A biophysical approach to the optimisation of dendritic-tumour cell electrofusion

Electrofusion of tumour and dendritic cells (DCs) is a promising approach for production of DC-based anti-tumour vaccines. Although human DCs are well characterised immunologically, little is known about their biophysical properties, including dielectric and osmotic parameters, both of which are essential for the development of efficient electrofusion protocols. In the present study, human DCs from the peripheral blood along with a tumour cell line used as a model fusion partner were examined by means of time-resolved cell volumetry and electrorotation. Based on the biophysical cell data, the electrofusion protocol could be rapidly optimised with respect to the sugar composition of the fusion medium, duration of hypotonic treatment, frequency range for stable cell alignment, and field strengths of breakdown pulses triggering membrane fusion. The hypotonic electrofusion consistently gave a tumour-DC hybrid rate of up to 19%, as determined by counting dually labelled fluorescent hybrids in a microscope. This fusion rate is nearly twice as high as that usually reported in the literature for isotonic media. The experimental findings and biophysical approach presented here are generally useful for the development of efficient electrofusion protocols, especially for rare and valuable human cells.     

Approaching tumour therapy beyond platinum drugs: status of the art and perspectives of ruthenium drug candidates

The study of metal complexes for the treatment of cancer diseases has resulted in the identification of some unique properties of ruthenium-based compounds. Among these inorganic-based agents, two of them, namely the ruthenium(III) drugs NAMI-A and KP1019 have undertaken with some success the clinical evaluations of phase I and preliminary phase II trials in patients. Here we highlight the strategies that have led to the discovery of metal-based (NAMI-A and KP1019) and of organometallic (RM175, RAPTA-T, RDC11 and DW1/2) ruthenium-based complexes, and we report their main biological/pharmacological characteristics and expectations for further development.     

Mast cells, angiogenesis, and tumour growth

Accumulation of mast cells (MCs) in tumours was described by Ehrlich in his doctoral thesis. Since this early account, ample evidence has been provided highlighting participation of MCs to the inflammatory reaction that occurs in many clinical and experimental tumour settings. MCs are bone marrow-derived tissue-homing leukocytes that are endowed with a panoply of releasable mediators and surface receptors. These cells actively take part to innate and acquired immune reactions as well as to a series of fundamental functions such as angiogenesis, tissue repair, and tissue remodelling. The involvement of MCs in tumour development is debated. Although some evidence suggests that MCs can promote tumourigenesis and tumour progression, there are some clinical sets as well as experimental tumour models in which MCs seem to have functions that favour the host. One of the major issues linking MCs to cancer is the ability of these cells to release potent pro-angiogenic factors. This review will focus on the most recent acquisitions about this intriguing field of research. This article is part of a Special Issue entitled: Mast cells in inflammation.     

Assessment of the humoral immune response to cancer

One of the deadly hallmarks of cancer is its ability to prosper within the constraints of the host immune system. Recent advances in immunoproteomics and high-throughput technologies have lead to profiling of the antibody repertoire in cancer patients. This in turn has lead to the identification of tumour associated antigens/autoantibodies. Autoantibodies are extremely attractive and promising biomarker entities, however there has been relatively little discussion on how to interpret the humoral immune response. It may be that autoantibody profiles hold the key to ultimately uncovering neoplastic associated pathways and through the process of immunosculpting the tumour may have yielded an immune response in the early stages of malignant tumour development. The aim of this review is to discuss the utility of the autoantibody response that is elicited as a result of malignancy and discuss the advantages and limitations of autoantibody profiling. This article is part of a Special Issue entitled: Translational Proteomics.     

DNA tumour viruses promote tumour cell invasion and metastasis by deregulating the normal processes of cell adhesion and motility

Approximately 15-20% of global cancer incidence is causally linked to viral infection, yet the low incidence of cancers in healthy infected individuals suggests that malignant conversion of virus-infected cells occurs after a long period as a result of additional genetic modifications. There are four families of viruses that are now documented to be involved in the development of human cancers which include members of the polyomavirus, hepadnavirus, papillomavirus and herpesvirus families. Although a number of these viruses are implicated in the aetiology of lymphomas or leukaemias, the vast majority are associated with malignancies of epithelial cells. In epithelial tissues, several classes of proteins are involved in maintaining tissue architecture, including those that promote cell-cell adhesion, and others, which mediate cell-matrix interactions. Proteins representative of all classes are frequently altered in malignant tumour cells that possess invasive and metastatic properties. Malignant tumour cells acquire mechanisms to degrade basement membranes and invade the underlying tissue. Many viruses encode proteins which engage signalling pathways that affect one or more of these mechanisms. It is believed that activation of these processes by chronic viral infection can, under certain circumstances, promote tumour cell invasion and metastasis. This review will take a brief look at the current knowledge of viral-induced alterations in cell motility and invasiveness in the context of tumour invasion and metastasis.     

The construction and in vitro testing of photo-activatable cancer targeting folated anti-CD3 conjugates

The construction and in vitro testing of a photo-activatable anti-tumour immuno-regulatory antibody is described. In this ‘cloaked’ folated anti-CD3 antibody conjugate, the folate portion of the conjugate is free to bind to folate receptor expressing cancer cells, whilst the anti-CD3 activity is effectively rendered inert by a coating of photo-labile 2-nitrobenzyl groups. On irradiation with UV-A light the activity of the anti-CD3 antibody is restored, not only when it is required, but more importantly, only where it is required. The conjugate can then attract killer T-cells to the surface of the tumour cells and kill them. Unirradiated normal tissues, to which the conjugate has been targeted by specific and non-specific binding, remain unharmed. We believe that these ‘photo-switchable’ conjugates could be used to markedly improve the targeting of the immune response to folate receptor (FR) expressing ovarian and breast cancers whilst minimising the side effects in the rest of the body.     

Photodynamic therapy of murine fibrosarcoma with topical and systemic administration of Hypericin

The in vivo antitumour activity of the natural photosensitizer hypericin was evaluated. C3H/DiSn mice inoculated with fibrosarcoma G5:1:13 cells were intraperitoneally or intratumourally injected with hypericin (5 mg/kg) and 2 hours later the mice were locally irradiated with laser light (488 nm, 150 mW/cm2, 180 J/cm2) when the tumour reached volume of 40-80 mm3 (approximately 17 days after inoculation). Tumours treated with hypericin alone as well as those irradiated with laser light alone have similar growth rates and none of these tumours regressed spontaneously. The mean tumour volume in hypericin-PDT treated groups was significantly lower in comparison to that found in the control group 3-5 weeks after the therapy. A higher proportion of animals with tumour volume less than 5-fold of the initial volume has been observed in both hypericin-PDT treated groups. Complete response to PDT has been observed for 44.4% of the animals with intraperitoneally administered hypericin and for 33.3% of the animals with intratumourally administered hypericin. Complete remission occurred in treated lesions with 3 mm or less in height. Hypericin-PDT significantly increased survival. However, no statistically significant difference in survival rate of animals has been found between the intratumoural and the intraperitoneal schedule of administration of hypericin.     

Optimization of permeability in a series of pyrrolotriazine inhibitors of IRAK4

We have developed a series of orally efficacious IRAK4 inhibitors, based on a scaffold hopping strategy and using rational structure based design. Efforts to tackle low permeability and high efflux in our previously reported pyrrolopyrimidine series (Scott et al., 2017) led to the identification of pyrrolotriazines which contained one less formal hydrogen bond donor and were intrinsically more lipophilic. Further optimisation of substituents on this pyrrolotriazine core culminated with the discovery of 30 as a promising in vivo probe to assess the potential of IRAK4 inhibition for the treatment of MyD88 mutant DLBCL in combination with a BTK inhibitor. When tested in an ABC-DLBCL model with a dual MyD88/CD79 mutation (OCI-LY10), 30 demonstrated tumour regressions in combination with ibrutinib.     

前哨淋巴结检测方法及其在肿瘤中的研究进展

前哨淋巴结(sentinel lymph node,SLN)是肿瘤淋巴结转移的第一站,SLN活检肿瘤阳性的患者需要做系统性淋巴结清扫;SLN活检阴性的患者,不需要做系统性淋巴结清扫,可以缩短手术时间,降低手术费用,减少手术并发症;目前识别SLN的方法包括生物活性染料示踪法,放射性核素示踪法,联合示踪法,纳米炭(carbon nanoparticles,CNP)标记前哨淋巴结活检技术以及吲哚菁绿(Indocyanine Green,ICG)荧光标记法。SLN活检技术在乳腺癌、甲状腺癌、胃癌、恶性黑色素瘤、宫颈癌、子宫内膜癌等肿瘤中皆有不同程度的研究。本文通过复习文献,对前哨淋巴结检测方法予以归纳及其在常见肿瘤中的研究进展予以综述,旨在为恶性肿瘤临床治疗提供参考。