Dickkopf-related protein 1 (Dkk1) regulates the accumulation and function of myeloid derived suppressor cells in cancer

Tumor–stroma interactions contribute to tumorigenesis. Tumor cells can educate the stroma at primary and distant sites to facilitate the recruitment of heterogeneous populations of immature myeloid cells, known as myeloid-derived suppressor cells (MDSCs). MDSCs suppress T cell responses and promote tumor proliferation. One outstanding question is how the local and distant stroma modulate MDSCs during tumor progression. Down-regulation of β-catenin is critical for MDSC accumulation and immune suppressive functions in mice and humans. Here, we demonstrate that stroma-derived Dickkopf-1 (Dkk1) targets β-catenin in MDSCs, thus exerting immune suppressive effects during tumor progression. Mice bearing extraskeletal tumors show significantly elevated levels of Dkk1 in bone microenvironment relative to tumor site. Strikingly, Dkk1 neutralization decreases tumor growth and MDSC numbers by rescuing β-catenin in these cells and restores T cell recruitment at the tumor site. Recombinant Dkk1 suppresses β-catenin target genes in MDSCs from mice and humans and anti-Dkk1 loses its antitumor effects in mice lacking β-catenin in myeloid cells or after depletion of MDSCs, demonstrating that Dkk1 directly targets MDSCs. Furthermore, we find a correlation between CD15(+) myeloid cells and Dkk1 in pancreatic cancer patients. We establish a novel immunomodulatory role for Dkk1 in regulating tumor-induced immune suppression via targeting β-catenin in MDSCs

Insulin binding to erythrocytes in diabetes mellitus.

Insulin binding to erythrocytes was studied in diabetic patients. Insulin binding was lower in untreated diabetics and diabetic patients treated with diet or insulin than in normal subjects. Binding variation was mainly due to decreased binding site concentration in untreated and insulin-treated patients, and to lowered insulin binding site affinity in diet-treated patients. Several patients treated with hypoglycemic agents showed higher insulin binding due to increased binding site concentration. Insulin binding to erythrocytes may not always reflect the insulin binding status of insulin sensitive tissues.</p

Expression of Dickkopf-1 and Beta-Catenin Related to the Prognosis of Breast Cancer Patients with Triple Negative Phenotype

BACKGROUND AND AIM: We investigated the prognostic importance of dickkopf-1(DKK1) and beta-catenin expression in triple negative breast cancers. METHODS: The expression of DKK1 and beta-catenin was evaluated in breast cell lines using RT-PCR and western blot. Immunohistochemistry was used to characterize the expression pattern of DKK1 and beta-catenin in 85 triple negative breast cancers and prognostic significance was assessed by Kaplan-Meier analysis and Cox proportional hazards regression modeling. RESULTS: The expression of DKK1 was confirmed in hormone-resistant breast cell lines MDA-MB-231, MDA-MB-231-HM and MDA-MB-435. Expression of DKK1 in triple negative breast cancers correlated with cytoplasmic/nuclear beta-catenin (p = 0.000). Elevated expression of DKK1 and cytoplasmic/nuclear beta-catenin in triple negative cancers indicate poor outcome of patients. DKK1 was also a prognostic factor for patients with earlier stage or no lymph node metastasis. CONCLUSION: DKK1 together with beta-catenin might be important prognostic factors in triple negative breast carcinoma. DKK1 might be a valuable biomarker in predicting the prognosis of patients with earlier stage or no lymph node metastasis. It is possible that through further understanding of the role of Wnt/beta-catenin pathway activation, beta-catenin would be a potential therapeutic target for the triple negative breast cancer

Studies on the Formation Process of Bile Pigment in Vitro Part 1 Studies on the Formation Process of Bile Pigment from Hemin Dimethyl Ester

Spectrochemical observations were chiefly attempted on the formation process of verdohemochrome from protohemin dimethyl ester by O(2) in the presence of ascorbic acid. And the results were as follows. 1. Verdohemochrome was obtained from pyridine hemin dimethyl ester by the action of ascorbic acid and O(2). And the process of this reaction was spectrophotometrically similar to that of hemin. 2. The reaction construction was same to that of hemin and the compound with the absorption maximum at 630mμ. was found in the course of this reaction, as a intermediate product. This product was purely obtained from pyridine hemin dimethyl ester by the action of H(2)O(2) in the presence of ascorbic acid, and it was transformed into verdohemochrome by O(2). 3. It was supposed that the compound with the absorption maximum at 630mμ. and verdohemochrome were dimethyl ester. Biliverdin could be extracted from the latter by HCl and it was difficult to conclude if it was dimethyl ester, but it was thought that some part of it was probably ester. The absorption curves of these reaction products were nearly same to that obtained from hemin. 4. The necessary concentration of ascorbic acid for the formation of verdohemochrome in 60% pyridine water was 9.4 Mol. to 1 Mol. of hemin dimethyl ester, and it was equivalent to 3/4 on the occation of hemin. It was thought that the difference was caused by the reactivity. And the necessary concentration of ascorbic acid decreased with increasing pyridine concentration. 5. The most appropriate concentration of ascorbic acid was the smallest amount described the above, on the view point of reaction velocity and verdohemochrome yield, and they decreased with the higher concentration of ascorbic acid than the above. However, the formation velocity of the compound with the absorption maximum at 630mμ. was increased with increasing the ascorbic acid concentration. 6. It was supposed that the catalytic action of the compound with the absorption maximum at 630mμ. and verdohemochrome was remarkably reinforced in the higher concentration of pyridine and it was thought that the secondary reaction by the excessive concentration of ascorbic acid was caused by the above action. The secondary reaction velocity of them was 1/2 of that obtained from hemin. 7. The abnormal reaction of the compound with the absorption maximum at 630mμ. was observed as the absorption band around 610mμ. The process of the further oxidation of verdohemochrome by ascorbic acid was, spectrophotometrically, quite similar to the oxidation of it by H(2)O(2), and both of them were oxidized to yellow substances. Positive pentdyopent reaction was observed in this process. 8. Since the above results, the reactivity of hemin was fairly declined by the esterification of carboxylic acid groups in the side chains, but it was recognized that the formation process of verdohemochrome was not essentially effected by the above esterification

Studies on the Formation Process of Bile Pigment in Vitro Part 2 Studies on the Influence of the Reaction Solution to the Formation Process of Verdohemochrome from Hemin Derivatives

The formation process of verdohemochrome from pyridine hemin by O(2) in the presence of ascorbic acid on the use of pyridine chloroform as the reaction solution was spectrochemically observed, in comparison with that on the use of pyridine water. And the results were as follows. 1. The formation process of verdohemochrome from pyridine hemin by O(2) in the presence of ascorbic acid on the use of pyridine chloroform as the reaction solution spectrophoto metrically showed the same process with that on the use of pyridine water and verdohemochrome was finally produced. The reaction construction was same to that on the use of pyridine water and the compound with the absorption maximum at 630mμ., as a intermediate product, was found in this reaction. 2. On the use of pyridine chloroform with the pyridine concentration below 10% as the reaction solution, the stadium thought to have only pure compound with the absorption maximum at 630mμ. was observed. And both of the formation process of the compound with the absorption maximum at 630mμ. from pyridine hemin and of verdohemochrome from the compound with the absorption maximum at 630mμ. were clearly observed in the same reaction. The above results were caused by that the compound with the absorption maximum at 630mμ. from pyridine hemin was formed with momentary speed on the use of pyridine chloroform in the low concentration. 3. The property of verdohemochrome obtained from pyridine hemin in pyridine chloroform agreed with that of verdohemochrome obtained from pyridine hemin in pyridine water and biliverdin was obtained from it by HCl. 4. The formation velocity of the compound with the absorption maximum at 630mμ. from pyridine hemin was very rapid on the use of pyridine in the low concentration (2.5-5%), when the concentration of ascorbic acid was kept constant. And it decreased with increasing pyridine concentration; at higher concentration of pyridine it decreased remarkably. This had relation to pyridine itself, and not to water or chloroform in the reaction solution. On the other hand, it's velocity was proportional to the concentration of ascorbic acid, when pyridine concentration was kept constant. 5. The necessary concentration of ascorbic acid for the formation of verdohemochrome from pyridine heroin in pyridine chloroform was not related to the pyridine concentration, and it was 6.3 Mol. to 1 Mol. of hemin and it was equivalent to 1/3 on the use of 20 % pyridine water. 6. The yield of verdohemohcrome was not related to the pyridine concentration up to a concentration of 20%, and it was the best with smallest amount of ascorbic acid discribed the above, but it became less regularly with increasing ascorbic acid concentration over the above. It became much less in 60% pyridine chloroform. 7. The velocity of th reaction was easily influenced by the pyridine concentration and the yield of verdohemochrome was easily influenced by the concentration of ascorbic acid. 8. The necessary concentration of ascorbic acid for the formation of verdohemochrome had relation with the presence and it's quantity of water in the reaction solution, and the less water decreased, the less was the ascorbic acid and it had no direct relation with pyridine. On the other hand, the catalytic action of pyridine hemin, the compound with the absorption maximum at 630mμ. and verdohemochrome had relation to the former and it was remarkably influenced, and it was reinforced with the decrease of water. The secondary reaction of the above reaction had same relation with the above. 9. The secondary reaction on the use of pyridine chloroform was due to the abnormal decomposition of the compound with the absorption maximum at 630mμ. and verdohemochrome as same as that on the use of pyridine water. 10. In this reaction, the existence of water was not necessary