/AKT signaling pathway

Glioblastoma (GBM) is one of the most malignant forms of intracranial tumors, with high mortality rates and invariably poor prognosis, due to the limited clinical treatment strategies available. As a natural compound, peimine's favorable pharmacological activities have been widely revealed. However, potential inhibitory effects of peimine on GBM have not been explored. In the present study, both in vitro and in vivo experiments were performed to elucidate the effects of peimine on GBM and to further delineate the underlying molecular mechanism of action. Different doses (0, 25 and 50 µM) of peimine were added to U87 cells, before MTT, colony formation, wound healing, Transwell migration and invasion, reactive oxygen species and mitochondrial transmembrane potential assays were used to measure proliferation, migration, invasion and apoptosis. Furthermore, western blotting was used to examine the possible effects of peimine on the expression of proteins associated with apoptosis and the PI3K/AKT signaling pathway. Subsequently, a GBM mouse xenograft model was used to assess the effects of peimine in vivo. The findings showed that peimine inhibited GBM proliferation, migration and invasion in a dose-dependent manner, whilst also inducing apoptosis. Peimine also reduced tumor growth in vivo. Mechanistically, peimine downregulated the expression of Bcl-2 and Caspase 3, whilst upregulating the protein expression levels of p53, Bax and Cleaved-Caspase 3 in a dose-dependent manner. In addition, PI3K and AKT phosphorylation levels were found to be decreased by peimine in a dose-dependent manner. In conclusion, these findings suggest that peimine may limit GBM growth by regulating the PI3K/AKT signaling pathway both in vitro and in vivo. These findings may have promising clinical implications.

Multi-omics analysis reveals that Cas13d contributes to PI3K-AKT signaling and facilitates cell proliferation via PFKFB4 upregulation

The CRISPR-Cas system is a powerful gene editing technology, the clinical application of which is currently constrained due to safety concerns. A substantial body of safety research concerning Cas9 exists; however, scant attention has been directed toward investigating the safety profile of the emergent Cas13 system, which confers RNA editing capabilities. In particular, uncertainties persist regarding the potential cellular impacts of Cas13d in the absence of reliance on a cleavage effect. In this study, we conducted an initial exploration of the effects of Cas13d on HeLa cells. Total RNA and protein samples were extracted after transfection with a Cas13d-expressing plasmid construct, followed by transcriptomic and proteomic sequencing. Differential gene expression analysis identified 94 upregulated and 847 downregulated genes, while differential protein expression analysis identified 185 upregulated and 231 downregulated proteins. Subsequently, enrichment analysis was conducted on the transcriptome and proteome sequencing data, revealing that the PI3K-Akt signaling pathway is a common term. After intersecting the differentially expressed genes enriched in the PI3K-Akt signaling pathway with all the differentially expressed proteins, it was found that the expression of the related regulatory gene PFKFB4 was upregulated. Moreover, western blot analysis demonstrated that Cas13d can mediate PI3K-Akt signaling upregulation through overexpression of PFKFB4. CCK-8 assay, colony formation, and EdU experiments showed that Cas13d can promote cell proliferation. Our data demonstrate, for the first time, that Cas13d significantly impacts the transcriptomic and proteomic profiles, and proliferation phenotype, of HeLa cells, thus offering novel insights into safety considerations regarding gene editing systems.

Podocan unraveled: Understanding its role in tumor proliferation and smooth muscle regulation

Podocan, a small leucine-rich repeat protein, is expressed in HIV-associated nephropathy, the cardiovascular system, and smooth muscle. Studies have linked PODN and PODNL to cancers such as osteosarcoma, glioma, and stomach cancer. Research has primarily focused on podocan's role in renal podocytes, injured smooth muscle cells, and various tumor cells. Bioinformatics studies have examined the role of PODN as a biomarker in tumors. Our research summarizes the modulatory role of podocan in smooth muscle and tumor proliferation through its suppression of cell proliferation and promotion of cell differentiation via various signaling pathways, including Wnt/β-catenin, TGF-β, and Akt/mTOR. We aim to provide a comprehensive overview of PODN's involvement in smooth muscle, cardiovascular system, and tumors by integrating current and past research. This review aims to enhance understanding and inform in the diagnosis, prognosis, and treatment of various diseases.

UBA5 inhibition restricts lung adenocarcinoma via blocking macrophage M2 polarization and cisplatin resistance

UBA5, a ubiquitin-like activated enzyme involved in ufmylation and sumoylation, presents a viable target for pancreatic and breast cancer treatments, yet its role in lung adenocarcinoma (LUAD) remains underexplored. This study reveals UBA5's tumor-promoting effect in LUAD, as evidenced by its upregulation in patients and positive correlation with TNM stages. Elevated UBA5 levels predict poor outcomes for these patients. Pharmacological inhibition of UBA5 using DKM 2-93 significantly curtails the growth of A549, H1299, and cisplatin-resistant A549 (A549/DDP) LUAD cells in vitro. Additionally, UBA5 knockdown via shRNA lentivirus suppresses tumor growth both in vitro and in vivo. High UBA5 expression adversely alters the tumor immune microenvironment, affecting immunostimulators, MHC molecules, chemokines, receptors, and immune cell infiltration. Notably, UBA5 expression correlates positively with M2 macrophage infiltration, the predominant immune cells in LUAD. Co-culture experiments further demonstrate that UBA5 knockdown directly inhibits M2 macrophage polarization and lactate production in LUAD. Moreover, in vivo studies show reduced M2 macrophage infiltration following UBA5 knockdown. UBA5 expression is also associated with increased tumor heterogeneity, including tumor mutational burden, microsatellite instability, neoantigen presence, and homologous recombination deficiency. Experiments indicate that UBA5 overexpression promotes cisplatin resistance in vitro, whereas UBA5 inhibition enhances cisplatin sensitivity in both in vitro and in vivo settings. Overall, these findings suggest that targeting UBA5 inhibits LUAD by impeding cancer cell proliferation, M2 macrophage polarization, and cisplatin resistance.

Metabolic Roles of HIF1, c-Myc, and p53 in Glioma Cells

The metabolic reprogramming that promotes tumorigenesis in glioblastoma is induced by dynamic alterations in the hypoxic tumor microenvironment, as well as in transcriptional and signaling networks, which result in changes in global genetic expression. The signaling pathways PI3K/AKT/mTOR and RAS/RAF/MEK/ERK stimulate cell metabolism, either directly or indirectly, by modulating the transcriptional factors p53, HIF1, and c-Myc. The overexpression of HIF1 and c-Myc, master regulators of cellular metabolism, is a key contributor to the synthesis of bioenergetic molecules that mediate glioma cell transformation, proliferation, survival, migration, and invasion by modifying the transcription levels of key gene groups involved in metabolism. Meanwhile, the tumor-suppressing protein p53, which negatively regulates HIF1 and c-Myc, is often lost in glioblastoma. Alterations in this triad of transcriptional factors induce a metabolic shift in glioma cells that allows them to adapt and survive changes such as mutations, hypoxia, acidosis, the presence of reactive oxygen species, and nutrient deprivation, by modulating the activity and expression of signaling molecules, enzymes, metabolites, transporters, and regulators involved in glycolysis and glutamine metabolism, the pentose phosphate cycle, the tricarboxylic acid cycle, and oxidative phosphorylation, as well as the synthesis and degradation of fatty acids and nucleic acids. This review summarizes our current knowledge on the role of HIF1, c-Myc, and p53 in the genic regulatory network for metabolism in glioma cells, as well as potential therapeutic inhibitors of these factors.

VRK3 depletion induces cell cycle arrest and metabolic reprogramming of pontine diffuse midline glioma - H3K27 altered cells

We previously identified VRK3 as a specific vulnerability in DMG-H3K27M cells in a synthetic lethality screen targeting the whole kinome. The aim of the present study was to elucidate the mechanisms by which VRK3 depletion impact DMG-H3K27M cell fitness. Gene expression studies after VRK3 knockdown emphasized the inhibition of genes involved in G1/S transition of the cell cycle resulting in growth arrest in G1. Additionally, a massive modulation of genes involved in chromosome segregation was observed, concomitantly with a reduction in the level of phosphorylation of serine 10 and serine 28 of histone H3 supporting the regulation of chromatin condensation during cell division. This last effect could be partly due to a concomitant decrease of the chromatin kinase VRK1 in DMG following VRK3 knockdown. Furthermore, a metabolic switch specific to VRK3 function was observed towards increased oxidative phosphorylation without change in mitochondria content, that we hypothesized would represent a cell rescue mechanism. This study further explored the vulnerability of DMG-H3K27M cells to VRK3 depletion suggesting potential therapeutic combinations, e.g. with the mitochondrial ClpP protease activator ONC201.

E2F2 modulates cell adhesion through the transcriptional regulation of PECAM1 in multiple myeloma

Multiple myeloma (MM) is the second most common haematological malignancy. Despite the development of new drugs and treatments in recent years, the therapeutic outcomes of patients are not satisfactory. It is necessary to further investigate the molecular mechanism underlying MM progression. Herein, we found that high E2F2 expression was correlated with poor overall survival and advanced clinical stages in MM patients. Gain- and loss-of-function studies showed that E2F2 inhibited cell adhesion and consequently activated cell epithelial-to-mesenchymal transition (EMT) and migration. Further experiments revealed that E2F2 interacted with the PECAM1 promoter to suppress its transcriptional activity. The E2F2-knockdown-mediated promotion of cell adhesion was significantly reversed by the repression of PECAM1 expression. Finally, we observed that silencing E2F2 significantly inhibited viability and tumour progression in MM cell models and xenograft mouse models respectively. This study demonstrates that E2F2 plays a vital role as a tumour accelerator by inhibiting PECAM1-dependent cell adhesion and accelerating MM cell proliferation. Therefore, E2F2 may serve as a potential independent prognostic marker and therapeutic target for MM.

Tumor-Associated Macrophage-Derived Exosomal LINC01232 Induces the Immune Escape in Glioma by Decreasing Surface MHC-I Expression

Tumor-associated macrophage (TAM) infiltration facilitates glioma malignancy, but the underlying mechanisms remain unclear. Herein, it is reported that TAMs secrete exosomal LINC01232 to induce tumor immune escape. Mechanistically, LINC01232 is found to directly bind E2F2 and promote E2F2 entry into the nucleus; the two synergistically promots the transcription of NBR1. The increase in binding between NBR1 binding and the ubiquitinating MHC-I protein through the ubiquitin domain causes an increase in the degradation of MHC-I in autophagolysosomes and a decrease in the expression of MHC-I on the surface of tumor cells, which in turn led to tumor cell escape from CD8+ CTL immune attack. Disruption of E2F2/NBR1/MHC-I signaling with shRNAs or blockade with the corresponding antibodies largely abolishes the tumor-supportive effects of LINC01232 and inhibits tumor growth driven by M2-type macrophages. Importantly, knockdown of LINC01232 enhances the expression of MHC-I on the surface of tumor cells and improves the response to reinfusion with CD8+ T cells. This study reveals the existence of critical molecular crosstalk between TAMs and glioma mediates through the LINC01232/E2F2/NBR1/MHC-I axis to support malignant tumor growth, indicating that targeting this axis may have therapeutic potential.

Insight into the transcription factors regulating Ischemic Stroke and Glioma in Response to Shared Stimuli

Cerebral ischemic stroke and glioma are the two leading causes of patient mortality globally. Despite physiological variations, 1 in 10 people who have an ischemic stroke go on to develop brain cancer, most notably gliomas. In addition, glioma treatments have also been shown to increase the risk of ischemic strokes. Stroke occurs more frequently in cancer patients than in the general population, according to traditional literature. Unbelievably, these events share multiple pathways, but the precise mechanism underlying their co-occurrence remains unknown. Transcription factors (TFs), the main components of gene expression programmes, finally determine the fate of cells and homeostasis. Both ischemic stroke and glioma exhibit aberrant expression of a large number of TFs, which are strongly linked to the pathophysiology and progression of both diseases. The precise genomic binding locations of TFs and how TF binding ultimately relates to transcriptional regulation remain elusive despite a strong interest in understanding how TFs regulate gene expression in both stroke and glioma. As a result, the importance of continuing efforts to understand TF-mediated gene regulation is highlighted in this review, along with some of the primary shared events in stroke and glioma.

Non-coding RNAs in metabolic reprogramming of bone and soft tissue sarcoma: Fundamental mechanism and clinical implication

Sarcomas, comprising approximately 1% of human malignancies, show a poor response to treatment and easy recurrence. Metabolic reprogramming play an important role in tumor development in sarcomas. Accumulating evidence shows that non-coding RNAs (ncRNAs) participate in regulating the cellular metabolism of sarcomas, which improves the understanding of the development of therapy-resistant tumors. This review addresses the regulatory roles of metabolism-related ncRNAs and their implications for sarcoma initiation and progression. Dysregulation of metabolism-related ncRNAs is common in sarcomas and is associated with poor survival. Emerging studies show that abnormal expression of metabolism-related ncRNAs affects cellular metabolism, including glucose, lipid, and mitochondrial metabolism, and leads to the development of aggressive sarcomas. This review summarizes recent advances in the roles of dysregulated metabolism-related ncRNAs in sarcoma development and stemness and describes their potential to serve as biological biomarkers for disease diagnosis and prognosis prediction, as well as therapeutic targets for treating refractory sarcomas.

COL1A2 inhibition suppresses glioblastoma cell proliferation and invasion

OBJECTIVE

An extracellular matrix such as collagen is an essential component of the tumor microenvironment. Collagen alpha-2(I) chain (COL1A2) is a chain of type I collagen whose triple helix comprises two alpha-1 chains and one alpha-2 chain. The authors' proteomics data showed that COL1A2 is significantly higher in the blood of patients with glioblastoma (GBM) compared with healthy controls. COL1A2 has many different functions in various types of cancers. However, the functions of COL1A2 in GBM are poorly understood. In this study, the authors analyzed the functions of COL1A2 and its signaling pathways in GBM.

METHODS

Surgical specimens and GBM cell lines (T98, U87, and U251) were used. The expression level of COL1A2 was examined using GBM tissues and normal brain tissues by quantitative real-time polymerase chain reaction. The clinical significance of these levels was evaluated using Kaplan-Meier analysis. Small interfering RNA (siRNA) and small hairpin RNA of COL1A2 were transfected into GBM cell lines to investigate the function of COL1A2 in vitro and in vivo. Flow cytometry was introduced to analyze the alteration of cell cycles. Western blot and immunohistochemistry were performed to analyze the underlying mechanisms.

RESULTS

The expression level of COL1A2 was upregulated in GBM compared with normal brain tissues. A higher expression of COL1A2 was correlated with poor progression-free survival and overall survival. COL1A2 inhibition significantly suppressed cell proliferation in vitro and in vivo, likely due to G1 arrest. The invasion ability was notably deteriorated by inhibiting COL1A2. Cyclin D1, cyclin-dependent kinase 1, and cyclin-dependent kinase 4, which are involved in the cell cycle, were all downregulated after blockade of COL1A2 in vitro and in vivo. Phosphoinositide 3-kinase inhibitor reduced the expression of COL1A2. Although downregulation of COL1A2 decreased the protein kinase B (Akt) phosphorylation, Akt activator can phosphorylate Akt in siRNA-treated cells. This finding suggests that Akt phosphorylation is partially dependent on COL1A2.

CONCLUSIONS

COL1A2 plays an important role in driving GBM progression. COL1A2 inhibition attenuated GBM proliferation by promoting cell cycle arrest, indicating that COL1A2 could be a promising therapeutic target for GBM treatment.

Overexpression of TPM4 is associated with worse prognosis and immune infiltration in patients with glioma

BACKGROUND

Tropomyosin 4 (TPM4), a member of the tropomyosin family, is aberrantly expressed and plays an important role in a variety of cancers. However, studies on TPM4 in glioma patients are currently lacking.

OBJECTIVE

Our study aimed to evaluate the diagnostic and prognostic characteristics of TPM4 in glioma and its correlation with immune infiltration.

METHODS

Bioinformatic analysis was performed to determine whether TPM4 has diagnostic and prognostic value for glioma. The following databases and analytical tools were used to explore the clinical significance of TPM4 in glioma: TCGA, GTEx, GEO, STRING, and TISIDB.

RESULTS

Our study showed that the mRNA and protein expression levels of TPM4 were significantly higher in glioma than in healthy brain tissue. Kaplan-Meier analysis indicated that high expression of TPM4 in glioma correlated with poor prognosis. Univariate Cox analysis indicated that the high expression level of TPM4 in glioma was an independent prognostic characteristic for low overall survival (OS). The areas under the 1-year survival ROC, 2-year survival ROC, and 3-year survival ROC were all greater than 0.8. GO and KEGG enrichment analysis and GSEA showed that humoral immune response and cytokine receptor interaction were significantly enriched in the TPM4 high expression group, where M phase of the cell cycle, neutrophil degranulation, signaling by interleukins, and signaling by rho GTPases were significantly enriched. Furthermore, according to the analysis of immune cell infiltration, TPM4 was associated with tumor infiltration of a variety of immune cells.

CONCLUSIONS

In conclusion, our study suggests that TPM4 may be an effective prognostic biomarker for glioma patients, providing new ideas and research directions for glioma research.

RNF7 promotes glioma growth via the PI3K/AKT signalling axis

RNF7 has been reported to play critical roles in various cancers. However, the underlying mechanisms of RNF7 in glioma development remain largely unknown. Herein, the expression level of RNF7 was examined in tissues by quantitative real-time PCR, Western blotting and immunohistochemistry. The effect of RNF7 on glioma progression was measured by performing CCK-8 and apoptosis assays, cell cycle-related experiments and animal experiments. The effect of RNF7 on PI3K/AKT signalling pathway was tested by Western blotting. First, we found that RNF7 was upregulated in tumour tissue compared with normal brain tissue, especially in high-grade glioma, and the high expression of RNF7 was significantly related to tumour size, Karnofsky Performance Scale score and a poor prognosis. Second, RNF7 overexpression facilitated tumour cell cycle progression and cell proliferation and suppressed apoptosis. Conversely, RNF7 knockdown suppressed tumour cell cycle progression and cell proliferation and facilitated apoptosis. Furthermore, follow-up mechanistic studies indicated that RNF7 could facilitate glioma cell proliferation and cell cycle progression and inhibit apoptosis by activating the PI3K/AKT signalling pathway. This study shows that RNF7 can clearly promote glioma cell proliferation by facilitating cell cycle progression and inhibiting apoptosis by activating the PI3K/AKT signalling pathway. Targeting the RNF7/PI3K/AKT axis may provide a new perspective on the prevention or treatment of glioma.

Disorders of cancer metabolism: The therapeutic potential of cannabinoids

Abnormal energy metabolism, as one of the important hallmarks of cancer, was induced by multiple carcinogenic factors and tumor-specific microenvironments. It comprises aerobic glycolysis, de novo lipid biosynthesis, and glutamine-dependent anaplerosis. Considering that metabolic reprogramming provides various nutrients for tumor survival and development, it has been considered a potential target for cancer therapy. Cannabinoids have been shown to exhibit a variety of anticancer activities by unclear mechanisms. This paper first reviews the recent progress of related signaling pathways (reactive oxygen species (ROS), AMP-activated protein kinase (AMPK), mitogen-activated protein kinases (MAPK), phosphoinositide 3-kinase (PI3K), hypoxia-inducible factor-1alpha (HIF-1α), and p53) mediating the reprogramming of cancer metabolism (including glucose metabolism, lipid metabolism, and amino acid metabolism). Then we comprehensively explore the latest discoveries and possible mechanisms of the anticancer effects of cannabinoids through the regulation of the above-mentioned related signaling pathways, to provide new targets and insights for cancer prevention and treatment.

β-elemene Isopropanolamine Derivative LXX-8250 Induces Apoptosis Through Impairing Autophagic Flux via PFKFB4 Repression in Melanoma Cells

Melanoma is a highly aggressive skin cancer and accounts for most of the skin cancer-related deaths. The efficacy of current therapies for melanoma remains to be improved. The isopropanolamine derivative of β-elemene LXX-8250 was reported to present better water solubility and stronger toxicity to tumor cells than β-elemene. Herein, LXX-8250 treatment showed 4-5-fold more toxicity to melanoma cells than the well-known anti-melanoma drug, Dacarbazine. LXX-8250 treatment induced apoptosis remarkably, which was caused by the impairment of autophagic flux. To clarify the molecular mechanism, microarray analyses were conducted, and PFKFB4 expression was found to be suppressed by LXX-8250 treatment. The cells overexpressed with PFKFB4 exhibited resistance to apoptosis induction and autophagic flux inhibition by LXX-8250 treatment. Moreover, LXX-8250 treatment suppressed glycolysis, to which the cells overexpressed with PFKFB4 were tolerant. LXX-8250 treatment inhibited the growth of melanoma xenografts and suppressed PFKFB4 expression and glycolysis in vivo. Taken together, LXX-8250 treatment induced apoptosis through inhibiting autophagic flux and glycolysis in melanoma cells, which was mediated by suppression of PFKFB4 expression. The study provides a novel strategy to melanoma treatment.

Effect of PFKFB4 on the Prognosis and Immune Regulation of NSCLC and Its Mechanism

Background

NSCLC (non-small cell lung cancer) has become the malignancy with the highest incidence and mortality rate worldwide. Fructose-6-phosphate 2-kinase/fructose-2,6-bisphosphatase 4 (PFKFB4) is a key regulator of glycolysis with both kinase and phosphatase activities. The Warburg effect, or increased glycolysis in tumors, provides the metabolic basis for cancer cell proliferation and metastasis, and the Warburg pathway enzyme PFKFB4 is a newly identified important kinase. This study aimed to elucidate the poor prognostic relevance of PFKFB4 in non-small cell lung cancer tissues and its relationship with immune cell infiltration, immune cell biomarkers, and immune checkpoints.

Methods

In this study, immunohistochemical methods were used to assess PFKFB4 expression levels in 140 surgical specimens from patients with histologically confirmed non-small cell lung cancer and to investigate the relationship between PFKFB4 expression levels and the patients’ clinicopathological characteristics. The impact of PFKFB4 expression on prognosis was evaluated using Kaplan–Meier survival analysis and Cox regression analysis.

Results

When compared to normal paracrine tissues, PFKFB4 expression was enhanced in lung cancer tissues, and Kaplan–Meier survival analysis revealed that patients with high PFKFB4 expression had a worse prognosis. In NSCLC, PFKFB4 was found to be associated with immune cell infiltration and immunological checkpoints.

Conclusion

PFKFB4 expression may be upregulated as a sign of poor prognosis in NSCLC, and PFKFB4 may be implicated not only in the genesis and progression of NSCLC but also in its immunological control.

Comprehensive Analysis of the E2F Transcription Factor Family in Human Lung Adenocarcinoma

Background

E2F transcription factors (E2Fs), code a family of pivotal transcription factors, have been identified as key regulators in tumor tumorigenesis. However, the function of E2F family in human lung adenocarcinoma (LUAD) have not been fully elucidated.

Methods

Herein, The Cancer Genome Atlas (TCGA) databases, Kaplan-Meier plotter, cBioPortal and TIMER were used to analyze differential expression, prognostic value, genetic alteration and immune cell infiltration of E2Fs in LUAD patients.

Results

The expression levels of E2Fs (E2F1-8) were all significantly upregulated in LUAD tissues compared with normal lung tissues. All eight E2Fs had low rates of gene mutation in LUAD patients from cBioPortal databases. Survival analysis revealed that E2F2 (P=0.038; HR 1.36; 95% CI 1.02–1.81), E2F7 (P<0.001; HR 1.78; 95% CI 1.33–2.39) and E2F8 (P=0.03; HR 1.37; 95% CI 1.02–1.82) were significantly associated with poor prognosis. Multivariate cox regression analysis found that only E2F7 (P<0.001; HR 2.72; 95% CI 1.75–4.25) was an independent prognostic predictor in LUAD after adjusting common clinical parameters. The receiver operating characteristic (ROC) analysis also found that E2F7 had high diagnostic value for LUAD (AUC=0.901). Further analysis found that E2F7 was significantly associated with LUAD immune cell infiltration of B cell, T cell, neutrophil, and myeloid dendritic cell. E2F7 also have positive correlations with immune checkpoint genes including SIGLEC15, CD274, HAVCR2, PDCD1LG2, CTLA4, TIGIT, LAG3 and PDCD1 in LUAD.

Conclusion

Our findings showed various association of E2F7 in LUAD diagnostic and prognostic aspects, which suggested its potential in becoming a novel biomarker.

The Invasion and Metastasis of Colon Adenocarcinoma (COAD) Induced by SALL4

Objective

The development and progression of many cancers may be related to SALL4, the role and molecular mechanism of which are unclear in colon adenocarcinoma (COAD).

Methods

The SALL4 expression in adjacent normal mucosa tissues and carcinoma tissues of patients with COAD was detected through bioinformatic analysis based on TCGA database and immunohistochemistry. Single-cell analysis showed that the expression of SALL4 in normal tissue was noticeably low. GSEA analysis suggested that the SALL4 upregulated the GO and pathway of growth and cancer development and downregulated metabolization pathway. The relationship between lymph node metastasis, histological grading, clinical staging, and the expression of SALL4 in carcinoma tissues was analyzed. The upregulated or downregulated SALL4 expression of COAD cell lines was established. The influence of SALL4 on COAD cells invasion and proliferation was detected using plate cloning assay and Transwell. The expressions of EMT-related proteins E-cadherin, N-cadherin, vimentin, and Twist were detected by Western blot. The EMT phenotype was analyzed by immunofluorescence.

Results

The study confirmed that the expression of SALL4 was upregulated in COAD and positively correlated with the degree of tumor differentiation, tumor staging, and metastasis. The overexpression of SALL4 was related to a poor prognosis, promoted the invasion and proliferation of colorectal cancer cells, and accelerated the occurrence of EMT, which was characterized by upregulation of Twist, vimentin, and N-cadherin expressions and downregulation of E-cadherin. The immunofluorescence staining confirmed the EMT phenotype. On the contrary, knocking out SALL4 gene reversed EMT, weakened cell proliferation and invasion, inhibited upregulation of Twist, vimentin, and N-cadherin expressions and downregulation of E-cadherin.

Conclusion

To sum up, TNM grading, histological grading, and lymphatic metastasis were significantly correlated with SALL4 in tumor tissues. SALL4 played a vital role in tumor proliferation, invasion, and tumor EMT and may be a novel target for COAD.

MicroRNA-631 deriving from bone marrow mesenchymal stem cell exosomes facilitates the malignant behavior of non-small cell lung cancer via modulating the E2F family of transcription factor 2/phosphatidylinositol 3-kinase/Akt signaling pathway

The exosomes (Exo) had always been considered as transport vectors for microRNA (miRNA). An increasing number of data had clarified the influence of Exo on the cell progression of non-small cell lung cancer (NSCLC). Nevertheless, its specific mechanism had not yet been verified. This work was to explore the potential mechanism of Exo-derived miR-631 targeting and regulating E2F family of transcription factor 2 (E2F2) to repress the malignant behavior of NSCLC cells. Test of microRNA (miR)-631 and E2F2 in NSCLC was performed. BMSCs-Exo that altered miR-631 was co-cultured with NSCLC cells. Detection of the cloning and progression of NSCLC cells was performed. Testification of the targeting of miR-631 with E2F2 was conducted. In vivo experiments were performed to verify the results in vitro. In short, elevation of miR-631 Exo repressed the advancement and phosphatidylinositol 3‐kinase/Akt activation of NSCLC cells, while silence of miR-631 was in the opposite. In terms of mechanism, miR-631 exerted the influence via targeting E2F2. The coincident results were obtained in animal models. In brief, BMSC-Exo mediated E2F2 via delivering miR-631 to NSCLC cells to modulate the malignant behavior of NSCLC.

Long Non-Coding RNA LINC01572 Promotes Hepatocellular Carcinoma Progression via Sponging miR-195-5p to Enhance PFKFB4-Mediated Glycolysis and PI3K/AKT Activation

Background: Accumulating evidence indicates that type 2 diabetes mellitus (T2DM) is a risk factor for hepatocellular carcinoma (HCC), and T2DM-associated HCC represents a common type of HCC cases. We herein identify an lncRNA LINC01572 that was aberrantly upregulated in T2DM-related HCC via high-throughput screening. Based on this, the study was undertaken to identify the functional role and mechanism of LINC01572 in HCC progression.

Methods: RT-qPCR was used to detect the expressions of LINC01572 in HCC tissues and cell lines. Gain- or loss-of-function assays were applied to evaluate the in vitro and in vivo functional significance of LINC01572 in the HCC cell proliferation, migration, and invasion using corresponding experiments. Bioinformatics, RIP, RNA pull-down, and luciferase reporter assays were performed to explore the regulatory relationship of the LINC01572/miR-195-5p/PFKFB4 signaling axis.

Result: In this study, we profiled lncRNAs in HCC tissues and corresponding adjacent tissues from HCC patients with T2DM by RNA sequencing. Our data showed that LINC01572 was aberrantly upregulated in HCC tissues as compared with control, especially in those with concurrent T2DM. The high level of LINC01572 was correlated with advanced tumor stage, increased blood HbA1c level, and shortened survival time. The overexpression of LINC01572 significantly promoted HCC cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT), while the knockdown of LINC01572 had the opposite effects on HCC cells. A mechanistic study revealed that LINC01572-regulated HCC progression via sponging miR-195-5p to increase the level of PFKFB4 and subsequent enhancement of glycolysis and activation of PI3K-AKT signaling.

Conclusion: LINC01572 acts as ceRNA of miR-195-5p to restrict its inhibition of PFKFB4, thereby enhancing glycolysis and activates PI3K/AKT signaling to trigger HCC malignancy.

Exploring the mechanism of Yixinyin for myocardial infarction by weighted co-expression network and molecular docking

Yixinyin, the traditional Chinese medicine, has the effects of replenishing righteous qi, and promoting blood circulation to eliminate blood stagnation. It is often used to treat patients with acute myocardial infarction (MI). The purpose of our study is to explore the key components and targets of Yixinyin in the treatment of MI. In this study, we analyzed gene expression data and clinical information from 248 samples of MI patients with the GSE34198, GSE29111 and GSE66360 data sets. By constructing a weighted gene co-expression network, gene modules related to myocardial infarction are obtained. These modules can be mapped in Yixinyin PPI network. By integrating differential genes of healthy/MI and unstable angina/MI, key targets of Yixinyin for the treatment of myocardial infarction were screened. We validated the key objectives with external data sets. GSEA analysis is used to identify the biological processes involved in key targets. Through molecular docking screening, active components that can combine with key targets in Yixinyin were obtained. In the treatment of myocardial infarction, we have obtained key targets of Yixinyin, which are ALDH2, C5AR1, FOS, IL1B, TLR2, TXNRD1. External data sets prove that they behave differently in the healthy and MI (P < 0.05). GSEA enrichment analysis revealed that they are mainly involved in pathways associated with myocardial infarction, such as viral myocarditis, VEGF signaling pathway and type I diabetes mellitus. The docking results showed that the components that can be combined with key targets in YixinYin are Supraene, Prostaglandin B1, isomucronulatol-7,2'-di-O-glucosiole, angusifolin B, Linolenic acid ethyl ester, and Mandenol. For that matter, they may be active ingredients of Yixinyin in treating MI. These findings provide a basis for the preliminary research of myocardial infarction therapy in traditional Chinese medicine and provide ideas for the design of related drugs.

Comprehensive Analysis of Regulatory Factors and Immune-Associated Patterns to Decipher Common and BRCA1/2 Mutation-Type-Specific Critical Regulation in Breast Cancer

Background: BRCA1/2 mutations are closely related to high lifetime risk of breast cancer (BC). The objective of this study was to identify the genes, regulators, and immune-associated patterns underlying disease pathology in BC with BRCA1/2 somatic mutations and their associations with clinical traits. Methods: RNA sequencing data and clinical information from The Cancer Genome Atlas (TCGA; N = 36 BRCA1-mutant BC; N = 49 BRCA2-mutant BC; and N = 117 BRCA1/2-wild-type BC samples) were used for discovery, which included consensus network analysis, function enrichment, and analysis of hub genes; other TCGA data (N = 117 triple-negative BC) and two Gene Expression Omnibus database expression profiles were used as validation cohorts. Results: Consensus network analysis helped to identify specific co-expressed modules that showed positive correlations with tumor stage, number of positive lymph nodes, and margin status in BRCA1/2-mutant BC but lacking correlations in BRCA1/2-wild-type BC. Functional enrichment suggested potential mechanisms in BRCA1/2 carriers that could regulate the cell cycle, immune response, cellular metabolic processes, and cell migration, via enriched pathways including p53 and JAK-STAT signaling. Consensus network analysis identified the specific and common carcinogenic mechanisms involving BRCA mutations. Regulators cross-linking these modules include E2F or IRF transcription factor family, associated with cell cycle or immune response regulation module, respectively. Eight hub genes, including ISG15, BUB1, and TTK, were upregulated in several BRCA1/2-mutant BC datasets and showed prognostic value in BC. Furthermore, their genetic expression was related to higher levels of immune infiltration in BRCA1/2-mutant BC, which manifested as recruitment of T helper cells (Th1 cells), follicular helper T cells, and regulatory T cells, and T cell exhaustion. Moreover, important indicators for evaluation of BC immunotherapy, tumor mutational burden and neoantigen load also positively correlated with expression of some hub genes. Conclusion: We constructed a BRCA1/2 mutation-type-specific co-expressed gene network with related transcription factors and immune-associated patterns that could regulate and influence tumor metastasis and immune microenvironment, providing novel insights into the pathological process of this disease and the corresponding BRCA mutations.

Early 2 factor (E2F) transcription factors contribute to malignant progression and have clinical prognostic value in lower-grade glioma

Early 2 factor (E2F) genes encoding a family of transcription factors are significantly associated with apoptosis, metabolism, and angiogenesis in several tumor types. However, the biological functions of E2F transcription factors (E2Fs) and their potential involvement in the malignancy of lower-grade glioma (LGG) remain unclear. We explored the effects of the expression of eight E2F family members on the clinical characteristics of LGG based on the Chinese Glioma Genome Atlas (CGGA), The Cancer Genome Atlas (TCGA), and GSE16011 datasets. Two LGG subgroups were identified according to the consensus clustering of the eight E2Fs. We employed the least absolute shrinkage and selection operator (LASSO) Cox regression algorithm for further functional experiments and the development of a potential risk score. Two categories of patients with LGG were identified based on the median risk scores. We then developed a nomogram based on the results of the multivariate analysis. Real-time quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry were performed to validate the bioinformatics results. Our results indicated that E2F family members were significantly involved in the malignancy of LGG and might serve as effective prognostic biomarkers of the disease.

Elevated Ras related GTP binding B (RRAGB) expression predicts poor overall survival and constructs a prognostic nomogram for colon adenocarcinoma

Currently, no articles have explored the roles of RRAGB gene in the occurrence and development of cancer. By means of The Cancer Genome Atlas (TCGA) data mining, we found that this gene might be a novel prognostic predictor for colon adenocarcinoma (COAD). Hence, this article was carried out to explore its roles in COAD and associations with immunity. RRAGB single-gene expression matrix and corresponding clinical information were extracted from TCGA database. Univariate/multivariate cox regression analyses and gene set enrichment analysis (GSEA) were utilized to identify independent prognostic factors and RRAGB related pathways, respectively. Relationships between RRAGB and immunity were also analyzed. Boxplot and K-M survival analysis indicated that RRAGB was not only differently expressed in COAD (P < 0.05), but also significantly associated with overall survival (OS; P < 0.05). Univariate and multivariate Cox hazard regression analyses indicated that RRAGB could serve as an independent prognostic factor for COAD (both P < 0.05). GSEA identified five signaling pathways significantly enriched in the high-RRAGB expression phenotype. Moreover, a RRAGB-based nomogram was successfully constructed and displayed a satisfactory performance. In addition, RRAGB expression was found to be significantly associated with microsatellite instability (MSI), tumor mutational burden (TMB) and immunity. Our results revealed that RRAGB could be a prognostic biomarker for COAD in terms of OS and markedly related to MSI, TMB, and immunity. We also constructed an RRAGB-based nomogram with a satisfactory performance. Further researches should be carried out to validate our findings.