Atorvastatin induces autophagy in MDA-MB-231 breast cancer cells.

This article explores the effects of atorvastatin on cultured breast cancer cells. Our experiment demonstrated that atorvastatin triggered autophagy and inhibited proliferation in breast cancer cells. A CCK8 assay indicated that atorvastatin can inhibit the activity of MDA-MB-231 breast cancer cells. Western blotting results showed that atorvastatin increased the conversion of light chain 3 (LC3)-I to LC3-phosphatidylethanolamine conjugate (LC3-II). Confocal microscopy was used to reveal the appearance of a punctate structure in the cytoplasm, and electron microscopy was used to reveal the formation of double-membrane autophagosome. In conclusion, our study showed that atorvastatin may affect MDA-MB-231 breast cancer cells by inducing autophagy.

The effects of X-ray irradiation on the proliferation and apoptosis of MCF-7 breast cancer cells.

To investigate the effects of X-ray irradiation on the proliferation and apoptosis of MCF-7 breast cancer cells; MCF-7 breast cancer cells were irradiated with X-ray. After irradiation, morphological changes and growth inhibition rate of the irradiated cells were observed under an inverted microscope. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to assess the proliferation of the irradiated MCF-7 cells. Transmission electron microscope was used to observe the morphology and ultrastructure of the irradiated MCF-7 cells. Western blotting was used to analyze the expression level of apoptosis-related protein caspase-3. Our results showed, at 48 h after the irradiation (0 Gy and 8 Gy), cells oval in shape, cell shrinkage or swelling and partial formation of debris under inverted microscope; as well as cytoplasmic vacuolization or inspissation, increased electron density of cytoplasm, structural damage of organelles, blurred mitochondrial cristae and chromatin margination under transmission electron microscopy; the survival rate of MCF-7 cells in X-ray group was 17.3% lower than that in control group (0 Gy) (p < 0.001); while caspase-3 expression increased evidently in X-ray group compared with control group (0 Gy) (p < 0.05). In conclusion, X-ray irradiation can inhibit the proliferation of MCF-7 cells and induce apoptosis through increasing caspase-3 expression.

[Clinical significance of detecting lymph node micrometastasis of colorectal cancer by reverse transcriptase-polymerase chain reaction (RT-PCR)].

BACKGROUND & OBJECTIVE: It remains controversial whether lymph node micrometastasis has impact on staging and prognosis of colorectal cancer. This study was to compare the sensitivity of reverse transcriptase- polymerase chain reaction (RT-PCR) in detecting lymph node micrometastasis of colorectal cancer with pathological morphology and immunohistochemistry, and assess the impact of lymph node micrometastasis on clinical staging and prognosis of colorectal cancer. METHODS: Lymph nodes from 56 cases of colorectal cancer radical resection specimens were studied by RT-PCR to detect the expression of cytokeratin 20 (CK20) mRNA, and compared with routine pathology detection using hematoxylin and eosine (HE) staining, and immunohistochemistry using monoclonal antibody specifically against CK20. The patients had been followed up for 5 years. RESULTS: A total of 432 lymph nodes in 56 patients were analysed by pathological morphology, immunohistochemistry, and RT-PCR, the detected positive lymph node numbers were 247 (57.2%), 269 (62.3%), and 316 (73.1%), respectively. The difference in metastatic lymph node numbers was significant between pathological morphology and RT-PCR method (P< 0.05). Five-year disease- free survival rates of PN0,PN1, and PN2 stages detected by RT-PCR method were 100%, 61.9%, and 55.6%, respectively, significantly higher than those obtained by pathological morphology method, which were 80.0%, 60.0%, and 50.0%, respectively (P< 0.05). CONCLUSIONS: Detecting lymph node micrometastasis of colorectal cancer with RT-PCR method is more sensitive than pathological morphology. RT-PCR method could define the TNM stage and make accurate prognosis for patients with colorectal cancer.

gamma-hydroxybutyrate protects the liver from warm ischemia-reperfusion injury in rat.

BACKGROUND: Ischemia-reperfusion (I/R) syndrome remains an important clinical consideration in hepatic surgery, hemorrhagic shock, and liver transplantation. gamma-hydroxybutyrate (GHB) has been reported to exert protective effects against ischemia-reperfusion injury to various organs. To investigate whether GHB protects the liver from warm ischemia-reperfusion injury, we performed this study in rats. METHODS: Thirty male Wistar rats were randomly divided into a sham-operation group, a control group,and three I/R groups pretreated with GHB, GHB plus naloxone or naloxone. After 30 minutes of partial ischemia, followed by 60 minutes of reperfusion in the liver, histomorphological and enzymological changes, lipid peroxidation, apoptosis, and the plasma level of endothelin-1 were observed. RESULTS: I/R increased the serum levels of alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase and the plasma level of endothelin-1 significantly (P<0.01), in addition to increase of apoptotic index (AI) from 0.28%+/-0.25% to 17.68%+/-1.91%. The levels of hepatic malondialdehyde were markedly increased, whereas the activities of superoxide dismutase were markedly decreased. GHB pretreatment prevented the liver from warm ischemia-reperfusion injury significantly, but naloxone partially blocked this effect. CONCLUSION: GHB may significantly protect the liver from hepatic warm ischemia-reperfusion injury via several different mechanisms.

Transforming growth factor-beta1 in invasion and metastasis in colorectal cancer.

AIM: To investigate the role of TGFbeta1 in invasion and metastasis in colorectal cancer by analysing TGFbeta1 correlated with depth of tumor invasion, stage and metastasis. METHODS: Serum TGFbeta1 levels were determined in 50 patients with colorectal cancer and 30 healthy volunteers using a TGFbeta1 enzyme-linked immunosorbent assay. TGFbeta1 expression in primary and lymph node metastatic lesions were detected in 98 cases of colorectal cancer by immunohistochemical staining and in situ hybridization. RESULTS: Serum levels of TGFbeta1 in patients with colorectal cancer(40+/-18 microg.L(-1)) were significantly higher than those in the healthy control group(19+/-8 microg.L(-1)), P<0.05. Elevated levels of serum TGFbeta1 were found in 60 % of patients with colorectal cancer when the mean +2 s was used as the upper limit of the normal range (35.1 microg.L(-1)). Increases in serum TGFbeta1 levels were significantly associated with Duke's stage (P<0.05), but there was no significant difference between Duke's stage B patients and Duke's stage C patients. In the cytoplasm of cancer cells, TGFbeta1 was immunostained in 37.8 % (37/98) of colorectal cancer, and this expression was confirmed by in situ hybridization. Among 35 cases of colorectal cancer with lymph node metastatic lesions, TGFbeta1 positive staining was found in 18 (51.4 %) cases of primary tumor, and 25 (71.4 %) cases with lymph node metastatic lesions, respectively. Of 17 cases w ith no staining in the primary lesion, 7 (41.2%) casesshowed TGFbeta1 staining in the metastatic lesion. Serum TGFbeta1 levels and TGFbeta1 expression in colorectal cancer tissues were correlated significantly with depth of tumor invasion, stage and metastasis. Patients in stage C-D,T3-T4 and with metastasis had significantly higher TGFbeta1 levels than patients in stage A-B,T1-T2 and without metastasis (P<0.05). CONCLUSION: These results suggest that transforming growth factor-beta1 is closely related to the invasion and metastasis of colorectal cancer. It increased the invasive and metastatic potential of tumor by altering a tumor microenvironment. TGFbeta1 may be used as a possible biomarker.