In vivo tumor imaging using a novel RNAi-based detection mechanism.

A new concept of tumor imaging is introduced using a siRNA-based probe that is capable of amplifying a specific endogenous fluorescence emission in cancerous tissue. In previous studies, we demonstrated a significant downregulation of Ferrochelatase (FECH) mRNA-expression in colorectal carcinomas leading to the accumulation of protoporphyrin IX (PpIX), a fluorescent metabolite of the heme synthesis. In this article, we report on first in vivo experiments in xenografted nude mice using folate-coupled liposomes or dendritic polyglycerolamine nanoparticles carrying ferrochelatase-siRNA to enhance PpIX-derived fluorescence in the tumor tissue. Tiny tumor foci could be monitored by the emission of PpIX fluorescence in vivo. Due to the omnipresence of the heme synthesis pathway, targeted application of ferrochelatase-siRNA may provide a general means for molecular imaging. FROM THE CLINICAL EDITOR: A new concept of tumor imaging is presented in this paper using a siRNA-based probe detecting protoporphyrin IX (PpIX), a fluorescent metabolite of the heme synthesis previously demonstrated to accumulate in cancer tissue.

The correlation between intestinal mucosal lesions and hepatic dysfunction in patients without chronic liver disease.

Patients with cirrhosis are known to develop small bowel mucosal lesions. However, the occurrence of mucosal lesions in patients with abnormal liver function test results in the absence of chronic liver disease has not been fully evaluated. This study aims to examine the association between small bowel endoscopic lesions and liver dysfunction in patients without confirmed chronic liver disease.Two hundred ninety six consecutive patients who met the selection criteria underwent capsule endoscopy. The severity of the small intestinal mucosal lesions was evaluated quantitatively using the Lewis scoring system, and hepatic dysfunction was evaluated using an algorithm-based combination scoring system with 8 individual serological markers.Small bowel lesions were observed in 121 patients (40.88%). Hepatic dysfunction was significantly more prevalent in patients with small bowel lesions than in those without lesions (33.1%; 40/121 and 5.7%; 10/175, respectively; P < .001). The mean serum ALT and AST levels were significantly higher in patients with small bowel lesions than in those without lesions (P = .007 and P = .004, respectively). The mean scores for AST to Platelet Ratio Index, Forns Index, S-Index, Fibrosis-4 Index and BARD were significantly higher in patients with small bowel lesions than those without lesions. The Lewis score significantly and positively correlated with the Forns Index (P = .008) and the FIB-4 Index (P = .006).There is a close correlation between small intestinal mucosal lesions and hepatic dysfunction. The severity of hepatic dysfunction is directly proportional to the severity of the small intestinal mucosal lesions in patients without confirmed chronic liver disease.

Silencing of human ferrochelatase causes abundant protoporphyrin-IX accumulation in colon cancer.

Hemes and heme proteins are vital components of essentially every cell of virtually every eukaryote organism. Previously, we demonstrated accumulation of the heme precursor protoporphyrin-IX (PpIX) in gastrointestinal tumor tissues. To elucidate the mechanisms of PpIX accumulation by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we studied expression of the relevant enzymes of the heme synthetic pathway. Here, we describe a significant down-regulation of ferrochelatase (FECH) mRNA expression in gastric, colonic, and rectal carcinomas. Accordingly, in an in vitro model of several carcinoma cell lines, ferrochelatase down-regulation and loss of enzymatic activity corresponded with an enhanced PpIX-dependent fluorescence. Direct detection of PpIX in minute amounts was achieved by a specifically developed pulsed solid-state laser dual delay fluorimetry setup. Silencing of FECH using small interfering RNA (siRNA) technology led to a maximum 50-fold increased PpIX accumulation, imageable by a specifically adapted two-photon microscopy unit. Our results show that in malignant tissue a transcriptional down-regulation of FECH occurs, which causes endogenous PpIX accumulation. Furthermore, accumulation of intracellular PpIX because of FECH siRNA silencing provides a small-molecule-based approach to molecular imaging and molecular therapy.

Synergistic effect of bone marrow-derived mesenchymal stem cells and platelet-rich plasma in streptozotocin-induced diabetic rats.

BACKGROUND: Diabetic wounds are a major clinical challenge, because minor skin wounds can lead to chronic, unhealed ulcers and ultimately result in infection, gangrene, or even amputation. Studies on bone marrow derived mesenchymal stem cells (BMSCs) and a series of growth factors have revealed their many benefits for wound healing and regeneration. Platelet-rich plasma (PRP) may improve the environment for BMSC development and differentiation. However, whether combined use of BMSCs and PRP may be more effective for accelerating diabetic ulcer healing remains unclear. OBJECTIVE: We investigated the efficacy of BMSCs and PRP for the repair of refractory wound healing in a diabetic rat model. METHODS: Forty-eight rats with diabetes mellitus induced by streptozotocin were divided into four groups: treatment with BMSCs plus PRP, BMSCs alone, PRP alone, phosphate buffered saline. The rate of wound closure was quantified. A histopathological study was conducted regarding wound depth and the skin edge at 7, 14, and 28 days after surgery. RESULTS: Wound healing rates were significantly higher in the BMSC plus PRP group than in the other groups. The immunohistochemistry results showed that the expression of platelet/endothelial cell adhesion molecule 1, proliferating cell nuclear antigen, and transforming growth factor-ß1 increased significantly in the BMSC plus PRP group compared to the other treatment groups. On day 7, CD68 expression increased significantly in the wounds of the BMSC plus PRP group, but decreased markedly at day 14 compared to the controls. CONCLUSION: The combination of BMSCs and PRP aids diabetic wound repair and regeneration.