Russian Journal of Oncology

BACKGROUND: According to statistics, gastric cancer is in a leading position among all gastrointestinal cancers. The most effective treatment for gastric cancer is surgery. There are now heterogeneous clinical outcomes for patients in the same stage of the disease. The main reason for this is the fact that differences in types of gastric cancer occur not only at the histological level, but also at the molecular level. Finding the universal biomarkers that can provide information about patient prognosis is a subject of interest to scientists around the world. MMP-7 is the smallest molecule in the family of matrix metalloproteinases that contributes significantly to oncogenesis by affecting apoptosis and degradation of the extracellular matrix. MMP-7 hyperexpression is associated with aggressive tumor phenotype and worsens prognosis in patients with gastric cancer. Therefore, MMP-7 can be a promising biomarker in the treatment of gastric cancer.

AIM: To identify possible correlations between the expression of MMP-7 in patients with gastric cancer and their prognosis.

MATERIALS AND METHODS: The study included samples of 80 patients diagnosed with diffuse gastric cancer, who were selected based on our inclusion and exclusion criteria. 30 sectional stomach samples were taken as a comparison group. Of the 80 patients included in the study, gastrectomy was performed in 55% cases (44 people) and gastric resection was performed in 45% cases (36 people).

RESULTS: In our work, the expression level of MMP-7 0.8±0.07 was indicated as high, and the expression rate of 0.40±0.067 as low. During the study, we assessed the link between the level of MMP-7 expression and the clinical characteristics of the tumor. We evaluated the following indicators: the disease stage, the presence of lesions of lymph nodes, the size of the tumor. Patients with increased MMP-7 expression in tumor tissue have a better prognosis than patients with low MMP-7 expression.

CONCLUSION: The results of our study showed high MMP-7 expression in tumor tissue, which allowed us to establish a correlation between MMP-7 expression and adverse clinical outcomes. The data obtained may indicate the possible use of MMP-7 as a biomarker for gastric cancer.

BACKGROUND: Despite a large number of publications on preclinical studies of compounds with a suspected antitumor effect on in silico and in vitro models, in vivo studies are the most informative. The experimental part of the work on laboratory animals has its own peculiarities in the field of preclinical research: a large number of animals and analog compounds in the series, two- and three-phase staging, and, consequently, high cost and labor-intensive execution.

AIM: Optimization of algorithms for screening preclinical in vivo studies of compounds with a suspected antitumor effect.

MATERIALS AND METHODS: To form the algorithm in the preclinical study, primary data was obtained using standard pharmacological (determination of the toxicity class index, antitumor and antimetastatic activity, inhibition of tumor growth by weight, average life expectancy of animals) and morphological (autopsy, micropreparations with hematoxylin and eosin staining, as well as immunohistochemical study using monoclonal antibodies) methods with the selection of leading compounds for in-depth study with a description of the mechanism of pharmacological activity.

RESULTS: Based on a series of comparative experiments, the following algorithm of preclinical in vivo study for newly synthesized compounds with an alleged antitumor effect has been tested.

Stage 1. Determination of the toxicity class with a single intragastric administration to Wistar rats according to the Organization for Economic Co-operation and Development 420 protocol and selection of candidates for antitumor drugs according to the principle of the greatest safety of use.

Stage 2. Determination of the presence/absence of pharmacological activity of the tested compounds. Compounds of toxicity classes IV and V (according to the Globally Harmonized System of Hazard Classification and Labeling of Chemical Products) in a wide range of doses (doses are selected depending on the toxicity class) are examined for pharmacological activity before the natural death of tumor-bearing animals with the identification of leader substances, in-depth study of which is appropriate. The selection of promising substances and total doses for administration at the next stage is determined by the life expectancy of tumor-bearing animals.

Stage 3. Determination of indicators of antitumor and antimetastatic activity of leader substances with a fixed euthanasia period for all tumor-bearing animals and determination of possible mechanisms for the implementation of the therapeutic effect using immunohistochemical analysis.

Stage 4. To study the effect of the tested compounds on the growth rates of the primary tumor node and metastatic foci at different stages of the development of the tumor process, when administered in different modes, as part of combined and monochemotherapy, with mandatory clarification of the mechanisms for the implementation of antitumor and antimetastatic activity using biochemical and immunohistochemical techniques.

Stage 5. The study of the most promising compounds according to the guidelines for preclinical safety studies for the purpose of clinical trials and registration of medicines (the document was approved by the decision of the Board of the Eurasian Economic Commission of November 26, 2019, N 202): «Toxicity studies with repeated (multiple) administration of the drug, preclinical studies conducted in order to justify the conduct of exploratory clinical studies, studies of local tolerability of the drug, studies of genotoxicity of the drug, carcinogenicity of the drug, etc.»

CONCLUSIONS: The step-by-step exclusion of the tested compounds from the line of similarly-structured substances described by us will increase the efficiency of selecting promising candidates for antitumor drugs and reduce the cost of conducting preclinical studies of compounds with an alleged antitumor effect.

BACKGROUND: During maturation, dendritic cells begin to synthesize peptides that include the major histocompatibility complex MHC-II molecules, costimulatory molecules CD40⁺, CD80⁺, and CD86⁺, as well as CD83⁺ proteins. In cancer patients, dendritic cells dysfunction can lead to serious consequences in the form of deficiency of antitumor immunity, tumor progression, and decreased response to immunotherapy. All this is important to take into account to rethink the tumor immunotherapy strategy. Thus, approaches aimed at enhancing the viability of dendritic cells and preventing their dysfunction and polarization should be considered as a necessary step in order to increase the effectiveness of dendritic cell vaccines.

AIM: To evaluate the expression characteristics of differentiation markers of dendritic cell maturation obtained from peripheral blood monocytes under culture conditions in patients with breast cancer.

MATERIALS AND METHODS: With informed voluntary consent, 19 patients diagnosed with breast cancer were examined. Mononuclear cells were isolated on a Ficoll density gradient. For adhesion of monocytes to the bottom of 75 cm² culture flasks, they were pre-incubated for 1.5 hours in conditions of 5% CO₂ at 37 ℃. Growth and differentiation factors — GM-CSF (40 µl) and IL-٤ (٤٠ µl) — were added to the attached monocytes on the 1^st, 3^rd and 5^th days of cultivation. Immunophenotyping of dendritic cells was carried out on days 7 and 9 of cultivation using flow cytometry.

RESULTS: Flow cytometry data indicate that the viability of cultured dendritic cells in cancer patients is significantly reduced on day 9 compared to day 7 of cultivation. On day 9, there was a significant increase in CD80⁺ expression (2.40, p=0.028) and a decrease in CD83⁺ (1.65, p=0.036) compared to day 7.

CONCLUSION: In general, significant signs of maturation were observed: loss of the monocyte marker CD14⁺, increased expression of CD80⁺, CD83⁺, CD86⁺ — the main markers. A decrease in CD83⁺ can be considered as a suppression of excessive activation of immune responses. In the future, a more in-depth study of the characteristics of maturation and activation of cultured dendritic cells is necessary to understand the mechanisms and factors influencing the decrease in the effectiveness of immunotherapy with an autologous dendritic cell vaccine.