Generation and characterisation of an estrogen receptor-positive GEMM-derived Pten p53 null transplantable breast tumour model for therapeutic testing

Assessing the signalling pathway dependencies of tumours that arise autochthonously in genetically engineered mouse models (GEMMs) of breast cancer is particularly challenging due to the high degree of intra- and inter-tumour heterogeneity, as well as the long latency of tumour development in such models. Use of transplantable tumour lines derived from autochthonous tumours (‘Mouse Derived Xenografts’ or MDXs) is one possible solution and has been used successfully in models of BRCA1-associated triple negative breast cancer. However, their potential in ER+ breast cancer models has not been addressed. Here, we assess the utility of orthotopic transplantable tumour lines derived from an autochthonous ER+ Blg-cre Ptenfl/fl p53fl/fl breast cancer model. We show that initial tumour implantation and early passage results in the development of lines of progeny with heterogeneous histopathological phenotypes which is coincident with an accumulation of, or selection for, de novo mutations. Importantly, these lines also display different dependencies on the key pathways that drive tumourigenesis, which can lead to inherent resistance to treatment with pharmacological agents targeting these pathways and makes them important models to test strategies to overcome such resistance.

The Role of Hvem and its Interaction with Btla and Cd160 in b-Cell Lymphoma Progression

SUMMARYDespite the fact that the cell surface receptor HVEM (TNFRSF14) appears to be implicated in the development and progression of B-cell lymphomas, its specific role in these tumours is still unclear. On the one hand, HVEM over-expression is related to worse prognosis in some types of B-cell lymphoma and other solid tumours. On the other hand, most mutations of HVEM in B-cell lymphomas are thought to promote tumour growth through the loss of function. Here, we used a CRISPR-Cas9 system to study the effect of HVEM loss on gene expression in a murine model of A20 B-cell lymphoma (belonging to the diffuse large B-cell lymphoma group). We show that loss of HVEM does not affect the doubling rate of A20 tumour cells in culture, but leads to a decrease in BTLA expression. HVEM-deficient A20 cells do not present a different pattern of metastatic dissemination to lymphoid organs compared with unmodified A20 cells. However, we observed a significant expansion of endogenous B-cells as a result of A20 tumour implantation in the thymus. Although we found no differences in the dissemination or progression of HVEM-deficient A20 cells, our results reveal that loss of HVEM alters the leukocyte recruitment capacity of A20 cells in hepatic tumour nodules at the intermediate stage of tumour development, which may be of relevance as a mechanism of immune evasion.

Surgical Trauma Leads to a Shorter Survival in a Murine Orthotopic Pancreatic Cancer Model

Background: Abdominal surgery is frequently followed by immune dysfunction usually lasting for several days. This is especially important in cases with tumour diseases as an intact immune function is essential in this situation. Therefore, we analysed the outcome of tumour-bearing mice in a mouse model of surgically induced immune dysfunction (SID). Methods: In male C57BL/6 mice, a pancreatic tumour was implanted orthotopically. Following tumour implantation, the model of SID was applied. The control groups were either laparotomised or underwent no surgical procedure. The survival rate was determined by observation for >60 days. The tumour growth progress was imaged by a 7-tesla small animal MRI. Results: On day 60 after tumour implantation, the survival rate in SID mice was reduced to 41%. In the laparotomised group, 81% of mice survived, while the control group had a survival rate of 75%. These differences were significant (SID vs. control: p < 0.02, and SID vs. laparotomy: p < 0.002). The tumour volume was not influenced by the degree of surgical trauma. Conclusion: In pancreatic cancer, the SID model is ideally suited to investigate the influence of SID on this tumour entity.

Neoadjuvant Therapy in Pancreatic Cancer: An Emerging Strategy

Pancreatic adenocarcinoma (PDAC) is the fourth leading cause of cancer deaths among men and women, being responsible for 6% of all cancer-related deaths. Surgical resection offers the only chance of cure, but only 15 to 20 percent of cases are potentially resectable at presentation. In recent years, increasing evidences support the use of neoadjuvant strategies in pancreatic cancer in patients with resectable pancreatic cancer as well as in patients with borderline resectable or locally advanced PDAC in order to allow early treatment of micrometastatic disease, tumour regression, and reduced risk of peritoneal tumour implantation during surgery. Furthermore, neoadjuvant treatment allows evaluation of tumour response and increases patient’s compliance. However, most evidences in this setting come from retrospective analysis or small case series and in many studies chemotherapy or chemoradiation therapies used were suboptimal. Currently, prospective randomized trials using the most active chemotherapy regimens available are trying to define the real benefit of neoadjuvant strategies compared to conventional adjuvant strategies. In this review, the authors examined available data on neoadjuvant treatment in patients with resectable pancreatic cancer as well as in patients with borderline resectable or locally advanced PDAC and the future directions in this peculiar setting.

Heterogeneous time-dependent response of adipose tissue during the development of cancer cachexia

Cancer cachexia induces loss of fat mass that accounts for a large part of the dramatic weight loss observed both in humans and in animal models; however, the literature does not provide consistent information regarding the set point of weight loss and how the different visceral adipose tissue depots contribute to this symptom. To evaluate that, 8-week-old male Wistar rats were subcutaneously inoculated with 1 ml (2×107) of tumour cells (Walker 256). Samples of different visceral white adipose tissue (WAT) depots were collected at days 0, 4, 7 and 14 and stored at −80 °C (seven to ten animals/each day per group). Mesenteric and retroperitoneal depot mass was decreased to the greatest extent on day 14 compared with day 0. Gene and protein expression of PPARγ2 (PPARG) fell significantly following tumour implantation in all three adipose tissue depots while C/EBPα (CEBPA) and SREBP-1c (SREBF1) expression decreased over time only in epididymal and retroperitoneal depots. Decreased adipogenic gene expression and morphological disruption of visceral WAT are further supported by the dramatic reduction in mRNA and protein levels of perilipin. Classical markers of inflammation and macrophage infiltration (f4/80, CD68 and MIF-1α) in WAT were significantly increased in the later stage of cachexia (although showing a incremental pattern along the course of cachexia) and presented a depot-specific regulation. These results indicate that impairment in the lipid-storing function of adipose tissue occurs at different times and that the mesenteric adipose tissue is more resistant to the ‘fat-reducing effect’ than the other visceral depots during cancer cachexia progression.

Antitumor and anti-inflammatory activities of polysaccharides isolated from Ganoderma lucidum

Antitumor and anti-inflammatory activities of polysaccharides isolated fromGanoderma lucidumIn this study, polysaccharides were isolated fromGanoderma lucidum (Polyporaceae)and their antitumor and anti-inflammatory activities were investigated usingin vivomodels. Potential antitumor activity was shown byG. lucidumpolysaccharides (GLP) against solid tumor induced by Ehrlich's ascites carcinoma cells. GLP at 100 mg kg-1body mass showed 80.8 and 77.6 % reduction in tumour volume and tumour mass, respectively, when administered 24 h after tumour implantation. Again, GLP at the same dose but when administered prior to tumour inoculation, showed 79.5 and 81.2 % inhibition of tumour volume and tumour mass, respectively. GLP showed significant dose-dependent activity in carrageenean-induced (acute) and formalin-induced (chronic) inflammation assays. At 100 mg kg-1, GLP exhibited 57.6 and 58.2 % inhibition in carrageenean-induced and formalin-induced assays, respectively.