Proapoptotic CD95L levels in normal human serum and sera of breast cancer patients

The mechanisms on evasion of anti-tumor immune responses in gastric cancer

The immune system and the tumor have been at each other's throats for so long that the neoplasm has learned to avoid detection and avoid being attacked, which is called immune evasion. Malignant tumors, such as gastric cancer (GC), share the ability to evade the body's immune system as a defining feature. Immune evasion includes alterations to tumor-associated antigens (TAAs), antigen presentation mechanisms (APMs), and the tumor microenvironment (TME). While TAA and APM are simpler in nature, they both involve mutations or epigenetic regulation of genes. The TME is comprised of numerous cell types, cytokines, chemokines and extracellular matrix, any one of which might be altered to have an effect on the surrounding ecosystem. The NF-kB, MAPK, PI3K/AKT, JAK/STAT, Wnt/β-catenin, Notch, Hippo and TGF-β/Smad signaling pathways are all associated with gastric cancer tumor immune evasion. In this review, we will delineate the functions of these pathways in immune evasion.

HET0016 decreases lung metastasis from breast cancer in immune-competent mouse model

Distant metastasis is the primary cause of death in the majority of the cancer types. Recently, much importance has been given to tumor microenvironment (TME) in the development of invasive malignant tumors, as well as the metastasis potential. The ability of tumor cells to modulate TME and to escape immune-mediated attack by releasing immunosuppressive cytokines has become a hallmark of breast cancer. Our study shows the effect of IV formulation of HET0016 (HPßCD-HET0016) a selective inhibitor of 20-HETE synthesis, administered intravenously in immune-competent in vivo mouse model of murine breast cancer. 4T1 luciferase positive cells were implanted to the mammary fat pad in Balb/c mice. Treatment started on day 15, and was administered for 5 days a week for 3 weeks. The development of metastasis was detected via optical imaging. Blood, spleen, lungs, bone marrow and tumor were collected for flow cytometry, to investigate changes in myeloid-derived suppressive cells (MDSCs) populations and endothelial phenotype. Tumor and lungs were collected for protein analysis. Our results show that HPßCD-HET0016: (1) decreased tumor volume and lung metastasis compared to the vehicle group; (2) reduced migration and invasion of tumor cells and levels of metalloproteinases in the lungs of animals treated with HPßCD-HET0016 via PI3K/AKT pathway; and (3) decreased expression of pro-inflammatory cytokines, growth factors and granulocytic MDSCs population in the lung microenvironment in treated animals. Thus, HPßCD-HET0016 showed potential in treating lung metastasis in a preclinical mouse model and needs further investigations on TME.

Diagnostic and Therapeutic Potential of Exosomes in Cancer: The Beginning of a New Tale?

Exosomes have emerged as one of the main players in intercellular communication. These small nano-sized particles have many roles in various physiological pathways in normal and abnormal cells. Exosomes can carry various cargos such as proteins, mRNAs, and miRNAs to recipient cells. Uptake of exosomes and their cargo can induce and/or inhibit different cellular and molecular pathways that lead to the alteration of cell behavior. Multiple lines of evidence have indicated that exosomes released from cancer cells can effect development of cancer in different stages. These particles and their cargo could regulate different processes such as tumor growth, metastasis, drug resistance, angiogenesis, and immune system functioning. It has been observed that exosomes can be used as potential diagnostic biomarkers in various cancer types. Moreover, some studies have used these particles as biological vehicles for delivery of various drugs such as doxorubicin, siRNAs, and miRNAs. Here, we summarized the findings on the role of exosomes in different pathological processes involved in cancer. Moreover, application of these particles as diagnostic and therapeutic biomarkers in different types of cancers is discussed. J. Cell. Physiol. 232: 3251-3260, 2017. © 2016 Wiley Periodicals, Inc.

Mechanism of immune evasion in breast cancer

Breast cancer (BC) is the most common malignant tumor among women, with high morbidity and mortality. Its onset, development, metastasis, and prognosis vary among individuals due to the interactions between tumors and host immunity. Many diverse mechanisms have been associated with BC, with immune evasion being the most widely studied to date. Tumor cells can escape from the body’s immune response, which targets abnormal components and foreign bodies, using different approaches including modification of surface antigens and modulation of the surrounding environment. In this review, we summarize the mechanisms and factors that impact the immunoediting process and analyze their functions in detail.

Correlation between toxic organochlorine pesticides and breast cancer

Organochlorines (OCs) are common environmental pollutants that have been linked to cancer. This work aims to assess the role of OCs as a risk factor for breast cancer and to evaluate the cellular changes induced by exposure to such environmental contaminants. The study included 70 cancer patients subjected to thorough history taking and routine investigations. Samples from tumor and normal adjacent tissue were taken to measure OCs’ levels and to perform molecular analysis (some oncogenic and apoptotic markers) by flow cytometry. There were significantly higher concentrations of methoxychlor, dichloro-diphenyl-trichloroethane (DDT), hexa-chlorobenzene (HCB), and chlordane in tumor tissue samples compared to the surrounding normal tissue. There was a positive statistically significant correlation between G2m and dichloro-diphenyl-dichloroethane, DDT, and methoxychlor. There was also a negative correlation between propidium iodide (PI) and heptachlor as well as between PI, B-cell lymphoma 2, and methoxychlor. Annexin showed a negative correlation with HCB and methoxychlor. In conclusion, the higher level of organochlorine pesticides in the tissue specimens of breast cancer and the resultant molecular dysfunction highlight a possible association. Further research is warranted to elucidate the other possible mechanisms involved in the process of carcinogenesis.

Apoptosis and death receptor signaling in diaphragm of burnt rats

BACKGROUND

Respiratory dysfunction is a frequent complication after severe burn injury. Respiratory muscle atrophy may induce respiratory dysfunction due to insufficient inspiratory motive power. Accumulated evidence suggests that apoptosis is very important in skeletal muscle atrophy in multiple pathologic conditions. Therefore, we hypothesize that myonuclear apoptosis contributes to diaphragm atrophy induced by burn injury, and death receptor signaling activation plays a role in this process.

METHODS

Wistar rats in the burn-injured group were subjected to a full-thickness scald injury around 40% of total body surface area. Diaphragm samples were examined for myonuclear apoptosis by transmission electron microscope, terminal deoxynucleotidyl transferase-mediated nick end labeling assay, and immunohistochemistry for caspase-3. Serum level of apoptotic ligands were assessed by ELISA. Activation of death receptor signaling was examined by Western blotting.

RESULTS

Burn injury resulted in significant reductions of diaphragm muscle mass and myofiber cross-section area. Apoptosis in diaphragm appeared from day 1 and peaked on day 4 after injury. The level of soluble TNF-related apoptosis-inducing ligand and the ratio of Fas ligand to soluble Fas in serum significantly increased after burn injury. In diaphragm of burnt animals, the expressions of proapoptotic proteins, such as cleaved caspase-8, cleaved caspase-3, and Bax-to-Bcl-2 ratio were upregulated, whereas expression of pAkt, an antiapoptotic protein, was downregulated. Immunohistochemistry revealed that the most of the caspase-3 was expressed in myofiber nuclei and their surrounding cytoplasm area in tissue sections.

CONCLUSIONS

Severe burn injury induces myonuclear apoptosis in diaphragm, which could be a contributor to diaphragm muscle atrophy. Activation of death receptor signaling may be a mechanism of apoptosis in diaphragm.

Exosomes: Potent regulators of tumor malignancy and potential bio-tools in clinical application

Multiple lines of evidence indicate that exosomes, as efficient messengers in cell-to-cell communication, play pleiotropic roles in regulating tumor malignancy. The cargos (proteins, mRNAs, and miRNAs) carried by exosomes can be functionally delivered between different types of cells and even transferred to distant locations, influencing the biological activities of tumor and non-tumor cells and promoting tumor growth, invasion, metastasis, angiogenesis, and drug resistance. Tumor-associated exosomes have been identified in biological (plasma, urine, saliva) and pathological (malignant effusions, pleural effusions, ascites) fluids from cancer patients. The contents of exosomes may vary depending on tumor types and status. Detection of exosomes in biofluids of cancer patients may represent a promising strategy to gain pathogenic information and to select specific biomarkers for the diagnosis and prognosis of cancer. Utilization of exosomes as delivery vehicles for siRNAs and therapeutic drugs brings out new concepts such as biomimetics in cancer treatment. In this review, we will mainly discuss emerging roles of exosomes in tumor invasion, metastasis, angiogenesis, and drug resistance and potential clinical application of exosomes as biomarkers and therapeutic tools.

Extracellular vesicles: potential applications in cancer diagnosis, prognosis, and epidemiology

Both normal and diseased cells continuously shed extracellular vesicles (EVs) into extracellular space, and the EVs carry molecular signatures and effectors of both health and disease. EVs reflect dynamic changes that are occurring in cells and tissue microenvironment in health and at a different stage of a disease. EVs are capable of altering the function of the recipient cells. Trafficking and reciprocal exchange of molecular information by EVs among different organs and cell types have been shown to contribute to horizontal cellular transformation, cellular reprogramming, functional alterations, and metastasis. EV contents may include tumor suppressors, phosphoproteins, proteases, growth factors, bioactive lipids, mutant oncoproteins, oncogenic transcripts, microRNAs, and DNA sequences. Therefore, the EVs present in biofluids offer unprecedented, remote, and non-invasive access to crucial molecular information about the health status of cells, including their driver mutations, classifiers, molecular subtypes, therapeutic targets, and biomarkers of drug resistance. In addition, EVs may offer a non-invasive means to assess cancer initiation, progression, risk, survival, and treatment outcomes. The goal of this review is to highlight the current status of information on the role of EVs in cancer, and to explore the utility of EVs for cancer diagnosis, prognosis, and epidemiology.