Polyploid giant cancer cells: origin, possible pathways of formation, characteristics, and mechanisms of regulation

Formation of polyploid giant cancer cells and the transformative role of human cytomegalovirus IE1 protein

Human cytomegalovirus (HCMV) infection has been linked to various cancers, including glioblastoma (GB), breast cancer (BC), and ovarian epithelial cancer (OC) especially high grade serous ovarian cancer (HGSOC). HCMV gene products control tumorigenic cellular pathways and processes associated with all the hallmarks of cancer. Among the suspected HCMV proteins involved in cellular transformation, the immediate early-1 (IE1) protein stands out as a significant player. Herein, we presented the experimental evidence supporting HCMV-IE1 role as a reprogramming factor that induces the transformation of human ovarian epithelial cells (OECs) resulting in the generation of "CMV transformed ovarian epithelial cells-IE1″ or CTO-IE1. These transformed cells exhibit similarities to those previously reported by our group, following infection with the high-risk oncogenic HCMV strain DB. HCMV-IE1-DB protein triggered distinct cellular and molecular mechanisms in stably transduced OECs. This included downregulation of Rb/p53 and upregulation of Myc/EZH2, concurrent with the emergence of polyploid giant cancer cells (PGCCs) and giant cell cycling in the culture. HCMV-IE1-DB silencing limited cellular transformation and stemness. In HGSOC, PGCCs were detected in the presence of IE1; the latter positively correlated with Myc. In addition, HCMV IE1 exhibits transforming capabilities in human mammary epithelial cells (HMECs) and human astrocytes (HAs) in vitro, reflecting its potential role in the transformation observed in vivo. This highlights the tumorigenic properties of Myc/EZH2 in the context of IE1-mediated transformation parallel to PGCCs appearance.

miR-1246 enhances chemo-resistance of polyploid giant cancer cells in H1299 cells by targeting GSK3β/β-catenin

Non-small cell lung cancer (NSCLC) is characterized by a high mortality rate. Chemotherapy has been observed to potentially increase the prevalence of polyploid giant cancer cells (PGCCs), which may play a role in the development of chemo-resistance in NSCLC. The dysregulated expression of miR-1246 has been implicated in the modulation of gene expression related to drug resistance. Therefore, the objective of this study is to examine the role of miRNA-1246 in PGCCs and to elucidate its regulatory mechanisms. H1299 cells were treated with 100 nM docetaxel (Doc) for 24 h, then allowed to recover for 3 days to form polyploid giant cancer cells (PGCCs). The miRNA profiles of these PGCCs were analyzed, focusing on miR-1246. Transfection with miR-1246 mimics or inhibitors was performed, and various assays were used to assess the effects of miR-1246 inn PGCCs. The study found miR-1246 levels were significantly higher in PGCCs than in the original cells, affecting chemo-resistance, apoptosis, migration, and epithelial-mesenchymal transition. These findings suggested that NSCLC H1299 cells may employ polyploidy formation as a survival mechanism in response to docetaxel-based treatment, mediated by the miR-1246/GSK3β/β-catenin axis, ultimately leading to enhanced chemo-resistance.

Interleukin-6 Is a Crucial Factor in Shaping the Inflammatory Tumor Microenvironment in Ovarian Cancer and Determining Its Hot or Cold Nature with Diagnostic and Prognostic Utilities

Ovarian cancer (OC) remains the leading cause of cancer-related deaths among women, often diagnosed at advanced stages due to the lack of effective early diagnostic procedures. To reduce the high mortality rates in OC, reliable biomarkers are urgently needed, especially to detect OC at its earliest stage, predict specific drug responses, and monitor patients. The cytokine interleukin-6 (IL6) is associated with low survival rates, treatment resistance, and recurrence. In this review, we summarize the role of IL6 in inflammation and how IL6 contributes to ovarian tumorigenesis within the tumor microenvironment, influencing whether the tumor is subsequently classified as "hot" or "cold". We further dissect the molecular and cellular mechanisms through which IL6 production and downstream signaling are regulated, to enhance our understanding of its involvement in OC development, as well as OC resistance to treatment. We highlight the potential of IL6 to be used as a reliable diagnostic biomarker to help detect OC at its earliest stage, and as a part of predictive and prognostic signatures to improve OC management. We further discuss ways to leverage artificial intelligence and machine learning to integrate IL6 into diverse biomarker-based strategies.

Misconceptions Thrive in the Field of Cancer as Technological Advances Continue to Confuse Stem Cell Biology

Despite the huge thrust on targeted therapies, cancer survival rates have not improved and both cancer incidence and fatalities continue to rise globally. There is no consensus on how cancer initiates and two contrasting views were published in 2024 regarding cancer initiation. Based on the premise that no stem cells exist in tissues like liver, lungs, and pancreas but they are still affected by cancer; it was suggested that somatic cells dedifferentiate and undergo 'paligenosis' to initiate cancer. The second view discussed that tissue-resident, very small embryonic-like stem cells (VSELs) are vulnerable to extrinsic/intrinsic insults and their dysfunctions initiate cancer. The present article examines the underlying technical reasons that have led to these conflicting views. Scientists have struggled to detect quiescent cancer stem cells (CSCs) that survive chemotherapy, and radiotherapy and escape immunotherapy, cause recurrence and eventually therapeutic resistance leading to death. Lineage tracing studies fail to detect quiescent, acyclic stem cells and instead, the role of actively dividing LGR5+ cells was highlighted for tumor initiation, growth, and metastasis. Similarly, technologies like flow cytometry, and single-cell RNAseq, widely used to comprehend cancer biology, provide insights into cell populations present in abundance. Our article reviews why VSELs/CSCs in the pancreas have remained elusive despite employing advanced technologies, and the critique can be generalized to multiple other organs. This understanding is crucial as it will help to develop better therapeutic strategies for cancer, offer early detection when cancer is a weak disease, and pave the path for prevention over treatment.

Immunohistochemical analysis of smooth muscle actin and CD31 in feline post-injection site fibrosarcomas: association with tumour grade, vascular density, and multinucleated giant cells

BACKGROUND

Multinucleated giant cells are commonly observed in various malignancies; however their clinical and biological significance remains largely unexplored and it has been hypothesised that the cells may play a role in vascular mimicry, tumour progression and tumour survival. This study aimed to investigate the expression of smooth muscle actin and CD31 in feline post-injection site fibrosarcomas, focusing on relationships between multinucleated giant cells presence, tumour grade, and vascular density to elucidate their potential role in tumour progression.

RESULTS

A total of 61 feline post-injection site fibrosarcomas, histologically graded into grades I, II, and III, were examined immunohistochemically. Smooth muscle actin immunoreactivity was detected in 57/61 (93.4%) cases. Multinucleated giant cells expressing CD31 were identified in 39/61 (63.9%) cases, predominantly in high-grade tumours, with a correlation observed between multinucleated giant cell presence, tumour grade, and mitotic index. Vascular density differed across tumour grades. A negative correlation between vascular density, tumour grade and necrosis score was identified. Additionally, a negative correlation was observed between multinucleated giant cells presence and vascular density.

CONCLUSIONS

The findings suggest a complex tumour microenvironment in which multinucleated giant cells and vascular mimicry may facilitate tumour survival under hypoxic conditions, potentially contributing to an aggressive tumour phenotype.

Activation of a Src-JNK pathway in unscheduled endocycling cells of the Drosophila wing disc induces a chronic wounding response

The endocycle is a specialized cell cycle during which cells undergo repeated G / S phases to replicate DNA without division, leading to large polyploid cells. The transition from a mitotic cycle to an endocycle can be triggered by various stresses, which results in unscheduled, or induced endocycling cells (iECs). While iECs can be beneficial for wound healing, they can also be detrimental by impairing tissue growth or promoting cancer. However, the regulation of endocycling and its role in tissue growth remain poorly understood. Using the Drosophila wing disc as a model, we previously demonstrated that iEC growth is arrested through a Jun N-Terminal Kinase (JNK)-dependent, reversible senescence-like response. However, it remains unclear how JNK is activated in iECs and how iECs impact overall tissue structure. In this study, we performed a genetic screen and identified the Src42A-Shark-Slpr pathway as an upstream regulator of JNK in iECs, leading to their senescence-like arrest. We found that tissues recognize iECs as wounds, releasing wound-related signals that induce a JNK-dependent developmental delay. Similar to wound closure, this response triggers Src-JNK-mediated actomyosin remodeling, yet iECs persist rather than being eliminated. Our findings suggest that the tissue response to iECs shares key signaling and cytoskeletal regulatory mechanisms with wound healing and dorsal closure, a developmental process during Drosophila embryogenesis. However, because iECs are retained within the tissue, they create a unique system that may serve as a model for studying chronic wounds and tumor progression.

NUP155 and NDC1 interaction in NSCLC: a promising target for tumor progression

Background

NUP155 was reported to involve breast invasive carcinoma and hepatocellular carcinoma. We hypothesized that NUP155 and NDC1impacted the progression of NSCLC.

Methods

The dataset was analyzed to find differentially expressed genes. Functional enrichment analysis and Kaplan-Meier survival analysis were performed for differentially expressed genes. Western blot, Clone formation assay, Transwell assay and CCK-8 assay were performed to determine the performance and role of the target gene in NSCLC.

Results

The research found that the NUP family played a role in various diseases. Differential expression analysis and survival analysis were performed to identify 6 related-genes, including NUP155, NDC1, KPNA2, MAD2L1, NUP62CL, and POM121L2NUP155 and NDC1 could interact with NUP53, respectively. This effect was necessary to complete the assembly of the nuclear pore complex.

Conclusion

NUP155 interacted with NDC1 to complete the assembly of the nuclear pore complex, which promoted the development of NSCLC. Our study demonstrated that NUP155 was expected to be a potential target for the treatment of NSCLC.

Emerging Paradigms in Cancer Metastasis: Ghost Mitochondria, Vasculogenic Mimicry, and Polyploid Giant Cancer Cells

The capacity of cancer cells to migrate from a primary tumor, disseminate throughout the body, and eventually establish secondary tumors is a fundamental aspect of metastasis. A detailed understanding of the cellular and molecular mechanisms underpinning this multifaceted process would facilitate the rational development of therapies aimed at treating metastatic disease. Although various hypotheses and models have been proposed, no single concept fully explains the mechanism of metastasis or integrates all observations and experimental findings. Recent advancements in metastasis research have refined existing theories and introduced new ones. This review evaluates several novel/emerging theories, focusing on ghost mitochondria (GM), vasculogenic mimicry (VM), and polyploid giant cancer cells (PGCCs).