PURPOSE To provide evidence for the relationship between degree of invasion and tumor metastasis. The tumor cells of transplantable mouse histiocytic sarcoma (L1) were inoculated at the right hind footpads of inbred 615-strain mice. METHODS Once bearing the tumor, all the mice were sacrificed respectively on the 1st. 3th, 5th. 10th, 20th, 30th, and 40th day as to observe the degree of tumor invasion and the process of tumor metastasis. RESULTS When the degree of tumor invasion was grade Ⅲ or Ⅳ , the metastasis of tumor cells was found earliest in draining lymph nodes. However, the tumor metastasis in lung appeared later than in lymph nodes. CONCLUSION According to the time of tumor growth and degree of invasion and metastasis, the authors suggest a new classification for cancer staging, namely, latent, invasive and metastatic stages. During the stage of tumor invasion, it is redivided into early, middle and late invasive phases. During the stage of tumor metastasis, it is redivided into early, middle and late metastatic phases.

Objective To construct human canstatin gene eukaryotic expression vector and investigate the therapeutic effect of intramuscular canstatin gene delivered by electroporation on tumor growth.Methods Canstatin cDNA was amplified from total RNA extracted from fresh fetal liver by reversing transcription polymerase chain reaction (RT-PCR).The canstatin cDNA fragment was in serted into pEGFP-N1 eukaryotic expression vector.The recombination plasmid was delivered to the quadriceps of the mice with Lewis lung carcinomas by electroporation intramuscular.Fluorescence intension measured by fluorescence microscope,reverse-PCR assay,and immunohistochemistry assay were performed to detect the expression of canstatin gene in the muscle and in circulation.The tumor weight and volume were used to detect the biological effects of canstatin gene delivery.Results Recombinant eukaryotic expression vector of recombinant human canstatin was successfully constructed.The canstatin mRNA was significantly increased in the skeletal muscle and intramuscular delivery of canatatin gene by electroporation acquired the expression of enhanced green fluorescent protein (EGFP)/canstatin protein in the circulation and significantly inhibited tumor growth.The percent of the inhibition of tumor weight was 57.7 ％.Conclusions Electroporation mediated gene transfer efficiency in skeletal muscle was compared to simple plasmid injection and lasted for a long time.It was an efficient and safe,convenient and economic,gene transfer methods and might have certain clinical application value.Electroporation mediated canstatin gene transfer in skeletal muscle had obvious inhibitory effect on Lewis lung cancer in mice subcutaneous xenograft tumor growth.

[ ABSTRACT] AIM:To investigate the effects of pathological products, urinary proteins and advanced glycosyla-tion end products ( AGE) produced in the progression of chronic kidney disease ( CKD) , on the structure and function of lysosomes in renal tubular epithelial cells ( TECs ) , and try to find a novel approach for preventing or delaying CKD. METHODS:The renal specimens of the untreated patients with minimal change nephrotic syndrome (MCNS), diabetic nephropathy (DN) or normal kidney were collected.The expression of lysosomal-associated membrane protein 1 (LAMP1) and cathepsin B ( CB) was studied in TECs by indirect immunofluorescent staining.Human renal tubular epithelial cell line HK-2 was incubated with 8 g/L urinary proteins or 100 mg/L AGE.The expression of LAMP1 and CB was investigated by indirect immunofluorescence and the activity of CB and cathepsin L ( CL) was measured by biochemical and enzymatic as-says.The degradation of DQ-ovalbumin was also determined.RESULTS: The lysosomal membrane permeabilization oc-curred in the TECs of MCNS and DN patients.After treatment with urinary proteins or AGE-BSA, the lysosomal membrane permeabilization of the HK-2 cells was increased.The activity of CB and CL and degradation of DQ-ovalbumin were de-creased as compared with normal control group.CONCLUSION:The digestive function of lysosome was decreased and ly-sosomal membrane permeabilization occurred in the TECs exposed to urinary proteins and AGE, which might be a key factor to induce the tubulointerstitial fibrosis.