Biomedical subjects

Chien-Fu Hung

Publications and source records attributed to Chien-Fu Hung.

At least 37 records · Page 2Linked to original sources

PubMed2004

Naked RNA vaccine controls tumors with down-regulated MHC class I expression through NK cells and perforin-dependent pathways.

One of the major issues facing cancer immunotherapy is that many human cancers down-regulate expression of MHC class I molecules. The understanding of the mechanisms of antitumor effects against tumors with down-regulated MHC class I will facilitate rational design of vaccines and immunotherapeutic strategies to control such tumors. A naked Sindbis RNA replicon vector (SINrep5) encoding the herpes simplex virus type 1 protein VP22 linked to E7 (SINrep5-VP22/E7) generated significant antitumor effects against TC-1 and TC-1 P3(A15), tumors with down-regulated MHC class I expression. Naked SINrep5 RNA without the insert or an E7 vaccine also produced antitumor effects against TC-1 P3(A15) but not TC-1. Mice vaccinated with any of these naked RNA vaccines generated higher percentages of NK cells. In vivo Ab depletion experiments revealed that NK cells were important for the antitumor effects of naked RNA vaccines against TC-1 P3(A15) and that the antitumor effects were perforin-dependent. Poly I:C also increased the percentage of NK cells and generated antitumor effects against the tumors with down-regulated MHC class I. Thus, the SINrep5-VP22/E7 naked RNA vaccine controls MHC class I-positive and MHC class I-down-regulated tumor cells via different mechanisms, and NK cells play an important role in the antitumor effects generated by naked RNA replicon vaccines.

Adoptive Transfer↗

PubMed2004

Vaccination with a DNA vaccine encoding herpes simplex virus type 1 VP22 linked to antigen generates long-term antigen-specific CD8-positive memory T cells and protective immunity.

Intradermal vaccination with DNA encoding herpes simplex virus type 1 (HSV-1) VP22 linked to antigen leads to spread of antigen within the epithelium and results in enhanced antigen-specific CD8+ T cell immune responses in vaccinated mice. In this study, we characterized the number of antigen-expressing dendritic cells (DCs) in the draining lymph nodes of vaccinated mice and determined whether the linkage of VP22 to antigen would influence the ability of antigen-expressing DCs to activate antigen-specific CD8+ T cells in vivo. Vaccination with DNA encoding HSV-1 VP22 linked to human papillomavirus type 16 E7 antigen generated more antigen-expressing DCs in the draining lymph nodes of vaccinated mice than E7 alone. In addition, the linkage of VP22 to E7 improved the MHC class I presentation of E7 in transfected DCs and led to enhanced activation of E7-specific CD8+ T cells. We also observed that vaccination with DNA encoding VP22 linked to E7 generated more E7-specific CD8+ memory T cells, and enhanced long-term protective antitumor immunity against an E7-expressing tumor in vaccinated mice compared with vaccination with DNA encoding E7 alone. Thus, administration of DNA encoding VP22 linked to antigen represents a plausible approach for the development of protective DNA vaccines.

Animals↗

PubMed2004

Development of a DNA vaccine targeting human papillomavirus type 16 oncoprotein E6.

Human papillomavirus (HPV), particularly type 16 (HPV-16), is present in more than 99% of cervical cancers. The HPV oncoproteins E6 and E7 are constantly expressed and therefore represent ideal targets for HPV vaccine development. We previously developed DNA vaccines encoding calreticulin (CRT) linked to HPV-16 E7 and generated potent E7-specific CD8(+) T-cell immune responses and antitumor effects against an E7-expressing tumor. Since vaccines targeting E6 also represent an important strategy for controlling HPV-associated lesions, we developed a DNA vaccine encoding CRT linked to E6 (CRT/E6). Our results indicated that the CRT/E6 DNA vaccine, but not a wild-type E6 DNA vaccine, generated significant E6-specific CD8(+) T-cell immune responses in vaccinated mice. Mapping of the immunodominant epitope of E6 revealed that an E6 peptide comprising amino acids (aa) 48 to 57 (E6 aa48-57), presented by H-2K(b), is the optimal peptide and that the region of E6 comprising aa 50 to 57 represents the minimal core sequence required for activating E6-specific CD8(+) T lymphocytes. We also demonstrated that E6 aa48-57 contains cytotoxic T-lymphocyte epitopes naturally presented by E6-expressing TC-1 cells. Vaccination with a CRT/E6 but not a CRT/mtE6 (lacking aa 50 to 57 of E6) DNA vaccine could protect vaccinated mice from challenge with E6-expressing TC-1 tumors. Thus, our data indicate that E6 aa48-57 contains the immunodominant epitope and that a CRT/E6 DNA vaccine may be useful for control of HPV infection and HPV-associated lesions.

Amino Acid Sequence↗

PubMed2004

Generation and characterization of DNA vaccines targeting the nucleocapsid protein of severe acute respiratory syndrome coronavirus.

Severe acute respiratory syndrome (SARS) is a serious threat to public health and the economy on a global scale. The SARS coronavirus (SARS-CoV) has been identified as the etiological agent for SARS. Thus, vaccination against SARS-CoV may represent an effective approach to controlling SARS. DNA vaccines are an attractive approach for SARS vaccine development, as they offer many advantages over conventional vaccines, including stability, simplicity, and safety. Our investigators have previously shown that DNA vaccination with antigen linked to calreticulin (CRT) dramatically enhances major histocompatibility complex class I presentation of linked antigen to CD8(+) T cells. In this study, we have employed this CRT-based enhancement strategy to create effective DNA vaccines using SARS-CoV nucleocapsid (N) protein as a target antigen. Vaccination with naked CRT/N DNA generated the most potent N-specific humoral and T-cell-mediated immune responses in vaccinated C57BL/6 mice among all of the DNA constructs tested. Furthermore, mice vaccinated with CRT/N DNA were capable of significantly reducing the titer of challenging vaccinia virus expressing the N protein of the SARS virus. These results show that a DNA vaccine encoding CRT linked to a SARS-CoV antigen is capable of generating strong N-specific humoral and cellular immunity and may potentially be useful for control of infection with SARS-CoV.

Amino Acid Sequence↗

PubMed2003

Enhancing DNA vaccine potency by combining a strategy to prolong dendritic cell life with intracellular targeting strategies.

We have recently shown that intradermal coadministration of DNA encoding Ag with DNA encoding inhibitors of apoptosis, including Bcl-x(L), prolongs dendritic cell (DC) life and thereby enhances the potency of DNA vaccines in vivo. We have also demonstrated that DNA vaccines targeting Ag to subcellular compartments, using proteins such as Mycobacterium tuberculosis heat shock protein 70, calreticulin, or the sorting signal of the lysosome-associated membrane protein type 1 (LAMP-1), enhanced DNA vaccine potency. In this study, we reasoned that the combination of a strategy to prolong DC life with intracellular targeting strategies might produce a more effective DNA vaccine against human papillomavirus E7. We showed that coadministration of DNA encoding Bcl-x(L) with DNA encoding E7/heat shock protein 70, calreticulin/E7, or Sig/E7/LAMP-1 resulted in further enhancement of the E7-specific CD8(+) T cell response for all three constructs. Of these strategies, mice vaccinated with Sig/E7/LAMP-1 DNA mixed with Bcl-x(L) DNA showed the greatest increase in E7-specific CD8(+) T cells ( approximately 13-fold increase). This combination of strategies resulted in increased CD8(+) T cell functional avidity, an increased E7-specific CD4(+) Th1 cell response, enhanced tumor treatment ability, and stronger long-term tumor protection when compared with mice vaccinated without Bcl-x(L) DNA. Therefore, DNA vaccines that combine strategies to enhance intracellular Ag processing and prolong DC life have potential clinical implications for control of viral infection and neoplasia.

Adjuvants, Immunologic↗

PubMed2003

Comparison of the CD8+ T cell responses and antitumor effects generated by DNA vaccine administered through gene gun, biojector, and syringe.

DNA vaccines have emerged as an attractive approach for antigen-specific cancer immunotherapy. We have previously linked Mycobacterium tuberculosis heat shock protein 70 (HSP70) to human papillomavirus type 16 (HPV-16) E7 in the context of a DNA vaccine. Vaccination with DNA encoding E7/HSP70 has generated a dramatic increase of E7-specific CD8+ T cell precursors and a strong antitumor effect against E7-expressing tumor (TC-1) in vaccinated mice. The success of our strategy has led to two phases I/II clinical trial proposals in patients with HPV-16 associated high-grade squamous intraepithelial lesion (HSIL) of the cervix and in patients with advanced HPV-associated head and neck squamous cell carcinoma (HNSCC). To translate our HPV DNA vaccines into the clinical domain, the efficacy of pNGVL4a-Sig/E7(detox)/HSP70 DNA vaccine and of various routes of administrations were assessed in mice. Our results indicated that pNGVL4a-Sig/E7(detox)/HSP70 DNA vaccine administered via gene gun generated the highest number of E7-specific CD8+ T cells. In addition, DNA vaccination via gene gun required the least dose to generate similar or slightly better antitumor effects compared to needle intramuscular (i.m.) and biojector administrations. Thus, our data suggest that DNA vaccination via gene gun represents the most potent regimen for DNA administration.

Animals↗

PubMed2003

Enhancing major histocompatibility complex class I antigen presentation by targeting antigen to centrosomes.

Several strategies that increase proteasomal degradation of antigen have been shown to improve MHC class I presentation of antigen. Because recent studies have demonstrated that the centrosome is a subcellular compartment rich in proteasomes, we hypothesized that targeting a tumor antigen to centrosomal compartments would enhance both the MHC class I presentation of antigen and the vaccine potency. We, therefore, created a chimera of gamma-tubulin, an established centrosomal marker, with a model tumor antigen, human papillomavirus type 16 (HPV-16) E7, in a DNA vaccine. The linkage of gamma-tubulin to E7-targeted antigen to centrosomal compartments, resulted in enhanced MHC class I presentation of E7, and led to a marked increase in the number of E7-specific CD8(+) T-cell precursors as well as a potent CD4-independent antitumor effect against an E7-expressing tumor cell line, TC-1. In addition, vaccination with gamma-tubulin/E7 DNA in transporter associated with antigen presentation (TAP)-1-knockout mice revealed that the enhancement of E7-specific CD8(+) T-cell immune responses is TAP-1-dependent. Our data suggest that the centrosome may be an important locus for MHC class I antigen processing and that targeting antigen to the centrosome can improve DNA vaccine potency.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2003

HPV DNA vaccines.

Human papillomaviruses (HPV), particularly HPV type 16, are the primary etiologic agent of cervical cancer. Thus, HPV-associated cervical malignancies might be prevented or treated by induction of the appropriate virus-specific immune responses in patients. HPV capsid proteins including L1 and L2 proteins have been shown to generate neutralizing antibodies against HPV particles in vaccinated individuals. Furthermore, HPV oncogenic proteins such as E6 and E7 proteins are important in the induction and maintenance of cellular transformation and are co-expressed in the majority of HPV-containing carcinomas. They represent ideal targets for the development of therapeutic vaccines against HPV infections and HPV-associated neoplasia. Vaccines targeting these proteins may provide an opportunity to control HPV-associated malignancies. Genetic immunization with naked DNA has emerged as an important strategy for vaccine development. Plasmid DNA encoding antigen of interest, such as capsid protein L1 and L2 (for preventive vaccines) and non-structural proteins E6 and E7 (for therapeutic vaccines) enters the host and stimulates an antigen-specific humoral and cellular immune response. Various strategies to enhance preventive and therapeutic effects of DNA vaccines are currently under active investigation. Should they fulfill their promise, these DNA vaccines may prevent HPV infection or control HPV-related cervical lesions.

Animals↗

PubMed2003

Boosting with recombinant vaccinia increases HPV-16 E7-Specific T cell precursor frequencies and antitumor effects of HPV-16 E7-expressing Sindbis virus replicon particles.

Immunotherapy using the heterologous prime-boost regimen has emerged as an attractive approach for generating antigen-specific T-cell-mediated immune responses against tumors and infectious diseases. We have previously linked the Mycobacterium tuberculosis heat-shock protein 70 (HSP70) to the HPV-16 E7 antigen creating a chimera, E7/HSP70. We found that nucleic acid vaccines encoding E7/HSP70 can generate strong antitumor immunity. Recently, replication-defective Sindbis virus replicon particle vaccines have been considered as an important vector system for vaccine development. In this study, we assessed whether the combination of E7/HSP70 Sindbis virus replicon particles (SINrep5-E7/HSP70) and E7/HSP70 vaccinia (Vac-E7/HSP70) can further enhance E7-specific immune responses using sequential vaccination. We found that priming with SINrep5-E7/HSP70 and boosting with Vac-E7/HSP70 generated the highest number of E7-specific CD8(+) T cells and best antitumor effect compared to other combinations. Moreover, our data showed that at the dosage and route of immunization used in this study, mice treated with the Sindbis virus replicon particle prime-vaccinia boost regimen generated stronger antitumor responses compared to mice treated with the DNA prime-vaccinia boost vaccine regimen. Our results encourage the use of the Sindbis virus replicon particle prime-vaccinia boost regimen in future clinical trials.

Animals↗

PubMed2003

Cell surface-binding motifs of L2 that facilitate papillomavirus infection.

Human papillomavirus type 16 (HPV16) is the primary etiologic agent of cervical carcinoma, whereas bovine papillomavirus type 1 (BPV1) causes benign fibropapillomas. However, the capsid proteins, L1 and L2, of these divergent papillomaviruses exhibit functional conservation. A peptide comprising residues 1 to 88 of BPV1 L2 binds to a variety of cell lines, but not to the monocyte-derived cell line D32, and blocks BPV1 infection of mouse C127 cells. Residues 13 to 31 of HPV16 L2 and BPV1 L2 residues 1 to 88 compete for binding to the cell surface, and their binding, unlike that of HPV16 L1/L2 virus-like particles, is unaffected by heparinase or trypsin pretreatment of HeLa cells. A fusion of HPV16 L2 peptide 13-31 and GFP binds (K(d), approximately 1 nM) to approximately 45,000 receptors per HeLa cell. Furthermore, mutation of L2 residues 18 and 19 or 21 and 22 significantly reduces both the ability of the HPV16 L2 13-31-GFP fusion protein to bind to SiHa cells and the infectivity of HPV16 pseudovirions. Antibody to BPV1 L2 peptides comprising residues 115 to 135 binds to intact BPV1 virions, but fails to neutralize at a 1:10 dilution. However, deletion of residues 91 to 129 from L2 abolishes the infectivity of BPV1, but not their binding to the cell surface. In summary, L2 residues 91 to 129 contain epitopes displayed on the virion surface and are required for infection, but not virion binding to the cell surface. Upon the binding of papillomavirus to the cell surface, residues 13 to 31 of L2 interact with a widely expressed, trypsin- and heparinase-resistant cell surface molecule and facilitate infection.

Amino Acid Motifs↗

PubMed2003

Enhancing DNA vaccine potency by coadministration of DNA encoding antiapoptotic proteins.

Intradermal vaccination by gene gun efficiently delivers DNA vaccines into DCs of the skin, resulting in the activation and priming of antigen-specific T cells in vivo. DCs, however, have a limited life span, hindering their long-term ability to prime antigen-specific T cells. We reason that a strategy that prolongs the survival of DNA-transduced DCs will enhance priming of antigen-specific T cells and DNA vaccine potency. Here we show that codelivery of DNA encoding inhibitors of apoptosis (BCL-xL, BCL-2, XIAP, dominant negative caspase-9, or dominant negative caspase-8) with DNA encoding model antigens prolongs the survival of transduced DCs. More importantly, vaccinated mice exhibited significant enhancement in antigen-specific CD8+ T cell immune responses, resulting in a potent antitumor effect against antigen-expressing tumors. Among these antiapoptotic factors, BCL-xL demonstrated the greatest enhancement in antigen-specific immune responses and antitumor effects. Thus, coadministration of DNA vaccines with DNA encoding antiapoptotic proteins represents an innovative approach to enhance DNA vaccine potency.

Animals↗

PubMed2003

Improving DNA vaccine potency via modification of professional antigen presenting cells.

DNA vaccines are potentially important immunotherapeutic agents for combating infectious diseases and cancers. Continuing progress in our understanding of how professional antigen presenting cells (APCs) orchestrate immune responses has provided a framework from which to design effective DNA vaccines. Similarly, manipulation of DNA using advances in molecular biology technology has enabled implementation of novel DNA vaccine strategies. This review summarizes recent vaccine strategies that utilize intercellular and intracellular modification of professional APCs, including those involving plasmid delivery, intracellular processing of antigen and enhancement of APC interaction with T-cells.

Animals↗

PubMed2003

DNA vaccines for cancer.

Immunotherapy has become a potentially feasible strategy for the control of cancers; the goal of cancer vaccines is to achieve this via tumor antigen-specific humoral or cell-mediated immunity, as well as via innate immunity. DNA vaccines have become important immunotherapeutic agents for combating cancers due to their simplicity and safety, and their capacity for repeated administration. Continuing progress in our understanding of how professional antigen-presenting cells orchestrate immune responses provides a framework from which to design more effective DNA vaccines. To this end, innovative strategies to enhance DNA vaccine potency have been developed, including the modification of enhancement of antigen delivery, antigen processing, manipulation of apoptosis, and anti-angiogenic strategies. Furthermore, strategies for breaking immune tolerance to endogenous tumor-associated antigens have begun to be developed. These advances in DNA vaccine technology have led to significant results in preclinical tumor models, prompting the execution of a number of clinical trials of DNA vaccines for cancer. If these trials prove DNA vaccines to be clinically effective, they could lead to the development of a new generation of therapies for the treatment and/or prevention of cancer.

Animals↗

PubMed2003

Uterine artery embolization for symptomatic uterine leiomyoma and adenomyosis.

BACKGROUND AND PURPOSE: Uterine artery embolization (UAE) is increasingly accepted as an alternative treatment for symptomatic uterine leiomyoma and adenomyosis. The purpose of this study was to compare the outcomes of UAE in 3 diagnostic categories--submucosal leiomyoma, intramural leiomyoma, and adenomyosis--to assist in patient selection for this relative new form of therapy. METHODS: The medical records of 43 patients (aged 22 to 54 years) who underwent UAE for symptomatic uterine leiomyoma or adenomyosis were retrospectively reviewed. Magnetic resonance imaging (MRI) was used for categorization of the patients into the 3 diagnostic categories, and also for objective measurement of the uterine and leiomyoma size, and subsequent imaging follow-up. UAE was performed using polyvinyl alcohol particles. Symptom improvement and complications after treatment were evaluated at gynecologist clinics using monthly questionnaires. The group differences in complete symptom resolution, uterine and leiomyoma size reduction, incidence of complications, and subsequent surgeries were analyzed. RESULTS: The mean duration of follow-up was 10.9 months. Complete resolution of symptoms was achieved in 13 out of 16 patients with submucosal leiomyoma (81%), 3 out of 15 patients (20%) with intramural leiomyoma (p = 0.002) and 3 out of 12 patients (25%) with adenomyosis (p = 0.01). The average reduction of leiomyoma size in the submucosal and intramural groups was 56% and 29%, respectively (p = 0.02). None of the patients died. Severe complications occurred in 3 of 43 patients (7%), including permanent amenorrhea in 2 and pelvic actinomycosis in 1 patient. The incidence of complications (p = 0.17) and subsequent surgery (p = 0.67) did not differ significantly among the 3 groups. CONCLUSIONS: UAE is an effective treatment for patients with symptomatic leiomyoma or adenomyosis. In this study, patients with submucosal leiomyoma had the best treatment outcome.

Adult↗

PubMed2002

Cancer immunotherapy using Sindbis virus replicon particles encoding a VP22-antigen fusion.

Alphavirus vectors have emerged as a strategy for the development of cancer vaccines and gene therapy applications. The availability of a new packaging cell line (PCL), which is capable of generating alphavirus replicon particles without contamination from replication-competent virus, has advanced the field of vaccine development. This replication-defective vaccine vector has potential advantages over naked nucleic acid vaccines, such as increased efficiency of gene delivery and large-scale production. We have developed a new strategy to enhance nucleic acid vaccine potency by linking VP22, a herpes simplex virus type 1 (HSV-1) tegument protein, to a model antigen. This strategy facilitated the spread of linked E7 antigen to neighboring cells. In this study, we created a recombinant Sindbis virus (SIN)-based replicon particle encoding VP22 linked to a model tumor antigen, human papillomavirus type 16 (HPV-16) E7, using a stable SIN PCL. The linkage of VP22 to E7 in these SIN replicon particles resulted in a significant increase in the number of E7-specific CD8(+) T cell precursors and a strong antitumor effect against E7-expressing tumors in vaccinated C57BL/6 mice relative to wild-type E7 SIN replicon particles. Furthermore, a head-to-head comparison of VP22-E7-containing naked DNA, naked RNA replicons, or RNA replicon particle vaccines indicated that SINrep5-VP22/E7 replicon particles generated the most potent therapeutic antitumor effect. Our results indicated that the VP22 strategy used in the context of SIN replicon particles may facilitate the generation of a highly effective vaccine for widespread immunization.

Animals↗

PubMed2002

Improving DNA vaccine potency by linking Marek's disease virus type 1 VP22 to an antigen.

We have previously employed an intercellular spreading strategy using herpes simplex virus type 1 (HSV-1) VP22 protein to enhance DNA vaccine potency because DNA vaccines lack the intrinsic ability to amplify in cells. Recently, studies have demonstrated that the protein encoded by UL49 of Marek's disease virus type 1 (MDV-1) exhibits some degree of homology to the HSV-1 VP22 protein and features the property of intercellular transport. We therefore generated a DNA vaccine encoding MDV-1 VP22 linked to a model antigen, human papillomavirus type 16 E7. We demonstrated that compared with mice vaccinated with DNA encoding wild-type E7, mice vaccinated with MDV-1 VP22/E7 DNA exhibited a significant increase in number of gamma-interferon-secreting, E7-specific CD8(+)-T-cell precursors as well as stronger tumor prevention and treatment effects. Furthermore, our data indicated that the antitumor effect was CD8 dependent. These results suggested that the development of vaccines encoding VP22 fused to a target antigen might be a promising strategy for improving DNA vaccine potency.

Amino Acid Sequence↗

PubMedDate not supplied

A DNA vaccine co-expressing antigen and an anti-apoptotic molecule further enhances the antigen-specific CD8+ T-cell immune response.

We have shown that DNA encoding the anti-apoptotic protein Bcl-xL enhances E7-specific CD8+ T-cell responses and DNA encoding pro-apoptotic protein caspase-3 suppresses E7-specific CD8+ T-cell responses when co-administered intradermally via gene gun with DNA encoding human papillomavirus type 16 (HPV-16) E7 linked to the sorting signal of the lysosome-associated membrane protein type 1 (LAMP-1). E7 and LAMP-1 are linked to form the chimeric Sig/E7/LAMP-1 (SEL). Because co-administration does not ensure delivery of both constructs to a single cell, we used pVITRO, a mammalian expression vector with double promoters, to ensure expression of both molecules in the same cell. We vaccinated C57BL/6 mice with pVITRO-SEL-Bcl-xL, pVITRO-SEL-mtBcl-xL, pVITRO-SEL, or pVITRO-SEL-caspase-3 intradermally via gene gun and intramuscularly via injection. We demonstrated that vaccination with pVITRO achieved similar results to a co-administration strategy: that Bcl-xL enhanced the E7-specific CTL response and caspase-3 suppressed the E7-specific CTL response. In addition, we found intradermal vaccination elicited significantly higher numbers of E7-specific CD8+ T cells compared to intramuscular vaccination. Thus, intradermal vaccination with a pVITRO vector combining an anti-apoptotic strategy (Bcl-xL) and an intracellular targeting strategy (SEL) further enhances the E7-specific CD8+ T-cell response and guarantees co-expression of both encoded molecules in transfected cells.

Animals↗

PubMedDate not supplied

Diagnosis and staging of gallbladder carcinoma. Evaluation with dynamic MR imaging.

The purpose of this study is to determine the ability of dynamic magnetic resonance imaging (MRI) in the diagnosis and staging of gallbladder cancer (GBC). Images of dynamic MRI of hepatobiliary system combined with MR cholangiography (MRC) of 18 patients with pathologically proved gallbladder cancer were correlated with pathological and operative findings. Focal or diffuse wall thickening was present in 10 patients. In five patients, the tumor appeared as a fungating or intramural mass. A tumor replacing the gallbladder was found in two patients and a small cancer in cystic duct in one patient. The tumor featured early and irregular enhancement, which persisted throughout the dynamic study. Metastatic nodes were found by surgicopathology in 13 patients and were depicted by the dynamic MRI in 11 patients. Local invasion to liver was found by surgery in 12 patients and correctly detected by MRI in 11 patients. MRI detected duodenum invasion in three out of six patients and none of the three cases with omental metastasis. In conclusion, dynamic MRI is useful and reliable in staging of advanced gallbladder cancer. MRI combined with MRC is sensitive in detection of obstructive jaundice, liver invasion as well as liver and lymph nodes metastasis. It is more difficult to delineate the invasion to duodenum and omental metastasis by MRI.

Aged↗