HLA class I molecules present antigenic peptides to cytotoxic T lymphocytes and thus play an important role in immune surveillance of cells infected with virus or altered by malignant transformation. Immunochemical studies have demonstrated a marked deficiency or lack of expression of class I molecu
Lack of expression for the suppressor PML in human small cell lung carcinoma
β Scribed by Ping Zhang; Wai Chin; Louis T.C. Chow; Andrew S.K. Chan; Anthony P.C. Yim; Sing-Fai Leung; Tony S.K. Mok; Kung-Sang Chang; Philip J. Johnson; John Y.H. Chan
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- French
- Weight
- 884 KB
- Volume
- 85
- Category
- Article
- ISSN
- 0020-7136
No coin nor oath required. For personal study only.
β¦ Synopsis
The promyelocytic leukemia (PML) gene, which encodes a transformation and growth suppressor, was first identified at the chromosomal translocation break point t(15;17) in acute promyelocytic leukemia (PML). To determine if the PML gene might be involved in other neoplasias such as lung cancer, PML expression was analyzed by immunohistochemical staining and in situ hybridization. Considerable PML protein expression in the PML-oncogenic domain (POD) structure was found in adenocarcinomas (ADC) and squamous cell carcinomas (SCC) of the lung, but was almost completely absent in all the small cell lung carcinomas (SCLC) examined. In situ hybridization showed that both mRNA and DNA of PML were present in SCLC and in normal lung, suggesting that the decreased protein expression was due to either a defect in translation or protein instability, rather than the consequence of decreased transcription or gene deletion. Double staining showed that PML expression was inversely correlated with the proliferation marker Ki-67 and positively correlated with levels of apoptotic cells in these tumors. To determine if the precursor cells of SCLC, the neuroendocrine-producing cells, express PML, double labeling was performed with PML and chromogranin A, a bio-marker for neuroendocrine cells. Neuroendocrine cells from normal tissues were found to be PML positive, indicating that the lack of PML protein in SCLC is associated with the tumorigenic phenotype and is not the result of cell-lineage specificity. Thus, the decreased PML expression may play an important role in SCLC development.
π SIMILAR VOLUMES
The retinoblastoma protein (pRB), p16, and cyclin D1 are major components of the RB pathway, which controls the G1 checkpoint of the cell cycle. Proper regulation of this pathway is crucial for normal cell proliferation. Abnormal forms of these proteins have been found in various types of malignant
## BACKGROUND. The number of elderly people with small cell lung carcinoma (SCLC) is increasing and currently nearly 25% are older than 70 years. Elderly patients may not tolerate intensive therapy and, therefore, often do not receive such treatment. Additionally, age may be an independent predicto
## Abstract Small cell carcinoma of the lung is extremely sensitive to chemotherapy and radiation therapy. We describe the case of a patient who had a complete response to such treatment but relapsed with meningeal carcinomatosis. We propose that prophylactic therapy to the spinal cord as well as t