
Clinical Cancer Research Vol. 6, 178-184, January 2000
© 2000 American Association for Cancer Research
Molecular Oncology, Markers, Clinical Correlates |
Prognostic Significance of DNA Ploidy, S-Phase Fraction, and Tissue Levels of Aspartic, Cysteine, and Serine Proteases in Operable Gastric Carcinoma1
Antonio Russo2,
Viviana Bazan,
Manuela Migliavacca,
Ines Zanna,
Carla Tubiolo,
Francesca Maria Tumminello,
Gabriella Dardanoni,
Massimo Cajozzo,
Pietro Bazan,
Giuseppe Modica,
Mario Latteri,
Rosa Maria Tomasino,
Giuseppe Colucci,
Nicola Gebbia and
Gaetano Leto
Laboratory of Oncobiology [A. R., V. B., M. M., I. Z., C. T.], Sections of Chemotherapy [F. M. T., N. G., G. L.] and Surgery [M. C., G. M., P. B., M. L.], Department of Anatomy, Surgery, and Oncology, and Institute of Pathology "R" [R. M. T.], School of Medicine, University of Palermo, 90127 Palermo, Italy; Unit of Medical and Experimental Oncology, National Cancer Institute of Bari, 70126 Bari, Italy [G. C.]; and Epidemiological Observatory, Center of Sicilian Region, 90100 Palermo, Italy [G. D.]
 |
ABSTRACT
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A
consecutive series of 63 untreated patients undergoing surgical
resection for stage I-IV gastric adenocarcinomas (GCs) has been
prospectively studied. Our purpose was to analyze the predictive
relevance of DNA ploidy, S-phase fraction (SPF), and tissue levels of
lysosomal proteinases cathepsin D (CD), cathepsin B (CB), cathepsin L
(CL), and urokinase-type plasminogen activator (uPA) and that of the
intracellular cysteine proteinase inhibitor stefin A on clinical
outcome. All of the patients taking part in this study were followed up
for a median of 73 months. DNA aneuploidy was present in 71% of the
cases (45/63), whereas 9% of these (4/45) showed multiclonality. Both
DNA ploidy and SPF were associated with tumor-node-metastasis (TNM)
stage and node status, whereas only DNA ploidy was related to depth of
invasion. CB, CL, uPA, but not CD, levels were significantly higher in
GC as compared to paired normal mucosa, whereas stefin A levels were
lower in tumor tissues. CB levels were significantly associated with
TNM stage, nodal status, histological grade, and DNA ploidy. At
univariate analysis, only node involvement, advanced TNM stage, DNA
aneuploidy, and high SPF proved to be significantly related to quicker
relapse and to shorter overall survival, whereas depth of invasion was
related only to survival. With multivariate analysis, only high SPF
(>15.2%) was related to risk of relapse (RR = 8.50), whereas
high SPF and DNA aneuploidy were independently related to risk of death
(RR = 1.88 and 2.09, respectively). Our preliminary prospective
study has identified SPF and DNA ploidy as important biological
indicators for predicting the outcome of patients with GC.
 |
INTRODUCTION
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The traditional factors of
GC3
are still
inadequate for the prognostic characterization because patients with
identical clinical or pathological stages may differ widely in the
clinical evolution (1)
. It is therefore extremely
important to define the prognostic factors that may help to recognize
the more aggressive types of such tumors. Reliable and reproducible
prognostic indicators are being investigated to help clinicians
identify high-risk groups and address more rational treatment
decisions. Thus, the identification of factors more strictly related to
tumor biology may be useful in characterizing patients with a different
prognosis. Recently, more and more attention has been focused on the
cell kinetics of many human tumors with possible prognostic
significance, including gastrointestinal neoplasias (2)
.
At the present time, one of the most widely used approaches is cellular
proliferation rate measured by flow cytometric analysis (SPF), proposed
as a rapid, simple, and particularly versatile method applicable to
fresh, frozen, and paraffin-embedded tissues. In fact, some reports
have observed that SPF was an independent prognostic variable in GC
(3, 4, 5)
. Previous studies have also identified a DI and/or
DNA ploidy as a useful biological factor, which may predict the
clinical outcome of GC (4, 5, 6, 7, 8)
. Furthermore, a consistent
bulk of investigations has shown that the expression levels of
lysosomal aspartic and cysteine proteinase CD, CB, and CL and serine
protease uPA may be significantly altered in tumor cells and tissues as
compared to their normal counterpart (9
, 10)
. These
alterations appear to be associated with the malignant progression of
several human neoplastic diseases including GC (10, 11, 12, 13, 14, 15, 16)
.
However, recent studies indicate that at least for CB and CL, this
phenomenon may very likely be due to an altered regulation and/or
decreased affinity of specific intracellular inhibitors of these
proteases (17
, 18)
or also, as recently reported for CB,
the amplification of the gene encoding for these enzymes (19
, 20)
, rather than to an increased enzyme activity per
se.
The aims of this paper were, firstly, to compare DNA ploidy and SPF,
their possible relations to the proteinases CD, CB, CL, and uPA, and
that of SA, a specific intracellular inhibitor of cysteine proteinases
and clinicopathological features; and secondly, to evaluate the
possible prognostic role of either DNA ploidy and SPF or proteinases in
GC.
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MATERIALS AND METHODS
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Patient Features.
Paired tumor and normal tissue samples collected (January 1992 to June
1996) by the Laboratory of Oncobiology of the University of Palermo
from a consecutive series of 63 patients undergoing resective surgery
for primary operable GC at a single institution (Department of Anatomy,
Surgery, and Oncology) were prospectively studied. Briefly, exclusion
criteria included: (a) history of previous neoplasias, and
(b) prior chemotherapy or radiation therapy. Resection of
the primary GC was performed in all cases. All patients underwent
potentially curative tumor resection, including radical lymph node
dissection. To avoid evaluator variability, all resection specimens and
microscopic slides had been meticulously examined by a single
pathologist (R. M. T.). In addition, the same pathologist
assessed tumor size and site, depth of invasion, TNM stage, tumor grade
(histological differentiation), and lymph node metastasis. The depth of
tumor invasion was also evaluated histologically as reported by
Watanabe et al. (13)
. Tumors were staged
according to the latest TNM classification (21)
. Finally,
metastatic cases were identified by clinical and histopathological
analyses of neoplastic cells in organs such as lymph nodes, liver, and
so forth along with the primary tumor. Clinicopathological data of all
patients were available (Table 1)
.
Postoperatively, all patients were checked at 3-month intervals for the
first 2 years, at 6-month intervals for the next 2 years, and annually
thereafter. The follow-up program included a clinical examination,
routine check of circulating tumor markers (CEA, TPA, CA19.9, and
CA72.4 assay), annual chest radiography, and endoscopy. Abdominopelvic
computed tomography scan was also performed every year for the first 2
years. Disease relapse (local recurrence or distant metastasis) was
confirmed histologically where possible. All of the patients with
relapse disease after surgery received a standard
chemotherapeutic regimen for GC (5-fluorouracil, epirubicin,
methotrexate, etoposide, doxorubicin, cisplatin).
Tissue Handling.
Multiple samples of the primary tumor tissue were taken from different
representative areas and processed within 30 min of surgical resection
or biopsy. All tissues were carefully trimmed to remove as much
nonneoplastic tissue as possible, avoiding the nonviable areas.
Furthermore, from each patient, multiple samples of normal mucosa (as
confirmed by histology) were taken in a corresponding nontumor area as
far as possible from the tumor site to be used as a control for
biochemical/cytochemical and flow cytometric analysis. The tissues were
bisected, one-half of each sample was processed for pathological
examination, and the remaining half of the sample pool was immediately
frozen and stored at -80°C until analyzed. The adequacy of the
material was checked on frozen tissue sections, and only tissue samples
with >80% tumor content were used in subsequent
biochemical/cytochemical and flow-cytometric analysis.
Cellular DNA Content and SPF Flow Cytometric Examination.
DNA flow cytometry was performed on mechanically disaggregated samples
of frozen tumor tissue as in previously described protocols
(22)
. DNA histogram analysis was carried out by the
Multicycle Software Program (Phoenix Flow Systems, San Diego, CA),
including systematic background substraction (23
, 24)
. DNA ploidy, DI, and SPF were determined as previously
reported (22)
. Briefly, healthy gastric mucosa was used as
an internal DNA-diploid control for each sample. Tumors with a DI = 1 were defined as DNA-diploid, and tumors with lower or higher DI
values were considered DNA-aneuploid if they contained >10% aneuploid
cells.
Tissue Extraction and Determination of CB, CD, CL, uPA, and SA
Tissue Content.
Paired sets of tumor and normal tissue specimens (70210 mg) were
thawed, minced, and suspended at 25 mg/ml in a tissue homogenization
buffer [50 mM Tris-HCl, 5 mM EDTA, 0.5
mM DTT, and 0.2% v/v Triton X-100 (pH 6.9)]. Samples were
homogenized at 2°C in an ice slurry in a Willelms Polytron PT-10
homogenizer (Kinematica, Luzern, Switzerland) set to rotate at 9, with
two bursts of 30 s and a 1-min intercooling period. The homogenate
was centrifuged at 500 g for 10 min. The supernatant was respun at
13,000 g for 15 min at 4°C in a preparative ultracentrifuge (Beckman
Model L80). The 13,000-g supernatant (i.e., cytosol) was
stored at -80°C until assays. Total CD content was determined, as
previously reported (25)
, by an antibody-based
immunoenzymatic assay kit (Triton, Ciba Corning, Diagnostics, Alameda,
CA) according to the manufacturers instructions. The detection limit
was 0.018 pmol/ml. Total CB, CL, and SA tissue levels were determined
by commercially available solid phase ELISA kits (KRKA d.d.,
Novo mesto, Slovenia) in cytosol diluted 1:2 or 1:5 (v/v) according to
the manufacturers protocol. Antibodies used for CB and CL assays
recognized mature forms, precursor molecules, and inhibitor-cathepsin
complexes. For the determination of SA, MoAbs used in sandwich ELISA
were obtained by hybridoma cell lines different from those used to
produce other cysteine protease inhibitor MoAbs
(26)
. The minimal detectable concentrations were
0.9 ng/ml for CB, 1.6 ng/ml for CL, and 1.04 ng/ml for SA. uPA levels
were determined by a commercially available immunoluminometric assay
kit (Byk Sangtec, Cormano, Italy). The MoAbs used bind either to the
proenzyme or to the active form as well as to the enzyme bound to its
receptor (uPA-R) or to its endogenous inhibitor (PAI-1). The detection
limit was reported to be <0.005 ng/ml. The cytosol protein content was
determined by a commercially available colorimetric micromethod kit
(Sigma, St. Louis, MO).
Statistical Analysis.
Because of their asymmetric distribution, the Mann-Whitney U
test was used to evaluate differences in proteinases and SPF
values between the two categories of DNA ploidy. The nonparametric
Spearman correlation method was used to evaluate the correlation
between the proteinases variables examined. DFS was measured from the
day of primary surgery to the date of first relapse (locoregional or
metastatic), and OS was measured from the day of surgery to the date of
death specifically due to the tumor. Clinical and morphobiological
variables were examined univariately by means of the Kaplan-Meier
method (27)
, and significance of differences for each
prognostic factor was assessed by the log-rank test and Wilcoxon test
or test for trend when appropriate (28)
. Multivariate
analysis was carried out by means of the Coxs logistic regression
model using a backward procedure (29)
. The null hypothesis
ß = 0 was tested by the Wald statistic. The relative
contribution of clinicopathological and biological variables was
assessed by means of the likelihood ratio test. For the prognostic
variables contributing significantly to the model, the effect was
calculated in terms of RR and the associated 95% confidence limits.
The 0.05 level of probability was taken as significant.
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RESULTS
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Cellular DNA Content and S-Phase Evaluation.
Adequate DNA histograms were obtained for all normal and tumoral
gastric tissues by means of flow-cytometry. The coefficients of
variation of the diploid
G0/G1 peak ranged from
2.6% to 4.8% (mean, 3.6%). DNA aneuploidy was found in 71% of the
cases (45/63), while 9% of these (4/45) showed multiclonality. The SPF
ranged from 3.5% to 37.2% (median, 15.2% and interquartile range,
12.119.1%). By using the SPF median value as the cutoff point,
tumors were accordingly divided into low (
15.2%) and high (>15.2%)
SPF tumors. Table 2
gives a summary of
the significant associations of DNA ploidy and SPF to the
clinicopathological variables for GC. Both DNA ploidy and SPF were
associated with TNM stage and node status, whereas only DNA ploidy was
related with depth of invasion. Furthermore, a significant association
was found between flow cytometric variables (DNA ploidy and SPF). No
association was found between DNA ploidy and SPF and any of the
following factors: age, sex, histological grade, tumor size, and tumor
site.
CB, CD, CL, SA, and uPA Activity Levels in Gastric Tumor and Normal
Tissues.
Table 3
reports the tissue levels of CD,
CB, CL, uPA, and SA determined in GC and in the corresponding normal
mucosa. Only CB, CL, and uPA levels were significantly increased in
tumor tissue as compared to the paired normal counterpart
(P < .05 for CL and P < .01 for CB
and uPA; Table 3
). Moreover, the SA levels were lower in tumor tissue
as compared to normal tissue; however, this decrease was not
statistically significant. CD tumor levels were significantly
correlated with CB, uPA, and SA (P < .05), whereas CB
levels were correlated with CD, uPA, and SA but not with CL (Table 4)
. SA levels correlate with all of the
enzymes considered, but not with CL. Moreover, CB levels were
significantly associated with TNM stage [I (median) = 93.3;
II = 142.0; III-IV = 159.8; P < .05], node
status [node negative (median) = 91.5; node positive =
159.7; P < .06], histological grade
[G1 (median) = 63.2;
G2 = 121.7; G3 = 159.8;
P < .01] and DNA ploidy [Diploid (median) =
92.4; Aneuploid monoclonal = 156.3; Aneuploid
multiclonal = 250.9; P < .01].
Impact on Relapse and Survival.
The median follow-up of patients was 73 months (range, 12108 months).
At the time of analysis (April 1998), 31 patients had relapsed (2 had
local-regional recurrence and 29 had distant metastases) and 30 had
died of a tumor-related cause. The overall 5-year survival was 45.8%
(SE, 6.9) for the whole series. At the univariate analysis, high stage,
lymph-node positivity, DNA aneuploidy, and high SPF proved to be
significantly related to quicker relapse and to shorter OS (Table 5)
, whereas depth of invasion was related
only to survival. Univariate analysis failed to reveal any significant
association between age, sex, histological grade, tumor location, tumor
size, CB, CD, CL, uPA, or SA, and relapse, or survival. Fig. 1
shows the probability of disease-free
interval in relation to SPF; Fig. 2
shows
the probability of OS by SPF and DNA ploidy. In Coxs model for
multivariate analysis, only the significant variables at univariate
analysis were considered. The estimated hazards ratio was higher for
SPF (>15.2%), which appeared to be the most relevant indicator of
relapse (RR = 8.50), whereas multiple regression analysis carried
out for OS showed that SPF and DNA ploidy provided independent
information for predicting risk of death (Table 6)
.
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Table 5 Univariate analysis of DFS and OS: distribution
of patients for the significant variables according to Kaplan-Meier
method
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Fig. 2. Probabilty of OS according to (a)
SPF ( 15.2% versus >15.2%; P <
0.01) and to (b) DNA ploidy status (DNA-diploid
versus DNA-aneuploid monoclonal versus
DNA-aneuploid multiclonal; P < 0.01) in GC
patients.
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DISCUSSION
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Many attempts have been made to find new prognostic indicators for
patients with GC to identify the subgroup with highly aggressive tumors
and a high likelihood of disease relapse or death. Aggressive surgical
approaches, such as extended lymph node dissection or at least
intensive postoperative therapy, might be options for these poor
prognosis patients. There is still some controversy as to whether or
not the DNA content and SPF are significant prognostic factors in GC.
Several reports have shown that patients with DNA-aneuploid and/or high
SPF tumors had a worse prognosis than those with DNA-diploid and/or low
SPF tumors (3, 4, 5, 6, 7)
. Recently, in a study performed on fresh
tumor specimens taken from 76 patients with GC, Abad et
al. (6)
found that DNA aneuploidy, histological type,
and the presence of extranodal metastases were independent predictors
of OS. By contrast, SPF did not predict patient outcome. These results
agree with those of Setala et al. (7)
and
Victorzon et al. (8)
, whose respective analysis
of 289 and 242 GC cases led to the observation that DNA ploidy and TNM
stage significantly predicted OS, whereas no significant difference was
found between SPF and prognosis. In contrast, Lee et al.
(3)
, in a 5-year prospective study of 217 patients with
GC, found that SPF was an independent prognostic variable, whereas DNA
ploidy was not associated with patient survival. Finally, Yonemura
et al. (4)
and Ohyama et al.
(5)
, in their respective series of 493 and 117 patients
with GC using multivariate analysis, found that DNA content and SPF
(measured by in vivo bromodeoxyuridine) were independent
prognostic factors for OS. In our prospective study, which was based on
univariate and multivariate analyses with established prognostic
parameters (depth of invasion, TNM stage, node status, histological
grade), we found that SPF was the only predictor of disease
relapse. Furthermore, the present study clearly shows that both
DNA ploidy and SPF are significant and independent prognostic factors
for OS in patients with GC who have undergone surgical resection. Our
data also show that DNA multiploidy represents the most powerful
predictive indicator for survival. These results suggest that studies
of pathological prognostic factors should include these biological
variables. Moreover, because DNA analysis of endoscopic biopsy
specimens correlates well with surgical specimen DNA analysis
(30)
, preoperative evaluation of flow cytometric variables
may be useful for predicting prognosis and choosing an adequate
therapeutic modality in patients with GC. The frequency of DNA
aneuploidy has been reported in a variable percentage of GC, from 36%
to 71% (3, 4, 5
, 6, 7, 8
, 31
, 32)
. In the present series, the
DNA-aneuploid rate (71%) was among the highest published thus far.
This is probably due to the use of multiple tissue sampling of all
cases studied, which greatly reduces the probability of missing
DNA-aneuploid clones, and to the method chosen to preserve the samples
(freezing at -80°C), which makes it possible to obtain a higher
histogram resolution compared with paraffin-embedded samples. The
present study shows that DNA ploidy and/or SPF are significantly
associated to depth of invasion, advanced clinical stage, and the
presence of lymph node metastases. Histopathological features are
universally considered bad prognostic factors (14)
. Thus,
the association with these variables suggests that flow cytometric
indicators are related to tumor aggressiveness. This is in accordance
with previous studies (6, 7, 8)
. Moreover, the perturbance of
cell cycle due to an increased proliferative activity of aneuploid
clones or to a prolongation of the S phase may enhance the risk of
genetic alterations. This phenomenon may result in the onset of
DNA-aneuploid cells, which would explain the significant relationship
between high SPF and aneuploidy observed in the present study. Finally,
unlike other investigators (7
, 31)
, we did not observe a
significant association between DNA ploidy and tumor site (fundus or
cardia) as noted in three other series (3
, 8
, 33,)
. The
present results confirm, in part, the data obtained from other studies,
which have reported elevated content or activity levels of CB, CL, and
uPA in GC tissues as compared to normal gastric mucosa (11, 12, 13
, 15
, 16
, 32)
.
However, only CB proved to be significantly associated with most of the
clinicobiological parameters of progression of this tumor. Moreover,
the intracellular cysteine proteinase inhibitor SA levels were lower in
tumor tissue as compared to those in its normal counterpart. These
results indicate that the alterated regulation of cysteine
proteinases/SA ratio at the tumor level may facilitate the progression
of GC. In fact, this phenomenon has been observed "in
vitro " in human cancer cell lines, and it has proved to be
associated with a more malignant phenotype (34
, 35)
. Furthermore, decreased levels of SA have also been
seen "in vivo " in different human tumors of epithelial
origin and have proved to be associated with the metastatic potential
and differentiation of these tumors (11
, 18
, 19)
. These
data suggest that the increased level of CB, together with other
proteolytic enzyme (metalloproteases), which appear to determine the
malignant phenotype of GC, may play a major role in the progression of
this tumor (34
, 36
, 37)
. However, the recent observations,
which showed that proteinase inhibitors at subinhibitor concentrations
may act as mitogens thus facilitating cell proliferation (19
, 35)
, indicate that SA may also directly share the malignant
progression of GC with a mechanism not related to its
proteinase-inhibiting activity. This may in part explain the
direct and not the inverse correlation, which might be expected,
observed between CB and SA at the tumor level. On the other hand,
conflicting results have been obtained regarding the distribution of
CD. In fact, unlike the results reported in other studies (14
, 16)
, we did not observe any significant difference in the levels
of this protease between GC and normal mucosa or the association with
most of the clinicobiological parameters considered, including disease
relapse and death. These conflicting results may be partly explained by
the different methodological approaches used to assess this parameter
(i.e., immunohistochemistry versus immunoenzyme
assay). Our investigations also showed significantly higher levels of
uPA content in tumor tissue as compared to those in normal tissue; no
significant association was found, however, between the uPA system and
the clinicobiological parameters of GC. These results are partly in
agreement with those from other studies (12
, 16
, 37)
and
further indicate that the evaluation of the single components of the
uPA system, namely the uPA receptor or uPA inhibitors PAI-1 and PAI-2,
may be more appropriate for the assessment of the prognostic
significance of this serine protease in human cancer (15
, 16)
. However, it cannot be ruled out that the different results
we obtained on the prognostic significance of the uPA complex may also
be due to the different number of patients evaluated in our study.
In conclusion, DNA ploidy and SPF may be reasonably considered as
indicators of biological and clinical aggressiveness. If our results
are confirmed in larger prospective studies, it might be possible to
add such variables to other prognostic factors for more aggressive
strategies such as extended lymph node dissection or intensive
postoperative therapy in high risk groups (patients with high SPF
and/or DNA-aneuploid tumors) to prevent disease relapse or death. In
addition, the clinical impact of the CB/SA system as biochemical
prognostic parameters in this tumor has still to be sufficiently
assessed.
 |
FOOTNOTES
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
1 Supported by grants from the Gruppo Oncologico
dellItalia Meridionale special project "Caratterizzazione
biomolecolare del carcinoma gastrico resecato," (protocol N.9602
bis), Associazione Italiana per la Ricerca sul Cancro, Consiglio
Nazionale della Ricerca, PF Clinical Application of Cancer Research
(ACRO), (contracts 92.02199.PF39 and 96.00570.PF39) and
Ministero Universitá Ricecca Scientifica e Tecnologica
60%. 
2 To whom requests for reprints should be
addressed, at Via Veneto 5, 90144 Palermo Italy. Phone/fax:
39-091-6554529; E-mail: Lab-oncobiologia{at}usa.net 
3 The abbreviations used are: GC, gastric
adenocarcinoma; SPF, S-phase fraction; CD, cathepsin D; CB,
cathepsin B; CL, cathepsin L; uPA, urokinase-type plasminogen
activator; TNM, tumor-node-metastasis; SA, stefin A; DFS, disease-free
survival; OS, overall survival; RR, relative risk; DI, DNA index; MoAb,
monoclonal antibody. 
Received 7/20/99;
revised 10/ 1/99;
accepted 10/ 7/99.
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REFERENCES
|
|---|
-
Allgayer H., Heiss M. M., Schildberg F. W. Prognostic factors in gastric cancer. Br. J. Surg., 84: 1651-1664, 1997.[CrossRef][Medline]
-
Silvestrini R. Cell kinetics: prognostic and therapeutic implications in human tumours. Cell. Proliferation, 27: 579-596, 1994.
-
Lee K. H., Lee J. S., Lee J. H., Kim S. W., Suh C., Kim W. K., Kim S. H., Min Y. I., Kim B. S., Park K. C., Lee M. S., Sun H. S. Prognostic value of DNA flow cytometry in stomach cancer: a 5-year prospective study. Br. J. Cancer, 79: 1727-1735, 1999.[CrossRef][Medline]
-
Yonemura Y., Ooyama S., Sugiyama K., Kamata T., De Aretxabala X., Kimura H., Kosaka T., Yamaguchi A., Miwa K., Miyazaki I. Retrospective analysis of the prognostic significance of DNA ploidy patterns and S-phase fraction in gastric carcinoma. Cancer Res., 50: 509-514, 1990.[Abstract/Free Full Text]
-
Ohyama S., Yonemura Y., Miyazaki I. Prognostic value of S-phase fraction and DNA ploidy studied with in vivo administration of bromodeoxyuridine on human gastric cancers. Cancer (Phila.), 65: 116-121, 1990.[CrossRef][Medline]
-
Abad M., Ciudad J., Rincon M. R., Silva I., Paz-Bouza J. I., Lopez A., Alonso A. G., Bullon A., Orfao A. DNA aneuploidy by flow cytometry is an independent prognostic factor in gastric cancer. Anal. Cell. Pathol., 16: 223-231, 1998.[Medline]
-
Setala L. P., Nordling S., Kosma V. M., Lipponen P. K., Eskelinen M. J., Hollmen S. M., Syrjanen K. J., Alhava E. M. Comparison of DNA ploidy and S-phase fraction with prognostic factors in gastric cancer. Anal. Quant. Cytol. Histol., 19: 524-532, 1997.[Medline]
-
Victorzon M., Roberts P. J., Haglund C., von Boguslawsky K., Nordling S. Ki-67 immunoreactivity, ploidy and S-phase fraction as prognostic factors in patients with gastric carcinoma. Oncology, 53: 182-191, 1996.[CrossRef][Medline]
-
Rochefort H., Liaudet E., Garcia M. Alterations and role of human cathepsin D in cancer metastasis. Enzyme Protein, 49: 106-116, 1996.[Medline]
-
Lah T. T., Kos J. Cysteine proteinases in cancer progression and their clinical relevance for prognosis. Biol. Chem., 379: 125-130, 1998.[Medline]
-
Farinati F., Herszenyi L., Plebani M., Carraro P., De Paoli M., Cardin R., Roveroni G., Rugge M., Nitti D., Grigioni W. F., DErrico A., Naccarato R. Increased levels of cathepsin B and L, urokinase-type plasminogen activator and its inhibitor type-1 as an early event in gastric carcinogenesis. Carcinogenesis (Lond.), 17: 2581-2587, 1996.[Abstract/Free Full Text]
-
Plebani M., Herszènyi L., Cardin R., Roveroni G., Carraro P., Paoli M. D., Rugge M., Grigioni W. F., Nitti D., Naccarato R., Farinati F. Cysteine and serine proteases in gastric cancer. Cancer (Phila.), 76: 367-375, 1996.
-
Watanabe M., Higashi T., Watanabe A., Osawa T., Sato Y., Kimura Y., Tominaga S., Hashimoto N., Yoshida Y., Morimoto S., Shiota T., Hashimoto M., Kobayashi M., Tomoda J., Tsuji T. Cathepsin B and L activities in gastric cancer tissue: correlation with histological findings. Biochem. Med. Metab. Biol., 42: 21-29, 1989.[CrossRef][Medline]
-
Allgayer H., Babic R., Grutzner K. U., Beyer B. C., Tarabichi A., Schildberg W. F., Heiss M. M. An immunohistochemical assessment of cathepsin D in gastric carcinoma: its impact on clinical prognosis. Cancer (Phila.), 80: 179-187, 1997.[CrossRef][Medline]
-
Ganesh S., Sier C. F. M., Heerding M. M., van Krieken J. H. J. M., Griffioen G., Welwaart K., van de Velde C. J. H., Lamers C. B. H. W., Verspaget H. W. Prognostic value of the plasminogen activation system in patients with gastric carcinoma. Cancer (Phila.), 77: 1035-1043, 1996.[CrossRef][Medline]
-
Allgayer H., Babic R., Grutzner U., Beyer B. C. M., Tarabichi A., Schildberg F. W., Heiss M. M. Tumor-associated proteases and inhibitors in gastric cancer: analysis of prognostic impact and individual risk protease patterns. Clin. Exp. Metastasis, 16: 62-73, 1998.[CrossRef][Medline]
-
Henskens Y. M. C., Veerman E. C. I., Amerongen A. V. N. Cystatins in health and disease. Biol. Chem. Hoppe-Seyler, 377: 71-86, 1996.[Medline]
-
Scott G. K. Proteinases and proteinase inhibitors in tumor cell growth and metastasis. Cancer J., 10: 80-86, 1997.
-
Abdollahi A., Getts L. A., Sonoda G., Miller P. D., Taguchi T., Godwin A. K., Testa J. H., Hamilton T. C. Genome scanning detects amplification of the cathepsin B gene (CTsB) in transformed rat ovarian surface epithelial cells. J. Gynecol. Invest., 6: 32-40, 1999.
-
Hughes S. J., Glover T. W., Zhu X. X., Kuick R., Thornual D., Orringer M. B., Beer D. G., Hananh S. A novel amplicon at 8p2223 results in overexpression of cathepsin B in esophageal adenocarcinoma. Proc. Natl. Acad. Sci. USA, 95: 12410-12415, 1998.[Abstract/Free Full Text]
-
Bears, O. H., Hensen, D. E., Hutter, R. V. P., and Meyers, M. H. Manual for Staging of Cancer, 3rd ed., pp. 6971. Philadelphia: J. B. Lippincott, 1988.
-
Russo A., Bazan V., Morello V., Tralongo V., Nagar C., Nuara R., Dardanoni G., Bazan P., Tomasino R. M. Vimentin expression, proliferating cell nuclear antigen and flow cytometric factors. Anal. Quant. Cytol. Histol., 16: 365-374, 1994.[Medline]
-
Dean P. N., Jett J. H. Mathematical analysis of DNA distribution derived from flow cytometry. J. Cell Biol., 60: 523-527, 1974.[Free Full Text]
-
Rabinovitch P. S. Numerical compensation for the effects of cell clumping on DNA histograms. Cytometry, 4: 27 1990.
-
Tumminello F. M., Gebbia N., Pizzolanti G., Russo A., Bazan V., Leto G. Cathepsin D content in colorectal cancer. Correlation with cathepsin D activity and other biological parameters. A Preliminary Report. Oncology, 52: 237-242, 1995.[Medline]
-
Jerala R., Zerounik E., Lohner K., Turk V. Structural basis for the difference in thermodynamic proprieties between the two cysteine proteinase inhibitors human stefin A and B. Protein Eng., 7: 977-984, 1994.[Abstract/Free Full Text]
-
Kaplan E. L., Meier P. Non parametric estimation for incomplete observations. J. Am. Stat. Assoc., 53: 457-481, 1958.[CrossRef]
-
Peto R., Pike M. C., Armitage P., Breslow N. E., Cox D. R., Howard S. V., Mantel N., McPherson K., Peto J., Smith P. G. Design and analysis of randomized clinical trials requiring prolonged observation of each patients. II. Analysis and examples. Br. J. Cancer, 35: 1-39, 1977.[Medline]
-
Cox D. R. Regression models and life tables. J. R. Stat. Soc., 34: 187-220, 1972.
-
Etoh K., Kaketani K., Saito T., Uchino S., Shimoda K., Miyahara M., Kobayashi M. DNA stem-line heterogeneity as preoperative prognostic factor in esophageal cancer. Gan to Kagakn Ryoho, 21: 1-5, 1994.
-
Johnson H., Jr., Belluco C., Masood S., Abou-Azama A. M., Kahn L., Wise L. The value of flow cytometric analysis in patients with gastric cancer. Arch. Surg., 128: 314-317, 1993.[Abstract]
-
Danova M., Riccardi A., Mazzini G., Wilson G., Dionigi P., Brugnatelli S., Fiocca R., Ucci G., Jemos V., Ascari E. Flow cytometric analysis of paraffin-embedded material in human gastric cancer. Anal. Quant. Cytol. Histol., 10: 200-206, 1988.[Medline]
-
Nanus D. M., Kelsen D. P., Niedzwiecki D., Chapman D., Brennan M., Cheng E., Melamed M. Flow cytometry as a predictive indicator in patients with operable gastric cancer. J. Clin. Oncol., 7: 1105-1112, 1989.[Abstract]
-
Scaddan P. B., Dufresne M. J. Characterization of cysteine proteases and their endogenous inhibitors in MCF-7 and Adriamycin-resistant MCF-7 human breast cancer lines. Invasion Metastasis, 13: 301-313, 1993.[Medline]
-
Sun Q. Growth stimulation of 3T3 fibroblast by cystatin. Exp. Cell. Res., 180: 150-160, 1989.[CrossRef][Medline]
-
Chambers A., Colella R., Denhardt D. T., Wilson S. Increased expression of cathepsin L and B and decreased activity of their inhibitors in metastatic ras transformed NIH 3T3 cells. Mol. Carcinog., 5: 238-245, 1992.[Medline]
-
Schwartz G. K., Wang H., Lampen N., Altorki N., Kelsen D., Albino A. P. Defining the invasive phenotype of proximal gastric cancer cells. Cancer (Phila.), 73: 22-27, 1994.[CrossRef][Medline]
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