Visfatin and Resveratrol Differentially Regulate the Expression of Thymidylate Synthase to Control the Sensitivity of Human Colorectal Cancer Cells to Capecitabine Cytotoxicity

Colorectal cancer (CRC) is a highly lethal malignant cancer. Capecitabine, a 5-fluororacil (5-FU) derivate, is its first-line drug, but the resistance of CRC to capecitabine is still the most challenging factor for curing patients. It has been suggested that thymidylate synthase (TYMS) level might affect the capecitabine efficacy in CRC patients, but the mechanism still needs more elucidation. Obesity is a risk factor for CRC. Recently, a correlation between serum visfatin, an obesity-elicited adipokine, and CRC development has been found. Thus, the aim of present study is to examine the visfatin capacity in TYMS expression and in the development of capecitabine resistance of CRC. Moreover, an attractive natural component, i.e., resveratrol, has been proposed in anticancer therapy and has hence been examined in the present study to see its potential capacity in the alleviation of CRC resistance. Our results found that visfatin significantly reduces the CRC sensitivity to capecitabine by controlling the TYMS expression via p38 signaling and Sp1 transcription factor. Moreover, resveratrol could significantly alleviate the visfatin effect on capecitabine-treated CRC cells. These results provided new insights to understand the capecitabine susceptibility of CRC under a visfatin-containing environment and a possible therapeutic application of resveratrol in CRC patients with obesity.

Exploring the Phytochemicals of Acacia melanoxylon R. Br.

Invasive species are currently a world menace to the environment, although the study of their chemistry may provide a means for their future beneficial use. From a study of Portuguese Acacia melanoxylon R. Br. five known compounds were isolated: lupeol, 3β-Z-coumaroyl lupeol, 3β-E-coumaroyl lupeol (dioslupecin A), kolavic acid 15-methyl ester and vomifoliol (blumenol A). Their structures were elucidated by 1D and 2D NMR spectroscopy and mass spectrometry, and as a result some corrections are made to their previous 13C NMR assignments. Cytotoxicity of 3β-E-coumaroyl lupeol (dioslupecin A) and kolavic acid 15-methyl ester was evaluated against HCT116 human colorectal cancer cells although biological activity was not evident.

Silencing of HOTAIR Induced Apoptosis in Human Colorectal Cancer Cells through Up-Regulation of Bax and Down-Regulation of Bcl2

: HOX transcript antisense RNA (HOTAIR), as a long noncoding RNA (lncRNA) is a highly cited transcript modulating variety of signaling pathways such as cell growth and apoptosis. Altered expression of HOTAIR has been reported in human cancers, which contributes with cancer progression and metastasis. Increased expression level of HOTAIR has been observed in colorectal cancer (CRC). It seems that dysregulation of HOTAIR may inhibit the apoptosis. The present study was aimed to evaluate the effect of HOTAIR silencing on expression of apoptosis markers Bax and Bcl2 using real-time polymerase chain reaction (PCR). The data showed that HOTAIR and Bcl2 are highly expressed in CRC cells while the expression level of Bax is low. Following siRNA treatment, Blc2 was downregulated but Bcl2 was upregulated. These findings suggest that HOTAIR silencing can promote apoptosis, and thus it can be considered as a promising strategy to kill cancer cells.