• Title/Summary/Keyword: Cancer biology

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Detection of Serum Anti-Extracellular Protein Kinase a Autoantibodies as a Potential Tumor Marker

  • Lee, Seung-Ho;Kim, Ki-Nam;Seo, Sang-Hui;Sohn, Sung-Hwa;Kim, Yu-Ri;Kim, Hye-Won;Choi, Chul-Won;Kim, Jun-Suk;Kim, Meyoung-Kon
    • Molecular & Cellular Toxicology
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    • v.2 no.1
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    • pp.67-73
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    • 2006
  • In previous studies, it has been discovered that cancer cells not only overexpress regulatory subunit I (Rl)/protein kinase type I (PKA-I) but also secrete outside the cell an extracellular form of PKA (ECPKA) and that the ECPKA secretion detected in patients' serum is obviously greater than that found in non-cancer patients or healthy subjects. We now found that ECPKA elicits the formation of serum autoantibodies that can serve as a cancer diagnostic and prognostic marker. To measure the presence of anti-ECPKA autoantibody in the human sera, basic methodology for ECPKA assay was established an enzyme-linked immunosorbent assay (ELISA). We obtained serum samples from 199 patients with different types of cancer, and also obtained 31 serum samples to compare with ECPKA concentrations from non-cancer patients and 119 normal volunteers. Compared with normal or non-cancer patient sera, we found that the frequency of anti-ECPKA autoantibody was significantly higher in cancer patients (88%) than in those without cancer (17%). Furthermore the presence of anti-ECPKA autoantibodies in the serum of cancer patients was highly correlated with the site of metastasis. The immunoassay developed for anti-ECPKA antibodies is highly sensitive and specific. Therefore, this discovery of an autoantibody-based cancer diagnostic may have serious clinical application and may become an important advance over current technology.

Growht Ingibition of Human Ovarian Cancer Cells by Differential Modulation of Protein Kinase A Isozymes

  • Seo, Jin;Kim, Se-Nyun;Lee, Gap-Ryol;Kim, So-Young;Park, Sang-Dal;Hong, Seung-Hwan
    • Animal cells and systems
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    • v.1 no.2
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    • pp.389-394
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    • 1997
  • We examined the effect of modulation of PKA isozymes on the growth of human ovarian cancer cells. Three ovarian cancer cell lines, 2774, SK-OV-3, and OVCAR-3, were examined in this study. The treatment of 5 uM 8-CI-cAMP, which has been known to down-regulate RI (or type 1 PKA) and up-regulate RII (or type II PKA), markedly inhibited the growth of all cell lines (50-80% at day 6). To test whether alteration in PKA regulatory subunits level can change the growth characteristics of ovarian cancer cells, we introduced RIIB- expression construct and Rla antisense-expression construct into 2774 cells. The overexpression of RIIB down-regulated Rla protein, and the antisense-expression of Rla up-regulated RIIB protein, showing that the intracellular levels of RI and RII are reciprocally regulated. In both cases, cell growth was reduced by 30% at day 2. These results indicate that the growth of ovarian cancer cells is controlled by the signals from PKA isozymes, and the modulation of PKA isozymes can be employed for the human ovarian cancer therapy.

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Plasma Post-operative miR-21 Expression in the Prognosis of Gastric Cancers

  • Ma, Guo-Jian;Gu, Rong-Min;Zhu, Ming;Wen, Xu;Li, Jin-Tian;Zhang, Yuan-Ying;Zhang, Xiao-Mei;Chen, Sen-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.12
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    • pp.7551-7554
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    • 2013
  • Tumor-associated microRNAs have been detected in serum or plasma, but whether plasma microRNA-21 (miR-21) could be a potential circulating biomarker for gastric cancer (GC) prognosis in Chinese is still uncertain. Real-time quantitative reverse transcription PCR (qRT-PCR) was employed in this study to compare the relative expression of miR-21 between pre-operative and post-operative paired plasmas from 42 patients with primary GCs. The results showed that the expression levels of miR-21 in the post-operative plasmas were significantly reduced by an average of 18.2 times in all patients when compared to the pre-operative plasmas, and by 22.1 times in the subgroup of patients without family history, while only 1.76 times in the subgroup of patients with a family history. With respect of clinicopathological characteristics, the plasma miR-21 expression was highly associated with differentiation degree and lymph node metastasis rate. The results suggested plasma miR-21 could be a novel potential biomarker for GC prognosis and evaluation of surgery outcomes, especially in patients without a family history.

GRP78 Secreted by Colon Cancer Cells Facilitates Cell Proliferation via PI3K/Akt Signaling

  • Fu, Rong;Yang, Peng;Wu, Hai-Li;Li, Zong-Wei;Li, Zhuo-Yu
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7245-7249
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    • 2014
  • Glucose regulated protein 78 (GRP78) is usually recognized as a chaperone in the endoplasmic reticulum. However, increasing evidence indicates that GRP78 can be translocated to the cell surface, acting as a signaling receptor for a variety of ligands. Since little is known about the secretion of GRP78 and its role in the progression of colon cancer we here focused on GRP78 from colon cancer cells, and purified GRP78 protein mimicking the secreted GRP78 was able to utilize cell surface GRP78 as its receptor, activating downstream PI3K/Akt and Wnt/${\beta}$-catenin signaling and promote colon cancer cell proliferation. Our study revealed a new mode of action of autocrine GRP78 in cancer progression: secreted GRP78 binds to cell surface GRP78 as its receptor and activates intracellular proliferation signaling.

Databases and tools for constructing signal transduction networks in cancer

  • Nam, Seungyoon
    • BMB Reports
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    • v.50 no.1
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    • pp.12-19
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    • 2017
  • Traditionally, biologists have devoted their careers to studying individual biological entities of their own interest, partly due to lack of available data regarding that entity. Large, high-throughput data, too complex for conventional processing methods (i.e., "big data"), has accumulated in cancer biology, which is freely available in public data repositories. Such challenges urge biologists to inspect their biological entities of interest using novel approaches, firstly including repository data retrieval. Essentially, these revolutionary changes demand new interpretations of huge datasets at a systems-level, by so called "systems biology". One of the representative applications of systems biology is to generate a biological network from high-throughput big data, providing a global map of molecular events associated with specific phenotype changes. In this review, we introduce the repositories of cancer big data and cutting-edge systems biology tools for network generation, and improved identification of therapeutic targets.

Anticancer activity of CopA3 dimer peptide in human gastric cancer cells

  • Lee, Joon Ha;Kim, In-Woo;Kim, Sang-Hee;Yun, Eun-Young;Nam, Sung-Hee;Ahn, Mi-Young;Kang, Dong-Chul;Hwang, Jae Sam
    • BMB Reports
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    • v.48 no.6
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    • pp.324-329
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    • 2015
  • CopA3 is a homodimeric ${\alpha}$-helical peptide derived from coprisin which is a defensin-like antimicrobial peptide that was identified from the dung beetle, Copris tripartitus. CopA3 has been reported to have anticancer activity against leukemia cancer cells. In the present study, we investigated the anticancer activity of CopA3 in human gastric cancer cells. CopA3 reduced cell viability and it was cytotoxic to gastric cancer cells in the MTS and LDH release assay, respectively. CopA3 was shown to induce necrotic cell death of the gastric cancer cells by flow cytometric analysis and acridine orange/ethidium bromide staining. CopA3-induced cell death was mediated by specific interactions with phosphatidylserine, a membrane component of cancer cells. Taken together, these data indicated that CopA3 mainly caused necrosis of gastric cancer cells, probably through interactions with phosphatidylserine, which suggests the potential utility of CopA3 as a cancer therapeutic. [BMB Reports 2015; 48(6): 324-329]

Mechanics behind Breast Cancer Prevention - Focus on Obesity, Exercise and Dietary Fat

  • Alegre, Melissa Marie;Knowles, McKay Hovis;Robison, Richard A.;O'Neill, Kim Leslie
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.4
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    • pp.2207-2212
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    • 2013
  • Cancer prevention is rapidly emerging as a major strategy to reduce cancer mortality. In the field of breast cancer, significant strides have recently been made in the understanding of underlying preventive mechanisms. Currently, three major strategies have been linked to an increase in breast cancer risk: obesity, lack of physical exercise, and high levels of saturated dietary fat. As a result, prevention strategies for breast cancer are usually centered on these lifestyle factors. Unfortunately, there remains controversy regarding epidemiological studies that seek to determine the benefit of these lifestyle changes. We have identified crucial mechanisms that may help clarify these conflicting studies. For example, recent reports with olive oil have demonstrated that it may influence crucial transcription factors and reduce breast tumor aggressiveness by targeting HER2. Similarly, physical exercise reduces sex hormone levels, which may help protect against breast cancer. Obesity promotes tumor cell growth and cell survival through upregulation of leptin and insulin-like growth factors. This review seeks to discuss these underlying mechanisms, and more behind the three major prevention strategies, as a means of understanding how breast cancer can be prevented.

Fangchinoline Inhibits Cell Proliferation Via Akt/GSK-3beta/cyclin D1 Signaling and Induces Apoptosis in MDA-MB-231 Breast Cancer Cells

  • Wang, Chang-Dong;Yuan, Cheng-Fu;Bu, You-Quan;Wu, Xiang-Mei;Wan, Jin-Yuan;Zhang, Li;Hu, Ning;Liu, Xian-Jun;Zu, Yong;Liu, Ge-Li;Song, Fang-Zhou
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.2
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    • pp.769-773
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    • 2014
  • Fangchinoline (Fan) inhibits cell proliferation and induces apoptosis in several cancer cell lines. The effects of Fan on cell growth and proliferation in breast cancer cells remain to be elucidated. Here, we show that Fan inhibited cell proliferation in the MDA-MB-231 breast cancer cell line through suppression of the AKT/Gsk-3beta/cyclin D1 signaling pathway. Furthermore, Fan induced apoptosis by increasing the expression of Bax (relative to Bcl-2), active caspase 3 and cytochrome-c. Fan significantly inhibited cell proliferation of MDA-MB-231 cells in a concentration and time dependent manner as determined by MTT assay. Flow cytometry analysis demonstrated that Fan treatment of MDA-MB-231 cells resulted in cell cycle arrest at the G1 phase, which correlated with apparent downregulation of both mRNA and protein levels of both PCNA and cyclin D1. Further analysis demonstrated that Fan decreased the phosphorylation of AKT and GSK-3beta. In addition, Fan up-regulated active caspase3, cytochrome-c protein levels and the ratio of Bax/Bcl-2, accompanied by apoptosis. Taken together, these results suggest that Fan is a potential natural product for the treatment of breast cancer.