Neutrophil elastase (NE), a serine protease secreted by neutrophils, contributes to the progression of cancers to enhance tumor invasion and metastasis. It has been well reported that the regions surrounding the colorectal cancerous tissues usually are decorated with increased accumulation or aggregation of neutrophils coupled with a higher deposition/expression of NE. Therefore, we hypothesized that an increased expressional level of NE in patients with colorectal cancer (CRC) may represent as one of putative biomarkers for CRC. The aim of this study was to evaluate and assure our hypothesis by measurements of the expressional level of NE in the sera and tissues from CRC patients. Moreover, we also proposed a potential therapeutic strategy by blocking enzymatic activity of NE using sivelestat to inhibit the progression of tumor developments. The infiltrated numbers of neutrophils from specimen tissues of CRC patients, and the secreted forms of NE in the sera were quantitatively measured and compared. To evaluate the serum NE as one of putative biomarkers of CRC patients, the receiver operating characteristic (ROC) curve was made to determine the cut-off value of NE in sera for assurance of CRC diagnosis. To evaluate NE as therapeutic target for CRC, sivelestat, a NE inhibitor, was used and administrated into the CRC xenografts. NE expression level coupled with tumor volume were measured and compared between the control and sivelestat-treated xenografts. We found that more infiltrated neutrophils and an increased NE expression were detected in the cancerous tissues compared to the normal tissues. The serum NE concentration in CRC patients was statistically higher than that in the healthy controls (0.56±0.08 μg/ml vs. 0.22±0.03ug/ml) (p<0.05), indicating that serum NE can potentially be a putative marker of CRC. To characterize the role of NE in tumorigenesis, the NE avtivity was detected in HCT-15-xenografts using in vivo imaging system (IVIS). Compare to normal mice, the amounts of active NE in xenografts are significantly higher than normal control animals. In the therapeutic characterizing studies, we found that sivelestat can inhibit tumor growth in the HCT-15-induced xenografts. This study suggests that NE is not only as a putative diagnostic biomarker of CRC, but also a potential therapeutic target for patients suffered with CRC.

Purpose To use pathologic indicators to determine which patients benefit from postmastectomy radiation therapy (PMRT) for breast cancer after neoadjuvant chemotherapy (NACT) and total mastectomy (TM). Patients and methods We enrolled 4236 patients with breast invasive ductal carcinoma who received NACT followed by TM. Cox regression analysis was used to calculate hazard ratios (HRs) and confidence intervals; independent predictors were controlled for or stratified in the analysis. Results After multivariate Cox regression analyses, the adjusted HRs derived for PMRT for all-cause mortality were 0.65 (0.52–0.81, P < 0.0001) and 0.58 (0.47–0.71, P < 0.0001) in postchemotherapy pathologic tumor stages T2–4 (ypT3–4) and postchemotherapy pathologic nodal stages N2–3 (ypN2–3), respectively. Moreover, adjusted HRs derived for PMRT with all-cause mortality were 0.51 (0.38–0.69, P < 0.0001), 0.60 (0.40–0.88, P = 0.0096), and 0.64 (0.48–0.86, P = 0.0024) in pathological stages IIIA, IIIB, and IIIC, respectively. Additionally, the PMRT group showed significant locoregional control irrespective of the pathologic response, even ypT0, ypN0, or pathological complete response (pCR), compared with the No-PMRT group. The multivariate analysis showed no statistical differences between the PMRT and No-PMRT groups for distant metastasis-free survival in any pathologic response of ypT0–4, ypN0–3, and pathologic American Joint Committee on Cancer stages pCR to IIIC. Conclusion For patients with breast cancer ypT3–4, ypN2–3, or pathologic stages IIIA–IIIC receiving NACT and TM, benefit from PMRT if it is associated with OS benefits, regardless of the clinical stage of the disease. Compared with No-PMRT, PMRT improved locoregional recurrence-free survival, even pCR, in patients with breast cancer receiving NACT and TM.

Previous report showed that epidermal growth factor (EGF) promotes tumor progression. Several studies demonstrated that growth factors can induce heme oxygenase (HO)-1 expression, protect against cellular injury and cancer cell proliferation. In this study, we investigated the involvement of the c-Src, NADPH oxidase, reactive oxygen species (ROS), PI3K/Akt, and NF-κB signaling pathways in EGF-induced HO-1 expression in human HT-29 colon cancer cells. Treatment of HT-29 cells with EGF caused HO-1 to be expressed in concentration- and time-dependent manners. Treatment of HT-29 cells with AG1478 (an EGF receptor (EGFR) inhibitor), small interfering RNA of EGFR (EGFR siRNA), a dominant negative mutant of c-Src (c-Src DN), DPI (an NADPH oxidase inhibitor), glutathione (an ROS inhibitor), LY294002 (a PI3K inhibitor), and an Akt DN inhibited EGF-induced HO-1 expression. Stimulation of cells with EGF caused an increase in c-Src phosphorylation at Tyr406 in a time-dependent manner. Treatment of HT-29 cells with EGF induced an increase in p47phox translocation from the cytosol to membranes. The EGF-induced ROS production was inhibited by DPI. Stimulation of cells with EGF resulted in an increase in Akt phosphorylation at Ser473, which was inhibited by c-Src DN, DPI, and LY 294002. Moreover, treatment of HT-29 cells with a dominant negative mutant of IκB (IκBαM) inhibited EGF-induced HO-1 expression. Stimulation of cells with EGF induced p65 translocation from the cytosol to nuclei. Treatment of HT-29 cells with EGF induced an increase in κB-luciferase activity, which was inhibited by a c-Src DN, LY 294002, and an Akt DN. Furthermore, EGF-induced colon cancer cell proliferation was inhibited by Sn(IV)protoporphyrin-IX (snPP, an HO-1 inhibitor). Taken together, these results suggest that the c-Src, NADPH oxidase, PI3K, and Akt signaling pathways play important roles in EGF-induced NF-κB activation and HO-1 expression in HT-29 cells. Moreover, overexpression of HO-1 mediates EGF-induced colon cancer cell proliferation.