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

被引：83

作者：

Kemmner, Wolfgang ^{[1
]}

Wan, Kayiu ^{[1
]}

Ruettinger, Steffen ^{[2
]}

Ebert, Bernd ^{[2
]}

Macdonald, Rainer ^{[2
]}

Klamm, Ursula ^{[3
]}

MoestaO, K. Thomas ^{[3
]}

机构：

[1] Max Delbruck Ctr Mol Med, D-13125 Berlin, Germany

[2] Phys Tech Bundesanstalt, Dept Biomed Opt, Berlin, Germany

[3] Charite Univ Med Berlin, Clin Surg Oncol, Robert Roessle Clin, Berlin, Germany

来源：

FASEB JOURNAL | 2008年 / 22卷 / 02期

关键词：

heme metabolism; gastrointestinal carcinomas; siRNA silencing; cytoplasmatic red fluorescence;

D O I：

10.1096/fj.07-8888com

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

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 (RTPCR), 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.

引用

页码：500 / 509

页数：10

共 31 条

[1] Eradication of high-grade dysplasia in columnar-lined (Barrett's) oesophagus by photodynamic therapy with endogenously generated protoporphyrin IX [J].