A New Method of Establishing Orthotopic Bladder Transplantable Tumor in Mice

Objective The present study aims to find a convenient, rapid, and stable method to establish bladder tumor in mice. Methods Female Balb/C-nu-nu nude mice （or female T739 mice） were narcotized by sodium pentobarbital at a dosage of 60 mg/ kg. The stylet of the 24# venous retention needles was bent in a 5° to 7° angle at a distance of 15 mm from the needlepoint to form a circle with 2.61 mm to 3.66 mm radius when the stylet is rotated. The pipe casing was lubricated with liquid paraffin, and inserted into the bladder cavity. The drift angle stylet was inserted into the pipe casing slowly, rotated for five times, and then pulled out. A cell 6 suspension （0.1 mL） of approximately lx10 T24 cells （or BTT cells） was then injected imme＆ately. Results A total of 60 T739 mice and 60 Balb/C-nu-nu nude mice were inoculated with BTT cells and T24 cells, respectively. The bladder tumor incidence and the average survival time of the tumor-bearing mice were 100% and （26.69±9.24） d and 100% and （34.59±9.8） d for the T739 mice and Balb/C-nu-nu nude mice, respectively. Conclusions Using the drift angle stylet to injure the mucous membrane of the urinary bladder can establish a stable bladder transplantable tumor model in mice.

A Comparative Study on Proteomics between LNCap and DU145 Cells by Quantitative Detection and SELDI Analysis

The differences in intracellular and extracellular protein expressions between human prostate cancer lines LNCap and DU145 were examined, The proteins of the two cell lines were extracted and condensed by using protein extraction kits. And the intracellular and extracellular proteins were quantitatively detected on a micro-plate reader by using bicinchoninic acid （BCA） method. The proteins in cell culture fluid were qualitatively assayed by SELDI-TOF-MS, The results showed that the intracellular protein contents of LNCap cells were extremely higher than those of DU145 cells. After serum-free culture, both intracellular and extracellular protein contents of LNCap and DU145 were decreased to some extent. And the intracellular proteins were decreased by 5% in LNCap and by 36% in DU145 respectively, while the extracellular proteins were decreased by 89% in LNCap and 96% in DU145 respectively. SELDI assay revealed that there were 5 marker proteins in LNCap and 6 in DU145. Although both LNCap and DU145 cell lines originated from human prostate cancer, they had some differences in protein expression.

CHROMOSOMAL FRAGILE SITES TO LYMPHOMA WITH OBSERVATION OF 40 PATIENTS

Chromosomal fragile sites studies were performed in 40 patients with lymphoma and 30 individuals as healthy controls. The results showed that there was a statistical difference of chromosomal aberration between the two groups; The patients carried 46 fragile sites totally; 21 out of 46 fragile sites in lymphoma corresponded with cancer breakpoints, and 9 fragile sites were located in the bands where oncogenes exist. These suggest a certain association between fragile sites, cancer breakpoints and oncogenes and thus indicate a possible important role of fragile sites in the pathogenesis of lymphoma.

Overcoming EGFR-TKI resistance by targeting the tumor microenvironment

Targeted therapy has ushered in a new era of precision medicine for non-small cell lung cancer(NSCLC).Currently,epidermal growth factor receptor(EGFR)-tyrosine kinase inhibitors(TKIs)stand as the recommended first-line therapy for advanced NSCLC harboring sensitive EGFR mutations.Nevertheless,most patients inevitably confront the challenge of drug resistance.This phenomenon arises not solely from intrinsic alterations within cancer cells but also from the intricate dynamics of the tumor microenvironment and the complex interactions that occur between cancer cells and their immediate surroundings.This review consolidates the current knowledge regarding EGFR-TKI resistance mechanisms,with a specific emphasis on unraveling the role played by the tumor microenvironment.In addition,the review delineates strategic approaches to surmount TKI resistance,thereby enriching the understanding of the interplay between therapeutic agents and the intricate milieu surrounding cancer cells.