4-Acetyl-12,13-epoxyl-9-trichothecene-3, 15-diol from Isaria japonica mediates apoptosis of rat bladder carcinoma NBT-II cells by decreasing anti-apoptotic Bcl-2 expression and increasing pro-apoptotic Bax expression

We studied the effect of 4-acetyl-12,13-epoxyl-9-trichothecene-3, 15-diol (AETD) isolated from Isaria japonica, one of the most popular Chinese fungal medicines, on the induction of apoptosis in rat bladder carcinoma NBT-II cells. AETD was cytotoxic to NBT-II cells, and this cytotoxic effect appears to be attributed to its induction of apoptotic cell death, as AETD induced nuclear morphological changes and internucleosomal DNA fragmentation, and increased the proportion of hypodiploid cells and activity of caspase-3. AETD treatment also decreased the expression of the anti-apoptotic protein Bcl-2 and increased the expression of the pro-apoptotic protein Bax. These results provide important information in understanding the mechanism(s) of AETD-induced apoptosis.     

Isolation and anticomplement activity of compounds from Dendropanax morbifera

Dendropanax morbifera Leveille (Araliaceae) is used in Korea for a variety of disease, such as migraine headache and dysmenorrheal. A new polyacetylene (1) and six known compounds (2–7) were isolated from the leaves of this plant by conventional chromatographic techniques. The structure of the new polyacetylene (1) was determined as (9Z,16S)-16-hydroxy-9,17-octadecadiene-12,14-diynoic acid by spectroscopic means including 2D NMR, which comprised the determination of a chiral by modified Mosher’s ester method. Compounds 1–7 were investigated in vitro for their anticomplement activity against the classical pathway of the complement system. Of these, compound 1 showed significant anticomplement activity with 50% inhibitory concentration (IC₅₀) value of 56.98 μM, whereas compounds 2–7 were inactive.     

Rosiglitazone versus placebo for men with prostate carcinoma and a rising serum prostate-specific antigen level after radical prostatectomy and/or radiation therapy

BACKGROUND: The objective of this study was to assess the biologic activity of rosiglitazone, a peroxisome proliferator-activated receptor gamma agonist that has been approved to treat type 2 diabetes, in men with recurrent prostate carcinoma using change in prostate specific antigen (PSA) doubling time (PSADT) as the primary outcome variable. METHODS: Men with histologically confirmed prostate carcinoma, no recent hormone therapy, a rising serum PSA level after radical prostatectomy and/or radiation therapy, and no radiographic evidence of metastases were assigned randomly to receive either oral rosiglitazone (4 mg twice daily) or placebo. The treatment was continued until the men developed disease progression or adverse effects. A positive outcome was defined as a posttreatment PSADT > 150% the baseline PSADT and no new metastases. RESULTS: One hundred six men were enrolled. The median treatment duration was 315 days for men in the placebo group and 338 days for men in the rosiglitazone group (P = 0.28). Forty percent of men in the in the placebo group and 38% of men in the rosiglitazone group had a posttreatment PSADT > 150% of the baseline PSADT and no new metastases (P = 1.00). In exploratory analyses, the rate of a positive outcome remained higher than expected in the placebo group, even when a positive outcome was redefined using more stringent criteria. The time to disease progression was similar between the groups. CONCLUSIONS: Rosiglitazone did not increase PSADT or prolong the time to disease progression more than placebo in men with a rising PSA level after radical prostatectomy and/or radiation therapy. The unexpected discordance between baseline and posttreatment PSADT in the placebo group reinforced the importance of randomized controlled trials in this setting.     

Human CTLs to wild-type and enhanced epitopes of a novel prostate and breast tumor-associated protein, TARP, lyse human breast cancer cells

Vaccine therapy for prostate and breast cancer may have potential for treating these major causes of death in males and females, respectively. Critical to the development of tumor-specific vaccines is finding and characterizing novel antigens to be recognized by CD8(+) T cells. To define new CD8(+) T-cell tumor antigens, we determined two wild-type HLA-A2 epitopes from a recently found tumor-associated protein, TARP (T-cell receptor gamma alternate reading frame protein), expressed in prostate and breast cancer cells. We were also able to engineer epitope-enhanced peptides by sequence modifications. Both wild-type and enhanced epitopes induced peptide-specific CD8(+) T-cell responses in A2K(b) transgenic mice. In vitro restimulation of human CD8(+) T cells from a prostate cancer patient resulted in CD8(+) T cells reactive to the peptide epitopes that could lyse HLA-A2(+) human breast cancer cells (MCF-7) expressing TARP. Epitope-specific human CD8(+) T cells were also enumerated in patients' peripheral blood by tetramer staining. Our data suggest that HLA-A2-binding TARP epitopes and enhanced epitopes discovered in this study could be incorporated into a potential vaccine for both breast and prostate cancer.     

Tissue inhibitors of metalloproteinase 2 inhibits endothelial cell migration through increased expression of RECK

The antiangiogenic function of the tissue inhibitors of metalloproteinases (TIMPs) has been attributed to their matrix metalloproteinase inhibitory activity. Here we demonstrate that TIMP-1 but not Ala+TIMP-1 inhibits both basal and vascular endothelial growth factor (VEGF)-stimulated migration of human microvascular endothelial cells (hMVECs), suggesting that this effect is dependent on direct inhibition of matrix metalloproteinase (MMP) activity. In contrast, TIMP-2 and mutant Ala+TIMP-2, which is devoid of MMP inhibitory activity, block hMVEC migration in response to VEGF-A stimulation. TIMP-2 and Ala+TIMP-2 also suppress basal hMVEC migration via a time-dependent mechanism mediated by enhanced expression of RECK, a membrane-anchored MMP inhibitor, which, in turn, inhibits cell migration. TIMP-2 treatment of hMVECs increases the association of Crk with C3G, resulting in enhanced Rap1 activation. hMVECs stably expressing Rap1 have increased RECK expression and display reduced cell migration compared with those expressing inactive Rap1(38N). RECK-null murine embryo fibroblasts fail to demonstrate TIMP-2-mediated decrease in cell migration despite activation of Rap1. TIMP-2-induced RECK decreases cell-associated MMP activity. Anti-RECK antibody increases MMP activity and reverses the TIMP-2-mediated reduction in cell migration. The effects of TIMP-2 on RECK expression and cell migration were confirmed in A2058 melanoma cells. These results suggest that TIMP-2 can inhibit cell migration via several distinct mechanisms. First, TIMP-2 can inhibit cell migration after VEGF stimulation by direct inhibition of MMP activity induced in response to VEGF stimulation. Secondly, TIMP-2 can disrupt VEGF signaling required for initiation of hMVEC migration. Third, TIMP-2 can enhance expression of RECK via Rap1 signaling resulting in an indirect, time-dependent inhibition of endothelial cell migration.     

20(S)-Protopanaxatriol, one of ginsenoside metabolites, inhibits inducible nitric oxide synthase and cyclooxygenase-2 expressions through inactivation of nuclear factor-kappaB in RAW 264.7 macrophages stimulated with lipopolysaccharide

Ginsenosides from Panax ginseng are metabolized by human intestinal bacteria after oral administration of ginseng extract. 20(S)-Protopanaxatriol (PPT) is one of the major metabolites of ginsenosides. Inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are important enzymes that mediate inflammatory processes. Improper up-regulation of iNOS and/or COX-2 has been associated with the pathogenesis of inflammatory diseases and certain types of human cancers. Here, we investigated whether PPT could modulate iNOS and COX-2 expressions in RAW 264.7 macrophages stimulated with the endotoxin lipopolysaccharide (LPS). We found that PPT blocked the increase in LPS-induced iNOS and COX-2 expressions through inactivation of nuclear factor-kappaB by preventing I-kappaBalpha phosphorylation and degradation. Thus, it may be possible to develop PPT as a useful agent for chemoprevention of cancer or inflammatory diseases.     

Inhibition of cell cycle progression on HepG2 cells by hypsiziprenol A9, isolated from Hypsizigus marmoreus

Antiproliferative activities of fractions of Hypsizigus marmoreus were examined using HepG2 cells in vitro. The methanol extract of H. marmoreus markedly induced antiproliferative activity, and an active compound from this mushroom was identified as hypsiziprenol A9. Hypsiziprenol A9 inhibited cell proliferation in a time- and concentration-dependent manner by up to 80% on HepG2 cells by inducing arrest of the G1 phase. Further investigation revealed that hypsiziprenol A9 decreased expression of phosphorylated retinoblastoma protein (ppRb), cyclin D1, and cyclin E in a dose-dependent manner. These results suggest that hypsiziprenol A9 can inhibit the growth of HepG2 cells through inducing G1 phase cell cycle arrest due to the inhibition of pRb phosphorylation.     

Transgenic mouse model for breast cancer: induction of breast cancer in novel oncogene HCCR-2 transgenic mice

Transgenic mice containing novel oncogene HCCR-2 were generated to analyse the phenotype and to characterize the role of HCCR-2 in cellular events. Mice transgenic for HCCR-2 developed breast cancers and metastasis. The level of p53 in HCCR-2 transgenic mice was elevated in most tissues including breast, brain, heart, lung, liver, stomach, kidney, spleen, and lymph node. We examined whether stabilized p53 is functional in HCCR-2 transgenic mice. Defective induction of p53 responsive genes including p21WAF1, MDM2, and bax indicates that stabilized p53 in HCCR-2 transgenic mice exists in an inactive form. These results suggest that HCCR-2 represents an oncoprotein that is related to breast cancer development and regulation of the p53 tumor suppressor.     

Response of pulmonary tuberculomas to anti-tuberculous treatment.

Pulmonary tuberculomas are well-circumscribed masses caused by Mycobacterium tuberculosis. However, the response of tuberculomas to anti-tuberculous (TB) treatment has not been well defined as yet. The response of pulmonary tuberculomas to anti-TB treatment was retrospectively reviewed in 45 patients diagnosed between January 1997 and December 2001. The areas of pulmonary tuberculomas were estimated by calculating products of the longest and their perpendicular short diameters on chest radiographs. The response to anti-TB treatment was categorised as "decreased" (> 25% reduction in area versus its initial area), "increased" (> 251% increase) and "no change" (the remainder). The mean of treatment duration was 11.5 +/- 3.6 months. Three months after treatment, 18 patients (40.0%) were categorised as decreased, 25 (55.6%) as no change and two (4.4%) as increased. Twelve months after treatment, out of 42 patients available for chest radiographs, 32 patients (76.2%) were categorised as decreased, nine (21.4%) as no change and one patient (2.4%) as increased. At the last follow-up (mean follow-up 27.0 +/- 10.2 months), 37 patients (82.2%) were categorised as decreased. The majority of pulmonary tuberculomas were decreased by anti-tuberculosis treatment during and even after treatment, although a transient enlargement during the early period of treatment was observed infrequently.