Exploring the dynamic interplay between exosomes and the immune tumor microenvironment: implications for breast cancer progression and therapeutic strategies.

Breast cancer continues to pose a substantial worldwide health concern, demanding a thorough comprehension of the complex interaction between cancerous cells and the immune system. Recent studies have shown the significant function of exosomes in facilitating intercellular communication and their participation in the advancement of cancer. Tumor-derived exosomes have been identified as significant regulators in the context of breast cancer, playing a crucial role in modulating immune cell activity and contributing to the advancement of the illness. This study aims to investigate the many effects of tumor-derived exosomes on immune cells in the setting of breast cancer. Specifically, we will examine their role in influencing immune cell polarization, facilitating immunological evasion, and modifying the tumor microenvironment. Furthermore, we explore the nascent domain of exosomes produced from immune cells and their prospective involvement in the prevention of breast cancer. This paper focuses on new research that emphasizes the immunomodulatory characteristics of exosomes produced from immune cells. It also explores the possibility of these exosomes as therapeutic agents or biomarkers for the early identification and prevention of breast cancer. The exploration of the reciprocal connections between exosomes formed from tumors and immune cells, together with the rising significance of exosomes derived from immune cells, presents a potential avenue for the advancement of novel approaches in the field of breast cancer therapy and prevention.

siRNA-mediated downregulation of BATF3 diminished proliferation and induced apoptosis through downregulating c-Myc expression in chronic myelogenous leukemia cells.

OBJECTIVE: Despite considerable improvement in therapeutic approaches to chronic myeloid leukemia (CML) treatment, this malignancy is considered incurable due to resistance. However, investigating the molecular mechanism of CML may give rise to the development of extremely efficient targeted therapies that improve the prognosis of patients. Basic leucine zipper transcription factor ATF-like3 (BATF3), as transcription factor, is considered a key regulator of cellular activities and its function has been evaluated in tumor development and growth in several cancer types. This study aimed to evaluate the potential of the cellular impact of siRNA-mediated downregulation of BATF3 on CML cancer cells through cell proliferation, induction of apoptosis, and cell cycle distribution. MATERIALS AND METHODS: The transfection of BATF3 siRNA to K562 CML cells was performed by electroporation device. To measure cellular viability and apoptosis, MTT assay and Annexin V/PI staining were carried out, respectively. Also, cell cycle assay and flow cytometry instrument were applied to assess cell cycle distribution of K562 cells. For more validation, mRNA expression of correlated genes was relatively evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: The data indicated that siRNA-mediated BATF3 inactivating severely promoted the cell apoptosis. Also, the targeted therapy led to high expression of Caspase-3 gene and Bax/Bcl-2 ratio. Silenced BATF3 also induced cell cycle arrest in phase sub-G1 compared to control. Finally, a noticeable decrement was obtained in c-Myc gene expression through suppression of BATF3 in CML cells. CONCLUSION: The findings of this research illustrated the suppression of BATF3 as an effective targeted therapy strategy for CML.

Diagnostic Significance of Hypomethylated IGFBP3 and TWIST1 Genes in Patients with Colorectal Cancer.

Background: Colorectal cancer (CRC) has been often the main reason for dying worldwide. Many factors are implicated in the progress of colorectal carcinoma, one of the chiefs of which is DNA methylation. Insulin-like growth factor-binding protein 3 (IGFBP3) and twist homolog 1 (TWIST1) genes have already been studied and are potential biomarkers for early colorectal diagnosis. Therefore, we designed this research to assess the levels of methylation of these genes in stool specimens of patients with CRC. Materials and Methods: A whole of 80 specimens containing 40 stool specimens from CRC patients and 40 specimens from healthy individuals as a control group was investigated. DNA was extracted using the bisulfate method and methylation of the candidate genes was assessed using methylation-sensitive high-resolution melting method. Differences in the methylation levels between CRC patients and controls were assessed by statistical analysis. Results: Our study showed significant hypomethylation in both IGFBP3 and TWIST1 promoters in patients' samples compared with normal individuals and notably the promoter hypomethylation found in these genes appeared to occur simultaneously (P < 0.0001 and P < 0.0025, respectively). Meantime, hypomethylation of these genes had not any significant connection with medical results. Conclusion: Our results propose that the IGFBP3 and TWIST1 genes' methylation status can serve as potential biomarkers for early CRC diagnosis. However, more studies are still necessary to better appreciate the methylation pattern of these two genes in CRC and to prove their effects on protein levels.

siRNA-Mediated B7H7 Knockdown in Gastric Cancer Lysate-Loaded Dendritic Cells Amplifies Expansion and Cytokine Secretion of Autologous T Cells.

BACKGROUND: Gastric cancer, ranked as the fifth most common cancer worldwide, presents multiple treatment challenges. These obstacles often arise due to cancer stem cells, which are associated with recurrence, metastasis, and drug resistance. While dendritic cell (DC)-based immunotherapy has shown promise as a therapeutic strategy, its efficacy can be limited by the tumor microenvironment and certain inhibitory immune checkpoint molecules, such as B7H7. SiRNA-medicated knockdown of B7H7 in tumor cell lysate-pulsed DCs can increase cytokine secretion and autologous T lymphocyte expansion. This study aimed to evaluate the impact of B7H7 suppression in gastric cancer cell lysate-pulsed DCs on the stimulatory potential of autologous CD3+ T lymphocytes. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated and monocytes were obtained; then, they were differentiated to immature DCs (iDCs) by GM-CSF and IL-4. Tumor cell lysates from human gastric cancer cell lines were harvested, and iDCs were transformed into mature DCs (mDCs) by stimulating iDCs with tumor cell lysate and lipopolysaccharide. B7H7-siRNA was delivered into mDCs using electroporation, and gene silencing efficiency was assessed. The phenotypic characteristics of iDCs, mDCs, and B7H7-silenced mDCs were evaluated using specific surface markers, an inverted light microscope, and flow cytometry. CD3+ T cells were isolated via magnetically activated cell sorting. They were labeled with CFSE dye and co-cultured with mDCs and B7H7-silenced mDCs to evaluate their ability to induce T-cell proliferation. T-cell proliferation was assessed using flow cytometry. The concentration of TGF-ß, IL-4, and IFN-γ secreted from CD3+ T cells in the co-cultured supernatant was evaluated to investigate the cytokine secretory activity of the cells. RESULTS: Transfection of B7H7 siRNA into mDCs was performed in optimal conditions, and the siRNA transfection effectively reduced B7H7 mRNA expression in a dose-dependent manner. SiRNA-mediated B7H7 knockdown in mDCs enhanced maturation and activation of the DCs, as demonstrated by an increased surface expression of CD11c, CD86, and CD40. Co-culture experiments revealed that B7H7-silenced mDCs had more capacity to induce T cell proliferation compared to non-transfected mDCs. The cytokine production patterns of T cells were also altered. Upon examining the levels of TGF-ß, IL-4, and IFN-γ released by CD3+ T cells in the co-culture supernatant, we found that silencing B7H7 in mDCs resulted in a rise in IL-4 secretion and a reduction in TGF-ß levels compared to mDCs that were not transfected. CONCLUSIONS: The study found that suppressing B7H7 expression in DCs significantly enhances their maturation and stimulatory activity when exposed to gastric cancer cell lysate. These B7H7-silenced DCs can substantially increase cytokine production and promote co-cultured T-cell expansion. Consequently, inhibiting B7H7 in DCs may offer a practical strategy to enhance the ability of DCs to initiate T lymphocyte responses and improve the effectiveness of DC-based cell therapy for cancer patients.

NRF2 Suppression Enhances the Susceptibility of Pancreatic Cancer Cells, Miapaca-2 to Paclitaxel.

Pancreatic cancer is one of the most deadly diseases, with a very high metastasis and low survival rate. High levels of NRF2 have been detected in numerous malignancies, including head, neck, lung, and colon cancers, promoting the expansion and survival of cancer cells and chemical resistance to stressful conditions and affecting the response to treatment. To evaluate the possibility that modulation of NRF2 expression could be effective in treating pancreatic cancer cells, we explored the effect of knockdown of the NRF2 gene by NRF2-specific siRNA and its influence in combination with paclitaxel on pancreatic cancer cells. Miapaca-2 cell line, due to the high expression of the NRF2 gene, was selected for this study. Then, Miapaca-2 cells in different groups were treated with NRF2 siRNA and paclitaxel separately and in combination. After that, cell viability was measured by MTT assay and apoptosis induction by Annexin V-FITC/PI staining test. Cell cycle and autophagy were examined by flow cytometry, and cell migration was assessed by wound-healing assay. Finally, the expression of genes involved in apoptosis, Bax, Caspase-3, Caspase-9, and genes related to migration pathway, MMP-2, and MMP-9 in different groups were measured using qRT-PCR. Combined use of NRF2-specific siRNA with paclitaxel significantly reduced NRF2 gene expression in pancreatic cancer cells. NRF2 siRNA transfection significantly reduced cell viability. In addition, paclitaxel combination therapy with NRF2 siRNA strengthens the anti-tumor effects, such as inhibiting cell migration and provoking apoptosis, and autophagy and the cell cycle arrest in the G2 phase. NRF2 suppression augmented the expression of Bax, Caspase-3, and Caspase-9 genes and lowered the expression of Bcl-2, MMP-2, and MMP-9 genes, which play crucial roles in the pathways of apoptosis and cell migration, respectively. NRF2 siRNA enhances the susceptibility of Miapaca-2 cells to paclitaxel in pancreatic cancer cells. Thereby, suppressing NRF2 in combination with paclitaxel can be a new and efficacious treatment approach in treating pancreatic cancer.

Targeting Nanog expression increased Cisplatin chemosensitivity and inhibited cell migration in Gastric cancer cells.

Regardless of significant advances in cancer treatment, gastric cancer (GC) incidence rate is increasing worldwide. As one of the main transcription factors participating in stemness, Nanog plays a pivotal role in various aspects of tumorigenesis, metastasis, and chemosensitivity. Given that, the current research intended to evaluate the potential effects of Nanog suppression on the GC cell Cisplatin chemosensitivity and in vitro tumorigenesis. First, bioinformatics analysis was performed to evaluate the effect of Nanog expression on GC patients' survival. The MKN-45 human GC cells were transfected with specific siRNA targeting Nanog and/or treated with Cisplatin. Then, to study cellular viability and apoptosis, MTT assay and Annexin V/PI staining were done, respectively. Also, the scratch assay was performed to investigate cell migration, and MKN-45 cell stemness was followed using colony formation assay. Western blotting and qRT-PCR were used for gene expression analysis. The findings demonstrated that Nanog overexpression was significantly correlated with poor survival of GC patients, and siRNA-mediated Nanog silencing strongly increased MKN-45 cell sensitivity to Cisplatin through apoptosis induction. Also, Nanog suppression combined with Cisplatin resulted in the upregulation of the Caspase-3 and Bax/Bcl-2 ratio at mRNA levels and increased Caspase-3 activation. Moreover, reduced expression of Nanog, separately or combined with Cisplatin, inhibited MKN-45 cell migration by downregulating MMP2 mRNA and protein expression levels. The results also evidenced CD44 and SOX-2 downregulation aligned with a decreased rate of MKN-45 cell colony formation ability through treatments. Besides, Nanog downregulation significantly decreased MDR-1 mRNA expression. Taken together, the results of this study indicated that Nanog could be suggested as a promising target combined with Cisplatin-based GC therapies for reducing drug side effects and improving patients' outcomes.

STA-21, a small molecule STAT3 inhibitor, ameliorates experimental autoimmune encephalomyelitis by altering Th-17/Treg balance.

BACKGROUND: Numerous studies have demonstrated the role of T helper (Th) 17 and T regulatory (reg) cells and pro-inflammatory and anti-inflammatory cytokines related to these cells in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). STAT3 is one of the downstream signaling proteins of IL-23, IL-6, and IL-21 that are required for Th17 cells differentiation. STA-21 is a STAT3 inhibitor that functions by inhibiting STAT3 dimerization and binding to DNA impairing the expression of STAT3 target genes including, RORγt, IL-21 and IL-23R that are also required for Th17 cell differentiation. AIM: In this study, we evaluated the effect of STA-21 on EAE Model and investigated how this small molecule can change Th17/Treg balance leading to amelioration of disease. METHODS: After EAE induction and treatment with STA-21, its effects were assessed. Major assays were H&E and LFB staining, Flow cytometric analysis, Reverse transcription-PCR (RT-PCR), and ELISA. RESULTS: STA-21 ameliorated the EAE severity and decreased the EAE inflammation and demyelination. It also decreased STAT3 phosphorylation, the proportion of Th17 cells and the protein level of IL-17. In contrast, the balance of Tregs and the level of anti-inflammatory cytokine, IL-10 increased in STA-21-treated mice. Moreover, STA-21 significantly decreased the expression of Th17 related transcription factors, RORɣt and IL-23R while FOXP3 expression associated with Treg differentiation was increased. CONCLUSION: This study showed that STA-21 has therapeutic effects in EAE by reducing inflammation and shifting inflammatory immune responses to anti-inflammatory and can be used as a suitable treatment strategy for the treatment of EAE. The effectiveness of inhibiting or strengthening the functional cells of the immune system by these small molecules in terms of easy to access, simple construction and inexpensive expansion make them as a suitable tool for the treatment of inflammatory and autoimmune diseases.

MiR-146a Restoration Suppresses Triple-Negative Breast Cancer Cell Migration: A Bioinformatic and In Vitro Study.

Purpose: Breast cancer is one of the most commonly diagnosed types of cancer worldwide. This cancer is treated with various methods like mastectomy, chemotherapy, hormone therapy, and radiotherapy. Among them, targeted therapy, like microRNA (miRNA) replacement therapy, is considered a new approach to treating breast cancer. Methods: Data analysis from TCGA datasets were used to investigate the expression of hsa-miR-146a-5p in breast cancer. MTT assay was used to evaluate the viability of MDA-MB-231 cells after hsa-miR-146a-5p ectopic expression. A wound-healing assay was used to observe migration in the MDA-MB-231 cell line and the effect of the hsa-miR-146a-5p ectopic expression on migration. Finally, quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used as a method to determine the effect of the hsa-miR-146a-5p ectopic expression on the expression of CXCR4, ß-catenin, MMP2, MMP9, and Vimentin genes known to be involved in invasion and migration of MDA-MB-231 cells. Results: Our results indicated that hsa-miR-146a-5p is not involved in apoptosis in the MDAMB-231 cells, while it is highly effective in migration inhibition. MMP9, MMP2, CXCR4, and Vimentin expressions were suppressed by hsa-miR-146a-5p induction; however, it induced the expression of ß-catenin. Conclusion: Some non-coding RNAs, such as hsa-miR-146a-5p, are effective in breast cancer targeted therapy. As cancer is a complicated disorder, therefore the combination of therapies might lead to novel therapeutic strategies.

miR-200c increases the sensitivity of breast cancer cells to Doxorubicin through downregulating MDR1 gene.

BACKGROUND: Breast cancer (BC) has been known as the most common type of cancer worldwide and resulted in death among women. BC is usually resistant to standard therapies that are significant problems in managing BC patients. miR-200c belongs to the miRNA family, which is considered as a tumor suppressor with reduced expression levels in various kinds of cancer like BC. Increased expression of miR-200c has been reported as a potent inhibitor of drug resistance and tumor advancement. The purpose of this paper is to examine the outcome of miR-200c restoring on enhancing the BC cells' sensitivity to Doxorubicin through downregulating the MDR1 expression. METHODS: Initially, MDA-MB-231 cells were transfected with miR-200c to perform functional analyses. After that, MTT assay was performed to investigate the viability of the cell. Finally, qRT-PCR was used to assess gene expression. RESULTS: According to the results, the miR-200c expression was downregulated in BC cells compared to control. Moreover, the cell viability was reduced in transfected cells via regulation in gene expression associated with apoptosis. Furthermore, miR-200c could increase the BC cells' sensitivity to Doxorubicin by reducing the MDR1 gene expression. CONCLUSION: Hence, this study's findings recommend that miR-200c can consider as a method of therapy for the treatment of BC.

The Regulatory Role of Pivotal MicroRNAs in the AKT Signaling Pathway in Breast Cancer.

Breast cancer is the most prevalent type of cancer among women, and it remains the main challenge despite improved treatments. MicroRNAs (miRNAs) are a small non-coding family of RNAs that play an indispensable role in regulating major physiological processes, including differentiation, proliferation, invasion, migration, cell cycle regulation, stem cell maintenance apoptosis, and organ development. The dysregulation of these tiny molecules is associated with various human malignancies. More than 50% of these non-coding RNA sequences estimated have been placed on genomic regions or fragile sites linked to cancer. Following the discovery of the first signatures of specific miRNA in breast cancer, numerous researches focused on involving these tiny RNAs in breast cancer physiopathology as a new therapeutic approach or as reliable prognostic biomarkers. In the current review, we focus on recent findings related to the involvement of miRNAs in breast cancer via the AKT signaling pathway related to their clinical implications.

Evaluation of lncRNA FOXD2-AS1 Expression as a Diagnostic Biomarker in Colorectal Cancer.

Background: Colorectal cancer (CRC) is still considered one of the prevalent cancers worldwide. Investigation of potential biomarkers for early detection of CRC is essential for the effective management of patients using therapeutic strategies. Considering that, this study was aimed to examine the changes in lncRNA FOXD2-AS1 expression through colorectal tumorigenesis. Methods: Fifty CRC tumor tissues and fifty adjacent normal tissue samples were prepared and involved in the current study. Total RNA was extracted from the samples and then reverse transcribed to complementary DNA. Next, the expression levels of lncRNA FOXD2-AS1 were evaluated using real-time PCR in CRC samples compared to normal ones. Also, receiver operating characteristic curve analysis was used to evaluate the diagnostic value of FOXD2-AS1 for CRC. Results: The obtained results showed that the expression level of FOXD2-AS1 gene was significantly (p<0.0001) up-regulated in tumor tissues compared to normal marginal tissues. Also, a significant correlation was observed between higher the expression of FOXD2-AS1and the differentiation of tumor cells. Furthermore, ROC curve analysis estimated an AUC value of 0.59 for FOXD2-AS1, suggesting its potential as a diagnostic target. Conclusion: Taken together, the current study implied that tissue-specific upregulation of lncRNA FOXD2-AS1 might be appropriate diagnostic biomarkers for CRC. Nonetheless, more studies are needed to validate these results and further illustrate FOXD2-AS1 function through colorectal tumorigenesis.

A Systematic Review on the Therapeutic Potentiality of PD-L1-Inhibiting MicroRNAs for Triple-Negative Breast Cancer: Toward Single-Cell Sequencing-Guided Biomimetic Delivery.

The programmed death-ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) is a well-established inhibitory immune checkpoint axis in triple-negative breast cancer (TNBC). Growing evidence indicates that tumoral PD-L1 can lead to TNBC development. Although conventional immune checkpoint inhibitors have improved TNBC patients' prognosis, their effect is mainly focused on improving anti-tumoral immune responses without substantially regulating oncogenic signaling pathways in tumoral cells. Moreover, the conventional immune checkpoint inhibitors cannot impede the de novo expression of oncoproteins, like PD-L1, in tumoral cells. Accumulating evidence has indicated that the restoration of specific microRNAs (miRs) can downregulate tumoral PD-L1 and inhibit TNBC development. Since miRs can target multiple mRNAs, miR-based gene therapy can be an appealing approach to inhibit the de novo expression of oncoproteins, like PD-L1, restore anti-tumoral immune responses, and regulate various intracellular singling pathways in TNBC. Therefore, we conducted the current systematic review based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) to provide a comprehensive and unbiased synthesis of currently available evidence regarding the effect of PD-L1-inhibiting miRs restoration on TNBC development and tumor microenvironment. For this purpose, we systematically searched the Cochrane Library, Embase, Scopus, PubMed, ProQuest, Web of Science, Ovid, and IranDoc databases to obtain the relevant peer-reviewed studies published before 25 May 2021. Based on the current evidence, the restoration of miR-424-5p, miR-138-5p, miR-570-3p, miR-200c-3p, miR-383-5p, miR-34a-5p, miR-3609, miR-195-5p, and miR-497-5p can inhibit tumoral PD-L1 expression, transform immunosuppressive tumor microenvironment into the pro-inflammatory tumor microenvironment, inhibit tumor proliferation, suppress tumor migration, enhance chemosensitivity of tumoral cells, stimulate tumor apoptosis, arrest cell cycle, repress the clonogenicity of tumoral cells, and regulate various oncogenic signaling pathways in TNBC cells. Concerning the biocompatibility of biomimetic carriers and the valuable insights provided by the single-cell sequencing technologies, single-cell sequencing-guided biomimetic delivery of these PD-L1-inhibiting miRs can decrease the toxicity of traditional approaches, increase the specificity of miR-delivery, enhance the efficacy of miR delivery, and provide the affected patients with personalized cancer therapy.

PD-L1 silencing inhibits triple-negative breast cancer development and upregulates T-cell-induced pro-inflammatory cytokines.

Triple-negative breast cancer (TNBC) is an invasive tumor with a high incidence of distant metastasis and poor prognosis. In TNBC cells, high PD-L1 expression can induce an immunosuppressive tumor microenvironment, repressing the anti-tumoral immune responses. Although FDA-approved agents targeting the PD-1/PD-L1 axis are potent to eliminate tumoral cells, their immune-related adverse events have become worrisome. As the regulator of gene expression, siRNAs can directly target PD-L1 in breast cancer cells. The gene modification of tumoral PD-L1 can reduce our reliance on the current method of targeting the PD-L1/PD-1 axis. We initiated the study with bioinformatics analysis; the results indicated that TNBC and the MDA-MB-231 cells significantly overexpressed PD-L1 compared to other breast cancer subtypes and cell lines. Our results demonstrated that PD-L1 silencing substantially reduced PD-L1 expression at mRNA and protein levels in MDA-MB-231 cells. Moreover, our results demonstrated that PD-L1 knockdown reduced cancer cell proliferation and induced apoptosis via intrinsic and extrinsic apoptosis pathways. We observed that PD-L1 silencing effectively inhibited the migration of TNBC cells. Further investigation also displayed that silencing of PD-L1 in breast cancer cells induced T-cell cytotoxic function by upregulating the gene expression of pro-inflammatory cytokines, i.e., IL-2, IFN-γ, and TNF-α, and downregulating the gene expression of anti-inflammatory cytokines, i.e., IL-10, and TGF-ß, in a co-culture system.

The combination effect of Prominin1 (CD133) suppression and Oxaliplatin treatment in colorectal cancer therapy.

Colorectal cancer (CRC) is considered one of the leading types of cancer in the world. CD133, as a cancer stem cell marker, has a pivotal role in the development of drug resistance, migration, and stemness properties of CRC cells. This study was designed to check the combined effect of CD133 siRNA and Oxaliplatin on proliferation, migration, apoptosis, and stemness properties of CRC cells in the HT-29 cell line. MTT assay was performed to define the combined effect of CD133 siRNA and Oxaliplatin on the viability of HT-29 cells, and it showed that the combination of CD133 siRNA and Oxaliplatin could reduce the IC50 of this drug from 32.85 to 19.75 nmol. In order to figure out the effect of this combination therapy on CD133 expression at the gene and protein level, qRT-PCR and western blot were exploited, respectively. The results demonstrated that the silencing of CD133 could reduce the relative expression of this marker to about 0.00001 compared to the control group and reduce the protein level to 0.01. The ability of cell migration was tested by wound healing assay as well. Also, colony formation and sphere formation were conducted to assess the stemness properties in the combination group. Flow cytometry was conducted to investigate the apoptosis (15%), cell cycle (about 10% arresting in G0-G1 phase), and surface expression of CD133 in different groups (from 39.3% in the control group to 2.41 in the combination group). Finally, the expression of migration-, and stemness-associated genes were measured by qRT-PCR. We indicated that silencing of CD133 reduces the migration and stemness properties of colorectal cancerous cells. This suppression makes HT-29 cells more sensitive to Oxaliplatin and reduces the effective dose of this chemical drug. Therefore, the suppression of CD133 in combination with Oxaliplatin treatment might be a promising therapeutic approach in the treatment of colorectal cancer.

Suppression of Nanog inhibited cell migration and increased the sensitivity of colorectal cancer cells to 5-fluorouracil.

Nanog is a major transcription factor related to cellular multipotency that plays important roles in the development of tumor cells, drug resistance, migration, and stemness; indicating its great potential as a therapeutic target for various malignancies including colorectal cancer (CRC). Therefore, this study was aimed to evaluate the Nanog suppression effect using small interference RNA (siRNA) combined with 5-fluorouracil (5-FU) on CRC cells. Nanog-overexpressing SW-480 cells were transfected with Nanog si-RNA and treated with 5-FU, in combination or separately. Subsequently, it was observed that Nanog expression was significantly reduced after transfection of SW-480 cells using Nanog siRNA in mRNA and protein levels. Furthermore, Nanog knockdown significantly increased CRC cell sensitivity to 5-FU drug via modulating Bax and Bcl-2 mRNA expression. Also, Nanog knockdown and 5-FU treatment cooperatively decreased the migration and self-renewal ability of SW-480 cells by regulating the expression of relevant genes. Moreover, combination therapy led to cell cycle arrest at the sub-G1 phase in CRC cells. In conclusion, our results indicated that Nanog may play an important role in the drug sensitivity, migration, and self-renewal of CRC cells; suggesting Nanog as a promising target in combination with 5-FU for the development of new therapeutic approaches for CRC.

MicroRNAs and lncRNAs-A New Layer of Myeloid-Derived Suppressor Cells Regulation.

Myeloid-derived suppressor cells (MDSCs) constitute an important component in regulating immune responses in several abnormal physiological conditions such as cancer. Recently, novel regulatory tumor MDSC biology modulating mechanisms, including differentiation, expansion and function, were defined. There is growing evidence that miRNAs and long non-coding RNAs (lncRNA) are involved in modulating transcriptional factors to become complex regulatory networks that regulate the MDSCs in the tumor microenvironment. It is possible that aberrant expression of miRNAs and lncRNA contributes to MDSC biological characteristics under pathophysiological conditions. This review provides an overview on miRNAs and lncRNAs epiregulation of MDSCs development and immunosuppressive functions in cancer.

PD-1/PD-L1 axis importance and tumor microenvironment immune cells.

Triple-negative breast cancer (TNBC) is heterogeneous cancer with poor prognosis among the other breast tumors. Rapid recurrence and increased progression rate could be reasons for the poor prognosis of this type of breast cancer. Recently, because of the lack of specific targets in multiple cancer treatment, immune checkpoint blockade therapies with targeting PD-1/PD-L1 axis have displayed significant advances and improved survival. Among different types of breast cancers, TNBC is considered more immunogenic with high T-cell and other immune cells infiltration compared to other breast cancer subtypes. This immunogenic characteristic of TNBC is a beneficial marker in the immunotherapy of these tumors. Clinical studies with a focus on immune checkpoint therapy have demonstrated promising results in TNBC treatment. In this review, we summarize clinical trials with the immunotherapy-based treatment of different cancers and also discuss the interaction between infiltrating immune cells and breast tumor microenvironment. In addition, we focus on the signaling pathway that controls PD-L1 expression and continues with CAR T-cell therapy and siRNA as novel strategies and potential tools in targeted therapy.

Combination of Ipilimumab and Nivolumab in Cancers: From Clinical Practice to Ongoing Clinical Trials.

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD-1) are inhibitory checkpoints that are commonly seen on activated T cells and have been offered as promising targets for the treatment of cancers. Immune checkpoint inhibitors (ICIs)targeting PD-1, including pembrolizumab and nivolumab, and those targeting its ligand PD-L1, including avelumab, atezolizumab, and durvalumab, and two drugs targeting CTLA-4, including ipilimumab and tremelimumab have been approved for the treatment of several cancers and many others are under investigating in advanced trial phases. ICIs increased antitumor T cells' responses and showed a key role in reducing the acquired immune system tolerance which is overexpressed by cancer and tumor microenvironment. However, 50% of patients could not benefit from ICIs monotherapy. To overcome this, a combination of ipilimumab and nivolumab is frequently investigated as an approach to improve oncological outcomes. Despite promising results for the combination of ipilimumab and nivolumab, safety concerns slowed down the development of such strategies. Herein, we review data concerning the clinical activity and the adverse events of ipilimumab and nivolumab combination therapy, assessing ongoing clinical trials to identify clinical outlines that may support combination therapy as an effective treatment. To the best of our knowledge, this paper is one of the first studies to evaluate the efficacy and safety of ipilimumab and nivolumab combination therapy in several cancers.

Current Approaches for Combination Therapy of Cancer: The Role of Immunogenic Cell Death.

Cell death resistance is a key feature of tumor cells. One of the main anticancer therapies is increasing the susceptibility of cells to death. Cancer cells have developed a capability of tumor immune escape. Hence, restoring the immunogenicity of cancer cells can be suggested as an effective approach against cancer. Accumulating evidence proposes that several anticancer agents provoke the release of danger-associated molecular patterns (DAMPs) that are determinants of immunogenicity and stimulate immunogenic cell death (ICD). It has been suggested that ICD inducers are two different types according to their various activities. Here, we review the well-characterized DAMPs and focus on the different types of ICD inducers and recent combination therapies that can augment the immunogenicity of cancer cells.