bluuebunny/crossref_metadata_2025_split huggingface dataset:
mTOR and P70 S6 Kinase Expression in Primary Liver Neoplasms
Authors: Sahin Fikret , Kannangai Rajesh , Adegbola Onikepe , Wang Jianzhou , Su Gloria , Torbenson Michael 
Published: September 2005

Abstract
Purpose: mTOR and P70 S6 kinase (S6K) play a key role in regulating protein translation. The role of mTOR and S6K in hepatocellular carcinoma has not been investigated, but this pathway is of particular interest because an effective inhibitor, rapamycin, is available. This study was undertaken to determine the prevalence and clinicopathological correlates of mTOR pathway activation in hepatocellular carcinoma and to determine whether rapamycin inhibits the pathway in cell culture.
Experimental Design: Total and phosphorylated mTOR and S6K protein expression were studied by immunohistochemistry in hepatocellular carcinomas (n = 73), fibrolamellar carcinomas (n = 13), and hepatic adenomas (n = 15). Results were correlated with tumor growth pattern as defined by the WHO (trabecular, pseudoglandular/acinar, compact, and scirrhous), tumor size, Ki-67 proliferation index, and the modified Edmondson nuclear grade, which has a scale of 1 to 4. HepG2 and Hep3B cell lines were treated with rapamycin to see the effect on proliferation and S6K phosphorylation.
Results: Increased expression of total mTOR was seen in 5% of hepatocellular carcinoma, whereas overexpression of phospho-mTOR was evident in 15% of hepatocellular carcinoma. Phospho-mTOR positivity correlated with increased expression of total S6K, which was found in 45% of cases. Total S6K overexpression was positively correlated with tumor nuclear grade, inversely with tumor size, and was unassociated with the proliferation index or WHO growth pattern. Rapamycin treatment of HepG2 and Hep3B cell lines markedly inhibited cell proliferation and reduced S6K phosphorylation in both cell lines.
Conclusions: The mTOR pathway is activated in a subset of hepatocellular carcinoma. Rapamycin can inhibit proliferation of neoplastic hepatocytes in cell culture.
Flt-4–Positive Endothelial Cell Density and Its Clinical Significance in Non–Small Cell Lung Cancer
Authors: Chen Fengshi , Takenaka Kazumasa , Ogawa Eiji , Yanagihara Kazuhiro , Otake Yosuke , Wada Hiromi , Tanaka Fumihiro 
Published: September 2005

Abstract
Purpose: Experimental studies have revealed that fms-like tyrosine kinase (Flt)-4 plays important roles in lymphangiogenesis in malignant tumors, but the clinical significance remains unclear. We assessed Flt-4 expression in tumor cells and in endothelial cells in correlation with clinical outcomes in non–small cell lung cancer (NSCLC).
Experimental Design: A total of 206 consecutive patients with resected pathological stage I-IIIA NSCLC were reviewed. Expression of Flt-4 was examined immunohistochemically, and Flt-4–positive microvessels were quantitatively evaluated (Flt-4–positive endothelial cell density).
Results: There was no significant correlation between Flt-4–positive endothelial cell density and any characteristic of patients including nodal metastases. A significant correlation between Flt-4–positive endothelial cell density and Flt-4 status in tumor cells was documented (P &lt; 0.001), but there was no significant difference in the mean Flt-4–positive endothelial cell density according to vascular endothelial growth factor-C or -D status in tumor cells. The 5-year survival rate for higher Flt-4–positive endothelial cell density tumor (56.4%) was significantly lower than that of lower Flt-4–positive endothelial cell density tumor (69.0%, P = 0.046); the prognostic significance was enhanced in pIIIA-N2 patients (5-year survival rates, 18.8% for higher Flt-4–positive endothelial cell density tumor and 50.0% for lower Flt-4–positive endothelial cell density tumor, respectively; P = 0.012). A multivariate analysis confirmed that higher Flt-4–positive endothelial cell density was a significant and independent prognostic factor (P = 0.019). CD34-positive vessel density or Flt-4 status in tumor cells was not a significant prognostic factor.
Conclusions: Flt-4–positive endothelial cell density, not Flt-4 status in tumor cells, was a significant prognostic factor in NSCLC.
Prognostic Relevance of Increased Angiogenesis in Osteosarcoma
Authors: Kreuter Michael , Bieker Ralf , Bielack Stefan S. , Auras Tanja , Buerger Horst , Gosheger Georg , Jurgens Heribert , Berdel Wolfgang E. , Mesters Rolf M. 
Published: September 2005

Abstract
Purpose: The purpose of this work was to evaluate the prognostic relevance of microvessel density (MVD) for response to chemotherapy and long-term outcome in osteosarcoma.
Experimental Design: Pretherapeutic tumor biopsies of 60 patients with high-grade central osteosarcoma, who were treated according to multimodal neoadjuvant protocols of the German-Austrian-Swiss Cooperative Osteosarcoma Study Group, were evaluated for intratumoral MVD. MVD was correlated with demographic and tumor-related variables, response, and survival.
Results: The median intratumoral MVD was 52 microvessels per 0.26-mm2 field area (interquartile range, 31–77 microvessels per 0.26-mm2 field area). At a median follow-up period of 3.5 years, patients with a high (&gt;median) MVD had significantly higher 5- and 10-year overall survival rates (84%) than patients with low (≤median) MVD (49%; P = 0.0029). Furthermore, increased relapse-free survival for patients with high MVD (P = 0.0064) was observed. In a subgroup analysis of 44 patients with primary high-grade central osteosarcoma of the extremities without primary metastases and good surgical remission, high MVD was associated with 5- and 10-year overall survival rates of 91% compared with 58% for low MVD (P = 0.034). Cox regression analysis revealed that MVD was an independent prognostic factor for survival. A good response to chemotherapy (histologic grading scale of Salzer-Kuntschik) correlated significantly with a high MVD (P = 0.006).
Conclusions: Increased angiogenesis is a prognostic indicator for higher survival and response rates to chemotherapy in patients with osteosarcoma. Thus, measurement of MVD might be useful in decisions selecting patients for future neoadjuvant treatment.
Loss of Methylthioadenosine Phosphorylase and Elevated Ornithine Decarboxylase Is Common in Pancreatic Cancer
Authors: Subhi Ahmad L. , Tang Baiqing , Balsara Binaifer R. , Altomare Deborah A. , Testa Joseph R. , Cooper Harry S. , Hoffman John P. , Meropol Neal J. , Kruger Warren D. 
Published: September 2005

Abstract
Purpose: Loss of the methylthioadenosine phosphorylase (MTAP) gene at 9p21 is observed frequently in a variety of human cancers. We have shown previously that MTAP can act as a tumor suppressor gene and that its tumor suppressor function is related to its effect on polyamine homeostasis. Ornithine decarboxylase is a key enzyme in the regulation of polyamine metabolism. The aim of this study is to analyze MTAP and ornithine decarboxylase (ODC) expression in primary pancreatic tumor specimens.
Experimental Design: We measured MTAP and ODC activity in protein extracts derived from 30 surgically resected tumor samples and eight normal pancreas samples. In a subset of six samples, we also examined MTAP DNA using interphase fluorescence in situ hybridization. In addition, we examined the effect of the ODC inhibitor difluoromethylornithine on two pancreatic adenocarcinoma-derived cell lines.
Result: MTAP activity was 2.8-fold reduced in adenocarcinomas and 6.3-fold reduced in neuroendocrine tumors compared with control pancreas. Conversely, ODC activity was 3.6-fold elevated in adenocarcinomas and 3.9-fold elevated in neuroendocrine tumors compared with control pancreas. Using interphase fluorescence in situ hybridization, we found in tumor samples that 43 to 75% of the nuclei had lost at least one copy of MTAP locus, indicating that loss of MTAP activity was at least partially because of deletion of the MTAP locus. We also show that inhibition of ODC by difluoromethylornithine caused decreased cell growth and increased apoptosis in two MTAP-deleted pancreatic adenocarcinoma-derived cell lines.
Conclusions: MTAP activity is frequently lost, and ODC activity is frequently elevated in both pancreatic adenocarcinoma and neuroendocrine tumors. Inhibition of ODC activity caused decreased cell growth and increased apoptosis in pancreatic tumor-derived cell lines. These findings suggest that MTAP and polyamine metabolism could be potential therapeutic targets in the treatment of pancreatic cancer.
A Selective Retinoid X Receptor Agonist Bexarotene (Targretin) Prevents and Overcomes Acquired Paclitaxel (Taxol) Resistance in Human Non–Small Cell Lung Cancer
Authors: Yen Wan-Ching , Corpuz Manny R. , Prudente Rene Y. , Cooke Tracy A. , Bissonnette Reid P. , Negro-Vilar Andrés , Lamph William W. 
Published: September 2005

Abstract
Purpose: Paclitaxel is an important anticancer agent for the treatment of non–small cell lung cancer (NSCLC). However, its use in cancer therapy is limited by development of acquired drug resistance. The goal of this study was to determine the effect of bexarotene on development of acquired paclitaxel resistance in NSCLC.
Experimental Design: Human NSCLC Calu3 cells were repeatedly treated in culture with intermittent paclitaxel alone or in combination with continuous bexarotene for 3 months. Thereafter, cells were isolated and characterized for their drug sensitivity in vitro and in vivo.
Results: Repeat exposure to paclitaxel alone resulted in development of paclitaxel resistance with cross-resistance to multidrug resistance P-glycoprotein substrates, whereas the bexarotene/paclitaxel combination prevented the development of drug resistance and the cells remained chemosensitive. Furthermore, paclitaxel resistance could be overcome when the resistant cells were treated with the combination regimen. Fluctuation analysis showed that treatment with bexarotene decreased the rate of spontaneous development of paclitaxel resistance. In vivo, the bexarotene/paclitaxel combination regimen produced a statistically significant decrease in tumor growth in a Calu3 NSCLC xenograft model compared with the single agents (two-tailed, P &lt; 0.05). In addition, paclitaxel-resistant Calu3 tumors treated with the bexarotene/paclitaxel combination showed greater delay in tumor growth compared with those treated with paclitaxel alone.
Conclusions: Our results suggest that bexarotene may offer a novel approach to prevent and overcome paclitaxel resistance in patients with NSCLC.
Detection of Overexpressed and Phosphorylated Wild-Type Kit Receptor in Surgical Specimens of Small Cell Lung Cancer
Authors: Tamborini Elena , Bonadiman Lorena , Negri Tiziana , Greco Angela , Staurengo Samantha , Bidoli Paolo , Pastorino Ugo , Pierotti Marco A. , Pilotti Silvana 
Published: September 2005

Abstract
Purpose: The combinations of various chemotherapeutic drugs currently used to treat advanced small cell lung cancer (SCLC) led to similarly poor survival outcomes, which is why new molecular biology approaches are needed to design and select targeted therapies.
Experimental Design: Thirteen stage I SCLC surgical specimens were screened for c-Kit gene mutations by sequencing whole cDNA and for KIT receptor expression/activation by immunoprecipitation and Western blotting. Both the paraffin-embedded and frozen materials were analyzed by immunocytochemistry, and the stem cell factor cognate ligand was assessed by retrotranscription PCR.
Results: In all cases, we showed the presence of wild-type KIT receptors by analyzing the entire coding sequence, which together with the detection of the cognate ligand stem cell factor, supports the establishment of an autocrine loop. In addition, the KIT receptor was activated/phosphorylated. The immunoprecipitation/Western blotting data fit the observed immunophenotype. Interestingly, comparison of the level of KIT expression was at least 10 times higher in the tumoral specimens than the normal reference lungs.
Conclusions: The KIT molecular profile derived from the analysis of SCLC surgical specimens shows that wild-type KIT is overexpressed and phosphorylated in the presence of stem cell factor. This finding, which is consistent with pathological KIT activation driven by an autocrine loop, is particularly interesting in the light of the recent development of new tyrosine kinase inhibitory drugs, which are highly effective in blocking wild-type KIT receptors.
Inhibition of Metastatic Tumor Growth in Mouse Lung by Repeated Administration of Polyethylene Glycol-Conjugated Catalase
Authors: Hyoudou Kenji , Nishikawa Makiya , Umeyama Yukari , Kobayashi Yuki , Yamashita Fumiyoshi , Hashida Mitsuru 
Published: September 2005

Abstract
Purpose: To develop a novel and effective approach to inhibit tumor metastasis based on controlled delivery of catalase, we first evaluated the characteristics of the disposition and proliferation of tumor cells. Then, we examined the effects of polyethylene glycol-conjugated catalase (PEG-catalase) on tumor metastasis. On the basis of the results obtained, PEG-catalase was repetitively administered to completely suppress the growth of tumor cells.
Experimental Design: Murine melanoma B16-BL6 cells were stably transfected with firefly luciferase gene to obtain B16-BL6/Luc cells. These cells were injected intravenously into syngeneic C57BL/6 mice. PEG-catalase was injected intravenously, and the effect was evaluated by measuring the luciferase activity as the indicator of the number of tumor cells.
Results: At 1 hour after injection of B16-BL6/Luc cells, 60 to 90% of the injected cells were recovered in the lung. The numbers decreased to 2 to 4% at 24 hours, then increased. An injection of PEG-catalase just before inoculation significantly reduced the number of tumor cells at 24 hours. Injection of PEG-catalase at 1 or 3 days after inoculation was also effective in reducing the cell numbers. Daily dosing of PEG-catalase greatly inhibited the proliferation and the number assayed at 14 days after inoculation was not significantly different from the minimal number observed at 1 day, suggesting that the growth had been markedly suppressed by the treatment.
Conclusions: These findings indicate that sustained catalase activity in the blood circulation can prevent the multiple processes of tumor metastasis in the lung, which could lead to a state of tumor dormancy.
Histone Deacetylase Inhibitor Trichostatin A Represses Estrogen Receptor α-Dependent Transcription and Promotes Proteasomal Degradation of Cyclin D1 in Human Breast Carcinoma Cell Lines
Authors: Alao John Patrick , Lam Eric W-F. , Ali Simak , Buluwela Laki , Bordogna Walter , Lockey Peter , Varshochi Rana , Stavropoulou Alexandra V. , Coombes R. Charles , Vigushin David M. 
Published: September 2005

Abstract
Purpose: Estrogen receptor α (ERα)-positive breast cancer cell lines are up to 10 times more sensitive than ERα-negative cell lines to the antiproliferative activity of the histone deacetylase inhibitor trichostatin A (TSA). The purpose of the study was to investigate the mechanisms underlying this differential response.
Experimental Design and Results: In the ERα-positive MCF-7 cell line, TSA repressed ERα and cyclin D1 transcription and induced ubiquitin dependent proteasomal degradation of cyclin D1, leading primarily to G1-S-phase cell cycle arrest. By contrast, cyclin D1 degradation was enhanced but its transcription unaffected by TSA in the ERα-negative MDA-MB-231 cell line, which arrested in G2-M phase. Cyclin D1 degradation involved Skp2/p45, a regulatory component of the Skp1/Cullin/F-box complex; silencing SKP2 gene expression by RNA interference stabilized cyclin D1 and abrogated the cyclin D1 down-regulation response to TSA.
Conclusions: Tamoxifen has been shown to inhibit ERα-mediated cyclin D1 transcription, and acquired resistance to tamoxifen is associated with a shift to ERα-independent cyclin D1 up-regulation. Taken together, our data show that TSA effectively induces cyclin D1 down-regulation through both ERα-dependent and ERα-independent mechanisms, providing an important new strategy for combating resistance to antiestrogens.
Cancer-Associated Expression of
Minichromosome Maintenance 3
Gene in Several Human Cancers and Its Involvement in Tumorigenesis
Authors: Ha Seon-Ah , Shin Seung Min , Namkoong Hong , Lee Heejeong , Cho Goang Won , Hur Soo Young , Kim Tae Eung , Kim Jin Woo 
Published: September 2005

Abstract
Purpose: The purpose of our study was to identify an unique gene that shows cancer-associated expression, evaluates its potential usefulness in cancer diagnosis, and characterizes its function related to human carcinogenesis.
Experimental Design: We used the differential display reverse transcription-PCR method with normal cervical, cervical cancer and metastatic tissues, and cervical cancer cell line to identify genes overexpressed in cancers.
Results: We identified a minichromosome maintenance 3 (MCM3) gene that was overexpressed in various human cancers, including leukemia, lymphoma, and carcinomas of the uterine cervix, colon, lung, stomach, kidney and breast, and malignant melanoma. Western blot and immunohistochemical analyses also revealed that MCM3 protein was elevated in most of human cancer tissues tested. We compared the MCM3 protein expression levels in human cancers with conventional proliferation markers, Ki-67 and proliferating cell nuclear antigen. MCM3 antibody was the most specific for multiple human cancers, whereas proliferating cell nuclear antigen was relatively less effective in specificity, and Ki-67 failed to detect several human cancers. The down-regulation of MCM3 protein level was examined under serum starvation in both normal and cancer cells. Interestingly, MCM3 protein was stable in MCF-7 breast cancer cells even up to 96 hours after serum starvation, whereas it was gradually degraded in normal BJ fibroblast cells. Nude mice who received injections of HEK 293 cells stably transfected with MCM3 formed tumors in 6 weeks.
Conclusions: Our study indicates that determination of MCM3 expression level will facilitate the assessment of many different human malignancies in tumor diagnosis, and MCM3 is involved in multiple types of human carcino-genesis.
Antitumor Efficacy of Oblimersen Bcl-2 Antisense Oligonucleotide Alone and in Combination with Vinorelbine in Xenograft Models of Human Non–Small Cell Lung Cancer
Authors: Hu YanPing , Bebb Gwyn , Tan Sophia , Ng Rebecca , Yan Hong , Sartor Jason R. , Mayer Lawrence D. , Bally Marcel B. 
Published: September 2005

AbstractOverexpression of Bcl-2 protein in cancer cells can inhibit programmed cell death and engender chemoresistance. Reducing Bcl-2 protein levels by using antisense oligonucleotides targeting the gene message can increase the sensitivity of cancer cells to cytotoxic agents. The objective of this work was to investigate the antitumor efficacy of the Bcl-2 antisense oligonucleotide oblimersen (Genasense; G3139), alone and in combination with vinorelbine (VNB), in an ectopic and orthotopic xenograft model of NCI-H460 human non–small-cell lung cancer. In addition to assessing therapeutic effect, Bcl-2 protein expression in tumor tissue isolated from lung and heart was measured. In the ectopic xenograft model, oblimersen at 5 and 10 mg/kg significantly inhibited tumor growth compared with saline-treated control groups, and furthermore, the antitumor effect of oblimersen was associated with down-regulation of Bcl-2 protein in isolated tumor tissue. Moreover, the combination of oblimersen with VNB was more active in inhibiting tumor growth than either drug used alone. In the orthotopic model, oblimersen treatment (5 mg/kg) increased the median survival time of mice to 33 days in comparison with a median survival time of 21 days in the control animals. With this model, the anticancer effect was demonstrated by assessing tumor growth in lung and heart tissues by hematoxylin and eosin staining and Bcl-2 expression by immunohistochemistry. When VNB at 5 mg/kg was combined with oblimersen administered at 5 mg/kg, 33% of mice survived more than 90 days. These data suggest that the combination of oblimersen and VNB may provide enhanced antitumor activities against non–small-cell lung cancer.
Antitumor Activity of Small Interfering RNA/Cationic Liposome Complex in Mouse Models of Cancer
Authors: Yano Junichi , Hirabayashi Kazuko , Nakagawa Shin-ichiro , Yamaguchi Tohru , Nogawa Masaki , Kashimori Isao , Naito Haruna , Kitagawa Hidetoshi , Ishiyama Kouichi , Ohgi Tadaaki , Irimura Tatsuro 
Published: September 2005

Abstract
Purpose: The RNA interference effect is an alternative to antisense DNA as an experimental method of down-regulating a specific target protein. Although the RNA interference effect, which is mediated by small interfering RNA (siRNA) or micro-RNA, has potential application to human therapy, the hydrodynamic method usually used for rapid administration of oligonucleotides is unsuitable for use in humans. In this study, we have investigated the antitumor activity of a synthetic siRNA, B717, which is sequence specific for the human bcl-2 oncogene, complexed with a novel cationic liposome, LIC-101.
Experimental Design: In a mouse model of liver metastasis, we administered B717/LIC-101 by bolus intravenous injection, adjusting the rate and volume of administration to what is feasible in human therapy. In a mouse model bearing prostate cancer in which the cells were inoculated under the skin, B717/LIC-101 was administered subcutaneously around the tumor.
Results: The B717/LIC-101 complex inhibited the expression of bcl-2 protein and the growth of tumor cell lines in vitro in a sequence-specific manner in the concentration range of 3 to 100 nmol/L. Furthermore, the complex had a strong antitumor activity when administered intravenously in the mouse model of liver metastasis. B717 (siRNA) was shown to be delivered to tumor cells in the mouse liver, but only when complexed with LIC-101. The complex also inhibited tumor cell growth in the mouse model bearing prostate cancer.
Conclusions: By combining siRNA with our cationic liposome, we overcame the difficulty of administering siRNA to animals in ways that can be applied in human therapy. Although our siRNA/liposome complex is not yet in clinical trials, it is expected to provide a novel siRNA therapy for cancer patients.
Selective Induction of Apoptosis with Proton Pump Inhibitor in Gastric Cancer Cells
Authors: Yeo Marie , Kim Dong-Kyu , Kim Young-Bae , Oh Tae Young , Lee Jong-Eun , Cho Sung Won , Kim Hugh Chul , Hahm Ki-Baik 
Published: September 2005

AbstractPurpose: To survive in an ischemic microenvironment with a lower extracellular pH, ability to up-regulate proton extrusion is critical for cancer cell survival. Gastric H+/K+-ATPase exchanges luminal K+ for cytoplasmic H+ and is the enzyme primarily responsible for gastric acidification. On the basis of the fact that blocking the clearance of acidic metabolites are known to induce the cell death, we hypothesized that pantoprazole (PPZ), one of gastric H+/K+-ATPase inhibitors used frequently to treat acid-related diseases, could inhibit growth of tumor cells.Experimental Design: Genomic DNA fragmentation, terminal deoxynucleotidyl transferase (Tdt)-mediated nick end labeling assay, and annexin V staining were performed to detect PPZ-induced apoptosis. Mitogen-activated protein kinase activation and heat shock proteins expression were determined by immunoblot with specific antibodies. The antitumor effect of PPZ was evaluated in vivo by a xenograft model of nude mice.Results: After PPZ treatment, apoptotic cell death was seen selectively in cancer cells and was accompanied with extracellular signal-regulated kinase deactivation. By contrast, normal gastric mucosal cells showed the resistance to PPZ-induced apoptosis through the overexpression of antiapoptotic regulators including HSP70 and HSP27. In a xenograft model of nude mice, administration of PPZ significantly inhibited tumorigenesis and induced large-scale apoptosis of tumor cells.Conclusions: PPZ selectively induced in vivo and in vitro apoptotic cell death in gastric cancer, suggesting that proton pump inhibitors could be used for selective anticancer effects.