Ya-Chien Yang

Curcumin Suppresses Metastasis via Sp-1, FAK Inhibition, and E-Cadherin Upregulation in Colorectal Cancer

Colorectal cancer (CRC) is a serious public health problem that results due to changes of diet and various environmental stress factors in the world. Curcumin is a traditional medicine used for treatment of a wide variety of tumors. However, antimetastasis mechanism of curcumin on CRC has not yet been completely investigated. Here, we explored the underlying molecular mechanisms of curcumin on metastasis of CRC cells in vitro and in vivo. Curcumin significantly inhibits cell migration, invasion, and colony formation in vitro and reduces tumor growth and liver metastasis in vivo. We found that curcumin suppresses Sp-1 transcriptional activity and Sp-1 regulated genes including ADEM10, calmodulin, EPHB2, HDAC4, and SEPP1 in CRC cells. Curcumin inhibits focal adhesion kinase (FAK) phosphorylation and enhances the expressions of several extracellular matrix components which play a critical role in invasion and metastasis. Curcumin reduces CD24 expression in a dose-dependent manner in CRC cells. Moreover, E-cadherin expression is upregulated by curcumin and serves as an inhibitor of EMT. These results suggest that curcumin executes its antimetastasis function through downregulation of Sp-1, FAK, and CD24 and by promoting E-cadherin expression in CRC cells.

Loss of heterozygosity and DNA aneuploidy in colorectal adenocarcinoma.

AbstractBackground: This study evaluated the relationship between DNA aneuploidy and loss of heterozygosity (LOH) at different genetic loci in colorectal adenocarcinoma. Methods: A total of 112 patients with surgically removed colorectal adenocarcinoma in Taipei Veterans General Hospital from January 1999 to July 2001 were included in this study. The pattern of DNA ploidy was determined with DNA flow cytometry, and the LOH of various genetic loci was determined with fluorescence polymerase chain reaction and denaturing gradient gel electrophoresis. The relationship between DNA ploidy, LOH of various genetic loci, and clinicopathologic variables was analyzed with the χ2 test with Yates’ correction as well as by multivariate binary logistic regression analysis. Results: Seventy-one (63.4%) of the 112 carcinomas had DNA aneuploidy. The DNA aneuploidy was not associated with any clinicopathologic variable. Ninety-one tumors (81.3%) exhibited LOH in at least one genetic locus. In the univariate analysis, the DNA aneuploidy was associated with LOH of Tp53-penta, D8S254, D5S346, and high-frequency LOH (P = .001, P = .016, P = .041, and P < .001, respectively). In the multivariate analysis, the most significant factor influencing DNA aneuploidy was D8S254, followed by Tp53-penta, high-frequency LOH, and D5S346. Conclusions: DNA aneuploidy is strongly associated with LOH at specific genetic loci.

Functional polymorphism of CTLA-4 and ICOS genes in allogeneic hematopoietic stem cell transplantation.

BACKGROUND T cells play a critical role in alloimmune recognition and thus contribute to graft-versus-host disease (GVHD) and relapse prevention in hematopoietic stem cell transplantation (HSCT). Cytotoxic T lymphocyte antigen-4 (CTLA-4) and inducible costimulator (ICOS) are costimulatory molecules of T cell activation and their genetic variations can affect the capacity of T cells to become activated or inactivated. METHODS We examined CTLA-4 (-318 C/T and +49 A/G) and ICOS (c.602 A/C and c.1624 C/T) genotypes in 123 patients with HSCT and their HLA-matched sibling donors, and then evaluated the impacts of the genetic polymorphisms on GVHD, disease relapse, and survival. RESULTS By multivariate analysis, the donor CTLA-4 -318 TT genotype increased the risk of disease relapse (Hazard ratio [HR]: 5.91, 95% confidence interval [CI]: 1.17-29.79, P=0.0313). Recipients who received a graft from a donor with ICOS c.602 CC genotype had worse disease-free survival (HR: 5.97, 95% CI: 1.49-23.87, P=0.0115). Additionally, recipients with ICOS c.1624 TT genotype had worse overall survival (HR: 12.98, 95% CI: 2.58-65.35, P=0.0019). Nevertheless, CTLA-4 and ICOS genotypes were not associated with acute and chronic GVHD. CONCLUSIONS Both donor and recipient CTLA-4 and ICOS gene polymorphisms might be of importance for the outcome of allogeneic HSCT.

Tumour necrosis factor‐α‐induced apoptosis in cord blood T lymphocytes: involvement of both tumour necrosis factor receptor types 1 and 2

Cord blood T cells are much more likely to be induced to apoptosis in vitro than adult T cells. Nevertheless, the expression of Fas is markedly lower on cord blood lymphocytes than on peripheral blood lymphocytes. In the current investigation, we determined the capacity of tumour necrosis factor‐α (TNF‐α) to induce apoptosis in human naïve T cells in cord blood, and assessed the roles of two distinct TNF receptors (TNFRs) in mediating death signals. After activation, cord blood T cells were sensitive to TNF‐α‐induced apoptosis, and interleukin 2 (IL‐2) could prevent this apoptotic response. Both TNFR1 (p55) and TNFR2 (p75) expressed on activated cord blood T cells were able to transmit apoptotic signals. Moreover, a synergistic effect was observed by a combination of TNFR1‐ and TNFR2‐signals. Additionally, CD4+ T cells showed higher sensitivity to TNFR‐mediated apoptosis than CD8+ T cells. These data suggest that TNF‐α probably is a mediator of apoptosis in cord blood T cells in vivo and may contribute to the low incidence of graft‐versus‐host disease in cord blood transplantation.

Molecular subtyping of human T-lymphotropic virus type I (HTLV-I) by a nested polymerase chain reaction-restriction fragment length polymorphism analysis of the envelope gene: Two distinct lineages of HTLV-I in Taiwan

The major type of human T‐lymphotropic virus type I (HTLV‐I), generally referred to as the cosmopolitan type, has been grouped into three subtypes (A, B, and C) by phylogenetic analysis of the long terminal repeat sequences of the viral genome. Twelve subtype‐specific nucleotide variations have been deduced by comparison between the envelope (env) sequences of 16 HTLV‐I strains with defined subtypes and 9 Taiwanese HTLV‐I strains. To gain further insights into the molecular epidemiology of HTLV‐I and the origin of this virus in Taiwan, a rapid method of identification for the cosmopolitan subtypes was developed by using a nested polymerase chain reaction (PCR) and subsequent restriction fragment length polymorphism (RFLP) studies using the two subtype B‐specific and four subtype C‐specific nucleotides located within the positions 5708 to 6320 of the env gene. The nested PCR‐RFLP method was used to subtype HTLV‐I from four virus‐positive cell lines derived from 1 Japanese and 3 North American patients, as well as 41 blood‐unrelated Taiwan Chinese. The sequences of PCR products were determined and the six positions of subtype‐specific nucleotide variations were examined. The sequence data completely supported the subtyping data via the nested PCR‐RFLP method. The results demonstrated that, as is the case in Japan, at least two distinct cosmopolitan subtypes (A and B) of HTLV‐I were present in Taiwan, but the more prevalent subtype in Taiwan is A in contrast to subtype B in Japan. Furthermore, rapid subtyping could facilitate molecular epidemiological studies of HTLV‐I infection and linkage between HTLV‐I subtypes and virus‐associated diseases. J Med Virol 51:25–31, 1997.

Short Communication: Resistance to Tumor Necrosis Factor-α-Induced Apoptosis in Human T-Lymphotropic Virus Type I-Infected T Cell Lines

Induction of apoptosis of virus-infected cells is an important host cell defense mechanism. It is well documented that T cells may undergo apoptosis due to interactions between Fas and Fas ligand (FasL). In addition, signals that induce apoptosis in T cells can result from interaction of tumor necrosis factor (TNF)-α with TNF receptors (TNFRs). It has been shown that human T cell lines expressing HTLV-I have decreased sensitivity to Fas-mediated apoptosis. The susceptibility of HTLV-I-infected cells to TNF-α-induced apoptosis remains to be elucidated. In the present study, we examined the expression of TNFRs on HTLV-I-infected T cell lines that expressed T-cell activation markers and thus phenotypically resemble activated T cells. Different from primary activated T cells that expressed both TNFRs, none of the five HTLV-I-infected T cell lines studied had detectable TNFR1 and only three had TNFR2 on their cell surfaces, although, the RNA transcripts of both TNFR genes could be detected via reverse transcri...

Protocadherin 10 suppresses tumorigenesis and metastasis in colorectal cancer and its genetic loss predicts adverse prognosis.

Protocadherin 10 (PCDH10), a novel tumor suppressor gene in human cancers, is located in a common deleted region at chromosome 4q28 in colorectal cancer (CRC). This study aimed to ascertain the genetic loss of PCDH10 and its clinical relevance in CRC and to explore the tumor suppressor function of PCDH10. The genetic deletion of PCDH10 was determined in 171 pairs of primary tumors and corresponding normal mucosae by loss of heterozygosity study. In total, 53 carcinomas were positive for allelic loss of PCDH10. The genetic aberration was significantly associated with tumor progression and distant metastasis (p = 0.021 and p = 0.018, respectively) and was an independent predictor of poor survival for CRC patients (p = 0.005). Expression of PCDH10 gene was silenced or markedly down‐regulated in all of 12 CRC cell lines tested and in 41 of 53 colorectal carcinomas compared with their matched normal mucosae. Ectopic expression of PCDH10 suppressed cancer cell proliferation, anchorage‐independent growth, migration and invasion in vitro. Subcutaneous injection of PCDH10‐expressing CRC cells into SCID mice revealed the reduction of tumor growth compared with that observed in mock‐inoculated mice. Furthermore, through intrasplenic implantation, the re‐expression of PCDH10 in silenced cells restrained liver metastasis and improved survival in SCID mice. In conclusion, PCDH10 is a pivotal tumor suppressor in CRC, and the loss of its function promotes not only tumor progression but also liver metastasis. In addition, the genetic deletion of PCDH10 represents an adverse prognostic marker for the survival of patients with CRC.

NDST4 Is a Novel Candidate Tumor Suppressor Gene at Chromosome 4q26 and Its Genetic Loss Predicts Adverse Prognosis in Colorectal Cancer

Background Genomic deletion at tumor suppressor loci is a common genetic aberration in human cancers. The study aimed to explore candidate tumor suppressor genes at chromosome 4q25-q28.2 and to delineate novel prognostic biomarkers associated with colorectal cancer (CRC). Methods Deletion mapping of chromosome 4q25-q28.2 was conducted in 114 sporadic CRC by loss of heterozygosity study with 11 microsatellite markers. A novel candidate tumor suppressor gene, namely NDST4, was identified at 4q26. Gene expression of NDST4 was investigated in 52 pairs of primary CRC tissues by quantitative reverse transcription-polymerase chain reaction. Allelic loss of NDST4 gene was further determined in 174 colorectal carcinomas by loss of heterozygosity analysis, and then was assessed for clinical relevance. Results One minimal deletion region was delineated between D4S2297 and D4S2303 loci at 4q26, where NDST4 was the only gene that had markedly been downregulated in CRC tumors. By laser capture microdissection, NDST4 RNA expression was demonstrated in colonic epithelial cells, but was undetectable in tumor cells. In total, 30 (57.7%) of 52 colorectal carcinomas showed a dramatic reduction in NDST4 gene expression compared with matched normal mucosae. The genetic loss of NDST4 was significantly associated with advanced pathological stage (P = 0.039) and poorer overall survival of patients (P = 0.036). Conclusions NDST4 gene is a novel candidate tumor suppressor gene in human cancer, and the loss of its function might be involved in CRC progression. In addition, the loss of heterozygosity assay, which was established to determine the allelic loss of NDST4 gene, could be a cost-effective tool for providing a useful biomarker of adverse prognosis in CRC.

Shisa3 Is Associated with Prolonged Survival through Promoting β-Catenin Degradation in Lung Cancer

RATIONALE Despite advances in treatment and prognosis of non-small cell lung cancer (NSCLC), patient outcomes are still unsatisfactory. OBJECTIVES To reduce the morbidity and mortality of patients with NSCLC, a more comprehensive understanding of mechanisms involved in cancer progression is urgently needed. METHODS By comparison of gene expression profiles in the cell line pair with differential invasion ability, CL1-0 and CL1-5, we found that Shisa3 was highly expressed in the low invasive cells. The effect of Shisa3 on invasion, migration, proliferation, apoptosis, epithelial-mesenchymal transition, and anchorage-independent growth activities in vitro and on tumor growth and metastasis in mice models were examined. The underlying mechanism of Shisa3 was explored by microarray and pathway analysis. Finally, the correlation of Shisa3 expression and clinical outcome was also calculated. MEASUREMENTS AND MAIN RESULTS We identified Shisa3 as a novel tumor suppressor, which induces β-catenin degradation resulting in suppression of tumorigenesis and invasion in vitro. Shisa3 decreased the tumor growth in mice with subcutaneous implantation and reduced the number of metastatic nodules in mice with tail vein injection and orthotopic implantation. Shisa3 performs the tumor suppression activity through WNT signaling predicted by microarray analysis. Our data found that Shisa3 accelerates β-catenin degradation and was positively associated with overall survival and progression-free survival of NSCLC. CONCLUSIONS Our results reveal that Shisa3 acts as a tumor suppressor by acceleration of β-catenin degradation and provide new insight for cancer prognosis and therapy.

Human T-lymphotropic virus type II infection in Vietnamese thalassemic patients

SummaryAnti-human T-lymphotropic virus type I/II (HTLV-I/II) antibodies were screened by particle agglutination test in a total of 66 patients with thalassemia major who received multiple transfusion from paid donors at the Blood Transfusion Hematology Center of Ho Chi Minh City in South Vietnam. HTLV-II infection was confirmed in 6 patients (9.1%) by Western blot analysis and/or polymerase chain reaction. Phylogenetic analysis revealed that long terminal repeat sequences of HTLV-II proviruses from 5 thalassemic patients in Vietnam belonged to the same phylogenetic subgroup of HTLV-IIb as those from intravenous drug abusers in North America and Europe. These data shed light on the route of introducing HTLV-II into Vietnam.