Hepatic Tumor Cells Research Articles

An in vitro study on the overlapping growth of hepatic tumor cells

An in vitro study on the overlapping growth of hepatic tumor cells

Inhibition of hepatic tumor cell proliferationin vitroand tumor growthin vivoby taltobulin, a synthetic analogue of the tripeptide hemiasterlin

To investigate the inhibitory effects of taltobulin (HTI-286), a synthetic analogue of natural hemiasterlin derived from marine sponges, on hepatic tumor growth in vitro and in vivo. The potential anti-proliferative effects of HTI-286 on different hepatic tumor cell lines in vitro and in vivo were examined. HTI-286 significantly inhibited proliferation of all three hepatic tumor cell lines (mean IC50 = 2 nmol/L +/- 1 nmol/L) in vitro. Interestingly, no decrease in viable primary human hepatocytes (PHH) was detected under HTI-286 exposure. Moreover, intravenous administration of HTI-286 significantly inhibited tumor growth in vivo (rat allograft model). HTI-286 might be considered a potent promising drug in treatment of liver malignancies. HTI-286 is currently undergoing clinical evaluation in cancer patients.

Adenoviral modulation of the tumor‐associated system L amino acid transporter, LAT1, alters amino acid transport, cell growth and 4F2/CD98 expressionwith cell‐type specific effects in cultured hepatic cells

Altered expression of metabolite transporters is observed frequently in tumor cell lines and primary neoplasms. The extent to which these may to contribute to the growth autonomy associated with cancer is not clear. LAT1 is a major L-type amino acid transporter over-expressed in a variety of cancer types and a light chain component of the CD98 heterodimer. We utilized an adenoviral expression system to modulate the level of LAT1 in a hepatic in vitro model to examine phenotypic changes associated with short-term exogenous and blocked expression. LAT1 levels were increased three fold and resulted in increased L-type amino acid transport as a result of adenoviral expression in murine hepatocytes. The protein was expressed on the cell surface and complexed with the CD98 heavy chain known as 4F2. Surprisingly, levels of the total CD98 protein complex were increased 2.4-fold as a result of adenoviral expression of light chain only, suggesting coordinate regulation. Exogenous overexpression was less effective in normal rat liver cells relative to mouse. LAT1 antisense expression in hepatic tumor cells resulted in a modest though statistically significant decrease in cell number, viability and S-phase cells over a 5-day period relative to controls despite the absence of a significant decrease in L-type transport over this period. These studies are preparatory to in vivo efforts focusing on LAT1/CD98 as a potential therapeutic target.

Synthetic tubulin inhibitor HTI-286 and hepatocellular carcinoma: an in-vitro and and in-vivo study

4201 Background: HTI-286 (HTI) is a synthetic tubulin inhibitor and a hemiasterlin analogue. It is a potent inhibitor of cell growth with an additional advantage of circumventing the P-glycoprotein-mediated resistance, which hampers efficacy of several antimicrotubule agents. Aim of our study was to investigate in-vitro antiproliferative effect of HTI in several hepatic cancer cell lines (Morris hepatoma (MH), Hep G2 and Hep 3B) and on primary human hepatocytes. Furthermore tumor growth inhibition was analyzed in a rat in-vivo study. Methods: MTT assay was done to determine the doubling time of each cell line. Exponentially growing cells were seeded with different concentrations of HTI for several doubling times. We determined the cytotoxicity and IC(50) by the MTT method. Microtubule structure was visualized by alpha-tubulin-immunofluoresence (aTIF). All animal experiments were approved by the local ethic commission. MH were implanted into American cancer institute rats (ACI) and tumor growth was pursued with MR-imaging (MR). HTI was administered via tail injection at several time points. The tumor growth was followed for over a period of one month. Results: In MH, HepG2 and Hep3B cells HTI has shown an antiproliferative effect already after one doubling time (22, 48 and 55 hours). IC(50) in MH cells was around 1 nM. Cytotoxic effect of HTI rose with increasing concentration. Proliferation of primary human hepatocytes was not affected by the HTI-treatment. aTIF showed a significant difference in HTI-treated compared to non-treated cells. The in-vivo study revealed significant growth inhibition in HTI treated group compared to a saline solution treated group. Conclusions: Our in-vitro data show that HTI inhibits proliferation of hepatic tumor cells in-vitro and tumor growth in-vivo. aTIF confirmed disrupture of microtubule organization. Furthermore primary human hepatocytes do not seem to be affected by the HTI treatment. The data suggest HTI to be considered as a potent promising cytotoxic and antiproliferative drug in liver oncology especially as it circumvents the P-glycoprotein-mediated drug resistance, being responsible for resistance to taxanes and vinca alkaloids. No significant financial relationships to disclose.

Nuclear location–dependent role of peripheral benzodiazepine receptor (PBR) in hepatic tumoral cell lines proliferation

PBR is involved in numerous biological functions, including steroid biosynthesis, mitochondrial oxidative phosphorylation and cell proliferation. The presence of PBR at the perinuclear/nuclear subcellular level has been demonstrated in aggressive breast cancer cell lines and human glioma cells where it seems to be involved in cell proliferation. In our study we investigated the presence of perinuclear/nuclear PBR in different hepatic tumor cell lines with regard to binding to [ 3H] PK 11195 and protein analysis. The results obtained by saturation binding experiments and scatchard analysis of perinuclear/nuclear PBR density in parallel with the results on the growth curves of the cell lines tested, indicate that the perinuclear/nuclear PBR density correlates inversely with cell doubling time. Moreover, the cell line with high perinuclear/nuclear PBR proliferated in response to PBR ligand, whereas that with low perinuclear/nuclear PBR did not. Our results reinforce the idea that the subcellular localisation of PBR defines its function and that this receptor could be a possible target for new strategies against cancer.

Morphology and immunohistochemical characteristics of hepatic primary and metastatic malignant spindle cell tumors

To investigate the morphology and immunohistochemical characteristics of hepatic primary and metastatic malignant spindle cell tumors, and to conclude the diagnostic and differential diagnostic criteria for these morphologically similar tumors. Forty-six specimens of hepatic spindle cell tumors. 20 primary tumors (43.4%), including 3 cases of sarcomatoid carcinoma (6.5%), 11 of angiosarcoma (23.9%), 2 of epithelioid hemangioendothelioma (5%), 1 of spindle cell carcinoid (2.2%), and 3 of undifferentiated sarcoma (6.5%). and 26 metastatic malignant tumors (56.5%), including 20 cases of gastrointestinal stromal tumors (GIST, 43.4%), 3 of leiomyosarcoma (6.5%), 2 of malignant peripheral never sheath tumor (4.3%), and 1 of meningeal hemangiopericytoma (2.2%), resected during operation or collected during imaging-mediated liver puncture underwent hematoxylin-eosin staining, SP staining, and EnVision immunohistochemical staining. Either primary or metastatic tumors showed extensive overlapping in histopathologic appearance, and hemangiopericytoma-like structure was the predominant pattern, which could be seen in nearly every kind of hepatic spindle cell tumors. The morphology of GIST was the most complex. Two or three entirely different kinds of structure could be seen in one specimen of GIST, especially in the resected ones. Most stromal tumor cases were CD117 positive, and existed the condition that the primary tumor was positive and the metastatic tumor was negative or vice versa or one part of specimen was positive but other part was negative. Leiomyosarcoma was immunoreactive to smooth muscle specific antigen (SMA), malignant peripheral nerve sheath tumor was immunoreactive to S-100 protein and neurofilament (NF), and both were CD117 negative. Angiosarcoma and epithelioid hemangioendothelioma expressed different immunoreactivity to CD31, CD34 and factor VIII related antigen. Sarcomatoid carcinoma was positive for CK and vimentin. Spindle cell carcinoid was positive for CK and neuroendocrine markers, such as synaptophysin and chromogranin A. Primary angiosarcoma is the most common form of primary spindle cell tumor in liver, and metastatic GIST is predominant in hepatic metastatic spindle cell tumors. A penal of immunohistochemical markers is necessary for the final diagnosis of these tumors because of the complexity and similarity of different tumors of this kind.

Long-Term Radioiodine Retention and Regression of Liver Cancer after Sodium Iodide Symporter Gene Transfer in Wistar Rats

Radioiodine therapy of nonthyroid cancers after sodium iodide symporter (NIS) gene delivery has been proposed as a potential application of gene therapy. However, it seems to be precluded by the rapid efflux of taken up iodine from most transduced xenografted tumors. We present an in vivo kinetic study of NIS-related hepatic iodine uptake in an aggressive model of hepatocarcinoma induced by diethylnitrosamine in immunocompetent Wistar rats. We followed the whole-body iodine distribution by repeated imaging of live animals. We constructed a rat NIS (rNIS) adenoviral vector, Ad-CMV-rNIS, using the cytomegalovirus (CMV) as a promoter. Injected in the portal vein in 5 healthy and 25 hepatocarcinoma-bearing rats and liver tumors in 9 hepatocarcinoma-bearing rats, Ad-CMV-rNIS drove expression of a functional NIS protein by hepatocytes and allowed marked (from 20 to 30% of the injected dose) and sustained (>11 days) iodine uptake. This contrasts with the massive iodine efflux found in vitro in human hepatic tumor cell lines. In vivo specific inhibition of NIS by sodium perchlorate led to a rapid iodine efflux from the liver, indicating that the sustained uptake was not attributable to an active retention mechanism but to permanent recycling of the effluent radioiodine via the high hepatic blood flow. Radioiodine therapy after Ad-CMV-rNIS administration achieved a strong inhibition of tumor growth, the complete regression of small nodules, and prolonged survival of hepatocarcinoma-bearing rats. This demonstrates for the first time the efficacy of NIS-based radiotherapy in a relevant preclinical model of nonthyroid human carcinogenesis.

Selective antiproliferative and apoptotic effects of flavonoids purified from Rhus verniciflua Stokes on normal versus transformed hepatic cell lines

Considerable attention is being concentrated on dietary flavonoids in developing novel cancer-preventive approaches due to their potential ability to induce selective apoptosis of cancer cells. In this study, we prepared a flavonoid-containing fraction from a crude acetone extract of Rhus verniciflua Stokes (RVS), traditionally used as a food additive and as an herbal medicine, and named RVS chloroform–methanol fraction (RCMF). We evaluated the effects of RCMF on proliferation and apoptosis using mouse embryonic primary hepatic cells (MPHC), embryonic normal hepatic cell line (BNL CL.2), and its SV40-mediated transformed cell line (BNL SV A.8). We also investigated the effects of RCMF on the antioxidant defense system in those cells. This study demonstrated that RCMF exhibited a selective growth inhibition and apoptosis induction on transformed cells. BNL SV A.8 cells were more sensitive to RCMF-mediated cytotoxicity than were MPHC or BNL CL.2. RCMF-mediated reduction of MnSOD activity and glutathione (GSH) content in BNL SV A.8 cells is thought to be associated with RCMF-induced apoptosis. Our findings suggest that RCMF is an agent which may be capable of inducing growth inhibition and apoptosis of hepatic tumor cells.

Selective effects of quercetin on the cell growth and antioxidant defense system in normal versus transformed mouse hepatic cell lines

Quercetin is a dietary anticancer chemical that is capable of inducing apoptosis in tumor cells. However, little is known about its biological effect on nonmalignant cells, although the effect is one of the critical criteria to evaluate the clinical efficacy of the anticancer agent. In this study, we investigated the effects of quercetin on cell growth and apoptosis using embryonic normal hepatic cell line (BNL CL.2) and its SV40-transformed cell line (BNL SV A.8). We also evaluated the effects of quercetin on the antioxidant defense system in those cells. BNL SV A.8 cells were more sensitive to quercetin-mediated cytotoxicity than BNL CL.2 cells. In addition, the enzyme assays showed that quercetin actively stimulated the antioxidant defense systems including superoxide dismutase, catalase, glutathione, and glutathione reductase only in the BNL CL.2 cells. In particular, quercetin significantly reduced superoxide dismutase activity and increased the malonaldehyde content in BNL SV A.8 cells. These are thought to be closely related to quercetin-mediated apoptosis. Our findings suggest that quercetin is a dietary flavonoid that is capable of inducing selective growth inhibition and apoptosis in hepatic tumor cells, but not in normal cells.

Chemoembolization of rat liver metastasis with microspheres and gemcitabine followed by evaluation of tumor cell load by chemiluminescence

An orthotopic, isogenic rat model was used to determine the potential of chemoembolization (CHE) for reducing the tumor cell load of a diffusely metastatic liver. Seven days after injecting CC531-lac-Z cells intraportally to male WAG/Rij rats, tumor positive animals were treated by injection into the hepatic artery with solvent (n=17), degradable starch microspheres (DSM, 30 mg/kg; n=16), DSM plus 5-fluorouracil (5-FU, dosages: 90, 60, and 40 mg/kg) or DSM plus gemcitabine (Gem, dosages: 100, 80, 50, and 10 mg/kg). After 3 more weeks the experiment was terminated, the livers were weighted and the number of CC531-lac-Z cells per liver was determined. Injection of DSM reduced the tumor cell load by 21% (T/C%=79), the combination with 5-FU caused a stimulation of growth at 40 mg/kg (T/C%=291; n=10), but effected dose-dependent reductions in tumor cell number at 60 mg/kg (T/C%=86; n=16), and 90 mg/kg (T/C=19; n=17). None of these effects was significantly different from controls. The combination of DSM plus Gem was toxic at the highest dose (100 mg/kg), but well tolerated and highly effective at 80 mg/kg (T/C%= 16; n=12), 50 mg/kg (T/C%=9; n=12), and 10 mg/kg (T/C%=26; n=14). These results were significantly different from controls (p<0.05), respectively. In summary, the comparison of CHE with 5-FU or Gem shows that the efficacy of Gem in reducing the hepatic tumor cell load was significantly higher and its therapeutic ratio was greater than that of 5-FU.

Ajoene (natural garlic compound): a new anti-leukaemia agent for AML therapy

The reputation of garlic ( Allium sativum) as an effective remedy for tumours extends back to the Egyptian Codex Ebers of 1550 b.c. Several garlic compounds including allicin and its corresponding sulfide inhibit the proliferation and induce apoptosis of several human non-leukaemia malignant cells including breast, bladder, colorectal, hepatic, prostate cancer, lymphoma and skin tumour cell lines. Ajoene (4,5,9-trithiadodeca-1,6,11-triene-9-oxide) is a garlic-derived compound produced most efficiently from pure allicin and has the advantage of a greater chemical stability than allicin. Several clinical trials and in vitro studies of ajoene have demonstrated its best-known anti-thrombosis, anti-microbial and cholesterol lowering activities. Recently, topic application of ajoene has produced significant clinical response in patients with skin basal cell carcinoma. Ajoene was shown to inhibit proliferation and induce apoptosis of several human leukaemia CD34-negative cells including HL-60, U937, HEL and OCIM-1. Also, ajoene induces 30% apoptosis in myeloblasts from chronic myeloid leukaemia patient in blast crisis. More significantly, ajoene profoundly enhanced the apoptotic effect of the two chemotherapeutic drugs: cytarabine and fludarabine in human CD34-positive resistant myeloid leukaemia cells through enhancing their bcl-2 inhibitory and caspase-3 activation activities. The two key anti-leukaemia biological actions of ajoene were the inhibition of proliferation and the induction of apoptosis. Studies have shown the anti-proliferation activity of ajoene to be associated with a block in the G2/M phase of cell cycle in human myeloid leukaemia cells. The apoptosis inducing activity of ajoene is via the mitochondria-dependent caspase cascade through a significant reduction of the anti-apoptotic bcl-2 that results in release of cytochrome c and the activation of caspase-3. Since acute myeloid leukaemia (AML) is a heterogeneous malignant disease in which disease progression at the level of CD34-positive cells has a major impact on resistance to chemotherapy and relapse and the inability to undergo apoptosis is a crucial mechanism of multi-drug resistance in AML patients. The recent findings of the potent enhancing activity of ajoene on chemotherapy-induced apoptosis in CD34-positive resistant human myeloid leukaemia cells suggest a novel promising role for the treatment of refractory and/or relapsed AML patients as well as elderly AML patients. Further studies are warranted to evaluate similar enhancing effect for ajoene in blast cells from AML patients in primary cultures before its introduction in pilot clinical study.

Heparanase expression in hepatocellular carcinoma and the cirrhotic liver

The endoglycosidase heparanase plays an important role in tumor cell invasion, angiogenesis and metastasis. In this study, we analyzed heparanase expression in primary hepatocellular carcinoma (HCC), liver cirrhosis and normal liver tissues to further evaluate its role in tumor pathogenesis. Heparanase mRNA expression was measured by real-time quantitative RT-PCR and localized at the cellular level by in situ hybridization. Heparanase protein levels and its localization were determined by Western blotting and immunohistochemistry. Expression of heparanase mRNA in primary HCC was increased 2-fold compared with liver cirrhosis and 2.2-fold in comparison with normal liver tissues, and this overexpression was even more pronounced in advanced stage HCC. In contrast, heparanase expression levels between cirrhotic tissues and normal liver tissues were not significantly different. In HCC the increased heparanase expression was localized in hepatic tumor cells and was only weakly present or absent in normal hepatocytes, bile duct epithelial cells and the connective tissues. These results suggest that increased heparanase expression is involved in the pathogenesis and progression of HCC. Its specific up-regulation in HCC but not in liver cirrhosis indicates that it might be used as a molecular marker for the differentiation of these disorders.

Peptide targeting of CCK-2 receptor in hepatic and pancreatic tumour cell lines

Peptide targeting of CCK-2 receptor in hepatic and pancreatic tumour cell lines

Loss of Igf2 Imprinting in Monoclonal Mouse Hepatic Tumor Cells Is Not Associated with Abnormal Methylation Patterns for the H19, Igf2, andKvlqt1 Differentially Methylated Regions

IGFII, the peptide encoded by the Igf2 gene, is a broad spectrum mitogen with important roles in prenatal growth as well as cancer progression. Igf2 is transcribed from the paternally inherited allele, whereas the linked H19 is transcribed from the maternal allele. Igf2 imprinting is thought to be maintained by differentially methylated regions (DMRs) located at multiple sites such as upstream of H19 and Igf2 and within Kvlqt1 loci. Biallelic expression (loss of imprinting (LOI)) of Igf2 is frequently observed in cancers, and a subset of Wilms' and intestinal tumors have been shown to exhibit abnormal methylation at H19DMR associated with loss of maternal H19 expression, but it is not known whether such changes are common in other neoplasms. Because cancers consist of diverse cell populations with and without Igf2 LOI, we established four independent monoclonal cell lines with Igf2 LOI from mouse hepatic tumors. We here demonstrate retention of normal differential methylation at H19, Igf2, or Kvlqt1 DMR by all of the cell lines. Furthermore, H19 was found to be expressed exclusively from the maternal allele, and levels of CTCF, a multifunctional nuclear factor that has an important role in the Igf2 imprinting, were comparable with those in normal hepatic tissues with no mutational changes detected. These data indicate that Igf2 LOI in tumor cells is not necessarily linked to abnormal methylation at H19, Igf2, or Kvlqt1 loci.

The hepatitis B virus X protein promotes tumor cell invasion by inducing membrane-type matrix metalloproteinase-1 and cyclooxygenase-2 expression.

Hepatocellular carcinoma is strongly associated with chronic infection by the hepatitis B virus (HBV) and has poor prognosis due to intrahepatic metastasis. HBx is often the only HBV protein detected in hepatic tumor cells; however, its contribution to tumor invasion and metastasis has not been established so far. In this work, we show that HBx enhances tumor cell invasion, both in vivo and in vitro. The increased invasive capacity induced by HBx is mediated by an upregulation of membrane-type 1 matrix metalloproteinase (MT1-MMP) expression, which in turn activates matrix metalloproteinase-2. Induction of both MT1-MMP expression and cell invasion by HBx is dependent on cyclooxygenase-2 (COX-2) activity. In addition, HBx upregulates the expression of COX-2, which is mediated by the transcriptional activation of the COX-2 gene promoter in a nuclear factor of activated T cell-dependent (NF-AT-dependent) manner. These results demonstrate the ability of HBx to promote tumor cell invasion by a mechanism involving the upregulation of MT1-MMP and COX-2 and provide new insights into the mechanism of action of this viral protein and its involvement in tumor metastasis and recurrence of hepatocellular carcinoma.

The hepatitis B virus X protein promotes tumor cell invasion by inducing membrane-type matrix metalloproteinase-1 and cyclooxygenase-2 expression

Hepatocellular carcinoma is strongly associated with chronic infection by the hepatitis B virus (HBV) and has poor prognosis due to intrahepatic metastasis. HBx is often the only HBV protein detected in hepatic tumor cells; however, its contribution to tumor invasion and metastasis has not been established so far. In this work, we show that HBx enhances tumor cell invasion, both in vivo and in vitro. The increased invasive capacity induced by HBx is mediated by an upregulation of membrane-type 1 matrix metalloproteinase (MT1-MMP) expression, which in turn activates matrix metalloproteinase-2. Induction of both MT1-MMP expression and cell invasion by HBx is dependent on cyclooxygenase-2 (COX-2) activity. In addition, HBx upregulates the expression of COX-2, which is mediated by the transcriptional activation of the COX-2 gene promoter in a nuclear factor of activated T cell–dependent (NF-AT–dependent) manner. These results demonstrate the ability of HBx to promote tumor cell invasion by a mechanism involving the upregulation of MT1-MMP and COX-2 and provide new insights into the mechanism of action of this viral protein and its involvement in tumor metastasis and recurrence of hepatocellular carcinoma.

STAT3 Down-regulates the Expression of Cyclin D during Liver Development

As the expression of cyclin D1 is induced during liver regeneration and also in hepatic tumor cells, cyclin D1 is likely to play an important role in the proliferation and transformation of hepatocytes. However, the role of cyclin D1 in liver development remains unknown. Here we show that the expression of D-type cyclins including cyclin D1, D2, and D3 is down-regulated along with liver development. In addition, oncostatin M (OSM), an interleukin-6 family cytokine, down-regulated the expression of cyclin D1 and D2 in a primary culture of fetal hepatocytes in which OSM induces hepatic differentiation. Ectopic expression of receptor mutants defective in the activation of either STAT3 or SHP-2/Ras indicated that the down-regulation of D1 and D2 cyclins by OSM was mediated by STAT3 but not by SHP-2/Ras. Consistently, expression of dominant negative STAT3 but not Ras relieved OSM-induced suppression of cyclin D expression. Activation of STAT3 in fetal hepatocytes of transgenic mice expressing the STAT3-estrogen receptor fusion protein by 4-hydroxytamoxifen resulted in the suppression of cyclin D1 and D2 expression. These results indicate that STAT3 activation is necessary and sufficient for down-regulation of D1 and D2 cyclins in fetal hepatocytes. Furthermore, STAT3-C, a constitutively active form of STAT3, suppressed transcription of the cyclin D1 promoter in fetal hepatocytes, whereas it activated the transcription in hepatic tumor cells, huH7 and HepG2. Thus, STAT3-mediated down-regulation of cyclin D expression is rather specific to fetal hepatocytes that are undergoing maturation processes including a reduction of their proliferation potential.

Overexpression of p28/gankyrin in human hepatocellular carcinoma and its clinical significance.

To investigate the expression of p28/gankyrin gene and its role in the carcinogenetic process of human hepatocellular carcinoma (HCC). 64 specimens of HCC and para-carcinoma tissues, 22 specimens of non-tumor liver tissues (7 normal, 15 cirrhosis), 10 specimens of normal human tissues and 5 hepatoma cell lines were studied for the expression of p28/gankyrin by Northern blot. The expression of p28/gankyrin protein was detected immunohistochemically by using the specific polyclonal antibody. Northern blot analysis indicated that the expression of p28/gankyrin mRNA was intensively distributed in brain and heart, weakly in lung, spleen and muscle, undetectable in digestive system including liver, pancreas, stomach, small and large intestines. p28/gankyrin mRNA was absent in normal liver, weakly detected in liver cirrhosis and in 18 of 64 para-carcinoma liver tissues. In contrast, the expression of p28/gankyrin mRNA was intensively detected in all 5 hepatoma cell lines tested, markedly increased in 57 of 64 and moderately increased in 5 of 64 HCC samples. In comparison with liver cirrhosis and para-carcinoma liver tissues, the average expression of p28/gankyrin mRNA in HCC was increased 3.6- (2.901+/-0.507 vs 0.805+/-0.252, P<0.05) and 5.2-fold (2.901+/-0.507 vs 0.557+/-0.203, P<0.01), respectively. In addition, p28/gankyrin mRNA expression level was higher in HCC with portal vein tumor thrombus and microscopic hepatic vein involvement (P=0.021 and P=0.047, respectively). The overexpression of p28/gankyrin protein in HCC was targeted in hepatic tumor cells, not in bile duct cells and other interstitial cells. Overexpression of p28/gankyrin in HCC plays an important role and contributes to the metastasis potential in the process of carcinogenesis. p28/gankyrin may become a specific biological tissue marker for the pathological diagnosis of HCC.

Fission yeast ch-TOG/XMAP215 homologue Alp14 connects mitotic spindles with the kinetochore and is a component of the Mad2-dependent spindle checkpoint.

The TOG/XMAP215-related proteins play a role in microtubule dynamics at its plus end. Fission yeast Alp14, a newly identified TOG/XMAP215 family protein, is essential for proper chromosome segregation in concert with a second homologue Dis1. We show that the alp14 mutant fails to progress towards normal bipolar spindle formation. Intriguingly, Alp14 itself is a component of the Mad2-dependent spindle checkpoint cascade, as upon addition of microtubule-destabilizing drugs the alp14 mutant is incapable of maintaining high H1 kinase activity, which results in securin destruction and premature chromosome separation. Live imaging of Alp14-green fluorescent protein shows that during mitosis, Alp14 is associated with the peripheral region of the kinetochores as well as with the spindle poles. This is supported by ChIP (chromatin immunoprecipitation) and overlapping localization with the kinetochore marker Mis6. An intact spindle is required for Alp14 localization to the kinetochore periphery, but not to the poles. These results indicate that the TOG/XMAP215 family may play a central role as a bridge between the kinetochores and the plus end of pole to chromosome microtubules.

Study on the Anticancer Drug 5-Fluorouracil-Conjugated Polyaspartamide Containing Hepatocyte-Targeting Group

Anticancer conjugates of 5-fluorouracil (5-Fu) and polyaspartamide, containing pyridoxamine as the hepatocyte-targeting group, were synthesized and characterized. Their sustained release properties and biodistribution were evaluated. The 5-Fu was targeted to specific organs, such as the liver, and had a sustained in vitro release rate in PBS. In vitro cytotoxicity assay showed that the polymeric drugs exhibited low cytotoxicity to the human liver cells (L-02). These polymeric drugs possess high anticancer efficiencies and induced apoptosis in the human hepatic tumor cells (Bel-7204).