| Background and Objective The goals of this study were to image oncogene c-erbB2 using 99mTc-radiolabelled antisense oligodeoxy-nucleotides(ASODN) to bind complementally target gene to diagnose breast cancer. The target of antisense oligonucleotide is amplification ribonucleic acid mRNA of mammary tumor protooncogene c-erbB2. 9 mTc-ladled ASODN was connected with epidermal growth factor(EGF) to enhance uptake percentage of cell. To establish tumor oncogene imaging new method which has combined two specific conjugation force of DNA-mRNA complementation and ligand-receptor binding. So the new imaging method has such characters as higher sensibility, higher selectivity and higher target-tropism.Oncogene active can induce cell malignant changes and result in cell mRNA overexpression. ASODN can identify mRNA and specially conjugated mRNA to form mRNA/ASODN. Radiolabelled ASODN was designed complementation to target mRNA for imaging changes in the level of gene expression in vivo. In theory antisense oncogene imagingcan diagnose the position and size of tumor, and detect this neoplasm which have only had oncogene amplification and overexpression, but did not form entity tumor. To realize the earlier period and no-wound diagnosis for neoplasm.Breast cancer is mostly female malignant tumor which 5 year survival and long-term survival were lower. To investigate how to diagnose earlier mammary neoplasm subgroups is very important for performing clinical therapy projects that are the most suitable for personal treatment to rise survival rate. Compelling clinical studies on breast cancer have revealed that amplification of c-erbB2 has a high degree of correlation with disease recurrence and poor survival. Breast cancer genesis may dependent on overexpression of c-erbB2. c-erbB2 active and amplification were found in earlier period of mammary neoplasm and thought to play an important role in the process of breast cancer invasive and metastasis. 20%~30% invasive breast cancer have c-erbB2 amplification. The breast cancer of c-erbB2 overexpression have such characteres as higher tumor cell proliferation, higher invasiveness and metastasis potency, lower survival rate, poor prognosis, and tolerance for hormone treatment,chemistry therapy and radiation therapy. The blood serum c-erbB2 level is also associated with neoplasm constitution grades, clinical staging, tumor recurrence, lymph node invasive and metastasis, lymph node size, disease-free survival rate(DFSR), and overall survivalrate(OSR). Therefore c-erbB2 overexpression could be used to estimated the prognosis, DFSR and OSR of earlier period mammary neoplasm. Epidermal growth factor receptor (EGFR) have high homogeneity with c-erbB2. EGFR was detected overexpression in 35% breast cancer and distributed to specificity constitution.This study employed an 15-mer phosphorothioate oligodeoxynu-cleotide complementary to the zone which contains the translation initiation codon of c-erbB2 gene.The radiopharmaceutical of 99mTc-labeled ASODN combine EGF may identify intracellular c-erbB2 amplification at the level of gene transcription. The diagnosis would be extremely valuable for mammary neoplasm subgroups which are found in earlier period, and prescripted best treatment project to rise therapy efficiency and reduce mortality rate.Methods1. An 15 mer antisense oligodeoxynucleotide target is c-erbB2 mRNA translation initiation codon of location 160-174, ASODN sequence is 5'-NH2GGTGCTCACTGCGGC-3'. The control sense oligodeoxynucleotide (SODN) sequence is 5'-NH2GCCGCAGTGAG CACC-3'; The control nonsense oligodeoxynucleotide (NODN) sequence is 5'-NH2 GGTCGATGCCGCGTC-3'. ASODN,SODN and NODN are named oligodeoxynucleotide (ODN).2. Synthesis EC-ODN: Chelator L,L-ethylene dicysteine (EC)were connected with ODN. EC-ODN was purified by C18Sep-Pak reversecolumn and lyophilized, then EC-ODN frezze-drying reagent was obtained. EC-ODN was identified by 'H-NMRs IR, UV and agarose electrophorsis.3. WmTc-labeled EC-ODN and biology proper...
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