ERGIC3, which is regulated by miR-203a, is a potential biomarker for non-small cell lung cancer.

In a previous study, we found that ERGIC3 was a novel lung cancer-related gene by screening libraries of differentially expressed genes. In this study, we developed a new murine monoclonal antibody (mAb) against ERGIC3. This avid antibody (6-C4) is well suited for immunohistochemistry, immunoblotting and solid-phase immunoassays. Furthermore, we systematically investigated expressions of ERGIC3 in a broad variety of normal human tissues and various types of tumors by immunohistochemistry. In normal human tissues, 6-C4 reacted only in some epithelial cells, such as hepatocytes, gastrointestinal epithelium, ducts and acini of the pancreas, proximal and distal tubules of the kidney, and mammary epithelial cells; however, most normal human tissues were not stained. Moreover, almost all carcinomas that originated from the epithelial cells were positive for 6-C4, whereas all sarcomas were negative. Notably, 6-C4 strongly stained non-small cell lung cancer (NSCLC) cells but did not react with normal lung tissues. Hence, ERGIC3 mAb could be used in histopathological diagnosis and cytopathological testing to detect early-stage NSCLC. We also studied the mechanisms of ERGIC3 regulation in vitro and in vivo by means of bioinformatics analysis, luciferase reporter assay, miRNA expression profiling and miRNA transfection. Results showed that miR-203a downregulation induced ERGIC3 overexpression in NSCLC cells.

[Promoter methylation of ASPP1 and ASPP2 genes in non-small cell lung cancers].

OBJECTIVE: To investigate the methylation status of CpG islands in the promoter region and the protein expression of ASPP1 and ASPP2 genes in non-small-cell lung cancer (NSCLC) and their relationship with cellular apoptosis and p53 gene expression. METHODS: The 5'CpG island methylation patterns of ASPP1 and ASPP2 were evaluated by methylation specific polymerase chain reaction (MSP) followed by confirmation of sequencing. Immunohistochemistry was used to detect the expression of ASPP1, ASPP2 and p53 in lung carcinoma tissue samples (n = 90) and adjacent non-neoplastic lung tissue samples (n = 25). TUNEL assay was used to detect the apoptotic activity. RESULTS: The presence of ASPP1 methylation was significantly higher in NSCLC than that in the adjacent non-neoplastic lung tissue [42.2% (38/90) vs. 16.0% (4/25), P = 0.019]. ASPP1 promoter methylation had a close relationship with TNM stage and lymph node metastasis (P = 0.031, P = 0.030), but was not related to the age, sex, histological types and the grades of tumor differentiation (P = 0.389, P = 0.278, P = 0.570, and P = 0.103). Tumors with ASPP1 promoter methylation demonstrated a lower expression of ASPP1 as compared with those without the methylation (P = 0.002). ASPP1 expression was associated with a higher apoptotic index (AI) (P = 0.022) and a decreased p53 expression (r = -0.259, P < 0.01). Methylation in the promoter region of ASPP2 gene was not detected in lung cancer (n = 90) or adjacent non-neoplastic lung tissue (n = 25). Expression of ASPP2 protein did not correlate with AI (P = 0.282) and p53 status in NSCLC. CONCLUSIONS: High methylation of ASPP1 gene promoter regions is one of the important mechanisms that down-regulate its protein expression in NSCLC. ASPP1 promoter methylation may be associated with the malignant progression of the tumor, and ASPP1 expression promotes cellular apoptosis.

Correlation of N-myc downstream-regulated gene 1 overexpression with progressive growth of colorectal neoplasm.

AIM: To study the function of N-myc downstream-regulated gene 1 (NDRG1) in colorectal carcinogenesis and its correlation with tumor lymph node metastasis. METHODS: NDRG1 was detected at its protein level by immunohistochemistry (IHC) and image analysis (IA), and NDRG1 mRNA was detected by in situ hybridization (ISH) in formalin-fixed and paraffin-embedded sections with a total of 190 specimens including 38 normal colorectal mucosae, 31 colorectal adenomas, 45 non-metastatic colorectal carcinomas (CRCs), 38 metastatic primary CRC and subsequently regional lymph nodes respectively. At the same time, the correlations of NDRG1 with sex, age of patients and histological types of colorectal carcinomas were observed. RESULTS: NDRG1 proteins were gradually increased in colorectal carcinogenesis (P<0.05 or P<0.01). There was a significant difference in the expression of NDRG1 between non-metastatic and metastatic CRCs (P<0.05), and the correlation was positive (P<0.01, r(s)=0.329). However, there was no obvious difference in the expression of NDRG1 between the primary sites of CRCs and that in the metastatic sites of corresponding regional lymph nodes, nor was there an apparent difference in sex, age, and histological types. The expression of NDRG1 mRNA was generally in concordance with that of NDRG1 protein. CONCLUSION: NDRG1 gene may play an important role in colorectal carcinogenesis. In addition, NDRG1 may be a putative tumor metastasis promoter gene and is regarded as one of the molecular biological markers that can forecast early metastasis of CRCs. NDRG1 gene in the metastatic sites of regional lymph nodes may preserve its expression characteristics in the primary sites of CRCs to some extent. The expression of NDRG1 is not affected by sex, age and histological types. The role of NDRG1 in tumor metastatic process can be demonstrated by in vivo and in vitro.

[Comparison and analysis of expression of c-myc and p16 in cervical carcinoma].

BACKGROUND & OBJECTIVE: Activation of proto-oncogene and inactivation of tumor suppressor genes is related to the carcinogenesis of many tumors. It is still unclear whether abnormal expression of c-myc and p16 cooperate in the occurrence and progression of cervical carcinoma, and whether there exists a connection between the expression of two genes and the chemotherapy response of cervical carcinoma. This study was designed to investigate the correlation between the expression of c-myc and p16 and their roles in the genesis and development of the uterine cervical carcinoma and chemotherapy response. METHODS: Using in situ hybridization, 37 cases of cervical carcinoma (including 11 cases after chemotherapy), 21 cases of precancerous lesion and 5 cases of normal cervix were observed for c-myc and p16 mRNA with dig-labeled probes. An image analytic system was used to detect the gray degree values of the positive signals. RESULTS: The positive expression rates of p16 in normal cervix,CIN (cervical intraepithelial neoplasia) and cervical carcinoma were 100%, 71.4%, and 21.6%, respectively (P=0.0001), whereas the expression rates of c-myc were 0%, 42.9%, and 75.7% (P=0.0011), respectively. Statistically significant difference was found among the three groups for both p16 and c-myc. The expression of positive signals of c-myc increased with the increase of malignant degree, and the positive signals in CIN III were also higher than that in CIN II and CIN I. The expression rates of c-myc were decreased in cervical carcinoma after chemotherapy. There was a tendency of negative correlation between the expression of c-myc and p16(r(s)=-0.907). Expression of p16 and c-myc showed no significant difference between effectual and ineffectual chemotherapy groups. CONCLUSION: Both over expression of c-myc and descended expression of p16 may play an important role in the genesis and development of uterine cervical carcinoma. The increased expression of c-myc in different grade CIN suggests that carcinogenesis of cervix be progressive.