Binzhou Medical College

About: Binzhou Medical College is a education organization based out in Yantai, China. It is known for research contribution in the topics: Apoptosis & Cancer. The organization has 959 authors who have published 619 publications receiving 7642 citations.

A comparison of the excited-state processes of nearly symmetrical perylene quinones: hypocrellin A and hypomycin B

Abstract: The excited-state photophysics of two naturally occurring nearly symmetrical perylene quinones are discussed: hypocrellin A and hypomycin B. Hypocrellin A has a hydroxyl group peri to a carbonyl group on either end of its long molecular axis in addition to a hydroxyl group on its seven-membered ring. On the other hand, hypomycin B is unique among this class of known naturally occurring perylene quinones in that it possesses only one hydroxyl group, which is peri to a carbonyl group. These quinones are investigated in different nonionic micellar environments. For hypocrellin A and hypomycin B, a micelle concentration 10 times in excess of that used for hypericin in a previous study, i.e. 100 times the critical micelle concentration, must be employed to obviate aggregation. Under such conditions, the p K a of the peri hydroxyl groups of hypocrellin A have been determined to be 8.9. The p K a of the protonated carbonyl groups could not be measured. A comparable value is estimated for hypomycin B. The differing solubilities and behaviors of hypericin and hypocrellin in micellar environments are briefly discussed in the context of their biological activity. The excited-state processes in hypocrellin A and hypomycin B are compared on a time scale of several hundreds of picoseconds. No deuterium isotope effect is observed for hypomycin B. This result is discussed in the light of the previous assignment of the primary photoprocess in hypocrellin A to hydrogen atom transfer.

Colorimetric detection of heparin with high sensitivity based on the aggregation of gold nanoparticles induced by polymer nanoparticles

Abstract: Herein, a new colorimetric strategy based on polymer nanoparticles (PNPs) and Au nanoparticles (AuNPs) is developed to detect heparin (Hep). The cationic PNPs can directly induce the aggregation of AuNPs, which are stabilized by negatively charged coating of citrate ions, and hence the absorption peak of AuNPs moves to 675 nm corresponding with a color change from wine red to blue. However, the negatively charged Hep competes with AuNPs and binds to PNPs, hindering the interaction between PNPs and AuNPs. As a result, the absorption band of AuNPs blue shifts and the color turns to red again. The reaction can be completed within 10 min, and the color variation produced by 150 nM of Hep can be distinguished by the naked eye. In addition, this strategy also shows good selectivity and sensitivity, and the linear range of Hep is from 10 to 400 nM with detection limit of 2.5 nM. Finally, this colorimetric assay has been applied to measure Hep in Hep sodium injection and human serum samples with satisfactory recoveries.

Expression and clinical significance of mammalian target of rapamycin/P70 ribosomal protein S6 kinase signaling pathway in human colorectal carcinoma tissue.

Abstract: The activation of mammalian target of rapamycin (mTOR) has been reported in tumor development, but the role of mTOR in colorectal carcinomas remains unclear. The aim of the present study was to investigate the significance of mTOR and its downstream effector 70 kDa ribosomal protein S6 kinase (P70S6K) in human colorectal carcinomas. The phosphorylated (p-)mTOR and p-P70S6K proteins were examined by immunohistochemistry performed on tissue microarray containing tissue samples obtained from colorectal carcinoma (n=111), adenomatous polyps (n=40) and normal colonic mucosa (n=40), with a comparison between the expression of these proteins and the clinicopathological parameters of patients with carcinomas. The positive expression rates of p-mTOR and p-P70S6k were 60.4 and 65.8%, respectively, in colorectal carcinoma tissue, which was significantly increased compared with the tissue from adenomatous polyps (27.5 and 20%, respectively) and normal colonic mucosa (10.0 and 5.0%, respectively) (P<0.05). Overexpression of the p-mTOR and p-P70S6K proteins was significantly associated with the tumor-node-metastasis stage, the occurrence of distal and lymph node metastasis and the degree of differentiation. Aberrant expression of p-mTOR and p-P70S6K may contribute to the pathogenesis, growth, invasion and metastasis of colorectal carcinoma. The phosphorylation of these proteins was considered to be a promising marker to indicate the aggressive behaviors and prognosis of colorectal carcinomas. The overexpression of the mTOR/P70S6K signaling pathway may play an important role in colorectal carcinoma carcinogenesis. The expression of p-mTOR and p-P70S6K was considered as a promising marker to indicate the aggressive behaviors and prognosis of human colorectal carcinomas.

DNA Methylation of Heparanase Promoter Influences Its Expression and Associated with the Progression of Human Breast Cancer

Abstract: Heparanase promotes tumor invasion and metastasis in several malignancies including breast cancer. However, the roles and regulation mechanisms of heparanase during breast cancer progression are still not fully understood. The aim of this study is to determine the differential regulation of heparanase gene expression in specific stages of breast cancer by DNA methylation. We detected levels of heparanase expression and DNA methylation patterns of its promoter in breast cancer cell lines (MCF-7 and MDA-MB-435) and clinical tissues, respectively. It has been observed that heparanase is highly expressed in the invasive MDA-MB-435 cells with low methylation modification in the heparanase promoter. In contrast, lower expression of heparanase in MCF-7 cells is accompanied by higher methylation in the promoter. Treatment of MCF-7 cells with 5-aza-2′-deoxycytidine (5-aza-dC), a potent demethylating agent, results in induction of heparanase expression and higher invasion potential in vitro and leads to an advantage of tumor formation in vivo. In 54 tissue samples, cancer samples at late stages (stage IV) showed the highest heparanase expression accomplished by little DNA methylation. On the contrary, methylation prevalence is highest in normal tissue and inversely correlated with heparanase expression. A significant correlation between DNA methylation and clinical stage was demonstrated (p = 0.012). Collectively, these results demonstrate that DNA methylation play the regulation role in heparanase gene in different stages of breast cancer and present a direct effect on tumor progression.

The role of cofilin-l in vulvar squamous cell carcinoma: A marker of carcinogenesis, progression and targeted therapy.

Abstract: Numerous studies have revealed that cofilin-l (CFL1) is associated with cancer cell migration and invasion in various types of tumor tissues. We investigated the roles of CFL1 in vulvar squamous cell carcinoma (VSCC). CFL1 expression was detected in VSCC and normal vulvar tissues using immunohistochemistry and western blotting. The vulvar carcinoma SW962 cell line was transfected with CFL1 small interfering RNA (siRNA) and exposed to periplocoside. We then assessed changes in cell proliferation, apoptosis, invasion and metastasis. We detected changes in CFL1 mRNA and protein expression by RT-PCR and western blotting, and alterations in protein expression of various relevant molecules by western blotting. CFL1 expression was found to be significantly upregulated in the VSCC tissues compared with the normal vulvar tissues by immunohistochemistry and western blotting (P<0.05) and was positively correlated with International Federation of Gynecology and Obstetrics (FIGO) stage, differentiation and lymphatic metastasis (P<0.05). After CFL1 knockdown by siRNA transfection, SW962 cells exhibited a decrease in growth, G1 phase cell cycle arrest, induction of apoptotic, low invasion and metastasis, and disrupted lamellipodium formation. We found that the protein expression of Bcl-xL, cyclin A1, MMP2, MMP9 and STAT3 was decreased, while expression of Bax was increased. Periplocoside inhibited SW962 cell growth, promoted apoptosis, suppressed invasion and migration, and lamellipodium formation. Periplocoside exposure resulted in lower CFL1, Bcl-xL, cyclin A1, MMP2, MMP9 and STAT3 levels, but a higher Bax level compared with the control group. We demonstrated that abnormal CFL1 expression may affect vulvar carcinogenesis and subsequent progression. CFL1 silencing by siRNA significantly inhibited VSCC cell progression, which suggests that CFL1 is a potential therapeutic target for vulvar cancer. Periplocoside, which was utilized in the present study for the clinical treatment of vulvar cancer, showed strong antitumor effects by suppression of CFL1 expression.