Biochemistry and Biophysics Reports

Parathyroid hormone-related peptide (PTHrP), encoded by PTHLH, has been implicated in tumor progression through its involvement in epithelial-mesenchymal transition (EMT), angiogenesis, and tumor cell migration. Previous experimental studies suggest that PTHrP may promote these processes in colorectal cancer (CRC), partly through the modulation of factors such as secreted protein acidic and rich in cysteine (SPARC) and vascular endothelial growth factor (VEGFA). These events play a key role in the acquisition of an aggressive phenotype in our experimental models. In this study, we performed an integrative in silico analysis of multiple transcriptomic datasets to investigate the potential role of PTHLH in CRC. Differential expression analysis identified a set of consistently dysregulated genes across independent datasets. Functional enrichment and network analyses revealed that PTHLH expression is associated with biological processes related to extracellular matrix remodeling, EMT, and angiogenesis. Correlation analyses showed a positive association between PTHLH and SPARC expression, while network-based approaches suggested a potential functional connection with VEGFA. To assess the clinical relevance of these findings, survival analysis was performed using publicly available datasets. High expression levels of PTHLH, SPARC, and VEGFA were significantly associated with reduced overall survival in patients. Notably, a combined gene signature based on these three factors demonstrated a stronger prognostic effect than individual genes, indicating enhanced predictive value. These findings suggest that PTHrP is associated with molecular pathways involved in tumor progression and, together with SPARC and VEGF, may contribute to a coordinated regulatory axis with prognostic relevance in CRC, warranting further experimental validation.

Stem cell technologies have become a vital component of conservation efforts around the globe. Biobanks and pluripotent stem cell lines help to ensure species and their genetic diversity are preserved. These efforts have however, focussed mostly on mammals and birds, and the cryopreservation protocols for embryos and cells were developed decades ago laying the basis for artificial reproductive techniques for species conservation. With over 20% of non-avian reptile species facing extinction, it is imperative to establish protocols for reptiles to ensure species preservation and also to facilitate the establishment of new reptile model organisms to match the standard of mammals. Here, we have generated a cryopreservation method for preserving early gastrulating veiled chameleon embryos as a representative squamate species. To this end, we first developed a tissue culture method for maintaining cells extracted from peri-gastrulation chameleon embryos and then tested different cryopreservation methods altering the concentration of the penetrating cryoprotectant DMSO and assessing the effect of the addition of non-penetrating cryoprotectants Trehalose and Sucrose. We then optimised a protocol for whole embryo vitrification in 20% DMSO with added Trehalose or Sucrose that can easily be adapted for fieldwork. Taken together, our method not only provides a protocol for conservation efforts but also lays the basis for mechanistic studies of early squamate embryo development by enabling cryopreservation of whole embryos in a fieldwork setting, which facilitates their live transport back to a laboratory for functional experiments or molecular analyses.

The KCNE (KCNE1-6) proteins are single-pass transmembrane auxiliary subunits of the voltage-gated K+ channel KCNQ1. KCNQ1-KCNE complexes have been well studied in jawed vertebrates ranging from zebrafish to humans, but KCNE subunits from earlier-diverging vertebrates remain poorly characterized. Here, we functionally characterize a single KCNE-like gene in lamprey, a jawless vertebrate, and designate it kcne0 as an early-diverging member of the KCNE family. KCNE0 shows moderate amino acid sequence similarity to KCNE1-6 but is not particularly similar to any single isoform. Both kcnq1 and kcne0 transcripts were detected in multiple lamprey organs. When co-expressed with lamprey KCNQ1, KCNE0 produced a constitutively active current, similar to KCNE3. By contrast, KCNE0 modulated KCNQ1 from other species less effectively, suggesting species-specific tuning of KCNQ1-KCNE compatibility. Introducing into KCNE0 an intracellular tetra-leucine motif analogous to that in KCNE4 markedly reduced KCNQ1 current amplitude, conferring a KCNE4-like inhibitory effect. Overall, this work provides a functional reference for comparing KCNE-dependent modulation of KCNQ1 across vertebrates and suggests an underlying compatibility mechanism.

Proper forebrain development relies on precise spatial and temporal control of early neural stem cell (NSC) proliferation and later neurogenesis. Brain malformations can arise when these processes are defective. Joubert Syndrome (JS) is a neurodevelopmental disorder that is diagnosed by a mid-hindbrain malformation, but often includes forebrain defects such as microcephaly, which are less understood. One gene recently linked to Joubert Syndrome with microcephaly is Togaram1, which encodes a TOG domain microtubule binding protein shown to affect primary cilia. In the embryonic dorsal forebrain, NSCs have primary cilia on their apical membranes that play a role in regulating proliferation and neurogenesis, but how they do this is not well understood. Here we investigate the role of Togaram1 in mammalian forebrain development using a mouse knockout. We find that Togaram1 is crucial for forebrain size, thickness, and morphology. In particular, knockout forebrains have sporadic indentations of the lateral ventricles, and the neuronal layer is thin with gaps and heterotopias. The dorsal forebrain NSCs have increased proliferation and apoptosis. Finally, the primary cilia of Togaram1 knockout NSCs have abnormal morphology and function. This study begins to elucidate the role of Togaram1 in forebrain morphogenesis and the involvement of NSC primary cilia in forebrain malformations.

Colonic adenocarcinoma (COAD) is a major cause of cancer-related mortality worldwide. Various tumors are linked to metastasis-associated in colon cancer 1 (MACC1). This study aimed to analyze public datasets to examine MACC1 expression, signaling pathways, copy number variations, and associations with immune cell subsets in COAD employing bioinformatics. MACC1 expression was elevated in COAD, especially in Wnt signaling and chromatin modifier pathways. Analysis of somatic copy number alterations in The Cancer Genome Atlas-COAD dataset revealed a link between MACC1 and DNA damage repair. MACC1 also showed a negative correlation with genes involved in immune cell infiltration in patients with COAD, including cluster of differentiation (CD)8+ T cells, activated dendritic cells, CD8 T cells, and cytotoxic cells. Collectively, these findings suggest MACC1 as a potential prognostic biomarker and therapeutic target for COAD.

BackgroundThe ability of TRAIL to specifically induce apoptosis in cancer cells makes it a promising candidate to be an effective chemotherapeutic drug. But resistance to TRAIL treatment is a major obstacle. Finding combinatorial therapies that make resistant tumors more susceptible to TRAIL is an effective preclinical approach. In this work, we investigated the possibility that pre-treatment of paclitaxel may promote apoptosis in TRAIL-resistant breast cancer cells. MethodsIn silico analysis was done to investigate the binding affinity between TRAIL receptors (DR5 and DCR2) and paclitaxel via docking and MD simulation. To check whether any non-lethal dose of paclitaxel can modulate the expression of TRAIL receptors, qPCR was done in paclitaxel treated breast cancer cells. Next, paclitaxel was pre-administered to TRAIL-resistant MCF7 and MDA-MB-453 human breast cancer cells followed by rhTRAIL treatment. Cell viability and survival was evaluated using the MTT assay and colony formation assay, respectively. Immunoblot for caspase-3 was performed to study apoptosis. The expression level changes of DR5 and DCR2 were analyzed post-treatment using qPCR and immunoblot assay. ResultsIn silico analysis showed that paclitaxel can bind with higher stability to DCR2 in comparison to DR5 thereby changing the preference of TRAIL molecules towards DR5. Next, in cell line experiments we observed that administering a non-lethal dose of paclitaxel to MDA-MB-231 and MCF7 breast cancer cells resulted in no significant cell death but led to an increase in DR5 and a decrease in DCR2 expression at both the transcript and protein levels. Furthermore, in TRAIL-resistant MCF7 and MDA-MB-453 cells, pre-treatment with paclitaxel followed by rhTRAIL administration induced significant cell death due to paclitaxel induced increase in DR5 as well as decrease in DCR2 expression at both the transcript and protein levels. Moreover, long term survival of MDA-MB-453 cells was significantly lower when pretreated with paclitaxel and exposed to rhTRAIL compared to control, paclitaxel alone or rhTRAIL alone group. ConclusionThus, our study uncovers a novel therapeutic strategy to overcome TRAIL resistance underscoring the clinical potential of using a non-lethal dose of paclitaxel to modulate TRAIL receptor dynamics. Future research should be aimed at exploring the potentiality of using paclitaxel-based combinatorial approaches in crafting effective TRAIL therapies.

BACKGROUNDDuring spermiogenesis, histones are exchanged by protamines (PRMs) in spermatids, which results in DNA hypercondensation and protection. Rodents and primates express two PRMs (PRM1 and PRM2) in a species-specific ratio. Maintaining this ratio is necessary for functional chromatin reorganization and alteration is associated with sub- or infertility in mice and humans. Prm1 and Prm2 deficient mice are infertile, while Prm1+/- males are subfertile showing a severely altered PRM ratio. Prm2+/- males are fertile and display a protamine ratio comparable to WT. OBJECTIVESHere, we addressed the question whether loss of one allele of Prm1 and one allele of Prm2 affects fertility. MATERIAL AND METHODSDouble heterozygous (dHET) mice lacking one allele of Prm1 and one allele of Prm2 were generated and analyzed RESULTSdHET males were infertile with sperm showing retention of histones and TNPs, high levels of PRM2 precursor and decreased levels of mature PRM2. In mature sperm the PRM ratio and the total PRM content was not altered. However, CMA3 staining revealed incomplete protamination and sperm nuclei appeared more rounded and slightly bigger, suggesting impaired DNA-hypercondensation. In dHET sperm, DNA degradation was apparent, but to a lower level compared to sperm from Prm1 and Prm2 deficient males. Increased 8-OHdG levels suggested oxidative stress in the epididymis of dHET mice. However, a fraction of dHET sperm were capable of fertilization, with embryonic development up to 8-cell stage. DISCUSSION AND CONCLUSIONThese results suggest, that male factor infertility might not be reliably detected by measuring PRM1/PRM2 ratio but rather by determining the level of protamination by e.g. CMA3 analysis and pre-PRM2 retention.

Mutations in MAPT, the tau gene, give rise to forms of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17T), with abundant filamentous tau inclusions in brain cells. Some mutations that encode missense and deletion variants can give rise to a clinical picture of Picks disease and filaments made of three-repeat tau. Here we report the electron cryo-microscopy (cryo-EM) structures of tau filaments from individuals with MAPT mutations D252V, G272V, S320F and {Delta}G389-I392. The two-layered Pick fold was present in the individuals with mutations D252V and {Delta}G389-I392. By contrast, mutations G272V and S320F gave rise to a more open variant of the Pick fold, with residues 272-341 rotated by 20-25{degrees} with respect to the rest of the structure. These findings show that missense mutations within the filament core can modify the Pick fold, generating closely related structural variants. In addition, we were able to reconstitute the Pick fold and some of its variants using seeded assembly with recombinant 0N3R tau carrying 12 serine or threonine to aspartate substitutions (PAD12) and missense mutations D252V, G272V or S320F. This work provides a foundation for the development of structure-based diagnostic and therapeutic approaches.

The molecular basis of triple-negative breast cancer (TNBC), a highly aggressive and therapy-resistant subtype of breast cancer, is poorly understood. This study aims to identify key genes and pathways involved in TNBC development and progression using a systems biology approach followed by experimental validation. Here, two transcriptome microarray datasets from the GEO database were analysed using the R package LIMMA to detect differentially expressed genes (DEGs) in TNBC tumors. Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) enrichment analyses using the DAVID database were performed to identify DEGs regulated biological functions and pathways. Further, a protein-protein interaction (PPI) network was constructed using the STRING online database, and the topological properties were determined using MCODE and Cytohubba plug-ins. The expression and the prognostic value of the hub genes were validated using the Cancer Genome Atlas (TCGA) survival analysis. We found 727 DEGs, of which 473 were downregulated and 254 were upregulated in TNBC vs. non-TNBC samples. The GO and KEGG analyses indicated that the DEGs were mainly related to cell adhesion, tumorigenesis, and cellular immunity. The PPI network had shown six hub genes, namely CCND1, CDH1, ESR1, FN1, IL6, and PPARG, as the top key regulators. All these genes were validated by quantitative real-time PCR in the TNBC cell line using non-TNBC cell line as a calibrator, and the obtained results were in accordance with the bioinformatics data. This information may contribute to understanding the various molecular mechanisms that drive the development and progression of TNBC tumors.

Glioblastoma is a very aggressive brain tumor with few therapeutics options. Type I and II Interferons (IFNs) co-formulation HeberFERON has been used in cancer treatment, with promising results in high grade brain tumors. High throughput techniques in easy-to-handle models have been important to interrogate biomolecules changes, describe mechanisms and find pharmacodynamic biomarkers. This study aims to elucidate the effect of HeberFERON over the cell proteome in comparison to its individual IFNs components. Proteomic changes with HeberFERON in the glioblastoma-derived cell line U-87MG, in comparison with individual IFN-2b and IFN-{gamma}, were studied using a nanoLC instrument EasyLC coupled to Velos Pro mass spectrometer; Maxquant and Perseus were also used. Several enrichment tools, networking analysis and canSAR for drug targets were employed. Translation, RNA processing, mitotic cell cycle, cytoskeleton and chromosome organization, apoptosis, autophagy, DNA repair are enriched to limit cellular growing together with changes in immune response components, supporting HeberFERON as a multitarget treatment. This co-formulation is distinguished at modulating RNA splicing with SMN complex, cytoskeleton organization and microtubule-based movement, nuclear envelope breakdown, DNA conformational changes, and oxidative phosphorylation, with a better drawing of effects over a variety of systems inside the tumoral cell. Together with previous microarray experiment, informative genes and proteins as pharmacodynamic biomarkers for antiproliferative effects showed up (ex. STAT1/2, CENPE, ATRIP, MAP1B, LIMA1, VCP, several ribosomal, spliceosome and proteasomal complexes proteins). This study complements transcriptomic and phosphoproteomic previous experiments in this model and underscore HeberFERON as a glioblastoma therapeutic.

Cryopreservation is essential for long-term storage of biological tissues. Yet, surprisingly, the precise molecular impact of cryopreservation on tissue transcriptomes remains poorly defined. This study provides the first resource of whole-genome transcriptomic changes following cryopreservation. This study used bulk RNA sequencing to examine how preservation method (snap freezing or vitrification) affects transcriptomes in mouse cerebral cortex and hippocampus. This allowed us to separate cryoprotectant-specific changes from cold induced-changes via snap freezing. In a subset of genes, tissues processed under vitrification conditions showed selective under-representation of a small but structurally coherent group of transcripts, with the hippocampus exhibiting greater vulnerability than the cortex. UniProt annotation revealed that affected transcripts were strongly enriched for proteins with membrane-associated, secretory-pathway, and multi-pass topologies, indicating that structurally complex membrane-integrated architectures are disproportionately sensitive to vitrification. Pathway-level analysis using iPANDA further showed that negative preservation scores in vitrified tissue clustered primarily within signal transduction and metabolic pathways, suggesting coordinated pathway-level disruption rather than global transcript loss. Together, these results demonstrate that vitrification conditions induce selective and structured molecular perturbations in neural tissue, defined by the under-recovery of transcripts associated with membrane and secretory pathway organization. This work highlights molecular vulnerability during vitrification and emphasizes the need for transcript-level evaluation when optimizing cryopreservation approaches for neural systems.

Regulation of water permeability in the collecting duct is important for osmoregulatory acclimation in teleost fish. In hyperosmotic environments such as seawater (SW), the teleost kidney functions as a site of divalent ion excretion. The collecting ducts reabsorb Na+, Cl-, and water, thereby reducing urine volume and producing small amounts of isotonic urine with high concentrations of divalent ions. In hypoosmotic environments such as freshwater (FW) or low-salinity brackish water (BW), the kidney produces large volumes of hypotonic urine and serves as a site of water excretion; under these conditions, the collecting ducts reabsorb Na+ and Cl- but not water. To identify aquaporins (Aqps) involved in regulating water permeability in the collecting ducts of teleosts, we analyzed renal Aqp expression in a euryhaline marine fish, the Japanese pufferfish (Takifugu rubripes), which possesses 16 Aqp genes in its genome, seven of which (Aqp1aa, 1ab, 3a, 4a, 7, 8bb, and 11a) are expressed in the kidney. Quantitative RT-PCR analysis showed that Aqp1aa and Aqp4a were highly expressed in collecting duct tissues, and that Aqp1aa expression was markedly reduced in fish acclimated to BW. Immunohistochemistry revealed apical localization of Aqp1aa and basolateral localization of Aqp4 in collecting duct cells, with apical Aqp1aa downregulated in BW. These results suggest that Aqp1aa and Aqp4 mediate water reabsorption in SW and that downregulation of Aqp1aa contributes to hypotonic urine production in BW. NEW & NOTEWORTHYRegulation of water permeability in the collecting duct is important for osmoregulation in teleost fish. Expression analyses of aquaporins (Aqps) in the marine pufferfish Takifugu rubripes showed that Aqp1aa and Aqp4a are highly expressed in the collecting duct and localized to the apical and basolateral membranes, respectively. Renal Aqp1aa expression was markedly reduced in fish acclimated to hypoosmotic brackish water. These results indicate that collecting duct water permeability is regulated by Aqp1aa expression.

PurposeDifferentially expressed genes (DEGs) between colorectal cancer liver metastasis (CRLM) epithelium and primary colorectal cancer (CRC) epithelium (LMR DEGs) identified based on single-cell RNA sequencing (scRNA-seq) data may become new biomarkers for CRC prognosis. MethodsAn scRNA-seq dataset was used to describe the cellular landscape of primary CRC and CRLM and identify LMR DEGs. Prognostic LMR DEGs were identified in the bulk RNA-seq dataset. Based on the prognostic LMR DEGs, multiple machine learning algorithm combinations were compared in terms of their C-index, and the best model was selected for the construction of the LMR score. ResultsAmong the 2070 LMR DEGs, 426 prognostic LMR DEGs were ultimately obtained. The combination of the randomized survival forest (RSF) model and ridge regression had the highest C-index and was therefore used to construct a 15-gene scoring system (LMR score). In the external validation set, the 1- and 5-year AUCs of the LMR score were greater than those of the AJCC stage and other scoring systems constructed with a similar dataset. In addition, the LMR score was closely associated with factors that influence CRC outcomes, such as immune infiltration. ConclusionThe LMR score may be a reliable new biomarker for predicting the prognosis of patients with CRC.

MRPL47 (Mitochondrial Ribosomal Protein Large Subunit 47) gene in chromosome 3q26 encodes a protein that is part of the large subunit of the mitochondrial ribosome. We observed that MRPL47 is frequently amplified and overexpressed in ovarian cancer samples. Importantly, increased expression of MRPL47 mRNA is associated with high levels of MRPL47 protein in ovarian cancer patients. High expression of MRPL47 is also associated with poor overall and recurrence free survival of ovarian cancer patients. Notably, MRPL47 improved metabolic fitness by enhancing cellular respiration, and glycolysis in cancer cells. Gene set enrichment analysis and target specific knockdown assays revealed that MYC transcription factor regulates MRPL47 expression. Furthermore, MRPL47 was identified very high in the plasma samples of ovarian cancer patients compared to those of healthy volunteers. MRPL47 was also associated with cisplatin resistance, whereas its expression predicted sensitivity to cisplatin therapy. Taken together, we demonstrated that MRPL47 can be used as a diagnostic biomarker for ovarian cancer and other cancers with 3q26 chromosomal amplification.

Glioblastoma (GBM) is the most aggressive primary brain malignancy, characterized by hypoxia-driven proliferation, therapeutic resistance, and poor prognosis. While hypoxia-induced transcriptional changes are well documented, the temporal regulation of cell cycle genes under sustained hypoxia remains unclear. This study profiled transcriptomic alterations in U87MG cells cultured under normoxia and graded hypoxia for one to three days. Differentially expressed genes (DEGs) were identified and analyzed using STRING, Cytoscape, MCODE, and CytoHubba to construct protein-protein interaction (PPI) networks and extract hub genes. Functional enrichment was assessed through DAVID, ClueGO, and KEGG, while prognostic relevance was evaluated using GlioVis and ONCOMINE datasets. qRT-PCR validated expression of selected hub genes. A total of 294 DEGs were identified, forming two main functional modules enriched in cell cycle regulation and chemokine signaling pathways. Eighteen hub genes (KIF20A, CCNB1, AURKA, EGR1, CDCA3, CENPF, CDCA2, ASPM, KIF11, CCL2, CCNA2, DLGAP5, RACGAP1, TPX2, PTGS2, CTGF, and KIFC1) were significantly associated with mitotic processes and GBM progression. Survival analysis demonstrated that 17 of these genes correlated with poor overall survival (p < 0.05). qRT-PCR confirmed that hub gene expression peaked during early hypoxia and declined with prolonged exposure, indicating dynamic regulatory adaptation. These findings identify key hypoxia-responsive genes governing cell cycle progression and highlight their prognostic and therapeutic potential in glioblastoma.

In this study, we evaluated the impact of different in vitro 3D culture modelling methods on the activity of doxorubicin (DOX) and 5-fluorouracil (5-FU) in human melanoma spheroids. Human melanoma A375 and IGR39 spheroids were generated using the hanging drop and non-adhesive surface methods. Spheroid growth dynamics were assessed by measuring changes in spheroid diameter. To compare the effects of anticancer drugs in spheroids of different sizes, spheroids of approximately 200 and 400 {micro}m were formed. Drug activity was evaluated based on spheroid growth and cell viability using the MTT assay. A375 spheroids formed using the non-adhesive surface method were more sensitive to DOX than spheroids formed using the hanging drop method. In smaller A375 spheroids, 10 {micro}M 5-FU reduced cell viability more effectively in spheroids formed using the hanging drop method. In contrast, IGR39 spheroids formed by the hanging drop method were more resistant than those formed on a non-adhesive surface. However, in IGR39 spheroids, the effects of DOX and 5-FU on growth and viability did not significantly differ between formation methods. In conclusion, A375 spheroid growth was not significantly influenced by the formation method, whereas IGR39 spheroid growth depended on the method used. A375 spheroids formed on non-adhesive surfaces were more sensitive to DOX, whereas 5-FU activity depended on drug concentration and spheroid size. In IGR39 spheroids, the effects of DOX and 5-FU on growth and viability were largely independent of the spheroid formation method. Based on these results, it can be concluded that the researchers should carefully select the spheroid formation method for their studies, as this may influence the results of the tested compounds effect on their size and viability.

BackgroundKATNIP (Katanin-interacting protein), also known as KIAA0556, is one of the human genes with pathogenic variants linked to Joubert syndrome, an archetypal neurodevelopmental ciliopathy. KATNIP is a scaffolding protein with a critical role in ciliogenesis. In this study, we characterized the ciliopathy phenotypes due to KATNIP gene deletion. ResultsWe produced a Katnip null mouse model using CRISPR-Cas12a (Cpf1). The null heterozygotes appeared normal while the homozygotes died around postnatal day 9, showing severe hydrocephalus and deficiency in neuroprogenitor cell proliferation. Katnip-deficient cells in the brain have a higher rate of cilia formation and longer cilia than wild type cells. ConclusionKATNIP loss of function gives rise to hydrocephalus found in Joubert syndrome. The results indicate that KATNIP restricts ciliogenesis and cilia extension and supports proliferation of neuroprogenitor cells in the brain.

The role of DNA topoisomerase II beta (TOP2B) in cardiomyocyte differentiation is poorly understood. To address this, Human induced pluripotent stem cells (hiPSC) were differentiated into cardiomyocytes (CM) that are wildtype or contain a genomic deletion of Topoisomerase 2B (BKO). Both WT and BKO hiPSC could be induced to differentiate into sheets of beating cardiomyocytes. BKO hiPSC take slightly longer to differentiate into sheets of beating CM than WT iPSC. RNA was prepared from both undifferentiated and differentiated WT and BKO hiPSC. RNA seq was used to examine gene expression changes when the WT and BKO hiPSC were differentiated into CM. Gene expression changes following differentiation of BKO cells were largely similar to those in WT cells. In addition, the differentiated WT CM were treated with dexrazoxane (ICRF-187), a TOP2 catalytic inhibitor that targets both TOP2A and TOP2B, or topobexin, a new TOP2B selective catalytic inhibitor. Topobexin inhibition partially phenocopied a TOP2B deletion and thus providing an alternative to TOP2B gene knockout in many cell lines. In future, hiPSC derived CM with and without TOP2B and inhibition by topobexin ex vivo CM could be used to study anthracycline-induced cardiotoxicity and to screen for cardioprotectants. HighlightsO_LIUsed CRISPR-Cas9 to delete TOP2B from hiPSC C_LIO_LIProduced beating cardiomyocytes from both WT and TOP2B null hiPSC C_LIO_LITranscriptome analysis of WT and TOP2B null hiPSC and derived cardiomyocytes C_LIO_LIRNA seq showed he specific TOP2B inhibitor topobexin largely phenocopies TOP2B gene inactivation in iPSC derived cardiomyocytes. C_LIO_LITopobexin inhibition could be used as an alternative to a TOP2B gene knockout in many different cell types, speeding up the analysis of the function of TOP2B. C_LI

Hepatocellular carcinoma (HCC) remains a leading cause of cancer-related mortality worldwide. Current treatments offer limited efficacy and no definitive cure, underscoring the urgent need for more selective and effective therapeutic strategies. This study investigated the synthetic lethality caused by co-targeting two metabolic genes, ATP citrate lyase (ACLY) and oxoglutarate dehydrogenase (OGDH), in HCC cells. Using valproic acid (VPA) and bempedoic acid (BA) as pharmacological inhibitors of OGDH and ACLY, respectively, we observed a strong synergistic effect in inhibiting the proliferation of HCC cell lines (Hep3B and Huh7), compared to using these drugs individually. Importantly, this combination treatment exhibited little increased cytotoxicity in the non-cancerous liver cell line THLE-2, indicating a degree of selectivity. Our findings are consistent with previous reports implicating USP13 as a metabolic regulator of ACLY and OGDH in various cancers, suggesting that the inhibition of USP13 may prevent HCC cell proliferation primarily through its downstream effects on ACLY and OGDH. By directly co-targeting ACLY and OGDH, our approach may offer a more precise and safer alternative to USP13 inhibition. Additionally, while both VPA and BA have been individually associated with beneficial effects in liver disease, their combined application in the context of HCC has not been previously investigated. Limitations include the reliance on cell line models, highlighting the need for validation in more physiologically relevant systems such as human organoids and animal models. Overall, this study provides a compelling rationale for further investigation into ACLY and OGDH as a synthetic lethal pair and the therapeutic potential of the VPA-BA combination treatment in HCC.

Stress Granules (SGs) are cytoplasmic biomolecular condensates that form in response to a variety of stress conditions, though their function remains unclear. "Canonical" SGs - caused by stressors like sodium arsenite - are dynamic and cytoprotective, allowing cells to evade cell death during periods of stress. Ultraviolet (UV) irradiation is known to elicit a "non-canonical" SG subtype, lacking canonical SG components such as eukaryotic initiation factor 3 and polyadenylated mRNAs. The exact function of UV SGs, and the mechanisms driving their formation, remain unknown. Here we report the findings of a comparative analysis of UVA, UVB and UVC exposures on SG formation in three cell types: osteosarcoma (U2OS), keratinocytes (HaCaT), and mouse embryonic fibroblasts (MEF). We observed that SG formation in response to UV is highly cell type dependent. UVB and UVC induce robust SG formation in U2OS cells. However, only UVC exposure induced modest SG formation in MEFs, and none of the wavelengths caused SGs in HaCaT. While UVC-induced SGs in U2OS cells appear to be cell cycle dependent and specific to G1, UVB induced SG formation regardless of cell cycle stage. We tested the hypothesis that oxidative stress triggered by UV may be driving UV SG formation, and that keratin may buffer this effect, by overexpressing keratin in U2OS. Interestingly, we found that keratin and antioxidant treatment efficiently suppressed arsenite-induced SGs but had no effect on UV SGs. Our work confirms that UV SG formation is cell type specific and is not driven by oxidative stress.