FoxM1: Repurposing an oncogene as a biomarker

New mechanism of miR-34a-5p in regulating the biological behavior of osteosarcoma by targeting FoxM1

Osteosarcoma (OS), the most common primary malignant bone tumor in pediatric and adolescent populations, is characterized by significant morbidity and mortality. MicroRNAs (miRNAs) are essential non-coding RNAs that exert pivotal regulatory functions in diverse physiological and pathological processes, including tumorigenesis, disease progression, and drug resistance. The association of miR-34a-5p with osteosarcoma has been documented; However, its underlying mechanisms remain poorly understood.This investigation delineates the impact of miR-34a-5p on the proliferation, invasion, migration, and apoptosis of osteosarcoma cells via in vitro assays, aiming to elucidate the associated mechanisms. Employing up-regulation and knockdown strategies, this study evaluated the roles of miR-34a-5p and FoxM1 in modulating osteosarcoma cell behaviors.These effects were further validated through a rescue experiment, providing robust evidence of the miRNA's impact. Quantitative RT-PCR showed that, compared with normal tissues, miR-34a-5p was significantly downregulated while FoxM1 was markedly upregulated in nine osteosarcoma samples.Increased miR-34a-5p expression attenuated proliferation, migration, and invasion in MG-63 and U2OS cell lines, while enhancing apoptosis.Bioinformatic analyses and dual luciferase assays identified FoxM1 as a downstream target of miR-34a-5p, a finding corroborated by quantitative RT-PCR and Western blotting, which confirmed the negative regulation of FoxM1 by miR-34a-5p.Additionally, FoxM1 knockdown reduced tumor cell proliferation, migration, and invasion, concurrently promoting apoptosis; co-inhibition of miR-34a-5p and FoxM1 partially mitigated these effects. This study demonstrates that miR-34a-5p significantly inhibits osteosarcoma cell proliferation, migration, and invasion, while promoting apoptosis, by targeting and suppressing FoxM1. Our findings suggest that miR-34a-5p is a potential tumor suppressor with therapeutic value. The establishment of the miR-34a-5p/FoxM1 regulatory axis provides new insights into the molecular mechanisms of osteosarcoma. Targeting this axis could offer a promising strategy for improving the prognosis of osteosarcoma.

(-)-Epicatechin regulates the resistance of lung adenocarcinoma cells to radiotherapy through the downregulation of FOXM1

Radioresistance, particularly as manifested by cancer stem cells (CSCs), is the most common reason for the failure of cancer radiotherapy. It is essential for effective radiotherapy to inhibit cancer cell stemness. Research indicates that (-)-epicatechin (EC) enhances the radiosensitivity of non-small cell lung cancer (NSCLC); however, its influence on cell stemness in lung adenocarcinoma (LUAD) resistant to radiotherapy is still not well understood. In this study, radioresistant cell lines A549R and H1299R were constructed by repeatedly irradiating A549 and H1299 cells with gradient doses of X-rays. CCK-8, cell cloning, flow cytometry, RT-qPCR, Western blot, sphere formation detection, and other methods were used for experimental exploration. This study revealed that the radioresistance of LUAD cells was related to their stemness. By inhibiting KLF4, SOX2, CD133, and ALDH1A1 expression, EC treatment increased radiosensitivity and reduced cell sphere formation. Also, FOXM1 expression was upregulated in LUAD and in radioresistant LUAD cells. Knocking down FOXM1 inhibited the stemness of radioresistant LUAD cells. Mechanistically, EC inhibited radiotherapy-resistant LUAD cell stemness by downregulating FOXM1 expression, thereby increasing radiosensitivity. In summary, our study revealed that EC inhibited radiotherapy resistance in LUAD cells through downregulating FOXM1, and it provides a theoretical framework for treating LUAD clinically.

FOXM1 promotes malignant biological behavior and metabolic reprogramming by targeting SPINK1 in hepatocellular carcinoma and affecting the p53 pathway

This study investigates the role of SPINK1 in liver cancer and its regulatory relationship with FOXM1. Using differential gene analysis in the GEO database, SPINK1 was identified as overexpressed in liver cancer tissues and associated with poor prognosis, confirmed via PCR. Functional assays demonstrated that SPINK1 knockdown reduced proliferation, migration, and invasion in liver cancer cells, while promoting apoptosis. In vivo experiments revealed that SPINK1 knockdown inhibited tumor growth, decreased Ki-67 and N-cadherin levels, increased E-cadherin levels, and suppressed lung metastasis. Analysis of upstream factors indicated that FOXM1 binds to the SPINK1 promoter, as validated by dual-luciferase and ChIP assays, thereby promoting SPINK1 transcription. TCGA database analysis and clinical tissue validation showed that FOXM1 expression correlates with poor prognosis in liver cancer. Functional studies demonstrated that FOXM1 knockdown suppressed liver cancer progression, while SPINK1 overexpression reversed these effects. KEGG enrichment analysis identified the p53 pathway as a key downstream target of SPINK1, and Western blotting confirmed its role in modulating p53 pathway activity. These findings reveal a critical FOXM1-SPINK1 axis in liver cancer progression. FOXM1 directly promotes SPINK1 transcription, enhancing tumor cell proliferation and metastasis while regulating the p53 pathway. Targeting this axis could provide a potential therapeutic approach for liver cancer.

Emerging Role of the DREAM Complex in Cancer and Therapeutic Opportunities

The DREAM (dimerization partner, RB-like, E2F, and multi-vulval class B) complex is an evolutionarily conserved transcriptional repression complex that coordinates nearly one thousand target genes, primarily associated with the cell cycle processes. The formation of the DREAM complex consequently inhibits cell cycle progression and induces cellular quiescence. Given its unique role in cell cycle control, the DREAM complex has gained significant interest across various physiological and pathological contexts, particularly in conditions marked by dysregulated cell cycles, such as cancer. However, the specific cancer types most significantly affected by alterations in the DREAM complex are yet to be determined. Moreover, the possibility of restoring or pharmacologically targeting the DREAM complex as a therapeutic intervention against cancer remains a relatively unexplored area of research and is currently under active investigation. In this review, we provide an overview of the latest advances in understanding the DREAM complex, focusing on its role in cancer. We also explore strategies for targeting the DREAM complex as a potential approach for cancer therapeutics. Advances in understanding the precise role of the DREAM complex in cancer, combined with ongoing efforts to develop targeted therapies, may pave the way for new options in cancer therapy.

Casticin suppresses self-renewal related stemness via miR-342-3p-mediated FoxM1 downregulation in cervical cancer cells

BACKGROUND

Casticin (CAS), a natural flavonoid found in Viticis Fructus, Viticis Cannabifoliae Fructus, and Semen Euphorbiae, shows anti-inflammatory activity and efficacy against various cancers. However, its effect on stemness associated with self-renewal in cervical cancer (CC) cells remains unclear, as well as the underlying mechanism.

PURPOSE

The primary objective of this study was to examine the effect of CAS on CC stemness and to explore the underpinning regulatory mechanism.

METHODS

HeLa cells underwent treatment with varying concentrations of CAS (0, 10, 30, 100 nM). To evaluate the impacts of CAS on CC stemness and tumorigenicity, sphere- and colony-formation assays and a xenograft model were employed. The study involved screening for changes in miRNAs and their target genes. The miRNA array identified an upregulation in miRNAs, whereas the mRNA array detected a downregulation of specific target genes. The latter genes were found to regulate stem cell-related genes through miR-342-3p in HeLa cells administered CAS. Next, whether miR-342-3p directly targets FOXM1 when upregulated by CAS was assessed by the luciferase reporter assay. qRT-PCR was performed to analyze miR-342-3p expression. Additionally, immunoblotting was conducted to assess the protein amounts of FoxM1 and stemness-related factors (CD133, CD49f, Nanog, and Sox2). Function rescue experiments were conducted to determine the mechanism of CAS in stemness regulation. These experiments involved utilizing a miR-342-3p inhibitor and overexpressing FOXM1 in HeLa cells.

RESULTS

CAS decreased in vitro stemness, suppressing sphere- and colony-formation capabilities of CC. It also dose-dependently downregulated the expression of stemness-associated proteins, including CD133, CD49f, Nanog, and Sox2. Moreover, CAS inhibited in vivo carcinogenesis, remarkably reducing tumor growth in mice bearing HeLa cell xenografts. Analysis revealed downregulated FOXM1 expression in HeLa cells treated with CAS. In the luciferase reporter assay, miR-342-3p was found to directly target FOXM1 in CAS-treated HeLa cells. Additionally, miR-342-3p inhibitor transfection successfully rescued CAS' suppressive impact on stemness. Furthermore, overexpression of FOXM1 did not induce changes in miR-342-3p expression. However, it effectively rescued CAS' suppressive effects on stemness. Moreover, CAS also inhibited stemness, upregulated miR-342-3p, and lowered FOXM1 expression in the SiHa cell line.

CONCLUSION

CAS suppresses self-renewal-associated stemness by targeting FOXM1 via miR-342-3p upregulation. These findings suggest CAS is promising as a novel therapeutic candidate in CC.

FOXM1 affects oxidative stress, mitochondrial function, and the DNA damage response by regulating p21 in aging oocytes

Fertilization capacity and embryo survival rate are decreased in postovulatory aging oocytes, which results in a reduced reproductive rate in female animals. However, the key regulatory genes and related regulatory mechanisms involved in the process of postovulatory aging in oocytes remain unclear. In this study, RNA-Seq revealed that 3237 genes were differentially expressed in porcine oocytes between the MII and aging stages (MII + 24 h). The expression level of FOXM1 was increased at the aging stage, and FOXM1 was also observed to be enriched in many key biological processes, such as cell senescence, response to oxidative stress, and transcription, during porcine oocyte aging. Previous studies have shown that FOXM1 is involved in the regulation of various biological processes, such as oxidative stress, DNA damage repair, mitochondrial function, and cellular senescence, which suggests that FOXM1 may play a crucial role in the process of postovulatory aging. Therefore, in this study, we investigated the effects and mechanisms of FOXM1 on oxidative stress, mitochondrial function, DNA damage, and apoptosis during oocyte aging. Our study revealed that aging oocytes exhibited significantly increased ROS levels and significantly decreased GSH, SOD, T-AOC, and CAT levels than did oocytes at the MII stage and that FOXM1 inhibition exacerbated the changes in these levels in aging oocytes. In addition, FOXM1 inhibition increased the levels of DNA damage, apoptosis, and cell senescence in aging oocytes. A p21 inhibitor alleviated the effects of FOXM1 inhibition on oxidative stress, mitochondrial function, and DNA damage and thus alleviated the degree of senescence in aging oocytes. These results indicate that FOXM1 plays a crucial role in porcine oocyte aging. This study contributes to the understanding of the function and mechanism of FOXM1 during porcine oocyte aging and provides a theoretical basis for preventing oocyte aging and optimizing conditions for the in vitro culture of oocytes.

Identification of FOXM1 as a novel protein biomarker and therapeutic target for colorectal cancer progression: Evidence from immune infiltration and bioinformatic analyses

Colorectal cancer (CRC) remains a major global health challenge, with its underlying molecular mechanisms, particularly the role of FOXM1, not yet fully understood. This study employed an integrated approach combining bioinformatics along with experimental validation to explore the role of FOXM1 in CRC. Using advanced computational tools and experimental techniques, we aimed to clarify the biological significance of FOXM1 and its potential impact on CRC progression and treatment. Bioinformatic analyses, including pan-cancer views, mRNA expression analysis, immune infiltrations, pathway enrichment, and functional annotations, highlighted the oncogenic potential of FOXM1 in CRC. Protein and gene expression analyses (western blot and qPCR) were conducted in HCT-116 and HT-29 cells. Platforms like GEPIA and UALCAN confirmed the diagnostic relevance of FOXM1, showing upregulated mRNA expression across various stages and metastasis. The influence of FOXM1 on immune cells, particularly CD4+, CD8+, and B cells, was significant, as revealed by immunohistochemistry. Protein-protein interaction analysis through STRING and CYTOSCAPE identified genes closely linked to FOXM1 in CRC. KEGG pathway enrichment suggested FOXM1's involvement in the p53 pathway, reinforcing its role in oncogenesis. Experimental validation confirmed elevated FOXM1 expression in HCT-116 and HT-29 cells. In summary, this study indicates that targeting FOXM1 could be a promising therapeutic strategy in CRC, emphasizing its importance in the molecular landscape of cancer progression.

The role of kinesin superfamily proteins in hepatocellular carcinoma

The most prevalent form of primary liver cancer, hepatocellular carcinoma (HCC) poses a significant global health challenge due to its limited therapeutic options. Researchers are currently focused on the complex molecular landscape that governs the initiation and progression of HCC in order to identify new avenues for diagnosis, prognosis, and treatment. In the context of HCC, the Kinesin Superfamily Proteins (KIFs) have become critical regulators of cellular processes, prompting a growing interest in their function among the diverse array of molecular actors implicated in cancer. The KIFs, a family of microtubule-based molecular motors, are renowned for their essential roles in the dynamics of mitotic spindles and intracellular transport. Beyond their well-established functions in normal cellular physiology, emerging evidence indicates that dysregulation of KIFs significantly contributes to the pathogenesis of HCC. Novel therapeutic targets and diagnostic markers are revealed through the unique opportunity to comprehend the complex interplay between KIFs and the molecular events that drive HCC.

FOXM1/DEPDC1 feedback loop promotes hepatocarcinogenesis and represents promising targets for cancer therapy

Forkhead box M1 (FOXM1) is a key regulator of mitosis and is identified as an oncogene involved in several kinds of human malignancies. However, how it induces carcinogenesis and related therapeutic approaches remains not fully understood. In this study, we aimed to identify a regulatory axis involving FOXM1 and its target gene DEP domain containing 1 (DEPDC1) and investigate their biological functions. FOXM1 bound to the promoter and transcriptionally induced DEPDC1 expression, in turn, DEPDC1 physically interacted with FOXM1, promoted its nuclear translocation, and reinforced its transcriptional activities. The FOXM1/DEPDC1 axis was indispensable for cancer cells, as evidenced by the fact that DEPDC1 rescued cell growth inhibition caused by FOXM1 knockdown, and silencing DEPDC1 efficiently attenuated tumor growth in a murine hepatocellular carcinoma model. Furthermore, strong positive associations between FOXM1/DEPDC1 axis and poor clinical outcome were observed in human hepatocellular carcinoma samples, further indicating their significance for hepatocarcinogenesis. Finally, we attempted to exploit immunotherapy approaches to target the FOXM1/DEPDC1 axis. Several HLA-A24:02-restricted T-cell epitopes targeting FOXM1 or DEPDC1 were identified through bioinformatic analysis. Then, T cell receptor (TCR)-engineered T cells targeting FOXM1262-270 or DEPDC1294-302 were successfully established and proved to efficiently eradicate tumor cells. Our findings highlight the significance of the FOXM1/DEPDC1 axis in the process of oncogenesis and indicate their potential as immunotherapy targets.

FOXM1 transcriptional regulation

FOXM1 is a key transcriptional regulator involved in various biological processes in mammals, including carbohydrate and lipid metabolism, aging, immune regulation, development, and disease. Early studies have shown that FOXM1 acts as an oncogene by regulating cell proliferation, cell cycle, migration, metastasis, and apoptosis, as well as genes related to diagnosis, treatment, chemotherapy resistance, and prognosis. Researchers are increasingly focusing on FOXM1 functions in tumor microenvironment, epigenetics, and immune infiltration. However, researchers have not comprehensively described FOXM1's involvement in tumor microenvironment shaping, epigenetics, and immune cell infiltration. Here we review the role of FOXM1 in the formation and development of malignant tumors, and we will provide a comprehensive summary of the role of FOXM1 in transcriptional regulation, interacting proteins, tumor microenvironment, epigenetics, and immune infiltration, and suggest areas for further research.

LncRNA SH3PXD2A-AS1 facilitates cisplatin resistance in non-small cell lung cancer by regulating FOXM1 succinylation

BACKGROUND

Long noncoding RNAs (lncRNAs) play vital regulatory functions in non-small cell lung cancer (NSCLC). Cisplatin (DDP) resistance has significantly decreased the effectiveness of DDP-based chemotherapy in NSCLC patients. This study aimed to investigate the effects of SH3PXD2A antisense RNA 1 (SH3PXD2A-AS1) on DDP resistance in NSCLC.

METHODS

Proliferation and apoptosis of DDP-resistant NSCLC cells were detected using cell counting kit-8 and flow cytometry assays. The interaction between SH3PXD2A-AS1 and sirtuin 7 (SIRT7) was assessed using co-immunoprecipitation (Co-IP), RNA pull-down, RNA immunoprecipitation (RIP), RNA fluorescence in situ hybridization, and immunofluorescence assays, while succinylation (SUCC) of Forkhead Box M1 (FOXM1) was analyzed by IP and Western blot assays. The role of SH3PXD2A-AS1 in vivo was explored using a xenografted tumor model.

RESULTS

Expression of SH3PXD2A-AS1 was found elevated in DDP-resistant NSCLC cells, while it's knocking down translated into suppression of cell viability and promotion of apoptosis. Moreover, silencing of SH3PXD2A-AS1 resulted in decreased FOXM1 protein level and enhanced FOXM1-SUCC protein level. The SIRT7 was found to interact with FOXM1, translating into inhibition of FOXM1 SUCC at the K259 site in human embryonic kidney (HEK)-293T cells. Overexpressing of SIRT7 reversed the increase of FOXM1-SUCC protein level and apoptosis, and the decrease of cell viability induced by silencing of SH3PXD2A-AS1. In tumor-bearing mice, SH3PXD2A-AS1 inhibition suppressed tumor growth and the protein levels of Ki67, SIRT7, and FOXM1.

CONCLUSION

SH3PXD2A-AS1 promoted DDP resistance in NSCLC cells by regulating FOXM1 SUCC via SIRT7, offering a promising therapeutic approach for NSCLC.

Huaier enhances the tumor-killing effect and reverses gemcitabine-induced stemness by suppressing FoxM1

BACKGROUND

Gemcitabine is the first-line chemotherapy drug that can easily cause chemotherapy resistance. Huaier is a traditional Chinese medicine and shows an antitumor effect in pancreatic cancer, but whether it can enhance the gemcitabine chemotherapeutic response and the potential mechanism remain unknown.

PURPOSE

This study was performed to explore the effect of Huaier in promoting the tumor-killing effect of gemcitabine and elucidate the possible mechanism in pancreatic cancer.

METHODS

Cell Counting Kit-8 assays and colony formation assays were used to detect proliferation after different treatments. Protein coimmunoprecipitation was applied to demonstrate protein interactions. Nuclear protein extraction and immunofluorescence were used to confirm the intracellular localization of the proteins. Western blotting was performed to detect cell proliferation-related protein expression or cancer stem cell-associated protein expression. Sphere formation assays and flow cytometry were used to assess the stemness of pancreatic cancer cells. The in vivo xenograft model was used to confirm the inhibitory effect under physiological conditions, and immunohistochemistry was used to detect protein expression.

RESULTS

Huaier suppressed the proliferation and stem cell-like properties of pancreatic cancer cells. We found that Huaier suppressed the expression of forkhead box protein M1 (FoxM1). In addition, Huaier inhibited FoxM1 function by blocking its nuclear translocation. Treatment with Huaier reversed the stemness induced by gemcitabine in a FoxM1-dependent manner. Furthermore, we verified the above results by an in vivo study, which reached the same conclusion as those in vitro.

CONCLUSION

Overall, this study illustrates that Huaier augments the tumor-killing effect of gemcitabine through suppressing the stemness induced by gemcitabine in a FoxM1-dependent way. These results indicate that Huaier can be applied to overcome gemcitabine resistance.

A new tandem repeat-enriched lncRNA XLOC_008672 promotes gastric carcinogenesis by regulating G3BP1 expression

Aberrant expression of forkhead box transcription factor 1 (FOXM1) plays critical roles in a variety of human malignancies and predicts poor prognosis. However, little is known about the crosstalk between FOXM1 and long noncoding RNAs (lncRNAs) in tumorigenesis. The present study identifies a previously uncharacterized lncRNA XLOC_008672 in gastric cancer (GC), which is regulated by FOXM1 and possesses multiple copies of tandem repetitive sequences. LncRNA microarrays are used to screen differentially expressed lncRNAs in FOXM1 knockdown GC cells, and then the highest fold downregulation lncRNA XLOC_008672 is screened out. Sequence analysis reveals that the new lncRNA contains 62 copies of 37-bp tandem repeats. It is transcriptionally activated by FOXM1 and functions as a downstream effector of FOXM1 in GC cells through in vitro and in vivo functional assays. Elevated expression of XLOC_008672 is found in GC tissues and indicates worse prognosis. Mechanistically, XLOC_008672 can bind to small nuclear ribonucleoprotein polypeptide A (SNRPA), thereby enhancing mRNA stability of Ras-GTPase-activating protein SH3 domain-binding protein 1 (G3BP1) and, consequently, facilitating GC cell proliferation and migration. Our study discovers a new uncharacterized lncRNA XLOC_008672 involved in GC carcinogenesis and progression. Targeting FOXM1/XLOC_008672/SNRPA/G3BP1 signaling axis might be a promising therapeutic strategy for GC.

Meningioma achieves malignancy and erastin-induced ferroptosis resistance through FOXM1-AURKA-NRF2 axis

The oncogene Aurora kinase A (AURKA) has been implicated in various tumor, yet its role in meningioma remains unexplored. Recent studies have suggested a potential link between AURKA and ferroptosis, although the underlying mechanisms are unclear. This study presented evidence of AURKA upregulation in high grade meningioma and its ability to enhance malignant characteristics. We identified AURKA as a suppressor of erastin-induced ferroptosis in meningioma. Mechanistically, AURKA directly interacted with and phosphorylated kelch-like ECH-associated protein 1 (KEAP1), thereby activating nuclear factor erythroid 2 related factor 2 (NFE2L2/NRF2) and target genes transcription. Additionally, forkhead box protein M1 (FOXM1) facilitated the transcription of AURKA. Suppression of AURKA, in conjunction with erastin, yields significant enhancements in the prognosis of a murine model of meningioma. Our study elucidates an unidentified mechanism by which AURKA governs ferroptosis, and strongly suggests that the combination of AURKA inhibition and ferroptosis-inducing agents could potentially provide therapeutic benefits for meningioma treatment.

The splicing factor WBP11 mediates MCM7 intron retention to promote the malignant progression of ovarian cancer

Accumulating studies suggest that splicing factors play important roles in many diseases including human cancers. Our study revealed that WBP11, a core splicing factor, is highly expressed in ovarian cancer (OC) tissues and associated with a poor prognosis. WBP11 inhibition significantly impaired the proliferation and mobility of ovarian cancer cells in vitro and in vivo. Furthermore, FOXM1 transcriptionally activated WBP11 expression by directly binding to its promoter in OC cells. Importantly, RNA-seq and alternative splicing event analysis revealed that WBP11 silencing decreased the expression of MCM7 by regulating intron 4 retention. MCM7 inhibition attenuated the increase in malignant behaviors of WBP11-overexpressing OC cells. Overall, WBP11 was identified as an oncogenic splicing factor that contributes to malignant progression by repressing intron 4 retention of MCM7 in OC cells. Thus, WBP11 is an oncogenic splicing factor with potential therapeutic and prognostic implications in OC.

The Promise of Combination Therapies with FOXM1 Inhibitors for Cancer Treatment

Forkhead box M1 (FOXM1) is a transcription factor in the forkhead (FOX) family, which is required for cellular proliferation in normal and neoplastic cells. FOXM1 is highly expressed in many different cancers, and its expression is associated with a higher tumor stage and worse patient-related outcomes. Abnormally high expression of FOXM1 in cancers compared to normal tissue makes FOXM1 an attractive target for pharmacological inhibition. FOXM1-inhibiting agents and specific FOXM1-targeted small-molecule inhibitors have been developed in the lab and some of them have shown promising efficacy and safety profiles in mouse models. While the future goal is to translate FOXM1 inhibitors to clinical trials, potential synergistic drug combinations can maximize anti-tumor efficacy while minimizing off-target side effects. Hence, we discuss the rationale and efficacy of all previously studied drug combinations with FOXM1 inhibitors for cancer therapies.

USP39 interacts with SIRT7 to promote cervical squamous cell carcinoma by modulating autophagy and oxidative stress via FOXM1

BACKGROUND

Sirtuin 7 (SIRT7) is an oncogene that promotes tumor progression in various malignancies, however, its role and regulatory mechanism in cervical squamous cell carcinoma (CSCC) is unknown. Herein, we attempted to investigate the functional role and molecular mechanism of SIRT7 underlying CSCC progression.

METHODS

SIRT7 expression was evaluated in CSCC cells using various assays. We then used a series of function gain-and-loss experiments to determine the role of SIRT7 in CSCC progression. Furthermore, mechanism experiments were conducted to assess the interaction between SIRT7/USP39/FOXM1 in CSCC cells. Additionally, rescue assays were conducted to explore the regulatory function of USP39/FOXM1 in CSCC cellular processes.

RESULTS

SIRT7 was highly expressed in CSCC patient tissues and cell lines. SIRT7 deficiency showed significant repression on the proliferation, and autophagy of CSCC cells in vitro and tumorigenesis in vivo. Similarly, apoptosis and ROS production in CSCC cells were accelerated after the SIRT7 knockdown. Moreover, SIRT7 and USP39 were found colocalized in the cell nucleus. Interestingly, SIRT7 was revealed to deacetylate USP39 to promote its protein stability in CSCC cells. USP39 protein was also verified to be upregulated in CSCC tissues and cells. USP39 silencing showed suppressive effects on CSCC cell growth. Mechanistically, USP39 was revealed to upregulate SIRT7 by promoting the transcriptional activity of FOXM1. Rescue assays also indicated that SIRT7 promoted autophagy and inhibited ROS production in CSCC cells by regulating USP39/FOXM1.

CONCLUSION

The SIRT7/USP39/FOXM1 positive feedback network regulates autophagy and oxidative stress in CSCC, thus providing a new direction for CSCC-targeted therapy.

Transcription factor FOXM1 promotes hepatocellular carcinoma malignant progression through activation of the WNT pathway by binding to SETDB1

BACKGROUND

FOXM1 is a transcription factor confirmed by studies to promote the development of hepatocellular carcinoma (HCC) and various other cancers, yet the molecular mechanism remains rather enigmatic. This study attempted to unveil the function and regulatory mechanism of FOXM1 in the progression of HCC.

METHODS

Bioinformatics methods first analyzed the expression of FOXM1 in HCC tissues and then screened target genes downstream of FOXM1. Possible pathways of the target gene were specified through Gene Set Enrichment Analysis (GSEA). After using qRT-PCR to measure the expression of FOXM1 and its downstream regulatory gene SETDB1 in HCC tissues, ChIP and dual-luciferase assays were employed and verified the binding relationship between FOXM1 and the promoter of SETDB1. Then the effects of the FOXM1/SETDB1/Wnt pathway on the proliferation, migration, and invasion of HCC cells were profiled by CCK-8, colony formation, wound healing, and transwell assays. WNT and EMT-related protein expression levels were detected by western blot and immunofluorescence assay, respectively.

RESULTS

The bioinformatics prediction showed that SETDB1 was the target downstream of FOXM1, and their binding relationship was verified by ChIP and dual-luciferase assays. Cell experiments showed that FOXM1 could enhance the proliferative, migratory, and invasive abilities of HCC cells through binding to SETDB1. Rescue assay suggested that the activation of key genes of the WNT pathway and EMT-related genes were part of the regulatory mechanism that FOXM1 bound to SETDB1.

CONCLUSION

This study found that FOXM1 could bind with SETDB1 and hence activate the WNT signaling pathway to promote the malignant progression of HCC. It indicated that FOXM1 could be the possible target for treating HCC.

The role of FoxM1 in immune cells

Forkhead box M1 (FoxM1), a proliferation specific transcriptional modulator, plays a principal role in many physiological and pathological processes. FoxM1-mediated oncogenic processes have been well addressed. However, functions of FoxM1 in immune cells are less summarized. The literatures about the expression of FoxM1 and its regulation on immune cells were searched on PubMed and Google Scholar. In this review, we provide an overview on the roles of FoxM1 in regulating functions of immune cells, including T cells, B cells, monocytes, macrophages, and dendritic cells, and discuss their contributions to diseases.

TRIM6 silencing for inhibiting growth and angiogenesis of gliomas by regulating VEGFA

Gliomas are the highest prevalent primary central nervous system (CNS) cancers with poor overall survival rate. There is an urgent need to conduct more research into molecular therapies targeting critical elements of gliomas. This study herein targeted to assess the impact of tripartite motif protein 6 (TRIM6) on gliomas. Using public databases, we found the increased TRIM6 expression in tissues of glioma which was linked with worst overall survival. Silencing TRIM6 promoted glioma cell proliferation, migration and angiogenesis, suggesting the promoting effects of TRIM6 on gliomas. Knockdown of TRIM6 expression downregulated the expression levels of Forkhead box M1 (FOXM1) and vascular endothelial growth factor A (VEGFA) in glioma cells. Afterwards, impact of TRIM6 on VEGFA expression was regulated by FOXM1. VEGFA overexpression reversed the decreased abilities of glioma cell proliferation, migration and angiogenesis caused by silencing TRIM6. Furthermore, we also found that TRIM6 promoted the growth of gliomas in the xenograft mouse model. In summary, the expression of TRIM6 was increased which was related to poor prognosis of glioma patients. TRIM6 promoted glioma cell proliferation, migration and angiogenesis through the FOXM1-VEGFA pathway. Therefore, TRIM6 carries capacity to be explored as a novel therapeutic target in clinical.

RNF112-mediated FOXM1 ubiquitination suppresses the proliferation and invasion of gastric cancer

Forkhead box M1 (FOXM1) plays a critical role in development physiologically and tumorigenesis pathologically. However, insufficient efforts have been dedicated to exploring the regulation, in particular the degradation of FOXM1. Here, the ON-TARGETplus siRNA library targeting E3 ligases was used to screen potential candidates to repress FOXM1. Of note, mechanism study revealed that RNF112 directly ubiquitinates FOXM1 in gastric cancer, resulting in a decreased FOXM1 transcriptional network and suppressing the proliferation and invasion of gastric cancer. Interestingly, the well-established small-molecule compound RCM-1 significantly enhanced the interaction between RNF112 and FOXM1, which further promoted FOXM1 ubiquitination and subsequently exerted promising anticancer effects in vitro and in vivo. Altogether, we demonstrate that RNF112 suppresses gastric cancer progression by ubiquitinating FOXM1 and highlight the RNF112/FOXM1 axis serves as both prognosis biomarker and therapeutic target in gastric cancer.

HMGA1 and FOXM1 Cooperate to Promote G2/M Cell Cycle Progression in Cancer Cells

HMGA1 is a chromatin-binding protein and performs its biological function by remodeling chromatin structure or recruiting other transcription factors. However, the role of abnormally high level of HMGA1 in cancer cells and its regulatory mechanism still require further investigation. In this study, we performed a prognostic analysis and showed that high level of either HMGA1 or FOXM1 was associated with poor prognosis in various cancers based on the TCGA database. Furthermore, the expression pattern of HMGA1 and FOXM1 showed a significant strong positive correlation in most type of cancers, especially lung adenocarcinoma, pancreatic cancer and liver cancer. Further analysis of the biological effects of their high correlation in cancers suggested that cell cycle was the most significant related pathway commonly regulated by HMGA1 and FOXM1. After knockdown of HMGA1 and FOXM1 by specific siRNAs, an obvious increased G2/M phase was observed in the siHMGA1 and siFOXM1 groups compared to the siNC group. The expression levels of key G2/M phase regulatory genes PLK1 and CCNB1 were significantly downregulated. Importantly, HMGA1 and FOXM1 were identified to form a protein complex and co-located in the nucleus based on co-immunoprecipitation and immunofluorescence staining, respectively. Thus, our results provide the basic evidence that HMGA1 and FOXM1 cooperatively accelerate cell cycle progression by up-regulating PLK1 and CCNB1 to promote cancer cell proliferation.

Comprehensive analysis of FOXM1 immune infiltrates, m6a, glycolysis and ceRNA network in human hepatocellular carcinoma

Background

Forkhead box M1 (FOXM1) is a member of the Forkhead box (Fox) transcription factor family. It regulates cell mitosis, cell proliferation, and genome stability. However, the relationship between the expression of FOXM1 and the levels of m6a modification, immune infiltration, glycolysis, and ketone body metabolism in HCC has yet to be fully elucidated.

Methods

Transcriptome and somatic mutation profiles of HCC were downloaded from the TCGA database. Somatic mutations were analyzed by maftools R package and visualized in oncoplots. GO, KEGG and GSEA function enrichment was performed on FOXM1 co-expression using R. We used Cox regression and machine learning algorithms (CIBERSORT, LASSO, random forest, and SVM-RFE) to study the prognostic value of FOXM1 and immune infiltrating characteristic immune cells in HCC. The relationship between FOXM1 and m6A modification, glycolysis, and ketone body metabolism were analyzed by RNA-seq and CHIP-seq. The competing endogenous RNA (ceRNA) network construction relies on the multiMiR R package, ENCORI, and miRNET platforms.

Results

FOXM1 is highly expressed in HCC and is associated with a poorer prognosis. At the same time, the expression level of FOXM1 is significantly related to the T, N, and stage. Subsequently, based on the machine learning strategies, we found that the infiltration level of T follicular helper cells (Tfh) was a risk factor affecting the prognosis of HCC patients. The high infiltration of Tfh was significantly related to the poor overall survival rate of HCC. Besides, the CHIP-seq demonstrated that FOXM1 regulates m6a modification by binding to the promoter of IGF2BP3 and affects the glycolytic process by initiating the transcription of HK2 and PKM in HCC. A ceRNA network was successfully obtained, including FOXM1 - has-miR-125-5p - DANCR/MIR4435-2HG ceRNA network related to the prognosis of HCC.

Conclusion

Our study implicates that the aberrant infiltration of Tfh associated with FOXM1 is a crucial prognostic factor for HCC patients. FOXM1 regulates genes related to m6a modification and glycolysis at the transcriptional level. Furthermore, the specific ceRNA network can be used as a potential therapeutic target for HCC.

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.

CircRNAs: emerging factors for regulating glucose metabolism in colorectal cancer

Colorectal cancer is a malignant disease with a high incidence and low survival rate, and the effectiveness of traditional treatments, such as surgery and radiotherapy, is very limited. CircRNAs, a kind of stable endogenous circular RNA, generally function by sponging miRNAs and binding or translating proteins. CircRNAs have been identified to play an important role in regulating the proliferation and metabolism of CRC. In recent years, many reports have indicated that by regulating the expression of glycolysis-related proteins, such as GLUT1 and HK2, or directly translating proteins, circRNAs can promote the Warburg effect in cancer cells, thereby driving CRC metabolism. Moreover, the Warburg effect increases lactate production in cancer cells and promotes acidification of the TME, which further drives cancer progression. In this review, we summarized the remarkable role of circRNAs in regulating glucose metabolism in CRC in recent years, which might be useful for finding new targets for the clinical treatment of CRC.

USP21 Promotes the Progression of Nasopharyngeal Carcinoma by Regulating FOXM1

The purpose of this work was to explore the molecular mechanisms by which USP21 regulates nasopharyngeal carcinoma tumor growth and cancer cell stemness. In this study, the USP21 transcript data was obtained from TCGA database. Then, qPCR and western blot tests revealed that, in contrast to normal tissue or normal nasopharyngeal epithelial cells, the expression of USP21 was greater in nasopharyngeal carcinoma tissues or cell lines, respectively. CCK-8 and EdU immunofluorescent staining assays revealed that USP21 promoted the proliferation of nasopharyngeal carcinoma cells. Meanwhile, scratch and transwell assays showed that USP21 facilitated migration and invasion of nasopharyngeal carcinoma cells. Sphere formation assay was performed on nasopharyngeal carcinoma cells after knockdown of USP21, which revealed that knockdown of USP21 inhibited the stemness profiles of nasopharyngeal carcinoma cells. Then, the western blot assays indicated that knockdown of USP21 in nasopharyngeal carcinoma cells would inhibit FOXM1 expression, and overexpression of FOXM1 could reverse the cell proliferation ability, cell migration and invasion ability, and cell stemness profiles. Finally, a nasopharyngeal xenograft model suggested that USP21 facilitated tumor growth in mice. These findings proved that USP21 promoted tumor growth and cancer cell stemness in nasopharyngeal carcinoma by regulating FOXM1.

Improving anti-tumor efficacy of low-dose Vincristine in rhabdomyosarcoma via the combination therapy with FOXM1 inhibitor RCM1

Rhabdomyosarcoma (RMS) is a highly metastatic soft-tissue sarcoma that often develops resistance to current therapies, including vincristine. Since the existing treatments have not significantly improved survival, there is a critical need for new therapeutic approaches for RMS patients. FOXM1, a known oncogene, is highly expressed in RMS, and is associated with the worst prognosis in RMS patients. In the present study, we found that the combination treatment with specific FOXM1 inhibitor RCM1 and low doses of vincristine is more effective in increasing apoptosis and decreasing RMS cell proliferation in vitro compared to single drugs alone. Since RCM1 is highly hydrophobic, we developed innovative nanoparticle delivery system containing poly-beta-amino-esters and folic acid (NP^FA), which efficiently delivers RCM1 to mouse RMS tumors in vivo. The combination of low doses of vincristine together with intravenous administration of NP^FA nanoparticles containing RCM1 effectively reduced RMS tumor volumes, increased tumor cell death and decreased tumor cell proliferation in RMS tumors compared to RCM1 or vincristine alone. The combination therapy was non-toxic as demonstrated by liver metabolic panels using peripheral blood serum. Using RNA-seq of dissected RMS tumors, we identified Chac1 as a uniquely downregulated gene after the combination treatment. Knockdown of Chac1 in RMS cells in vitro recapitulated the effects of the combination therapy. Altogether, combination treatment with low doses of vincristine and nanoparticle delivery of FOXM1 inhibitor RCM1 in a pre-clinical model of RMS has superior anti-tumor effects and decreases CHAC1 while reducing vincristine toxicity.

CKAP4-mediated activation of FOXM1 via phosphorylation pathways regulates malignant behavior of glioblastoma cells

OBJECTIVE

CKAP4 (Cytoskeleton Associated Protein 4) has been reported as an important regulator of carcinogenesis. A great deal of uncertainty still surrounds the possible molecular mechanism of CKAP4 involvement in GBM. We aimed to specifically elucidate the putative role of CKAP4 in the development of GBM.

METHODS

We identified divergent proteomics landscapes of GBM and adjacent normal tissues using mass spectrometry-based label-free quantification. Bioinformatics analysis of differentially expressed proteins (DEPs) led to the identification of CKAP4 as a hub gene. Based on the Chinese Glioma Genome Atlas data, we characterized the elevated expression of CKAP4 in GBM and developed a prognostic model. The influence of CKAP4 on malignant behavior of GBM was detected in vitro and vivo, as well as its downstream target and signaling pathways.

RESULTS

The prognosis model displayed accuracy and reliability for the probability of survival of patients with gliomas. CKAP4 knockdown remarkably reduced the malignant potential of GBM cells, whereas its overexpression reversed these effects in GBM cells and xenograft mice. Moreover, we demonstrated that overexpression of CKAP4 leads to increased FOXM1 (Forkhead Box M1) expression in conjunction with an increased level of AKT and ERK phosphorylation. Inhibition of both pathways had synergistic effects, resulting in greater effectiveness of inhibition. CKAP4 could reverse the deregulation of FOXM1 triggered by inhibition of AKT and ERK signaling.

CONCLUSIONS

This is the first study to reveal a CKAP4-FOXM1 signaling cascade that contributes to the malignant phenotype of GBMs. The CKAP4-based prognostic model would facilitate individualized treatment decisions for glioma patients.

FOXM1-Mediated Regulation of Reactive Oxygen Species and Radioresistance in Oral Squamous Cell Carcinoma Cells

Radioresistance is a major obstacle to the successful treatment of oral squamous cell carcinoma (OSCC). To help overcome this issue, we have developed clinically relevant radioresistant (CRR) cell lines generated by irradiating parental cells over time, which are useful for OSCC research. In the present study, we conducted gene expression analysis using CRR cells and their parental lines to investigate the regulation of radioresistance in OSCC cells. Based on gene expression changes over time in CRR cells and parental lines subjected to irradiation, forkhead box M1 (FOXM1) was selected for further analysis in terms of its expression in OSCC cell lines, including CRR cell lines and clinical specimens. We suppressed or upregulated the expression of FOXM1 in OSCC cell lines, including CRR cell lines, and examined radiosensitivity, DNA damage, and cell viability under various conditions. The molecular network regulating radiotolerance was also investigated, especially the redox pathway, and the radiosensitizing effect of FOXM1 inhibitors was examined as a potential therapeutic application. We found that FOXM1 was not expressed in normal human keratinocytes but was expressed in several OSCC cell lines. The expression of FOXM1 was upregulated in CRR cells compared with that detected in the parental cell lines. In a xenograft model and clinical specimens, FOXM1 expression was upregulated in cells that survived irradiation. FOXM1-specific small interfering RNA (siRNA) treatment increased radiosensitivity, whereas FOXM1 overexpression decreased radiosensitivity, and DNA damage was altered significantly under both conditions, as well as the levels of redox-related molecules and reactive oxygen species production. Treatment with the FOXM1 inhibitor thiostrepton had a radiosensitizing effect and overcame radiotolerance in CRR cells. According to these results, the FOXM1-mediated regulation of reactive oxygen species could be a novel therapeutic target for the treatment of radioresistant OSCC; thus, treatment strategies targeting this axis might overcome radioresistance in this disease.

PVECs-Derived Exosomal microRNAs Regulate PASMCs via FoxM1 Signaling in IUGR-induced Pulmonary Hypertension

Background Intrauterine growth restriction (IUGR) is closely related to systemic or pulmonary hypertension (PH) in adulthood. Aberrant crosstalk between pulmonary vascular endothelial cells (PVECs) and pulmonary arterial smooth muscle cells (PASMCs) that is mediated by exosomes plays an essential role in the progression of PH. FoxM1 (Forkhead box M1) is a key transcription factor that governs many important biological processes. Methods and Results IUGR-induced PH rat models were established. Transwell plates were used to coculture PVECs and PASMCs. Exosomes were isolated from PVEC-derived medium, and a microRNA (miRNA) screening was proceeded to identify effects of IUGR on small RNAs enclosed within exosomes. Dual-Luciferase assay was performed to validate the predicted binding sites of miRNAs on FoxM1 3' untranslated region. FoxM1 inhibitor thiostrepton was used in IUGR-induced PH rats. In this study, we found that FoxM1 expression was remarkably increased in IUGR-induced PH, and PASMCs were regulated by PVECs through FoxM1 signaling in a non-contact way. An miRNA screening showed that miR-214-3p, miR-326-3p, and miR-125b-2-3p were downregulated in PVEC-derived exosomes of the IUGR group, which were associated with overexpression of FoxM1 and more significant proliferation and migration of PASMCs. Dual-Luciferase assay demonstrated that the 3 miRNAs directly targeted FoxM1 3' untranslated region. FoxM1 inhibition blocked the PVECs-PASMCs crosstalk and reversed the abnormal functions of PASMCs. In vivo, treatment with thiostrepton significantly reduced the severity of PH. Conclusions Transmission of exosomal miRNAs from PVECs regulated the functions of PASMCs via FoxM1 signaling, and FoxM1 may serve as a potential therapeutic target in IUGR-induced PH.

The anaphase-promoting complex/cyclosome co-activator, Cdh1, is a novel target of human papillomavirus 16 E7 oncoprotein in cervical oncogenesis

The transforming properties of the high-risk human papillomavirus (HPV) E7 oncoprotein are indispensable for driving the virus life cycle and pathogenesis. Besides inactivation of the retinoblastoma family of tumor suppressors as part of its oncogenic endeavors, E7-mediated perturbations of eminent cell cycle regulators, checkpoint proteins and proto-oncogenes are considered to be the tricks of its transformative traits. However, many such critical interactions are still unknown. In the present study, we have identified the anaphase-promoting complex/cyclosome (APC) co-activator, Cdh1, as a novel interacting partner and a degradation target of E7. We found that HPV16 E7-induced inactivation of Cdh1 promoted abnormal accumulation of multiple Cdh1 substrates. Such a mode of deregulation possibly contributes to HPV-mediated cervical oncogenesis. Our mapping studies recognized the C-terminal zinc-finger motif of E7 to associate with Cdh1 and interfere with the timely degradation of FoxM1, a bona fide Cdh1 substrate and a potent oncogene. Importantly, the E7 mutant with impaired interaction with Cdh1 exhibited defects in its ability for overriding typical cell cycle transition and oncogenic transformation, thereby validating the functional and pathological significance of the E7-Cdh1 axis during cervical carcinoma progression. Altogether, the findings from our study discover a unique nexus between E7 and APC/C-Cdh1, thereby adding to our understanding of the mechanism of E7-induced carcinogenesis and provide a promising target for the management of cervical carcinoma.

c-FLIP promotes drug resistance in non-small-cell lung cancer cells via upregulating FoxM1 expression

The forkhead box M1 (FoxM1) protein, a transcription factor, plays critical roles in regulating tumor growth and drug resistance, while cellular FLICE-inhibitory protein (c-FLIP), an anti-apoptotic regulator, is involved in the ubiquitin-proteasome pathway. In this study, we investigated the effects of c-FLIP on the expression and ubiquitination levels of FoxM1 along with drug susceptibility in non-small-cell lung cancer (NSCLC) cells. We first showed that the expression levels of FoxM1 and c-FLIP were increased and positively correlated (R2 = 0.1106, P < 0.0001) in 90 NSCLC samples. The survival data from prognostic analysis demonstrated that high expression of c-FLIP and/or FoxM1 was related to poor prognosis in NSCLC patients and that the combination of FoxM1 and c-FLIP could be a more precise prognostic biomarker than either alone. Then, we explored the functions of c-FLIP/FoxM1 in drug resistance in NSCLC cell lines and a xenograft mouse model in vivo. We showed that c-FLIP stabilized FoxM1 by inhibiting its ubiquitination, thus upregulated the expression of FoxM1 at post-transcriptional level. In addition, a positive feedback loop composed of FoxM1, β-catenin and p65 also participated in c-FLIP-FoxM1 axis. We revealed that c-FLIP promoted the resistance of NSCLC cells to thiostrepton and osimertinib by upregulating FoxM1. Taken together, these results reveal a new mechanism by which c-FLIP regulates FoxM1 and the function of this interaction in the development of thiostrepton and osimertinib resistance. This study provides experimental evidence for the potential therapeutic benefit of targeting the c-FLIP-FoxM1 axis for lung cancer treatment.

Activation of Autophagy Induces Monocrotaline-Induced Pulmonary Arterial Hypertension by FOXM1-Mediated FAK Phosphorylation

PURPOSE

It has been shown that activation of autophagy promotes the development of pulmonary arterial hypertension (PAH). Meanwhile, forkhead box M1 (FOXM1) has been found to induce autophagy in several types of cancer. However, it is still unclear whether FOXM1 mediates autophagy activation in PAH, and detailed mechanisms responsible for these processes are indefinite.

METHOD

PAH was induced by a single intraperitoneal injection of monocrotaline (MCT) to rats. The right ventricle systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), percentage of medial wall thickness (%MT), α-smooth muscle actin (α-SMA) staining, and Ki67 staining were performed to evaluate the development of PAH. The protein levels of FOXM1, phospho-focal adhesion kinase (p-FAK), FAK, and LC3B were determined by immunoblotting or immunohistochemistry.

RESULTS

FOXM1 protein level and FAK activity were significantly increased in MCT-induced PAH rats, this was accompanied with the activation of autophagy. Pharmacological inhibition of FOXM1 or FAK suppressed MCT-induced autophagy activation, decreased RVSP, RVHI and %MT in MCT-induced PAH rats, and inhibited the proliferation of pulmonary arterial smooth muscle cells and pulmonary vessel muscularization in MCT-induced PAH rats.

CONCLUSION

FOXM1 promotes the development of PAH by inducing FAK phosphorylation and subsequent activation of autophagy in MCT-treated rats.

Anticancer and Anti-Inflammatory Mechanisms of NOSH-Aspirin and Its Biological Effects

NOSH-Aspirin, which is generated from NO, H2S, and aspirin, affects a variety of essential pathophysiological processes, including anti-inflammatory, analgesic, antipyretic, antiplatelet, and anticancer properties. Although many people acknowledge the biological significance of NOSH-Aspirin and its therapeutic effects, the mechanism of action of NOSH-Aspirin and its regulation of tissue levels remains obscure. This is in part due to its chemical and physical features, which make processing and analysis difficult. This review focuses on the biological effects of NOSH-Aspirin and provides a comprehensive analysis to elucidate the mechanism underlying its disease-protective benefits.

Chalcone 9X Contributed to Repressing Glioma Cell Growth and Migration and Inducing Cell Apoptosis by Reducing FOXM1 Expression In Vitro and Repressing Tumor Growth In Vivo

Objective. Natural and synthetic chalcones played roles in inflammation and cancers. Chalcone 9X was an aromatic ketone that was found to inhibit cell growth of hepatic cancer and lung cancer cells. In this study, we wanted to investigate the functions of Chalcone 9X in glioma. Materials and Methods. Chemical Chalcone 9X was added in human glioma cell lines (U87 and T98G cells) and normal astrocyte cell lines (HA1800) with various concentrations (0 μmol/L, 20 μmol/L, 50 μmol/L, and 100 μmol/L). CCK-8 assay was used to measure cell viability. Flow cytometric assay was used to measure cell apoptotic rates. Wound healing assay and transwell assay were used to measure cell invasion. RT-PCR was used to detect relative mRNA expressions, and the protein expressions were detected by western blot (WB) and immunohistochemical staining (IHC). Finally, nude mouse xenograft assay was performed to prove the effects of Chalcone 9X in vivo. Results. Results revealed that Chalcone 9X treatment suppressed cell viability and cell migration capacity; it could also induce cell apoptosis in U87 and T98G cells with dose dependence. However, it had little cytotoxicity to normal astrocyte HA1800 cells. Moreover, Chalcone 9X treatment could repress the mRNA and protein expressions of FOXM1 in human glioma cell lines, which was an oncogene that could promote the progression and malignancy of glioma. In addition, FOXM1 overexpression dismissed the Chalcone 9X effects on cell proliferation, apoptosis, and migration in human glioma cell lines. Finally, in vivo assay showed that Chalcone 9X treatment repressed the expression of FOXM1, which inhibited the tumor growth of a xenograft model injected with U87 in nude mice. Conclusions. In all, we found that Chalcone 9X could suppress cell proliferation and migration and induce cell apoptosis in human glioma cells, while it has little cytotoxicity to normal astrocyte cells. Therefore, we uncovered a novel way that Chalcone 9X could inhibit FOXM1 expression and repress the progression and biofunctions of glioma cells, which might be a potential therapeutic drug for treating human glioma.

IFNα Potentiates Anti-PD-1 Efficacy by Remodeling Glucose Metabolism in the Hepatocellular Carcinoma Microenvironment

The overall response rate for anti-PD-1 therapy remains modest in hepatocellular carcinoma (HCC). We found that a combination of IFNα and anti-PD-1-based immunotherapy resulted in enhanced antitumor activity in patients with unresectable HCC. In both immunocompetent orthotopic and spontaneous HCC models, IFNα therapy synergized with anti-PD-1 and the combination treatment led to significant enrichment of cytotoxic CD27+CD8+ T cells. Mechanistically, IFNα suppressed HIF1α signaling by inhibiting FosB transcription in HCC cells, resulting in reduced glucose consumption capacity and consequentially establishing a high-glucose microenvironment that fostered transcription of the T-cell costimulatory molecule Cd27 via mTOR-FOXM1 signaling in infiltrating CD8+ T cells. Together, these data reveal that IFNα reprograms glucose metabolism within the HCC tumor microenvironment, thereby liberating T-cell cytotoxic capacities and potentiating the PD-1 blockade-induced immune response. Our findings suggest that IFNα and anti-PD-1 cotreatment is an effective novel combination strategy for patients with HCC.

SIGNIFICANCE

Our study supports a role of tumor glucose metabolism in IFNα-mediated antitumor immunity in HCC, and tumor-infiltrating CD27+CD8+ T cells may be a promising biomarker for stratifying patients for anti-PD-1 therapy. See related commentary by Kao et al., p. 1615. This article is highlighted in the In This Issue feature, p. 1599.

Integrated multi-omics characterization of KRAS mutant colorectal cancer

KRAS mutation is the most frequent oncogenic aberration in colorectal cancer (CRC). The molecular mechanism and clinical implications of KRAS mutation in CRC remain unclear and show high heterogeneity within these tumors. Methods: We harnessed the multi-omics data (genomic, transcriptomic, proteomic, and phosphoproteomic etc.) of KRAS-mutant CRC tumors and performed unsupervised clustering to identify proteomics-based subgroups and molecular characterization. Results: In-depth analysis of the tumor microenvironment by single-cell transcriptomic revealed the cellular landscape of KRAS-mutant CRC tumors and identified the specific cell subsets with KRAS mutation. Integrated multi-omics analyses separated the KRAS-mutant tumors into two distinct molecular subtypes, termed KRAS-M1 (KM1) and KRAS-M2 (KM2). The two subtypes had a similar distribution of mutated residues in KRAS (G12D/V/C etc.) but were characterized by distinct features in terms of prognosis, genetic alterations, microenvironment dysregulation, biological phenotype, and potential therapeutic approaches. Proteogenomic analyses revealed that the EMT, TGF-β and angiogenesis pathways were enriched in the KM2 subtype and that the KM2 subtype was associated with the mesenchymal phenotype-related CMS4 subtype, which indicated stromal invasion and worse prognosis. The KM1 subtype was characterized predominantly by activation of the cell cycle, E2F and RNA transcription and was associated with the chromosomal instability (CIN)-related ProS-E proteomic subtype, which suggested cyclin-dependent features and better survival outcomes. Moreover, drug sensitivity analyses based on three compound databases revealed subgroup-specific agents for KM1 and KM2 tumors. Conclusions: This study clarifies the molecular heterogeneity of KRAS-mutant CRC and reveals new biological subtypes and therapeutic possibilities for these tumors.

FOXM1 regulates glycolysis in nasopharyngeal carcinoma cells through PDK1

The transcription factor forkhead box M1 (FOXM1) is a well-known proto-oncogene that plays a significant role in the pathogenesis of various human cancers. However, the regulatory role and underlying mechanisms of FOXM1 in nasopharyngeal carcinoma (NPC) metabolism remain unclear. We demonstrated that FOXM1 could positively regulate glycolysis in NPC cells. Functional studies have shown that pyruvate dehydrogenase kinase 1 (PDK1) is involved in FOXM1-regulated lactate production, ATP generation and glycolysis. FOXM1 binds directly to the PDK1 promoter region and increases the expression of PDK1 at the transcriptional level, leading to the phosphorylation of pyruvate dehydrogenase (PDH) at serine 293, inhibiting its activity. Knocking down FOXM1 using specific short hairpin RNAs (shRNAs) can significantly decrease glycolysis and the expression of PDK1 in NPC cells. Furthermore, microenvironmental factors can increase the expression of FOXM1 by regulating hypoxia-inducible factor 1α (HIF-1α) expression. Clinical data and in vivo studies confirmed the positive roles of FOXM1/PDK1 in NPC proliferation and progression. In conclusion, our findings revealed that FOXM1 regulates glycolysis and proliferation of NPC through PDK1-mediated PDH phosphorylation. Therefore, targeting the FOXM1-PDK1 axis may be a potential therapeutic strategy for NPC.

TRIM56 Reduces Radiosensitization of Human Glioblastoma by Regulating FOXM1-Mediated DNA Repair

Recurrent glioblastoma is characterized by resistance to radiotherapy or chemotherapy. In this study, we investigated the role of TRIM56 in radiosensitization and its potential underlying molecular mechanism. TRIM56 expression levels were measured in glioblastoma tissues and cell lines by immunohistochemical staining, western blot, and qRT-PCR. MTT assay, colony formation assay, and TUNEL assay were used to investigate the effect of TRIM56 on cell viability, cell proliferation, and cell apoptosis. Co-immunoprecipitation was used to clarify the interaction between TRIM56 and FOXM1. Finally, tumor xenograft experiments were performed to analyze the effect of TRIM56 on tumor growth in vivo. The expression of TRIM56 was significantly increased in glioblastoma tissues and cell lines and its expression was associated with poor prognosis of patients with glioblastoma. Moreover, TRIM56 reduced the radiosensitivity of glioblastoma cells and promoted DNA repairment. Mechanistically, TRIM56 promoted FOXM1 protein level, enhanced the stability of FOXM1 by de-ubiquitination, and promoted DNA damage repair through FOXM1 in glioblastoma cells. TRIM56 could reduce the radiosensitivity of glioblastoma in vivo. TRIM56 may suppress the radiosensitization of human glioblastoma by regulating FOXM1-mediated DNA repair. Targeting the TRIM56 may be an effective method to reverse radiotherapy-resistant in glioblastoma recurrent.

FOXM1 Promotes Malignant Proliferation of Esophageal Squamous Cell Carcinoma Through Transcriptional Activating CDC6

Forkhead box M1 (FOXM1) is a proliferative transcription factor and plays a vital role in many cancers. However, the function and molecular mechanism of FOXM1 in esophageal squamous cell carcinoma (ESCC) remain poorly understood. Hence, we aim to clarify the molecular basis of FOXM1-mediated ESCC progression. In this study, bioinformatics analysis showed that FOXM1 was mainly involved in key signal pathways, including cell proliferation, cell cycle, and homologous recombination in ESCC, and predicted that CDC6 might be a potential regulatory target gene of FOXM1. The results revealed that FOXM1 and CDC6 were significantly overexpressed in ESCC tissue and cell line, and their expression was positively correlated. Further studies showed that FOXM1 directly transcriptionally activated CDC6 by binding to its promoter region in ESCC cells. Moreover, FOXM1 mediated ESCC cell proliferation by regulating CDC6 expression, which may be related to promoting G1-S phase transition of cell cycle. Taken together, FOXM1-CDC6 axis mediates ESCC malignant proliferation and may serve as a potential biological target for ESCC treatment.

FAM64A promotes HNSCC tumorigenesis by mediating transcriptional autoregulation of FOXM1

Head and neck squamous cell carcinoma (HNSCC) still lacks effective targeted treatment. Therefore, exploring novel and robust molecular targets is critical for improving the clinical outcome of HNSCC. Here, we reported that the expression levels of family with sequence similarity 64, member A (FAM64A) were significantly higher in HNSCC tissues and cell lines. In addition, FAM64A overexpression was found to be strongly associated with an unfavorable prognosis of HNSCC. Both in vitro and in vivo evidence showed that FAM64A depletion suppressed the malignant activities of HNSCC cells, and vice versa. Moreover, we found that the FAM64A level was progressively increased from normal to dysplastic to cancerous tissues in a carcinogenic 4-nitroquinoline-1-oxide mouse model. Mechanistically, a physical interaction was found between FAM64A and forkhead box protein M1 (FOXM1) in HNSCC cells. FAM64A promoted HNSCC tumorigenesis not only by enhancing the transcriptional activity of FOXM1, but also, more importantly, by modulating FOXM1 expression via the autoregulation loop. Furthermore, a positive correlation between FAM64A and FOXM1 was found in multiple independent cohorts. Taken together, our findings reveal a previously unknown mechanism behind the activation of FOXM1 in HNSCC, and FAM64A might be a promising molecular therapeutic target for treating HNSCC.

Construction of Bone Metastasis-Specific Regulation Network Based on Prognostic Stemness-Related Signatures in Prostate Cancer

Background

We planned to uncover the cancer stemness-related genes (SRGs) in prostate cancer (PCa) and its underlying mechanism in PCa metastasis.

Methods

We acquired the RNA-seq data of 406 patients with PCa from the TCGA database. Based on the mRNA stemness index (mRNAsi) calculated by one-class logistic regression (OCLR) algorithm, SRGs in PCa were extracted by WGCNA. Univariate and multivariate regression analyses were applied to uncover OS-associated SRGs. Gene Set Variation Analysis (GSVA), Gene Set Enrichment Analysis (GSEA), and Pearson's correlation analysis were performed to discover the possible mechanism of PCa metastasis. The significantly correlated transcription factors of OS-associated SRGs were also identified by Pearson's correlation analysis. ChIP-seq was applied to validate the binding relationship of TFs and OS-associated SRGs and spatial transcriptome and single-cell sequencing were performed to uncover the location of key biomarkers expression. Lastly, we explored the specific inhibitors for SRGs using CMap algorithm.

Results

We identified 538 differentially expressed genes (DEGs) between non-metastatic and metastatic PCa. Furthermore, OS-associated SRGs were identified. The Pearson correlation analysis revealed that FOXM1 was significantly correlated with NEIL3 (correlation efficient =0.89, p < 0.001) and identified hallmark_E2F_targets as the potential pathway mechanism of NEIL3 promoting PCa metastasis (correlation efficient =0.58, p < 0.001). Single-cell sequencing results indicated that FOXM1 regulating NEIL3 may get involved in the antiandrogen resistance of PCa. Rottlerin was discovered to be a potential target drug for PCa.

Conclusion

We constructed a regulatory network based on SRGs associated with PCa metastasis and explored possible mechanism.

Transcription Factors with Targeting Potential in Gliomas

Gliomas portray a large and heterogeneous group of CNS tumors, encompassing a wide range of low- to high-grade tumors, as defined by histological and molecular characteristics. The identification of signature mutations and other molecular abnormalities has largely impacted tumor classification, diagnosis, and therapy. Transcription factors (TFs) are master regulators of gene expression programs, which ultimately shape cell fate and homeostasis. A variety of TFs have been detected to be aberrantly expressed in brain tumors, being highly implicated in critical pathological aspects and progression of gliomas. Herein, we describe a selection of oncogenic (GLI-1/2/3, E2F1–8, STAT3, and HIF-1/2) and tumor suppressor (NFI-A/B, TBXT, MYT1, and MYT1L) TFs that are deregulated in gliomas and are subsequently associated with tumor development, progression, and migratory potential. We further discuss the current targeting options against these TFs, including chemical (Bortezomib) and natural (Plumbagin) compounds, small molecules, and inhibitors, and address their potential implications in glioma therapy.

OPA Interacting Protein 5 Antisense RNA 1 Expedites Cell Migration and Invasion Through FOXM1/ Wnt/β-Catenin Pathway in Pancreatic Cancer

BACKGROUND

Pancreatic cancer (PC) is a digestive tract malignancy with poor prognosis. Long noncoding RNA (lncRNA) OPA interacting protein 5 antisense RNA 1 (OIP5-AS1) was regarded to be correlated with human malignancy, working as tumor suppressor or promoter on the basis of tumor types. However, the function of OIP5-AS1 in PC remained unclear.

AIMS

The study focused on the function and regulatory mechanism of OIP5-AS1 in PC.

METHODS

OIP5-AS1 expression was assessed by the quantitative reverse transcription PCR (RT-qPCR) in tumor tissues and PC cell lines. 5-ethynyl-2'-deoxyuridine (EdU) incorporation and cell counting kit-8 (CCK-8) assays were applied to detect cell proliferation ability. Through wound healing and transwell assays, cell migration and invasion capacities were estimated. Flow cytometry analysis was performed to examine apoptosis capability of PC cells.

RESULTS

OIP5-AS1 downregulating inhibited cell proliferation, migration, and invasion capacities, while promoting cell apoptosis rates. As a competing endogenous RNA (ceRNA), OIP5-AS1 competed with Forkhead Box M1 (FOXM1) for the binding sites on microRNA-320b (miR-320b). OIP5-AS1 was able to upregulate FOXM1 expression via silencing miR-320b. Furthermore, FOXM1 served as an activator of Wnt/β-catenin pathway and mediated the effect of OIP5-AS1 on Wnt/β-catenin pathway.

CONCLUSION

OIP5-AS1 expedites the proliferative, migrated, and invasive capability of PC cells, while repressing cell apoptosis through regulating miRNA-320b/FOXM1 axis and FOXM1/Wnt/β-catenin pathway in PC. OIP5-AS1 regulation on FOXM1/Wnt/β-catenin pathway may offer novel efficient markers for PC treatments.

Berberine Inhibits FOXM1 Dependent Transcriptional Regulation of POLE2 and Interferes With the Survival of Lung Adenocarcinoma

Background: Berberine is one of the most interesting and promising natural anticancer drugs. POLE2 is involved in many cellular functions such as DNA replication and is highly expressed in a variety of cancers. However, the specific molecular mechanism of berberine interfering with POLE2 expression in lung adenocarcinoma (LUAD) is still unknown to a great extent.

Method: The KEGG database (Release 91.0) and Gene Ontology (GO) category database were used for functional annotation of differentially expressed genes after berberine treatment. Reproducibility assessment using TCGA dataset. The biological functions of berberine in LUAD were investigated by a series of in vitro and in vivo experiments: MTT, colony formation, mouse xenograft and plasmid transfection. The molecular mechanisms of berberine were demonstrated by plasmid transfection, quantitative RT-PCR and Western blotting.

Result: The elevated expression of FOXM1 and the high enrichment of DNA replication pathway were confirmed in LUAD by microarray and TCGA analysis, and were positively correlated with poor prognosis. Functionally, berberine inhibited the proliferation and survival of LUAD cell lines in vitro and in vivo. Mechanistically, berberine treatment down regulated the expression of FOXM1which closely related to survival, survival related genes in Cell cycle and DNA replication pathway, and significantly down regulated the expression of survival related POLE2. Interestingly, we found that the transcription factor FOXM1 could act as a bridge between berberine and POLE2.

Conclusion: Berberine significantly inhibited LUAD progression via the FOXM1/POLE2, and FOXM1/POLE2 may act as a clinical prognostic factor and a therapeutic target for LUAD. Berberine may be used as a promising therapeutic candidate for LUAD patients.

FOXM1 accelerates wound healing in diabetic foot ulcer by inducing M2 macrophage polarization through a mechanism involving SEMA3C/NRP2/Hedgehog signaling

AIMS

The diabetic wound environment is accompanied with prolonged inflammation leading to impaired wound healing in diabetic foot ulcer (DFU). Our study illustrated the molecular mechanisms by which Forkhead box M1 (FOXM1) enhanced M2 polarization and wound healing of DFU.

METHODS

Diabetes was modeled in vivo by streptozotocin injection in rats and in vitro by exposure to high glucose in human dermal fibroblasts (HDF). Macrophages were exposed to IL-4 to induce M2 phenotype polarization. Ectopic expression or knockdown of FOXM1 was performed to observe collagen deposition, angiogenesis, the proliferation and migration of HDF, as well as macrophage polarization.

RESULTS

FOXM1 was lowly expressed in the wound tissue of DFU rats. In vitro experiments showed that silencing FOXM1 reversed the M2 polarization-induced promotion of HDF proliferation and migration. We further found that FOXM1 bound to the promoter region of SEMA3C to elevate its expression, and SEMA3C upregulated NRP2 and activated the Hedgehog signaling pathway. Silencing of SMO, a signal transducer in the Hedgehog pathway, negated the promoting effect of FOXM1 overexpression in M2 polarization and HDF proliferation.

CONCLUSIONS

Thus, our results suggest that targeting transcription factor FOXM1 may provide a therapeutic target for promoting wound healing in DFU.

FOXM1 Promotes Drug Resistance in Cervical Cancer Cells by Regulating ABCC5 Gene Transcription

Objective

The aim of the present study was to investigate the effect of forkhead box M1 (FOXM1) to paclitaxel resistance in cervical cancer cells, to determine the underlying mechanism, and to identify novel targets for the treatment of paclitaxel-resistant cervical cancer.

Methods

Paclitaxel-resistant Caski cells (Caski/Taxol cells) were established by intermittently exposing the Caski cells to gradually increasing concentrations of paclitaxel. The association between FOXM1, ATP-binding cassette subfamily C member 5 (ABCC5), and cervical cancer cell drug resistance was assessed by overexpressing or knocking down the expression of FOXM1 in Caski or Caski/Taxol cells. The protein and mRNA expression levels, the ratio of cellular apoptosis, and cell migration as well as intracellular drug concentrations were measured in cells following the different treatments.

Results

After the successful establishment of resistant Caski/Taxol cells, cell cycle distribution analysis showed that a significantly larger percentage of Caski/Taxol cells was in the G0/G1 stage compared with the Caski cells (P < 0.01), whereas a significantly larger percentage of Caski cells was in the S and G2/M stage compared with the Caski/Taxol cells following treatment with paclitaxel (P < 0.01). Both the protein and mRNA expression levels of FOXM1 and ABCC5 transporters were significantly higher in the paclitaxel-resistant Caski/Taxol cells compared with Caski cells (P < 0.05). Knockdown of FOXM1 significantly lowered the protein expression levels of FOXM1 and ABCC5. Intracellular paclitaxel concentrations were significantly higher amongst the Caski/Taxol cells following the knockdown of FOXM1 by shRNA or Siomycin A (P < 0.05).

Conclusion

FOXM1 promotes drug resistance in cervical cancer cells by regulating ABCC5 gene transcription. The knockdown of FOXM1 with shRNA or Siomycin A promotes paclitaxel-induced cell death by regulating ABCC5 gene transcription.

Single-cell RNA Sequencing Reveals How the Aryl Hydrocarbon Receptor Shapes Cellular Differentiation Potency in the Mouse Colon

Despite recent progress recognizing the importance of aryl hydrocarbon receptor (Ahr)-dependent signaling in suppressing colon tumorigenesis, its role in regulating colonic crypt homeostasis remains unclear. To assess the effects of Ahr on intestinal epithelial cell heterogeneity and functional phenotypes, we utilized single-cell transcriptomics and advanced analytic strategies to generate a high-quality atlas for colonic intestinal crypts from wild-type and intestinal-specific Ahr knockout mice. Here we observed the promotive effects of Ahr deletion on Foxm1-regulated genes in crypt-associated canonical epithelial cell types and subtypes of goblet cells and deep crypt-secretory cells. We also show that intestinal Ahr deletion elevated single-cell entropy (a measure of differentiation potency or cell stemness) and RNA velocity length (a measure of the rate of cell differentiation) in noncycling and cycling Lgr5+ stem cells. In general, intercellular signaling cross-talk via soluble and membrane-bound factors was perturbed in Ahr-null colonocytes. Taken together, our single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating putative stem cell driver genes, cell potency lineage decisions, and cell-cell communication in vivo. PREVENTION RELEVANCE: Our mouse single-cell RNA sequencing analyses provide new evidence of the molecular function of Ahr in modulating colonic stemness and cell-cell communication in vivo. From a cancer prevention perspective, Ahr should be considered a therapeutic target to recalibrate remodeling of the intestinal stem cell niche.

Artemisinin Mediates Its Tumor-Suppressive Activity in Hepatocellular Carcinoma Through Targeted Inhibition of FoxM1

The aberrant up-regulation of the oncogenic transcription factor Forkhead box M1 (FoxM1) is associated with tumor development, progression and metastasis in a myriad of carcinomas, thus establishing it as an attractive target for anticancer drug development. FoxM1 overexpression in hepatocellular carcinoma is reflective of tumor aggressiveness and recurrence, poor prognosis and low survival in patients. In our study, we have identified the antimalarial natural product, Artemisinin, to efficiently curb FoxM1 expression and activity in hepatic cancer cells, thereby exhibiting potential anticancer efficacy. Here, we demonstrated that Artemisinin considerably mitigates FoxM1 transcriptional activity by disrupting its interaction with the promoter region of its downstream targets, thereby suppressing the expression of numerous oncogenic drivers. Augmented level of FoxM1 is implicated in drug resistance of cancer cells, including hepatic tumor cells. Notably, FoxM1 overexpression rendered HCC cells poorly responsive to Artemisinin-mediated cytotoxicity while FoxM1 depletion in resistant liver cancer cells sensitized them to Artemisinin treatment, manifested in lower proliferative and growth index, drop in invasive potential and repressed expression of EMT markers with a concomitantly increased apoptosis. Moreover, Artemisinin, when used in combination with Thiostrepton, an established FoxM1 inhibitor, markedly reduced anchorage-independent growth and displayed more pronounced death in liver cancer cells. We found this effect to be evident even in the resistant HCC cells, thereby putting forth a novel combination therapy for resistant cancer patients. Altogether, our findings provide insight into the pivotal involvement of FoxM1 in the tumor suppressive activities of Artemisinin and shed light on the potential application of Artemisinin for improved therapeutic response, especially in resistant hepatic malignancies. Considering that Artemisinin compounds are in current clinical use with favorable safety profiles, the results from our study will potentiate its utility in juxtaposition with established FoxM1 inhibitors, promoting maximal therapeutic efficacy with minimal adverse effects in liver cancer patients.

FOXM1 Inhibitors as Potential Diagnostic Agents: First Generation of a PET Probe Targeting FOXM1 To Detect Triple-Negative Breast Cancer in vitro and in vivo

The FOXM1 protein controls the expression of essential genes related to cancer cell cycle progression, metastasis, and chemoresistance. We hypothesize that FOXM1 inhibitors could represent a novel approach to develop 18 F-based radiotracers for Positron Emission Tomography (PET). Therefore, in this report we describe the first attempt to use 18 F-labeled FOXM1 inhibitors to detect triple-negative breast cancer (TNBC). Briefly, we replaced the original amide group in the parent drug FDI-6 for a ketone group in the novel AF-FDI molecule, to carry out an aromatic nucleophilic (18 F)-fluorination. AF-FDI dissociated the FOXM1-DNA complex, decreased FOXM1 levels, and inhibited cell proliferation in a TNBC cell line (MDA-MB-231). [18 F]AF-FDI was internalized in MDA-MB-231 cells. Cell uptake inhibition experiments showed that AF-FDI and FDI-6 significantly decreased the maximum uptake of [18 F]AF-FDI, suggesting specificity towards FOXM1. [18 F]AF-FDI reached a tumor uptake of SUV=0.31 in MDA-MB-231 tumor-bearing mice and was metabolically stable 60 min post-injection. These results provide preliminary evidence supporting the potential role of FOXM1 to develop PET radiotracers.