miR-25 Regulates Gastric Cancer Cell Growth and Apoptosis by Targeting EGR2

Gastric cancer is one of the most common malignancies harmful to human health. The search for effective drugs or gene therapy has aroused the attention of scientists. So far, microRNAs, as small non-coding RNAs, have the potential to be therapeutic targets for cancer. Herein, we found a highly expressed miR-25 in gastric cancer cell. However, the function of miR-25 for gastric cancer cell growth and apoptosis was unknown. Functionally, we used RT-qPCR, western blot, CCK-8, and flow cytometry to detect gastric cancer cell growth and apoptosis. The results indicated that miR-25 promoted gastric cancer cell growth and inhibited their apoptosis. Mechanistically, we found that a gene EGR2 was a potential target gene of miR-25. Further dual-luciferase results supported this prediction. Moreover, knockdown of EGR2 promoted gastric cancer cell growth and inhibited their apoptosis by flow cytometry detection. Altogether, these findings revealed miR-25 as a regulator of gastric cancer cell growth and apoptosis through targeting EGR2.

Flow cytometry detection of sustained humoral immune response (IgG + IgA) against native spike glycoprotein in asymptomatic/mild SARS-CoV-2 infection

SARS-CoV-2 is the virus that causes the disease called COVID-19, which has caused the worst pandemic of the century. Both, to know the immunological status of general population and to evaluate the efficacy of the vaccination process that is taking place around the world, serological tests represent a key tool. Classic serological tests, based on colorimetric techniques, such as ELISA or CLIA, continue to be the most widely used option. However, a real improvement in results is still needed. We developed a highly sensitive and specific FCM assay that allows the detection of IgG and IgA antibodies, directed against the native and functional S-protein of SARS-CoV-2 exposed on the membrane of a transfected cell line, up to 8 months after infection.

Abstract 15499: The Increase of Proplatelets and Tpo in Circulation May be a New Pathological Mechanism of Thrombosis

Introduction: Platelets are produced from megakaryocytes, which mainly regulated by thrombopoietin (TPO) and 5-HT. We hypothesized that the secretion of inflammatory cytokines increased in patients with thrombosis under stress or inflammation, leading to increased TPO levels, which in turn increased production capacity of platelet, and increased the number of platelet intermediates proplatelets into the circulation. Therefore, the increase in the number of proplatelets in the circulation, and the increase in plasma TPO levels may be a new pathological mechanism of thrombosis. Methods: TPO was detected by ELISA. Proplatelets from patients were stained with CD41-FITC and further confirmed by a fluorescence microscope and flow cytometry. The in vitro proplatelets were tested by CD41-FITC staining under a fluorescence microscope and flow cytometry detection. Results: Our clinical data demonstrated that patients' plasma TPO levels were significantly higher with acute inflammation state compared with healthy subjects (181.1 ± 35.38 vs 96.1 ± 9.7 pg/ml, p<0.001, n=65). The plasma TPO levels of cerebral infarction patients (186.2±12.5 pg/ml, n=20) were significantly higher than that of the control group (122.3±10.2 pg/ml, n=20). The number of platelets in patients with cerebral infarction (222.11±8.55 х10 9 /L, n=20) was slightly higher than that in the control group (206.55±8.83 х10 9 /L, n=20). More large platelets or proplatelets were found in the circulating blood of patients with cerebral infarction, which was significantly different from the control group (n=8, p<0.05). In vitro study confirmed that in 200 megakaryocytes (MKs), more proplatelets were produced in the TPO group (100 ng/ml, 18±2.5%) and in the 5-HT group (100 nM, 15±3.2%), while the control group was only (7±3.2) % (n=5). The effects of TPO/ 5-HT were interfered with by its receptor blockers, confirming that their effects were mediated by its receptors. Both TPO and 5-HT affect the cytoskeleton by activating p-ERK1/2, reorganizing F-actin to generate proplatelets, and its role was blocked by PD98059. Conclusions: The studies showed that the increase of proplatelets in circulation and TPO levels in plasma may be a new pathological mechanism of cerebral infarction or thrombosis.

Bing-Neel Syndrome – A Challenging Diagnosis: Case Report

Bing-Neel syndrome is a rare neurologic complication of Waldenström’s macroglobulinemia, characterized by infiltration of the central nervous system by clonal lymphoplasmacytes. We present a rare clinical case of a patient, who one year after the diagnosis of Waldenström’s macroglobulinemia, progressed with diverse neurologic presentation and cerebrospinal fluid involvement. The diagnosis was based on magnetic resonance imaging and flow cytometry detection of clonal B-cells in the cerebrospinal fluid. Bing-Neel syndrome should be considered in patients with neurologic symptoms and a history of Waldenström’s macroglobulinemia.

Changes of viral and prokaryote abundances in a high rate algal pond using flow cytometry detection

High rate algal ponds (HRAPs) are shallow, mixed systems for wastewater treatment, which use sunlight exposure for disinfection. Little is known regarding the relationships between the bacteria and viruses within HRAP systems. Uniquely, flow cytometry permits the rapid identification of bacterial and viral populations in wastewater samples, separating populations based on genome and particle size. Treated wastewater samples were collected from an HRAP at Kingston on Murray, South Australia. Flow cytometry analysis detected bacterial populations and discriminated virus-like particles (VLP) and large VLP (LVLP). Rapid, short term, fluctuations in the abundance of all three populations were observed. Changes in the abundance of these populations was compared; wastewater composition was used as metadata for the comparisons. Linear regression determined relationships in abundances between bacteria and LVLP (R2 0.2985); LVLP and VLP (R2 0.5829) and bacteria and VLP (R2 0.5778) all with p-values of &lt;0.001. Bacterial, LVLP and VLP abundance positively correlated with each other, indicating potential microbial interactions. Overall, the results suggest a parasitic relationship was occurring and driving the abundances of bacteria and viruses within the system.