Up-regulation of Krüppel-like factor 8 promotes tumor invasion and indicates poor prognosis for hepatocellular carcinoma.

BACKGROUND & AIMS: The transcription factor Krüppel-like factor 8 (KLF8) has a role in tumor development, growth, and metastasis, but its role in hepatocellular carcinoma (HCC) is not clear. METHODS: KLF8 expression in human HCC cell lines and tumor tissues was measured by quantitative real-time polymerase chain reaction, immunoblot, and immunochemical analyses. The effects of KLF8 depletion or overexpression in HCC cells were observed in cultured cells and in mice. Changes in gene expression patterns in HCC cells in which levels of KLF8 were reduced using small interfering RNA were investigated by microarray analysis. The clinical significance of KLF8 expression levels were validated using tissue microarray analysis of surgical samples from 314 HCC patients. RESULTS: KLF8 was overexpressed in highly metastatic HCC cell lines and in samples from patients with recurrent HCC. In cultured cells, KLF8 up-regulation promoted cell proliferation and invasion; inhibited apoptosis; down-regulated N-cadherin, vimentin, and fibronectin; and up-regulated E-cadherin. In mice, overexpression of KLF8 increased HCC progression and metastasis. Microarray analysis showed that reduction of KLF8 in HCC cells down-regulated expression of multiple genes involved in tumor progression and metastasis. KLF8 expression was a significant predictor of overall survival (P = .040) and time to HCC recurrence (P = .006) and was associated with early tumor recurrence (P = .001). CONCLUSIONS: KLF8 promotes HCC cell proliferation and invasion, inhibits apoptosis, and induces the epithelial-to-mesenchymal transition. KLF8 up-regulation might be used to indicate poor prognosis or early recurrence of cancer in patients who have had surgery for HCC.

Small interference RNA targeting Krüppel-like factor 8 inhibits the renal carcinoma 786-0 cells growth in vitro and in vivo.

PURPOSE: Krüppel-like factor 8 (KLF8) plays an important role in oncogenic transformation and is highly overexpressed in several types of human cancer. We investigated the expression of KLF8 in renal cell carcinoma (RCC) tissues and the role of small interference RNA targeting KLF8 on growth, cell cycle, and apoptosis of human renal carcinoma cell line 786-0 in vitro and in vivo. METHODS: The expression of KLF8 protein and mRNA in human renal carcinoma samples was detected by immunochemistry and reverse transcription polymerase chain reaction (RT-PCR). The effects of small interference RNA (siRNA) targeting KLF8 on growth, invasiveness, cell cycle, and apoptosis of 786-0 cells were evaluated by MTT assay, Matrigel Invasion Assay, and flow cytometry in vitro. We also investigated effect of siRNA targeting KLF8 on growth of 786-0 cells in nude mice in vivo. RESULTS: Immunohistochemistry and RT-PCR results showed the expression of KLF8 protein and mRNA in RCC specimens was significantly higher than that in the adjacent non-tumorous renal tissues (P < 0.001). KLF8-siRNA depressed the cellular growth and invasion of 786-0 cells in vitro. The flow cytometry results revealed that KLF8-siRNA could induce an increase in G0/G1 phase cells and induce cell apoptosis. Intratumor injection of siRNA targeting KLF8 inhibited the growth of 786-0 cells in vivo in nude mice tumor model. CONCLUSIONS: KLF8 possibly involved in regulating the cell growth, invasion, apoptosis, and proliferation of renal carcinoma cancer cells. Blocking the KLF8 channel might be a potential therapeutic strategy for RCC.

Proteomic identification of a monoclonal antibody recognizing caveolin-1 in hepatocellular carcinoma with metastatic potential.

A monoclonal antibody, McAb9E (IgG3), was generated against a metastatic HCC cell line, MHCC-1. The antigen was characterized as human Caveolin-1 (Cav-1, 21kDa), with pI of 5.65. The Cav-1 antigen was found significantly over expressed in metastatic HCC cell lines as well as in tumor specimens. The Cav-1 specific McAb may be a useful molecular agent for metastatic HCC.

Role of overexpression of CD151 and/or c-Met in predicting prognosis of hepatocellular carcinoma.

UNLABELLED: It has been reported that tetraspanin CD151 acts as a promoter of metastasis in several tumors and plays an important role in c-Met/hepatocyte growth factor signaling. However, the role of CD151 alone and coexpression of CD151/c-Met in hepatocellular carcinoma (HCC) remains unclear. We found that expression of CD151 was positively related to metastatic potential of HCC cell lines, and modified cells with CD151(high) showed higher secretion of matrix metalloproteinase 9 and aggressiveness in vitro and higher metastatic ability in vivo. Furthermore, HCC patients with vascular invasion, large tumors, multiple tumors, high tumor-node-metastasis stage, and undifferentiated tumor were prone to have higher CD151 expression. The postoperative 3-, 5-, and 7-year overall survival (OS) of patients in HCCs with CD151(high) were significantly lower than those in the CD151(low) group, and correspondingly cumulative recurrence rates in HCCs with CD151(high) were significantly higher than those in the CD151(low) group. Both CD151 and c-Met were remarkably overexpressed in HCCs, compared with adjacent nontumorous and normal liver tissues. Pearson correlation analysis showed a slight correlation between CD151 and c-Met in HCCs. Importantly, the 5- and 7-year OS rates in CD151(high)/c-Met(high) patients were 50.5% and 37.8%, respectively, significantly lower than those of CD151(low)/c-Met(low) patients (63.9% and 54.6%, respectively). Five- and 7-year cumulative recurrence rates in CD151(high)/c-Met(high) patients were 53.3% and 71.9%, respectively, markedly higher than those of CD151(low)/c-Met(low) patients (39.0% and 52.5%, respectively). Multivariate analysis revealed that CD151 and combination of CD151/c-Met were independent prognostic indicators for OS and cumulative recurrence. CONCLUSION: CD151 is positively associated with invasiveness of HCC, and CD151 or combination of CD151/c-Met is a novel marker in predicting the prognosis of HCC and a potential therapeutic target.

Biological characteristics of fluorescent protein-expressing human hepatocellular carcinoma xenograft model in nude mice.

OBJECTIVES: To study biological characteristics of stable red fluorescent protein (RFP)-expressing or green fluorescent protein (GFP)-expressing HCCLM3 cell lines and those of their relevant xenograft models in nude mice. METHODS: HCCLM3, a human hepatocellular carcinoma cell line with high metastatic potential was infected with RFP or GFP full-length cDNA via lentivirus. Stable RFP-expressing or GFP-expressing HCCLM3 cells, namely HCCLM3-R and HCCLM3-G, were subcutaneously injected and two patient-like metastatic models of HCCLM3-R and HCCLM3-G in nude mice were established using surgical orthotopic implantation from subcutaneous tumor tissues. Cell proliferation, karyotype, biomarker expression, tumor growth, and metastasis of HCCLM3-R and HCCLM3-G were analyzed in vitro and in vivo. RESULTS: RFP and GFP genes were integrated in genomic DNA of HCCLM3. HCCLM3-R and HCCLM3-G expressed red and green fluorescence, stable and intense, 300 days after 60 consecutive passages, and also positively expressed CK8+, P16+, AFP+ and negatively expressed HBsAg-. Their biomarker expression and karyotype were found to be similar to those of the parental HCCLM3, and their tumorigenesis occurred in 10 nude mice without exception after a subcutaneous injection and did the same in 20 nude mice after an orthotopic implantation. The results showed that the rate of spontaneous metastasis to the liver and lung and peritoneal seeding was 100, 100, and 90%, respectively. CONCLUSION: Stable fluorescent protein-expressing HCCLM3-R and HCCLM3-G xenografts in nude mice could be of two useful models for studying mechanisms of hepatocellular carcinoma growth and metastasis in real time.

[The effects of ezrin on the proliferation and the invasiveness of cells of different hepatocellular carcinoma cell lines].

OBJECTIVE: To investigate the different expressions of cytoskeletal organizer ezrin and cytoskeleton protein beta- and gamma-actin in hepatocellular carcinoma (HCC) cell lines with different metastatic potentials and to explore the role of ezrin in cell growth and metastasis in HCC cell lines SF7721 and MHCC97-H. METHODS: Immunofluorescence, RT-PCR and Western blot were used to detect the gene and protein expressions of ezrin and actin in hepatocellular carcinoma cell lines with different metastatic potentials. RNA interference (RNAi) was applied to down-regulate the ezrin expression in SF7721 and MHCC97-H. Changes of the cell growth and metastasis potentials after the RNAi treatment were studied. MTT assay was used to detect cell proliferation changes and Transwell assay was applied to observe the changes of cell motility and invasiveness. RESULTS: Both ezrin and cytoskeleton protein were demonstrated in the cytoplasma of the cells at the same time. The expression of them in cell lines with high metastatic potential, such as SF7721, MHCC-1 and MHCC97-H was obviously higher than in those with low metastatic potentials, such as SMMC-7721, Hep3B and HepG2 (chi2= 13.277, P = 0.010; chi2= 21.815). The mRNA and ezrin and cytoskeleton protein gamma-actin were over-expressed in HCC cell lines with high metastatic potentials. The expressions of beta-actin of cell lines with different metastatic potentials showed no differences. Ezrin protein was successfully down-regulated and the proliferation and the invasiveness of the cells decreased with low ezrin protein level in SF7721 and MHCC97-H. CONCLUSION: Over-expression of ezrin and cytoskeleton protein gamma-actin are associated with the process of metastasis of hepatocellular carcinoma cells. The growth and invasiveness of SF7721 and MHCC97-H cells can be inhibited by down-regulating ezrin expression.

The membrane-cytoskeleton organizer ezrin is necessary for hepatocellular carcinoma cell growth and invasiveness.

PURPOSE: The change of cell mobility is one of the preconditions of tumor metastasis. Cell skeleton alteration and rearrangement of F-actin was closely related to cell mobility. Ezrin is a membrane-cytoskeleton organizer that can mediate the rearrangement and the function of F-actin. In this paper, we investigated the effect of ezrin on hepatocellular carcinoma cell growth and invasiveness. METHODS: Hepatocellular carcinoma cell lines such as MHCC-1, MHCC97-H, SF7721, SMMC7721, Hep3B, and HepG2 were chosen in this study. We first examined the expression and the distribution of ezrin and F-actin in these cell lines using immunofluorescence, RT-PCR, and the western blot. Next we used small interfering RNA (siRNA) to down-regulate ezrin expression in MHCC-1, MHCC97-H, SF7721, and HepG2 to investigate the role of ezrin in tumor cell growth and invasiveness. RESULTS: Our preliminary results showed that the expression of ezrin and gamma-actin in MHCC-1, MHCC97-H, and SF7721 with higher metastatic potential were obviously up-regulated than those in SMMC7721, Hep3B, and HepG2 with lower potential. No different expression of beta-actin was found in the above tumor cell lines. The outcome of RNAi indicated that decreasing ezrin expression can notably inhibit the proliferation of the four hepatocellular carcinoma cell lines (p < 0.01, n = 10). The proportion of cells in G2-M phase also decreased after RNAi. The number of pseudopods decreased as well after RNAi treatment (p < 0.01, n = 5). The mobility and invasiveness of cancer cells decreased with decreasing ezrin expression tested by transwell assay (p < 0.01, n = 8). CONCLUSION: Ezrin plays an important role in the process of hepatocellular carcinoma cell proliferation, migration, and invasiveness.

[The influence of downregulation of ezrin expression by RNA interference on the growth and metastasis of hepatocellular carcinoma: experiment in vitro].

OBJECTIVE: To investigate the effect of membrane-cytoskeleton linker ezrin on the growth and metastasis of human hepatocellular carcinoma cell (HCC) lines. METHODS: Human HCC cells of the lines SF/SMMC7721, MHCC97-H, MHCC-1, and HepG2 were cultured. Four pairs of small interfering RNA (siRNA) targeting erzin were designed and transfected into the HCC cells. 48 h after transfection the cell total RNA was extracted and 72 h later the total cell protein was extracted. RT-PCR and Western blotting were used to detect the transfection rates so as to screen the most effective siRNA to be transfected into the HCC cells. HCC cells were collected every day for 7 days to extract the total RNA and protein. Real-time PCR and Western blotting were used to detect the downregulation rate of erzin at different times. MTT method was used to detect the proliferation of the cells. Flow cytometry was used to detect the cell cycle and apoptosis. Scanning electron microscopy was used to observe the cell pseudopods. Transwell test was used to detect the invasion ability of the transfected HCC cells. RESULTS: Real-time PCR and western-blotting revealed that ezrin siRNA notably down-regulated ezrin expression at both mRNA and protein levels. Down-regulation of ezrin expression distinctly decreased the proliferation rates of these 4 kinds of HCC line. After RNAi treatment the cell proportion in G(2)-M phase decreased from 28.07% to 21.53% in the SF/SMMC7721 cells, from 24.94% to 13.92% in the MHCC97-H cells, from 19.30% to 13.2% in the MHCC-1cells, and from 7.73% to 4.24% in the HepG2 cells. After RNAi treatment, the number of pseudopods decreased from 20.8 +/- 3.0 to 13.2 +/- 2.4 in the SF/SMMC7721: cells (P < 0.05), from 18.4 +/- 2.7 to 14.0 +/- 2.9 in the MHCC97-H cells (P < 0.01), from 22.6 +/- 3.5 to 13.3 +/- 1.9 in the MHCC-1: cells (P < 0.01), and from 31.0 +/- 2.9 to 17.8 +/- 2.3 in the HepG2 cells (P < 0.01); and the motility and invasiveness decreased from 49.9 +/- 7.7 to 31.9 +/- 5.2 in the SF/SMMC7721 cells (P < 0.05), from 58.5 +/- 4.2 to 33.0 +/- 3.3 in the MHCC97-H cells (P < 0.01), from 57.6 +/- 6.1 to 28.3 +/- 3.4 in the MHCC-1 cells (P < 0.01), and from 37.3 +/- 3.0 to 25.3 +/- 2.3 in the HepG2 cells (P < 0.01). The pseudopods of the HCC cells remarkably shortened and decreased in number (for the SF/SMMC7721 cells: t = 4.95, P < 0.05, for the MHCC97-H cells: t = 5.88, P < 0.01, for the MHCC-1 cells: t = 5.56, P < 0.01, and for the HepG2 cells: t = 5.71, P < 0.01) after siRNA interference. CONCLUSION: Ezrin is necessary for HCC proliferation and invasion. It is probably an important factor to inhibit tumor reoccurrence and metastasis.

[Reconstructing the JAK/STATs signal pathway restored the anti-proliferative response of MHCC97 on interferon alpha].

OBJECTIVE: To elucidate the roles of JAK/STATs signal pathway on anti-proliferative effects induced by IFN-alpha in MHCC97. METHODS: An IRF9 expression vector was transfected into MHCC97 with Dosper. The expression of IRF9, cycle regulating proteins and the forming of ISGF3 complex were detected using Western blot and EMSA, respectively. Cell proliferation and distribution were monitored using MTT and flow cytometry. RESULTS: High expression of IRF9 restored the anti-proliferative response of MHCC97 on IFN-alpha treatment and delayed the cell transition from S phase to G2 phase induced by IFN-alpha. CONCLUSION: The integrity and functions of JAK/STATs signal pathway played an important role in mediating the anti-proliferative effects of IFN-alpha in MHCC97.

Interferon alpha 2a down-regulates VEGF expression through PI3 kinase and MAP kinase signaling pathways.

An earlier report demonstrated that interferon alpha (IFN-alpha) inhibited tumor growth and recurrence in an MHCC97 xenograft model in nude mice by suppressing tumor angiogenesis rather than by inhibiting tumor cell proliferation. However, the underlying molecular mechanism was not fully elucidated. In this study, we demonstrated that IFN-alpha 2a could down-regulate VEGF expression both in mRNA and in protein levels, as well as down-regulating HIF-1 alpha mRNA expression in MHCC97 cells in vitro. A cDNA micro array analysis followed by Northern and Western blot analysis revealed that PI3 kinase and MAP kinase signaling pathways might be inhibited by IFN-alpha 2a. Blocking the function of IFN-alpha receptor with a specific peptide could eliminate the inhibitory effects of IFN-alpha 2a on VEGF expression. In addition, wortmannin and PD098059, respective inhibitors of the PI3 kinase and the MAP kinase signaling pathways, when used independently or in combination, could also down-regulate the VEGF synthesis and secretion in a similar pattern of IFN-alpha 2a. These observations may lead to the conclusion that IFN-alpha 2a could suppress VEGF synthesis and secretion by down-regulating HIF-1 alpha expression, via inhibition of the PI3 kinase and/or the MAP kinase signaling pathways.

Modulation of gene expression in MHCC97 cells by interferon alpha.

AIM: To elucidate the molecular mechanisms of the inhibitory effects of IFN-alpha on tumor growth and metastasis in MHCC97 xenografts. METHODS: Three thousand international units per milliliter of IFN-alpha-treated and -untreated MHCC97 cells were enrolled for gene expression analysis using cDNA microarray. The mRNA levels of several differentially expressed genes in cDNA microarray were further identified by Northern blot and RT-PCR. RESULTS: A total of 190 differentially expressed genes including 151 IFN-alpha-repressed and 39-stimulated genes or expressed sequence tags from 8,464 known human genes were found to be regulated by IFN-alpha in MHCC97. With a few exceptions, mRNA levels of the selected genes in RT-PCR and Northern blot were in good agreement with those in cDNA microarray. CONCLUSION: IFN-alpha might exert its complicated anti-tumor effects on MHCC97 xenografts by regulating the expression of functional genes involved in cell metabolism, proliferation, morphogenesis, angiogenesis, and signaling.

A decade's studies on metastasis of hepatocellular carcinoma.

Metastasis remains one of the major challenges before hepatocellular carcinoma (HCC) is finally conquered. This paper summarized a decade's studies on HCC metastasis at the Liver Cancer Institute of Fudan University. We have established a stepwise metastatic human HCC model system, which included a metastatic HCC model in nude mice (LCI-D20), a HCC cell line with high metastatic potential (MHCC97), a relatively low metastatic potential cell clone (MHCC97L) and several stepwise high metastatic potential cell clones (MHCC97H, HCCLM3, and HCCLM6) from their parent MHCC97 cell. Endeavors have been made for searching human HCC metastasis-related chromosomes/proteins/genes. Monogene-based studies revealed that HCC invasion/metastasis was similar to that of other solid tumors, and the biological characteristics of small HCC were only slightly better than that of large HCC. Using comparative genomic hybridization (CGH), fluorescence in situ hybridization (FISH), genotyping, cDNA microarray, and 2-dimensional gel electrophoresis, we obtained some interesting results. In particular, in collaboration with the National Institute of Health (NIH) in the United States, we generated a molecular signature that can classify metastatic HCC patients, identified osteopontin as a lead gene in the signature, and found that genes favoring metastasis progression were initiated in the primary tumors. We also found that chromosome 8p deletion, particularly in the region of 8p23, was associated with HCC metastasis. Cytokeratin 19 was identified as one of the proteins, which was found in MHCC97H, but not in MHCC97L cells. Experimental interventions using the high metastatic nude mice model have provided clues for the prevention of HCC metastasis. Translation from workbench to bedside demonstrated that serum VEGF, microvessel density, and p53 scoring may be of value for the prediction of postoperative metastatic recurrence. Interferon alpha proved effective for the prevention of recurrence both experimentally and clinically. In conclusion, HCC metastasis that probably initiated in the primary tumor is a multigene-involved, multistep, and changing process. The further elucidation of the mechanism underlying HCC metastasis will provide a more solid basis for the prediction and prevention of the metastatic recurrence of HCC.

Reduction in p48-ISGFgamma levels confers resistance to interferon-alpha2a in MHCC97 cells.

OBJECTIVES: Hepatocellular carcinoma (HCC) is one of the most prevalent malignancies in China and, due to the limited efficacy of currently available therapies, is responsible for a large number of deaths. IFN-alpha therapy has shown promise in the treatment of various forms of human cancer and is considered in the treatment of HCC. Previous results from our group showed that high doses of IFN-alpha exert a significant antiproliferative effect on MHCC97 human xenografts in nude mice, but not on MHCC97 cells when tested in vitro. Here we present experiments designed to characterize the molecular mechanism underlying the defective response of MHCC97 cells to IFN-alpha. Elucidation of the mechanism underlying the defective response of MHCC97 to IFN-alpha may help to explain and possibly to overcome clinical failures of this form of tumor therapy. METHODS: IFN-alpha(2a) was administered between 3,000 and 10,000 IU/ml, a range strongly inhibiting proliferation in other cell lines. Gene expression profiles of MHCC97 cells were obtained before and after treatment with IFN-alpha(2a) using cDNA microarray analysis. The transcriptional activity of relevant genes responding to IFN-alpha(2a) in the cDNA microarray experiments was confirmed by RT-PCR and Northern blot analysis. Transient transfection with an expression vector was used to restore p48-ISGFgamma (IRF9) protein levels. Cell proliferation was evaluated using the MTT assay. RESULTS: Although IFN-alpha treatment caused the activation of several signal transduction pathways in MHCC97 cells, the lack of an antiproliferative effect was found to mainly derive from a defect in the activation of the transcription factor ISGF3 required for Jak/STATS signaling. We show that the defect in ISGF3 activation is mainly caused by the absence of one of its essential components, the protein p48-ISGFgamma from MHCC97 cells. Indeed, transient expression of p48-ISGFgamma restores sensitivity to IFN-alpha(2a). Although the mRNA levels of p48-ISGFgamma were normal in MHCC97 cells, mutations could be detected in the gene coding for the protein. We hypothesize, therefore, that these mutations alter the message or protein stability, leading to the reduced protein levels observed. CONCLUSION: Our results confirm the important role of Jak/STATS signaling in the antiproliferative effects of IFN-alpha in tumor cells and indicate that defects in ISGF3 can cause resistance to IFN-alpha(2a) treatment.

[Influence of the inhibitor of c-Met on the growth and motility of hepatocellular carcinoma cells].

OBJECTIVES: To explore the influence of c-Met inhibitor by synthetic c-Met antisense oligonucleotide, constructive c-Met antisense plasmid and the complex plasmid of U1SnRNA/ ribozyme/anti-Met on the growth and metastasis of hepatocellular carcinoma cells. METHODS: Gene transfection was operated by Lipofectin on SF7721 cells. The difference of the cells before and after transfection was compared by MTT, growth curves and transwell test in vitro. In vivo, the cells before and after transfection were implanted subcutaneously into nude mice respectively to observe tumor growth and metastasis. RESULTS: C-Met antisense oligonucleotide could inhibit the growth of hepatocellular carcinoma SF7721 cells (t=3.58, P<0.05). After transfection, the expression of c-Met protein decreased. Growth curves showed that the cells after transfection proliferated more slowly, about 50% of control cells (F=4.87, P<0.05), and their motility and invasiveness decreased, compared with those before transfected. In vivo experiment, tumors originated from c-Met antisense oligonucleotide treated cells and the antisense/ribozyme/U1SnRNA treated cells grew more slowly (about 54.5% of those from the control cells), and the latent prolonged. After 35 days, the average weight of tumors in the two group nude mice were lighter than that in the control group nude mice (F=5.17, P<0.05). CONCLUSION: Inhibition of c-Met expression by c-Met antisense oligonucleotide and the complex of antisense/ribozyme/U1SnRNA can inhibit the growth and metastasis of SF7721 hepatocarcinoma cells in vitro and in vivo.

Mechanism of interferon alpha on inhibition of metastasis and angiogenesis of hepatocellular carcinoma after curative resection in nude mice.

The aim of this study was to examine the mechanism of interferon alpha (IFN-alpha) on inhibition of metastasis and recurrence of hepatocellular carcinoma (HCC). Nude mice bearing human HCC xenografts with high metastatic potential (LCI-D20) underwent curative resection of tumors on postimplant day 11. IFN-alpha was begun the next day at different dosages given subcutaneously for 35 consecutive days; normal saline solution was injected into the control mice. The mice were killed 48 hours after the final treatment, and the parameters were evaluated. The HCC intrahepatic recurrence rate, the size of the recurrent lesions, the rate of lung metastasis, the serum vascular endothelial growth factor level, and the microvessel density (immunohistochemistry) were as follows: 100%, 2136+/-794 mm(3)(mean+/-standard deviation), 100%, 265.7+/-154.7 pg/ml, and 144+/-37/HP, respectively, in the control mice, whereas these same values were 62.5%, 89+/-45 mm(3), 12.5%, 53.3+/-9.9 pg/ml, and 86+/-25/HP, respectively, in the IFN-alpha 1.5 x 10(7)U/kg treatment group (P<0.05) and 26.7%, 46+/-21 mm(3), 0%, 65.2+/-17.9 pg/ml, and 39+/-14/HP in the IFN-alpha 3 x 10(7)U/kg treatment group, respectively (P<0.05). However, a significant difference was not found in the serum levels of basic fibroblast growth factor among the control and IFN-alpha treatment groups. IFN-alpha inhibits metastasis and recurrence of human HCC after curative resection in nude mice mediated by antiangiogenesis through downregulating expression of vascular endothelial growth factor but not basic fibroblast growth factor.

Comparison between radioimmunotherapy and external beam radiation therapy for patients with hepatocellular carcinoma.

It has previously been observed in animal studies that, at equivalent doses, radioimmunotherapy (RIT) is 2.5 times more effective than multiple fractions of external beam radiation therapy (EBRT) in inhibiting tumour growth. In this study, we compared the use of RIT and EBRT in patients with hepatocellular carcinoma (HCC), treated during the past 10 years. Of 67 patients without extrahepatic involvement, 32 were treated with hepatic artery ligation combined with RIT (the RIT group) while 35 were treated with a combination of hepatic arterial chemo-embolisation and EBRT (the EBRT group). The patients in the RIT group received (131)I-Hepama-1 monoclonal antibody, which was infused through the hepatic artery catheter. The patients in the EBRT group received transcatheter arterial chemo-embolisation and limited-field EBRT using a linear accelerator. Parameters observed include tumour response, alpha-fetoprotein (AFP) level in serum, human anti-murine antibody (HAMA) assay, T lymphocyte subsets, survival rates, routine parameters, sequential resection rates and histopathological status of the resection specimens. The sequential resection rates were 53% (17/32) and 23% (8/35), and tumour response rates were 72% (23/32) and 86% (30/35) in the RIT and EBRT groups, respectively. The main side-effects in the RIT group were mild allergic reactions. The most common toxicity in the EBRT group was an increase in liver enzymes. The liver tissue in the target volume was injured by EBRT. The injured liver tissue revealed a low-attenuation area adjacent to the hepatic tumour within the target volume on follow-up computed tomography studies after EBRT. On pathological evaluation, the low-attenuation area revealed hyperaemia, distended hepatic sinusoids packed with erythrocytes and hepatic cell loss. The sequential resection specimens from both the RIT and the EBRT group showed residual cancer tissue located at the edge of the mass. The residual cancer cells presented as giant cells under microscopy. T lymphocyte subsets observed prior to treatment did not significantly change after RIT, but were significantly disturbed by EBRT. HAMA formation was the major reason for discontinuing RIT, the incidence being as high as 34% (11/32). Intrahepatic and pulmonary metastases occurred more frequently in the EBRT group (63%) than in the RIT group (22%). The 1-, 2-, 3- and 4-year survival rates were 50%, 41%, 34% and 31% in the RIT group, and 77%, 39%, 11% and 7% in the EBRT group, respectively. It is interesting that the serum AFP level showed a transient increase, the mechanism and importance of which are not known, but are discussed. Both RIT and EBRT are useful treatment modalities for unresectable HCC, serving to prolong survival. However, RIT is much less toxic than EBRT, the side-effects of which include radiation injury to the liver and disturbance of T lymphocyte subsets.

Construction and preliminary screening of a human phage single-chain antibody library associated with gastric cancer.

BACKGROUND: The aim of this study was to construct a phage library of human single-chain antibodies associated with gastric cancer and screen such a library for CEA binding scFv. MATERIALS AND METHODS: The cDNA library of antibody variable regions was constructed using mRNA from metastatic lymph nodes or spleen of patients with stomach cancer by RT-PCR. These cDNA were assembled into a single-chain format and cloned into phagemid pCANTAB-5 and then transformed into Escherichia coli TG1. The scFv gene library was rescued by M13KO7 helper phage. CEA and the viable CEA-positive gastric cancer cell line MKN-28 were used to screen the phage antibody library. Indirect and tumor cell ELISA was used to determine the specificity of phage antibody. Fixed cell immunofluorescence and live cell FACS analysis were used to further characterize the binding of phage scFv. RESULTS: After transformation into E. coli TG1, 2.5 x 10(7) cfu/microg ampicillin-resistant clones grew. Sequences of those positive insert clones showed that the V(H) genes were derived from the V(H) III subgroup, while the V(L) genes belonged to the V(kappa) III subgroup. After four rounds of panning, the titer of eluted binding phage increased 135- to 158-fold and ELISA results showed that 20/95 clones can bind CEA and 47/95 clones can bind fixed tumor cells. Immunofluorescence and FACS analysis results showed that these phage scFv fragments could bind CEA-positive cells. CONCLUSIONS: We successfully constructed a human phage antibody library from lymph nodes of stomach cancer patients. Such kinds of library prove useful for generating tumor-antigen-specific human antibody fragments.