• Journal of Chest Surgery
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• v.31 no.12
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• pp.1134-1146
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• 1998

Background: The tumor suppressor gene p53 is one of the most frequently altered genes in human tumors, including those of the lung. There is now a compelling evidence that wild-type p53 can negatively influence cell growth by causing G1 arrest or by inducing apoptosis. The possibilities of using p53 for gene therapy are also gathering much interest. Material and Method: Our approach towards understanding p53 function would be to study the biological consequences of overexpression of wild-type p53 in normal and tumor cells by using adenovirus vectors capable of giving high levels of the p53 gene product in cells. We have used this vector containing wild-type p53 to infect tumor cells with different p53 status (null, mutant, or wild-type) to confirm that expression of p53 in null or mutant cell lines becomes possible by Adenovirus-p53 transduction, to examine the effects of high levels of p53 expression on the growth properties of tumor cells, to evaluate the role of apoptosis in p53-mediated biological effects, and to examine the effect of Adenovirus-p53 on the tumorigenicities of the lung cancer cell lines in vitro. Result: The results of our study showed that cells expressing endogenous mutant p53 and those devoid of p53 expression altogether were significantly more sensitive to Adenovirus-p53-mediated cytotoxicity compared to tumor cells expressing endogenous wild-type p53 and that overexpression of wild-type p53 induced programmed cell death. Also we knew that Adenovirus-p53 significantly reduced tumor colony formation of human non-small cell lung cancer cell lines, and decreased the growth of pre-formed colonies in vitro. Conclusion: These results suggest that adenovirus is an efficient vector for mediating transfer and expression of tumor suppressor genes in human non-small cell lung cancer cells and that the tumor cells null for p53 or expressing mutant p53 readily undergo apoptosis by Adenovirus-p53.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.6
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• pp.529-539
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• 2008

Background and Purpose : Oral squamous cell carcinoma (OSCC) is one of the most aggressive tumors of the head and neck area. OSCC is known to preferentially metastasize via lymphatic system, and resulting cervical lymph node metastasis is the most reliable of treatment failure. But the biological mechanism of the regional nodal metastasis is not clear. So, we determined metastasis-related factors in orthotopic nude mouse models of OSCC. Experimental Design : Two cell lines-KB and YD-10B cells, established from human oral mucosal squamous cell carcinoma, were xenografted into the tissue space of athymic murine mouth floor. The mice were followed for tumor development and growth, the murine tumors were examined histopathologically for local invasion or regional or distant metastasis. Finally, we performed immunohistochemical assays with antiepithelial growth factor (EGF), EGF receptor (EGFR), phosphorylated EGFR (pEGFR), and anti-vascular endothelial growth factor (VEGF), VEGF receptor (VEGFR)-2, phosphorylated VEGFR-2/3 (pVEGFR-2/3) antibodies. We also determined the microvessel density. Results : Transplantation of human OSCC tumor cells into the mouth floor successfully resulted in the formation of orthotopic tumors. KB cell line showed significantly higher tumor proliferation and higher nodal metastatic potential than YD-10B cell line. Furthermore, immunohistochemical staining demonstrated higher expression of EGFR/pEGFR, VEGF, and pVEGFR-2/3 as well as higher microvessel density in KB murine tumors than in YD-10B murine tumors. Conclusion : An orthotopic model of OSCC in athymic mice was established which copies the cervical lymph nodal metastasis of human OSCC. Our mouth floor model should facillitate the understanding of the molecular pathogenesis of cervical nodal metastasis of OSCC.

• Journal of Radiation Industry
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• v.9 no.4
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• pp.187-192
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• 2015

CD44 is a particular adhesion molecule and facilitates both cell-cell and cell-matrix interactions. In particular, splice variants of CD44 are particularly overexpressed in a large number of malignancies and carcinomas. In this study, the $^{177}Lu$-labelled CD44 targeting antibody was prepared and bioevaluated in vitro and in vivo. Anti-CD44 was immunoconjugated with the equivalent molar ratio of cysteine-based DTPA-NCS and radioimmunoconjugated with $^{177}Lu$ at room temperature within 15 minutes. The stability was tested in human serum. An in vitro study was carried out in HT-29 human colon cancer cell lines. For the biodistribution study $^{177}Lu$-labelled anti-CD44 was injected in xenograft mice. Anti-CD44 was immunoconjugated with cysteine-based DTPA-NCS and purified by a centricon filter system having a molecular cut-off of 50 kDa. Radioimmunoconjugation with $^{177}Lu$ was reacted for 15 min at room temperature. The radiolabeling yield was >99%, and it was stable in human serum without any fragmentation or degradation. The radioimmunoconjugate showed a high binding affinity on HT-29 colon cancer cell surfaces. In a biodistribution study, the tumor-to-blood ratio of the radioimmunoconjugate was 43 : 1 at 1 day post injection (p.i) in human colon cancer bearing mice. The anti-CD44 monoclonal antibody for the targeting of colon cancer was effectively radioimmunoconjugated with $^{177}Lu$. The in vitro high immunoactivity of this radioimmunoconjugate was determined by a cell binding assay. In addition, the antibody's tumor targeting ability was demonstrated with very high uptake in tumors. This radioimmunoconjugate is applicable to therapy in human colon cancer with highly expressed CD44.

• IMMUNE NETWORK
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• v.2 no.2
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• pp.115-124
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• 2002

Background: The chemical characteristics of the exo-secretion from Phellinus linteus (referred to as exo-secretion) including the compositions of amino acids and monosaccharides were investigated. In addition, cytotoxicity of the exo-secretion on 5 tumor cell lines derived from human cancers and its antitumor activity against ascitic sarcoma-180 cells were examined. Methods: The antitumor activity of exo-secretion from Phellinus linteus was determined by measuring parameters including tumor weight, life span of mice, chemotatic activity of leukocytes, counts of immune cells, and activity of cytokines. Results: The exo-secretion from Phellinus linteus showed no direct cytotoxicity to the five tumor cell lines tested, but it had a strong antitumor activity against sarcoma-180 cells in ICR mice as measured by tumor weight and life span of mice. The exo-secretion stimulated the chemotaxis of leukocytes and production of immune cells and cytokines. Conclusion: These results suggest that the exo-secretion from Phellinus linteus do not act as a direct cytotoxic substance to cancer cells but as an immunomodulator.

• Journal of Microbiology and Biotechnology
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• v.25 no.4
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• pp.439-447
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• 2015

The objective of this study was to isolate and identify the chemical structure of a biosurfactant produced by Nocardia farcinica strain BN26 isolated from soil, and evaluate its in vitro antitumor activity on a panel of human cancer cell lines. Strain BN26 was found to produce glycolipid biosurfactant on n-hexadecane as the sole carbon source. The biosurfactant was purified using medium-pressure liquid chromatography and characterized as trehalose lipid tetraester (THL) by nuclear magnetic resonance spectroscopy and mass spectrometry. Subsequently, the cytotoxic effects of THL on cancer cell lines BV-173, KE-37 (SKW-3), HL-60, HL-60/DOX, and JMSU-1 were evaluated by MTT assay. It was shown that THL exerted concentration-dependent antiproliferative activity against the human tumor cell lines and mediated cell death by the induction of partial oligonucleosomal DNA fragmentation. These findings suggest that THL could be of potential to apply in biomedicine as a therapeutic agent.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.618-626
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• 2016

Pleural effusion lymphoma (PEL) is a rare B-cell lymphoma that has a very poor prognosis with a median survival time of around 6 months. PEL is caused by Kaposi's sarcoma-associated herpesvirus, and is often co-infected with the Epstein Barr virus. The complement system is fundamental in the innate immune system against pathogen invasion and tumor development. In the present study, we investigated the activation of the complement system in PEL cells using human serum complements. Interestingly, two widely used PEL cell lines, BCP-1 and BCBL-1, showed different susceptibility to the complement system, which may be due to CD46 expression on their cell membranes. Complement activation did not induce apoptosis but supported cell survival considerably. Our results demonstrated the susceptibility of PEL to the complement system and its underlying mechanisms, which would provide insight into understanding the pathogenesis of PEL.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1575-1579
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• 2015

Some microRNAs (miRNAs) have been shown to act as oncogenes or tumor suppressor genes in human melanomas. miR-328 is upregulated in blood cells of melanoma patients compared to in healthy controls. This suggests a role for miR-328 in melanoma that warrants investigation. In this study, we demonstrated miR-328 levels to be dramatically decreased in human melanoma cell lines. Moreover, forced expression of miR-328 inhibited proliferation and induced G1-phase arrest of the SK-MEL-1 melanoma cell line. We identified TGFB2 as a direct target gene for miR-328 using a fluorescent reporter assay and western blotting. Levels of TGFB2 were dramatically increased in human melanoma cell lines and were inversely correlated with the miR-328 expression level. Our findings provide new insights into the mechanisms of human melanoma development, indicating that miR-328 has therapeutic potential for this disease.

• IMMUNE NETWORK
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• v.1 no.2
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• pp.151-161
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• 2001

Background: Inactivation in p53 tumor suppressor gene through a point mutation and deletion is one of the most frequent genetic changes found in human cancer, with 50% of an incidence. This high rate of mutation mostly suggests that the gene plays a central role in the development of cancer and the mutations detected so far were found in exons 5 to 8. Mutation of p53 locus produced accumulation of abnormal p53 protein, and negative regulation of cell proliferation and transcriptional activation as a suppressor of transformation were lost. In addition, inhibition of its normal cellular function of wild-type by mutant is an important step in tumorigenesis. Method: 4 colon cancer cell lines (SNU C1, C2A, C4, C5) were examined for mutation in exons 5 to 8 of the p53 tumor suppressor gene by PCR-SSCP analysis and expression pattern by western blotting and immunoprecipitation. p53-mediated transactivation ability were examined by CAT assay and base substitution of p53 in SNU C2A cell were detected by DNA sequencing. Results: 1) SNU C2A cell and SNU C5 cell were detected mobility shifts each in exon 5 and exon 7 of p53 gene by the PCR-SSCP method, implicating being of p53 mutation. 2) 3 colon cancer cell lines (SNU C1, SNU C2A, SNU C5) expressed wild type and mutant type p53 protein. 3) In northern blot experiment, SNU C2A and SNU C5 cell expressed high level of p53 mRNA. 4) Results of p53-mediated transactivation in colon cancer cell lines by CAT assay represented only SNU C2A cell has transcriptional activity. 5) DNA sequencing in SNU C2A cell showed missense mutation in codon 179 of one allele, histidine to arginine and wild type p53 in the other allele. Conclusion: Colon cancer cell lines showed correlation with mutation in p53 gene and accumulation of abnormal p53 protein. Colon cancer cell SNU C2A retained p53-mediated transactivation as heterozygous p53 with one mutant allele in 179 codon and the other wild-type allele.

• Archives of Pharmacal Research
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• v.20 no.5
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• pp.410-413
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• 1997

In the course of screening synthetic compounds to inhibit tumor cell growth, pyrrolo[1,2-.alpha.] benzimidazole (PBI), an intermediate of azamitosene, was found to inhibit a proliferation of gastric cancer cell lines. Despite a potential cytotoxic activity against solid tumor cells as opposed to that against rapidly-doubled leukemic cells, there has been no report on the inhibition of gastric cancer cell line by PBI and its' derivatives. The present experiment was designed to determine if PBI derivatives can effectively inhibit the cellular proliferation of gastric cancer cells by using in vitro as well as in vivo chemosensitivity system (MTT assay, clonogenic assay and human tumor xenografted assay). Of the tested PBI derivatives, PBI (18) and PBI (20), displayed the effective growth inhibition of cultured gastric cancer cells or even in the xenografted nude mouse model.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.18
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• pp.7553-7558
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• 2014

The Piwi subfamily comprises two argonaute (Ago) family proteins, which are defined by the presence of PAZ and Piwi domains, with well known roles in RNA silencing. Hiwi, a human Piwi subfamily member, has been shown to play essential roles in stem cell self-renewal and gametogenesis. Recently, accumulating reports have indicated that abnormal hiwi expression is associated with poorer prognosis of multiple types of human cancers, including examples in the breast. However, little is known about details of the oncogenic role of hiwi in breast cancers. In present study, we confirmed overexpression of hiwi in breast cancer specimens and breast cancer cell lines at both mRNA and protein levels. Thus both RT-qPCR and Western blot data revealed significantly higher hiwi in intratumor than peritumor specimens, overexpression being associated with tumor size, lymph node metastasis and histological grade. Hiwi overexpression was also identified in breast cancer cell lines, MDA-MB-231 and MCF-7, and gain-of-function and loss-of-function strategies were adopted to identify the role of hiwi in the MCF-7 cell growth. Results demonstrated that hiwi expression in MCF-7 cells was significantly up- or down-regulated by the two strategies. We next evaluated the influence of hiwi overexpression or knockdown on the growth of breast cancer cells. Both cell count and colony formation assays confirmed promoting roles of hiwi in MCF-7 cells, which could be inhibited by hiwi specific blockage by siRNAs. In summary, the present study confirmed overexpression of hiwi in breast cancer specimens and breast cancer cell lines, and provided e vidence of promotion by hiwi of cell growth. The results imply an oncogenic role of hiwi in breast cancers.