Cell proliferation, apoptosis and the related regulators p27, p53 expression in hepatocellular carcinoma

AIM: To investigate the expression of cell apoptosis, proliferation and the related regulators p27,p53 in hepatocellular carcinoma (HCC). METHODS: The expression of p27, p53, proliferating cell nuclear antigen (PCNA) and apoptosis in 47 HCC specimens and 42 surrounding non-cancerous tissues were detected by the immunohistochemistry and terminal deoxy-nudeotidyl transferase-mediated nick end labeling (TUNEL) technique. Meanwhile, the clinical significance of them was analyzed combining with the clinicopathological factors and follow-up data. RESULTS: (1) The average proliferating index and apoptotic index in HCC were significantly higher than that in adjacent liver tissues. The proliferating index was associated with extrahepatic metastasis. The apoptotic index was significantly lower in TNM stage Ⅰ-Ⅱ than in stage Ⅲ-Ⅳ. The proliferating index of groups with p53-/p27+ was significantly lower than that in group with p53+/p27- (P= 0.030); (2) The level of p27 in the cytoplasmic fraction was higher in non-tumoral liver tissues and was associated with clinical stage; (3) Survival analysis showed advanced stage (P=0.031) and with extrahepatic metastasis (P = 0.045) was significantly associated with shorter survival. In addition, the prognosis of patients with p53-/p27+ was longer than that of patients with p53+/p27- (P= 0.0356). CONCLUSION: The p53 mutation and decreased p27 expression might be involved in the imbalance of proliferation and apoptosis in HCC. Cytoplasmic displacement might lead to the inactivation of p27 protein in HCC cells and acts early during carcinogenesis of HCC. The combined examination of p27, and p53 expression allows reliable estimation of prognosis for patients with primary hepatic carcinoma.     

Inhibitory effect of tumor suppressor p33(ING1b) and its synergy with p53 gene in hepatocellular carcinoma

AIM: To investigate the inhibitory effect of tumor suppressor p33ING1b and its synergy with p53 gene in hepatocellular carcinoma (HCC). METHODS: Recombinant sense and antisense p33ING1b plasmids were transfected into hepatoma cell line HepG2 with lipofectamine. Apoptosis, G0/G1 arrest, cell growth rate and cloning efficiency in soft agar of HepG2 were analyzed after transfection. In three hepatoma cell lines with different endogenous p53 gene expressions, the synergistic effect of p33ING1b with p53 was analyzed by flow cytometry and luciferase assay was performed to detect the activation of p53 downstream gene p21WAF1/CIP1. In addition, the expression and mutation rates of p33ING1b in HCC tissues were measured by immunohistochemistry and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). RESULTS: Overexpression of p33ING1b inhibited cell growth of HepG2, induced more apoptosis and protected cells from growth in soft agar. Combined transfer of p33ING1b and p53 gene promoted hepatoma cell apoptosis, G0/G1 arrest and elevated expression of p21WAF1/CIP1. Immunostaining results showed co-localized P33ING1b with P53 protein in HCC tissues and there was a significant relation between protein expression rates of these two genes (P<0.01). Among 28 HCC samples, p33ING1b presented a low gene mutation rate (7.1%). CONCLUSION: p33ING1b collaborates with p53 in cell growth inhibition, cell cycle arrest and apoptosis in HCC. Loss or inactivation of p33ING1b normal function may be an important mechanism for the development of HCC retaining wildtype p53.     

Effect of Bcl-2 and Bax on survival of side population cells from hepatocellular carcinoma cells

AIM： To understand the role and significance of side population （SP） cells from hepatocellular carcinoma （HCC） in hepatocarcinogenesis, development, relapse and metastasis, we simulated the denutrition conditions that cancer cells experience in clinical therapy, observed the different anti-apoptosis ability of SP cells and non-SP cells under such conditions, and established the possible effects of P53, Bcl-2 and Bax on survival of SP cells. METHODS： We used flow cytometry to analyze and sort the SP and non-SP cells in established HCC lines MHCC97 and hHCC. We evaluated cell proliferation by methyl thiazolyl tetrazolium （MTT） assay and investigated the expression of p53, bcl-2 and bax genes during denutrition, by RT-PCR and immunofluorescence staining. RESULTS： The percentage of SP cells in the two established HCC lines was 0.25% and 0.5%, respectively. SP cells had greater anti-apoptosis and proliferation ability than non-SP cells. Expression of Bcl-2 and Bax in SP and non-SP cells differed during denutrition. The former was up-regulated in SP cells, and the latter was up-regulated in non-SP cells. CONCLUSION： It may be that different upstream molecules acted and led to different expression levels of Bcl-2 and Bax in these two cell lines. There was a direct relationship between up-regulation of Bcl-2 and down-regulation of Bax and higher anti-apoptosis ability in SP cells. It may be that the existence and activity of SP cells are partly responsible for some of the clinical phenomena which are seen in HCC, such as relapse or metastasis. Further research on SP cells may have potential applications in the field of anticancer therapy.     

Expression and significance of new inhibitor of apoptosis protein survivin in hepatocellular carcinoma

AM: To investigate expression and significance of inhibitor of apoptosis protein survivin in hepatocellular carcinoma (HCC). METHODS: The expression of survivin and vascular endothelial growth factor (VEGF) was investigated in 38 cases of HCC tissues and 38 liver cirrhosis tissues by immunohistochemistry and Western blot. The relationship between the expression of survivin and clinicopathological factors of HCC was analyzed. RESULTS: Survivin protein was detected in 23 (60.5%) of 38 HCCs and 3 (7.9%) of 38 liver cirrhosis tissues. In 23 cases of HCC which expressed survivin, the expression of VEGF was positive in 18 cases and slight positive or negative in 5 cases. While in 15 cases of HCC which did not express survivin, 12 cases did not express or slightly expressed, and 3 cases expressed VEGF. In liver cirrhosis tissues, the expression of VEGF was as follows: 24 cases were negative, 10 cases were weak positive and 4 cases were strong positive. The expression of survivin was coincident with the expression of VEGF in HCC (P<0.01). The expression of survivin in HCC had no relationship with the patients' age, gender, tumor size and differentiation level of HCC, while it was related to the metastasis of HCC. The protein quantitative analysis by Western blot also showed that overexpression of survivin in HCC was closely correlated to the expression of VEGF (P<0.01). Furthermore, stronger expression of survivin and VEGF was also found in patients with metastasis rather than in those with no metastasis (P<0.01). CONCLUSION: Survivin plays a pivotal role in the metastasis of HCC, and it has some correlation with tumorigenesis. The expression of survivin in the primary lesion is very useful as an indicator for metastasis and prognosis of HCC. It could become a new target of gene therapy of HCC.     

Apoptosis of human pancreatic cancer cells induced by Triptolide

AIM： To investigate apoptosis in human pancreatic cancer cells induced by Triptolide （TL）, and the relationship between this apoptosis and expression of caspase-3＇ bcl-2 and bax. METHODS： Human pancreatic cancer cell line SW1990 was cultured in DMEM media for this study. MTT assay was used to determine the cell growth inhibitory rate in vitro. Flow cytometry and TUNEL assay were used to detect the apoptosis of human pancreatic cancer cells before and after TL treatment. RT-PCR was used to detect the expression of apoptosis-associated gene caspase-3＇ bcl-2 and bax. RESULTS： TL inhibited the growth of human pancreatic cancer cells in a dose-and time-dependent manner. TL induced human pancreatic cancer cells to undergo apoptosis with typically apoptotic characteristics. TUNEL assay showed that after the treatment of human pancreatic cancer cells with 40 ng/mL TL for 12 h and 24 h, the apoptotic rates of human pancreatic cancer cells increased significantly. RT-PCR demonstrated that caspase-3 and bax were significantly up-regulated in SW1990 cells treated with TL while bcl-2 mRNA was not. CONCLUSION： TL is able to induce the apoptosis in human pancreatic cancer cells. This apoptosis may be mediated by up-regulating the expression of apoptosisassociated caspase-3 and bax gene.     

Correlation of survivin,p53 and Ki-67 in laryngeal cancer Hep-2 cell proliferation and invasion

Objective: To investigate the mechanism of survivin, p53 and Ki-67 on Hep-2 human laryngeal cancer endothelial cell proliferation and invasion. Methods: Laryngeal squamous cell carcinoma and paracancerous normal tissues were collected, total RNA was extracted from tissues, survivin, p53 and Ki-67 gene m RNA expression levels in laryngeal cancer and the adjacent tissues were detected by Real-time PCR. Human laryngeal cancer Hep-2 epithelial cells were selected, survivin gene was overexpressed, and cell proliferation was detected by MTT. p53 and Ki-67 gene expression changes in overexpressed survivin gene were detected by Western blot. Changes in Hep-2 cell invasive ability were studied when survivin was overexpressed as detected by Transwell invasion assay. Results: In the adjacent tissues, survivin, p53 and Ki-67 gene relative expression levels were 1.72 ± 0.9, 13.7 ± 5.7 and 5.7 ± 1.3, respectively; while in cancer tissues, gene relative expression levels were 53.7 ± 8.3, 66.7 ± 5.2 and 61.0 ± 3.1, respectively, which was significantly increased. As detected by MTT, relative cell survival rate within 12 h of survivin overexpression were: load control group,(88.5±1.6)%; overexpressed group,(90.3±1.9)%. Transwell invasion assay results indicated that overexpressed survivin could significantly increase the relative survival rate of cells. Conclusions: Expressions of p53, Ki67 and survivin are increased in cancer; and there is a positive correlation between survivin, p53 and Ki67 expressions in laryngeal carcinoma.     

Expression of p53and C—myc genes and its clinical relevance in the hepatocellular carcinomatous and pericarcinomatous tissues

AIM：To investigate the possible roles of p53and C-myc genes in the primary hepatocellular carciogenesis and the relationship between the liver hyperplastic nodule(LHN)and hepatocellular carcinoma(HCC).METHODS:The expression of p53and C-myc genes was detcted immunohist-ochemically in 73and 60cases of HCCand pericarcinomatous tissues,respectively.RESULTS:The positive expression of p53in HCCwas significantly higher than that in pericarcinomatous tissues(P&lt;0.050.In pericarcinomatous tissues,the p53 expression was observed onlyin LHN,but not in liver cirrhosis(LC)and normal liver tissues.The positive expression rate of C-myc in HCC or LHN was significantly higher than that in LCor normal liver tissues(P&lt;0.05and P&lt;0.01).however,no significant difference was found between HCCand LHN(P&gt;0.05).The positive expression rate of p53and C-myc in HCCwas correlated with the histological differentiation,that in the poorly6 differentiated was significantly higher than that in well differentiated samples(P&lt;0.05).CONCLUSION:The overexpression of p53and C-myc genes might play a orle in the carcinogenesis of HCC;And LHN seems a preneoplastic lesion related to hepatocarcinogenesis.No evidence supports that LC contribute directly to the hepatocarcinogenesis.     

Alteration of somatostatin receptor subtype 2 gene expression in pancreatic tumor angiogenesis

AIM:To explore the difference of somatostatin receptorsubtype 2 (SST2R) gene expression in pancreatic canceroustissue and its adjacent tissue,and the relationship betweenthe change of SST2R gene expression and pancreatic tumorangiogenesis related genes.METHODS:The expressions of SST2R,DPC4,p53 and rasgenes in cancer tissues of 40 patients with primary pancreaticcancer,and the expression of SST2R gene in its adjacenttissue were determined by immunohistochemiscal LSABmethod and EnVision~(TM) method.Chi-square test was usedto analyze the difference in expression of SST2R in pancreaticcancer tissue and its adjacent tissue,and the correlation ofSST2R gene expression with the expression of p53,ras andDPC4 genes.RESULTS:Of the tissue specimens from 40 patients withprimary pancreatic cancer,35 (87.5%) cancer tissues showeda negative expression of SST2R gene,whereas 34 (85%) apositive expression of SST2R gene in its adjacent tissues.Five (12.5%) cancer tissues and its adjacent tissuessimultaneously expressed SST2R.The expression of SST2Rgene was markedly higher in pancreatic tissues adjacent tocancer than in pancreatic cancer tissues (P<0.05).Theexpression rates of p53,ras and DPC4 genes were 50%,60% and 72.5%,respectively.There was a significant negativecorrelation of SST2R with p53 and ras genes (X_~2=9.33,x_~2=15.43,P<0.01),but no significant correlation with DPC4gene (X~2=2.08,P>0.05).CONCLUSION:There was a significant difference of SST2Rgene expression in pancreatic cancer tissues and its adjacenttissues,which might be one cause for the differenttherapeutic effects of somatostatin and its analogs onpancreatic cancer patients.There were abnormal expressionsof SST2R,DPC4,p53 and ras genes in pancreaticcarcinogenesis,and moreover,the loss or decrease of SST2Rgene expression was significantly negatively correlated withthe overexpression of tumor angiogenesis correlated p53and ras genes,suggesting that SST2R gene together withp53 and ras genes may participate in pancreatic cancerousangiogenesis.     

Down-regulation of survivin expression by small interfering RNA induces pancreatic cancer cell apoptosis and enhances its radiosensitivity

AIM: To investigate the inhibitory effect of small interfering RNA (siRNA) on the expression of survivin in pancreatic cancer cell line PC-2 and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity. METHODS: A siRNA plasmid expression vector against survivin was constructed and transfected into PC-2 cells with LipofectamineTM 2000. The down regulation of survivin expression was detected by semi-quantitive RT-PCR and immunohistochemical SP method and the role of siRNA in inducing PC-2 cell apoptosis and enhancing its radiosensitivity was detected by flow cytometry. RESULTS: The sequence-specific siRNA efficiently and specifically down-regulated the expression of survivin at both mRNA and protein levels. The expression inhibition ratio was 81.25% at mRNA level detected by semi-quantitive RT-PCR and 74.24% at protein level detected by immunohistochemical method. Forty-eight hours after transfection,apoptosis was induced in 7.03% cells by siRNA and in 14.58% cells by siRNA combined with radiation. CONCLUSION: The siRNA plasmid expression vector against survivin can inhibit the expression of survivin in PC-2 cells efficiently and specifically. Inhibiting the expression of survivin can induce ipoptosis of PC-2 cells and enhance its radiosensitivity significantly. RNAi against survivin is of potential value in gene t(?)erapy of pancreatic cancer.     

Dynamic expression of apoptosis-related genes during development of laboratory hepatocellular carcinoma and its relation to apoptosis

AIM:To explore the expression of p53,bcl-2,bax,survivin and the cell apoptosis during the development of tree shrew hepatocellular carcinoma(HCC),the relationship between expression of these genes,its impact on HCC development,and its relation to cell apoptosis.METHONS:Tree shrew HCC was induced with aflatoxin B1(AFB1),and regular biopsy of liver tissues was carried out and the biopsy tissues were collected during cancer inducement.Liver biopsy tisue and HCC tissue were collected from 35pre-cancerous experimental animats at wk 30 and 60 and at the 30th_,60th_,and 90th-wk,Liver biopsy tissues were collected from 13 blank control animals at wk 30,60,and 90.Expression of p53,bcl-2,bax,and survivin at each stage was examined by immunohistochemistry method.Apoptotic cells were detected in situ by the terminal deoxynucleotidyl transferase-mediated nick end labeling(tunel)technique.RESULTS:The apoptosis rate of normal hepatic cells was extremely low,whereas it increased during the formation of HCC.Expression of the apoptosis-related genes p53,bd-2,bax,and suvivin during the formation of HCC presented an increasing tendency.Expression of p53 did not noticeably relate to that of bcl-2,bax,and survivin,whereas expression of bcl-2 and bax was closely related.In HCC,p53 did not present a distinct relation to cell apoptosis,whereas its high level expression was probably related to liver cell proliferation.Survivin negetively correlated apoptosis index,and its overexpression could inhibit cell apoptosis.CONCLUSION:Apoptosis-related genes p53,bcl-2,bax,and survivin are all related to the occurrence of HCC.The anti-apoptosis effect of bcl-2 is influenced by bax,and ratio bcl/bax reflects more correctly the extent of cell apoptosis.     

Expression of p53, bcl-2, and bax as predictors of response to radiotherapy in esophageal cancer

The sensitivity of cancers to radiotherapy or chemotherapy may be influenced by susceptibility to apoptosis. We evaluated whether expression of three proteins regulating apoptosis, p53, bcl-2, and bax, could predict the effect of radiotherapy in esophageal cancers. We used immunohistochemical staining for these protein regulators of apoptosis to study biopsy specimens obtained from 25 patients with esophageal squamous cell carcinoma before they underwent preoperative radiotherapy. Effectiveness of radiotherapy was assessed by barium esophagography, esophagoscopy, and computed tomography. Radiotherapy was effective in 12 patients and ineffective in 13 patients. Biopsy specimens from the 25 patients showed expression of p53, bcl-2, and bax to be 48.0%, 32.0%, and 76.0% respectively. Effectiveness of radiotherapy was correlated with p53 expression (p = 0.047), but bcl-2 and bax expression showed no relationship to effectiveness of radiotherapy. Expression of p53 protein in biopsy specimens may predict effectiveness of preoperative radiotherapy in esophageal cancers.     

凋亡抑制基因survivin bcl-2 bax在肺癌中表达的研究

目的检测肺癌患者癌组织和癌旁组织中survivin、bcl-2及bax的基因表达,探讨它们的相关性及与肺癌发生、发展的关系。方法应用TUNEL原位细胞凋亡检测方法及免疫组化方法,对1998—2004年华中科技大学同济医学院附属协和医院收治的163例肺癌患者手术常规石蜡包埋组织中癌基因survivin、bcl-2及bax的表达进行检测,并与其中106例患者的癌旁组织对比,分析免疫组化结果及其与肺癌的病理特征和预后关系。结果在癌旁肺组织中,survivin、bcl-2、bax蛋白阳性表达率分别为1·9%(2例)、29·2%(31例)、93·47%(99例);肺癌组织内,三者阳性表达率分别为69·9%(114例)、62·0%(101例)、52·8%(86例)。异常增高的survivin、bcl-2表达呈明显相关。结论细胞凋亡和增殖失控,相关基因survivin、bcl-2和bax蛋白异常表达在肺癌发生发展中起重要作用。survivin、bcl-2可能在肺癌癌变及浸润过程中起着重要作用,可作为判断肺癌生物学行为和预后的参考指标。     

Effect of bax,bcl—2 and bcl—xL on regulating apoptosis in tissues of normal liver and hepatocellular carcinoma

AIM: To investigate the expression of bax, bcl-2 and bcl-xL mRNA in the tissues of normal liver and hepatocellular carcinoma (HCC), and analyze the relationship between the expression of bax, bcl-2 and bcl-xL mRNA and clinical parameters of HCC patients. METHODS: The expression of bax, bcl-2 and bcl-xL mRNA of normal liver and HCC was measured by Northern blot. Statistical analyses were made by t test and correlation analysis. RESULTS: A very low mRNA level was indicated at bax, bcl-2 and bcl-xL in the HCC tissues in contrast to the tissues of normal liver by Northern blot analysis. The analyses of mRNA level revealed that HCC tissues exhibited a mean 7.6-fold decrease in bax, 4.2-fold in bcl-2 and 3.5-fold in bcl-xL in comparison with normal control tissues, respectively. Positive correlation was found between bax and bcl-xL (r=0.7061, P<0.01). There was no significance between the mRNA expression of these three genes and age, gender, tumor differentiation and tumor stage of HCC patients. CONCLUSION: The results are consistent with the fact that apoptosis rarely occurs in normal livers but increases in HCC, indicating that bcl-2 and bcl-xL may play a very important role in regulating the apoptosis of normal liver and HCC.     

叶酸对胃癌前病变bcl-2、bax及p53 基因的影响

目的研究叶酸治疗对胃癌前病变组织中bcl-2、bax及p53基因表达的影响.方法胃镜活检经病理证实为胃癌前病变患者38例,利用逆转录聚合酶链式反应(RT-PCR)方法检测胃癌前病变组织bcl-2、bax基因表达率,利用流式细胞仪检测组织p53蛋白表达率.将患者随机分为治疗组(叶酸10mg,每天三次)与对照组(硫糖铝1.0,每天四次)各19例,治疗结束复查组织中bcl-2,bax基因表达率及p53蛋白表达率.结果治疗组治疗后bcl-2基因表达率降低(P<0.05),bax基因表达率无明显变化(P>0.05),p53蛋白表达率增高(P<0.05),对照组治疗后各项指标无明显变化(P>0.05).结论叶酸干预可促进胃癌前病变组织中p53基因的表达,抑制bcl-2基因的表达,而对bax基因表达无明显影响.     

低剂量X射线照射对荷人小细胞肺癌(NCI-H446)裸小鼠移植瘤细胞凋亡相关基因mRNA表达的影响

目的 研究低剂量照射（LDR）对荷人小细胞肺癌（NCI-H446）裸小鼠移植瘤细胞凋亡相关基因mRNA表达的影响。方法 对荷人小细胞肺癌裸小鼠进行全身深部X射线照射，采用原位杂交技术检测荷人小细胞肺癌裸小鼠移植瘤组织的p53、Bcl-2、Bax的mRNA表达水平。结果 D1（75mGy）、D2（4Gy）照射后，小细胞肺癌细胞的p53、Bax的mRNA表达呈上升趋势，Bcl-2的mRNA表达呈下降趋势，但与假照组（0 mGy）比较，无明显差异；D1＋D2组的p53、Bax的mRNA表达明显增多，Bcl-2mRNA表达显著下降，与假照组（0mGy）比较有统计学差异（P〈0．05）。结论 LDR在一定程度上可能上调小细胞肺癌细胞的p53、Bax的mRNA表达，下调了Bcl-2mRNA的表达，同时对其后的大剂量照射有协同作用。     

Dissection of the genetic programs of p53-mediated G1 growth arrest and apoptosis: blocking p53-induced apoptosis unmasks G1 arrest

Employing the myeloblastic leukemia M1 cell line, which does not express endogenous p53, and genetically engineered variants, it was recently shown that activation of p53, using a p53 temperature- sensitive mutant transgene (p53ts), resulted in rapid apoptosis that was delayed by high level ectopic expression of bcl-2. In this report, advantage has been taken of these M1 variants to investigate the relationship between p53-mediated G1 arrest and apoptosis. Flow cytometric cell cycle analysis has provided evidence that activation of wild-type (wt) p53 function in M1 cells resulted in the induction of G1 growth arrest; this was clearly seen in the M1p53/bcl-2 cells because of the delay in apoptosis that unmasked p53-induced G1 growth arrest. This finding was further corroborated at the molecular level by analysis of the expression and function of key cell cycle regulatory genes in M1p53 versus M1p53/bcl-2 cells after the activation of wt p53 function; events that take place at early times during the p53-induced G1 arrest occur in both the M1p53 and the M1p53/bcl-2 cells, whereas later events occur only in the M1p53/bcl-2 cells, which undergo delayed apoptosis, thereby allowing the cells to complete G1 arrest. Finally, it was observed that a spectrum of p53 target genes implicated in p53- induced growth suppression and apoptosis were similarly regulated, either induced (gadd45, waf1, mdm2, and bax) or suppressed (c-myc and bcl-2), after activation of wt p53 function in M1p53 and M1p53/bcl-2 cells. Taken together, these findings show that wt p53 can simultaneously induce the genetic programs of both G1 growth arrest and apoptosis within the same cell type, in which the genetic program of cell death can proceed in either G1-arrested (M1p53/bcl-2) or cycling (M1p53) cells. These findings increase our understanding of the functions of p53 as a tumor suppressor and how alterations in these functions could contribute to malignancy.     

Expression of apoptotic and antiapoptotic markers in epithelial cells in idiopathic pulmonary fibrosis

STUDY OBJECTIVE: Idiopathic pulmonary fibrosis (IPF) is a chronic, usually fatal lung disease of unknown etiology. A common feature is the presence of microscopic areas of epithelial cell dropout. Increased apoptosis of these cells could elucidate the speculative pathogenesis of the disease. Therefore, the aim of our study was to examine the expression of p53, p21, bcl-2, bax, and caspase-3 in association with DNA strand breaks in bronchial and alveolar epithelial cells in lung specimens from IPF patients and control subjects. PATIENTS AND METHODS: We examined by immunohistochemistry the expression of p53, p21, bax, bcl-2, and caspase-3 in association with DNA strand breaks detected by terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate-biotin nick end-labeling (TUNEL) in bronchial and alveolar epithelial cells in lung specimens taken by biopsy in 12 IPF patients and 10 control subjects. An independent tissue evaluation by two pathologists graded semiquantatively the degree of staining present. RESULTS: TUNEL was positive in epithelial cells in all IPF patients and only in one control subject. The expression of p53, p21, bax, and caspase-3 was up-regulated in IPF patients compared to control subjects. Bcl-2 was expressed less in IPF patients than in control subjects. CONCLUSIONS: These results confirm that apoptotic hyperplastic epithelial cells are present in patients with IPF and that the expression of p53, p21, bax, and caspase-3 appears to be up-regulated and that of bcl-2 down-regulated in these cells. The increased expression of proapoptotic molecules in epithelial cells in IPF may be involved in the inadequate and delayed reepithelialization, which in turn contributes to fibroblast proliferation.     

Imbalance between cell proliferation and cellular DNA fragmentation in hepatocellular carcinoma.

AIM/BACKGROUND: Hepatocellular carcinoma (HCC) is known for its rapid growth. This study was undertaken to determine the expression of proliferative markers, apoptosis (DNA fragmentation) and oncogene products known to regulate apoptosis (p53, bcl-2) in HCC. METHODS: 150 Chinese patients with HCC were studied (M:F 128:22, age 14-88 years). Immunohistochemistry was employed to detect cell proliferative markers (PCNA, Ki67), and oncogene products known to regulate apoptosis (p53, bcl-2). DNA fragmentation was determined by terminal dUTP nick end labeling (TUNEL). RESULTS: 98% and 95% of HCC had PCNA (median 2+) and Ki67 (median 2+) detected respectively. TUNEL labeling was detected in only a small number of tumor cells (no labeling in 11%, median 1/1000 cell labeled, range: 0-70/1000 cells). There was no correlation between TUNEL labeling and the clinical parameters (sex, age, cirrhosis, and survival) and the expression of cell proliferative markers. p53 was detected in 53% of the patients (median 1+, range: 0-4+) and bcl-2 was detected in a small proportion of tumor cells in only 13% of the HCCs (range: 0-1 +). The expression of p53 and Bcl-2 did not correlate with TUNEL labeling or the natural survival. CONCLUSIONS: Cell proliferation in HCC is unmatched by apoptosis, accounting for the rapid growth of this tumor. This lack of apoptosis in HCC is unrelated to the expression of p53 or bcl-2 over-expression.