Clinical significance of spontaneous apoptosis in advanced gastric adenocarcinoma

Clearance of apoptotic cells by neutrophils in inflammation and cancer

When a cell dies of apoptosis, it is eliminated either by neighbouring cells or by attracted professional phagocytes. Although it was generally believed that neutrophils also have the ability to perform efferocytosis, their contribution to the clearance of apoptotic cells was considered less important compared with macrophages. Therefore, this ability of neutrophils remained unexplored for a long time. Over the past decade, it has been shown that during inflammation, neutrophils contribute significantly to the clearance of apoptotic neutrophils that accumulate in large numbers at the site of tissue damage. This "neutrophil cannibalism" is accompanied by inhibition of pro-inflammatory activities of these cells, such as respiratory burst and formation of neutrophil extracellular traps (NETs). Furthermore, efferocytosing neutrophils secrete anti-inflammatory mediators and mitogens including hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF2), vascular endothelial growth factors (VEGF), and transforming growth factor beta (TGFβ). Thus, efferocytosis by neutrophils is involved in resolution of inflammation. Recent research indicates that it plays also a role in cancer. Many different solid tumours contain aggregates of dead tumour cells that have undergone spontaneous apoptosis. Their extent correlates with poor clinical outcome in most cancer types. These clusters of apoptotic tumour cells are strongly infiltrated by tumour-associated neutrophils (TANs) that acquired an anti-inflammatory and pro-resolving polarization state. This review summarizes the potential consequences discussed in the current literature. Although the picture of the role of efferocytosis by neutrophils in inflammation and cancer is becoming clearer, many questions are still unexplored.

The role of SPARC protein expression in the progress of gastric cancer

We aimed to investigate the expression of SPARC (secreted protein, acidic and rich in cysteine) in gastric cancer and its relationship with tumor angiogenesis and cancer cells proliferation. Protein expression of SPARC, VEGF, CD34 and Ki-67 in 80 cases of gastric cancer and 30 cases of normal gastric tissue was evaluated by immunohistochemistry. CD34 staining was used as an indicator of microvessel density (MVD). Ki-67 labeling Index (LI) indicated cancer cells proliferation. Statistical analysis was used to investigate its relationship with clinical characteristics, tumor angiogenesis and cancer cells proliferation. SPARC expression was mainly in the stromal cells surrounding the gastric cancer cells, and was statistically significant differences between gastric cancer and normal gastric tissue (P < 0.05). Both the expression of SPARC and VEGF were related to differentiation degree, clinical stage, Lauren classification and lymph node metastasis (P < 0.05). Expression of SPARC was significantly negatively correlated with the expression of VEGF and MVD in gastric cancer tissues. Expression of SPARC was also negatively correlated with Ki-67-LI. Our findings suggest that both the expression of SPARC and VEGF are closed to tumor angiogenesis in gastric cancer, SPARC inhibited tumor angiogenesis but VEGF promoted tumor angiogenesis. SPARC also inhibited cells proliferation of gastric cancer.

Apoptosis and Microvessel Density in Gastric Cancer: Correlation with Tumor Stage and Prognosis

Gastric cancer remains one of the most common human malignancies with a poor prognosis. Apoptosis is known to be a programmed cell death and its inhibition is involved in the unregulated cellular growth that leads to neoplasms. Microvessel density (MVD) has been investigated as a promoting factor for angiogenesis with conflicting results about its relation to survival. The aim of our study was to search a correlation between these factors and some clinicopathological features and prognosis. Identification of apoptotic cells was performed applying the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling technique and recorded as apoptotic index (A.I.), whereas monoclonal antibodies were used for the study of MVD. A significant correlation was found between low and high A.I. and the subgroup of patients in Stages I and II (P < 0.02); 20 per cent of patients with a low A.I. showed an overall survival longer than 5 years versus 44 per cent of patients with an high A.I. (P = 0.041). High MVD was significantly related to the T stage ( P = 0.036) and to a poorer 5-year overall survival (P < 0.05). Further studies are required to confirm the role of apoptosis and MVD in the development and progression of gastric cancer.

Immunohistochemical expression of osteopontin in gastric cancer

BACKGROUND/AIMS

Osteopontin (OPN) is significantly overexpressed in a variety of malignancies. However, little is known concerning the significance of OPN expression in human cancers. Thus, the aim of this study was to determine the relationship between the degree of OPN expression, the proliferative activity of cancer cells, and the clinicopathological findings for surgically resected gastric cancer.

METHODOLOGY

We evaluated the immunohistochemical expression of OPN in 85 specimens of cancer. Additionally, we investigated a cancer cell proliferative index using an anti-MIB-1 antibody and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling staining. Levels of OPN expression in gastric cancers were classified into three groups. To compare the relationship between OPN expression and clinicopathological findings, the features of cancer lesions were classified using the TNM Classification of Malignant Tumors, 6th Edition.

RESULTS

Immunohistochemical examination of OPN expression in gastric cancer revealed diffuse granular staining in the cytoplasm. High OPN expression was observed in 37 of 85 carcinomas. Strong OPN expression was significantly associated with a low apoptotic index, a high proliferative index, depth of invasion, lymphatic invasion, and venous invasion. Pathologically, intestinal type carcinoma showed strong expression of OPN.

CONCLUSIONS

These data suggested that OPN may play an important role in the invasiveness and the progressive nature of gastric cancer.

[Analysis of clinicopathological, tumor cell proliferation and apoptosis parameters in adenocarcinoma of the gastric cardia]

BACKGROUND/AIMS

In view of the increased incidence of carcinoma of the cardia over recent years, this work had the aim of studying the clinicopathological aspects, cell proliferative and tumor apoptotic indices of this neoplasm, their interrelations and possible influences on the prognosis.

MATERIAL AND METHODS

Forty cases of adenocarcinoma of the cardia were studied between 1988 and 2001, with a minimum clinical follow-up of 3 years. Patients were excluded if they had previous chemotherapy or radiotherapy treatment, presented early neoplasia, or died during the operations or for other reasons unrelated to cancer. Gender; age, Laurén and Ming histological type, staging, and the presence or absence of intestinal metaplasia, epithelial dysplasia and Helicobacter pylori in the adjacent mucosa were analyzed. The apoptotic index was evaluated via hematoxylin-eosin in the primary tumor. To analyze the cell proliferation tumor, PCNA was utilized. The immunohistochemical technique utilized was streptavidin-biotin-peroxidase. For the survival analysis, cases with distant metastasis upon diagnosis were excluded. For the statistical analysis, the Student t and Mann-Whitney tests, Kaplan-Meier curves and Cox regression model were utilized.

RESULTS

The mean age was 61 years (median: 63). There was predominance of the male gender (72.5%), diffuse histological type (55%) and infiltrative histological type (72.5%), and the more advanced stages (III and IV: 67.5%). There was no association with intestinal metaplasia and/or H. pylori. No epithelial dysplasia was detected in adjacent mucosa in any of the cases. The mean apoptotic index was 7.05 in 10 high power fields and 11.40 in 500 cells (2.28%). The mean positivity to PCNA was 275.05 cells in ten high power fields and 409.33 in 500 cells (81.9%). There was a positive correlation between the cell proliferative and apoptotic indices. There was a positive correlation for intestinal histological type with PCNA and apoptotic indices, in 10 high power fields. The mean survival was 28.41 months. Age over 63 and apoptotic index over 7.05 showed a negative correlation with survival, in multivariate analysis.

CONCLUSIONS

Adenocarcinoma of the cardia predominated in male adults of mean age 61 years, and the predominant type was diffuse in more advanced stages. There was a correlation between apoptosis and tumoral cell proliferation. Survival in cases of adenocarcinoma of the cardia is still low. Both age and apoptosis were independent prognostic factors in cancer of the cardia.

Progress in research on applying Sijunzi Decoction in treating digestive malignant tumor

Patients with digestive malignant tumor always have their immune function, especially the cellular immunity, suppressed to a certain extent. Traditional Chinese medicine (TCM) holds that Pi-Wei is the essence of postnatal life, and the genesis and development of digestive tumor are chiefly due to the insufficiency of vital-qi, which makes the body open to the invasion of evil pathogens. Starting from regulating the immune function of organisms, researchers recently obtained some therapeutic effects by applying the Chinese recipe, Sijunzi Decoction, in the treatment of digestive malignant tumors. In this paper, the related studies on the concerned basic theory and clinical application were reviewed.

In vitro and in vivo evidence of metallopanstimulin-1 in gastric cancer progression and tumorigenicity

PURPOSE

The metallopanstimulin-1 (MPS-1) gene is a growth factor-inducible gene, which is highly expressed in many human cancers and may be involved in the progression towards tumor malignancy. However, it is unclear whether MPS-1 plays any role in gastric cancer development or progression. Our studies were designed to clarify the MPS-1 expression pattern and to explore its potential role in gastric cancer.

EXPERIMENTAL DESIGN

The expression pattern of MPS-1 was determined in primary gastric cancer specimens and gastric cancer cell lines via immunohistochemistry and Western blotting. To investigate the functional significance of MPS-1 expression, three small interfering RNA (siRNA) expression plasmids were constructed and transfected into gastric cancer cell line SGC7901. The stable cell lines transfected with the siRNA targeting MPS-1 mRNA plasmids were selected and the biological features of these cells were examined.

RESULTS

MPS-1 was overexpressed in 86% of the gastric cancer tissues and all gastric cancer cells. In addition, MPS-1 expression was significantly increased and corresponded with the tumor-node-metastasis clinical stage, and was significantly higher in the late stage (P < 0.01). The MPS-1 expression level was significantly decreased in the transfected cells with MPS-1-specific siRNA expression plasmid pRNAT-133. Furthermore, the stable transfected cancer cells exhibited an increase in the incidence of spontaneous apoptosis and a decrease in growth ability and tumorigenicity in nude mice.

CONCLUSIONS

These results provide strong evidence that MPS-1 plays an important role in gastric cancer cell proliferation and development, and suggests that MPS-1 is a promising target for gastric cancer treatment.

VEGF and bFGF expression and microvessel density of maxillary sinus squamous cell carcinoma in relation to p53 status, spontaneous apoptosis and prognosis

We have previously reported that p53 mutations, loss of bax expression or decreased spontaneous tumor apoptosis were associated with poorer prognoses in maxillary sinus squamous cell carcinoma (SCC)(Cancer 94: 1968-1980, 2002). In the present study, we analyzed tumor angiogenesis monitored by expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and tumor microvessel density, in correlation with p53 status, spontaneous apoptosis or disease prognosis in the same group of 70 maxillary sinus SCC patients. Tumor biopsy specimens obtained prior to initiation of treatment were examined for expression of VEGF and bFGF and tumor microvessel density using immunohistological methods. Average vessel density (AVD) (range: 3-75; median: 25) and maximum vessel density (MVD) (range: 4-125; median: 53) were assessed by the number of microvessels stained with anti-CD31 mAb in tumor lesions. VEGF was expressed in 35 (50%) of 70 patients and bFGF was in 43 (61%). Patients with VEGF expression showed significantly higher levels of MVD than those without VEGF expression (57 vs. 38; P=0.019). The VEGF expression was observed more frequently in patients with p53 overexpression and/or mutation than in those with normal p53 status (P=0.048). The MVD inversely correlated with the apoptotic index (AI) defined as the number of single stranded (ss)-DNA-positive cells per 1000 tumor cells (r= -0.23; P=0.022). Patients with neck lymph node and/or distant metastases after surgery showed significantly higher levels of MVD than patients without any metastasis (64 vs. 42; P=0.048). Low histological effectiveness of radiochemotherapy correlated with bFGF expression (P=0.0059). To clarify actual prognostic factors for maxillary sinus SCC, we selected 57 patients treated uniformly with preoperative radiochemotherapy followed by maxillectomy. Kaplan-Meier analysis showed that survival was significantly worse in patients with high MVD (> or =80) than in those with low MVD (<80) (P=0.042). These data suggest that the VEGF expression in association with the p53 overexpression and/or mutations may cause increased microvascularity, decreased spontaneous apoptosis or metastases, while the bFGF expression may be associated with resistance to radiochemotherapy, thereby resulting in poorer prognoses in maxillary sinus SCC. VEGF and bFGF expression and tumor microvessel density in tumor lesions were analyzed in 70 patients with maxillary sinus squamous cell carcinoma. The VEGF expression dependent of p53 overexpression and/or mutations was associated with angiogenesis, decreased spontaneous tumor apoptosis and metastases, while the bFGF expression was associated with resistance to radiochemotherapy, resulting in poor prognosis.

Cell death regulation in oral squamous cell carcinoma: methodological considerations and clinical significance

In the last three decades, more work has been done on apoptosis and its role in the pathogenesis of many diseases including cancer. In almost all instances of cancer, dysregulation of cell death (apoptosis) and cell proliferation have been found to play a major role in tumourigenesis. A lot of progress has been made on understanding the molecular basis of apoptosis and its regulatory mechanisms. This review focuses on current knowledge on the regulation of apoptosis in oral squamous cell carcinoma, current methodologies and methodological consideration in estimation of cell death in tissue sections and the clinical significance of apoptosis related molecules in progression of oral squamous cell carcinoma.

Apoptosis and cell proliferation in the development of gastric carcinomas: associations with c-myc and p53 protein expression

BACKGROUND AND AIM

Patients with gastric carcinomas have a poor prognosis and low survival rates. The aim of the present paper was to characterize cellular and molecular properties to provide insight into aspects of tumor progression in early compared with advanced gastric cancers.

METHODS

One hundred and nine graded gastric carcinomas (early or advanced stage, undifferentiated or differentiated type) with paired non-cancer tissue were studied to define the correlation between apoptosis (morphology, terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling), cell proliferation (Ki-67 expression, morphology) and expression and localization of two proteins frequently having altered expression in cancers, namely p53 and c-myc.

RESULTS

Overall, apoptosis was lower in early stage, differentiated and undifferentiated gastric carcinomas compared with advanced-stage cancers. Cell proliferation was comparatively high in all stages. There was a high level of p53 positivity in all stages. Only the early- and advanced-stage undifferentiated cancers that were p53 positive had a significantly higher level of apoptosis (P < 0.05). Cell proliferation was significantly greater (P < 0.05) only in the early undifferentiated cancers that had either c-myc or p53-positivity.

CONCLUSIONS

The results indicate that low apoptosis and high cell proliferation combine to drive gastric cancer development. The molecular controls for high cell proliferation of the early stage undifferentiated gastric cancers involve overexpression of both p53 and c-myc. Overexpression of p53 may also control cancer development in that its expression is associated with higher levels of apoptosis in early and late-stage undifferentiated, cancers.

The expression of thymidine phosphorylase suppresses spontaneous apoptosis of cancer cells in esophageal squamous cell carcinoma

OBJECTIVE

Thymidine phosphorylase (TP) is an enzyme which converts thymidine to thymine. TP is expressed in a variety of human carcinomas and is known to be a potent angiogenic factor. A recent in vitro study indicated that TP is involved in the intracellular apoptotic signal transduction pathway. The aim of this study was to investigate the correlations between the expression of TP, microvessel density (MVD) and the occurrence of spontaneous apoptosis in esophageal squamous cell carcinoma (ESCC).

METHODS

The expression of TP, intratumoral MVDs and percentages of apoptotic cancer cells, expressed by the apoptotic index (AI), of 155 tumors from 155 patients with ESCC were analyzed by immunohistochemistry and compared.

RESULTS

Positive TP expression in cancer and stromal cells was detected in 89 (57.4%) and 104 (67.1%) cases, respectively. The mean MVD and mean AI of the 155 tumors were 288/mm(2) (range: 36-668/mm(2)) and 2.1% (range: 0-20.4%). The mean MVD of 104 tumors with TP-positive stromal cells (336/mm(2)) was higher than that of 51 tumors with TP-negative stromal cells (188/mm(2), p < 0.001). However, the mean MVD of 89 tumors with TP-positive cancer cells (293/mm(2)) did not differ from that of 66 tumors with TP-negative cancer cells (280/mm(2), p = 0.509). On the other hand, the mean AI of 89 tumors with TP-positive cancer cells (1.2%) was lower than that of 66 tumors with TP-negative cancer cells (3.4%, p < 0.001). However, the mean AI of 104 tumors with TP-positive stromal cells (1.9%) did not differ from that of 51 tumors with TP-negative stromal cells (2.6%, p = 0.058). No significant correlation between the MVDs and the AIs was observed (rho = -0.067, p = 0.409).

CONCLUSION

In ESCC, TP may play an important role in tumor progression by increasing microvessels and suppressing apoptosis of cancer cells.

Expression of Bax and apoptosis-related proteins in human esophageal squamous cell carcinoma including dysplasia

The rate of tumor growth depends on the balance between proliferation and death of tumor cells. It is known that Bax, caspase-3, and p53 proteins are death-promoting factors, whereas Bcl-2 protein is a death antagonist. We immunohistochemically examined the expression of Bax and apoptosis-related proteins such as caspase-3, p53, and Bcl-2 in 76 patients with human esophageal squamous cell carcinoma (SCC) including dysplasia to determine the relationship of expression of each protein to tumor behavior and patients' prognosis. No significant relationships in immunopositivity were found among these proteins in SCCs. Cytoplasmic Bax expression was exhibited in 63 cases of SCCs (82.9%). The apoptotic index of caspase-3-positive lesions was significantly higher than that of caspase-3-negative lesions in both dysplasia and SCC (P =.016, P =.012). On the other hand, the apoptotic index (1.18%) was significantly correlated with Bax overexpression in dysplasia (P =.006), but not in SCC lesions (P =.129). The patients with Bax-positive SCCs were found to have a poor prognosis by the Kaplan-Meier method (P =.043). These findings suggested that Bax expressed in dysplasia may play a role as an apoptotic factor, but that it may be functionally inactive in some cancerous lesions and thus not contribute to suppression of the tumor progression in some cases of human esophageal SCCs.

Abundance of apoptotic neoplastic cells in diagnostic biopsy samples is not a prognostic factor in childhood primitive neuroectodermal tumors of the central nervous system

PURPOSE

To assess if the abundance of apoptotic tumor cells is an independent prognostic factor in primitive neuroectodermal tumors (PNET) of the central nervous system.

PATIENTS AND METHODS

Formalin-fixed paraffin-embedded tumor tissue sections from 78 clinically well-characterized children with PNET were evaluated by terminal deoxytransferase-mediated deoxyuridinie-5'-triphosphate (dUTP) nick-end labeling (TUNEL). Apoptotic indices (AI) were determined by counting TUNEL-positive tumor cells either in the highest staining region (AI hot spot) or in at least 15 randomly chosen fields (AI random). The AI hot spot and AI random were then correlated with clinical variables and survival outcome.

RESULTS

AI hot spot (median 0.56%; range 0%-6.54%) and AI random (median 0.30%; range 0%-3.21%) showed considerable intertumor variability. Moreover, 53% of the evaluated PNET showed a more than two-fold difference between AI hot spot and AI random, showing important intratumoral variability of the abundance of apoptotic cells in a subset of the evaluated PNET. No significant associations were found between AI hot spot and AI random with clinical variables or survival outcome.

CONCLUSION

The apoptotic index does not predict survival outcome and is not specifically associated with clinical variables of prognostic significance in childhood PNET.

Expression of CD34 in gastric cancer and its correlation with histology, stage, proliferation activity, p53 expression and apoptotic index

The formation of new blood vessels is essential for tumor growth and progression. Until today there are only few studies of the immunohistochemical assessment of angiogenesis in gastric cancer by the evaluation of the expression of CD34 antigen. The aim of this study was to analyze the relationship between microvessel density (MVD) expressed as the mean count of CD34 immunostained vessels and clinicopathologic features of gastric tumors (the histological type according to the Lauren classification, tumor grade G; presence of lymph node metastases N; depth of tumor invasion; stage of disease (UICC-AJCC 1988 1992), p53 expression, tumor cell proliferative activity described as the Ki67 labelling index and apoptotic index of tumor cells TUNEL method). We assessed formalin-fixed, paraffin-embedded tissue samples obtained during potentially radical gastrectomy from 58 patients with primary gastric adenocarcinoma. The representative tissue blocks from each tumor were used for the immunohistochemical assay and examined by two pathologists independently. MVD was counted in five tumor areas of the most intensive neovascularization (x 200 field by light microscopy) and the mean counts were recorded. The mean MVD (CD34 expression value+/-SD) in this study was 43,15+/-19,8 per x 200 field. The study demonstrated the statistically significant correlation between MVD and two main histological parameters: tumor grading (p < 0.001) and tumor histological type according to Lauren s classification (p<0.05). In well and moderately differentiated tumors (G1/2) MVD was significantly lower in comparison to the group of poorly differentiated cancer G3 (mean value: 31,62 vs. 49,89). MVD was higher in diffuse type of gastric cancer comparing to intestinal type (50.05+/-19,03 vs. 39.17+/-20,09). However, the authors failed to find a significant correlation between MVD and other investigated histopathological features in malignant gastric tumors. The close relationship between CD34 immunostaining, gastric cancer tumor vascularity and main histological parameters was shown in this study. It can be stated that analysis of expression of angiogenesis in gastric cancer may be helpful for better estimation of hematogenous recurrence and the selection of the group of patients for adjuvant antiangiogenic treatment.

Prognostic significance of Fas and Fas ligand system-associated apoptosis in gastric cancer

BACKGROUND

Previous studies indicate that gastric carcinomas express Fas ligand and down-regulate Fas to escape from the host immune attack; however, the prognostic importance of Fas/FasL expression in this tumor is yet to be evaluated.

METHODS

Specimens from 87 gastric carcinoma patients of different stages treated in a defined period with curative intent were evaluated for apoptosis, Fas, FasL, and CD8 expression using an immunohistochemical method.

RESULTS

The percentage of terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive apoptotic cells expressed as apoptotic index (AI) was higher in 43 patients when the cut-off value was set at the median value. There were no significant correlations between AI and clinicopathologic parameters. Thirty-nine patients showed a high number of CD8+ cells within cancer nests. Positive FasL and Fas expression was seen in 53 and 72 patients, respectively. CD8 and FasL expressions were related only to patients' age. Fas expression had significant correlations with tumor invasion and Lauren classification. There were significant direct correlations between AI and number of nest CD8+ cells and between AI and grade of Fas expression. Apoptotic index, pT stage, CD8 expression, and Fas expression were identified as independent prognostic factors.

CONCLUSIONS

Spontaneous apoptosis in gastric carcinoma may be an independent prognosticator for survival and is significantly influenced by tumor Fas expression and number of nest CD8 + cells.

Microvessel count, proliferating cell nuclear antigen and Ki-67 indices in gastric adenocarcinoma

The aim of the present study was to immunohistochemically investigate the prognostic value of neovascularization (expressed as microvessel count-MVC) and tumor cell proliferation (expressed as PCNA labeling index PLI and Ki-67 labeling index KLI) in gastric adenocarcinoma. Correlations with clinicopathologic features were also evaluated. Tumor specimens from 74 patients diagnosed as gastric adenocarcinoma were included in this study. Formalin fixed, paraffin embedded tissue sections stained immunohistochemically with F-VIII, PC10 and MIB-1 monoclonal antibodies. By ocular grid subdivided into 100 areas, number of microvessels and PC10, MIB-1 positive and negative cells were counted at x400 magnification. Chi-square test, Kaplan-Meier method and cox regression analysis were used for statistical analysis. The results showed that, MVC and PLI had a significant correlation with invasion and lymph node metastasis. The prognosis was significantly worse in patients with high MVC (>14 ) and with high PLI (>49%). However any relationship was not observed between KLI (38%) and clinicopathologic parameters, so KLI failed to predict the prognosis. Cox model showed that, MVC and PLI were independent prognostic variables. Ki-67 labeling index in gastric carcinomas has no prognostic relevance. However, the evaluation of microvessel count and proliferating cell nuclear antigen index in gastric carcinomas could be reliable indicators of prognosis.