Kruppel-like Factors 3 Regulates Migration and Invasion of Gastric Cancer Cells Through NF-κB Pathway.

Context: The poorly understood regulatory mechanisms impede gastric cancer therapy. Kruppel-like factors (KLFs) are associated with the development of various tumors, The studies on the role of the KLF transcription factor 13 (KLF13) in gastric cancer progression haven't been studied. Objective: The current study aimed to investigate the role of KLF13 in the migration and invasion of gastric cancer and the regulatory mechanism of KLF13 in gastric cancer progression. Design: The research team performed a laboratory study. Setting: The study took place at the Zengcheng District People's Hospital of Guangzhou in Zengcheng, China. Participants: In addition to using normal gastric cells, GES1, and seven gastric cancer cell lines, the research team compared the fresh, gastric cancer tissues (T) and paired, adjacent, noncancerous gastric tissues (ANT) from eight patients undergoing surgical resection at the hospital. The research team also downloaded the data for 33 gastric cancer tissues and adjacent, normal gastric tissues from the Cancer Genome Atlas' TCGA database. Intervention: The research team used: (1) short hairpin RNAs (shRNAs) to knock down KLF13, (2) wound healing and transwell invasion analyses to determine the effects of KLF13 on the migration and invasion of gastric cancer, and (3) a Luciferase reporter assay to determine the effects of KLF13 on nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activity. Results: KLF13 was upregulated in gastric cancer cells and tissues, and the patients with a high KLF13 expression had poor outcome. Downregulation of KLF13 significantly inhibited the migration and invasion of gastric cancer cells. Mechanistically, downregulation of KLF13 significantly inhibited NF-κB activity, and its targets such as: (1) snail family transcriptional repressor 1 (SNAI1 or Snail), (2) snail family transcriptional repressor 2 (SNAI2 or Slug), (3) zinc finger e-box binding homeobox 1 (ZEB1), (4) Smad interacting protein 1 (Sip1), (5) twist family basic helix-loop-helix (BHLH) transcription factor (Twist), (6) matrix metallopeptidase 2 (MMP2), and (7) MMP9. Tumor necrosis factor alpha (TNF-α) can activate NF-κB. Treating with TNF-α can reverse the effects of KLF13 downregulation on migration and invasion, confirming that KLF13 promotes the migration and invasion of gastric cancer cells through activating the NF-κB pathway. Conclusions: KLF13 promoted the migration and invasion of gastric cancer cells through activating the NF-κB pathway, providing a new target for gastric cancer therapy.

L-carnitine ameliorates the muscle wasting of cancer cachexia through the AKT/FOXO3a/MaFbx axis.

BACKGROUND: Recent studies suggest potential benefits of applying L-carnitine in the treatment of cancer cachexia, but the precise mechanisms underlying these benefits remain unknown. This study was conducted to determine the mechanism by which L-carnitine reduces cancer cachexia. METHODS: C2C12 cells were differentiated into myotubes by growing them in DMEM for 24 h (hrs) and then changing the media to DMEM supplemented with 2% horse serum. Differentiated myotubes were treated for 2 h with TNF-α to establish a muscle atrophy cell model. After treated with L-carnitine, protein expression of MuRF1, MaFbx, FOXO3, p-FOXO3a, Akt, p-Akt, p70S6K and p-p70S6K was determined by Western blotting. Then siRNA-Akt was used to determine that L-carnitine ameliorated cancer cachexia via the Akt/FOXO3/MaFbx. In vivo, the cancer cachexia model was established by subcutaneously transplanting CT26 cells into the left flanks of the BALB/c nude mice. After treated with L-carnitine, serum levels of IL-1, IL-6 and TNF-α, and the skeletal muscle content of MuRF1, MaFbx, FOXO3, p-FOXO3a, Akt, p-Akt, p70S6K and p-p70S6K were measured. RESULTS: L-carnitine increased the gastrocnemius muscle (GM) weight in the CT26-bearing cachexia mouse model and the cross-sectional fiber area of the GM and myotube diameters of C2C12 cells treated with TNF-α. Additionally, L-carnitine reduced the protein expression of MuRF1, MaFbx and FOXO3a, and increased the p-FOXO3a level in vivo and in vitro. Inhibition of Akt, upstream of FOXO3a, reversed the effects of L-carnitine on the FOXO3a/MaFbx pathway and myotube diameters, without affecting FOXO3a/MuRF-1. In addition to regulating the ubiquitination of muscle proteins, L-carnitine also increased the levels of p-p70S6K and p70S6K, which are involved in protein synthesis. Akt inhibition did not reverse the effects of L-carnitine on p70S6K and p-p70S6K. Hence, L-carnitine ameliorated cancer cachexia via the Akt/FOXO3/MaFbx and p70S6K pathways. Moreover, L-carnitine reduced the serum levels of IL-1 and IL-6, factors known to induce cancer cachexia. However, there were minimal effects on TNF-α, another inducer of cachexia, in the in vivo model. CONCLUSION: These results revealed a novel mechanism by which L-carnitine protects muscle cells and reduces inflammation related to cancer cachexia.

Multivitamin and mineral supplementation is associated with the reduction of fracture risk and hospitalization rate in Chinese adult males: a randomized controlled study.

Controversy exists in the literature regarding the efficacy of bone health-related nutrients, especially calcium and vitamin D, in preventing fractures. The aim of our present study was to determine the effect of multivitamin and mineral supplementation on fracture incidence among 3,318 participants from a nutritional intervention trial in Linxian, China. A total of 1,461 men and 1,857 women were enrolled and randomized to daily supplementation with 26 vitamins and minerals tablet or placebo pills for 6 years, followed by a 16-year post-interventional follow-up. The dates, sites, and causes of the fractures were collected retrospectively via a standardized questionnaire. Cox proportional hazard model was used to estimate hazard ratios and 95% confidence intervals of fracture incidence in the intervention versus the placebo group. A total of 221 fractures (57 in men and 164 in women) occurred during the entire study period of 21 years and 9 months. In men, the supplement reduced the risk of fracture by 63% during the trial period, and this protective effect was sustained and statistically significant when analysis included both the trial period and 5- or 10-year post-intervention follow-up (years 0-11, P = 0.04; years 0-16, P = 0.02, respectively). The protection against fracture was not apparent >10 years after cessation of the intervention. In women, no significant effect of supplementation on fracture incidence was seen in any of the study periods. These results demonstrate that a 6-year multivitamin and mineral intervention was associated with significant reduction of fracture risk and fracture-related hospitalization in men, but not in women.