Resistance to gefitinib

Subsets of patients with non-small cell lung cancer (NSCLC) who carry somatic mutations in the epidermal growth factor receptor (EGFR) have responded remarkably well to a tyrosine kinase inhibitor (TKI), gefitinib. Despite the dramatic response to this inhibitor, most patients nevertheless ultimately have a relapse. We herein report a case of advanced NSCLC in a patient carrying mutated EGFR (delE746-A750) who had a relapse after dramatic improvement by gefitinib treatment. The DNA sequence of the EGFR gene in a tumor biopsy specimen obtained from the relapse site revealed the presence of a second point mutation, resulting in a threonine-to-methionine amino acid substitution at position 790 of EGFR, which could not be detected in the tumor specimen taken before the treatment. Screening subjects with EGFR mutations therefore allows us to identify patients who can be successfully treated with gefitinib. Such observations should also help us in the search for more effective therapies against a specific subset of NSCLC.

Identification of HLA-A24 restricted shared antigen recognized by autologous cytotoxic T lymphocytes from a patient with large cell carcinoma of the lung

The aim of the present study was to elucidate the tumor-specific cellular immunological responses occurring in a patient with large cell carcinoma of the lung who had no evidence of recurrence following surgical resections of both a primary lung lesion and a metastatic adrenal lesion. We analyzed an autologous tumor-specific cytotoxic T lymphocytes (CTL clone F2b), which were HLA-A*2402 restricted from regional lymph node lymphocytes. The F2b possessed T cell receptor (TCR) using the Valpha5 and Vbeta7 gene segment. The existence of precursor CTL (pCTL) against autologous tumor cells (A904L) was analyzed using CTL clone-specific PCR. Lymphocytes with the same TCR as F2b were detected in the primary tumor tissue, regional lymph node and the peripheral blood collected from the patient 3 years after the operation. Using the F2b, we identified a cDNA clone encoding the tumor antigen using cDNA expression cloning method. The gene was found to encode splicing variant of the Tara gene. Finally, we identified the 9-mer Ag peptide, using constructions of mini-genes. The F2b recognized 3 out of 7 HLA-A24 positive allogeneic tumor cell lines and in 1 out of 7 HLA-A24 negative allogeneic tumor cell lines when transfected with HLA-A24. This peptide is therefore considered to be potentially useful for performing specific immunotherapy in a significant proportion of lung cancer patients bearing HLA-A24.

Tracheobronchopathia osteochondroplastica occurring in a subsegmental bronchus and causing obstructive pneumonia

A 59-year-old man was referred to the University of Occupational and Environmental Health hospital because a chest roentgenogram obtained at an annual medical examination showed an abnormal shadow. We treated the patient for tracheobronchopathia osteochondroplastica, which caused segmental obstructive pneumonia that proved to be difficult to accurately diagnose before surgery.

Clinical characterization of node-negative lung adenocarcinoma: results of a prospective investigation

OBJECTIVES

In clinical stage IA lung adenocarcinoma, the clinical features of a truly node-negative population were prospectively investigated by means of a prospective investigational study.

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 and the clinical factors associated with the presence of the nodal metastasis were evaluated.

RESULTS

In 114 assessable cases with adenocarcinomas, 15 (13.1%) were node-positive. The serum carcinoembryonic antigen (CEA), retraction sign, and intratumoral air-bronchogram 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 (p = 0.0073), respectively. In combination with the radiologic features and serum CEA, cases with elevated serum CEA or presence of retraction sign included 15.6% of node metastasis-positive, whereas all cases with normal CEA and absence of retraction sign showed no nodal metastasis. Cases with elevated serum CEA or absence of intratumoral air-bronchogram included 24.5% of node metastasis, whereas cases with normal CEA and presence of air-bronchogram showed 4.6% of node metastasis. 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 measuring 3 cm or less in size.

Immunohistochemical α- and β-catenin and E-cadherin expression and their clinicopathological significance in human lung adenocarcinoma

The E-cadherin/catenin complex (alpha-catenin, beta-catenin, and E-cadherin) plays a crucial role in cell-cell adhesion and tissue remodeling, and abnormalities in these molecules have been suggested to participate in the proliferation and invasive and metastatic potentials of several human carcinomas. However, in human lung adenocarcinomas, its importance has not yet been sufficiently investigated. We immunohistochemically examined the expressions of E-cadherin/catenin complex in 35 primary lung adenocarinomas, and evaluated their expressions in a semiquantitative manner. Correlations between these expression levels, MIB-1 and nuclear p53 indices, and clinicopathological factors were analyzed by subdividing the cases into high- and low-expression groups for each protein. The reduction in membranous E-cadherin/catenin complex expression correlated significantly with low-grade histological differentiation and with high MIB-1 index. Survival analyses were also performed to clarify which factors potentially affected the prognosis of lung adenocarcinoma patients. The low expression of beta-catenin and the high MIB-1 index had a significantly unfavorable influence on the patients' survival. Moreover, the immunohistochemical expression of beta-catenin by cancer cells and MIB-1 index are considered useful prognostic factors for lung adenocarcinoma.

Antigens recognized by IgG derived from tumor-infiltrating B lymphocytes in human lung cancer

BACKGROUND

Lung cancer tissues are often infiltrated by B lymphocytes, but it is not clear whether these infiltrations represent tumor-specific immune response or a nonspecific reaction.

MATERIALS AND METHODS

The serological analysis of recombinant cDNA expression libraries (SEREX) were previously modified using a severe combined immunodeficient (SCID) mice model engrafted with fresh human lung cancer. Here, a panel of antigens recognized by tumor-infiltrating B lymphocytes (TIB) in human lung cancer were characterized.

RESULTS

The modified SEREX analysis identified 22 distinct antigens in a large cell carcinoma of the lung. Sequence analysis and real time-PCR analysis showed that 55% of isolated antigens were overexpressed in tumor tissues and 9% had mutation.

CONCLUSION

The results of this study indicate that the humoral immune response of TIB in lung cancer patients can be detected in the xenotransplanted SCID mouse model and our modification shows high sensitivity and specificity for identification of tumor antigens.

Smoking cessation program and CYP2A6 polymorphism

The relationship between CYP2A6 genotype and smoking status remains unclear although several studies have been reported. In this study, we have investigated the significance of CYP2A6 genotype on smoking habit and treatment of nicotine patch. Sixty-one smokers (1.7%) working in a Japanese company (n = 3585) participated in this smoking cessation program. Forty-four of 61 (72.1%) smokers were treated by nicotine patch. A genotyping analysis was carried out for 41 (40 men and 1 women) of 61 participants (67.2%). The smoking cessation rate at 90 days was 54.1% (33/61). Age and smoking years in re-smoking group are significantly lower than those in smoking cessation group. The smoking cessation rate of participants treated with nicotine patch (63.6%; 28/44) was significantly higher than that of the group non-treated with nicotine patch (29.4%; 5/17) at 90 days (p < 0.05). The incidence of homozygotes of CYP2A6 gene deletion (CYP2A619934/19934) in 41 cases (9.8%; 4/41) could be higher than that in 894 healthy controls (3.7%; 33/894) (p = 0.12), while no other variant alleles (CYP2A619932, CYP2A619933 and CYP2A619936) were found. Age and smoking years of participants with CYP2A619934/19934 are significantly higher than those with CYP2A619931 positive. The scores of Fagerstrom test, an analysis for nicotine-dependence, were slightly different between participants with CYP2A619934/19934 and CYP2A619931 positive. Although treatment of nicotine patch is efficacious to smoking cessation, cases with CYP2A619934/19934 might be more sensitive to nicotine adverse effects and more difficult to quit smoking once they have smoking habit.

Iris metastasis of esophageal cancer

Ocular metastasis in patients with esophageal cancer is quite rare. Several cases have been reported in the literature, but no successful treatments for such metastases have ever been described. We herein report a case of esophageal cancer in which the ocular metastasis was controlled by systemic chemotherapy.

Primary pulmonary collision cancer consisting of large cell carcinoma and adenocarcinoma

A case of pulmonary collision tumor is herein reported. An abnormal shadow was discovered in the right lung of a 53-year-old man. A right upper lobectomy with a mediastinal lymph node dissection was performed. Based on the findings of a postoperative pathologic examination, this tumor was considered to be a collision tumor of large cell carcinoma and adenocarcinoma, as the distribution of each tumor was clearly separated. This case is the first report of a primary pulmonary collision tumor consisting of large cell carcinoma and adenocarcinoma.

Identification of a new cancer/germline gene, KK-LC-1, encoding an antigen recognized by autologous CTL induced on human lung adenocarcinoma

The purpose of our present study is to identify a tumor-specific antigen capable of inducing a specific cellular immune response in lung cancer patients. We established a lung adenocarcinoma cell line, designated as F1121L, and induced tumor-specific CTL clone H1 from regional lymph node lymphocytes of patient F1121. CTL clone H1 lysed autologous tumor cells in an HLA-B*1507-restricted manner, but not autologous EBV-B, phytohemagglutinin-blast cells, and K562. The CTL clone also recognized allogeneic HLA-B*1501- or 1507-positive lung cancer cell lines in the HLA-restricted manner. Using the CTL clone, we identified an antigen-coding gene by cDNA expression cloning technique. The gene consisted of 556 bp, including an open reading frame consisted of 113 amino acids, designated as Kita-kyushu lung cancer antigen 1 (KK-LC-1). A 9-mer peptide (KK-LC-1(76-84); RQKRILVNL) was identified as an epitope peptide. The genomic DNA of this antigen was located in chromosome Xq22. A reverse transcription-PCR analysis revealed that the mRNA of this gene was only expressed in the testis among normal tissues. It was expressed in 9 of 18 (50%) allogeneic non-small-cell lung cancer cell lines and in 40 of 100 (40%) non-small-cell lung cancer tissues. We thus identified a new tumor antigen-coding gene categorized as a cancer/germline gene by an autologous lung cancer and CTL system. The new cancer/germline gene was located in Xq22, which is apparently different from the locations of previously reported cancer/germline genes.

The methylation status and protein expression of CDH1, p16(INK4A), and fragile histidine triad in nonsmall cell lung carcinoma: epigenetic silencing, clinical features, and prognostic significance

BACKGROUND

Aberrant methylation of the promoter CpG island (methylation) is known as a major inactivation mechanism of tumor suppressor and tumor-related genes. In this study, the authors studied the presence of methylation by investigated the inactivation of genes and prognostic factors in patients with nonsmall cell lung carcinoma (NSCLC) by examining resection samples for the presence of methylation.

METHODS

Samples were obtained from 224 patients who underwent pulmonary resection for NSCLC. The authors used those samples to study methylation status with methylation-specific polymerase chain reaction analysis and to study protein expression with immunohistochemistry for 3 different genes: CDH1, p16INK4A, and fragile histidine triad (FHIT).

RESULTS

The frequency of methylation in NSCLC was determined as 58.0% for CDH1, 21.9% for p16INK4A, and 52.2% for FHIT. The methylation of p16INK4A was observed significantly in heavy smokers compared either with nonsmokers or with patients who had smoked for <20 pack-years (P = .0420); it also was more significant in squamous cell carcinomas than in adenocarcinomas (P = .0343). FHIT methylation also was correlated significantly with lymph node metastasis (P = .0361). Patients who had tumors with both methylation and reduced expression of CDH1 had a significantly poorer prognosis compared with patients who had tumors both without methylation and with positive expression of CDH1 (P = .0259 and P = .0369, respectively; multivariate Cox analysis). For p16INK4A methylation, 63.3% of tumors showed reduced expression; whereas, in p16INK4A-unmethylated tumors, 33.7% showed reduced expression (P = .0002). However, for CDH1 and FHIT, no significant correlation was found for either methylation or reduced expression.

CONCLUSIONS

Although protein expression was not inactivated by methylation alone, p16 expression was inactivated strongly by methylation. In addition, the analysis of methylation and expression of CDH1 played a clinically important role in treatment strategies for patients with NSCLC.

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

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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.

Expression of FHIT in esophageal epithelium and carcinoma: reference to drinking, smoking and multicentric carcinogenesis

BACKGROUND

Both alcohol consumption and cigarette smoking are risk factors for esophageal cancer. The purpose of this study was to clarify whether the fragile histidine triad (FHIT) is their target gene in esophageal carcinogenesis as well as in multicentric carcinogenesis.

PATIENTS AND METHODS

The expression of FHIT was immunohistochemically examined in the squamous cell carcinoma as well as in the normal esophageal epithelium of 55 cases with esophageal cancer.

RESULTS

The median drinking indices (DIs) were 546 and 1092 (p<0.01) in cases with positive FHIT expression and those with a diminished expression in the esophageal epithelium, respectively. Furthermore, the incidences of intra-esophageal multiple cancer were 44% and 13%, respectively (p<0.05). Regarding the expression in cancer lesions, the median DIs were 280 and 721 in positive and diminished cases, respectively (p=0.081).

CONCLUSION

A loss of FHIT expression is associated not only with alcohol-induced esophageal carcinogenesis, but also with multicentric carcinogenesis.

Expression of the p53 family in lung cancer

BACKGROUND

p53 is mutated in about 50% of various malignant diseases including lung cancer. The p53 family consists of p53, p73 and p63. Although transactivating protein isoforms display p53-like functions, the deltaNp73 or deltaNp63 isoforms act toward p53 in a dominantly negative way. The aim of this study was to detect p53, deltaNp73 and deltaNp63 expressions in lung cancer and to evaluate the relationship between the expression levels of the proteins and the prognosis of patients with resectable lung cancer.

MATERIALS AND METHODS

Immunohistochemistry was employed to analyze the protein expression of p53, deltaNp73 and deltaNp63 in paraffin-embedded tumor samples from 132 well-characterized lung cancer patients. The correlation among the expression levels of p53, deltaNp73 and deltaNp63, clinical variables and survival outcome was analyzed.

RESULTS

Positive expressions of p53, deltaNp73 and deltaNp63 were detected in the tumor cells in 52, 77 and 44 of the 132 patients, respectively (39.4%, 58.3% and 33.3%) with lung cancer. The incidence of p53 positive expression was 54.5% and 27.6% in patients with squamous cell carcinoma and adenocarcinoma, respectively (p = 0.03). The incidence of a positive expression of deltaNp73 was 64.5% and 43.6% in male and female patients, respectively (p = 0.03). The incidence of deltaNp63 positive expression was 68.2% and 15.8% in the patients with squamous cell carcinoma and adenocarcinoma, respectively (p < 0.0001). The expressions of p53 and deltaNp63 were not found to significantly affect survival. However, lung cancer patients with a positive deltaNp73 expression had a poorer prognosis than those with a negative deltaNp73 expression. In addition, multivariate analysis indicated that a positive expression of deltaNp73 was a significantly independent factor for predicting a poor prognosis (p < 0.0001, risk ratio = 3.38).

CONCLUSION

Clinical evidence that the p53 family is frequently overexpressed in lung cancer specimens, especially deltaNp63 in squamous cell carcinoma, was provided. The expression of deltaNp73 may be a useful marker for predicting a poor prognosis in resectable lung cancer. Understanding how groups of lung cancer cell genes are coordinately expressed in response to physiological, immunological and micro-environmental stimuli remains an important goal. A better understanding of the gene expression profiles of tumors may help to identify molecular targets, such as deltaNp73, for effective therapy.

Effect of IgG produced by tumor-infiltrating B lymphocytes on lung tumor growth

BACKGROUND

Tumor-infiltrating B lymphocytes (TIB) are often observed in lung cancer. The role of TIB in tumor growth has not been well investigated.

MATERIALS AND METHODS

Forty-four surgically-resected human lung cancer tissues were xenotransplanted into SCID mice. Their blood was collected and the volume of the transplanted tumors was measured regularly. The correlations between the IgG titer in the sera and the growth of the transplanted tumors according to the clinicopathological variables were examined.

RESULTS

Human IgG production from TIB was observed in the all xenotransplanted mice. Twenty-seven out of the 44 tumors regressed gradually. The average serum human IgG level of the tumor regressors (n = 10) was significantly higher than that of the progressors (n = 9) in squamous cell carcinoma (p = 0.02), while there was no significant difference in the other histological groups.

CONCLUSION

IgG produced by TIB might play a crucial role in preventing tumor growth in squamous cell carcinoma.

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.

A point mutation in the NFYC gene generates an antigenic peptide recognized by autologous cytolytic T lymphocytes on a human squamous cell lung carcinoma

We have identified an antigen recognized by cytolytic T lymphocytes (CTL) on the autologous tumor cells of a nonsmall cell lung cancer patient. The antigenic peptide, presented by HLA-B*5201 molecules, was encoded by a mutated sequence in the gene coding for the C subunit of transcription factor NF-Y. The mutation was present in the tumor sample from which the cell line was derived, and appeared to be unique to the tumor of this patient. In a lymph node draining the tumor, precursors of CTL recognizing the autologous tumor cells were detected at a frequency of about 1/30,000 of the CD8 cells, and 85% of them recognized the mutated NF-YC peptide, suggesting that the patient mounted a T cell response against this antigen. These results strengthened the notion that unique tumor-specific antigens are highly represented not only in melanoma but also in other types of tumors, like nonsmall cell lung cancer.

P53R2, p53 inducible ribonucleotide reductase gene, correlated with tumor progression of non-small cell lung cancer

p53R2 plays a crucial role in supplying dNTPs for DNA repair. The expression of p53R2 is induced by DNA-damaging agents in a p53-dependent manner and p53R2 translocates to the nucleus upon DNA damage. Immunohistochemistry was used to analyze the protein expression of p53R2 in paraffin-embedded tumor samples from 130 well-characterized non-small cell lung cancer (NSCLC) patients and the expression level of p53R2, clinical variables and survival outcome were compared. A positive expression of p53R2 was detected in the cytoplasm of tumor cells in 61 of the 130 patients (46.2%) with NSCLC. The positive ratio was significantly higher in the patients with pathological stage II/III, pathological T3-4 and pathological N1-3 than in those with stage I, T1-2 and N0, respectively. No significant difference was observed between the p53R2 expression and the gender, age at operation, histological type or p53 expression. Though our findings do not support that the p53R2 immunocytochemical marker alone plays an important prognostic role in NSCLC, the DNA repair pathway mediated by p53R2 may be responsible for controlling the growth of lung cancer.

A lack of prognostic significance regarding DeltaNp63 immunoreactivity in lung cancer

DeltaNp63 is an isoform of the p53 homologue p63, which lacks an amino-terminal transactivation domain and antagonizes the induction of the gene expression by Deltap63. The aim of this study was to detect the DeltaNp63 expression in lung cancer using immunohistochemical (IHC) staining, and to evaluate the relationship between theDeltaNp63 expression level and the prognosis based on resected lung cancer tissues specimens from the of patients. We used immunohistochemistry to analyze the protein expression of DeltaNp63 in paraffin-embedded tumor samples from 161 well-characterized squamous cell carcinoma patients and compared the expression level of DeltaNp63, clinical variables and the survival outcome. Seventy-seven patients (47.8%) showed positive staining for DeltaNp63 in the nuclei of tumor cells. No significant difference was observed between the DeltaNp63 expression and the gender, age at operation, pathologic stage, pathologic T status, and pathologic N status. Based on the actuarial survival method, Kaplan-Meier method, and the log-rank test, the DeltaNp63 expression was not associated with survival for lung cancer. Differences in survival remained insignificant even after lung cancer patients were stratified according to stage or differentiation. The prognostic effects of DeltaNp63 expression do not appear to act as an important prognostic indicator in lung cancer. Our findings do not support that immunocytochemical markers demonstrate a relevant prognostic role in lung cancer.

Expression of endoplasmic reticulum molecular chaperone Grp78 in human lung cancer and its clinical significance

All eukaryotic cells respond to the accumulation of unfolded proteins in the endoplasmic reticulum (ER) by signaling an adaptive pathway termed the unfolded protein response (UPR). Glucose-regulated protein (Grp) 78 is a molecular chaperone involved in the UPR. The aim of this study was to detect Grp78 expression in lung cancer using immunohistochemical (IHC) staining, and also to evaluate the relationship between the Grp78 expression level and the prognosis of patients with lung cancer. We used immunohistochemistry to analyze the protein expression of Grp78 in paraffin-embedded tumor samples from 132 well-characterized lung cancer patients and compared the expression level of Grp78, clinical variables and survival outcome. A positive expression of Grp78 was detected in the cytoplasm of tumor cells in 88 of the 132 patients (66.7%) with lung cancer. No significant difference was observed between the Grp78 expression and the gender, age at operation, histological type, pathologic stage, pathologic T status, and pathologic N status. Lung cancer patients with a positive Grp78 expression tended to show a better prognosis than those with a negative Grp78 expression. In addition, a multivariate analysis of the clinicopathologic characteristics of lung cancer indicated a positive expression of Grp78 to be a significant factor for predicting a favorable prognosis (p < 0.001, risk ratio = 2.35). A positive expression of Grp78 may thus be a useful marker for predicting a favorable prognosis in patients undergoing a resection of lung cancer. The ER stress pathway mediated by Grp78 may therefore be responsible for controlling the growth of lung cancer cells.

Identification of tumor associated antigens recognized by IgG from tumor-infiltrating B cells of lung cancer: correlation between Ab titer of the patient's sera and the clinical course

We previously demonstrated that TIB recognize tumor antigens and produce antibodies against them. In the present study, we identified three tumor antigens recognized by TIB in lung cancer and evaluated whether changes in the antibody titer against these antigens correlated with the patient's clinical course. A lung cancer cell line, G603L, was established from a primary lung tumor of a patient, G603. Seven months later, adrenal metastasis was detected and surgically resected. The latter tumor was mildly infiltrated with B cells and xenotransplanted into SCID mice to obtain human IgG. A cDNA library was constructed from G603L and SEREX was carried out using TIB-derived IgG. The sero-reactive clones were sequenced and one of these antigens was revealed to be MAGE-B2 whereas the others were novel antigens. In the immuno-monitoring of the patient's sera, high antibody titer against MAGE-B2 was observed before operation and the titer decreased after resection of the primary tumor. It was elevated again at the time of adrenal metastasis, but then decreased after resection. The change in antibody titer against the second antigen was similar to MAGE-B2, and the antibody titer against the third antigen was low before the primary operation but increased at the time of recurrence. Our results suggest that TIB recognized tumor antigens and the antibody titers against these antigens were changed along with the patient's clinical course. Therefore, these antibodies could be used as tumor markers for the patient.

Identification of the HLA-Cw*0702-restricted tumor-associated antigen recognized by a CTL clone from a lung cancer patient

PURPOSE

A large number of tumor-associated antigens have been used in vaccination trials for mainly melanomas. Our purpose of this study is to identify a novel tumor antigen useful for immunotherapy of lung cancer patients.

EXPERIMENTAL DESIGN

Analysis of an autologous tumor-specific CTL clone F2a that was established from regional lymph node lymphocytes of a patient with lung cancer (A904) by a mixed lymphocyte-tumor cell culture.

RESULTS

F2a recognized and killed autologous tumor cells (A904L), whereas it did not respond to autologous EBV-transformed B cells, phytohemagglutinin-blastoid T cells, and K562 cells. cDNA clone 31.2 was isolated by using cDNA expression cloning method as a gene encoding antigen. This gene was identical to the reported gene whose function was unknown. The antigen encoded by the cDNA was recognized by the CTL in a HLA-Cw*0702-restricted manner. Furthermore, a 9-mer peptide at positions 659 to 685 in cDNA clone 31.2 was identified as a novel epitope peptide. The CTL recognized some allogeneic cancer cell lines with HLA-Cw*0702 as well as some HLA-Cw*0702-negative cell lines when transfected with HLA-Cw*0702, thus indicating that the identified antigen was a cross-reactive antigen.

CONCLUSIONS

Although exact mechanism to process the encoded protein and present the antigen in the context of HLA class I remains to be elucidated, the CTL recognized some of tumor cells in the context of HLA-Cw*0702 but did not recognize a variety of normal cells and also autologous EBV-transformed B cells. These results indicated that the antigen identified in this study may therefore be a possible target of tumor-specific immunotherapy for lung cancer patients.

Epidermal growth factor receptor mutations are associated with gefitinib sensitivity in non-small cell lung cancer in Japanese

The protein-kinase family is the most frequently mutated gene family found in human cancer. Gefitinib, an ATP-competitive inhibitor of epidermal growth factor receptor (EGFR), also appears to be particularly effective in adenocarcinoma of the lung and in patients without smoking history. To determine whether lung tumors sensitive to gefitinib contained mutations within the tyrosine kinase (TK) domain of EGFR, we screened exons 18-23 of EGFR of tumors in 20 patients with non-small cell lung cancer (NSCLC) who had been treated with gefitinib. Nine (45%) tumors had TK domain mutations. All mutations were observed in adenocarcinoma. Seven (77.8%) of 9 cases with mutated types showed sensitivity to gefitinib, while no cases of 11 with wild type showed gefitinib sensitivity. Such mutations were more frequently observed in patients who had never smoked (5/8 or 62.5%) than in smokers (4/12 or 33.3%). The patients with mutations of EGFR to have a more favorable prognosis than those with wild type (p=0.033). These data show that adenocarcinomas from patients who had never smoked comprise a specific subset of patients with NSCLC sensitive to gefitinib treatment.