Study on the clinical significance of Argonaute2 expression in colonic carcinoma by tissue microarray.

BACKGROUND: To study the expression levels and clinical significance of Argonaute2 (EIF2C2) on colonic carcinomas and normal tissues. METHODS: Colon tissue samples from 90 cases of colonic carcinomas and 90 normal subjects were accumulated and made into a tissue microarray containing 360 dots. Expression of Argonaute2 (EIF2C2) was detected by immunohistochemical staining of the tissue microarray. RESULTS: There was significant difference in the expression levels of Argonaute2 (EIF2C2) between colonic carcinomas and normal tissues (P<0.01). However, the expression of Argonaute2 (EIF2C2) was not related to sex, age, position, differentiation, lymphatic metastasis and clinical stage of the tumor (P>0.05). CONCLUSION: Abnormal expression of Argonaute2 (EIF2C2) may be correlated with colon tumorigenesis.

Tissue microarrays in Chinese human rectal cancer: study of expressions of the tumor-associated genes.

BACKGROUNDS/AIMS: The cellular basis for rectal cancer development is still unclear. The aim of this study was to evaluate the relationship between the expression of p53, cyclinD1, bcl-2, ß-catenin, c-myc, cyclooxygenase-2 (COX-2) and nm23-H1 and the clinicopathological characteristics of rectal cancer. METHODOLOGY: Expressions of p53, cyclinD1, bcl-2, ß-catenin, c-myc, COX-2 and nm23-H1 proteins were detected by immunohistochemical staining to two tissue microarrays containing tissues accumulated from 54 human rectal cancers and 40 para-cancer mucosa. RESULTS: Significant differences were demonstrated between the rectal cancers and their benign para-cancer counterparts according to the expressions of p53, cyclinD1, bcl-2, ß-catenin, c-myc, COX-2 and nm23-H1 (p<0.05). Additionally, positive correlations of ß-catenin with cyclinD1 and c-myc (r=0.412, p=0.002; r=0.447, p=0.000) and of p53 with bcl-2 (r=0.332, p=0.001) were found. Cancer tissues with overexpression of ß-catenin or bcl-2 were less likely to differentiate to advanced grade. Expression of cyclinD1 had a correlation with clinical stages (p=0.039). In addition, a negative correlation was found between nm23-H1 expression and the histological grades, distance metastasis and Duke's stages. CONCLUSIONS: Aberrant expression of p53, cyclinD1, bcl-2, ß-catenin, c-myc, COX-2 and nm23-H1 might attribute to the carcinogenesis of human rectal cancer. Furthermore, cyclinD1 and nm23-H1 might be involved in rectal cancer progression. This study recommends the application of tissue microarrays in rectal cancer research for its reliable quick throughput.

Expression of PPARγ and PTEN in human colorectal cancer: An immunohistochemical study using tissue microarray methodology.

Although aberrations of peroxisome proliferator-activated receptor γ (PPARγ) and phosphatase and tensin homolog (PTEN) expression have been identified in several other cancer types, certain previous studies have revealed that PPARγ is abundant in normal and malignant tissue in the colon. The question of whether aberrant PTEN is involved in the initial stage or is a later event during colorectal carcinogenesis remains controversial. Relatively few studies have focused on the correlation of expression of PPARγ and PTEN in various tissues. In the present study, paraffin-embedded blocks from 139 patients with CRC, 18 adenomatous polyps and 50 paired paracancerous benign mucosas were selected and analysed in 4 tissue microarray (TMA) blocks comprising 104, 72, 130 and 54 cores, respectively. Expression of PPARγ and PTEN was examined using immunohistochemical staining on TMAs. There were no significant differences in the expression of PPARγ (P=0.055) and PTEN (P=0.100) between the colorectal cancers, adenomas and paracancerous mucosas. However, correlations of PPARγ expression with clinical stage (P=0.004) and PTEN expression with histological grade (P=0.006) and distant metastasis (P=0.015) were demonstrated in the CRC specimens. Although the differences in PPARγ and PTEN protein expression in human colorectal cancer may not be considered as early diagnostic markers, our results indicate that CRCs with a low expression or deletion of PTEN may progress towards invasion and even metastasis; thus, PTEN may have potential as a prognostic marker in human CRC.

Initial study of microRNA expression profiles of colonic cancer without lymph node metastasis.

OBJECTIVE: To investigate the difference of microRNA expression profiles between colonic cancer without lymph node metastasis and the para-cancerous control, to identify the specific microRNA associated with the cancer and to predict the carcinogenetic mechanism of microRNA on the basis of these results. METHODS: The microRNA (miRNA) were extracted and isolated from six specimens, including colonic cancerous and para-cancerous ones, all of which were confirmed to be without lymph node metastasis. Agilent microRNA microarrays consisting of 723 probes were used for screening the expression differences of microRNA. Data were analyzed using feature extraction software. The expression level of differentially expressed microRNA using quantitative real-time polymerase chain reaction (RT-PCR) was validated. RESULTS: A total of 14 miRNAs were found to be associated with colonic cancer, in which the expression of miR-106b, miR-135b, miR-18a, miR-18b, miR-196b, miR-19a, miR-224, miR-335, miR-424, miR-20a*, miR-301b and miR-374a were up-regulated and the expression of miR-378 and miR-378* were downregulated in colonic cancer tissues, compared with the para-cancerous control. The expression level of miR-18a and miR-135b were validated in accordance with the results of RT-PCR. CONCLUSION: The miRNAs are differentially expressed between colonic tumor tissues and para-cancerous tissues. Many of these miRNAs are expected to participate in the process of multiple tumorigenesis. These miRNAs could play an important role in the carcinogenesis of colon. These results provide new insights in human colorectal cancer genesis.

MicroRNA expression profile in non-cancerous colonic tissue associated with lymph node metastasis of colon cancer.

OBJECTIVE: To identify microRNA expression patterns associated with the lymph node metastasis of colon cancer. METHODS: MicroRNA were isolated from six frozen non-cancerous surrounding colonic tissues derived from stage II-III colon cancer patients with (n = 3) and without (n = 3) lymph node metastasis. We compared the microRNA expression profiles of the six non-cancerous colonic tissues from two colon cancer patient groups; those with confirmed lymph node metastasis, termed the lymph node positive group, and those without detectable lymph node metastasis, termed the lymph node negative group. MicroRNA expression was analyzed with Agilent microarrays containing 723 human microRNA probes. We validated the expression level of differentially expressed microRNA using quantitative real-time PCR analysis. RESULTS: Two microRNA (hsa-miR-129*, hsa-miR-137) were differentially expressed in the lymph node positive group compared with the lymph node negative group. The expression level of hsa-miR-137 was quantified via quantitative real-time PCR analysis for validation. Hsa-miR-137 expression was significantly upregulated nearly 6.6-fold in lymph node positive specimens (P = 0.036). The quantitative real-time PCR result correlates with the microarray finding. CONCLUSION: The non-cancerous colonic tissues from colon cancer patients with lymph node metastasis have a significantly different microRNA expression profile compared to that from colon cancer patients without lymph node metastasis. The differentially expressed microRNA could have relevance to the lymph node metastasis of colon cancer and may provide a simple profiling method to assist in identifying patients with lymph node metastasis. Besides, these data might offer new ideas for preventing and controlling lymphatic metastasis in colon cancer.

[Establishment of the pipeline for RNA quality assessment from the cells obtained by laser capture microdissection].

We developed a standard protocol for quality assessment of low amount RNA from the cells obtained by laser capture microdissection (LCM). Three gastric noncancerous tissues were cryo-sectioned, stained with Cresyl Violet, and pathologically rechecked. Epithelial cells were obtained by LCM and RNA was isolated. Agilent 2100 bioanalyzer was used to check the RNA quality. To validate the results from 2100 bioanalyzer, RT-PCR was performed with six genes at both 5'and 3' end-regions of different abundance (EF1A and ATCB of high abundance, GAPDH and B2M of moderate abundance, and MED1 and CK20 of low abundance). RT-PCR analysis of 3 good quality RNAs from cultured cell lines and 3 poor quality RNAs from gastric noncancerous tissues showed high correlations with that from 2100 bioanalyzer. In conclusion, the pipeline for low amount RNA quality assessment by RT-PCR from tissue cryo-section, pathological recheck, LCM purification and RNA isolation is applicable as a routine method in cancer genome research.

Computed tomography perfusion in evaluating the therapeutic effect of transarterial chemoembolization for hepatocellular carcinoma.

AIM: To prospectively assess the changes in parameters of computed tomography (CT) perfusion pre- and post-transarterial chemoembolization (TACE) of hepatocellular carcinoma (HCC) in different treatment response groups, and to correlate the changes with various responses of HCC to TACE. METHODS: Thirty-nine HCC patients underwent CT perfusion examinations pre-(1 d before TACE) and post-treatment (4 wk after TACE). The response evaluation criteria for solid tumors (RECIST) were referred to when treatment responses were distributed. Wilcoxon-signed ranks test was used to compare the differences in CT perfusion parameters pre- and post-TACE for different response groups. RESULTS: Only one case had treatment response to CR and the CT perfusion maps of post-treatment lesion displayed complete absence of signals. In the PR treatment response group, hepatic artery perfusion (HAP), hepatic arterial fracture (HAF) and hepatic blood volume (HBV) of viable tumors post-TACE were reduced compared with pre-TACE (P = 0.001, 0.030 and 0.001, respectively). In the SD group, all CT perfusion parameters were not significantly different pre- and post-TACE. In the PD group, HAP, HAF, portal vein perfusion (PVP) and hepatic blood flow (HBF) of viable tumors post-TACE were significantly increased compared with pre-TACE (P = 0.005, 0.012, 0.035 and 0.005, respectively). CONCLUSION: Changes in CT perfusion parameters of viable tumors are correlated with different responses of HCC to TACE. Therefore, CT perfusion imaging is a feasible technique for monitoring response of HCC to TACE.

Expression of p53, p16 and cyclooxygenase-2 in esophageal cancer with tissue microarray.

OBJECTIVE: The aim of this study was to obtain a comprehensive survey on the expression of p53, p16 and cyclooxygenase-2 (COX-2) in esophageal cancer progression and their clinical significance. METHODS: A tissue microarray containing 86 specimens from esophageal cancer and 40 specimens from adjacent non-cancer tissue was constructed to survey the expression of p53, p16 and COX-2 by immunohistochemistry. The influence of each biomarker on the histotype of esophageal lesion was assessed by logistic regression analysis. RESULTS: The expression of p53 and COX-2 was significantly higher in tumorous tissue than in non-tumorous tissue. As to p16, no significant difference was detected between tumorous and non-tumorous tissue. A significant correlation was observed among p53, COX-2 and p16 expression. Logistic regression analysis revealed that the risk factors of a tumorous histotype were the positive expression of p53 (odds ratio [OR] = 18.214) or COX-2 (OR = 42.703), and no reciprocal relationship to neoplastic progression was recognized with p53, p16 and COX-2. CONCLUSIONS: p53 and COX-2 were independent predictors in esophageal carcinogenesis. Esophageal tissue with a positive expression of p53 or COX-2 was more likely to develop esophageal cancer.

Survey of molecular profiling during human colon cancer development and progression by immunohistochemical staining on tissue microarray.

AIM: To explore the molecular events taking place during human colon cancer development and progression through high-throughput tissue microarray analysis. METHODS: We constructed two separate tissue microarrays containing 1.0 mm or 1.5 mm cylindrical samples acquired from 112 formalin-fixed and paraffin-embedded blocks, including carcinomas (n = 85), adenomatous polyps (n = 18), as well as normal para-cancerous colon tissues (n = 9). Immunohistochemical staining was applied to the analysis of the consecutive tissue microarray sections with antibodies for 11 different proteins, including p53, p21, bcl-2, bax, cyclin D1, PTEN, p-Akt1, beta-catenin, c-myc, nm23-h1 and Cox-2. RESULTS: The protein expressions of p53, bcl-2, bax, cyclin D1, beta-catenin, c-myc, Cox-2 and nm23-h1 varied significantly among tissues from cancer, adenomatous polyps and normal colon mucosa (P = 0.003, P = 0.001, P = 0.000, P = 0.000, P = 0.034, P = 0.003, P = 0.002, and P = 0.007, respectively). Chi-square analysis showed that the statistically significant variables were p53, p21, bax, beta-catenin, c-myc, PTEN, p-Akt1, Cox-2 and nm23-h1 for histological grade (P = 0.005, P = 0.013, P = 0.044, P = 0.000, P = 0.000, P = 0.029, P = 0.000, P = 0.008, and P = 0.000, respectively), beta-catenin, c-myc and p-Akt1 for lymph node metastasis (P = 0.011, P = 0.005, and P = 0.032, respectively), beta-catenin, c-myc, Cox-2 and nm23-h1 for distance metastasis (P = 0.020, P = 0.000, P = 0.026, and P = 0.008, respectively), and cyclin D1, beta-catenin, c-myc, Cox-2 and nm23-h1 for clinical stages (P = 0.038, P = 0.008, P = 0.000, P = 0.016, and P = 0.014, respectively). CONCLUSION: Tissue microarray immunohistochemical staining enables high-throughput analysis of genetic alterations contributing to human colon cancer development and progression. Our results implicate the potential roles of p53, cyclin D1, bcl-2, bax, Cox-2, beta-catenin and c-myc in development of human colon cancer and that of bcl-2, nm23-h1, PTEN and p-Akt1 in progression of human colon cancer.

[Expression of tissue microarray p53, p16 and cyclooxygenase-2 in gastric cancer].

OBJECTIVE: To constructed tissue microarray containing specimens from gastric cancer and adjacent non-cancer tissue to survey the expression of p53, p16 and cyclooxygenase-2 (COX-2), and to obtain a comprehensive survey on the expression of three proteins in gastric cancer progression and their clinical significance. METHODS: We constructed a tissue microarray containing 50 specimens from gastric cancer and 78 specimens from adjacent non-cancer tissue, and assayed three different proteins (p53, p16 and COX-2) by immunohistochemistry to consecutive formalin-fixed tissue microarray sections. RESULTS: In non-cancer tissue, p53, p16 and COX-2 positive staining were 19%, 15% and 74% respectively. In gastric cancer tissue, p53, p16 and COX-2 positive staining were 50%, 54% and 94% respectively. There were a significant difference between two different tissues (P < 0.05). 52% (66/128) cases were COX-2+/p53-, only 1 case were COX-2-/p53+. There was a significant association between COX-2 and p53 (P < 0.05). COX-2 negative expression tissues were found significantly more often in p53-negative than in p53-positive cases. 52% (67/128) cases were COX-2+/p16-, only 1 case were COX-2-/p16+. A significant correlation was recognized between expression of COX-2 and p16 (P < 0.05). Logistic regression analysis revealed that the risk factors of tumorous histotype were p53, p16 and COX-2 positive expression together, determined by Wald chi2 test (P < 0.05; odds ratio, 18.889). There was reciprocal relationship among p53, p16 and COX-2. CONCLUSION: Combination analysis of p53, p16 and COX-2 may be useful for the prediction of gastric carcinogenesis.

[Detection of expression of p53, p16, and cyclooxygenase 2 in pancreatic cancer by tissue microarray and correlation among these three genes].

OBJECTIVE: To detect the expression of tumor suppressor protein p53, cyclin-dependent kinase inhibitor p16, and cyclooxygenase 2 (COX-2) in pancreatic cancer by tissue microarray and investigate the correlation among these three genes. METHODS: 104 specimens of tissues, including pancreatic cancer tissue, non-cancer tissues not more than 1.5 cm from the cancer, and normal tissues, underwent microarray examination and immunohistochemistry to detect the expression of p53, p16, and COX-2. The correlation among these 3 genes was analyzed. RESULTS: p53, p16, and COX-2 were all significantly highly expressed in the cancerous tissues in comparison with other tissues. P53 and p16 were both significantly correlated with COX-2 (both P < 0.05), however, there was not a correlation between p53 and p16 (P > 0.05). There was a reciprocal relationship between p53 and COX-2 (P < 0.05, OR = 19.686) influencing the pathogenesis of pancreatic cancer. CONCLUSION: Tissue microarray technique is effective method to detect multiple gene protein expression. Pathogenesis of pancreatic cancer is associated with p53, p16, and COX-2.

Expression of p53, p16 and COX-2 in pancreatic cancer with tissue microarray.

BACKGROUND: Pancreatic cancer development and progression is driven by the accumulation of genetic changes. In this study we constructed tissue microarray containing specimens from pancreatic cancer, adjacent non-cancer tissue and normal tissue to survey the expression of p53, p16 and cyclooxygenase-2 (COX-2). METHODS: Tissue microarray containing 337 specimens from different stages of pancreatic cancer, adjacent non-cancer tissue and normal tissues was constructed, and the expression of p53, p16 and COX-2 was assayed by immunohistochemistry to consecutive formalin-fixed tissue microarray sections. RESULTS: The expression of p53, p16 and COX-2 was significantly higher in tumorous tissues than in non-tumorous ones. A significant relationship was observed between p53 and COX-2, or p16 and COX-2. But no obvious correlation was seen between p53 and p16 expressions. Logistic regression analysis showed p53 and COX-2 as dependent predictors in pancreatic carcinogenesis, and a reciprocal relationship to neoplastic progression between p53 and COX-2. CONCLUSION: Combination analysis of p53 and COX-2 may be useful in predicting pancreatic carcinogenesis.