ARTICLEMen have a substantially higher risk of bladder cancer than women ( 1 ). Excessive exposure of men to cigarette smoke and industrial chemicals, both of which include amines, has been suggested to result in the development of bladder cancer ( 2 ). However, sexrelated differences in the risk of bladder cancer have been shown to persist in the absence of exposure to known carcinogenic factors ( 2 ). In animal experimental models, males are more likely than females to develop bladder cancer induced by certain chemical carcinogens (e.g., aromatic amines, such as N -butyl-N -(4-hydroxybutyl) nitrosamine [BBN]) ( 3 ). In contrast, a recent study ( 4 ) showed that certain other carcinogens, such as the arsenical metabolite dimethylarsinic acid, are more toxic to the female bladder than the male bladder in rats. This finding is consistent with epidemiologic evidence suggesting that women are more susceptible to arsenic-induced bladder cancer than men ( 5 ). Thus, the basis for the sex-specific difference in bladder cancer incidence is not understood.A potential mediator of sex-specifi c differences is the androgen receptor (AR). The AR, a member of the nuclear receptor superfamily, is a ligand-dependent transcriptional factor that mediates the biologic effects of androgens ( 6 , 7 ). Expression of the AR has been detected in normal bladder epithelium ( 8 ) and in bladder carcinomas from both male and female patients ( 9 ). However, little is known about AR function in the bladder or about androgen metabolism in the bladder urothelium. Early studies ( 10 ) showed that levels of cytochrome P450 CYP4B1, which is present at higher levels in male bladder than female bladder and activates
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Background-Thrombomodulin is an anticoagulant, endothelial-cell-membrane glycoprotein. A recombinant thrombomodulin domain containing 6 epidermal growth factor-like structures exhibits mitogenic activity. This study explored the novel angiogenic effects of the recombinant domain using in vitro and in vivo models. Methods and Results-Human recombinant thrombomodulin containing 6 epidermal growth factor-like structures (TMD2) and TMD2 plus a serine and threonine-rich domain (TMD23) were prepared using the Pichia pastoris expression system. Combined with purified TMD2 or TMD23, thrombin effectively activated protein C. TMD23 had higher activity than TMD2 in stimulating DNA synthesis in cultured human umbilical vein endothelial cells. Additionally, TMD23 stimulated chemotactic motility and capillarylike tube formation in human umbilical vein endothelial cells, an effect mediated through phosphorylation of extracellular signal-regulated kinase 1/2 and p38 mitogen-activated protein kinase and the phosphatidylinositol-3 kinase/Akt/endothelial nitric oxide synthase pathway. TMD23 also stimulated endothelial cell expression of matrix metalloproteinases and plasminogen activators, which mediated extracellular proteolysis, leading to endothelial cell invasion and migration during angiogenesis. Furthermore, TMD23-containing implants in rat cornea induced ingrowth of new blood vessels from the limbus. With the murine angiogenesis assay, TMD23 not only induced neovascularization coinjected with Matrigel and heparin but also enhanced angiogenesis in Matrigel containing melanoma A2058 cells in nude mice.
Conclusions-The
The androgen receptor (AR) requires coregulators for its optimal function. However, whether AR coregulators further need interacting protein(s) for their proper function remains unclear. Here we describe transgelin as the first ARA54-associated negative modulator for AR. Transgelin suppressed ARA54-enhanced AR function in ARA54-positive, but not in ARA54-negative, cells. Transgelin suppressed AR transactivation via interruption of ARA54 homodimerization and AR-ARA54 heterodimerization, resulting in the cytoplasmic retention of AR and ARA54. Stable transfection of transgelin in LNCaP cells suppressed AR-mediated cell growth and prostate-specific antigen expression, whereas this suppressive effect was abolished by the addition of ARA54-small interfering RNA. Results from tissue surveys showing decreased expression of transgelin in prostate cancer specimens further strengthened the suppressor role of transgelin. Our findings reveal the novel mechanisms of how transgelin functions as a suppressor to inhibit prostate cancer cell growth. They also demonstrate that AR coregulators, like ARA54, might have dual in vivo roles functioning as both a direct coactivator and as an indirect mediator in AR function. The finding that a protein can modulate AR function without direct interaction with AR might provide a new therapeutic approach, with fewer side effects, to battle prostate cancer by targeting AR indirectly.
The primary aim of this study was to elucidate the role of the estrogen receptor (ER), a transcription factor involved in the nicotine- and 17β-estradiol (E2)-mediated up-regulation of α9-nAChR gene expression. A real-time polymerase chain reaction (PCR) assay was used to quantify the α9-nAChR mRNA expression levels of surgically isolated (n=339) and laser-capture microdissected tissues (ER+ versus ER-, n= 6 per group). Chromatin immunoprecipitation (ChIP) and luciferase-promoter activity assays were used to investigate the ER-mediated transcriptional regulation of α9-nAChR gene expression. We observed that breast tumors with higher α9-nAChR mRNA expression levels (i.e., a mean fold ratio in the tumor/normal-paired samples of greater than tenfold) were associated with the lowest 5-year disease-specific survival rate (50%, dead/alive= 4/4, total = 8 patients, P= 0.006), in contrast to breast tumors with low levels (i.e., a mean fold ratio of less than onefold) of α9-nAChR expression (88%, dead/alive= 3/22, total= 25 patients). Furthermore, higher α9-nAChR mRNA expression levels were preferentially detected in ER+ tumor tissues in comparison to ER- tumor tissues (ER+ versus ER- patients: n=160 vs. 72; mean fold ratios of α9-nAChR expression = 11 ± 3 vs. 6.7 ± 2.3 fold, respectively). In vitro promoter-binding assays demonstrated that the ER is a major transcription factor that mediates nicotine- and E2-induced up-regulation of α9-nAChR gene expression in MCF-7 cells. In conclusion, our data indicate that the ER plays a central role in mediating α9-nAChR gene up-regulation in response to either nicotine or E2 stimulation.
Our data shows that robot-assisted ISR for low rectal cancer is feasible and safe with no compromising oncological outcomes. The surgeons' experience improves operating time in robotic surgery.
Colorectal cancer is a common cancer worldwide, and chemotherapy is a mainstream approach for advanced and recurrent cases. Development of effective complementary drugs could help improve tumor suppression efficiency and control adverse effects from chemotherapy. The aqueous extract of Solanum nigrum leaves (AE-SN) is an essential component in many traditional Chinese medicine formulas for treating cancer, but there is a lack of evidence verifying its tumor suppression efficacy in colorectal cancer. The purpose of this study is to evaluate the tumor suppression efficacy of AE-SN using DLD-1 and HT-29 human colorectal carcinoma cells and examine the combined drug effect when combined with the chemotherapeutic drugs cisplatin, doxorubicin, docetaxel, and 5-fluorouracil. The results indicated that AE-SN induced autophagy via microtubule-associated protein 1 light chain 3 A/B II accumulation but not caspase-3-dependent apoptosis in both cell lines. The IC50s after 48 hours of treatment were 0.541 and 0.948 mg/ml AE-SN in DLD-1 and HT-29, respectively. AE-SN also demonstrated a combined drug effect with all tested drugs by enhancing cytotoxicity in tumor cells. Our results suggest that AE-SN has potential in the development of complementary chemotherapy for colorectal cancer.
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