Epitranscriptomic regulation has emerged as a critical mechanism in cancer biology, particularly in the development of chemoresistance. RNA modifications including N6-methyladenosine (m6A), 5-methylcytosine (m5C), N1-methyladenosine (m1A), 7-methylguanosine (m7G), pseudouridine (Ψ), and A-to-I editing dynamically control mRNA stability, splicing, translation, and degradation. RNA-modifying proteins called 'writers,' 'erasers,' and 'readers' regulate post-transcriptional networks to enable tumor adaptation and chemoresistance. In platinum-resistant tumors, epitranscriptomic changes modulate DNA damage response, apoptosis, drug efflux, and detoxification pathways. Preclinical studies demonstrate that pharmacological inhibition of key regulators, such as METTL3 inhibitors (STC-15, STM2457, UZH2) or FTO inhibitors, can sensitize tumors to platinum drugs and stimulate anti-tumor immunity. However, clinical translation remains limited by off-target effects, toxicity, and highly context-specific responses. Epitranscriptomic profiling may help identify novel biomarkers and guiding precision strategies to overcome chemoresistance.

The emergence of tumor cell resistance is one of the major issues in current oncology practice. It reduces the effectiveness of therapy and worsens cancer patients' prognoses. However, it confirms a wide range of molecular interactions as well as the complexity of the human organism. Our previous research confirmed the functionality of the erythropoietin receptor (EPOR) in ovarian and breast cancer cells, as well as its relationship to these cells' sensitivity to specific therapies. The current study demonstrates that EPOR overexpression in human ovarian adenocarcinoma cells A2780 is directly linked to paclitaxel resistance. Furthermore, EPOR overexpression results in morphological changes that vary according to the pattern of EPOR isotypes expressed. In this regard, the most interesting result appears to be the change in the shape of the T clone, which has a tendency to form spheroidal structures. In addition, functional enrichment analysis demonstrated that EPOR-associated differentially expressed genes are involved in several biological and cell processes. Indeed, a T clone with a single 68 kDa EPOR isotype demonstrates significant resistance to paclitaxel therapy and is associated with the upregulation of tubulin beta 6.

Plant-derived bioactive compounds represent a major foundation of modern anticancer therapy and remain a prolific source of molecules with clinically relevant activity. This review provides an integrated classification of plant-derived anticancer compounds based on their clinical development status and predominant molecular mechanisms of action. Established chemotherapeutic agents, including taxanes, vinca alkaloids, and camptothecin derivatives, are distinguished from investigational phytochemicals such as polyphenols, flavonoids, terpenoids, and alkaloids that are under preclinical or clinical evaluation. These compounds target key hallmarks of cancer through modulation of microtubule dynamics, inhibition of topoisomerases, regulation of oncogenic signaling and epigenetic processes, and suppression of angiogenesis, invasion, and metastasis. Particular emphasis is placed on multitarget phytochemicals that interfere with PI3K/Akt, NF-κB, JAK/STAT, and MAPK pathways, induce apoptosis, and promote epigenetic reprogramming. In addition, major translational challenges, especially limited bioavailability, are discussed alongside advances in nano-enabled delivery systems designed to enhance therapeutic efficacy and reduce systemic toxicity. Collectively, this framework highlights the continuing relevance of plant-derived compounds in oncology and supports their rational integration into precision cancer therapy.

AIMS:Scavenger Receptor Class B Member 2 (SCARB2) is an integral lysosomal membrane protein essential for lysosomal integrity and autophagy regulation. The aim of this study was to investigate the functional impact of SCARB2 overexpression on chemotherapy response, reactive oxygen species (ROS) production and proteomic composition of human ovarian adenocarcinoma cells A2780. METHODS:To induce SCARB2 overexpression, A2780 cells were transfected using a PiggyBac vector system. Two clones with the highest SCARB2 expression (L and V) were selected for further analyses. Differences in chemosensitivity were assessed using the MTS assay. Proteomic analysis was used to identify differentially expressed proteins and enriched pathways. We also performed flow cytometry to investigate changes in ROS production and lysosomal activity. Lysosomal distribution was assessed using LAMP1 immunofluorescence staining followed by confocal microscopy, and total cholesterol levels were determined using an enzymatic colorimetric assay. RESULTS:Both clones showed increased sensitivity to cisplatin compared to the control group. In contrast, clone V showed resistance to doxorubicin and no significant differences were observed for gemcitabine, except for a transient sensitizing effect when low concentrations used. Elevated ROS levels were detected in untreated clones, and after doxorubicin exposition. Proteomic analysis showed significant changes in lysosome-associated proteins, with consistent enrichment of the lysosomal pathway across all experimental comparisons. Immunofluorescence analysis of LAMP1 and LysoTracker staining demonstrated altered lysosomal distribution and activity in SCARB2-overexpressing clones. In addition, both SCARB2-overexpressing clones exhibited significantly reduced total cholesterol levels compared with control cells. CONCLUSIONS:This study broadens our understanding of SCARB2 in ovarian cancer. SCARB2 overexpression induces extensive lysosomal reprogramming in A2780 ovarian cancer cells and modulates chemotherapy response.

AIMS:Biliverdin reductase A (BLVRA) is a key enzyme in bilirubin metabolism, where it reduces biliverdin to bilirubin. Bilirubin is a potent antioxidant that protects cells from oxidative stress. Therefore, reduced or deregulated BLVRA activity may contribute to increased oxidative DNA damage, which is one of the factors leading to the neoplastic transformation of cells. METHODS:Human ovarian adenocarcinoma A2780 cells were transfected with a PiggyBac vector to achieve BLVRA overexpression. A2780 clones showing the most significant BLVRA gene overexpression were analyzed by proteomics and flow cytometry to assess rective oxygen species (ROS) production. RESULTS:Our results indicate that BLVRA overexpression increases the sensitivity of A2780 cells to doxorubicin and gemcitabine, with the most pronounced effect observed in the J clone. In this clone, the highest level of BLVRA overexpression correlated with significant alterations in the p53 signaling pathway. Upregulation of key effectors such as Bax and CDKN2A indicates a potential role for BLVRA in promoting pro-apoptotic responses. Moreover, BLVRA overexpression increased the sensitivity of A2780 cells to gemcitabine independently of ROS. CONCLUSIONS:This study broadens our understanding of BLVRA in ovarian cancer. In cells with intact p53 signaling, BLVRA overexpression can paradoxically enhance cytotoxic response to certain drugs, particularly gemcitabine.

Brain metastases (BMs) are the most common intracranial tumors in adults and occur 3–10 times more frequently than primary brain tumors. Despite intensive multimodal therapies, including resection, radiotherapy, and chemotherapy, BMs are associated with poor prognosis and remain challenging to treat. BMs predominantly originate from primary lung (20–56

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is an RNA virus responsible for coronavirus disease 2019 (COVID-19). While SARS-CoV-2 primarily targets the lungs and airways, it can also infect other organs, including the central nervous system (CNS). The aim of this study was to investigate whether the choroid plexus could serve as a potential entry site for SARS-CoV-2 into the brain. Tissue samples from 24 deceased COVID-19-positive individuals were analyzed. Reverse transcription real-time PCR (RT-qPCR) was performed on selected brain regions, including the choroid plexus, to detect SARS-CoV-2 viral RNA. Additionally, immunofluorescence staining and confocal microscopy were used to detect and localize two characteristic proteins of SARS-CoV-2: the spike protein S1 and the nucleocapsid protein. RT-qPCR analysis confirmed the presence of SARS-CoV-2 viral RNA in the choroid plexus. Immunohistochemical staining revealed viral particles localized in the epithelial cells of the choroid plexus, with the spike protein S1 detected in the late endosomes. Our findings suggest that the blood-cerebrospinal fluid (B-CSF) barrier in the choroid plexus serves as a route of entry for SARS-CoV-2 into the CNS. This study contributes to the understanding of the mechanisms underlying CNS involvement in COVID-19 and highlights the importance of further research to explore potential therapeutic strategies targeting this entry pathway.

Ovarian tumours are these days one of the biggest oncogynecological problems. In addition to surgery, the treatment of ovarian cancer includes also chemotherapy in which platinum preparations are one of the most used chemotherapeutic drugs. The principle of antineoplastic effects of cisplatin (cis-diamminedichloroplatinum(II), CDDP) is its binding to the DNA and the formation of adducts. While DNA adducts induce the process of apoptosis, or inhibit the process of DNA replication, which prevents further division of tumour cells, various molecular mechanisms can reverse this process. On the other hand, with increasing scientific knowledge, it is becoming clearer that chemotherapy resistance is a very complex process. In this regard, factors and the amount of their expression may regulate the effect of resistance to chemotherapy. This review focuses on new molecular mechanisms and factors such as mitochondrial dynamics, epithelial-mesenchymal transition (EMT), cluster of differentiation, exosomes and others, that could be involved in the emergence of CDDP resistance.

IntroductionThe choroid plexus is located in the cerebral ventricles. It consists of a stromal core and a single layer of cuboidal epithelial cells that forms the blood-cerebrospinal barrier. The main function of the choroid plexus is to produce cerebrospinal fluid. Subarachnoid hemorrhage due to aneurysm rupture is a devastating type of hemorrhagic stroke. Following subarachnoid hemorrhage, blood and the blood degradation products that disperse into the cerebrospinal fluid come in direct contact with choroid plexus epithelial cells. The aim of the current study was to elucidate the pathophysiological cascades responsible for the inflammatory reaction that is seen in the choroid plexus following subarachnoid hemorrhage.MethodsSubarachnoid hemorrhage was induced in rats by injecting non-heparinized autologous blood to the cisterna magna. Increased intracranial pressure following subarachnoid hemorrhage was modeled by using artificial cerebrospinal fluid instead of blood. Subarachnoid hemorrhage and artificial cerebrospinal fluid animals were left to survive for 1, 3, 7 and 14 days. Immunohistochemical staining of TLR4, TLR9, FPR2, CCL2, TNFα, IL-1β, CCR2 and CX3CR1 was performed on the cryostat sections of choroid plexus tissue. The level of TLR4, TLR9, FPR2, CCL2, TNFα, IL-1β was detected by measuring immunofluorescence intensity in randomly selected epithelial cells. The number of CCR2 and CX3CR1 positive cells per choroid plexus area was manually counted. Immunohistochemical changes were confirmed by Western blot analyses.ResultsImmunohistochemical methods and Western blot showed increased levels of TLR9 and a slight increase in TLR4 and FRP2 following both subarachnoid hemorrhage as well as the application of artificial cerebrospinal fluid over time, although the individual periods were different. The levels of TNFα and IL-1β increased, while CCL2 level decreased slightly. Accumulation of macrophages positive for CCR2 and CX3CR1 was found in all periods after subarachnoid hemorrhage as well as after the application of artificial cerebrospinal fluid.DiscussionOur results suggest that the inflammation develops in the choroid plexus and blood-cerebrospinal fluid barrier in response to blood components as well as acutely increased intracranial pressure following subarachnoid hemorrhage. These pro-inflammatory changes include accumulation in the choroid plexus of pro-inflammatory cytokines, innate immune receptors, and monocyte-derived macrophages.

Background Hemoglobinopathies, as a group of hereditary blood disorders that affect both the structure and production of hemoglobin, have traditionally been prevalent in areas with a high incidence of malaria, such as the Mediterranean region, parts of Africa, and Southeast Asia. Beta-thalassemia is one of the most common hemoglobinopathies, characterized by reduced or absent production of the beta-globin chain of hemoglobin, leading to anemia and other health complications. Despite the relatively low incidence of hemoglobinopathies in Slovakia, there is a need to improve the healthcare strategy, including early detection, genetic counseling, and comprehensive care, especially in relation to the increased migration of the population. Methods Patients suspected of having hemoglobinopathy were referred to local hematology clinics. Following positive biochemical tests and obtaining informed consent, their samples were sent for mutational variant analysis to the private laboratory Unilabs Ltd. Genetic diagnostics involved PCR with intronic primers flanking the relevant region, as well as direct sequencing using the ABI Prism 3130xl Genetic Analyzer. Results The most frequent beta-globin gene mutation variant in the Slovak population is the single nucleotide variant c.118 C > T (28.41%) which results in a premature termination codon and is classified as pathogenic beta-zero thalassemia. For the first time, we have detected single nucleotide variants of beta-globin gene c.79 G > A (p.Glu27Lys) and c.92 G > C (p.Arg31Thr) in Slovakia. Conclusion The expansion of genetic testing should be a priority due to its role in detecting and preventing the development of severe forms of hemoglobinopathies, which pose significant health, economic, and social issues.

OBJECTIVES: The aim of our work was to determine the presence of GPx8, the latest discovered member of glutathione peroxidase family, in rat male genital organs. BACKGROUND: The oxidative stress is considered as one of the most important causalities of male infertility. To defend itself, the organism comprises many different antioxidants. METHODS: We assessed the GPx8 presence in tissues of genital organs from adult rat Sprague-Dawley males by mRNA expression, Western Blot analysis, and immunohistochemistry. RESULTS: The highest mRNA and protein levels were detected in the testis, followed by seminal vesicle. Within testis the enzyme was observed predominantly in the Leydig and Sertoli cells, residual and Hermes bodies. In other organs, such as epididymis, seminal vesicle and prostate gland, the GPx8 was seen in the cytoplasm of epithelial cells. The enzyme was also observed in the muscular layer of hollow organs, in blood plasma and extracellular matrix. CONCLUSIONS: The antioxidant enzyme GPx8 was detected in all examined male genital organs. The fact, that the enzyme was released into lumen of genital organs probably means, that GPx8 is also a component of the semen. To our knowledge, this is the first paper describing GPx8 presence in male genital organs of mammals (Fig. 8, Ref. 63). Text in PDF www.elis.sk

The emergence of tumour cell resistance is one of the major issues in current oncology practice. It reduces the effectiveness of therapy and worsens cancer patients' prognoses. However, it confirms a wide range of molecular interactions as well as the complexity of the human organism. Our previous research confirmed the functionality of the erythropoietin receptor (EPOR) in ovarian and breast cancer cells, as well as its relationship to these cells' sensitivity to specific therapies. The current study demonstrates that EPOR overexpression in human ovarian adenocarcinoma cells A2780 is directly linked to paclitaxel resistance. Furthermore, EPOR overexpression results in morphological changes that vary according to the pattern of EPOR isotypes expressed. In this regard, the most interesting result appears to be the change in the shape of T clone, which has a tendency to form spheroidal structures. Indeed, T clone with single 68 kDa EPOR isotype demonstrates also significant resistance to paclitaxel therapy.

DNA topoisomerases regulate conformational changes in DNA topology during normal cell growth, such as replication, transcription, recombination, and repair, and may be targeted for anticancer drugs. A DNA topology assay was used to investigate DNA-damaging/protective activities of extracts from Habanero Red (HR), Habanero Maya Red (HMR), Trinidad Moruga Scorpion (TMS), Jalapeno (J), Serrano pepper (SP), Habanero Red Savina (HRS), Bhut Jolokia (BJ), and Jamaica Rosso (JR) peppers, demonstrating their inhibitory effect on the relaxation of pBR by Topo I. DNA topoisomerase II (Topo II) is proven therapeutic target of anticancer drugs. Complete inhibition of Topo II was observed for samples TMS, HR, and HMR. Extracts J and SP had the lowest capsaicin and dihydrocapsaicin content compared to other peppers. HR, HMR, TMS, J, S, HRS, BJ, JR extracts showed the anticancer effect, examined by MTS and xCell assay on the in vitro culture of human colon carcinoma cell line HCT116.

OBJECTIVES:This study describes the presence of glutathione peroxidase (GPx) 1 and 2 in oocytes, preimplantation embryos, and mouse female genital organs.BACKGROUND:GPx1 and 2 are antioxidant enzymes, which play important roles in protection of cells against oxidation, which may be formed during cell physiological processes.METHODS:After superovulation of female mice, oocytes and preimplantation embryos (O/PE) were isolated for immunofluorescent analysis, female genital organs were removed for immunohistochemical and Western blot analyses.RESULTS:Using immunofluorescence, GPx1 was detected in all OP/E, where it formed clusters near nuclei, or under the cytoplasmic membrane. GPx2 was not detected in any O/PE. Using immunohistochemistry, GPx1 was observed in corpus luteum and oocytes, and in oviductal and uterine epithelium. GPx2 was detected in corpus luteum, but not in oocytes. Oviductal and uterine epithelium was mostly negative. Using Western blot, two GPx1 bands of different molecular weights were detected in uterus. One GPx2 band was observed in all investigated organs.CONCLUSION:These results show that both enzymes may be important during preimplantation period of pregnancy in genital organs, GPx1 also in O/PE. GPx2 may play roles in embryo after the implantation, when gastrointestinal tract is formed (Fig. 10, Ref. 75).

Abstract This study aimed to explain the effect of extracts from chili pepper varieties containing capsaicin and dihydrocapsaicin, among other substances, on the growth of colon cancer in humans through therapeutic research and drug screening. DNA topoisomerases regulate conformational changes in DNA topology during normal cell growth, such as replication, transcription, recombination, and repair, and may be targeted for anticancer drugs. A DNA topology assay was used to investigate DNA-damaging/protective activities of extracts from Habanero Red (HR), Habanero Maya Red (HMR), Trinidad Moruga Scorpion (TMS), Jalapeno (J), Serrano (SP), Habanero Red Savina (HRS), Bhut Jolokia (BJ), and Jamaica Rosso (JR) peppers, demonstrating their inhibitory effect on the relaxation of pBR by Topo I. DNA topoisomerase II (Topo II) is proven therapeutic target of anticancer drugs. Complete inhibition of Topo II was observed for samples TMS, HR, and HMR. Extracts J and SP had the lowest capsaicin and dihydrocapsaicin content compared to other peppers. HR, HMR, TMS, J, S, HRS, BJ, JR extracts showed the antiproliferative effect, examined by MTS and xCell assay on the in vitro culture of the cancer cell line HCT116.

Heat shock proteins (HSPs) represent cellular chaperones that are classified into several families, including HSP27, HSP40, HSP60, HSP70, and HSP90. The role of HSPs in the cell includes the facilitation of protein folding and maintaining protein structure. Both processes play crucial roles during stress conditions in the cell such as heat shock, degradation, and hypoxia. Moreover, HSPs are important modulators of cellular proliferation and differentiation, and are strongly associated with the molecular orchestration of carcinogenesis. The expression and/or activity of HSPs in cancer cells is generally abnormally high and is associated with increased metastatic potential and activity of cancer stem cells, more pronounced angiogenesis, downregulated apoptosis, and the resistance to anticancer therapy in many patients. Based on the mentioned reasons, HSPs have strong potential as valid diagnostic, prognostic, and therapeutic biomarkers in clinical oncology. In addition, numerous papers describe the role of HSPs as chaperones in the regulation of immune responses inside and outside the cell. Importantly, highly expressed/activated HSPs may be inhibited via immunotherapeutic targets in various types of cancers. The aim of this work is to provide a comprehensive overview of the relationship between HSPs and the tumor cell with the intention of highlighting the potential use of HSPs in personalized cancer management.

Programmed cell death plays a crucial role in maintaining the homeostasis and integrity of multicellular organisms, and its dysregulation contributes to the pathogenesis of many diseases. Programmed cell death is regulated by a range of macromolecules and low-molecular messengers, including ceramides. Endogenous ceramides have different functions, that are influenced by their localization and the presence of their target molecules. This article provides an overview of the current understanding of ceramides and their impact on various types of programmed cell death, including apoptosis, anoikis, macroautophagy and mitophagy, and necroptosis. Moreover, it highlights the emergence of dihydroceramides as a new class of bioactive sphingolipids and their downstream targets as well as their future roles in cancer cell growth, drug resistance and tumor metastasis.

The erythropoietin receptor (EPOR) is a transmembrane type I receptor with an essential role in the proliferation and differentiation of erythroid progenitors. Besides its function during erythropoiesis, EPOR is expressed and has protective effect in various non-hematopoietic tissues, including tumors. Currently, the advantageous aspect of EPOR related to different cellular events is still under scientific investigation. Besides its well-known effect on cell proliferation, apoptosis and differentiation, our integrative functional study revealed its possible associations with metabolic processes, transport of small molecules, signal transduction and tumorigenesis. Comparative transcriptome analysis (RNA-seq) identified 233 differentially expressed genes (DEGs) in EPOR overexpressed RAMA 37-28 cells compared to parental RAMA 37 cells, whereas 145 genes were downregulated and 88 upregulated. Of these, for example, GPC4, RAP2C, STK26, ZFP955A, KIT, GAS6, PTPRF and CXCR4 were downregulated and CDH13, NR0B1, OCM2, GPM6B, TM7SF3, PARVB, VEGFD and STAT5A were upregulated. Surprisingly, two ephrin receptors, EPHA4 and EPHB3, and EFNB1 ligand were found to be upregulated as well. Our study is the first demonstrating robust differentially expressed genes evoked by simple EPOR overexpression without the addition of erythropoietin ligand in a manner which remains to be elucidated.

Background and objectivesCerebrospinal fluid (CSF) leakage is a significant complication in cranial and spinal interventions.Hemostatic patches such as Hemopatch ® are therefore used to support the watertight closure of the dura mater.Recently, we published the results of a large registry documenting the effectiveness and safety of Hemopatch ® in various surgical specialties, including neurosurgery.Here we aimed to analyze the outcomes from the neurological/spinal cohort of this registry in more detail. MethodsBased on the data from the original registry, we performed a post hoc analysis for the neurological/spinal cohort.The Hemopatch ® registry was designed as a prospective, multicenter, single-arm observational study.All surgeons were familiar with the application of Hemopatch ® and it was used at the discretion of the responsible surgeon.The neurological/spinal cohort was open for patients of any age if they had received Hemopatch ® during an open or minimally invasive cranial or spinal procedure.Patients with known hypersensitivity to bovine proteins or brilliant blue, intraoperative pulsatile severe bleeding, or an active infection at the potential target application site (TAS) were excluded from the registry.For the posthoc evaluation, we stratified the patients of the neurological/spinal cohort into two sub-cohorts: cranial and spinal.We collected information about the TAS, intraoperative achievement of watertight closure of the dura, and occurrence of postoperative CSF leaks. ResultsThe registry comprised 148 patients in the neurological/spinal cohort when enrolment was stopped.The dura was the application site for Hemopatch ® in 147 patients (in one patient in the sacral region after tumor excision), of which 123 underwent a cranial procedure.Twenty-four patients underwent a spinal procedure.Intraoperatively, watertight closure was achieved in 130 patients (cranial sub-cohort: 119; spinal subcohort: 11).Postoperative CSF leakage occurred in 11 patients (cranial sub-cohort: nine; spinal sub-cohort: two).We observed no serious adverse events related to Hemopatch ® . ConclusionOur post hoc analysis of real-world data from a European registry confirms the safe and effective use of Hemopatch ® in neurosurgery, including cranial and spinal procedures, as also observed in some case series.

Diffusion-weighted imaging (DWI) and its numerical expression via apparent diffusion coefficient (ADC) values are commonly utilized in non-invasive assessment of various brain pathologies. Although numerous studies have confirmed that ADC values could be pathognomic for various ring-enhancing lesions (RELs), their true potential is yet to be exploited in full. The article was designed to introduce an image analysis method allowing REL recognition independently of either absolute ADC values or specifically defined regions of interest within the evaluated image. For this purpose, the line of interest (LOI) was marked on each ADC map to cross all of the RELs' compartments. Using a machine learning approach, we analyzed the LOI between two representatives of the RELs, namely, brain abscess and glioblastoma (GBM). The diagnostic ability of the selected parameters as predictors for the machine learning algorithms was assessed using two models, the k-NN model and the SVM model with a Gaussian kernel. With the k-NN machine learning method, 80% of the abscesses and 100% of the GBM were classified correctly at high accuracy. Similar results were obtained via the SVM method. The proposed assessment of the LOI offers a new approach for evaluating ADC maps obtained from different RELs and contributing to the standardization of the ADC map assessment.