Overexpression of GP73 promotes cell invasion, migration and metastasis by inducing epithelial-mesenchymal transition in pancreatic cancer.

Pancreatic cancer is one of the most difficult clinical cases to diagnose with a very low 5-year survival rate of 5%, regardless of the advances made in both the medical and surgical treatment of the disease. One of the contributing factors for the high mortality rate seen of pancreatic cancer patients is the lack of effective chemotherapies, which is believed to be due to drug-resistance. Based on recent evidence, epithelial-mesenchymal transition (ETM) of pancreatic cancer cells has been found to be associated with the development of drug resistance and an increase in cell invasion. Therefore, we conducted the present study in order to investigate the regulatory effects of Golgi protein-73 (GP73) on PC. GP73 and EMT-related gene expressions in PC, along with the adjacent and chronic pancreatitis tissues were determined by means of RT-qPCR and Western blot analysis. Cultured PC cells were treated with pAdTrack-CMV, si-NC, GP73 overexpression, Si-GP73, Snail-siRNA and GP73 + Snail-siRNA. Cell invasion, migration and metastasis were measured in vitro and in vivo. The results revealed that the PC tissues and chronic pancreatitis tissues exhibited diminished E-cadherin expression and amplified GP73, N-cadherin, Vimentin and Snail expression. In response to GP73 gene silencing, PC cells presented with increased E-cadherin expression and decreased N-cadherin, Vimentin, Snail expression in addition to the inhibition of the number of invasive cells, tumor volume and number of liver lesions. These findings highly indicated that the overexpression of GP73 promotes cell invasion, migration and metastasis by inducing EMT in PC.

[Label-free monitoring 5-FU induced SW 620 cells apoptosis using FTIR microspectroscopy].

The aim of the present study was to evaluate Fourier transform infrared spectroscopy (FTIR) monitoring of biochemical changes in apoptosis cells. Different concentrations of 5-fluorouracil (5-FU) treated colon cancer cell lines SW620 were used to determine the optimum concentration of 5-FU IC50 by means of MTT assay. Cell starvation and 5-Fu synergistic cell cycle arrest was in G1 and S phase. FTIR combined with flow cytometry was applied to analysis of SW 620 cells and SW620 cells treated with 5-FU for 12h, 24h (early apoptosis) and 48 h (late apoptosis) respectively. The peak position and the intensity of all bands were measured and comparison was made between the SW620 and apoptotic SW620 cells. Apoptosis cells have following characteristics compared with SW620 cells (1) The band at 1 740 cm-1 is an C=O stretching vibration. Changes in these bands can reflect lipid changes, and relative peak intensity ratio 11740/11460 significantly increased (p<0. 05), indicating that the relative contents of lipid in apoptosis cells increased. (2) The band at the 1 410 cm-1 peak represents that C-H stretching related was increased to amino acid residues and shifted to higher wave numbers compared to other groups. I1410o/I 460 at early and late death phase was significantly increased, which suggests that the relative contents of amino acid residues in apoptosis cells increased (p <0. 05). New vibrational bands at 1 120 cm-1 appeared at 24 h and increased at 48 h compared with other groups. The 1 120 cm-1 absorption band is mainly due to ser, serine and threonine C-O(H) stretching vibration, and I1120/I 1460 significantly increased (p<0. 05), indicating that the relative quantity of amino acid residues in apoptosis cells increased due to that DNA unwinds the double helix. (3) 1 240 cm-1 is mainly due to the asymmetric stretching modes of phosphodiester groups shifting to higher wave number, illustrating that nucleic acid conformation was changed in apoptosis cells. (4) The band 1 040 cm-1 associated with polysaccharide appeared at 24 and 48 h, meanwhile shifted to higher wave number, suggesting that polysaccharide decreased in late apoptotic cells, and I 1040/I1400 increased at late stage apoptosis, indicating that the relative content of polysaccharide in apoptosis cells increased. The authors' results suggest that FTIR applied to monitoring SW620 cells apoptosis may be as a potential diagnostic tool for cancer chemotherapy monitoring.

Fourier transform infrared spectroscopy of gallbladder carcinoma cell line.

BACKGROUND: Fourier transform infrared (FT-IR) spectroscopy is a physical method applied to the study of cellular changes at the molecular level in various normal and diseased human tissues, including cancer. This study was undertaken to establish a cellular basis for the diagnosis of carcinoma tissue, using FT-IR spectroscopy to study a carcinoma cell line and investigating the specific spectral features of the cell line. METHODS: The FT-IR spectra of cultured gallbladder carcinoma cells (GBC-SD) smeared on a BaF2 window were measured with a Nicolet Magna750-II FT-IR spectrometer. A comparative study was subsequently carried out between the spectra of cultured gallbladder carcinoma cells and those of corresponding carcinoma tissue. RESULTS: Several infrared spectral features were obtained, and the results suggest that the spectral features of the carcinoma cell line reflect those of carcinoma tissue, though the latter are more complex, probably due to the intrinsic complexity of the tissue. CONCLUSION: The diagnosis of carcinoma tissue by FT-IR spectroscopy has a sufficient cellular basis.

[FTIR spectroscopic study on gallbladder carcinoma cell and nucleus].

The aim of the present research is to establish the cell basis for the carcinoma tissue diagnosis by exploring a method to obtain the FTIR (Fourier transform infrared spectra) of the cultured carcinoma cell and nucleus with FTIR spectroscopy, and investigating the special spectral features of the carcinoma cell and nucleus compared with the carcinoma tissues. In this paper, the gallbladder carcinoma tissues confirmed by histology were measured using a Nicolet Magna 5700-II FTIR spectrometer and the corresponding FTIR spectra were obtained. The cultured gallbladder carcinoma cell (GBC-SD) and nucleus were centrifuged to provide a small pellet of cell and nucleus for FTIR analysis. The cell and nucleus pellet was then placed on the OMNIC sampler. Then the infrared spectra were recorded by the same equipment. Based on the previously established criteria, a comparative study was subsequently carried out between the spectra of the cultured carcinoma cell and nucleus (GBC-SD) and that of the corresponding gallbladder tissues. Several infrared spectral features of the carcinoma cell and nucleus were obtained. All the results suggest that the spectral features of the carcinoma cell and nucleus can be well reflected by that of the carcinoma tissue, though the later is more complicated, which might originate from the intrinsic complexity of the tissue. This study shows that the diagnosis of carcinoma tissue by FTIR method exhibits sufficient cell basis.

[Study on malignant and normal rectum tissues using IR and 1H and 31P NMR spectroscopy].

In the present paper, NMR spectroscopy, an effective tool to detect the variation in, molecular structure and changes in chemical composition of metabolites in tissues, was used to study the differences between malignant and normal tissues from rectum. 1H and 31P spectra of seven malignant rectum tissue samples and five normal control tissues were investigated by using a 300 M NMR spectrometers and compared with the results of the infrared spectra of normal and malignant rectum organ tissues. The results indicate that the 1H and 31P spectra of rectum cancer tissues are significantly different from those of the normal controls and most differences present in the form of variation in relative intensities of the characteristic peaks of various metabolites. Systematic differences in the NMR spectra between malignant tissues and normal controls are as follows: in the 1H NMR spectra, differences lie in fatty acids with the concentration of fatty acid decreasing significantly in malignant tissues. In the 31P NMR spectra, differences lie in phospholipid, with the chemical shift of phospholipid decreasing significantly in malignant tissues. This phenomenon may reflect the fact that the activity of protein synthesis is enhanced in cancerous tissues. The difference in the chemical shift of phospholipid between normal rectal tissue and malignant tissue may be considered as a detection criterion. Therefore, the above spectral variations in 31P NMR spectra may be utilized as a potential tool to diagnose rectum cancer.

[Study of malignant and normal tissues of the rectum using NMR spectroscopy].

In the present paper, NMR spectroscopy, an effective tool to detect the variation in molecular structure and changes in chemical composition of metabolites in tissues, was used to study the differences between malignant and normal tissues from rectum. 1H spectra of four malignant rectum tissue samples and two normal control tissues were investigated by using a 500M NMR high-resolution magic angle spinning magnetic resonance spectrometers (HR-MAS NMR). The results indicate that the 1H HR-MAS spectra of rectum cancer tissues are significantly different from those of the normal controls and most differences are presents in the form of variation in the relative intensities of the characteristic peak of various metabolites. In order to characterize the variation in the relative intensities in a quantitative manner, the intensity of the methyl peak of fatty acid at 0.88 was utilized as inner standard. Systematic differences between NMR spectra of malignant tissue and normal controls are as follows: (1) The concentration of amino acid increases significantly in malignant tissues, since the relative intensities of characteristic peaks of amino acid including valine, isoleucine, leucine, lysine, glutamate, glutamine, and aspartate are stronger in the NMR spectra of the malignant tissues. This phenomenon may reflect the fact that the activity of protein synthesis is enhanced in cancerous tissues. (2) The intensities of the characteristic peaks of lactic acid in malignant tissues are higher than those from normal controls. This may be related to the nature of anaerobic metabolism activity in malignant tissues. (3) The level of choline and its derivatives, taurine and creatine, increases significantly in malignant tissues, suggesting that the metabolic activity of malignant tissues changes. (4) In the spectral region between 4.5 and 10, observable changes occur on the peaks for unsaturated fatty acid and nuclear acids. Therefore, the above spectral variations in high resolution magic angle spinning NMR spectroscopy may be utilized as a potential tool to diagnose rectum cancer.

[FTIR spectroscopic study on carcinoma cells].

The aim of this research is to establish the cell basis for the carcinoma tissue diagnosis by exploring a method to obtain the FTIR (Fourier transform infrared) spectra of the cultured carcinoma cells with FTIR spectroscopy and investigating the special spectral features of the carcinoma cells compared with the carcinoma tissues. In the present paper, the gastric carcinoma tissues confirmed by histology were measured using a Nicolet Magna750-II FTIR spectrometer and the corresponding FTIR spectra were obtained. The cultured gastric carcinoma cells (SGC7901) were centrifuged to provide a small pellet of cells for FTIR analysis. The cell pellet was then placed on a specially designed salt plate made of BaF2. Then the infrared spectra were recorded by the same equipment. Based on the previously established criteria, a comparative study was subsequently carried out between the spectra of the cultured carcinoma cells (SGC7901) and that of the corresponding gastric tissues. Several infrared spectral features of the carcinoma cells were obtained: the different bands between cells and tissues locate in the range of 3 000-3 600 cm(-1) and 1 640 cm(-1) which are the range of the hydroxy stretching and blending bands of H2O. There are more H2O out of carcinoma cells in carcinoma tissues, so the strong bands of H2O cover the distinctive bands of carcinoma cells in carcinoma tissues. Although the carcinoma tissue is more complicated, which might originate from the intrinsic complexity of the tissue, the results suggest that the spectral features of the carcinoma cells can be well reflected by that of the carcinoma tissue. This study shows that the diagnosis of carcinoma tissue by FTIR method exhibits sufficient cell basis.

Effects of homeodomain protein CDX2 expression on the proliferation and migration of lovo colon cancer cells.

The homeobox gene, CDX2, plays a major role in development, especially in the gut, and also functions as a tumor suppressor in the adult colon. In the present study, we investigated the effects of CDX2 expression on the proliferation, migration, and apoptosis of the human colon cancer cell line, Lovo. Lovo cells exogenously expressing CDX2 exhibited no significant differences in the percentage of cells in G1- and S-phase or in apoptosis, as determined by flow cytometry. MTT assay also confirmed that CDX2 expression had no effect on proliferation in these cells. Interestingly, conditioned medium collected from CDX2-overexpressing Lovo cells showed a significant decrease in secretion of MMP-2 and the invasive potential of these cells was significantly inhibited. Collectively, these data suggest that CDX2 may play a critical role in the migration and metastasis of colon carcinoma and over-expression of CDX2 in colon cancer cells markedly inhibits invasion. Based on these results, exogenous expression of CDX2 might be a promising option in the treatment of colon carcinoma.