The sensitivity of acute myeloid leukemia cells to cytarabine is increased by suppressing the expression of Heme oxygenase-1 and hypoxia-inducible factor 1-alpha.

BACKGROUND: Acute myeloid leukemia (AML), a malignancy Often resistant to common chemotherapy regimens (Cytarabine (Ara-c) + Daunorubicin (DNR)), is accompanied by frequent relapses. Many factors are involved in causing chemoresistance. Heme Oxygenase-1 (HO-1) and Hypoxia-Inducible Factor 1-alpha (HIF-1α) are two of the most well-known genes, reported to be overexpressed in AML and promote resistance against chemotherapy according to several studies. The main chemotherapy agent used for AML treatment is Ara-c. We hypothesized that simultaneous targeting of HO-1 and HIF-1α could sensitize AML cells to Ara-c. METHOD: In this study, we used our recently developed, Trans-Activator of Transcription (TAT) - Chitosan-Carboxymethyl Dextran (CCMD) - Poly Ethylene Glycol (PEG) - Nanoparticles (NPs), to deliver Ara-c along with siRNA molecules against the HO-1 and HIF-1α genes to AML primary cells (ex vivo) and cell lines including THP-1, KG-1, and HL-60 (in vitro). Subsequently, the effect of the single or combinational treatment on the growth, proliferation, apoptosis, and Reactive Oxygen Species (ROS) formation was evaluated. RESULTS: The designed NPs had a high potential in transfecting cells with siRNAs and drug. The results demonstrated that treatment of cells with Ara-c elevated the generation of ROS in the cells while decreasing the proliferation potential. Following the silencing of HO-1, the rate of apoptosis and ROS generation in response to Ara-c increased significantly. While proliferation and growth inhibition were considerably evident in HIF-1α-siRNA-transfected-AML cells compared to cells treated with free Ara-c. We found that the co-inhibition of genes could further sensitize AML cells to Ara-c treatment. CONCLUSIONS: As far as we are aware, this study is the first to simultaneously inhibit the HO-1 and HIF-1α genes in AML using NPs. It can be concluded that HO-1 causes chemoresistance by protecting cells from ROS damage. Whereas, HIF-1α mostly exerts prolific and direct anti-apoptotic effects. These findings imply that simultaneous inhibition of HO-1 and HIF-1α can overcome Ara-c resistance and help improve the prognosis of AML patients.

Targeted Silencing of NRF2 by rituximab-conjugated nanoparticles increases the sensitivity of chronic lymphoblastic leukemia cells to Cyclophosphamide.

BACKGROUND: Targeting influential factors in resistance to chemotherapy is one way to increase the effectiveness of chemotherapeutics. The nuclear factor erythroid 2-related factor 2 (Nrf2) pathway overexpresses in chronic lymphocytic leukemia (CLL) cells and appears to have a significant part in their survival and chemotherapy resistance. Here we produced novel nanoparticles (NPs) specific for CD20-expressing CLL cells with simultaneous anti-Nrf2 and cytotoxic properties. METHODS: Chitosan lactate (CL) was used to produce the primary NPs which were then respectively loaded with rituximab (RTX), anti-Nrf2 Small interfering RNA (siRNAs) and Cyclophosphamide (CP) to prepare the final version of the NPs (NP-Nrf2_siRNA-CP). All interventions were done on both peripheral blood mononuclear cells (PBMCs) and bone marrow mononuclear cells (BMNCs). RESULTS: NP-Nrf2_siRNA-CP had satisfying physicochemical properties, showed controlled anti-Nrf2 siRNA/CP release, and were efficiently transfected into CLL primary cells (both PBMCs and BMNCs). NP-Nrf2_siRNA-CP were significantly capable of cell apoptosis induction and proliferation prevention marked by respectively decreased and increased anti-apoptotic and pro-apoptotic factors. Furthermore, use of anti-Nrf2 siRNA was corresponding to elevated sensitivity of CLL cells to CP. CONCLUSION: Our findings imply that the combination therapy of malignant CLL cells with RTX, CP and anti-Nrf2 siRNA is a novel and efficient therapeutic strategy that was capable of destroying malignant cells. Furthermore, the use of NPs as a multiple drug delivery method showed fulfilling properties; however, the need for further future studies is undeniable. Video Abstract.

Natural killer cell-derived exosomes for cancer immunotherapy: innovative therapeutics art.

Chimeric antigen receptor natural killer cells (CAR-NK) promote off-the-shelf cellular therapy for solid tumors and malignancy.However,, the development of CAR-NK is due to their immune surveillance uncertainty and cytotoxicity challenge was restricted. Natural killer cell-derived exosome (NK-Exo) combine crucial targeted cellular therapies of NK cell therapies with unique non-toxic Exo as a self-origin shuttle against cancer immunotherapy. This review study covers cytokines, adoptive (autologous and allogenic) NK immunotherapy, stimulatory and regulatory functions, and cell-free derivatives from NK cells. The future path of NK-Exo cytotoxicity and anti-tumor activity with considering non-caspase-independent/dependent apoptosis and Fas/FasL pathway in cancer immunotherapy. Finally, the significance and implication of NK-Exo therapeutics through combination therapy and the development of emerging approaches for the purification and delivery NK-Exo to severe immune and tumor cells and tissues were discussed in detail.

The role of SF3B1 and NOTCH1 in the pathogenesis of leukemia.

The discovery of new genes/pathways improves our knowledge of cancer pathogenesis and presents novel potential therapeutic options. For instance, splicing factor 3b subunit 1 (SF3B1) and NOTCH1 genetic alterations have been identified at a high frequency in hematological malignancies, such as leukemia, and may be related to the prognosis of involved patients because they change the nature of malignancies in different ways like mediating therapeutic resistance; therefore, studying these gene/pathways is essential. This review aims to discuss SF3B1 and NOTCH1 roles in the pathogenesis of various types of leukemia and the therapeutic potential of targeting these genes or their mutations to provide a foundation for leukemia treatment.

Combined inhibition of EZH2 and CD73 molecules by folic acid-conjugated SPION-TMC nanocarriers loaded with siRNA molecules prevents TNBC progression and restores anti-tumor responses.

BACKGROUND: Abnormal function or overexpression of CD73 and EZH2 within the tumor microenvironment and tumor cells enhances tumor growth and progression, and in many cases, causes drug resistance. Hence, it seems that silencing the expression of CD73 and EZH2 molecules in breast cancer reduces cancer development and enhances anti-tumor immune responses. METHODS: we used siRNA-loaded superparamagnetic iron oxide (SPIONs) nanoparticles (NPs) coated with trimethyl chitosan (TMC) and functionalized with folic acid for co-delivery of EZH2/CD73 siRNAs to 4 T1 murine cancer cells both in vitro and in vivo. RESULTS: Combination therapy markedly inhibited cancer cells' proliferation, migration, and viability and induced apoptosis in vitro. Moreover, in vivo administration of this combination therapy promoted tumor regression and induced anti-tumor immune responses. DISCUSSION: The findings indicated the CD73/EZH2 factors inhibition by SPION-TMC-FA NPs as a promising therapeutic strategy in breast cancer treatment.

The molecular biology and therapeutic potential of Nrf2 in leukemia.

NF-E2-related factor 2 (Nrf2) transcription factor has contradictory roles in cancer, which can act as a tumor suppressor or a proto-oncogene in different cell conditions (depending on the cell type and the conditions of the cell environment). Nrf2 pathway regulates several cellular processes, including signaling, energy metabolism, autophagy, inflammation, redox homeostasis, and antioxidant regulation. As a result, it plays a crucial role in cell survival. Conversely, Nrf2 protects cancerous cells from apoptosis and increases proliferation, angiogenesis, and metastasis. It promotes resistance to chemotherapy and radiotherapy in various solid tumors and hematological malignancies, so we want to elucidate the role of Nrf2 in cancer and the positive point of its targeting. Also, in the past few years, many studies have shown that Nrf2 protects cancer cells, especially leukemic cells, from the effects of chemotherapeutic drugs. The present paper summarizes these studies to scrutinize whether targeting Nrf2 combined with chemotherapy would be a therapeutic approach for leukemia treatment. Also, we discussed how Nrf2 and NF-κB work together to control the cellular redox pathway. The role of these two factors in inflammation (antagonistic) and leukemia (synergistic) is also summarized.

Dual Blockade of PD-1 and LAG3 Immune Checkpoints Increases Dendritic Cell Vaccine Mediated T Cell Responses in Breast Cancer Model.

PURPOSE: Increasing the efficiency of unsuccessful immunotherapy methods is one of the most important research fields. Therefore, the use of combination therapy is considered as one of the ways to increase the effectiveness of the dendritic cell (DC) vaccine. In this study, the inhibition of immune checkpoint receptors such as LAG3 and PD-1 on T cells was investigated to increase the efficiency of T cells in response to the DC vaccine. METHODS: We used trimethyl chitosan-dextran sulfate-lactate (TMC-DS-L) nanoparticles (NPs) loaded with siRNA molecules to quench the PD-1 and LAG3 checkpoints' expression. RESULTS: Appropriate physicochemical characteristics of the generated NPs led to efficient inhibition of LAG3 and PD-1 on T cells, which was associated with increased survival and activity of T cells, ex vivo. Also, treating mice with established breast tumors (4T1) using NPs loaded with siRNA molecules in combination with DC vaccine pulsed with tumor lysate significantly inhibited tumor growth and increased survival in mice. These ameliorative effects were associated with increased anti-tumor T cell responses and downregulation of immunosuppressive cells in the tumor microenvironment and spleen. CONCLUSION: These findings strongly suggest that TMC-DS-L NPs loaded with siRNA could act as a novel tool in inhibiting the expression of immune checkpoints in the tumor microenvironment. Also, combination therapy based on inhibition of PD-1 and LAG3 in combination with DC vaccine is an effective method in treating cancer that needs to be further studied.

The role of Th17 cells in the pathogenesis and treatment of breast cancer.

Breast cancer is a severe problem worldwide due to an increase in mortality and prevalence among women. Despite early diagnostic procedures as well as advanced therapies, more investigation is required to find new treatment targets. Various factors and mechanisms, such as inflammatory conditions, can play a crucial role in cancer progression. Among them, Th17 cells are identified as effective CD4+ T cells that play an essential role in autoimmune diseases and inflammation which may be associated with anti-tumor responses. In addition, Th17 cells are one of the main factors involved in cancer, especially breast cancer via the inflammatory process. In tumor immunity, the exact mechanism of Th17 cells is not entirely understood and seems to have a dual function in tumor development. Various studies have reported that cytokines secreted by Th17 cells are in close relation to cancer stem cells and tumor microenvironment. Therefore, they play a critical role in the growth, proliferation, and invasion of tumor cells. On the other hand, most studies have reported that T cells suppress the growth of tumor cells by the induction of immune responses. In patients with breast cancer compared to normal individuals, various studies have been reported that the Th17 population dramatically increases in peripheral blood which results in cancer progression. It seems that Th17 cells by creating inflammatory conditions through the secretion of cytokines, including IL-22, IL-17, TNF-α, IL-21, and IL-6, can significantly enhance breast cancer progression. Therefore, to identify the mechanisms and factors involved in the activation and development of Th17 cells, they can provide an essential role in preventing breast cancer progression. In the present review, the role of Th17 cells in breast cancer progression and its therapeutic potential was investigated.

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.

Simultaneous silencing of the A2aR and PD-1 immune checkpoints by siRNA-loaded nanoparticles enhances the immunotherapeutic potential of dendritic cell vaccine in tumor experimental models.

Following various immunotherapies, lack of proper anti-tumor immune responses is considered a significant problem in novel cancer therapeutic approaches. The expression of inhibitory checkpoint molecules on tumor-infiltrating T cells is one of the main reasons for the ineffectiveness of various immunotherapies. Therefore, we decided to inhibit two of the most important immune checkpoints expressed on tumor-associated T cells, PD-1 and A2aR. Ligation of PD-1 with PD-L1 and A2aR with adenosine significantly suppress T cell responses against tumor cells. Whitin tumors, specific inhibition of these molecules on T cells is of particular importance for successful immunotherapy as well as the elimination of treatment-associated side-effects. Thus, in this study, superparamagnetic iron oxide (SPION) nanoparticles (NPs) were covered by chitosan lactate (CL), functionalized with TAT peptide, and loaded with siRNA molecules against PD-1 and A2aR. Appropriate physicochemical properties of the prepared NPs resulted in efficient delivery of siRNA to tumor-derived T cells and suppressed the expression of A2aR and PD-1, ex vivo. T cell functions such as cytokine secretion and proliferation were considerably enhanced by the downregulation of these molecules which led to an increase in their survival time. Interestingly, treatment of CT26 and 4T1 mouse tumors with siRNA-loaded NPs not only inhibited tumor growth but also markedly increased anti-tumor immune responses and survival time. The results strongly support the efficacy of SPION-CL-TAT NPs loaded with anti-PD-1/A2aR siRNAs in cancer therapy and their further development for cancer patients in the near future.

Simultaneous blockade of TIGIT and HIF-1α induces synergistic anti-tumor effect and decreases the growth and development of cancer cells.

PURPOSE: T-cell immunoglobulin and ITIM domain (TIGIT) is an immune checkpoint that is overexpressed on both immune cells and some cancer cells. TIGIT can alter the anti-tumor responses inside the tumor microenvironment. Hypoxia-inducible factor 1-alpha (HIF-1α) plays a significant role in the TME and involves suppressing the anti-tumor responses. Under hypoxic conditions, HIF-1α can enhance the expression of different immune checkpoints. Accordingly, hypoxic TME and TIGIT overexpression cause cancer development. Thus, we decided to inhibit tumor cell expansion by inhibiting TIGIT and HIF-1α molecules and discovering the relationship between TIGIT and HIF-1α. METHODS: In this research, we utilized superparamagnetic iron oxide-based NPs (SPIONs) combined with chitosan lactate (CL) and folic acid (FA) nanoparticles (NPs) loaded with TIGIT-siRNA and HIF-1α- siRNA for suppressing TIGIT and HIF-1α in tumor cells and evaluated the consequences of this treatment strategy on tumor growth, apoptosis, and metastasis. RESULTS: The results showed that cancer cells treated with TIGIT and HIF-1α siRNA-loaded SPIONs-CL-FA NPs, strongly suppressed the TIGIT and HIF-1α expression, colony formation ability, angiogenesis, and the growth rate of cancer cells. CONCLUSIONS: Present data suggest the combination treatment of TIGIT and HIF-1α as a novel treatment strategy against colorectal and breast cancer, but more researches are required to realize the complete role of TIGIT and HIF-1α inside the TME.

Targeting Wee1 kinase as a therapeutic approach in Hematological Malignancies.

Hematologic malignancies include various diseases that develop from hematopoietic stem cells of bone marrow or lymphatic organs. Currently, conventional DNA-damage-based chemotherapy drugs are approved as standard therapeutic regimens for these malignancies. Although many improvements have been made, patients with relapsed or refractory hematological malignancies have a poor prognosis. Therefore, novel and practical therapeutic approaches are required for the treatment of these diseases. Interestingly several studies have shown that targeting Wee1 kinase in the Hematological malignancies, including AML, ALL, CML, CLL, DLBCL, BL, MCL, etc., can be an effective therapeutic strategy. It plays an essential role in regulating the cell cycle process by abrogating the G2-M cell-cycle checkpoint, which provides time for DNA damage repair before mitotic entry. Consistently, Wee1 overexpression is observed in various Hematological malignancies. Also, in healthy normal cells, repairing DNA damages occurs due to G1-S checkpoint function; however, in the cancer cells, which have an impaired G1-S checkpoint, the damaged DNA repair process depends on the G2-M checkpoint function. Thus, Wee1 inhibition could be a promising target in the presence of DNA damage in order to potentiate multiple therapeutic drugs. This review summarized the potentials and challenges of Wee1 inhibition combined with other therapies as a novel effective therapeutic strategy in Hematological malignancies.

Blockade of CD73 using siRNA loaded chitosan lactate nanoparticles functionalized with TAT-hyaluronate enhances doxorubicin mediated cytotoxicity in cancer cells both in vitro and in vivo.

Chemotherapy drugs are still one of the first treatment options used in many cancers; however, problems such as cytotoxic side effects on normal cells after systemic administration and resistance to treatment have reduced the use of chemotherapeutics day by day. Targeted delivery of these drugs to the tumor site and sensitization of cancer cells to death induced by chemotherapy drugs are ways that can overcome the limitations of the use of these drugs. In this study, we designed and generated a novel nanocarrier composed of chitosan lactate nanoparticles (NPs) functionalized by HIV-1 derived TAT peptide (Transactivating transcriptional activator) and hyaluronate (HA) to deliver CD73 siRNA and doxorubicin to 4T1 and CT26 cancer cells, both in vivo and in vitro, as a novel combinatorial treatment strategy. The CD73 molecule plays a key role in many cancer cell behaviors such as proliferation, angiogenesis, metastasis, imunosuppression, and resistance to chemotherapy. Therefore, we decided to reduce the side effects of DOX by simultaneously transmitting CD73 siRNA and DOX by CL-TAT-HA NPs, increase the susceptibility of cancer cells to DOX-induced cell death, and stimulate anti-tumor immune responses, for the first time. These results indicated that simultaneous transfer of CD73 siRNA and DOX to cancer cells (4 T1 and CT26) increased cell death and inhibited the prolifration and spread of cancer cells. Also, the preferential aggregation of NPs in the tumor microenvironment reduced tumor growh, promoted the survival of tumor-bearing mice, and induced anti-tumor immune responses. These findings indicate that CL-TAT-HA NPs are a good candidate for targeted siRNA/drug delivery to cancer cells and the simultaneous transfer of CD73 siRNA and DOX to cancer cells using this nanocarrier can be used to treat cancer.

Different T cell related immunological profiles in COVID-19 patients compared to healthy controls.

In various pathological conditions, cellular immunity plays an important role in immune responses. Amongimmunecells, T lymphocytes pdomotecellular and humoralresponses as well as innate immunity. Therefore, careful investigation of these cells has a significant impact on accurate knowledge in COVID-19diseasepathogenesis. In current research, the frequency and function of various T lymphocytes involved in immune responses examined in SARS-CoV-2 patients with various disease severity compared to normal subjects. In order to make an accurate comparison among patients with various disease severity, this study was performed on asymptomatic recovered cases (n = 20), ICU hospitalized patients (n = 30), non-ICU hospitalized patients (n = 30), and normal subjects (n = 20). To precisely evaluate T cells activity following purification, their cytokine secretion activity was examined. Similarly, immediately after purification of Treg cells, their inhibitory activity on T cells was investigated. The results showed that COVID-19 patients with severe disease (ICU hospitalized patients) not only had a remarkable increase in Th1 and Th17 but also a considerable decrease in Th2 and Treg cells. More importantly, as the IL-17 and IFN-γ secretion was sharply increased in severe disease, the secretion of IL-10 and IL-4 was decreased. Furthermore, the inhibitory activity of Treg cells was reduced in severe disease patients in comparison to other groups. In severe COVID-19 disease, current findings indicate when the inflammatory arm of cellular immunity is significantly increased, a considerable reduction in anti-inflammatory and regulatory arm occurred.

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.

T-cell immunoglobulin and ITIM domain, as a potential immune checkpoint target for immunotherapy of colorectal cancer.

The importance of the tumor microenvironment in cancer progression has been well studied for many years. Immune checkpoint inhibitors (ICIs) are regarded as potential strategies in enhancing the immune responses in patients with cancer, particularly colorectal cancer (CRC). Notably, CRCs are extraordinarily heterogeneous and mostly are microsatellite-stable (MSS) or cold tumors, which means that the immune response is not usually as strong as that of foreign cells. T-cell immunoglobulin and ITIM domain (TIGIT) is a new immune checkpoint receptor overexpressed inside the CRC tumor-immune microenvironments. Moreover, several studies have shown that TIGIT in combination with other ICIs and/or conventional treatments, can lead to a robust anti-tumor response in CRC. This review looks deep inside TIGIT expression patterns, their various functions, and possible immunotherapy strategies to increase survival rates and decrease immune-related adverse events.