The transmembrane cell adhesion protein ADAM9 has been implicated in cancer cell migration and lung cancer metastasis to the brain, but the underpinning mechanisms are unclear and clinical support has been lacking. Here, we demonstrate that ADAM9 enhances the ability of tissue plasminogen activator (tPA) to cleave and stimulate the function of the promigratory protein CDCP1 to promote lung metastasis. Blocking this mechanism of cancer cell migration prolonged survival in tumor-bearing mice and cooperated with dexamethasone and dasatinib (a dual Src/Abl kinase inhibitor) treatment to enhance cytotoxic treatment. In clinical specimens, high levels of ADAM9 and CDCP1 correlated with poor prognosis and high risk of mortality in patients with lung cancer. Moreover, ADAM9 levels in brain metastases derived from lung tumors were relatively higher than the levels observed in primary lung tumors. Our results show how ADAM9 regulates lung cancer metastasis to the brain by facilitating the tPA-mediated cleavage of CDCP1, with potential implications to target this network as a strategy to prevent or treat brain metastatic disease. Cancer Res; 74(18); 5229-43. Ó2014 AACR.

This pilot, double-blind, randomized, placebo-controlled study is aimed at evaluating the effectiveness of low-level laser therapy (LLLT) as a complementary treatment to complete decongestive therapy (CDT) treating lymphedema among breast cancer patients for 12 months post-intervention. Study population was breast cancer patients who were diagnosed and referred to lymphedema clinic for CDT. Participants (n = 22) were randomized and assigned into either an active laser intervention group or an inactive laser placebo-control group. Active LLLT was administered to participants twice a week at the beginning of each CDT session. Outcome measures included lymphedema symptoms, symptom distress, and limb volume by an infrared perometer. Participants in the active and placebo laser groups were comparable in demographic and clinical predictors of lymphedema. In comparison with the placebo group (83.3%), significantly fewer participants in the active laser group (55.6%) reported more than one lymphedema symptom (p = 0.012) at 12 months post-intervention. Significantly, more patients in the active laser group (44.4%) reported less than two impaired limb mobility symptoms in comparison with the placebo group (33.3%) at 12 months post-intervention (p = 0.017). The active laser group had statistically significant improvements in symptom distress of sadness (p = 0.005) from 73 to 11% and self-perception (p = 0.030) from 36 to 0% over time from baseline to 12months post-intervention. There was no significant reduction in limb volume. Findings of the trial demonstrated significant benefits of complementary LLLT for relieving symptoms and improvement of emotional distress in breast cancer patients with lymphedema.

Lung cancer is the leading cause of cancer death worldwide, and brain metastasis is a major cause of morbidity and mortality in lung cancer. CDH2 (N-cadherin, a mesenchymal marker of the epithelial-mesenchymal transition) and ADAM9 (a type I transmembrane protein) are related to lung cancer brain metastasis; however, it is unclear how they interact to mediate this metastasis. Because microRNAs regulate many biological functions and disease processes (e.g., cancer) by down-regulating their target genes, microRNA microarrays were used to identify ADAM9-regulated miRNAs that target CDH2 in aggressive lung cancer cells. Luciferase assays and western blot analysis showed that CDH2 is a target gene of miR-218. MiR-218 was generated from pri-mir-218-1, which is located in SLIT2, in non-invasive lung adenocarcinoma cells, whereas its expression was inhibited in aggressive lung adenocarcinoma. The down-regulation of ADAM9 up-regulated SLIT2 and miR-218, thus down-regulating CDH2 expression. This study revealed that ADAM9 activates CDH2 through the release of miR-218 inhibition on CDH2 in lung adenocarcinoma.

Lung cancer has a very high prevalence of brain metastasis, which results in a poor clinical outcome. Up-regulation of a disintegrin and metalloproteinase 9 (ADAM9) in lung cancer cells is correlated with metastasis to the brain. However, the molecular mechanism underlying this correlation remains to be elucidated. Since angiogenesis is an essential step for brain metastasis, microarray experiments were used to explore ADAM9-regulated genes that function in vascular remodeling. The results showed that the expression levels of vascular endothelial growth factor A (VEGFA), angiopoietin-2 (ANGPT2), and tissue plasminogen activator (PLAT) were suppressed in ADAM9-silenced cells, which in turn leads to decreases in angiogenesis, vascular remodeling, and tumor growth in vivo. Furthermore, simultaneous high expression of ADAM9 and VEGFA or of ADAM9 and ANGPT2 was correlated with poor prognosis in a clinical dataset. These findings suggest that ADAM9 promotes tumorigenesis through vascular remodeling, particularly by increasing the function of VEGFA, ANGPT2, and PLAT.