Tumor suppressor p73 induces apoptosis of murine peritoneal cell after exposure to hydatid cyst antigens; a possibly survival mechanism of cystic echinococcosis in vivo mice model.

Cystic echinococcosis (CE) is a life-threatening helminthic disease caused by the Echinococcus granulosus sensulato complex. Previous evidence indicates that the host's innate immune responses against CE can combat and regulate the growth rate and mortality of hydatid cyst in the host's internal organs. However, the survival mechanisms of CE are not yet fully elucidated in the human body. In the present study, the apoptotic effects of fertile and infertile hydatid fluid (HF) were tested on murine peritoneal cells in vivo mice model. Mice were divided into five groups including; control group, fertile HF-treated peritoneal cells, infertile HF-treated peritoneal cells, protoscolices (PSCs)-treated peritoneal cells and HF+PSCs-treated peritoneal cells group. Mice groups were intraperitoneally inoculated with PBS, HF, and/or PSCs. Afterwards, peritoneal cells were isolated and mRNA expression of STAT3, caspase-3, p73 and Smac genes were evaluated by quantitative Real-time PCR. After 48 hours of exposure, the protein levels of Smac and STAT3 was determined by western blotting technique. After 6 hours of exposure, Caspase-3 activity was also measured by fluorometric assay. The intracellular reactive oxygen species (ROS) production was examined in all groups. The mRNA expression levels of p73, caspase-3 and also Caspase-3 activity in HF+PSCs-treated peritoneal cells were higher than in the test and control groups (Pv<0.05), while the mRNA expression level of anti-apoptotic STAT3 and Smac genes in HF+PSC-treated peritoneal cells were lower than in the other groups (Pv<0.05). As well, the level of intracellular ROS in the fertile HCF-treated peritoneal cells, infertile HCF-treated peritoneal cells, PSC-treated peritoneal cells and HF+PSC-treated peritoneal cells groups were significantly higher than in the control group (Pv<0.05).Current findings indicates that oxidative stress and p73 can trigger the apoptosis of murine peritoneal cells through modulator of HF-treated PSCs that is likely one of the hydatid cyst survival mechanisms in vivo mice model.

MicroRNAs and their vital role in apoptosis in hepatocellular carcinoma: miRNA-based diagnostic and treatment methods.

Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies with high invasive and metastatic capability. Although significant advances have been made in the treatment of HCC, the overall survival rate of patients is still low. It is essential to explore accurate biomarkers for early diagnosis and prognosis along with therapeutic procedures to increase the survival rate of these patients. Anticancer therapies can contribute to induce apoptosis for the elimination of cancerous cells. However, dysregulated apoptosis and proliferation signaling pathways lead to treatment resistance, a significant challenge in improving efficient therapies. MiRNAs, short non-coding RNAs, play crucial roles in the progression of HCC, which regulate gene expression through post-transcriptional inhibition and targeting mRNA degradation in cancers. Dysregulated expression of multiple miRNAs is associated with numerous biological processes, including cell proliferation, apoptosis, invasion and metastasis, epithelial-mesenchymal transition (EMT), angiogenesis, and drug resistance in HCC. This review summarizes the role and potential efficacy of miRNAs in promoting and inhibiting cell proliferation and apoptosis in HCC, as well as the role of miRNAs in therapy resistance in HCC.

The modulatory role of dendritic cell-T cell cross-talk in breast cancer: Challenges and prospects.

Antigen recognition and presentation are highlighted as the first steps in developing specialized antigen responses. Dendritic cells (DCs) are outstanding professional antigen-presenting cells (APCs) responsible for priming cellular immunity in pathological states, including cancer. However, the diminished or repressed function of DCs is thought to be a substantial mechanism through which tumors escape from the immune system. In this regard, DCs obtained from breast cancer (BC) patients represent a notably weakened potency to encourage specific T-cell responses. Additionally, impaired DC-T-cell cross-talk in BC facilitates the immune evade of cancer cells and is connected with tumor advancement, immune tolerance, and adverse prognosis for patients. In this review we aim to highlight the available knowledge on DC-T-cell interactions in BC aggressiveness and show its therapeutic potential in BC treatment.

Combination Cancer Immunotherapy with Dendritic Cell Vaccine and Nanoparticles Loaded with Interleukin-15 and Anti-beta-catenin siRNA Significantly Inhibits Cancer Growth and Induces Anti-Tumor Immune Response.

PURPOSE: The invention and application of new immunotherapeutic methods can compensate for the inefficiency of conventional cancer treatment approaches, partly due to the inhibitory microenvironment of the tumor. In this study, we tried to inhibit the growth of cancer cells and induce anti-tumor immune responses by silencing the expression of the ß-catenin in the tumor microenvironment and transmitting interleukin (IL)-15 cytokine to provide optimal conditions for the dendritic cell (DC) vaccine. METHODS: For this purpose, we used folic acid (FA)-conjugated SPION-carboxymethyl dextran (CMD) chitosan (C) nanoparticles (NPs) to deliver anti-ß-catenin siRNA and IL-15 to cancer cells. RESULTS: The results showed that the codelivery of ß-catenin siRNA and IL-15 significantly reduced the growth of cancer cells and increased the immune response. The treatment also considerably stimulated the performance of the DC vaccine in triggering anti-tumor immunity, which inhibited tumor development and increased survival in mice in two different cancer models. CONCLUSIONS: These findings suggest that the use of new nanocarriers such as SPION-C-CMD-FA could be an effective way to use as a novel combination therapy consisting of ß-catenin siRNA, IL-15, and DC vaccine to treat cancer.

Co-stimulatory agonists: An insight into the immunotherapy of cancer.

Immune checkpoint pathways consist of stimulatory pathways, which can function like a strong impulse to promote T helper cells or killer CD8+ cells activation and proliferation. On the other hand, inhibitory pathways keep self-tolerance of the immune response. Increasing immunological activity by stimulating and blocking these signaling pathways are recognized as immune checkpoint therapies. Providing the best responses of CD8+ T cell needs the activation of T cell receptor along with the co-stimulation that is generated via stimulatory checkpoint pathways ligation including Inducible Co-Stimulator (ICOS), CD40, 4-1BB, GITR, and OX40. In cancer, programmed cell death receptor-1 (PD-1), Programmed cell death ligand-1(PD-L1) and Cytotoxic T Lymphocyte-Associated molecule-4 (CTLA-4) are the most known inhibitory checkpoint pathways, which can hinder the immune responses which have specifically anti-tumor characteristics and attenuate T cell activation and also cytokine production. The use of antagonistic monoclonal antibodies (mAbs) that block CTLA-4 or PD-1 activation is used in a variety of malignancies. It has been reported that they can lead to an increase in T cells and thereby strengthen anti-tumor immunity. Agonists of stimulatory checkpoint pathways can induce strong immunologic responses in metastatic patients; however, for achieving long-lasting benefits for the wide range of patients, efficient combinatorial therapies are required. In the present review, we focus on the preclinical and basic research on the molecular and cellular mechanisms by which immune checkpoint inhibitor blockade or other approaches with co-stimulatory agonists work together to improve T-cell antitumor immunity.

Simultaneous inhibition of CD73 and IL-6 molecules by siRNA-loaded nanoparticles prevents the growth and spread of cancer.

High concentrations of adenosine and interleukin (IL)-6 in the tumor microenvironment have been identified as one of the leading causes of cancer growth. Thus, we decided to inhibit the growth of cancer cells by inhibiting the production of adenosine and IL-6 in the tumor environment at the same time. For this purpose, we used chitosan-lactate-PEG-TAT (CLP-TAT) nanoparticles (NPs) loaded with siRNA molecules against CD73, an adenosine-producing enzyme, and IL-6. Proper physicochemical properties of the produced NPs led to high cell uptake and suppression of target molecules. Administration of these NPs to tumor-bearing mice (4T1 and CT26 models) greatly reduced the size of the tumor and increased the survival of the mice, which was accompanied by an increase in anti-tumor T lymphocyte responses. These findings suggest that combination therapy using siRNA-loaded CLP-TAT NPs against CD73 and IL-6 molecules could be an effective treatment strategy against cancer that needs further study.

Silencing STAT3 enhances sensitivity of cancer cells to doxorubicin and inhibits tumor progression.

AIMS: Despite extensive efforts to find new treatments, chemotherapy is still one of the first and foremost choices for cancer treatment. The main problems of using these drugs are the resistance of cancer cells and reducing their sensitivity to chemotherapy as well as the side effects of their systemic administration. Because STAT3 plays a very important role in the survival and susceptibility of cancer cells to apoptosis, we hypothesized that suppression of STAT3 expression could induce greater susceptibility to DOX-induced cancer cell death. MATERIALS AND METHODS: We used pegylated chitosan lactate nanoparticles (NPs) functionalized by TAT peptide and folate to deliver STAT3 siRNA and DOX to cancer cells simultaneously, both in vitro and in vivo. KEY FINDINGS: The results showed that NPs could effectively deliver siRNA and DOX to cancer cells, which was associated with suppression of STAT3 expression and increased induction of DOX-mediated cell death. Concomitant delivery of DOX and STAT3 siRNA also suppressed tumor growth in 4T1 and CT26 cancer models, which was associated with induction of anti-tumor immune responses. SIGNIFICANCE: These findings suggest that the use of NPs can be an effective strategy for the targeted delivery of STAT3-specific siRNA/DOX to cancer cells.

Tumor-associated neutrophils as new players in immunosuppressive process of the tumor microenvironment in breast cancer.

Despite the conventional reputation of neutrophils to have antibacterial properties, recent studies have put emphasis and are interested in the role of neutrophils in the spread and treatment of cancer. It has been shown that the infiltration of neutrophils, either by exerting pro- or anti-tumoral effects, probably affects tumor prognosis. Tumor-associated neutrophils (TANs) probably participate in tumor promotion and development in different ways, such as increasing genomic instability, induction of immunosuppression, and increasing angiogenesis. Despite major advances in breast cancer treatment, it is the second leading cause of death in American women. It has been revealed that inflammation is a fundamental issue in the treatment of this cancer because tumor growth, invasion, metastasis, and vascularization can be affected by inflammatory factors. It is demonstrated that enhanced neutrophil to lymphocyte ratio probably contributes to the raised rate of mortality and decreased survival among breast cancer cases. The present review explores the biology of TANs, their suspected interactions in the breast cancer microenvironment, and their functions in preserving the tumor microenvironment and progression of tumors. Furthermore, their potential as therapeutic targets and clinical biomarkers has been discussed in this paper.

Inhibition of HIF-1α/EP4 axis by hyaluronate-trimethyl chitosan-SPION nanoparticles markedly suppresses the growth and development of cancer cells.

Increased expression of Hypoxia-inducible factor-1α (HIF-1α) in the tumor microenvironment, mainly due to tumor growth, plays a major role in the growth of cancer. Tumor cells induce the expression of cyclooxygenase 2 (COX2) and its product, prostaglandin E2 (PGE2), through overexpression of HIF-1α. It has been shown that ligation of PGE2 with its receptor, EP4, robustly promotes cancer progression. HIF-1α/COX2/PGE2/EP4 signaling pathways appear to play an important role in tumor growth. Therefore, we decided to block the expansion of cancer cells by blocking the initiator (HIF-1α) and end (EP4) of this pathway. In this study, we used hyaluronate (HA), and trimethyl chitosan (TMC) recoated superparamagnetic iron oxide nanoparticles (SPIONs) loaded with HIF-1α-silencing siRNA and the EP4 antagonist (E7046) to treat cancer cells and assessed the effect of combination therapy on cancer progression. The results showed that optimum physicochemical characteristics of NPs (size 126.9 nm, zeta potential 27 mV, PDI < 0.2) and linkage of HA with CD44 molecules overexpressed on cancer cells could deliver siRNAs to cancer cells and significantly suppress the HIF-1α in them. Combination therapy of cancer cells by using HIF-1α siRNA-loaded SPION-TMC-HA NPs and E7046 also prevent proliferation, migration, invasion, angiogenesis, and colony formation of the cancer cells, remarkably.

Combined inhibition of CD73 and ZEB1 by Arg-Gly-Asp (RGD)-targeted nanoparticles inhibits tumor growth.

Abnormal expression of several macromolecules within tumor milieu helps the development of neoplasia and immune suppression in various cancers. ZEB-1 and CD73 are important factors in tumor progression, which their overexpression in tumor site enhances several cancer hallmarks, including proliferation, angiogenesis, metastasis, migration, and invasion. In this study, we decided to inhibit the expression of these factors in the tumor site by using RGD-conjugated chitosan lactate (RGD-CL) nanoparticles (NPs) encapsulating CD73/ZEB-1 siRNA molecules, in vitro and in vivo. The NPs were about 127 nm in size, non-toxic, and RGD conjugation to NPs could efficiently increase cell transfection through interaction with αvß3 integrins expressed on cancer cells and tumoral endothelial cells.Moreover, RGD-conjugated CL NPs containing siRNAs could significantly reduce the ZEB-1 and CD73 expression levels in cancer cells. Following transfection, cancer cells showed a significant reduction in migration and proliferation. Furthermore, the administration of these NPs into 4T1 and CT26 tumor-bearing mice resulted in tumor suppression and prolonged survival. These findings indicate the importance of targeting the CD73/ZEB1 axis in cancer cells, which could encourage their use in cancer patients in the near future.

Oncostatin M: A mysterious cytokine in cancers.

Oncostatin M (OSM), as a member of the Interleukin-6 family cytokines, plays a significant role in inflammation, autoimmunity, and cancers. It is mainly secreted by T lymphocytes, neutrophils, and macrophages and was initially introduced as anti-cancer agent. However, in some cases, it promotes cancer progression. Overexpression of OSM and OSM receptor has been detected in various cancers including colon cancer, breast cancer, pancreatic cancer, myeloma, brain tumors, chronic lymphocytic leukemia, and hepatoblastoma. STAT3 is the main downstream signaling molecule of OSM, which operates the leading role in modifications of cancer cells and enhancing cell growth, invasion, survival, and all other hallmarks of cancer cells. However, due to the presence of multiple signaling pathways, it can act contradictory in some cancers. In this review, we will discuss the emerging roles of OSM in cancer and elucidate its function in tumor control or progression and finally discuss therapeutic approaches designed to manipulate this cytokine in cancer.

Codelivery of HIF-1α siRNA and Dinaciclib by Carboxylated Graphene Oxide-Trimethyl Chitosan-Hyaluronate Nanoparticles Significantly Suppresses Cancer Cell Progression.

PURPOSE: Hypoxia-inducible factor (HIF) is one of the critical components of the tumor microenvironment that is involved in tumor development. HIF-1α functionally and physically interacts with CDK1, 2, and 5 and stimulates the cell cycle progression and Cyclin-Dependent Kinase (CDK) expression. Therefore, hypoxic tumor microenvironment and CDK overexpression lead to increased cell cycle progression and tumor expansion. Therefore, we decided to suppress cancer cell expansion by blocking HIF-1α and CDK molecules. METHODS: In the present study, we used the carboxylated graphene oxide (CGO) conjugated with trimethyl chitosan (TMC) and hyaluronate (HA) nanoparticles (NPs) loaded with HIF-1α-siRNA and Dinaciclib, the CDK inhibitor, for silencing HIF-1α and blockade of CDKs in CD44-expressing cancer cells and evaluated the impact of combination therapy on proliferation, metastasis, apoptosis, and tumor growth. RESULTS: The results indicated that the manufactured NPs had conceivable physicochemical properties, high cellular uptake, and low toxicity. Moreover, combination therapy of cancer cells using CGO-TMC-HA NPs loaded with HIF-1α siRNA and Dinaciclib (SCH 727965) significantly suppressed the CDKs/HIF-1α and consequently, decreased the proliferation, migration, angiogenesis, and colony formation in tumor cells. CONCLUSIONS: These results indicate the ability of CGO-TMC-HA NPs for dual drug/gene delivery in cancer treatment. Furthermore, the simultaneous inhibition of CDKs/HIF-1α can be considered as a novel anti-cancer treatment strategy; however, further research is needed to confirm this treatment in vivo. Graphical Abstract The suppression of HIF-1α and CDKs inhibits cancer growth. HIF-1α is overexpressed by the cells present in the tumor microenvironment. The hypoxic environment elevates mitochondrial ROS production and increases p38 MAP kinase, JAK/STAT, ERK, JNK, and Akt/PI3K signaling, resulting in cyclin accumulation and aberrant cell cycle progression. Furthermore, the overexpression of HIF-1α/CDK results in increased expression of genes such as BCL2, Bcl-xl, Ki-67, TGFß, VEGF, FGF, MMP2, MMP9, and, HIF-1α and consequently raise the survival, proliferation, angiogenesis, metastasis, and invasion of tumor cells. In conclusion, HIF-1α-siRNA/Dinaciclib-loaded CGO-TMC-HA NPs can inhibit the tumor expansion by blockage of CDKs and HIF-1α (JAK: Janus kinase, STAT: Signal transducer and activator of transcription, MAPK: mitogen-activated protein kinase, ERK: extracellular signal-regulated kinase, JNK: c-Jun N-terminal kinase, PI3K: phosphatidylinositol 3-kinase).

Adenosine and adenosine receptors in colorectal cancer.

CD39 (nucleoside triphosphate diphosphohydrolase) and Ecto-5-nucleotidase (CD73) have been recognized as important factors mediating various pathological and physiological responses in the tumor microenvironment. Elevated expression of CD73 and CD39 is correlated with the over-production of adenosine in the tumor region. This increase is associated with an immunosuppressive state in the tumor site that enhances various tumor hallmarks such as metastasis, angiogenesis, and cell proliferation. Adenosine promotes these behaviors through interaction with four adenosine receptors, including A3R, A2BR, A2AR, and A1R. Signaling of these receptors reduces the function of immune effector cells and enhances the expansion and function of tumor-associated immune cells. Several studies have been shown the important role of adenosine/CD73/CD39/ARs axis in the immunopathogenesis of colorectal cancer. These findings imply that components of this axis can be considered as a worthy target for colorectal cancer immunotherapy. In this review, we summarized the role of CD73/CD39/adenosine/ARs in the immunopathogenesis of colorectal cancer.

Silencing of HIF-1α/CD73 axis by siRNA-loaded TAT-chitosan-spion nanoparticles robustly blocks cancer cell progression.

Induction of Hypoxia Inducible Factor (HIF) as a direct consequence of oxygen deficiency in tumor tissues is a potent stimulus of CD73 (ecto-5'-nucleotidase) expression. Hypoxic environment and CD73 overexpression are associated with altered metabolism, elevated cancer cell proliferation, and tumor vascularization. Herein, a delivery system was developed for silencing CD73 and HIF-1α gene using siRNA-loaded Superparamagnetic iron oxide (SPION) nanocarriers for cancer treatment. SPIONs were encapsulated with thiolated chitosan (TC) and trimethyl chitosan (TMC) for improving their stabilization and functionalization. The nanoparticles (NPs) were about 133 nm in size, spherical, and non-toxic, and the addition of TAT peptide (derived from HIV-1 TAT protein) to TMC-TC-SPIONs significantly increased their cellular uptake by cancer cells. The produced NPs could efficiently accumulate in the tumor site, indicating their stability and targeting ability in reaching the tumor region. TAT-conjugated TMC-TC-SPIONs containing siRNAs could significantly reduce the HIF-1α and CD73 expression levels in cancer cells. Following transfection, cancer cells showed a significant reduction in migration and proliferation. Moreover, siRNA-loaded NPs could effectively reduce tumor growth and angiogenesis, as investigated by the chick chorioallantoic membrane (CAM) assay. This study suggested that TAT-TMC-TC-SPIONs can be potential nanocarrier for gene transfection in cancer therapy. Moreover, the co-silencing of CD73 and HIF-1α can be assumed as a novel anti-cancer treatment strategy with high tumor suppression potential.

Hypoxia inducible factors in the tumor microenvironment as therapeutic targets of cancer stem cells.

Cancer stem cells (CSC) constitute a small area of the tumor mass and are characterized by self-renewal, differentiation and the ability to promote the development of secondary chemo-resistant tumors. Self-renewal of CSCs is regulated through various signaling pathways including Hedgehog, Notch, and Wnt/ß-catenin pathways. A few surface markers have been identified, which provide a means of targeting CSCs according to tumor type. Depending on the proximity of CSCs to the tumor hypoxic niche, hypoxia-inducible factors (HIFs) can play a critical role in modulating several CSC-related characteristics. For instance, the upregulation of HIF-1 and HIF-2 at tumor sites, which correlates with the expansion of CSCs and poor cancer prognosis, has been demonstrated. In this review, we will discuss the mechanisms by which hypoxia enhances the development of CSCs in the tumor microenvironment. Targeting HIFs in combination with other common therapeutics is pre-requisite for effective eradication of CSCs.