Hou-Quan Tao, Shou-Chun Zou, Department of Surgery, Zhejiang Provincial People's Hospital, Hangzhou 310014,Zhejiang Province, China
Correspondence to: Dr. Hou-quan Tao, Department of Surgery, Zhejiang Provincial People's Hospital, Hangzhou 310014, Zhejiang Province, China. houquantao@yahoo.com
Telephone: +86-571-85236842 Fax:+86-571-85131448
Received 2001-12-20 Accepted 2002-02-23

Abstract
AIM: To study the effects of preoperative regional artery chemotherapy (PRACT) in inducing growth inhibition and apoptosis of gastric carcinoma (GC) cells.

METHODS: TUNEL (terminal-deoxynucleotidyl-transferase TdT-mediated dUTP-fluorescein and labeling) method and immunohistochemical techniques were used to detect the state of apoptosis and proliferation of GC cells in histopathologic sections. A total of 110 cases of GC and 68 cases of metastatic lymph node with or without PRACT were adopted. Correlations between apoptosis index (AI), proliferation index (PI) and PRACT and prognosis were analysed.

RESULTS: The apoptosis index (AI) was significantly higher in the PRACT group (12.5‰±4.33‰) than in the untreated group (7.1‰±3.43‰, P<0.001), whereas the proliferation index (PI) in the PRACT group (33.8%±8.8%) was significantly lower than that in untreated group (43.6%±12.8%, P<0.01). Both AI and PI were correlated to the differentiation degree of GC in PRACT group, the AI in the differentiated group was higher than that in undifferentiated group (P<0.001), but the PI was lower in the differentiated group than that of the undifferentiated group (P<0.01). The AI of GC cells in metastatic lymph node was also significantly higher in the PRACT group (7.9‰±3.41‰) than in the untreated group (3.6‰±2.93‰, P<0.01), though the PI of GC cells in metastatic lymph nodes in the PRACT group (17.2%±6.8%) was significantly lower than that in the untreated group (26.7%±9.3%, P<0.01). The severity of histopathologic changes was significantly higher in the PRACT group than in the untreated group (P<0.05). In addition, postoperative surveys demonstrated that the 5-year survival rate of GC patients in the PRACT group was significantly higher than that of patients in the untreated group (P<0.01).

CONCLUSION: Preoperative regional artery chemotherapy (PRACT) showed inhibitory action on the growth of GC cells mainly through inhibiting proliferation and inducing the apoptosis of tumor cells. PRACT can improve the prognosis of GC patients also.

Tao HQ, Zou SC. Effect of preoperative regional artery chemotherapy on proliferation and apoptosis of gastric carcinoma cells. World J Gastroenterol 2002;8(3):451-454

INTRODUCTION
Human gastric carcinogenesis is a multistep and multifactorial process^{[ 1-8]}. In this process, the state of apoptosis and proliferation of gastric epithelium will change^{[ 9,10]}. The loss of balance between cell proliferation and apoptosis may result in tumor development and progression^{[ 11-16]}. Cell necrosis and apoptosis are two fundamental processes of tumor cell death. Apoptosis is the biological process of tumor cell death regulated by genes^{[ 17-28]}. Many (and perhaps all) agents of cancer chemotherapy effect tumor cell killing in vitro and in vivo through inducing the mechanisms of apoptosis. Many chemotherapy-induced side-effects and mass shrinkage may result from the increase of tumor cell apoptosis and the inhibition of tumor cell proliferation^{[ 17, 29-34]}.
      To clarify the relationship between the effects of preoperative regional artery chemotherapy (PRACT) on inhibition and killing of GC cells with apoptosis, methods of terminal-deoxynucleotidyl-transferase (TdT)-mediated dUTP-fluorescein and labeling (TUNEL) and immunohistochemical techniques were used to detect the apoptosis and proliferation of GC cells in 110 cases of GC with or without PRACT. Histopathologic changes and prognosis were also observed and compared between the two groups.

MATERIALS AND METHODS
Clinical data
110 patients with GC who underwent curative resections at Zhejiang Provincial Peoples' Hospital from Dec. 1988 to July 1996 were studied, including 68 cases with PRACT and 42 cases without PRACT. No significant difference was found in the age, sex, and TNM staging between the two groups. The surgical specimens were fixed in 10% formaldehyde solution, and paraffin embedded tissue blocks were cut into 6μm sections and mounted on glass slides. All patients had been followed up at least 5 years after operation.

Scheme of preoperative chemotherapy
Celiac arteriography was performed by precutaneous transfemoral-artery catheters according to Seldinger's method and superselective catheterization proceeded to the supplying artery of focus of lesion. Antineoplastic agents of FAP(5-FU 1.0g/m², MMC 10mg/m², CDDP 80mg/m²) or FMP(5-FU 1.0g/m², ADR 20mg/m², CDDP 80mg/m²) scheme was infused into regional artery by a single administration and thereafter surgical operation was performed in 10-14 days.

Main reagents
Terminal-deoxynucletotidyl-transferase(TdT)-mediated dUTP-fluorescein and labeling(TUNEL) kits were purchased from Boehringers Inc. and stored in -20℃ for use. SP kits and PCNA monoclonal antibody were produced by Maixin Inc.(Fujian).

Histochemical detection of apoptosis
Tumor cell apoptosis was identified by the TUNEL method^{[ 35,36]}. Briefly, deparaffinized and rehydrated sections were treated with proteinase K (20mg/L in 10mmol/L Tris, pH 8.0) for 20min at room temperature and washed with 1×TBS (20mmol/L Tris, pH 7.6, 140mmol/L NaCl). After, endogenous peroxidase was inactivated by using 30ml/L hydrogen for 5min and washing with 1×TBS. Equilibration buffer was added to each section and samples were incubated at room temperature for 20min. Terminal deoxynucleotidyl transferase (TdT) enzyme in TdT labeling reaction mixture at 1:20 dilution was piped onto the sections, followed by 2h incubation at 37℃. After terminating the reaction by immersing sections into stop solution and washing with blocking buffer for 10min at room temperature, the anti-digoxingenin-peroxidase was added to the sections. NBT/BCIP solution was used for color development. Sections were counterstained by fast red. A positive control was generated by covering a specimen with DNase I(1mg/L) as the first step of the procedure. Specific positive tissue sections were used for negative controls by substituting distilled water for the TdT in the reaction mixture. Positively stained tumor cells were identified as nuclei that were blue-brown in color, and were counted in ten randomly selected fields under high power of microscope to determine the rate of apoptosis cell among all tumor cells. Apoptotic index (AI)=(the number of apoptosis cells/total number of tumor cells)×1000‰.

Immunohistochemical staining for PCNA
SP immunohistochemical staining techniques were used. The primary antibody was PCNA monoclonal antibody (diluted 1:50). Before staining,the sections were microwave heated in 0.05mol·L^-1 citric acid solution for antigen retrieval. PBS was substituted for primary antibodies as negative control. PCNA-positive cells (proliferative cells) were observed. The proliferative index (PI) was obtained by calculating the percentage of positively stained cells evaluated for each tissue section after counting 1000 cells at ten high power fields randomly.

Comparison of pathologichistology change
In H&E staining sections, tumor cell necrosis and degeneration, endothelium change, and the degree of fibrosis were observed and compared between the PRACT group and untreated group. The degree of histopathologic change was divided into four grades from 0 to III.

Statistical analysis
Data were expressed as mean±SD, and the t test or Wilcoxin test were used for statistical analysis. Survival rate was calculated by using Kaplan-Meier method and analyzed by the log-rank test. The level of significance was P<0.05.

RESULTS
Comparison of tumor cell proliferation and apoptosis between PRACT and untreated groups
The main morphological characteristics of apoptosis cell consist of cell shrinkage, cytoplasmic condensation, nuclear pryknosis, cytomembrane blebbing or fragmentation, and formation of apoptotic bodies. More apoptosis and less proliferation were detected in the patients in the PRACT group. The apoptosis index (AI) of the PRACT group and untreated group was (12.5‰±4.33‰) and (7.1‰±3.43‰), respectively. The t test showed that the AI of the PRACT group was significantly higher than that of the untreated group (P<0.001), whereas the proliferation index (PI) in the PRACT group (33.8%±8.8%) was significantly lower than that in untreated group (43.6%±12.8%, P<0.01).

Relationship between tumor cell proliferation, apoptosis and the tumor differentiation degree in PRACT group
The pathologic diagnosis and grading of GC was determined according to the Histopathologic Standard of the Chinese National Gastric Cancer Association. GC was divided mainly into two histologic subtypes: a differentiated type which consists of papillary and tubular adenocarcinomas, and an undifferentiated type which consists of poorly differentiated adenocarcinomas, signet ring-cell carcinomas and mucinous adenocarcinomas. Among the 68 patients with PRACT, AI of 32 tumors of the differentiated type was (14.8‰±4.99‰), while that of undifferentiated type tumor was only (6.6‰±3.31‰), AI was significantly different between the two groups (P<0.001). However, the PI of 32 tumors of the differentiated type (29.6%±7.4%) was lower than that in the undifferentiated group (38.5%±11.2%, P<0.01).

Effect of PRACT on proliferation and apoptosis of metastatic lymph node GC cells
Among the 62 cases with lymph node metastasis, AI of metastatic lymph node GC cells in 34 cases with PRACT was (7.9‰±3.41‰), and that of 28 cases without PRACT was (7.9‰±2.93‰). The t test indicated that there was a significant difference between two groups (P<0.01). On the contrary, the PI in the metastatic lymph node GC cells in 34 cases with PRACT (17.2%±6.8%) was significantly lower than that of 28 untreated cases (26.7%±9.3%, P<0.01).

Comparison of histopathologic changes between PRACT and untreated groups (Table1)
The data are shown in Table 1. No change was marked as grade 0, I to III grade was defined change. The Wilcoxin test showed a significance difference between the two groups.

Table 1 Comparison of histopathologic changes between the PRACT group and the untreated group

^aP<0.05, vs I+II+III

Effect of PRACT on the survival rate of GC patients
All patients underwent curative resection and had been followed up for at least 5 years, 49 died of tumor recurrence. A postoperative survey demonstrated that the 5-year survival rate of patients with PRACT (63.2%, 43/68) was significantly higher than that of patients without PRACT (42.8%, 18/42, P<0.01).

DISCUSSION
PRACT can effectively inhibit or kill cancer cells by a single administration of high concentration antineoplastic agent into the main supplying artery of the cancer focus. It can not only limit and reduced the tumor mass and improve the curative rate, but it can also act on the peri-operative area by means of drug infiltration to kill subclinical tumor foci which may exist before the operation as well as the invisible micrometastatic foci so as to increase the opportunity of curative resection^{[ 33,37]}. Many in vitro and in vivo experiments indicated that the induction of apoptosis and inhibition of proliferation are the main mechanisms of eliminating tumor cells by most chemotherapeutic agents^{[ 17,29-34,38]}. To explore the effect of PRACT on human GC cell apoptosis, TUNEL, a combined molecular biological and morphological technique, was used to investigate and compare the number of apoptotic cells in GC tissue sections as well as that in metastatic lymph node sections of the PRACT and untreated groups. This method, using an in situ staining technique, demonstrates not only the distribution pattern of apoptotic cells, but also the sensitivity of the tequnique: it can detect very small amount of apoptotic cells, so it is wildly used in cell apoptosis studies^{[ 35,36]}. Moreover, PCNA expression was detected by using an immunohistochemical technique in order to count the proliferation index.
      Cell apoptosis is different from cell necrosis; the latter is a pathological form of extensive cell death under strong cell damage and it is not under gene regulation, while cell apoptosis is a normal physiological phenomenon for the active elimination of surplus cells or defective cells under strict genetic control^{[ 29]}. It plays an important role in regulating total cell amount and also in malignant disease. After gene mutation and formation of malignancy, the rate of cell apoptosis lowers significantly. It is this depletion of cell apoptosis contributing to the expansion of tumor mass; hence it is possible to treat the cancer by means of increasing the proportion of tumor cell apoptosis. Recent studies have shown that 5-Fu, MMC, CDDP, ADR and many other chemotherapeutic drugs treat cancer by inhibiting proliferation and inducing apoptosis^{[ 29-34,39-41]}. So induction of tumor cell apoptosis has already been used as an important indicator to detect the ability of chemotherapeutic drugs to inhibit tumor growth. FMC or FAP schemes composed of the aforementioned drugs are now frequently used for pre-operative chemotherapy of GC.
      Our results demonstrate that: (1) The apoptosis index of GC cells in the PRACT group is significantly higher than that of the untreated group, and PI of GC cells in the PRACT group is significantly lower than that of the untreated group, indicating that PRACT has an obvious inhibition effect on GC cells. We also found that no significant necrosis was found in the rich blood supply area around the blood vessels, but instead much apoptosis was observed there, indicating that induction of apoptosis by PRACT is the main mechanism of inhibition of tumor growth. (2) Apoptosis rate is correlated with tumor differentiation degree in the PRACT group. AI of differentiated type of GC is significantly higher than that of undifferentiated type, but PI of differentiated type of GC is significantly lower than that of undifferentiated type. This may be due to the better blood supply of the differentiated type of GC^{[ 42]}, allowing more chemotherapeutic drugs to be delivered to the tumor tissue to increase the induction of tumor cell apoptosis so it is more sensitive to chemotherapy. (3) AI of GC cells in metastatic lymph nodes is significantly higher in the PRACT group than that of the untreated group, and PI of GC cells in metastatic lymph nodes is significantly lower in the PRACT group than that of the untreated group, suggesting that PRACT is able to inhibit proliferation and induce apoptosis of metastatic tumor cells. This is very interesting, because lymph node metastasis and recurrence of GC are main factors influencing the overall postoperative survival rate. If the apoptotic cell proportion in metastatic lymph nodes can be increased by effective measures, the prognosis of postoperative GC patients can be improved. Our results suggest that PRACT may approach this goal. (4) With respect to the histopathologic change of GC, including cancer cell reactions, endothelium changes, and the degree of fibrosis, the degree of severity is higher in PRACT group than that in untreated group, suggesting that PRACT can lead to more structural changes of GC tissue so as to enhance the killing effect of cancer cells by chemotherapy drugs. (5) With regard to prognosis, we have showed that PRACT can increase the relapse-free survival rate of GC patients^{[ 37]}. In fact, altering the balance between apoptosis and proliferation may contribute to improving the prognosis of cancer^{[ 43-49]}. The results of this paper indicate that PRACT can induce apoptosis and inhibit proliferation of GC cells. So we suggest that PRACT is a useful therapeutic scheme for GC.
      In conclusion, this study of detecting the proliferation and apoptosis of GC with or without PRACT showed significant inhibition of GC cell growth by PRACT, with its mechanism mainly through inducing tumor cell apoptosis. PRACT can increase the survival rate of GC patients after operation.

REFERENCES
1    Ma JL, Liu WD, Zhang ZZ, Zhang L, You WC, Chang YS. Relationship between gastric cancer and precancerous lesions.
      Huaren Xiaohua Zazhi 1998;6:222-223
2    Liu WZ, Zheng X, Shi Y, Dong QJ, Xiao SD. Effect of Helicobacter pylori infection on gastric epithelial proliferation in 
      progressionfrom normal mucosa to gastric carcinoma. World J Gastroenterol 1998;4:246-248
3    Badov D, Lambert JR, Finlay M, Balazs ND. Helicobacter pylori as a pathogenic factor in Menetrier's disease. Am J       
      Gastroenterol 1998;93:1976-1979
4    Tucci A, Poli L, Tosetti C, Biasco G, Grigioni W, Varoli O, Mazzoni C, Paparo GF, Stanghellini V, Caletti G. Reversal of 
      fundic atrophy after eradication of Helicobacter pylori. Am J Gastroenterol 1998;93:1425-1431
5    Pan CJ, Zhong P, Huang XR, Liu KY, Wang SX. Study on the correlation between proliferation and apoptosis in atrophy
      and intestinal metaplasia of gastric mucosa. Shejie Huaren Xiaohua Zazhi 2000;8:143-146
6    Xia HX, Zhang GS. Apoptosis and proliferation in gastric cancer caused by Hp infection. Shijie Huaren Xiaohua Zazhii 
      1999;7:740-742
7    Lu W, Chen LY, Gong HS. PCNA and c-erbB-2 expression in gastric mucosal intestinal metaplasia with Helicobacter
      pylori infection. Shijie Huaren Xiaohua Zazhi 1999;7:111-113
8    Ishida M, Gomyo Y, Tatebe S, Ohfuji S, Ito H. Apoptosis in human gastric mucosa, chronic gastritis, dysplasia, and 
      carinoma: analysis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling. Virchows Arch 
      1996;428:229-235
9    Wang YK, Ji XL, Ma NX. Expressions of p53 bcl-2 and c-erbB-2 proteins in precarcinomatous gastric mucosa.
      Shijie Huaren Xiaohua Zazhi 1999;7:114-116
10  Tu SP, Jiang SH, Tan JH, Jiang XH, Qiao MM, Zhang YP, Wu YL, WU YX. Proliferation inhibition and apoptosis induced by 
      arsenic trioxide on gastric cancer cell SGC-7901. Shejie Huaren Xiaohuan Zazhi 1999;7:18-21
11  Anti M, Armuzzi A, Gasbarrini A, Gasbarrini G. Importance of changes in epithelial cell turnover during Helicobacter
      pylori infection in gastric carcinogenesis. Gut 1998;43:S27-S32
12  Akira K, Yoshihiko M, Tadashi K, Yoshihiro K, Keizo S. The biologic features of intramucosal gastric carcinoma with
      lymph node metastasis. Surgery 2002;131:S71-77
13  Martin SJ, Green DR. Apoptosis and cancer: the failure of controls on cell death and cell survival. Crit Rev Oncol/
      Hematol 1995;18:137-153
14  Guo YQ, Zhu ZH, Li JF. Flow cytometric analysis of apoptosis and proliferation in gastric cancer and precancerous lesion.
      Shijie Huaren Xiaohua Zazhi 2000;8:983-915
15  Shen YF, Zhuang H, Shen JW, Chen SB. Cell apoptosis and neoplasms. Shijie Huaren Xiaohua Zazhi 1999;7:267-268
16  Hale AJ, Smith CA, Satherland LC, Stomeman VEA, Longthorne VL, Culhane AL. Apoptosis: molecular regulation of cell 
      death. Eur J Biochem 1996;236:1-26
17  Kimura H, Konishi K, Kaji M, Maeda K, Yabushita K, Tsuji M, Ogino H, Satomura Y, Unoura m, Miwa A. Apoptosis, cell 
      proliferation and expression of oncogenes in gastric carcinomas induced by preoperative admonistration of 5-
      fluorouracil. Oncol Rep 2000;7:971-976
18  Liu HF, Liu WW, Fang DC, Men RP. Expression and significance of proapoptotic gene Bax in gastric carcinoma.
      World J Gastroenterol 1999;5:15-17
19  Liu HF, Liu WW, Fang DC, Men RP. Expression of bcl-2 protein in gastric carcinoma and its significance. World J 
      Gastroenterol 1998;4:228-230
20  Xu AG, Li SG, Liu JH, Gan AH. Function of apoptosis and expression of the proteins Bcl-2, p53 and C-myc in the 
      development of gastric cancer. World J Gastroenterol 2001;7:403-406
21  Guo CQ, Wang YP, Liu GY, Ma SW, Ding GY, Li JC. Study on Helicobacter pylori infection and -p53, c-erbB-2 gene 
      expression in carcinogenesis of gastric mucosa. Shijie Huaren Xiaohua Zazhi 1999;7:313-315
22  Qin LJ. In situ hybridization of P53 tumor suppressor gene in human gastric precancerous lesions and gastric cancer.
      Shijie Huaren Xiaohua Zazhi 1999;7:494-497
23  Zhang ZW, Farthing MJG. Molecular mechanisms of H. pylori associated gastric carcinogenesis. World J Gastroenterol 
      1999;5:369-374
24  Mao LZ, Wang SX, Ji WF, Ren JP, Du HZ, He RZ. Comparative studies on p53 and PCNA expressions in gastric carcinoma 
      between young and aged patients. Huaren Xiaohua Zazhi 1998;6:397-399
25  Wang XH,Zhang WD,Zhang YL,Zheng JZ,Sun Y.Relationship between Hp infection and oncogene and tumor suppressor 
      gene expressions in gastric cancer and precancerosis.Huaren Xiaohua Zazhi 1998;6:516-518
26  Sun YX, Chen CJ, Zhou HG, Shi YQ, Pan BR, Feng WY. Expression of c-myc and p53 in colorectal adenoma and 
      adenocarcinoma. Huaren Xiaohua Zazhi 1998;6:1054-1056
27  Xu QW, Li YS, Zhu HG. Relationship between expression P53 protein, PCNA and CEA in colorectal cancer and lymph
      node metastasis. World J Gastroenterol 1998;4:218
28  Lin GY, Chen ZL, Lu CM, Li Y, Ping XJ, Huang R. Immunohistochemical study on p53, H-rasp21, c-erbB-2 protein and
      PCNA expression in HCC tissues of Han and minority ethnic patients. World J Gastroenterol 2000;6:234-238
29  Yusuf AH. Apoptosis and the dilemma of cancer chemotherapy. Blood 1997;89:1845-1853
30  Zain J, Huang YQ, Feng X, nierodzik ML, Li JJ, Karpatkin S. Concerntration-dependent dual effect of thrombin on
      impaired growth/apoptosis or mitogenesis in tumor cells. Blood 2000;95:3133-3138
31  Kelly JD, Williamson KE, Weir HP, McManus DT, Hamilton PW, Keane PF, Johnston SR. Induction of apoptosis by 
      mitomycin-C in an ex vivo model of bladder cancer. Bju Int 2000;85:911-917
32  Shah SA, Potter MW, McDade TP, Ricciardi R, Perugini RA, Elliott PT, Adams J, Callery MP. 26S proteasome inhibition 
      induces apoptosis and limits growth of human pancreatic cancer. J Cell Biochem 2001;82:110-122
33  Huang j, He X, Lin X, Zhang C, Li J. Effect of preoperative transcatheter arterial chemoembolization on tumor cell activity 
      in hepatocellular carcinoma. Zhonghua Yixue Zazhi 2000;113:446-448
34  Wu YL, Sun B, Zhang XJ, Wang SN, He HY, Qiao MM, Zhong J, Xu JY. Growth inhibition and apoptosis induction of
      Sulindac on Human gastric cancer cells. World J Gastroenterol 2001;7:796-800
35  Wijsmal JH, Jonker RR, Keijizer R, van de Velde CJ, Cornelisse CJ. A new method to detect apoptosis in paraffin sections 
      in situ end labeling of fragmented DNA. J Histochem Cytochem 1993;41:7-12
36  Kiyozuka Y, Akamatsu T, Singh Y, Ichiyoshi H, Senzaki H, Tsubura A. Optimal prefiration of cells to demonstrate
      apoptosis by the TUNEL method. Acta Cytol 1999;43:393-399
37  Zou SC, Qiu HS, Zhang CW, Tao HQ. A clinical and long-term follow-up study of perioperative sequential triple therapy
      for gastric cancer. World J Gastroenterol 2000;6:284-286
38  Hickman JA. Apoptosis induced by anticancer drugs. Cancer metasis Rev 1992;11:121-139
39  Dive C, Hickman JA. Drug-target interactive: only first step in the comitment to a programmed cell death? Br J Cancer 
      1991;64:192-196
40  Inada T, Ichikawa A, Igarashi S, Kubota T, Ogata Y. Effect of preoperative 5-fluorouracial on apoptosis of advanced
      gastric cancer. J Surg Oncol 1997;65:106-110
41  Inada T, Ichikawa A, Kubota T, Ogata Y, Moossa AR, Hoffman RM. 5-Fu-induced apoptosis correlates with efficacy
      against human gastric and colon cancer xenografts in nude mice. Anticancer Res 1997;17:1965-1971
42  Tao HQ, Lin YZ, Wang RN. Significance of microvessel count and vascular endotjelial growth factor expression in 
      intestinal-type gastric carcinoma. Zhongguo Zhongliu Linchuang 1998;25:786-789
43  Shen XB, Zhao XM, Hu JG, Jin XP, Wang J. Significance of cell apoptosis and proliferation in gastric cancer.
      Shejie Huaren Xiaohua Zazhi 2000;8:1050-1052
44  Zhang M, Cai S, Shi D. Prognostic value of cell proliferation and apoptosis in uterine cervical cancer treated with
      radiation. Zhonghua Zhongliu Zazhi 1999;21:290-292
45  Xie X, Clausen OPF, De Angelis P, Boysen M. Bax expression has prognostic significance that is enhanced when
      combined with AgNOR counts in glottic carcinoma. Br J Cancer 1998;78:100-105
46  Rieger L, Weller M, Bornemann A, Schabet M, Dichgans J, Meyermann R. Bcl-2 family protein expression in human 
      malignant glioma: a clinical-pathological correlative study. J Neurol Sci 1998;155:68-75
47  Re GG, Hazen-Martin DJ, EL-Bahtimi R, Brownlee NA, Willingham MC, Garvin AJ. Prognostic significance of Bcl-2 in
      Wilm's tumors and oncogenic protential of Bcl-Xl in rare tumor cases. Int J Cancer 1999;84:192-200
48  Ghanem MA, van der Kwast TH, Den Hollander JC, Sudaryo MK, Van den Heuvel MM, Noordzij MA, Nijman RJM,
      Soliman EH, van Steenbrugge GJ. The prognostic significance of apoptosis-associated protein Bcl-2, BAX, and Bcl-X in 
      clinical nephroblastoma. Br J Cancer 2001;85:1557-1563
49  Apolinario RM, van der Valk P, de Jong JS, Deville W, van Art-Otte J, Dingemans AM, van Mourik JC, Postmus PE,
      Pinedo HM, Giaccone G. Prognostic value of the expression of p53, bcl-2, and bax oncoproteins, and neovascularization
      in patient with radically resected non-small-cell lung cancer. J Clin Oncol 1997;15:2456-2466

Edited by Pagliarini R

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