No abstract

The present study revealed that an overexpression of Wnt5a could produce more aggressive NSCLC, especially in squamous cell carcinomas, during tumor progression.

The results of this preliminary study suggest that, compared with FDG, FLT may be less sensitive for primary staging in patients with NSCLC. Although FLT uptake correlated significantly with proliferative activity in NSCLC, the correlation was not better than that for FDG uptake.

Purpose: We investigated the clinical significance of E2F1gene expression in relation to its target genes, thymidylate synthase (TS) and Survivin, in case of non^small-cell lung cancer (NSCLC). Experimental Design: One hundred twenty-seven cases of resected NSCLC were analyzed. Quantitative reverse transcription-PCR was done to evaluate the gene expression of E2F1, TS, and Survivin. Immunohistochemistry was done to investigate the protein expression of E2F1,TS, and Survivin. The Ki-67 proliferation index and the apoptotic index using the terminal deoxyribonucleotidyl transferase^mediated dUTP nick-end labeling method were also evaluated. Results: E2F1 gene expression significantly correlated with the Ki-67 proliferation index (r = 0.487; P < 0.0001), although no correlation was observed between E2F1 gene expression and the apoptotic index.With regard to E2F1 target genes, E2F1 gene expression significantly correlated withTS gene expression (r = 0.709; P < 0.0001) and Survivin gene expression (r = 0.403; P < 0.0001). The overall survival rate was significantly lower in patients with high-E2F1 tumors than in those with low-E2F1 tumors (P = 0.0027), especially among patients with stage II to III NSCLCs (P = 0.0188). A Cox regression analysis showed that the E2F1 status was a significant prognostic factor for NSCLC patients (hazard ratio, 2.052; P = 0.0261).Conclusions: The present study revealed that E2F1 gene expression correlates with TS and Survivin gene expressions and tumor proliferation. During the progression of NSCLC, E2F1 overexpression could produce more aggressive tumors with a high proliferation rate and chemoresistance.Lung cancer is a major cause of cancer-related deaths, and non -small-cell lung cancer (NSCLC) comprises f75% of all lung cancers (1). It is important to design an optimal therapeutic strategy according to tumor biology to improve the treatment of NSCLC (2). The selection of effective chemotherapies based on the evaluation of biomarkers (i.e., ''tailormade chemotherapy'') can improve the clinical outcome of NSCLC patients (3). For example, 5-fluorouracil (5-FU) -derived agents would be useful for tumors with a low expression of thymidylate synthase (TS; refs. 4,5). Gefitinib and erlotinib would be effective for tumors with epidermal growth factor receptor (EGFR) mutations or increased EGFR gene copy numbers (6). Furthermore, the apoptotic index is also a useful indicator to predict the efficacy of chemotherapy for NSCLC patients (7).The E2F1 transcription factor plays a key role in G 1 -to-S phase transition by attracting numerous upstream signals (8). Experimental studies showed that E2F1 induces various genes encoding S phase -activating proteins, including TS (9, 10). Furthermore, a recent experimental study revealed that E2F1 induced the gene expression of Survivin (11), a member of the inhibitor of apoptosis protein family (12). It is important to clarify the molecular mechanisms of these biomarkers in NSCLCs to develop effective cancer treatments. Therefore, we conducted a...

No abstract

Immobilization is often associated with a decrease in muscle elasticity. This condition is called muscle contracture, but the mechanism is not yet clear. We examined changes in ankle joint mobility, sarcomere length, collagen fibril arrangement in the endomysium, and hyaluronic acid (HYA) in muscular tissue 1, 2, 4, 8, and 12 weeks after immobilization of rat soleus muscles in shortened position. Ankle joint mobility decreased with the duration of immobilization. Sarcomere length had shortened 1 week after immobilization, but did not show further change 2, 4, 8, and 12 weeks after immobilization. Collagen fibril arrangement in the endomysium 1 and 2 weeks after immobilization was longitudinal to the axis of the muscle fibers, whereas 4, 8, and 12 weeks after immobilization it was circumferential. HYA in muscular tissue had increased 1 week after immobilization but remained at the same level at weeks 2, 4, 8, and 12. Histochemically, HYA in the endomysium of immobilized muscular tissue was stained more strongly and widely than that in the control tissue. Increased HYA in muscular tissue may induce muscle stiffness, but the significance of how HYA is related to the mechanism of muscle contracture was not clear. The findings suggest that muscle contracture started 1 week after immobilization and increased with the length of immobilization. Consequently, muscle contracture is affected by the shortening muscle fibers during the early stage of immobilization, after which the collagen adapts by the fibril arrangement in the endomysium becoming more circumferential. This change in collagen fibril arrangement may cause advanced muscle contracture in the late stage of immobilization.

In the early stages of immobilization, upregulation of IL-1β/TGF-β1 via macrophages may promote fibroblast differentiation that could affect muscle contracture. The soleus muscle became hypoxic in the later stages of immobilization, suggesting that hypoxia influences the progression of muscle contracture.

Low-level laser (LLL) irradiation promotes proliferation of muscle satellite cells, angiogenesis and expression of growth factors. Satellite cells, angiogenesis and growth factors play important roles in the regeneration of muscle. The objective of this study was to examine the effect of LLL irradiation on rat gastrocnemius muscle recovering from disuse muscle atrophy. Eight-week-old rats were subjected to hindlimb suspension for 2 weeks, after which they were released and recovered. During the recovery period, rats underwent daily LLL irradiation (Ga-Al-As laser; 830 nm; 60 mW; total, 180 s) to the right gastrocnemius muscle through the skin. The untreated left gastrocnemius muscle served as the control. In conjunction with LLL irradiation, 5-bromo-2 -deoxyuridine (BrdU) was injected subcutaneously to label the nuclei of proliferating cells. After 2 weeks, myofibre diameters of irradiated muscle increased in comparison with those of untreated muscle, but did not recover back to normal levels. Additionally, in the superficial region of the irradiated muscle, the number of capillaries and fibroblast growth factor levels exhibited significant elevation relative to those of untreated muscle. In the deep region of irradiated muscle, BrdU-positive nuclei of satellite cells and/or myofibres increased significantly relative to those of the untreated muscle. The results of this study suggest that LLL irradiation can promote recovery from disuse muscle atrophy in association with proliferation of satellite cells and angiogenesis.