Evaluation of 111In-DOTA-F56 peptide targeting VEGFR1 for potential non-invasive gastric cancer xenografted tumor mice Micro-SPECT imaging.

Non-invasive imaging of vascular endothelial growth factor receptor 1 (VEGFR1) remains a great challenge in the early diagnosis of tumors, especially in gastric cancer. Here, we designed and evaluated a novel 111In-DOTA-F56 peptide as a radioactive analogue of F56 (peptide WHSDMEWWYLLG) to bind VEGFR1. It was obtained by radiolabeling DOTA-F56 with 111InCl3 with 98% radiochemical purity and 1.4 ± 0.4 GBq/µmol specific activity. 111In-DOTA-F56 was obtained by the reaction of DOTA-F56 (10 µg) with 111InCl3 in pH 4.0 sodium acetate buffer at 85 °C for 20 min. 111In-DOTA-F56 shows good stability in 0.01 M Phosphate Buffered Saline (PBS) and 5% Human Serum Albumin (HSA). 111In-DOTA-F56 has a high binding affinity for human gastric cancer BGC-823 cells. Bio-distribution studies of 111In-DOTA-F56 were performed in nude mice xenografted with human gastric cancer BGC-823 cells and the results revealed tumor uptake accumulation. A blocking dose of DOTA-F56 significantly reduced the tumor uptake of 111In-DOTA-F56. Tumors were observed with Micro-SPECT images, and the uptake in the tumor increased with time from 4 h to 24 h. The MIP of the Micro-SPECT also showed that the excess DOTA-F56 can specifically block 111In-DOTA-F56 in a mouse tumor model. We successfully synthesized the 111In-DOTA-F56 VEGFR1-targeted peptide as a non-invasive molecule with fine radiochemical properties. Micro-SPECT indicates tumor uptake, which can be further blocked by excess of the F56 peptide, indicating that 111In-DOTA-F56 peptide has potential for early detection of VEGFR1 positive gastric cancer and is worthy of further clinical investigations.

Mycoplasma hyorhinis and Mycoplasma fermentans induce cell apoptosis and changes in gene expression profiles of 32D cells.

Infection of mycoplasmas has been linked to various human diseases including arthritis, pneumonia, infertility and cancer. While Mycoplasma hyorhinis and Mycoplasma fermentans have been detected in gastric adenocarcinomas, the mechanisms underlyine the pathogenesis are unknown. In this study, cell growth kinetics, Hoechst 33258 staining, DNA ladder assays, Western blotting analysis and cDNA microarray assays were performed to investigate the roles of M. hyorhinis and M. fermentans during infection of mammalian cells. Our data demonstrated that these mycoplasmas inhibid the growth of immortalised cell lines (32D and COS-7) ane tumor cell lines (HeLa and AGS). In addition, the infection of the 32D cell line with M. hyorhinis and M. fermentans induced compression of the nucleus, degradation of the cell genome and dysregulation of the expression of genes related to proliferation, apoptosis, tumorigenesis, signaling pathway and metabolism. Apoptosis related proteins Bcl-2, Bid and p53 were down-regulated, Fas was up-regulated and Bax was dysregulated in mycoplasma-infected 32D cells. Together, our data demonstrated that infection of mycoplasmas inhibitd cele growts through modification of gene expression profiles and post-translation modification of proliferation and apoptosis related proteins.

Mycoplasma hyorhinis and Mycoplasma fermentans induce cell apoptosis and changes in gene expression profiles of 32D cells

Infection of mycoplasmas has been linked to various human diseases including arthritis, pneumonia, infertility and cancer. While Mycoplasma hyorhinis and Mycoplasma fermentans have been detected in gastric adenocarcinomas, the mechanisms underlyine the pathogenesis are unknown. In this study, cell growth kinetics, Hoechst 33258 staining, DNA ladder assays, Western blotting analysis and cDNA microarray assays were performed to investigate the roles of M. hyorhinis and M. fermentans during infection of mammalian cells. Our data demonstrated that these mycoplasmas inhibid the growth of immortalised cell lines (32D and COS-7) ane tumor cell lines (HeLa and AGS). In addition, the infection of the 32D cell line with M. hyorhinis and M. fermentans induced compression of the nucleus, degradation of the cell genome and dysregulation of the expression of genes related to proliferation, apoptosis, tumorigenesis, signaling pathway and metabolism. Apoptosis related proteins Bcl-2, Bid and p53 were down-regulated, Fas was up-regulated and Bax was dysregulated in mycoplasma-infected 32D cells. Together, our data demonstrated that infection of mycoplasmas inhibitd cele growts through modification of gene expression profiles and post-translation modification of proliferation and apoptosis related proteins.