ABSTRACT
Objective:To investigate the possibility of using radioiodine labeled framework region(FR)antisense oligonucleotides(ASONs)as an imaging agent or antisense therapeutic radiopharmaceu-tical in lymphoma.Methods:A 18-mer partial phosphorothioate oligonucleotide sequence was synthe-sized and grafted in 5'with a tyramine group which was further radioiodinated.Radioiodination of the tyra-mine derivatized oligonucleotides was performed using the chloramine T method.(1)Normal CD-1 micewere injected via a tail vein with 148 kBq (125)~I-FR-ASON(2-3?g).Animals were sacrificed at the endof 1,2,4 and 24h,and tissue samples were studied.(2)Liposome-mediated 3.33 MBq (131)I-FR-ASON(7-9?g)were injected intralumorally into tumor-bearing BALB/c mice(6 weeks after innculation of10~7 Namalwa cells)meanwhile liposome-mediated (131)~I labeled sense oligonucleotides served as controls.Biodistribution was monitored by sequential scintigraphy and organ radioactivity measurement 24h afterinjection.Percentage of the injected dose per gram of tumor and tumor/non-tumor tissue ratios(T/NT)were calculated tot each group of mice and the difference between two groups was assessed.Results:The5′tyramine group allowed specific and stable radinlabeling of the ASON with radioiodine.The radioactivi-ty reached its peak 1h after injection,and then decreased rapidly in normal mice after intravenous ad-ministration of (125)~I-FR-ASON.The liver,stomach and intestine played an important role in biodistributionand radioactivity counts were low in bone,brain and blood.When (131)I-FR-ASON was injected intratumor-ally into mice grafted with Namalwa cell line,images showed the tracer accumulated in the tumor,Imme-diately after intratumoral administration,only the tumor was visible.Scintiscans performed at the end of 1and 2h showed elimination of the tracer from the tumor to the abdomen and at the end of 24h the tumorwas clearly seen.Percentage of the injected dose per gram of tumor and T/NT ratios for the sense group(control)were significantly lower than those of the antisense group.Conclusion:Radiolabeled Ig FRASON showed high specificity in V1 family B-cell lymphoma,which should be further investigated for nu-clear medicine imaging application and radionuclide antisense therapy.
ABSTRACT
Objective In order to understand the relationship between myoblast and Schwann cell,our purpose was to investigate the effects of biological characters of myoblasts co-cul tured with Schwann cells and pro vide the basic theory for constructing artificial muscle involving artificial nerve.Methods After sterilizing with iodine tincture and alcohol,the brachial plexus,sciatic nerve and triceps surae muscle of neonatal SD rat were harvested and peeled off their membranes,blood vessels and fat tissues under operating microscope thor oughly.The nerve and muscle tissues were cut in pieces by microscis sors,and then digested and isolated by collagenase and pancreatin in20and15minutes respectively.DMEM medium was employed to culture my oblasts and Schwann cells.After co-culturing myoblasts of rats with Schwann cells in vitro,the morphological characteristics and the growth condition of two cells were observed under inverted phase contrast mi croscope,the effects of Schwann cells secretion for proliferation of myoblasts were detected by 3 HTdR iso topic tracing and expressed by disintegration per minute(DPM),formation rate of myotubes was counted under micro scope and statistic data was analyzed,the functional differentiation degree of my oblasts affected by Schwann cells was analysed by?-sarcomeric actin immunohistochemistry(SABC)and imaging analysis tech nique.Results Co-cultured myoblasts proliferated,and myotubes ap peared earlier.Comparing with sole-cultured my oblasts,the shape of myobutes from co-cultured myoblasts tended to be elongating and robust.The value of DPM far-exceeded the control group,and reached its peak of 2500(just800for con-trol group).The positive cells of ?-sarcomeric actin appeared in brown red color.However,syn thesis and excre tion of a-sarcome ric actin in co-cultured myoblasts were much greater than control group,and the gray ash value between two groups was of a significant difference.Conclusion Primary rat myoblasts co-cultured with Schwann cells in vitro is beneficial in regulating its the growth,proliferation and the differentiation.