Recently, CSE1L was shown to be associated with a subset of p53 target promoters, and reduced CSE1L mTOR inhibitor expression decreased 53-mediated transcription and lowered apoptosis [31]. p53 is known to be able to promote the expression of cell-cycle arrest target genes while enhancing the transactivation of proapoptotic genes [61]. Therefore, that report further suggested that although CSE1L definitely plays an important role in cancer progression, it does not stimulate cancer proliferation. Finally, CSE1L is highly, not barely, expressed in cancer. However, studies reporting

Lonafarnib price that human CSE1L (also yeast CSE1) is associated with cell proliferation were only based on the effect of CSE1L reduction or CSE1 deletion on the growth of human or yeast cells. Therefore, it is

inappropriate to use the results of CSE1L reduction experiments to assume that CSE1L JSH-23 can stimulate or increase cancer cell proliferation and draw a conclusion that the role of CSE1L in cancer development is to stimulate cancer proliferation. CSE1L enhances matrix metalloproteinase-2 secretion and increases cancer cell invasion Increased CSE1L expression is unable to enhance the proliferation of cancer cells, thus CSE1L may promote cancer progression by other mechanisms. A pathological study by Brustmann et al. reported that the immunoreactivity of CSE1L was positively related to high cancer grade (p = 0.0107) and adverse outcomes (p = 0.0035) in serous ovarian carcinoma [44]. By studying 89 samples of endometrial carcinomas and 56 samples of the non-neoplastic adjacent endometrium, Peiro et al. reported that CSE1L expression was higher in grade 3 tumors (p = 0.002), and a shorter survival was observed for patients whose tumors

contained > 50% of CSE1L-positive cells (p = 0.04) [22]. A tissue array study composed of 244 serous tumors of different grades (0-3) and stages (I-IV) showed a higher expression of CSE1L in poorly compared to highly differentiated invasive ovarian tumors [46]. The expression of CSE1L was correlated with advanced stages of melanomas and clinical stages according to the UICC which showed an increase CYTH4 from 43% ± 34% of CSE1L in stage I, to 53% ± 26% in stage II, 68% ± 24% in stage III, and 72% ± 24% in stage IV [7]. Heavy CSE1L staining was observed in all of the metastatic melanoma (n = 23) they studied [7]. The results of these pathological studies indicated that the expression of CSE1L was positively related to high cancer stage and worse outcomes of cancer patients. Metastasis is the main characteristic of high cancer stages and is also the main cause of cancer-related mortality. Therefore, CSE1L may regulate the invasion and metastasis of cancer. CSE1L can associate with microtubules [4] and the nuclear-transport receptor, importin-α [62].