Human telomerase catalytic subunit gene re-expression is an early event in oral carcinogenesis

AIMS: Detection of telomerase catalytic subunit (hTERT) mRNA has been used as a surrogate marker for estimation of telomerase activity. The exact role and timing of telomerase re-activation, a key enzyme implicated in cellular immortalization and transformation, in the multistep process of oral carcinogenesis is still unknown. The aim was to test the hypothesis that (i) quantitative rather than qualitative differences exist in the level of hTERT mRNA expression between normal oral mucosa, different grades of oral epithelial abnormalities and squamous cell carcinomas of the oral cavity, and that (ii) hTERT gene re-expression is an important, probably early event in oral carcinogenesis. METHODS AND RESULTS: The relative quantity of hTERT mRNA was analysed in 45 frozen oral epithelia representing different morphological stages of oral carcinogenesis classified according to the Ljubljana classification and in 37 oral squamous cell carcinomas, using a commercially available LightCycler Telo TAGGG hTERT Quantification kit. hTERT mRNA was not detected in normal or reactive hyperplastic oral epithelia, but was present in 43% of atypical hyperplasias (premalignant lesions), 60% of intraepithelial carcinomas and 68% of oral squamous cell carcinomas. Statistical analysis revealed two groups of oral epithelial changes, with significant differences in the levels of hTERT mRNA expression: 1, normal and reactive hyperplastic oral epithelium, and 2, atypical hyperplasia, intraepithelial carcinomas and squamous cell carcinomas. CONCLUSION: These data suggest that hTERT gene re-expression represents an early event in the multistep process of oral carcinogenesis, already detectable at the stage of precancerous oral epithelial changes. Nevertheless, other genetic aberrations appear to be necessary for progression of oral epithelial abnormalities towards invasive squamous cell carcinoma.     

Langerhans cells and serum precipitating antibodies against fungal antigens in bronchioloalveolar cell carcinoma: possible association with pulmonary eosinophilic granuloma

In an ultrastructural study of 37 cases of bronchioloalveolar cell carcinoma (BAC), we identified seven cases (19%) in which Langerhans cells (LC) were closely associated with tumor cells. Serum precipitating antibodies against Aspergillus species and/or thermophilic actinomyces were present in five BAC patients whose tumors contained LC and in six patients whose tumors lacked LC. In a simultaneous study we identified marked atypical bronchiolar and alveolar lining cell hypertrophy and hyperplasma in pulmonary eosinophilic granuloma (PEG). Our data plus current information suggesting that PEG is a form of hypersensitivity pneumonitis support our hypothesis that those cases of BAC in which LC are present may arise in localized or diffuse pulmonary scars caused by PEG.     

Peripheral lung carcinomas associated with central fibrosis and mixed small cell and other histologic components

Three cases of peripheral small cell lung carcinoma (SCLC) with central fibrosis are presented. Central fibrosis is usually present in adenocarcinomas. Cases 1 and 2 are combined SCLCs with components of papillary adenocar-cinoma, and case 3 is a mixed SCLC with a large cell component. Small cell Components showed intermediate cell type in ail cases. In cases 1 and 2, there was a gradual transition between small cell carcinoma and papillary ade-nocarcinoma. Small cell components showed Grimelius argyrophilia, but other neuroendocrine markers such as neuronspecific enorase, chromogranin A, Leu-7 and syn-aptophysln were negative. The chest X-ray examination of case 1 demonstrated rapid enlargement of a tumor shadow, which was present two years before, for a recent year. Central fibrosis, coexistence of small cell carcinoma and papillary adenocarcinoma, and a change of growth rate in the chest x-ray may suggest that some SCLC derive from papillary adenocarcinomas.     

针对单克隆抗体MGb1的重组抗独特型抗体的筛选与鉴定

目的 利用噬菌体呈现技术筛选针对抗胃癌单克隆抗体（简称单抗）MGb1的重组抗独特型抗体（抗-Id），为研制胃癌重组抗-Id瘤苗提供候选分子。方法 以单克隆抗体MGb1免疫Balb／c小鼠，取脾分离mRNA。RT-PCR分别扩增抗体VL和VH cDNA，经linker DNA连接形成ScFv DNA。将scFv DNA与载体pCANTAB5E的连接产物转化于大肠杆菌TG1，经M13KO7感染后，获得重组噬菌体抗体ScFv文库。以单抗MGb1对文库进行4轮淘选后，随机挑取克隆经ELISA筛选呈现抗-Id scFv的噬菌体单克隆，进而经竞争ELISA对其所属抗-Id类型进行初步鉴定。结果 VL和VH cDNA分别约为320和340bp，ScFv DNA约为750bp。抗体ScFv文库经四轮淘选后，在随机筛检的50个克隆中得到18个呈现抗-Id ScFv的噬菌体单克隆。在18个克隆中，有4个呈现β或γ型抗-Id ScFv。结论 经重组噬菌体抗体技术成功地筛选到了针对单抗MGb1的噬菌体呈现型抗-Id ScFv，从而为进一步获得能诱导抗胃癌免疫的抗-Id ScFv奠定了基础。     

Favorable efficacy of long-term lamivudine therapy in patients with chronic hepatitis B: an 8-year follow-up study

The long-term efficacy of lamivudine therapy in patients with hepatitis B virus (HBV) infection is still not clear. In this study, 20 non-cirrhotic Japanese patients infected with HBV received lamivudine therapy for more than 1 year and were followed for a median period of 8.5 years (range, 6.7-8.7 years). The rates of HBe antigen (HbeAg) negative, HBV-DNA undetectable, and alanine aminotransferase (ALT) normal level at the start of lamivudine were 55%, 25%, and 20% and 85%, 80%, and were 80%, respectively, at the last visit, including patients who received additional treatment. The values at the last visit tended to and were significantly higher than those at the start. The values improved at the last visit regardless of the emergence of YMDD motif mutant and continuation of lamivudine. YMDD mutant and biochemical relapse with mutant virus (breakthrough hepatitis) appeared in 65% and 45% during follow-up, respectively, but severe breakthrough hepatitis occurred in only 5%. Furthermore, 80% of patients who received additional treatment for breakthrough hepatitis, regardless of continuation of lamivudine, were ALT normal level at the last visit, in contrast to 25% untreated. HBsAg clearance occurred in two patients of the discontinuous lamivudine group with non-vertical transmission, who were relatively young. One was infected with HBV genotype C with breakthrough hepatitis and the other had no YMDD mutant and was infected with genotype D, a rare type in Japan. None developed cirrhosis or hepatocellular carcinoma (HCC) during follow-up. Our results suggest that long-term lamivudine therapy improves long-term prognosis, especially when additional treatment for breakthrough hepatitis is used.     

Cellular and molecular analyses of major histocompatibility complex (MHC) restricted and non-MHC-restricted effector cells recognizing renal cell carcinomas: problems and perspectives for immunotherapy

 Renal cell carcinomas belong to the small group of tumors that are able to induce antitumor responses. Here we describe two general types of cytotoxic effector lymphocytes that can eliminate autologous tumor cells and discuss the role that major histocompatibility complex encoded molecules play in governing their specificities. Improved understanding of the cellular and molecular basis of renal cell carcinoma recognition opens new avenues of research with the potential to develop better immunotherapies for patients with metastatic disease. Received: 24 July 1996 / Accepted: 1 November 1996     

Anin vitro invasion model for human renal cell carcinoma cell lines mimicking their metastatic abilities

We developed a modifiedin vitro invasion assay system using monolayers of vascular endothelial cells. A type I collagen gel was formed in plastic dishes, and overlaid with type IV collagen. Calf pulmonary arterial endothelial (CPAE) cells were seeded onto these plates, and incubated until they reached confluence. Five human renal cell carcinoma cell lines with various metastatic potentialsin vivo were then seeded on the monolayer CPAE cells, and their colony formation and invasion activities were examined for 9 days. At day 4, the highly metastatic cell lines increased the number of colony foci on monolayer CPAE cells several fold higher than their poorly metastatic counterpart. The horizontal spreading patterns were also different between poorly and highly metastatic cell lines. On day 9, the number of carcinoma foci that penetrated the monolayer of CPAE cells and type IV collagen sheets into type I collagen gels in highly metastatic cell lines greatly increased as compared with that of poorly metastatic cell lines. Ourin vitro invasion assay using monolayer CPAE cells would be useful to evaluate protease activities and colony formation during invasion.     

Nuclear and cytoplasmic bcl-2 expression in endometrial hyperplasia and adenocarcinoma

The bcl-2 proto-oncogene, which inhibits programmed cell death (apoptosis), has recently been found to be cyclically expressed in human endometrium. In order to investigate its role in endometrial hyperlasia and neoplasia, bcl-2 expression was studied in 25 cases of endometrial carcinoma and 20 cases of endometrial hyperplasia (eight simple, two complex, and ten atypical hyperplasias). Uniform intense cytoplasmic bcl-2 expression was found in all cases of non-atypical hyperplasia, and less strong positivity in eight out of ten cases of atypical hyperplasia. In well-differentiated carcinomas, nine out of ten showed weak to moderate bcl-2 expression, whereas six out of seven poorly differentiated carcinomas were bcl-2-negative. Moderately differentiated tumours were an intermediate group, with six out of eight being positive. Widespread localization of bcl-2 protein to the chromosomes of dividing cells was also demonstrated, regardless of cytoplasmic bcl-2 expression, with rare staining of interphase nuclei. Our findings suggest a role for bcl-2 in the natural history of endometrial neoplasia and studies are needed to determine its usefulness as a prognostic marker. The finding of bcl-2 localization to chromosomes has important implications for its mode and site of action.     

Proliferative activity in benign and neoplastic prostatic epithelium

The increasing availability of means for the early detection of prostatic cancer has brought under scrutiny the criteria used for prognosis and emphasized our limitations in understanding what determines the rate of progression in these cancers. The rate of cancer cell proliferation has been under intense investigation, which, however, has yielded conflicting results. In this study we evaluated the proliferative activity of benign and neoplastic prostatic epithelium, using various existing methodologies. We first analysed the variability introduced by the methodological approach and then attempted to demonstrate whether determination of the proliferative capacity had any clinical consequence that complemented the histological grading. Tissue samples from patients, 88 with cancer and 46 with benign prostatic pathology, were studied using in vitro bromodeoxyuridine (BrdU) incorporation as well as Ki67 and the proliferating cell nuclear antigen (PCNA) to estimate the proliferative activity. Increased proliferation was found consistently in inflammation and metaplasia, but not in hyperplasia. In contrast, cancers showed marked variability. Although average proliferation indices increased with grade, there was a wide scatter of values. Correlation was stronger with stage, but also depended on the methodology. Bromodeoxyuridine indices over 10 per mille had a positive predictive value of 79 per cent for cancers extending beyond the prostatic capsule and may prove particularly helpful for evaluating patients with grade 7 cancer. This observation is significant, since grade 7 cancers are the most frequent and the least predictable.     

Localization of CEA,HCG, Lysozyme,alpha-1-antitrypsin,and alpha-1-antichymotrypsin in gastric cancer and prognosis

Summary Carcinoembryonic antigen (CEA),-human chorionic gonadotropin (HCG), alpha-1-antichymotrypsin (ACT), alpha-1-antitrypsin (AAT) and Lysozyme (LYS) were traced by immunoperoxidase staining in gastric carcinomas. The immunohistological results were evaluated in relation to histological types (WHO and Laurén), stage of disease, grade and survival time. CEA was demonstrated in 96% of the tumours, HCG in 34%, ACT in 78%, AAT in 42%, and LYS in 71%. Comparing the staining patterns of the antigens and the intensity of staining some differences were notable. Except for signet-ring cell carcinomas, all of which were intensively positive, CEA expression decreased significantly with loss of differentiation. This observation was not seen with the other marker substances. None of the tested markers was characteristic for one particular histological type, nor could they be correlated with the tumour stage or grade. The marker positivity of CEA, ACT and LYS was not related to survival time. For HCG only, a correlation between tissue expression and a restricted survival time was established. Patients with AAT positive carcinomas had a significantly better survival probability.