Research On The Expression Of IDO In Hepatocellular Carcinoma (HCC)

Hepatocellular Carcinoma (HCC) is one of the most common and deadly malignant neoplasms worldwide. Globally, HCC is the fifth most common cancer and the third most common cause of deaths by cancer, behind lung and stomach cancers. Surgical resection is an important therapeutic option for those who have operation indication, but the recurrence rate remains high and overall survival of resected patients at5years is dismal which reported ranging from17%to53%. Even many clinicopathological characteristics and biomarker have the role of predict recurrence and prognosis in patients with HCC after hepatectomy, such as tumor size, associated cirrhosis, HBV or HCV infection, presence of daughter nodules, adequate resection margin, permeation, histological Edmondson grade of tumor differentiation. But the tumor recurrence mechanism and the influencing factor is not very clear.Indoleamine2,3-dioxygenase (IDO) is a tryptophan-catabolizing enzyme with immune-regulating. Emerging Research demonstrate that IDO activity correlates with immune counter regulation in a range of clinically significant syndromes such as fetal protection, chronic infections, autoimmunity, cancer progression, and allograft resistance to destructive host immunity. Among many cancer patients, high expression of IDO tend to be associated with poorer prognosis. Meanwhile, study proves that IDO expressions conneted with tumor microenvironment, for instance,in ovarian carcinoma and endometrial cancer patients, IDO expression heighten can cause a reduction number of CD8+T and CD57+lymphocyte.In cervical cancer, IDO downregulation can enhanced the sensitivity of cervical cancer cells to natural killer (NK) cells in vitro and promoted NK cell accumulation in the tumor stroma in vivo.Further more, an increase in Foxp3+Tregs can be induced by local IDO-positive cells in Intraductal papillary mucinous neoplasms (IPMNs).In addition,peripheral Foxp3+Tregs accurately reflect the aggressiveness of IPMNs. a significant correlation was found between Foxp3+CD4+T cells among the PBMCs and the TNM stage.IDO can increase the number of CD4+CD25+Foxp3+T cells,and this effect is completely abrogated by the indoleamine2,3-dioxygenase-inhibitor,l-methyl tryptophan.More and more research have proofed that Tumor-infiltrating Lymphocytes which exist In the tumor microenvironment associate with tumor recurrence in a great extent.At the same time, IDO have the role of Inducing immune tolerance by changing tumor environment and promote the development of tumor, influenced the prognosis of patients largely. So research of the relationship between IDO and primary liver cancer has a profound significance. This study is divided into two parts:Chapter1Expression of IDO in Hepatocellular Carcinoma (HCC)Objective:To investigate the relationships between IDO mRNA、IDO protein expression and clinical pathological features.Methods:1、 All tissues were collected from the Department of Hepatobiliary Surgery of Southern Medical University Nanfang Hospital from November2009to December2012.2、Quantitative real-time PCR was used to determined the expression of IDO mRNA in61cases with hepatocellular carcinoma, including tumor、non-cancer tissues and7cases of normal liver tissues from liver benign lesions.3、The expression of IDO protein was detected by immunohistochemical and immunofluorescence staining in89patients with hepatocellular carcinoma, including tumor、tumor surrounding、non-cancer tissues and7cases of normal liver tissues from liver benign lesions.4、Statistical analysis:SPSS13.0software was used to analyse all data. The relationships between expression of IDO in HCC and clinicopathological features were analysisResults:1、The expression of IDO mRNA in61tumor tissues was higher than non-cancer tissues and normal liver tissues from liver benign lesions (P<0.001).2、The over expression of IDO mRNA in HCC was associated wth recurrence and Disease-free Survival time、metastasis and TNM stage (P<0.05),but not associated with patient’s cirrhosis、AFP level、histological differentiation type、BCLC, gender、age、HbsAg positivity、number of tumors and tumor size (P>0.05).3、The over expression of IDO protein in HCC was associated wth recurrence and Disease-free Survival time、metastasis and TNM stage (P<0.05),but not associated with patient’s cirrhosis、AFP level、histological differentiation type、 BCLC, gender、age、HbsAg positivity、number of tumors and tumor size (P>0.05).4、The recurrence and metastasis rate were higher in patients with tumor-surrounding tissues IDO expressed higher than tumor tissues.Conclusions:1、The expression of IDO mRNA in tumor tissues was significantly higher than non-cancer tissues and normal liver tissues from liver benign lesions.2、IDO protein express in cell cytoplasm of hepatocellular carcinoma tissues and tumor-surrounding tissues.3、The over expression of IDO mRNA and protein may affect the prognosis of patients with HCC Chapter2Detection of the lymphocytes infiltrate in the tissues of liver cancerObjective:To analyze the relationships between IDO expression and Tumor-infiltrating CD3+、CD4+、CD8+、FOXP3+T Lymphocytes and CD4/CD3、 CD8/CD3、FOXP3/CD3proportional in HCC tissues.Methods：1、89tissues were collected from the Department of Hepatobiliary Surgery of Southern Medical University Nanfang Hospital from November2009to December2012.2、The number of tumor-infiltrating CD3、CD4+、CD8+、and Foxp3+lymphocytes was assessed by immunohistochemistry in89Hepatocellular carcinoma patients.3、Statistical analysis：SPSS13.0software was used to analyse all data. The relationships between IDO expression and the number of tumor-infiltrating CD4+、 CD8+、and Foxp3+lymphocytes and CD4/CD3、CD8/CD3、FOXP3/CD3ratios.Results:The number of Tumor-infiltrating Lymphocytes Foxp3+cells、 CD4+cells、and CD8+cells and the ratios of Foxp3+Tregs to CD3+T cells (Foxp3/CD3ratio),CD4+T cells to CD3+T cells (CD4/CD3ratio) and CD8+T cells to CD3+T cells (CD8/CD3ratio) were related with IDO protein expression.The number of Foxp3+Tregs were significant higher in patients with IDO over expression than other patients,but the CD4+, and CD8+cells are fewer.Also, Foxp3/CD3ratio is significant higher in patients with IDO high express than other patients,and CD4/CD3ratio、CD8/CD3ratio are lower (p<0.001)Conclusions:The strength of IDO protein expression and tumor infiltrating lymphocyte disproportionality were related closely in HCC tissue, Immune dysfunction might be exist in the tumor microenvironment, which affected patients’ prognosis.