Inhibition of CDC25B With WG-391D Impedes the Tumorigenesis of Ovarian Cancer

E2F1 Facilitates the Proliferation and Stemness of Gastric Cancer Cells by Activating CDC25B Transcription and Modulating the MAPK Pathway

Gastric cancer (GC) is a health problem that concerns people around the world. CDC25B is an essential cell cycle regulatory factor that is overexpressed in a variety of tumor cells. CDC25B plays a vital part in the progression and proliferation of malignant tumors. However, it is not yet clear that how CDC25B affects the stemness of GC cells. The study used bioinformatics to detect the expression of E2F1 and CDC25B in GC tissues and their correlation, as well as pathways enriched by CDC25B. We detected the expression of E2F1 and CDC25B in GC cell lines using quantitative reverse transcription polymerase chain reaction and tested the combination relationship between E2F1 and CDC25B using chromatin immunoprecipitation (ChIP) and dual-luciferase assays. We measured cell viability using CCK-8 assay, evaluated sphere-forming efficiency using sphere formation assay, and determined cell proliferation ability using colony formation assay. We also analyzed the expression of stemness markers and MAPK pathway-related proteins using western blot. In GC tissues and cells, CDC25B was upregulated. Silencing CDC25B could affect the MAPK pathway, thereby repressing the proliferation and stemness of GC cells. As predicted by bioinformatics, CDC25B had an upstream transcription factor, E2F1, which also had a high expression level in GC. Dual-luciferase and ChIP assays confirmed the combination relationship between the two. Rescue experiments uncovered that overexpression of CDC25B could reverse the impact induced by E2F1 knockdown on proliferation and stemness of cells. In conclusion, E2F1 could activate CDC25B transcription to regulate the MAPK pathway and enhance the proliferation and stemness of GC cells. We revealed a potential regulatory pathway of stemness of GC cells that was mediated by CDC25B, providing new ideas for improving and innovating GC treatment.

Potential of CDC25 phosphatases in cancer research and treatment: key to precision medicine

The global burden of cancer continues to rise, underscoring the urgency of developing more effective and precisely targeted therapies. This comprehensive review explores the confluence of precision medicine and CDC25 phosphatases in the context of cancer research. Precision medicine, alternatively referred to as customized medicine, aims to customize medical interventions by taking into account the genetic, genomic, and epigenetic characteristics of individual patients. The identification of particular genetic and molecular drivers driving cancer helps both diagnostic accuracy and treatment selection. Precision medicine utilizes sophisticated technology such as genome sequencing and bioinformatics to elucidate genetic differences that underlie the proliferation of cancer cells, hence facilitating the development of customized therapeutic interventions. CDC25 phosphatases, which play a crucial role in governing the progression of the cell cycle, have garnered significant attention as potential targets for cancer treatment. The dysregulation of CDC25 is a characteristic feature observed in various types of malignancies, hence classifying them as proto-oncogenes. The proteins in question, which operate as phosphatases, play a role in the activation of Cyclin-dependent kinases (CDKs), so promoting the advancement of the cell cycle. CDC25 inhibitors demonstrate potential as therapeutic drugs for cancer treatment by specifically blocking the activity of CDKs and modulating the cell cycle in malignant cells. In brief, precision medicine presents a potentially fruitful option for augmenting cancer research, diagnosis, and treatment, with an emphasis on individualized care predicated upon patients' genetic and molecular profiles. The review highlights the significance of CDC25 phosphatases in the advancement of cancer and identifies them as promising candidates for therapeutic intervention. This statement underscores the significance of doing thorough molecular profiling in order to uncover the complex molecular characteristics of cancer cells.

Selectively targeting BCL6 using a small molecule inhibitor is a potential therapeutic strategy for ovarian cancer

Ovarian cancer is one of the tumors with the highest fatality rate among gynecological tumors. The current 5-year survival rate of ovarian cancer is <35%. Therefore, more novel alternative strategies and drugs are needed to treat ovarian cancer. The transcription factor B-cell lymphoma 6 (BCL6) is critically associated with poor prognosis and cisplatin resistance in ovarian cancer treatment. Therefore, BCL6 may be an attractive therapeutic target for ovarian cancer. However, the role of targeting BCL6 in ovarian cancer remains elusive. Here, we developed a novel BCL6 small molecule inhibitor, WK369, which exhibits excellent anti-ovarian cancer bioactivity, induces cell cycle arrest and causes apoptosis. WK369 effectively inhibits the growth and metastasis of ovarian cancer without obvious toxicity in vitro and in vivo. meanwhile, WK369 can prolong the survival of ovarian cancer-bearing mice. It is worth noting that WK369 also has significant anti-tumor effects on cisplatin-resistant ovarian cancer cell lines. Mechanistic studies have shown that WK369 can directly bind to the BCL6-BTB domain and block the interaction between BCL6 and SMRT, leading to the reactivation of p53, ATR and CDKN1A. BCL6-AKT, BCL6-MEK/ERK crosstalk is suppressed. As a first attempt, our study demonstrates that targeting BCL6 may be an effective approach to treat ovarian cancer and that WK369 has the potential to be used as a candidate therapeutic agent for ovarian cancer.

Micelle encapsulation zinc-doped copper oxide nanocomposites reverse Olaparib resistance in ovarian cancer by disrupting homologous recombination repair

Micelle Encapsulation Zinc-doped copper oxide nanocomposites (MEnZn-CuO NPs) is a novel doped metal nanomaterial prepared by our group based on Zinc doped copper oxide nanocomposites (Zn-CuO NPs) using non-micellar beam. Compared with Zn-CuO NPs, MEnZn-CuO NPs have uniform nanoproperties and high stability. In this study, we explored the anticancer effects of MEnZn-CuO NPs on human ovarian cancer cells. In addition to affecting cell proliferation, migration, apoptosis and autophagy, MEnZn-CuO NPs have a greater potential for clinical application by inducing HR repair defects in ovarian cancer cells in combination with poly (ADP-ribose) polymerase inhibitors for lethal effects.

Exploring the mechanism of C473D mutation on CDC25B causing weak binding affinity with CDK2/CyclinA by molecular dynamics study

CDC25B belongs to the CDC25 family, and it plays an important part in regulating the activity of CDK/CyclinA. Studies have shown that CDC25B is closely related to cancer development. When CYS473 on CDC25B is mutated into ASP, the affinity between CDC25B and CDK2/CyclinA weakens, and their dissociation speed is greatly improved. However, the mechanism by which the CDC25BC473D mutant weakens its binding to CDK2/CyclinA is unclear. In order to study the effect of CDC25BC473D mutants on CDK2/CyclinA substrates, we constructed and verified the rationality of the CDC25BWT:CDK2/CyclinA system and CDC25BC473D:CDK2/CyclinA system and conducted molecular dynamics (MD) simulation analysis. In the post-analysis, the fluctuations of residues ARG488-SER499, LYS541-TRP550 on CDC25B and residues ASP206-ASP210 on CDK2 were massive in the mutant CDC25BC473D:CDK2/CyclinA system. And the interactions between residue ARG492 and residue GLU208, residue ARG544 and residue GLU42, residue ARG544 and TRP550 were weakened in the mutant CDC25BC473D:CDK2/CyclinA system. The results showed that when CYS473 on CDC25B was mutated into ASP473, the mutant CDC25BC473D:CDK2/CyclinA system was less stable than the wild-type CDC25BWT:CDK2/CyclinA system. Finally, active site CYS473 of CDC25B was speculated to be the key residue, which had great effects on the binding between CDC25BCYS473 and CDK2 in the CDC25BC473D:CDK2/CyclinA system. Consequently, overall analyses appeared in this study ultimately provided a useful understanding of the weak interactions between CDC25BCYS473D and CDK2/CyclinA.Communicated by Ramaswamy H. Sarma.

Comprehensive Analysis and Experimental Validation of a Novel Estrogen/Progesterone-Related Prognostic Signature for Endometrial Cancer

Estrogen and progesterone are the major determinants of the occurrence and development of endometrial cancer (EC), which is one of the most common gynecological cancers worldwide. Our purpose was to develop a novel estrogen/progesterone-related gene signature to better predict the prognosis of EC and help discover effective therapeutic strategies. We downloaded the clinical and RNA-seq data of 397 EC patients from The Cancer Genome Atlas (TCGA) database. The “limma” R package was used to screen for estrogen/progesterone-related differentially expressed genes (DEGs) between EC and normal tissues. Univariate and multivariate Cox proportional hazards regression analyses were applied to identify these DEGs that were associated with prognosis; then, a novel estrogen/progesterone-related prognostic signature comprising CDC25B, GNG3, ITIH3, PRXL2A and SDHB was established. The Kaplan–Meier (KM) survival analysis showed that the low-risk group identified by this signature had significantly longer overall survival (OS) than the high-risk group; the receiver operating characteristic (ROC) and risk distribution curves suggested this signature was an accurate predictor independent of risk factors. A nomogram incorporating the signature risk score and stage was constructed, and the calibration plot suggested it could accurately predict the survival rate. Compared with normal tissues, tumor tissues had increased mRNA levels of GNG3 and PRXL2A and a reduced mRNA level of ITIH3. The knockdown of PRXL2A and GNG3 significantly inhibited the proliferation and colony formation of Ishikawa and AN3CA cells, while the inhibition of PRXL2A expression suppressed xenograft growth. In this study, five estrogen/progesterone-related genes were identified and incorporated into a novel signature, which provided a new classification tool for improved risk assessment and potential molecular targets for EC therapies.

Cyclin-dependent kinase 5 promotes the growth of tongue squamous cell carcinoma through the microRNA 513c-5p/cell division cycle 25B pathway and is associated with a poor prognosis

Background

The objective of this study was to investigate the role and molecular mechanism of cyclin‐dependent kinase 5 (CDK5) in regulating the growth of tongue squamous cell carcinoma (TSCC).

Methods

The authors used multiple methods to detect the levels of CDK5 expression in samples of TSCC and to explore the relation between CDK5 expression and various clinicopathologic factors. In vivo and in vitro cell experiments were performed to detect the proliferation, invasion, and migration of TSCC cells with CDK5 knockdown or overexpression. These studies verified that CDK5 regulates the occurrence and development of TSCC cells through the microRNA 513c‐5p/cell division cycle 25B pathway.

Results

An elevated level of CDK5 expression in TSCC tissues was identified as an independent risk factor affecting TSCC growth and patient prognosis. Patients who had TSCC with low levels of CDK5 expression had a higher survival rate than those with high levels. Knockdown of CDK5 reduced the proliferation, migration, and invasion of TSCC cells both in vitro and in vivo. In addition, the authors observed that CDK5 regulated the growth of TSCC through the microRNA 513c‐5p/cell division cycle C25B pathway.

Conclusions

CDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC.

Lay Summary

Tongue squamous cell carcinoma (TSCC) is 1 of the most common malignant tumors of the head and neck, and the survival rate of patients with tongue cancer has been very low.

Therefore, it is important to study the molecular mechanism of TSCC progression to identify biomarkers that can be used to improve its clinical diagnosis and treatment.

Cyclin‐dependent kinase 5 (CDK5) is an atypical member of the cyclin‐dependent kinase family and is involved in regulating the cell cycle.

Changes in the cell cycle are of great significance for the occurrence and development of tumor cells; and, in recent years, increasing evidence has suggested that CDK5 exists in a disordered state in cancer cells.

In this study, the authors demonstrate that CDK5 functions as an oncogene in TSCC and might serve as a molecular marker for use in the diagnosis and treatment of TSCC.

The role of cyclin‐dependent kinase 5 and its molecular mechanism in regulating the growth of tongue squamous cell carcinoma (TSCC) are investigated. The results indicate that cyclin‐dependent kinase 5 is involved in the occurrence and development of TSCC and could possibly serve as a new prognostic marker and molecular target for treating TSCC.

The Exocrine Differentiation and Proliferation Factor (EXDPF) Gene Promotes Ovarian Cancer Tumorigenesis by Up-Regulating DNA Replication Pathway

The Exocrine Differentiation and Proliferation Factor (EXDPF) gene could promote exocrine while inhibit endocrine functions. Although it is well known that ovary is an endocrine organ, the functions of EXDPF in ovarian cancer development is still unknown. This study demonstrated that EXDPF gene is significantly higher expressed in ovarian tumors compared to normal ovarian tissue controls. EXDPF DNA amplification was exhibited in lots of human tumors including 7.19% of ovarian tumors. Also, high expression of EXDPF positively correlated with poor overall survival (OS) of ovarian cancer patients. EXDPF expression could be universally detected in most epithelial ovarian cancer cells (SKOV3, IGROV1, MACS, HO8910PM, ES2, COV362 and A2780) tested in this study. Knock-down of EXDPF by siRNA delivered by plasmid or lentivirus largely inhibited ovarian cancer cells, IGROV1 and SKOV3 proliferation, migration and tumorigenesis in vitro and/or in vivo. Knock-down of EXDPF sensitized SKOV3 cells to the treatment of the front-line drug, paclitaxel. Mechanism study showed that EXDPF enhanced DNA replication pathway to promote ovarian cancer tumorigenesis. In conclusion, this study demonstrated that EXDPF could be a potential therapeutic target as a pro-oncogene of ovarian cancer.

LncRNA FAM83A-AS1 promotes ESCC progression by regulating miR-214/CDC25B axis

Background: Recent researches have pinpointed that long non-coding RNA (lncRNA) was tightly related to the carcinogenesis. However, the function of lncRNA in esophageal cell squamous carcinoma (ESCC) remains to be explored. In the current study, we assessed the expression pattern and the biological function of FAM83A-AS1 in ESCC.

Methods: qRT-PCR was used to detect the expression of FAM83A-AS1, miR-214, and CDC25B expression in ESCC tissues and cell lines. CCK-8, transwell, apoptosis and cell cycle assays were performed to define the function of FAM83A-AS1 in ESCC cells. Furthermore, the regulation of miR-214 by FAM83A-AS1 was defined by qRT- PCR and rescue assays. In addition, the association between CDC25B, miR-214, CDC25B was confirmed by qRT-PCR.

Results: Here, we discovered that FAM83A-AS1 was strongly expressed in ESCC tissues. FAM83A-AS1 abundance was associated with TNM stages and the differentiation grade of ESCC patients. The receiver operating characteristic curve (ROC) analysis indicated the high accuracy of FAM83A-AS1 in ESCC diagnosis. Functionally, inhibiting FAM83A-AS1 repressed cell proliferation, migration, and invasion in ESCC. In addition, we found that FAM83A-AS1 accelerated the cell cycle while inhibited cell apoptosis. Mechanistically, we found that FAM83A-AS1 regulated miR-214 expression, and there was a negative correlation between miR-214 and FAM83A-AS1 in ESCC. Rescue assay indicated that miR-214 could impair the suppressing effect of cell migration induced by FAM83A-AS1 depletion. Furthermore, CDC25B was a direct target of miR-214, and FAM83A-AS1 enhanced CDC25B expression while miR-214 positively CDC25B expression in ESCC.

Conclusions: Collectively, we concluded that FAM83A-AS1 facilitated ESCC progression by regulating the miR-214/CDC25B axis. Our study showed FAM83A-AS1 may act as a promising target for ESCC diagnosis and therapy.

The Application of Patient-Derived Xenograft Models in Gynecologic Cancers

Recently, due to the limitations of cell line models and animal models in the preclinical research with insufficient reflecting the physiological situation of humans, patient-derived xenograft (PDX) models of many cancers have been widely developed because of their better representation of the tumor heterogeneity and tumor microenvironment with retention of the cellular complexity, cytogenetics, and stromal architecture. PDX models now have been identified as a powerful tool for determining cancer characteristics, developing new treatment, and predicting drug efficacy. An increase in attempts to generate PDX models in gynecologic cancers has emerged in recent years to understand tumorigenesis. Hence, this review summarized the generation of PDX models and engraftment success of PDX models in gynecologic cancers. Furthermore, we illustrated the similarity between PDX model and original tumor, and described preclinical utilization of PDX models in gynecologic cancers. It would help supply better personalized therapy for gynecologic cancer patients.

The PI3K/mTOR dual inhibitor GSK458 potently impedes ovarian cancer tumorigenesis and metastasis

PURPOSE

The PI3K/AKT/mTOR pathway is one of the most highly activated cellular signaling pathways in advanced ovarian cancer. Although several PI3K/AKT/mTOR inhibitors have been developed to treat various types of cancer, the antitumor efficacy of many of these compounds against ovarian cancer has remained unclear.

METHODS

Here, we tested and compared a panel of 16 PI3K/AKT/mTOR inhibitors (XL765, Miltefosine, Rapamycin, CCI-779, RAD001, FK506, XL147, GSK2110183, IPI-145, GSK2141795, BYL719, GSK458, CAL-101, XL765 analogue SAR245409, Triciribine, and GDC0941) that have entered clinical trials for antitumor activity against ovarian cancer, as well as the front line drug, paclitaxel. Antitumor efficacy was measured in both ovarian cancer cell lines and patient-derived ovarian primary tumor cell lines in vitro and in vivo.

RESULTS

We identified the PI3K/mTOR dual inhibitor GSK458 as a potent inhibitor of proliferation in all cell lines tested at half maximal inhibitory concentrations (IC₅₀) of approximately 0.01-1 µM, a range tens to hundreds fold lower than that of the other PI3K/AKT/mTOR inhibitors tested. Additionally, GSK458 showed the highest inhibitory efficacy against ovarian cancer cell migration. GSK458 also inhibited tumor growth and metastasis in nude mice intraperitoneally engrafted with SKOV3 cells or a patient-derived tumor cell xenograft (PDCX). Importantly, the inhibitory efficiency of GSK458 on cell proliferation and migration both in vitro and in vivo was comparable to that of paclitaxel. Mechanistically, the anti-tumor activity of GSK458 was found to be associated with inactivation of AKT and mTOR, and induction of cell cycle arrest at the G0/G1 phase.

CONCLUSIONS

Based on our results, we conclude that GSK458 may serve as an attractive candidate to treat ovarian cancer.

Integrative Bioinformatics Approaches to Map Potential Novel Genes and Pathways Involved in Ovarian Cancer

Background and aims: Ovarian cancer (OC) is the seventh most commonly detected cancer among women. This study aimed to map the hub and core genes and potential pathways that might be involved in the molecular pathogenesis of OC.

Methods: In the present work, we analyzed a microarray dataset (GSE126519) from the Gene Expression Omnibus (GEO) database and used the GEO2R tool to screen OC cells and ovarian SINE-resistant cancer cells for differentially expressed genes (DEGs). For the functional annotation of the DEGs, we conducted Gene Ontology (GO) and pathway enrichment analyses (KEGG) using the DAVID v6.8 online server and GenoGo Metacore™, Cortellis Solution software. Protein–protein interaction (PPI) networks were constructed using the STRING database, and Cytoscape software was used for visualization. The survival analysis was performed using the online platform GEPIA2 to determine the prognostic value of the expression of hub genes in cell lines from OC patients.

Results: We identified a total of 809 upregulated and 700 downregulated DEGs. GO analysis revealed that the genes with statistically significant differences in expression were mainly associated with biological processes involved in the cell cycle, the mitotic cell cycle, mitotic nuclear division, organ morphogenesis, cell development, and cell morphogenesis. By using the Analyze Networks (AN) algorithm in GeneGo, we identified the most relevant biological networks involving DEGs that were mainly enriched in the cell cycle (in metaphase checkpoints) and revealed the role of APC in cell cycle regulation pathways. We found 10 hub genes and four core genes (FZD6, FZD8, CDK2, and RBBP8) that are strongly linked to OC.

Conclusion: This study sheds light on the molecular pathogenesis of OC and is expected to provide potential molecular biomarkers that are beneficial for the treatment and clinical molecular diagnosis of OC.