Endometrial stromal sarcoma (ESS) of the uterus is a rare uterine malignancy that has not been characterized in detail. To characterize the phenotype of ESS of the uterus, we extracted RNA from ESS and the stroma of normal endometrium using a tissue microdissection system and compared the expression profiles in the two tissues. After suppression subtractive hybridization and differential screening, we detected the metastasis‐associated lung adenocarcinoma transcript 1 (MALAT‐1) gene as one of the major genes upregulated in ESS, and a full‐length placental cDNA clone (CS0DI066YJ10) as one of the major genes downregulated. The results were confirmed by in situ hybridization in four resected specimens of ESS and 36 biopsy specimens of normal endometrial tissue. All ESS (4/4) and all cases of endometrial stromal cells in the proliferative phase (13/13) were positive for MALAT‐1, but samples of normal stroma in the secretory phase and menopausal state included some that were negative or weakly positive for MALAT‐1 (5/13 and 3/10, respectively). In contrast, all ESS and 12 of 13 cases of stromal cells in the proliferative phase were negative for the full‐length placental cDNA clone but 10 of 13 cases of endometrial stromal cells in the secretory phase were positive for transcripts of the gene (P < 0.05). These results indicated that endometrial stromal cells have different phenotypic characteristics between proliferative and secretory phases and the tumor cells of ESS have the phenotypic character of endometrial stromal cells in the proliferative phase. (Cancer Sci 2006; 97: 106 – 112)

Adenocarcinoma in situ (AIS) of the lung has an extremely favorable prognosis. However, early but invasive adenocarcinoma (eIA) sometimes has a fatal outcome. We had previously compared the expression profiles of AIS with those of eIA showing lymph node metastasis or a fatal outcome, and found that stratifin (SFN, 14-3-3 sigma) was a differentially expressed gene related to cell proliferation. Here, we performed an in vivo study to clarify the role of SFN in initiation and progression of lung adenocarcinoma. Suppression of SFN expression in A549 (a human lung adenocarcinoma cell line) by siSFN significantly reduced cell proliferation activity and the S-phase subpopulation. In vivo, tumor development or metastasis to the lung was reduced in shSFN-transfected A549 cells. Moreover, we generated SFN-transgenic mice (Tg-SPC-SFN+/−) showing lung-specific expression of human SFN under the control of a tissue-specific enhancer, the SPC promoter. We found that Tg-SPC-SFN+/− mice developed lung tumors at a significantly higher rate than control mice after administration of chemical carcinogen, NNK. Interestingly, several Tg-SPC-SFN+/− mice developed tumors without NNK. These tumor cells showed high hSFN expression. These results suggest that SFN facilitates lung tumor development and progression. SFN appears to be a novel oncogene with potential as a therapeutic target.

BACKGROUND Stepwise progression of peripheral‐type lung adenocarcinoma was characterized morphologically and was related to prognosis. Expression of the tumor suppressor gene p16 in pulmonary adenocarcinoma decreased, mainly as a result of aberrant methylation of the CpG islands of the promoter region. METHODS Aberrant methylation status of the p16 promoter region, the expression of its product, and loss of heterozygosity (LOH) on 9p21 were examined in surgically resected lung specimens from 57 patients (28 males and 29 females) with peripheral‐type lung adenocarcinoma measuring ≤ 2 cm in diameter. RESULTS Aberrant methylation of the p16 promoter region, negative p16 protein expression, and LOH of the 9p21 region were detected in 40.4%, 50.9%, and 40.4% of tumor samples, respectively. The alterations of the p16 gene were associated with poor prognosis, and in particular the prognosis of patients with aberrant p16 methylation was significantly worse than that of patients without aberrant methylation. These alterations also were associated with morphologic classification into bronchioloalveolar carcinoma (BAC) and non‐BAC adenocarcinoma. Both aberrant methylation and LOH of 9p21 were associated with negative protein expression, but the former was correlated more closely with loss of function than was the latter. Cases with both alterations were completely negative for expression of the p16 gene product. CONCLUSIONS Aberrant methylation of the promoter region of the p16 gene and loss of expression of its product were in accord with the multistep progression of peripheral‐type lung adenocarcinoma, and these alterations were associated closely with poor prognosis of the disease. Cancer 2005. © 2004 American Cancer Society.