Synthesis Of Polyamine Derivatives For Pancreatic Cancer Cell Tracing

Objective In this paper,based on the structure of polyamines we designed and synthesized new polyamines derivatives F1 and N2.Through pancreatic cancer cellular models and tumor bearing mice models,we tried to evaluate the trace effects of F1 and N2in vivo and in vitro.Besides,whether difluoro methylornithine（DFMO）could promote the effects was also evaluated at the same time.The study aims to provide a theoretical basis for polyamine derivatives and DFMO in diagnosing and treating pancreatic cancer.We hope to find more anti-pancreatic cancer drugs and diagnostic methods based on polyamine derivatives.Methods（1）FITC-putrescine derivative（F1）and 4-dimethylamino-1,8-naphthalimide spermine derivative（N2）were characterized by hydrogen spectra.（2）The ultraviolet absorption spectra,emission and excitation spectra were detected by ultraviolet-visible spectrophotometry and fluorescence spectrophotometry.（3）MTT assays were used to evaluate the toxic effects of DFMO and N2 on pancreatic cancer cell line PANC-1 and normal human pancreatic ductal epithelial cell line h TERT-HPNE.（4）Cytofluorescence techniques were used to analyze the uptake of N2 in PANC-1 cell line and whether DFMO could promote the process.（5）Flow cytometry was used to quantitatively analyze the above effects as（4）mentioned.（6）In vivo imaging technique was used to detect the tumor tracer effect of N2 on pancreatic cancer-bearing nude mice.（7）The methods of frozen section were used to detect the distribution of N2 in tumor tissues and other important organs of pancreatic cancer-bearing nude mice.Results（1）Two new compounds and one intermediate,4-dimethylamino-1,8-naphthalimide（N1）have been synthesized and characterized.N1 is the parent structure of N2 without spermine.All of the three compounds could emit green fluorescence and have not been reported so far.（2）The maximum excitation wavelength（Ex）and the maximum emission wavelength（Em）of the compounds were known.The Ex and Em of F1 were494nm and 517nm.The Ex and Em of N2 were 421nm and 532nm respectively.N1 had the similar spectral properties with N2.Thus the ranges of excitation and emission wavelengths in the next experiments were determined.（3）The MTT results showed that DFMO and N2only had a little toxicity effects for PANC-1 and h TERT-HPNE cells with the concentration no more than 10 mmol·L^-1 and 10μmol·L^-1 after they were given for 24 hours.（4）Cell experiment results showed that F1 could rarely entered into PANC-1 cells.And N2 could efficiently be untaken by PANC-1 cells but not h TERT-HPNE cells.Meanwhile the uptake ability of N1 by PANC-1 cells was also extremely weak.Besides we also found that after treating with DFMO on PANC-1 cells for 12 hours,the uptake capacity of N2 increased with the increase of DFMO concentration.（5）Flow cytometry results confirmed the findings as（4）mentioned.And in the absence of DFMO in PANC-1 cells,the fluorescence intensity increased at first and then remained plateau as the concentration of N2 increased,which presented a saturation phenomenon.（6）The in vivo results showed that it was difficult to separate tumor tissues from the background fluorescence in mice because the short excitation and emission wavelengths of N2.As a result,the structure of N2 need to be modified in the future study.（7）The results of frozen section showed that N2 mainly distributed in cells in tumor tissues.However,in organs tissues N2 was mainly distributed in extracellular matrix and partly distributed in kidney cells and lung cells.Conclusions N2 can be specifically enriched in pancreatic cancer cells with high expression of PTS on pancreatic cancer cell membranes.And DFMO can promote the uptake of N2 in pancreatic cancer cells.The above conclusions provide new ideas for the study of polyamine derivatives and DFMO in the diagnosis and targeted therapy of pancreatic cancer.