The catalytic subunit of DNA-dependent protein kinase (DNA-PKcs) plays an important role in DNA double-strand break (DSB) repair as the underlying mechanism of the nonhomologous end joining pathway. When DSBs occur, DNAPKcs is rapidly phosphorylated at both the Thr-2609 and Ser-2056 residues, and such phosphorylations are critical for DSB repair. In this study we report that, in addition to responding to DSBs, DNA-PKcs is activated and phosphorylated in normal cell cycle progression through mitosis. Mitotic induction of DNAPKcs phosphorylation is closely associated with the spindle apparatus at centrosomes and kinetochores. Furthermore, depletion of DNA-PKcs protein levels or inhibition of DNAPKcs kinase activity results in the delay of mitotic transition because of chromosome misalignment. These results demonstrate for the first time that DNA-PKcs, in addition to its role in DSB repair, is a critical regulator of mitosis and could modulate microtubule dynamics in chromosome segregation. DNA-PKcs,3 the catalytic subunit of DNA-dependent protein kinase (DNA-PK), is known to play an essential role in non-homologous end joining-mediated DNA double-strand break (DSB) repair in mammalian cells. In response to DSBs, the Ku70/80 subunits of DNA-PK immediately bind to the broken DSB ends and subsequently recruit and activate DNA-PKcs kinase activity (1). The intrinsic kinase activity of DNA-PKcs is essential for its role in DSB repair (2), likely through phosphorylation and regulation of non-homologous end joining components, including DNA-PKcs itself. DNA-PKcs is rapidly autophosphorylated in vitro upon activation and is also phosphorylated in vivo after exposure to ionizing radiation (IR). Among all the phosphorylation sites identified (3-6), phosphorylation in vivo was clearly detected at the Ser-2056 residue and at the Thr-2609 cluster region (3,7,8). Whereas IR-induced DNA-PKcs phosphorylation at Ser-2056 is clearly mediated by the autophosphorylation of DNA-PKcs (7), IR-induced DNAPKcs phosphorylation at the Thr-2609 cluster is mainly dependent on ataxia telangiectasia mutated (ATM) kinase but not DNA-PKcs itself (8). In addition, the Thr-2609 cluster region can be phosphorylated by ATR kinase in response to UV irradiation or replication stresses (9). Although the precise mechanism of DNA-PKcs phosphorylation remains to be clarified, like its kinase activity, DNA-PKcs phosphorylation at Ser-2056 and the Thr-2609 cluster are required for DSB repair.In addition to its roles in DNA damage response, DNA-PKcsmediated DSB repair is required for V(D)J recombination during T-and B-cell maturation (10). Recently, it has also been reported that DNA-PKcs phosphorylates and activates the upstream stimulatory factor, which in turn regulates the expression of fatty acid synthase in response to feeding (11). In contrast to the well studied role of DNA-PKcs in DSB repair, not much is known about the involvement of DNA-PKcs kinase and its phosphorylations in other cellular activities, particularly under normal conditions. While an...

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Curcumin has been reported to exhibit anti-invasive and/or antimetastatic activities, but the mechanism remains unclear. In this study, microarray analysis of gene expression profiles were used to characterize the anti-invasive mechanisms of curcumin in highly invasive lung adenocarcinoma cells (CL1-5). Results showed that curcumin significantly reduces the invasive capacity of CL1-5 cells in a concentration range far below its levels of cytotoxicity (20 M) and that this anti-invasive effect was concentration dependent (10.17 Ϯ 0.76 ϫ 10 3 cells at 0 M; 5.67 Ϯ 1.53 ϫ 10 3 cells at 1 M; 2.67 Ϯ 0.58 ϫ 10 3 cells at 5 M; 1.15 Ϯ 1.03 ϫ 10 3 cells at 10 M; P Ͻ 0.05) in the Transwell cell culture chamber assay. Using microarray analysis, 81 genes were down-regulated and 71 genes were up-regulated after curcumin treatment. Below sublethal concentrations of curcumin (10 M), several invasion-related genes were suppressed, including matrix metalloproteinase 14 (MMP14; 0.65-fold), neuronal cell adhesion molecule (0.54-fold), and integrins ␣6 (0.67-fold) and ␤4 (0.63-fold). In addition, several heatshock proteins (Hsp) [Hsp27 (2.78-fold), Hsp70 (3.75-fold), and Hsp40-like protein (3.21-fold)] were induced by curcumin. Realtime quantitative reverse transcription-polymerase chain reaction, Western blotting, and immunohistochemistry confirmed these results in both RNA and protein levels. Curcumin (1 to 10 M) reduced the MMP14 expression in both mRNA and protein levels and also inhibited the activity of MMP2, the down-stream gelatinase of MMP14, by gelatin zymographic analysis. Based on these data, it can be concluded that curcumin might be an effective antimetastatic agent with a mechanism of anti-invasion via the regulation of certain gene expressions.Curcumin, or diferuloylmethane, is a major chemical component of turmeric (Curcuma longa) and is used as a spice to give a specific flavor and yellow color to curry. It is also used as a cosmetic and in some medical preparations (Govindarajan, 1980). Curcumin has been shown to display anticarcinogenic properties in animals, as indicated by its ability to inhibit phorbol ester-induced skin tumors in a mouse model system (Huang et al., 1988). In addition to its anticarcinogenic effect, curcumin is also shown to exhibit anti-inflammatory, antiproliferative, antiangiogenic, and antioxidant properties . These effects of curcumin may be mediated by its inhibitory effect on a host of cell-signaling factors, including AP-1 transcription factor, c-Myc, Egr-1, NF-B, protein kinase C, epidermal growth factor receptor tyrosine kinase, c-Jun N-terminal kinase, protein tyrosine kinases, protein serine/threonine kinases, and IB kinase (Huang et al., 1988;Hong et al., 1999;Lin et al., 2000). In our previous study, it was also found that curcumin could inhibit cell cycle progression and induce cell apoptosis by regulating the gene expression of c-myc and bcl-2 (Chen and Huang, 1998).

IGF2BP3 enhances cell invasion ability and tumorigenicity in human OSCC in vitro and in vivo. IGF2BP3 is an independent prognostic factor in patients with OSCC. Targeting of IGF2BP3 could potentially suppress the tumor growth and metastasis to improve the outcome of patients with OSCC.

If metastasis of lung cancer can be found and treated early, a victim might have an improved chance to prevail over it, but routine examinations such as chest radiography, computed tomography and biopsy cannot characterize the metastatic potential of lung cancer cells; critical diagnoses to define optimal therapeutic strategies are thus lost. We designed a portable microfluidic device for the rapid diagnosis of cancer metastatic potential. Featuring a micro system to control temperature and a bicarbonate buffered environment, our device discriminates a rate of surface detachment as an index of the migratory ability of cells cultured on pH-responsive chitosan. We labeled metastatic subpopulations of lung cancer cell lines, and verified that our device is capable of separating cells according to their metastatic ability. As only few cells are needed, a patient's specimen from biopsies, e.g. from fine-needle aspiration, can be processed on site to offer immediate information to physicians. We expect that our design will provide valuable information in pre-operative evaluations to assist the definition of therapeutic plans for lung cancer, as well as for metastatic tumors of other types.