Capsaicin induces apoptosis and terminal differentiation in human glioma A172 cells.

Capsaicin (8-methyl-N-vanillyl-6-nonenamide), the major pungent ingredient of red pepper, has been reported to possess anti-carcinogenic and anti-mutagenic activities. In this study, the effects of capsaicin on human glioblastoma A172 cells were investigated. Treatment of A172 cells with capsaicin inhibited cell growth and induced apoptosis through down-regulation of Bcl-2 and activation of caspase-3. Interestingly, synergistic induction of morphological alternation was observed when A172 cells were treated with capsaicin. A double immunostaining analysis indicated that capsaicin stimulated terminal differentiation predominantly to astrocyte-like cells. Moreover, capsaicin increased the transcription levels of glial fibrillary acidic protein (GFAP) and neuronal microtubule-associated protein 2ab (MAP2ab). These results demonstrated that capsaicin inhibits A172 cell growth through apoptosis and terminal differentiation. Consequently, this research may provide further support for capsaicin-based anti-tumor therapies and consideration should be given to developing capsaicin for use in chemotherapy for malignant human glioblastoma.

Diameter of vessels across the tonsillar capsule as an anatomical consideration for tonsillectomy.

The authors measured the diameters of vessels around the surgical plane of tonsillectomy to investigate an anatomical basis to reduce hemorrhage. Thirty tonsils removed from 15 adult cadavers with the mean age of 56 years (range 44-71 years) at the time of death were studied. Calibration of the vessels across the tonsillar capsule was performed at the 1-mm intracapsular, capsular, and 1-mm extracapsular plane as artery and vein, respectively. The average diameter of the arteries was 73.0 +/- 33.1 mum at the 1-mm intracapsular plane, 94.7 +/- 33.5 mum at the capsular plane, and 139.5 +/- 51.2 mum at the 1-mm extracapsular plane. For the veins, it was 62.9 +/- 38.7 mum at the 1-mm intracapsular plane, 86.8 +/- 50.4 mum at the capsular plane, and 133.6 +/- 78.6 mum at the 1-mm extracapsular plane. The diameters of the vessels at the 1-mm intracapsular plane were significantly smaller than those at the capsular plane (P < 0.01), and likewise the diameters of the vessels at the capsular plane were significantly smaller than those at the 1-mm extracapsular plane (P < 0.01). The result of this study on the diameter of the vessels across the tonsillar capsule could be considered to be an important factor providing an anatomical rationale for a change in recommendation leading to safer tonsillectomies that minimize vascular injury.

Glycoconjugates of the gastric mucosa in cold-treated chipmunks.

During seasonal hibernation, there is reduced gastrointestinal activity, but relatively little is known of the physiology involved. In the present experimental study, male Korean chipmunks (Tamias sibiricus barberi) were maintained in cold conditions (6 degrees C) for 3, 5 or 9 months to mimic conditions occurring during seasonal hibernation. Changes in the composition of glycoconjugates (Gcs) of the gastric mucosa were determined after cold-treatment. Cold-treated chipmunks, in comparison with warm control animals, revealed a thinner layer of Gcs on the free surface gastric epithelium with reduced depth of their pits. Cold-treated chipmunks showed similar staining patterns and lectin affinity for Gcs as compared with warm control animals. After long-term cold treatment, reduction in the amounts of Gcs were more severe in gastric pit epithelium and glandular mucous cells than in the free surface gastric epithelium. A significant reduction in immunostaining of nitric oxide synthase (NOS) was also observed in chipmunks after long-term cold-treatment. The changes in Gcs and NOS staining patterns may be interpreted in relation with a continued but reduced functioning of the gastric mucosa throughout hibernation. However, the findings in the present experimental model for hibernation, which shows significant changes in Gcs and NOS staining patterns, need to be demonstrated during seasonal hibernation in the wild.

Pseudomonas aeruginosa exotoxin A reduces chemoresistance of oral squamous carcinoma cell via inhibition of heat shock proteins 70 (HSP70).

PURPOSE: Oral squamous carcinoma (OSCC) cells exhibit resistance to chemotherapeutic agent-mediated apoptosis in the late stage of malignancy. Increased levels of heat shock proteins 70 (HSP70) in cancer cells are known to confer resistance to apoptosis. Since recent advances in the understanding of bacterial toxins have produced new strategies for the treatment of cancers, we investigated the effect of Pseudomonas aeruginosa exotoxin A (PEA) on HSP70 expression and induction of apoptosis in chemoresistant OSCC cell line (YD-9). MATERIALS AND METHODS: The apoptotic effect of PEA on chemoresistant YD-9 cells was confirmed by MTT, Hoechst and TUNEL stains, DNA electrophoresis, and Western blot analysis. RESULTS: While YD-9 cells showed high resistance to chemotherapeutic agents such as etoposide and 5-fluorouraci (5-FU), HSP70 antisense oligonucelotides sensitized chemoresistant YD-9 cells to etoposide and 5-FU. On the other hand, PEA significantly decreased the viability of YD-9 cells by deteriorating the HSP70-relating protecting system through inhibition of HSP70 expression and inducing apoptosis in YD-9 cells. Apoptotic manifestations were evidenced by changes in nuclear morphology, generation of DNA fragmentation, and activation of caspases. While p53, p21, and E2F-1 were upregulated, cdk2 and cyclin B were downregulated by PEA treatment, suggesting that PEA caused cell cycle arrest at the G2/M checkpoint. CONCLUSION: Therefore, these results indicate that PEA reduced the chemoresistance through inhibition of HSP70 expression and also induced apoptosis in chemoresistant YD-9 cells.