Jong Yeon Shin

Bio: Jong Yeon Shin is an academic researcher from Seoul National University. The author has contributed to research in topics: Cancer & Neural cell adhesion molecule. The author has an hindex of 2, co-authored 2 publications receiving 16 citations.

Effect of combined treatment with progesterone and tamoxifen on the growth and apoptosis of human ovarian cancer cells.

Abstract: Progesterone has a potential protective effect against ovarian carcinoma induced by estrogen. Progesterone is also known to cause apoptosis while tamoxifen induces growth arrest. Therefore, we attempted to determine whether combined treatment with progesterone and tamoxifen has a synergistic effect on anti-cancer activity. Although progesterone is known to cause apoptosis while tamoxifen induces growth arrest in many cancer cells, the detailed action of progesterone and tamoxifen and the anticancer effect of combined treatment have not been tested in ovarian cancer cells. Therefore, we tested the growth and apoptosis activity of progesterone and tamoxifen and the anticancer effect of combined treatment of progesterone and tamoxifen in ovarian cancer cells. Ovarian cancer cells, PA-1, were treated with progesterone, tamoxifen, or a combination of progesterone and tamoxifen. The anti-cancer effects were investigated by use of flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, DNA fragmentation analysis, and Western blot analysis. We found that 100 µM progesterone induced typical apoptosis in PA-1 cells. Treatment of PA-1 cells with 10 µM tamoxifen resulted in an increase in the levels of p21, p27, p16 and phospho-pRb, indicating typical G1 arrest. Co-treatment of PA-1 cells with 100 µM progesterone and 10 µM tamoxifen resulted in typical apoptosis, similar to that induced by treatment with 100 µM progesterone alone. These results indicate that progesterone caused apoptosis and tamoxifen induced G1 arrest. Combined treatment with tamoxifen and progesterone caused apoptosis similar to that induced by treatment with progesterone alone and had no additional anti-cancer effect in ovarian cancer cells.

Butyrate-induced differentiation of PC12 cells to chromaffin cells involves cell adhesion and induction of extracellular proteins and cell adhesion proteins

Abstract: PC12 cells were differentiated into the cells of chromaffin phenotype by butyrate treatment. Cells were aggregated and formed tight cell adhesion. To investigate the molecular change in this differentiation, we examined expression levels of cell adhesion proteins and extracellular proteins during butyrate induced-differentiation of PC12 cells. Integrin β1, integrin α7, E cadherin, VCAM, collagen-I, fibronectin, desmoglein and connexin were increased during differentiation. The levels of clusterin and secreted clusterin were also increased. These increased levels of cell adhesion proteins and extracellular proteins appear to induce cell aggregation and tight cell adhesion. The levels of p21, p27 and p16 were increased probably because of differentiation-related growth arrest during differentiation. Prolonged incubation of butyrate up to 1 day was required for differentiation. Signal transduction pathways for this differentiatiom could not be identified since various inhibitors had no effect. The r...

Review of Drug Repositioning Approaches and Resources.

Abstract: Drug discovery is a time-consuming, high-investment, and high-risk process in traditional drug development. Drug repositioning has become a popular strategy in recent years. Different from traditional drug development strategies, the strategy is efficient, economical and riskless. There are usually three kinds of approaches: computational approaches, biological experimental approaches, and mixed approaches, all of which are widely used in drug repositioning. In this paper, we reviewed computational approaches and highlighted their characteristics to provide references for researchers to develop more powerful approaches. At the same time, the important findings obtained using these approaches are listed. Furthermore, we summarized 76 important resources about drug repositioning. Finally, challenges and opportunities in drug repositioning are discussed from multiple perspectives, including technology, commercial models, patents and investment.

The transition from proliferation to differentiation in colorectal cancer is regulated by the calcium activated chloride channel A1

Abstract: Breaking the balance between proliferation and differentiation in animal cells can lead to cancer, but the mechanisms maintaining this balance remain largely undefined. The calcium activated chloride channel A1 (CLCA1) is a member of the calcium sensitive chloride conductance family of proteins and is expressed mainly in the colon, small intestine and appendix. We show that CLCA1 plays a functional role in differentiation and proliferation of Caco-2 cells and of intestinal tissue. Caco-2 cells spontaneously differentiate either in confluent culture or when treated with butyrate, a molecule present naturally in the diet. Here, we compared CLCA1 expressional levels between patients with and without colorectal cancer (CRC) and determined the functional role of CLCA1 in differentiation and proliferation of Caco-2 cells. We showed that: 1) CLCA1 and CLCA4 expression were down-regulated significantly in CRC patients; 2) CLCA1 expression was up-regulated in Caco-2 cells induced to differentiate by confluent culture or by treatment with sodium butyrate (NaBT); 3) Knockdown of CLCA1 with siRNA significantly inhibited cell differentiation and promoted cell proliferation in Caco-2 confluent cultures, and 4) In Caco-2 3D culture, suppression of CLCA1 significantly increased cell proliferation and compromised NaBT-induced inhibition of proliferation. In conclusion, CLCA1 may contribute to promoting spontaneous differentiation and reducing proliferation of Caco-2 cells and may be a target of NaBT-induced inhibition of proliferation and therefore a potential diagnostic marker for CRC prognosis.

Steroid hormone receptors as prognostic markers in breast cancer.

Abstract: Despite the existence of many promising anti-cancer therapies, not all breast cancers are equally treatable, due partly to the fact that focus has been primarily on a few select breast cancer biomarkers- notably ERα, PR and HER2 In cases like triple negative breast cancer (ERα-, PR-, and HER2-), there is a complete lack of available biomarkers for prognosis and therapeutic purposes The goal of this review is to determine if other steroid receptors, like ERβ and AR, could play a prognostic and/or therapeutic role Data from various in vitro, in vivo, and clinical breast cancer studies were examined to analyze the presence and function of ERβ, PR, and AR in the presence and absence of ERα Additionally, we focused on studies that examined how expression of the various steroid receptor isoforms affects breast cancer progression Our findings suggest that while we have a solid understanding of how these receptors work individually, how they interact and behave in the presence and absence of other receptors requires further research Furthermore, there is an incomplete understanding of how the various steroid receptor isoforms interact and impact receptor function and breast cancer progression, partly due to the difficulty in detecting all the various isoforms More large-scale clinical studies must be made to analyze systematically the expression of steroid hormone receptors and their respective isoforms in breast cancer patients in order to determine how these receptors interact with each other and in turn affect cancer progression

Can ovarian aging be delayed by pharmacological strategies

Abstract: Aging has been regarded as a treatable condition, and delaying aging could prevent some diseases. Ovarian aging, a special type of organ senescence, is the earliest-aging organ, as ovaries exhibit an accelerated rate of aging with characteristics of gradual declines in ovarian follicle quantity and quality since birth, compared to other organs. Ovarian aging is considered as the pacemaker of female body aging, which drives the aging of multiple organs of the body. Hence, anti-ovarian aging has become a research topic broadly interesting to both biomedical scientists and pharmaceutical industry. A marked progress has been made in exploration of possible anti-ovarian agents or approaches, such as calorie restriction mimetics, antioxidants, autophagy inducers etc., over the past years. This review is attempted to discuss recent advances in the area of anti-ovarian aging pharmacology and to offer new insights into our better understanding of molecular mechanisms underlying ovarian aging, which might be informative for future prevention and treatment of ovarian aging and its related diseases.