| Liver cancer is one of the most common cancers in China. It is the secondmost common cause of cancer death right after gastric cancer. It is often hard tofind liver cancer early because signs and symptoms do not usually appear until itis in its later stages, which increases the difficulty of treatment and threatenspatients’ health and life seriously. Early diagnosis is the key to improve thesurvival rate. Therefore, it is in a great need to identify a quick and accuratediagnosis method of early stage liver cancer for getting more treatment time forpatients is in a great need.Currently, many serum biomarkers have been used for diagnosing livercancer in clinic like AFP, AFP-L3. However, the diagnostic value of them islimited by low sensitivity or low specificity. Hence, there is a great need foridentification of novel biomarkers for early stage tumor detection.MicroRNAs (miRNAs), a class of naturally occurring small non-codingRNAs have recently been known to regulate many important physiologicalprocesses. It has also been shown that miRNAs may have tumor suppressive or oncogenic activity and may become potential cancer biomarkers. As one kind ofmiRNAs, microRNA-200a (miR-200a) has been linked to liver cancer. Recentstudies show that miR-200a presents lower expressions in liver cancer patients.However, til now the published data are rare and inconsistent.In this study, diethylnirtosamine (DEN) intraperitoneal injection wasapplied to inducing liver cancer in F344rats. During the process, blood samplesof rats were collected and used for evaluating miR-200a and AFP levels. Theaim was to explore whether serum miR-200a could be used as a novel biomarkerof liver cancer. Additionally, we collected some blood samples from the clinicalpatients and also performed the testing, which may provide clinical reference forthe analysis of this study.Experiment one: establishment and evaluation of rat liver cancermodel induced by DENMethod: a total of50F344rats were divided into control group (C group,n=10) and experimental group (E group, n=40). The rats of E group receivedDEN ip(30mg/kg) once per three days for12weeks, The rats of C groupreceived the same quantitative saline. General changes of all the rats wereobserved and recorded per day. From week8to week16,8rats of E group and2rats of C group were selected randomly. After weighing, the rats wereanesthetized and laparotomy were performed.4-5ml blood was then collectedthrough abdominal aorta for the following test. The livers were harvest and thegross and pathological changes of liver were observed as well.Result: the rats of group C had normal diet, sensitive reaction and soft hair,while the rats of group E had lower appetite, slower reaction and messier hairgradually. The mean weight of rats in group C was301.28±55.04g, while that ofrats in group E was247.31±29.90g (P <0.01). Four rats died in group E, the death rate is10%. None of the rats died in group C. The results of both grossobservation and pathological analysis showed that hepatic lesions of the rats ofgroup E had experienced four stages: liver fibrosis stage, liver cirrhosis stage,early liver cancer stage and late liver cancer stage.Conclusion: Low doses of DEN intraperitoneal injection successfullyinduces liver cancer in rats, which provides animal model for latter studies.Experiment two: a comparison analysis between the dynamic expressionsof serum miR-200a and AFP during the process of liver cancer development inrats.Methods: blood samples of rats were collected for analysis. Real-timequantitative PCR and ELISA test were used to measure the expressions of serummiR-200a and AFP respectively during the liver cancer developing process.Results: Comparing with group E rats and group C rats, serum miR-200adecreased in liver cirrhosis rats, early stage liver cancer rats and advanced stageliver cancer rats (P<0.05), while AFP increased only in early and advancedstage liver cancer rats (P<0.05). Generally, during the development of livercancer, the miR-200a expression kept on decreasing; while the AFP expressiononly increased after tumor formation.Conclusion: miR-200a played an important role in liver cancerdevelopment and had diagnostic value for indicating early stage liver cancer.Experiment three: a comparison analysis between the expressions ofserum miR-200a and AFP in liver cirrhosis and liver cancer patientsMethods: Patients with normal liver, liver cirrhosis and liver cancer inclinic were included in this study. Blood samples of the patients were collectedfor analysis. After written consent, real time quantitative PCR technique wasused to measure the expression level of serum miR-200a. The AFP expression was from clinical data.Results: Comparing with normal liver patients, miR-200a presented lowerexpressions in both liver cirrhosis patients and liver cancer patients (P<0.05),while AFP presented higher expressions only in liver cancer patients (P<0.05).Conclusions: miR-200a have potential diagnostic value for liver cirrhosisand liver cancer. |
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