PubMed Health⌕ Search

Biomedical subjects

Yongfen Min

Publications and source records attributed to Yongfen Min.

8 recordsLinked to original sources
PubMed2006

Insulin-like growth factor-I receptor as a marker for prognosis and a therapeutic target in human esophageal squamous cell carcinoma.

Insulin-like growth factor (IGF)-I receptor (IGF-Ir) signaling is required for tumorigenicity and progression of many tumors but this pathway has not been well studied as a prognostic factor or potential therapeutic target in esophageal squamous cell carcinoma (ESCC). In this paper, the association between the expression of IGF-Ir and IGF-II ligand and prognosis was investigated immunohistochemically in 100 surgically resected ESCC. We then assessed the therapeutic effect of blocking IGF receptor signaling using dominant negative IGF-Ir (IGF-Ir/dn) in ESCC in vitro. Expression of IGF-Ir and IGF-II were detected in 60 and 50% of tumors, respectively, and were associated with invasion depth, metastasis, advanced tumor stage and recurrence. Patients with tumors expressing both IGF-Ir and IGF-II had a significantly shorter survival than those expressing either alone or neither in both single and multivariate analysis. IGF-Ir/dn suppressed proliferation and motility as well as upregulating chemotherapy-induced apoptosis through blocking ligand-induced Akt activation. We propose that detection of IGF-Ir/IGF-II in ESCC may be useful for the prediction of recurrence and poor prognosis and for selecting patients for IGF-Ir-targeted therapy. Therapeutic blockade of IGF-Ir may be a useful anticancer therapeutic for ESCC.

Adenoviridae↗
PubMed2003

Expression of ets-related transcriptional factor E1AF is associated with tumor progression and over-expression of matrilysin in human gastric cancer.

Expression of E1AF/PEA3 (ETV4), an ets family transcriptional factor, has been implicated in tumor progression through induction of matrix metalloproteinase (MMP) expression. The aim of this study was to examine E1AF mRNA expression and to determine whether it is correlated with progression of, and/or MMP expression in, human gastric cancer. Using the semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), we analyzed 100 gastric cancer tissues for E1AF mRNA expression. Expression of ER81 (ETV1) and ERM (ETV5), the other two members of the PEA3 subfamily, and Ets-1 and Ets-2 was also analyzed. The results were correlated with clinicopathological characteristics and MMP expression. Immunohistochemical analysis and an in vitro invasion assay were also performed. E1AF mRNA expression was detected in 64% of the 100 gastric cancer tissues, but was undetectable or only faintly detected in adjacent non-tumor tissues. E1AF expression was significantly correlated with depth of invasion, lymphatic and venous invasion, lymph node and distant metastasis, advance in pathological tumor-node-metastasis stage and recurrence. Patients with E1AF-positive tumors had significantly shorter overall and disease-free survival periods than did those with E1AF-negative tumors (P < 0.0001 and P < 0.0001, respectively). E1AF expression retained its significant predictive value for overall and disease-free survival in multivariate analysis that included conventional clinicopathological factors (P = 0.0082 and P = 0.0096, respectively). Among the MMPs analyzed, expression of matrilysin (MMP-7) was significantly correlated with E1AF expression. Immunohistochemical expression of E1AF was predominantly observed at the invasive front, where the expression of matrilysin was often co-localized. Antisense E1AF-transfected MKN45 gastric cancer cells expressed reduced levels of matrilysin and were less invasive in vitro than mock-transfected MKN45 cells. The results of this study suggest that E1AF, the expression of which is closely correlated with the expression of matrilysin, plays a key role in the progression of gastric cancer.

Adenovirus E1A Proteins↗
PubMed2003

Genetic blockade of the insulin-like growth factor-I receptor: a promising strategy for human pancreatic cancer.

Pancreatic cancer is one of the most lethal malignant tumors. Insulin-like growth factor (IGF)-I receptor (IGF-Ir) signaling is required for maintenance of growth and tumorigenicity of many tumors, but this pathway has not been well studied in pancreatic cancer. We have shown previously successful therapy in colorectal and lung cancer xenograft models using recombinant adenoviruses expressing dominant negative IGF-I receptors. In this study, we sought to better dissect the mechanism of action of this virus and determine whether IGF-Ir targeted adenoviruses represent potentially effective therapeutics for human pancreatic cancer cells. Truncated IGF-I receptors (IGF-Ir/dn; 482 and 950 amino acids long, respectively, IGF-Ir/482st and IGF-Ir/950st) that function as dominant negative inhibitor were cloned into recombinant adenoviruses and used to treat human pancreatic cancer cells. We assessed the effect of IGF-Ir/dn on signaling blockade, growth, stress response, chemotherapy, radiation-induced apoptosis, and in vivo therapeutic efficacy in xenografts. IGF-Ir/dn expression suppressed tumorigenicity both in vitro and in vivo and up-regulated stressor-induced apoptosis. It effectively blocked both IGF-I and IGF-II-induced activation of Akt-1. IGF-Ir/dn expression increased radiation and chemotherapy-induced apoptosis, and the combination therapy of IGF-Ir/dn with chemotherapy was very effective against tumors in mice. In an i.p. model, IGF-Ir/dn therapy reduced dissemination and prolonged survival times. Moreover, IGF-Ir/482st was more effective than IGF-Ir/950st because of its bystander effect. The antitumor activity of IGF-Ir/dn is mediated through inhibition of Akt-1 and enhances the efficacy of chemotherapy. Adenovirus-IGF-Ir/482st may be a useful anticancer therapeutic for pancreatic cancer.

Adenoviruses, Human↗
PubMed2003

Association of trypsin expression with tumour progression and matrilysin expression in human colorectal cancer.

Overexpression of the matrix serine protease (MSP) trypsin has been implicated in tumour growth, invasion, and metastasis. The objective of this study was to clarify the clinicopathological and prognostic significance of trypsin expression in colorectal cancer. This study analysed the association between immunohistochemically detected trypsin expression in colorectal cancer and clinicopathological characteristics, and investigated whether trypsin is a predictor of recurrence and/or survival. Trypsin immunoreactivity was more intense at the invasive front than in the superficial part of the tumour. Sections with immunostaining signals in more than 30% of carcinoma cells at the invasive front, which were observed in 48 cases (48%), were judged to be positive for trypsin. Trypsin positivity was significantly correlated with depth of invasion, lymphatic and venous invasion, lymph node and distant metastasis, advanced pathological tumour-node-metastasis (TNM) stage, and recurrence. Patients with trypsin-positive carcinoma had significantly shorter overall and disease-free survival periods than did those with trypsin-negative carcinoma. Trypsin retained its significant predictive value for overall and disease-free survival in multivariate analysis that included conventional clinicopathological factors. It is well known that trypsin activates matrilysin (matrix metalloproteinase-7), which plays an important role in colorectal cancer progression. Patients with concordant overexpression of trypsin and matrilysin at the invasive front, in which they were often co-localized, had the worst prognosis. Trypsinogen-1-transfected HCT116 colon cancer cells showed not only trypsin activity, but also active matrilysin activity and were more invasive in vitro than mock-transfected HCT116 cells. These results suggest that trypsin plays a key role in the progression of colorectal cancer. Detection of trypsin expression as well as matrilysin is useful for the prediction of recurrence in and poor prognosis of colorectal cancer patients.

Aged↗
PubMed2003

Association of ets-related transcriptional factor E1AF expression with tumour progression and overexpression of MMP-1 and matrilysin in human colorectal cancer.

Expression of E1AF/PEA3 (ETV4), an ets family transcription factor, has been implicated in the invasive potential of several cancer cell lines through induction of matrix metalloproteinase (MMP) expression. The aim of this study was to examine E1AF mRNA expression and to determine whether it is correlated with progression of, and/or MMP expression in, human colorectal cancer. Using the semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), 100 colorectal cancer tissues were analysed for E1AF mRNA expression. Expression of ER81 (ETV1) and ERM (ETV5), the other two members of the PEA3 subfamily, and Ets-1 and Ets-2 was also analysed. The results were correlated with clinicopathological characteristics and MMP expression. Immunohistochemical analysis and an in vitro invasion assay were also performed. E1AF mRNA expression was detected in 62% of the 100 colorectal cancer tissues, but was undetectable or only faintly detected in adjacent non-tumour tissues. E1AF mRNA was detected in all of the ten liver metastases from colorectal cancers. E1AF expression correlated significantly with depth of invasion, lymphatic and venous invasion, lymph node and distant metastasis, advance in pathological tumour-node-metastasis stage, and recurrence. Patients with E1AF-positive tumours had significantly shorter overall and disease-free survival periods than did those with E1AF-negative tumours (p < 0.0001 and p < 0.0001, respectively). E1AF expression retained its significant predictive value for overall and disease-free survival in multivariate analysis that included conventional clinicopathological factors (p = 0.0066 and p = 0.0109, respectively). Among the MMPs analysed, expression of MMP-1 and matrilysin correlated significantly with E1AF expression. In contrast, expression of ER81 and ERM did not correlate with clinicopathological characteristics or the expression of these MMPs. Immunohistochemical expression of E1AF was predominantly observed at the invasive front, where the expression of MMP-1 and matrilysin and nuclear beta-catenin expression were often co-localized. Antisense E1AF-transfected HT-29 colon cancer cells expressed reduced levels of MMP-1 and matrilysin and were less invasive in vitro than neo-transfected HT-29 cells. The results of this study suggest that E1AF, the expression of which is closely correlated with the expression of MMP-1 and matrilysin, plays a key role in the progression of colorectal cancer.

Adenocarcinoma↗
PubMed2002

Differential involvement of the hypermethylator phenotype in hereditary and sporadic colorectal cancers with high-frequency microsatellite instability.

High-frequency microsatellite instability (MSI-H) due to defective DNA mismatch repair occurs in the majority of hereditary nonpolyposis colorectal cancers (HNPCCs) and in a subset of sporadic malignant tumors. Clinicopathologic and genotypic features of MSI-H colorectal tumors in HNPCC patients and those in sporadic cases are very similar but not identical. Correlation between the MSI phenotype and aberrant DNA methylation has been highlighted recently. A strong association between MSI and CpG island methylation has been well characterized in sporadic colorectal cancers with MSI-H but not in those of hereditary origin. To address the issue, we analyzed hereditary and sporadic colorectal cancers for aberrant DNA methylation of target genes using methylation-specific polymerase chain reaction. DNA methylation of the MLH1, CDKN2A, MGMT, THBS1, RARB, APC, and p14ARF genes was found in 0%, 23%, 10%, 3%, 73%, 53%, and 33% of 30 MSI-H cancers in HNPCC patients and in 80%, 55%, 23%, 23%, 58%, 35%, and 50% of 40 sporadic colorectal cancers with MSI-H, respectively. Cases showing methylation at three or more loci of six genes other than MLH1 were defined as CpG island methylator phenotype-positive (CIMP +), and 23% of HNPCC tumors and 53% of sporadic cancers with MSI-H were CIMP+ (P = 0.018). Differences in the extent of CpG island methylation, coupled with the differential involvement of several genes by methylation, in HNPCC tumors and sporadic MSI-H colorectal cancers may be associated with diverging developmental pathways in hereditary and sporadic cancers despite similar MSI-H phenotypes.

Adenocarcinoma↗
PubMed2002

Analysis of gene expression in human colorectal cancer tissues by cDNA array.

BACKGROUND: The development and progression of cancer are accompanied by complex changes in patterns of gene expression. The purpose of this study was to clarify the relevance of macroarray analysis of human colorectal cancer tissues. METHODS: Hybridization of cDNA macroarray filters on which 550 genes had been spotted was performed with biotin-labeled cDNA targets that were prepared from mRNA extracted from 20 pairs of colorectal cancer and corresponding noncancerous tissues. Expression of differentially expressed genes was further studied by semiquantitative RT-PCR. RESULTS: Fourteen (2.5%) of the 550 genes were differentially expressed and up- or downregulated in cancer tissues by at least threefold compared with matched noncancerous tissues in 10 or more of the 20 patients. The genes that were upregulated in cancer tissues were associated with transcription, cell cycle, growth factor receptor, cell adhesion, extracellular matrix-degrading enzymes, and angiogenesis, and the downregulated genes were those involved in apoptosis and immune recognition. Semiquantitative RT-PCR analysis of these differentially expressed genes gave results consistent with those by cDNA array analysis. CONCLUSIONS: Although the macroarray used in this study contained only a small number of genes, our results support the feasibility and usefulness of this approach to study variation in gene expression patterns in human colorectal cancer tissues. The results also suggest the possibility of a diagnostic application of cDNA macroarrays in daily clinical settings.

Biopsy, Needle↗