[Determination of alpha-amylase in microbial glucoamylase preparations]

Therapeutic anti-glioma effect of the combined action of PCSK inhibitor with the anti-tumoral factors secreted by Poly (I:C)-stimulated macrophages

Macrophages plasticity is a key feature in cancer progression. Neoplastic cells can alter their immune functions and orient them into a pro-tumoral phenotype. In this context, we developed a new therapeutic strategy to switch macrophages phenotype and reactivate their anti-tumoral functions. We showed a dual activity of a proprotein convertases inhibitor as anti-glioma drug and anti-tumoral macrophages' reactivation drug. Proprotein convertases are proteases that cleave proteins into functional proteins. Several of their substrates are involved in tumorigenesis and immunosuppression. We combine here proprotein convertases inhibitor with Poly (I:C), a TLR3 ligand, to increase the anti-tumoral activity of macrophages. With mass spectrometry-based proteomics, system biology, combined with biological assays, we established that a stimulation of macrophages with Poly (I:C) increased their secretion of pro-inflammatory cytokines and anti-tumoral factors. 3D invasion assay showed the efficacy of these anti-tumoral factors against mixed glioma cells and macrophages spheroids. Besides, immunofluorescence and proliferation assays showed an additive effect of the proprotein convertases inhibitor and the anti-tumoral factors secreted by Poly (I:C)-treated macrophages on both anti-glioma activity and macrophages anti-tumoral orientation directly in tumor microenvironment, leading to an innovative glioma therapy.

Nicaraven prevents the fast growth of inflamed tumors by an anti-inflammatory mechanism

Inflammatory microenvironment is known to accelerate the progression of malignant tumors. We investigated the possible anti-inflammatory effect of nicaraven on slowing tumor growth. Tumor-bearing mice randomly received nicaraven injection (50 mg/kg daily, i.p, n = 8) or placebo treatment (n = 8) for 10 days, and then sacrificed for evaluations. Nicaraven administration effectively inhibited the fast growth of tumor, as a large tumor (> 1.0 g) developed finally in three of the eight mice received placebo treatment. Cytokines/chemokines array indicated that nicaraven reduced the levels of CXCL10 and SDF-1 in the tumor as well as the levels of IL-2 and MIP-2 in serum. Immunofluorescence staining showed that nicaraven significantly reduced the recruitment of macrophages and neutrophils in the tumor. Interestingly, western blot indicated that the expression of CD86, CD206, and NIMP-R14 was especially enhanced in the three large-size tumors, suggesting the potential role of nicaraven in preventing the hyper-inflammatory tumor microenvironment. Moreover, the expression of PARP-1 was downregulated, but the expression of phospho-p38 MAPK, phospho-MKK-3/6, and phospho-MSK-1 was upregulated in the large-size tumors, suggesting the involvement of p38 MAPK pathway in the anti-inflammatory effect of nicaraven. Taken together, our study suggests that nicaraven may effectively prevent the fast growth of inflamed tumors by an anti-inflammatory mechanism.

Intratumoral heterogeneity in cancer progression and response to immunotherapy

Most (if not all) tumors emerge and progress under a strong evolutionary pressure imposed by trophic, metabolic, immunological, and therapeutic factors. The relative impact of these factors on tumor evolution changes over space and time, ultimately favoring the establishment of a neoplastic microenvironment that exhibits considerable genetic, phenotypic, and behavioral heterogeneity in all its components. Here, we discuss the main sources of intratumoral heterogeneity and its impact on the natural history of the disease, including sensitivity to treatment, as we delineate potential strategies to target such a detrimental feature of aggressive malignancies.

Neutrophil diversity and plasticity in tumour progression and therapy

Neutrophils play a key role in defence against infection and in the activation and regulation of innate and adaptive immunity. In cancer, tumour-associated neutrophils (TANs) have emerged as an important component of the tumour microenvironment. Here, they can exert dual functions. TANs can be part of tumour-promoting inflammation by driving angiogenesis, extracellular matrix remodelling, metastasis and immunosuppression. Conversely, neutrophils can also mediate antitumour responses by direct killing of tumour cells and by participating in cellular networks that mediate antitumour resistance. Neutrophil diversity and plasticity underlie the dual potential of TANs in the tumour microenvironment. Myeloid checkpoints as well as the tumour and tissue contexture shape neutrophil function in response to conventional therapies and immunotherapy. We surmise that neutrophils can provide tools to tailor current immunotherapy strategies and pave the way to myeloid cell-centred therapeutic strategies, which would be complementary to current approaches.

[Determination of glucoamylase activity using an enzyme electrode]

Both, the differing definitions of glucoamylase activity and the different determination of the fragment, glucose, preclude a comparison of literature data. Specific enzymatic determination of the fragment, glucose, with an enzyme electrode is proposed. The contribution describes the manufacture of an enzyme electrode from a commercial pO2-electrode and immobilized GOD. The measurement may be carried out by kinetic determination of utilized oxygen or oxygen peroxide formed. The continuous measurement proposed for serial experiments is made via a calibration curve, whose regression coefficient was determined to be 0.999. Depending on the enzyme activity, the reaction time is between 15 s and 3 min.