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This study investigates the potential of germinated black bean extracts (GBBE) to modulate the activity of topoisomerase IIα (topo IIα), a key enzyme involved in DNA replication and repair, particularly in triple-negative breast cancer (TNBC). Germination significantly elevated the polyphenolic content of black beans, thereby enhancing their antioxidant properties. Molecular docking studies demonstrated a strong interaction between GBBE and the active site of topo IIα, suggesting a possible mechanism for its inhibitory action. In vitro experiments revealed a significant inhibitory effect of GBBE on topo IIα ATPase activity, which was further confirmed by the decatenation assay, with bean extracts germinated for three days showing the highest effect. The study underscores the significance of GBBE as a promising natural source of bioactive compounds with the capacity to inhibit topo IIα activity, offering a potential novel therapeutic strategy against TNBC. Warranting further investigation to clarify the molecular mechanisms underlying these effects., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Abstract Background Despite rising incidence rates of colorectal malignancies, only a few prognostic tools have been implemented in proven clinical routine. Cell division and proliferation play a significant role in malignancies. In terms of colorectal cancer, the impact of proliferation associated proteins is controversially debated. The aim of our study was to examine the expression of topoisomerase II α and minichromosome maintenance protein 6 and to correlate these findings with the clinical data. Methods Tissue samples of 619 patients in total were stained using the antibodies Ki-S4 and Ki-MCM6 targeting topoisomerase II α as well as minichromosome maintenance protein 6. The median rate of proliferation was correlated with clinical and follow up data. Results The expression rate of minichromosome maintenance protein 6 is significantly higher than the proportion of topoisomerase II α in tumour cells (p

Background: Despite rising incidence rates of colorectal malignancies, only a few prognostic tools have been implemented in proven clinical routine. Cell division and proliferation play a significant role in malignancies. In terms of colorectal cancer, the impact of proliferation associated proteins is controversially debated. The aim of our study was to examine the expression of topoisomerase II α and minichromosome maintenance protein 6 and to correlate these findings with the clinical data.Methods: Tissue samples of 619 patients in total were stained using the antibodies Ki-S4 and Ki-MCM6 targeting topoisomerase II α as well as minichromosome maintenance protein 6. The median rate of proliferation was correlated with clinical and follow up data.Results: The expression rate of minichromosome maintenance protein 6 is significantly higher than the proportion of topoisomerase II α in tumour cells (p < 0.001). A high expression of both proteins coincides with a beneficial outcome for the patient, indicating a favourable prognostic marker (p < 0.001 and p = 0.008).Conclusions: We have demonstrated that high expression rates of proliferative markers is linked to a beneficial patient outcome. According to the general opinion, a high expression rate correlates with a poor patient outcome. In this study, we were able to refute this assertion. [ABSTRACT FROM AUTHOR]

Amsacrine is an effective topoisomerase II enzyme inhibitor in acute lymphatic leukemia. Previous experimental studies have successfully identified two important mutations (R487K and E571K) conferring 100 and 25 fold resistance to Amsacrine respectively. Although the reduction of the cleavage ligand-DNA-protein ternary complex has been well thought as the major cause of drug resistance, the detailed energetic, structural and dynamic mechanisms remain to be elusive. In this study, we constructed human topoisomerase II alpha (hTop2α) homology model docked with Amsacrine based on crystal structure of human Top2β in complex with etoposide. This wild type complex was used to build the ternary complex with R487K and E571K mutants. Three 500 ns molecular dynamics simulations were performed on complex systems of wild type and two mutants. The detailed energetic, structural and dynamic analysis were performed on the simulation data. Our binding data indicated a significant impairment of Amsacrine binding energy in the two mutants compared with the wild type. The order of weakening (R487K > E571K) was in agreement with the order of experimental drug resistance fold (R489K > E571K). Our binding energy decomposition further indicated that weakening of the ligand-protein interaction rather than the ligand-DNA interaction was the major contributor of the binding energy difference between R487K and E571K. In addition, key residues contributing to the binding energy (ΔG) or the decrease of the binding energy (ΔΔG) were identified through the energy decomposition analysis. The change in ligand binding pose, dynamics of protein, DNA and ligand upon the mutations were thoroughly analyzed and discussed. Deciphering the molecular basis of drug resistance is crucial to overcome drug resistance using rational drug design. [ABSTRACT FROM AUTHOR]

The present study aimed to ascertain the significance of topoisomerase II a (TOP2A) and minichromosome maintenance protein (MCM) 2 expression in anal carcinoma. A total of 75 anal lesions were retrieved from the files of the Department of Pathology of Barretos Cancer Hospital (Barretos, Brazil) in order to verify the human papillomavirus (HPV) statuses of these lesions and characterize the immunohistochemical expression levels of TOP2A and MCM2 in anal carcinoma, as these are important markers for cervical HPV-induced lesions; their expression was also compared with respect to p16 and Ki-67. The vast majority of the cases tested positive for HPV16 (84%); 1 case tested positive for both HPV16 and HPV18. Positive HPV16 status was more frequent in early stages than in advanced stages (P=0.008). Positive immunohistochemical reactivity for MCM2 and TOP2A protein was observed in 71.6 and 100% of cases, respectively. Positive reactivity for p16 was significantly associated (P=0.001) with histological grade, and was more commonly expressed in squamous cell carcinoma than adenocarcinomas. HPV16 was strongly associated with positive p16 protein expression (76.6%). However, the high expression of Ki-67 combined with the high expression of p16 was predominantly observed in Stage III-IV cases. MCM2, TOP2A, p16 and Ki-67 exhibited intense positive staining in the anal lesions, indicating that these markers were significantly and constantly expressed in anal carcinoma. [ABSTRACT FROM AUTHOR]

Background. The immunopathogenesis of psoriasis is complex, and involves alterations in the innate immunologic system Case Report: A 57-year-old female was evaluated for the presence of rapidly appearing plaques on the knees and elbows. Methods: Skin biopsies for hematoxylin and eosin examination, as well as for direct immunofluorescence and immunohistochemistry analysis were performed. Results: H&E examination demonstrated classic features of psoriasis. Direct immunofluorescence revealed positive anti-corneal antibodies with several immunoglobulins, as well as positivity to upper and deep small dermal blood vessels. Immunohistochemistry revealed an increased expression of survivin, anti-human-ribosomal protein S6-p240, Topoisomerase II ά, cyclin D1, and Bcl-2 in lesional plaques. Conclusions: The pathobiology of psoriasis seems to involve a series of molecules involved in a complex interaction between the inflammation itself, cell cycle regulation, and ectopic expression of selected molecules.

Abstract: Cholangiocarcinoma (CCA), the common primary malignant tumor of bile duct epithelial cells, is unresponsive to most chemotherapeutic drugs. Diagnosis with CCA has a poor prognosis, and therefore urgently requires effective therapeutic agents. In the present study we investigated anti-cancer effects of andrographolide analogue 3A.1 (19-tert-butyldiphenylsilyl-8, 17-epoxy andrographolide) and its mechanism in human CCA cell line KKU-M213 derived from a Thai CCA patient. By 24h after exposure, the analogue 3A.1 exhibited a potent cytotoxic effect on KKU-M213 cells with an inhibition concentration 50 (IC50) of approximately 8.0µM. Analogue 3A.1 suppressed DNA topoisomerase II α (Topo II α) protein expression, arrested the cell cycle at sub G0/G1 phase, induced cleavage of DNA repair protein poly (ADP-ribose) polymerases-1 (PARP-1), and enhanced expression of tumor suppressor protein p53 and pro-apoptotic protein Bax. In addition, analogue 3A.1 induced caspase 3 activity and inhibited cyclin D1, CDK6, and COX-2 protein expression. These results suggest that andrographolide analogue 3A.1, a novel topo II inhibitor, has significant potential to be developed as a new anticancer agent for the treatment of CCA. [Copyright &y& Elsevier]

Abstract: Background and study aims: Recently, survivin was shown to inhibit apoptosis and accelerate cancer cell proliferation as well. The expression of survivin may be of prognostic significance and therapeutic relevance in many cancers. This study investigated the expression of survivin in hepatocellular carcinoma (HCC); correlated results with tumour differentiation and proliferation (topoisomerase II α) and compared the expression with the surrounding cirrhotic liver tissue. Patients and methods: The expression of survivin and topoisomerase II α was evaluated by immunohistochemistry in 20 cases of HCC and 20 liver cirrhosis tissues. The relationships between two survivin scoring methods – topoisomerase II α nuclear labelling index (LI) and tumour differentiation – were analysed. Results: Eighteen (90%) HCC cases expressed survivin. Median survivin nuclear LI was 75% and 6.5% in HCC and cirrhotic liver tissue, respectively. Median survivin weighted score was 8 and 0 in HCC and cirrhotic liver tissue, respectively. Survivin expression was significantly higher in HCC than in cirrhotic liver tissue (p <0.001). Median survivin expression L1 was 83% and the weighted score was 12 in moderately differentiated HCC versus 33% and 4, respectively in well-differentiated HCC with statistically significant p< 0.001. Median topoisomerase II α LI was 22.5% and 3% in HCC and cirrhotic liver tissue respectively, with a statistically significant difference (p <0.001). Median topoisomerase II α was 27.5, 9% in moderately and well-differentiated HCC respectively, with a statistically significant difference (p <0.001). The increase in survivin nuclear expression in HCC correlates significantly with the increase in topoisomerase II α nuclear expression (p <0.001, r =0.987). Conclusion: Both survivin scoring methods were sensitive in discriminating between studied groups; however, nuclear LI showed more specificity. Both survivin and topoisomerase II α expressions were significantly higher in HCC than in cirrhotic liver tissue and correlated significantly with tumour de-differentiation in HCC cases. Survivin nuclear LI correlated significantly with tumour cell proliferation. [Copyright &y& Elsevier]

Abstract: Topoisomerase II α (TopoIIα) and Topoisomerase II β (TopoIIβ) isoforms are different gene products having conserved catalytic activities. The α isoform is present in proliferating cell, while β isoform is predominantly present in non-proliferating cells namely neurons suggesting its role in non-replicating functions of DNA. The functions of TopoIIα and TopoIIβ isoforms are analyzed in peroxide-mediated DNA damage and double strand breaks (DSBs) repair in neuroblastoma and astrocytoma cells. The results show a strong correlation of TopoIIα level with the progression of DNA damage, while the TopoIIβ expression is correlated with the DNA DSBs repair activity of cells in Ku70, Werner’s helicase and pol-β dependent pathways. The functional roles of TopoIIα and TopoIIβ are assessed using siRNA mediated TopoIIα and TopoIIβ knockdown in cells. The results show that TopoIIα−TopoIIβ+ cells are resistant to peroxide-mediated DNA damage, while TopoIIα+TopoIIβ− cells are 2-fold more sensitive to peroxide and TopoIIβ deficiency lead to cellular apoptosis. These results are correlated with cell survival from peroxide-mediated insult. The result of this study that TopoIIα accelerates peroxide-mediated DNA damage, while TopoIIβ promotes DNA DSBs repair activity should provide new directions toward understanding of normalytic ageing processes in human brain. [Copyright &y& Elsevier]

Abstract: Human Topoisomerase II is present in two isoforms, 170KDa α and 180KDa β. Both the isoforms play a crucial role in maintenance of topological changes during DNA replication and recombination. It has been shown that Topoisomerase II activity is required for HIV-1 replication and the enzyme is phosphorylated during early time points of HIV-1 replication. In the present study, we have studied the molecular action of Topoisomerase II inhibitors, azalactone ferrocene (AzaFecp), Thiomorpholide amido methyl ferrocene (ThioFecp), and Ruthenium benzene amino pyridine (Ru(ben)Apy) on cell proliferation and also on various events of HIV-1 replication cycle. The Topoisomerase II β over-expressing neuroblastoma cell line shows a higher sensitivity to these compounds compared to the Sup-T1 cell line. All the three Topoisomerase II inhibitors show significant anti-HIV activity at nanomolar concentrations against an Indian isolate of HIV-193IN101 in Sup-T1 cell line. An analysis of action of these compounds on proviral DNA synthesis at 5h of post-infection shows that they inhibit proviral DNA synthesis as well as the formation of pre-integration complexes completely. Further analysis, using polymerase chain reaction and western blot, showed that both the Topoisomerase II α and β isoforms are present in the pre-integration complexes, suggesting their significant role in HIV-1 replication. [Copyright &y& Elsevier]

Abstract: Human topoisomerase II plays a crucial role in DNA replication and repair. It exists in two isoforms: topoisomerase II alpha (α) and topoisomerase II beta (β). The α isoform is localized predominantly in the nucleus, while the β isoform exhibits a reticular pattern of distribution both in the cytosol and in the nucleus. We show that both isoforms of topoisomerase II are phosphorylated in HIV infected cells and also by purified viral lysate. An analysis of the phosphorylation of topoisomerase II isoforms showed that extracts of HIV infected cells at 8 and 32h. post-infection (p.i.) contain maximal phosphorylated topoisomerase II α, whereas infected cell extracts at 4 and 64h p.i. contain maximum levels of phosphorylated topoisomerase II β. In concurrent to phosphorylated topoisomerase II isoforms, we have also observed increased topoisomerase II α kinase activity after 8h p.i and topoisomerase β kinase activity at 4 and 64h p.i. These findings suggest that both topoisomerase II α and β kinase activities play an important role in early as well as late stages of HIV-1 replication. Further analysis of purified virus showed that HIV-1 virion contained topoisomerase II isoform-specific kinase activities, which were partially isolated. One of the kinase activities of higher hydrophobicity can phosphorylate both topoisomerase II α and β, while lower hydrophobic kinase could predominantly phosphorylate topoisomerase II α. The phosphorylation status was correlated with catalytic activity of the enzyme. Western blot analysis using phosphoamino-specific antibodies shows that both the kinase activities catalyze the phosphorylation at serine residues of topoisomerase II α and β. The catalytic inhibitions by serine kinase inhibitors further suggest that the α and β kinase activities associated with virus are distinctly different. [Copyright &y& Elsevier]

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Propofol-based anesthesia has been reported to reduce the recurrence and metastasis of a number of cancer types following surgical resection. However, the effects of propofol in bladder cancer (BC) are yet to be fully elucidated. The aim of the present study was to investigate the functions of propofol in BC and their underlying mechanisms. In the study, the expression of microRNA (miR)-145-5p in BC tissues and cell lines was evaluated using reverse transcription-quantitative PCR, and the effects of propofol on BC cells were determined using cell viability, wound healing and Transwell cell invasion assays, bioinformatics analysis, western blotting, immunohistochemistry and in vivo tumor xenograft models. It was found that propofol significantly suppressed the proliferation, migration and invasion of BC cells in vitro. In addition, propofol induced miR-145-5p expression in a time-dependent manner, and miR-145-5p knockdown attenuated the inhibitory effects of propofol on the proliferation, migration and invasion of BC cells. Topoisomerase II α (TOP2A) was a direct target of miR-145-5p, and silencing TOP2A reversed the effects of miR-145-5p knockdown in propofol-treated cells. Furthermore, propofol suppressed tumor xenograft growth, which was partially attenuated by miR-145-5p knockdown. The present study provided novel insight into the advantages of surgical intervention with propofol anesthesia in patients with BC. [ABSTRACT FROM AUTHOR]

Telomerase activity has been demonstrated in human immortal cell lines and in tumors, whereas it is generally absent from normal tissues, with the exception of germ cells. Low levels have also been detected in blood and skin cells. In this report we describe up-regulation of telomerase activity in normal human blood lymphocytes by mitogen stimulation. After 24 h of mitogen treatment a strong induction was detectable using the PCR-based telomeric repeat amplification protocol. The level of activity remained almost constant when the cultivation lasted 72 h. By contrast, topoisomerase II α was induced later with a maximum expression after 48–72 h. Our data show that telomerase can be induced in normal peripheral lymphocytes prior to expression of the S-phase typical protein topoisomerase II α indicating that telomere elongation might be initiated before DNA replication. [ABSTRACT FROM AUTHOR]