Exploring the therapeutic efficacy of crocetin in oncology: an evidence-based review

With cancer being a leading cause of death globally, there is an urgent need to improve therapeutic strategies and identify effective chemotherapeutics. This study aims to highlight the potential of crocetin, a natural product derived from certain plants, as an anticancer agent. It was  conducted an extensive review of the existing literature to gather and analyze the most recent data on the chemical properties of crocetin and its observed effects in various in vitro and in vivo studies. The study  particularly focused on studies that examined crocetin's impact on cell cycle dynamics, apoptosis, caspases and antioxidant enzyme levels, tumor angiogenesis, inflammation, and overall tumor growth. Crocetin exhibited diverse anti-tumorigenic activities including inhibition of tumor cell proliferation, apoptosis induction, angiogenesis suppression, and potentiation of chemotherapy. Multiple cellular and molecular pathways such as the PI3K/Akt, MAPK and NF-κB were modulated by it. Crocetin demonstrates promising anti-cancer properties and offers potential as an adjunctive or alternative therapy in oncology. More large-scale, rigorously designed clinical trials are needed to establish therapeutic protocols and ascertain the comprehensive benefits and safety profile of crocetin in diverse cancer types.

Gentiopicroside-An Insight into Its Pharmacological Significance and Future Perspectives

Gentiopicroside (GPS) is a leading component of several plant species from the Gentianaceae botanical family. As a compound with plenty of biological activities and a component of herbal drugs, GPS has an important role in the regulation of physiological processes in humans. The results of recently published scientific studies underline a meaningful role of this molecule as an active factor in metabolic pathways and mechanisms, which may have an influence in the treatment of different diseases, including digestive tract disorders, malignant changes, neurological disorders, microbial infections, bone formation disorders, inflammatory conditions, and others. This review aims to collect previously published reports on the biological properties of GPS as a single compound that were confirmed by in vitro and in vivo studies, and to draw attention to the newly discovered role of this bitter-tasting secoiridoid. Thanks to these properties, the research on this substance could be revisited.

Therapeutic Potential of 1,8-Dihydroanthraquinone Derivatives for Breast Cancer

Breast cancer (BC) is the most common malignancy among women worldwide. In recent years, significant progress has been made in BC therapy. However, serious side effects resulting from the use of standard chemotherapeutic drugs, as well as the phenomenon of multidrug resistance (MDR), limit the effectiveness of approved therapies. Advanced research in the BC area is necessary to create more effective and safer forms of therapy to improve the outlook for individuals diagnosed with this aggressive neoplasm. For decades, plants and natural products with anticancer properties have been successfully utilized in treating various medical conditions. Anthraquinone derivatives are tricyclic secondary metabolites of natural origin that have been identified in plants, lichens, and fungi. They represent a few botanical families, e.g., Rhamnaceae, Rubiaceae, Fabaceae, Polygonaceae, and others. The review comprehensively covers and analyzes the most recent advances in the anticancer activity of 1,8-dihydroanthraquinone derivatives (emodin, aloe-emodin, hypericin, chrysophanol, rhein, and physcion) applied both individually, or in combination with other chemotherapeutic agents, in in vitro and in vivo BC models. The application of nanoparticles for in vitro and in vivo evidence in the context of 1,8-dihydroanthraquinone derivatives was also described.

Emodin-8-O-Glucoside-Isolation and the Screening of the Anticancer Potential against the Nervous System Tumors

Emodin-8-O-glucoside (E-8-O-G) is a glycosylated derivative of emodin that exhibits numerous biological activities, including immunomodulatory, anti-inflammatory, antioxidant, hepatoprotective, or anticancer activities. However, there are no reports on the activity of E-8-O-G against cancers of the nervous system. Therefore, the aim of the study was to investigate the antiproliferative and cytotoxic effect of E-8-O-G in the SK-N-AS neuroblastoma, T98G human glioblastoma, and C6 mouse glioblastoma cancer cells. As a source of E-8-O-G the methanolic extract from the aerial parts of Reynoutria japonica Houtt. (Polygonaceae) was used. Thanks to the application of centrifugal partition chromatography (CPC) operated in the descending mode using a mixture of petroleum ether:ethyl acetate:methanol:water (4:5:4:5 v/v/v/v) and a subsequent purification with preparative HPLC, E-8-O-G was obtained in high purity in a sufficient quantity for the bioactivity tests. Assessment of the cancer cell viability and proliferation were performed with the MTT (3-(bromide 4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium), CTG (CellTiter-Glo®) and BrdU (5-bromo-2'-deoxyuridine) assays, respectively. E-8-O-G inhibits the viability and proliferation of SK-N-AS neuroblastoma, T98G human glioblastoma multiforme, and C6 mouse glioblastoma cells dose-dependently. E-8-O-G seems to be a promising natural antitumor compound in the therapy of nervous system tumors.

p53 isoform expression promotes a stemness phenotype and inhibits doxorubicin sensitivity in breast cancer

In breast cancer, dysregulated TP53 expression signatures are a better predictor of chemotherapy response and survival outcomes than TP53 mutations. Our previous studies have shown that high levels of Δ40p53 are associated with worse disease-free survival and disruption of p53-induced DNA damage response in breast cancers. Here, we further investigated the in vitro and in vivo implications of Δ40p53 expression in breast cancer. We have shown that genes associated with cell differentiation are downregulated while those associated with stem cell regulation are upregulated in invasive ductal carcinomas expressing high levels of Δ40p53. In contrast to p53, endogenous ∆40p53 co-localised with the stem cell markers Sox2, Oct4, and Nanog in MCF-7 and ZR75-1 cell lines. ∆40p53 and Sox2 co-localisation was also detected in breast cancer specimens. Further, in cells expressing a high ∆40p53:p53 ratio, increased expression of stem cell markers, greater mammosphere and colony formation capacities, and downregulation of miR-145 and miR-200 (p53-target microRNAs that repress stemness) were observed compared to the control subline. In vivo, a high ∆40p53:p53 ratio led to increased tumour growth, Ki67 and Sox2 expression, and blood microvessel areas in the vehicle-treated mice. High expression of ∆40p53 also reduced tumour sensitivity to doxorubicin compared to control tumours. Enhanced therapeutic efficacy of doxorubicin was observed when transiently targeting Δ40p53 or when treating cells with OTSSP167 with concomitant chemotherapy. Taken together, high Δ40p53 levels induce tumour growth and may promote chemoresistance by inducing a stemness phenotype in breast cancer; thus, targeting Δ40p53 in tumours that have a high Δ40p53:p53 ratio could enhance the efficacy of standard-of-care therapies such as doxorubicin.

Advancements in Zebrafish Models for Breast Cancer Research: Unveiling Biomarkers, Targeted Therapies, and Personalized Medicine

Breast cancer (BC) is the most frequently diagnosed malignancy in women worldwide. Despite the wide variety of therapeutic methods for BC, their results are not satisfying, especially in triple-negative breast cancer (TNBC) patients. One of the main challenges in efficient oncology is achieving optimal conditions to evaluate a molecular genotype and phenotype of a tumor. Therefore, new therapeutic strategies are urgently needed. Animal models are an important tool for the molecular and functional characterization of BC, and for the development of targeted BC therapies. Zebrafish, as a promising screening model organism, has been widely applied in the development of patient-derived xenografts (PDX) for the discovery of novel potential antineoplastic drugs. Moreover, the generation of BC xenografts in zebrafish embryos/larvae allows for a description of the tumor growth, cell invasion, and systemic interaction between tumor and host in vivo without immunogenic rejection of transplanted cancer cells. Interestingly, zebrafish can be genetically manipulated and their genome has been fully sequenced. Genetic studies in zebrafish have described new genes and molecular pathways involved in BC carcinogenesis. Thus, the zebrafish in vivo model is becoming an exquisite alternative for metastatic research and for discovering new active agents for BC therapy. Herein, we systematically reviewed the recent cutting-edge advances in zebrafish BC models for carcinogenesis, metastasis, and drug screening. This article aims to review the current status of the role of the zebrafish (Danio reiro) in preclinical and clinical models of biomarker identification and drug targeting, and developments in personalized medicine in BC.

Kaiso Protein Expression Correlates with Overall Survival in TNBC Patients

Triple-negative breast cancers (TNBCs) are histologically heterogenic invasive carcinomas of no specific type that lack distinctive histological characteristics. The prognosis for women with TNBC is poor. Regardless of the applied treatments, recurrences and deaths are observed 3-5 years after the diagnosis. Thus, new diagnostic markers and targets for personalized treatment are needed. The subject of our study-the Kaiso transcription factor has been found to correlate with the invasion and progression of breast cancer. The publicly available TCGA breast cancer cohort containing Illumina HiSeq RNAseq and clinical data was explored in the study. Additionally, Kaiso protein expression was assessed in formalin-fixed and paraffin-embedded tissue archive specimens using the tissue microarray technique. In this retrospective study, Kaiso protein expression (nuclear localization) was compared with several clinical factors in the cohort of 103 patients with TNBC with long follow-up time. In univariate and multivariate analysis, high Kaiso protein but not mRNA expression was correlated with better overall survival and disease-free survival, as well as with premenopausal age. The use of radiotherapy was correlated with better disease-free survival (DFS) and overall survival (OS). However, given the heterogeneity of TNBC and context-dependent molecular diversity of Kaiso signaling in cancer progression, these results must be taken with caution and require further studies.

Additive pharmacological interaction between sirtuin inhibitor cambinol and paclitaxel in MCF7 luminal and MDA-MB-231 triple-negative breast cancer cells

Background

Breast cancer (BC) is the most common malignancy and the leading cause of cancer-related death in women worldwide. Sirtuin inhibitors (SIRTi), belonging to the histone deacetylase inhibitors group (HDIs), are potent epigenetic drugs that have been investigated for therapeutic use in different clinical disorders, including hematological malignancies and solid tumors.

Methods

The influence of cambinol (CAM; SIRTi) used individually or in combination with standard chemotherapeutic paclitaxel (PAX) on viability (MTT assay), proliferation (BrdU assay), induction of apoptosis and cell cycle arrest (FACS analysis) was determined in MCF7 luminal and MDA-MB-231 triple-negative breast cancer (TNBC) cells. The types of pharmacological drug–drug interaction between CAM and PAX were determined by an exact and rigorous pharmacodynamic method—an isobolography, to determine the presence of synergism, addition or antagonism between analyzed drugs using a variety of fixed-dose ratios.

Results

The combination of CAM and PAX at a fixed ratio of 1:1 exerted additive interaction in the viability of MCF7 and MDA-MB-231 BC cells. Both active agents used separately reduced viability and proliferation of BC cells as well as induced apoptosis and cell cycle arrest. These effects were much more evident in MCF7 than in MDA-MB-231 BC cells. Additionally, CAM combined with PAX increased anti-cancer activity compared to PAX used alone.

Conclusion

CAM might be considered a potential therapeutic agent individually or in combined therapy with PAX against luminal or TNBC.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s43440-022-00393-w.

Assessment of Pharmacological Interactions between SIRT2 Inhibitor AGK2 and Paclitaxel in Different Molecular Subtypes of Breast Cancer Cells

Breast carcinoma (BC) is the most commonly diagnosed type of cancer in women in the world. Although the advances in the treatment of BC patients are significant, numerous side effects, severe toxicity towards normal cells as well as the multidrug resistance (MDR) phenomenon restrict the effectiveness of the therapies used. Therefore, new active compounds which decrease the MDR, extend disease-free survival, thereby ameliorating the effectiveness of the current treatment regimens, are greatly needed. Histone deacetylase inhibitors (HDIs), including sirtuin inhibitors (SIRTi), are the epigenetic antitumor agents which induce a cytotoxic effect in different types of cancer cells, including BC cells. Currently, combined forms of therapy with two or even more chemotherapeutics are promising antineoplastic tools to obtain a better response to therapy and limit adverse effects. Thus, on the one hand, much more effective chemotherapeutics, e.g., sirtuin inhibitors (SIRTi), are in demand; on the other hand, combinations of accepted cytostatics are trialed. Thus, the aim of our research was to examine the combination effects of a renowned cytotoxic drug paclitaxel (PAX) and SIRT2 inhibitor AGK2 on the proliferation and viability of the T47D, MCF7, MDA-MB-231, MDA-MB-468, BT-549 and HCC1937 BC cells. Moreover, cell cycle arrest and apoptosis induction were explored. The type of pharmacological interactions between AGK2 and PAX in different molecular subtypes of BC cells was assessed using the advanced isobolographic method. Our findings demonstrated that the tested active agents singly inhibited viability and proliferation of BC cells as well as induced cell cycle arrest and apoptosis in the cell-dependent context. Additionally, AGK2 increased the antitumor effect of PAX in most BC cell lines. We observed that, depending on the BC cell lines, the combinations of tested drugs showed synergistic, additive or antagonistic pharmacological interaction. In conclusion, our studies demonstrated that the consolidated therapy with the use of AGK2 and PAX can be considered as a potential therapeutic regimen in the personalized cure of BC patients in the future.

Deacetylation of Transcription Factors in Carcinogenesis

Reversible Nε-lysine acetylation/deacetylation is one of the most common post-translational modifications (PTM) of histones and non-histone proteins that is regulated by histone acetyltransferases (HATs) and histone deacetylases (HDACs). This epigenetic process is highly involved in carcinogenesis, affecting histone and non-histone proteins' properties and their biological functions. Some of the transcription factors, including tumor suppressors and oncoproteins, undergo this modification altering different cell signaling pathways. HDACs deacetylate their targets, which leads to either the upregulation or downregulation of proteins involved in the regulation of cell cycle and apoptosis, ultimately influencing tumor growth, invasion, and drug resistance. Therefore, epigenetic modifications are of great clinical importance and may constitute a new therapeutic target in cancer treatment. This review is aimed to present the significance of HDACs in carcinogenesis through their influence on functions of transcription factors, and therefore regulation of different signaling pathways, cancer progression, and metastasis.

Antagonistic Interaction between Histone Deacetylase Inhibitor: Cambinol and Cisplatin-An Isobolographic Analysis in Breast Cancer In Vitro Models

Breast cancer (BC) is the leading cause of death in women all over the world. Currently, combined chemotherapy with two or more agents is considered a promising anti-cancer tool to achieve better therapeutic response and to reduce therapy-related side effects. In our study, we demonstrated an antagonistic effect of cytostatic agent-cisplatin (CDDP) and histone deacetylase inhibitor: cambinol (CAM) for breast cancer cell lines with different phenotypes: estrogen receptor positive (MCF7, T47D) and triple negative (MDA-MB-231, MDA-MB-468). The type of pharmacological interaction was assessed by an isobolographic analysis. Our results showed that both agents used separately induced cell apoptosis; however, applying them in combination ameliorated antiproliferative effect for all BC cell lines indicating antagonistic interaction. Cell cycle analysis showed that CAM abolished cell cycle arrest in S phase, which was induced by CDDP. Additionally, CAM increased cell proliferation compared to CDDP used alone. Our data indicate that CAM and CDDP used in combination produce antagonistic interaction, which could inhibit anti-cancer treatment efficacy, showing importance of preclinical testing.

Valproic Acid and Breast Cancer: State of the Art in 2021

Valproic acid (2-propylpentanoic acid, VPA) is a short-chain fatty acid, a member of the group of histone deacetylase inhibitors (HDIs). VPA has been successfully used in the treatment of epilepsy, bipolar disorders, and schizophrenia for over 50 years. Numerous in vitro and in vivo pre-clinical studies suggest that this well-known anticonvulsant drug significantly inhibits cancer cell proliferation by modulating multiple signaling pathways. Breast cancer (BC) is the most common malignancy affecting women worldwide. Despite significant progress in the treatment of BC, serious adverse effects, high toxicity to normal cells, and the occurrence of multi-drug resistance (MDR) still limit the effective therapy of BC patients. Thus, new agents which improve the effectiveness of currently used methods, decrease the emergence of MDR, and increase disease-free survival are highly needed. This review focuses on in vitro and in vivo experimental data on VPA, applied individually or in combination with other anti-cancer agents, in the treatment of different histological subtypes of BC.

Differential molecular response of larynx cancer cell lines to combined VPA/CDDP treatment

Successful treatment of advanced larynx squamous cell carcinoma (LSCC) remains a challenge, mainly due to limited response to chemotherapy and the phenomenon of the drug resistance. Therefore, new chemotherapeutic solutions are needed. The aim of this study was to explore benefit of combined cisplatin (CDDP) and valproic acid (VPA) therapy in patients' derived LSCC cell lines. Cell viability assay was used to establish cellular response to the drug by isobolography followed by RNA sequencing (RNAseq) analysis. Danio rerio were used for in vivo studies. Depending on the cell line, we found that the combinations of drugs resulted in synergistic or antagonistic pharmacological interaction, which was accompanied by significant changes in genes expression profiles. The presented therapeutic scheme efficiently blocked tumor growth in an in vivo model, corresponding to the in vitro performed studies. Interestingly the RK5 cell line, upon the combined treatment acquired a molecular profile typically associated with epithelial to mesenchymal transition (EMT). Hence, our studies demonstrates that patient-specific personalized therapy of larynx cancer should be considered and the combination of cisplatin and valproic acid should be explored as a potential therapeutic strategy in the treatment of larynx cancer.

Sensitization of MCF7 Cells with High Notch1 Activity by Cisplatin and Histone Deacetylase Inhibitors Applied Together

Histone deacetylase inhibitors (HDIs) are promising anti-cancer agents that inhibit proliferation of many types of cancer cells including breast carcinoma (BC) cells. In the present study, we investigated the influence of the Notch1 activity level on the pharmacological interaction between cisplatin (CDDP) and two HDIs, valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA, vorinostat), in luminal-like BC cells. The type of drug-drug interaction between CDDP and HDIs was determined by isobolographic analysis. MCF7 cells were genetically modified to express differential levels of Notch1 activity. The cytotoxic effect of SAHA or VPA was higher on cells with decreased Notch1 activity and lower for cells with increased Notch1 activity than native BC cells. The isobolographic analysis demonstrated that combinations of CDDP with SAHA or VPA at a fixed ratio of 1:1 exerted additive or additive with tendency toward synergism interactions. Therefore, treatment of CDDP with HDIs could be used to optimize a combined therapy based on CDDP against Notch1-altered luminal BC. In conclusion, the combined therapy of HDIs and CDDP may be a promising therapeutic tool in the treatment of luminal-type BC with altered Notch1 activity.

Phytosterols: From Preclinical Evidence to Potential Clinical Applications

Phytosterols (PSs) are plant-originated steroids. Over 250 PSs have been isolated, and each plant species contains a characteristic phytosterol composition. A wide number of studies have reported remarkable pharmacological effects of PSs, acting as chemopreventive, anti-inflammatory, antioxidant, antidiabetic, and antiatherosclerotic agents. However, PS bioavailability is a key issue, as it can be influenced by several factors (type, source, processing, preparation, delivery method, food matrix, dose, time of administration into the body, and genetic factors), and the existence of a close relationship between their chemical structures (e.g., saturation degree and side-chain length) and low absorption rates has been stated. In this sense, the present review intends to provide in-depth data on PS therapeutic potential for human health, also emphasizing their preclinical effects and bioavailability-related issues.

Gemcitabine and Selected mTOR Inhibitors in Uterine Sarcomas and Carcinosarcoma Cells- an Isobolographic Analysis

Introduction: mTOR inhibitors are anticancer agents affecting mTOR/AKT/PI3K pathway that is one of the most important in human cancer cells. Hyperactivation of mTOR/AKT/PI3K and overexpression of this pathway members are frequently reported in uterine sarcoma and carcinosarcoma. Present study is aimed to assess the activity of the two mTOR inhibitors (rapamycin - RAP and sapanisertib - MLN) as a single agent and combined with gemcitabine (GEM, one of substances commonly used in systemic anticancer treatment) in uterine sarcoma and carcinosarcoma in vitro models. Material and methods: SK-UT-1 and SK-UT1-B (uterine carcinosarcoma), MES-SA (leiomyosarcoma) and ESS-1 (endometrial stromal sarcoma) cell lines were used. An MTT assay was performed to examine the cytotoxicity of RAP, MLN and mixtures: RAP+MLN, RAP+GEM, MLN+GEM against these cells. The interactions between tested compounds were assessed in isobolographic analysis. Results and conclusions: Carcinosarcoma cell lines (both SK-UT-1 and SK-UT-1B) do not respond to RAP and respond relatively weakly to MLN treatment. Additive and supraadditive effects were noted for combined treatment with GEM and MLN. Endometrial stromal sarcoma cell line (ESS-1) occured to be sensitive to both RAP and MLN, but the response was stronger for MLN. Additive effect of all tested drug combinations was observed for ESS-1. Leiomyosarcoma cell line (MES-SA) was found sensitive to both mTOR inhibitors. Additive effects in combinations of GEM, RAP and MLN were observed, what makes them promising for future preclinical and clinical trials. Additivity with slight tendency towards antagonism between GEM and MLN observed in MES-SA cell line is unexpected finding and might prompt the mechanistic research aimed to explain this phenomenon.

Mortalin peptides exert antitumor activities and act as adjuvants to antibody-mediated complement-dependent cytotoxicity

Cancer cells have developed numerous strategies to maintain their proliferative capacity and to withstand different kinds of stress. The mitochondrial stress‑70 protein named glucose regulated protein 75 (GRP75), also known as mortalin, is an intriguing cancer pro‑survival factor. It is constitutively expressed in normal tissues but is upregulated in many tumors, and was shown to be a cancer prognostic biomarker. Mortalin is an inhibitor of complement‑dependent cytotoxicity (CDC) and may therefore protect cells from antibody‑based immunotherapy. To target mortalin for cancer therapy, our laboratory designed several mortalin mimetic peptides with sequences predicted to be involved in mortalin binding to its client proteins. The peptides were synthesized with a C‑terminal transactivator of transcription sequence. By using cell death methodologies, the mechanism of action of the mortalin mimetic peptides on cancer cells was studied. Two peptides in particular, Mot‑P2 and Mot‑P7, were found to be highly toxic to lymphoma and ovarian, breast and prostate carcinoma cells. The analysis of their mode of action revealed that they may induce, within minutes, plasma membrane perturbations and mitochondrial stress. Furthermore, Mot‑P2 and Mot‑P7 activated necrotic cell death, leading to plasma membrane perforation, mitochondrial inner membrane depolarization and decrease in ATP level. In addition, Mot‑P7, but not Mot‑P2, required extracellular calcium ions to fully mediate cell death and was partially inhibited by plasma membrane cholesterol. At sub‑toxic concentrations, the two peptides moderately inhibited cancer cell proliferation and blocked cell cycle at G2/M. Both peptides may bind intracellularly to mortalin and/or a mortalin‑binding protein, hence knocking down mortalin expression reduced cell death. Combining treatment with Mot‑P2 or Mot‑P7 and CDC resulted in increased cell death. This study identified highly cytotoxic mortalin mimetic peptides that may be used as monotherapy or combined with complement‑activating antibody therapy to target mortalin for precision cancer therapy.

Accumulation of blood-circulating PD-L1-expressing M-MDSCs and monocytes/macrophages in pretreatment ovarian cancer patients is associated with soluble PD-L1

BACKGROUND

Previous studies have shown clinical relevance of programmed death-ligand 1 (PD-L1) and soluble PD-L1 (sPD-L1) in human cancers. However, still contradictory results exist. Our aim was evaluation of PD-L1-expressing monocytic myeloid-derived suppressor cells (M-MDSCs), monocytes/macrophages (MO/MA), tumour cells (TC) and immune/inflammatory cells (IC) as well as investigation of the sPD-L1 in ovarian cancer (OC) patients.

METHODS

The group of 74 pretreatment women were enrollment to the study. The expression of PD-L1 on M-MDSCS and MO/MA was assessed by flow cytometry. The profile of sPD-L1 was examined with ELISA. The expression of PD-L1 in mononuclear cells (MCs) was analyzed using real time PCR. PD-L1 immunohistochemical analysis was prepared on TC and IC. An in silico validation of prognostic significance of PD-L1 mRNA expression was performed based microarray datasets.

RESULTS

OC patients had significantly higher frequency of MO/MA versus M-MDSC in the blood, ascites and tumour (each p < 0.0001). In contrast, PD-L1 expression was higher on M-MDSCs versus MO/MA in the blood and ascites (each p < 0.0001), but not in the tumour (p > 0.05). Significantly higher accumulation of blood-circulating M-MDSC, MO/MA, PD-L1⁺M-MDSC, PD-L1⁺MO/MA and sPD-L1 was observed in patients versus control (p < 0.001, p < 0.05, p < 0.001, p < 0.001 and p < 0.0001, respectively). Accumulation of these factors was clinicopathologic-independent (p > 0.05). The expression of PD-L1 was significantly higher on IC versus TC (p < 0.0001) and was clinicopathologic-independent (p > 0.05) except higher level of PD-L1⁺TC in the endometrioid versus mucinous tumours. Interestingly, blood-circulating sPD-L1 positively correlated with PD-L1⁺M-MDSCs (p = 0.03) and PD-L1⁺MO/MA (p = 0.02) in the blood but not with these cells in the ascites and tumours nor with PD-L1⁺TC/IC (each p > 0.05). PD-L1 and sPD-L1 were not predictors of overall survival (OS; each p > 0.05). Further validation revealed no association between PD-L1 mRNA expression and OS in large independent OC patient cohort (n = 655, p > 0.05).

CONCLUSIONS

Although PD-L1 may not be a prognostic factor for OC, our study demonstrated impaired immunity manifested by up-regulation of PD-L1/sPD-L1. Furthermore, there was a positive association between PD-L1⁺ myeloid cells and sPD-L1 in the blood, suggesting that sPD-L1 may be a noninvasive surrogate marker for PD-L1⁺myeloid cells immunomonitoring in OC. Overall, these data should be under consideration during future clinical studies/trials.

Synergistic or Additive Pharmacological Interactions between Magnoflorine and Cisplatin in Human Cancer Cells of Different Histological Origin

Magnoflorine is an aporphine alkaloid present in plant species belonging to the Berberidaceae, Magnoliaceae, Menispermaceae, or Papaveraceae botanical families. The interest of magnoflorine has increased recently due to its multiplicity of pharmacological properties. The aim of this study was the analysis of combined anti-proliferative effect of magnoflorine and cisplatin and the assessment of drug–drug pharmacological interaction between these agents using isobolographic method in MDA-MB-468 human breast, NCIH1299 lung, TE671 rhabdomyosarcoma, or T98G glioblastoma cancer cell lines. Magnoflorine in combination with cisplatin at a fixed ratio of 1:1 augmented their anticancer action and yielded synergistic or additive pharmacological interactions by means of isobolographic method, therefore combined therapy using these two active agents can be a promising chemotherapy regimen in the treatment of some types of breast, lung, rhabdomyosarcoma, and glioblastoma cancers.

Advances in Chemistry and Bioactivity of Magnoflorine and Magnoflorine-Containing Extracts

The review collects together some recent information on the identity and pharmacological properties of magnoflorine, a quaternary aporphine alkaloid, that is widely distributed within the representatives of several botanical families like Berberidaceae, Magnoliaceae, Papaveraceae, or Menispermaceae. Several findings published in the scientific publications mention its application in the treatment of a wide spectrum of diseases including inflammatory ones, allergies, hypertension, osteoporosis, bacterial, viral and fungal infections, and some civilization diseases like cancer, obesity, diabetes, dementia, or depression. The pharmacokinetics and perspectives on its introduction to therapeutic strategies will also be discussed.

Isobolographic Analysis Demonstrates the Additive and Synergistic Effects of Gemcitabine Combined with Fucoidan in Uterine Sarcomas and Carcinosarcoma Cells

Background: Uterine sarcomas and carcinosarcoma are associated with unfavorable prognosis. The regimens that are used in chemotherapy are associated with high incidence of side effects and usually do not significantly increase patients’ survival rates. In this study we investigated the activity and interactions between gemcitabine and fucoidan, the natural compound known for its anti-tumor properties, in human sarcomas and carcinosarcoma cell models. Methods: SK-UT-1, SK-UT1-B (carcinosarcoma), MES-SA (leiomyosarcoma), and ESS-1 (endometrial stromal sarcoma) cell lines were used for the experiments. Cells were incubated in the presence of gemcitabine, fucoidan, and mixtures, after the incubation the MTT tests were performed. In order to assess the interactions between tested compounds isobolographic analysis was performed. Additional assessments of apoptosis and cell cycle were done. Results: Additive effect of combined treatment with gemcitabine and fucoidan was observed in ESS-1 and SK-UT-1 cell line. Although the supra-additive (synergistic) effect noticed in SK-UT-1B cell line. It was not possible to determine the interactions of fucoidan and gemcitabine in MES-SA cell line due to insufficient response to treatment. Addition of fucoidan to gemcitabine enhances its proapoptotic activity, what was observed especially in ESS-1 and SK-UT-1B cell lines. The arrest of cell cycle induced by mixture of gemcitabine and fucoidan, superior comparing gemcitabine alone was observed in SK-UT-1B. Conclusions: Obtained data showed that a combination of fucoidan and gemcitabine in uterine endometrial stromal sarcoma and carcinosarcoma cell lines has additive or even synergistic effect in decreasing cell viability. Furthermore, this drug combination induces apoptosis and arrest of cell cycle. The resistance of uterine leiomyosarcoma cell line, justifies searching for other drugs combinations to improve therapy efficacy.

Histone deacetylase inhibitors reinforce the phenotypical markers of breast epithelial or mesenchymal cancer cells but inhibit their migratory properties

Introduction

Histone deacetylase inhibitors (HDIs) are a group of compounds that exhibit anticancer activity, but their significance and usefulness in breast cancer (BC) treatment are still controversial. The ability of cancer cells to invade and migrate is augmented by the acquisition of a mesenchymal phenotype – a process known as epithelial-to-mesenchymal transition (EMT). Changes in the expression level of different cadherins, so-called cadherin switches, have been used to monitor the EMT process in development and tumor progression, in particular migration and invasion potential. The aim of this study was to analyze the influence of two HDIs – valproic acid (VPA) and vorinostat (SAHA) – on the migration potential of different BC cell types, as well as on EMT, or its reverse process – mesenchymal-to-epithelial transition, progression by means of shift in epithelial and mesenchymal marker expression.

Methods

HDI treatment-induced expression of E- and N-cadherin at the mRNA and protein levels was evaluated by qPCR, Western blotting and immunostaining methods, respectively. BC cell proliferation and migration were assessed by BrdU, xCELLigence system and wound-healing assay.

Results

VPA and SAHA inhibited the proliferation and migration in a dose- and time-dependent manner, regardless of the BC cell type. Unawares, BC cells having a more mesenchymal phenotype (MDA-MB-468) were found to overexpress N-cadherin, whereas BC lines having an epithelial phenotype (T47D, MCF7) responded to HDI treatment by a significant increase of E-cadherin expression.

Discussion

We suggest that HDAC inhibition results in a more relaxed chromatin concomitant to an increase in the expression of already expressing genes.

Conclusion

By using multiple cancer cell lines, we conclude that HDI induction or reversal of EMT is not a universal mechanism, yet inhibition of cell migration is, and thus EMT should not be considered as the only measurement for tumor aggressiveness.

Clinical Relevance and Immunosuppressive Pattern of Circulating and Infiltrating Subsets of Myeloid-Derived Suppressor Cells (MDSCs) in Epithelial Ovarian Cancer

Myeloid-derived suppressor cells (MDSCs) expansion is a hallmark of cancer. Three major MDSC subsets defined as monocytic (M)-MDSCs, polymorphonuclear (PMN)-MDSCs and early stage (e)MDSCs can be revealed in human diseases. However, the clinical relevance and immunosupressive pattern of these cells in epithelial ovarian cancer (EOC) are unknown. Therefore, we performed a comprehensive analysis of each MDSC subset and immunosupressive factors in the peripheral blood (PB), peritoneal fluid (PF), and the tumor tissue (TT) samples from EOC and integrated this data with the patients' clinicopathological characteristic. MDSCs were analyzed using multicolor flow cytometry. Immunosuppressive factors analysis was performed with ELISA and qRT-PCR. The level of M-MDSCs in the PB/PF/TT of EOC was significantly higher than in healthy donors (HD); frequency of PMN-MDSCs was significantly greater in the TT than in the PB/PF and HD; while the level of eMDSCs was greater in the PB compared with the PF and HD. Elevated abundance of tumor-infiltrating M-MDSCs was associated with advanced stage and high grade of EOC. An analysis of immunosuppressive pattern showed significantly increased blood-circulating ARG/IDO/IL-10-expressing M- and PMN-MDSCs in the EOC patients compared with HD and differences in the accumulation of these subsets in the three tumor immune microenvironments (TIME). This accumulation was positively correlated with levels of TGF-β and ARG1 in the plasma and PF. Low level of blood-circulating and tumor-infiltrating M-MDSCs, but neither PMN-MDSCs nor eMDSCs was strongly associated with prolonged survival in ovarian cancer patients. Our results highlight M-MDSCs as the subset with potential the highest clinical significance.

The Effect of Fucoidan, a Potential New, Natural, Anti-Neoplastic Agent on Uterine Sarcomas and Carcinosarcoma Cell Lines: ENITEC Collaborative Study

The aim of the study was to assess the activity of fucoidan on the uterine sarcomas (MES-SA and ESS-1) and carcinosarcoma cell lines (SK-UT-1 and SK-UT-1B) and its toxicity on the human skin fibroblasts (HSF). Two uterine sarcomas and two carcinosarcoma cell lines were examined, as a control HSF were used. Cell viability was assessed with MTT test, apoptosis with caspase-3 activity and cell cycle by assessment of DNA synthesis. Fucoidan significantly decreases cell viability in SK-UT-1, SK-UT-1B, and ESS-1 cell lines, such effect was not observed in MES-SA. Fucoidan was not substantially affecting proliferation among normal cells. The tested agent induced apoptosis in all cell cultures used in the experiment. Fucoidan affects cell cycle of all tested cell lines except MES-SA by increasing percentage of cells in G0/sub-G1/G1 phase. Fucoidan do not only affect proliferation but induces apoptosis in selected uterine sarcoma and carcinosarcoma cell lines, so it has potential to be used as cytotoxic agent. Fucoidan seems to be promising anti-cancer agent for endometrial stromal sarcoma and carcinosarcoma.

Histone Deacetylase Inhibitors and Phenotypical Transformation of Cancer Cells

Histone deacetylase inhibitors (HDIs) are a group of potent epigenetic drugs which have been investigated for their therapeutic potential in various clinical disorders, including hematological malignancies and solid tumors. Currently, several HDIs are already in clinical use and many more are on clinical trials. HDIs have shown efficacy to inhibit initiation and progression of cancer cells. Nevertheless, both pro-invasive and anti-invasive activities of HDIs have been reported, questioning their impact in carcinogenesis. The aim of this review is to compile and discuss the most recent findings on the effect of HDIs on the epithelial-mesenchymal transition (EMT) process in human cancers. We have summarized the impact of HDIs on epithelial (E-cadherin, β-catenin) and mesenchymal (N-cadherin, vimentin) markers, EMT activators (TWIST, SNAIL, SLUG, SMAD, ZEB), as well as morphology, migration and invasion potential of cancer cells. We further discuss the use of HDIs as monotherapy or in combination with existing or novel anti-neoplastic drugs in relation to changes in EMT.

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.

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.

Isobolographic analysis demonstrates additive effect of cisplatin and HDIs combined treatment augmenting their anti-cancer activity in lung cancer cell lines

Histone deacetylase inhibitors (HDIs) are a new class of drugs which affect the activity of HDACs resulting in changed of acetylation in many proteins. HDIs can induce differentiation, cell growth arrest, apoptosis, inhibit proliferation and angiogenesis in cancer, whereas normal cells are comparatively resistant to the action of HDIs. The aim of this study was to investigate the combined effect of a well-known cytostatic agent-cisplatin (CDDP) and a histone deacetylase inhibitors-either suberoylanilide hydroxamic acid (SAHA, vorinostat) or valproic acid (VPA), on the proliferation of lung cancer cells, as well as induction of apoptosis and inhibition of the cell cycle progression. The anti-proliferative activity of VPA or SAHA used alone, or in combination with CDDP were determined by means of MTT test. The type of pharmacologic interactions between HDAC inhibitors and CDDP was assessed using isobolographic analysis. We observed additive interactions for the CCDP with SAHA, as well as for the CDDP with VPA combinations with respect to their anti-proliferative effects on three different lung cancer cell lines (A549, NCI-H1563 and NCI-H2170). Such additive effects were observed regardless of the histologic type (adenocarcinoma or squamous cell carcinoma) and sensitivity for the drugs applied. Combination treatment also augmented the induction of apoptosis and cell cycle perturbation mediated by CDDP alone, thereby enhancing anti-cancer effect of tested drugs. In conclusion, the combined therapy of HDIs and CDDP may be a promising therapeutic tool in the treatment of lung cancer.

Tumor-Associated Macrophages and Myeloid-Derived Suppressor Cells as Immunosuppressive Mechanism in Ovarian Cancer Patients: Progress and Challenges

Cancers are complex masses of malignant cells and nonmalignant cells that create the tumor microenvironment (TME). Non-transformed cells of the TME such as tumor-associated macrophages (TAMs) and myeloid-derived suppressor cells (MDSCs) have been observed in the TME of ovarian cancer (OC) patients. Although these subsets may contribute to each step of carcinogenesis and are commonly associated with poor prognosis, still little is known about creation of the protumor microenvironment in OC. In this review, we focused on the nature and prognostic significance of TAMs and MDSCs in OC patients. Moreover, we discuss the main problems and challenges that must be overcome by researchers and clinicians to enrich our knowledge about the immunosuppressive microenvironment of cancers.

Assessment of Interactions between Cisplatin and Two Histone Deacetylase Inhibitors in MCF7, T47D and MDA-MB-231 Human Breast Cancer Cell Lines - An Isobolographic Analysis

Histone deacetylase inhibitors (HDIs) are promising anticancer drugs, which inhibit proliferation of a wide variety of cancer cells including breast carcinoma cells. In the present study, we investigated the influence of valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA, vorinostat), alone or in combination with cisplatin (CDDP) on proliferation, induction of apoptosis and cell cycle progression in MCF7, T47D and MDA-MB-231 human breast carcinoma cell lines. The type of interaction between HDIs and CDDP was determined by an isobolographic analysis. The isobolographic analysis is a very precise and rigorous pharmacodynamic method, to determine the presence of synergism, addition or antagonism between different drugs with using variety of fixed dose ratios. Our experiments show that the combinations of CDDP with SAHA or VPA at a fixed-ratio of 1:1 exerted additive interaction in the viability of MCF7 cells, while in T47D cells there was a tendency to synergy. In contrast, sub-additive (antagonistic) interaction was observed for the combination of CDDP with VPA in MDA-MB-231 “triple-negative” (i.e. estrogen receptor negative, progesterone receptor negative, and HER-2 negative) human breast cancer cells, whereas combination of CDDP with SAHA in the same MDA-MB-231 cell line yielded additive interaction. Additionally, combined HDIs/CDDP treatment resulted in increase in apoptosis and cell cycle arrest in all tested breast cancer cell lines in comparison with a single therapy. In conclusion, the additive interaction of CDDP with SAHA or VPA suggests that HDIs could be combined with CDDP in order to optimize treatment regimen in some human breast cancers.

Anticancer effect of ethanol Lycium barbarum (Goji berry) extract on human breast cancer T47D cell line

The anticancer activity of ethanol extract isolated from Goji berry (EEGB) on T47D human breast cancer cell line has been reported. Cell viability and cell proliferation were examined with the use of BrdU, MTT and NR methods. Induction of apoptosis was assessed by propidium iodide and Hoechst 33342 staining. Expression of genes involved in cell proliferation, apoptosis, cell cycle control and regulation of transcription was estimated using Western blotting analysis. EEGB inhibited the proliferation of breast cancer cells in a time-, and dose-dependent manner. The study confirmed the lack of EEGB cytotoxic activity to normal human skin fibroblasts. Western blot analysis demonstrated an increase in pro-apoptotic and a decrease in anti-apoptotic proteins' expression in cells treated with the extract. Anticancer activity and lack of toxicity against normal cells indicate a chemopreventive potential of Goji berries in breast cancer treatment.