Drug resistance effects of ribosomal protein L24 overexpression in hepatocellular carcinoma HepG2 cells.

BACKGROUND: The morbidity and mortality rate of liver cancer continues to rise in China and advanced cases respond poorly to chemotherapy. Ribosomal protein L24 has been reported to be a potential therapeutic target whose depletion or acetylation inhibits polysome assembly and cell growth of cancer. MATERIALS AND METHODS: Total RNA of cultured amycin-resistant and susceptible HepG2 cells was isolated, and real time quantitative RT-PCR were used to indicate differences between amycin-resistant and susceptible strains of HepG2 cells. Viability assays were used to determine amycin resistance in RPL24 transfected and control vector and null- transfected HepG2 cell lines. RESULTS: The ribosomal protein L24 transcription level was 7.7 times higher in the drug-resistant HepG2 cells as compared to susceptible cells on quantitative RT-PCR analysis. This was associated with enhanced drug resistance as determined by methyl tritiated thymidine (3H-TdR) incorporation. CONCLUSIONS: The ribosomal protein L24 gene may have effects on drug resistance mechanisms in hepatocellular carcinoma HepG2 cells.

[Comparative study on EEG and neuroimaging of patients with cerebral cysticercosis before and after treatment].

OBJECTIVE: To study the changes of cerebral function and pathological morphology before and after the antiparasitic treatment with albendazole and praziquantel in patients with cerebral cysticercosis. METHODS: The data of EEG and neuroimaging of 412 patients with cerebral cysticercosis were retrospectively analyzed. RESULTS: Before the treatment, the mild abnormality, moderate abnormality, and severe abnormality were observed in 40.53%, 45.63% and 13.84% of the patients respectively, which mainly showed the diffuse or focal irregular slow waves, or epileptiform discharges found in the abnormal brain waves. CT/MRI manifestation could be divided into six types, including single sacculus type (23.59%), multiple sacculus type (44.42%), encephalitis type (13.59%), coexistence of macrocyst and sacculus type (4.85%), calcification type (2.18%), and mixed type (11.41%). After 3 courses of the treatment, the normal and improved EEGs were observed in 79.85% and 20.15%, respectively. CT/MRI showed the foci being all absorbed (77.18%), being most absorbed (20.63%), and being no changes (20.18%) which were calcified focus. When cerebral cysticercosis were in acute stage (the single and multiple sacculus type, encephalitis type, and macrocyst and sacculus coexistence type), the therapeutic effect was good; while in the mixed type, the therapeutic effect was relatively poor. If cysticercosis were in the calcification stage, the patients only needed the heteropathy. CONCLUSIONS: In the patients with cerebral cysticercosis, EEGs show the mild to severe abnormalities, and CT/MRI mainly shows the multiple sacculus type. After the treatment, the abnormal EEGs are gradually recovered and the low density foci can be all absorbed, but some calcified focus still exist in some patients.

Influence of ribosomal protein L39-L in the drug resistance mechanisms of lacrimal gland adenoid cystic carcinoma cells.

BACKGROUND: Cancer constitutes a key pressure on public health regardless of the economy state in different countries. As a kind of highly malignant epithelial tumor, lacrimal gland adenoid cystic carcinoma can occur in any part of the body, such as salivary gland, submandibular gland, trachea, lung, breast, skin and lacrimal gland. Chemotherapy is one of the key treatment techniques, but drug resistance, especially MDR, seriously blunts its effects. As an element of the 60S large ribosomal subunit, the ribosomal protein L39-L gene appears to be documented specifically in the human testis and many human cancer samples of different origins. MATERIALS AND METHODS: Total RNA of cultured drug-resistant and susceptible lacrimal gland adenoid cystic carcinoma cells was seperated, and real time quantitative RT-PCR were used to reveal transcription differences between amycin resistant and susceptible strains of lacrimal gland adenoid cystic carcinoma cells. Viability assays were used to present the amycin resistance difference in a RPL39-L transfected lacrimal gland adenoid cystic carcinoma cell line as compared to control vector and null-transfected lacrimal gland adenoid cystic carcinoma cell lines. RESULTS: The ribosomal protein L39-L transcription level was 6.5-fold higher in the drug-resistant human lacrimal gland adenoid cystic carcinoma cell line than in the susceptible cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells revealed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. CONCLUSIONS: The ribosomal protein L39-L gene could possibly have influence on the drug resistance mechanism of lacrimal gland adenoid cystic carcinoma cells.

Effects of ribosomal protein l39-L on the drug resistance mechanisms of lung cancer A549 cells.

BACKGROUND: Cancer is a major threat to the public health whether in developed or in developing countries. As the most common primary malignant tumor, the morbidity and mortality rate of lung cancer continues to rise in recent ten years worldwide. Chemotherapy is one of the main methods in the treatment of lung cancer, but this is hampered by chemotherapy drug resistance, especially MDR. As a component of the 60S large ribosomal subunit, ribosomal protein L39-L gene was reported to be expressed specifically in the human testis and human cancer samples of various tissue origins. MATERIALS AND METHODS: Total RNA of cultured drug-resistant and susceptible A549 cells was isolated, and real time quantitative RT-PCR were used to indicate the transcribe difference between amycin resistant and susceptible strain of A549 cells. Viability assay were used to show the amycin resistance difference in RPL39-L transfected A549 cell line than control vector and null-transfected A549 cell line. RESULTS: The ribosomal protein L39-L transcription level was 8.2 times higher in drug-resistant human lung cancer A549 cell line than in susceptible A549 cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells showed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: The ribosomal protein L39-L gene may have effects on the drug resistance mechanism of lung cancer A549 cells.

Influence of chemical and structural evolution of dissolved organic matter on electron transfer capacity during composting.

Dissolved organic matter (DOM) can mediate electron transfer and change chemical speciation of heavy metals. In this study, the electron transfer capability (ETC) of compost-derived DOM was investigated through electrochemical approaches, and the factors influencing the ETC were studied using spectral and elemental analysis. The results showed that the electron accepting capacity (EAC) and electron donating capacity (EDC) of compost-derived DOM were 3.29-40.14µmole- (gC)(-1) and 57.1- 346.07µmole- (gC)(-1), respectively. Composting treatment increased the fulvic- and humic-like substance content, oxygenated aliphatic carbon content, lignin-derived aromatic carbon content, molecule weight, and N and S content of DOM, but decreased the aliphatic carbon content and the C and H content. This conversion increased the EDC and EAC of the DOM during composting.

[Experimental study on cross-resistance of Culex pipiens pallens to 3 kinds of chemical pesticides].

OBJECTIVE: To understand the cross-resistance of Culex pipiens pallens to common pesticides, so as to provide the evidence for improving the application of chemical pesticides. METHODS: The IV instar larvae of DDVP-resistant, propoxur-resistant and cypermethrin-resistant strains as well as the sensitive strain of Culex pipiens pallens were collected to detect the resistance to DDVP, propoxur and cypermethrin based on the WHO bioassay method. RESULTS: The resistance coefficients of DDVP-resistant strain to DDVP, propoxur and cypermethrin were 14.47, 8.96 and 207.27 respectively. The resistance coefficients of propoxur-resistant strain to DDVP, propoxur and cypermethrin were 3.27, 6.93 and 8.65 respectively. The resistance coefficients of cypermethrin-resistant strain to DDVP, propoxur and cypermethrin were 2.93, 1.61 and 501.11 respectively. CONCLUSION: The resistance and cross-resistance could be generated during the long-term application of a single kind of chemical pesticide, and we should pay more attention to the varieties and dosages of them.

[The correlation between DDVP resistance of Culex pipiens pallens and esterase activity].

OBJECTIVE: To detect the resistance index and esterase activity of each generation of DDVP-resistant Culex mosquitoes and analyze the relationship between insecticide resistance and esterase. METHODS: WHO bioassay and micro-plate measurement were used for the detection. RESULTS: The resistance index increased to 12.17 after 43 generations' insecticide selection compared to 1.00 as sensitive isolate. The nonspecific esterase(NSE) activity of the mosquitoes became strengthened with the extension of the generations, and the individual frequency of those with OD values no less than 0.9 increased gradually, consistent basically to the bioassay. The AChE average inhibition rate decreased with the extended generation and increased resistance, and the individual frequency of those with inhibition rate less than 30% became strengthened with the extension of generations, showing a positive correlation. CONCLUSION: The activity of NSE and AChE shows a correlation with DDVP resistance.

Identification of Novel Regulatory Elements of Human Stem Cell Factor Gene in MCF Cell.

Human stem cell factor(hSCF)is a pluripotent growth factor that regulates proliferation, differentiation and migration of certain mammalian stem cells, such as primordial germ cells etc. It is shown that hSCF and its receptor are commonly co-expressed in human breast cancer cells. Up to now, the definite regulatory mechanism of hSCF gene in breast cancer cells is unclear, except that its 5'flanking sequence contains essential elements for regulating transcription. To localize the regulatory elements responsible for the regulation of the hSCF gene, we performed transient transfection study in MCF cells, with a series of luciferase reporter gene constructs, containing different 5x end deletions of hSCF gene. This study indicates that the region of -1190 -853 significantly enhanced the luc gene expression, while the region of -339 -162 inhibited the expression. Eletrophoretic mobility shift assay confirmed that MCF nuclear extract proteins bound to both -1190 -853 and -339 -273 regions, forming specific DNA-protein complexes, indicating that there were nuclear protein binding sites in these regions. The results suggest that both -1190 -853 and -339 -273 DNA fragments of the hSCF 5'flanking sequence may be novel regulatory elements, and may play a role in the regulation of hSCF gene expression in MCF cells.