| Objective: Oral and maxillofacial tumor is the importantcomposition within tumor of head and neck. The usualclassification is squamous cell carcinoma (SCC) in oral andmaxillofacial malignant tumor in our country. At present, thebest method against oral squamous cell carcinoma (OSCC) isgiving one cycle chemotherapy first, then operation, at lastradiotherapy and Chinese traditional medicines. Because thechemotherapy before operation can obviously improve thesurvival rate of OSCCs, improving the effectiveness ofchemotherapy and declining the recurrent rate are becoming oneof the most important tasks against OSCCs. Recently, someresearchs show that one of the important reasons of failuring tochemotherapy is the resistance of tumor cells tochemotherapentic agent. There are some reasons about how thetumor cells can acquire the resistance, the most common reasonis the Multidrug Resistance(MDR). Some research about MDRcarried out in other countries and it was connected with theclinical practices. But this study is only at the beginning in ourcountry. The conception of MDR is: When the tumor cellsacquired drug resistance to one anti-tumor drug, at the sametime, they got drug resistance to other chemotherapy drugswhich had different constructors and mechanisms. This is aspecial wide-ranch resistance drugs phenomenon. Theexpression of multidrug resistance gene is related to thephenomenon. It can express the P-glucoprotein on the cellmembrane, so the drugs can be pumped out of the cells, theconcentration of this drugs will be reduced. Squamous cellcarcinoma is the familiar malignant tumor in oral maxillofacialtissues. This experience is to investigate the expression ofmultidrug resistant gene(mdr1) in OSCC tissues before and afterpingyangmycin chemotherapy and adjacent normal tissues, thento evaluate the influence of chemotherapy on the expression ofmdr1 in OSCCs.Methods: All samples were excised from the patients whowere accepted treatment from 2003.3 to 2004.7 in department ofStomatology, the Fourth Hospital of Hebei Medical University.All samples included 31 cases of OSCCs and their adjacentnormal tissues. All of them did not received any kind oftreatments before then and received one cycle chemotherapybefore operation. They were extracted and testified by steadypathologist. The examples were obtained before and afterchemotherapy, and 9 cases oral normal mucosa tissues beforechemotherapy as the contrastment. They were conserved in -80℃. According to the growth position, there were 15 carcinomasof tongue, 4 carcinomas of palate, 7 carcinomas of gingival, 5carcinomas of floor of mouth. According to the differentiation,they were 18 well-differentiated squamous cell carcinomas(SCCs), 13 mid and low-differentiated SCCs. Reverse-transcription polymerase chain reaction (RT-PCR) was used toinvestigate mdr1 gene expression in all samples including theoral normal mucosa tissues and the OSCCs before and afterpingyangmycin chemotherapy.Results: In contral group, it was found that themdr1mRNA activity was positive in 2 of 9 in oral normalmucosa tissues, the expression rate was 22.2%. Mdr1mRNAexpression rate was 35.5%(11/31)and 42.0%(13/31)in OSCCbefore and after pingyangmycin chemotherapy respectivety(P>0.05), there was no significant difference between them(Tab.1). Mdr1mRNA expression rate was 38.9% (7/18) in well-differentiated squamous cell carcinomas (SCCs)and it was30.8%(4/13)in mid-differentiated and low-differentiated SCCsbefore pingyangmycin chemotherapy (P>0.05),there was nosignificant difference between them (Tab.2). Mdr1mRNAexpression rate were 44.4%(8/18)and 38.5% (5/13)in well-differentiated SCCs and mid/low-differentiated SCCs afterpingyangmycin chemotherapy (P>0.05), they had no significantdifference after statistical analysis (Tab.3). Mdr1mRNAexpression rate were 38.9% (7/18)and 44.4%(8/18)in well-differentiated SCCs before and after pingyangmycinchemotherapy respectivety (P>0.05), no significant difference(Tab.4). Mdr1mRNA expression rate were 30.8%(4/13)and38.5%(5/13)in mid/low-differentiated SCCs before and after... |
PDF Full Text Request