This review analyzed 21 scientific papers on the determination of amino acids in various types of cancer in saliva. Most of the studies are on oral cancer (8/21), breast cancer (4/21), gastric cancer (3/21), lung cancer (2/21), glioblastoma (2/21) and one study on colorectal, pancreatic, thyroid and liver cancer. The amino acids alanine, valine, phenylalanine, leucine and isoleucine play a leading role in the diagnosis of cancer via the saliva. In an independent version, amino acids are rarely used; the authors combine either amino acids with each other or with other metabolites, which makes it possible to obtain high values of sensitivity and specificity. Nevertheless, a logical and complete substantiation of the changes in saliva occurring in cancer, including changes in salivary amino acid levels, has not yet been formed, which makes it important to continue research in this direction.

The study of salivary amino acid profiles has attracted the attention of researchers, since amino acids are actively involved in most metabolic processes, including breast cancer. In this study, we analyzed the amino acid profile of saliva in a sample including all molecular biological subtypes of breast cancer to obtain a more complete picture and evaluate the potential utility of individual amino acids or their combinations for diagnostic purposes. This study included 116 patients with breast cancer, 24 patients with benign breast disease, and 25 healthy controls. From all patients, strictly before the start of treatment, saliva samples were collected, and the quantitative content of 26 amino acids was determined. Statistically significant differences between the three groups are shown in the content of Asp, Gly, Leu + Ile, Orn, Phe, Pro, Thr, and Tyr. To differentiate the three groups from each other, a decision tree was built. To construct it, we selected those amino acids for which the change in concentrations in the subgroups was multidirectional (GABA, Hyl, Arg, His, Pro, and Car). For the first time, it is shown that the amino acid profile of saliva depends on the molecular biological subtype of breast cancer. The most significant differences are shown for the luminal B HER2-positive and TNBC subgroups. In our opinion, it is critically important to consider the molecular biological subtype of breast cancer when searching for potential diagnostic markers.

Changes in the concentration of tryptophan (Trp) indicate a serious metabolic restructuring, which is both a cause and a consequence of many diseases. This work examines the upward change in salivary Trp concentrations among patients with breast cancer. This study involved volunteers divided into three groups: breast cancer (n = 104), non-malignant breast pathologies (n = 30) and healthy controls (n = 20). In all participants, before treatment, the quantitative content of Trp in saliva was determined by capillary electrophoresis. In 20 patients with breast cancer, Trp was re-tested four weeks after surgical removal of the tumor. An increase in the Trp content in saliva in breast cancer has been shown, which statistically significantly decreases after surgical removal of the tumor. A direct correlation was found between increased Trp levels with the degree of malignancy and aggressive molecular subtypes of breast cancer, namely triple negative and luminal B-like HER2-negative. These conclusions were based on an increase in Ki-67 and an increase in Trp in HER2-negative and progesterone-negative subtypes. Factors under which an increase in Trp concentration in saliva was observed were identified: advanced stage of breast cancer, the presence of regional metastasis, low tumor differentiation, a lack of expression of HER2, estrogen and progesterone receptors and the high proliferative activity of the tumor. Thus, the determination of salivary Trp may be a valuable tool in the study of metabolic changes associated with cancer, particularly breast cancer.

In this work, we focused on the analysis of VEGF content in saliva and its relationship with pro-inflammatory cytokines and amino acids involved in immunomodulation and angiogenesis in breast cancer. The study included 230 breast cancer patients, 92 patients with benign breast disease, and 59 healthy controls. Before treatment, saliva samples were obtained from all participants, and the content of VEGF and cytokines in saliva was determined by an enzyme-linked immunosorbent assay, as well as the content of amino acids by high-performance liquid chromatography. It was found that VEGF was positively correlated with the level of pro-inflammatory cytokines IL-1β (r = 0.6367), IL-6 (r = 0.3813), IL-8 (r = 0.4370), and IL-18 (r = 0.4184). Weak correlations were shown for MCP-1 (r = 0.2663) and TNF-α (r = 0.2817). For the first time, we demonstrated changes in the concentration of VEGF and related cytokines in saliva in different molecular biological subtypes of breast cancer depending on the stage of the disease, differentiation, proliferation, and metastasis to the lymph nodes. A correlation was established between the expression of VEGF and the content of aspartic acid (r = −0.3050), citrulline (r = −0.2914), and tryptophan (r = 0.3382) in saliva. It has been suggested that aspartic acid and citrulline influence the expression of VEGF via the synthesis of the signaling molecule NO, and then tryptophan ensures tolerance of the immune system to tumor cells.

BACKGROUND: Chemical homeostasis is a necessary component for maintaining health, and an excessive or insufficient level of macro and microelements in the body is considered a risk factor for the development of pathological changes. AIM: To determine the micro and macro-element composition of the saliva of СHPP workers by capillary electrophoresis. MATERIALS AND METHODS: We used the saliva samples from Omsk СHPP personnel aged 2545 years (main group; n=104) and healthy volunteers aged 2345 years who were not related to the СHРP company (control group; n=195). Capillary electrophoresis was used to evaluate the potassium, sodium, magnesium, calcium, lithium, strontium, barium, and manganese content of all samples. RESULTS: It has been established that potassium, sodium, magnesium, and calcium ions were present in all the samples investigated; however, their balance is considerably disrupted under conditions of technogenic pollution. It was observed that lithium, barium, strontium, and manganese were identified in a greater number of saliva samples from СHPP workers compared to the control group. Strontium was not identified in the saliva of volunteers in the control group; its appearance correlated with working conditions. CONCLUSION: The proposed method allows estimating the degree of technogenic load on the body and identifying a risk group for which appropriate preventive measures and greater attention to the diagnosis of occupational diseases as part of a planned medical evaluation are required.

ЦЕЛЬ ИССЛЕДОВАНИЯ Дать сравнительную оценку движению эмалевой и дентинной жидкости в зависимости от морфологического строения различных отделов твердых тканей зубов человека. МАТЕРИАЛ И МЕТОДЫ В исследовании приняли участие 140 человек женского пола в возрасте от 21 года до 30 лет. У всех анализировали размеры, форму, поверхность эмалево-дентинного соединения; эмалевых призм и их кристаллов в поверхностном, среднем и глубоком отделах; ширину, извитость, облитерацию дентинных канальцев исследуемых зубов с помощью растрового электронного микроскопа Jeol JCM-5700 и атомно-силового микроскопа Ntegra Prima. При биохимическом исследовании изучали количественное содержание воды в образцах эмали, дентина, эмалево-дентинного соединения с помощью взвешивания навесок образцов до и после высушивания. Обработка полученных данных проводилась методами вариационной статистики с использованием стандартных пакетов Microsoft Excel 2008, Statistica 12.0. РЕЗУЛЬТАТЫ Крупнофестончатый тип эмалево-дентинного соединения характеризуется зонами внедрения дентина в эмаль на расстоянии более 10 мм, с правильным расположением эмалевых призм и широкими дентинными канальцами диаметром от 3,55 до 4,70 мкм, воды достаточно во всех отделах. Мелкофестончатый тип отличается меньшей выраженностью участков взаимовнедрения дентина в эмаль от 2 до 10 мкм, дентинные канальцы незначительно искривлены диаметром от 2,90 до 3,60 мкм, содержание воды в дентине уменьшено. При микрофестончатом типе наблюдается линейная форма строения с зонами взаимовнедрения до 2 мкм, эмалевые призмы слабо упорядоченные, дентинные канальцы суженные и искривленные диаметром от 1,30 до 1,95 мкм, содержание воды в эмали и дентине снижено. ВЫВОД При микрофестончатом типе эмалево-дентинного соединения, хаотичном расположении эмалевых призм и узких дентинных канальцах нарушено движение воды и снижены обменные процессы, что определяет высокую вероятность возникновения болезней твердых тканей зубов.