Depilatory creams increase the number of hair follicles, and dermal fibroblasts expressing interleukin-6, tumor necrosis factor-α, and tumor necrosis factor-ß in mouse skin.

Besides using for hair removal, depilatory agents have been considered to be used as a penetration enhancer for transepidermal drug delivery. To examine the effect in hair follicles (HFs), two commercially available depilatory creams were tested on the dorsal skin of mice to monitor the effect deep into the skin structure. Fifteen male BALB/c mice were used in this study. Depilatory creams were applied to the dorsal skin of the same animal using shaved and untouched treatments as controls to minimize individual differences. Skin samples were collected at three days, one week and two weeks (n = 5 for each) after the treatment, and subjected for hematoxylin-eosin staining, and immunohistochemical analysis for proinflammatory cytokines. The morphological examination showed an increase in the thickness of epidermal layer of the depilatory cream-treated skin at early time points and in the subcutis at two weeks. Depilatory cream promoted entry of anagen phase and increased the number of hair follicles in the subcutis at one and two weeks. Immunohistochemistry showed elevated percentages of dermal fibroblasts expressing interleukin-6, tumor necrosis factor-α, and tumor necrosis factor-ß. Shaving process increased the thickness of epidermis and dermis as depilatory creams did, but did neither induce the expression of proinflammatory cytokines in the dermal fibroblasts nor the number of HFs. The results suggested that the commercially available depilatory creams caused a transient minor inflammatory response of the skin and increased the levels of cytokines that might subsequently affect hair growth.

Perspiration promotes the effect of sulphite on the shielding response of rodent skin.

Perspiration and environmental chemicals, such as air pollutants, are two of the complicating factors of skin disease. It has not been studied how perspiration affect the skin responding to air pollutants. We applied topically artificial eccrine perspiration, sulphite or both to the mouse skin for one and two weeks to examine the influence of both factors on the shielding ability of healthy skin. Morphological examination showed apparent thickening of the epidermal layer in the skin samples with combined treatment at 1 week, and in the sections applied with sulphite and combined treatment at 2 weeks without significant difference in the extent of epidermal hyperplasia between two groups. The outcomes of immunohistochemical (IHC) analysis showed elevated percentages of dermal fibroblasts expressing interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), tumor necrosis factor ß (TNF-ß) and cyclooxygenase-2 (Cox-2). Results of two-way repeated measured analysis of variance (two-way RMANOVA) showed that both perspiration and sulphite, but not the interaction between them, were significant factors affecting the expression of proinflammatory cytokines. The evidences indicated that perspiration induced cytokines expressions in the dermal fibroblasts and promoted the effect of sulphite on the shielding response of the skin by inducing epidermis hyperplasia.

Shielding response of rodent skin to water soluble ambient air pollutants.

Given the increasing levels of air pollution, understanding the direct shielding response of the skin to air pollutants as a whole under exclusion of the influence from the inside of body is important. We applied topically the water soluble ambient air pollutants to the mouse skin and observed the histological response using 0.3 mM of H2SO3 as a positive control. Water soluble air pollutants samples, WSAP24h and WSA72h, were collected by pumping the outdoor air into ddH2O for 24 and 72 h respectively during two periods with different air quality index (AQI). Morphological examination showed apparent thickening of the epidermal layer in the H2SO3 skin section and in the sections applied with WSAP24h and WSAP72h without significant difference in the extent of epidermal hyperplasia among three groups. The cell viability assay showed no cytotoxic effect by the treatment of H2SO3 and WSAP24h in human skin fibroblast WS-1 cells. WSAP72h sample revealed a dose-dependent cytotoxicity to skin fibroblasts at 48 hr. The evidences indicated that the barrier function of the skin by epidermis hyperplasia could be activated by the insult of a component of air pollution, and the protection could be hold against a more complex and concentrated ambient air pollutants.

Induction of Mitotic Catastrophe via Inhibition of Aurora B by Ionizing Radiation With Additive of Mulberry Water Extract in Human Bladder Cancer Cells.

Mulberry fruit water extract (MWE) has been reported to synergistically enhance the cytotoxic effect of paclitaxel by promoting mitotic catastrophe to induce apoptosis in bladder cancer cells in our previous work. The aim of this study was to evaluate and to mechanistically explore the effects of MWE on bladder cancer responses to ionizing radiation (IR) by treating TSGH 8301 bladder carcinoma cells with MWE after exposing to IR. The results of MTT assay showed a synergistic cytotoxicity of IR with the co-treatment of MWE (IR/MWE) by inducing G2/M phase arrest as demonstrated by flow cytometry analysis in TSGH 8301, HT1367 and HT1197 bladder carcinoma cells lines. The IR/MWE-treated cells expressed increased levels of the G2/M phase arrest-related proteins cdc2/cyclin B1 and displayed giant multinucleated morphology, a typical characteristic of mitotic catastrophe. Immunofluorescent confocal microscopy revealed that the combined strategy inhibited Aurora B phosphorylation through Ras/Raf/MEK/ERK signaling cascade as demonstrated by Western blotting analysis. IR/MWE also caused an inhibitory effect on Plk1 and the subsequent downstream regulator RhoA repression and Cep55 induction, which would influence cell cycle progression in the early steps of cytokinesis. A profound tumor growth suppression and inactivation of Aurora B activity in the tumor tissues by IR/MWE treatment were confirmed in the TSGH 8301 xenograft model in vivo. These data demonstrated that MWE could be an effective auxiliary to synergize with radiation on the anticancer efficacy by promoting mitotic catastrophe through inhibition of Aurora B, providing a novel and effective therapeutic option for bladder cancer management.

Secreted gelsolin desensitizes and induces apoptosis of infiltrated lymphocytes in prostate cancer.

Loss of immunosurveillance is a major cause of cancer progression. Here, we demonstrate that gelsolin, a constituent of ejaculate, induces apoptosis of activated lymphocytes in prostate cancer. Gelsolin was highly expressed in prostate cancer cells, and was associated with tumor progression, recurrence, metastasis, and poor prognosis. In vitro, secreted gelsolin inactivated CD4+ T cells by binding to CD37, and induced apoptosis of activated CD8+ T lymphocytes by binding to Fas ligand during cell contact dependent on major histocompatibility complex I. Moreover, secreted gelsolin bound to sortilin, which in turn bound to Wiskott-Aldrich syndrome protein family member 3, thereby enhancing the endocytosis and intracellular transport of essential lipids needed to facilitate tumor growth and expansion. Under normal conditions, gelsolin is a seemingly harmless protein that prevents immune responses in female recipients. In disease states, however, this protein can inhibit immunosurveillance and promote cancer progression.

Promotion of mitotic catastrophe via activation of PTEN by paclitaxel with supplement of mulberry water extract in bladder cancer cells.

Paclitaxel is a mitotic inhibitor used in cancer chemotherapy. Mulberry fruit is rich in phenolic compounds and flavonoids and exhibits chemopreventive activities. In this study, mulberry water extract (MWE) was used as a supplement to synergize with the effects of paclitaxel in the treatment of the TSGH 8301 human bladder cancer cell line. Treatment with paclitaxel combined with MWE (paclitaxel/MWE) enhanced the cytotoxicity of paclitaxel and induced severe G2/M arrest, mitotic catastrophe and subsequent apoptosis, as shown by MTT assay, HE staining and flow cytometry analyses. Differences in the expression and activation of Aurora A and Plk1 between cells treated with paclitaxel/MWE and paclitaxel alone suggested that the combined treatment caused a defect in the early steps of cytokinesis. Paclitaxel/MWE decreased EEA1 immunofluorescence staining and increased the expression of PTEN, indicating that the regimen inhibited the formation of the recycling endosome, which is required for cytokinesis. Paclitaxel/MWE also retarded tumor growth in a TSGH 8301 xenograft model via activation of PTEN and Caspase 3. These data demonstrated a synergistic effect on the anticancer efficacy of paclitaxel through MWE supplementation by promoting mitotic catastrophe through the activation of PTEN, providing a novel and effective therapeutic option for bladder cancer treatment strategies.

The induction of apoptosis and autophagy by Wasabia japonica extract in colon cancer.

PURPOSE: Wasabia japonica (wasabi) has been shown to exhibit properties of detoxification, anti-inflammation and the induction of apoptosis in cancer cells. This study aimed to investigate the molecular mechanism of the cytotoxicity of wasabi extract (WE) in colon cancer cells to evaluate the potential of wasabi as a functional food for chemoprevention. METHODS: Colo 205 cells were treated with different doses of WE, and the cytotoxicity was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide. Apoptosis and autophagy were detected by 4',6-diamidino-2-phenylindole, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbo-yanine iodide and staining for acidic vascular organelles (AVOs), along with Western blotting. RESULTS: The results demonstrated that WE induced the extrinsic pathway and mitochondrial death machinery through the activation of TNF-α, Fas-L, caspases, truncated Bid and cytochrome C. WE also induced autophagy by decreasing the phosphorylation of Akt and mTOR and promoting the expression of microtubule-associated protein 1 light chain 3-II and AVO formation. An in vivo xenograft model verified that tumor growth was delayed by WE treatment. CONCLUSION: Our studies revealed that WE exhibits anti-colon cancer properties through the induction of apoptosis and autophagy. These results provide support for the application of WE as a chemopreventive functional food and as a prospective treatment of colon cancer.

Hibiscus sabdariffa Leaf Extract Inhibits Human Prostate Cancer Cell Invasion via Down-Regulation of Akt/NF-kB/MMP-9 Pathway.

Hibiscus sabdariffa leaf has been previously shown to possess hypoglycemic, hypolipidemic, and antioxidant effects, and induce tumor cell apoptosis. However, the molecular mechanisms involved in the anticancer activity of H. sabdariffa leaf extract (HLE) are poorly understood. The object of the study was to examine the anti-invasive potential of HLE. First, HLE was demonstrated to be rich in polyphenols. The results of wound-healing assay and in vitro transwell assay revealed that HLE dose-dependently inhibited the migration and invasion of human prostate cancer LNCaP (lymph node carcinoma of the prostate) cells under non-cytotoxic concentrations. Our results further showed that HLE exerted an inhibitory effect on the activity and expressions of matrix metalloproteinase-9 (MMP-9). The HLE-inhibited MMP-9 expression appeared to be a consequence of nuclear factor-kappaB (NF-κB) inactivation because its DNA-binding activity was suppressed by HLE. Molecular data showed all these influences of HLE might be mediated via inhibition of protein kinase B (PKB, also known as Akt)/NF-kB/MMP-9 cascade pathway, as demonstrated by the transfection of Akt1 overexpression vector. Finally, the inhibitory effect of HLE was proven by its inhibition on the growth of LNCaP cells and the expressions of metastasis-related molecular proteins in vivo. These findings suggested that the inhibition of MMP-9 expression by HLE may act through the suppression of the Akt/NF-kB signaling pathway, which in turn led to the reduced invasiveness of the cancer cells.

Hibiscus sabdariffa leaf polyphenolic extract induces human melanoma cell death, apoptosis, and autophagy.

Melanoma is the least common but most fatal form of skin cancer. Previous studies have indicated that an aqueous extract of Hibiscus sabdariffa leaves possess hypoglycemic, hypolipidemic, and antioxidant effects. In this study, we want to investigate the anticancer activity of Hibiscus leaf polyphenolic (HLP) extract in melanoma cells. First, HLP was exhibited to be rich in epicatechin gallate (ECG) and other polyphenols. Apoptotic and autophagic activities of HLP and ECG were further evaluated by DAPI stain, cell-cycle analysis, and acidic vascular organelle (AVO) stain. Our results revealed that both HLP and ECG induced the caspases cleavages, Bcl-2 family proteins regulation, and Fas/FasL activation in A375 cells. In addition, we also revealed that the cells presented AVO-positive after HLP treatments. HLP could increase the expressions of autophagy-related proteins autophagy-related gene 5 (ATG5), Beclin1, and light chain 3-II (LC3-II), and induce autophagic cell death in A375 cells. These data indicated that the anticancer effect of HLP, partly contributed by ECG, in A375 cells. HLP potentially could be developed as an antimelanoma agent.

Id3 induces an Elk-1-caspase-8-dependent apoptotic pathway in squamous carcinoma cells.

Inhibitor of differentiation/DNA-binding (Id) proteins are helix-loop-helix (HLH) transcription factors. The Id protein family (Id1-Id4) mediates tissue homeostasis by regulating cellular processes including differentiation, proliferation, and apoptosis. Ids typically function as dominant negative HLH proteins, which bind other HLH proteins and sequester them away from DNA promoter regions. Previously, we have found that Id3 induced apoptosis in immortalized human keratinocytes upon UVB exposure, consistent with its role as a tumor suppressor. To investigate the role of Id3 in malignant squamous cell carcinoma (SCC) cells (A431), a tetracycline-regulated inducible system was used to induce Id3 in cell culture and mouse xenograft models. We found that upon Id3 induction, there was a decrease in cell number under low serum conditions, as well as in soft agar. Microarray, RT-PCR, immunoblot, siRNA, and inhibitor studies revealed that Id3 induced expression of Elk-1, an E-twenty-six (ETS)-domain transcription factor, inducing procaspase-8 expression and activation. Id3 deletion mutants revealed that 80 C-terminal amino acids, including the HLH, are important for Id3-induced apoptosis. In a mouse xenograft model, Id3 induction decreased tumor size by 30%. Using immunofluorescent analysis, we determined that the tumor size decrease was also mediated through apoptosis. Furthermore, we show that Id3 synergizes with 5-FU and cisplatin therapies for nonmelanoma skin cancer cells. Our studies have shown a molecular mechanism by which Id3 induces apoptosis in SCC, and this information can potentially be used to develop new treatments for SCC patients.

Piper betle leaf extracts induced human hepatocellular carcinoma Hep3B cell death via MAPKs regulating the p73 pathway in vitro and in vivo.

Extracts of Piper betle leaf (PBLs) are rich in bioactive compounds with potential chemopreventive ability. In this study, Hep3B cells which are p53 null were used to investigate the anti-tumor effect of PBLs in the cell and in the xenograft model. The results revealed that PBLs (0.1 to 1 mg mL(-1)) induced a dose- and time-dependent increase of cell toxicity. The underlying mechanisms as evidenced by flow cytometry and western blot analysis showed that PBLs triggered ATM, cAbl, and p73 expressions and activated JNK and p38 pathways that subsequently led to cell cycle arrest and mitochondria-dependent apoptosis. PBLs also inhibited tumor growth in Hep3B-bearing mice via inducing the MAPK-p73 pathway. Our results demonstrated the in vitro and in vivo anti-tumor potential of PBLs, supporting their application as a novel chemopreventive agent for the treatment of human hepatocellular carcinoma (HCC) in the future via targeting the p73 pathway.

Short and long-term impact of lipectomy on expression profile of hepatic anabolic genes in rats: a high fat and high cholesterol diet-induced obese model.

OBJECTIVE: To understand the molecular basis of the short and long-term effects of an immediate shortage of energy storage caused by lipectomy on expression profile of genes involved in lipid and carbohydrate metabolism in high fat and high cholesterol diet-induced obese rats. METHODS: The hepatic mRNA levels of enzymes, regulator and transcription factors involved in glucose and lipid metabolism were analyzed by quantitative real time polymerase chain reaction (RT-qPCR) ten days and eight weeks after lipectomy in obese rats. Body and liver weights and serum biochemical parameters, adiponectin, leptin and insulin were determined. RESULTS: No significant difference was observed on the food intake between the lipectomized and sham-operated groups during the experimental period. Ten days after the operation, the lipectomized animals showed significant higher triacylglycerol, glucose and insulin levels, a lower adiponectin concentration than the sham-operated rats, along with significant higher hepatic mRNA levels of hepatocyte nuclear factor 4α (HNF4α) and the enzymes involved in lipogenesis, sterol biosynthesis and gluconeogenesis. The results of immunohistochemical (IHC) analysis also confirmed increased levels of lipogenic enzymes in the liver of lipectomized versus sham-operated animals. The lipectomized group had a significantly lower adiponectin/leptin ratio that was positively correlated to the level of LDL (r = 0.823, P<0.05) and negatively to glucose and insulin (r = -0.821 and -0.892 respectively, P<0.05). Eight weeks after the operation, the lipectomized animals revealed significant higher body and liver weights, weight gain, liver to body weight ratio, hepatic triacylglycerol and serum insulin level. CONCLUSIONS: In response to lipectomy a short term enhancement of the expression of hepatic anabolic genes involved in lipid and carbohydrate metabolism was triggered that might eventually lead to the final extra weight gain. These metabolic changes could be the results of reduced circulating adiponectin that further influences the functions of insulin and hepatic HNF4α.

Malignant phyllodes tumors display mesenchymal stem cell features and aldehyde dehydrogenase/disialoganglioside identify their tumor stem cells.

INTRODUCTION: Although breast phyllodes tumors are rare, there is no effective therapy other than surgery. Little is known about their tumor biology. A malignant phyllodes tumor contains heterologous stromal elements, and can transform into rhabdomyosarcoma, liposarcoma and osteosarcoma. These versatile properties prompted us to explore their possible relationship to mesenchymal stem cells (MSCs) and to search for the presence of cancer stem cells (CSCs) in phyllodes tumors. METHODS: Paraffin sections of malignant phyllodes tumors were examined for various markers by immunohistochemical staining. Xenografts of human primary phyllodes tumors were established by injecting freshly isolated tumor cells into the mammary fat pad of non-obese diabetic-severe combined immunodeficient (NOD-SCID) mice. To search for CSCs, xenografted tumor cells were sorted into various subpopulations by flow cytometry and examined for their in vitro mammosphere forming capacity, in vivo tumorigenicity in NOD-SCID mice and their ability to undergo differentiation. RESULTS: Immunohistochemical analysis revealed the expression of the following 10 markers: CD44, CD29, CD106, CD166, CD105, CD90, disialoganglioside (GD2), CD117, Aldehyde dehydrogenase 1 (ALDH), and Oct-4, and 7 clinically relevant markers (CD10, CD34, p53, p63, Ki-67, Bcl-2, vimentin, and Globo H) in all 51 malignant phyllodes tumors examined, albeit to different extents. Four xenografts were successfully established from human primary phyllodes tumors. In vitro, ALDH+ cells sorted from xenografts displayed approximately 10-fold greater mammosphere-forming capacity than ALDH- cells. GD2+ cells showed a 3.9-fold greater capacity than GD2- cells. ALDH+/GD2+cells displayed 12.8-fold greater mammosphere forming ability than ALDH-/GD2- cells. In vivo, the tumor-initiating frequency of ALDH+/GD2+ cells were up to 33-fold higher than that of ALDH+ cells, with as few as 50 ALDH+/GD2+ cells being sufficient for engraftment. Moreover, we provided the first evidence for the induction of ALDH+/GD2+ cells to differentiate into neural cells of various lineages, along with the observation of neural differentiation in clinical specimens and xenografts of malignant phyllodes tumors. ALDH+ or ALDH+/GD2+ cells could also be induced to differentiate into adipocytes, osteocytes or chondrocytes. CONCLUSIONS: Our findings revealed that malignant phyllodes tumors possessed many characteristics of MSC, and their CSCs were enriched in ALDH+ and ALDH+/GD2+ subpopulations.

Inhibitory effect of Piper betel leaf extracts on copper-mediated LDL oxidation and oxLDL-induced lipid accumulation via inducing reverse cholesterol transport in macrophages.

Piper betel leaf (PBL) has the biological capabilities of detoxification and can work as an anti-inflammatory agent and an anti-oxidant. In this study, we evaluated the anti-oxidative activity of the extract of Piper betel leaves (PBLs) on the basis of Cu(2+)-mediated oxidation, and its ability to prevent foam cell formation in a model for oxidised low density lipoprotein (oxLDL)-induced lipid accumulation in macrophages. Our data demonstrated that PBLs were able to inhibit LDL oxidation in vitro and are able to reduce the lipid accumulation in macrophages. We showed the underlying mechanisms to be the following: PBLs up-regulated the protein levels of the class A and class B scavenger receptors, the membrane lipid transporter ABCA1, and its upstream regulator Liver X receptor (LXR) in the macrophages exposed to oxLDL. The results suggested that PBLs activated the reverse cholesterol transport mechanism to enhance the metabolism of the oxLDL that could prevent both lipid accumulation and foam cell formation and further minimise the possible damage of vessels caused by the oxLDL.

Sensitizing effect of 3-methyladenine on radiation-induced cytotoxicity in radio-resistant HepG2 cells in vitro and in tumor xenografts.

Many recent efforts have focused on targeting cell death pathways for discovering new cancer therapies. The relative resistance of liver cancer cells to ionizing radiation (IR) and chemotherapeutic agents due to autophagic response limits the available treatment options for this type of cancer. In this study, 3-methyladenine (3-MA), an autophagy inhibitor, was investigated for its potential to enhance radio-sensitivity under radio-resistant conditions both in vitro and in vivo. Hep3B and HepG2 cells were used to examine the radio-resistance of liver cancer cells. The results show that Hep3B cells respond to irradiation with increased apoptotic cell death and that HepG2 is radio-resistant due to the IR-induced autophagy, as verified by DNA fragmentation, electron microscopy, acidic vesicular organelle formation, and Western blot analysis. Application of IR with 3-MA to inhibit autophagy simultaneously suppressed the expression of LC3 and enhanced cell death. The tumor xenograft model in nude mice verified the synergistic cytotoxic effect of 3-MA and IR, which resulted in significant repression of tumor growth. The results demonstrate that IR-induced autophagy provides a self-protective mechanism against radiotherapy in HepG2 cells. In addition, 3-MA enhances the cytotoxicity of IR in cell models and suppresses tumor growth in animal models. Based on the results, application of 3-MA, or other autophagy inhibitors, could be used as an adjuvant for radiotherapy when radio-resistance develops as a result of autophagy response.

Andrographolide down-regulates hypoxia-inducible factor-1α in human non-small cell lung cancer A549 cells.

Andrographolide (Andro), a diterpenoid lactone isolated from a traditional herbal medicine Andrographis paniculata, is known to possess multiple pharmacological activities. In our previous study, Andro had been shown to inhibit non-small cell lung cancer (NSCLC) A549 cell migration and invasion via down-regulation of phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. Here we demonstrated that Andro inhibited the expression of hypoxia-inducible factor-1α (HIF-1α) in A549 cells. HIF-1α plays an important role in tumor growth, angiogenesis and lymph node metastasis of NSCLC. The Andro-induced decrease of cellular protein level of HIF-1α was correlated with a rapid ubiquitin-dependent degradation of HIF-1α, and was accompanied by increased expressions of hydroxyl-HIF-1α and prolyl hydroxylase (PHD2), and a later decrease of vascular endothelial growth factor (VEGF) upon the treatment of Andro. The Andro-inhibited VEGF expression appeared to be a consequence of HIF-1α inactivation, because its DNA binding activity was suppressed by Andro. Molecular data showed that all these effects of Andro might be mediated via TGFß1/PHD2/HIF-1α pathway, as demonstrated by the transfection of TGFß1 overexpression vector and PHD2 siRNA, and the usage of a pharmacological MG132 inhibitor. Furthermore, we elucidated the involvement of Andro in HIF-1α transduced VEGF expression in A549 cells and other NSCLC cell lines. In conclusion, these results highlighted the potential effects of Andro, which may be developed as a chemotherapeutic or an anti-angiogenesis agent for NSCLC in the future.

Relative down-regulation of apoptosis and autophagy genes in colorectal cancer.

BACKGROUND: Cancer is often caused by disturbance in the regulation and/or execution of programmed cell death (PCD, including apoptosis and autophagy). Our aim was to investigate these two pathways simultaneously in the same samples to understand further the pathological roles of PCDs in colorectal cancer. MATERIALS AND METHODS: Real time quantitative PCR (RT-qPCR) array was used to analyse the mRNA levels of 22 apoptosis and autophagy-related genes involved in pro- and anti-action of the pathways in 15 paired (tumour and non-cancerous part) colorectal samples using Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) as the reference gene. RESULTS: GAPDH mRNA content was significantly higher (approximately 4·01 fold) in tumour tissue than that of paired non-cancerous part. The absolute mRNA levels for most of the 22 genes were higher in the tumour tissue also. However, after normalization with GAPDH Ct, the expressions of all the analysed genes were decreased in the tumour tissues, except for damage-regulated autophagy modulator (DRAM). The expression of most of the genes involved in the same pathway was closely correlated to each other in both tumour and non-cancerous tissues, and the correlation of tumour necrosis factor receptor (TNFR) and Akt to other genes in the same pathway was increased in tumour tissues. CONCLUSIONS: The high level expression of GAPDH might reflect the metabolic state of cancer cells, and PCDs were down-regulated in the tumour tissues when metabolic state was taken into consideration. This relative suppression of PCDs in tumour tissue is supposed to be in favour of cancer cell survival.

Protocatechuic acid inhibits cancer cell metastasis involving the down-regulation of Ras/Akt/NF-κB pathway and MMP-2 production by targeting RhoB activation.

BACKGROUND AND PURPOSE: Protocatechuic acid (PCA) is plentiful in edible fruits and vegetables and is thus one anti-oxidative component of normal human diets. However, the molecular mechanisms involved in the chemopreventive activity of PCA are poorly understood. Here, we investigated the mechanism(s) underlying the anti-metastatic potential of PCA. EXPERIMENTAL APPROACH: We used AGS cells in a wound healing model and Boyden chamber assays in vitro and injection of B16/F10 melanoma cells in mice (metastasis model in vivo) to analyse the effect of PCA on cancer cell invasion and metastasis. The activities and expression of molecular proteins were measured by zymographic assay, real-time RT-PCR and Western blotting. KEY RESULTS: PCA inhibited cell migration and invasion at non-cytotoxic concentrations. Decreased expression of matrix metalloproteinase (MMP)-2 and a coincident increase in tissue inhibitor of MMP followed treatment with PCA. The PCA-inhibited MMP-2 activity and expression was accompanied by inactivation of NF-κB. All these effects of PCA could be mediated via the RhoB/ protein kinase Cε (PKCε) and Ras/Akt cascade pathways, as demonstrated by inhibition of PKCε and transfection of PKCε siRNA and ras overexpression vector. Finally, PCA inhibited metastasis of B16/F10 melanoma cells to the liver in mice. CONCLUSION AND IMPLICATIONS: Our data imply that PCA down-regulated the Ras/Akt/NF-κB pathway by targeting RhoB activation, which in turn led to a reduction of MMP-mediated cellular events in cancer cells and provides a new mechanism for the anti-cancer activity of PCA.

Expression of protein kinase C family in human hepatocellular carcinoma.

Protein kinase Cs (PKCs) play important roles in signal transduction, cell regulation, and tumor formation. In the present study, we analyzed the expression of PKCs in human hepatocellular carcinoma (HCC) tissues and explored their roles in the development of HCC. Real-time quantitative PCR and immunohistochemistry showed that PKCbeta and PKCtheta were down-regulated in HCC tissues. Reduced expression of PKCtheta is well correlated with the grade of cancer cells (p = 0.009), and the down-regulated expression of PKCbetaII is associated with HBV infection (p = 0.035). Our findings suggest particular roles of the two PKC isoenzymes in the hepatocarcinogenesis of human HCC.

Analysing the expression of protein kinase C eta in human hepatocellular carcinoma.

AIMS: Protein kinase Cs (PKCs) play important roles in cell proliferation, differentiation, apoptosis, migration and tumorigenesis. In this report, we investigated the expression of PKCeta in human hepatocellular carcinoma (HCC) tissues and explored its role in the development of HCC. METHODS: We used real-time quantitative RT-PCR, mutation analysis, and immunohistochemical staining to analyse the expression of PKCeta in 50 pairs of human hepatocellular carcinoma (HCC) tissues. RESULTS: Expression of PKCeta was down-regulated in 82% of HCC tissues and the reduction of PKCeta was associated with poorer long-term survival of HCC patients. CONCLUSION: Reduced expression of PKCeta may represent a molecular lesion in the development of more aggressive disease of HCC.