Retinoic acid-loaded PLGA nanocarriers targeting cell cholesterol potentialize the antitumour effect of PD-L1 antibody by preventing epithelial-mesenchymal transition mediated by M2-TAM in colorectal cancer.

Tumour-associated macrophages (TAMs) often promote cancer progression through immunosuppression in the tumour microenvironment (TME). However, the signalling pathways crosstalk responsible for this mechanism remain unclear. The aim of our study was to investigate whether the interaction between TAMs and colorectal cancer cells could be down-regulated by nanoparticles (NPs) loaded with retinoic acid (RA) and coated with cholesterol (CHO), in combination with an anti-PD-L1 immune checkpoint inhibitor. Tumours were evaluated by qRT-PCR and immunohistochemistry from allographic tumour growth model. In addition, human tumours were evaluated by Tissue Microarray (TMA) and immunohistochemistry. Complementary analysis of epithelial-mesenchymal transition, cell migration, and macrophage polarisation were evaluated in vitro. We showed that the IL-10R/IL-10 axis is involved in overstimulation of the STAT3 pathway as well as downregulation of the NF-κB signalling pathway, which supports a loop of immunosuppressive cytokines that induces the M2-TAM phenotype. Furthermore, our combined findings suggest that the upregulation of STAT3/NF-κB pathways crosstalk mediated by immunosuppressive cytokines, such as IL-10/PD-L1/TGF-ß, via M2-TAMs in the TME, leads to immunosuppression and epithelial-mesenchymal-transition of the colorectal cancer for stimulating Vimentin, CXCL12 and CD163 in the primary tumours. Importantly, NPs holding RA and coated with CHO in combination with anti-PD-L1 were more efficient in blocking this signalling pathway. These results contribute to our understanding of the immunological mechanisms, especially the re-educating of TAMs, and provide a novel management strategy for aggressive colorectal cancers using anti-PD-L1-conjugated nanocarriers.

Telmisartan decreases inflammation by modulating TNF-α, IL-10, and RANK/RANKL in a rat model of ulcerative colitis.

BACKGROUND: Telmisartan is an antihypertensive angiotensin II receptor blocker. This antihypertensive shows antiinflammatory activity. PURPOSE: In this study, the antiinflammatory activity of telmisartan was tested in an acetic acid (10%) model of ulcerative colitis (UC) in rats. METHODS: Rats were given 1, 3, and 5mg/kg/day of telmisartan orally for 3 days before induction of UC. The same doses were also administered 2 and 24h after induction. Rats from the non-colitis and non-treated colitis groups were administered vehicle (saline, 5 ml/kg) orally and another group received sulfasalazine (50mg/kg/day). Colons tissue was analyzed by macroscopic, by histopathology, by the immunohistochemical examination of RANKL/RANK pathway; by ELISA analysis of the levels of IL-10, TNF-α, myeloperoxidase (MPO) and malonaldehyde (MDA). RESULTS: Telmisartan at 5mg/kg reduced levels of MPO, MDA, TNF-α and increased of IL-10 (p<0.05). Additionally, telmisartan reduced macroscopic damage, number of ulcers, and inflammatory and histopathological processes such as neutrophil infiltration, changes in cytoarchitecture, and necrosis. Immunohistochemistry revealed down-regulation of nuclear factor-kappaB receptor/nuclear factor-kappaB ligand (RANK/RANKL) in groups treated with sulfasalazine or telmisartan. CONCLUSION: Telmisartan exerts beneficial effects in an acetic acid model of colitis in rats. These effects may be due to accelerated termination of the acute inflammatory phase, indicated by decreased TNF-α and increased production of IL-10 and low expression of RANKL and RANK.

Lifestyle and family history influence cancer prognosis in Brazilian individuals.

The aim of this research was to study prognostic parameters of CRC by analyzing clinical and pathological variables associated with cancer patients at a northeastern Brazilian Hospital. This was a retrospective study evaluating CRC-diagnosed patients across a 10-year period (1995-2005) at Dr. Luiz Antônio Hospital in Natal, RN, Brazil. Data were collected from patients' medical files. A total of 358 patients were included over the 10-year period. The average age at diagnosis was 58.8 years (S.D.=15.26), 48.3% of the patients were males and 51.7% were females. Alcohol consumption significantly increased the chance of dying (p<0.023) from colorectal cancer; this increased risk of death was approximately 71%, compared to 52.2% of the non-alcoholics. In addition, tobacco increased the chance of developing high TNM stage tumors (level III, IV; p<0.001). Another risk factor for increased mortality was a family history for colorectal cancer (p<0.002). Our analysis found that patients with an unhealthy lifestyle and/or family history of colorectal cancer were more likely to develop advanced stage colorectal cancer and to have a poor disease prognosis compared to patients with healthy lifestyle and/or sporadic colorectal cancer. These data suggest that a mass screening program should be implemented in northeastern Brazil in order to better prevent and treat colorectal cancer.