The anticancer effect of (1S,2S,3E,7E,11E)-3,7,11, 15-cembratetraen-17,2-olide(LS-1) through the activation of TGF-ß signaling in SNU-C5/5-FU, fluorouracil-resistant human colon cancer cells.

The anticancer effect of (1S,2S,3E,7E,11E)-3,7,11,15-cembratetraen-17,2-olide (LS-1) from Lobophytum sp. has been already reported in HT-29 human colorectal cancer cells. In this study, we examined the effect of LS-1 on the apoptosis induction of SNU-C5/5-FU, fluorouracil-resistant human colon cancer cells. Furthermore, we investigated whether the apoptosis-induction effect of LS-1 could arise from the activation of the TGF-ß pathway. In SNU-C5/5-FU treated with LS-1 of 7.1 µM (IC50), we could observe the various apoptotic characteristics, such as the increase of apoptotic bodies, the increase of the sub-G1 hypodiploid cell population, the decrease of the Bcl-2 level, the increase of procaspase-9 cleavage, the increase of procaspase-3 cleavage and the increase of poly(ADP-ribose) polymerase cleavage. Interestingly, the apoptosis-induction effect of LS-1 was also accompanied by the increase of Smad-3 phosphorylation and the downregulation of c-Myc in SNU-C5/5-FU. LS-1 also increased the nuclear localization of phospho-Smad-3 and Smad-4. We examined whether LS-1 could downregulate the expression of carcinoembryonic antigen (CEA), a direct inhibitor of TGF-ß signaling. LS-1 decreased the CEA level, as well as the direct interaction between CEA and TGF-ßR1 in the apoptosis-induction condition of SNU-C5/5-FU. To examine whether LS-1 can induce apoptosis via the activation of TGF-ß signaling, the SNU-C5/5-FU cells were treated with LS-1 in the presence or absence of SB525334, a TGF-ßRI kinase inhibitor. SB525334 inhibited the effect of LS-1 on the apoptosis induction. These findings provide evidence demonstrating that the apoptosis-induction effect of LS-1 results from the activation of the TGF-ß pathway via the downregulation of CEA in SNU-C5/5-FU.

Bilateral variations of musculocutaneous nerves with rare pattern in a Korean female cadaver.

Bilateral variations in the formation and branching of brachial plexus are rare. Variations between median and musculocutaneous nerves were observed on both sides during the dissection of an 87-year-old Korean female cadaver, whose cause of death was cholangiocarcinoma. The variations found were bilateral, in which each musculocutaneous nerve did not pierce the coracobrachialis muscle. The musculocutaneous nerve was rudimentary in the right arm and all branches arose from the median nerve separately, which corresponds to previous classification type 0-2. In the case of the left arm, the musculocutaneous nerve originated from the lateral cord, but had connections between median and musculocutaneous nerves below the coracobrachialis muscle, which corresponds to previous classification type 1-B-2. To the best of our knowledge, the bilateral variations between median and musculocutaneous nerves in this case have different features from other previous reports. Awareness of the possible variations between median and musculocutaneous nerves is important to both anatomists and clinicians.