Novel microdeletion in the transforming growth factor beta type II receptor gene is associated with giant and large cell variants of nonsmall cell lung carcinoma.

Mutations in the tumor suppressor gene transforming growth factor beta (TGFB) Type II receptor (TGFBR2) are frequently found in many cancers with microsatellite instability, but are less common in lung cancer. In the present study, we looked for mutations in TGFBR2 in nonsmall cell lung carcinoma (NSCLC) cells and tissues. A novel homozygous microdeletion (c.492_507del) was identified in two cell lines derived from the same giant cell carcinoma (GCC) and was confirmed in the corresponding tumor tissues. Furthermore, a heterozygous c.492_507del was found in the germ-line of one patient, as well as in the other GCC cases and some large cell carcinomas (LCC) but not in other subtypes of NSCLC. The 16 bp-microdeletion introduced a premature stop codon at positions 590-592 of the cDNA, resulting in a truncated TGFBR2 protein with a mutated transmembrane domain and loss of kinase domain. The GCC cells were characterized as being unresponsive to TGFB induction both in growth inhibition and stimulation of extracellular matrix protein. Moreover, after the reconstitution of wild-type TGFBR2 expression, the sensitivity to TGFB was restored. Therefore, mutated TGFBR2 seems to play an important role in the abrogation of TGFB signal transduction in GCC cells.

[Preoperational misdiagnosis of extragastrointestinal stromal tumors as ovarian cancer: report of three cases with literature review].

OBJECTIVE: This report was to review how extragastrointestinal stromal tumor (EGIST) was similar to ovarian cancer, its differential diagnosis and treatment. METHODS: Three cases of EGIST were reported and discussed by reviewing literatures. RESULTS: The cases of EGIST were presented with peritoneal and pelvic mass, or ascites, diagnosed as ovarian cancer at first, and finally diagnosed as EGIST by pathological method and positive CD(117) and CD(34) expression. Surgery in combination with chemotherapy was an effective therapeutic method. CONCLUSIONS: Clinical presentation of EGIST is similar to ovarian cancer in some aspects. Detection of CD(117) and CD(34) positive expression is helpful in the diagnosis of EGIST.

[Immunohistochemical study on telomerase activity in ovarian sex-cord stromal tumors].

BACKGROUND & OBJECTIVE: Telomerase activity has been detected in a broad range of human cancers including epithelial malignancies from in female genital tract, but the expression of the telomerase activity in ovarian sex-cord tumors has not been reported up to now. In this report we investigated the telomerase activity in ovarian sex-cord stromal tumors and its relationship with clinicopathological feature. METHODS: Twenty-five cases of ovarian sex-cord stromal tumor, including granulosa cell tumors, thecofibromas, sclerosing stromal tumors, and Sertoli-Leydig cell tumors were retrieved, and the expression of human telomerase reverse transcriptase (hTRT) was assessed immunohistochemically using polyclonal antibody H231. RESULTS: hTRT were positive in 60.0% of all cases, and the signal mainly located in the cytoplasm of tumor cells, especially in luteinized cells and Ledig cells. The positive rate was significantly related to different histological types and the patients' clinical endocrinal manifestation (P value were 0.01 and 0.041, respectively), but no statistically significant difference was found between the expression of hTRT and tumor histological grade or patients' prognosis. CONCLUSIONS: In ovarian sex-cord stromal tumors, the tumor component differentiating to luteinized stromal cell has high telomerase activity, and the telomerase activity may play an important role in patients' endocrinal disorder.

Detection of hepatitis C virus NS5 protein and genome in Chinese carcinoma of the extrahepatic bile duct and its significance.

AIM:To investigate the hepatitis C virus (HCV) infection in the tissues of carcinoma of extrahepatic bile duct and study their correlation.METHODS:HCV NS5 protein and HCV RNA were detected by labeled streptavidin biotin (LSAB) method and in situ reverse transcription polymerase chain reaction(IS-RT-PCR) in sections of 51 cases of carcinoma of extrahepatic bile duct and 34 cases of control group (without malignant biliary disease).RESULTS:In 51 cases of carcinoma of extrahepatic bile duct, HCV NS5 protein was detected in 14 (27.5%), which was clearly stained in the cytoplasm of cancer cell but not in the nucleus or cell membrane. HCV RNA was detected in 18 (35.4%), which was located in the nucleus of cancer cell in 12 cases and in the cytoplasm in 6 cases. HCV NS5 protein and RNA coexistence was found in 2 cases. In 34 cases of control group, HCV RNA was detected in 2 (5.9%). HCV NS5 protein and RNA positive cells were found either scattered or in clusters.CONCLUSION:The prevalence of hepatitis C viral infection in the tissues of carcinoma of extrahepatic bile duct was significantly higher than in control group (X(2) = 9.808,P=0.002). The findingssuggest a correlation between HCV infection and carcinoma of extrahepatic bile duct, which is different from the traditional viewpoint. HCV infection might be involved in the development of carcinoma of extrahepatic bile duct.