Apoptosis of neoplasm cell lines induced by hepatic peptides extracted from sucking porcine hepatocytes

Morphology of apoptosis of human hepatocellular carcinoma cell line induced by 2-[(3-carboxy-1-oxoprogy1) amino]-2-deoxy-D-glucose

AIM: To investigate the changes of apoptosis in hepatocellular carcinoma cells induced by 2-[(3-carboxy-1-oxoprogy1) amino]-2-deoxy-D-glucose.

METHODS: Fluorescent microscopy and transmission electron microscopy were used to observe the morphologic changes of apoptosis with different concentration of2-[(3-carboxy-1-oxoprogy1) amino]-2-deoxy-D-glucose at different time.

RESULTS: The morphologic changes of apoptosis were exhibited, including shrinkage of cell, condensation of chromatin, breakage of nuclear and formation of apoptotic bodies, but the number of apoptosis increased with the concentration 2-[(3-carboxy-1-oxoprogy1) amino]-2-deoxy-D-glucose and time.

CONCLUSION: 2-[(3-carboxy-1-oxoprogy1) amino]-2-deoxy-D-glucose can induce apoptosis of human hepatocelluar carcinoma cells (HepG2).

Effects of Chinese Jianpi herbs on cell apoptosis and related gene expression in human gastric cancer grafted onto nude mice

AIM: To explore the mechanism of the Sijunzi decoction and another Chinese herbal recipe (SRRS) based mainly on the Sijunzi decoction in treatment of gastric cancer.

METHODS: A human gastric adenocarcinoma cell line SGC-7901 grafted onto nude mouse was used as the animal model. The mice were divided into 3 groups, one control and the two representative experimental conditions. Animals in the two experimental groups received either Sijunzi decoction or SRRS over a 40-day period starting at 1st day after grafting. Control animals received saline on an identical schedule. Animals were killed 41 d after being grafted. The effect of therapy was assessed by two ways: (1) tumor size was periodically measured during the life of the animals; (2) tumor weight was determined by a electron balance immediately after the animals killed. For detection of apoptotic cells, apoptotic indices (AI) were examined by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate fluorescence nick end labeling (TUNEL) method. Morphological alterations were observed with electron microscopy. S-P immunohistochemical method was used to detect the expression of Ki-67 in xenografts. Expression of bcl-2 and p53 was semiquantitatively detected using a reverse transcriptase-polymerase chain reaction (RT-PCR) technique.

RESULTS: When compared with controls, tumor growth (size and weight) was significantly inhibited by treatment with the Sijunzi decoction (P < 0.05) or SRRS (P < 0.01). The tumor inhibitory rate in the Sijunzi decoction group was 34.33% and SRRS group 46.53%. AI of human gastric cancer xenografts in nude mice was significantly increased to 16.24% ± 3.21% using TUNEL method and 11.38% ± 6.46% by FACScan in the Sijunzi decoction group compared with the controls (TUNEL: 2.63% ± 1.03%, P < 0.01; FACScan: 7.15% ± 1.32%, P < 0.05). SRRS group was also found a significantly increased AI by using TUNEL method and flow cytometry analysis compared with the controls (TUNEL: 13.18% ± 3.05%, P < 0.05; FACScan: 11.58% ± 5.71% (P < 0.05). Under electron microscope, cell shrinkage, nuclear chromatin condensation, formation of membrane blebs and apoptotic bodies were frequently observed in Sijunzi decoction group and SRRS group. The average labeling index (LI) for Ki-67 in SRRS group was significantly decreased to 8.43% ± 2.22% compared with the control group (10.37% ± 4.91%) (P < 0.05). The average labeling index for Ki-67 in sijunzi decoction group was 7.95% ± 2.54% which was lower than that of the control group, but showed no significance (P = 0.07). The expression level of p53 mRNA was lower in both Sijunzi decoction group and SRRS group than that in control group (P < 0.05; P < 0.01). The expression of bcl-2 mRNA was also decreased in SRRS group compared with the control (P < 0.01).

CONCLUSION: The inhibition of gastric cancer cell growth in vivo by Chinese Jianpi herbs and SRRS is related to induction of the cell apoptosis which may be involved in aberrant expression of p53 and bcl-2 genes.

Extraction and purification of TGFβ and its effect on the induction of apoptosis of hepatocytes

AIM: To extract and purify the transforming growth factor β (TGFβ), and to demonstrate its biological activity in vivo and induction of apoptosis of hepatocytes in vitro.

METHODS: TGFβ was isolated from fresh bovine platelets by acid/ethanol extraction method and purified with ion exchange and gel chromatography. The extracted TGFβ as injected subcutaneously to mice, and its biological activity in vivo was observed 72 hrs post-injection by HE staining. The morphological changes were observed by HE staining and the occurrence of apoptosis was detected by TUNEL method after the human normal hepatic cell line QZG was treated with 8 μg·L^-1TGFβ for 12 hrs in vitro.

RESULTS: The molecular mass 25 ku TGFβ protein was successfully extracted. It was able to induce localized granulation tissue formation in vivo. TGFβ-treated hepatocytes showed obvious apoptotic morphological changes, including the pyknosis and dense-stained nuclei and cytoplasm, the fragmentary, annular or crescent nuclei, and the “bubbling” cytoplasm. Moreover, its apoptotic rate was significantly higher than that of the control group (P < 0.05).

CONCLUSION: Biological active TGFβ protein is extracted and purified successfully from bovine platelets, and it is able to induce the apoptosis of hepatocytes.

Effect of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro

AIM: To study the effect of a varying concentrations of arsenic trioxide on human hepatoma cell line BEL-7402 cultured in vitro and its mechanism of action.

METHODS: The BEL-7402 cells were treated with arsenic trioxide (at the concentrations of 0.5, 1, 2 μmol/L, respectively) for 4 successive days. The cell growth and proliferation were observed by cell counting and cell-growth curve. Morphologic changes were studied with electronmicroscopy. Flow cytometry was used to assay cell-DNA distribution and the protein expression of Bcl-2 and Bax detected by immuno cytochemical method.

RESULTS: The cell growth was significantly inhibited by varying concentrations of arsenic trioxide as revealed by cell counting and cell-growth curve, which was dose- and time-dependent. Arsenic trioxide treatment at 0.5, 1 and 2 μmol/L resulted in a sub G1 cell peak, the apoptosis rate of the control group was 9.31% and that of 0.5 μmol/L arsenic trioxide 15.53%, no significant difference was seen between the two. The apoptosis rates of 1, 2 μmol/L arsenic trioxide were 19.10% and 21.87% respectively, which were much higher (both P < 0.05). Decrease of G₀/G₁ phase cells and increase of S phase cells were observed by flow cytometry, suggesting the inhibition effect of 0.5, 1, 2 μmol/L arsenic trioxide on BEL-7402 cell lay in the G₀/G₁ phase. Morphologic changes such as intact cell membrane, nucleic condensation, apoptotic body formation were seen under transmission electronmicrescopy, whereas the 0.5 mol/L arsenic trioxide-treated BEL-7402 cells showed decrease of nucleocytoplasmic ratio, round nucleus, well-differentiated organelles in the cytoplasm. The processes and microvilli on the cell surface of the experimental groups under scanning electron microscopy were significantly decreased. High expressions of Bcl-2 and Bax were detected in 1 and 2 μmol/L arsenic trioxide-treated cells, these were 46%, 87.33% and 83.08%, 95.83% respectively, among which that of Bax was more significant. Arsenic trioxide treatment at 0.5 μmol/L resulted in a higher expression level of Bcl-2 and lower expression level of Bax, which were 8.81% and 3.83% respectively, as compared with that of the control group (15.33%) (P₁ <0.01, P₂ < 0.01).

CONCLUSION: Arsenic trioxide not only inhibited proliferation but also induced apoptosis of human hepatoma cell line BEL-7402. The induced-apoptosis effect of 1, 2 μmol/L arsenic trioxide was related to the expression level of Bcl-2 and Bax.