Background and Purpose Inflammation associated with the tumour microenvironment (TME) is critical for cancer development, and immunotherapeutic strategies modulating the immune response in cancer... Show moreBackground and Purpose Inflammation associated with the tumour microenvironment (TME) is critical for cancer development, and immunotherapeutic strategies modulating the immune response in cancer have been crucial. In this study, a methotrexate-loaded (MTX) poly(lactic-co-glycolic acid)-based (PLGA) drug nanocarrier covered with polyethyleneimine (Pei) and hyaluronic acid (HA) was developed and combined with an PD-L1 antibody to investigate anti-cancer and immunomodulatory effects in breast cancer TME.Experimental Approach Naked or HA-coated PeiPLGA-MTX nanoparticles (NPs) were assessed on 4T1 breast cancer cells grown in culture and in a mouse model of orthotopic tumour growth. Tumours were evaluated by qRT-PCR and immunohistochemistry. The cell death profile and cell migration were analysed in vitro in 4T1 cells. Polarization of murine macrophages (RAW cells) was also carried out.Key Results Naked or HA-coated PeiPLGA-MTX NPs used alone or combined with PD-L1 antibody modified the tumourigenic course by TME immunomodulation, leading to reduction of primary tumour size and metastases. STAT3 and NF-kappa B were the major genes downregulated by NPs. In tumor-associated macrophages (TAM) such regulation switched M2 phenotype (CD163) towards M1 (CD68) and reduced levels of IL-10, TGF-beta and CCL22. Moreover, malignant cells showed overexpression of FADD, APAF-1, caspase-3 and E-cadherin, and decreased expression of Bcl-2, MDR-1, survivin, vimentin, CXCR4 and PD-L1 after treatment with NPs.Conclusion and Implications NPs-mediated STAT3/NF-kappa B signalling axis suppression disrupted crosstalk between immune and malignant cells, reducing immunosuppression and critical pro-tumour events. These findings provide a promising therapeutic approach capable of guiding the immune TME to suppress the development of breast cancer. Show less
Y Cutaneous T-cell lymphomas and leukemias (CTCLs) are a heterogeneous group of extranodal non-Hodgkin's lymphomas. These are characterized by an accumulation of malignant CD4(+) T-lymphocytes in... Show moreY Cutaneous T-cell lymphomas and leukemias (CTCLs) are a heterogeneous group of extranodal non-Hodgkin's lymphomas. These are characterized by an accumulation of malignant CD4(+) T-lymphocytes in the skin, lymph nodes, and peripheral blood. Novel treatment options are needed for patients who progress to advanced stage disease. Cucurbitacin I has previously shown promising results in Sezary syndrome (Sz). A plethora of cucurbitacins, however, have not yet been tested in CTCL. Herein, we investigated the effect of cucurbitacin E and I in two CTCL cell lines. We show that both cucurbitacins decrease viability and cause apoptosis in these cell lines, although HuT-78 was more affected than SeAx (IC50 of 17.38 versus 22.01 mu M for cucurbitacin E and 13.36 versus 24.47 mu M for cucurbitacin I). Moreover, both cucurbitacins decrease viability of primary cells of a Sz patient (56.46% for cucurbitacin E and 59.07% for cucurbitacin I). Furthermore, while JAK2 inhibition leads to decreased viability in SeAx cells (IC50 of 9.98 and 29.15 mu M for AZD1480 and ruxolitinib respectively), both JAK1 and JAK3 do not. This suggests that JAK2 has a preferential role in promoting survival. Western blotting in SeAx cells revealed that both cucurbitacins inhibit STAT3 activation (P < 0.0001), while only cucurbitacin I inhibits STAT5 activation (P = 0.05). This suggests that STAT3 plays a preferential role in the mechanism of action of these cucurbitacins. Nevertheless, a role of STAT5 and JAK2 cannot be excluded and should be explored further. This knowledge could contribute to the development of effective therapies for CTCL and other malignancies involving dysfunction of the JAK/STAT pathway. Show less
