PANC-1 pancreatic cancer cell growth inhibited by cucurmosin alone and in combination with an epidermal growth factor receptor-targeted drug

OBJECTIVES

To investigate the inhibition of PANC-1 pancreatic cancer cell growth by cucurmosin (CUS) and its possible mechanism.

METHODS

We observed the inhibition of PANC-1 cell growth by sulforhodamine B and colony-forming experiments in vitro and established nonobese diabetic/severe combined immunodeficiency mouse subcutaneous tumor models in vivo. We used Western blot to analyze protein levels related to apoptosis and epidermal growth factor receptor (EGFR) signaling pathways after drug intervention, whereas the messenger RNA expression of EGFR was analyzed by quantitative real-time polymerase chain reaction.

RESULTS

Sulforhodamine B and colony-forming experiments indicated that CUS inhibited PANC-1 cell proliferation in a dose- and time-dependent manner. A stronger inhibitory effect was observed when CUS was combined with gefitinib. The subcutaneous tumor growth was also inhibited. Western blot showed that all the examined proteins decreased, except for 4E-BP1 and the active fragments of caspase 3 and caspase 9 increased. Epidermal growth factor receptor expression did not change significantly in quantitative real-time polymerase chain reaction.

CONCLUSIONS

Cucurmosin can strongly inhibit the growth of PANC-1 cells in vitro and in vivo. Cucurmosin can down-regulate EGFR protein expression, but not at the messenger RNA level. Cucurmosin can also inhibit the ras/raf and phosphatidylinositol 3-kinase/Akt downstream signaling pathways and enhance the sensitivity of the EGFR-targeted drug gefitinib.

A Cancer and Leukemia Group B phase II study of sunitinib malate in patients with previously treated metastatic pancreatic adenocarcinoma (CALGB 80603)

BACKGROUND

The Cancer and Leukemia Group B (CALGB) conducted a phase II study evaluating sunitinib in patients with progressive metastatic pancreas adenocarcinoma following prior gemcitabine-based therapy (trial CALGB 80603; ClinicalTrials.gov identifier, NCT00397787). The primary endpoint was to determine the disease control rate (DCR) as measured by the Response Evaluation Criteria in Solid Tumors (complete response, partial response [PR], and stable disease) at 6 weeks.

PATIENTS AND METHODS

Patients aged ≥18 years with an Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2 and with progressive pancreas adenocarcinoma following treatment with gemcitabine were eligible. Sunitinib was dosed at 50 mg orally days 1-28, every 42 days (1 cycle). The statistical plan called for a three-stage design. A DCR ≥15% was considered worthy of further study.

RESULTS

In total, 77 patients were enrolled. Forty-two (54.6%) enrollees were male. The median age was 65 years. The ECOG performance status score distribution was: 0, 39%; 1, 50%; 2, 11%. The DCR was 21.6%; one patient (1.4%) had a PR and 15 patients (20.3%) had stable disease as their best response. The progression-free survival time was 1.31 months (95% confidence interval [CI] 1.25-1.38 months) and overall survival time was 3.68 months (95% CI, 3.06-4.24 months).

CONCLUSIONS

The study met its primary endpoint; however sunitinib had minimal activity and moderate toxicity in a population of gemcitabine-refractory pancreas adenocarcinoma patients. For future studies, limiting enrollment to patients with an ECOG performance status score of 0-1 is recommended.