Diagnostic performance of CT, PET, side-by-side, and fused image interpretations for restaging of non-Hodgkin lymphoma.

The purpose of this study was to compare the diagnostic performance of positron emission tomography (PET) alone, computed tomography (CT) alone, side-by-side reading, and fused images for restaging or follow-up of patients with malignant lymphoma. METHODS: Fifty patients with histologically confirmed non-Hodgkin lymphoma underwent an (18)fluoro-2-deoxyglucose (FDG)-PET scan, followed by a CT scan. CT alone, PET alone, side-by-side reading, and fused images were interpreted separately and visually using a five-point grading scale for the following eight regions: cervical, supraclavicular, axillary, mediastinal, para-aortic to iliac, mesenteric, inguinal, and extra-nodal. Diagnostic accuracy was compared on the basis of the final diagnoses determined by histological confirmation and/or clinical course. RESULTS: For all regions combined, the interpretation of PET alone (sensitivity = 86.1%, specificity = 99.4%, accuracy = 91.0%), side-by-side reading (96.0%, 99.4%, 98.9%), and fused images (98.0%, 99.4%, 99.2%) yielded significantly higher diagnostic performance than that of CT alone (59.4%, 96.1%, 91.0%; P < 0.001). The cervical, supraclavicular, and extra-nodal regions were more accurately diagnosed with PET (P < 0.05), whereas the para-aortic to iliac regions were diagnosed more accurately with side-by-side reading and fused images than with CT alone or PET alone (P < 0.05). CONCLUSIONS: Although fused images are clinically valuable, side-by-side reading showed equivalent performance, whereas the interpretation of PET alone yielded reasonably high diagnostic performance for restaging or follow-up of patients with malignant lymphoma

Class III β-Tubulin Overexpression Induces Chemoresistance to Eribulin in a Leiomyosarcoma Cell Line

Eribulin is a new drug to treat soft tissue sarcoma (STS) that exerts antitumor activity by binding to microtubules. The prognosis of STS is poor, and eribulin is expected to improve the treatment outcome. We observed several cases that exhibited resistance to eribulin and developed an eribulin-resistant leiomyosarcoma cell line to investigate the mechanism of resistance. The IC50 of eribulin was 125 times higher in the resistant cell line than in the parental cell line, and eribulin did not induce G2/M arrest in resistant cells. The resistant cell line showed increased expression of MDR1 transcript, but protein levels and functional analysis results were similar to the parental cell line. We found that class III β-tubulin (TUBB3) was overexpressed in the resistant cell line, and siRNA knockdown of TUBB3 partially recovered sensitivity to eribulin. TUBB3 expression in clinical samples varied, suggesting that TUBB3 has the potential to be a biomarker for selection of anticancer drugs and may be a target for overcoming resistance to eribulin

Hypoxia-inducible factor 1 alpha is a poor prognostic factor and potential therapeutic target in malignant peripheral nerve sheath tumor

<div><p>Background</p><p>Malignant peripheral nerve sheath tumor (MPNST) is a rare soft tissue sarcoma with poor prognosis. Hypoxia-inducible factor 1 (HIF-1) plays a crucial role in the cellular response to hypoxia and regulates the expression of multiple genes involved in tumor progression in various cancers. However, the importance of the expression of HIF-1α in MPNSTs is unclear.</p><p>Methods</p><p>The expression of HIF-1α was examined immunohistochemically in 82 MPNST specimens. Cell culture assays of human MPNST cells under normoxic and hypoxic conditions were used to evaluate the impact of anti-HIF-1α–specific siRNA inhibition on cell survival. A screening kit was employed to identify small molecules that inhibited HIF-1α.</p><p>Results</p><p>The nuclear expression of HIF-1α was positive in 75.6% of MPNST samples (62/82 cases). Positivity for HIF-1α was a significant poor prognostic factor both in univariate (<i>P</i> = 0.048) and multivariate (<i>P</i> ≤ 0.0001) analyses. HIF-1α knockdown abrogated MPNST cell growth, inducing apoptosis. Finally, chetomin, an inhibitor of HIF-1α, effectively inhibited the growth of MPNST cells and induced their apoptosis.</p><p>Conclusion</p><p>Inhibition of HIF-1α signaling is a potential treatment option for MPNSTs.</p></div

Knockdown of HIF-1α by si-RNA and effects of si-HIF-1α on cell proliferation and cell cycle progression.

<p>Assessment of HIF-1α knockdown in MPNST cell lines by the following: <b>a</b>. Real-time quantitative PCR (mean ± SD; *<i>P</i> < 0.05) under normoxia; and <b>b</b>. Western blotting of HIF-1α after induction of HIF-1α–specific si-RNA under hypoxia. The si-HIF-1α suppressed the expression of HIF-1α compared to control si-RNA. Actin was used for internal normalization. <b>c</b>. Downregulation of downstream genes by si-HIF-1α. VEGFA, GLUT1, and BNIP3 expression downstream of HIF-1α was decreased by si-HIF-1α, whereas expression of CCND1 downstream of HIF-2α remained unchanged. <b>d</b>. Effects of si-HIF-1α on cell proliferation in MPNST cell lines. Knockdown of HIF-1α by si-RNA suppressed the proliferation of MPNST cell lines under hypoxia. Data in graphs are presented as box-and-whisker plots, and statistical comparisons were performed using the Mann-Whitney U test. *<i>P</i> < 0.05. <b>e and f</b>. Effects of si-HIF-1α on cell cycle progression in MPNST cell lines. <b>e</b>. Representative cell cycle profile of MPNST cell lines after knockdown of HIF-1α by si-RNA. The areas labelled “sG1” in the figures represent subG1 fractions. <b>f</b>. SubG1 fractions increased by HIF-1α knockdown in MPNST cell lines under normoxia and hypoxia. Experiments were performed in triplicate or more, and data are expressed as the mean ± SD. *<i>P</i> < 0.05. Each value is listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178064#pone.0178064.s003" target="_blank">S1 Table</a>.</p

Chetomin, an inhibitor of HIF-1α/p300 interaction, effectively inhibited the growth of MPNST cells and induced their apoptosis by attenuating the transcriptional activity of HIF-1.

<p><b>a</b>. Effects of chetomin on cell proliferation in MPNST cell lines. Chetomin inhibited the cell proliferation of MPNST cell lines under hypoxic conditions. Data are expressed as the mean ± SD. *<i>P</i> < 0.05. <b>b</b>. Effects of chetomin on apoptosis in MPNST cell lines. Twelve hours after the addition of chetomin, double staining with annexin V FITC and 7-AAD was performed, and apoptosis was analyzed by flow cytometer. An increase in apoptotic and necrotic fractions was observed in all cell lines in a dose-dependent manner. The early apoptotic component is annexin V–positive and 7-AAD–negative, corresponding to the lower right quadrant of each panel. On the other hand, the necrotic component is positive for both annexin V and 7-AAD, and is indicated by the upper right quadrant of each panel. The areas surrounded by broken lines and labelled “A” represent apoptotic fractions, while those labelled “N” correspond to necrotic fractions. <b>c</b>. Representative cell cycle profile of MPNST cell lines after treatment of chetomin. The areas labelled “sG1” represent subG1 fractions. <b>d and e</b>. Chetomin increases apoptosis and subG1 fractions in MPNST cell lines. Experiments were performed in triplicate, and data are expressed as the mean ± SD. *<i>P</i> < 0.05. Each value is provided in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178064#pone.0178064.s005" target="_blank">S3</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0178064#pone.0178064.s006" target="_blank">S4</a> Tables. <b>f</b>. Effects of chetomin on the nuclear expression of HIF-1α. MPNST cell lines were treated with chetomin and the nuclear expression of HIF-1α was evaluated by Western blotting. Actin was used for internal normalization. The nuclear expression of HIF-1α was not affected by chetomin, even under normoxia or hypoxia. <b>g</b>. Hypoxia-inducible reporter assay. MPNST cell lines were transfected with a luciferase HIF reporter. Reporter activities under normoxic or hypoxic conditions and in the absence or presence of the indicated concentrations of chetomin were normalized to an internal control and expressed as relative light units (RLUs). Experiments were performed in triplicate, and data are expressed as the mean ± SD. *<i>P</i> < 0.05.</p

Hematoxylin and eosin staining and immunohistochemical staining of HIF-1α in MPNST samples and association between nuclear HIF-1α expression and poor prognosis in MPNSTs.

<p><b>a</b>–<b>f</b>. Staining with hematoxylin and eosin (a and b) and immunohistochemical staining of HIF-1α (c–f) in MPNST specimens. Representative cases: a HIF-1α–negative specimen (a, c, and e) and a HIF-1α–positive specimen (b, d, and f). Scale bar, 100 μm in a–d and 20 μm in e and f. <b>g</b>–<b>j</b>. Kaplan-Meier survival curves for all patients based on positive or negative nuclear HIF-1α expression (g), tumor diameter of 5 cm or more (h), positive or negative MIB-1 expression (i), and deep tumor location (j). Log-rank tests were performed to determine statistical significance.</p