Both preclinical and epidemiology studies associate β-adrenoceptors-blockers (β-blockers) with activity against melanoma. However, the underlying mechanism is still unclear, especially in acral melanoma. In this study, we explored the effect of propranolol, a non-selective β-blocker, on the A375 melanoma cell line, two primary acral melanoma cell lines (P-3, P-6) and mice xenografts. Cell viability assay demonstrated that 50μM-400μM of propranolol inhibited viability in a concentration and time dependent manner with an IC50 ranging from 65.33μM to 148.60μM for 24h −72h treatment, but propranolol (less than 200μM) had no effect on HaCaT cell line. Western blots showed 100μM propranolol significantly reduced the expression of Bcl-2 while increasing the expressions of Bax, cytochrome c, cleaved capase-9 and cleaved caspase-3, and down-regulated the levels of p-AKT, p-BRAF, p-MEK1/2 and p-ERK1/2 in melanoma cells, after a 24h incubation. The in vivo data confirmed the isolation results. Mice received daily ip. administration of propranolol at the dose of 2 mg/kg for 3 weeks and the control group was treated with the same volume of saline. The mean tumor volume at day 21 in A375 xenografts was 82.33 ± 3.75mm3vs. 2044.67 ± 54.57mm3 for the propranolol-treated mice and the control group, respectively, and 31.66 ± 4.67 mm3 vs. 1074.67 ± 32.17 mm3 for the P-3 xenografts. Propranolol also reduced Ki67, inhibited phosphorylation of AKT, BRAF, MEK1/2 and ERK1/2 in xenografts. These are the first data to demonstrate that propranolol might inhibit melanoma by activating the intrinsic apoptosis pathway and inactivating the MAPK and AKT pathways.

Dysregulated long noncoding RNAs (lncRNAs) are potential markers of several tumor prognoses. This study aimed to develop a lncRNA expression signature that can predict chemotherapeutic sensitivity for patients with advanced stage and high-grade serous ovarian cancer (HGS-OvCa) treated with platinum-based chemotherapy. The lncRNA expression profiles of 258 HGS-OvCa patients from The Cancer Genome Atlas were analyzed. Results revealed that an eight-lncRNA signature was significantly associated with chemosensitivity in the multivariate logistic regression model, which can accurately predict the chemosensitivity of patients [Area under curve (AUC) = 0.83]. The association of a chemosensitivity predictor with molecular subtypes indicated the excellent prognosis performance of this marker in differentiated, mesenchymal, and immunoreactive subtypes (AUC > 0.8). The significant correlation between ZFAS1 expression and chemosensitivity was confirmed in 233 HGS-OvCa patients from the Gene Expression Omnibus datasets (GSE9891, GSE63885, and GSE51373). In vitro experiments demonstrated that the ZFAS1 expression was upregulated by cisplatin in A2008, HeyA8, and HeyC2 cell lines. This finding suggested that ZFAS1 may participate in platinum resistance. Therefore, the evaluation of the eight-lncRNA signature may be clinically implicated in the selection of platinumresistant HGS-OvCa patients. The role of ZFAS1 in platinum resistance should be further investigated.Ovarian cancer yields the highest mortality rate of all lethal gynecologic cancers and represents approximately 3% of all cancers diagnosed in women worldwide 1,2 . The prognosis of ovarian cancer is unsatisfactory, with a 5-year survival rate of approximately 30% 3 . Approximately 70% of patient deaths are advanced stage and high-grade serous ovarian cancers (HGS-OvCa) 4 . Despite advancements in surgery and chemotherapy, platinum-resistant cancer recurs in approximately 25% of patients within 6 months after they undergo initial standard treatments consisting of aggressive surgery and platinum-based chemotherapy 5 . Some patients with a complete response to first-line chemotherapy develop acquired drug resistance 6 . Several molecular mechanisms, including drug efflux and tolerance, increased DNA repair, and increased cellular glutathione levels 7-9 , are implicated in chemosensitivity. However, exact mechanisms have yet to be fully investigated. Clinical biomarkers that accurately predict sensitivity to chemotherapy have yet to be developed 10,11 . These factors should be understood to identify prognostic signatures, which can be utilized to develop effective treatment modalities for stratified patients who unlikely respond to platinum-based chemotherapy and thus can benefit from alternative strategies 10 .Dysregulated and functional long noncoding RNAs (lncRNAs) are associated with the tumorigenesis and progression of various human cancers [12][13][14] . lncRNAs are mRNA-like transcripts range from 200 nucleotides (bp) to multiple kilobases (kb) in length but lack ...

BackgroundFormaldehyde (FA) induces neurotoxicity by overproduction of intracellular reactive oxygen species (ROS). Increasing studies have shown that hydrogen sulfide (H2S), an endogenous gastransmitter, protects nerve cells against oxidative stress by its antioxidant effect. It has been shown that overproduction of nitric oxide (NO) inhibits the activity of cystathionine-beta-synthase (CBS), the predominant H2S-generating enzyme in the central nervous system.ObjectiveWe hypothesize that FA-caused neurotoxicity involves the deficiency of this endogenous protective antioxidant gas, which results from excessive generation of NO. The aim of this study is to evaluate whether FA disturbs H2S synthesis in PC12 cells, and whether this disturbance is associated with overproduction of NO.Principal FindingsWe showed that exposure of PC12 cells to FA causes reduction of viability, inhibition of CBS expression, decrease of endogenous H2S production, and NO production. CBS silencing deteriorates FA-induced decreases in endogenous H2S generation, neurotoxicity, and intracellular ROS accumulation in PC12 cells; while ADMA, a specific inhibitor of NOS significantly attenuates FA-induced decreases in endogenous H2S generation, neurotoxicity, and intracellular ROS accumulation in PC12 cells.Conclusion/SignificanceOur data indicate that FA induces neurotoxicity by inhibiting the generation of H2S through excess of NO and suggest that strategies to manipulate endogenous H2S could open a suitable novel therapeutic avenue for FA-induced neurotoxicity.

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Formaldehyde (FA) is a common environmental contaminant that has toxic effects on the central nervous system (CNS). Our previous data demonstrated that hydrogen sulfide (H2S), the third endogenous gaseous mediator, has protective effects against FA-induced neurotoxicity. As is known to all, Brain-derived neurotropic factor (BDNF), a member of the neurotrophin gene family, mediates its neuroprotective properties via various intracellular signaling pathways triggered by activating the tyrosine kinase receptor B (TrkB). Intriguingly, our previous data have illustrated the upregulatory role of H2S on BDNF protein expression in the hippocampus of rats. Therefore, in this study, we hypothesized that H2S provides neuroprotection against FA toxicity by regulating BDNF-TrkB pathway. In the present study, we found that NaHS, a donor of H2S, upregulated the level of BDNF protein in PC12 cells, and significantly rescued FA-induced downregulation of BDNF levels. Furthermore, we found that pretreatment of PC12 cells with K252a, an inhibitor of the BDNF receptor TrkB, markedly reversed the inhibition of NaHS on FA-induced cytotoxicity and ablated the protective effects of NaHS on FA-induced oxidative stress, including the accumulation of intracellular reactive oxygen species (ROS), 4-hydroxy-2-trans-nonenal (4-HNE), and malondialdehyde (MDA). We also showed that K252a abolished the inhibition of NaHS on FA-induced apoptosis, as well as the activation of caspase-3 in PC12 cells. In addition, K252a reversed the protection of H2S against FA-induced downregulation of Bcl-2 protein expression and upregulation of Bax protein expression in PC12 cells. These data indicate that the BDNF-TrkB pathway mediates the neuroprotection of H2S against FA-induced cytotoxicity, oxidative stress and apoptosis in PC12 cells. These findings provide a novel mechanism underlying the protection of H2S against FA-induced neurotoxicity.

Both sunitinib, a multi-target tyrosine kinase inhibitor (TKI) and propranolol, a non-selective β-blocker, have proven therapeutic effects on malignant melanoma (MM). This study reports a synergistic effect of propranolol and sunitinib upon A375, P8 MM cell lines and mice xenografts. Cell viability assays detected a significant decrease of sunitinib IC50 in combination with propranolol, which was confirmed by a colony formation assay. Western blot showed that propranolol and sunitinib combination significantly down-regulated phospho-Rb, phospho-ERK, Cyclin D1, and Cyclin E, but had no effect on Bax, Bcl-2, or cleaved PARP expression. The average tumor size of propranolol and low-dose sunitinib (Sun L) combination treated mice was reduced and similar to high-dose sunitinib treated A375 xenografts. The Ki67 index was significantly reduced in propranolol and Sun L combination treated group compared with single Sun L treated group. This synergistic effect between propranolol and sunitinib to inhibit MM proliferation was through suppressing ERK/Cyclin D1/Rb/Cyclin E pathways and inducing G0/G1/S phase arrest, rather than by inducing tumor cell apoptosis.

Formaldehyde (FA), a well-known indoor and outdoor pollutant, has been implicated as the responsible agent in the development of neurocognitive disorders. Hydrogen sulfide (H(2)S), the third gasotransimitter, is an endogenous neuromodulator, which facilitates the induction of hippocampal long-term potentiation, involving the functions of learning and memory. In the present study, we analyzed the effects of intracerebroventricular injection of FA on the formation of learning and memory and the generation of endogenous H(2)S in the hippocampus of rats. We found that the intracerebroventricular injection of FA in rats impairs the function of learning and memory in the Morris water maze and novel object recognition test and increases the formation of apoptosis and lipid peroxidation in the hippocampus. We also showed that FA exposure inhibits the expression of cystathionine β-synthase, the major enzyme responsible for endogenous H(2)S generation in hippocampus and decreases the production of endogenous H(2)S in hippocampus in rats. These results suggested that FA-disturbed generation of endogenous H(2)S in hippocampus leads to the oxidative stress-mediated neuron damage, ultimately impairing the function of learning and memory. Our findings imply that the disturbance of endogenous H(2)S generation in hippocampus is a potential contributing mechanism underling FA-caused learning and memory impairment.

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