Telomerase activity in small-cell and non-small-cell lung cancers.

BACKGROUND: Telomerase is an enzyme that adds hexameric TTAGGG nucleotide repeats onto the ends of vertebrate chromosomal DNAs (i.e., telomeres) to compensate for losses that occur with each round of DNA replication. Somatic cells do not have telomerase activity and stop dividing when the telomeric ends of at least some chromosomes have been shortened to a critical length. It has been suggested that immortalized cells (including some, but probably not all, cancer cells) continue to proliferate indefinitely because they express telomerase. PURPOSE: To investigate whether expression of telomerase is a prerequisite for the development of naturally occurring human cancers, we assayed the levels of telomerase activity in specimens of human lung tumor and adjacent normal tissue. METHODS: Using a polymerase chain reaction-based assay, we examined telomerase activity in 136 primary lung cancer tissues and 68 adjacent noncancerous tissues obtained by surgical resection. We also studied telomerase activity in four primary and 23 metastatic lesions obtained through biopsy, (two patients) or autopsy (10 patients). Relative telomerase activity levels were estimated by serial dilutions of extracts prepared from the specimens. Telomerase activity was also assayed in extracts of cells present in pleural fluids from three patients with adenocarcinoma of the lung. RESULTS: Among surgically resected samples, telomerase activity was detected in 109 (80.1%) of 136 primary lung cancer tissues and in three (4.4%) of 68 normal adjacent tissues. All 11 surgically resected specimens of primary small-cell lung cancer (from 11 patients) revealed high levels of telomerase activity, whereas the activity ranged from undetectable to high levels in the 125 surgically resected specimens of primary non-small-cell lung cancer tissue (from 125 patients). Generally, high levels of telomerase activity were observed in metastatic lesions and tumors with altered telomere length. A few primary and, surprisingly, some metastatic tumors did not appear to have detectable telomerase activity. Telomerase activity was, however, detected in cells present in all tested pleural fluids obtained (from three patients with adenocarcinoma of the lung). CONCLUSION: The subset of non-small-cell lung cancers that exhibits only low or undetectable levels of telomerase activity may contain primarily mortal cancer cells. Cancers that exhibit high levels of telomerase activity, such as all of the small-cell lung cancers examined in this study, are likely to consist mainly of immortal cells. IMPLICATIONS: Telomerase activity may be useful both as a diagnostic marker to detect the existence of immortal lung cancer cells in clinical materials and as a target for therapeutic intervention.

Monoclonal antibodies to human squamous cell carcinoma of the lung and their application to tumor diagnosis.

Three immunoglobulin G1 monoclonal antibodies, LuCa2, LuCa3, and LuCa4, were produced by fusing murine myeloma NS1 cells with splenocytes obtained from a BALB/c mouse immunized with SK-MES1 cells derived from human squamous cell carcinoma of the lung. These three monoclonal antibodies were shown to recognize different protein antigens on SK-MES1 cells by indirect immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. While the pattern of cell line distribution of antigens recognized by these antibodies was not tumor type specific, their reactivity with tissue and pleural effusion was much more informative than with cell lines. The presence of target antigens in vivo was analyzed by immunoperoxidase staining of frozen tissue sections and immunofluorescence staining of tumor cells in pleural effusions. LuCa2 antibody was reactive with lung squamous carcinoma and adenocarcinoma tumor tissues and pleural effusions, but only infrequently with those of small cell carcinoma. This antibody was also reactive with many tumor tissues from other organs as well as with various normal tissues, including alveoli and bronchus. LuCa3 and LuCa4 antibodies reacted with lung squamous carcinoma in tissues and pleural effusions, but not with lung adenocarcinoma nor with small cell carcinoma. These two antibodies reacted only weakly with normal squamous tissues of the esophagus, skin, and cervix uteri, but not with various other normal tissues. Moreover, LuCa3 had weak reactivity with squamous cell carcinoma tissue of tongue and esophagus, whereas LuCa4 had no reactivity with nonpulmonary tumor tissues. LuCa3 and LuCa4 antibodies should be of clinical interest, because our data suggest that these antibodies may be potentially useful for the diagnosis of the histological type of lung tumor cells in both cancer tissue and pleural effusions.

Detection of a circulating tumor-associated antigen with a murine monoclonal antibody, LISA 101, selected by reversed indirect enzyme-linked immunosorbent assay.

In the presence of a characterized monoclonal antibody recognizing a soluble molecule, additional monoclonal antibodies reactive with unknown antigenic determinants on the molecule can be easily selected by reversed indirect enzyme-linked immunosorbent assay. A novel murine monoclonal antibody, LISA 101, was selected by reversed indirect enzyme-linked immunosorbent assay against soluble antigens, which exist in sera and in pleural effusions derived from lung adenocarcinoma patients and which bear determinants recognized by the previously characterized murine monoclonal antibody KL-6. Antigenic determinants recognized by the LISA 101 antibody appear to be sialylated carbohydrate in nature and different from those recognized by previously reported monoclonal antibodies against sialylated carbohydrates, such as NS 19-9, FH-6, and KL-6, suggested by competitive inhibition assay and immunostaining of tissues. A circulating antigen, LISA 1-6, was detected by a bimonoclonal bideterminant assay using immobilized LISA 101 antibody and enzyme-labeled KL-6 antibody. It was found that serum LISA 1-6 levels were elevated in 63% (25 of 40) of patients with lung adenocarcinoma and in 92% (11 of 12) of patients with pancreatic carcinoma, but only in 6.5% (2 of 31) of patients with benign lung diseases and in 7.1% (1 of 14) of patients with pancreatitis. The present observations indicate that the LISA 1-6 antigen may serve as a new tumor marker for adenocarcinomas of the lung and the pancreas. Additionally, the reversed indirect enzyme-linked immunosorbent assay may be a widely applicable method for selecting new monoclonal antibodies against as yet unknown antigenic determinants on soluble molecules.

Alterations in telomeric repeat length in lung cancer are associated with loss of heterozygosity in p53 and Rb.

In the two-stage model of controlling cellular senescence in cultured human fibroblasts, retinoblastoma (Rb) and p53 proteins may be key factors regulating the mortality stage 1 mechanism. In addition, the critical loss of telomeric DNA due to the end-replication problem may result in the mortality stage 2 mechanism. Cells which acquire telomerase activity can overcome the M2 mechanism by stabilizing telomere length and thus become immortal (telomere hypothesis). At present it is known whether cellular immortality is a prerequisite for all human cancers. To investigate this question and the applicability of the two-stage model to human cancers, we analysed the relationship between alterations of telomere length and other genetic changes in lung cancer. Among 60 primary lung cancer tissues, telomere length alterations were observed in 16 tumors (26.7%) including 14 with short and two with elongated telomeres. Ten of them revealed allelic loss of both p53 and Rb genes, and remaining six showed no abnormalities in both genes. We propose that inactivation of both p53 and Rb genes may promote cell divisions causing telomere shortening in lung cancer as in the two-stage model, while there may be another pathway to overcome both M1 and M2 mechanisms, especially for adenocarcinoma.

Prediction of short- and intermediate-term prognoses of patients with acute myocardial infarction using myocardial contrast echocardiography one day after recanalization.

OBJECTIVES: This study sought to determine whether microvascular integrity in the risk area (RA) for myocardial infarction (MI) one day after recanalization predicts the outcome in patients with first acute MI. BACKGROUND: Immediately after recanalization, microcirculation in the RA is modified by both hyperemic response and microvascular impairment. METHODS: Fifty consecutive patients who underwent serial myocardial contrast echocardiography before and one day after recanalization (day 2) were studied. All patients had a completely occluded lesion in the left anterior descending coronary artery alone, and underwent successful reperfusion therapy. The relative size of the initial RA (RA ratio) and peak gray scale ratio (PGSR) within the RA on day 2 were determined. Patients were followed for a median of 22 months to evaluate clinical outcome. RESULTS: On day 2, PGSR was a median of 0.46. Study patients were subdivided into two groups, group A of 24 patients with acceptable opacification (PGSR > 0.46 on day 2) and group B of 26 patients without it. Major cardiac events (cardiac death, nonfatal MI and repeat admission for congestive heart failure) were more frequently observed in group B (28% vs. 4%, Cox hazard ratio=8.5, p=0.05, 95% confidence interval [CI] 1.03 to 69.9). The median value of the RA ratio was 0.45. Patients (n=15) with RA ratio > 0.45 on day 1 and PGSR on day 2 < or = 0.46 exhibited a 10.7-fold relative risk for major cardiac events (p=0.005, 95% CI 2.06 to 55.8) and a 3.69-fold relative risk for composite cardiac events (major cardiac events and target lesion revascularizations) after the initial intervention (p=0.004, 95% CI 1.51 to 9.04). CONCLUSIONS: The assessment of both the size of the initial RA and microvascular integrity on day 2 enables precise determination of the efficacy of reperfusion therapy and prediction of the short- and intermediate-term prognoses of patients with recanalized MI.

p53 gene mutations are associated with shortened survival in patients with advanced non-small cell lung cancer: an analysis of medically managed patients.

Mutations in the p53 gene are common in many cancers. Nevertheless, the relationship between mutations of this tumor suppressor gene and patient survival in non-small cell lung cancer (NSCLC) remains unclear. Interpretation of prior studies of patient outcomes are complicated by the inclusion of both surgical and nonsurgical patients. To better isolate the potential effects of p53 gene mutations per se on tumor progression, we chose to examine patients with advanced disease in whom surgery was not performed (stages IIIA, IIIB, and IV). We have used PCR-denaturing gradient gel electrophoresis, a sensitive and specific method for the detection of a variety of p53 mutations in cytology or biopsy specimens, to evaluate the prognostic significance of p53 gene mutations in nonsurgical patients with advanced NSCLC. In 70 consecutive medical patients, p53 mutations were found in 29 cases (41%) at the time of initial diagnosis. Followed prospectively, patients with p53 mutations had a significantly reduced survival time after diagnosis than those without mutations (median survival, 17 versus 39 weeks; P = 0.0003) independent of other clinical factors. This abbreviated survival occurred in both patients who received chemotherapy (n = 39, P = 0.002) or best supportive care (n = 31, P = 0.018). These results indicate that mutations of the p53 gene in patients with NSCLC who do not undergo surgical resection portends a significantly worse prognosis.

Carotid atherosclerosis and serum lipoprotein(a) concentrations in patients with NIDDM.

OBJECTIVE: To investigate the association of carotid atherosclerosis and serum lipoprotein(a) [Lp(a)] concentrations in subjects with NIDDM. RESEARCH DESIGN AND METHODS: We measured carotid intima-media thickness (IMT) and Lp(a) concentrations in 117 NIDDM subjects. Subjects were divided into tertiles according to IMT values and number of plaques. RESULTS: Serum Lp(a), but not lipid and apoprotein levels, increased significantly with increasing IMT (20.0 +/- 2.3, 24.7 +/- 3.3, and 39.8 +/- 4.3 mg/dl [mean +/- SE], respectively, P < 0.001). Serum Lp(a) increased with increasing number of plaques (18.4 +/- 2.5 mg/dl in 59 subjects with no plaques, 25.8 +/- 2.5 mg/dl in 24 subjects with 1 plaque, and 38.7 +/- 5.1 mg/dl in 34 subjects with more than 1 plaque; P < 0.05). Furthermore, the mean IMT and Lp(a) levels in the subjects with cerebrovascular disease (CD) were significantly higher than in those without CD (1.25 +/- 0.04 mm and 41.2 +/- 4.7 mg/dl vs. 1.08 +/- 0.03 mm and 22.2 +/- 1.9 mg/dl; P < 0.005). The mean IMT and Lp(a) levels were higher in subjects with ischemic heart disease (IHD) than in those without IHD, although statistical significance was not observed (1.21 +/- 0.06 mm and 31.7 +/- 4.7 mg/dl vs. 1.10 +/- 0.03 mm and 27.0 +/- 2.4 mg/dl, respectively). CONCLUSIONS: Elevated serum Lp(a) concentrations are associated with carotid atherosclerosis in NIDDM subjects.

Dissociation of microangiopathy and macroangiopathy in patients with type 2 diabetes.

OBJECTIVE: Although persistent hyperglycemia contributes greatly to the progression of diabetic micro- and macroangiopathy, microangiopathy progresses more rapidly than macroangiopathy in some type 2 diabetic patients, with the opposite being true in others. This study was conducted to identify factors responsible for such dissociation. RESEARCH DESIGN AND METHODS: Patients with proliferative diabetic retinopathy and a carotid intima-media thickness (IMT) level < or =1.0 mm were classified as the microangiopathy group (MIG); those with an IMT level >1.1 mm and without retinopathy or with background retinopathy were assigned to the macroangiopathy group (MAG). Only middle-aged patients, 50-69 years old, were included in this study. There were 54 patients in the MIG and 68 patients in the MAG. RESULTS: Patients in the MIG were significantly younger at the onset of diabetes, and those in the MAG had a significantly higher mean ratio of apoprotein (apo) B to apoAI. The percentage of patients with a family history of diabetes was significantly higher in the MIG. Maternal inheritance was common among these patients. Those with obesity, a family history of diabetes, and younger onset of hypertension were more common in the MAG. In the multiple logistic regression analyses, maternal inheritance and early onset of diabetes were independent risk factors for the acceleration of microangiopathy. A personal history of obesity and a family history of hypertension were independently related to the development of macroangiopathy. CONCLUSIONS: Our results suggest that patients with early onset and maternal inheritance of diabetes may have a high risk for the progression of diabetic microangiopathy, while patients with hyperlipidemia, a history of obesity, and a family history of hypertension seem prone to the development of atherosclerosis.

Diabetes mellitus and its vascular complications in Japanese migrants on the Island of Hawaii.

Japanese migrants and their offspring on the island of Hawaii and Japanese living in Hiroshima were examined for diabetes mellitus and its vascular complications. the same methods and investigators were used in both locations. Death certificates of Japanese and Caucasians dying on the island during the past 26 yr were analyzed. Diabetes, defined as a venous serum glucose concentration of at least 200 mg/dl 2 h after a 50-g oral glucose load, was significantly more common in the Hawaiian Japanese than in the Hiroshima Japanese subjects. This suggests that diabetes is more prevalent in Japanese in Hawaii than in Japan, although lack of knowledge about the total population of Japanese migrants in Hawaii makes this generalization uncertain. The proportion of deaths attributed to diabetes was much higher in Japanese migrants and their offspring in Hawaii than in Japan. During the 1950s, the proportional death rate from diabetes was about half as large in Japanese Hawaiians as in Caucasian Hawaiians, but it increased to become 1.6 times the Caucasian rate during the 1970s. A nutritional study revealed that the total caloric intake was similar in Japanese in Hawaii and Hiroshima, although the estimated level of physical activity was less in the Hawaiian subjects. Consumption of animal fat and simple carbohydrates (sucrose and fructose) were at least twice as high in Hawaiian as in Hiroshima Japanese. Conversely, Hiroshima Japanese consumed about twice the amount of complex carbohydrate as the Hawaiian Japanese. These observations support the hypothesis that a high fat, high simple carbohydrate, low complex carbohydrate diet and/or reduced levels of physical activity increase risk of diabetes. The proportion of deaths attributed to ischemic heart disease was higher in both diabetic and nondiabetic Japanese Hawaiians than in diabetic subjects in Japan. The rates were similar for Japanese and Caucasians in Hawaii. There was no evidence of an environmental influence on the development of microangiopathy (retinopathy) in diabetes, as the prevalence of diabetic retinopathy (stratified for diabetes duration) was similar in Japanese subjects in Hawaii and in Japan, and it was similar to previous reports from England. On the other hand, diabetes alone did not appear to account for the greater prevalence of macroangiopathy in Hawaiian Japanese than in Hiroshima. Thus environmental factors, possibly including diet, appear to be involved in the development of macrovascular complications of diabetes.

Allelotype frequency of the thiopurine methyltransferase (TPMT) gene in Japanese.

Polymorphisms at three loci in the thiopurine methyltransferase (TPMT) gene are known to be responsible for azathioprine and 6-mercaptopurine (6MP) toxicity. Among them, only TPMT*3C variant allele with A719G mutation was found in 15/522 (2.9%; 17/1044 alleles; 1.6%) Japanese individuals including two homozygotes. The allele frequency was different from that in Caucasians, and investigation of TPMT polymorphisms with consideration of ethnic differences before administration of azathioprine or 6MP may provide clinically useful information.

The Krüppel-type zinc finger family gene, HKR1, is induced in lung cancer by exposure to platinum drugs.

To investigate the molecular mechanism associated with the signaling pathway of platinum drug administration, we focused on the C2H2-type zinc finger (ZNF) transcription factor gene family. Here we show cloning of a Krüppel-type ZNF gene, HKR1, which contains Krüppel-associated box (KRAB) domain and ZNF motifs. We found that mRNA expression of the HKR1 gene was induced in lung-cancer cell lines by exposure to cisplatin using Northern blot analysis. Moreover, we also found that HKR1 mRNA expression levels in lung cancers were higher than those in normal lung tissues, and that high expression levels in lung cancers were associated with antemortem platinum drug administration. These results suggest that HKR1 may be associated with the regulation of a signaling pathway involved in the progression of lung cancer or the acquisition of resistance to platinum drugs.

Safety and efficacy of the neuraminidase inhibitor zanamivir in treating influenza virus infection in adults: results from Japan. GG167 Group.

The study was carried out to evaluate the therapeutic effects of zanamivir, a highly selective, potent and specific inhibitor of influenza A and B virus neuraminidases, in adult patients with acute influenza-like illness. Patients who presented within 36 h of the onset of influenza-like symptoms were randomly assigned to receive one of three treatments, twice daily, for 5 days: 10 mg zanamivir powder for inhalation (zanamivir inhalation group), 10 mg zanamivir powder for inhalation plus 6.4 mg zanamivir nasal spray (zanamivir inhalation plus intranasal group) or placebo (placebo group). The primary end point was the time to alleviation of the three major symptoms (fever, headache and myalgia). The secondary end point was the time to alleviation of five influenza symptoms (fever, headache, myalgia, cough and sore throat). One hundred and sixteen patients with influenza-like illness were recruited to the study. No differences were observed between the two groups of patients who received zanamivir (inhalation group or inhalation plus intranasal group). Patients who received zanamivir recovered significantly faster (median 3 days to recovery) than the patients in the placebo group (median 4 days to recovery; P < 0.01). Topically administered zanamivir was well tolerated. This study confirms that in adults, topically administered zanamivir is well tolerated and is effective in reducing the time to alleviation of influenza symptoms.

Westernized food habits and concentrations of serum lipids in the Japanese.

To investigate the association of westernized food habits and concentrations of serum lipids in the Japanese, we studied 1200 healthy Japanese living in Hiroshima prefecture and 1483 ethnic Japanese from Hiroshima prefecture living in the Hawaii Islands and Los Angeles. The nutritional assessments were made by the same dietitians. No major difference was observed in the total energy intake between the Japanese and the Japanese-Americans in both males and females. However, the intake of animal fat and simple carbohydrates (especially fructose) were markedly greater, and that of complex carbohydrates lower, in the Japanese-Americans compared with the Japanese. The mean serum cholesterol (CH), LDL-CH and serum triglyceride (TG) levels were significantly higher in the Japanese-Americans in both sexes. The mean HDL-CH concentration was similar between the two groups in males, but it was approximately 7 mg/dl higher in Japanese-American females. Using the 75 percentile values of CH and TG in the Japanese in Hiroshima, the frequency of WHO types IIa and IIb hyperlipidemia was about twice as high in the Japanese-Americans. These results suggest that westernized food habits in the Japanese include qualitative changes in animal fat, simple carbohydrate and complex carbohydrate diet rather than an increase in the total energy intake. These changes are associated with marked increases in the concentrations of serum CH and TG and increased prevalence of types IIa and IIb hyperlipidemia.

Whole-blood incubation method to study neutrophil cytoskeletal dynamics.

To reduce artifactual effects in the study of filamentous (F)-actin dynamics in neutrophils, we have developed a whole-blood incubation method. Neutrophils in whole blood contained significantly less basal F-actin than did separated neutrophils. Although the peak relative F-actin content of neutrophils in whole blood after formyl-methionyl-leucyl-phenylalanine (fMLP) stimulation was significantly higher than that of separated neutrophils at 10(-9) to 10(-6) M fMLP concentrations (p < 0.05), there was no significant difference in increase in mean fluorescence intensity and the EC50 (concentration of stimulant giving a half-maximum response). On the other hand, the EC50 of platelet-activating factor (PAF) between separated neutrophils and whole-blood-incubated neutrophils differed significantly (1.6 +/- 1.1 x 10(-9) M in separated neutrophils and 2.0 +/- 0.7 x 10(-8) M in whole-blood-incubated neutrophils, p < 0.05). The whole-blood incubation method described presently reduces the sample volume, cost and time needed to separate neutrophils, prevents neutrophil activation during separation, and reserves all blood components that may affect neutrophil function. For these reasons, the conditions adopted in the present method are thought to simulate well neutrophils circulating in vivo and the method would be preferable to other neutrophil function tests performed to study actin dynamics.

Cryopreservation of human lymphocytes for assessment of lymphocyte subsets and natural killer cytotoxicity.

Cryopreservation of lymphocytes has become increasingly important, especially when the cells are to be used in retrospective studies of selected and dwindling populations, such as A-bomb survivors. This report describes an efficient method for cryopreservation of human lymphocytes which does not significantly alter various immunological characteristics of these cells. The proportions of Leu-1+ cells (T cells), Leu-2a+ cells (suppressor-cytotoxic T cells), Leu-3a+ cells (helper-inducer T cells), HLA-DR+ cells, Mo2+ cells (monocytes), B1+ cells (B cells), and Leu-7+ cells (natural killer (NK) cells), as determined by monoclonal antibodies, were found to be stable following cryopreservation. NK cell activity against K-562 target cells showed a 40-60% decrease immediately after thawing, but recovered to approximate pre-freezing levels after preincubation for 18 h. Neither lymphocyte subsets nor cell viability significantly changed following preincubation after cryopreservation. However, the ratio of cells binding to K-562 cells increased after this preincubation and may account for the observed recovery of NK cell activity. NK cell activity remained relatively stable up to 14 months of storage which confirms that freezing damage depends on the freezing process rather than on the duration of cryopreservation.

Predicting angiographic narrowing > or = 50% in diameter in each of the three major arteries by amounts of calcium detected by electron beam computed tomographic scanning in patients with chest pain.

The evaluation of calcium of the coronary arteries on a vessel-by-vessel basis by use of electron beam computed tomography was useful in obstructed coronary arteries. The absence of coronary calcification in any vessel was highly specific for the absence of an obstructive lesion.

Glutathione S-transferase-pi gene expression and platinum drug exposure in human lung cancer.

We examined the association between the gene expression levels of glutathione S-transferase-pi (GST-pi) and platinum drug exposure in human lung cancer. First we monitored GST-pi gene expression levels in two lung cancer cell lines and in peripheral mononuclear cells of ten previously untreated lung cancer patients after platinum drug exposure. Next we examined GST-pi gene expression levels in 40 lung cancer autopsy specimens. The GST-pi gene expression levels were assessed by the quantitative reverse transcription-polymerase chain reaction or Northern blot analysis. The GST-pi gene expression was not induced by platinum drugs either in vitro and in vivo within 24 h of exposure. In contrast, GST-pi gene expression levels in lung cancer tissues of patients who had been exposed to platinum drugs at least 1 month before death were significantly higher than that in those of patients who had not been exposed. These results suggest that GST-pi gene expression is associated with chronic exposure to platinum drugs in lung cancer and/or the stress response to xenobiotics.

Former poison gas workers and cancer: incidence and inhibition of tumor formation by treatment with biological response modifier N-CWS.

Mustard gas is known to have mutagenic and carcinogenic effects on animal and human cells. In this report, 1,632 male Japanese who worked in poison gas factories at some time between the years 1927 and 1945 were studied to determine comparative risk for development of cancer, the reference population being data on Japanese males overall. The standardized mortality ratio (SMR) for lung cancer in workers directly and indirectly involved in the production of mustard gas was significantly elevated. In addition, SMR for lung cancer in worker who had worked for more than 5 years was also significantly elevated. Thus, poison gas workers who had engaged in the production of mustard gas or related work for more than 5 years are a high-risk group for lung cancer. Under the cancer preventive program, Nocardia rubra cell-wall skeleton (N-CWS) was administered to 146 former poison gas workers. During a 4.5 year observation period, development of cancers was found in 7 treated workers and 17 untreated controls. After elimination of the influence of smoking level, a significant suppression of development of cancers was noted in the N-CWS-treated workers as compared to the untreated controls. Although the molecular mechanisms of carcinogenesis in former poison gas workers remains unclear, our study proposes the possible effect of biological response modifiers in the prevention of cancer development in high-risk human subjects.

Scid mice model for the in-vivo study of human oncotherapy - studies on the growth and metastasis of human lung-cancer.

For the study of the growth and metastasis of human lung cancer, we established a severe combined immunodeficient (SCID) mouse model for engraftment of intact human lung-cancer tissue dissected from patient specimens. Small fragments of human lung-cancer tissues (14 cases) obtained from surgery or autopsy were implanted into the mammary fat pads of SCID mice. Seven of the fourteen cases (50%) showed an evident enlargement of the implanted lung-cancer tissue, the histopathology of which was almost identical to that of the original cancer tissues for as long as 2 months following implantation. There was slight correlation between the implantation success rate and the clinical stage of the patient at implantation. A second implantation of cancer tissues on four of these cases was successful. In contrast, no significant enlargement of the implanted tissue was observed in the cases of normal human peripheral-lung tissues (five cases), but a bronchial epidermal feature was observed in all of them. Matrigel (Collaborative Research, Bedford, MA) coating of the tissues significantly increased the growth rate of lung-cancer implants, and a high correlation (R=O.806) between the size of the implanted human lung-cancer tissues and carcinoembryonic antigen levels in the SCID mice was seen. Additionally, human lung-cancer cell lines subcutaneously injected into the backs of mice showed more metastatic lesions in the lungs and lymph nodes of SCID mice than in nude mice. Also, fresh human lung cancer metastasized to the lymph nodes and lungs of SCID mice. The results demonstrate the utility of SCID mice as recipients of human lung-cancer tissue and the applicability of this model to the in vivo study of mechanisms of human lung-cancer growth and metastasis.

Alternative splicing, but not allelic loss, of the FHIT gene increases with development of lung cancer.

The FHIT gene is considered to be a tumor suppressor gene, its role and inactivation mechanism remain unclear. We analyzed FHIT gene aberrations in 64 lung cancer tissues and found that the appearance of the aberrant FHIT transcripts depends on the condition of RT-PCR and high telomerase activity, shortened telomere length, and advanced pathological stage were likely associated with the prevalence of aberrant FHIT transcripts, but not with allelic loss of the FHIT gene. These observations would indicate that an additional unknown gene may exist, which is more responsible for the allelic loss around the FHIT gene locus.