Human amniotic epithelial cells exert anti-cancer effects through secretion of immunomodulatory small extracellular vesicles (sEV).

We identified here mechanism by which hAECs exert their anti-cancer effects. We showed that vaccination with live hAEC conferred effective protection against murine colon cancer and melanoma but not against breast cancer in an orthotopic cancer cell inoculation model. hAEC induced strong cross-reactive antibody response to CT26 cells, but not against B16F10 and 4T1 cells. Neither heterotopic injection of tumor cells in AEC-vaccinated mice nor vaccination with hAEC lysate conferred protection against melanoma or colon cancer. Nano-sized AEC-derived small-extracellular vesicles (sEV) (AD-sEV) induced apoptosis in CT26 cells and inhibited their proliferation. Co-administration of AD-sEV with tumor cells substantially inhibited tumor development and increased CTL responses in vaccinated mice. AD-sEV triggered the Warburg's effect leading to Arginine consumption and cancer cell apoptosis. Our results clearly showed that it is AD-sEV but not the cross-reactive immune responses against tumor cells that mediate inhibitory effects of hAEC on cancer development. Our results highlight the potential anti-cancer effects of extracellular vesicles derived from hAEC.

Introduction of an efficient method for placenta decellularization with high potential to preserve ultrastructure and support cell attachment.

The placenta, as a large discarded tissue and rich in extracellular matrix (ECM), is an excellent candidate for biological scaffolds in reconstructive medicine. Considering the importance of ECM structure in cell fate, the aim of this study was to achieve human placenta decellularization protocol that preserve the structure of scaffolds. Thus, human placenta was decellularized by four protocols and decellularization efficacy was compared by hematoxylin and eosin (H&E), 4',6-diamidino-2-phenylindole (DAPI) staining, and DNA measurement. Decellularized placenta structure preservation was assessed by Masson's trichrome staining, scanning electron microscopy (SEM), and immunofluorescence (IF) for collagen I, IV, and fibronectin. Finally, liquid displacement measured scaffolds' porosity. After culturing menstrual blood-derived stem cells (MenSCs) on placenta scaffolds, cell adhesion was investigated by SEM imaging, and cell viability and proliferation were assessed by MTT assay. According to H&E and DAPI staining, only protocols 1 and 3 could completely remove cells from the scaffolds. DNA measurements confirmed a significant reduction in the genetic material of decellularized scaffolds compared to native placenta. According to Masson's trichrome, IF, and SEM imaging, scaffold structure is better preserved in P3 than P1 protocol. Liquid displacement showed higher porosity of P3 scaffold than P1. SEM imaging confirmed cells adhesion to the decellularized placenta, and the attached cells showed good viability and maintained their proliferative capacity, indicating the suitability of the scaffolds for cell growth. Results introduced an optimized protocol for placenta decellularization that preserves the scaffold structure and supports cell adhesion and proliferation.

Overexpression of bHLH domain of HIF-1 failed to inhibit the HIF-1 transcriptional activity in hypoxia.

BACKGROUND: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. METHODS: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 µM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. RESULTS: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and ß-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 µM CoCl2. The gene expression of VEGF, vimentin, and ß-catenin and protein level of ß-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of ß-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. CONCLUSION: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor.

The effect of smoking on latent tuberculosis infection susceptibility in high risk individuals in Iran.

Tuberculosis has been declared as a global emergency. Latent tuberculosis infection (LTBI) is a state in which host immunity cannot completely eradicate Mycobacterium tuberculosis. Cigarette smoke increases the risk of respiratory infections, such a TB, as it has adverse effects on respiratory immune function. In this cross-sectional study, which was performed from 2016 to 2017, 31 patients with newly diagnosed lung cancer, 63 Chronic obstructive pulmonary disease (COPD), 46 with problems in respiratory system, and 40 healthy subjects were studied. Demographic data of all subjects were recorded via a questionnaire. IGRAs (Interferon-γ release assays) were used to determine LTBI. We showed that smoking has significant odds ratio for COPD patients (OR: 4.58, 95% CI: 1.93-10.87). Also, the concordance of smoking with COPD (OR: 22, 95% CI: 2.7-179.2), lung cancer (OR: 10, 95% CI: 1.03-97), and other respiratory diseases (OR: 4.54, 95% CI: 1.93-10.87) is a significant risk factor for the presence of LTBI whereas the existence of LTBI in the study groups did not show any significant odds ratio. This study is the first to analyze the relationship between smoking in patients with respiratory diseases and LTBI susceptibility in Iran by IGRAs, which proposes cigarette smoking as a powerful risk factor for LTBI.

Discovery of a potential biomarker for immunotherapy of melanoma: PLAC1 as an emerging target.

BACKGROUND: Melanoma has increased in incidence worldwide prompting investigators to search for new biomarkers for targeted immunotherapy of this disease. Placenta specific 1 (PLAC1) is a new member of cancer-testis antigens with widespread expression in many types of cancer. Here, we aimed to study for the first time the expression pattern of PLAC1 in skin cancer samples including cutaneous melanoma, basal cell carcinoma (BCC), squamous cell carcinoma (SCC) in comparison to normal skin and nevus tissues and potential therapeutic effect of anti-PLAC1 antibody in melanoma cancer cell lines in vitro. MATERIALS AND METHODS: Polyclonal and monoclonal antibodies were applied for immunohistochemical profiling of PLAC1 expression using tissue microarray. The cytotoxic action of anti-PLAC1 antibody alone or as an antibody drug conjugate (with anti-neoplastic agent SN38) was investigated in melanoma cell lines. RESULTS: We observed that 100% (39 of 39) of melanoma tissues highly expressed PLAC1 with both cytoplasmic and surface expression pattern. Investigation of PLAC1 expression in BCC (n = 110) samples showed negative results. Cancer cells in SCC samples (n = 66) showed very weak staining. Normal skin tissues and nevus samples including congenital melanocytic nevus failed to express PLAC1. Anti-PLAC1-SN38 exerted a specific pattern of cytotoxicity in a dose- and time-dependent manner in melanoma cells expressing surface PLAC1. CONCLUSIONS: Our findings re-inforce the concept of re-expression of embryonic/placental tissue antigens in cancer and highlight the possibility of melanoma targeted therapy by employing anti-PLAC1 antibodies. The data presented here should lead to the future research on targeted immunotherapy of patients with melanoma.

Competitive Effect of Overexpressed C-terminal of Snail-1 (CSnail) in Control of the Growth and Metastasis of Melanoma Cells.

BACKGROUND: Epithelial-to-mesenchymal transition (EMT) plays a role in the invasion and metastasis of cancer cells. During this phenomenon, Snail can promote tumor progression by upregulating mesenchymal factors and downregulating the expression of pro-apoptotic proteins. OBJECTIVE: Therefore, interventions on the expression rate of Snails may show beneficial therapeutic applications. METHODS: In this study, the C-terminal region of Snail1, capable of binding to E-box genomic sequences, was subcloned into the pAAV-IRES-EGFP backbone to make complete AAV-CSnail viral particles. B16F10 as a metastatic melanoma cell line, with a null expression of wild type TP53 was transduced by AAV-CSnail. Moreover, the transduced cells were analyzed for in vitro expression of apoptosis, migration, and EMT-related genes, and in vivo inhibition of metastasis. RESULTS: In more than 80% of the AAV-CSnail transduced cells, the CSnail gene expression competitively reduced the wild-type Snail functionality and consequently lowered the mRNA expression level of EMT-related genes. Furthermore, the transcription level of cell cycle inhibitory factor p21 and pro-apoptotic factors were promoted. The scratch test showed a decrease in the migration ability of AAV-CSnail transduced group compared to control. Finally, metastasis of cancer cells to lung tissue in the AAV-CSnail-treated B16F10 melanoma mouse model was significantly reduced, pointing out to prevention of EMT by the competitive inhibitory effect of CSnail on Snail1 and increased apoptosis of B16F10 cells. CONCLUSION: The capability of this successful competition in reducing the growth, invasion, and metastasis of melanoma cells indicates that gene therapy is a promising strategy for the control of the growth and metastasis of cancer cells.

Catalase-gold nanoaggregates manipulate the tumor microenvironment and enhance the effect of low-dose radiation therapy by reducing hypoxia.

Radiotherapy as a standard method for cancer treatment faces tumor recurrence and antitumoral unresponsiveness. Suppressive tumor microenvironment (TME) and hypoxia are significant challenges affecting efficacy of radiotherapy. Herein, a versatile method is introduced for the preparation of pH-sensitive catalase-gold cross-linked nanoaggregate (Au@CAT) having acceptable stability and selective activity in tumor microenvironment. Combining Au@CAT with low-dose radiotherapy enhanced radiotherapy effects via polarizing protumoral immune cells to the antitumoral landscape. This therapeutic approach also attenuated hypoxia, confirmed by downregulating hypoxia hallmarks, such as hypoxia-inducible factor α-subunits (HIF-α), vascular endothelial growth factor (VEGF), and EGF. Catalase stability against protease digestion was improved significantly in Au@CAT compared to the free catalase. Moreover, minimal toxicity of Au@CAT on normal cells and increased reactive oxygen species (ROS) were confirmed in vitro compared with radiotherapy. Using the nanoaggregates combined with radiotherapy led to a significant reduction of immunosuppressive infiltrating cells such as myeloid-derived suppressor cells (MDSCs) and regulatory T cells (T-regs) compared to the other groups. While, this combined therapy could significantly increase the frequency of CD8+ cells as well as M1 to M2 macrophages (MQs) ratio. The combination therapy also reduced the tumor size and increased survival rate in mice models of colorectal cancer (CRC). Our results indicate that this innovative nanocomposite could be an excellent system for catalase delivery, manipulating the TME and providing a potential therapeutic strategy for treating CRC.

Oridonin Could Inhibit Inflammation and T-cell Immunoglobulin and Mucin-3/Galectin-9 (TIM-3/Gal-9) Autocrine Loop in the Acute Myeloid Leukemia Cell Line (U937) as Compared to Doxorubicin.

The T-cell immunoglobulin and mucin-3 (TIM-3)/galectin-9 (Gal-9) autocrine loop is an indispensable signaling in acute myeloid leukemia (AML) cells, which induces their self-renewal through activation of nuclear factor-kappa b (NF-kB) and ß-catenin pathways. In this study, we evaluated the effects of oridonin and doxorubicin on the TIM-3/Gal-9 autocrine loop. We also evaluated oridonin anti-inflammatory and anti-cancer properties on U937 cells, as an AML cell line in comparison to doxorubicin as a common anthracycline drug for AML treatment. Cell counting kit-8 (CCK-8) was applied to evaluate the cytotoxicity of oridonin and doxorubicin on U937 cells and also to determine the impact of galectin-9 (Gal-9) on their proliferation. The effects of oridonin and doxorubicin on Gal-9, TIM-3, and interleukin-1ß (IL-1ß) gene expression were determined by real-time polymerase chain reaction (RT-PCR). The Gal-9 secretion level was measured by enzyme-linked immunosorbent assay (ELISA) and activation of NF-kB pathway was assessed by western blotting. In a dose-dependent manner, oridonin and doxorubicin were capable to eradicate U937 cells while Gal-9 expanded them. Following the treatment of U937 cells with oridonin, the expression of Gal-9, TIM-3, and IL-1ß genes was down-regulated, and the Gal-9 secretion and NF-kB phosphorylation were diminished, whereas doxorubicin increased all of these factors. Doxorubicin is a common treatment agent in AML, but it may induce inflammation and up-regulate the TIM3/Gal-9 autocrine loop, consequently can enhance the possibility of disease relapse. Meanwhile, oridonin is capable to inhibit the essential signaling pathways in AML cells and reduce the inflammation and expansion of tumor cells and postpone AML recurrence.

Evaluating the Immunoreactivity of Ailanthus Altissima (The Tree of Heaven) Pollen Extract in Atopic Patients.

IgE-mediated hypersensitivity reaction to pollens is a common health problem in atopic patients. In this regard, the assessment of the allergenicity of highly pollinating plants would be demanding. Based on the increment of Ailanthus altissima (A. altissima) tree in some parts of Iran and considering its probable role in respiratory allergy, in this study, we aimed to investigate its IgE-immunoreactivity and in diagnostic applications. One hundred and twenty-five allergic rhinitis patients who were diagnosed as high IgE responders and demonstrated seasonal rhinitis or rhinoconjunctivitis, as well as 20 healthy controls (HCs) with no allergic symptoms, were enrolled in this study. Total protein extract was prepared from A. altissima pollens and subjected to quality control experiments and finally used in ELISA and western blotting studies. Approximately 24% of the atopic patients (30 from 125) showed positive immunoreactivity to A. altissima extract. The median (IQR) of absorbance (450 nm) of the specific IgE against A. altissima pollen extract in HCs and positive groups were 0.33 (0.28-0.42) and 0.59 (0.36-0.79), respectively (p<0.001). Receiver operating characteristics (ROC) curve analysis of the specific ELISA results, revealed a cut-off value of 0.46 and a sensitivity of 70% and specificity of 100%. Western blotting with the sera positive cases revealed that the main immunoreactive proteins range from 10 to 70 kDa. This study revealed that some of A. altissima pollen proteins ranging from 10 to 70 kDa show IgE-reactivity in atopic patients and may play a role in their allergic reaction symptoms.

Overexpression of bHLH domain of HIF-1 failed to inhibit the HIF-1 transcriptional activity in hypoxia

BACKGROUND: Hypoxia inducible factor-1 (HIF-1) is considered as the most activated transcriptional factor in response to low oxygen level or hypoxia. HIF-1 binds the hypoxia response element (HRE) sequence in the promoter of different genes, mainly through the bHLH domain and activates the transcription of genes, especially those involved in angiogenesis and EMT. Considering the critical role of bHLH in binding HIF-1 to the HRE sequence, we hypothesized that bHLH could be a promising candidate to be targeted in hypoxia condition. METHODS: We inserted an inhibitory bHLH (ibHLH) domain in a pIRES2-EGFP vector and transfected HEK293T cells with either the control vector or the designed construct. The ibHLH domain consisted of bHLH domains of both HIF-1a and Arnt, capable of competing with HIF-1 in binding to HRE sequences. The transfected cells were then treated with 200 µM of cobalt chloride (CoCl2) for 48 h to induce hypoxia. Real-time PCR and western blot were performed to evaluate the effect of ibHLH on the genes and proteins involved in angiogenesis and EMT. RESULTS: Hypoxia was successfully induced in the HEK293T cell line as the gene expression of VEGF, vimentin, and ß-catenin were significantly increased after treatment of untransfected HEK293T cells with 200 µM CoCl2. The gene expression of VEGF, vimentin, and ß-catenin and protein level of ß-catenin were significantly decreased in the cells transfected with either control or ibHLH vectors in hypoxia. However, ibHLH failed to be effective on these genes and the protein level of ß-catenin, when compared to the control vector. We also observed that overexpression of ibHLH had more inhibitory effect on gene and protein expression of N-cadherin compared to the control vector. However, it was not statistically significant. CONCLUSION: bHLH has been reported to be an important domain involved in the DNA binding activity of HIF. However, we found that targeting this domain is not sufficient to inhibit the endogenous HIF-1 transcriptional activity. Further studies about the function of critical domains of HIF-1 are necessary for developing a specific HIF-1 inhibitor.

Neuroimaging of hypoxia and cocaine-induced hippocampal stroke.

The hippocampus has been a subject of numerous studies of behavior and memory in patients who demonstrate atrophy, sclerosis, or injury by autopsy or imaging. It has also been studied in patients who undergo surgical treatment for intractable epilepsy. The effects of hypoxia and ischemia on the hippocampus have been studied in animals; however, human cases of hippocampal stroke are rarely reported. The authors report a case of bilateral hippocampal stroke in a patient with severe ischemia secondary to cardiac arrest and cocaine exposure. These findings likely resulted from the combination of hypoxia and cocaine-related excitotoxicity.