Correlation of Insulin-like Growth Factor 1 Receptor Expression With Different Molecular Subtypes of Breast Cancer in the UAE

BACKGROUND

Insulin-like growth factor 1 receptor (IGF1R) activation triggers multiple signaling pathways involved in proliferation and anti-apoptosis in breast cancer (BC).

MATERIALS AND METHODS

Immunohistochemistry for IGF1R was performed on 50 BC cases; expression was assessed for staining intensity and localization pattern (mixed, membranous, and cytoplasmic) which was correlated to hormone receptor status.

RESULTS

Of estrogen receptor-positive (ER⁺) cases, 97.2% were IGF1R⁺ (48.6% mixed, 43.2% membranous, and 5.4% cytoplasmic pattern) compared to ER^- cases (38.5%, 7.7% and 30.8%, respectively) (p=0.003). In progesterone receptor-positive (PR⁺) cases, 97.2% were IGF1R⁺, (47.2%, 41.7% and 8.3%, respectively) compared to PR^- ones (42.9%, 14.3% and 21.4%, respectively) (p=0.036). For human epidermal growth factor receptor 2-negative (HER2^-) cases, 88.8% were IGF1R⁺ (44.4%, 8.3% and 36.1%, respectively). All HER2⁺ cases were IGF1R⁺ (71.4%, 7.1% and 21.4%, respectively) (p=0.015). In conclusion, hormone receptor-positive HER2^- cases showed membranous and mixed IGF1R localization. However, hormone receptor-negative and HER2⁺ showed cytoplasmic or diminished IGF1R expression.

CONCLUSION

These luminal subtypes may benefit from targeted IGFR therapy in the future.

Elevated expression of endothelin-1 and endothelin-converting enzyme-1 in idiopathic pulmonary fibrosis: possible involvement of proinflammatory cytokines

Endothelin-1 (ET-1) is a vasoconstrictor, bronchoconstrictor, and mitogenic peptide which is enzymatically converted from a biologically inactive big ET to mature ET (21 amino acid) by the ET-converting enzyme (ECE). Here, we investigate the expression of ECE-1, big ET-1, and ET-1 in the lungs of patients with idiopathic pulmonary fibrosis (IPF) and compare it to those of normal subjects using immunohistochemistry and in situ hybridization. In normal lungs, focal moderate expression of all three molecules is localized to airway epithelium, pulmonary endothelium, and airway and vascular smooth muscle cells. Serous bronchial glands also expressed ET-1 and ECE-1. In IPF, strong diffuse expression of ECE-1 was seen in airway epithelium, proliferating type II pneumocytes, and in endothelial and inflammatory cells. ECE-1 immunostaining was colocalized to big ET-1 and ET-1 immunostaining, and correlated with disease activity (P < 0.05). To study regulatory mechanisms of ET-1 and ECE-1 expression, human normal bronchial epithelial (NBE) cells were treated with cytokines and analyzed by radioimmunoassay and Northern blot. Incubation of human NBE cells with IL-1alpha and -beta or tumor necrosis factor alpha (TNFalpha) resulted in a significant increase in ET-1 release and mRNA expression. TNFalpha resulted in a significant increase in ECE-1 mRNA expression. These findings demonstrated the colocalization of the precursor and active ET-1, and ECE-1 in the same cell, and that ECE-1 expression is elevated in IPF. In addition, increased expression of ET-1 and ECE-1 in IPF may be mediated by proinflammatory cytokines.

Soluble CD4, soluble CD8, soluble CD25, lymphopoieitic recovery, and endogenous cytokines after high-dose chemotherapy and blood stem cell transplantation

Mononuclear cell preparations from peripheral blood after mobilization with hematopoietic growth factors have been shown to induce accelerated neutrophil and platelet recovery as compared with that induced by autologous bone marrow transplantation after myeloablative chemotherapy. Because these mononuclear cell products contain many immunocompetent cells other than hematopoietic progenitors, these accessory cells might contribute to the rapid immunohematopoietic reconstitution. We have monitored the concentrations of soluble CD4 (sCD4), sCD8, and sCD25; the recovery of the lymphocyte subsets and of natural killer (NK) cells; and the endogenous levels of granulocyte colony-stimulating factor (G-CSF), interleukin-3 (IL-3), IL-6, and granulocyte-macrophage-CSF (GM-CSF) in 12 patients who underwent high-dose chemotherapy supported by blood stem cells that were obtained by mobilization with chemotherapy and GM-CSF. The concentrations of both G-CSF and IL-6 peaked at 7 days after reinfusion of stem cells, and this transient elevation preceded the increase in the white blood cell count by approximately 5 to 7 days. The levels of sCD4 and sCD8 increased to a maximum on day 21, and the time to peak levels coincided with the maximum increase in white blood cell count, absolute neutrophil count, or lymphocytes. The levels of sCD25 were found to be elevated from day 7 to day 21. Statistically, the increases in sCD4, sCD8, sCD25, G-CSF, and IL-6 were highly significant, whereas there were no significant changes in IL-3 and GM-CSF. A rapid recovery of the NK activity was found in all 8 of the patients who could be monitored for this assay. Therefore, our study suggests that recovery of CD4+ cells, CD8+ cells, and NK activity coincided with that of neutrophils, which is preceded by a marked, but transient, elevation of IL-6 and G-CSF.