Prognostic value of p16INK4A expression in lung adenocarcinoma

The analysis attempted to determine whether the expression of p16INK4A has prognostic relevance for patients with lung adenocarcinomas. For this purpose, immunohistochemistry was used to analyze 58 adenocarcinomas. Of the tumors investigated, 20 did not express p16INK4A, while 38 yielded a positive staining result. Median survival time was shorter for patients with p16INK4A negative carcinomas than for those with p16INK4A positive tumors (47 vs. 79 weeks, P = 0.11). The relative risk for patients with p16INK4A negative tumors was increased by a factor of 1.6 in comparison to positively stained tumors. There exists a direct correlation between the proportion of G0/G1 phase cells and the p16INK4A expression. Additionally, there is an inverse relationship between S phases and p16INK4A expression. Furthermore, p16INK4A negative adenocarcinomas show more frequent growth in nude mice than p16INK4A positive carcinomas.

Spontaneous apoptosis in ovarian cancer: an unfavorable prognostic factor

Apoptosis and cell proliferation play important roles in the cellular response to chemotherapy, and may have prognostic value. The percentage of apoptotic cells [apoptotic index (AI)] was evaluated in ovarian carcinomas of 25 patients by the terminal desoxynucleotidyl transferase-mediated dUTP-nick end labeling (TUNEL) technique. All patients were surgically treated and received postoperatively chemotherapy consisting of cytoxan and cisplatin or carboplatin. As a marker of proliferation the mRNA expression of histone H3 in tumor tissue was determined. In addition, tumor vascularity was assessed by immunohistochemistry and factor VIII. Patients with high AI had significantly shorter survival times (p=0. 0001) or recurrence-free intervals (p=0.004) than patients with low AI. No significant relationship was found between AI and histone H3 mRNA expression, however, an inverse correlation of AI with microvessel density was detected. Tumors with high AI had significantly lower microvessel count than tumors with low AI (p=0. 002). The obtained data suggest that AI can be predictive of treatment outcome in ovarian cancer.

Expression of lung resistance-related protein (LRP) in non-small cell lung carcinomas of smokers and non-smokers and its predictive value for doxorubicin resistance

Immunohistochemical methods were used to determine the expression of the lung resistance-related protein (LRP) in 87 cases of untreated non-small cell lung carcinoma. LRP expression was detected in 39 patients (45%). A significant correlation between LRP expression and tumor resistance to doxorubicin was found (p=0.03, Fisher's exact test). An inter-relationship between LRP expression and gender, age, stage, lymph node status and survival times was not observed. Furthermore, a relationship between LRP expression and proliferation (cell cycle phases, take rate of lung tumors in nude mice and cyclin A expression) was not detectable. However, a correlation of borderline significance was noticed between LRP expression and the patients' smoking habits. Carcinomas in heavy smokers (more than 30 cigarettes daily) were more frequently LRP-positive than carcinomas found in non-smokers (p=0.09, Fisher's exact test).

Coexpression of VEGF and bFGF in human epidermoid lung carcinoma is associated with increased vessel density

Tumor specimens from 84 patients with untreated epidermoid lung carcinomas were analysed immunohistochemically for the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), tumor cell proliferation (PCNA index) and tumor vascularity (vessel density). The purpose of this study was to find out whether differences in tumor cell proliferation and tumor vascularity might be associated with differential angiogenic growth factor expression. The present results indicate that the proliferation of the tumors is closely related to their expression of VEGF, but not for bFGF. The PCNA labelling index in VEGF positive tumors (VEGF+/bFGF- or VEGF+/bFGF+) was significantly higher than that in VEGF negative tumors (VEGF-/bFGF- or VEGF-/bFGF+; Wilcaxon rank sum test, p < 0.0001). To investigate whether VEGF or bFGF is involved in lung tumor angiogenesis, the data of VEGF and bFGF expression were correlated with vessel density. It was found that the expression of VEGF and bFGF were associated with increment of vessel density, however, vessel density was significantly increased only when VEGF and bFGF were coexpressed (p < 0.02). It is suggested that VEGF and bFGF might act cooperatively in the neovascularization of human epidermoid lung carcinomas.

Prognostic value of basic fibroblast growth factor and its receptor (FGFR-1) in patients with non-small cell lung carcinomas

Tumour specimens of 206 patients with untreated non-small cell lung carcinomas (NSCLC) were analysed immunohistochemically for the expression of the basic fibroblast growth factor (bFGF) and for its receptor (FGFR-1, Flg). Seventy of the tumours showed weak expression, 109 moderate and 27 high expression of bFGF. Thirty-eight tumours had low expression of FGFR-1, 116 had moderate and 52 cases high expression. Patients with high FGFR-1 expression had significantly shorter survival times than patients with weak or moderate expressions (P < 0.05), but there was no significant correlation between bFGF expression and patient survival. The results of the multivariate analysis demonstrated that FGFR-1 in the presence of stage is not an independent prognostic factor.

Prognostic value of vascular endothelial growth factor and its receptor Flt-1 in squamous cell lung cancer

Tumor specimens from 109 patients with previously untreated squamous cell lung carcinomas were analyzed immunohistologically for the expression of vascular endothelial growth factor (VEGF) and its receptor Flt-1. Our analysis attempted to determine whether these factors have additional prognostic value for the patients' survival. VEGF staining was seen in 59% and Flt-1 staining in 68% of the cases. No significant correlations were detected between VEGF or Flt-1 expression and stage or metastasis. Patients with VEGF-stained tumors had significantly lower survival times than patients with negative tumors. Expression of Flt-1 showed no significant correlation with survival. Combining VEGF and Flt-1 expressions did not improve the prognostic value. Multivariate analysis showed that metastasis and VEGF expression are significant and independent prognostic factors for the survival of patients with squamous cell lung carcinomas.

Prognostic value of vascular endothelial growth factor and its receptor Flt-1 in squamous cell lung cancer

Tumor specimens from 109 patients with previously untreated squamous cell lung carcinomas were analyzed immunohistologically for the expression of vascular endothelial growth factor (VEGF) and its receptor Flt-1. Our analysis attempted to determine whether these factors have additional prognostic value for the patients' survival. VEGF staining was seen in 59% and Flt-1 staining in 68% of the cases. No significant correlations were detected between VEGF or Flt-1 expression and stage or metastasis. Patients with VEGF-stained tumors had significantly lower survival times than patients with negative tumors. Expression of Flt-1 showed no significant correlation with survival. Combining VEGF and Flt-1 expressions did not improve the prognostic value. Multivariate analysis showed that metastasis and VEGF expression are significant and independent prognostic factors for the survival of patients with squamous cell lung carcinomas.

Prognostic value of vascular endothelial growth factor and its receptor Flt-1 in squamous cell lung cancer

Tumor specimens from 109 patients with previously untreated squamous cell lung carcinomas were analyzed immunohistologically for the expression of vascular endothelial growth factor (VEGF) and its receptor Flt-1. Our analysis attempted to determine whether these factors have additional prognostic value for the patients' survival. VEGF staining was seen in 59% and Flt-1 staining in 68% of the cases. No significant correlations were detected between VEGF or Flt-1 expression and stage or metastasis. Patients with VEGF-stained tumors had significantly lower survival times than patients with negative tumors. Expression of Flt-1 showed no significant correlation with survival. Combining VEGF and Flt-1 expressions did not improve the prognostic value. Multivariate analysis showed that metastasis and VEGF expression are significant and independent prognostic factors for the survival of patients with squamous cell lung carcinomas.

Cyclin A is associated with an unfavourable outcome in patients with non-small-cell lung carcinomas

Specimens of formalin-fixed, paraffin-embedded non-small-cell lung carcinomas (NSCLCs; n = 187) were analysed immunohistochemically for expression of cyclin A. The analysis was intended to determine whether cyclin A has additional prognostic value for predicting patients' survival and drug response. Of the 187 NSCLCs, 141 cases (75%) showed expression of cyclin A. Patients with cyclin A-positive carcinomas had significantly shorter median survival times than patients with cyclin A-negative carcinomas (79 vs 129 weeks, P = 0.045). Similar results were obtained with more homogeneous groups of patients: patients with only T3 tumours, patients with epidermoid carcinomas and patients with lymph node involvement. The clinical parameters (age, stage, histology, extent of tumour size, lymph node involvement) had no influence on expression of cyclin A. A direct correlation between cyclin A and the proportion of S-phase cells (P = 0.08) and an inverse relationship between cyclin A and the proportion of G0/G1-phase cells (P = 0.04) were found. Furthermore, a significant correlation between the expression of cyclin A and the response of NSCLC to doxorubicin in vitro was detected (P = 0.026).

Angiogenic growth factors and their receptors in non-small cell lung carcinomas and their relationships to drug response in vitro

Tumor specimens of non-small cell lung carcinomas (NSCLC) from previously untreated patients (n = 153) were analysed immunohistochemically for expression of vascular endothelial growth factor (VEGF), VEGF-receptor (Flt-1), basic fibroblast growth factor (bFGF) and FGF-receptor (FGFR-1, (Flg). Expression of the proteins was compared with the in vitro response of the tumors against doxorubicin. The data clearly demonstrate that a significant relationship exists between VEGF (p < 0.001) and Flt-1 expression (p < 0.01) and drug response. The expression of VEGF and Flt-1 was lower in resistant than in sensitive tumors. In contrast, no significant interrelationship was found between expression of bFGF and response to doxorubicin. However, there exists a significant correlation between the expression of FGF-receptor (FGFR-1) and the response of the carcinomas to doxorubicin (p < 0.05). Expression of FGFR-1 was more frequently negative or weak in resistant and more frequently moderate or high in sensitive NSCLC. The data from this investigation clearly demonstrate that a significant interrelationship exists between the expression of VEGF, VEGF-receptor Flt-1 and FGF-receptor, FGFR-1 and the response of NSCLC to doxorubicin in vitro.

Association of vascular endothelial growth factor expression with tumor cell proliferation in ovarian carcinoma

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that may also function as an autocrine growth regulator. Thirty-one ovarian carcinomas were investigated for mRNA expression of VEGF and of a proliferation-dependent gene (histone H3) using slot-blot analysis. Tumor vascularity was assessed by immunohistochemistry and factor VIII. All tumors were demonstrated to express VEGF and histone H3, though to various degrees. There was a good correlation between VEGF mRNA values and histone H3 mRNA values (r = 0.71, p < 0.05). No correlation was found between tumor cell proliferation and tumor vascularity. There was no significant difference in relapse-free interval or overall survival between tumors with low and high VEGF expression. The close correlation of VEGF expression with tumor cell proliferation in this study raises the possibility of autocrine stimulation of ovarian carcinoma.

Expression of resistance-related proteins in tumoral and peritumoral tissues of patients with lung cancer

Twenty tumoral and peritumoral tissues from patients with lung cancer were analyzed immunohistochemically for the drug resistance-related proteins P-glycoprotein (P-170), topoisomerase II (Topo-II), glutathione S-transferase-pi (GST-pi), metallothionein (MT), heat shock protein-70 (HSP-70) and the putative regulators of resistance (ErbB1, Fos and Jun). Protein expression of Topo-II, GST-pi, MT, HSP-70, ErbB1, Fos and Jun was elevated in tumor tissue in comparison to normal tissue. The different expression of the proteins between tumoral and normal tissues was statistically significant for Topo-II (P = 0.05), MT (P = 0.03), and HSP-70 (P = 0.01), whereas ErbB1 showed a borderline significance. The expression of the proteins was frequently increased in smokers in comparison to non-smokers. In general, the increase of the proteins of smokers corresponded in tumoral and non-tumoral tissue. Different expression was only found with MT and HSP-70 which were higher in tissues of smokers.

Coexpression of cyclin D1 and retinoblastoma gene product (pRb) in human squamous cell lung carcinomas is associated with increased tumor take rate in nude mice

Samples from 72 squamous cell lung carcinomas were analyzed immunohistochemically for the expression of cyclin D1 and pRb. Expression of cyclin D1 was found in 61% and expression of pRb in 39% of the cases. The take rate of human squamous cell lung carcinomas in nude mice was significantly different according to the expression of cyclin D1 and expression of pRb in primary human tumors [cyclin D1-negative (32%) vs. cyclin D1-positive (59%); P=0.026; pRb-negative (34%) vs. pRb-positive (71%); P=0.002]. The take rate was improved by coexpression of both proteins [both proteins negative/both proteins positive: 12% vs. 80% (P=0.00005)]. An association of the take rate and clinical parameters (age, extent of tumors, lymph node involvement, stage) could not be observed. Coexpression of cyclin D1 and pRb is also a prognostic factor for the patients' survival.

Vascular endothelial growth factor and basic fibroblast growth factor in primary lung carcinomas and the incidence of metastases

Paraffin-embedded tumor sections from 166 patients with squamous cell lung carcinomas (n=114) and lung adenocarcinomas (n=52) were analyzed for the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) by immunohistochemistry. The results were compared with the incidence of metastatic spread. Sixty-five tumors were characterized as VEGF-negative and 101 tumors as VEGF-positive. Fifty-eight tumors were bFGF-negative and 108 tumors classified as bFGF-positive. Tumors with expression of VEGF or bFGF showed an increase in the formation of metastases. Combining the VEGF and bFGF expressions improved the prognostic value. Corresponding results were obtained when the analysis was restricted to squamous cell lung carcinomas or adenocarcinomas of the lung. These data provide evidence that VEGF and bFGF may be relevant factors associated with the metastatic potential of primary lung carcinomas.

Association of resistance-related protein expression with poor vascularization and low levels of oxygen in human rectal cancer

Rectal carcinomas of previously untreated patients were analyzed for oxygen status using a computerized polarographic needle electrode histograph. Microvessel density and expression of c-jun, vascular endothelial growth factor (VEGF) and several resistance-related proteins (glutathione S-transferase-pi, GST; thymidylate synthase, TS; metallothioneine, MT) were determined using immunohistochemistry. To examine whether a relationship exists between intratumoral vessel density and tumor oxygenation, microvessel counts were determined in a 400x field using factor-VIII-related antigen and were correlated with the corresponding pO2 values. Linear regression analysis revealed a significant relationship between vessel density and oxygenation status of the tumors. Expression of c-jun, VEGF and resistance-related proteins was correlated with microvessel counts and pO2 values. Significantly lower vessel counts were found in GST- and MT-positive tumors and in tumors with overexpression of c-jun and VEGF than in negative tumors. In addition, significantly lower pO2 values were found in c-jun- and VEGF-positive tumors as well as a tendency for pO2 values to be lower in tumors where MT, GST and TS were expressed. These data show that expression of c-jun, VEGF, and resistance-related proteins is linked with poor vascularization and low oxygenation status in rectal cancer.

Association of resistance-related protein expression with poor vascularization and low levels of oxygen in human rectal cancer

Rectal carcinomas of previously untreated patients were analyzed for oxygen status using a computerized polarographic needle electrode histograph. Microvessel density and expression of c-jun, vascular endothelial growth factor (VEGF) and several resistance-related proteins (glutathione S-transferase-pi, GST; thymidylate synthase, TS; metallothioneine, MT) were determined using immunohistochemistry. To examine whether a relationship exists between intratumoral vessel density and tumor oxygenation, microvessel counts were determined in a 400x field using factor-VIII-related antigen and were correlated with the corresponding pO2 values. Linear regression analysis revealed a significant relationship between vessel density and oxygenation status of the tumors. Expression of c-jun, VEGF and resistance-related proteins was correlated with microvessel counts and pO2 values. Significantly lower vessel counts were found in GST- and MT-positive tumors and in tumors with overexpression of c-jun and VEGF than in negative tumors. In addition, significantly lower pO2 values were found in c-jun- and VEGF-positive tumors as well as a tendency for pO2 values to be lower in tumors where MT, GST and TS were expressed. These data show that expression of c-jun, VEGF, and resistance-related proteins is linked with poor vascularization and low oxygenation status in rectal cancer.

Microvessel density, expression of proto-oncogenes, resistance-related proteins and incidence of metastases in primary ovarian carcinomas

Relationships between the incidence of metastatic spread and microvessel density, expression of proto-oncogene products, or expression of resistance-related proteins were investigated in human ovarian carcinomas by immunohistochemistry. Ovarian carcinomas with a high microvessel density showed a significantly increased formation of metastases (P = 0.005). Tumors with positive immunoreactivity of c-jun and c-myc products had a higher metastatic spread; however, these results were not statistically significant. A marginally significant correlation existed between the expression of erbB1 (EGFR) and metastatic spread (P = 0.05). No significant relationship was found between the expression of the resistance-related proteins P-glycoprotein or glutathione S-transferase-pi and the incidence of metastases. Furthermore, no correlation was detected between expression of the heat shock protein 70 and the occurrence of metastases.

Association of vascular endothelial growth factor expression with intratumoral microvessel density and tumour cell proliferation in human epidermoid lung carcinoma

Vascular endothelial growth factor (VEGF) expression, vascularisation and tumour cell proliferation were analysed in 91 human epidermoid lung carcinomas using immunohistochemistry. A polyclonal anti-VEGF antibody was used for VEGF expression, a polyclonal antibody directed against human von Willebrand factor (factor VIII) to identify blood vessels and the proliferating cell nuclear antigen (PCNA) as a marker for proliferating cells. Positive staining for VEGF was obtained in 54 out of 91 cases (59%), the number of blood vessels varied from zero to 64 counts (mean 9.4) and the proportion of PCNA-positive cells varied from 1.3% to 72.1% (mean 25.2%). The mean PCNA labelling index and mean microvessel count in VEGF-positive tumours were significantly higher than those in VEGF-negative tumours (Wilcoxon rank sum test, P<0.0001; p<0.05). In addition, PCNA labelling index significantly increased with increasing VEGF expression (Jonckheere test, P<0.0001). In contrast, no association was found between PCNA labelling index and tumour vascularity (r=0.07, P=0.48). The close correlation of VEGF expression with tumour cell proliferation and microvessel density suggests that VEGF acts both as an autocrine growth factor and as stimulator for angiogenesis. However, tumour cell proliferation and microvessel growth and/or density may be regulated by separate mechanisms.

[Vascular thickness and cytostatic-resistant bronchial carcinoma]

BACKGROUND AND OBJECTIVE

A new way of treatment of malignant tumours was suggested by blocking angiogenesis and thus creating subpopulations of cells which, due to their decreased oxygen content, react differently to treatment. The relationship between angiogenesis (vessel density) and resistance to cytostatic drugs was investigated.

PATIENTS AND METHODS

Results were analysed retrospectively for 83 untreated patients (73 men, 10 women; mean age 60 [37-75] years) with non-small cell bronchial carcinoma. Vessel density and resistance proteins were determined immunohistochemically. Radioactive incorporation of nucleic acid precursors with and without doxorubicin was measured with the in vitro short-term test.

RESULTS

There were significant differences between vessel density and various resistance proteins. With low vessel density (less than mean value) glutathione-S-transferase pi (P < 0.01), thymidylate synthase (P < 0.05) and metallothioneine (P < 0.05) were significantly increased. P-glycoprotein showed a corresponding relationship, but it was not statistically significant, while there was no relationship with topoisomerase II. Bronchial carcinoma with low vessel density was more frequently resistant in vitro to doxorubicin than carcinomas with higher vessel density (P < 0.05).

CONCLUSIONS

Non-small cell bronchial carcinoma with low vessel density more frequently expresses resistance proteins and is more commonly resistant to doxorubicin. Blocking angiogenesis to improve the results of treatment is therefore problematic.

Resistance mechanisms and their regulation in lung cancer

Data obtained from multiple sources indicate that no single mechanism can explain the drug resistance and the poor prognosis of patients with lung cancer. The resistance-related proteins P-glycoprotein, glutathione-dependent enzymes, topoisomerase II, metallothioneins, O-6-alkylguanine-DNA alkyltransferase, thymidylate synthase, dihydrofolate reductase and heat shock proteins have been found in lung carcinomas, but these alone cannot explain the drug-resistant phenotype. Cell cycle-related proteins, angiogenic factors, protooncogenes, and tumor suppressor genes also play a role in the phenotype that is resistant lung cancer. A key future challenge involves determining the relative quantitative contributions of each of these mechanisms to overall resistance.

Messenger RNA expression of resistance factors in human tumor cell lines after single exposure to radiation

Resistance of tumor cells to chemotherapeutic drugs can not only be caused by treatment with antineoplastic agents but also by radiotherapy. The aim of this study was to analyze whether ionizing radiation can influence the mRNA expression of proteins which have been found to be involved in drug resistance of tumor cells. Human tumor cell lines (MCF-7, LXF and Sk-Mel) were treated with single doses of irradiation (5, 10 and 20 Gy). The expression of the resistance related proteins glutathione S-transferase-pi (GST-pi), topoisomerase II alpha (Topo II), thymidylate synthase (TS), O6-methylguanine-DNA-methyltransferase (MGMT), P-glycoprotein (Pgp), glutathione peroxidase (GPX) multidrug resistance-associated protein (MRP) and also of the heat-shock protein 70 (HSP 70) were determined at the mRNA level during the time interval from 1.5 to 72 h post-irradiation and compared with their corresponding controls. We also examined whether a relationship exists between these proteins and the proliferative activity (histone 3, Ki-67, statin) of the cells. We found that exposure of MCF-7, LXF and Sk-Mel cells to ionizing radiation increases the expression of the mRNA of GST-pi. Topo II, TS, HSP 70 and proliferation markers were also altered by exposure to ionizing radiation, but there was no common response of the three cell lines. No significant changes were observed in the expression of MGMT, Pgp, GPX and MRP after radiation treatment. Drug resistance tests revealed that irradiated MCF 7 cells were less sensitive to doxorubicin than non-irradiated control cells. Our results indicate that ionizing irradiation modifies the expression of some proteins involved in drug resistance and the response of MCF 7 cells to doxorubicin and may, therefore, play a role in clinical drug response.

Interrelationships between microvessel density, expression of VEGF and resistance to doxorubicin of non-small lung cell carcinoma

It has been shown that hypoxia can induce resistance to a number of antineoplastic agents. Since vessel density may be considered as an indirect measure of the oxygenation of tumours, in this study we analysed the relationship between tumour vascularity or vascular endothelial growth factor (VEGF) expression and drug resistance. Tumour specimens of 152 non-small cell lung carcinomas (NSCLC) of previously untreated patients were analysed for microvessel density by staining with factor VIII (von Willebrand factor) antibody and for expression of vascular endothelial growth factor (VEGF) using an anti-VEGF-antibody. Both proteins were determined by immunohistochemistry and the expression was compared with the resistance to doxorubicin measured in vitro. Microvessel density was significantly reduced in resistant tumours when compared with sensitive tumours. Of the 98 tumours with low microvessel density 83 (85%) were resistant; whereas of the 54 tumours with high microvessel density only 34 (63%) were resistant (p = 0.004). Expression of VEGF was significantly lower in resistant than in sensitive lung carcinomas. Of the 102 tumors with low expression of VEGF, 87 (85%) were resistant; whereas of the 50 tumors with high expression only 30 (60%) were resistant (p = 0.0009). Corresponding results were obtained when the analysis was restricted to squamous cell lung carcinomas or adenocarcinomas of the lung. Analysis of microvessel density or VEGF expression and clinical data (stage, histology, metastasis) revealed no significant interrelationships. These data show clearly that poor microvessel density (vascularisation) and reduced expression of VEGF are linked with resistance to doxorubicin.