The forkhead box M1 (FOXM1) expression and antitumor effect of FOXM1 inhibition in malignant rhabdoid tumor

TWIST1 Regulates FOXM1/β-Catenin to Promote the Growth, Migration, and Invasion of Ovarian Cancer Cells by Activating MFAP2

TWIST1 is aberrantly expressed in ovarian cancer (OC). MFAP2 is a downstream target of TWIST1, and we previously found MFAP2 facilitated OC development by activating FOXM1/β-catenin. We planned to investigate the mechanisms of TWIST1 in OC. GEPIA (a database for gene expression analysis) and UALCAN (a database containing comprehensive cancer transcriptome and clinical patient data) investigated TWIST1's connection to MFAP2 and patient survival in ovarian serous cystadenocarcinoma (OV). Human OC cells (A2780 and CAOV3) were transfected with si-TWIST1, oe-TWIST1, oe-MFAP2, or si-TWIST1 + oe-MFAP2. Cellular apoptosis, viability, migration, and invasion were detected. TWIST1, MFAP2, FOXM1, and β-catenin protein expressions were tested. Dual-luciferase and ChIP-qPCR validated the correlation between MFAP2 and TWIST1. Moreover, OC mice were established by injecting OC cells subcutaneously. The pathology, apoptosis, as well as Ki67, TWIST1, MFAP2, FOXM1, and β-catenin protein levels of tumors were assessed. TWIST1 expression positively correlated with MFAP2 expression, but negatively related to patients' survival in OV. TWIST1 overexpression promoted malignant behaviors, and increased MFAP2, FOXM1, and β-catenin protein levels for OC cells. TWIST1 knockdown exhibited the opposite trend. In vivo, TWIST1 knockdown disrupted tissue structure, induced apoptosis, decreased Ki67, TWIST1, MFAP2, FOXM1, and β-catenin protein levels in tumor. Interestingly, MFAP2 overexpression reversed the effects of TWIST1 knockdown in vitro and in vivo. Additionally, dual-luciferase and ChIP-qPCR confirmed MFAP2 was a downstream target for TWIST1 in OC. TWIST1 regulated FOXM1/β-catenin to promote the growth, migration, and invasion of OC cells by activating MFAP2, indicating that targeting TWIST1 may be effective for treating OC.

CD133+/ABCC5+ cervical cancer cells exhibit cancer stem cell properties

Objective

This study explores the correlation between Forkhead box M1 (FOXM1) and ATP-binding cassette subfamily C member 5 (ABCC5) in relation to paclitaxel resistance in cervical cancer. It aims to identify potential cervical cancer stem cell markers, offering fresh perspectives for developing therapeutic strategies to overcome paclitaxel chemoresistance in cervical cancer.

Methods

Paclitaxel-resistant Hela cells (Hela/Taxol) were developed by intermittently exposing Hela cells to progressively increasing concentrations of paclitaxel. We assessed the biological properties of both Hela and Hela/Taxol cells using various assays: cell proliferation, clonogenic, cell cycle, apoptosis, scratch, and transwell. To determine which markers better represent tumor stem cells, we analyzed various known and potential stem cell markers in combination. Flow cytometry was employed to measure the proportion of positive markers in both parental and drug-resistant cell lines. Following statistical analysis to establish relative stability, CD133+ABCC5+ cells were sorted for further examination. Subsequent tests included sphere-forming assays and Western blot analysis to detect the presence of the stem cell-specific protein Sox2, aiding in the identification of viable cervical cancer stem cell markers.

Results

The Hela/Taxol cell line exhibited significantly enhanced proliferation, migration, and invasion capabilities compared to the Hela cell line, alongside a marked reduction in apoptosis rates (P < 0.01). Notably, proportions of CD44+, CD24+CD44+, ABCC5+, CD24+CD44+ABCC5+, CD44+ABCC5+, CD24+CD44+FOXM1+, CD44+FOXM1+, CD133+ABCC5+, and CD133+FOXM1+ were significantly higher (P < 0.05). Furthermore, the size and number of spheres formed byCD133+ABCC5+ cells were greater in the sorted Hela/Taxol line (P < 0.01), with increased expression of the stem cell marker Sox2 (P < 0.001).

Conclusion

The Hela/Taxol cells demonstrate increased tumoral stemness, suggesting that CD133+ABCC5+ may serve as a novel marker for cervical cancer stem cells.

Expression of Forkhead Box M1 and Anticancer Effects of FOXM1 Inhibition in Epithelioid Sarcoma

Epithelioid sarcoma (ES) is a rare aggressive sarcoma that, unlike most soft-tissue sarcomas, shows a tendency toward local recurrence and lymph node metastasis. Novel antitumor agents are needed for ES patients. Forkhead box transcription factor 1 (FOXM1) is a member of the Forkhead transcription factor family and is associated with multiple oncogenic functions; FOXM1 is known to be overexpressed and correlated with pathogenesis in various malignancies. In this study, we immunohistochemically analyzed FOXM1 expression levels and their clinical, clinicopathologic, and prognostic significance in 38 ES specimens. In addition, to investigate potential correlations between FOXM1 downregulation and oncologic characteristics, we treated ES cell lines with thiostrepton, a naturally occurring antibiotic that inhibits both small interfering RNA (siRNA) and FOXM1. In the analyses using ES samples, all 38 specimens were diagnosed as positive for FOXM1 by immunohistochemistry. We separated specimens into high (n = 19) and low (n = 19) FOXM1-protein expression groups by staining index score, and into large (n = 12), small (n = 25), and unknown (n = 1) tumor-size groups using a cutoff of 5 cm maximum diameter. Although there were significantly more samples with high FOXM1 expression in the large tumor group (P = .013), there were no significant differences with respect to age (P = 1.00), sex (P = .51), primary site of origin (P = .74), histologic subtypes (P = 1.00), depth (P = .74), or survival rate (P = .288) between the high and low FOXM1-protein expression groups. In the in vitro experiments using ES cell lines, FOXM1 siRNA and thiostrepton successfully downregulated FOXM1 mRNA and protein expression. Furthermore, downregulation of FOXM1 inhibited cell proliferation, drug resistance against chemotherapeutic agents, migration, and invasion and caused cell cycle arrest in the ES cell lines. Finally, cDNA microarray analysis data showed that FOXM1 regulated cIAP2, which is one of the apoptosis inhibitors activated by the TNFα-mediated NF-κB pathway. In conclusion, the FOXM1 gene may be a promising therapeutic target for ES.

FOXM1 and CHD4 expression is associated with chemoresistance in hepatoblastoma

Hepatoblastoma (HB) is the most common malignant liver tumor in childhood. Although pre-operative cisplatin (CDDP)-based chemotherapy is often used in cases of HB, about 20％ of HB patients exhibit resistance to CDDP. Forkhead box protein M1 (FOXM1) and chromo-domain-helicase-DNA-binding protein 4 (CHD4) have been associated with CDDP resistance in various tumors. We here analyzed the immunohistochemical expression of FOXM1 and CHD4 in HB specimens of 33 patients (mean age: 20 months) post-chemotherapy. The differentiation of specimens was assessed using the digital pathology software QuPath®, and then the relation between the FOXM1 or CHD4 expression and the differentiation and various other clinicopathological parameters was investigated. The histological type was epithelial in 19 cases (57.6%) and mixed epithelial and mesenchymal in 14 cases (42.4%). Nine cases had only a fetal component, 1 case had only an embryonal component, 22 cases had both fetal and embryonal components, and 1 case had no viable tumor. Both the FOXM1 and CHD4 immunoexpressions were found significantly more frequently in the embryonal than fetal components (p<0.0001 and p<0.0001, respectively). Regarding chemotherapy efficacy, the alpha-fetoprotein (AFP) level after chemotherapy was correlated with both the imaging shrinkage rate (R=-0.52) and histological residual rate (the percentage of the viable tumors of HB after chemotherapy)(R=0.62). High FOXM1 score was correlated with a high-postoperative AFP value (p<0.01) and a low AFP attenuation rate (p<0.05), but the FOXM1 score was not correlated with the imaging shrinkage rate (p=0.4418) or histological residual rate (p=0.4418). High CHD4 score showed a nonsignificant trend toward correlation with high postoperative AFP value (p=0.0849) and was not significantly correlated with the other parameters. Collectively, our results showed that FOXM1 expression may be useful in evaluating the response to CDDP-based chemotherapeutic regimens. Accurate measurement of FOXM1 expression by our scoring system using QuPath® is important in cases with mixed HB components of various differentiation levels.

Epigenetic regulation of FOXI2 promotes clear cell renal cell carcinoma progression

In recent decades, substantial advancements in epigenetics have unveiled a profound understanding of its mechanisms in tumorigenesis and have offered promising strategies for epigenetic therapy in cancer patients. In our study, through bioinformatics analysis, we discovered a significant downregulation and hypermethylation of FOXI2 in clear cell renal cell carcinoma (ccRCC), while the expression in chromophobe cell carcinoma (chRCC) exhibited the opposite trend. Moreover, we established a strong correlation between FOXI2 expression levels and the prognosis of ccRCC. Gene enrichment analysis and cell function experiments unequivocally demonstrate that FOXI2 possesses the capability to induce cell cycle arrest and inhibit cell proliferation. Our research findings demonstrate that the expression of FOXI2 in ccRCC is under the regulation of promoter hypermethylation. Furthermore, in vitro experiments have conclusively shown that the overexpression of FOXI2 induces cell cycle arrest and inhibits cell proliferation.

Abnormal expression of FOXM1 in carcinogenesis of renal cell carcinoma: From experimental findings to clinical applications

Renal cell carcinoma (RCC) is a prevalent malignancy within the genitourinary system. At present, patients with high-grade or advanced RCC continue to have a bleak prognosis. Mounting research have emphasized the significant involvement of Forkhead box M1 (FOXM1) in RCC development and progression. Therefore, it is imperative to consolidate the existing evidence regarding the contributions of FOXM1 to RCC tumorigenesis through a comprehensive review. This study elucidated the essential functions of FOXM1 in promoting RCC growth, invasion, and metastasis by regulating cell cycle progression, DNA repair, angiogenesis, and epithelial-mesenchymal transition (EMT). Also, FOXM1 might serve as a novel diagnostic and prognostic biomarker as well as a therapeutic target for RCC. Clinical findings demonstrated that the expression of FOXM1 was markedly upregulated in RCC samples, while a high level of FOXM1 was found to be associated with a poor overall survival rate of RCC. Furthermore, it is worth noting that FOXM1 may have a significant impact on the resistance of renal cell carcinoma (RCC) to radiotherapy. This observation suggests that inhibiting FOXM1 could be a promising strategy to impede the progression of RCC and enhance its sensitivity to radiotherapy. The present review highlighted the pivotal role of FOXM1 in RCC development. FOXM1 has the capacity to emerge as not only a valuable diagnostic and prognostic tool but also a viable therapeutic option for unresectable RCC.

Pan-cancer analyses reveal multi-omic signatures and clinical implementations of the forkhead-box gene family

BACKGROUND

Forkhead box (FOX) proteins belong to one of the largest transcription factor families and play crucial roles in the initiation and progression of cancer. Prior research has linked several FOX genes, such as FOXA1 and FOXM1, to the crucial process of carcinogenesis. However, the overall picture of FOX gene family across human cancers is far from clear.

METHODS

To investigate the broad molecular signatures of the FOX gene family, we conducted study on multi-omics data (including genomics, epigenomics and transcriptomics) from over 11,000 patients with 33 different types of human cancers.

RESULTS

Pan-cancer analysis reveals that FOX gene mutations were found in 17.4% of tumor patients with a substantial cancer type-dependent pattern. Additionally, high expression heterogeneity of FOX genes across cancer types was discovered, which can be partially attributed to the genomic or epigenomic alteration. Co-expression network analysis reveals that FOX genes may exert functions by regulating the expression of both their own and target genes. For a clinical standpoint, we provided 103 FOX gene-drug target-drug predictions and found FOX gene expression have potential survival predictive value. All of the results have been included in the FOX2Cancer database, which is freely accessible at http://hainmu-biobigdata.com/FOX2Cancer.

CONCLUSION

Our findings may provide a better understanding of roles FOX genes played in the development of tumors, and help to offer new avenues for uncovering tumorigenesis and unprecedented therapeutic targets.

Current and Emerging Therapeutic Approaches for Extracranial Malignant Rhabdoid Tumors

Extracranial malignant rhabdoid tumors (extracranial MRT) are rare, highly aggressive malignancies affecting mainly infants and children younger than 3 years. Common anatomic sites comprise the kidneys (RTK – rhabdoid tumor of kidney) and other soft tissues (eMRT – extracranial, extrarenal malignant rhabdoid tumor). The genetic origin of these diseases is linked to biallelic pathogenic variants in the genes SMARCB1, or rarely SMARCA4, encoding subunits of the SWI/SNF chromatin-remodeling complex. Even if extracranial MRT seem to be quite homogeneous, recent epigenome analyses reveal a certain degree of epigenetic heterogeneity. Use of intensified therapies has modestly improved survival for extracranial MRT. Patients at standard risk profit from conventional therapies; most high-risk patients still experience a dismal course and often therapy resistance. Discoveries of clinical and molecular hallmarks and the exploration of experimental therapeutic approaches open exciting perspectives for clinical and molecularly stratified experimental treatment approaches. To ultimately improve the outcome of patients with extracranial MRTs, they need to be characterized and stratified clinically and molecularly. High-risk patients need novel therapeutic approaches including selective experimental agents in phase I/II clinical trials.

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.