DataSheet_1_The Significance of MET Expression and Strategies of Targeting MET Treatment in Advanced Gastric Cancer.pdf

BackgroundAccurate assessment of predictive biomarker expression is critical in patient selection in clinical trials or clinical practice. However, changes in biomarker expression may occur after treatment. The aim of the present study was to evaluate the effects of chemotherapy on MET expression in gastric cancer (GC).MethodsMET expression was examined immunohistochemically before and after treatment in 122 patients with unresectable or recurrent GC, and was evaluated according to H-score or the scoring criteria used in the MetMAb trial. MET gene amplification was assessed by chromogenic in situ hybridization (CISH). The antitumor effect of MET targeted therapy was investigated in human gastric cancer cells in vitro and in vivo, and the underlying molecular mechanisms were analyzed by western blot.ResultsMET expression was associated with Lauren classification as well as tumor differentiation by either scoring system. MET amplification was not associated with clinical characteristics. Of the 71 patients who had paired pre- and post-treatment tumor tissues, 28 patients (39%) were initially positive for MET expression, and 43 (61%) were negative. Twenty-five patients (35%) showed significant changes in MET expression after treatment (P=0.007). Additionally, there was a concomitant overexpression of MET and HER2 in a subset of GC patients. MET inhibitor volitinib could significantly inhibit cell proliferation and xenograft growth in vitro and in vivo in MKN45 cells with MET and phosphorylated MET (pMET) high expressions via suppressing downstream PI3K/Akt and MAPK signaling pathways. Furthermore, combination therapy targeting both MET and HER2 demonstrated a synergistic antitumor activity.ConclusionsMET expression is altered post chemotherapy and MET status should be evaluated in real-time. Both MET and pMET expressions might need to be considered for patients suitable for volitinib treatment.</p

Circulating Chromogranin A as A Marker for Monitoring Clinical Response in Advanced Gastroenteropancreatic Neuroendocrine Tumors

<div><p>Chromogranin A (CgA), present in the chromaffin granules of neuroendocrine cells, is a useful biomarker for the diagnosis of patients with gastroenteropancreatic neuroendocrine tumors (GEP-NETs). This study was conducted to investigate the potential role of circulating CgA in monitoring clinical response in Chinese patients with advanced GEP-NETs. Eighty patients with advanced GEP-NETs treated in Peking University Cancer Hospital from September 2011 to May 2014 and 65 healthy individuals were included in this study. Serum CgA levels were analyzed for relationship with patient’s baseline characteristics and clinical outcome. Median CgA levels were significantly higher in patients with advanced GEP-NETs than in healthy individuals (93.8 ng/mL vs. 37.1 ng/mL; P<0.01), as well as significantly higher in patients with carcinoid syndrome or liver metastasis than in those without carcinoid syndrome (298.8 ng/mL vs. 82.9 ng/mL; P = 0.011) or liver metastasis (137.0 ng/mL vs. 64.4 ng/mL; P = 0.023). A CgA cutoff value of 46.2 ng/mL was used in this study with a sensitivity of 78.8% and specificity of 73.8%. Patients with CgA levels higher than 46.2 ng/mL had a worse prognosis than patients with CgA levels lower than 46.2 ng/mL (P = 0.045). Notably, a weak correlation was observed between changes in serum CgA levels and clinical response to the IP regimen as well as SSAs. Our data also indicate that serum CgA could be a useful indicator of patient prognosis though there is more research required in order to validate such claims.</p></div

Relationship between CgA level changes and clinical response.

<p>(A) Of the twenty-eight patients that received IP chemotherapy as the first-line treatment, sixteen of twenty-three with non-progressive disease (PR and SD) showed decreased or stable CgA levels; three out of five with progressive disease (PD) exhibited increased CgA levels. (B) Of the eighteen patients who received somatostatin analogs as the first-line treatment, twelve of thirteen with non-progressive disease had decreased or stable CgA levels; two of the five patients having progressive disease showed increased CgA levels.</p

Dynamic changes of CgA levels during treatment.

<p>(A), Patient 1 was treated with IP regimen for three months (6 cycles) with partial response (PR) followed by 6 months (6 cycles) of somatostatin analogues with progressive disease (PD) and 3 cycles of IP regimen with PR. (B), Patient 2 was treated with 6 cycles of IP regimen with PR followed by 3 cycles of SSAs with PD and 3 cycles of IP regimen with PD. Patient 3 (C) and patient 4 (D) were treated with 6 cycles of IP regimen with SD followed by 6 cycles of SSAs. Patient 5 (E) and patient 6 (F) were treated with 6 cycles of IP regimen followed by 6 cycles of SSAs.</p

Clinical characteristics and serum CgA levels of patients.

<p>Clinical characteristics and serum CgA levels of patients.</p

The patient screening process.

<p>IP: irinotecan plus cisplatin; SSAs: somatostatin analogs.</p

Overall survival curve of patients based on CgA levels.

<p>Patients with high CgA levels (≥46.2 ng/mL) had a significantly poorer survival than patients with low CgA levels (<46.2 ng/mL).</p

The ROC curve of serum CgA levels.

<p>The sensitivity and specificity were 78.8% and 73.8% at the cutoff level of 46.2 ng/mL. The area under the curve (AUC) was 0.85 with 95% confidence interval of 0.79–0.91.</p

Serum CgA levels in patients with GEP-NETs and healthy individuals.

<p>There were higher CgA levels in patients with GEP-NETs compared with healthy individuals (Log10 scale). **P<0.01 (Mann–Whitney test).</p

Additional file 1: Figure S1. of Dual PI3K/mTOR inhibitor BEZ235 exerts extensive antitumor activity in HER2-positive gastric cancer

The expression of HER2 in two HER2-positive patient-derived xenografts (PDXs). Cases 1 and 2 with HER2 positive expression of primary tumors maintained positive expression of xenografts based on IHC and DISH results. Scale bars, 100 μm. Figure S2. BEZ235 or trastuzumab did not induce cell apoptosis. Flow cytometry analysis showed that the percentage of apoptotic cells did not increased after treatment with trastuzumab alone (4.2 and 4.3 %, respectively), BEZ235 alone (3.0 and 3.2 %, respectively), compared to the control (4.0 and 5.2 %, respectively). The data are expressed as the mean ± s.d of three independent experiments. *P >0.05 by one-way ANOVA or unpaired two-tailed t-test. Table S1. Antibodies used in this study. Table S2. The characteristics of two patients. (DOC 2229 kb