A novel resveratrol derivative selectively inhibits the proliferation of colorectal cancer cells with KRAS mutation.

Resveratrol is a polyphenolic compound in many edible foods including grapes, peanuts, and berries. Several studies have revealed the beneficial effects of resveratrol against various diseases such as heart disease, diabetes, obesity, neurological disorders, and cancer. A recent study showed that resveratrol inhibits the proliferation of HCT116 human colorectal cancer cells in three-dimensional culture (3DC) via induction of luminal apoptosis in HCT116 cell spheroids. In this study, we showed that a novel compound, caffeic acid-adducted resveratrol, has a stronger inhibitory effect on the growth of HCT116 cell spheroids in 3DC than resveratrol. It showed almost the same inhibitory efficacy as 5-fluorouracil, a conventional anticancer drug. We further showed that the resveratrol derivative did not affect the growth of HKe3 cell spheroids derived from HCT116 cells by disruption of the activating mutant KRAS gene. These results suggest that the resveratrol derivative inhibits the growth of HCT116 cell spheroids via inhibition of an oncogenic KRAS-mediated signaling pathway.

ANRIL regulates the proliferation of human colorectal cancer cells in both two- and three-dimensional culture.

ANRIL is a long noncoding RNA transcribed from the INK4 locus that encodes three tumor suppressor genes, p15, p16, and ARF. Previous studies demonstrated that ANRIL represses p15 and p16, which positively regulate the pRB pathway, leading to repression of cellular senescence of human normal fibroblasts. However, the role of ANRIL in cancer cell proliferation is less well understood. Here we report that ANRIL is involved in the proliferation of colorectal cancer HCT116 cells in two- and three-dimensional culture. Silencing ANRIL by both transfection with small interfering RNA and retrovirally produced small hairpin RNA reduced HCT116 cell proliferation in both two- and three-dimensional culture. HCT116 cells depleted for ANRIL were arrested in the S phase of cell cycle. Notably, silencing ANRIL did not result in the activation of expression of the INK4 locus. These results suggest that ANRIL positively regulates the proliferation of HCT116 cells in two- and three-dimensional culture in a p15/p16-pRB pathway-independent manner.

Laterality of asymmetry in movements of the corners of the mouth during voluntary smile.

OBJECTIVES: To examine (1) the laterality of asymmetry in movements of the right and left corners of the mouth in space during voluntary smile and (2) the laterality of asymmetry in relation to the difference between the right and left hemiface size and the handedness. MATERIALS AND METHODS: Participants were 155 volunteer Japanese female adults. They were categorized into the symmetric group (n = 120) and the right-side hemiface dominant group (n = 26) according to the hemiface size. In addition, the symmetric group was categorized into the right-handed group (n = 98) and the left-handed group (n = 22) according to the Edinburgh Handedness Inventory. Position vectors of the right and left corners of the mouth were obtained from the three-dimensional facial images for the rest, the maximal lip corner retraction, and the portrait smile. The displacements of the right and left corners of the mouth for each expression and the proportions of the subjects with the right- and left-sided laterality were compared. RESULTS: The left corner of the mouth showed significantly greater displacement (P < .01) than the right in the symmetric group for the portrait smile. The left-sided laterality was found regardless of the handedness. CONCLUSIONS: Displacements of the right and left corners of the mouth during voluntary smile were asymmetric, and the left-sided laterality was found. Also, the laterality of the facedness differed in relation to the hemiface size, but was not related to the handedness.

Long Noncoding RNA PANDA Positively Regulates Proliferation of Osteosarcoma Cells.

BACKGROUND: A long noncoding RNA, p21-associated ncRNA DNA damage-activated (PANDA), associates with nuclear transcription factor Y subunit alpha (NF-YA) and inhibits its binding to promoters of apoptosis-related genes, thereby repressing apoptosis in normal human fibroblasts. Here, we show that PANDA is involved in regulating proliferation in the U2OS human osteosarcoma cell line. MATERIALS AND METHODS: U2OS cells were transfected with siRNAs against PANDA 72 h later and they were subjected to reverse transcription-polymerase chain reaction (RT-PCR), quantitative RT-PCR and cell-cycle analysis. RESULTS: PANDA was highly expressed in U2OS cells, and its expression was induced by DNA damage. Silencing PANDA caused arrest at the G1 phase of the cell cycle, leading to inhibition of cell proliferation. Quantitative RT-PCR showed that silencing PANDA increased mRNA levels of the cyclin-dependent kinase inhibitor p18, which caused G1 phase arrest. CONCLUSION: These results suggest that PANDA promotes G1-S transition by repressing p18 transcription, and thus promotes U2OS cell proliferation.

Long Noncoding RNA ANRIL Regulates Proliferation of Non-small Cell Lung Cancer and Cervical Cancer Cells.

BACKGROUND: Long noncoding RNA ANRIL (antisense non-coding RNA in the INK4 locus) represses p15 and p16, which induce cell-cycle arrest at G1 phase, leading to enhanced cell proliferation of normal fibroblasts. Herein we report that ANRIL is also involved in the regulation of cancer-cell proliferation. MATERIALS AND METHODS: HeLa and H1299 cells were transfected with ANRIL siRNAs. At 72 h post-transfection, cells were subjected to quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and cell-cycle analysis. RESULTS: qRT-PCR showed that ANRIL is highly expressed in these cancer cells compared to normal fibroblasts. Depletion of ANRIL increased p15 expression, with no impact on p16 or ARF (alternative reading frame) expression, and caused cell-cycle arrest at the G2/M phase, leading to inhibition of proliferation of H1299 and HeLa cells. CONCLUSION: ANRIL positively regulates the proliferation of cancer cells, such as H1299 and HeLa cells, via regulating p15 and other genes related to G2/M phase control.

Transcriptional Regulation of the p16 Tumor Suppressor Gene.

The p16 tumor suppressor gene encodes a specific inhibitor of cyclin-dependent kinase (CDK) 4 and 6 and is found altered in a wide range of human cancers. p16 plays a pivotal role in tumor suppressor networks through inducing cellular senescence that acts as a barrier to cellular transformation by oncogenic signals. p16 protein is relatively stable and its expression is primary regulated by transcriptional control. Polycomb group (PcG) proteins associate with the p16 locus in a long non-coding RNA, ANRIL-dependent manner, leading to repression of p16 transcription. YB1, a transcription factor, also represses the p16 transcription through direct association with its promoter region. Conversely, the transcription factors Ets1/2 and histone H3K4 methyltransferase MLL1 directly bind to the p16 locus and mediate p16 induction during replicative and premature senescence. In the present review, we discuss the molecular mechanisms by which these factors regulate p16 transcription.