Experimental oncology最新文献

On August 10, 2023, an outstanding Ukrainian scientist, Doctor of medical sciences, Professor, pathophysiologist, oncoimmunologist, laureate of the State Prize of Ukraine in the field of science and technology and laureate of the priz- es of the NASU named after I.I. Mechnikov, R.E. Kavetsky, and O.O. Bohomolets, the leading scientist of the Labora- tory of Oncoimmunology and Antitumor Vaccine Design of R.E. Kavetsky Institute of Experimental Pathology, On- cology and Radiobiology of the NASU Ninel Mykhailivna Berezhna passed away. N.M. Berezhna was born on March 19, 1928 in the Kharkiv Oblast. Upon graduating from Bohomolets Kyiv Medical Institute, she began her career as a scientist at the Kyiv Research Institute of Epidemiology, Microbiology and Parasitology of the Ministry of Health of the Ukrainian SSR, where she defended her PhD thesis in 1959. In 1964, she was awarded the title of senior researcher in the specialty "pathophysiology". In 1972, N.M. Berezhna defended her doctoral thesis. The sharp, inquisitive mind of a scientist and the insatiable passion of a researcher inherent to Ninel Mykhailivna led her in 1974 to the Institute of Oncology Problems of the Academy of Sciences of Ukraine, presently RE. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology of the National Academy of Sciences of Ukraine, with which her entire scientific and creative life was inextricably linked until her last breath. From 1980, she was heading the Department of Immunology and Allergology for over 25 years. In 1983, N.M. Berezhna was awarded the scientific title of Professor in the specialty "allergology and immunology". Oncoimmunology became the main area of research activity of Prof. Berezhna. She focused on the potential of immunotherapy of cancer accounting for the interactions between lymphocytes and can- cer cells, the mechanisms of tumor-associated suppression, interleukin-2 production, and the expres- sion of its receptors on lymphocytes and cancer cells in the dynamics of tumor growth. The scientific achievements and the practical developments by Prof. Berezhna contributed much to the national theoretical and applied oncoimmunology justifying that the result of the lymphocyte-cancer cell interaction depends equally on the functional activity of the immune system and the biological features inherent to the tumor. In recent years, Prof. Berezhna focused on studying the physiological system of the connective tissue as a key factor of the tumor microenvironment. Prof. N.M. Berezhna is the author of 10 monographs and more than 300 scientific works on various aspects of oncoimmunology. The monographs of recent years "The Interleukin System and Cancer (New Aspects of the Tumor-Host Interaction)" (2000), "Immunology of Malignant Growth" (2005), and "Interleukin Families: Biology and Oncogenesis" (2013) are real encyclopedic publications for specialists in oncoimmunology, pathophysiology, and oncology. Prof. N.M. Berezhna combined he

Background: Epigenetic alteration is one of the most common molecular changes identified in the progression of breast cancer (BC).

Aim: To study the frequency and relation between methylation of BRCA1, MLH1, MGMT, GSTP1, APC, RASSF1A, p16, WIF, and EGFR and the clinicopathological features in Vietnamese BC patients.

Materials and methods: Methylation-specific polymerase chain reaction (MS-PCR) and SPSS 20.0 software were utilized in order to identify methylated frequency as well as evaluate its relationship with the patient's clinical features.

Results: In 162 BC cases, the methylation rates of the selected genes were 53.7%, 22.8%, 38.9%, 34.6%, 29.0%, 46.3%, 20.4%, 18.5%, and 28.4% respectively. In 32 cases of benign breast diseases (BBD) - 12.5%, 15.6%, 6.3%, 3.1%, 12.5%, 21.9%, 3.1%, 15.6% and 3.1%. BC samples displayed higher BRCA1, MGMT, GSTP1, APC, RASSF1A, WIF1, and p16 methylation levels than BBD samples (p < 0.001). Hypermethylation of BRCA1, GSTP1, and RASSF1A was predominant in the invasive ductal carcinoma, while hypermethylation of BRCA1, GSTP1, RASSF1A, WIF-1, and p16 was found to significantly correlate with lymph node metastasis (p < 0.05). Hypermethylation of BRCA1, MGMT, and GSTP1 was more common in stage III (p < 0.05) than in stages I/II, whereas MLH1 methylation was predominant in stage I and APC methylation was less common in stage III (p = 0.03). In addition, methylation of RASSF1A and EGFR was more frequent in younger patients (p < 0.01) than in elder patients.

Conclusion: These data suggest that a gene panel (BRCA1/MGMT/GSTP1) can be used to support the diagnosis and screening of Vietnamese patients' BC with a sensitivity of 70%, and a specificity of 85%.

Background: Malignant gliomas are the most frequent and lethal brain tumors. Their molecular aspects remain intangible but current studies have pointed to certain genetic polymorphic loci that pose the risk. The polymorphic sequence variations of the epidermal growth factor receptor gene (EGFR) pathway play a vital role in the glioma risk, and the EGFR variants (216G>T and 191C>A) are identified to affect the risk for the development of different tumors including glioma.

Aim: To examine genetic variations of EGFR T rs712829 (216G/T) and rs712830 (191C>A) with respect to glioma risk.

Materials and methods: 129 confirmed glioma cases were genotyped against 180 malignancy-free healthy controls by polymerase chain reaction-restriction fragment length polymorphism technique (RFLP).

Results: The frequency of the TT homozygous variant of the EGFR -216 G/T genotype differed significantly between cases and controls (49.6% vs. 23.0%) (p < 0.0001). The EGFR -216 G>T allele 'T' was found significantly more frequently in cases (0.56 vs. 0.33 in controls; p < 0.0001). The EGFR -191C>A homozygous 'AA' genotype was implicated significantly more frequently in cases than in controls (p < 0.0001). The distribution of the 'A' variant allele was also more frequent in cases (41.9%) than in controls (14.0%) (0.55 vs. 0.30; p < 0.0001). TC and TA haplotypes showed varied frequency in cases and controls.

Conclusion: EGFR -216 G>T and -191 C>A variants and haplotypes (TA and TC) of the EGFR gene are very strong risk factors in the development of glioma in the Kashmiri population.

Background: Today, the ability for metabolic reprogramming is considered one of the distinguishing features of metastatically active tumor cells, a classic example of which is aerobic glycolysis. Despite a large number of studies in this direction, the question of the relationship between the intensity of aerobic glycolysis and the metastatic potential of tumor cells remains almost completely open. The work aimed to investigate the effect of the lactate dehydrogenase (LDH) inhibitor on the viability and several characteristics of Lewis lung carcinoma cells with different metastatic potential.

Materials and methods: High-metastatic (LLC) and low-metastatic (LLC/R9) variants of Lewis lung carcinoma cells were used. After 24 h of tumor cells incubation with or without 40 mM sodium oxamate, cell viability, the concentration of glucose and lactate in the incubation medium, distribution of cells by the cell cycle phases, and intracellular ROS production were estimated.

Results: It was revealed that regardless of the metastatic potential, LLC cells are heterogeneous in terms of both the involvement of aerobic glycolysis in their growth and survival processes and the sensitivity to the cytotoxic/cytostatic action of an LDH inhibitor. 35% of cells of either LLC variant form an oxamate-resistant subpopulation while 65% are oxamate-sensitive. The rate of glucose consumption of LLC/R9 cells in the absence of oxamate is almost twice higher compared to LLC and, as a result, the sensitivity of these cells to the cytotoxic/cytostatic effect of oxamate also is significantly higher (the IC50 for LLC/R9 cells is by 35.8% lower than that for LLC cells, p < 0.05). Approximately one-third of the cells of both LLC and LLC/R9 variants can survive and proliferate when aerobic glycolysis is completely inhibited by oxamate. This indicates metabolic reprogramming (either pre-existing or dynamically arising in response to inhibition of glycolysis) of this subpopulation of cells, within which not only the survival of cells but also their proliferative activity is most likely based on glutamine metabolism.

Conclusions: Such metabolic heterogeneity of metastatically active cells indicates that inhibition of glycolysis as monotherapy is insufficient for effective antimetastatic therapy. Presumably, more effective would be to involve various inhibitors of metabolic processes that ensure the metabolic plasticity of metastatic cells.

The statistical data of the recent decades demonstrate a rapid growth of breast cancer (BCa) incidence and a tendency toward its increase especially in young women. In the structure of morbidity of women in the age group of 18-29 years, BCa ranks first and in the age range of 15-39 years, BCa is one of the leading causes of mortality. According to the data of the epidemiological and clinical studies, the young age is an independent unfavorable prognostic factor of BCa that is associated with an unfavorable prognosis and low survival rates and is considered an important predictor of the disease aggressiveness, a high risk of metastasis and recurrence. The variability of clinicopathological and molecular-biological features of BCa in patients of different age groups as well as the varying course of the disease and different responses to the therapy are mediated by many factors. The analysis of the literature data on the factors and mechanisms of BCa initiation in patients of different age groups demonstrates that the pathogen- esis of BCa depends not only on the molecular-genetic alterations but also on the metabolic disorders caused by the current social and household rhythm of life and nutrition peculiarities. All these factors affect both the general con- dition of the body and the formation of an aggressive microenvironment of the tumor lesion. The identified features of transcriptome and the differential gene expression give evidence of different regulations of the immune response and the metabolic processes in BCa patients of different age groups. Association between the high expression of the components of the stromal microenvironment and the inflammatory immune infiltrate as well as the increased vascu- larization of the tumor lesion has been found in BCa tissue of young patients. Proving the nature of the formation of the landscape comprising molecular-genetic, cytokine, and immune factors of the tumor microenvironment will undoubtedly contribute to our understanding of the mechanisms of tumor growth allowing for the development of algorithms for delineating the groups at high risk of tumor progression, which requires more careful monitoring and personalized treatment approach. Th s will be helpful in the development of innovative technologies for complex BCa treatment.

Background: Germline alterations of the CDH1 (E-cadherin) tumor suppressor gene have been reported in several epithelial malignancies like hereditary diffuse gastric cancer and lobular breast cancer. E-cadherin plays a central role in proliferation, maintenance of cell-to-cell adhesion, polarity, and epithelial-mesenchymal transition of tissue cells. It is necessary to analyze the impact of the CDH1 germline sequence variants on protein and predict its clinical significance in breast cancer (BC) progression. The aim of the current study was to evaluate the impact and association of CDH1 gene potentially pathogenic variants/likely pathogenic variants (PVs/LPVs) with the initiation and progression of BC.

Materials and methods: In this study, the clinical data of 200 BC patients have been analyzed based on the type of BC, age, grade, stage, hormonal status, and risk factors. Blood samples from 50 healthy donors were used as a control. Furthermore, CDH1 gene molecular analysis, along with in silico analysis, was provided to assess the invasiveness and progression of BC caused by the E-cadherin protein.

Results: Four variants were identified by genetic screening within the CDH1 gene that included variations in exons 7, 8, 10, 11, and 13. Exon 10 had splice site mutation at position c.1337C>A, affecting the protein structure. In exon 11, there was an insertion of T base at position 1669, resulting in truncated protein compared to a normal one that can lead to the disease-causing non- sense-mediated decay and exon 13 variant c.2076T>C has already known polymorphism. In silico analysis of CDH1 showed the presence of the different variants that indicated the overall disruption of protein structure and function.

Conclusions: The further functional analysis of these variants and their association with BC can be ensured by increasing the sample size and in vivo studies using mouse models.

The aim of our study was to measure the levels of 8-hydroxy-2-deoxyguanosine, malondialdehyde, and antioxidant enzymes in patients with locally advanced cervical cancer prior to treatment to determine how these evaluated biomarkers are associated with cervical cancer recurrence and to estimate their potential in further research and clinical use.

Materials and methods: The study included 45 female patients with newly diagnosed advanced cervical cancer who underwent concomitant chemoradiotherapy. The blood and urine samples were collected prior to treatment, between December 2013 and April 2016, and subsequent laboratory analysis was performed. After the medium follow-up of 29 months, the patients were divided into 3 groups according to the time of disease recurrence. A statistical analysis was performed in order to evaluate the relationship between the previously measured biomarkers and recurrence.

Results: Taken individually, the parameters of oxidative stress did not reveal significant differences between the three groups in our study. Nevertheless, the catalase and glutathione S-transferase activities were the best predictors of the recurrence. Based on the activities of these two oxidative enzymes, it was possible to separate the group of patients without recurrence after follow-up from the other two groups of patients with recurrent disease.

Conclusions: The parameters of oxidative stress have a certain predictive value on the outcome of patients with advanced cervical cancer after concomitant chemo-radiotherapy.

Background: Currently, there is a great interest in the genetic testing of BRCA1 and BRCA2 due to the fact that for patients with breast cancer (BC) with pathogenic variants of these genes, the use of the PARP inhibitors could be also provided in addition to implemented treatment protocols. The aim of this study was to characterize the molecular genetic structure of the BRCA1 gene in BC patients without progenitor germline mutations taking into account the methylation state of the promoter region.

Materials and methods: The study involved 210 patients with newly diagnosed BC. The most common germline pathogenic variants of the BRCA1 (185delAG, 5382insC, 4153delA, T300G) and BRCA2 (6174delT) genes were identified in the peripheral blood. A subgroup of 14 patients without progenitor pathological variants of the BRCA1 and BRCA2 genes and with a family history of cancer was randomly selected. For them, BRCA1 gene sequencing by Sanger and hypermethylation of the BRCA1 gene promoter region were analyzed.

Results: The following frequencies of BRCA1 mutations were determined in the general group: 5382insC - 8.6%, 4153delA - 0.5%, T300G - 0.5%. The analysis of the BRCA1 gene by Sanger sequencing revealed 11 BRCA1 gene variants in 10 out of 14 BC patients. All of them, according to the currently available data, were defined as "benign" and not clinically relevant. The frequency of the detection of hypermethylation of the BRCA1 gene promoter region in the randomly selected group of patients was 14.3%.

Conclusions: In BC patients, not only common mutations but also the methylation status of the BRCA1 gene promoter region in the peripheral blood should be determined. The whole-genome sequencing of the BRCA1 gene may be the last step in determining the genetic characteristics of BC patients carried out to optimize the treatment and improve survival thanks to the higher prevalence of the progenitor mutations and hypermethylation of the BRCA1 gene promoter.