CTGF is overexpressed in malignant melanoma and promotes cell invasion and migration.

BACKGROUND: Malignant melanoma cells are known to have altered expression of growth factors compared with normal human melanocytes. These changes most likely favour tumour growth and progression, and influence tumour environment. The induction of transforming growth factor beta1, 2 and 3 as well as BMP4 and BMP7 expression in malignant melanoma has been reported before, whereas the expression of an important modulator of these molecules, connective tissue growth factor (CTGF), has not been investigated in melanomas until now. METHODS: Expression of CTGF was analysed in melanoma cell lines and tissue samples by qRT-PCR and immunohistochemistry. To determine the regulation of CTGF expression in malignant melanoma, specific siRNA was used. Additionally, migration, invasion and attachment assays were carried out. RESULTS: We were able to demonstrate that CTGF expression is upregulated in nine melanoma cell lines and in primary and metastatic melanoma in situ. The transcription factor HIF-1α was revealed as a positive regulator for CTGF expression. Melanoma cells, in which CTGF expression is diminished, show a strong reduction of migratory and invasive properties when compared with controls. Further, treatment of normal human epidermal melanocytes with recombinant CTGF leads to an increase of migratory and invasive behaviour of these cells. CONCLUSION: These results suggest that CTGF promotes melanoma cell invasion and migration and, therefore, has an important role in the progression of malignant melanoma.

Effects of low-dose L-arginine on insulin-mediated vasodilatation and insulin sensitivity.

The present study was carried out to evaluate the effect of a low-dose intravenous supplementation of L-arginine on insulin-mediated vasodilatation and insulin sensitivity. The study was performed in healthy subjects (n = 7) and patients with obesity (n = 9) and non-insulin-dependent diabetes mellitus (NIDDM) (n = 9). Insulin-mediated vasodilatation was measured by venous occlusion plethysmography during the insulin suppression test, evaluating insulin sensitivity. Experiments were performed twice in each subject in the presence or absence of a concomitant infusion of L-arginine (0.52 mg kg-1 min-1). L-Arginine restored the imparied insulin-mediated vasodilatation observed in obesity (22.4 +/- 4.1%, P < 0.01 vs. without L-arginine) and NIDDM (20.3 +/- 3.2%, P < 0.01 vs. without L-arginine). In healthy subjects, no effect on insulin mediated-vasodilatation was observed (24.8 +/- 3.1% vs. 21.4 +/- 3.1%). Insulin sensitivity was improved significantly (P < 0.001) in all three groups by infusion of L-arginine. No effect of L-arginine was observed on insulin, insulin-like growth factor I (IGF-I), free fatty acids (FFAs) or C-peptide levels during the insulin suppression test. Our data indicate that defective insulin-mediated vasodilatation in obesity and NIDDM can be normalized by intravenous L-arginine. Furthermore, L-arginine improves insulin sensitivity in obese patients and NIDDM patients as well as in healthy subjects, indicating a possible mechanism that is different from the restoration of insulin-mediated vasodilatation.

Vascular effects of L-arginine: anything beyond a substrate for the NO-synthase?

L-arginine supplementation is hypothesized to reduce endothelial dysfunction and atherogenesis via increased biosynthesis of nitric oxide. Here we describe superoxide scavenging properties of arginine as an additional aspect which needs to be considered. Furthermore, arginine reduced copper-induced lipid peroxidation, indicating that superoxide anions essentially contribute to this process. In intact endothelial cells, L-arginine but not D-arginine diminished superoxide release and reduced cell-mediated breakdown of nitric oxide. Our data indicate that the reported vascular effects of L-arginine supplementation might involve an increased bioavailability of nitric oxide due to its superoxide scavenging properties beside a potential increased NO biosynthesis.

Influence of autologous blood transfusion on natural killer and lymphokine-activated killer cell activities in cancer surgery.

BACKGROUND AND OBJECTIVES: Immunosuppression associated with blood transfusion may influence postoperative infection rates. It may also affect the prognosis of patients treated surgically for colorectal cancer. To control this effect, study protocols have applied autologous blood donation programs, which are thought to be immunologically neutral. However, evidence has emerged that blood donation itself might have suppressive effects on natural killer (NK) cell activities. At present, there are no data available on the effects of autologous blood transfusion on NK or lymphokine-activated killer (LAK) cells. This might be of interest as LAK cells may be active in tumor control. MATERIALS AND METHODS: 26 patients who underwent surgical resection for colorectal cancer, were assigned at random into two groups: (1) autologous blood donation and transfusion, or (2) allogeneic blood transfusion. NK and LAK activities were determined before blood donation, at surgery, and on the 3rd and 8th postoperative day. RESULTS: Blood donation induced a small decrease in NK and LAK activities. The postoperative courses of the two groups differed. In the allogeneic group, NK activity (-50%, p = 0.018) and LAK activity decreased (-60.7%, p = 0.043), whereas in the autologous group the decline in LAK was less pronounced (-33.7%, p = 0.091), and their NK activity even increased (+17.4%, p = 0.315). NK activity was modulated differently in the two study groups (0.0036). Differences in LAK activities were found between the 3rd and 8th day postoperatively (p = 0.354). CONCLUSIONS: In patients receiving autologous blood transfusion, postoperative suppressed NK and LAK activities were modulated. This implies that autologous blood transfusion is not immunologically neutral, but has an intrinsic immunomodulatory potential.

[Effect of chromium yeast and chromium picolinate on body composition of obese, non-diabetic patients during and after a formula diet]. / Effekt von Chromhefe und Chrompicolinat auf die Körperzusammensetzung bei übergewichtigen, nichtdiabetischen Patienten während und nach einer Formula-Diät.

The objective of this study was to assess the effects of chromium yeast and chromium picolinate on lean body mass during and after weight reduction with a very-low-calorie diet. 36 obese (BMI 33.7 +/- 5.4 kg/m2), non-diabetic patients aged 45 +/- 6 years undergoing a 8-week very-low-calorie diet followed by a 18-week maintenance period. During the whole 26 week treatment period subjects received either placebo or chromium yeast (200 micrograms/d) or chromium-picolinate (200 micrograms/d) in a double-blind manner. Body weight was measured as BMI and body composition after calculation from skinfold thickness. As a result all three groups showed comparable weight loss after 8 and 26 weeks. Lean body mass was reduced in all groups after 8 weeks. However, after 26 weeks chromium picolinate supplemented subjects showed increased lean body mass (p < 0.029) whereas the other treatment groups still had reduced lean body mass. Chromium picolinate, but not chromium yeast, is able to increase lean body mass in obese patients in the maintenance period after a very-low-calorie diet without counteracting the weight loss achieved.

The anemia of chronic renal failure: studies of the effect of organic solvent extraction of serum.

CRF serum contains a material(s) which is inhibitory to erythropoiesis in vitro. The chemical nature and mechanism of action of this material are unclear at the present time. To further study this problem, we extracted NL serum and CRF serum samples with two organic solvents, chloroform and petroleum ether. The serum samples were studied before and after extraction in a tissue culture system in which dog erythroblasts were stimulated by EP to synthesize heme. Before extraction, cells suspended in CRF serum synthesized less heme than cells cultured in NL serum. Extraction of CRF serum with chloroform, but not petroleum ether, resulted in an improvement in its ability to support heme synthesis. Studies of the material extracted by chloroform from CRF serum showed that it was inhibitory to erythropoiesis. We propose that the erythropoietic inhibitory substance in uremic serum in soluble in chloroform but not in petroleum ether, suggesting that it is a polar lipid.