The Status Of Genomic Imprinting Of The Long Noncoding RNA-IRAIN In Laryngocarcinoma Tissue

Objective:Human insulin-like growth factor I (IGF1) is tumor growth promotingfactor. With an increased expression in malignant tumor tissues, itpromotes tumors by aggravating cell proliferation, inhibiting cellapoptosis, as well as interaction with signaling pathways of other growthfactors, resulting in tumor growth and development. IGF1imprintingdeletion or double allele expression is considered to be notable featuresofearly tumorigenesis. Scientists discovered recently that a long non-codingRNA(lncRNA) within the IGF1R gene loci transcripted from the intron ofthe antisense direction of promoter, named " IGF1receptor antisenseimprinted noncoding RNA--IRAIN ". The non-coding RNA genes isexpressed exclusively from the father allel and inhibited from maternalallele. In order to investigate the imprinting status of this lncRNA inlaryngeal squamous cancer cells, we extracted DNA and RNA fromlaryngeal Squamous Cell Carcinoma tissues and confirmed the status ofimprinting of lncRNA-IRAIN allelic gene by PCR and sequencing. Theaim of the research is to help explore new approaches for laryngealcancer diagnosis and treatment on genetic level and to find newtherapeutic targets for cancer management and ideas. Methods:20laryngocarcinoma tissue samples, provided by Department ofOtolaryngology of the Second Hospital,Jilin University, were allconfirmed postoperatively to be laryngeal squamous carcinomapathologically.All samples were stored at-80degrees freezer.PCRamplification, product purification and direct sequencing technologieswere used to detect imprinting status of the20laryngeal carcinoma tissuesamples.Result:DNA and cDNA sequence analysis of20laryngocarcinoma samplesshowed that there are12cases double allelic gene expression, namely thedeletion of gene loci in mark, the rest8are single allelic gene expressionwithout genetic imprinting deletion. We discovered a heterozygous peakvia sequencing of genomic DNA amplification, suggesting heterozygousmutation. Another heterozygous peak was found in sequencing of cDNAamplification, indicating double allelic genes expression, whichsuggested that internal transcription spacer of laryngocarcinoma cellsIRAIN alleles mark is missing. It can be proved that there is deletion ofgenetic imprinting of that pair of alleles in laryngocarcinoma tissues.Conclusion:There is deletion of genetic imprinting of that pair of alleles inlaryngocarcinoma tissues. Detecting of imprinting status of transcription IRAIN alleles is expected to be applied to the early diagnosis of tumorsand the newly discovered lncRNA-IRAIN can also be used in tumortargeting therapy and become a new role of long chain noncoding RNA intumor treatment.