Soluble forms of PD-1/PD-L immune checkpoint receptor and ligand in blood serum of breast cancer patients: association with clinical pathologic factors and molecular type of the tumor.

Results of enzyme-linked immunosorbent assay of the soluble forms of PD-1/PD-L immune checkpoint receptor and ligand (sPD-1 and sPD-L1) in pretreatment blood serum of 88 breast cancer patients at various disease stages aged 30-83 years are presented. The control group included 55 practically healthy women aged 19-82 years. Serum sPD-1 and sPD-L1 levels in breast cancer patients highly significantly (p<0.0001) differ from control and these changes are opposite: soluble receptor level is more than 6-fold decreased, while soluble ligand concentration - 5.5 fold increased. Both markers separately, as well as their ratio demonstrate very high sensitivity (94-100%) and specificity (95-100%) in relation to healthy control. No statistically significant associations of sPD-1 and sPD-L1 levels with clinical stage, individual TNM system criteria, tumor histological structure, grade, receptor status, and molecular type were established. In particular, no significant peculiarities of the markers' levels in triple negative breast cancer successfully treated with anti-PD-1/PD-L1 preparations were revealed. Long-term follow-up and dynamic studies of sPD-1 and sPD-L1serum levels in the course of treatment are required for evaluation of their independent from clinical and morphological factors prognostic significance and the possibility of application as low invasive tests for prediction and monitoring of corresponding targeted therapy efficiency.

Prognostic significance of VEGF signaling system components and matrix metalloproteinases in blood serum of gastric cancer patients.

Analysis of long-term treatment results of 77 primary gastric cancer patients at stage I-IV of the tumor process followed during 1 - 41 months (median - 6.4 months) from the onset of specific treatment are presented depending on the basal levels of VEGF, soluble forms of its receptors (sVEGFR1, sVEGFR2) and matrix metalloproteinases (MMP-2, 7, 9) in blood serum. Overall survival assessed by Kaplan-Meyer analysis and with the help of Cox multiparametric regression model was applied as the criterion of prognostic value. It was found that at high (≥ 420 pg/ml) serum VEGF, the overall survival of patients with gastric cancer was statistically significantly lower than at the marker's levels below 420 pg/ml (p<0.011): 3-year's survival comprised 46,3±12,5% and 88,2±7,8% respectively. Median survival of patients with high VEGF level comprised 21.7 months, of those with low VEGF was not achieved during the whole follow-up period. Serum sVEGFR1, sVEGFR2, MMP-2, 7 and 9 levels were not significantly associated with the overall survival of patients included in this study. Only index M of TNM system and serum VEGF level demonstrated an independent prognostic value in multiparametric model (p=0.036). Thus, it was confirmed that VEGF signaling pathway plays an important role in gastric cancer, and its components - in the first place, VEGF A - are substantial factors of disease prognosis, and can also be useful for monitoring of treatment efficiency.

Prognostic significance of the TNM system criteria, levels of serum insulin-like growth factors and their transport proteins, VEGF and MMP-7 in colorectal cancer.

The analysis of long-term results of treatment of 88 primary patients with colon adenocarcinoma at various stages of tumor process is presented, taking into account the TNM system criteria, and serum IGF-1, IGF-2, IGFBP-1, IGFBP-2, IGFBP-3, VEGF, and MMP-7 levels. The overall survival rate assessed by Kaplan-Meier method and Cox multivariate regression model was used as the criterion of prognosis. It was established that IGF-1, IGFBP-2 and VEGF serum levels along with the stage of colorectal cancer might be considered as statistically significant independent predictors of overall survival in patients.

Clinical prospects of IGF-signaling system components study in ovarian cancer patients.

Among various auto/paracrine growth-regulating signaling pathways an important role belongs to that of insulin-like growth factors (IGFs) and insulin. IGF-signaling system is actively involved in the regulation of both normal ovarian function and ovarian tumor growth. On the one hand, all members of this system are expressed in malignant ovarian epithelial cells, and the prognostic significance of this expression has been revealed for some of them in ovarian cancer patients in several studies. On the other hand, circulating IGFs/IGFBPs levels have not been undoubtedly associated with ovarian cancer risk or disease progression, but some of them can be regarded as supplementary serological ovarian cancer markers. An important route to the clinical application of IGF-signaling system studies in ovarian cancer is the growing possibility of using specific molecular targeted agents to suppress its growth-stimulating and other activities. However, the introduction of such agents to practical oncology has met serious problems, with the main difficulties resulting from the absence of reliable predictive molecular markers and metabolic side effects due to the tight connection between IGF-signaling and insulin-regulated processes. The prognostic and diagnostic values of various IGF system components and the current state of corresponding molecular targeted therapies development for ovarian cancer are reviewed.

Phosphatidylinositol 3-kinase/AKT signalling pathway components in human breast cancer: clinicopathological correlations.

BACKGROUND: The phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway plays a major role in the regulation of breast cancer growth and survival, but the clinical value of its components in human tumours is unclear. PATIENTS AND METHODS: PI3K was analysed using Western blotting with monoclonal antibodies to the p85 subunit in tumour and adjacent mammary gland samples from 33 breast cancer patients. Activated Akt1 (pAkt1) expression was quantified in 46 sample pairs by a direct sandwich ELISA assay. RESULTS: Tumour PI3K expression was increased in 79% of the investigated sample pairs and was not associated with the main clinico-pathological features. Only 49% of breast cancers had increased pAkt1, but the frequency of its elevation was positively associated with tumour size and histological grade, and controversially related to estrogen and progesterone receptor status. CONCLUSION: Increased PI3K but not pAkt1, expression appears to be a widespread feature of human breast cancer indicating the different roles of the two components of one signalling system.

Activation of mitogenic pathways and sensitization to estrogen-induced apoptosis: two independent characteristics of tamoxifen-resistant breast cancer cells?

Paradoxical induction of apoptosis by estrogen has been described previously for estrogen-deprived and antiestrogen-resistant breast cancer cells. In this study we analyzed the possible interrelations between cell sensitization to estrogen apoptotic action and cell ability to (anti)estrogen-independent growth. Using tamoxifen-resistant sublines derived from the parent MCF-7 breast cancer cells by long-term tamoxifen treatment we demonstrated that resistant cells are characterized by increased level of EGF receptor and unexpected increase of VEGF receptor 2 (Flk-1/KDR) and its specific ligand, VEGF-A. The importance of the VEGF signaling in the autocrine regulation of cell growth was indicated by the ability of VEGF inhibitor, soluble fragment of Flt-1/Fc chimera, to suppress the phosphorylation of MAP kinases as well as to inhibit the estrogen-independent growth of MCF-7 cells. Sensitization of tamoxifen-resistant cells to estrogen-induced apoptosis required the additional continuous cultivation in steroid-depleted medium and did not depend on the activity of both EGF and VEGF pathways. Finally, we showed that treatment of the cells with 17beta-estradiol (10(-9) M) resulted in a marked increase in p53 level both in the resistant cells undergoing apoptosis and in the parent MCF-7 cells insensitive to apoptotic estrogen action. These data provide an important support for the existence of a disbalance between pro- and anti-apoptotic machinery in the resistant breast cancer cells that forms independently of the acquired ability to estrogen-independent growth.