Expression of hnRNP A2/B1 proteins in small airway epithelial cells

The overexpression of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1, especially of B1 has been reported informative to detect pre-clinical lung cancer for early detection. However, relatively little work has been performed on the expression of hnRNP A2/B1 in non-malignant airway cells; such information is clearly required to investigate whether overexpression of this protein could be a specific marker for early lung cancer detection. In order to evaluate whether the expression of hnRNP A2/B1 is specific for cancer cells, we investigated the expression of the protein in human small airway epithelial (HSAE) cells. Using immunostaining and Western blotting with monoclonal antibodies, 4G8 (specifically reacts A2) and 2B2 (specific to B1), expression of hnRNP A2/B1 in HSAE cells was evaluated. Northern blotting and quantitative RT-PCR were also performed. In HSAE cells, hnRNP A2 as well as B1 were expressed primarily in the nucleus excluding the nucleolus, although the expression of A2 protein was weaker than that of B1 protein. Staining pattern of hnRNP A2/B1 in HSAE cells was similar to that observed in control cancer cells. Western blotting with 4G8 and 2B2 apparently demonstrated expression of A2 and B1 in HSAE cells. In Northern blotting, both hnRNP A2 mRNA and B1 mRNA were observed in HSAE cells as shown in control cancer cells. hnRNP A2/B1 was apparently expressed in HSAE cells, although the expression in HSAE cells was weaker than that of cancer cells. More quantitative determination of A2/B1 is required to elucidate their significance in early lung cancer detection.

Expression and alternative splicing pattern of human telomerase reverse transcriptase in human lung cancer cells

Telomerase activity is generally considered to be necessary for cancer cells to avoid senescence. The expression of human telomerase reverse transcriptase (hTERT) is believed to be a rate-limiting step in telomerase activation. Recently, it has been proposed that the alternative splicing of hTERT is also involved in regulation of telomerase activity. However, the regulatory mechanism of telomerase in cancer cells has not been thoroughly investigated. To clarify it in lung cancer cells, we measured the expression of the hTERT transcript, analyzed its alternative splicing by RT-PCR, and compared it with telomerase activity and telomere length. The expression of the hTERT transcript was positively correlated with telomerase activity in lung cancer cells. Cancer cells with high telomerase activity contained 4 splicing variants of hTERT, and the full-length variant was 31.3-54.2% of the total transcripts. Cells of the TKB-20 cell line, which has extremely low telomerase activity, showed a different splicing pattern of hTERT in addition to low expression. The functional full-length variant was scarcely detected in TKB-20 cells, suggesting that the telomerase activity was repressed by alternative splicing of hTERT. Telomere length was not necessarily correlated with telomerase activity or hTERT expression in lung cancer cells. Cells of the TKB-4 cell line that also showed relatively low telomerase activity (as TKB-20 cells) had long telomeres. In conclusion, hTERT expression is regulated at both the transcriptional and post-transcriptional levels in lung cancer cells, and the alternative splicing of hTERT is involved in the control of telomerase activity.

Expression of the human telomerase reverse transcriptase in pheochromocytoma and neuroblastoma tissues

In an effort to clarify the role of telomerase in the pathogenesis of pheochromocytomas and neuroblastomas, and to test whether its component could serve as a marker of malignancy, we measured telomerase reverse transcriptase (TERT) mRNA in 31 human pheochromocytoma tissue samples (5 malignant, 23 benign and 3 suspected malignant) and 16 neuroblastoma tissues (9 unfavorable and 7 favorable). All cases were classified by both the clinical course and histopathological examination. Malignancy was defined as the presence of metastasis and/or extensive local invasion. TERT mRNA was determined by nested PCR and a real-time PCR system (LightCycler). By nested PCR methods, 5 of the 5 malignant pheochromocytoma samples were positive (sensitivity = 100%), and 21 of 23 benign pheochromocytoma samples were negative (specificity = 91%) in pheochromocytomas. Four out of five malignant tumors were positive for either hTERT expression or Ki-67/MIB-1 immunoreactivity. In the neuroblastoma tissues, 9 of the 9 unfavorable samples were positive (sensitivity = 100%), and only 2 of 7 favorable samples were negative (specificity = 29%). We also determined the expression of the hTERT mRNA by real-time PCR to quantitate the mRNA. The mean values of hTERT mRNA by real time PCR in benign and malignant pheochromocytomas were 2 and 26 arbitrary units (AU), respectively. The difference was not significant by the U-test. The mean values of hTERT mRNA in favorable and unfavorable neuroblastoma were 203 and 497 AU, respectively. This difference was also not significant (U-test). N-Myc mRNA expression correlated with the expression of hTERT mRNA in the neuroblastoma samples (r = 0.534, p = 0.0317). Thus, hTERT mRNA might be a potential marker for estimating the malignancy of pheochromocytomas and neuroblastomas.

Alterations of heterogeneous nuclear RNP A2 and B1 in the hippocampus of the rat after perforant pathway lesion

We examined alterations in post-transcriptional regulation following deafferentation of the perforant pathway by focusing on heterogeneous nuclear ribonucleoprotein (hnRNP) A2 and B1 in rat hippocampi subjected to perforant pathway lesions. In control brains, immunoreactivity to both was observed in the nuclei of neurons throughout the hippocampus using immunohistochemical techniques. From 1 to 14 days post-lesion, a slight increase in A2 immunoreactivity was observed in neurons within the dentate granular layer as well in the pyramidal cells of the cornus Ammon fields ipsilateral to the lesion. In contrast, we observed a marked decrease in B1 immunoreactivity in the same regions at 1, 3 and 7 days post-lesion. All these alterations, however, were transient. A2 immunoreactivity returned to normal levels by 30 days post-lesion, and B1 immunoreactivity had completely recovered by 14 days post-lesion. The results of immunoblot analysis for A2 and B1 were wholly consistent with immunohistochemical observations. Our study suggests that post-transcriptional regulation in the hippocampal neurons changes after a perforant pathway lesion. Our study further suggests that the functions of hnRNPA2 and B1 are different, as each was differentially involved in the plastic response to deafferentation of the perforant pathway.

Establishment and characterization of novel xenograft models of human biliary tract carcinomas

In order to develop new therapeutic regimens for biliary tract cancers, which carry dismal prognoses, the establishment of a human biliary tract cancer xenograft model is essential. Herein, we report the successful establishment and characterization of two xenograft models of human biliary tract cancers. An adenosquamous gallbladder cancer cell line (TGBC-44) and a bile duct adenocarcinoma cell line (TGBC-47) were obtained from fresh surgical specimens in our department and subcutaneously inoculated into nude mice. The overall tumor take rate was 100% and solid tumors grew measurable after 5 and 7 days for TGBC-44 and TGBC-47, respectively. Tumor doubling time was 3.9+/-1.1 and 4.1+/-0.5 days in the exponential growth phase in TGBC-44 and TGBC-47 xenografts, respectively. Isozyme test and karyotype analysis confirmed the human origin. Histopathology analysis revealed that the TGBC-44 xenograft retained both the squamous and the adenocarcinoma components, and the TGBC-47 xenograft exhibited poorly differentiated adenocarcinoma as in the corresponding original tumors. Immunohistochemistry and Western blotting studies revealed positive and similar expression of platelet derived endothelial growth factor/thymidine phosphorylase (PDGF/TP), thymidylate synthase (TS), and cyclooxygenase-2 (COX-2) in both original tumors and xenograft models. No macroscopic metastases were found at the time of sacrifice. We have successfully established two models of human biliary tract cancer, gallbladder and bile duct cancer. Models retained the morphological and biochemical characteristics of the original tumor and demonstrated constant biological behavior in all transplanted mice. These models could be useful tools for developing new diagnostic and therapeutic strategies against biliary tract cancers.

HnRNP A2/B1 Proteins in Nontumorous Alveolar Cells

The overexpression of heterogeneous nuclear ribonucleoprotein (hnRNP) A2/B1, especially of B1, had been reported to detect preclinical lung cancer for early detection. In order to examine whether the expression of the protein is specific for lung cancer, we investigated the expression of the protein in human nonmalignant alveolar cells. Human airway cells obtained by bronchoalveolar lavage (BAL) were analyzed by immunostaining and Western blotting using monoclonal antibodies 4G8 (specifically reacts to A2) and 2B2 (specific to B1). In alveolar cells obtained by BAL, hnRNP A2/B1 proteins were localized primarily in the nucleus, excluding the nucleolus, although the expression of A2 protein was weaker than that of B1 protein. Staining pattern of these cells was similar to those observed in cancer cells. Western blotting with 4G8 and 2B2 demonstrated expression of A2 and B1 proteins in the airway cells. HnRNP A2/B1 proteins were apparently expressed in nonmalignant alveolar cells as well as cancer cells, although the expression in alveolar cells was weaker than that of cancer cells. More quantitative determination of A2/B1 is required to elucidate their significance in early lung cancer detection.

Imbalance between apoptosis and telomerase activity in myelodysplastic syndromes: possible role in ineffective hemopoiesis

The myelodysplastic syndromes (MDS) are a group of disorders characterized by peripheral pancytopenia despite normo- or hyper-cellular bone marrow. This is thought to be due to apoptosis of hematopoietic bone marrow cells, resulting in ineffective hematopoiesis. The heterogeneous nuclear ribonucleoprotein (hnRNP) B1 is involved in pre-mRNA processing and binds to telomeric cDNA repeats. The hnRNP B1 is a marker for early cancer. The aim of our study was to clarify the relationships between prognosis and apoptosis, telomerase activity (TA) and hnRNP expression in the bone marrow. The subjects were 51 patients with MDS, including patients with refractory anemia (RA) (n = 32), refractory anemia with ringed sideroblasts (RARS) (n = 1), refractory anemia with excess blasts (RAEB) (n = 7), refractory anemia with excess blasts in transformation (RAEB-t) (n = 8) and chronic myelomonocytic leukemia (CMMoL) (n = 3). We also studied 6 cases with acute myelogenous leukemia (AML) arising from MDS (AML-MDS) and 10 control subjects. Bone marrow biopsies were stained immunohistochemically for caspase-3 (marker of apoptotic activity) and human telomerase reverse transcriptase (hTERT), and hnRNP B1. Fatal pancytopenia was the cause of death in 19 of the 51 patients. The caspase-3 positive cell rate was higher in MDS (16.3%) than in controls (4.4%) and AML-MDS (0.5%). The percentage of hnRNP B1-positive cells was higher in MDS (15.3%) and AML-MDS (56.3%) than in controls (5.6%). In MDS, hnRNP B1 levels were higher in RAEB and RAEB-t subtypes than in RA and RARS. The percentage of hTERT-positive cells was higher in AML-MDS (50.0%) than in controls (20.2%) and MDS (23.6%). Our findings suggest that activation of apoptosis occurs in MDS in the absence of hTERT expression, implicating high apoptosis in the absence of high TA with ineffective hematopoiesis. Poor prognosis correlated with higher caspase-3 and lower hTERT rates. In MDS, hnRNP B1 activity may be associated with leukemic transformation.

Cytokeratin 19 fragment in patients with nonmalignant respiratory diseases

STUDY OBJECTIVE

Cytokeratin 19 fragment (CYFRA) is a specific tumor marker in patients with lung cancer; however, it has been reported that serum CYFRA levels are elevated in some patients with nonmalignant respiratory diseases such as interstitial pulmonary fibrosis (IPF) and collagen disease-associated pulmonary fibrosis (CDPF). To investigate the serum CYFRA levels in nonmalignant respiratory diseases in detail, we studied 413 patients with respiratory diseases.

DESIGN

Retrospective study.

SETTING

University hospital.

PATIENTS

Four hundred thirteen patients with nonmalignant respiratory diseases and lung cancer.

MEASUREMENTS AND RESULTS

Serum CYFRA levels were measured with a commercially available enzyme immunoassay kit. Immunohistochemical study was performed using monoclonal antibody Ks 19.1 (Rosch Diagnosica; Bern, Switzerland) on surgically resected or autopsied lung specimens. Gel electrophoresis and immunoblotting was performed with serum samples. In 149 patients with nonmalignant diseases except IPF and CDPF, the ratio of patients with > 3.5 ng/mL of serum CYFRA was 13.4%. In 13 of 30 patients (43.3%) with IPF and CDPF, the serum CYFRA levels were abnormally elevated. The 95th percentile serum CYFRA level of the patients with nonmalignant respiratory diseases was 6.2 ng/mL, and none of them had CYFRA levels > 20.3 ng/mL. Survival in patients with IPF and CDPF with elevated serum CYFRA levels were significantly lower than in those with normal range (p = 0.0335). Western blotting using serum from nonmalignant lung diseases and patients with lung cancer showed no apparent difference between them. An immunohistochemical study indicated CYFRA was selectively expressed in the pulmonary epithelial cells that covered the remodeling alveolar septi in nonmalignant respiratory disease.

CONCLUSION

Serum CYFRA was elevated in some nonmalignant respiratory diseases, especially in IPF and CDPF. The value of serum CYFRA would reflect the severity of lung injury in nonmalignant respiratory diseases and might be related to the prognosis in patients with IPF and CDPF.

hnRNP B1 expression in benign and malignant lung disease

Evidence is accumulating to suggest that hnRNP B1 expression may be a useful tool in the early diagnosis of lung cancer. This study examined the immunohistochemical expression of hnRNP B1 in archived sections of resected lung cancers and compared the patterns of expression with those seen in similar archived sections of non-neoplastic lung. Particular attention was paid to the expression of hnRNP B1 in the benign bronchial cells in both cases, to establish if overexpression of this protein in respiratory epithelial cells is specific for malignancy. Nineteen cases of different types of non-small cell carcinoma were examined (eight squamous cell, six adenocarcinomas, two carcinosarcomas, two undifferentiated large cell carcinomas, and one mucoepidermoid carcinoma) and compared with sections from 16 open lung biopsies (three cases of cryptogenic fibrosing alveolitis, two cases of sarcoidosis, two cases of organizing pneumonia, and one case each of tuberculosis, extrinsic allergic alveolitis, non-specific interstitial pneumonitis, pneumocystis pneumonia, aspergilloma, respiratory bronchiolitis-interstitial lung disease, mineral dust disease, Sjögren's syndrome and systemic sclerosis vascular variant). All the tumours showed positive staining, with the vast majority, 16/19 (84%), showing strong diffuse nuclear staining. The background cells of these cases showed positive staining in alveolar macrophages, lymph node germinal centres, bronchial mucous glands, and bronchial epithelial cells. No significant difference was seen in the percentage of positive bronchial epithelial cells in bronchi adjacent to the tumour compared with the resection margins. In the benign lung cases, positive bronchial epithelial cells were seen in a small percentage, 3/16 (18%), of cases, but the majority of cases showed no or very focal staining. The levels of expression between benign epithelial cells of malignant cases, compared with benign, showed a significant difference when the staining was assessed in percentage of positive nuclei (p = 0.001, Fisher's exact test). The results confirm that hnRNP B1 is widely expressed in a range of lung carcinomas; that expression is seen in benign bronchial epithelial cells and inflammatory cells; and that expression in background bronchial epithelial cells appears to be higher in malignant than in benign lung disease. It is feasible that this biomarker may be of use in the detection of early lung cancer, provided that levels of expression can be accurately quantified.

Reduced expression of heterogeneous nuclear ribonucleoprotein B1 in adult T-cell lymphoma/leukemia

It is considered that hnRNP B1 expresses similarly in the various types of tumor cells. Recently, we demonstrated high B1 expression in B-cell lymphoma and carcinoma. To evaluate the difference of B1 expression between B and T-cell lymphoma, we immunologically studied the B1 expression in 22 cases with nodal T-cell lymphoma, comprising adult T-cell leukemia/lymphoma (ATLL; n=15) and angioimmunoblastic T-cell lymphoma (AILD; n=7), using an anti-hnRNP B1 monoclonal antibody, 2B2. In ATLL cases, scattered large transformed lymphoma cells demonstrated strong B1 expression, while the medium-sized lymphoma cells were negative. On the one hand, lymphoma cells in AILD diffusely expressed B1. The mean B1 expression rate in ATLL was 22%, which was significantly lower than that in AILDs (45%), B-cell lymphomas (44%), and metastatic carcinomas (53%) (p<0.01). Our result might suggest that process of hnRNP B1 expression in ATLL differs from those in other lymphoid neoplasms and carcinoma.

Overexpression of heterogeneous nuclear ribonucleoprotein B1 in lymphoproliferative disorders: high expression in cells of follicular center origin

It is reported that overexpression of hnRNP A2 and B1 proteins is useful for detecting early cancers, and that B1, a splicing minor isoform of A2, is more specific than A2. The B1 expression is still undetermined in human lymphoid tissues. We quantitatively studied the B1 expression in 85 lymph node specimens, comprising reactive lymphoid hyperplasia (RLH; n=8), B-cell lymphoma (n=23), T-cell lymphoma (n=22), and metastatic carcinoma (n=32). Immunostaining and immunoblotting analyses with an anti-B1 monoclonal antibody, 2B2 were performed, and the two sets of results correlated with each other (p<0.05). In RLH specimens, B1 expression rate was significantly higher in follicular centers (FC; 44%) than in mantle zone (MZ; 15%) and paracortex (16%) (p<0.01). B1 expression was statistically higher in B-cell lymphoma than in T-cell lymphoma (p<0.01). In B-cell lymphomas, B1 expression rates were 51% in diffuse large B-cell lymphoma (DLBL; n=5) and 45% in follicular lymphoma (FL; n=16), and they were almost the same as that of the FC. Especially in DLBLs, CD10+ FC-origin lymphomas expressed greater amount of B1 than CD10- non-FC-origin lymphomas. B1 expression rate was low in mantle cell lymphoma (MCL; n=2) and similar to that of MZ in RLH. These results suggest that B1 expression is associated with differentiation in lymphoid tissue rather than transformation. B1 expression increases during the process of B-cell differentiation in the FC, and that high B1 expression is maintained in B-cell lymphomagenesis, especially in cells of FC-origin DLBL.

The intraductal component of breast cancer is poorly responsive to neo-adjuvant chemotherapy

Neo-adjuvant chemotherapy has been used for locally advanced breast cancers. With special attention to the proportion of intraductal component, we pathologically studied 25 patients that underwent neo-adjuvant chemotherapy via intra-arterial infusion or intravenous injection. In general, neo-adjuvant chemotherapy had a favorable effect on tumor reduction. The effectiveness varies depending on the predominance of intraductal component. The cases with a high proportion of intraductal component had lower response to the chemotherapies. The larger number of cancer cells remained within the mammary ducts. The residual cancer cells conserved proliferative activity. Intraductal component is poorly responsive to neoadjuvant chemotherapy.

Complicated mechanisms of class II transactivator transcription deficiency in small cell lung cancer and neuroblastoma

Small cell lung cancer (SCLC) and neuroblastoma (NB), the most aggressive adult and infant neuroendocrine cancers, respectively, are immunologically characterized by a severe reduction in major histocompatibility complex (MHC) that is indispensable for anti-tumor immunity. We had reported that the severe reduction of MHC in SCLC was caused by a deficient interferon (IFN)-gamma-inducible expression of class II transactivator (CIITA) that is known as a very important transcription factor for IFN-gamma-inducible class II and class I MHC expression (Yazawa T, Kamma H, Fujiwara M, Matsui M, Horiguchi H, Satoh H, Fujimoto M, Yokohama K, Ogata T: Lack of class II transactivator causes severe deficiency of HLA-DR expression in small cell lung cancer. J Pathol 1999, 187:191-199). Here, we demonstrate that the reduction of MHC in NB was also caused by a deficient IFN-gamma-inducible expression of CIITA and that the deficiency in SCLC and NB was caused by similar mechanisms. Human achaete-scute complex homologue (HASH)-1, L-myc, and N-myc, which are specifically overexpressed in SCLC and NB, bound to the E-box in CIITA promoter IV and reduced the transcriptional activity. Anti-sense oligonucleotide experiments revealed that overexpressed L-myc and N-myc lie upstream in the regulatory pathway of HASH-1 expression. The expression of HASH-1 was also up-regulated by IFN-gamma. Our results suggest that SCLC and NB have complicated mechanisms of IFN-gamma-inducible CIITA transcription deficiency through the overexpressed HASH-1, L-myc, and N-myc. These complicated mechanisms may play an important role in the escape from anti-tumor immunity.

In vivo advantage of combined administration with CPT-11 and 5-fluorouracil in rats

In vivo effect of a bolus combination with 5-fluorouracil (5-FU) and CPT-11 was studied against experimental rat lung cancer, SLC cells. 5-FU and CPT-11, when administrated individually, showed dose-dependent inhibition against the tumor (ID50, 7.0 mg/kg/day and 16.0 mg/kg/day, respectively). 5-FU synergistically enhanced the sensitivity of the tumor cells to CPT-11 and permitted the administration of approximately a one-third lower dose of CPT-11 to obtain the same inhibition against the tumor cell growth. The ID50 of CPT-11 alone (16.0 mg/kg/day) was reduced to 4.8 mg/kg/day when combined with 5-FU at 2.5 mg/kg. There were no deaths caused by toxicity in the combination group, and for lower doses (less than 4 mg/kg/day) of CPT-11 combined with 2.5 mg/kg/day of 5-FU, all rats showed less than 10% body weight loss at the end of the experiments. When the tumor weights were evaluated by using isoeffect plot analysis, the data points resulting from the combination showed a synergistic interaction between these agents. There was no significant increase of toxicity as assessed by the body weight. The results might support for the use of the combination of 5-FU and CPT-11 in cancer chemotherapy.

Topographical analysis of p53 expression and DNA ploidy in early bronchial squamous cell carcinoma and preneoplastic lesions

The significance of p53 mutations and DNA aneuploidy in carcinoma cells has been investigated on the basis of a multi-step development theory of carcinogenesis. It has, however, not been determined whether these alterations can be used as diagnostic markers for the early detection of bronchial squamous cell carcinoma (BSqCC). To address this problem, we topographically investigated p53 alterations and DNA aneuploidy in 24 X-ray-negative, early BSqCC patients with various preneoplastic lesions and in 25 non-carcinoma patients with preneoplastic lesions. Bronchial lesions (n=88) were morphologically classified as hyperplasia (HP, n=5), squamous metaplasia (SM, n=23), low-grade dysplasia (LGD, n=14), high-grade dysplasia (HGD, n=11), intraepithelial carcinoma including 'carcinoma in situ' (CIS) (IEC, n=15), and microinvasive carcinoma (MIC, n=20). Immunohistochemistry for the p53 protein and image cytometry for DNA ploidy detection were performed in serial sections of each lesion. Overexpression of p53 protein was detected in 36, 73, and 65% of the HGD, IEC, and MIC lesions, respectively. Aneuploid DNA profiles were found only in carcinoma lesions, 33% in IEC and 85% in MIC. The topographical analysis revealed two types of early BSqCCs, one with adjacent preneoplastic lesions (sequential type, n=8) and another without such lesions (de novo type, n=16). The p53 protein was frequently overexpressed in both types (sequential type, 79%; de novo type, 62%). In the sequential type, however, the p53 protein was overexpressed in HGD lesions that were directly adjacent to p53-overexpressing carcinoma lesions without exception. The present topographical study suggests that p53 mutations play an important role in the carcinogenesis of BSqCC and that p53-overexpressing HGD lesions in sequential types should be regarded as 'truly' preneoplastic lesions that actually develop into carcinomas. In addition, our study demonstrated that DNA aneuploidy might occur at times after p53 alteration with increasing frequency, as invasive growth begins. Such combination analysis of p53 immunohistochemistry and nuclear DNA ploidy in routine histology may contribute to estimates of malignant potential in preneoplastic and intraepithelial squamous lesions and provide additional information for early detection of BSqCC.

Non-invasive lobular carcinoma within a fibroadenoma, a preoperatively diagnosed case

Breast cancer within a fibroadenoma is rare and usually diagnosed postoperatively from pathological specimens. This paper reports a 54-year-old female with non-invasive carcinoma within a fibroadenoma, diagnosed preoperatively. She underwent a medical examination and mastopathy was suspected. On physical examination a mass 2 cm in diameter was palpated in the left breast. Ultrasonography showed a mass with smooth margins and uniform internal echoes, but cytology showed malignancy. Mammography showed a round mass with distinct margins and no calcification. As fibroadenoma, diagnosed by ultrasonography and mammography, and breast cancer, diagnosed by cytology, were not consistent results several core biopsies were performed. Needle biopsy showed proliferation of atypical epithelial cells; breast cancer within a fibroadenoma was diagnosed. MRI showed a circular mass with distinct, smooth margins and in a dynamic study, the mass showed irregular staining and the presence of early staining. Left lumpectomy and dissection of the left axillary lymph nodes was performed. Histological examination showed non-invasive lobular carcinoma occurring within a fibroadenoma.

Persistent fifth aortic arch associated with type A aortic arch interruption. Histological study and morphogenesis

A male infant, having a persistent fifth aortic arch and interruption of the aorta distal to the left subclavian artery, underwent successful surgical treatment. A histological study of the excised segment of the aorta showed that the ductal tissue extended to the junction between the fifth arch and the descending aorta with consequent narrowing in the corresponding region. The ductal tissue, however, did not contribute to occlusion in the fourth aortic arch. The morphogenesis of this combination of aortic arch anomalies was also discussed.

Lung cancer in middle-aged patients

Clinicopathological features of middle-aged lung cancer patients were investigated in 1016 consecutive patients. Among them, 22.8% of patients were in their forties and fifties. The preponderance of adenocarcinomas and the higher female/male ratio in middle-aged groups compared with the older group were findings similar to those observed in younger patients. Smoking habit increased according to the age groups. Middle-aged patients had a propensity for advanced stage, however, survival was not inferior to younger patients. Middle-aged patients consisted of two different groups of patients, whose characteristics were similar to those observed in either younger or elderly patients.

Expression of hnRNP B1 in four major histological types of lung cancers

Heterogeneous nuclear ribonucleoprotein B1 is one of the nuclear pre-mRNA binding proteins involved in RNA metabolism. Recently, over-expression of B1 has been reported to be useful in the early detection of squamous cell carcinomas of the lung. To elucidate its significance in other histological types of lung cancers, we carried out a comparative study, four major types of lung cancers and normal lung tissues. 37 surgical specimens were examined using a B1-specific monoclonal antibody (2B2). Immunohistochemically, 2B2 demonstrated B1 protein in the nuclei not only of squamous cell carcinoma (10/10) but also of adenocarcinoma (17/18), small cell carcinoma (5/5) and large cell carcinoma (3/4). A lesser amount of B1 protein was also detected in normal cells. Quantitative immunoblotting revealed that B1 expression was markedly higher in cancer tissues than normal tissues and it varied among the four histological types. To establish the usefulness of B1, a threshold should be set for over-expression.