Reduction of Rapid Proliferating Tumour Cell Lines by Inhibition of the Specific Glycine Transporter GLYT1

Studies have highlighted the relevance of extracellular glycine and serine in supporting high growth rates of rapidly proliferating tumours. The present study analysed the role of the specific glycine transporter GLYT1 in supplying glycine to cancer cells and maintaining cell proliferation. GLYT1 knockdown in the rapidly proliferating tumour cell lines A549 and HT29 reduced the number of viable cells by approximately 30% and the replication rate presented a decrease of about 50% when compared to cells transfected with control siRNA. In contrast, when compared to control, GLYT1 siRNA had only a minimal effect on cell number of the slowly proliferating tumour cell line A498, reducing the number of viable cells by 7% and no significant difference was observed when analysing the replication rate between GLYT1 knockdown and control group. When utilising a specific GLYT1 inhibitor, ALX-5407, the doubling time of rapidly proliferating cells increased by about 8 h presenting a significant reduction in the number of viable cells after 96 h treatment when compared to untreated cells. Therefore, these results suggest that GLYT1 is required to maintain high proliferation rates in rapidly proliferating cancer cells and encourage further investigation of GLYT1 as a possible target in a novel therapeutic approach.

Immunohistochemical Evaluation of Adaptor Protein FAM159B Expression in Normal and Neoplastic Human Tissues

FAM159B is a so-called adaptor protein. These proteins are essential components in numerous cell signalling pathways. However, little is known regarding FAM159B expression in normal and neoplastic human tissues. The commercially available rabbit polyclonal anti-human FAM159B antibody HPA011778 was initially characterised for its specificity using Western blot analyses and immunocytochemistry and then applied to a large series of formalin-fixed, paraffin-embedded normal and neoplastic human tissue samples. Confirmation of FAM159B’s predicted size and antibody specificity was achieved in BON-1 cells, a neuroendocrine tumour cell line endogenously expressing FAM159B, using targeted siRNA. Immunocytochemical experiments additionally revealed cytoplasmic expression of the adaptor protein. Immunohistochemical staining detected FAM159B expression in neuronal and neuroendocrine tissues such as the cortex, the trigeminal ganglia, dorsal root and intestinal ganglia, the pancreatic islets and the neuroendocrine cells of the bronchopulmonary and gastrointestinal tract, but also in the syncytiotrophoblasts of the placenta. FAM159B was also expressed in many of the 28 tumour entities investigated, with high levels in medullary and anaplastic thyroid carcinomas, parathyroid adenomas, lung and ovarian carcinomas, lymphomas and neuroendocrine tumours of different origins. The antibody HPA011778 can act as a useful tool for basic research and identifying FAM159B expression in tissue samples.

Characterization of bioactive substances MHGF-68 on tumour cell lines with LiveFlow In Vitro Technology

As part of experimental research, growth factor-like substances associated with MHV-68, named MHGF-68, were discovered in our laboratory. MHGF-68 activity was manifested by the ability to alter cell morphology, that is, normal phenotype to transformed, resp. suppresses the transformed phenotype of tumour cells. The aim of the experiments was to monitor the effect of MHGF-68 on the change of the cell actin cytoskeleton in the tumour cell line Hepa1c1c7, as well as the normal cell line NIH3T3, and compare conventional stationary cultivation and dynamic cultivation conditions using a LiveFlow system (In Vitro Technologies). LiveFlow is an advanced system to test the impact of different compounds on the cell cultures, which allows simulation of in vivo conditions thanks to continuous flow of cultivation medium. MHGF-68 was prepared with the infection of BHK-21 cells with MHV-68 virus under non-permissive conditions (41°C). After dynamic cultivation with MHGF-68, we observed changes in morphology on Hepa1c1c7 cells. In cells cultured in a dynamic environment, we observed more pronounced changes in cell morphology in comparison with cells cultured statically. We observed no changes in the cytoskeletal structures in the NIH 3T3 cell line affected by MHGF-68 in both types of cultivation. The advantage of LiveFlow in comparison to in vivo testing is that the experiments performed in this system are less time and money consuming. Dynamic cultivation in the LiveFlow system is suitable for optimizing experiments before testing substances in vivo.

Sox11 regulates mammary tumour-initiating and metastatic capacity in Brca1-deficient mouse mammary tumour cells

ABSTRACT Little is known about the role of Sox11 in the regulation of mammary progenitor cells. Sox11 is expressed by mammary bud epithelial cells during embryonic mammary gland development and is not detected in mammary epithelial cells after birth. As Sox11 is an oncofetal gene, we investigated the effects of reducing Sox11 levels in embryonic mammary progenitor cells and found that Sox11 regulates proliferative state, stem cell activity and lineage marker expression. We also investigated the effect of reducing Sox11 levels in two transplantable Brca1-deficient oestrogen receptor-negative mouse mammary tumour cell lines, to assess whether Sox11 regulates similar functions in tumour progenitor cells. When Sox11 levels were reduced in one Brca1-deficient mammary tumour cell line that expressed both epithelial and mesenchymal markers, similar effects on proliferation, stem cell activity and expression of lineage markers to those seen in the embryonic mammary progenitor cells were observed. Orthotopic grafting of mammary tumour cells with reduced Sox11 levels led to alterations in tumour-initiating capacity, latency, expression of lineage markers and metastatic burden. Our results support a model in which tumours expressing higher levels of Sox11 have more stem and tumour-initiating cells, and are less proliferative, whereas tumours expressing lower levels of Sox11 become more proliferative and capable of morphogenetic/metastatic growth, similar to what occurs during embryonic mammary developmental progression.

First report on establishment and characterization of a carcinosarcoma tumour cell line model of the bladder

Carcinosarcoma of the urinary bladder is a very rare and aggressive subtype of bladder cancer with poor prognosis. Characteristically carcinosarcomas exhibit biphasic nature with both epithelial and mesenchymal differentiation. Limited information is available regarding its clinical features and appropriate treatments due to its rarity. Development of tumour models can further our understanding of bladder carcinosarcoma. We report establishment and characterization of the first-ever bladder carcinosarcoma cell line MaS-3. It is established by the outgrow method from 86 year-old caucasian male who underwent a radical pelvic resection after neoadjuvant radiotherapy. MaS-3 showed carcinosarcoma profile with high conformity with to the original tumour in terms of immunocytochemistry. Proteome analysis also aligned the MaS-3 cell line with the carcinosarcoma specimen rather than corresponding non-malignant tissue. Chemotherapy sensitivity testing revealed a great sensitivity of MaS-3 growth to 5-Fluorouracil, Gemcitabine and Cisplatin, with almost no impact of Irinotecan. Additionally, the suitability of MaS-3 for 3D in vitro experiments was also demonstrated. The newly established cell line MaS-3 shows typical characteristics of the tumour and may thus be a useful in vitro model system for studying the tumour biology and developing future of treatments of this rare but very aggressive entity.

Extensive variability in the composition of immune infiltrate in different mouse models of cancer

Mouse models are invaluable tools for cancer immunology research. However, there are differences in the immune response to the tumour depending on the model used, and these differences are not often characterised on their own. Instead they are often only analysed in response to a therapeutic immune modulation. There are important issues with translatability into effective clinical research when considering the choice of mouse models. Here we analysed the tumour immune microenvironment and modified aspects of the tumour model to determine the effect on the composition of the immune infiltrate. Mice injected subcutaneously with the melanoma cell line, B16-OVA, had a higher frequency of T cells, especially CD8+ T cells, than mice injected subcutaneously with CT26 colorectal adenocarcinoma cells. We compared the same tumour cell line (CT26) delivered either subcutaneously and intracaecally. To minimise immunological impacts due to the invasive surgery procedure, we optimised an existing intracaecal injection protocol. Intracaecal tumours had a higher frequency of infiltrating CD3+ CD4+ T cells and a lower frequency of CD3-CD19- (putative NK cells) than subcutaneous tumours. In contrast, there was a higher frequency of F480+ macrophages in subcutaneous tumours than intracaecal tumours. These data demonstrate that variability between animals, between experiments and within tumour models, can lead to difficulty in interpreting the infiltrating immune response and translating this response to clinical research.

The vitamin D analogue calcipotriol promotes an anti-tumorigenic phenotype of human pancreatic CAFs but reduces T cell mediated immunity

The pancreatic tumour stroma is composed of phenotypically heterogenous cancer-associated fibroblasts (CAFs) with both pro- and anti-tumorigenic functions. Here, we studied the impact of calcipotriol, a vitamin D3 analogue, on the activation of human pancreatic CAFs and T cells using 2- and 3-dimensional (2D, 3D) cell culture models. We found that calcipotriol decreased CAF proliferation and migration and reduced the release of the pro-tumorigenic factors prostaglandin E2, IL-6, periostin, and leukemia inhibitory factor. However, calcipotriol promoted PD-L1 upregulation, which could influence T cell mediated tumour immune surveillance. Calcipotriol reduced T cell proliferation and production of IFN-γ, granzyme B and IL-17, but increased IL-10 secretion. These effects were even more profound in the presence of CAFs in 2D cultures and in the presence of CAFs and pancreatic tumour cell line (PANC-1) spheroids in 3D cultures. Functional assays on tumour infiltrating lymphocytes also showed a reduction in T cell activation by calcipotriol. This suggests that calcipotriol reduces the tumour supportive activity of CAFs but at the same time reduces T cell effector functions, which could compromise the patients’ tumour immune surveillance. Thus, vitamin D3 analogues appear to have dual functions in the context of pancreatic cancer, which could have important clinical implications.

Exploration of the Electrophilic Reactivity of the Cytotoxic Marine Alkaloid Discorhabdin C and Subsequent Discovery of a New Dimeric C-1/N-13-Linked Discorhabdin Natural Product

The cytotoxic marine natural product discorhabdin C contains a 2,6-dibromo-cyclohexa-2,5-diene moiety, previously proposed to be a critical feature required for biological activity. We have determined that the dienone-ring of discorhabdin C is indeed electrophilic, reacting with thiol and amine nucleophiles, affording debrominated adducts. In the case of reaction with 1-aminopentane the product contains an unusual C-2/N-18 ring closed, double-hydrate moiety. This electrophilic reactivity also extends to proteins, with lysozyme-discorhabdin C adducts being detected by ESI mass spectrometry. These results prompted further examination of an extract of discorhabdin C-producing sponge, Latrunculia (Latrunculia) trivetricillata, leading to the isolation and characterisation of a new example of a C-1/N-13 linked discorhabdin dimer that shared structural similarities with the 1-aminopentane-discorhabdin C adduct. To definitively assess the influence of the dienone moiety of discorhabdin C on cytotoxicity, a semi-synthetic hydrogenation derivative was prepared, affording a didebrominated ring-closed carbinolamine that was essentially devoid of tumour cell line cytotoxicity. Antiparasitic activity was assessed for a set of 14 discorhabdin alkaloids composed of natural products and semi-synthetic derivatives. Three compounds, (-)-discorhabdin L, a dimer of discorhabdin B and the discorhabdin C hydrogenation carbinolamine, exhibited pronounced activity towards Plasmodium falciparum K1 (IC50 30–90 nM) with acceptable to excellent selectivity (selectivity index 19–510) versus a non-malignant cell line.

Synthesis and cytotoxic evaluation of gum arabic surface modified cadmium telluride quantum dots

Water-soluble cadmium telluride (CdTe) quantum dots (QDs) were capped with gum Arabic (GA) is a non-toxic, water-soluble glycoprotein polymer commonly used in the food and pharmaceutical industries. The GA was used to stabilise cadmium telluride quantum dots (GA-QDs) and provides functional groups for other molecules such as nucleic acids, peptides and antibodies to be attached to the QDs for biological and biomedical appli- cations. In this study, the GA was used to cap and stabilise QDs using two different methods. These QDs were characterised using Ultraviolet-visible (UV-vis) and Photoluminescence (PL) spectroscopy, X-powder ray diffraction (XRD), High-resolution transmission electron microscopy, zeta potential and particle size distribu- tions. Cytotoxicity of these QDs was also investigated using four different human cell lines; HeLa, MCF-7, PC-3 and U87 cancer cells. The QDs-MPA was capped with 3-mercaptopropionic acid, QDs-GA2 was stabilized and capped with GA at 60 °C for two hours, and QDs-GA12 was stabilized and capped with GA for twelve hours at room temperature (25 °C) with continuous stirring; These QDs were found to be highly luminescent with PL values of 675 nm, 678 nm and 677 nm respectively. The average polydispersity index (PDI) were 0.36 ± 0.02, 0.27 ± 0.02, 0.35 ± 0.01 for QDs-MPA, QDs-GA2 and QDs-GA12, respectively. The average particles size from HRTEM, XRD and hydrodynamic size showed that the QDs-GA have bigger particles sizes; (56.12 nm ± 1.14), (68.69 nm ± 2.08) and (77.85 nm ± 1.69) for QDs-MPA, QD-GA2 and QD-GA12 respectively. Cytotoxicity studies of these QDs were carried out using WST-1 cell proliferation assay on four different tumour cell line. The results showed that these cells were over 50 per cent viable and the QDs-GA capped had higher cell percentage viability.