A Feedback Control Model of Comprehensive Therapy for Treating Immunogenic Tumours

Surgery is the traditional method for treating cancers, but it often fails to cure patients for complex reasons so new therapeutic approaches that include both surgery and immunotherapy have recently been proposed. These have been shown to be effective, clinically, in inhibiting cancer cells while allowing retention of immunologic memory. This comprehensive strategy is guided by whether a population of tumour cells has or has not exceeded a threshold density. Conditions for successful control of tumours in an immune tumour system were modeled and the related dynamics were addressed. A mathematical model with state-dependent impulsive interventions is formulated to describe combinations of surgery with immunotherapy. By analyzing the properties of the Poincaré map, we examine the global dynamics of the immune tumour system with state-dependent feedback control, including the existence and stability of the semi-trivial order-1 periodic solution and the positive order-[Formula: see text] periodic solution. The main results showed that surgery alone can only control the tumour size below a certain level while there is no immunologic memory. If comprehensive therapy involving combining surgery with immunotherapy is considered, then not only can the cancers be controlled below a certain level, but the immune system can also retain its activity. The existence of positive order-[Formula: see text] periodic solutions implies that periodical therapy is needed to control the cancers. However, choosing the treatment frequency and the strength of the therapy remains challenging, and hence a strategy of individual-based therapy is suggested.

In SilicoModelling of Treatment-Induced Tumour Cell Kill: Developments and Advances

Mathematical and stochastic computer (in silico) models of tumour growth and treatment response of the past and current eras are presented, outlining the aims of the models, model methodology, the key parameters used to describe the tumour system, and treatment modality applied, as well as reported outcomes from simulations. Fractionated radiotherapy, chemotherapy, and combined therapies are reviewed, providing a comprehensive overview of the modelling literature for current modellers and radiobiologists to ignite the interest of other computational scientists and health professionals of the ever evolving and clinically relevant field of tumour modelling.

Вплив реній-платинової системи у вигляді наноліпосом на проліферативну активність ракових клітин

Decrease of proliferative activity of the cells of Guerin’s carcinoma T8 in the different conditions of administration of the Rhenium-Platinum anti-tumour system as nanolyposomes is shown. The Rhenium-Platinum anti-tumour system influenced on the morphological indices of tumour tissue. The cluster rhenium compounds reduced the indices of pathological mitoses 3.0–3.6 times in comparison with a control group. The amount of PCNA-positive cells under the Rhenium-Platinum system treatment went down by 82.5–84.5 %. The anti-tumour system led to the predominance of apoptotic cell death over the necrotic one. The most effective agent was the compound with cis-adamantan organic ligand cis-Re2(C10H15COO)2Cl4·2DMSO introducted on the 9th day.

A discoordinate increase in the cellular amount of 3-hydroxy-3-methylglutaryl-CoA reductase results in the loss of rate-limiting control over cholesterogenesis in a tumour cell-free system

Cholesterol biosynthesis was characterized in cell-free post-mitochondrial supernatant systems prepared from both normal rat liver and Morris hepatoma 3924A. The rate of cholesterol synthesis per cell was 9-fold greater in the tumour system than in that from normal liver, and the tumour systems showed the loss of rate-limiting control at the hydroxymethylglutaryl-CoA reductase (HMGR)-catalysed step. The apparent absence of rate-limiting control over cell-free tumour cholesterogenesis was traced primarily to a discoordinate and dramatic increase in the amount of HMGR in the tumour relative to the liver system. Preliminary evidence for an altered control of the post-lanosterol portion of the pathway was also obtained with the tumour system.