KLF14 targets ITGB1 to inhibit the progression of cervical cancer via the PI3K/AKT signalling pathway

Emerging roles of non-coding RNAs in modulating the PI3K/Akt pathway in cancer

Cancer progression results from the dysregulation of molecular pathways, each with unique features that can either promote or inhibit tumor growth. The complexity of carcinogenesis makes it challenging for researchers to target all pathways in cancer therapy, emphasizing the importance of focusing on specific pathways for targeted treatment. One such pathway is the PI3K/Akt pathway, which is often overexpressed in cancer. As tumor cells progress, the expression of PI3K/Akt increases, further driving cancer advancement. This study aims to explore how ncRNAs regulate the expression of PI3K/Akt. NcRNAs are found in both the cytoplasm and nucleus, and their functions vary depending on their location. They can bind to the promoters of PI3K or Akt, either reducing or increasing their expression, thus influencing tumorigenesis. The ncRNA/PI3K/Akt axis plays a crucial role in determining cell proliferation, metastasis, epithelial-mesenchymal transition (EMT), and even chemoresistance and radioresistance in human cancers. Anti-tumor compounds can target ncRNAs to modulate the PI3K/Akt axis. Moreover, ncRNAs can regulate the PI3K/Akt pathway both directly and indirectly.

KLF14 directly downregulates the expression of GPX4 to exert antitumor effects by promoting ferroptosis in cervical cancer

BACKGROUND

Cervical cancer is the fourth leading cause of cancer-related death among women worldwide, and effective therapeutic strategies for its treatment are limited. Recent studies have indicated that ferroptosis, a form of regulated cell death, is a promising therapeutic strategy. KLF14 has been shown to regulate both cell proliferation and apoptosis in cervical cancer. However, its role in modulating lipid peroxidation and ferroptosis remains largely unexplored and enigmatic.

METHODS

SiHa and HeLa cells were transduced with lentiviral vectors to overexpress KLF14. Protein levels were analyzed via western blotting and immunohistochemistry (IHC). LDH assays, calcein-AM/propidium iodide (PI) staining, and generation of cell growth curves using a real-time cell analysis (RTCA) system were used to detect cell damage and proliferation. Cellular ROS, lipid ROS, transmission electron microscopy (TEM), and Fe2+ assays and a xenograft mouse model were used to measure the level of ferroptosis. Proteomics combined with bioinformatics methods was used to screen target genes regulated by KLF14, and CUT&Tag and dual-luciferase assays confirmed the repression of GPX4 by KLF14 via direct binding to its promoter.

RESULTS

KLF14 is abnormally expressed in various tumors and downregulated in cervical cancer. Overexpression of KLF14 induced ferroptosis and inhibited cell proliferation in vitro as well as xenograft tumorigenicity in vivo. Mechanistic studies revealed that KLF14 binds to the promoter of GPX4, suppressing its transcriptional activity and thereby decreasing its expression, which contributes to the induction of ferroptosis. Truncation and point mutation analyses of the GPX4 promoter revealed multiple binding sites for KLF14 within the - 1000 bp to + 35 bp region, which are responsible for its inhibitory effect on GPX4 transcription. Additionally, deletion of the zinc finger motif in KLF14 abolished its inhibitory effect on GPX4 promoter activity and cell proliferation.

CONCLUSION

Our data revealed a previously unidentified function of KLF14 in promoting ferroptosis, which results in the suppression of cell proliferation. Mechanistically, we revealed a novel regulatory mechanism by which KLF14 targets GPX4. These findings suggest a novel strategy to induce ferroptosis through the targeting of KLF14 in human cervical cancer cells.

Molecular mechanism of WWP1-mediated ubiquitination modification affecting proliferation and invasion/migration of liver cancer cells

Liver cancer is the most prevalent fatal malignancy across the globe. The present study aims to explore the molecular mechanism of E3 ligase WWP1 in liver cancer cell proliferation and invasion/migration. RT-qPCR and Western blot were performed to detect WWP1, KLF14, and VEPH1 expressions in liver cancer cell lines. Furthermore, WWP1 expression was silenced in cells, followed by the detection of cell viability, proliferation, and invasion/migration by CCK-8, colony formation, and Transwell assays, respectively. ChIP was used to analyze the binding relationship between WWP1 and KLF14. We measured the KLF14 ubiquitination level and KLF14 enrichment on the VEPH1 promoter after MG132 treatment. Dual-luciferase reporter assay was used to validate the binding relationship between KLF14 and VEPH1. Consequently, WWP1 was highly expressed in liver cancer cells; WWP1 silencing reduced the proliferation and invasion/migration of liver cancer cells. Mechanistically, WWP1 promoted KLF14 ubiquitination degradation; KLF14 was enriched on the VEPH1 promoter to promote its transcription and protein expression. Inhibiting KLF14 or VEPH1 partially minimized the inhibitory effect of WWP1 silencing on liver cancer cell proliferation and invasion/migration. In summary, WWP1 degrades KLF14 through ubiquitination, hence repressing VEPH1 expression and accelerating proliferation and invasion/migration of liver cancer cells.

The kruppel-like factor (KLF) family, diseases, and physiological events

The Kruppel-Like Factor family of regulatory proteins, which has 18 members, is transcription factors. This family contains zinc finger proteins, regulates the activation and suppression of transcription, and binds to DNA, RNA, and proteins. Klfs related to the immune system are Klf1, Klf2, Klf3, Klf4, Klf6, and Klf14. Klfs related to adipose tissue development and/or glucose metabolism are Klf3, Klf7, Klf9, Klf10, Klf11, Klf14, Klf15, and Klf16. Klfs related to cancer are Klf3, Klf4, Klf5, Klf6, Klf7, Klf8, Klf9, Klf10, Klf11, Klf12, Klf13, Klf14, Klf16, and Klf17. Klfs related to the cardiovascular system are Klf4, Klf5, Klf10, Klf13, Klf14, and Klf15. Klfs related to the nervous system are Klf4, Klf7, Klf8, and Klf9. Klfs are associated with diseases such as carcinogenesis, oxidative stress, diabetes, liver fibrosis, thalassemia, and the metabolic syndrome. The aim of this review is to provide information about the relationship of Klfs with some diseases and physiological events and to guide future studies.

Circular RNAs and cervical cancer: friends or foes? A landscape on circRNA-mediated regulation of key signaling pathways involved in the onset and progression of HPV-related cervical neoplasms

Cervical cancer (CC) is a common gynecologic malignancy, accounting for a significant proportion of women death worldwide. Human papillomavirus (HPV) infection is one of the major etiological causes leading to CC onset; however, genetic, and epigenetic factors are also responsible for disease expansion. Circular RNAs (circRNAs), which are known as a particular subset of non-coding RNA (ncRNA) superfamily, with covalently closed loop structures, have been reported to be involved in the progression of diverse diseases, especially neoplasms. In this framework, abnormally expressed circRNAs are in strong correlation with CC pathogenesis through regulating substantial signaling pathways. Also, these RNA molecules can be considered as promising biomarkers and therapeutic targets for CC diagnosis/prognosis and treatment, respectively. Herein, we first review key molecular mechanisms, including Wnt/β-catenin, MAPK, and PI3K/Akt/mTOR signaling pathways, as well as angiogenesis and metastasis, by which circRNAs interfere with CC development. Then, diagnostic, prognostic, and therapeutic potentials of these ncRNA molecules will be highlighted in depth.

Molecular landscape of congenital vertebral malformations: recent discoveries and future directions

Vertebral malformations (VMs) pose a significant global health problem, causing chronic pain and disability. Vertebral defects occur as isolated conditions or within the spectrum of various congenital disorders, such as Klippel-Feil syndrome, congenital scoliosis, spondylocostal dysostosis, sacral agenesis, and neural tube defects. Although both genetic abnormalities and environmental factors can contribute to abnormal vertebral development, our knowledge on molecular mechanisms of numerous VMs is still limited. Furthermore, there is a lack of resource that consolidates the current knowledge in this field. In this pioneering review, we provide a comprehensive analysis of the latest research on the molecular basis of VMs and the association of the VMs-related causative genes with bone developmental signaling pathways. Our study identifies 118 genes linked to VMs, with 98 genes involved in biological pathways crucial for the formation of the vertebral column. Overall, the review summarizes the current knowledge on VM genetics, and provides new insights into potential involvement of biological pathways in VM pathogenesis. We also present an overview of available data regarding the role of epigenetic and environmental factors in VMs. We identify areas where knowledge is lacking, such as precise molecular mechanisms in which specific genes contribute to the development of VMs. Finally, we propose future research avenues that could address knowledge gaps.

KLF14 activates the JNK-signaling pathway to induce S-phase arrest in cervical cancer cells

Objective

To explore the role of Krüppel-like factor 14 (KLF14) and its underlying mechanism(s) of action in cell-cycle regulation in cervical cancer.

Methods

Lentiviral infection was used to construct KLF14, KLF14 zinc-finger structural mutations, and empty vector controls in SiHa and HeLa cervical cancer cells. The effect of KLF14 on cervical cancer cell cycle was detected by flow cytometry. The effect of KLF14 on the expression of cyclin-dependent kinase 2 (CDK2), cyclin A2 (CCNA2), and MAPK signalling pathway-related molecules was detected by fluorescence quantitative RT-PCR (qRT-PCR) and western blot. Cervical cancer cells were treated with JNK-pathway inhibitors/agonists before we assessed changes in the cell cycle and the expression of the CDK2, CCNA2, and p-JNK/JNK. Subcutaneous xenograft studies to explore the effects of KLF14 on cervical cancer cell proliferation in vivo, and western blotting was implemented to measure the expression of CCNA2, CDK2, and the activation levels of the MAPK-signaling pathway proteins in tumours.

Results

The proportion of cells in the S phase was increased in the KLF14-overexpressing group compared with the control group (P<0.001); CDK2, CCNA2, and p-JNK/JNK expression levels were elevated in the KLF14-overexpressing group relative to the control group (all P<0.05). When JNK-pathway activation was inhibited/promoted, the proportion of cells in the S phase was reduced/increased (P<0.05) and CDK2 and CCNA2 expression levels were reduced/decreased, respectively (all P<0.05). Vivo experiments revealed that KLF14 inhibited cervical cancer cell proliferation (P<0.01) and that p-JNK/JNK, CDK2, and CCNA2 expression levels were augmented in tumours in the overexpression group (P<0.01).

Conclusion

KLF14 induced S-phase arrest in cervical cancer cells and inhibited the proliferation of cervical cancer cells in vivo; the induction of S-phase arrest was related to its zinc-finger structure. KLF14 also activated the JNK pathway to induce S-phase arrest and promote the expression of CDK2 and CCNA2. In summary, KLF14 activates the JNK-signaling pathway to induce S-phase arrest in cervical cancer cells.

Potential Impact of PI3K-AKT Signaling Pathway Genes, KLF-14, MDM4, miRNAs 27a, miRNA-196a Genetic Alterations in the Predisposition and Progression of Breast Cancer Patients

Genome-wide association studies have reported link between SNPs and risk of breast cancer. This study investigated the association of the selected gene variants by predicting them as possible target genes. Molecular technique advances with the availability of whole-exome sequencing (WES), now offer opportunities for simultaneous investigations of many genes. The experimental protocol for PI3K, AKT-1, KLF-14, MDM4, miRNAs 27a, and miR-196a genotyping was done by ARMS-PCR and sanger sequencing. The novel and known gene variants were studied by Whole-exome sequencing using Illumina NovaSeq 6000 platform. This case control study reports significant association between BC patients, healthy controls with the polymorphic variants of PI3K C > T, AKT-1 G > A KLF 14 C > T, MDM4 A > G, miR-27a A > G, miR-196a-2 C > T genes (p < 0.05). MDM4 A > G genotypes were strongly associated with BC predisposition with OR 2.08 & 2.15, p < 0.05) in codominant and dominant models respectively. MDM4 A allele show the same effective (OR1.76, p < 0.05) whereas it remains protective in recessive model for BC risk. AKT1G > A genotypes were strongly associated with the BC susceptibility in all genetic models whereas PI3K C > T genotypes were associated with breast cancer predisposition in recessive model OR 6.96. Polymorphic variants of KLF-14 A > G, MDM4G > A, MiR-27aA >G, miR-196a-C > T were strongly associated with stage, tamoxifen treatment. Risk variants have been reported by whole exome sequencing in our BC patients. It was concluded that a strong association between the PI3K-AKT signaling pathway gene variants with the breast cancer susceptibility and progression. Similarly, KLF 14-AA, MDM4-GA, miR27a-GG and miR-196a-CT gene variants were associated with the higher risk probability of BC and were strongly correlated with staging of the BC patients. This study also reported Low, novel, and intermediate-genetic-risk variants of PI3K, AKT-1, MDM4G & KLF-14 by utilizing whole-exome sequencing. These variants should be further investigated in larger cohorts' studies.

Krüppel-like factors in tumors: Key regulators and therapeutic avenues

Krüppel-like factors (KLFs) are a group of DNA-binding transcriptional regulators with multiple essential functions in various cellular processes, including proliferation, migration, inflammation, and angiogenesis. The aberrant expression of KLFs is often found in tumor tissues and is essential for tumor development. At the molecular level, KLFs regulate multiple signaling pathways and mediate crosstalk among them. Some KLFs may also be molecular switches for specific biological signals, driving their transition from tumor suppressors to promoters. At the histological level, the abnormal expression of KLFs is closely associated with tumor cell stemness, proliferation, apoptosis, and alterations in the tumor microenvironment. Notably, the role of each KLF in tumors varies according to tumor type and different stages of tumor development rather than being invariant. In this review, we focus on the advances in the molecular biology of KLFs, particularly the regulations of several classical signaling pathways by these factors, and the critical role of KLFs in tumor development. We also highlight their strong potential as molecular targets in tumor therapy and suggest potential directions for clinical translational research.