Silencing of periostin inhibits nicotine-mediated tumor cell growth and epithelial-mesenchymal transition in lung cancer cells.

Nicotine has been found to induce the proliferation of lung cancer cells through tumor invasion and to confer resistance to apoptosis. Periostin is abnormally highly expressed in lung cancer and is correlated with angiogenesis, invasion and metastasis. Here, we investigated the roles of periostin in the lung cancer cell proliferation, drug resistance, invasion and epithelial-mesenchymal transition (EMT) induced by nicotine. The periostin gene was silenced using small interfering RNA (siRNA) in A549 non-small cell lung cancer (NSCLC) cells. The cells were transfected with control or periostin siRNA plasmids. Periostin mRNA was evaluated by quantitative reverse transcription-polymerase chain reaction (RT-PCR). Cell proliferation was detected using the MTT assay and cell apoptosis was detected by Annexin V-FITC and propidium iodide (PI) double staining. Tumor invasion was detected by the Boyden chamber invasion assay. Western blotting was performed to detect the expression of the EMT marker Snail. Our results revealed that stably periostin-silenced cells were acquired by G418 screening, and the periostin mRNA expression levels of which were decreased by nearly 80%. Periostin-silenced A549 cells exhibited reduced cell proliferation, elevated sensitivity to chemotherapy with cisplatin, decreased cell invasion and Snail expression (P<0.05). Nicotine upregulated the periostin protein levels in the A549 cells and this upregulation was not blocked by the generalized nicotinic acetylcholine receptor (nAChR) antagonist, hexamethonium. In conclusion, periostin is one of the targets regulated by nicotine in lung cancer cells and is involved in the cancer cell growth, drug resistance, invasion and EMT induced by nicotine.

Impact factors for microinvasion in intrahepatic cholangiocarcinoma: a possible system for defining clinical target volume.

PURPOSE: To quantify microscopic invasion of intrahepatic cholangiocarcinoma (IHC) into nontumor tissue and define the gross tumor volume (GTV)-to-clinical target volume (CTV) expansion necessary for radiotherapy. METHODS AND MATERIALS: One-hundred IHC patients undergoing radical resection from January 2004 to July 2008 were enrolled in this study. Pathologic and clinical data including maximum tumor diameter, tumor boundary type, TNM stage, histologic grade, tumor markers, and liver enzymes were reviewed. The distance of microinvasion from the tumor boundary was measured by microscopy. The contraction coefficient for tumor measurements in radiographs and slide-mounted tissue was calculated. SPSS15.0 was used for statistical analysis. RESULTS: Sixty-five patients (65%) exhibited tumor microinvasions. Microinvasions ranged from 0.4-8 mm, with 96% of patients having a microinvasion distance ≤6 mm measured on slide. The radiograph-to-slide contraction coefficient was 82.1%. The degree of microinvasion was correlated with tumor boundary type, TNM stage, histologic grade, and serum levels of carbohydrate antigen 19-9, alanine aminotransferase, aspartate aminotransferase, γ-glutamyltransferase and alkaline phosphatase. To define CTV accurately, we devised a scoring system based on combination of these factors. According to this system, a score ≤1.5 is associated with 96.1% sensitivity in detecting patients with a microextension ≤4.9 mm in radiographs, whereas a score ≥2 has a 95.1% sensitivity in detecting microextension ≤7.9 mm measured on radiograph. CONCLUSIONS: Patients with a score ≤1.5 and ≥2 require a radiographic GTV-to-CTV expansions of 4.9 and 7.9 mm, respectively, to encompass >95% of microinvasions.

Impact factors for microinvasion in patients with hepatocellular carcinoma: possible application to the definition of clinical tumor volume.

PURPOSE: To evaluate the degree of invasion of hepatocellular carcinoma (HCC) microscopically that will provide a potential application for gross tumor volume to clinical tumor volume (GTV-to-CTV) expansion. METHODS AND MATERIALS: From January 2002 to January 2006, 149 HCC patients were selected from those who had undergone surgical resection. Pathology slides and clinical data of all patients were reviewed, including platelet counts, serum alpha-fetoprotein (AFP) levels, degree of liver cirrhosis, tumor size, capsular status, portal vein invasion, TNM stage, and histologic tumor grade. The distance between the tumor margin (or fibrous capsule) and the invasive lesions was measured by senior pathologists. RESULTS: Of these 149 patients, 79 (53.0%) patients presented with tumor microinvasion between 0.5 and 4 mm. This degree of microinvasion was inversely correlated with lower platelet counts and positively correlated with higher AFP levels, larger tumor sizes, portal vein invasion, and advanced TNM stage. Microinvasion distances less than or equal to 2 mm were found in 96.1% of patients (74/77) with tumor dimensions less than or equal to 5 cm and in 94.5% of patients (85/90) with AFP levels less than 400 microg/l. CONCLUSIONS: Based on our study findings, GTV-to-CTV expansions of 4 mm for HCC are required to conceal the gross tumor and any microscopic disease with 100% accuracy. Tumor size and AFP levels are the simplest indicators for determining the GTV-to-CTV distance for HCC.