Prospective phase II trial of nimotuzumab in combination with radiotherapy and concurrent capecitabine in locally advanced rectal cancer.

PURPOSE: The aim of the study was to evaluate the safety and efficacy of adding concurrent nimotuzumab to preoperative radiotherapy with concurrent capecitabine in locally advanced rectal cancer. METHODS AND MATERIALS: Patients with rectal cancer (clinical stage T3/4 or N+) were scheduled to receive weekly nimotuzumab (400 mg; days -6, 1, 8, 15, 22, and 29). Capecitabine (825 mg/m(2)) was delivered orally twice daily for the duration of radiotherapy. Radiotherapy was administered at 50.4 Gy (45 + 5.4 Gy). The main endpoint was the pathologic complete response (pCR) rate. RESULTS: Twenty-one patients with T3 or T4 disease were enrolled; 66.7 % were nodal-positive; the median distance from the anal verge was 5.5 cm. A pCR was achieved in four patients (19.0 %); 71.4 % patients obtained moderate or good tumor regression (Grade 2 and 3). Downstaging occurred in 15/21 (71.4 %) patients by T stage and 11/14 (78.6 %) by N stage. The actual dose intensities (median/mean, %) were nimotuzumab (100, 100) and capecitabine (100, 99.5). The most frequent Grade 1/2 toxicities were radiation dermatitis (57.1 %), nausea/vomiting (52.4 %), leukocytopenia (47.6 %), diarrhea (47.6 %), and proctitis (38.1 %). Grade 3 diarrhea was observed in 9.5 % of patients and Grade 3 leukocytopenia in 4.8 %. CONCLUSION: These preliminary results indicate that nimotuzumab can be safely combined with radiotherapy plus concurrent capecitabine. The efficacy of this regimen (pCR = 19.0 %) was significantly higher than that observed in previous phase II trials of preoperative radiotherapy with concurrent capecitabine and cetuximab in rectal cancer. Further investigation of concurrent nimotuzumab with radiotherapy plus capecitabine is warranted.

[Detection of guanylate cyclase C mRNA and cytokeratin 20 mRNA in peripheral blood and analysis of prognosis in early to moderate colorectal cancer patients].

OBJECTIVE: To investigate the associations of guanylate cyclase C (GC-C) mRNA and cytokeratin 20 (CK20) mRNA with metastasis and prognosis in early to moderate colorectal cancer patients. METHODS: GC-C mRNA and CK 20 mRNA in peripheral blood of 74 colorectal cancer patients without distant metastasis were detected by fluorescent quantitative PCR (FQ-PCR). Based on their clinicopathological and postoperative follow-up data, the relationship and clinical significance of these data with metastasis hazards and prognosis factors were analyzed. RESULTS: The positive rate of GC-C mRNA in 74 colorectal cancer patients was 33.8% (25/74), and CK20 mRNA was 31.1% (23/74). The 1-, 2-, 3- year disease-free survival rates of patients were 94.6%, 82.4% and 78.4% respectively. There were significant differences in positive rates of GC-C mRNA and CK20 mRNA, tumor differentiation, mesentery lymph node metastasis, tumor embolus in vessel and postoperative chemotherapy associated with 3-year disease free survival rate by Kaplan-Meier analysis (all P<0.05). While mesentery lymph node metastasis and tumor embolus in vessel were independent risk factors of 3-year disease-free survival (P<0.05). CK20 mRNA and tumor embolus in vessel were independent risk factors of 3-year disease-free survival by analysis stratified with clinical stage (P<0.05). CONCLUSIONS: Detection of CK20 mRNA and GC-C mRNA in peripheral blood may be important for early detection of early metastasis of colorectal cancer.

Detection of circulating tumor cells in peripheral blood of colorectal cancer patients without distant organ metastases.

PURPOSE: Recently, the detection of circulating tumor cells (CTCs) in peripheral blood has become an important tool for the non-invasive assessment of micrometastases and to predict clinical outcome. The objective of this study was to investigate if the presence of CTCs in peripheral blood influences the prognosis in colorectal cancer (CRC) patients without distant organ metastases. METHODS: The GCC mRNA and CK20 mRNA levels in peripheral blood and the serum levels of CEA of 92 CRC patients without distant organ metastasis were analyzed by quantitative RT-PCR and ELISA, respectively. Its associations with overall survival (OS) and disease-free survival (DFS) rates were analyzed. RESULTS: Univariate analyses showed that lower OS and DFS rates were significantly associated with GCC and CK20 mRNA levels, the presence of lymph node metastases, the presence of mesenteric root lymph node metastases, and the presence of tumor emboli in vessels (p < 0.05), but not with CEA levels. Multivariate analyses showed a significant association between 1) OS and GCC mRNA levels and differentiation types and 2) DFS and the presence of tumor emboli in the vessels. Kaplan-Meier curves showed that DFS was significantly associated with the presence of poorly differentiated cells, the presence of mesenteric root lymph node metastases having received prior chemotherapy, and the presence of tumor emboli in vessels. CONCLUSION: The detection of CTCs in peripheral blood may be useful for the prediction of clinical outcome in CRC patients without distant organ metastases.

[Anti-tumor effect of adenovirus-mediated Bcl-XL shRNA in vitro].

OBJECTIVE: To investigate the anti-tumor effect of adenovirus-mediated Bcl-XL shRNA on colon cancer cells in vitro. METHODS: A recombinant Bcl-xl adenovirus was constructed, amplified, and purified. The effect on mRNA expression of Bcl-XL was assessed by RT-PCR, and the effect on apoptosis-induction of colon cancer(Lovo cell line) in vitro was assessed by MTT assay and cell clonogenic assay. RESULTS: RT-PCR showed that Ad/Bcl-XL shRNA significantly down-regulated the mRNA expression of Bcl-XL in Lovo cells. Ad/Bcl-XL shRNA suppressed the proliferation of Lovo cells in a dose-dependent as well as a time-dependent manner compared with Ad/GFP (P<0.05). Treatment with Ad/Bcl-XL shRNA dramatically suppressed the colony formation of Lovo cells in a dose-dependent manner (P<0.05). Ad/Bcl-XL shRNA showed no effect on normal human fibroblast. CONCLUSION: Ad/Bcl-XL shRNA exhibits cytotoxic effect on Lovo cells and may have the potential value in the treatment of colon cancer.

[Detection and clinical significance of apoptosis related protein in local advanced rectal cancer patients with preoperative neoadjuvant therapy].

OBJECTIVE: To discuss the mechanism of rectal cancer apoptosis induced by preoperative chemoradiotherapy and evaluate its effect by detection of apoptosis related proteins in locally advanced colorectal cancer patients who had received preoperative chemoradiation. METHODS: To detect Bcl-XL and Bax expression in rectal cancer before and after chemoradiotherapy by EnVision method, combined with patients clinical and pathological index, statistically analysis and evaluation their relationship and clinical significance. RESULTS: Patients with or without tumor shrinkage after preoperative chemoradiotherapy was 13 cases and 21 cases. While the positive rate of Bcl-XL in rectal cancer before and after chemoradiotherapy were 58.8% (20/34) and 52.9% (18/34), respectively. There were significant difference between Bcl-XL change before and after chemoradiation with tumor size, tumor cells shrinkage and operation pattern. The positive rate of Bax in rectal cancer before and after chemoradiotherapy were 32.4% (11/34) and 44.1% (15/34), respectively. There were no significant difference between Bax change before and after chemoradiotherapy with tumor cells shrinkage. There were statistically significant difference between Bax ratio (χ(2) = 9.607, P = 0.048) before and after chemoradiation while there were no significant difference between Bcl-XL/Bax ratio before and after chemoradiation with tumor shrinkage. According to layered analysis with preoperative therapy, there were statistically significant difference (χ(2) = 13.964, P = 0.007) between Bcl-XL change with operation pattern while the same of significant difference between Bax change with tumor infiltration and tumor shrinkage (χ(2) = 10.806 and 10.455, both P < 0.05). CONCLUSIONS: Preoperative chemoradiation can influence rectal cancer cell's apoptosis and treatment effect by changing Bcl-XL and Bax expression. Bcl-XL downregulation and Bax upregulation have shown important function in colorectal cancer cell apoptosis which induced by preoperative chemoradiation, it can also improve the effection of chemoradiation in rectal cancer.

[Differential expression of guanylin in colorectal cancer].

OBJECTIVE: To investigate the expression of guanylin in colorectal cancer. METHODS: The expression of guanylin was examined by RT-PCR and semiquantitative analysis in 20 cases of colorectal cancer, and its relationship with clinical characteristics was analyzed. RESULTS: The positive expression of guanylin in normal tissue (80%, 16/20) was significantly higher than that in tumor tissue (35%, 7/20) (P<0.01). The same result was found in the semiquantitative analysis of 14 cases with differential expression. Differential expression of guanylin in colorectal cancer was associate with TNM stage (P<0.05), not with sex, Borrmann type and degree of differentiation (all P>0.05). CONCLUSION: There is differential expression of guanylin in colorectal cancer, and this kind of differential expression is associated with tumor TNM stage.

Expression and purification of active recombinant cathepsin C (dipeptidyl aminopeptidase I) of kuruma prawn Marsupenaeus japonicus in insect cells.

Cathepsin C (CTSC) is a lysosomal cysteine protease belonging to the papain superfamily. Our previous study showed that CTSC precursor (zymogen) is localized exclusively in cortical rods (CRs) of mature oocyte in the kuruma prawn Marsupenaeus japonicus, suggesting that CTSC might have roles on regulating release and/or formation of a jelly layer. In this study, enzymically active CTSC of the kuruma prawn was prepared by recombinant expression in the High Five insect cell line. The recombinant enzyme with a polyhistidine tag at its C-terminus was considered to be initially secreted into the culture medium as an inactive form of zymogen, because Western blot with anti-CTSC antibody detected a 51 kDa protein corresponding to CTSC precursor. After purification by affinity chromatography on nickel-iminodiacetic acid resin, the enzyme displayed three forms of 51, 31, and 30 kDa polypeptides. All of the forms can be recognized by antiserum raised against C-terminal polyhistidine tag, indicating that the 31 and 30 kDa forms were generated from 51 kDa polypeptide by removal of a portion of the N-terminus of propeptide. Following activation at pH 5.5 and 37 degrees C for 40 hours under native conditions, the recombinant CTSC (rCTSC) exhibited increased activity against the synthetic substrate Gly-Phe-beta-naphthylamide and optimal pH at around 5. The purified rCTSC will be useful for further characterization of its exact physiological role on CRs release and/or formation of a jelly layer in kuruma prawn.

[Effects of enterostomy in treating locally advanced rectal cancer with combined chemoradiotherapy and operation].

OBJECTIVE: To investigate the effect of enterostomy in treatment of locally advanced rectal carcinoma patients with combined chemoradiotherapy and operation. METHODS: Clinical data from 51 cases of locally advanced rectal cancer patients treated with preoperative chemoradiotherapy and operation were analyzed. RESULTS: Thirty-three patients (64.9%) got staging down of their cancer after preoperative chemoradiotherapy, and 21.6% of patients (11 cases) had complete pathologic response. Thirty-seven patients received enterostomy, including extraperitoneal sigmoidostomy (29 cases), defunctioning ileostomy (8 cases) and double colostomy (3 cases with colon obstruction during preoperative therapy). One case experienced parastomal hernia and one stomal stenosis and 2 cases parastomal infection after enterostomy. No death of enterostomy occurred. CONCLUSION: Colostomy can reduce the pressure of obstructed intestinal tract and contribute much to the preoperative chemoradiotherapy, ileostomy can protect the distal stoma from leakage in sphincter saving operation. Enterostomy could be selected when needed in the favor of locally advanced rectal cancer patients.

[Preoperative chemoradiotherapy as neoadjuvant therapy for 35 patients with locally advanced lower rectal carcinoma].

OBJECTIVE: To explore the effect of combined preoperative chemotherapy with radiotherapy on locally advanced lower rectal carcinoma. METHODS: Thirty- five patients with locally advanced lower rectal carcinoma were received a new regimen of combined preoperative chemotherapy with radiotherapy. Routine fr action of radiation was given with total dose of 46 Gy,2 Gy per fraction,five ti mes a week. Patients received oxaliplatin 130 mg/m(2) (infusion) on day 1, plus leu novorin 200 mg/m(2) and 5- FU 500 mg/m(2)(intravenous bolus) from day 1 to day 3 eve ry 3 weeks for total two cycles before irradiation. Operation was performed 4 to 6 weeks later after neoadjuvant therapy. RESULTS: After neoadjuvant therapy,all patients underwent surgical resection with complete pathologic response in 7 patients,average tumor size decrease of in 34.4%, tumor stage decrease in 65.7% o f patients and nodal- negative change rate of 55.6%. Radical resection was per formed in 34 patients,in whom 18 patients received abdominoperineal resection(AP R) and 16 patients received sphincter- preserving surgery with 45.7% of anal preservation rate. One patient received palliative resection. No local recurrence occurred in all patients who received radical resection,but two cases had liver metastasis. CONCLUSION: Combined preoperative chemotherapy with radiotherapy is a better neoadjuvant therapy for lower advanced rectal cancer,which can decrease tumor stage,improve resectability and anal sphincter preservation rate,therefore ,this new neoadjuvant therapy with tolerable toxicity will has a promising application in the clinical setting.