• Asian-Australasian Journal of Animal Sciences
• /
• v.1 no.1
• /
• pp.43-46
• /
• 1988

Based on our previous results that among 4 strains of mice SHN and GR/A showed the highest mammary growth potentials in females and males, respectively. Effects of crossbreeding on normal and neoplastic mammary growth were studied in $(SHN\;{\times}\;GR/A)F_1$ virgin female mice. $F_1$ mice were higher than the parental strains in the end-bud formation and the ductal growth of mammary glands at 60 days of age and at tumorous age, respectively. While there was little difference between $F_1$ and both parental strains in the onset age of the first mammary tumors, mammary tumorigenic potential was apparently higher in the former than in the latters. This would be the first report that demonstrated directly the contribution of mammary growth potential of males to that of female offspring.

• Biomedical Science Letters
• /
• v.11 no.3
• /
• pp.253-258
• /
• 2005

Reactive oxygen species (ROS) and sex hormones affect the proliferation of cells and are believed to play important roles in tumorigenesis. However, little is known regarding how these two factors interact to affect cell proliferation. In this study, hepal-6 cells were treated with ROS and sex hormones (testosterone and steroidal) either separately or in combination. The sex hormones had no significant influence the cell proliferation up to a concentration of $1{\mu}M$. However, cell proliferation was inhibited when the cells were treated simultaneously with $H_2O_2$, which alone was found to promote cell proliferation at the concentrations of $15{\mu}M$. In conclusion, this study indicates that instead of promoting the cell proliferation, ROS interact with sex hormones to inhibit the Hepa 1-6 cell proliferation.

• BMB Reports
• /
• v.50 no.3
• /
• pp.132-137
• /
• 2017

Elevated glucose levels in cancer cells can be attributed to increased levels of glucose transporter (GLUT) proteins. Glut1 expression is increased in human malignant cells. To investigate alternative roles of Glut1 in breast cancer, we silenced Glut1 in triple-negative breast-cancer cell lines using a short hairpin RNA (shRNA) system. Glut1 silencing was verified by Western blotting and qRT-PCR. Knockdown of Glut1 resulted in decreased cell proliferation, glucose uptake, migration, and invasion through modulation of the EGFR/MAPK signaling pathway and integrin ${\beta}1$/Src/FAK signaling pathways. These results suggest that Glut1 not only plays a role as a glucose transporter, but also acts as a regulator of signaling cascades in the tumorigenesis of breast cancer.

• BMB Reports
• /
• v.53 no.4
• /
• pp.181-190
• /
• 2020

Protein phosphatase 4 (PP4), one of serine/threonine phosphatases, is involved in many critical cellular pathways, including DNA damage response (DNA repair, cell cycle regulation, and apoptosis), tumorigenesis, cell migration, immune response, stem cell development, glucose metabolism, and diabetes. PP4 has been steadily studied over the past decade about wide spectrum of physiological activities in cells. Given the many vital functions in cells, PP4 has great potential to develop into the finding of key working mechanisms and effective treatments for related diseases such as cancer and diabetes. In this review, we provide an overview of the cellular and molecular mechanisms by which PP4 impacts and also discuss the functional significance of it in cell health.

• Proceedings of the Korean Society of Life Science Conference
• /
• 2008.10a
• /
• pp.71.1-71.1
• /
• 2008

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.183-183
• /
• 1998

Telomerase synthesizes telomeric DNA repeats onto chromosome ends de novo. Telomerase activation and telomere shortening in human somatic cells have been implicated in cell tumorigenesis and immortalization. In order to find the potential inhibitors against telomerase activitiy which can be used as potential anticancer agents, we screened about 100 kinds of natural products after partition into n-hexane, ethyl acetate and aqueous layers from methanol extracts. The inhibitory effects of these materials against telomerase enzyme activity were tested in 293T cell culture using telomeric repeat amplification protocol(TRAP). The incorporation of $\^$32/P-dGTP into amplified DNA was measured by adsorption to Whatman DE81 paper instead of using TRAP assay for screening the extracts of natural products. Strong effective compounds were not found in this study but DE81 filter spotting method may be a useful model for the screening. Some of the compounds which showed somewhat inhibitory effects had cytotoxic effects also.

• Biomolecules & Therapeutics
• /
• v.23 no.5
• /
• pp.428-433
• /
• 2015

Acetylshikonin, a natural naphthoquinone derivative compound, has been used for treatment of inflammation and cancer. In the present study, we have investigated whether acetylshikonin could regulate the NF-${\kappa}B$ signaling pathway, thereby leading to suppression of tumorigenesis. We observed that acetylshikonin significantly reduced proliferation of several cancer cell lines, including human pancreatic PANC-1 cancer cells. In addition, acetylshikonin inhibited phorbol 12-myristate 13-acetate (PMA) or tumor necrosis-${\alpha}$ (TNF-${\alpha}$)-induced NF-${\kappa}B$ reporter activity. Proteome cytokine array and real-time RT-PCR results illustrated that acetylshikonin inhibition of PMA-induced production of cytokines was mediated at the transcriptional level and it was associated with suppression of NF-${\kappa}B$ activity and matrix metalloprotenases. Finally, we observed that an exposure of acetylshikonin significantly inhibited the anchorage-independent growth of PANC-1 cells. Together, our results indicate that acetylshikonin could serve as a promising therapeutic agent for future treatment of pancreatic cancer.

• Korean Journal of Veterinary Research
• /
• v.32 no.4
• /
• pp.635-640
• /
• 1992

Two cases of lingual masses were observed among 500 Fischer 344 (F344) rats which were used as control and treated animals in a 2 year carcinogenicity study in Toxicology Research Center, Korea Research Institute of Chemical Technology. The masses grossly appeared as tan, pedunculated, fungiform on the dorsal aspect of the base of the tongues. They were approximately $1.5{\times}1.2{\times}0.3cm$ in size. The microscopic features consisted of acanthosis, hyperkeratosis, papillary projection with connective tissue cores and multifocal chronic active inflammation with hair shafts. The results observed support the epigenetic mechanism of tumorigenesis which is caused by Physical stimuli of foreign bodies. Both of the masses were diagnosed as papillomas with the incidence rate of 0.4%(1/250) in each sex on the basis of the gross and microscopic features.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.11
• /
• pp.1607-1613
• /
• 2020

Colorectal cancer (CRC) is regarded as one of the most common and deadly forms of cancer. Gut microbiota is vital to retain and promote several functions of intestinal. Although previous researches have shown that some gut microbiota have the abilities to inhibit tumorigenesis and prevent cancer from progressing, they have not yet clearly identified associative mechanisms. This review not only concentrates on the antitumor effects of metabolites produced by gut microbiota, for example, SCFA, ferrichrome, urolithins, equol and conjugated linoleic acids, but also the molecules which constituted the bacterial cell wall have the antitumor effect in the host, including lipopolysaccharide, lipoteichoic acid, β-glucans and peptidoglycan. The aim of our review is to develop a possible therapeutic method, which use the products of gut microbiota metabolism or gut microbiota constituents to help treat or prevent colorectal cancer.

• Tuberculosis and Respiratory Diseases
• /
• v.77 no.2
• /
• pp.60-64
• /
• 2014

MicroRNAs (miRNAs) are a class of small noncoding RNAs that modulate target gene activity, and are aberrantly expressed in most types of cancer as well in lung cancer. A miRNA can potentially target a diverse set of mRNAs; further, it plays a critical role in lung tumorigenesis as well as affects patient outcome. Previous studies focused mainly on abnormal miRNAs expressions in lung cancer tissues. Interestingly, circulating miRNAs were identified in human plasma and serum in 2008. Since then, considerable effort has been directed to the study of circulating miRNAs as one of the biomarkers of lung cancer. miRNAs expression of tissues and blood in lung cancer patients is being analyzed by more researchers. Recently, to overcome the high false-positivity of low-dose chest computed tomography scan, miRNAs in lung cancer screening are being investigated. This article summarizes the recent researches regarding clinical applications of miRNAs in the diagnosis and management of lung cancer.