Objective To establish an adriamycin resistant human colon cancer cell line SW480 (SW480/ADM),and study their drug resistance mechanism and reversal.Methods An (ADM-resistant) human colon carcinoma cell line SW480/ADM was induced by continuously exposing human colon carcinoma cell line SW480 to gradually increasing doses of Adriamycin(ADM). The multidrug (resistance) of SW480/ADM was evaluated by MTT assay. The distribution of its cell cycle, the expressions of (P-gp), multidrug resistance-(associated) protein(MRP) and GSH/GST were detected by flow cytometry. ADM content in the SW480/ADM was detected by high-performance liquid chromatography(HPLC). Results Compared with parental cell line SW480, the SW480/ADM cell line had a slower growth rate and longer doubling time,and (distribution) of its cell cycle had changed. SW480/ADM was resistant to many anti-tumor agents. IC_(50) of ADM of SW480/ADM cells was 13.22 times higher than that of parental cell line SW480, and the (expressions) of P-gp,MRP and GSH/GST were enhanced significantly(P

Objective To determine the effect of caspase 9 in the apoptosis of hepatoma cells induced by flurouracil , and to investigate the activity alteration and proteolytic cleavage of caspase 9. Methods The human hepatoma HepG2 cells were treated with flurouracil for 2,4,8,16,24h respectively. The caspase 9 activity was detected using caspase 9 Fluorescent Assay Kit.Proteolytic cleavage of caspase 9 was analyzed by Western blot.The apoptotic rates of HepG2 cells induced by flurouracil with or without caspase 9 inhibitor treatment were measured by flow cytometry. Results Four hours after being treated with flurouracil, the caspase 9 activity in HepG2 cells increased gradually and reached the peak at 16h.Compared with the control group, the difference was significant (P

AIM: Eight melanoma cell lines were establi sh ed from human melanoma specimen and designated as HME 1-HME 8, and their charact eristics of cell biology and immunology in vitro were studied. METHODS: The tissues from biopsies of human melanoma were cultur ed in RPMI 1640 media. After growing to 90% confluence, the cells were detached for subculture and then their characteristics, including morphology, growth kine tic, tumor antigen and tumorigencity in nude mice were studied. RESULTS: These cell lines have been passaged more than 100 times within 2 years. Their characteristics demonstrated: ① The population doubling time calculated in the log phase of growth were 34.2-59.5 h. ② The cloning ef ficiency in soft agar averaged 8.6%-26.2%. ③ The melanoma cells transplan t ed in nude mice were high tumorigencity. ④ Karyo-type analysis showed that aneu ploidy with the modal chromosomal number 64-117. ⑤ Rich ribosomes and melanoid grains in the cytoplasm were observed under electronic microscope. ⑥ Immunohist ochemistry analysis showed that there were a lot of brown grains in the cytoplas m. ⑦ Detection of tumor-antigen demonstrated that melan-A antigen was 75.0%, M AGE-1 was 50.0%, MAGE-2 was 37.5%, MAGE-3 was 62.5%, respectively, for eight melanoma cell lines. CONCLUSION: The melanoma cells have immortalized after being cul tured in vitro and has specific characteristics of malignant melanoma.

Objective To investigate the distribution of islet autoantibodies (GAD-Ab, IA2-Ab, IAA) in new-onset diabetic patients with unprovoked ketosis and their association with clinical characteristics and pancreatic ? cell function.Methods Islet autoantibodies, including GAD-Ab、IA2-Ab and IAA were detected in 161 new-onset diabetic patients with unprovoked ketosis by radioligand assay. Prevalence of positive islet autoantibodies was compared among groups with different ages, body mass indexes (BMI), severity of ketosis and fasting C peptide (FCP) levels. Clinical characteristics and pancreatic ? cell function were compared between groups with positive and negative islet autoantibodies.Results One or more kinds of islet autoantibodies were detected in 68 from the 161 subjects (42.2%), with higher prevalence of positive islet autoantibodies in the patients aged equal to or less than 20 years, of BMI equal to or less than 18.5 and with FCP equal to or less than 300 pmol/L. Younger age of onset, lower BMI, more severe ketosis and poorer islet endocrine function were found in patients with positive islet autoantibodies, as compared with those with negative ones.Conclusions In diabetic patients with unprovoked ketosis, the younger, the lower C peptide and the lower BMI they are, the higher prevalence of positive islet autoantibodies, the more possibility that they are classified as type 1A diabetes and the less possibility as type 1B diabetes or type 2 diabetes.Pancreatic ? cell function was poorer in patients with positive islet autoantibodies,which should be treated with insulin as earlier as possible.

Objective To establish the cell line from specimens of resectable human gastrointestinal stromal tumors (GIST) and to verify the characteristics of cell biology in vitro. Methods The tissues from biopsies of human GIST were cultured in RPMI 1640 media supplemented with 10% fetal bovine serum. After growing to 90% confluence,the cells were detached for subculture and their characteristics,including morphology,growth kinetics,karyotype analysis,immunohistochemical analysis and tumorigenicity in nude mice were determined. Results GIST named GIST-H1 was successfully established. The cell line was passaged for more than 60 times 1 year. The characteristics demonstrated: The population doubling time calculated in the log phase of growth was 47.5 h. The cloning efficiency in the soft agar averaged 24.8%.Electronmicroscopically,there were rich ribosomes and mitochondrion in the cytoplasm. Immunohistochemical analysis showed CD117(+),SMA(+),dog-1(+),CD34(-),and S-100(-).Karyotype analysis illustrated aneuploidy with the modal chromosomal number 60-98.The GIST cells transplanted in nude mice had high tumorigenicity. Conclusion The immortalized GIST cells are devoloped in vitro and have specific characteristics of GIST.