Transcription factor Sp1 is upregulated by PKCι to drive the expression of YAP1 during pancreatic carcinogenesis.

Recently, we identified that the atypical protein kinase C isoform ι (PKCι) enhances the expression of Yes-associated protein 1 (YAP1) to promote the tumorigenesis of pancreatic adenocarcinoma harboring mutant KRAS (mu-KRAS). To advance our understanding about underlying mechanisms, we analyze the transcription of YAP1 in pancreatic cancer cells and reveal that transcription factor specificity protein 1 (Sp1) is upregulated by PKCι and subsequently binds to multiple sites in YAP1 promoter to drive the transactivation of YAP1 in pancreatic cancer cells carrying mu-KRAS. The bioinformatics analysis further substantiates that the expression of PKCι, Sp1 and YAP1 is correlated and associated with the stages and prognosis of pancreatic tumors. Moreover, our apoptotic detection data demonstrate that combination of PKCι and Sp1 inhibitors at subtoxic doses displays synergistic effects on inducing apoptosis and reversing the immunosuppression of pancreatic cancer cells, establishing the combination of PKCι and Sp1 inhibitors as a promising novel therapeutic approach, or an adjuvant strategy to potentiate the antitumor effects of other immunotherapeutic agents in pancreatic cancer treatment.

Effect of constituents from Fructus Aurantii Immaturus and Radix Paeoniae Alba on gastrointestinal movement.

Fructus Aurantii Immaturus and Radix Paeoniae Alba Powder (FPP) is a popular Chinese herbal prescription. The combination of Fructus Aurantii Immaturus and Radix Paeoniae Alba has been used to treat gastrointestinal disorders for hundreds of years. To our interest, this combination shows a bilateral effect on gastrointestinal peristalsis. Our present study was focused on the bilateral role of this combination on the gastrointestinal tract. The effective constituents and mechanisms were explored. Six monomer constituents from Radix Paeoniae Alba and Fructus Aurantii Immaturus were screened by intestinal transit assay. The bilateral roles of three effective constituents were authenticated by gastric emptying assay, and the combination of three constituents showed a bilateral effect. Then, the mediating receptors and the role of NO and NF- kappaB p65 were examined to determine the mechanism involved. The overall results suggest that the major effective constituents of this combination are synephrine, hesperidin and paeoniflorin. Synephrine inhibits the gastrointestinal movement, while hesperidin stimulates it. Paeoniflorin shows different effects on intestinal and gastric activity. The effect of synephrine relies on the alpha-adrenergic receptor, and the effect of hesperidin is mediated via the H1 histamine receptor. The regulation of hesperidin and synephrine on NF- kappaB p65 translocation and NO production through the alpha-receptor and the H1 receptor, respectively, is involved in the bilateral effect of the Fructus Aurantii Immaturus-Radix Paeoniae Alba combination.

Inhibition of tumor cell proliferation by Coleon C.

Coleon C (6,11,12,14,16-pentahydroxyabieta-5,8,11,13-tetraen-7-one), extracted from Coleus forskohlii Briq., was investigated for its anti-tumor activity on eight human tumor cell lines (95-D, A375, HeLa, A431, MKN45, BEL7402, LoVo and HL60) and two normal ones (293, L02) by MTT and colony-forming assay in vitro. The results indicated that A375 was the most sensitive of all the cell lines. Hoechst 33258 staining showed fragmentation and condensation of chromatin. DNA ladder assay indicated the fragments of DNA because of apoptosis. Flow cytometric analysis demonstrated hypodiploid cells existed in A375 after Coleon C treatment. In the acute toxicity studies of C57BL/6 mice, LD(50 )of Coleon C was 1496+/-150 mg/kg. In the model of Lewis lung carcinoma, the average tumor weight in groups injected with 80 mg/kg Coleon C decreased by 48.9+/-14.3% compared with that of the control. These results indicate that Coleon C could effectively inhibit tumor cell proliferation and growth by inducing apoptosis with low toxicity. To our knowledge, this is the first report on the anti-tumor activity of Coleon C both in vitro and in vivo.

Kaempferol-7-O-beta-D-glucoside (KG) isolated from Smilax china L. rhizome induces G2/M phase arrest and apoptosis on HeLa cells in a p53-independent manner.

Kaempferol-7-O-beta-D-glucoside (KG), a flavonoid glycoside, isolated from Smilax china L. rhizome, displayed marked anticancer activity on a panel of established cancer cells, of which, HeLa human cervix carcinoma cells were the most sensitive. Meanwhile, the cytotoxic effects of KG on normal human cells (HEK293 embryonic kidney cells and L-02 embryonic liver cells) were much smaller than on cancer cells. This work studied the molecular mechanisms underlying KG induced growth inhibition in HeLa cells. The results showed that KG induced G2/M phase growth arrest correlated with Cyclin B1 and Cdk1 decrease in a p53-independent manner, and also caused an increase in apoptosis, which was confirmed by characteristic morphological changes, evident DNA fragmentation, increased apoptotic sub-G1 population. Furthermore, inhibition of NF-kappaB nuclear translocation, up-regulation of Bax and down-regulation of Bcl-2, were observed in HeLa cells treated with KG, which indicated that the mitochondrial pathway was involved in the apoptosis signal pathway. In summary, KG displayed a significant anti-tumor effect through cell cycle arrest and apoptotic induction in HeLa cells, which suggested that KG might have therapeutic potential against cervix carcinoma.

A flavonoid glycoside isolated from Smilax china L. rhizome in vitro anticancer effects on human cancer cell lines.

The anticancer activity of eight crude extracts of Smilax china L. rhizome (SCR) against HeLa cells was assessed by MTT assay and clonogenic assay, the fraction rich in flavonoids had show good activity against HeLa cells. A bioassay-guided separation on this extract lead to the detection of kaempferol-7-O-beta-D-glucoside (KG), which belongs to flavonoid glycoside, displayed marked anticancer activity. We evaluated its in vitro cytotoxicity and antiproliferative effect in a panel of established cancer cell lines by MTT assay and clonogenic assay. KG induces A375 and HL60 cells apoptosis, which was demonstrated by morphological changes, DNA fragmentation and flow cytometric analysis. Fluorescent staining with Hoechst 33258 showed fragmentation and condensation of chromatin in the A375 and HL60 cells. Flow cytometric analysis shown that A375 and HL60 cells treated with KG resulted in the appearance of a hypodiploid peak (A0 region), probably due to the presence of apoptosing cells and/or apoptotic bodies with DNA content less than 2n. Quantitation of the hypodiploid cells shows a dose-dependent response to KG, and this result is in good accordance with that of the DNA fragmentation assay by agarose gel electrophoresis. Our results suggested that cell cycle arrest at G(1) phase and induce apoptosis as a mechanism by which KG exerts an antiproliferative effect.

Influence of dietary conjugated linoleic Acid and fat source on body fat and apoptosis in mice.

OBJECTIVE: To determine whether altered dietary essential fatty acid (linoleic and arachidonic acid) concentrations alter sensitivity to conjugated linoleic acid (CLA)-induced body fat loss or DNA fragmentation. RESEARCH METHODS AND PROCEDURES: Mice were fed diets containing soy oil (control), coconut oil [essential fatty acid deficient (EFAD)], or fish oil (FO) for 42 days, and then diets were supplemented with a mixture of CLA isomers (0.5% of the diet) for 14 days. Body fat index, fat pad and liver weights, DNA fragmentation in adipose tissue, and fatty acid profiles of adipose tissue were determined. RESULTS: The EFAD diet decreased (p < 0.05) linoleic and arachidonic acid in mouse adipose tissue but did not affect body fat. Dietary CLA caused a reduction (p < 0.05) in body fat. Mice fed the EFAD diet and then supplemented with CLA exhibited a greater reduction (p < 0.001) in body fat (20.21% vs. 6.94% in EFAD and EFAD + CLA-fed mice, respectively) compared with mice fed soy oil. Dietary FO decreased linoleic acid and increased arachidonic acid in mouse adipose tissue. Mice fed FO or CLA were leaner (p < 0.05) than control mice. FO + CLA-fed mice did not differ in body fat compared with FO-fed mice. Adipose tissue apoptosis was increased (p < 0.001) in CLA-supplemented mice and was not affected by fat source. DISCUSSION: Reductions in linoleic acid concentration made mice more sensitive to CLA-induced body fat loss only when arachidonic acid concentrations were also reduced. Dietary essential fatty acids did not affect CLA-induced DNA fragmentation.