High expression levels of nuclear factor kappaB, IkappaB kinase alpha and Akt kinase in squamous cell carcinoma of the oral cavity

Honokiol augments the anti-cancer effects of oxaliplatin in colon cancer cells

Oxaliplatin is an important drug in the chemotherapy of colorectal carcinoma, but its toxicity, especially dose-related neurosensory toxicity, is not well tolerated. In this study, we investigated whether honokiol could augment the anti-tumor effect of oxaliplatin in colon cancer HT-29 cells in vitro and whether honokiol could be used with oxaliplatin to decrease oxaliplatin dose. We used the normal colon cells, human colonic epithelial cells (HCoEpiCs) as control cells. Cell proliferation, apoptosis, prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) levels were also investigated. Expression levels of cyclo-oxygenase 2 (COX-2), VEGF, AKT/p-AKT, extracellular signal-related kinase (ERK)1/2/p-ERK1/2, nuclear factor kappa B (NF-κB) P65/p-P65, and caspase-3 were measured. Honokiol or oxaliplatin suppressed the proliferation of HT-29 cells in a concentration-dependent manner, but only high concentrations of honokiol would suppress the proliferation of HCoEpiCs. HT-29 cells were more sensitive to oxaliplatin treatment in the presence of honokiol. Oxaliplatin combined with honokiol improved the apoptosis rate of HT-29 cell and reduced PGE2 and VEGF secretion levels. Expression levels of COX-2 and VEGF protein and phosphorylation of AKT, ERK1/2, and NF-κB P65 were also inhibited. Caspase-3 levels were upregulated after honokiol treatment. Therefore, honokiol can be used in combination with oxaliplatin in the chemotherapy of colon cancer. This combination allows a reduction in oxaliplatin dose, and thereby reduces its adverse effects. It may also enhance the chemotherapeutic effect of oxaliplatin for this disease.

Expression of nuclear factor-kappa B and target genes in gastric precancerous lesions and adenocarcinoma: Association with Helicobactor pylori cagA (+) infection

AIM: To examine the expression of nuclear factor kappaB (NF-κB) and its target genes in intestinal metaplasia (IM), dysplasia (DYS) and gastric carcinoma (GC) infected with Helicobacter pylori (H pylori) and to investigate the mechanism underlying H pylori cytotoxin associated gene A (cag A) infection leading to gastric adenocarcinoma.

METHODS: Expressions of NF-κB/p65 and its target genes: c-myc, cyclinD1 and bcl-xl were immunohistochemically examined in 289 cases of gastric biopsy and resection specimens from patients with IM, DYS and GC infected with H pylori. H pylori in the above mentioned tissues was detected by Warthin-Starry stain and rapid urease tests. IgG antibody to cagA in sera of the patients was measured by ELISA.

RESULTS: The positive rates of NF-κB/p65 were significantly higher in groups with cagA of IMI-II(28/33), IM III(48/52), DYSI(27/31), DYS II-III(28/32), GC(35/40) than in groups without cagA of IMI-II(4/17), IMIII(3/20), DYSI(3/20), DYSII-III(6/21), GC(10/23). The expressions of c-myc, cyclinD1, and bcl-xl were significantly higher in groups with cagA of IM III(47/52, 49/52, 46/52), DYSII-III(29/32, 26/32, 25/32) than in groups without cagA of IM III(8/20, 7/20, 5/20), DYSII-III(10/21, 8/21, 3/21), which were in conformity with the expression of NF-κB in IM III, and DYSII-III. A significantly higher expression level of NF-κB/p65, c-myc, cyclinD1 and bcl-xl was detected in intestinal type GC(27/28, 18/28, 22/28, 24/28) than in diffuse type GC(8/12, 3/12, 3/12, 6/12), respectively.

CONCLUSION: There may be two different molecular mechanisms in the occurrence of intestinal and diffuse type gastric carcinomas. Intestinal type gastric carcinoma is strongly associated with high expression of c-myc, cyclinD1 and bcl-xl through NF-κB/p65 activated by H pylori cagA. Inhibiting the activity of NF-κB is an effective and promising way to prevent intestinal type gastric carcinoma.