Imaging of 99Tcm-labeled new cyclic RGDfK Dimer in nude mice bearing U87MG human glioma xenografts / 中华核医学杂志

Objective (1) To evaluate the effect of insertion of two 15-amino-4,7,10,13-tetraoxapentadecanoic (2 PEG4 ) linkers into cyclic Arg-Gly-Asp (RGD) Dimer E [c(RGDfK)]2 on receptor binding in vitro, (2) to assess its biodistribution in vivo and (3) to investigate the value of 99Tcm labeled 2PEG4-Dimer for integrin αvβ3-positive tumors imaging.Methods The expression of U87 human glioma cells and integrin αv β3 was determined by immunofluorescence staining.The half-inhibition concentrations (IC50) for 125 I-cyclo (Arg-Gly-Asp-D-Tyr-Lys) (c(RGDyK) ) of c ( RGDyK ), hydrazinonictinamide ( HYNIC )-Dimer and HYNIC-2PEG4-Dimer binding to integrin αvβ3 were measured.99Tcm-HYNIC-Dimer and 99Tcm-HYNIC-2PEG4-Dimer were synthesized using non-SnCl2 formulation.Biodistribution and imaging studies were performed in nude mice bearing human glioma xenografts.The unpaired t test was used for statistical analysis.Results The labeling yield of the two radiotracers was more than 95%, and the radiochemical purity was more than 99% through Sep-Pek C18 cartridge.HYNIC-2PEG4-Dimer had significantly higher binding affinity of integrin αvβ3 than c(RGDyK) and HYNIC-Dimer (IC50 = 0.8 nmol/L, 27 nmol/L and 2.4 nmol/L, respectively).Biodistribution study showed that 99Tcm-HYNIC-2PEG4-Dimer was mainly excreted via the kidney.The tumor uptake of 99Tcm-HYNIC-2PEG4-Dimer was higher than that of 99Tcm-HYNIC-Dimer at 2h post injection ((5.71 ±0.96) and (2.10 ±0.50) % ID/g, t =4.80, P＜0.05).The xenografted tumors were visible at 0.5 h post injection and the image contrast increased with time due to the tracer clearance of the background tissue.Conclusion 99 Tcm-HYNIC-2PEG4-Dimer is a promising radiotracer for integrin αvβ3-positive tumor imaging.

Expression of estrogen receptor, progesterone receptor and integrin αVβ3 in endometrium of patients with luteinized unruptured follicle / 中华妇产科杂志

Objective To investigate endometrium receptivity in patients with luteinized unruptured follicle(IUF)by measuring the expression of estrogen receptor(ER),progesterone receptor(PR)and integrin αVβ3 in the endometriunm Methods From May 2007 to Nov.2007,17 infertile women with LUF were selected as LUF group matched with 13 infertile cases with normal ovulation as control group.They all underwent frozen-thawed embryo transfer in Reproductive Medicine Center.Renmin Hospital of Wuhan University.Endometrial tissue in anterior and posterior wall of uterus of LUF group and control group were biopsied by a small curettage between 7 and 11 days after luteinizing hormone(LH)surge.The expression of ER,PR and integrin αVβ3 in endometriam were detected by immunohistochemistry staining.The level of estrogen and progesterone were measured by chemiluminescence assay.Then,the relationship between αVβ3 expression in endometrium and the level of estrogen/progesterone were analyzed in LUF patients.Results (1)There was no remarkable difference in the level of estrogen between LUF [(656±299)pmol/L]and control group[(727±275)pmol/L,P>0.05].However,the level of progesterone were(23±8)nmol/Lin LUF group and(35±10)nmol/L in control group,which reached statistical difference(P<0.01).(2) The expression of ER,PR in endometrium of LUF patients were 183.9±2.4 and 168±3.which were significantly higher than 109.4±6.3 and 106±4 in control group(P<0.01).The expression of integrin α Vβ3 in endometrium of 115±11 in LUF group were significantly lower than 191±9 in control group(P< 0.01).(4)In LUF group,the expression of αVβ3 in endometrium waft correlated positively with the level of progesterone(r=0.77,P<0.01)and irrelevant with the level of estrogen(r=0.01,P>0.05).Conclusion The higher expression of estrogen and progesterone and lower expression of integrin αVβ3 misht confer impaired receptivity of endometrium and interfere with embryo implantation.

Netrin-1 Specifically Enhances Cell Spreading on Fibronectin in Human Glioblastoma Cells

Netrins are secreted molecules and involved in axon guidance, cell migration and tumor development. Recent studies revealed that netrins perform novel functions in such processes as epithelial development and angiogenesis without operating through the classical netrin receptors, DCC (Deleted in Colorectal Cancer) and Unc5h. In the present study, we investigated the roles of netrin-1 and its receptors in cell spreading of human glioblastoma cells, and found that netrin-1 haptotactically enhanced fibronectin-induced cell spreading and focal adhesion formation in U373 glioblastoma cells. Netrin-1 binding to the U373 cell membrane was blocked by an antibody against alpha v integrin subunit, but not by an anti-DCC or anti-Unc5h antibody. In addition, enhancement of the fibronectin response by netrin-1 was abrogated by a function blocking antibody against integrin alpha v beta 3. Since the alpha v subunit of the integrin family plays an important role in the pathophysiological aspects of cell migration, including tumor angiogenesis and metastasis, our data provide important insight into the molecular mechanism of netrin function.

The expression of osteopontin and integrin αV in the laryngeal and hypopharyngeal squamous cell carcinoma andits correlation with tumor invasion as well as metastasis / 肿瘤

Objective: To investigate the expression of osteopontin (OPN) and integrin ot V (ITGA V) in the laryngeal and hypopharyngeal squamous cell carcinoma (LHSCC) and study the influence on the biological behaviors (invasion and migration) of tumor cells. Methods: The tissue microarray of LHSCC was designed and the OPN and ITGAV expressions were detected by immunohistochemistry. The professional software of pathological image manipulation (Image Pro Plus 5.02, IPP 5.02) was used to quantitate the results of the immunohistochemical staining. The relationship between OPN and ITGAV expressions and clinicopathological staging of LHSCC was analyzed. Results: The expression levels of OPN and ITGAV in primary and metastatic carcinoma were significantly higher than those in normal tissues (P < 0.001); their expressions in the well-differentiated group were significantly lower than those in the moderate- and poor-differentiated groups(P <0.01); the expression levels of OPN and ITGAV in the group with lymph node metastasis were significantly higher than those in the group without lymph node metastasis (P <0.001). The expression levels of OPN and ITGAV had no correlation with primary locations, the size of invasion area, and the age and sex of patients. Conclusion: The expressions of OPN and ITGAV are significantly related with the invasion and migration of the LHSCC. Over-expression of OPN and ITGAV may be one of the important factors contributing to the invasion and migration of LHSCC.

The altered expression of integrin αVβ3 in colon carcinoma cells cultured in three dimensional model and its relationship with sensitivity of tumor cells to chemotherapy / 肿瘤

Objective: To use three dimensional model in vitro to mimic solid tumor growth in vivo and explore the relationship between the multicellular resistance of colon carcinoma cell and the over-expression of cell adhesion molecules (integrin α V and integrin β3). Methods: The colon carcinoma HT-29 multicellular spheroids (MCS) model were constructed with three dimensional cell culture methods. The mRNA and protein expressions of integrin α V and integrin β3 was detected by RT-PCR and immunofluorescence analysis and compared between monolayer cells (MC) and MCS. The viability and apoptotic rate of MC and MCS were detected by flow cytometry (FCM) after treatment with 5-fluorouracil (5-FU). Results: The expression levels of integrin α V and integrin β3 in three dimensional cell culture model of HT29 MCS were much higher than those in MC (P < 0.01). Compared with MC, the sensitivity of MCS to the anticancer drug 5-FU significantly decreased ( P < 0.05), and the rate of 5-FU-induced apoptosis significantly decreased (0.346 ± 0.035 vs 0.235 ± 0.024, P < 0.05). Conclusion: Over-expression of cell adhesion molecules integrin α V and integrin β3 may increase the multi-cellular resistance of colon carcinoma cells.