PI3K/ c-Myc/AFF4 axis promotes pancreatic tumorigenesis through fueling nucleotide metabolism

Cinobufagin regulates the microRNA-149-3p/AFF4 axis to affect the proliferation and apoptosis of cisplatin-resistant ovarian cancer cells

Although cinobufagin has been demonstrated to inhibit the growth of various malignant tumors, its functional role in ovarian cancer remains unclear. In light of this, the present study aims to thoroughly investigate the effects of cinobufagin on ovarian cancer progression and elucidate its underlying molecular mechanisms, thereby providing novel insights into future therapeutic strategies. A2780/DDP, a cisplatin-resistant cell line for ovarian cancer, was treated with gradient doses of cinobufagin. The microRNA-149-3p and AFF4 binding sites were predicted by bioinformatics. In cisplatin-resistant ovarian cancer cells, microRNA-149-3p and AFF4 expression were detected using qRT-PCR, and the binding association between microRNA-149-3p and AFF4 was confirmed by dual-luciferase and RIP assays. Cell viability was assessed using the CCK-8 test, cell proliferation was identified using the EdU assay and colony formation, and cell apoptosis was identified using flow cytometry. The results showed that cinobufagin inhibited the proliferation and promoted apoptosis of cisplatin-resistant ovarian cancer cells. microRNA-149-3p was highly expressed in cisplatin-resistant ovarian cancer cells, while AFF4 was lowly expressed in these cells. Overexpression of microRNA-149-3p promoted the proliferation and inhibited the apoptosis of cisplatin-resistant ovarian cancer cells, which was reversed by the addition of cinobufagin. Overexpression of AFF4 suppressed proliferation and promoted apoptosis of cisplatin-resistant ovarian cancer cells. MicroRNA-149-3p repressed AFF4 expression, and partial attenuation of the effects of AFF4 overexpression on cell phenotype was observed when microRNA-149-3p was overexpressed. In conclusion,cinobufagin regulated microRNA-149-3p/AFF4 axis to inhibit proliferation of ovarian cancer cells and promote cell apoptosis. Targeting the microRNA-149-3p/AFF4 axis with cinobufagin could represent a novel therapeutic strategy for ovarian cancer.

IMPDH2's Central Role in Cellular Growth and Diseases: A Potential Therapeutic Target

IMPDH2 is a rate-limiting enzyme in guanine nucleotide biosynthesis. It plays diverse roles in various physiological and pathological processes: nucleotide metabolism, inflammation, immune function, ribosomal stress. Structural or regulatory alterations in IMPDH2 are linked to significant health issues, and critical relevance in disease progression. We aim to underscore the potential of IMPDH2 as a promising therapeutic target for clinical applications.

Xanthine negatively regulates c-MYC through the PI3K/AKT signaling pathway and inhibits the proliferation, invasion, and migration of breast cancer cells

BACKGROUND AIM

Breast cancer is a prevalent and aggressive malignancy associated with elevated mortality rates worldwide. Dysregulation of the c-MYC oncogene and aberrant activation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway are common features in breast cancer progression, rendering them attractive therapeutic targets. Here, we assessed the effects of the plant derivative, xanthine, on breast cancer cells and explored the molecular mechanisms underlying its activity.

METHODS

Breast cancer cell lines were treated with xanthine, followed by assessment of c-MYC expression levels. Cell proliferation, invasion, and migration were analyzed to assess the effects of xanthine treatment on breast cancer cell behavior.

RESULTS

Xanthine treatment induced a decrease in c-MYC expression, resulting in significant inhibition of breast cancer cell proliferation, invasion, and migration. Mechanistic investigations revealed that these effects were mediated by suppression of the PI3K/AKT signaling pathway.

CONCLUSIONS

Xanthine shows great potential for breast cancer treatment by targeting c-MYC via the PI3K/AKT signaling pathway. Our findings indicate that development of xanthine as a novel treatment option for breast cancer, which acts by influencing key oncogenic pathways involved in tumor progression, may be warranted.

Vitexicarpin suppresses malignant progression of colorectal cancer through affecting c-Myc ubiquitination by targeting IMPDH2

BACKGROUND

Colorectal cancer (CRC) is the second most common cause of cancer-related mortality and is characterised by extensive invasive and metastatic potential. Previous studies have shown that vitexicarpin extracted from the fruits of Vitex rotundifolia can impede tumour progression. However, the molecular mechanisms involved in CRC treatment are still not fully established.

PURPOSE

Our study aimed to investigate the anticancer activity, targets, and molecular mechanisms of vitexicarpin in CRC hoping to provide novel therapies for patients with CRC.

STUDY DESIGN/METHODS

The impact of vitexicarpin on CRC was assessed through various experiments including MTT, clone formation, EDU, cell cycle, and apoptosis assays, as well as a tumour xenograft model. CETSA, label-free quantitative proteomics, and Biacore were used to identify the vitexicarpin targets. WB, Co-IP, Ubiquitination assay, IF, molecular docking, MST, and cell transfection were used to investigate the mechanism of action of vitexicarpin in CRC cells. Furthermore, we analysed the expression patterns and correlation of target proteins in TCGA and GEPIA datasets and clinical samples. Finally, wound healing, Transwell, tail vein injection model, and tissue section staining were used to demonstrate the antimetastatic effect of vitexicarpin on CRC in vitro and in vivo.

RESULTS

Our findings demonstrated that vitexicarpin exhibits anticancer activity by directly binding to inosine monophosphate dehydrogenase 2 (IMPDH2) and that it promotes c-Myc ubiquitination by disrupting the interaction between IMPDH2 and c-Myc, leading to epithelial-mesenchymal transition (EMT) inhibition. Vitexicarpin hinders the migration and invasion of CRC cells by reversing EMT both in vitro and in vivo. Additionally, these results were validated by the overexpression and knockdown of IMPDH2 in CRC cells.

CONCLUSION

These results demonstrated that vitexicarpin regulates the interaction between IMPDH2 and c-Myc to inhibit CRC proliferation and metastasis both in vitro and in vivo. These discoveries introduce potential molecular targets for CRC treatment and shed light on new mechanisms for c-Myc regulation in tumours.

IMPDH2 suppression impedes cell proliferation by instigating cell cycle arrest and stimulates apoptosis in pediatric hepatoblastoma

BACKGROUND

Hepatoblastoma (HB) is the most common pediatric liver tumor, presenting significant therapeutic challenges due to its high rates of recurrence and metastasis. While Inosine Monophosphate Dehydrogenase 2(IMPDH2) has been associated with cancer progression, its specific role and clinical implications in HB have not been fully elucidated.

METHODS

This study utilized Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Tissue Microarray (TMA) for validation. Following this, IMPDH2 was suppressed, and a series of in vitro assays were conducted. Flow cytometry was employed to assess apoptosis and cell cycle arrest. Additionally, the study explored the synergistic therapeutic effects of mycophenolate mofetil (MMF) and doxorubicin (DOX) on HB cell lines.

RESULTS

The study identified a marked overexpression of IMPDH2 in HB tissues, which was strongly correlated with reduced Overall Survival (OS) and Event-Free Survival (EFS). IMPDH2 upregulation was also found to be associated with key clinical-pathological features, including pre-chemotherapy alpha-fetoprotein (AFP) levels, presence of preoperative metastasis, and the pre-treatment extent of tumor (PRETEXT) staging system. Knockdown of IMPDH2 significantly inhibited HB cell proliferation and tumorigenicity, inducing cell cycle arrest at the G0/G1 phase. Notably, the combination of MMF, identified as a specific IMPDH2 inhibitor, with DOX, substantially enhanced the therapeutic response.

CONCLUSION

The overexpression of IMPDH2 was closely linked to adverse outcomes in HB patients and appeared to accelerate cell cycle progression. These findings suggest that IMPDH2 may serve as a valuable prognostic indicator and a potential therapeutic target for HB.

IMPACT

The present study unveiled a significant overexpression of inosine monophosphate dehydrogenase 2 (IMPDH2) in hepatoblastoma (HB) tissues, particularly in association with metastasis and recurrence of the disease. The pronounced upregulation of IMPDH2 was found to be intimately correlated with adverse outcomes in HB patients. This overexpression appears to accelerate the progression of the cell cycle, suggesting that IMPDH2 may serve as a promising candidate for both a prognostic marker and a therapeutic target in the context of HB.

Molecular evolution of transcription factors AF4/FMR2 family member (AFF) gene family and the role of lamprey AFF3 in cell proliferation

AF4/FMR2 family member (AFF) proteins are a group of transcriptional regulators that can regulate gene transcription and play an important role in cellular physiological processes such as proliferation and differentiation. The transcriptome data of the lamprey spinal cord injury were analyzed in previous research. We then identified a hub gene, Lr-AFF3, from this dataset. Phylogenetic tree analysis determined the evolutionary relationships of the AFF gene family across different species. In addition, analysis of motifs, domains, and 3D structures further confirmed the conservatism of the AFF gene family. In particular, the gene structure of the AFF3 gene was not conserved, possibly because of intron insertion. It was also found that the neighboring genes of the Lr-AFF3 gene had a higher diversity than that in jawed vertebrates through synteny analysis. The results of the MTT and EdU experiments showed that the C-terminal homology domain (CHD) and N-terminal homology domain (NHD) of Lr-AFF3 promoted cell proliferation. In summary, our research will not only provide new insights into the origin and evolution of the AFF gene family in different species, but also provide new clues for the functions of Lr_AFF3.

Fundamental insights and molecular interactions in pancreatic cancer: Pathways to therapeutic approaches

The gastrointestinal tract can be affected by a number of diseases that pancreatic cancer (PC) is a malignant manifestation of them. The prognosis of PC patients is unfavorable and because of their diagnosis at advanced stage, the treatment of this tumor is problematic. Owing to low survival rate, there is much interest towards understanding the molecular profile of PC in an attempt in developing more effective therapeutics. The conventional therapeutics for PC include surgery, chemotherapy and radiotherapy as well as emerging immunotherapy. However, PC is still incurable and more effort should be performed. The molecular landscape of PC is an underlying factor involved in increase in progression of tumor cells. In the presence review, the newest advances in understanding the molecular and biological events in PC are discussed. The dysregulation of molecular pathways including AMPK, MAPK, STAT3, Wnt/β-catenin and non-coding RNA transcripts has been suggested as a factor in development of tumorigenesis in PC. Moreover, cell death mechanisms such as apoptosis, autophagy, ferroptosis and necroptosis demonstrate abnormal levels. The EMT and glycolysis in PC cells enhance to ensure their metastasis and proliferation. Furthermore, such abnormal changes have been used to develop corresponding pharmacological and nanotechnological therapeutics for PC.

The Biological Significance of AFF4: Promoting Transcription Elongation, Osteogenic Differentiation and Tumor Progression

As a member of the AF4/FMR2 (AFF) family, AFF4 is a scaffold protein in the superelongation complex (SEC). In this mini-view, we discuss the role of AFF4 as a transcription elongation factor that mediates HIV activation and replication and stem cell osteogenic differentiation. AFF4 also promotes the progression of head and neck squamous cell carcinoma, leukemia, breast cancer, bladder cancer and other malignant tumors. The biological function of AFF4 is largely achieved through SEC assembly, regulates SRY-box transcription factor 2 (SOX2), MYC, estrogen receptor alpha (ESR1), inhibitor of differentiation 1 (ID1), c-Jun and noncanonical nuclear factor-κB (NF-κB) transcription and combines with fusion in sarcoma (FUS), unique regulatory cyclins (CycT1), or mixed lineage leukemia (MLL). We explore the prospects of using AFF4 as a therapeutic in Acquired immunodeficiency syndrome (AIDS) and malignant tumors and its potential as a stemness regulator.