Post-intervention vessel remodeling

By-pass surgery and percutaneous transluminal (coronary) angioplasty, PT(C)A, are standard techniques for the treatment of vascular occlusions. Their usefulness is limited by by-pass graft failure and restenosis occurring after the procedures. Twenty percent of patients treated with PTCA/PTA need a new revascularization procedure within 6 months, despite a successful procedure. Stents are used to prevent restenosis in selected lesions, but in-stent restenosis also remains an important clinical problem. In this review we discuss progress of gene therapy for the treatment of post-PT(C)A restenosis, in-stent restenosis and by-pass graft stenosis over the last 2 years (2000-2002).     

Receptors for epidermal growth factor and insulin-like growth factor I and their relation to steroid receptors in human breast cancer

Levels of epidermal growth factor receptor (EGF-R) and insulin-like growth factor receptor (IGF-R) in breast cancer tissue were evaluated. The binding of growth factors was compared to the content of estrogen receptors (ER) and progesterone receptors (PgR). EGF-R correlated negatively to the ER and PgR (Kendall correlation, P less than 0.001), whereas the IGF-R correlated positively to ER and PgR (analysis of variance, P less than 0.001). In contrast, no correlation was found between EGF-R and IGF-R. IGF-R binding was higher in tumor tissues than in adjacent normal tissues (Wilcoxon rank test, P less than 0.001), whereas the EGF-R binding in normal tissue did not differ from that in cancer tissue. The degree of differentiation in ductal breast cancer correlated to EGF-R (chi 2 test, P = 0.018), but not to IGF-R. The bindings of both growth factors were the same in metastases and primary breast tumors. Our results show that EGF-R and IGF-R are present in normal breast tissue and breast cancer tissue. The growth factor receptors are related to steroid receptor content and their presence is associated with malignant transformation of breast cells and dedifferentiation of breast cancer.     

Insulin-like growth factors and their binding proteins.

Insulin-like growth factors are important multifunctional polypeptides interacting with cell membrane receptors and soluble binding proteins. With expanding knowledge on IGF binding proteins, it is becoming evident that the IGF actions are diverse, and depend on the context set by local binding proteins. In this minireview we attempt to provide a brief summary of the recent development in this field.     

Intrauterine progestin induces continuous insulin-like growth factor-binding protein-1 production in the human endometrium.

The effect of local intrauterine progestin on endometrial insulin-like growth factor-binding protein-1 (IGFBP-1) production was studied in 60 women using a levonorgestrel-releasing intrauterine device (IUD). Intrauterine progestin was a potent stimulator of stromal cell IGFBP-1 production, with 97% of endometrial specimens showing positive staining by immunohistological methods. After 5 yr or more of intrauterine progestin exposure, 100% (n = 20) of the tissues remained strongly positive for IGFBP-1. The IGFBP-1 content in endometrial tissue homogenates reached values as high as 10 micrograms/mg protein when measured by immunoradiometric assay. In contrast to the continuous endometrial IGFBP-1 production induced by local progestin, no such effect could be found in endometria from subjects with sc progestin-releasing implants or copper IUDs. Although the levonorgestrel-releasing IUD had a striking effect on local endometrial IGFBP-1 production, it had no effect on serum IGFBP-1 levels. By Western ligand blot analysis, the domainating IGF-binding species in endometria exposed to intrauterine progestin was of 28K mol wt, corresponding to IGFBP-1, whereas no IGFBP species of 31-43K, corresponding to IGFBP-2 or IGFBP-3, were detected.