Acute lung injury following an esophagectomy for esophageal cancer, with special reference to the clinical factors and cytokine levels of peripheral blood and pleural drainage fluid

Acute lung injury (ALI) is one of most serious complications to occur after an esophagectomy for esophageal cancer. However, the pathogenesis of ALI is still unclear. The cytokine levels of pleural drainage fluid as well as peripheral blood were measured in 27 patients who had undergone an extended radical esophagectomy. Both the clinical factors and cytokine levels were compared between 11 patients with (group I) and 16 without ALI (group II). ALI occurred more frequently in patients who underwent colon interposition than in those who received a gastric tube reconstruction (86%vs 25%, P = 0.009). The operation time of group I was significantly longer than that of group II. A logistic regression analysis revealed colon interposition to be an independent factor associated with the ALI (P < 0.05). Postoperative anastomotic leakage and systemic inflammatory response syndrome (SIRS) occurred more frequently in group I than in group II (P < 0.01). Both the serum interleukin-6 (IL-6) and IL-8 levels of group I were significantly higher than those of group II. IL-1beta and tumor necrosis factor-alpha were undetectable in the peripheral blood, whereas they were detectable in the pleural effusion. The IL-1beta of pleural effusion was higher in group I than group II. In conclusion, greater surgical stress, such as a longer operative time, is thus considered to be associated with the first attack of ALI. The adverse events developing in the extra-thoracic site, such as necrosis and local infection around anastomosis may therefore be the second attack. Furthermore, ALI may cause not only SIRS but also other complications such as anastomotic leakage.

Secondary T790M mutation and novel G796A mutation in exon20 of EGFR gene in patients with non-small cell lung cancer who show resistance to gefitinib

7703

Background: Somatically acquired mutations in the EGFR gene in non-small cell lung cancer are associated with a significant clinical response to a tyrosine kinase inhibitor (TKI). EGFR mutations occur predominantly in exon19 and/or exon21, namely, an in-frame deletion in exon19 or a missense mutation in exon21 (L858R), which have been found to be related to the sensitivity to TKI. However, most patients with such sensitive mutations in their tumor show progression during the TKI treatment. In such resistant tumors, a secondary threonine- to-methionine mutation at codon 790 (T790M) in exon20 has been reported to be related the resistance to either gefitinib or erlotinib. Methods: EGFR mutations in exons19–21 were examined by sequencing in 37 pretreatment tumors obtained from patients with NSCLC, who were treated by gefitinib. Of the 22 cases having sensitive EGFR mutations (19del or L858R), 15 showed CR/PR and 7 showed SD/PD. Of the 15 patients with CR/PR, 4 tumor samples (2 lung, 1 liver, and 1 pleural effusion) that became refractory to gefitinib, were obtained. In pretreatment tumor samples from 4 patients, an in-frame deletion of exon19 was observed in 3 tumors and a L858R mutation of exon21 was in 1 tumor. We next examined whether a secondary mutation occurred in a tumor with acquired resistance to gefitinib in 4 patients by the sequencing of exons 19–21, with informed consent. Results: Three of 4 tumor samples had a secondary T790M mutation, which was not detected in the pretreatment tumor samples. These 3 samples also had an in-frame deletion in exon19. There were no other novel secondary mutations in exons 19,20,21. In 7 cases showing resistance to gefitinib (SD/PD) in spite of the existence of sensitive mutations, 1 tumor demonstrated the co-existence of a missense mutation (G796A) in exon20. In vitro, a stable clone of cells bearing the G796A mutation was approximately 50,000-fold less sensitive to gefitinib in comparison to the cells carrying exon19 deletion. Conclusions: The T790M mutation is common in patients with acquired resistance to gefitinb. Our results suggest that screening tumor samples for a range of EGFR mutations may therefore improve our ability to identify the patients most likely to benefit from treatment with TKI.

No significant financial relationships to disclose.

A prospective phase II study of gefitinib in non-small cell cancer patients with epidermal growth factor receptor gene (EGFR) mutations

18081

Background: Somatically acquired mutations in the EGFR gene in non-small cell lung cancer are associated with a significant clinical response to gefitinib, a tyrosine kinase inhibitor that targets EGFR, especially in patients with adenocarcinoma, females, and/or never/light smokers. In our retrospective study, cases with EGFR mutations (exon19del or L858R) showed a high sensitivity to gefitinib, and the patients with sensitive EGFR mutations also tended to have a more favorable prognosis than those with wild-type after gefitinib treatment (Uramoto, et al. Lung Cancer 2006;51:71). In the present study, we prospectively assessed the efficacy of gefitinib and the survival benefit for patients with EGFR mutations. Methods: Patients with either recurrent disease after undergoing surgery or advanced disease (IIIB or IV) of NSCLC which demonstrated EGFR mutations were eligible for this study. EGFR mutations in exons 19–21 were examined by our previously described screening method (Sugio, et al. Br J Cancer 2006;94:896) and confirmed by direct sequencing after informed consent was obtained from all patients. The patients with EGFR mutations were enrolled in this study after obtaining informed consent a second time, and they were thereafter treated with gefitinib. Results: Between 2005 and 2006, 16 patients (10 males/6 females, all adenocarcinoma) who had EGFR mutations were enrolled onto this study. Six pts had a deletion in exon 19, 8 pts had a missense mutation in exon 21 (L858R), 1 pt had both an exon 19 del and L858R, and 1 pts had an exon19 del and missense mutation in exon 20 (G796A). The overall response rate was 50%, and the disease control rate was 88%. In patients with exon19 del and L858R, the response rates were 83% and 25%, respectively. A case with a deletion in exon19 and a missense mutation in exon20 (G796A) showed resistance to gefitinib. The median progression-free survival time was 8.8 months, and the median survival time was 15.4 months. No life-threatening toxicity was observed. Conclusions: EGFR mutations in exons 19 or 21 are therefore considered to a good predictor of the efficacy of gefitinib, and the treatment with gefitinib was also found to achieve a prolonged survival.

No significant financial relationships to disclose.

Clock and ATF4 transcription system regulates drug resistance in human cancer cell lines

The mechanisms underlying cellular drug resistance have been extensively studied, but little is known about its regulation. We have previously reported that activating transcription factor 4 (ATF4) is upregulated in cisplatin-resistant cells and plays a role in cisplatin resistance. Here, we find out a novel relationship between the circadian transcription factor Clock and drug resistance. Clock drives the periodical expression of many genes that regulate hormone release, cell division, sleep-awake cycle and tumor growth. We demonstrate that ATF4 is a direct target of Clock, and that Clock is overexpressed in cisplatin-resistant cells. Furthermore, Clock expression significantly correlates with cisplatin sensitivity, and that the downregulation of either Clock or ATF4 confers sensitivity of A549 cells to cisplatin and etoposide. Notably, ATF4-overexpressing cells show multidrug resistance and marked elevation of intracellular glutathione. The microarray study reveals that genes for glutathione metabolism are generally downregulated by the knockdown of ATF4 expression. These results suggest that the Clock and ATF4 transcription system might play an important role in multidrug resistance through glutathione-dependent redox system, and also indicate that physiological potentials of Clock-controlled redox system might be important to better understand the oxidative stress-associated disorders including cancer and systemic chronotherapy.

Clinical characterization of node-negative non-small cell lung cancer: Results of a prospective investigation

7218

Background: 20 to 30% of clinical stage IA non-small cell lung cancer cases were revealed to be node-positive by pathologic examination of resected specimens. In this prospective study, the clinical features of a truly node-negative population were prospectively investigated to search for candidates of a lesser resection or of a stereotactic radiotherapy. Methods: The clinical data and radiographic features of high-resolution computed tomography (HR-CT) were registered before operation in 169 clinical stage IA lung cancer patients, who were scheduled to undergo a standard lobectomy and systemic mediastinal node dissection. The nodal metastasis was pathologically defined, while the clinical factors associated with the presence of the nodal metastasis were evaluated. Results: In 130 evaluable cases, 16 of 114 adenocarcinoma and 3 of 16 other NSCLC were node-positive. Among all parameters, positivity of the serum carcinoembryonic antigen (CEA) was the only factor significantly associated with nodal metastasis (p = 0.0074). When we focused on adenocarcinomas, the serum CEA, retraction sign and intratumoral air-space on HR-CT were suggested to be predictive factors for lymph node metastasis with hazard ratios of 12.44 (p = 0.0003), 6.53 (p = 0.0533) and 0.17 (0.0073), respectively. In combination with the radiologic features of HR-CT imaging, none of 18 CEA-negative/retraction-negative cases and 3 of 65 CEA-negative/air-space positive cases showed nodal metastasis, in which the incidence of nodal metastasis was significantly lower than the counterparts with respective p-values of 0.0015 and 0.037. The tumor size and the proportion of ground glass attenuation were not associated with the incidence of nodal metastasis. Conclusions: The serum CEA and HR-CT features thus allowed us to identify node-negative lung adenocarcinomas. In clinical stage IA adenocarcinoma cases, a standard operation should be considered when positive serum CEA and/or retraction sign on HRCT is noticed.

No significant financial relationships to disclose.

Mutations within the tyrosine kinase domain of EGFR gene specifically occur in lung adenocarcinoma patients with a low exposure of tobacco smoking

Somatically acquired mutations in the epidermal growth factor receptor (EGFR) gene in lung cancer are associated with significant clinical responses to gefitinib, a tyrosine kinase inhibitor that targets EGFR. We screened the EGFR in 469 resected tumours of patients with lung cancer, which included 322 adenocarcinomas, 102 squamous cell carcinomas, 27 large cell carcinomas, 13 small cell carcinomas, and five other cell types. PCR with a specific condition was performed to identify any deletion in exon 19, while mutant-allele-specific amplification was performed to identify a mutation in codon 858 of exon 21. EGFR mutations were found in 136 cases (42.2%) with adenocarcinoma, in one case with large cell carcinoma, and in one case with pleomorphic carcinoma. An in-frame deletion in exon 19 was found in 62 cases while an L858R mutation was found in 77 cases. In the 322 cases with adenocarcinoma, these mutations were more frequently found in women than in men (P=0.0004), in well differentiated tumours than in poorly differentiated tumours (P=0.0014), and in patients who were never smokers than in patients who were current/former smokers (P<0.0001). The mutation was more frequently observed in patients who smoked ⩽20 pack-year, and in patients who quit at least 20 years before the date of diagnosis for lung cancer. The K-ras mutations were more frequently found in smokers than in never smokers, and in high-dose smokers than in low-dose smokers. In conclusion, the mutations within the tyrosine kinase domain of EGFR were found to specifically occur in lung adenocarcinoma patients with a low exposure of tobacco smoking.

Low expression of polypeptide GalNAc N-acetylgalactosaminyl transferase-3 in lung adenocarcinoma: impact on poor prognosis and early recurrence

Initial glycosylation of mucin-type O-linked protein is catalysed by one of the UDP-GalNAc: polypeptide N-acetyl-galactosaminyl transferase-3 (GalNAc-T3). O-glycosylation is important in the binding of cell adhesion molecules, cell differentiation, invasion, and metastasis in tumours. This study was designed to detect GalNAc-T3 expression in lung adenocarcinoma by using immunohistochemical staining, and to evaluate the relationship between the GalNAc-T3 expression level and prognosis and recurrence in completely resected lung adenocarcinoma patients. A low expression of GalNAc-T3 was detected in the cytoplasm of tumour cells in 79 of 148 patients (53.4%) with lung adenocarcinoma. The low expression of GalNAc-T3 was associated with poorly differentiated tumour (P<0.0001), poor pathologic stage (P<0.0001), lymph node metastasis (P<0.0001), and tumour recurrence (P=0.016). The lung carcinoma patients with low GalNAc-T3 expression had a poorer prognosis than those with high GalNAc-T3 expression, using both univariate and multivariate analyses (overall survival: P<0.0001 and P=0.011, respectively). In addition, multivariate analysis of the clinicopathological characteristics of stage I lung adenocarcinoma indicated that the low expression of GalNAc-T3 was a significant independent factor for predicting poor prognosis and early recurrence (P=0.006, rr=2.87 and P=0.019, rr=3.05, respectively). The low expression of GalNAc-T3 may be a useful marker for predicting poor prognosis and early recurrence in completely resected lung carcinoma patients, particularly patients with stage I diseases.

[Assessment of prognosis and p 53 mutations in patients with multiple tumors of the lung; intrapulmonary metastasis or double primary cancers?]

To assess whether a satellite lesion in the primary-tumor lobe is intrapulmonary metastasis from primary cancer (pm 1) or they are double primary lung cancers, we examined the postoperative prognosis of patients with pm 1 and the p 53 genetic differentiation between a satellite lesion and a primary lesion. Of 772 consecutive patients with N0-2M0 non-small cell lung cancer who underwent surgical resections between 1979 and 2000, 31 patients had a satellite lesion in the primary-tumor lobe. The 5-year survival rate was 26.3% in the pm 1 (+) T 4 group (n = 37), 14.7% in the pm 1 (-) T 4 group (n = 43), and 32.5% in the T 3 group (n = 132), suggesting that pm 1 cases should be classified as T 3. We examined 16 of 37 patients with pm 1 for mutations of the p 53 gene occurring exons 5 through 8 by the fluorescence-based polymerase chain reaction single-strand conformation polymorphism. Seven of the 16 patients analyzed had at least one p 53 mutations in their tumors. The mutational status of the p 53 gene was discordant in 5 patients, suggesting they were double primary lung cancers. The mutational status including DNA sequencing of the p 53 gene was concordant in 2 patients, suggesting they were intrapulmonary metastases. It remains arguable in the TNM staging system whether a satellite lesion in the primary-tumor lobe is intrapulmonary metastasis from primary cancer or they are double primary lung cancers.

DNA methylation profiles of lung tumors

Aberrant methylation of CpG islands in promoter regions of tumor cells is one of the major mechanisms for silencing of tumor suppressor genes. We determined the frequency of aberrant promoter methylation of the p16, adenomatous polyposis coli (APC), H-cadherin (CDH13), glutathione S-transferase P1 (GSTP1), O6-methylguanine-DNA-methyltransferase (MGMT), retinoic acid receptor beta-2 (RAR beta), E-cadherin (CDH1), and RAS association domain family 1A (RASSF1A) genes in 198 tumors consisting of small cell lung cancers [SCLCs (n = 43)], non-small cell lung cancers [NSCLCs (n = 115)], and bronchial carcinoids (n = 40). The profile of methylated genes in the two neuroendocrine tumors (SCLC and carcinoids) were very different from that of NSCLC. However, whereas the overall pattern of aberrant methylation of carcinoids was similar to that of SCLC, carcinoids had lower frequencies of methylation for some of the genes tested. There were also significant differences in the methylation profiles between the two major types of NSCLC, adenocarcinoma and squamous cell carcinoma. We performed cluster analysis and found that SCLCs clustered with other SCLCs and carcinoids but not with NSCLCs, whereas the NSCLCs tended to cluster together. Within NSCLCs, adenocarcinomas and squamous cell carcinomas clustered with their respective histological types. Finally, we compared the methylation profiles of SCLC and NSCLC tumors and their respective cell lines (n = 44). In general, methylation frequencies were higher in tumor cell lines, but these differences were seldom significant. Thus, tumor cell lines appear to be suitable models to study aberrant DNA methylation. We conclude that SCLC, carcinoids, squamous cell carcinomas, and adenocarcinomas of the lung have unique profiles of aberrant methylation. Our findings should help us understand differences in the pathogenetic mechanisms of lung cancers.

High vascularity in the peripheral region of non-small cell lung cancer tissue is associated with tumor progression

OBJECTIVES

We attempted to determine if the degree of angiogenesis can serve as a prognostic factor in the case of completely resected non-small cell lung cancer patients, with special reference to the center and the periphery of the tumor tissue.

METHOD

For 255 Japanese patients who underwent completely resected non-small cell lung cancer (NSCLC), micro vessel density (MVD) was assessed by visual quantification of microvessels immunostained with anti-CD34 monoclonal antibody in 5 m section. Vascular endothelial growth factor (VEGF) was also immunostained on the same paraffin block specimen.

RESULTS

MVD at the center (MVD-c) and that at the periphery (MVD-p) were frequently different in each individual although a weak positive correlation was observed (r=0.499, P<0.0001). One hundred and one patients with high MVD-p, but not the 107 patients with high MVD-c, showed a significantly higher proportion of advanced stage, larger tumor size and nodal metastasis as compared with MVD. The 5 year survival rate and median survival time for the high MVD-p group were significantly lower than that of low the MVD-p group (43.0%/31 months vs 48.6%/54 months, P=0.0256). As to the relationship among vascular endothelial growth factor (VEGF) and MVD, expression of VEGF was not associated with the degree of MVD. However, patients with high grade MVD-p showed an unfavorable prognosis in cases of high expression of VEGF.

CONCLUSION

High MVD-p is associated with advancement of NSCLC, and it was particularly apparent in conjunction with high VEGF expression.

Nuclear expression of the Y-box binding protein, YB-1, as a novel marker of disease progression in non-small cell lung cancer

Transcription factor Y-box binding protein 1 (YB-1) that binds to the inverted CCAAT box is involved not only in transcription of various genes but also in cell proliferation and DNA repair. We determined whether localization of YB-1 in either the nucleus or cytoplasm could serve as a prognostic marker for patients with non-small cell lung cancer (NSCLC). In 196 NSCLC patients, expression of YB-1 protein in the nucleus or cytoplasm was immunohistochemically evaluated. Of the 196 tumors examined, 88 (44.9%) were positive for YB-1 expression in the nucleus. Nuclear YB-1 expression significantly correlated with T factor, lymph node metastasis, and stage of the disease. Patients with a nuclear YB-1 tumor had a poorer prognosis than did those with a cytoplasmic YB-1 tumor in all of the NSCLC patients (P = 0.0494) and in patients with squamous cell carcinoma (P = 0.0313) but not in patients with adenocarcinomas. Nuclear localization of the YB-1 protein may prove to be an important factor of disease progression for patients with NSCLC, in particular, in cases of squamous cell carcinoma.

Reduced expression of cell-cycle regulator p27(Kip1) correlates with a shortened survival in non-small cell lung cancer

BACKGROUND

The cell cycle progression is governed by a family of cyclin-dependent kinases, which are regulated by associated cyclins and by phosphorylation. p27, a cyclin-dependent kinase inhibitor, regulates the progression from G1 into the S phase by binding and inhibiting cyclin/cdks. Although p27 mutations in human tumors are extremely rare, a reduced expression of p27 might to lead to a progression of cancer cells.

METHODS

We examined tissues that had been surgically excised from 161 unselected Japanese patients with non-small cell lung cancer, and investigated the p27 protein expression by immunohistochemistry.

RESULTS

A reduced expression of the p27 protein was found in 63 cases (39.0%). Statistical correlation was found between the reduced p27 expression and advanced stage, although no correlation was found between the level of p27 expression and the gender, T factor, N factor or histological differentiation. The 5-year survival rate in the reduced group was 35.4%, which was statistically poorer than the 63.2% rate in the normal group (P=0.0016), in patients with complete resection. In a multivariate analysis, the level of p27 expression was found to be an independent prognostic indicator.

CONCLUSIONS

We demonstrated the expression of p27 protein to be a biological prognostic indicator which can indicate the subsets of patients with either a good or poor prognosis, in patients who underwent surgical resection.

Heterogeneous distribution of P53 immunoreactivity in human lung adenocarcinoma correlates with MDM2 protein expression, rather than with P53 gene mutation

Although the tumor suppressor p53 protein (P53) immunoreactivity and its gene (p53) mutation were reported to be significant prognostic indicators for human lung adenocarcinomas, little is known regarding the relationship between the heterogeneous distribution of P53 and its genetic status in each tumor focus and the clinicopathological significance. To determine how P53 is heterogeneously stabilized in patients, we compared P53 expression to both the p53 allelic mutation in exon 2 approximately 9 by polymerase chain reaction-single strand conformation polymorphism using microdissected DNA fractions, and the immunohistochemical MDM2 expression. Of the 48 positive to P53 in 118 lung adenocarcinomas examined, 10 with heterogeneous P53 expression were closely examined. The higher P53 expression foci in 7 of 10 cases were less differentiated, histologically in respective cases, and were frequently associated with fibrous stroma. Two had genetic mutations in exon 7 of the p53 gene in both the high and low P53 expression foci of cancer tissue indicating no apparent correlation between heterogeneous P53 expression and the occurrence of gene mutation. Immunohistochemical expression of MDM2 was significantly lower in high P53 expression areas (p < 0.05, the mean labeling indices of high and low P53 expression areas being 4.2 +/- 5.4% and 13.6 +/- 12.2%, respectively). In addition, among all the 118 cases examined, MDM2 expression was significantly suppressed in cases of p53 gene mutation, simultaneously with P53 overexpression, as compared with cases without both the p53 mutation and expression (p < 0.001). These findings suggest that the heterogeneous stabilization of P53 in human lung adenocarcinomas could be partly due to suppressed MDM2 expression. The overexpression of non-mutated P53 may afford a protective mechanism in human lung adenocarcinomas.

Prognostic significance of p21waf1, cyclin D1 and retinoblastoma expression detected by immunohistochemistry in non-small cell lung cancer

p21waf1 is a downstream effector of p53, and mediates growth arrest by inhibiting the action of G1 cyclin-dependent kinases. Cyclin D1 is a cell-cycle regulator essential for G1 phases progression and a candidate proto-oncogene implicated in the pathogenesis of several human tumor types. Cyclin D1 overexpression and the absence of retinoblastoma (Rb) protein have been frequently seen in various types of cancer, including lung cancer. The aim of this study was to clarify the relationship between the expressions of p21waf1, cyclin D1, and Rb protein, and to investigate the correlation between these protein expressions and the clinical features of the patients, and their prognoses. We immunohistochemically examined 92 samples of resected non-small cell lung cancer for p21waf1, cyclin D1, and Rb expression. Of the 92 specimens examined, 43 cases (46.7%) showed p21waf1 expression, 23 cases (25.0%) showed cyclin D1 overexpression, and 61 cases (66.3%) showed Rb expression. No correlation was observed between the expressions of p21waf1, cyclin D1, and Rb. There was no association of p21waf1 and cyclin D1 immunoreactivity with gender, disease stage, or histological types of the tumor. Regarding the prognosis in 79 cases with complete resection, no statistical differences were observed according to the degree of expression of these three factors. However, when unfavorable prognostic factors were considered to be the positive expression of p21waf1, positive of cyclin D1, and negative of Rb, the 5-year disease-free survival rate in the group with 2 or 3 unfavorable prognostic factors was 21.1%, which was statistically poorer than the 45.4% in the group with 0 or 1 unfavorable prognostic factor (p=0.0138). We conclude that examination of the expression of cell cycle regulators, such as p21waf1, cyclin D1, and Rb, is useful as a prognostic indicator, when these proteins' expression is analyzed in combination.

Clinicopathological and molecular evidence indicating the independence of bronchioloalveolar components from other subtypes of human peripheral lung adenocarcinoma

Although human lung adenocarcinoma has diverse histological subtypes, the correlation between histological subtypes and occurrence of the p53 gene mutation has been given less attention. We investigated 145 surgically resected lung adenocarcinomas to search for the incidence of p53 mutations and for record data on survival in each histological subtype, according to the new WHO criteria (1999). The frequency of p53 mutation in bronchioloalveolar carcinoma (BAC; 0% in 17 cases) and BAC with invasive growth component (BAC-invasive; 11% in 27 cases), which is conventionally categorized as the mixed subtype in WHO typing, were apparently significantly lower than in other types (non-BAC including acinar, papillary, solid, or mixed histology with these subtypes; 48% in 101 cases; P < 0.01). Multivariate analysis revealed that the histological subtype including BAC-invasive was a strong, independent, and significant prognostic factor (P < 0.03), as were tumor size and pathological stage (P < 0.001 and 0.002, respectively) for overall survival. However, the occurrence of p53 mutation itself was seen to be significant only in case of the univariate analysis. Therefore, histological subtyping may be a better prognostic indicator than is p53 mutation. These findings suggest that the WHO classification with the BAC and BAC-invasive from other histological subtypes may prove useful to predict the outcome for surgically treated patients with lung adenocarcinoma.

Lung cancer with p53 expression and a solitary metastasis to the stomach: a case report

Lung cancer with a solitary metastasis to the stomach occurred in a 65-year-old man, surgically treated for gastric metastasis was followed by pulmonary resection. The gastric metastasis accompanied by upper gastrointestinal hemorrhage. After total gastrectomy to control this hemorrhage, a left lower lobectomy with a partial resection of the lingular segment and combined resection of the chest wall were done. Histopathological features of both the primary tumor in the left lower lobe and the gastric tumor were poorly differentiated adenocarcinoma, and showed the same immunoreactivities of p53 protein, carcinoembryonic antigen and keratin. These results indicate that the gastric tumor was a metastasis originated from the lung cancer.

Clinical significance of the Rb expression in adenocarcinoma of the lung

BACKGROUND

Altered retinoblastoma gene expression has been found in various types of cancers including non-small cell lung cancer (NSCLC) and some reports have shown it also to be associated with a poor clinical prognosis in NSCLC.

MATERIALS AND METHODS

We evaluated the expression of Rb protein by immunohistochemistry in 90 patients with lung adenocarcinoma who underwent surgical resection and determined its prognostic significance. Also, the expression of p27 by immunohistochemistry and the mutations of the p53 gene by PCR-SSCP were evaluated.

RESULTS

Fifty-one out of 90 tumors (56.7%) had reduced expression of the Rb gene. There were no statistical differences between the Rb expression level and clinicopathological status. There was no correlation between the Rb expression level and the p53 mutations or the p27 expression level. The 5-year survival rate in the normal group was 55.1%, which was poorer than that of 73.0% in the reduced group, but showed no statistical difference (p=0.0981). In patients with a reduced Rb-expression, the survival rate of the p53 mutation group tended to show a poorer prognosis than that of the p53 normal group (p=0.0880). In addition, the survival rate of the negative p27 expression group tended to show a poorer prognosis than that of the positive p27 expression group (p=0.0537).

CONCLUSIONS

The Rb expression status was not significant as an individual factor for evaluating the prognosis in adenocarcinoma of the lung. Analyses of the accumulation of genetic alteration are necessary to identify the subset of patients with a poor prognosis.

Direct IFNluence of interferon-gamma on proliferation and cell-surface antigen expression of non-small cell lung cancer cells

In order to clarify the anti-tumor activity of IFN-gamma, we investigated the direct IFNluence of IFN-gamma on both the growth and cell-surface antigen expression of tumor cells. In the present study, four human lung cancer cell lines were used; two squamous cell lines (QG-56, QG-95) and two adenocarcinoma cell lines (PC-9, PC-12). In all four tumor cell lines, mutations were detected in exon 7 of the p53 gene by a PCR-FSSCP analysis. The proliferation of QG-56 or QG-95 was inhibited by IFN-gamma in a dose-dependent manner with about 70% inhibition at 1000 JRU/ml while that of PC-9 was slightly inhibited with maximally 25% inhibition at 1000 JRU/ml. The growth of PC-12 was not inhibited at all. In QG-56, QG-95 and PC-9, the fraction of cells in G1 phase increased while the fractions of cells in both S and G2/M phases decreased after exposure to IFN-gamma (200 JRU/ml) for 72 h. The growth inhibition by long-term exposure to IFN-gamma was irreversible in QG-56. After culture in the presence of IFN-gamma (200 JRU/ml) for 14-16 days, tumor cells were examined for expression of various antigens, including HLA-class I, HLA-class II, and CEA. In all cell lines but PC-12, 100% of cells expressed HLA-class I after incubation with IFN-gamma. Both HLA-class II and CEA were also induced in those cell lines. The proportion of HLA-class II-positive cells or that of CEA-positive cells varied among the cell lines. Of the three antigens, the degree of HLA-class II expression paralleled that of growth inhibition by IFN-gamma treatment. These results suggested that in various function of IFN-gamma against tumor cells, the anti-proliferative effect might be closely linked with the induction of HLA-class II probably through a similar posttranscriptional process, independent of the function of p53 gene.