Cancer SLC43A2 alters T cell methionine metabolism and histone methylation.

Abnormal epigenetic patterns correlate with effector T cell malfunction in tumours1-4, but the cause of this link is unknown. Here we show that tumour cells disrupt methionine metabolism in CD8+ T cells, thereby lowering intracellular levels of methionine and the methyl donor S-adenosylmethionine (SAM) and resulting in loss of dimethylation at lysine 79 of histone H3 (H3K79me2). Loss of H3K79me2 led to low expression of STAT5 and impaired T cell immunity. Mechanistically, tumour cells avidly consumed methionine and outcompeted T cells for methionine by expressing high levels of the methionine transporter SLC43A2. Genetic and biochemical inhibition of tumour SLC43A2 restored H3K79me2 in T cells, thereby boosting spontaneous and checkpoint-induced tumour immunity. Moreover, methionine supplementation improved the expression of H3K79me2 and STAT5 in T cells, and this was accompanied by increased T cell immunity in tumour-bearing mice and patients with colon cancer. Clinically, tumour SLC43A2 correlated negatively with T cell histone methylation and functional gene signatures. Our results identify a mechanistic connection between methionine metabolism, histone patterns, and T cell immunity in the tumour microenvironment. Thus, cancer methionine consumption is an immune evasion mechanism, and targeting cancer methionine signalling may provide an immunotherapeutic approach.

Immune Checkpoints in Endometriosis-A New Insight in the Pathogenesis.

Endometriosis (EMS) is an oestrogen-dependent, chronic disease affecting women of a reproductive age. One of the important factors involved in the development of this disease is the complex disorders associated with the functioning of the immune system. Recent evidence has shown that EMS development is associated with changes in systemic and local immunity, including functional disturbances of effector and antigen-presenting cells. One of the reasons for immune imbalance can be the improper expression of immune checkpoints (ICPs). ICPs and their ligands are responsible for maintaining self-tolerance and the modulation of the initiation, duration, and magnitude of the immune response of effector cells in normal tissues to avoid tissue damage. Considering the complex nature of co-stimulatory or co-inhibitory ICPs and the signalling between effector cells and APCs, we hypothesise that changes in cells' activity caused by ICPs may lead to serious immune system disturbances in patients with endometriosis. Moreover, both upregulation and downregulation in the expression of ICPs may be implicated in this process, including the reduced activity of effector cells against endometrial implants and disturbances in the antigen-presenting process. In this narrative review, we discuss, for the first time, key findings from the emerging literature, describing the associations between ICPs and their possible implication in the pathogenesis of endometriosis.

circRNAs in Endometrial Cancer-A Promising Biomarker: State of the Art.

Endometrial cancer (EC) is one of the most common malignant tumors among women in the 21st century, whose mortality rate is increasing every year. Currently, the diagnosis of EC is possible only after a biopsy. However, it is necessary to find a new biomarker that will help in both the diagnosis and treatment of EC in a non-invasive way. Circular RNAs (circRNAs) are small, covalently closed spherical and stable long non-coding RNAs (lncRNAs) molecules, which are abundant in both body fluids and human tissues and are expressed in various ways. Considering the new molecular classification of EC, many studies have appeared, describing new insights into the functions and mechanisms of circRNAs in EC. In this review article, we focused on the problem of EC and the molecular aspects of its division, as well as the biogenesis, functions, and diagnostic and clinical significance of circRNAs in EC.

Current Understanding on Why Ovarian Cancer Is Resistant to Immune Checkpoint Inhibitors.

The standard treatment of ovarian cancer (OC) patients, including debulking surgery and first-line chemotherapy, is unsatisfactory because of recurrent episodes in the majority (~70%) of patients with advanced OC. Clinical trials have shown only a modest (10-15%) response of OC individuals to treatment based on immune checkpoint inhibitors (ICIs). The resistance of OC to therapy is caused by various factors, including OC heterogeneity, low density of tumor-infiltrating lymphocytes (TILs), non-cellular and cellular interactions in the tumor microenvironment (TME), as well as a network of microRNA regulating immune checkpoint pathways. Moreover, ICIs are the most efficient in tumors that are marked by high microsatellite instability and high tumor mutation burden, which is rare among OC patients. The great challenge in ICI implementation is connected with distinguishing hyper-, pseudo-, and real progression of the disease. The understanding of the immunological, molecular, and genetic mechanisms of OC resistance is crucial to selecting the group of OC individuals in whom personalized treatment would be beneficial. In this review, we summarize current knowledge about the selected factors inducing OC resistance and discuss the future directions of ICI-based immunotherapy development for OC patients.

Expression of Gal-9 on Dendritic Cells and Soluble Forms of TIM-3/Gal-9 in Patients Suffering from Endometriosis.

Immune system dysregulation is clinically evident in the pathogenesis of endometriosis (EMS). Changes in the dendritic cells (DCs) activity or phenotype may be involved in the implantation and growth of endometrial tissue outside the uterus in the disease. The TIM-3/Gal-9 axis is implicated in the development of immune tolerance. However, the knowledge about the exact role of this pathway in the EMS is extremely poor. In the present study, we evaluated the expression of Gal-9 on myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in the peripheral blood (PB) and peritoneal fluid (PF) of both EMS patients (n = 82) and healthy subjects (n = 10) via flow cytometry. We also investigated the concentrations of soluble Gal-9 and TIM-3 in the plasma and PF of EMS patients and the control group using ELISA. We showed significantly elevated percentages of mDCs-Gal-9+ and pDCs-Gal-9+, and significantly higher concentrations of the soluble form of Gal-9 and TIM-3 in the PF of EMS patients than in circulation. Our results led us to conclude that the accumulation of Gal-9 expressing mDCs and pDCs in the PF and high sTIM-3/Gal-9 production in the peritoneal cavity could represent the hallmark of immune regulation in EMS patients, which may augment the inflammatory process and development/maintenance of local immunosuppression.

γδ T Lymphocytes as a Double-Edged Sword-State of the Art in Gynecological Diseases.

Human gamma-delta (γδ) T cells are a heterogeneous cell population that bridges the gap between innate and acquired immunity. They are involved in a variety of immunological processes, including tumor escape mechanisms. However, by being prolific cytokine producers, these lymphocytes also participate in antitumor cytotoxicity. Which one of the two possibilities takes place depends on the tumor microenvironment (TME) and the subpopulation of γδ T lymphocytes. The aim of this paper is to summarize existing knowledge about the phenotype and dual role of γδ T cells in cancers, including ovarian cancer (OC). OC is the third most common gynecological cancer and the most lethal gynecological malignancy. Anticancer immunity in OC is modulated by the TME, including by immunosuppressive cells, cytokines, and soluble factors. Immune cells are exposed in the TME to many signals that determine their immunophenotype and can manipulate their functions. The significance of γδ T cells in the pathophysiology of OC is enigmatic and remains to be investigated.

Clinical Value of the PD-1/PD-L1/PD-L2 Pathway in Patients Suffering from Endometriosis.

The interaction between dendritic cells (DCs) and T cells mediated by the programmed cell death 1 (PD-1)/programmed cell death ligand 1 (PD-L1)/programmed cell death ligand 2 (PD-L2) pathway is the most important point in regulating immunological tolerance and autoimmunity. Disturbances in the quantity, maturity, and activity of DCs may be involved in the implantation and growth of endometrial tissue outside the uterus in endometriosis (EMS). However, little is known about the role of the immune checkpoint pathways in EMS. In our study, we examined the expression of PD-L1/PD-L2 on myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) in the peripheral blood (PB) and peritoneal fluid (PF) of both EMS patients (n = 72) and healthy subjects (n = 20) via flow cytometry. The concentration of soluble PD-L1 and PD-L2 in the plasma and PF of EMS patients and the control group were determined using ELISA. We demonstrated an elevated percentage of mDCs, mDCs and pDCs with the PD-L1or PD-L2 expression, and a higher concentration of the soluble forms of PD-L1 and PD-L2 in the PF than in the plasma of EMS patients. We conclude that the peritoneal cavity environment and the PD-1/PD-L1/PD-L2 axis may play an important role in the modulation of immune response and the development and/or progression of EMS.

Clinical and Prognostic Value of Antigen-Presenting Cells with PD-L1/PD-L2 Expression in Ovarian Cancer Patients.

The latest literature demonstrates the predominant role of the programmed cell death axis (PD-1/PD-L1/PD-L2) in ovarian cancer (OC) pathogenesis. However, data concerning this issue is ambiguous. Our research aimed to evaluate the clinical importance of PD-L1/PD-L2 expression in OC environments. We evaluated the role of PD-L1/PD-L2 in OC patients (n = 53). The analysis was performed via flow cytometry on myeloid (mDCs) and plasmacytoid dendritic cells (pDCs) and monocytes/macrophages (MO/MA) in peripheral blood, peritoneal fluid (PF), and tumor tissue (TT). The data were correlated with clinicopathological characteristics and prognosis of OC patients. The concentration of soluble PD-L1 (sPD-L1) and PD-1 in the plasma and PF were determined by ELISA. We established an accumulation of PD-L1+/PD-L2+ mDCs, pDCs, and MA in the tumor microenvironment. We showed an elevated level of sPD-L1 in the PF of OC patients in comparison to plasma and healthy subjects. sPD-L1 levels in PF showed a positive relationship with Ca125 concentration. Moreover, we established an association between higher sPD-L1 levels in PF and shorter survival of OC patients. An accumulation of PD-L1+/PD-L2+ mDCs, pDCs, and MA in the TT and high sPD-L1 levels in PF could represent the hallmark of immune regulation in OC patients.

Involvement of PI3K Pathway in Glioma Cell Resistance to Temozolomide Treatment.

The aim of the study was to investigate the anticancer potential of LY294002 (PI3K inhibitor) and temozolomide using glioblastoma multiforme (T98G) and anaplastic astrocytoma (MOGGCCM) cells. Apoptosis, autophagy, necrosis, and granules in the cytoplasm were identified microscopically (fluorescence and electron microscopes). The mitochondrial membrane potential was studied by flow cytometry. The activity of caspases 3, 8, and 9 and Akt was evaluated fluorometrically, while the expression of Beclin 1, PI3K, Akt, mTOR, caspase 12, and Hsp27 was determined by immunoblotting. SiRNA was used to block Hsp27 and PI3K expression. Cell migration and localization of Hsp27 were tested with the wound healing assay and immunocytochemistry, respectively. LY294002 effectively diminished the migratory potential and increased programmed death of T98G and MOGGCCM. Autophagy was dominant in MOGGCCM, while apoptosis was dominant in T98G. LY294002 with temozolomide did not potentiate cell death but redirected autophagy toward apoptosis, which was correlated with ER stress. A similar effect was observed after blocking PI3K expression with siRNA. Transfection with Hsp27 siRNA significantly increased apoptosis related to ER stress. Our results indicate that inhibition of the PI3K/Akt/mTOR pathway sensitizes glioma cells to apoptosis upon temozolomide treatment, which was correlated with ER stress. Hsp27 increases the resistance of glioma cells to cell death upon temozolomide treatment.

Potentilla alba Extracts Affect the Viability and Proliferation of Non-Cancerous and Cancerous Colon Human Epithelial Cells.

The aim of this study was to determine the anti-tumor activity of extracts isolated from Potentilla alba L. on human colon cancer cells of the HT-29 line and on non-cancer colon epithelial cells of the CCD 841 CoTr line. The research methods we used to determine the cytotoxic and proliferative properties were 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and neutral red (NR) assays, the ability to produce nitric oxide, the Griess method, and the biochemical properties like 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods indicating reduction activity of tested samples. Finally, the effects of the extracts on the morphology and cell counts were assessed by May-Grünwald-Giemsa staining. After a comprehensive analysis of all the experiments, the extracts were found to demonstrate cytotoxic properties, they stimulated the division of non-cancer cells, and they were able to scavenge free radicals. In the NR method, the cell viability dropped to approximately 80% compared to the control. In the MTT assay, tumor cell proliferation decreased to 9.5% compared to the control. Therefore, we concluded that this plant has medical potential.

[Selected mechanisms inducing resistance to immunotherapy in patients with ovarian cancer].

Recently, the intensive development of immunotherapies in the treatment of malignant tumors has been observed. The investigated treatment approaches including specific monoclonal antibodies, adoptive therapy and also anticancer vaccinations. The implementation of immunotherapy seems to be promising in treatment of the most malignant and fatal tumors including ovarian cancer. However, current findings have shown only a nonsignificant improvement of patients' survival. The possible cause of failure may be immunotherapy barriers that are a result of low immunogenicity level of ovarian cancer cells, mutation variability, and also the presence of a specific, immunosuppressive tumor microenvironment, which stimulates the cancer progression. The review presents the selected mechanisms of tumor resistance to immunological therapy. In order to project effective treatment approaches, it is necessary to understand both, mechanisms leading to the correct response for the treatment and causing therapeutic failures, resulting from resistance to therapy.

Blood-based analyses of cancer: Circulating myeloid-derived suppressor cells - is a new era coming?

Progress in cancer treatment made by the beginning of the 21st century has shifted the paradigm from one-size-fits-all to tailor-made treatment. The popular vision, to study solid tumors through the relatively noninvasive sampling of blood, is one of the most thrilling and rapidly advancing fields in global cancer diagnostics. From this perspective, immune-cell analysis in cancer could play a pivotal role in oncology practice. This approach is driven both by rapid technological developments, including the analysis of circulating myeloid-derived suppressor cells (cMDSCs), and by the increasing application of (immune) therapies, the success or failure of which may depend on effective and timely measurements of relevant biomarkers. Although the implementation of these powerful noninvasive diagnostic capabilities in guiding precision cancer treatment is poised to change the ways in which we select and monitor cancer therapy, challenges remain. Here, we discuss the challenges associated with the analysis and clinical aspects of cMDSCs and assess whether the problems in implementing tumor-evolution monitoring as a global tool in personalized oncology can be overcome.

Assessment of the clinicopathological relevance of mesothelin level in plasma, peritoneal fluid, and tumor tissue of epithelial ovarian cancer patients.

Ovarian cancer remains the most lethal gynecologic malignancy. This is due to lack of effective screening, diagnosis predominance in late stage of disease, a high recurrence rate after primary therapy, and poor treatment response in platinum-resistant tumor. Thus, unique biomarkers, predictive of individual disease course, and prognosis are urgently needed. The aim of our study was to assess the clinicopathological significance of plasma, peritoneal fluid, and tumor tissue levels of mesothelin in epithelial ovarian cancer patients. Plasma and peritoneal fluid levels of mesothelin were measured by enzyme-linked immunosorbent assay. Tissue expression of MSLN was evaluated using quantitative real-time polymerase chain reaction. Preoperative plasma mesothelin levels were significantly higher in epithelial ovarian cancer patients in comparison to the patients with benign tumor and controls. There have been noticed significant differences in the plasma mesothelin levels based on International Federation of Gynecology and Obstetrics stage, grade, and histology type. No significant changes were observed between Kurman and Shih type I versus type II epithelial ovarian cancer. Interestingly, peritoneal fluid mesothelin levels revealed significant differences based on both grade and Kurman and Shih-type epithelial ovarian cancer. There were no relevant changes in the mesothelin level in peritoneal fluid between different stages and histology types compared to benign tumor. MSLN expression level in tumor tissue was significantly higher based on stage, grade, and Kurman and Shih-type epithelial ovarian cancer than in the benign masses. In addition, data showed significant higher MSLN expression in endometrioid tumors compared to benign masses and serous tumors. Plasma, peritoneal fluid, and tumor tissue levels of mesothelin positively correlated with level of CA125. Low mesothelin concentrations in plasma were also associated with prolonged patient survival. More importantly, we revealed that plasma mesothelin level was correlated with both peritoneal fluid mesothelin level and tumor MSLN expression. This study highlights that plasma mesothelin level may be a useful noninvasive biomarker surrogate for local tumor mesothelin status in monitoring of epithelial ovarian cancer patients.

[The meaning of PD-1/PD-L1 pathway in ovarian cancer pathogenesis].

Ovarian cancer is a serious diagnostic and clinical issue. It belongs to the group of cancers with the highest mortality rate, that is why new, effective methods of therapy have been sought after. In recent years, researchers have been paying attention to the use of immunothetapy in the treatment of ovarian cancer. Currently, the numer of studies with the use of PD-1/PD-L1 pathway inhibitors is increasing. It has been reported that PD-1 receptor and its ligand are expressed on tumor cells and immunology system cells in patients with ovarian cancer. Increased expression of PD-1/PD-L1 is one of the inhibition mechanisms of the anti-tumor response by induction of peripheral tolerance. That seems why blocking PD-1/PD-L1 may be so important. A significant role in activation of programmed death cell-1 is attributed to tumor microenvironment (TME). In this review we have described the meaning of PD-1/PD-L1 pathway in ovarian cancer pathogenesis and current results of clinical trials using PD-1/PD-L1 inhibitors. Numerous clinical trials are focused on the effectiveness of immunotherapies as both monotherapy and combination therapy. The promising results of initial research phases are the basis for taking action on a larger scale. Perhaps this will allow in the future to use inhibitors of the PD-1/PD-L1 pathway in the treatment of ovarian cancer.

[Characterization of chosen pro-angiogenic factors and anti-angiogenic therapies in ovarian cancer].

Ovarian cancer is a neoplasm characterized by notably malignancy. The poor results of treatment result not only from the lack of screening tests making diagnosis possible at an early stage, but also because of the insufficiently effective treatment methods. High hopes are placed in targeted therapies, using agents such as angiogenesis inhibitors, immune checkpoint inhibitors or anticancer vaccines. The aim of the work is to present the latest results of research on antiangiogenic drugs. Databases such as PubMed, Google Scholar and ClinicalTrials.gov were used. Antiangiogenic drugs are substances of various structure, the common feature of which is the influence on signaling pathways associated with such factors as VEGF, PDGF or Ang1 / 2. Bevacizumab is an antibody directed against VEGF-A. It is the first anti-angiogenic drug with proven efficacy, expressed in the extension of overall survival. This was demonstrated both in the group of patients with newly diagnosed advanced disease and in the situation of relapse. Other anti-angiogenic agents, such as trebananib, nintedanib or pazopanib, currently have not been proven to possess comparably high efficacy in the treatment of ovarian cancer. There are no known causes of disease progression despite maintenance therapy. The potential for combining bevacizumab with other targeted drugs such as PD-L1 inhibitors is currently being investigated.

Does the patients age at cancer diagnosis affect microvessels density in uterine sarcoma tissues?

OBJECTIVES: The objective of the study was to retrospectively evaluate the density of vessels exhibiting positive glycoprotein CD34 expression in the uterine leiomyosarcoma tissues and their correlation with the age of patients at the time of tumor diagnosis. MATERIAL AND METHODS: The archival paraffin blocks with the cancer tissues collected from 50 patients suffering from uterine leiomyosarcoma were used together with their clinical and demographic data. The immunohistochemical peroxidase-de-pendent methods were used to detect microvessels with positive CD34 expression. The glycoprotein CD34 expression was evaluated as a density of microvessel showing the positive immunohistochemical reaction (MVDCD34). RESULTS: The negative, statistically significant correlation between the age of patients (at the moment diagnosis) and the MVDCD34+ (R = -0.289, p = 0.042) was found. CONCLUSIONS: The study's findings may suggest that the tissues of younger people constitute a permissive environment for pro-angiogenic factors.

[Why ovarian cancer cells escape from immune surveillance?]

Ovarian cancer is a malignancy of high mortality rates. In respect of the number of deaths caused by cancers it occupies the fourth place among women in Poland. Recent studies are focusing on the role of immune system in ovarian cancer pathogenesis. It has been reported that immune response against ovarian cancer cells may be inhibited by a number of immunosuppressive mechanisms active in cancer microenvironment. It causes difficulties in recognizing and destroying cancer cells by immune system which leads to the development of immune tolerance and is associated with a low efficacy of standard therapeutic strategies. In the presented paper we have described selected, new immunosuppressive mechanisms in ovarian cancer patients. They may be a novel, additional and relevant criterion that should be considered whilst developing new therapeutic strategies. Possibly, modulation of immunosuppressive mechanisms could contribute to modifying standard therapies and in consequence improve treatment outcome in ovarian cancer patients.

Management of uterine leiomyosarcoma.

The low incidence of uterine sarcomas requires many issues associated with its biology and clinical course to be followed with more research. Unsatisfactory surgical outcomes and a high risk of cancer dissemination make it worthwhile to consider the feasibility of supplementary systemic treatment. The currently employed chemo- and hormonal therapy is characterised by low efficacy. There is some hope in reports on targeted treatment. However, a comprehensive assessment of the efficacy of this kind of therapy is restricted by a small number of patients using it. Moreover, clinical studies using targeted therapies involve patients with a highly advanced disease, and the therapeutic results are assessed mainly via analysis of progression-free survival but not the clinical response.

[The prognostic value of selected immunological factors in ovarian cancer patients]. / Prognostyczna wartosc wybranych czynników immunologicznych u chorych na raka jajnika.

Ovarian cancer is the most aggressive gynecological cancer and is often diagnosed in advanced stage. Constantly we are looking for new prognostic factors which would enable early diagnosis, increase the effectiveness of therapeutic intervention. There is to little data about immunological predictors in ovarian cancer. The tumor's microenvironment is designated by regulatory T cells, cytotoxic T cells, dendritic cells (DCs), tumor - associated macrophages (TAMs), monocytes, plasma cells and cytokines, such as IL-6, IL-8, IL-10, IL-17 and TGF-beta. Some of them are responsible for the inhibition and others induce tumor growth. Ovarian cancer patients with high ratio of CD8 + TILs to Treg present longer overall survival time (OS). The presence of T helper cells in ascites is associated with longer OS. Furthermore, patients with a lower rate plasmocytoid DCs infiltrating tumor tissue demonstrate longer progression-free survival time (PFS). Women with increased M1/M2 ratio present higher five-year survival rate. The presence of immunologically competent cells and secreted cytokines give motivation to evaluate their prognostic value. Perhaps this strategy will contribute to longer progression-free survival time and overall survival time in those patients.

Telomeres and telomerase in endometrial cancer and hyperplasia.

Introduction: The study aimed to measure telomeres length (TL) and telomerase expression in normal endometrium and endometrial hyperplasia and cancer. Methods: Total RNA and DNA were isolated from endometrium samples of 117 patients. The RT-PCR method was used to determine telomerase expression and relative telomere length. Results: The control group had the longest telomeres in comparison to the hyperplasia and endometrial cancer groups. Only in the endometrial cancer group was telomerase expressed and positively correlated with telomere length. Conclusions: Telomere extension in endometrial cancer is mediated by telomerase, but telomere length may not be an indicator of endometrioid cancer development.