SIRT7, H3K18ac, and ELK4 Immunohistochemical Expression in Hepatocellular Carcinoma

BACKGROUND: SIRT7 is one of the histone deacetylases and is NAD-dependent. It forms a complex with ETS-like transcription factor 4 (ELK4), which deacetylates H3K18ac and works as a transcriptional suppressor. Overexpression of SIRT7 and deacetylation of H3K18ac have been shown to be associated with aggressive clinical behavior in some cancers, including hepatocellular carcinoma (HCC). The present study investigated the immunohistochemical expression of SIRT7, H3K18ac, and ELK4 in hepatocellular carcinoma. METHODS: A total of 278 HCC patients were enrolled in this study. Tissue microarray blocks were made from existing paraffin-embedded blocks. Immunohistochemical expressions of SIRT7, H3K18ac and ELK4 were scored and analyzed. RESULTS: High SIRT7 (p = .034), high H3K18ac (p = .001), and low ELK4 (p = .021) groups were associated with poor outcomes. Age < 65 years (p = .028), tumor size ≥ 5 cm (p = .001), presence of vascular emboli (p = .003), involvement of surgical margin (p = .001), and high American Joint Committee on Cancer stage (III&V) (p < .001) were correlated with worse prognoses. In multivariate analysis, H3K18ac (p = .001) and ELK4 (p = .015) were the significant independent prognostic factors. CONCLUSIONS: High SIRT7 expression with poor overall survival implies that deacetylation of H3K18ac contributes to progression of HCC. High H3K18ac expression with poor prognosis is predicted due to a compensation mechanism. In addition, high ELK4 expression with good prognosis suggests another role of ELK4 as a tumor suppressor beyond SIRT7's helper. In conclusion, we could assume that the H3K18ac deacetylation pathway is influenced by many other factors.

Mineralizing Pulmonary Elastosis Associated with a Giant Cell Carcinoma

Mineralizing pulmonary elastosis is a result of chronic alveolar hemorrhage forming iron encrustation of a pulmonary elastic tissue. It has been reported as a complication of some diseases such as bronchiectasis, idiopathic pulmonary hemosiderosis, and cardiac failure. It is extremely rare to occur with a giant cell carcinoma as we experienced. A 59 year-old man visited our hospital for cough and blood tinged sputum. A chest CT scan revealed 10 9 6 cm sized round mass in the left upper lobe. He had lobectomy of left upper lobe, but died of respiratory failure at the postoperative eighteenth day. The lung showed a necrotic tumor and a yellow tan consolidation around the mass. Microscopically, the tumor was composed of nests or syncytia of large bizarre cells and tumor giant cells, and was diagnosed as a giant cell carcinoma. Interestingly, in the surrounding lung parenchyma there were a lot of foreign body type giant cells phagocytizing iron encrustated elastic fibers, which were easily identified by elastic van Gieson and prussian blue stains. Those degenerated elastic fibers appeared in pulmonary interstitial tissue as well as blood vessel walls. The authors concluded tumoral hemorrhage and necrosis resulted in mineralizing pulmonary elastosis.

The Clinical Analysis of Primary Lung Cancer: A Hospital-based Study / 대한흉부외과학회지

A retrospective review of the histopathology and clinical information of primary lung cancer was performed to investigate the trends in the histologic type related to sex, age, and smoking history. During January 1988 and July 1995, 541 pateints were diagnosed as primary lung cancer at the Korea Univeristy Anam Hospital. Male (423) to female (118) ratio was 3.6:1. The most frequent histologic type of lung cancer in male patients was squamous cell carcinoma (223 patients, 52.7%) followed by adenocarcinoma (86, 20.3%) and small cell carcinoma (85, 20.1%). In female patients, adenocarcinoma (64, 54.2%) was most common, which was followed by squamous cell carcinoma (22, 18.6%) and small cell carcinoma (22, 18.6%). The incidence of adenocarnimoma had an increased tendency recently (14.3% in 1988, 33.3% in 1995)(P=0.019). The predominant type in smokers was squamous cell carcinoma, whereas adenocarcinoma was the most frequent type in non-smokers. The proportion of patients aged less than 40 years (YOUNGER GROUP) was 4.0% (n=22). Of them, adenocarcinoma (7) and small cell carcinoma (7) were most common. In patients older than 40 years (OLDER GROUP, n=519), 243 (46.8%) patients had squamous cell carcinoma, and 143 (27.6%) adenocarcinoma. As age increased, the prevalence of squamous cell carcinoma was increased (P=0.0005), adenocarcinoma decreased (P=NS), and small cell carcinoma remained unchanged. We suggest above data as a clinical guidance for management of primary lung cancer.