Melanoma is the deadliest form of skin cancer and one of the most aggressive cancers. ZFAS1 is a newly identified lncRNA, playing an oncogenic role in several types of cancer. The present study aimed to investigate the function and mechanism of ZFAS1-induced regulation of melanoma. ZFAS1 expression was increased in melanoma tissues and cells compared with normal controls. ZFAS1 expression in metastatic tissues was higher than that in nonmetastatic subjects. Higher expression of ZFAS1 predicted lower survival rates. Knockdown of ZFAS1 decreased proliferation, increased apoptosis, decreased migration and invasion, and reduced epithelial–mesenchymal transition potential in melanoma cells. Moreover, ZFAS1 knockdown inhibited tumor growth in nude mice. There was a direct binding between ZFAS1 and miR-150-5p. ZFAS1 negatively regulated miR-150-5p expression and upregulation of miR-150-5p was involved in ZFAS1 knockdown-induced effect on proliferation, apoptosis, migration, and invasion. Using bioinformatics, we predicted the binding between RAB9A and miR-150-5p, and the direct interaction between RAB9A and miR-150-5p was confirmed by luciferase reporter and RNA immunoprecipitation assays. We also showed that RAB9A expression was regulated negatively by miR-150-5p, but was regulated positively by ZFAS1. Downregulation of RAB9A significantly inhibited the increase in proliferation, decrease in apoptosis, and increase in migration and invasion induced by miR-150-5p inhibitors. Moreover, RAB9A knockdown decreased proliferation, increased apoptosis, and decreased migration and invasion in melanoma cells. In summary, we confirmed the tumor-promoting role of ZFAS1 in melanoma and provide evidence for the role and mechanism of the ZFAS1/miR-150-5p/RAB9A axis. These findings may lead to novel therapeutic strategies for melanoma.

Background/Aims: Malignant melanoma has high metastatic potential, is highly resistant to chemotherapy, and has a poor survival rate. Gambogic acid (GA), a polyprenylated xanthone extracted from a traditional Chinese medicinal herb, has been proven to exhibit antitumor activity. The present study aimed to investigate the signaling pathways that mediated GA-induced inhibition of human malignant skin melanoma proliferation. Methods: The study was conducted using A375 cells and the corresponding tumor transplanted in nude mice. Results: Incubation of A375 cells with 1-10 μg/ml GA decreased cell viability and increased apoptosis. GA concentration-dependently increased p66^shc expression and intracellular ROS levels. GA also decreased the oxygen consumption rate and the mitochondrial membrane potential (MMP) in A375 cells. Experimental inhibition of p66^shc by siRNA suppressed GA-induced increase of ROS, decrease of oxygen consumption rate, MMP and cell viability, whilst suppressing GA-induced increase of apoptosis. GA concentration-dependently upregulated p53 and Bax expression in A375 cells. GA also increased p53-TA-luciferase activity and p53-binding to Bax promoter, which was inhibited by Sip53. Experimental inhibition of p53 with Sip53 blocked GA-induced decrease of the oxygen consumption rate and cell viability, and blocked the increase of apoptosis. In tumor-bearing nude mice, GA notably inhibited tumor growth, and this action was suppressed by N-acetylcysteine (NAC), a potent antioxidant, and by PFT-α, a p53 inhibitor. In A375 tumors transplanted in nude mice, GA increased both p66^shc and p53 expression. NAC and PFT-α treatment did not significantly affect p66^shc expression in tumors grown in mice treated with GA. In contrast, both NAC and PFT-α treatment inhibited GA-induced p53 expression in mouse tumors. Conclusion: Results provided novel preclinical insights into the chemotherapeutic use of GA by highlighting the importance of p66^shc/ROS-p53/Bax pathways in the antitumor effect of GA in malignant melanoma.

Down-regulation of the miRNA miR-338-3p correlates with the invasive ability of hepatocellular carcinoma (HCC) cells. However, it is currently unclear whether down-regulation of miR-338-3p induces epithelial-mesenchymal transition (EMT), which may be the underlying mechanism governing HCC invasion. Here, we demonstrate that restoration of miR-338-3p expression via transfection of a miR-338-3p mimic reversed EMT and inhibited the motility and invasiveness of HCC cells. Conversely, silencing of endogenous miR-338-3p expression with a miR-338-3p-specific inhibitor induced EMT and enhanced HCC cell motility. Additionally, Snail1 (an upstream regulatory protein of EMT) and Gli1 (a key transcription factor in the sonic hedgehog (SHH) signaling pathway) expression was up-regulated in cells treated with the miR-338-3p inhibitor and down-regulated by the miR-338-3p mimic. Further analyses demonstrated that miR-338-3p inhibitor-induced EMT in HCC cells was blocked by treatment with a small interfering RNA (siRNA) targeting Snail1, that the SHH signaling pathway was required for both miR-338-3p inhibitor-induced EMT and up-regulation of Snail1, and that miR-338-3p targeted a sequence within the 3′-untranslated region of N-cadherin mRNA. Notably, miR-338-3p expression was significantly down-regulated in HCC samples from patients with metastases and was associated with poor metastasis-free survival rates. Lastly, correlations between the expression levels of miR-338-3p and E-cadherin, Smoothened (SMO), Gli1, Snail1, N-cadherin, and vimentin were confirmed in HCC xenograft tumors and HCC patient specimens. Our findings suggest that miR-338-3p suppresses EMT and metastasis via both inhibition of the SHH/Gli1 pathway and direct binding of N-cadherin. miR-338-3p is a potential therapeutic target for metastatic HCC.

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Objective. To evaluate the characteristics and antiangiogenic effects of endostatin-loaded PAMAM on endometriosis in a noninvasive animal model. Materials and Methods. A noninvasive animal model was established by injecting adenovirus-GFP transfected endometrial stromal and glandular epithelial cells subcutaneously into nude mice. Endostatin-loaded PAMAM was prepared and identified by transmission electron microscopy. For in vitro studies, the DNA protection and cytotoxicity of PAMAM were investigated and compared with Lipofectamine 2000. For in vivo study, endostatin-loaded PAMAM was injected into the noninvasive model and evaluated by continuously observing the fluorescent lesion, lesion weight, microvessel density and VEGF immunostaining. Results. Compared with Lipofectamine 2000, PAMAM and HC PAMAM-ES group, MC PAMAM-ES group and LC PAMAM-ES group demonstrated a better stromal cells protective such that MC PAMAM-ES group of CCK8 was 0.617 ± 0.122 at 24 hr and 0.668 ± 0.143 at 48 hr and LC PAMAM-ES group of CCK8 was 0.499 ± 0.103 at 24 hr and 0.610 ± 0.080 at 48 hr in stromal cells (P < 0.05) but similar cytotoxicity in glandular epithelial cells in vitro. After 16 hrs of digestion, DNA decreased slightly under the protection of PAMAM. Endostatin-loaded PAMAM of HD PAMAM-ES group and LD PAMAM-ES group inhibited the growth of the endometriotic lesion in vivo at days 15, 20, 25 and 30 detected by noninvasive observation after injecting one dose endostatin of various medicines into the endometrial lesion in each mouse on day 10 (P < 0.05) and confirmed by lesion weight at day 30 with HD PAMAM-ES group being 0.0104 ± 0.0077 g and LD PAMAM-ES group being 0.0140 ± 0.0097 g (P < 0.05). Immunohistochemistry results showed that endostatin-loaded PAMAM reduced the microvessel density 3.8 ± 2.4 especially in HD PAMAM-ES group in the lesion (P < 0.05). Conclusion. Endostatin-loaded PAMAM inhibits the development of endometriosis through an antiangiogenic mechanism and can be observed through the noninvasive endometriosis model.

Malignant melanoma is an aggressive form of cancer which is highly resistant to chemotherapy. We have previously found that gambogic acid (GA), a kind of polyprenylated xanthone, exhibits an antitumour role in melanoma. The study was designed to investigate novel mechanisms of the antitumour effect of GA in melanoma cells and implanted nude mice. Gambogic acid significantly decreased cell viability, increased apoptosis and reduced migration and invasion in A375 cells. In addition, cisplatin-induced cytotoxicity in both A375 and A375/CDDP cells was increased by GA. The expression of miR-199a-3p was increased by GA in A375 cells and implanted tumours, and inhibition of miR-199a-3p significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity in A375 cells. miR-199a-3p mimics reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. miR-199a-3p expression was decreased in melanoma tissues and cells, as compared with their controls. miR-199a-3p possessed a potential binding site in the 3'-UTR of zinc finger E-box binding homeobox (ZEB1). ZEB1 expression was increased in melanoma tissues and cells, as compared with their controls. ZEB1 and miR-199a-3p expression was negatively correlated in melanoma tissues. The expression of ZEB1 was decreased by GA in A375 cells and implanted tumours, and up-regulation of ZEB1 significantly prevented GA-induced effect on cell viability, apoptosis, migration, invasion and cisplatin sensitivity. Down-regulation of ZEB1 reduced tumour weight and volume in vivo and decreased cell viability, increased apoptosis and reduced migration and invasion in vitro. We identified the important roles of miR-199a-3p and ZEB1 in melanoma and elucidated the tumour suppressor function of miR-199a-3p through inhibition of ZEB1. The results highlight the importance of miR-199a-3p-ZEB1 signalling in antitumour effect of GA in malignant melanoma and provide novel targets for the chemotherapy of melanoma.

Recent studies showed that TWEAK/Fn14 signaling participates in the progression of internal malignancies. However, its role in the biological properties of cutaneous squamous cell carcinoma (SCC) remains unclear. This study was designed to explore the effect of TWEAK/Fn14 activation on cutaneous SCC as well as the relevant mechanism. The expression of TWEAK and Fn14 was determined in tissue samples of patients with cutaneous SCC. Human primary keratinocytes and SCC cell lines were cultured in vitro, receiving stimulation of TWEAK. The xenografts of SCC were generated subcutaneously in BALB/c nude mice. The results showed that both TWEAK and Fn14 were highly expressed in human cutaneous SCC. Moreover, TWEAK/Fn14 activation promoted the proliferation, migration, and invasion of cultured SCC cells. Interestingly, TNFR2 was upregulated in cultured SCC cells, and the transfection of TNFR2 small interfering RNA abrogated the effect of TWEAK on these cells. Finally, the favorable effect of TWEAK/Fn14 signals was confirmed in BALB/c nude mice with SCC xenografts. In conclusion, TWEAK/Fn14 signals contribute to the progression of cutaneous SCC, possibly involving the TNF-aeindependent TNFR2 signal transduction.

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