SNA077, an Extract of Marine Streptomyces sp., Inhibits Melanogenesis by Downregulating Melanogenic Proteins via Inactivation of cAMP/PKA/CREB Signaling.

Excess melanin in skin is known to be the main cause of hyper-pigmentary skin diseases such as freckles and lentigo. This study aimed to evaluate the depigmenting efficacy of an extract from the marine microorganism strain, Streptomyces sp. SNA077. To determine the anti-melanogenic efficacy of SNA077, we assessed the melanin contents of SNA077-treated B16, Melan-a, and MNT-1 cells. We observed the expression of key enzymes in melanogenesis via qRT-PCR and Western blot analyses. We further estimated the skin-whitening effect of SNA077 using a skin-equivalent model. SNA077 dramatically decreased the melanin production of B16 cells, Melan-a, and MNT-1 cells. In B16 cells treated with SNA077, the activity of cellular tyrosinase was clearly inhibited. In addition, the mRNA and protein expression levels of melanogenic genes were suppressed by SNA077 treatment in B16 and MNT-1 cells. Upstream of tyrosinase, the expression levels of phospho-CREB, phospho-p38, PKA activity, cyclic AMP production, and MC1R gene expression were inhibited by SNA077. Finally, SNA077 clearly showed a skin-brightening effect with a reduced melanin content in the skin tissue model. Collectively, our results suggest for the first time that an extract of marine Streptomyces sp. SNA077 could be a novel anti-melanogenic material for skin whitening.

On-schedule mammography rescreening in the National Cancer Screening Program for breast cancer in Korea.

Breast cancer is the most commonly diagnosed cancer among women in the Republic of Korea. However, many women are not aware of the importance of on-schedule mammography screening for breast cancer. The objectives of this study were to estimate the percentage of women that attended on-schedule mammography rescreening, and to examine the factors associated with rescreening, among the target screening population (women aged ≥ 40 years) in Korea. The study population was derived from the National Health Insurance (NHI) Corporation database for the National Cancer Screening Program (NCSP), and included 2,511,976 women from the target screening population who attended the NCSP for breast cancer in 2005-2006 (baseline). Study participants were followed-up to determine whether they attended mammography rescreening after 2 years as recommended. Among those who attended mammography screening in 2005-2006, 61.3% were rescreened on schedule 2 years later. The odds of being rescreened were the highest in study participants aged 60-69 years. NHI beneficiaries with a higher premium were significantly more likely to be rescreened than Medical Aid Program recipients. A false-positive screening result at baseline adversely affected subsequent screening behavior. Furthermore, those who had a history of mammography screening before baseline were more likely to return for rescreening. Therefore, assessment of a woman's screening history and socioeconomic status, in combination with interventions to reduce anxiety, such as involving primary care physicians or better informing women about breast cancer and mammography screening, are needed. Efforts to reduce false-positive results and improve the quality of mammography may also increase compliance with breast cancer screening recommendations.