Shenzhen Hanke Bioengineering (China)

Abstract The dissemination of cancer and development of metastases is the cause of nearly all cancer deaths. Circulating tumor cells (CTC) are cells that detach from the primary solid tumor or metastases and circulates through the peripheral blood. Accumulating evidence shows the importance of CTC detection for cancer prognosis also referred to as a “liquid biopsy”, biomarker for metastatic cancer, as well as therapeutic response monitoring. However, detection of CTC in peripheral blood is made difficult because they are present at extremely low concentrations; in some patients as little as a few CTC per million blood cells. Flow cytometry a standard equipment available in many laboratories is capable of analyzing thousands of cells per second, allowing rare cell detection and has been demonstrated to be useful for CTC studies. CTC detection can be further aided by affinity based enrichment methods that eliminate other blood cells from the sample before analysis. In these experiments, we analyzed a colon cancer cell line (SW620) by 2 methods; either direct flow cytometry identification or following EpCAM affinity based enrichment. First, SW620 cells were spiked into blood cells and analyzed of the NovoCyte Quanteon and other comparison cytometers to determine the rare event detection sensitivity. The results show a good linear relationship between the number of cells detected and the predicted number added with a sensitivity of 0.00001% or 1 CTC per million cells. Colon cancer CTC and many other CTC have high expression of epithelial markers, such as epithelial cell surface marker, EpCAM. Affinity based enrichment methods utilize distinct antigens expressed either by CTCs but not blood cells such as EpCAM to separate CTC from blood cells and increase the detection capacity of CTC in the blood. In the next experiments, SW620 cells were spiked into blood samples to simulate CTC in cancer patients. CTC were then enriched by EpCAM affinity based magnetic bead enrichment. The recovery rate of the spiked tumor cells was then detected by flow cytometry to determine the accuracy and specificity of the enrichment process. The results show that a greater number of CTC present in the spiked blood sample increased the recovery rate of CTC through the enrichment process. A high precision syringe pump allowed the direct enumeration of CTC without the need of reference beads. These data demonstrate the high specificity and accuracy of CTC detection by flow cytometry by both direct identification and the use bead based enrichment methods. Citation Format: Li Zhao, Lauren Jachimowicz, Ming Lei, Peifang Ye, Garret Guenther, Nancy LI. Comparison of two flow cytometry detection methods of circulating tumor cells: Direct identification and EpCAM affinity based enrichment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1626.

β-poly(L-malic acid) (PMLA) is a highly water-soluble biopolymer used in medicine and other industries. PMLA is usually biosynthesized by Aureobasidium pullulans, but in low concentrations, which has restricted its further large-scale production. Here effects of surfactants on PMLA production were investigated. Of various surfactants examined, the addition of Tween 80 at the start of cell growth increased mycelial growth, PMLA production, PMLA productivity and the ratio of PMLA to cell biomass concentration (Yp/x) of A. pullulans. Transmission electron microscopy and flow cytometry showed that cell membrane permeability was increased, improving the secretion of PMLA and uptake of nutrients and oxygen. Proteomic analysis showed that key pathways of PMLA synthesis, along with cellular energy metabolism, were enhanced. Moreover, glutathione (GSH) synthesis and anti-oxidation capacity were also improved. These results indicated that the addition of Tween 80 is an efficient approach for improving the production of PMLA.

PurposeTo study the safety and clinical efficacy on combination of irreversible electroporation and allogeneic natural killer cell therapy for treating Stage III/IV pancreatic cancer, evaluating median progression free survival (PFS), and overall survival (OS).ResultsAdverse events of all patients were limited to grades 1 and 2, including local (mainly tussis 13.4%, nausea and emesis 7.1%, pain of puncture point 29.6% and duodenum and gastric retention 4.3%) and systemic (mainly fatigue 22.3%, fever 31.6%, and transient reduction of intraoperative blood pressure 25.1% and white cell count reduction 18.3%) reactions, fever was the most frequent. The serum amylase level at 24 h and 7 d after IRE was not significantly changed compared to those before IRE (P > 0.05). CA19–9 value was lower in IRE-NK group than in IRE at 1 month after treatment (P < 0.05). After a median follow-up of 7.4 months (3.6–11.2 months): in stage III group, median PFS was higher in IRE-NK group (9.3 months) than in IRE group (8.1 months, P = 0.0465), median OS was higher in IRE-NK (13.2 months) than in IRE (11.4 months, P = 0.0411), and median PFS was higher in who received multiple NK than single NK (9.8 months vs.8.1 months, P = 0.0423, respectively), median OS who received multiple NK was higher than single NK (13.9 months vs.12.3 months, P = 0.0524, respectively), the RR in IRE-NK (63.2%) was higher than in IRE (50.0%, P < 0.05); in stage IV group, median OS was higher in IRE-NK (9.8 months) than in IRE (8.7 months, P = 0.0397), the DCR in IRE-NK (66.7%) was higher than in IRE (42.9%, P < 0.05).Materials and MethodsBetween July 2016 and May 2017, we enrolled 71 patients who met the enrollment criteria. The patients were divided into stage III (32 patients, 17 patients received only IRE and 15 patients received IRE-NK (Irreversible electroporation- natural killer): 8 patients underwent a course of NK and 7 patients underwent ≥ 3 courses) and stage IV (39 patients, 22 patients received only IRE and 17 patients received IRE-NK: 9 patients underwent a course of NK and 8 patients underwent ≥ 3 courses). The safety and short-term effects were evaluated firstly, then the median PFS, median OS, response rate (RR) and disease control rate (DCR) were assessed.ConclusionsCombination of irreversible electroporation and allogeneic natural killer cell immunotherapy significantly increased median PFS and median OS in stage III pancreatic cancer and extended the median OS of stage IV pancreatic cancer. Multiple allogeneic natural killer cells infusion was associated with better prognosis to stage III pancreatic cancer.

To investigate the "methyl" impact on bioactivity of sulfiliminyl dicarboxamides, a total of 16 novel N-cyano and N-trifluoroacetyl sulfiliminyl dicarboxamides containing m-heptafluoroisopropylated aromatic amino moiety were studied. Two series of sulfiliminyl substituents were designed, synthesized and evaluated against oriental armyworm (Pseudaletia separata Walker) for their insecticidal activities. Their chemical structures were established by corresponding [Formula: see text] NMR, HRMS and optical polarimetry. Bioassay results revealed that some of the title compounds showed potent insecticidal activities against oriental armyworm. Notably, compounds IIa, IIIa, IVa exhibited 100% activity at [Formula: see text], in particular, IIa showed a comparable control efficacy to that of the commercial product flubendiamide. The SAR of these N-cyano sulfiliminyl isomers can be summarized as follows (Sc, Ss) [Formula: see text] (Sc, Rs), while the N-trifluoroacetyl sulfiliminyl isomers is (Sc, Rs) [Formula: see text] (Sc, Ss). Comparative molecular field analysis indicated that an electropositive substituent, [Formula: see text] group in the benzene ring was very important for the improvement in biological activity. These results could hold promise for novel chiral sulfiliminyl RyR regulators.

In this study, the safety and clinical efficacy of cryosurgery combined with allogenic NK cell immunotherapy for the treatment of advanced non-small cell lung cancer (NSCLC) were evaluated. From July 2016 to March 2017, we enrolled 60 patients who met the enrollment criteria and divided them into two groups: (1) the simple cryoablation group (n=30) and (2) the cryoablation combined with allogenic NK cell group (n=30). The changes in immune function, quality of life, and clinical response were evaluated. We found that allogenic NK cells combined with cryosurgical treatment for advanced NSCLC have a synergistic effect, which not only enhancing the immune function of patients, improving the quality of life, and significantly increasing the response rate (RR) and disease control rate (DCR) compared to cryoablation group. This study is the first clinical trial of allogenic NK cells combined with cryosurgery for the treatment of advanced NSCLC and preliminaily its safety and efficacy.