5Alpha-reductase type 1 and aromatase in breast carcinoma as regulators of in situ androgen production

Previous in vitro studies demonstrated that bioactive androgen 5alpha-dihydrotestosterone (DHT) exerted antiproliferative effects through an interaction with androgen receptor (AR) in breast carcinoma cells. However, AR status has not been examined in association with DHT concentration in breast carcinoma tissues, and significance of androgenic actions remains unclear in breast carcinomas. Therefore, in our study, we first examined intratumoral DHT concentrations in 38 breast carcinoma tissues using liquid chromatography/electrospray tandem mass spectrometry. Intratumoral DHT concentration was positively associated with 5alpha-reductase type 1 (5alphaRed1), and negatively correlated with aromatase. We then examined clinical significance of AR and 5alphaRed1 status in 115 breast carcinoma tissues by immunohistochemistry. Breast carcinomas positive for both AR and 5alphaRed1 were inversely associated with tumor size or Ki-67. These patients showed significant associations with a decreased risk of recurrence and improved prognosis for overall survival, and the AR / 5alphaRed1 status was demonstrated an independent prognostic factor. Moreover, we examined possible regulation of DHT production by aromatase in in vitro studies. DHT synthesis from androstenedione in MCF-7 cells was significantly inhibited by coculture with aromatase-positive stromal cells, which was significantly reversed by addition of aromatase inhibitor exemestane. These results suggest that intratumoral DHT concentration is mainly determined by 5alphaRed1 and aromatase in breast carcinoma tissues, and antiproliferative effect of DHT may primarily occur in the cases positive for both AR and 5alphaRed1. Aromatase inhibitors may be more effective in these patients, possibly due to increasing local DHT concentration with estrogen deprivation.     

Modifying effect of dietary sesaminol glucosides on the formation of azoxymethane-induced premalignant lesions of rat colon

Sesame, which has been reported to have preventive effects against various disordered conditions, contains small quantities of lignans and several precursors to them such as sesaminol glucosides (SG). The lignans have the potent antioxidative activity and are suggested to have chemopreventive property. In the present study, we evaluated the modulating effect of SG on the development of colon precancerous lesions, aberrant crypt foci (ACF) and beta-catenin-accumulated crypts (BCAC), in the azoxymethane (AOM)-induced short-term model using male F344 rats. Dietary SG (500 ppm) significantly decreased the incidence of AOM-induced ACF when compared to the control (P<0.01). The incidences of AOM-induced BCAC in the SG-treated groups (250 or 500 ppm) were also significantly lower than that of the control group (P<0.01). Interestingly, administration of 500 ppm SG clearly decreased serum triglyceride level and mRNA expression of intestinal fatty acid-binding protein in the colonic mucosa, as compared to the control. These findings indicate that dietary SG inhibits AOM-induced carcinogenesis and suggest SG as a possible chemopreventive agent.     

Serum vaspin levels: A possible correlation with digital ulcers in patients with systemic sclerosis

Vaspin is an adipokine implicated in vascular inflammation and remodeling. We herein evaluated the clinical correlation of serum vaspin levels in systemic sclerosis (SSc). Consistent with previous reports, 12% of subjects exhibited serum vaspin levels over 10 ng/mL, likely due to genetic effects. Excluding these subjects, despite no difference between SSc and control subjects, serum vaspin levels were significantly decreased in SSc patients with digital ulcers compared with those without, suggesting the potential contribution of vaspin to digital ulcers of this disease.     

Systemic sclerosis

Systemic sclerosis (SSc) is a multisystem autoimmune disease characterized by vasculopathy and tissue fibrosis of the skin and various internal organs. A series of genetic and epidemiological studies have demonstrated that SSc onset is determined by the accumulation of predisposing factors related to environmental influences, while genetic factors affect the susceptibility to and the severity of this disease. This notion has been confirmed by recent advance in animal models. The initial trigger of SSc is believed to be autoimmune attacks to endothelial cells, which occur in individuals with the genetic susceptibility to autoimmune diseases and/or the cumulative exposure to certain SSc‐related environmental influences. Then, endothelial cells are aberrantly activated or damaged, leading to the development of vascular structural changes, such as destructive vasculopathy and proliferative obliterative vasculopathy, and tissue fibrosis. In parallel, inflammatory cells activate SSc fibroblasts and modify the metabolism of extracellular matrix by soluble factors and autoantibodies. Prior to or during these processes, SSc fibroblasts acquire the ability to selectively respond to profibrotic growth factors and cytokines, persistently producing excessive amount of extracellular matrix. SSc fibroblasts also modify immune responses, at least those of CD4⁺ T cells, in the microenvironment through the secretion of immune regulatory molecules. Thus, various types of individually activated cells interact with each other and coordinately drive an SSc‐specific disease cascade, leading to the development of unique clinical symptoms. This article provides an overview of the current understanding of the pathogenesis of SSc with the recent advance in the research field of this disease.     

Palmoplantar keratosis in oculodentodigital dysplasia with a GJA1 point mutation out of the C‐terminal region of connexin 43

Gap junction proteins are composed of 21 genes of the connexin (Cx) family. They play important roles in cell–cell contact by exchange of small molecules through hemichannels. Hence, mutations of Cx family genes affect various tissues of a body. The mutation of the GJA1 gene, which codes Cx43, causes oculodentodigital dysplasia (ODDD), commonly in an autosomal dominant manner with phenotypic variability. It has been believed that gene mutations causing truncation of the Cx43 C‐terminus is necessary and sufficient for palmoplantar keratosis (PPK) development in ODDD patients. Here, we report a case of an ODDD patient developing PPK with a GJA1 gene mutation (c.412G>A/p.Gly138Ser), which was previously reported in a case of ODDD without PPK and expected not to result in C‐terminal truncation of Cx43. This case suggests not only C‐terminal truncation, but also that a point mutation in the cytoplasmic region of Cx43 can cause PPK in ODDD patients.