Bax expression has prognostic significance that is enhanced when combined with AgNOR counts in glottic carcinomas

Bcl-xL overexpression and its association with the progress of tongue carcinoma

Apoptosis-related protein B-cell lymphoma-extra large (Bcl-xL) has a crucial role in the control of cell death through its inhibition of apoptosis. This study was designed to investigate the expression of Bcl-xL in relation to the development of tongue carcinoma and whether it has potential as a marker for the clinical diagnosis of tongue carcinoma and as a therapeutic target to evaluate the dynamic of tongue carcinoma progression. A statistical analysis of 100 cases oral tongue carcinoma tissue specimens were performed using pathological grading and clinical TNM staging, and 14 cases corresponding non-tumor tissues as control. The changes in Bcl-xL mRNA expression between different pathological grades and clinical TNM stages of tissue were analyzed by RT-PCR. Additionally, immunohistochemical SP method and Western blot assays were employed to detect changes in Bcl-xL protein expression in different tongue carcinoma tissues. The results showed the expression of Bcl-xL was significantly higher in tongue carcinoma tissues than in normal tongue tissues and was positively associated with the degree of differentiation and the clinical TNM staging, but negatively correlated with the degree of malignancy of the tumor. There was higher expression of Bcl-xL in oral tongue squamous cell carcinoma (OTSCC) tissues compared with oral tongue adenocarcinoma (OTA) tissues, but Bcl-xL expression in tissue with lymph node metastasis was significantly higher than that without lymph node metastasis. Thus, Bcl-xL overexpression may be closely related to the dynamic of the pathogenesis and development of tongue carcinoma. It may be a useful marker for clinical diagnosis and an aid to evaluating the efficacy of therapeutics in tongue carcinoma.

Prognostic value of Bcl-2 and Bax tumor cell expression in patients with non muscle-invasive bladder cancer receiving bacillus Calmette-Guerin immunotherapy

Apoptosis is the distinctive form of programmed cell death that complements cell proliferation in maintaining normal tissue homeostasis. The significance of constitutive apoptosis in the recurrence of Non Muscle Invasive Bladder Cancer has yet to be investigated. The aim of this study is to investigate the prognostic significance of Bax and Bcl-2 in terms of recurrence after BCG immunotherapy. Immunohistochemical analysis was performed on frozen biopsies to evaluate bcl-2 and Bax proteins expression in 28 cases of NMIBC. All patients with confirmed NMIBC were treated with intravesical BCG-immunotherapy. The follow up was performed for 26 months. The correlation between clinicopathological, immunohistochemical data and the response to BCG therapy was performed. Univariate analysis showed that, PT1 stage, High grade and Bax expression increased significantly the risk of recurrence (P = 0.015, P = 0.015 and P= 0.034 respectively). In addition, multivariate analysis selected the model involving stage, age, Bax and Bcl-2 expression as the best independent variables of recurrence. In conclusion, the expression of Bcl-2 and Bax in NMIBC could have a prognostic value in assessing the risk of recurrence after BCG immunotherapy. These findings require further investigations on larger cohort in order to ascertain new molecular markers of the response to BCG immunotherapy.

Prognostic significance of DNA cytometry in combination with AgNOR investigation

CONCLUSION

While most results concerning DNA and nucleolar organizer region (AgNOR) parameters fit with previous studies, the percentage of aneuploidy looks like a promising prognostic parameter. The observed intratumoral heterogeneity could represent a possible source of conflicting and inconsistent results.

OBJECTIVES

The aims of our study were to determine the prognostic relevance of different DNA and AgNOR parameters in laryngeal squamous cell carcinoma (SCC) and compare these findings with established prognostic factors including tumor stage and grade, as well as the detection of possible intratumoral heterogeneity.

MATERIALS AND METHODS

Sections from 62 laryngeal SCCs were analyzed for DNA content, DNA index, S-phase, percentage of aneuploidy, and AgNOR. Of 62 samples, 31 morphologically similar tumor samples were analyzed for the same parameters in three different tumor areas defined as tumor center, invasive tumor margin, and transformation margin between tumor and normal-appearing mucosa.

RESULTS

Our study showed that DNA and AgNOR parameters correlated with T stage, lymph node involvement, and histologic grade regardless of tumor areas. Significant correlation was found between mean number of AgNOR per nucleus and percentage of aneuploidy. Clinical stage and percentage of aneuploidy correlated with survival (p<0.02). Heterogeneity DNA study revealed aneuploidy in central portions of 90% of tumors, while in margins aneuploidy was demonstrated in about half of the patients.

Bcl-2 Expression in Oral Squamous Cell Carcinoma

Apoptosis is a genetically regulated process involved in tissue size regulation, morphogenesis, and elimination of genetically damaged cells. A pallet of genes is involved in the control of apoptosis, such as bcl-2 family whose oncogenic potential has been demonstrated in oral tumorigenesis. Different members of bcl-2 family may promote or inhibit apoptosis by synthesizing anti- and proapoptotic proteins. One of antiapoptotic proteins, bcl-2, with a crucial role in apoptosis regulation was the object of our study. By means of immunohistochemistry we estimated the level of overexpression of bcl-2 proteins in a series of the 26 formalin fixed, paraffin-embedded samples of oral squamous cell carcinoma (OSCC). Analyzed tumors originated from different sites of oral cavity; 7/26 belonged to stage II, 14/26 to stage III, and 5/26 to stage IV. Immunoreactivity was scored according to the percentage and intensity of positive cytoplasmic bcl-2 staining. All tumors had low percentage of positively stained bcl-2 cells, with mean values for lower/higher intensity of 8.3 +/- 2.5/34.4 +/- 7, 7.5 +/- 1.1/31.9 +/- 4.3, and 8.4 +/- 5.8/31.5 +/- 5.8 within stages II, III, and IV, respectively. Low level of bcl-2 expression in our sample seems to be associated with higher survival rate: 77% for the 5-year follow-up period. Comparing clinicopathologic and risk factors data within each and between three groups of analyzed tumors (lip-tongue P = 0.58, tongue-floor of the mouth, P = 0.21, lip-floor of the mouth, P = 0.50) there was no significant difference. However, our results suggest that the level of bcl-2 expression could be a valuable predictor of tumor behavior and disease outcome.

Predictive assay of neoadjuvant chemotherapy in management of oral cancer

Neoadjuvant chemotherapy (NAC) for oral squamous cell carcinoma has a positive impact on organ preservation and/or survival only in patients who achieve an excellent anti-tumour effect with this therapy. Predictive assay for NAC can play an important role in establishing tailor-made treatments for oral squamous cell carcinoma. In this retrospective study, the anti-tumour effects of cisplatin-based NAC in 70 patients with oral squamous cell carcinoma were reviewed in relation to biological markers of tumour cell proliferation activity: tumour grade, cellular DNA content, mitotic index, apoptotic index, ki-67 positive rate, and p53 and Bax expression. Tumour grade, Bax expression, apoptotic index and cellular DNA content were significantly correlated with the anti-tumour effects of NAC in univariate analysis. Tumour grade, Bax expression and apoptotic index were selected as independent predictive factors by means of multiple logistic analysis. Using the regression equation from these results, the prediction rate for anti-tumour effects was 70%. For patients in whom NAC is predicted to be ineffective, it may be necessary to choose another treatment option in order to improve their survival and quality of life.

Prognostic relevance of cell proliferation in head and neck tumors

Cell proliferative activity has been extensively investigated in head and neck tumors. Ki67/MIB-1 immunostaining, tritiated thymidine or bromodeoxyuridine labeling indices, DNA S-phase fraction, proliferating cell nuclear antigen expression, potential doubling time and analysis of the nucleolar organizer region associated proteins (AgNORs) have shown significant correlation with prognosis in 4806 cases of tumors of the oral cavity, salivary glands, pharynx and larynx. However, this was not observed in 2968 other reported cases. Discrepancies may depend on various factors: the heterogeneity of the series, which include tumors from various anatomic sites and patients treated with different therapy, and the lack of standardization of methods for assessing cell proliferation. Furthermore, none of the methods currently applied can by themselves define the actual proliferative activity, as it depends both on the proportion of cells committed to the cycle (growth fraction) and the speed of the cell cycle. Indeed, the actual proliferative activity of a tumor could well be measured by the equation [PA = Ki67 or MIB-1 scores x AgNORs], as we did in pharyngeal carcinoma. Provided that large and homogeneous series are evaluated by standardized methods, cell proliferative activity can still be regarded as an inexpensive and reliable prognostic factor in head and neck tumors.

Effect of preoperative regional artery chemotherapy on proliferation and apoptosis of gastric carcinoma cells

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.

Phyllodes tumors of the breast: correlation of nucleolar organizer regions with histopathological malignancy grading, flow cytometric DNA analysis and clinical outcome

To examine whether nucleolar organizer regions detected by argyrophilia (Ag-NOR counts) can be used as a prognostic indicator in phyllodes tumors of the breast, and to compare its usefulness with that of DNA flow cytometric analysis, 28 cases of breast phyllodes tumors (including 15 benign, two borderline and 11 malignant tumors) were subjected to Ag-NOR staining and counting as well as DNA flow cytometric analysis. S-phase fraction and DNA ploidy analysis showed useful trends for improving outcome predictions in malignant phyllodes tumors. However, high Ag-NOR counts were significant in predicting survival status (P = 0.013) and reached near statistical significance in predicting survival times (P = 0.07). In predicting survival status, results for Ag-NOR counts were significantly better than those for ploidy analysis (P = 0.02) and S-phase fraction (P < 0.01). Only S-phase fraction was significantly predictive of survival times (P = 0.025). It is concluded that Ag-NOR counts and DNA flow cytometric analysis, easily performed using paraffin sections, give information that can improve predictions made by histopathological classification. Ag-NOR counts are significant in predicting survival in the presence of histopathological features of malignancy.

The prognostic significance of apoptosis-associated proteins BCL-2, BAX and BCL-X in clinical nephroblastoma

Apoptotic cell death represents an important mechanism for the precise regulation of cell numbers in normal tissues. Various apoptosis-associated regulatory proteins, such as Bcl-2, Bax and Bcl-X, may contribute to the rate of apoptosis in neoplasia. The present study was performed to evaluate the prognostic value of these molecules in a group of 61 Wilms' tumours of chemotherapeutically pre-treated patients using an immunohistochemical approach. Generally, Bcl-2, Bax and for Bcl-X(S/L) were expressed in the blastemal and epithelial components of Wilms' tumour. Immunoreactive blastema cells were found in 53%, 41% and 38% of tumours for Bcl-2, Bax and for Bcl-X(S/L), respectively. An increased expression of Bcl-2 was observed in the blastemal component of increasing pathological stages. In contrast, a gradual decline of Bax expression was observed in the blastemal component of tumours with increasing pathological stages. Also blastemal Bcl-X(S/L) expression decreased with stage. Univariate analysis showed that blastemal Bcl-2 expression and the Bcl-2/Bax ratio were indicative for clinical progression, whereas epithelial staining was of no prognostic value. Multivariate analysis showed that blastemal Bcl-2 expression is an independent prognostic marker for clinical progression besides stage. These findings demonstrate that alterations of the Bcl-2/Bax balance may influence the clinical outcome of Wilms' tumour patients by deregulation of programmed cell death.

Clinical significance and prognostic value of apoptosis related proteins in superficial esophageal squamous cell carcinoma

BACKGROUND

The purpose of the present study was to examine the expression of cell cycle regulators [p53, p21WAF1/CIP1 (p21), and Rb] and apoptosis related proteins Bax and Bcl-X(L) and to evaluate the relationship between their expressions and clinicopathological findings in patients with superficial squamous cell carcinomas of the esophagus.

METHODS

We immunohistochemically investigated the expression of p53, p21, Rb, Bax, and Bcl-X(L) in 79 patients with superficial esophageal carcinoma.

RESULTS

p21 overexpression was found in mucosal carcinoma (P = 0.05) and a high Bcl-X(L) score was observed for submucosal carcinoma (P = 0.03). The patients with high Bcl-X(L) score had more frequent lymphatic invasion and lymph node metastasis than did those with low Bcl-X(L) score (P < 0.05). Univariate analysis revealed significantly shorter survival in patients with high Bcl-X(L) expression than in those with low Bcl-X(L) expression, but Bcl-X(L) expression was not identified as an independent prognostic factor by multivariate analysis.

CONCLUSIONS

Because Bcl-X(L) expression correlated well with depth of tumor invasion, lymphatic invasion, and lymph node metastasis, examination of Bcl-X(L) expression will help to estimate the properties in superficial squamous cell carcinoma of the esophagus.

Can expression of apoptosis genes, bcl-2 and bax, predict survival and responsiveness to chemotherapy in node-negative breast cancer patients?

BACKGROUND

Although the status of the axillary lymph nodes is widely accepted to be associated with prognosis in breast cancer patients, there is a need for biomarkers to be analyzed as indicators of responsiveness to treatment. The objective of this study was to test the hypothesis that the expression of apoptosis genes, bcl-2 and bax, predicts survival and responsiveness to chemotherapy in node-negative breast cancer patients.

METHODS

One hundred thirty premenopausal women with primary breast carcinoma were studied for the expression of bcl-2 and bax genes. The relationship between the expression of bcl-2 and bax proteins and a series of markers of known prognostic value [such as tumor size, nuclear grade, receptors of the steroid hormones estrogen (ER) and progesterone (PgR)]. The association of these proteins with survival and responsiveness to chemotherapy was also examined.

RESULTS

Sixty (46%) and sixty-four (49%) breast cancer cases were found positive for bcl-2 and bax, respectively, as indicated by immunohistochemistry. A statistically significant association was found between expression of bcl-2 and tumor size (P = 0.001), low grade (grade I) (P = 0.002), positivity of ER (P = 0.001), positivity of PR (P = 0.03), and superior disease-free survival (DFS) (P = 0.04), and superior overall survival (OS) (P = 0.03). In contrast, no similar associations were observed for the bax gene. Overall, there was a trend toward an association between adjuvant chemotherapy and DFS (P = 0.08) and OS (P = 0.07). This trend became statistically significant when the patients were analyzed by individual gene expression. In bax-positive patients, chemotherapy improves 6-year DFS (P = 0.01) and OS (P = 0.03) while similar effects were not observed in the other subgroups of patients.

CONCLUSION

Our results indicated that bcl-2 expression is associated with a number of favorable prognostic factors and better clinical outcome, while bax expression seems to have positive predictive value for responsiveness to chemotherapy in lymph node-negative breast cancer patients.

The importance of biological factors (bcl-2, bax, p53, PCNA, MI, HPV and angiogenesis) in invasive cervical cancer

OBJECTIVE

The present study was designed to analyse the relationship between apoptosis related proteins (bcl-2 and bax), tumour suppressor protein p53, proliferation markers (PCNA and mitotic index), human papillomavirus (HPV) and angiogenesis in cervical cancer and their impact on clinical outcome.

STUDY DESIGN

Tumours from 111 patients were assessed by immunohistochemistry for the expression of bcl-2, bax, p53 and PCNA, by PCR for the presence of HPV-DNA, for the quantification of the mitotic index and the microvessel density (CD 31). The results were correlated with various histopathologic characteristics and survival.

RESULTS

The multiple Cox's regression analysis for overall survival of all prognostic variables gave as best model: bcl-2 (P<0.001), lymphovascular permeation (P=0.004), mitotic index (P=0.019), tumour grade (P=0.048) and FIGO stage (P=0.070). Subanalysis was performed for the patients where the lymph node status was known (n=79). Adding the lymph node status gave as best model for overall survival bcl-2 (P=0.001), lymphovascular permeation (P=0.003) and mitotic index (P=0.044). However, they hardly influenced the association.

CONCLUSION

In the apoptotic pathway of cervical cancer, bcl-2 is one of most important proteins. It can probably not only mediate cell death but also regulate cell growth. A better understanding of their relations will probably provide the basis for more rational cancer therapies in the future.

Clinical implications of biomarkers in head and neck cancer

The term biomarker refers to a host of biologic factors found within a tumor or other clinical specimen that can be used to assess the tumor in some way. Biomarkers have many potential clinical applications. Before they are used in actual clinical settings, however, they must be carefully validated. The literature contains many reports of this ongoing work related to head and neck squamous cell carcinoma. Candidate biomarkers for this disease include the p53 gene and its protein; microsatellite regions throughout the genome; human papillomavirus; proteins involved in cellular proliferation, apoptosis, angiogenesis, and intracellular adhesion; epithelial growth factor receptor; and various measures of immune response to cancer. The best new evidence for the validity of each of these candidates is critiqued in this review.

Molecular biomarkers in HNSCC: prognostic and therapeutic implications

The prognosis of squamous cell carcinoma of head and neck (HNSCC) is influenced by many factors, such as performance status, TNM staging and pathological grading of differentiation. However, these factors are not sufficient for predicting outcome. Therefore, recent research has focused on the identification of molecular biomarkers. These markers help to stage patients in more meaningful prognostic groups and identify high-risk patients who may benefit from a more aggressive treatment approach. They also identify patients who are resistant to radiotherapy or chemotherapy, potentially avoiding the morbidity and cost of ineffective therapies. They can also identify patients with a high risk of recurrence who may benefit from chemoprevention. Finally, these markers may serve as targets for novel therapies, which would eventually change the outcome of HNSCC.

Apoptosis and apoptotic-related factors in mucoepidermoid carcinoma of the oral minor salivary glands

The oncoproteins Bcl-2 and Bax, the tumor suppressor gene product p53, TUNEL (TdT [terminal deoxynucleotidyl transferase] dUTP nick end-labeling) and the cell-cycle antigen Ki-67 were studied in 71 cases of mucoepidermoid carcinoma originating in the oral minor salivary glands. Grade I tumors had higher expression of Bcl-2 than Grade II and III tumors (chi2 test, 0.01<P<0.025) and the Bcl-2-positive group had a higher survival rate than the Bcl-2-negative group (generalized Wilcoxon, P = 0.00051). Patients with strong TUNEL positivity had a higher survival rate than those with either weak positivity or negativity (generalized Wilcoxon, P = 0.047). The expression of p53 and TUNEL had a positive correlation (P = 0.0315). Grade II and III tumors had a higher frequency of positive Ki-67 expression than Grade I tumors (chi2 test, 0.01<P<0.025) and patients with Ki-67-negative tumors had better survival than patients with Ki-67-positive tumors (generalized Wilcoxon, P = 0.000099). This study showed that Bcl-2 proteins, p53 protein, TUNEL and Ki-67 are potentially useful prognostic markers for survival in patients with mucoepidermoid carcinoma of the oral minor salivary glands.

Prognostic significance of p53/bcl-2 co-expression in patients with laryngeal squamous cell carcinoma

OBJECTIVE

The p53, bcl-2, and bax genes are known to be involved in control of cell cycle progression and regulation of apoptotic cell death. Although they are frequently altered in laryngeal squamous cell carcinoma, their clinical relevance is not yet fully understood. In the present study, individual and combined expressions of these genes were related with patient survival as well as with proliferative and apoptotic activity.

DESIGN

Retrospective study.

METHODS

Paraffin-embedded tissue sections of 88 laryngeal squamous cell carcinomas that were diagnosed and treated between 1986 and 1996 were investigated for p53, bcl-2, and bax protein expression by immunohistochemistry. Apoptotic cells were visualized using the nick end labeling method. To assess proliferative activity of tumors, mitotic indices were determined.

RESULTS

Age of patients, advanced disease (stages HI and IV), high mitotic activity, positive bcl-2 expression, high level of p53 expression, and p53/bcl-2 co-expression were significantly associated with shortened overall survival in univariate analysis. In multivariate analysis, only age and p53/bcl-2 co-expression had independent prognostic value. Other combinations of genes, i.e., bcl-2-to-bax and p53-to-bax ratios, were not associated with patient outcome. A significant positive correlation was found between apoptotic and mitotic activity. However, protein levels of p53, bcl-2, and bax were unrelated to proliferation and apoptosis of tumor cells.

CONCLUSIONS

The co-expression of p53/bcl-2 was an independent predictor of patient outcome and had a prognostic value superior to both parameters considered separately. The rate of apoptosis mainly counterbalanced proliferative activity but appeared not to be significantly influenced by p53, bcl-2, and bax.

Molecular cloning and functional analysis of the murine bax gene promoter

Bcl-2-associated X protein (Bax) is a proapoptotic protein and is suggested to have an important role in carcinogenesis. To investigate the mechanism of bax gene transcriptional regulation, we isolated and sequenced the genomic DNA fragment of the 5' flanking region of the murine bax gene, and subcloned its promoter region into a luciferase reporter construction. The murine bax promoter is TATA-less, and the sequence is only partially homologous to that of the human bax promoter. Transient transfection into NIH 3T3 cells using unidirectionally deleted promoters and mutants of Sp1 sites revealed that two Sp1 sites were partially responsible for the basal activity. The murine bax promoter was not responsive to exogenous p53, suggesting that the p53-responsive element may not exist in the region used in our current experiments.

The prognostic value of spontaneous apoptosis, Bax, Bcl-2, and p53 in oral squamous cell carcinoma of the tongue

BACKGROUND

Bax, Bcl-2, and p53 proteins are involved in the regulation of apoptosis and have been reported to correlate with prognosis in several tumor types.

METHODS

Bax, Bcl-2, p53, and the level of spontaneous apoptosis were evaluated in formalin fixed, paraffin embedded pretreatment specimens from 85 T1-4 squamous cell carcinomas (SCCs) of the tongue by immunohistochemical methods. The percentage of apoptotic cells labeled by the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP labeling (TUNEL) method was expressed as an apoptotic index (AI). For Bax and Bcl-2 evaluation, the fraction of tumor cells stained and the staining intensities were given scores that were added together, resulting in a final score. p53 immunostaining was expressed as a percentage of positive cells.

RESULTS

High AI was significantly associated with high Bax expression (P = 0.0122) and highly differentiated tumors (P = 0.0062). No correlation was found between AI and Bcl-2 expression. There was no correlation between p53 positivity and any of the other apoptosis-related parameters. Whereas low AI scores and low Bax expression correlated significantly with poor prognosis (P = 0.0053 and P = 0.0012, respectively), a low Bcl-2 expression was associated with a favorable clinical outcome (P = 0.0262). Patients with a high Bcl-2/Bax expression ratio had a significantly poorer prognosis than those with a low ratio (P < 0.0001). Multivariate analysis revealed that Bax expression, the Bcl-2/Bax expression ratio, and the T and N classifications were significantly independent prognostic variables. The Bcl-2/Bax expression ratio was the strongest independent prognostic parameter.

CONCLUSIONS

AI, individual Bax and Bcl-2 expression, and particularly the Bcl-2/Bax expression ratio have prognostic value in SCC of the tongue.

Prognostic value of Le(y) and H antigens in oral tongue carcinomas

OBJECTIVE

To investigate the prognostic significance of the carbohydrate epitopes H and Le(y) and their relationship with proliferation and apoptosis.

STUDY DESIGN

Eighty randomly selected patients with T1-T4 oral tongue squamous cell carcinoma (SCC) were studied. Serial sections were cut from diagnostic, formalin-fixed, paraffin-embedded specimens.

METHODS

Sections were stained immunohistochemically for H antigen and Le(y).

RESULTS

Expression of H antigen was associated positively with Le(y) expression (P = .0001). Expressions of H antigen or Le(y) correlated with the proliferative markers Ki67 (P = .0442 and P = .0003, respectively) and pAgNOR > 1 (P = .0674 and P = .0047, respectively), but not with apoptotic markers such as Bax expression or the apoptotic index (AI). Tumors that expressed H antigen and high levels of Le(y) (> 50%) had a poor prognosis (P = .0006 and P = .0056, respectively). Combinations of expression of H antigen and Le(y), and either proliferative or apoptotic markers revealed an enhanced prognostic potential (P < .0001). The combination of pAgNOR score greater than 1 and H-antigen expression appeared to be the best combination to predict good prognosis.

CONCLUSION

The expression of H antigen and Le(y), especially their combination with proliferative or apoptotic markers, has prognostic value in tongue SCC.

Prognostic significance of proliferative and apoptotic markers in oral tongue squamous cell carcinomas

The prognostic impact of proliferative and apoptotic markers was studied in 85 T1-4 oral tongue squamous cell carcinomas (SCCs). Ki67 immunoreactivity and AgNOR counts, including mean AgNOR counts (mAgNOR) and the percentage of nuclei with more than one AgNOR (pAgNOR > 1), were used as proliferative parameters. The apoptotic index (AI) was assessed using the TUNEL method. Bax expression was detected immunohistochemically and scored. Bax expression correlated positively with AI (p = 0.0122). Ki67 correlated with both pAgNOR > 1 (p = 0.0042) and mAgNOR (p = 0.0189). Low Bax expression and low AI correlated significantly with the disease-free period (p = 0.0001 and p = 0.0024, respectively). High values for Ki67, pAgNOR > 1 and mAgNOR correlated with poor prognosis (p = 0.0021, p = 0.0001 and p = 0.0244, respectively). Combinations of proliferative and apoptotic parameters were stronger predictors than individual parameters (p < 0.0001). pAgNOR > 1-Bax expression appeared to be the best combination (p < 0.0001). We conclude that proliferative and apoptotic markers, especially their combinations, have prognostic value in tongue SCC.

Apoptosis and expression of Bax, Bcl-x, and Bcl-2 apoptotic regulatory proteins in colorectal carcinomas, and association with p53 genotype/phenotype

AIMS

Spontaneous apoptosis and expression of the apoptotic regulatory proteins Bax, Bcl-x, and Bcl-2 were investigated in 50 colorectal carcinomas. The p53 genotypes/phenotypes and BAX genotypes were also determined, and possible associations of these with apoptosis and/or with expression of the different apoptotic regulatory proteins were studied.

METHODS

Terminal deoxynucleotidyl transferase (TdT) mediated dUTP labelling of DNA fragments was used to detect apoptotic tumour cells in sections and peroxidase immunohistochemistry was used to assess protein expression. p53 genotype/phenotype was determined using constant denaturant gel electrophoresis/immunoblotting and bax genotype was determined using polymerase chain reaction based methods.

RESULTS

The distribution of tumour apoptotic indices was bimodal with a natural cut off at 1.0% (range, 0.0-5.4%); the median fraction of apoptotic tumour cells was 0.8%. Tumour apoptosis was not associated significantly with tumour DNA ploidy status. Normal mucosal tissue had less than 0.1% apoptotic cells. Staining intensities for Bax, Bcl-x, and Bcl-2 were strong; that is, equivalent to or greater than positive normal mucosal cells, in 11 of 50, 20 of 49, and 20 of 48 carcinomas. Frameshift mutations in the bax gene were detected in three of 42 tumours analysed, all of which were DNA diploid, and Bax protein expression in these tumours was absent or very low. Bax, Bcl-x, and Bcl-2 protein expression were not correlated with tumour apoptosis or tumour DNA ploidy status. p53 was expressed in 34 of 50 tumours and p53 gene mutations were detected in 22 of 29 p53 positive tumours analysed. Apoptosis was significantly lower in a greater number of p53 positive tumours than p53 negative tumours. In addition, Bcl-2 protein expression was significantly higher in a greater number of p53 positive tumours compared with p53 negative tumours. Bax and Bcl-x protein expression were not significantly associated with p53 phenotype/genotype.

CONCLUSIONS

The results indicate that acquisition of a p53 phenotype is associated with lower spontaneous apoptosis and higher expression of Bcl-2. The results also suggest that p53 is not a major determinant for Bax expression in colorectal carcinomas in vivo.