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Objective:To explore whether spontaneous sene-scence widely existed in malignant tumor cells. Methods:Sene-scence-associated beta-galactosidase (SA-β-Gal) staining kit was used to detect the activity of SA-β-Gal in ten different malignant tumor cell lines before and after serum deprivation. Results:SA-β-Gal was expressed in some cells of 10 malignant tumor cell lines during exponential growth phase without any treatment. However, the percentage of senescent cells was significantly different among them, the lowest expression was observed in HeLa cell line (0.65%), and the highest expression was seen in HepG2 cell line (3.69 %, F=13.006, P= 0.000). Furthermore, not all the SA-β-Gal positive aging cells were polyploid cells. After 24-h serum deprivation, the number of SA-β-Gal positive cells was significantly increased (P=0.001). Conclusion:These findings indicate that immortal malignant tumor cell lines could undergo spontaneous senescence but the level was different between various cell lines. Short-term serum de-privation significantly increased the percentage of aging cells indicating that serum deprivation-induced cell senescence may be a rapid, easy, and effective way for anti-tumor therapy.
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Objective To study the effect of human cytomegalovirus (HCMV) on expressions of K8 and K18 in duct epithelial cells of salivary gland. Methods The expressions of immediate early antigen of HCMV, K8 and K18 were detected by immunohistochemistry staining in tissues embedded in paraffin of parotid cytomegalic inclusion disease(PCID). Results Cytomegly bearing inclusion appeared in duct epithelium of PCID. DDG9/CCH2 antigen of HCMV was expressed in cytomegly bearing inclusion. K8 was negative in these cytomegly while K18 was intensively positive. Conclusion It is suggested that breaking down of K8 be induced in parotid duct epithelial cells infected by HCMV and that up-regulation of K18 may be a reactive change. Keratin network in simple epithelium functions to impart mechanical integrity to cells.
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Objective To observe the changes and the mechanism of bcl-6 expression in K562 cells inducing differentiation along different Myelocyte-lineage cells,and to investigate the relationship between expression of bcl-6 and directional differentiation of K562 cells.Methods Models of K562 cells inducing differentiation along megakaryocyte-lineage,erythrocyte-lineage and macrophagocyte- lineage were established with inducers TPA(tetradecanoylphorbol 13-acetate),Hu(hydrozyurea)and HMBA(hexamethylene bisacet- amide)respectively,Western blot assay was applied to detect the expression of bcl-6 in K562 cells before and after the induction.Mean- while,PCR,cloning and direct DNA sequencing were used to identify mutations in the 5'regulatory region of bcl-6 in K.562 cells induced with TPA.Results Up-regulation of bcl-6 expression was found only in K562 cells inducing differentiation along megakaryocyte-line- age,and mutation of noncoding regulatory region of bcl-6 gene was not found.Conclusions bcl - 6 may be the key gene to regulate K.562 cells directional differentiation along different myelocyte-lineage ceils,the up-regulation of bcl-6 expression could play an important role in K562 cells inducing differentiation to megakaryocydte-lineage,and the change of bcl-6 expression might be not related with the mutation of the gene's 5'regulatory region.
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Objective To study the expression of aspartic proteinase cathepsin D in the germinal center of follicular lymphoma and follicular hyperplasia. Methods Immunohistochemical staining was performed to detect the expression of cathepsin D in paraffin sections of 10 cases of follicular lymphoma and 9 cases of follicular hyperplasia. Results Cathepsin D was weakly expressed in the plasma of dendritic cells and histiocytes in the germinal centers of 9 out of 10 cases of follicular hyperplasia. The number of positive cells were smaller in the center of follicles, but larger in the periphery. It was more strongly expressed in the plasma of dendritic cells and histiocytes located predominantly in the peripheral areas of germinal centers of follicular lymphoma in 10 patients. Some germinal centers were surrounded by T lymphocytes in 4 cases of follicular lymphoma, and cathepsin D positive cells in these germinal centers were more in number than that in the germinal centers without being surrounded by T cells in other 6 cases of follicular lymphoma, in which positive sign even absent in some germinal centers. Conclusion Cathepsin D is a good marker for the dendritic cells and histiocytes, and its differential expression in follicular lymphoma and follicular hyperplasia is helpful for differential diagnosis of the diseases. Based on the former reports of cathepsin D with its important roles in antigen processing, we suppose that lower expression of this protease is probably due to the decreased ability of immunological response to tumor in follicular lymphoma patients.
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Objective To review the clinical-pathological features, the tendency of incidence over 20 years, the predisposing factors, and the differences between the cases of cutaneous malignant melanoma from two hospitals. Methods A collection of 305 cases diagnosed as cutaneous malignant melanoma, among which 185 cases had complete clinical-pathological data, during 1981-2000 was analyzed. Results Acral malignant melanoma accounted for 63.3%, and the cases associated with congenital small nevi at the primary site accounted for 15.8% of 305 patients. During the period 1981-1990 and 1991-2000, cutaneous malignant melanoma constituted 0.053% and 0.094%, respectively, of all diagnoses with pathological sections, with an growth rate of 3.9% yearly. There was a tendency of the increased lesions located on face and neck, and decreased lesions on acra, over 20 years. Conclusion A rise of diagnosis of cutaneous malignant melanoma has been noticed from two hospitals over 20 years. Acra, especially planta, is the predominant anatomical site of cutaneous malignant melanoma.
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Objective To investigate the expression of anti-apoptosis gene bag-1 and its relation to the differentiation of intrahepatic cholangiocarcinoma (ICC). Methods Immunohistochemical techniques were adopted to study the expression of bag-1 in ICC tissue ( n=48) and para-hepatocarcinoma bile duct ( control group, n=25). Results Expression of bag-1 in the ICC group was significantly higher than that in the control group. In the ICC group (P