DPP3 expression promotes cell proliferation and migration in vitro and tumour growth in vivo, which is associated with poor prognosis of oesophageal carcinoma.

Dipeptidyl peptidase III (DPP3), a zinc­dependent metallopeptidase, is upregulated in a variety of malignancies. However, little is known about its roles in the pathogenesis of these malignancies. The present study was designed to investigate the roles of DPP3 in the pathogenesis and progression of oesophageal cancer (EC). The expression level of DPP3 in EC tissues and adjacent normal tissues was detected in 93 cases of tissue biopsies collected from patients diagnosed with oesophageal carcinoma by immunohistochemistry. The effect of DPP3 expression on cell proliferation, migration or apoptosis was determined in DPP3­depleted EC cells created by infection with lentivirus containing short hairpin RNA specific to the human DPP3 mRNA sequence, followed by detection at the cellular level using a Celigo cell count assay, flow cytometry, wound­healing assay and Transwell assay as well as chip screening with a Human Apoptosis Antibody Array kit, which enables the quantitative detection of 43 apoptosis­related genes. A xenograft model was applied to detect the tumour growth and invasion of DPP3­depleted cancer cells in nude mice. The results revealed that DPP3 expression was elevated in EC tissues compared with adjacent non­tumour tissues, and high DPP3 expression was significantly associated with poor prognosis. DPP3 depletion resulted in reduced cell proliferation and migration and enhanced cell cycle arrest and apoptosis of EC cells and led to the inhibition of tumour growth and invasion in a xenograft model. In addition, DPP3 depletion was associated with the upregulation of the proapoptotic proteins SMAC and p53 and the downregulation of the antiapoptotic proteins clAP­2, IGFBP­2 and TRAILR­4. Finally, DPP3 may promote cell proliferation, migration and survival of EC cells in vitro and tumour growth and invasion of oesophageal carcinoma in vivo, and thus may serve as a molecular target for tumour therapy.

Correlation analysis of riboflavin, RFT2 and Helicobater pylori in gastric carcinoma.

OBJECTIVE: To investigate the relationship between tissue riboflavin level and riboflavin transporter 2 (RFT2) protein expression, and the relationship between Helicobacter pylori (H.pylori) infection and the plasma riboflavin level in gastric carcinoma (GC). METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to detect tissue riboflavin level in patients with GC. Western blotting was applied to analyze the expression of RFT2 protein in 60 tissue samples from gastric carcinoma together with their normal tissues. The Warthin-starry method, rapid urease test and (14)C-UBT were administered to detect the infection of H.pylori. High performance liquid chromatography (H.PYLORILC) was performed to detect plasma riboflavin level in the GC. RESULTS: A significant decrease in the tissue riboflavin level was detected in GC samples compared to those in the normal mucous membrane (17.02 ± 3.91 vs. 21.0 ± 4.73; P = 0.043), and a significant decrease in the RFT2 protein was found in GC samples compared to those in the normal mucous membrane (0.92 ± 0.39 vs. 1.23 ± 0.51; P = 0.042). A positive correlation of tissue riboflavin level with defective expression of RFT2 protein was observed in GC patients (χ(2) = 1.969; P = 0.039). Plasma riboflavin level in gastric cancer without H.pylori infection group (1.6674 ng/mL ± 0.37009 ng/mL) was higher than H.pylori infection group (1.2207 ng/mL ± 0.17727 ng/mL, P = 0.043). CONCLUSION: The results indicate that RFT2 plays an important role in gastric carcinogenesis by modulating riboflavin absorption. H.pylori infection affects plasma riboflavin level and the prognosis of patients with gastric cancer.

[Plasma amino acid profiling of "same symptom for different disease" in Uyghur medicine based on high-performance liquid chromatography].

OBJECTIVE: To determine the plasma amino acid metabolism of "same symptom for different diseases" in different cancer patients in Uyghur medicine. METHODS: Plasma amino acid concentration was tested by high-performance liquid chromatography (HPLC) in cancer patients with different symptom, and the spectral profiles were subjected to a t-test for statistical significance. RESULTS: Compared with the healthy group, lung cancer, cervical cancer, breast cancer and gastric cancer patients with abnormal Savda had lower concentration of plasma amino acids except some amino acids. Lung cancer patients with abnormal Savda had higher concentration of plasma phenylalanine, serine, cystine, valine, isoleucine, leucine and aspartic acid than Unsavda patients (P<0.05). Cervical cancer patients with abnormal Savda had low concentration of plasma arginine, but higher concentration of plasma cystine than Unsavda patients (P<0.05). Breast cancer patients with abnormal Savda had higher concentration of plasma leucine, serine, taurine, cystine, tyrosine, valine, isoleucine and asparagine than Unsavda patients (P<0.05). Gastric cancer patients with abnormal Savda had high concentration of plasma cystine but lower concentration of plasma phenylalanine, threonine and arginine than Unsavda patients (P<0.05). CONCLUSION: Different tumor patients with abnormal Savda have common characteristics and significant differences.

Decreased blood riboflavin levels are correlated with defective expression of RFT2 gene in gastric cancer.

AIM: To investigate the relationship between blood riboflavin levels and riboflavin transporter 2 (RFT2) gene expression in gastric carcinoma (GC) development. METHODS: High-performance liquid chromatography was used to detect blood riboflavin levels in patients with GC. Real-time fluorogenic quantitative polymerase chain reaction and immunohistochemistry were used to analyze the expression of RFT2 mRNA and protein in samples from 60 GC patients consisting of both tumor and normal tissue. RESULTS: A significant decrease in the RFT2 mRNA levels was detected in GC samples compared with those in the normal mucous membrane (0.398 ± 0.149 vs 1.479 ± 0.587; P = 0.040). Tumors exhibited low RFT2 protein expression (75%, 16.7%, 8.3% and 0% for no RFT2 staining, weak staining, medium staining and strong staining, respectively), which was significantly lower than that in the normal mucous membrane (10%, 16.7%, 26.7% and 46.7% for no RFT2 staining, weak staining, medium staining and strong staining, respectively; P < 0.05). Tumors with low RFT2 expression were significantly associated with tumor stage and histological grade. Moreover, a significantly decrease in Uyghur patients was observed compared with Han patients. However, other parameters-gender, tumor location and lymph node metastasis-showed no significant relationship with RFT2 expression. Blood riboflavin levels were reverse correlated with development of GC (1.2000 ± 0.97569 ng/mL in high tumor stage patients vs 2.5980 ± 1.31129 ng/mL in low tumor stage patients; P < 0.05). A positive correlation of plasma riboflavin levels with defective expression of RFT2 protein was found in GC patients (χ² = 2.619; P = 0.019). CONCLUSION: Defective expression of RFT2 is associated with the development of GC and this may represent a mechanism underlying the decreased plasma riboflavin levels in GC.