Hongfu Xie

A small interfering CD147-targeting RNA inhibited the proliferation, invasiveness, and metastatic activity of malignant melanoma

CD147 plays a critical role in the invasive and metastatic activity of malignant melanoma cells by stimulating the surrounding fibroblasts to express matrix metalloproteinases and vascular endothelial growth factor. We developed a system that blocks CD147 in the human malignant melanoma cell line, A375, using RNA interference. By transfecting melanoma cells with the small interfering RNA (siRNA) that targets human CD147, we were able to establish two stable clones in which CD147 expression was significantly down-regulated. This resulted in the decreased proliferation and invasion of A375 cells in vitro. CD147 siRNA also down-regulated the expression of vascular endothelial growth factor in these cells and reduced the migration of vascular endothelial cells. The reduction in the CD147 level suppressed the size of s.c. tumors and the microvessel density in an A375 s.c. nude mouse xenograft model. In addition, the in vivo metastatic potential of A375 cells transfected with CD147 siRNA was suppressed in a nude mouse model of pulmonary metastasis.

Expression of high mobility group box chromosomal protein 1 and its modulating effects on downstream cytokines in systemic lupus erythematosus.

Objective. To compare the expression of high mobility group box chromosomal protein 1 (HMGB1) and the modulating effects on its downstream cytokines in patients with systemic lupus erythematosus (SLE) and healthy controls. Methods. HMGB1 concentrations in serum from SLE patients and controls were measured by immunoblot analysis. HMGB1 messenger RNA (mRNA) expression in peripheral blood mononuclear cells (PBMC) was detected by real-time reverse transcription–polymerase chain reaction. Immunofluorescence assay was employed to examine the translocation of HMGB1 in monocytes after endotoxin stimulation. Release of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) by PBMC after rHMGB1 stimulation was also measured. Results. Serum HMGB1 levels and HMGB1 mRNA expressions in PBMC were elevated in SLE patients compared with controls. A positive correlation was demonstrated between HMGB1 concentrations and SLE Disease Activity Index. There was an inverse correlation between HMGB1 levels and C4 and C3 concentrations in SLE patients. HMGB1 concentrations were higher in patients with vasculitis and myositis. Lipopolysaccharide stimulated a temporarily elevated release of HMGB1 in SLE patients compared with controls. The pattern and localization of HMGB1 staining in monocytes were similar in both groups. After stimulation with rHMGB1, TNF-α level decreased but IL-6 level increased in SLE patients compared with controls. Conclusion. Our findings suggest that increased serum levels of HMGB1 in SLE may be associated with lupus disease activity. The altered production of TNF-α and IL-6 in response to rHMGB1 stimulation may participate in the disruption of cytokine homeostasis in SLE.

Diethylstilbestrol enhances melanogenesis via cAMP-PKA-mediating up-regulation of tyrosinase and MITF in mouse B16 melanoma cells.

BACKGROUND It is well known that melanin synthesis in melanoma cells is controlled by melanogenic enzymes, which regulate the cAMP-PKA signaling pathway. Estrogen was previously reported to upregulate melanogenesis that is associated with human skin pigmentation. OBJECTIVE To investigate the influence and mechanism of diethylstilbestrol (DES) on melanogenesis in mouse B16 melanoma cells. METHODS The effects of diethylstilbestrol on cell viability, melanin content, tyrosinase activity, cAMP level, expression of the tyrosinase family and microphthalmia related transcription factor (MITF) were measured in B16 melanoma. Estrogen receptor (ER) expression were detected in B16 melanoma and A375 melanoma. Diethylstilbestrol-induced melanin synthesis were evaluated in the presence and absence of H89 (a PKA-specific inhibitor) and ICI182, 780 (a pure ER antagonist). Tyrosinase activity, the mRNA levels of tyrosinase and MITF were evaluated in the presence and absence of H89. RESULTS In B16 cells, diethylstilbestrol increased cell proliferation, melanin synthesis, tyrosinase activity and expression of the tyrosinase family and MITF. ER expression have not difference in human and mouse melanoma. When ER were inhibited by ICI182, 780, DES-induced melanogenesis was significantly reduced. Diethylstilbestrol enhanced the level of cAMP. The upregulation of melanin content and tyrosinase activity stimulated by diethylstilbestrol was significantly attenuated in the presence of H89. Further, diethylstilbestrol-induced upregulation of tyrosinase and MITF were significantly attenuated when the PKA pathway was blocked. CONCLUSIONS Diethylstilbestrol can enhance melanin synthesis in melanoma cells. This effect is associated with activation of the cAMP-PKA pathway and upregulation of expression and activity of the melanogenesis-related enzyme tyrosinase and MITF.

Aquaporin‐3 gene and protein expression in sun‐protected human skin decreases with skin ageing

Backgroud/Objectives:  Aquaporin 3 (AQP3) is a protein implicated in skin hydration. AQP3 null mice have relatively dry skin, reduced skin elasticity, and delayed recovery of barrier function after removal of the stratum corneum which is also present in skin of old people. A feature of skin aging is the change in both water content and barrier function of the skin. We investigated the expression of aquaporin 3 in non sun‐exposed human skin, normal human keratinocytes and fibroblasts from different age groups to further understand the relationship between AQP3 and intrinsic skin aging.

RASSF1A suppresses melanoma development by modulating apoptosis and cell-cycle progression.

The tumor suppressor candidate gene Ras association domain family 1, isoform A (RASSF1A) encodes a microtubule‐associated protein that is implicated in the regulation of cell proliferation, migration, and apoptosis. Several studies indicate that down‐regulation of RASSF1A resulting from promoter hypermethylation is a frequent epigenetic abnormality in malignant melanoma. In this study, we report that compared with melanocytes in normal skins or benign skin lesions, RASSF1A is down‐regulated in melanoma tissues as well as cell lines, and its expression negatively correlates with lymph node metastasis. Following ectopic expression in RASSF1A‐deficient melanoma A375 cell line, RASSF1A reduces cell viability, suppresses cell‐cycle progression but enhances apoptotic cell death. In vivo, RASSF1A expression inhibits the tumorigenic potential of A375 cells in nude mice, which also correlates with decreased cell proliferation and increased apoptosis. On the molecular level, ectopic RASSF1A expression leads to differential expression of 209 genes, including 26 down‐regulated and 183 up‐regulated ones. Among different signaling pathways, activation of the apoptosis signal‐regulating kinase 1 (ASK1)/p38 MAP kinase signaling is essential for RASSF1A‐induced mitochondrial apoptosis, and the inhibition of the Akt/p70S6 kinase/eIF4E signaling is also important for RASSF1A‐mediated apoptosis and cell‐cycle arrest. This is the first study exploring the biological functions and the underlying mechanisms of RASSF1A during melanoma development. It also identifies potential targets for further diagnosis and clinical therapy. J. Cell. Physiol. 226: 2360–2369, 2011.

Differential response of normal human epidermal keratinocytes and HaCaT cells to hydrogen peroxide-induced oxidative stress

Background.  Normal human epidermal keratinocytes (NHEKs) and HaCaT cells are the most common models used to study the effects of various factors on skin cells. These cell lines share some common characteristics, but little is known about their differences in handling hydrogen peroxide (H2O2)‐induced oxidative stress.

Demographic and Clinical Characteristics and Risk Factors for Infantile Hemangioma: A Chinese Case-Control Study

OBJECTIVES To study the demographic and clinical features of infantile hemangioma in China; to learn in more detail the risk factors for developing this disease; and to identify clinical characteristics associated with complications, associated risks, and the need for systemic treatment. DESIGN A case-control study of 1832 prospectively enrolled children with hemangiomas and 1832 controls matched for age, sex, region, and hospital attending the dermatology department between 2005 and 2008. SETTING Two large hospitals in central south China. PATIENTS A total of 1832 children with hemangiomas. MAIN OUTCOME MEASURES Demographic and clinical presentations were summarized and compared with data from previous studies of hemangiomas. Predictive clinical factors for complications and/or treatment and potential risk factors for infantile hemangioma were analyzed by logistic regression. RESULTS The clinical features of our study patients were different from those of other race/ethnicity groups reported by previous studies with regard to the morphologic subtypes, complications, and predictors for complications and/or oral corticosteroid treatment. After adjustment, significant risk factors for hemangiomas included lower level of maternal education (odds ratio [OR], 0.61; 95% confidence interval [CI], 0.57-0.66), mother engaged in manual labor (OR, 1.29; 95% CI, 1.12-1.48), multiple gestation (OR, 1.20; 95% CI,1.05-1.36), maternal medication use during the periconceptional period (OR, 2.08; 95% CI, 1.88-2.31), and a positive family history of hemangiomas (OR, 1.55; 95% CI, 1.40-1.72). CONCLUSION Besides yielding several new findings with respect to risk factors for hemangiomas, the current study also suggests that the Chinese clinical features of hemangiomas are somewhat different epidemiologically from those in the West.

Protective role of AQP3 in UVA-induced NHSFs apoptosis via Bcl2 up-regulation

Aquaporin-3 (AQP3), a water/glycerol-transporting protein that facilitates water, urea, and glycerol transport, can inhibit arsenite-induced apoptosis by up-regulating Bcl-2. However, whether it has a protective role in ultraviolet A (UVA)-induced apoptosis in normal human skin fibroblasts is not known. In this study, we demonstrate that mild UVA treatment fails to induce oxidative cell stress and apoptosis in normal human skin fibroblasts (NHSFs) overexpressing AQP3. After severe UVA irradiation, there was an increase in oxidative cell stress and apoptosis when AQP3 levels decreased. We also found that silencing AQP3 sensitized NHSFs to low-dose UVA. Overexpressing AQP3 was protective against high-dose UVA-induced oxidative stress and apoptosis. Besides, we observed that Bcl-2 may be involved in UVA-induced apoptosis. Our findings suggested that the water/glycerol-transporting protein AQP3 plays a role in resistance to UVA-induced apoptosis.

Propranolol induces apoptosis of human umbilical vein endothelial cells through downregulation of CD147.

Background  Infantile haemangiomas (IHs) are benign tumours in infancy. Most patients suffering from IHs do not require treatment. However, if there is a dramatic aesthetic or functional impairment, treatment is needed. Currently the most promising therapy for complicated IHs is the oral administration of propranolol, but its mechanism is unclear.

Adverse effects of propranolol treatment for infantile hemangiomas in China

Objectives: The β-blocker propranolol was discovered to be highly effective for the treatment of infantile hemangiomas (IHs), since 2008. Although some side effects have been reported earlier, no serious side effects of its use have been reported so far in Asia, especially in China. To determine the safety of this therapy, the side effects were analyzed in 97 infants who used propranolol (2 mg kg−1·d−1) against hemangioma from 2010 to 2011. Materials and methods: Routine blood and urine tests, hepatic and renal function tests, myocardial enzyme, electrolytes and blood sugar levels at baseline were performed. Electrocardiogram monitoring was performed 48 h after administration of the first dose (2 mg kg−1·d−1). Every patient (n = 97) was required to report to the hospital once a month. Results: The following adverse effects were observed: bronchial hyperactivity (n = 5), cyanosis and cold extremities (n = 1), agranulocytosis (n = 1), and low body temperature (n = 1). These side effects were reported for the first time in Asia. Conclusions: Although propranolol is effective against IHs, its potential side effects should be considered and appropriate monitoring performed. Further studies need to be conducted to determine the optimal dose and duration of propranolol treatment for large and complex hemangiomas.