A retrospective analysis of spontaneous chromosomal aberrations in human lymphocyte cultures of individuals from Bosnia and Herzegovina

Spontaneous chromosomal aberrations are structural or numerical changes of chromosomes that occur naturally, without exposure to external genotoxic factors. They are not inherited, occur randomly in the karyotype, and do not have direct clinical significance. However, they can affect genomic instability and disease predisposition. They can result from DNA replication or repair processes errors, and typically are observed in cells that are actively dividing. Spontaneous chromosomal aberrations may arise due to the natural chromosomal instability and can be elevated in individuals exposed to mutagens. We analyzed frequencies of spontaneous chromosomal aberrations in 137 individuals subjected to karyotype analysis at the Laboratory for Cytogenetics and Genotoxicology, University of Sarajevo – Institute for Genetic Engineering and Biotechnology, during 2008-2023. Whole blood samples were cultivated for 72 hours with the thymidine added in the 48th hour. Metaphases were arrested by colcemid 60 minutes before harvesting. GTG banding was performed and slides were analyzed under 1000x magnification in accordance with An International System for Human Cytogenetic Nomenclature and E.C.A. Cytogenetic Guidelines and Quality Assurance. Constitutionally aberrant karyotypes were found in 2.92% of analysed individuals as well as altered karyotypes considered as normal chromosomal variants. In the total of 3092 analyzed metaphases, 20 spontaneous chromosomal aberrations were found in 13 individuals. This study contributes to the limited knowledge of the cytogenetic status of the Bosnian and Herzegovinian population. Further monitoring of spontaneous chromosomal aberrations incidences is recommended

Nova in vitro otkrića o citotoksičnosti halogeniranoga boroksina i deregulaciji gena povezanih sa staničnom smrću u stanicama GR-M melanoma

Anti-proliferative effects of halogenated boroxine – K2(B3O3F4OH) (HB) – have been confirmed in multiple cancer cell lines, including melanoma, but the exact mechanism of action is still unknown. This study aimed to determine its cytotoxic effects on human Caucasian melanoma (GR-M) cell growth in vitro as well as on the expression of cell death-related genes BCL-2, BECN1, DRAM1, and SQSTM1. GR-M and peripheral blood mononuclear (PBM) cells were treated with different HB concentrations and their growth inhibition and relative gene expression profiles were determined using the Alamar blue assay and real-time PCR. HB significantly inhibited cell growth of both GR-M and PBM cells but was even more effective in GR-M melanoma cells, as significant inhibition occurred at a lower HB concentration of 0.2 mg/mL. GR-M BCL-2 expression was significantly downregulated (P=0.001) at HB concentration of 0.4 mg/mL, which suggests that HB is a potent tumour growth inhibitor. At the same time, it upregulated BCL-2 expression in normal (PBM) cells, probably by activating protective mechanisms against induced cytotoxicity. In addition, all but the lowest HB concentrations significantly upregulated SQSTM1 (P=0.001) in GR-M cells. Upregulated BECN1 expression suggests early activation of autophagy at the lowest HB concentration in SQSTM1 cells and at all HB concentrations in PBM cells. Our findings clearly show HB-associated cell death and, along with previous cytotoxicity studies, reveal its promising anti-tumour potential.Antiproliferativni učinci halogeniranoga boroksina – K2(B3O3F4OH) (HB) – potvrđeni su u više staničnih linija raka, uključujući melanom, ali točan mehanizam djelovanja još uvijek nije poznat. Cilj ovoga istraživanja bio je utvrditi njegove citotoksične učinke na rast stanica ljudskoga melanoma (GR-M) in vitro, kao i na ekspresiju gena BCL-2, BECN1, DRAM1 i SQSTM1, povezanih sa staničnom smrću. GR-M melanom i mononuklearne stanice periferne krvi (PBM) tretirane su različitim koncentracijama HB-a, a njihova inhibicija rasta i relativni profili ekspresije gena određeni su Alamar blue testom i real-time PCR-om. HB je značajno inhibirao rast GR-M melanoma i PBM stanica, no u GR-M melanomu učinci su registrirani pri nižim koncentracijama HB-a. Ekspresija BCL-2 gena u GR-M melanomu bila je značajno smanjena (P=0,001) pri koncentraciji od 0,4 mg/mL, što sugerira da je HB snažan inhibitor rasta tumora. Istodobno, pojačao je ekspresiju BCL-2 u normalnim PBM stanicama, vjerojatno aktiviranjem zaštitnih mehanizama protiv inducirane citotoksičnosti. Osim toga, sve osim najniže koncentracije HB-a značajno su povećale ekspresiju SQSTM1 (P=0,001) u GR-M melanomu. Povećana ekspresija BECN1 u najnižoj koncentraciji HB-a u GR-M stanicama i pri svim koncentracijama u PBM stanicama sugerira ranu aktivaciju autofagije. Naša otkrića jasno pokazuju indukciju stanične smrti povezane s HB-om i zajedno s prethodnim studijama citotoksičnosti otkrivaju njegov obećavajući antitumorski potencijal

New in vitro findings about halogenated boroxine cytotoxicity and deregulation of cell death-related genes in GR-M melanoma cells

Anti-proliferative effects of halogenated boroxine – K2(B3O3F4OH) (HB) – have been confirmed in multiple cancer cell lines, including melanoma, but the exact mechanism of action is still unknown. This study aimed to determine its cytotoxic effects on human Caucasian melanoma (GR-M) cell growth in vitro as well as on the expression of cell death-related genes BCL-2, BECN1, DRAM1, and SQSTM1. GR-M and peripheral blood mononuclear (PBM) cells were treated with different HB concentrations and their growth inhibition and relative gene expression profiles were determined using the Alamar blue assay and real-time PCR. HB significantly inhibited cell growth of both GR-M and PBM cells but was even more effective in GR-M melanoma cells, as significant inhibition occurred at a lower HB concentration of 0.2 mg/mL. GR-M BCL-2 expression was significantly downregulated (P=0.001) at HB concentration of 0.4 mg/mL, which suggests that HB is a potent tumour growth inhibitor. At the same time, it upregulated BCL-2 expression in normal (PBM) cells, probably by activating protective mechanisms against induced cytotoxicity. In addition, all but the lowest HB concentrations significantly upregulated SQSTM1 (P=0.001) in GR-M cells. Upregulated BECN1 expression suggests early activation of autophagy at the lowest HB concentration in SQSTM1 cells and at all HB concentrations in PBM cells. Our findings clearly show HB-associated cell death and, along with previous cytotoxicity studies, reveal its promising anti-tumour potential