The Study On The Correlation Of Tumor Suppressor Gene OVCA1 And Cervical Cancer

Objective:Cervical cancer and ovarian cancer are women's common malignant tumors. LOH (Loss of heterozygosity) of human chromosome 17p13.3 has been found in ovarian and cervical tumors, suggesting the presence of a tumor suppressor gene within this region. The OVCA1 gene is a candidate for the ovarian tumor suppressor gene at chromosome 17p13.3. High-risk HPVs(human papillomaviruse) have been well characterised as causative agents for cervical cancer. E6 and E7 of high-risk HPVs are known to inactivate the tumour suppressor Tp53, Rb and E6TP1. The close linkage of OVCA1 and Tp53 on human Chromosome 17 suggests that OVCA1 may be regulated by E6/7 protein. This experiment observed the relationship among HPV16/18 infection, OVCA1's mRNA and exon 1,3,6, 8,9,10,12 deletion in cervical cancer. The aims were to explore the mechanism of cervical cancer and to supply theory basement for biological mechanism in cervical cancer.Methods:DNA and RNA samples are isolated from specimens collected from consenting patients undergoing surgery for cervical cancer at the First Affiliated Hospital Of Dalian Medical Univercity and Dalian Maternity Hospital from april to august in 2008, and stored in-80℃refreshment. DNA samples:16 cases of cervical cancer samples (HPV16/18 positive in 12 cases),19 cases of normal samples (HPV16/18 positive in 3 cases). RNA samples:15 cases of cervical cancer samples (HPV16/18 positive in 10 cases),13 cases of normal samples (HPV16/18 positive in 3 cases). OVCA1 exons of 1/2/3/6/8/9/10/12 and mRNA were analyzed by PCR (Polymerase Chain Reaction) and Semi-quantitative RT-PCR (Reverse Transcription Polymerase Chain Reaction).Results: 1. The deletion rate of OVCAl exons in cervical cancer and normal group are 18.75%(3/16) and 5.26%(1/19) respectively for Exon 1(p>0.05), 14.29%(2/14) and 0%(0/18) respectively for Exon 3(p>0.05),14.29%(2/14) and 0%(0/18) respectively for Exon 6 (p>0.05),14.29%(2/14) and 0%(0/18) respectively for Exon 8(p>0.05),31.25%(5/16) and 26.32%(5/19) respectively for Exon 9 (p>0.05),14.29%(2/14) and 0%(0/18) respectively for Exon 10 (p>0.05),21.43%(3/14) and 11.11%(2/18) respectively for Exon 12 (p>0.05).2.The deletion rate of Exonl/3/6/8/9/10/12 in cervical cancer group with HPV16/18 infection is 25%(3/12),18.18%(2/11),18.18%(2/11), 18.18%(2/11),25%(3/12),18.18%(2/11),27.27%(3/11) respectively. The deletion rate of Exonl/3/6/8/9/10/12 in cervical cancer group with HPV16/18 negative is 0%(0/4),0%(0/3),0%(0/3),0%(0/3),50%(2/4), 0%(0/3),0%(0/3) respectively(p>0.05).3. The relative levels of OVCAl mRNA in cervical cancer and normal group are 0.1206±0.1347 and 0.2704±0.2231 respectively(p<0.05), there is significant difference between the two groups.4. The relative levels of OVCAl mRNA in cervical cancer group with HPV16/18 positive is 0.1018±0.1322 and 0.1582±0.1467 in negative group(p>0.05). There aren't significant differences of relative levels in OVCAl mRNA between HPV16/18 posotive and negtive group in cervical cancer.Conclusion:Expression of OVCAl mRNA is downregulated in cervical cancer, reflecting that there is a relationship between OVCAl and cervical cancer.