Esophageal squamous cell carcinomas with distinct invasive depth show different gene expression profiles associated with lymph node metastasis

We examined the gene expression profiles of esophageal squamous cell carcinomas (ESCCs) with respect to degree of invasive depth and lymph node (LN) involvement in a large cohort. We used high-density oligonucleotide microarrays to examine the expression of 22,115 genes in 54 ESCCs and 11 non-cancerous esophageal tissues. We found that 4,155 genes were biologically significant in both ESCC and non-cancerous esophageal tissue by analysis of Present Call (hybridization quality by Affymetrix) throughout all samples. From these genes, we used a supervised learning method to select genes responsible for the development of ESCC. We found that 999 genes were expressed differentially in pT1/pN0 tumors vs. non-cancerous esophageal tissue. In the same manner, 48, 66 and 30 genes were expressed differentially in pT1/pN0 tumors vs. pT1/pN1 tumors, pT1/pN0 tumors vs. pT2-4/pN0 tumors and pT2-4/pN0 tumors vs. pT2-4/pN1 tumors, respectively. Intriguingly, there were no overlaps between the 48 LN metastasis-related genes of pT1 tumors and the 30 LN metastasis-related genes of pT2-4 tumors, suggesting that ESCCs with distinct invasive depths express different genes linked to LN metastasis. Our present results suggest that the degree of invasive depth must be considered when predicting LN metastasis of ESCC from gene expression profiles.     

Cationized gelatin delivery of a plasmid DNA expressing small interference RNA for VEGF inhibits murine squamous cell carcinoma

Double-stranded RNA (dsRNA) plays a major role in RNA interference (RNAi), a process in which segments of dsRNA are initially cleaved by the Dicer into shorter segments (21-23 nt) called small interfering RNA (siRNA). These siRNA then specifically target homologous mRNA molecules causing them to be degraded by cellular ribonucleases. RNAi down regulates endogenous gene expression in mammalian cells. Vascular endothelial growth factor (VEGF) is a key molecule in vasculogenesis as well as in angiogenesis. Tumor growth is an angiogenesis-dependent process, and therapeutic strategies aimed at inhibiting angiogenesis are theoretically attractive. To investigate the feasibility of using siRNA for VEGF in the specific knockdown of VEGF mRNA, thereby inhibiting angiogenesis, we have performed experiments with a DNA vector based on a siRNA system that targets VEGF (siVEGF). It almost completely inhibited the expression of three different isoforms (VEGF120, VEGF164 and VEGF188) of VEGF mRNA and the secretion of VEGF protein in mouse squamous cell carcinoma NRS-1 cells. The siVEGF released from cationized gelatin microspheres suppressed tumor growth in vivo. A marked reduction in vascularity accompanied the inhibition of a siVEGF-transfected tumor. Fluorescent microscopic study showed that the complex of siVEGF with cationized gelatin microspheres was still present around the tumor 10 days after injection, while free siVEGF had vanished by that time. siVEGF gene therapy increased the fraction of vessels covered by pericytes and induced expression of angiopoietin-1 by pericytes. These data suggest that cationized-gelatin microspheres containing siVEGF can be used to normalize tumor vasculature and inhibit tumor growth in a NRS-1 squamous cell carcinoma xenograft model.     

Melanogenesis inhibitory and free radical scavenging activities of diarylheptanoids and other phenolic compounds from the bark of Acer nikoense

Melanogenesis inhibitory and free radical scavenging activities of nine cyclic (1-9) and one acyclic diarylheptanoids (10), and two phenolic compounds, (+)-rhododendrol (11) and (+)-catechin (12), isolated from the ethyl acetate-soluble fraction of the MeOH extract of the bark of Acer nikoense MAXIM. (Aceraceae) were examined. Upon evaluation of compounds 1-12 on the melanogenesis in the B16 melanoma cells, two compounds, 2 and 8, exhibited marked inhibitory activity with 55.6% and 46.8% reduction, respectively, of melanin content at 25 microg/ml without inhibition of cell proliferation. In addition, upon an evaluation of eleven compounds, 1-7 and 9-12 against the scavenging activities of free radicals (against the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical), compound 12 (IC(50) 9.0 microgM) followed by compounds 1, 3, 4, and 6 (IC(50) 40.2-44.0 microgM) showed potent scavenging activities.     

Molecular mechanisms and therapeutic strategies of chronic renal injury: the role of nuclear factor kappaB activation in the development of renal fibrosis

Tubulointerstitial fibrosis is a common feature of many progressive renal diseases and is a main determinant that leads to an irreversible loss of renal function. In chronic cyclosporin A nephrotoxicity, we previously reported that inflammatory responses such as macrophage infiltration preceded interstitial fibrosis. This inflammation was accompanied by an elevation in renal nuclear factor kappaB (NF-kappaB) activity. Similar findings were obtained in chronic tacrolimus nephrotoxicity and obstructive nephropathy. Inhibition of NF-kappaB markedly attenuated renal inflammation and interstitial fibrosis in these models. Furthermore, administration of oral adsorbent (Kremezin) significantly attenuated the increase in renal NF-kappaB activity and concomitantly reduced interstitial inflammation and renal fibrosis in chronic renal failure rats. Elimination of indoxyl sulfate by this adsorbent is likely involved in this mechanism since it is known that indoxyl sulfate activates NF-kappaB in renal tubular cells. It is suggested that strategy aiming at NF-kappaB inhibition is important to prevent the progression of renal fibrosis.