Naive primary neutrophils play a dual role in the tumor microenvironment.

The tumor microenvironment (TME) is characterized by a network of cancer cells, recruited immune cells and extracellular matrix (ECM) in a hypoxic microenvironment. However, the specific role of neutrophils during tumor development, and their interactions with other immune cells is still not well understood. Thus, there is a need to investigate the interaction between primary neutrophils and natural killer cells and the resulting effects on tumor development. Here we use both standard well plate culture and an under oil microfluidic (UOM) assay with an integrated extracellular cell matrix (ECM) bridge to elucidate how naive primary neutrophils respond to both patient derived tumor cells and tumor cell lines. Our data demonstrated that both patient derived head and neck squamous cell carcinoma (HNSCC) tumor cells and MDA-MB-231 breast cancer cells trigger cluster formation in neutrophils, and the swarm of neutrophils restricts tumor invasion through the generation of reactive oxygen species (ROS) and neutrophil extracellular trap (NETs) release within the neutrophil cluster. However, we also observed that the presence of neutrophils downregulates granzyme B in NK-92 cells and the resulting NETs can obstruct NK cells from penetrating the tumor mass in vitro suggesting a dual role for neutrophils in the TME. Further, using label-free optical metabolic imaging (OMI) we observed changes in the metabolic activities of primary neutrophils during the different swarming phases when challenged with tumor cells. Finally, our data demonstrates that neutrophils in direct contact, or in close proximity, with tumor cells exhibit greater metabolic activities (lower nicotinamide adenine dinucleotide phosphate (NAD(P)H) mean lifetime) compared to non-contact neutrophils.

Microfluidic capture of chromatin fibres measures neutrophil extracellular traps (NETs) released in a drop of human blood.

Neutrophils are the largest population of white blood cells in the circulation, and their primary function is to protect the body from microbes. They can release the chromatin in their nucleus, forming characteristic web structures and trap microbes, contributing to antimicrobial defenses. The chromatin webs are known as neutrophil extracellular traps (NETs). Importantly, neutrophils can also release NETs in pathological conditions related to rheumatic diseases, atherosclerosis, cancer, and sepsis. Thus, determining the concentration of NETs in the blood is increasingly important for monitoring patients, evaluating treatment efficacy, and understanding the pathology of various diseases. However, traditional methods for measuring NETs require separating cells and plasma from blood, are prone to sample preparation artifacts, and cannot distinguish between intact and degraded NETs. Here, we design a microfluidic analytical tool that captures NETs mechanically from a drop of blood and measures the amount of intact NETs unbiased by the presence of degraded NETs in the sample.

Chemotaxis and swarming in differentiated HL-60 neutrophil-like cells.

The human leukemia cell line (HL-60) is an alternative to primary neutrophils in research studies. However, because HL-60 cells proliferate in an incompletely differentiated state, they must undergo differentiation before they acquire the functional properties of neutrophils. Here we provide evidence of swarming and chemotaxis in differentiated HL-60 neutrophil-like cells (dHL-60) using precise microfluidic assays. We found that dimethyl sulfoxide differentiated HL-60 cells (DdHL-60) have a larger size, increased length, and lower ability to squeeze through narrow channels compared to primary neutrophils. They migrate through tapered microfluidic channels slower than primary neutrophils, but faster than HL-60s differentiated by other protocols, e.g., using all-trans retinoic acid. We found that dHL-60 can swarm toward zymosan particle clusters, though they display disorganized migratory patterns and produce swarms of smaller size compared to primary neutrophils.

Cancer/Testis genes in relation to sperm biology and function.

Cancer testis antigens (CTAs), a large family of tumor-associated and immunogenic antigens expressed in human tumors of various histological origins, are highly restricted to the testis and trophoblast. CTAs have been identified as potent targets for tumor-specific immunotherapeutic advances and have immensely lead to the development of different clinical trials of CTA-based vaccine therapy because of their resilient in vivo immunogenicity and tumor-restricted expression pattern. Bladder cancer, non-small cell lung carcinoma, and melanoma are grouped as high CT gene expressors. Prostate and breast cancer as moderate, and colon and renal cancers are considered as low CT gene expressors. Large percentages of these identified CT genes are expressed during spermatogenesis but their function is still vaguely unknown. Researchers have taken a keen interest in CT genes as pertaining to their role in tumor growth and spermatogenesis. Testis has many similarities with cancerous tissues like cell division, immigration, and immortalization. The aim is to give a concise in-depth review on the role of some specific CT genes in spermatogenesis.

Therapeutic angiogenesis promotes efficacy of human umbilical cord matrix stem cell transplantation in cardiac repair.

OBJECTIVES: Although previous studies have confirmed the beneficial effects of human umbilical cord matrix stem cell (hUCM) transplantation post myocardial infarction (MI), but this stem cell resource has no potential to induce angiogenesis. In order to achieve the process of angiogenesis and cardiomyocyte regeneration, two required factors for cardiac repair agents were examined namely; hUCM and VEGF on an infarcted heart. The main objective of this research is to investigate the combinatory effect of dhUCM and VEGF transplantation on an infarcted heart. MATERIALS AND METHODS: 45 min of ligating the left anterior descending coronary artery, the MI-induced animals received 50 µl PBS, 5 µg VEGF, 5×10(6) hUCM cells alone, combined with 5 µg VEGF and 5×10(6) differentiated hUCM cells alone or combined with 5 µg VEGF through intramyocardial injection. MI group, without hUCM and VEGF served as the control group. Left ventricular function and angiogenesis were also evaluated. RESULTS: After eight weeks post MI, there were significant rise in left ventricular ejection farction in dhUCM+VEGF group compared to the other treated and non-treated groups (P<0.05). Fibrosis tissue was markedly lower in the dhUCM+VEGF and hUCM+VEGF groups compared to the other treated and non-treated groups (P<0.05). Despite these benefits, vascular density in dhUCM+VEGF group was not markedly different compared to VEGF and hUCM+VEGF groups. The transplanted hUCM and dhUCM cells survived and migrated to the infarcted area. CONCLUSION: Our findings demonstrated that the dhUCM cells transplantation combined with VEGF were more efficient on an infarcted heart.

Human Wharton's jelly-derived mesenchymal stem cells express oocyte developmental genes during co-culture with placental cells.

OBJECTIVES: The present day challenge is how to obtain germ cells from stem cells to treat patients with cancer and infertility. Much more efforts have been made to develop a procedure for attaining germ cells in vitro. Recently, human umbilical cord-derived mesenchymal stem cells (HUMSCs) have been introduced with higher efficacy for differentiation. In this work, we tried to explore the efficacy of HUMSCs and some effective products of placental cells such as transforming growth factors. This study is aimed to optimize a co-culture condition for HUMSCs with placental cells to obtain primordial germ cells (PGCs) and reach into oocyte-like cells in vitro. MATERIALS AND METHODS: In this experimental study, HUMSCs and placental cells were co-cultured for 14 days without any external inducer in vitro. Then HUMSCs were assessed for expression of PGC markers; Octamer-binding transcription factor 4(OCT4), Tyrosine-protein kinase Kit (CKIT), Stage specific embryonic antigen 4 (SSEA4), DEAD (Asp-Glu-Ala-Asp) box polypeptide 4(DDX4) and oocyte specific markers; Growth differentiation factor-9(GDF9), Zona pellucida glycoprotein 3(ZP3). The pertinent markers were assessed by immunocytochemistry and Q-PCR. RESULTS: Co-cultured HUMSCs with placental cells (including amniotic and chorionic cells) presented Oct4 and DDX4, primordial germ cells specific markers significantly, but increment in expression of oocyte-like cell specific markers, GDF9 and ZP3 did not reach to statistically significant threshold. CONCLUSION: Placental cell supplements Transforming growth factor (TGF α, ß) and basic fibroblast growth factor (bFGF) in a co-culture model can provide proper environment for induction of HUMSCs into PGCs and expression of oocyte-like markers.