Phytoextraction of highly cadmium-polluted agricultural soil by Sedum plumbizincicola: An eight-hectare field study.

Phytoextraction with Sedum plumbizincicola is an in-situ, environmentally friendly and highly efficient remediation technique for slightly Cd-polluted soils but it remains a challenge to remediate highly Cd-polluted soils under field conditions. Here, an 8-ha field experiment was conducted to evaluate the feasibility of repeated phytoextraction by S. plumbizincicola of a highly Cd-polluted acid agricultural soil (pH 5.61, [Cd] 2.58 mg kg-1) in Yunnan province, southwest China. Mean shoot dry biomass production, Cd concentration and Cd uptake were 1.95 t ha-1, 170 mg kg-1 and 339 g ha-1 at the first harvest, and 0.91 t ha-1, 172 mg kg-1 and 142 g ha-1 at the second harvest. After two seasons of phytoextraction, soil total and CaCl2-extractable Cd concentrations decreased from 2.58 ± 0.69 to 1.53 ± 0.43 mg kg-1 and 0.22 ± 0.12 to 0.14 ± 0.07 mg kg-1, respectively. Stepwise multiple linear regression analysis shows that the shoot Cd concentration and uptake of S. plumbizincicola were positively related to soil CaCl2-extractable Cd concentrations, especially in the first crop. A negative relationship indicates that soil organic matter content played an important role in soil Cd availability and shoot Cd concentration in the first crop. In addition, the rhizosphere effect on soil CaCl2-extractable Cd concentration was negatively correlated with soil pH in the first crop. The accuracy of the calculation of soil Cd phytoextraction efficiency at field scale depends on all of the following factors being considered: shoot Cd uptake, cropping pattern, standardized sampling points, and the leaching and surface runoff of Cd. Phytoextraction with S. plumbizincicola is a feasible technique for efficient Cd removal from highly polluted soils and wide variation in soil properties can influence phytoextraction efficiency at the field scale.

Cadmium isotope fractionation during transport processes within agricultural soil profiles in a mining area: Implications for source tracing.

Cadmium (Cd) isotope fractionation patterns within soil profiles and the underlying mechanisms remain unclear and poorly documented. Here, Cd concentrations and isotope compositions of metal ore, surface soils and soil profile samples around a lead-zinc mine in southwest China were determined, and the relationships between soil properties and Cd isotope fractionation within the soil profiles were investigated. Cadmium concentrations of eleven surface soil samples were 0.49-66.1 mg kg-1 and the samples with high Cd concentrations had Cd isotope compositions similar to the metal ore (δ114/110Cd = 0.02‰), indicating that mining activity was the main Cd source at the study areas. Within three soil profiles with different Cd pollution levels the δ114/110Cd values gradually increased with increasing depth from 0 to 40 cm (Δ114/110Cd = 0.08-0.18‰), reaching a maximum at 30-40 cm depth, and then remained fairly constant or decreased with increasing soil depth below 40 cm. Soil δ114/110Cd values were negatively correlated with free iron and manganese oxides contents, which decreased at 0-40 cm depth then increased below 40 cm. This indicates that light Cd isotopes within 0-40 cm depth preferentially migrated downward with free iron and manganese oxides, leaving the soils at a depth of 0-40 cm enriched in heavy Cd isotopes. At 40-90 cm depth the preferential retention of heavy Cd isotopes by hydroxides may be responsible for the gradual decrease in δ114/110Cd values with increasing soil depth. These observations demonstrate that the vertical migration of Cd can induce detectable isotope fractionation within soil profiles and alter the δ114/110Cd values including those of the surface soils. Our study highlights the need to consider Cd mobilization and transport in soil profiles when tracing metal sources using isotope techniques.

Soil Metal Immobilization in Agricultural Land Contaminated with Cadmium and Lead: A Case Study of Effectiveness Evaluation in Lanping, Southwest China.

The growth of edible crops on land that is highly polluted with potentially toxic elements is prohibited in many developed countries, but the growth of fiber or energy crops may be permitted. Here, we have evaluated metal immobilization in a maize field polluted with cadmium (Cd) and lead (Pb) to determine the thresholds of soil CaCl2-extractable Cd and Pb and to assess management options designed to maximize food safety. Based on geographical and statistical methods we found that when the soil pH was increased from 5.24 to 6.24, the soil CaCl2-extractable Cd and Pb values decreased by 47.8 and 74.7%, respectively. Soil CaCl2-extractable Pb concentrations need to be < 2.14 mg kg-1 in order to comply with the Chinese maximum permissible grain Pb concentration (< 0.2 mg kg-1). Immobilization increased the percentage of samples that were below permissible levels from 77.4% to 96.2% (grain Cd) and 90.6% to 96.2% (grain Pb) during the period 2017 to 2019. To avoid excessive or inadequacy immobilization, the spatial distribution of correlation coefficients of soil pH, CaCl2-extractable or grain Cd/Pb may be helpful in the precise management of immobilization for long-term remediation.

An Integration of blockchain and AI for secure data sharing and detection of CT images for the hospitals.

Deep learning, for image data processing, has been widely used to solve a variety of problems related to medical practices. However, researchers are constantly struggling to introduce ever efficient classification models. Recent studies show that deep learning can perform better and generalize well when trained using a large amount of data. Organizations such as hospitals, testing labs, research centers, etc. can share their data and collaboratively build a better learning model. Every organization wants to retain the privacy of their data, while on the other hand, these organizations want accurate and efficient learning models for various applications. The concern for privacy in medical data limits the sharing of data among multiple organizations due to some ethical and legal issues. To retain privacy and enable data sharing, we present a unique method that combines locally learned deep learning models over the blockchain to improve the prediction of lung cancer in health-care systems by filling the defined gap. There are several challenges involved in sharing that data while maintaining privacy. In this paper, we identify and address such challenges. The contribution of our work is four-fold: (i) We propose a method to secure medical data by only sharing the weights of the trained deep learning model via smart contract. (ii) To deal with different sized computed tomography (CT) images from various sources, we adopted the Bat algorithm and data augmentation to reduce the noise and overfitting for the global learning model. (iii) We distribute the local deep learning model wights to the blockchain decentralized network to train a global model. iv) We propose a recurrent convolutional neural network (RCNN) to estimate the region of interest (ROI) in theCT images. An extensive empirical study has been conducted to verify the significance of our proposed method for better prediction of cancer in the early stage. Experimental results of the proposed model can show that our proposed technique can detect the lung cancer nodules and also achieve better performance.

[Cloning,expression and activity identification of human innate immune protein apolipoprotein B mRNA editing enzyme catalytic subunit 3A(APOBEC3A)].

Objective: To construct the expression vector of apolipoprotein B mRNA editing enzyme catalytic subunit 3A( APOBEC3A),express APOBEC3 A in eukaryotic cells and identify its cytosine deaminase activity. Methods: The APOBEC3 A gene was obtained by PCR and inserted into the eukaryotic expression vector pc DNA3. 0( +). The recombinant vector pc DNA3. 0-APOBEC3 A was then transfected into HEK293 T and Hep G2 cells after confirmed by DNA sequencing. The recombinant protein was purified by Ni-NTA His Bind affinity column. Western blot analysis was used to detect the expression of APOBEC3 A protein. The localization of APOBEC3 A protein in HEK293 T and Hep G2 cel s was identified by immunofluorescence cytochemistry. The deaminase activity of APOBEC3 A protein was characterized by fluorescence polarization. Results: DNA sequencing confirmed that APOBEC3 A gene( 600 bp) was inserted into pc DNA3. 0-APOBEC3 A,which was expressed in HEK293 T and Hep G2 cells successfully. APOBEC3 A protein was mainly expressed in cytoplasm of HEK293 T cells and cytoplasm and nuclei of Hep G2 cells. APOBEC3 A protein showed cytosine deaminase activity on the TTCA sequence in single-stranded DNA. Conclusion: The study constructed successfully APOBEC3 A eukaryotic expression vector,identified the differential expression of APOBEC3 A protein in HEK293 T and Hep G2 cells,and confirmed that the APOBEC3 A protein had cytosine deaminase activity.

Variational first hyperpolarizabilities of 2,3-naphtho-15-crown-5 ether derivatives with cation-complexing: a potential and selective cation detector.

Crown ethers, as a kind of heterocycle, have been the subject of great interest over recent decades due to their selective capability to bind to metal cations. The use of a constant crown ether, such as naphtho-15-crown-5 (N15C5), and varied metal cations (Li+, Na+, K+, Be2+, Mg2+, Ca2+, Co2+, Ni2+, Cu2+) makes it possible to determine the contributions of the metal cations to nonlinear optical (NLO) responses and to design an appropriate NLO-based cation detector. N15C5 and its metal cation derivatives have been systematically investigated by density functional theory. It is found that the dependency of the first hyperpolarizability relies on the metal cation, especially for transition metals. The decrease of the first hyperpolarizabilities for alkali metal cation derivatives is due to their relatively low oscillator strengths, whereas the significant increase of the first hyperpolarizabilities for transition metal cation derivatives can be further illustrated by their low transition energies, large amplitudes and separate distributions of first hyperpolarizability density. Thus, the alkali metal and transition metal cations are distinguishable and the transition metal cations are easier to detect by utilizing the variations in NLO responses.

Apoptosis-related protein-1 acts as a tumor suppressor in cholangiocarcinoma cells by inducing cell cycle arrest via downregulation of cyclin-dependent kinase subunits.

Cholangiocarcinoma, a malignancy arising from the biliary tract, is associated with high mortality due to the late diagnosis and lack of effective therapeutic approaches. Our knowledge of the molecular alterations during the carcinogenesis of cholangiocarcinoma is limited. Previous study suggests that apoptosis-related protein-1 (Apr-1) is involved in cancer cell proliferation and survival. In the present study, we first detected the expression pattern of Apr-1 in human cholangiocarcinoma tissues and the effects of forced Apr-1 expression on cell proliferation and cell cycle progression. Cell cycle gene array analysis was used to identify downstream molecules that were regulated by Apr-1, and their expression levels were further evaluated in human cholangiocarcinoma tissues. We showed that Apr-1 expression was downregulated in human cholangiocarcinoma tissues. Forced expression of Apr-1 inhibited cell proliferation of cholangiocarcinoma cell line QBC939 and induced G2/M phase arrest. Downregulation of cell cycle-related genes cyclin-dependent kinase (Cdk) 2, and cyclin-dependent kinase subunits (Cks) 1 and 2 was involved in Apr-1-induced cell cycle arrest. Furthermore, we found that Cdk2 and Cks1/2 expression levels were elevated in human cholangiocarcinoma tissues. Taken together, our data showed that Apr-1 plays a crucial role in cell proliferation by controlling cell cycle progression, implying a tumor-suppressor function of Apr-1 in cholangiocarcinoma carcinogenesis. Thus, the present study provides a rationale to further study the underlying mechanisms of Apr-1 downregulation in cholangiocarcinoma for exploring potential diagnostic and therapeutic targets.

[Effect of the insulation layer of tissue-engineering scaffold on collagen type II expression in the neo-cartilage].

OBJECTIVE: To investigate the effect of the insulation layer in the tissue-engineering composite osteochondral scaffolds on collagen type II expression in the neo-cartilage. METHODS: Chondral phases of insulation layer-free or insulation layer-containing biphasic scaffolds were seeded with autogeneic chondrocyte-induced bone marrow-derived mesenchymal stem cells. Then, the biphasic scaffolds-cells constructs were implanted into osteochondral defects of rabbits' knees. The expression of type II collagen in the tissue-engineering cartilages was evaluated by immunohistochemistry and Western blotting at 3 and 6 months after surgery, respectively. Moreover, the mRNA expression of collagen type II was also detected by qRT-PCR. RESULTS: The expression of the collagen type II at both protein and mRNA levels in tissue-engineering neo-cartilages generated by the insulation layer-containing biphasic scaffold were significantly higher than those by the insulation layer-free biphasic scaffold in vivo (P<0.05). CONCLUSION: After the insulation layer is added into the osteochondral composite scaffold, the collagen type II expression in the tissue-engineering neo-cartilage can be significantly enhanced.

Inhibition of notch signaling protects mouse lung against zymosan-induced injury.

Notch signaling, a critical pathway in cell fate determination, is well known to be involved in immune and inflammatory reactions, whereas its role in acute lung injury (ALI) remains unclear. Here, we report that notch signal activity is upregulated in lung tissue harvested from an ALI mouse model (induced by zymosan). We showed that notch signal activity in lung tissue was increased 6 h after zymosan injection and peaked at 24 h. Inhibition of notch signaling by either pre- or post-zymosan treatment with N-[N-(3,5-difluorophenacetyl)-l-alanyl]-(S)-phenylglycine t-butyl ester (DAPT) significantly reduced lung injury, characterized by improvement in lung histopathology, lung permeability (protein concentration in bronchoalveolar lavage fluid and lung wet-to-dry weight ratio), lung inflammation (bronchoalveolar lavage fluid cell count, lung myeloperoxidase, and tumor necrosis factor α), and also alleviated systemic inflammation and tissue damage, thus increasing the 7-day survival rate in zymosan-challenged mice. In conclusion, the role of notch signaling is functionally significant in the development of ALI. Inhibition of notch signaling by pretreatment or posttreatment with DAPT likely exerts its effects in part by mediating the expression of proinflammatory and anti-inflammatory cytokines and influencing tissue neutrophil recruitment. These results also imply that notch inhibitors may help attenuate local inflammatory lung damage.

Expression of NDRG2 in human lung cancer and its correlation with prognosis.

We had reported that N-myc downstream-regulated gene (NDRG2) regulates colorectal cancer, breast cancer, clear cell renal cell carcinoma, pancreatic cancer, thyroid cancer and esophageal squamous cell proliferation, development, and apoptosis. The goal of this study was to determine the expression pattern of NDRG2 in human lung cancer and its correlation with prognosis. Immunohistochemistry, RT-PCR and western blot were used to explore the expression of NDRG2 in 185 human lung cancer patients. The correlation of NDRG2 expression with patients' survival rate was assessed by Kaplan-Meier and Cox regression. Results showed that the expression level of NDRG2 was decreased in human lung cancer tissues, and NDRG2 was positively correlated with depth of invasion (P = 0.038), vascular invasion (P = 0.036), tumor grade (P = 0.039), and tumor size (P = 0.026). Both RT-PCR and Western blots demonstrated that NDRG2 mRNA and protein levels were lower in lung cancer compared to the adjacent normal tissue from the same individual, and NDRG2 level was negatively correlated with UICC stage. Additionally, survival time of lung cancer patients with high expression of NDRG2 was longer than those with low expression during the 5-year follow-up period (P = 0.001). Meanwhile, COX regression analysis indicated that low expression of NDRG2, ≥pT(3), pM(1), ≥pN(1) and vascular invasion were independent, poor prognostic factors of lung cancer patients. These data showed that NDRG2 may play an important role in human lung cancer tumourigenesis, and NDRG2 might serve as a novel prognostic marker in human lung cancer.

Design, synthesis, and structural analysis of D,L-mixed polypyrrolinones. 1. From nonpeptide peptidomimetics to nanotubes.

To expand the potential conformational space available to the polypyrroline structural motif, an open chain, D,L-alternating hexapyrrolinone was designed and synthesized. Structural studies, including solution NMR and X-ray crystallographic analysis, revealed that the hexapyrrolinone adopts a turn conformation both in solution and in the solid state, with aggregation in solution and a nanotube-like quaternary structure in the crystal.

Rapamycin inhibits re-endothelialization after percutaneous coronary intervention by impeding the proliferation and migration of endothelial cells and inducing apoptosis of endothelial progenitor cells.

Endothelial-cell function is important in the healing of damaged endothelium after percutaneous coronary artery damage. In 3 different animal models, we sought to determine whether rapamycin (sirolimus) affects the proliferation and migration of endothelial cells and endothelial progenitor cells. First, after we implanted stents in dogs, we found that re-endothelialization was impeded more by drug-eluting stents than by bare-metal stents, 30 days after percutaneous coronary intervention. Second, in vitro in rats, we found that 1-100 ng/mL of rapamycin time- and dose-dependently inhibited proliferation over 72 hr (with effects evident as early as 24 hr) and also dose-dependently induced endothelial progenitor-cell apoptosis. Finally, in vivo in rats, we observed that vascular endothelial growth factor expression was decreased after 5 days of rapamycin treatment. We conclude that rapamycin impedes re-endothelialization after drug-eluting stent implantation by inhibiting the proliferation and migration of coronary endothelial cells, inducing endothelial progenitor-cell apoptosis, and decreasing vascular endothelial growth factor expression in the circulation.

Granulocyte colony-stimulating factor treatment prevents cognitive impairment following status epilepticus in rats.

Status epilepticus (SE) rendered selective neuronal loss and cognitive impairments. Previous studies proved that granulocyte colony-stimulating factor (G-CSF) acted as a neuroprotectant in some nervous diseases. However, no investigations were focused on whether G-CSF could protect the hippocampus from SE. In this study, we administered recombinant human G-CSF into Sprague-Dawley rats with lithium-pilocarpine-induced SE subcutaneously for three times. The Morris water maze was employed to determine spatial learning ability from the 15th to 20th days after the treatment. The quantitative terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate (dUTP) nick end labeling (TUNEL) staining and levels of apoptosis-related molecules including cleaved caspase-3, Bcl-xL and Bax on hippocampal CA1 region were examined by immunohistochemical staining at the 3rd and the 5th day after the treatment. Moreover, the phosphorylation of AKT was evaluated with Western blot at the 6th, 24th and 48th hours after the treatment to explore apoptosis and detect the protective effects of G-CSF. We found G-CSF treatment prevented SE-induced cognitive impairments with the decreased escape latency time on the 17th (29.86+/-9.09 vs. 38.33+/-6.94, p<0.05) and 18th days (23.83+/-6.17 vs. 33.52+/-8.48, p<0.05). The reduced TUNEL staining demonstrated reduced neuronal apoptosis occurrences. The anti-apoptotic effects were associated with decreased cleaved caspase-3 and Bax expression and increased phosphorylation of AKT and Bcl-xL expression. Taken together, our results suggested that systemic G-CSF treatment conducted neuroprotective function following SE through an anti-apoptotic pathway and prevented cognitive impairments, which may provide novel insights into pathogenesis and treatment following SE injury.

2,3,5-Trisubstituted pyridines as selective AKT inhibitors-Part I: Substitution at 2-position of the core pyridine for ROCK1 selectivity.

2,3,5-Trisubstituted pyridines have been designed as potent AKT inhibitors that are selective against ROCK1 based on the comparison between AKT and ROCK1 structures. Substitution at the 2-position of the core pyridine is the key element to provide selectivity against ROCK1. An X-ray co-crystal structure of 9p in PKA supports the proposed rationale of ROCK1 selectivity.

Tetrasubstituted pyridines as potent and selective AKT inhibitors: Reduced CYP450 and hERG inhibition of aminopyridines.

The synthesis and evaluation of tetrasubstituted aminopyridines, bearing novel azaindazole hinge binders, as potent AKT inhibitors are described. Compound 14c was identified as a potent AKT inhibitor that demonstrated reduced CYP450 inhibition and an improved developability profile compared to those of previously described trisubstituted pyridines. It also displayed dose-dependent inhibition of both phosphorylation of GSK3beta and tumor growth in a BT474 tumor xenograft model in mice.

Subcellular localization of APMCF1 and its biological significance of expression pattern in normal and malignant human tissues.

BACKGROUND: APMCF1 is a novel human gene first cloned from apoptotic MCF-7 cells. Our previous study found ectogenic APMCF1 could induce G1 arrest in hepatocarcinoma cell line HHCC. In order to search its broad expression profile for further understanding of its mechanism in tumor, we investigated a subcellular location of APMCF1 and performed an immunohistochemistry study including various tumor and normal tissues. Discovery from the expression characterization of AMPCF1 may have applicability in the analysis of its biological function in tumor. METHODS: We investigated subcellular localization of APMCF1 by transient transfection in green monkey kidney epithelial cells (COS-7) with a fusion protein vector pEGFP-APMCF1 and detected expression profile in a broad range of normal and malignant human tissues via tissue microarray (TMA) by immunohistochemistry with polyclonal antibody first produced in our laboratory. RESULTS: EGFP-APMCF1 was generally localized in the cytoplasm of COS-7 cell. Positive staining of APMCF1 was found in liver, lung, breast, colon, stomach, esophagus and testis, exhibited a ubiquitous expression pattern while its expression was up-regulated in tumor tissues compared with corresponding normal tissues. Normal brain neuron cells also showed expression of APMCF1, but negative in gliocyte cells and glioma. Both the normal and tumor tissues of ovary were absent of APMCF1 expression. Positive immunostaining for APMCF1 with large samples in liver, colon, esophagus, lung and breast carcinomas were 96% (51/53), 80% (44/55), 57% (30/53), 58% (33/57) and 34% (16/47) respectively. CONCLUSION: These results revealed a cytoplastic expression pattern of APMCF1 and up-regulated in tumour tissues suggesting APMCF1 may have potential relationship with oncogenesis. The data presented should serve as a useful reference for further studies of APMCF1 functions in tumorigenesis and might provide a potential anti-tumor target.

Introduction of G1 phase arrest in Human Hepatocellular carcinoma cells (HHCC) by APMCF1 gene transfection through the down-regulation of TIMP3 and up-regulation of the CDK inhibitors p21.

We previously found that there was up-regulation of APMCF1 expression in apoptotic MCF-7 cells. Moreover, bioinformatics analysis has found that APMCF1 molecules had similar size and structure with molecules which belong to small G-protein superfamily. We presume that APMCF1 plays certain biological role in the regulation of cell proliferation and apoptosis. In this study, we first detected the expression pattern of APMCF1 in human hepatocellular carcinoma cell line and find no expression in Human Hepatocellular carcinoma cells (HHCC) and enhanced expression in HepG2 cells. Expression of liposome-mediated ectogenic APMCF1 induced inhibition of HHCC growth and cell cycle, and RNAi inhibited APMCF1 expression and promoted HepG2 cell growth. Results of cell cycle gene chips analysis showed up-regulation of p21 expression and down-regulation of TIMP3 in HHCC cells expressing ectogenic APMCF1, indicating that APMCF1 participates at least partially in cell cycle regulation through regulating genes such as p21 and TIMP3.

[Mutations of tumor suppressor gene PTEN mutations in hepatocellular carcinoma and its implications in tumor proliferation and apoptosis].

OBJECTIVE: To study mutations of tumor suppressor gene PTEN in human hepatocellular carcinomas and its effects on the proliferation and apoptosis of hepatocellular carcinoma cell line HHCC. METHODS: (1) PCR-SSCP and sequence analysis were used to detect the mutations of the 5th and 8th exon of PTEN in 42 cases of human primary hepatocellular carcinoma. (2) Eukaryotic expression vectors of the wild-type (pEGFP-wt-PTEN) and the mutant type (pEGFP-PTEN, G129R) of PTEN were constructed. Lipofectamine 2000 mediated gene transfection was used to transfect hepatocellular carcinoma cell line HHCC, in which the PTEN protein is not expressed. Culture medium containing G418 was used to select stable transfectants. MTT colorimetry was used to analyze the proliferation ability of selected cell lines. Naive HHCC cells and HHCC cells transfected with empty vector (pEGFP-C1) served as controls. (3) TNF-alpha was used to induce apoptosis of selected cell clones. RESULTS: (1) Point mutation involving the 5th exon of PTEN was detected in 4 of 42 primary hepatocellular carcinomas. (2) Compared with the control groups, the proliferation of hepatocellular carcinoma cells was significantly inhibited by the transfection of wild-type PTEN gene, while the transfection with mutant PTEN construct did not significantly change the proliferation. (3) The apoptosis indices of cells transfected with the wild-type and the mutant PTEN genes were 13.8% and 8.1% respectively. Compared with the control, the apoptosis index of HHCC cell transfected by the wild type PTEN was significantly lower (P < 0.05). There were no significant differences between HHCC cells transfected with mutated PTEN gene and the control (P > 0.05). The expression of internal 473-phosphorylated Akt of HHCC was weak, but was enhanced when the cells treated with TNF-alpha. However, it was down regulated by the wild type PTEN. CONCLUSIONS: (1) First time report that PTEN mutations can be found in 9.5% human primary hepatocellular carcinomas. (2) The expression of the wild-type PTEN can suppress the proliferation of HHCC cells, and such suppression was lost when PTEN gene was mutated. (3) PTEN inhibition of the proliferation and the enhancement of apoptosis of hepatocellular carcinoma cells is likely related to a down-regulation of the TNF-alpha induced activation of protein kinase Akt pathway.

[Apoptosis induced by curcumin and its effect on c-myc and caspase-3 expressions in human melanoma A375 cell line].

OBJECTIVE: To investigate the effect of curcumin on cell apoptosis and c-myc and caspase-3 expressions in human melanoma A375 cell line. METHODS: A375 cells were exposed to curcumin treatment and growth inhibition of the cells was examined by MTT assay. Annexin V/propidium iodide double staining and DNA fragmentation analysis were employed for assay of the cell apoptosis and morphological changes of the cells were observed with inverted microscopy and transmission electron microscopy, respectively. In situ hybridization and SABC immunohistochemistry were performed for detection of the expressions of c-Myc and caspase-3 in the A375 cells. RESULTS: Curcumin inhibited the growth of A375 cells in both time- and concentration-dependent manners. After treatment with 30 micromol/L curcumin for 48 h, apoptotic morphological changes were observed in the cells and an oligonucleosomal DNA ladder was clearly visualized in DNA fragmentation analysis. The apoptotic rates of the cells treated with curcumin at the concentration above 20 micromol/L were significantly higher than that of the control cells. c-myc expression level was decreased whereas caspase-3 expression increased with the increase in curcumin concentrations. CONCLUSION: Curcumin can inhibit the proliferation and induce apoptosis of A375 cells in vitro, and the genes encoding c-myc and caspase-3 may play a role in the process.