The major problem in lung cancer chemotherapy is the emergence of inherent and acquired drug resistance of the cancer cells. The cancer becomes resistant not only to the drugs used initially, but also to those to which it has not yet been exposed, This condition is known as multidrug resistance (MDR). MDR has been found to be related to three members of the ABC-superfamily of membrane transport proteins (transporters) and one member of the non-ABC-superfamily of transporter. The formers are P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP), and breast cancer resistance pro-tein (BCRP). The latter is lung resistance-related protein (LRP). These findings provided new molecular targets to predict drug resistance, and an atraumatic detection method by using Tc-99m methoxyisobutyl isonitrile ( 99m Tc-MIBI ) SPECT has been developed for predicting MDR in lung cancer. Based on these transporters, different strategies are tried attempting to reverse drug resistance in lung cancer. Encouraging results have been acquired, but further research is necessary.

Objective To investigate the relationship between hypervariable regionsⅠ(HVRⅠ) mutation of mitochondrial DNA (mtDNA) and lung squamous carcinoma and to explore its significance in carcinogenesis. Methods White blood cells and carcinoma tissues were obtained from 13 cases of lung squamous carcinoma patients and mtDNA were extracted by one step method. HVRⅠfragments were amplified by PCR. Mutations were determined by DNA sequencing. Results In 13 lung squamous carcinoma patients, 8 cases showed mutation in HVR Ⅰ, and 30 mutations were found in 25 different nucleotide sites, in which 17 were point mutations and 13 were insertions and deletions, including a 10-bp deletion in one patient. Conclusion These results suggest that the mutation rate of HVRⅠsequence in lung squamous carcinoma tissue was relatively high, and point mutation might play an important role in lung carcinogenesis.

Objective To explore the silence of B-cell specific Moloney murine leukaemia virus insertion site 1(Bmi-1)by RNA interference on the proliferation of human leukemia cell line K562 and its mechanisms.Methods Small interfering RNA(siRNA)targeting Bmi-1 gene was designed and double-stranded siRNA was chemically synthesized.After double-stranded siRNA was transfected into K562 cells with Lipofectamine 2000,the proliferation of K562 cells was detected by MTT colorimetry,cell cycle was determined by flow cytometry,and the expression of Bmi-1 and P16 were analyzed by Western blotting.Results The siRNA targeting human Bmi-1 gene effectively prolonged the double time of K562 cells,increased the percentage of cells at G1 phase,and the expression of Bmi-1 was significantly down-regulated but the expression of P16 was up-regulated.Conclusion The siRNA targeting human Bmi-1 gene inhibits the proliferation of K562 cells,and up-regulates the expression of P16 in the cells.

Objective To observe the changes of retinal sensitive cellular ultrastructure of rats in critical period of visual development.Methods Ten normal healthy Wistar rats were chosen,eight of which were neonatal rats and two were mature rats.The eight neonatal rats were randomized into four groups(n=2 in each group) and respectively sacrificed on postborn day 0,15,20,25.The eyeballs of the neonatal rats and the mature rats were resected and the retinas were observed by electron microscope.Results The rat retinal sensitive cellular ultrastructure on postborn day 0 was immature and the cellular arrangement was not clear.The organelle of sensitive cell in critical period developed mature gradually and the arrangement of them was very clear.Conclusion The retinal sensitive cell of rats develops and matures gradually in critical period.

Objective To evaluate the therapeutic efficacy and side effects of cyclopnosphamide, adriamycin, cisplatin (CAP) or CAP combined with verapamil(VPL) in chemotherapy of patients with advanced lung adenocarcinoma. Methods A total of 56 patients(male: 27, female: 29, average age: 48 years old, age range: 32-78 years old) with stage Ⅲb/Ⅳ lung adenocarcinoma confirmed pathologically from April 1998 to December 2001 were divided into two groups: group A(30 patients), treated with cyclophosphamide (CTX, 600 mg?m -2 ?d -1 ) on days 1 and 8, adriamycin (ADM, 40 mg/m 2) on day 1, and cisplatin (CDDP, 30 mg?m -2 ?d -1 ) on days 1, 2 and 3 and group B(26 patients), treated with the same dose of CTX, ADM and CDDP and an additional oral VPL treatment (60 mg t.i.d . on days 1-7). Each of the 3 cycles was repeated every 21 days. Results The patients in group A had a lower response rate (26.7% vs 38.5%, P

0.05).The major adverse effects were myelo-suppression,nausea,vomiting,phlebitis and alopecie.There were highest incidence of thrombocytopenia(51.1%) in GP regimen group compared with other groups,especially in the stage of Ⅲ? and Ⅳ?(totally accounting for 24.4%)(P

Objective To investigate the differential expression of mitochondrial genome and apoptosis-related genes in human lung adenocarcinoma A549 cell line induced by cisplatin. Methods A549 cells were cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum (FBS; Hyclone) in 150-mm dishes, and the test cells were exposed to 0.5?g/ml cisplatin continuously for 20h. Same volume PBS solution was added to culture of control cells instead of cisplatin. Human mitochondrial genome oligonucletide micoarray was used to detect the differential expression of 26 target genes. The apoptosis status was analyzed by the flow cytometry technique. Results Compared with the control cells, the expression levels of tRNA-Cys, tRNA-Asn, 12S rRNA and cytochrome oxidase subunit I were remarkably elevated in test cells. The expression levels of bax, NADH dehydrogenase subunit I, NADH dehydrogenase subunit Ⅱ and tRNA-Ser, tRNA-Asp, tRNA-Arg and tRNA-Ala also were elevated to some extent. Apoptosis rate of test cells was 8.5%?0.78%(n=5), which was remarkably higher than that of control cells 1.3%?0.56%(n=5,P

Objective To investigate the effects of co-transfection of the plasmid containing the wildtype (wt) INK4a/ARF gene on the chemosensitivity of human lung adenocarcinoma cell line A549. Methods Recombinant eukaryotic expression vectors pcDNA3-p16 INK4a and pcDNA3-p14 ARF were co-transfected into A549 cells by cationic liposome, in which the site of both genes was lost. By RT-PCR, immunocytochemistry and Western blotting analysis, G418 positive clone was obtained. The parental cell and negative control cell with plasmid pcDNA3-LacZ were used as controls. The 50% inhibition concentration (IC 50 ) of five commonly-used chemotherapy drugs and the apoptosis index (AI) of IC 50 were analysed respectively. Results Compared with the parental cells and negative control cells, the influence of the five drugs on IC50 was different. The values of IC 50 of doxorubicin and cisplatin decreased significantly but that of taxol, topotecan and vinorelbine remained unchanged. The apoptosis index of doxorubicin and cisplatin was much higher than that of other three drugs. Conclusion The chemosensitivity of a part of anti-cancer drugs could be changed by transfection of exogenous INK4a/ARF gene into lung adenocarcinoma cell A549.

Objective To investigate the influence of co-expression state of p14 ARF and p16 INK4a protein on radiochemotherapy and length of survival period in patients with non-small cell lung cancer(NSCLC)after resection. Methods Thirty-five patients with negative p14 ARF and p16 INK4a co-expression and 20 patients with positive p14 ARF and p16 INK4a co-expression were enrolled for the study. The co-expression of the said proteins were previously determined by immunohistochemistry (S-P). Clinical pathological characteristics were compared between two groups, and the survival time and the results of radiochemotherapy of patients were respectively recorded and analysed. Results No significant differences were found in age, TNM stages, degree of differentiation, recurrence/metastasis and radiochemotherapy between two groups. However, there was significant differences in sex, smoking index, and pathological classification. It was found that 2-year, 3-year and total survival rate were significantly lower in patients with p14 ARF and p16 INK4a co-expression than those with positive co-expression (P

Objective　To develop a new method to induce the gene transfection in high efficiency for eukaryotic cells in vitro. Methods　 Four kinds of p14ARF gene primarily deleted human carcinoma cell line including H460,A549,U251,and PC-3 were transfected with the human p14ARF expression vector (pCI-neo-p14ARF) by using the new nonliposomal transfection reagent Fugene 6. The efficiency of gene transfer was determined by screening the cells in G418. Results　 After 21 days' selection, G418-resistant clones were shown in all the transfected plate. PCR product of p14ARF gene was positive in all the G418-resistant clones. Cytotoxicity of Fugene 6 was detected. The cell proliferation activity was not affected when it was cultured in a high dose of Fugene 6. Conclusion　 These results demonstrate that Fugene 6 is a rapid, feasible, reproducible, and noncytotoxic gene transfection approach for eukaryotic expression vector in vitro.