The antitumor activity of recombinant antitumor antiviral protein and the associated molecular mechanism in pancreatic tumor cells.

BACKGROUND: Pancreatic cancer has poor prognosis and high mortality. Currently, the therapy of pancreatic cancer remains a challenge. In this study, we compared the antitumor activity of the recombinant antitumor antiviral protein (RAAP), an improved interferon, with gemcitabine, a classic chemotherapy agent used for pancreatic cancer treatment. METHODS: The proliferation of Bx-PC3 pancreatic cancer cells was evaluated by an MTT assay. Cell cycle arrest and apoptosis were evaluated by flow cytometry and annexin V-FITC/propidium iodide double staining, respectively. The expressions of matrix metalloproteinase (MMP)-2, MMP-9, caspase-3, caspase-8, and caspase-9 genes were evaluated by reverse transcription-polymerase chain reaction and the Western blot analysis. A xenograft pancreatic cancer model was established by inoculating Bx-PC3 cells into athymic nude mice. The antitumor activity of RAAP and gemcitabine was tested in the xenograft tumor model. RESULTS: RAAP significantly inhibited proliferation, induced cell cycle arrest, and induced apoptosis in Bx-PC3 cells in vitro and delayed tumor growth in vivo. The antitumor activity of 20 ng/mL of RAAP was a little more effective than 10 µM of gemcitabine. The antitumor activity of RAAP was associated with its role in inducing caspase-3 and caspase-8 expression as well as downregulating MMP-2 expression. CONCLUSIONS: RAAP can effectively suppress human pancreatic cancer cell growth in vitro and in vivo. The antitumor efficacy of RAAP is similar to gemcitabine.

[Modified serum-guided immunoblotting for differential proteomic study of prostate cancer].

OBJECTIVE: To search for a new method of screening for molecular targets for androgen-dependent prostate cancer. METHODS: We collected tissue samples and paired serum samples from 3 cases of androgen-dependent prostate cancer (ADPC) treated by surgical resection, and included another 3 samples of benign prostatic hyperplasia (BPH) tissue and normal human serum in the control group. The total proteins extracted were separated and transmembrane by two-dimensional gel electrophoresis, followed by hybridization with the sera of the patients with ADPC and those with hormone-independent prostate cancer (HIPC) as the primary antibodies. The differentially expressed proteins were compared by Western blot, analyzed by MALDI-TOF-MS mass spectrography, and verified by RT-PCR and Western blot following bioinformatic identification. RESULTS: This modified method exhibited a significantly better effect in displaying differentially expressed proteins, by which 12 differentially expressed protein spots were identified, including Beclin1, glutathione S-transferase P (GSTP1-1), ZBTB7, dihydrodiol dehydrogenase 2 (DDH), enolase (ENO1), glucose-dependent insulin-releasing peptide receptor (GIPR), Mn-superoxide dismutase (MnSOD), phosphoglycerate mutase 1 (PGAM1), amino-peptidyl-prolyl cistrons isomerase (PPIA), and phospholipid-PE-binding protein (PEBP). The mRNA and protein expressions of Beclin1 were significantly down-regulated in androgen-dependent prostate cancer tissues. CONCLUSION: This modified serum-guided immunoblotting technique has provided a new method for clarifying the molecular mechanisms of the occurrence and progression of HIPC, in which Beclin1-mediated autophagy may play a key role.

[Association of CK20 expression with the progression, metastasis and prognosis of breast cancer].

AIM: To analyze the expression of CK20 in human breast cancer, and to evaluate the association between its expression and tumor's progression and prognosis. METHODS: 86 cases with breast cancer, 20 cases of benign tumor tissues were examined for the expression of CK20 by immunohistochemical staining. RESULTS: The positive rate of CK20 expression in breast cancer was 80.23% (69/86), which was significantly higher than that in benign tumor tissues of breast [20.00% (4/20), P<0.01]. CK20 expression was associated with the histologic grades (P<0.05) and the pathological types (P<0.01). The expression of CK20 was observed to correlate positively with TNM stages (r=0.86, P<0.05), lymph node status (r=0.73, P<0.05) and HER-2 status (r=0.69, P<0.05), and correlate negatively with ER status (r=-0.58, P<0.05). Moreover, Kaplan Meier curves of overall survival analysis showed a significant difference between CK20 positive groups and negative group (P<0.01). CONCLUSION: The results suggest that the expression of CK20 may be associated with the progression and prognosis of breast cancer.

[Expression of MMP-2, MMP-9 and collagen type IV and their relationship in colorectal carcinomas].

AIM: To investigate the expression of MMP-2, MMP-9 and collagen type IV and their relationship in colorectal carcinomas. METHODS: The expressions of collagen type IV, MMP-2 and MMP-9 was in normal and colorectal cancer tissues of 30 patients whose clinical stages were Dukes'B and C was detected with immunohistochennical staining. And the relationship among collagen type IV, MMP-2 and MMP-9 was analysed. RESULTS: The expression of collagen type IV was significantly decreased in colorectal cancer tissues. The expression of MMP-2 and MMP-9 was not detected in normal colorectal tissues but it was significantly increased in colorectal cancer tissues. There was a negative correlation between the expression of collagen type IV and MMP-9. CONCLUSION: The expression of collagen type IV in colorectal cancer tissues is lower than that in normal tissues. MMP-9 may play an important role in the degradation of collagen type IV in colorectal cancer.