No abstract

HighlightsWe generated pyrrole–imidazole (PI) polyamides that could bind to an E-box motif.PI polyamide Myc-6 induces G1 arrest and apoptosis in human osteosarcoma MG63 cells.Myc-6 represses tumor growth both in vitro and in vivo.Myc-6 binds to the 5′-upstream region of noncoding RNA MALAT1 and reduces its expression.Myc-6 exerts its tumor-suppressive ability through the down-regulation of MALAT1.

Abstract.We investigated the clinical significance of the expression levels of matrix metalloproteinase 9 (MMP-9) in renal cell carcinoma (RCC). In addition, we validated the efficacy of pyrrole imidazole polyamide (PIP) targeting MMP-9 on inhibiting proliferation and invasion of RCC. We evaluated the expression levels of MMP-9 in 249 RCC specimens by immunostaining and analyzed the association between MMP-9 expression levels and cancer-specific survival. Furthermore, in a human RCC cell line, Caki-2, we tested the effect of a couple of PIPs targeting MMP-9 one recognizing an NF-κB binding site (MMP-9-NF-κB PIP) and another for the AP-1 binding site (MMP-9-AP-1 PIP) in the MMP-9 promoter. The expression levels of MMP-9, proliferative activity and invasive capability were tested by quantitative PCR, WST8 assay and Matrigel invasion assay, respectively. By immunostaining of the clinical specimens, strong MMP-9 staining was proven to be a significant predictor of poor prognosis for cancer-specific survival (P<0.01). In Caki-2 cells, MMP-9-NF-κB PIP significantly reduced the expression levels of MMP-9 mRNA and inhibited cell invasion, but did not affect the cell proliferation activity. On the other hand, no effect was found in MMP-9-AP-1 PIP on MMP-9 mRNA expression, cell proliferation and invasion. We confirmed the inhibitory effects of MMP-9-NF-κB PIP on the expression of MMP-9 and subsequent invasion of Caki-2 cells. Since it was clearly shown that high MMP-9 expression levels were associated with poor prognosis of RCC, MMP-9 is a potential candidate target for RCC treatment. Transcription therapy using a minor groove binder, such as NF-κB PIP, may be a potential therapeutic agent for RCC, although further investigation is required.

Sclerosing encapsulating peritonitis (SEP) is characterized by the diffuse appearance of marked sclerotic thickening of the peritoneal membrane. We experienced a case with SEP accompanied by regional changes of peritoneum. A 37-year-old woman with end-stage renal failure was started on continuous ambulatory peritoneal dialysis in 1985 and was transferred to hemodialysis in 1997. She was admitted because of ileus in 1998 with SEP and died of septicemia. The diagnosis of SEP was confirmed via the autopsy. The root of the mesentery was retracted and shortened. Since the peritoneal change was marked in the regions with free margin of mesentery and was less apparent in the regions not adhered to mesentery, it is indicated that mechanical stress also contributes to the occurrence of SEP. Since calcification and ossification were only seen in a free margin of small bowel from mesentery, it is suggested that there is a close relationship between calcification and ossification. Since fibrosis invaded into the muscle layer, dysfunction of bowel movement as well as bowel obstruction contributed to the appearance of ileus. It is suggested that mechanical stress by the root of mesentery which is retracted and shortened also contributes to the appearance of SEP.

The etiology of Cronkhite-Canada syndrome (CCS) remains unknown and many cases are refractory to treatment. Therefore, new therapies are urgently needed. Furthermore, a number of CCS cases with gastrointestinal carcinoma have been reported. Our patient had rapid onset of CCS and early development of colon carcinoma associated with adenomas. High anterior resection of the sigmoid colon and ileostomy were performed, and her symptoms and endoscopic and histological findings improved. Helicobacter pylori eradication was carried out 2 years later, surgical closure of an ileal fistula the following year. After 4 months, upper gastrointestinal endoscopy and colonoscopy showed that the CCS lesions had completely disappeared, and biopsies confirmed a normal stomach, duodenum, ileum and colon histologically. The patient has maintained remission for 2 years. The clinical course of this case, showing complete regression of CCS lesions following abdominal colectomy and H. pylori eradication, suggests the significance of H. pylori infection in the treatment of CCS.