Background/Aimγ-Glutamylcyclotransferase (GGCT) depletion suppresses breast cancer cell proliferation by inducing cellular senescence. However, the underlying molecular mechanisms have not been fully elucidated. Therefore, the objective of this study was to elucidate the mechanisms by which GGCT depletion suppresses cancer cell proliferation.Materials and MethodsHuman breast cancer MCF-7 cells were transfected with GGCT-specific or control siRNAs. Transcriptomic profiling by RNA sequencing identified differentially expressed genes (q<0.01, |log₂ fold change|>1), and Gene Ontology and KEGG analyses characterized affected pathways. Key genes and functional effects on the TGF-β2/SMAD3 axis, cell-cycle progression, and senescence were validated by qRT-PCR, western blotting, and SA-β-Gal assays.ResultsComprehensive gene expression analysis revealed that depletion of GGCT increases the expression levels of the cell cycle arrest factors CDKN1A (p21Cip1) and CDKN2B (p15INK4b), accompanied by elevated transforming growth factor-β2 (TGFB2) expression. Blocking this pathway through the simultaneous knockdown of TGFB2 was found to significantly restore the growth-inhibitory effect mediated by cellular senescence induced by GGCT depletion. This finding demonstrated that these phenotypes depend on the TGF-β2 pathway. Furthermore, we identified SMAD3 as a TGF-β2 downstream factor essential for the increase in p21Cip1 and p15INK4b and the growth-inhibitory effect induced by GGCT depletion.ConclusionActivation of the TGF-β2/SMAD3 pathway is a mechanism by which cellular senescence is induced through GGCT depletion, suggesting that GGCT inhibition represents a promising therapeutic strategy for the treatment of breast cancer.

For decades, the "death of cancer cytogenetics" has been repeatedly proclaimed and has grown louder in the era of omics. However, cytogenetics continues to evolve, retaining its central role in the study of chromosomes. From the microscopic visualization of numerical and structural aberrations using staining and banding techniques, the field has steadily incorporated new methodologies, including fluorescence in situ hybridization, array comparative genomic hybridization, high-throughput sequencing, and, most recently, optical genome mapping. These approaches have revealed unprecedented details of chromosome structure and behavior, uncovered catastrophic genomic events in cancer, and given rise to new concepts such as cytogenomics and chromosomics. Although cytogenetics is sometimes viewed as synonymous with chromosome banding, its scope, namely the study of chromosome structure and behavior, extends far beyond any single method. Chromosomes remain indispensable for understanding genome architecture, chromosomal instability, and fusion-gene mechanisms in neoplasia, irrespective of the technologies applied. Rooted in its past yet continually branching outwards with each scientific advance, today's cytogenetics integrates classical and modern approaches, carrying forward the legacy of chromosome banding while adopting genome-wide technologies. These developments underscore the enduring importance of cytogenetics for interpreting the structural complexity of cancer genomes. This review aims to demonstrate that cytogenetics, far from being obsolete, remains a vital component of modern cancer research by highlighting essential insights into chromosome structure, genome architecture, and fusion-gene mechanisms in the era of -omics.

Although aldehyde dehydrogenases 1 family member A1 (ALDH1A1) has been extensively studied in cancer, its role in hepatocellular carcinoma (HCC) remains poorly understood. This study was designed to characterize the expression pattern and functional roles of ALDH1A1 in HCC, and to further investigate its underlying molecular mechanisms using integrated proteomic analysis. This study performed a pan-cancer analysis of ALDH1A1 expression, followed by validation of its expression levels in HCC tissue samples and cell lines. The expression of ALDH1A1 was manipulated using small interfering RNAs and lentiviral vector in HCC cell lines. And then the proliferation, migration, invasion, and tumorigenicity of HCC cells were observed in vitro and in vivo. Quantitative proteomic and phosphoproteomic profiling were conducted by liquid chromatography-tandem mass spectrometry, with comprehensive analyses and key findings validated by experiments. ALDH1A1 was highly expressed in HCC tissues but exhibited notable expression heterogeneity among HCC cell lines. Functionally, ALDH1A1 promoted the proliferation, migration, and tumorigenicity of HCC cells, while suppressing apoptosis and modestly attenuates invasion. Quantitative proteomic and phosphoproteomic analyses revealed that ALDH1A1 profoundly reshaped both protein expression and phosphorylation landscapes in HCC. Furthermore, we validated that ALDH1A1 positively regulates the expression of DMPK, PCMTD2, VAMP4, ARHGAP19, NOL4L, and ST7, while suppressing SLC31A1, DSTYK, CYP4F12, GPNMB expression. Rescue experiments indicated that ALDH1A1 may promote HCC via activating Rho family small GTPase. ALDH1A1 also significantly upregulated mTOR phosphorylation. ALDH1A1 acts as an oncogenic driver and regulatory hub in HCC.

Background/AimSIRT4 is a mitochondrial regulator of metabolism and stress responses, yet the mechanisms underlying its induction upon DNA damage remains unclear. This study aimed to define the mechanism of SIRT4 regulation and the role of the miR-15/16 family in this process.Materials and MethodsSIRT4 expression was examined after DNA-damaging treatments in MEFs and HeLa cells. Reporter assays, mRNA decay analysis, and mutagenesis of the SIRT4 3’UTR were performed to identify regulatory mechanisms. Gain- and loss-of-function studies assessed the involvement of the miR-15/16 family. Cell viability was evaluated.ResultsSIRT4 was strongly induced by DNA damage and required for cell survival under genotoxic stress. This induction occurred through mRNA stabilization with the 3’UTR of SIRT4 serving as the determinant of stability. The miR-15/16 family targeted a conserved site within the SIRT4 3’UTR to destabilize its mRNA. Overexpression of miR-15/16 reduced SIRT4 expression and sensitized cells to chemotherapy.ConclusionThe miR-15/16-SIRT4 axis represents a novel mechanism of post-transcriptional regulation in the DNA damage response and may serve as a therapeutic target to improve the efficacy of chemotherapy.

Background/AimLocally advanced Rectal cancer (RC) is treated with neoadjuvant chemoradiation, but treatment resistance is common. We have previously shown that ST6GAL1 causes RC chemoradiation resistance. Exosomes are small particles that can transfer proteins between cells. We hypothesized that exosomes transfer ST6GAL1 between RC cells, spreading treatment resistance.Materials and MethodsWe characterized exosomes isolated from multiple ST6GAL1-expressing colorectal cancer (CRC) cell lines. Treatment response was assessed in ST6GAL1-knockdown (KD) cells treated with these exosomes. Single cell RNA sequencing (scRNA-seq) and flow cytometry for surface sialylation were performed on CRC organoids to compare presence of ST6GAL1 RNA and protein activity.ResultsExosomes from multiple CRC cell lines contained ST6GAL1 protein and ST6GAL1 KD cells treated with these exosomes demonstrated transfer of ST6GAL1 with increase in protein in treated cells, but not mRNA, and the protein localized to the Golgi complex. In addition, treated cells demonstrated increased resistance to chemoradiation-induced apoptosis (p=0.02, n=4) and increased colony formation after treatment (p=0.01, n=4). Single cell sequencing revealed that only 16 percent of cells have ST6GAL1 mRNA but 86 percent have evidence of ST6GAL1 protein activity.ConclusionThese findings demonstrate that ST6GAL1-containing rectal cancer exosomes transfer ST6GAL1 between cells causing treatment resistance.

Background/AimProstate cancer, a leading global malignancy, exhibits variable progression influenced by angiogenesis, the formation of new blood vessels critical for tumor growth and metastasis. We investigated the impact of genetic variants of angiogenesis-related genes on the survival outcomes of patients with prostate cancer receiving androgen deprivation therapy (ADT).Materials and MethodsWe conducted a genetic association study of 87 single-nucleotide polymorphisms across seven angiogenic genes in 630 patients with prostate cancer undergoing ADT. Survival analysis was used to assess progression-free survival (PFS) and overall survival (OS). Functional analyses, including gene ontology and pathway enrichment, were performed to elucidate the underlying biological mechanisms.ResultsANGPT2 rs2959822 was significantly associated with PFS [hazard ratio (HR)=1.22, p=0.015] and OS (HR=1.22, p=0.021). The minor allele A increased the risk of disease progression and mortality. Functional analyses revealed that rs2959822 influenced ANGPT2 expression. Elevated ANGPT2 expression was correlated with higher Gleason score, advanced tumor stage, and shorter PFS. Gene set enrichment analysis linked ANGPT2 to epithelial-mesenchymal transition (EMT), demonstrating positive correlations with several key EMT genes, along with increased immune cell infiltration, indicating its multifaceted oncogenic roles.ConclusionANGPT2 rs2959822 influences the survival outcomes of patients with prostate cancer undergoing ADT. In addition to angiogenesis, ANGPT2 plays a critical role in prostate cancer progression by promoting EMT and modulating the tumor immune microenvironment.

Background/AimHepatocellular carcinoma (HCC) is a heterogeneous liver cancer with limited treatment options and a poor prognosis in advanced stages. To identify novel biomarkers and therapeutic targets, we investigated the role of chromosome 1 open reading frame 50 (C1orf50), a gene with a previously uncharacterized function in HCC.Materials and MethodsWe performed a comprehensive transcriptome data analysis of the human hepatocellular carcinoma project from The Cancer Genome Atlas (TCGA) and subsequently validated the oncogenic roles of C1orf50 using HCC cell lines.ResultsUsing transcriptomic and clinical data from TCGA, we stratified 355 primary HCC samples based on C1orf50 expression levels. Patients with high C1orf50 expression exhibited significantly shorter overall survival, suggesting its association with aggressive tumor behavior. Differential expression and enrichment analyses revealed that C1orf50-high tumors were enriched in oncogenic pathways, including epithelial-mesenchymal transition (EMT), cell cycle activation, and stemness-related properties. Transcriptional regulatory network analysis detected 456 significantly dysregulated regulons, including ZEB1/2 and E2F2, key drivers of EMT and cell cycle, in the C1orf50-high group. In addition, we observed increased YAP1/TAZ signaling, further linking C1orf50 to stemness and therapeutic resistance. Functional data from CRISPR-based dependency screening suggested that several transcription factors up-regulated in the C1orf50-high state, such as ZBTB11 and CTCE, are essential for the survival of HCC cells. These findings indicate potential therapeutic vulnerabilities and support the rationale for targeting C1orf50-associated pathways.ConclusionC1orf50 is a novel biomarker of poor prognosis in HCC and a key regulator of oncogenic features such as EMT, cell cycle progression, and stemness. This study highlights the therapeutic potential of targeting C1orf50-related networks in aggressive subtypes of liver cancer.

Background/AimHepatocellular carcinoma (HCC) accounts for ~90% of primary liver cancer, which ranks as the third-leading cause of global cancer mortality. Emerging evidence establishes cancer stem cells (CSCs) as central regulators of HCC progression, metastasis, and therapeutic resistance, with stemness-related pathways like Wnt/β-catenin signaling critically maintaining CSC self-renewal. In this study, we aimed to investigate the role of Peptidyl-prolyl isomerase-like 1 (PPIL1) in HCC progression and CSC self-renewal.Materials and methodsPPIL1 expression patterns were systematically analyzed using The Cancer Genome Atlas Liver Hepatocellular Carcinoma (TCGA-LIHC) data and validated in primary HCC specimens via qRT-PCR and western blot. PPIL1 was knocked down in HCC cell lines using shRNAs, and cell viability, migration, and sphere formation were assessed in vitro. Xenograft mouse models were established to evaluate the effects of PPIL1 on tumor growth kinetics and liver CSC-related properties. Transcriptome analysis was performed to identify downstream targets and signaling pathways affected by PPIL1 knockdown.ResultsOur analysis revealed significantly elevated PPIL1 expression in HCC tumors and liver CSCs, with its expression level positively correlating with tumor stage and histological grade. PPIL1 knockdown effectively suppressed HCC cell proliferation, migration, and in vivo tumor growth. The essential role of PPIL1 in liver CSC maintenance was demonstrated by impaired sphere-forming capacity and diminished tumor initiation potential. Mechanistic studies identified PPIL1 as a regulator of Wnt/β-catenin signaling through transcriptional up-regulation of dishevelled associated activator of morphogenesis 2 (DAAM2).ConclusionOur findings suggest PPIL1 to be a crucial regulator of HCC progression and liver CSC maintenance via DAAM2-mediated Wnt/β-catenin activation. This positions PPIL1 as a promising molecular target for HCC therapy, with particular relevance for addressing CSC-driven therapeutic resistance.

Cluster of differentiation 84 (CD84), a member of the signalling lymphocytic activating molecule (SLAM) family, has emerged as a potential prognostic biomarker and therapeutic target in breast cancer. This study explored CD84 expression and its correlation with clinicopathological features in a well-characterised cohort. Using quantitative real-time PCR, mRNA expression levels of CD84 and related molecules, including PDL1, CD74, and other immune tolerance markers, were analysed. The findings reveal that elevated CD84 expression predicts poor overall survival, independent of conventional prognostic factors such as the Nottingham Prognostic Index (NPI). Notably, a combined signature of CD84, CD48, VAV1, and CTNNB1 demonstrated stronger prognostic power than individual markers. CD84 exhibited significant correlations with immunosuppressive molecules, including PDL1 and CD74, underscoring its role in fostering immune tolerance within the tumour microenvironment. CD84 may mediate an immunosuppressive phenotype, facilitating immune evasion in breast cancer. This highlights its potential as a therapeutic target, particularly in triple-negative breast cancer, to overcome immune resistance and enhance treatment efficacy.

Background/AimOvarian cancer is asymptomatic in its early stages, and often diagnosed at advanced stages, leading to a high recurrence rate. In recent years, exosomes have been shown to be useful for early-detection, prognosis prediction, and treatment of cancer. Although many studies of cancer-related exosomes using other bodily fluids have been reported, there are few studies examining vaginal discharge, but none related to ovarian cancer. In this study, we investigated a method for early-detection of ovarian cancer using vaginal discharge, which are physically close to the fallopian tubes, where ovarian cancer originates, and can be easily collected from outside the body.Materials and MethodsVaginal discharge was collected from 30 patients with ovarian cancer and 29 patients with benign gynecological diseases, and exosomal miRNAs were extracted. Samples from each group were submitted to miRNA microarray in order to examine miRNAs with significant differences in expression levels. We further narrowed down the list to four miRNAs based on literature and microarray data and examined the expression levels of miRNAs in the malignant and benign groups by RT-qPCR.ResultsMiR-575 expression was significantly decreased in the malignant group compared to the benign group (p=0.00861). qPCR results were analyzed for several patient characteristics and no significant differences were found.ConclusionThis is the first study to investigate exosomal miRNAs in vaginal discharge of ovarian cancer. Exosomal miR-575 in vaginal discharge may be used as a biomarker for ovarian cancer.