| This paper is composed of following two parts.PART ONE Gap junctional intercellular characteristics in nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT transgenic mice and its association with the precancerous lesion in nasopharyngeal epitheliaObjective:To investigate the characteristics of GJIC in nasopharyngeal epithelia of TgN(p53mt-LMP1)/HTcorrelation and its association with the precancerous lesion in nasopharyngeal epithelia.Methods:Included in this part of study were 36 animals randomly chosen from the generation of G10 TgN(p53mt-LMP1)/HT transgenic mice at the month age of 12th,15th and 18th respectively with positively expressed p53 and LMP1 activities, divided into 3 groups with 12 mice in each. Another 3 groups of wild mice in the same strain were taken as the negative control group, with the same age animals in each group and at the same month age as well respectively. Then, their nasopharyngeal mucosa membrane was taken to prepare tissue samples. The morphological changes and cell gap junction of nasopharyngeal epithelia were observed under light microscope and transmission electronic microscope at the same time. The expressive activities of Cx43, Cx32, Cx26 proteins and their responsible mRNA were detected by immunohistochemistry, western blot and reverse transcription polymerase chain reaction (RT-PCR), respectively.Results:An obviously increased tendency of precancerous lesions in the nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT transgenic mice was shown with the increase of the age, and the shape of nuclear and mitochondrial was abnormal as shown by the electronic microscopy. Meanwhile, the increased intercellular space, reduced cell junction length and decreased cell junction number were observed obviously, with the increasing of the age. There was a decreasing tendency seen in the expressive activities of Cx43, Cx32, Cx26 proteins and their responsible mRNA in these tissue samples. The expression of Cx43, Cx32, Cx26 proteins in the animals at the age of 15th and 18th was significantly lower than those at the age of 12th month (P<0.05). There was no statistical significance of the expression of Cx43, Cx32, Cx26 proteins and their responsible mRNA in the transgenic mice at the age of 15th and 18th(P> 0.05). The expression level of Cx43,Cx32,Cx26 protein and mRNA were decreased significantly compared with the wild groups at the same age (P<0.05). The correlation anlysis of Cx43,Cx32,Cx26 of the groups of the transgenics mice: Cx43-Cx32, Cx43-Cx26, Cx32-Cx26 were positive correlation (P<0.05). Conclusions:It can be concluded that the developing process of precancerous lesion in nasopharyngeal epithelia was possibly associated with the decreased expressive activity of Cx43, Cx32, Cx26 proteins and their responsible mRNA. Indeed, the carcinogenesis of nasopharyngeal epithelia of TgN (p53mt-LMP1)/ HT transgenic mice may be associated with the increased intercellular space,reduced cell junction length and decreased cell junction number,which lead to deficient or aberrant GJIC in nasopharyngeal epithelia of TgN(p53mt-LMP1)/HT transgenic mice.PART TWO The intervening effect of Qi-boosting toxin-resolving formula on the GJIC in nasopharyngeal epithelia of TgN (p53mt-LMP1)/HT transgenic mice and its affection on the developing process of precancerous lesion in nasopharyngeal epitheliaObjective:To investigate the effect of Qi-Boosting Toxin-Resolving Formula (QBTRF) on the GJIC in nasopharyngeal epithelia of TgN (p53mt-LMP1)/HT transgenic mice and its affection on the developing process of precancerous lesion in nasopharyngeal epithelia. Methods:Seventy two transgenic mice of TgN(p53mt-LMP1)/HT were randomly divided into 3 groups, i.e. modeling group (MG), treating group (QG) with QBTRF and positive controlling group (TG) with tretinoin, with 24 animals in each. All these animals were treated by N, N'-dinitrosopiperazine (DNP), given in a dose of 1.0mg/10 g each time by subcutaneous injection, two times per week and lasted for 14 weeks, with a total injection number of 28 times and without the use of 12-O-tetradecanoylphorbol (TPA) as carcinogenic promoting agent as in routine carcinogenesis-inducing experiment. The animals in MG were treated by 0.2 ml of normal saline in the way of intragastric administration, those in QG were treated by 0.2 ml of concentrated decoction of QBTRF by lavage, and ones in TG treated by 0.062 mg of tretinoin only in the same volume of solution for each mouse, all being treated once each day. Moreover,24 wild mice in the same strain were taken as the normal controlling group (NG), without any additional intervening treatment for them, other than the use of carcinogenesis-inducing agent in the same way as above. Then, these mice were put into death to collect tissue samples from their nasopharyngeal for pathohistological observation of precancerous lesion and expressive activity determination of Cx43, Cx32, Cx26 proteins and their responsible mRNA, respectively.Results:The nasopharyngeal epithelia of MG had the charactstics of malignant by pathohistological and the change of plasma membrane had the structure of pseudopodia. Meanwhile, the increased intercellular space, reduced cell junction length and decreased cell junction number were observed, and the shape and structrue of mitochondrial was abnormal under the electro microscopy. In contrast, those animals in QG, TG and NG had no such changes seen. The expressive levels of Cx43, Cx32, Cx26 proteins and their responsible mRNA were significantly higher in QG than those in MG, TG and NG (P＜0.05). Meanwhile, the expressive levels of proteins Cx43, Cx32, Cx26 and their transcripted mRNA were significantly declined respectively in QG, when compared with that of MG and TG (P＜0.05).Conclusions:The intervening effect of herbal medicine QBTRF on the development of precancerous lesion in nasopharyngeal epithelia of TgN (p53mt-LMP1)/HT may be correlated with the restoration of exogenous connexin expression and GJIC, which may effectively inhibit the proliferating potentiality and actively induce apoptotic activity of nasopharyngeal epithelia. Now GJIC become a potential anti-oncogenic target for cancer prevention and treatment.
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