A Study On The Tendency Of Genetic Alteration Of STR Loci In Human Lung Cancer Tissues

ObjectiveThis study aimed to explore the tendency of genetic instability in 20 s hort tandem repeats(STR)loci on autosomal and Amel loci in lung cancer t issue samples.Methods:1.Samples collection: We collected 75 cases of human lung cancer tissues and the adjacent normal tissues.2.DNA extraction: DNA samples were extracted from the deposit using tissue DNA extraction kit.3.PCR multipleamplification and automatic genetype: DNA were amplified using MicroreaderTM 21 Direct ID System PCR amplification kit.According to the instructions,the amplification was performed on the 9700 PCR amplification instrument.After that use API 3130 analyzer to capillary electrophoresis,and analyzed by genetic analysis software(Gene Mapper ID V3.2).Contrast genotype between normal tissue and tumor tissue to record the locus and type of STR mution.Samples of STR mution were repeated to verified.4.Statistical analysis: The above results were statistically analyzed using Excel and SPSS v18.0 software.Result:1.Statistics of mutation timesSTR alternations were detected in 24 specimens from 75 lung cancer tissue,accounted for 32% of the total sample.55 alternations were detected in the 20 short tandem repeats(STR)loci on autosomal and Amel loci in 75 tumor tissue samples from lung cancer.Among them,54 timesmutations were detected in the autosomal loci,and 1 timemutationwere detected in the Amel loci.Multiple genetic alteration types can occur in the same lung cancer tissue.In all loci,the highest alteration frequency occurred on D5S818(7 times),secondly on D3S1358 and D12S391(both 5 times),and no alterations on D2S441 and Penta E.2.Statistics of mutation types3 types of STR mutation were found in 75 tumor tissue samples from lung cancer,including additional alleles 10 times,loss of heterozygous 10 times,partial loss of heterozygous 35 times.Partial loss of heterozygous is the most common genetic alteration types accounting for 63.64% of the total alteration frequency.3.Analysis of STR mutation combined with clinical dataCombining the experimental results and analysis on clinical data,we found the statistical differences between the staging of lung cancer,and the age of the patients with the STR loci alterations(P<0.05).However,the alterations don’t have much relationship with the classification of lung cancer and the patient’s gender(P>0.05).Conclusion: STR loci of the lung cancer tissue are not stable,and the alteration occurred in the aged or high malignant degree lung cancer tissue more frequently.Meanwhile,no alterations were detected on D2S441 and Penta E.In the future research the two STR loci should be verified whether can be used as the stable STR loci in such cases by increase the sample size.