Screening And Studying Of Human Uterine Leiomyoma Related Genes

As the most common reproductive tract neoplasm in premenopausal women,Uterine Leiomyoma (UL) is a multi-gene involved benign tumor. It is the main causeof hysterectomy for women at reproductive age, which affects their health greatly. Inour lab, we used two different techniques to clone differentially expressed genes inleiomyoma and studied part of them, which may help us to understand the mechanismof UL formation at molecular level.In searching of differentially expressed genes in human uterine leiomyomas,differential display was used with twelve pairs of primers to compare human uterineleiomyomas with matched myometrium. False positives were eliminated by reverseNorthern analysis. Positives were confirmed by Northern blot analysis. RESULTS: [1]Four of 69 cDNA fragments (3 up-regulated named L1, L2 & L3 and 1 downregulatednamed M1 in leiomyoma) were confirmed by Northern analysis. [2]Sequence comparison and Northern analysis proved that L1 is exactly the humanribosome protein S19. [3] It was present ubiquitously in 13 tissues tested but invarious levels and even in different size. [4] L1 was highly expressed in parotideancystadenocarcinoma, pancreatic cancer and breast cancer examined. [5] No mutationshave been found in human uterine leiomyomas (n=6). CONCLUSIONS: hRPS19overexpression might be a universal signal in rapid cell growth tissues.In searching for differentially expressed genes in human uterine leiomyomas(ULs), suppression subtractive hybridization was used to construct an UL up-regulated library, which turned out to represent 88 genes. After two rounds ofscreening by reverse Northern analysis, twenty genes were proved to be up-regulated,three of them were picked up and confirmed by Northern analysis. Among the twentygenes, seventeen of them are known genes and the other three are genes withunknown function, which were firstly associated with UL. One gene namedPhospholipase A2 (PLA2) showed up-regulation in 4/6 of the patients andinvestigation of tissue distribution indicated that it had obvious expression in prostate,testis, liver, heart and skeletal muscle.From human ESTs database at Genbank, we got the nearly full length cDNAsequence (4.1Kb, full coding sequence) of a unknown gene (061) derived fromsubtracted library, which is verified by sequencing and Northern results. Bycomparing its sequence with human genome database, we found it having sevenexons and located it on chromosome 12q24.11. From its sequence, we deduced it hadtwo forms of mRNAs because of alternative splicing and Northern results proved it.Distribution analysis among 16 human tissues indicated that its mRNA in small formwas especially abundant in testis. We found it had 71% homology with a TNF -induced protein in human at aa level, but 97% with a unknown gene in mouse.