Inhibitory effects of Zengshengping fractions on DMBA-induced buccal pouch carcinogenesis in hamsters / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Zengshengping (ZSP) tablets had inhibitory effects on oral precancerous lesions by reducing the incidence of oral cancer. However, the severe liver toxicity caused by systemic administration of ZSP limits the long-term use of this anti-cancer drug. The purpose of this study was to evaluate the tumor inhibitory effects due to the topical application of extracts from ZSP, a Chinese herbal drug, on 7, 12-dimethlbenz(a)anthracene (DMBA) induced oral tumors in hamsters. The study also investigated the anti-cancer mechanisms of the ZSP extracts on oral carcinogenesis.</p><p><b>METHODS</b>DMBA (0.5%) was applied topically to the buccal pouches of Syrian golden hamsters (6 - 8 weeks old) three times per week for six weeks in order to induce the development of oral tumors. Different fractions of ZSP were either applied topically to the oral tumor lesions or fed orally at varying dosages to animals with oral tumors for 18 weeks. Tumor volume was measured by histopathological examination. Tumor cell proliferation was evaluated by counting BrdU labeled cells and by Western blotting for mitogen-activated protein kinase (MAPK) protein levels. The protein levels of apoptosis marker Caspase-3 and regulator Bcl-2 protein were also measured by Western blotting.</p><p><b>RESULTS</b>Topical application of DMBA to the left pouch of hamsters induced oral tumor formation. Animals treated with DMBA showed a loss in body weight while animals treated with ZSP maintained normal body weights. Both the ZSP n-butanol fraction and water fraction significantly reduced tumor volume by 32.6% (P < 0.01) and 22.9% (P < 0.01) respectively. Topical application of ZSP also markedly decreased the BrdU-positive cell numbers in oral tumor lesions and reduced the expression level of MAPK. In addition, ZSP promoted tumor cell apoptosis by increasing Caspase-3 expression but decreasing Bcl-2 protein production.</p><p><b>CONCLUSION</b>The n-butanol and water fractions of ZSP are effective at inhibiting tumor cell proliferation and stimulating apoptosis in oral cancer suggesting that these fractions have chemopreventive effects on DMBA induced oral carcinogenesis.</p>

Analysis of risk factors for carcinogenesis of oral leukoplakia / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the risk factors for malignant transformation of oral leukoplakia.</p><p><b>METHODS</b>A total of 409 cases with oral leukoplakia was retrospectively analyzed. Single factor test was first performed to examine the associations between oral leukoplakia's histopathological classification and each of risk factors including sex, age, systemic diseases, course of disease, clinical classification, site, size, numbers of lesion, alcohol and tobacco consumption, and symptom. Then the association of these selected factors with oral leukoplakia's histopathological classification was evaluated using multiple logistic regression analysis.</p><p><b>RESULTS</b>Fifty-two cases of all 409 patients with oral leukoplakia (including 9 severe dysplasia) developed oral cancer. The ratio of malignant transformation was 12.7%. Sex, age, clinical type, site and symptom were chosen as risk factors incorporated into the multiple logistic regression models. The risk of mild-moderate dysplasia in female was 2.40 times as high as that in male. The risk of mild-moderate dysplasia of speckled leukoplakia was 2.81 times as high as that of homogeneous leukoplakia. The risk of mild-moderate dysplasia of dangerous site was 1. 98 times as high as that non-dangerous site. The risk of mild-moderate dysplasia with symptom was 1.84 times as high as that without symptom. The risk of severe dysplasia and oral cancer in female was 3.11 times as high as that in male. The risk of severe dysplasia and oral cancer of speckled (4.50 times), ulcerative (5.63 times), verrucous leukoplakia (4.09 times) were much higher than that of homogeneous leukoplakia. The risk of severe dysplasia and oral cancer in dangerous site was 2.79 times as high as in non-dangerous site. The risk of severe dysplasia and oral cancer in leukoplakia with symptom was 4.38 times as high as without symptom.</p><p><b>CONCLUSIONS</b>The malignant transformation of oral leukoplakia is correlated to sex, clinical type, site and symptom.</p>