Deregulated transcription factors in cancer cell metabolisms and reprogramming

YTHDC2 manipulates anti-tumoral macrophage polarization and predicts favorable outcomes in triple negative breast cancer

Triple-negative breast cancer (TNBC) possesses high malignant and metastatic rates among all subtypes. Chemotherapy is a standard of care for TNBC but only a small moiety of patients achieved complete relief (CR) after chemotherapy. The recent concept of tumor ecosystem has provided new insights into solutions from an approach of enhancing anti-tumoral immunity of macrophages. We hereby observed a positive correlation of YTHDC2 abundance with anti-tumoral gene markers of macrophages. YTHDC2-high macrophages also exerted interactions with other immune cells such as T helper cells, cytotoxic T cells, and NK cells. Further investigation on the transcriptional regulatory network identified six transcriptional factors upregulated by YTHDC2, and they together influenced the expressions of TWISTNB and the oncogene MYC. Additionally, our survival analysis prompted that YTHDC2 is prognostic of higher chemo-therapeutic efficacy and better survival outcomes. We demonstrated that ample macrophage YTHDC2 indicates anti-tumoral phenotype polarization and propitious survival outcome in post-treatment TNBC patients (Clinical trial registry name: Chinese Clinical Trial Registry, Registration No.: ChiCTR2400084513, Registration Date: 2024-05-20).

Doublecortin-like kinase 1, regulated by STIP1 homology and U-box containing protein 1 or Sp1 transcription factor, affects the malignant behaviors and drug sensitivity in adriamycin-resistant breast cancer cells

BACKGROUND

The emergence of drug resistance poses a formidable obstacle in the treatment of breast cancer (BC). Doublecortin-like kinase 1 (DCLK1) has been identified as a tumor promoter in BC. However, the impact of DCLK1 on adriamycin (ADM) resistance in BC remains largely unknown.

METHODS

The factors linked to ADM resistance in BC, the interaction between DCLK1 and STIP1 homology and U-box containing protein 1 (STUB1), and the binding sequence between Sp1 transcription factor (SP1) and DCLK1 were predicted by bioinformatics. The impact on cell phenotypes was evaluated by measuring the IC50 value for ADM, cell apoptosis, proliferation, viability, invasion, and migration. The impact on tumor growth was tested using subcutaneous xenograft studies. The STUB1/DCLK1 relationship was validated by IP assay and protein stability analysis. The SP1/DCLK1 relationship was confirmed by chromatin immunoprecipitation (ChIP) and luciferase assays.

RESULTS

DCLK1 was upregulated in ADM-resistant BC tissues and cell lines. DCLK1 depletion impaired cell proliferation, invasion, and migration and sensitized them to ADM in vitro, as well as enhanced the sensitivity of subcutaneous xenografts to ADM. Mechanistically, STUB1 degraded DCLK1 protein through ubiquitination, and SP1 transcriptionally increased DCLK1 expression. DCLK1 upregulation reversed the effects of STUB1 on ADM sensitivity and malignant behaviors of ADM-resistant BC cells, and DCLK1 expression restoration reversed the impact of SP1 silencing.

CONCLUSION

Our findings have identified DCLK1 as a crucial regulator in the malignant phenotypes and ADM sensitivity of ADM-resistant BC cells, providing a potential target for enhancing the anti-cancer efficacy of ADM in BC.

G-quadruplex in cancer energy metabolism: A potential therapeutic target

In recent years, energy metabolism in cancer has received increasing attention as an important component of tumor biology, and the functions of transcription factors, mitochondria, reactive oxygen species (ROS) and the autophagy-lysosome system in which have been elucidated. G-quadruplex (G4) is a molecular switch that regulates gene transcription or translation. As an anticancer target, the effect of G4 on cancer cell proliferation, apoptosis, cycle and autophagy has been recognized. The energy metabolism system is a unified whole composed of transcription factors, metabolic regulators, metabolites and signaling pathways that run through the entire cancer process. However, the role of G4 in this complex metabolic network has not been systematically elucidated. In this review, we analyze the close correlation between G4 and transcription factors, mitochondria, ROS and the autophagy-lysosome system and suggest that G4 can exert a marked effect on cancer energy metabolism by regulating the above mentioned key regulatory elements. The anticancer effects of some G4 ligands through regulation of energy metabolism have also been summarized, confirming the clear involvement of G4 in energy metabolism. Although much more research is needed, we propose that G4 may play a critical role in the complex energy metabolism system of cancer, which is a promising target for anticancer strategies focusing on energy metabolism.

ELK4 induced upregulation of HOMER3 promotes the proliferation and metastasis in glioma via Wnt/β-catenin/EMT signaling pathway

Glioma is an aggressive brain tumor characterized by its high invasiveness, which complicates prognosis and contributes to patient resistance against various treatment options. The HOMER family, consisting of HOMER1, HOMER2, and HOMER3, has been implicated in various cancers, yet their specific roles in glioma remain inadequately understood. This study conducted a comprehensive pan-cancer analysis to evaluate the expression profiles of HOMER family members across different tumor types, utilizing data from public databases such as TCGA and GTEx. Our findings indicate significant dysregulation of HOMER1, HOMER2, and HOMER3 in multiple cancers, with HOMER3 emerging as a potential prognostic biomarker, particularly for lower-grade glioma. Elevated expression levels of HOMER3 were associated with shorter overall survival and disease-specific survival in LGG patients, supported by Cox regression analysis that confirmed HOMER3 as an independent prognostic factor. Furthermore, HOMER3 expression correlated positively with advanced clinical stages and key tumor markers. To elucidate the mechanisms behind HOMER3 dysregulation, we identified ELK4 as a transcription factor that binds to the HOMER3 promoter, promoting its expression in glioma cells. Functional assays demonstrated that silencing HOMER3 significantly reduced glioma cell proliferation and metastatic potential in vitro and in vivo, highlighting its oncogenic role. Additionally, HOMER3 was found to influence the Wnt/β-catenin/EMT signaling pathway, with knockdown resulting in altered expression of critical EMT markers. Collectively, our results indicated that HOMER3 plays a crucial role in glioma progression and metastasis, underscoring its potential as a therapeutic target and prognostic biomarker in glioma management.

MYCN/MNX1 Axis Drives NSCLC Progression by Inducing Macrophage M2 Polarization and CD8+ T Cell Apoptosis via the Wnt/β-Catenin Pathway

Enhanced macrophage M2 polarization and CD8+ T cell dysfunction contribute to the pathophysiology of non-small cell lung cancer (NSCLC). Motor neuron and pancreatic homeobox 1 (MNX1) has emerged as a potential tumor-promoting player. Here, we clarified the activity of MNX1 in NSCLC. PMA-induced THP-1 M0-like macrophages or CD8+ T cells were co-cultured with NSCLC cells. Cell colony formation, migration, proliferation, apoptosis, and invasiveness were assessed by colony formation, wound healing, CCK-8, flow cytometry, and transwell assays, respectively. The ratio of CD206+ macrophages was analyzed by flow cytometry. Ki-67 expression was tested by immunofluorescence. ChIP and luciferase assays were used to evaluate the relationship between MYCN and MNX1. MNX1 was highly expressed in NSCLC, and its loss-of-function suppressed cell growth, motility, and invasiveness in NSCLC cells. MNX1 depletion also diminished macrophage M2 polarization and CD8+ T cell apoptosis. Mechanistically, MYCN increased MNX1 expression at the transcriptional level. MNX1 increase reversed the impact of MYCN depletion on NSCLC cell malignant behaviors, macrophage M2 polarization, and CD8+ T cell viability. MYCN depletion diminished the in vivo growth of A549 subcutaneous xenografts. Additionally, MNX1 increase counteracted the impact of MYCN depletion on the Wnt/β-catenin pathway. Our findings elucidate the oncogenic role of the MYCN/MNX1/Wnt/β-catenin pathway in NSCLC by driving macrophage M2 polarization and diminishing CD8+ T cell viability. Our study thus uncovers a novel mechanism underlying NSCLC development and highlights potential targets for combating NSCLC.

TFAP4 Regulation of MCM5 Activates the PI3K/AKT Pathway to Promote Invasion and Metastasis of Gastric Cancer

AIMS

To investigate the role of transcription factor activating enhancer-binding protein 4 (TFAP4) in gastric cancer (GC) progression and elucidate its mechanism in promoting metastasis and invasion through the PI3K/AKT signaling pathway.

METHODS

Bioinformatics analysis was performed to assess TFAP4 expression in GC tissues. Clinical specimens were collected and validated for TFAP4 expression. Functional assays were conducted to evaluate the effects of TFAP4 overexpression and inhibition on GC cell proliferation, invasion, and metastasis. In vivo studies with HGC27 cells in BALB/c nude mice were used to assess tumor growth and metastasis. Mechanistic analysis included the measurement of MCM5 expression and activation of the PI3K/AKT signaling pathway, with PI3K inhibitor LY294002 and MCM5 knockdown applied to confirm the pathways involved.

RESULTS

Elevated TFAP4 expression was observed in GC tissues, and its overexpression promoted GC cell proliferation, invasion, and metastasis. Conversely, TFAP4 inhibition suppressed these behaviors. In vivo studies confirmed that TFAP4 knockdown reduced tumor growth and metastasis in nude mice. Mechanistically, TFAP4 was found to activate MCM5, which in turn facilitated GC cell invasion and metastasis. Furthermore, TFAP4 and MCM5 activated the PI3K/AKT signaling pathway, as evidenced by increased p-PI3K and p-AKT expression. The effects of TFAP4 overexpression were reversed by MCM5 knockdown or treatment with the PI3K inhibitor LY294002.

CONCLUSION

The TFAP4-MCM5 signaling axis promotes GC progression through the PI3K/AKT pathway, suggesting that targeting this axis could provide a potential therapeutic strategy for managing gastric cancer.

FLT3 inhibition upregulates OCT4/NANOG to promote maintenance and TKI resistance of FLT3-ITD+ acute myeloid leukemia

Up to 30% of acute myeloid leukemia (AML) patients face unfavorable outcomes due to the FMS-like receptor tyrosine kinase-3 (FLT3) internal tandem duplication (ITD) mutation. Although FLT3 inhibitors show encouraging outcomes in treatment, they fail to eliminate leukemia stem cells, the origin of persistent and resistant lesions. Exploration of the mechanism in FLT3-ITD+ AML maintenance and chemoresistance is crucial for the development of novel therapeutic approaches. The manifestation of pluripotency transcription factors (TFs) and their link to clinical outcomes have been documented in various tumors. This study investigates the correlation between core pluripotency TF and treatment in AML. We discovered that FLT3 inhibition induced upregulation of OCT4 and NANOG in FLT3-ITD+ AML cells. Subsequently, we demonstrated that downregulation of OCT4 or NANOG inhibited cell growth, promoted apoptosis, and induced G0/G1 cell cycle phase arrest in FLT3-ITD+ AML cells. Knockdown of OCT and NANOG inhibited tumor growth in a mouse tumor model. OCT4 promotes the malignant biological behavior of FLT3-ITD+ AML by enhancing the abnormal FLT3 signaling pathway through transcriptional activation of NANOG. Importantly, downregulation of OCT4 or NANOG increased responsiveness to FLT3-tyrosine kinase inhibitor (TKI) (Gilteritinib), implying that OCT4 and NANOG may contribute to TKI resistance in FLT3-ITD+ AML. Our study verifies the involvement of OCT4/NANOG in regulating TKI sensitivity and targeting them may improve the cytotoxicity of FLT3-TKIs in FLT3-ITD+ AML.

Association between individual Warburg-related proteins and prognosis in colorectal cancer

We previously showed that Warburg subtyping (low/moderate/high), based on the expression of six glycolytic proteins and transcriptional regulators [glucose transporter 1 (GLUT1), pyruvate kinase M2 (PKM2), lactate dehydrogenase A (LDHA), monocarboxylate transporter 4 (MCT4), p53, and PTEN], holds independent prognostic value in colorectal cancer (CRC) patients. The present study aimed to investigate whether the expression level of one of the proteins (GLUT1, PKM2, LDHA, MCT4, p53, and PTEN) can act as a proxy for our previously identified six protein-based Warburg subtypes. Protein expression levels for individual Warburg-related proteins were available for 2,251 CRC patients from the Netherlands Cohort Study. Kaplan-Meier curves and Cox regression were used to explore associations between individual Warburg-related proteins and CRC-specific and overall survival. Previously identified associations between Warburg subtypes and CRC-specific and overall survival were adjusted for individual proteins, showing a significant association with survival in the current study. Multivariable-adjusted analyses showed that the expression of GLUT1, LDHA, MCT4, PKM2, or p53 was associated with neither CRC-specific nor overall survival. Decreasing PTEN expression was associated with significantly poorer overall survival (p-trendcategories = 0.026). Additional adjustment for PTEN expression had minimal impact on the previously identified association between Warburg subtypes and survival, and the six protein-based Warburg-high subtype remained a statistically significant predictor of overall survival (hazard ratio 1.15; 95% CI 1.01-1.32). In conclusion, our results emphasise that individual Warburg-related proteins cannot serve as a proxy or surrogate marker for Warburg subtyping, thereby highlighting the importance of combining the expression levels of multiple Warburg-related proteins when examining the prognostic significance of a complex biological pathway such as the Warburg effect.

Metabolic crossroads: unravelling immune cell dynamics in gastrointestinal cancer drug resistance

Metabolic reprogramming within the tumor microenvironment (TME) plays a critical role in driving drug resistance in gastrointestinal cancers (GI), particularly through the pathways of fatty acid oxidation and glycolysis. Cancer cells often rewire their metabolism to sustain growth and reshape the TME, creating conditions such as nutrient depletion, hypoxia, and acidity that impair antitumor immune responses. Immune cells within the TME also undergo metabolic alterations, frequently adopting immunosuppressive phenotypes that promote tumor progression and reduce the efficacy of therapies. The competition for essential nutrients, particularly glucose, between cancer and immune cells compromises the antitumor functions of effector immune cells, such as T cells. Additionally, metabolic by-products like lactate and kynurenine further suppress immune activity and promote immunosuppressive populations, including regulatory T cells and M2 macrophages. Targeting metabolic pathways such as fatty acid oxidation and glycolysis presents new opportunities to overcome drug resistance and improve therapeutic outcomes in GI cancers. Modulating these key pathways has the potential to reinvigorate exhausted immune cells, shift immunosuppressive cells toward antitumor phenotypes, and enhance the effectiveness of immunotherapies and other treatments. Future strategies will require continued research into TME metabolism, the development of novel metabolic inhibitors, and clinical trials evaluating combination therapies. Identifying and validating metabolic biomarkers will also be crucial for patient stratification and treatment monitoring. Insights into metabolic reprogramming in GI cancers may have broader implications across multiple cancer types, offering new avenues for improving cancer treatment.

Molecular mechanisms of MAZ targeting up-regulation of NDUFS3 expression to promote malignant progression in melanoma

Myc-associated Zinc-finger Protein (MAZ) has been implicated in the malignant progression of various tumors. However, its expression and functional relationship of MAZ in melanoma have not been previously investigated. This study confirms elevated expression of MAZ in melanoma, correlating with poor patient prognosis. Furthermore, our findings demonstrate that MAZ enhances melanoma progression by promoting proliferation, migration and invasion. It is worth noting that we found that MAZ can target and regulate the transcription of NADH dehydrogenase [ubiquinone] iron-sulfur protein 3 (NDUFS3), a core subunit of mitochondrial complex I, to enhance mitochondrial metabolism and thus promote malignant progression of melanoma. Predictive modeling indicates that the co-expression of MAZ and NDUFS3 could serve as a potential prognostic marker for melanoma patients.

CypA/TAF15/STAT5A/miR-514a-3p feedback loop drives ovarian cancer metastasis

Cyclophilin A (CypA) is a peptidyl-prolyl isomerase that participates in multiple cancer events, but the molecular mechanisms of abnormal expression and regulation of CypA in ovarian cancer (OC) have never been considered. This study identifies CypA as a key driver of epithelial-mesenchymal transition (EMT) in ovarian cancer and explores the mechanisms that underly this process. We show that CypA is upregulated in tissues and serum of ovarian cancer patients and that CypA overexpression correlates with poor prognosis. CypA facilitates tumor growth and metastasis in vivo in subcutaneous tumor xenograft and abdominal metastatic models, and in vitro studies suggest a mechanism, showing that CypA accelerates ovarian cancer cell epithelial-mesenchymal transition by activating a PI3K/AKT signaling pathway. Mechanistic studies showed that STAT5A binds pri-miR-514a-3p and inhibits its activity, whereas miR-514a-3p directly binds to the 3'-UTR of CypA to suppress its expression, resulting in STAT5A promoting the expression of CypA, forming the STAT5A/miR-514a-3p/CypA axis. Furthermore, immunoprecipitates and mass spectrometry analysis identifies a CypA interaction with TAF15 that stabilizes TAF15 by suppressing its proteasome degradation and promotes its entry into the nucleus. While STAT5A is positively regulated by TAF15. Our findings identify a novel feedback loop for CypA that drives EMT and ovarian tumor growth and metastasis via a TAF15/STAT5A/miR-514a-3p pathway in ovarian cancer and facilitates the release of CypA into the extracellular, which provides a promising therapeutic target for OC treatment and a diagnostic biomarker.

MTFR2 accelerates hepatocellular carcinoma mediated by metabolic reprogramming via the Akt signaling pathway

Metabolic reprogramming has recently been identified as a hallmark of malignancies. The shift from oxidative phosphorylation to glycolysis in hepatocellular carcinoma (HCC) meets the demands of rapid cell growth and provides a microenvironment for tumor progression. This study sought to uncover the function and mechanism of MTFR2 in the metabolic reprogramming of HCC. Elevated MTFR2 expression was associated with poor patient prognosis. Downregulation of MTFR2 blocked malignant behaviors, epithelial-to-mesenchymal transition (EMT), and glycolysis in HCC cells. Nuclear transcription factor Y subunit gamma (NFYC) was also associated with poor patient prognosis, and NFYC bound to the promoter of MTFR2 to activate transcription and promote Akt signaling. The repressive effects of NFYC knockdown on EMT and glycolysis in HCC cells were compromised by MTFR2 overexpression, elicited through the activation of the Akt signaling. Knockdown of NFYC slowed the growth and intrahepatic metastasis in vivo, which was reversed by MTFR2 overexpression. In conclusion, our work shows that activation of MTFR2 by the transcription factor NFYC promotes Akt signaling, thereby potentiating metabolic reprogramming in HCC development. Targeting the NFYC/MTFR2/Akt axis may represent a therapeutic strategy for HCC.

Integrated analysis of patients with bladder cancer from prospective transcription factor activity: Implications for personalized treatment approaches

Transcription factors are a specialized group of proteins that play important roles in regulating gene expression in human. These proteins control the transcription and translation of genes by binding to specific sites on DNA, thereby regulating key biological processes such as cell differentiation, proliferation, immune response, and neural development. Moreover, transcription factors are also involved in apoptosis and the pathogenesis of various diseases. By investigating transcription factors, researchers can uncover the mechanisms of gene regulation in organisms and develop more effective methods for preventing and treating human diseases. In the present study, the Virtual Inference of Protein-activity by Enriched Regulon algorithm was utilized to calculate the protein activity of transcription factors, and the metabolic-related protein activity were used for classifying bladder cancer patients into different subtype. To identify chemotherapy drugs with clinical benefits, the differences in prognosis and drug sensitivity between two distinct subtypes of bladder cancer patients were investigated. Simultaneously, the master regulators that display varying levels of transcription factor activity between two different bladder cancer subtypes were explored. Additionally, the potential transcriptional regulatory mechanisms and targets of these factors were investigated, thereby generating novel insights into bladder cancer research at the transcriptional regulation level.

MiR-137 mediated high expression of TIGD1 promotes migration, invasion, and suppresses apoptosis of lung adenocarcinoma

OBJECTIVES

Tigger transposable element-derived 1 (TIGD1) expression and its underlying functions and regulatory mechanisms in lung adenocarcinoma (LUAD) remain unknown. Therefore, we intended to explore the expression, potential functions, and regulatory mechanisms of TIGD1 in LUAD.

MATERIALS AND METHODS

TIGD1 expression in LUAD tissues was determined by immunohistochemistry analysis of a tissue microarray. Functional experiments were conducted to determine how TIGD1 affects LUAD tumorigenesis and metastasis. The molecular mechanisms by which TIGD1 induces LUAD progression were determined.

RESULTS

TIGD1 was upregulated in LUAD tissues and was related to lymph node metastases. TIGD1 knockdown suppressed LUAD cell proliferation, migration, and invasion, while promoted cell apoptosis. Furthermore, decreased metastatic nodules were observed in the TIGD1 knockdown mouse metastasis model. Moreover, microarray analysis was performed to determine the potential downstream genes of TIGD1 in LUAD. Hallmark pathway analysis revealed that the downstream genes of TIGD1 were involved in epithelial-mesenchymal transition (EMT). Western blotting confirmed that vimentin and TWIST was downregulated in TIGD1 knockdown cells, while E-cadherin was upregulated. Ingenuity pathway and hallmark pathway analyses revealed that TIGD1 regulated the interleukin-6 signaling pathway and related gene members. Western blotting, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay indicated that downregulation of TIGD1 decreased interleukin-6 and CXCL1 expression. TIGD1 expression was negatively correlated with immune infiltration in LUAD. The upstream microRNA of TIGD1 was predicted, and subsequent luciferase reporter gene experiments confirmed the interactions between miR-137 and TIGD1. The expression of miR-137 was significantly downregulated in LUAD tissues and miR-137 suppressed the proliferation, migration, and invasion of LUAD cells, partially through negatively regulating the expression of TIGD1.

CONCLUSION

Our findings suggest that TIGD1, which was regulated by miR-137, contributed to LUAD progression by promoting cell proliferation, migration, invasion, and EMT and suppressing cell apoptosis.

Current concepts of the crosstalk between lncRNA and E2F1: shedding light on the cancer therapy

Long noncoding RNAs (lncRNAs) constitute a distinctive subset of RNA molecules with limited protein-coding potential, which exert crucial impacts on various biological activities. In the context of cancer, dysregulated lncRNAs function as essential regulators that affect tumor initiation and malignant progression. These lncRNAs serve as competitive endogenous RNAs (ceRNAs) through sponging microRNAs and regulating the expression of targeted genes. Moreover, they also directly bind to RNA-binding proteins, which can be integrated into a complex mechanistic network. E2F1, an extensively studied transcription factor, mediates multiple malignant behaviors by regulating cell cycle progression, tumor metastasis, and therapeutic response. Emerging evidence suggests that lncRNAs play a pivotal role in regulating the E2F1 pathway. This review aims to elucidate the intricate gene regulatory programs between lncRNAs and E2F1 in cancer progression. We elaborate on distinct mechanistic networks involved in cancer progression, emphasizing the potential of the lncRNAs/E2F1 axes as promising targets for cancer therapy. Additionally, we provide novel perspectives on current evidence, limitations, and future directions for targeting lncRNAs in human cancers. Fully deciphering the intricate network of lncRNA/E2F1-mediated regulatory mechanisms in cancer could facilitate the translation of current findings into clinical course, such efforts ultimately significantly improve the clinical prognosis of cancer patients.

Canonical WNT/β-catenin signaling upregulates aerobic glycolysis in diverse cancer types

Despite many efforts, a comprehensive understanding and clarification of the intricate connections within cancer cell metabolism remain elusive. This might pertain to intracellular dynamics and the complex interplay between cancer cells, and cells with the tumor stroma. Almost a century ago, Otto Warburg found that cancer cells exhibit a glycolytic phenotype, which continues to be a subject of thorough investigation. Past and ongoing investigations have demonstrated intricate mechanisms by which tumors modulate their functionality by utilizing extracellular glucose as a substrate, thereby sustaining the essential proliferation of cancer cells. This concept of "aerobic glycolysis," where cancer cells (even in the presence of enough oxygen) metabolize glucose to produce lactate plays a critical role in cancer progression and is regulated by various signaling pathways. Recent research has revealed that the canonical wingless-related integrated site (WNT) pathway promotes aerobic glycolysis, directly and indirectly, thereby influencing cancer development and progression. The present review seeks to gather knowledge about how the WNT/β-catenin pathway influences aerobic glycolysis, referring to relevant studies in different types of cancer. Furthermore, we propose the concept of impeding the glycolytic phenotype of tumors by employing specific inhibitors that target WNT/β-catenin signaling.

M6A-induced transcription factor IRF5 contributes to the progression of cervical cancer by upregulating PPP6C

Cervical cancer (CC) is a gynaecological malignancy tumour that seriously threatens women's health. Recent evidence has identified that interferon regulatory factor 5 (IRF5), a nucleoplasm shuttling protein, is a pivotal transcription factor regulating the growth and metastasis of various human tumours. This study aimed to investigate the function and molecular basis of IRF5 in CC development. IRF5, protein phosphatase 6 catalytic subunit (PPP6C) and methyltransferase-like 3 (METTL3) mRNA levels were evaluated by quantitative real-time (qRT)-polymerase chain reaction (PCR). IRF5, PPP6C, METTL3, B-cell lymphoma 2 and Bax protein levels were detected using western blot. Cell proliferation, migration, invasion, angiogenesis and apoptosis were determined by using colony formation, 5-ethynyl-2'-deoxyuridine (EdU), transwell, tube formation assay and flow cytometry assay, respectively. Glucose uptake and lactate production were measured using commercial kits. Xenograft tumour assay in vivo was used to explore the role of IRF5. After JASPAR predication, binding between IRF5 and PPP6C promoter was verified using chromatin immunoprecipitation and dual-luciferase reporter assays. Moreover, the interaction between METTL3 and IRF5 was verified using methylated RNA immunoprecipitation (MeRIP). IRF5, PPP6C and METTL3 were highly expressed in CC tissues and cells. IRF5 silencing significantly inhibited cell proliferation, migration, invasion, angiogenesis and glycolytic metabolism in CC cells, while induced cell apoptosis. Furthermore, the absence of IRF5 hindered tumour growth in vivo. At the molecular level, IRF5 might bind with PPP6C to positively regulate the expression of PPP6C mRNA. Meanwhile, IRF5 was identified as a downstream target of METTL3-mediated m6A modification. METTL3-mediated m6A modification of mRNA might promote CC malignant progression by regulating PPP6C, which might provide a promising therapeutic target for CC treatment.

FLI1 promotes IFN-γ-induced kynurenine production to impair anti-tumor immunity

Nasopharyngeal carcinoma (NPC)-mediated immunosuppression within the tumor microenvironment (TME) frequently culminates in the failure of otherwise promising immunotherapies. In this study, we identify tumor-intrinsic FLI1 as a critical mediator in impairing T cell anti-tumor immunity. A mechanistic inquiry reveals that FLI1 orchestrates the expression of CBP and STAT1, facilitating chromatin accessibility and transcriptional activation of IDO1 in response to T cell-released IFN-γ. This regulatory cascade ultimately leads to augmented IDO1 expression, resulting in heightened synthesis of kynurenine (Kyn) in tumor cells. This, in turn, fosters CD8+ T cell exhaustion and regulatory T cell (Treg) differentiation. Intriguingly, we find that pharmacological inhibition of FLI1 effectively obstructs the CBP/STAT1-IDO1-Kyn axis, thereby invigorating both spontaneous and checkpoint therapy-induced immune responses, culminating in enhanced tumor eradication. In conclusion, our findings delineate FLI1-mediated Kyn metabolism as an immune evasion mechanism in NPC, furnishing valuable insights into potential therapeutic interventions.

Genetic loss of Nrf1 and Nrf2 leads to distinct metabolism reprogramming of HepG2 cells by opposing regulation of the PI3K-AKT-mTOR signalling pathway

As a vital hallmarker of cancer, the metabolic reprogramming has been shown to play a pivotal role in tumour occurrence, metastasis and drug resistance. Amongst a vast variety of signalling molecules and metabolic enzymes involved in the regulation of cancer metabolism, two key transcription factors Nrf1 and Nrf2 are required for redox signal transduction and metabolic homeostasis. However, the regulatory effects of Nrf1 and Nrf2 (both encoded by Nfe2l1 and Nfe2l2, respectively) on the metabolic reprogramming of hepatocellular carcinoma cells have been not well understood to date. Here, we found that the genetic deletion of Nrf1 and Nrf2 from HepG2 cells resulted in distinct metabolic reprogramming. Loss of Nrf1α led to enhanced glycolysis, reduced mitochondrial oxygen consumption, enhanced gluconeogenesis and activation of the pentose phosphate pathway in the hepatocellular carcinoma cells. By striking contrast, loss of Nrf2 attenuated the glycolysis and gluconeogenesis pathways, but with not any significant effects on the pentose phosphate pathway. Moreover, knockout of Nrf1α also caused fat deposition and increased amino acid synthesis and transport, especially serine synthesis, whilst Nrf2 deficiency did not cause fat deposition, but attenuated amino acid synthesis and transport. Further experiments revealed that such distinctive metabolic programming of between Nrf1α-/- and Nrf2-/- resulted from substantial activation of the PI3K-AKT-mTOR signalling pathway upon the loss of Nrf1, leading to increased expression of critical genes for the glucose uptake, glycolysis, the pentose phosphate pathway, and the de novo lipid synthesis, whereas deficiency of Nrf2 resulted in the opposite phenomenon by inhibiting the PI3K-AKT-mTOR pathway. Altogether, these provide a novel insight into the cancer metabolic reprogramming and guide the exploration of a new strategy for targeted cancer therapy.

Recent Advances in Reprogramming Strategy of Tumor Microenvironment for Rejuvenating Photosensitizers-Mediated Photodynamic Therapy

Photodynamic therapy (PDT) has recently been considered a potential tumor therapy due to its time-space specificity and non-invasive advantages. PDT can not only directly kill tumor cells by using cytotoxic reactive oxygen species but also induce an anti-tumor immune response by causing immunogenic cell death of tumor cells. Although it exhibits a promising prospect in treating tumors, there are still many problems to be solved in its practical application. Tumor hypoxia and immunosuppressive microenvironment seriously affect the efficacy of PDT. The hypoxic and immunosuppressive microenvironment is mainly due to the abnormal vascular matrix around the tumor, its abnormal metabolism, and the influence of various immunosuppressive-related cells and their expressed molecules. Thus, reprogramming the tumor microenvironment (TME) is of great significance for rejuvenating PDT. This article reviews the latest strategies for rejuvenating PDT, from regulating tumor vascular matrix, interfering with tumor cell metabolism, and reprogramming immunosuppressive related cells and factors to reverse tumor hypoxia and immunosuppressive microenvironment. These strategies provide valuable information for a better understanding of the significance of TME in PDT and also guide the development of the next-generation multifunctional nanoplatforms for PDT.

YTHDF2 Is a Therapeutic Target for HCC by Suppressing Immune Evasion and Angiogenesis Through ETV5/PD-L1/VEGFA Axis

N6-methyladenosine (m6A) modification orchestrates cancer formation and progression by affecting the tumor microenvironment (TME). For hepatocellular carcinoma (HCC), immune evasion and angiogenesis are characteristic features of its TME. The role of YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), as an m6A reader, in regulating HCC TME are not fully understood. Herein, it is discovered that trimethylated histone H3 lysine 4 and H3 lysine 27 acetylation modification in the promoter region of YTHDF2 enhanced its expression in HCC, and upregulated YTHDF2 in HCC predicted a worse prognosis. Animal experiments demonstrated that Ythdf2 depletion inhibited spontaneous HCC formation, while its overexpression promoted xenografted HCC progression. Mechanistically, YTHDF2 recognized the m6A modification in the 5'-untranslational region of ETS variant transcription factor 5 (ETV5) mRNA and recruited eukaryotic translation initiation factor 3 subunit B to facilitate its translation. Elevated ETV5 expression induced the transcription of programmed death ligand-1 and vascular endothelial growth factor A, thereby promoting HCC immune evasion and angiogenesis. Targeting YTHDF2 via small interference RNA-containing aptamer/liposomes successfully both inhibited HCC immune evasion and angiogenesis. Together, this findings reveal the potential application of YTHDF2 in HCC prognosis and targeted treatment.

Zinc finger protein 468 up-regulation of TFAM contributes to the malignant growth and cisplatin resistance of breast cancer cells

BACKGROUND

Because of the progress on the diagnosis and treatment for patients with breast cancer (BC), the overall survival of the patients has been improved. However, a number of BC patients cannot benefit from the existing therapeutic strategies as the essential molecular events triggering the development of BC are not well understood. Previous studies have shown that abnormal expression of zinc finger proteins is involved in the development of various malignancies, whereas it remains largely unclear on their significance during the progression of BC. In this study, we aimed to explore the clinical relevance, cellular function and underlying mechanisms of zinc finger protein 468 (ZNF468) in BC.

METHODS

The clinical relevance of ZNF468 and TFAM was analyzed based on TCGA database. Overexpression or knockdown of ZNF468 and TFAM were performed by transfecting the cells with overexpression plasmids and siRNAs, respectively. Overexpression and knockdown efficacy was checked by immunoblotting. CCK-8, colony formation, transwell and apoptosis experiments were conducted to check the cellular function of ZNF468 and TFAM. The content of mtDNA was measured by the indicated assay kit. The effects of cisplatin on BC cells were detected by CCK-8 and colony formation assays. The regulation of ZNF468 on TFAM was analyzed by RT-qPCR, immunoblotting, dual luciferase activity and ChIP-qPCR assays.

RESULTS

ZNF468 was overexpressed in BC patients and inversely correlated with their prognosis. Based on overexpression and knockdown assays, we found that ectopic expression of ZNF468 was essential for the proliferation, growth and migration of BC cells. The expression of ZNF468 also negatively regulated the sensitivity of BC cells to the treatment of cisplatin. Mechanistically, ZNF468 potentiated the transcription activity of TFAM gene via direct binding on its promoter. Lastly, we demonstrated that ZNF468 up-regulation of TFAM was important for the growth, migration and cisplatin resistance in BC cells.

CONCLUSION

Our study indicates that ZNF468 promotes BC cell growth and migration via transcriptional activation of TFAM. ZNF468/TFAM axis can serve as the diagnostic and therapeutic target, as well as the predictor of cisplatin effectiveness in BC patients.

Current advances in modulating tumor hypoxia for enhanced therapeutic efficacy

Hypoxia is a common feature of most solid tumors, which promotes the proliferation, invasion, metastasis, and therapeutic resistance of tumors. Researchers have been developing advanced strategies and nanoplatforms to modulate tumor hypoxia to enhance therapeutic effects. A timely review of this rapidly developing research topic is therefore highly desirable. For this purpose, this review first introduces the impact of hypoxia on tumor development and therapeutic resistance in detail. Current developments in the construction of various nanoplatforms to enhance tumor treatment in response to hypoxia are also systematically summarized, including hypoxia-overcoming, hypoxia-exploiting, and hypoxia-disregarding strategies. We provide a detailed discussion of the rationale and research progress of these strategies. Through a review of current trends, it is hoped that this comprehensive overview can provide new prospects for clinical application in tumor treatment. STATEMENT OF SIGNIFICANCE: As a common feature of most solid tumors, hypoxia significantly promotes tumor progression. Advanced nanoplatforms have been developed to modulate tumor hypoxia to enhanced therapeutic effects. In this review, we first introduce the impact of hypoxia on tumor progression. Current developments in the construction of various nanoplatforms to enhance tumor treatment in response to hypoxia are systematically summarized, including hypoxia-overcoming, hypoxia-exploiting, and hypoxia-disregarding strategies. We discuss the rationale and research progress of the above strategies in detail, and finally introduce future challenges for treatment of hypoxic tumors. By reviewing the current trends, this comprehensive overview can provide new prospects for clinical translatable tumor therapy.

Jun Dimerization Protein 2 (JDP2) Increases p53 Transactivation by Decreasing MDM2

The AP-1 protein complex primarily consists of several proteins from the c-Fos, c-Jun, activating transcription factor (ATF), and Jun dimerization protein (JDP) families. JDP2 has been shown to interact with the cAMP response element (CRE) site present in many cis-elements of downstream target genes. JDP2 has also demonstrates important roles in cell-cycle regulation, cancer development and progression, inhibition of adipocyte differentiation, and the regulation of antibacterial immunity and bone homeostasis. JDP2 and ATF3 exhibit significant similarity in their C-terminal domains, sharing 60-65% identities. Previous studies have demonstrated that ATF3 is able to influence both the transcriptional activity and p53 stability via a p53-ATF3 interaction. While some studies have shown that JDP2 suppresses p53 transcriptional activity and in turn, p53 represses JDP2 promoter activity, the direct interaction between JDP2 and p53 and the regulatory role of JDP2 in p53 transactivation have not been explored. In the current study, we provide evidence, for the first time, that JDP2 interacts with p53 and regulates p53 transactivation. First, we demonstrated that JDP2 binds to p53 and the C-terminal domain of JDP2 is crucial for the interaction. Second, in p53-null H1299 cells, JDP2 shows a robust increase of p53 transactivation in the presence of p53 using p53 (14X)RE-Luc. Furthermore, JDP2 and ATF3 together additively enhance p53 transactivation in the presence of p53. While JDP2 can increase p53 transactivation in the presence of WT p53, JDP2 fails to enhance transactivation of hotspot mutant p53. Moreover, in CHX chase experiments, we showed that JDP2 slightly enhances p53 stability. Finally, our findings indicate that JDP2 has the ability to reverse MDM2-induced p53 repression, likely due to decreased levels of MDM2 by JDP2. In summary, our results provide evidence that JDP2 directly interacts with p53 and decreases MDM2 levels to enhance p53 transactivation, suggesting that JDP2 is a novel regulator of p53 and MDM2.

Deregulated transcription factors in the emerging cancer hallmarks

Cancer progression is a multifaceted process that entails several stages and demands the persistent expression or activation of transcription factors (TFs) to facilitate growth and survival. TFs are a cluster of proteins with DNA-binding domains that attach to promoter or enhancer DNA strands to start the transcription of genes by collaborating with RNA polymerase and other supporting proteins. They are generally acknowledged as the major regulatory molecules that coordinate biological homeostasis and the appropriate functioning of cellular components, subsequently contributing to human physiology. TFs proteins are crucial for controlling transcription during the embryonic stage and development, and the stability of different cell types depends on how they function in different cell types. The development and progression of cancer cells and tumors might be triggered by any anomaly in transcription factor function. It has long been acknowledged that cancer development is accompanied by the dysregulated activity of TF alterations which might result in faulty gene expression. Recent studies have suggested that dysregulated transcription factors play a major role in developing various human malignancies by altering and rewiring metabolic processes, modifying the immune response, and triggering oncogenic signaling cascades. This review emphasizes the interplay between TFs involved in metabolic and epigenetic reprogramming, evading immune attacks, cellular senescence, and the maintenance of cancer stemness in cancerous cells. The insights presented herein will facilitate the development of innovative therapeutic modalities to tackle the dysregulated transcription factors underlying cancer.

Transcription factors direct epigenetic reprogramming at specific loci in human cancers

The characterization of epigenetic changes during cancer development and progression led to notable insights regarding the roles of cancer-specific epigenetic reprogramming. Recent studies showed that transcription factors (TFs) are capable to regulate epigenetic reprogramming at specific loci in different cancer types through their DNA-binding activities. However, the causal association of dynamic histone modification change mediated by TFs is still not well elucidated. Here we evaluated the impacts of 636 transcription factor binding activities on histone modification in 24 cancer types. We performed Instrumental Variables analysis by using genetic lesions of TFs as our instrumental proxies, which previously discovered to be associated with histone mark activities. As a result, we showed a total of 6 EpiTFs as strong directors of epigenetic reprogramming of histone modification in cancers, which alters the molecular and clinical phenotypes of cancer. Together our findings highlight a causal mechanism driven by the TFs and genome-wide histone modification, which is relevant to multiple status of oncogenesis.

A novel transcription factor SIPA1: identification and verification in triple-negative breast cancer

Transcription factors (TFs) regulate the expression of genes responsible for cell growth, differentiation, and responses to environmental factors. In this study, we demonstrated that signal-induced proliferation-associated 1 (SIPA1), known as a Rap-GTPase-activating protein, bound DNA and served as a TF. Importin β1 was found to interact with SIPA1 upon fibronectin treatment. A TGAGTCAB motif was recognized and bound by DNA-binding region (DBR) of SIPA1, which was confirmed by electrophoretic mobility shift assay. SIPA1 regulated the transcription of multiple genes responsible for signal transduction, DNA synthesis, cell adhesion, cell migration, and so on. Transcription of fibronectin 1, which is crucial for cell junction and migration of triple-negative breast cancer (TNBC) cells, was regulated by SIPA1 in a DBR-dependent manner both in vivo and in vitro. Furthermore, single-cell transcriptome sequencing analysis of specimens from a metastatic TNBC patient revealed that SIPA1 was highly expressed in metastatic TNBC. Hence, this study demonstrated that SIPA1 served as a TF, promoting TNBC migration, invasion, and metastasis.

The critical roles of m6A RNA methylation in lung cancer: from mechanism to prognosis and therapy

Lung cancer, a highly malignant disease, greatly affects patients' quality of life. N6-methyladenosine (m6A) is one of the most common posttranscriptional modifications of various RNAs, including mRNAs and ncRNAs. Emerging studies have demonstrated that m6A participates in normal physiological processes and that its dysregulation is involved in many diseases, especially pulmonary tumorigenesis and progression. Among these, regulators including m6A writers, readers and erasers mediate m6A modification of lung cancer-related molecular RNAs to regulate their expression. Furthermore, the imbalance of this regulatory effect adversely affects signalling pathways related to lung cancer cell proliferation, invasion, metastasis and other biological behaviours. Based on the close association between m6A and lung cancer, various prognostic risk models have been established and novel drugs have been developed. Overall, this review comprehensively elaborates the mechanism of m6A regulation in the development of lung cancer, suggesting its potential for clinical application in the therapy and prognostic assessment of lung cancer.

Tumor Suppressor p53 Down-Regulates Programmed Cell Death Protein 4 (PDCD4) Expression

The programmed cell death protein 4 (PDCD4), a well-known tumor suppressor, inhibits translation initiation and cap-dependent translation by inhibiting the helicase activity of EIF4A. The EIF4A tends to target mRNAs with a structured 5'-UTR. In addition, PDCD4 can also prevent tumorigenesis by inhibiting tumor promoter-induced neoplastic transformation, and studies indicate that PDCD4 binding to certain mRNAs inhibits those mRNAs' translation. A previous study demonstrated that PDCD4 inhibits the translation of p53 mRNA and that treatment with DNA-damaging agents down-regulates PDCD4 expression but activates p53 expression. The study further demonstrated that treatment with DNA-damaging agents resulted in the downregulation of PDCD4 expression and an increase in p53 expression, suggesting a potential mechanism by which p53 regulates the expression of PDCD4. However, whether p53 directly regulates PDCD4 remains unknown. Herein, we demonstrate for the first time that p53 regulates PDCD4 expression. Firstly, we found that overexpression of p53 in p53-null cells (H1299 and Saos2 cells) decreased the PDCD4 protein level. Secondly, p53 decreased PDCD4 promoter activity in gene reporter assays. Moreover, we demonstrated that mutations in p53 (R273H: contact hotspot mutation, and R175H: conformational hotspot mutation) abolished p53-mediated PDCD4 repression. Furthermore, mutations in the DNA-binding domain, but not in the C-terminal regulatory domain, of p53 disrupted p53-mediated PDCD4 repression. Finally, the C-terminal regulatory domain truncation study showed that the region between aa374 and aa370 is critical for p53-mediated PDCD4 repression. Taken together, our results suggest that p53 functions as a novel regulator of PDCD4, and the relationship between p53 and PDCD4 may be involved in tumor development and progression.