Metastatic breast cancer cells in lymph nodes increase nodal collagen density

cRGD-installed polymeric micelles loading platinum anticancer drugs enable cooperative treatment against lymph node metastasis

Lymph node metastasis (LNM) is correlated with decreased survival, indicating high tumor malignancy and being a potential source for subsequent fatal metastases. Targeted therapies inhibiting the formation of LNM, while eliminating established metastatic foci, could provide synergistic effects by reducing the incidence and growth of metastasis. Based on the inhibitory activity of cRGD peptide against the development of metastasis, and the LNM targeting ability of systemically injected drug-loaded polymeric micelles, herein, we studied the capability of cRGD-installed polymeric micelles incorporating the platinum anticancer drug (1,2-diaminocylohexane)platinum(II) (DACHPt) for cooperatively inhibiting the formation and progression of LNM. As cRGD-installed DACHPt-loaded micelles (cRGD-DACHPt/m) presented similar size, drug loading and surface charge to non-conjugated micelles (MeO-DACHPt/m), the differences in the biological performance of the micelles were endorsed to the effect of the ligand. In a syngeneic melanoma model, both MeO-DACHPt/m and cRGD-DACHPt/m showed comparable antitumor activity against the primary tumors and the established metastatic foci in lymph nodes. However, cRGD-DACHPt/m significantly enhanced the efficacy against LNM draining from primary tumors through the effective inhibition of the spreading of cancer cells. This improved inhibition was associated with the ability of cRGD-DACHPt/m to reduce the migration of melanoma cells, which was higher than that of MeO-DACHPt/m, free cRGD and their combination. These results support our strategy of using cRGD-installed micelles for attaining cooperative therapies against LNM exploiting the inhibitory function of the peptide and the cytotoxic effect of the micelles.

Targeting ECM Disrupts Cancer Progression

Metastatic complications are responsible for more than 90% of cancer-related deaths. The progression from an isolated tumor to disseminated metastatic disease is a multistep process, with each step involving intricate cross talk between the cancer cells and their non-cellular surroundings, the extracellular matrix (ECM). Many ECM proteins are significantly deregulated during the progression of cancer, causing both biochemical and biomechanical changes that together promote the metastatic cascade. In this review, the influence of several ECM proteins on these multiple steps of cancer spread is summarized. In addition, we highlight the promising (pre-)clinical data showing benefits of targeting these ECM macromolecules to prevent cancer progression.

Lipopolysaccharide modulates neutrophil recruitment and macrophage polarization on lymphatic vessels and impairs lymphatic function in rat mesentery

Impairment of the lymphatic system is apparent in multiple inflammatory pathologies connected to elevated endotoxins such as LPS. However, the direct mechanisms by which LPS influences the lymphatic contractility are not well understood. We hypothesized that a dynamic modulation of innate immune cell populations in mesentery under inflammatory conditions perturbs tissue cytokine/chemokine homeostasis and subsequently influences lymphatic function. We used rats that were intraperitoneally injected with LPS (10 mg/kg) to determine the changes in the profiles of innate immune cells in the mesentery and in the stretch-mediated contractile responses of isolated lymphatic preparations. Results demonstrated a reduction in the phasic contractile activity of mesenteric lymphatic vessels from LPS-injected rats and a severe impairment of lymphatic pump function and flow. There was a significant reduction in the number of neutrophils and an increase in monocytes/macrophages present on the lymphatic vessels and in the clear mesentery of the LPS group. This population of monocytes and macrophages established a robust M2 phenotype, with the majority showing high expression of CD163 and CD206. Several cytokines and chemoattractants for neutrophils and macrophages were significantly changed in the mesentery of LPS-injected rats. Treatment of lymphatic muscle cells (LMCs) with LPS showed significant changes in the expression of adhesion molecules, VCAM1, ICAM1, CXCR2, and galectin-9. LPS-TLR4-mediated regulation of pAKT, pERK pI-κB, and pMLC20 in LMCs promoted both contractile and inflammatory pathways. Thus, our data provide the first evidence connecting the dynamic changes in innate immune cells on or near the lymphatics and complex cytokine milieu during inflammation with lymphatic dysfunction.