Apoptotic mechanisms in rabbits with blast-induced acute lung injury

Abstract Purpose: To investigate the apoptotic mechanisms in rabbits with blast-induced acute lung injury (ALI). Methods: A total of 40 rabbits were randomly divided into a blank control group (A, n=10) and an experimental group (EXP, n=30). Explosion-induced chest-ALI models were prepared and sampled at different time points (4, 12, and 24h after modeling, T1-T3) to test the lung dry weight/wet weight ratio (W/D) and arterial oxygen pressure (PaO2), apoptosis of lung tissue by the TUNEL assay, and Caspase-3, Bax, and Bcl-2 levels by immunohistochemical analysis. Furthermore, lung tissue was sampled to observe pathological morphology by microscopy. Results: Under a light microscope, Group EXP exhibited obvious edema in the pulmonary interstitial substance and alveoli, a large number of red blood cells, inflammatory cells, and serous exudation in the alveolar cavity, as well as thickening of the pulmonary interstitial fluid. Compared to Group A, the W/D ratio was significantly increased in Group EXP (P<0.01), while PaO2 was significantly reduced (P<0.01). The apoptosis index was significantly increased (P<0.01), and caspase-3 and Bax/Bcl-2 levels were increased (P<0.01). Conclusion: Apoptosis plays an important role in the occurrence and development of acute lung injury in rabbits by participating in lung injury and promoting the progression of ALI.

Inducible T-cell co-stimulators regulate the proliferation and invasion of human hepatocellular carcinoma HepG2 cells

Abstract Background This study determined the regulatory effects of inducible T-cell co-stimulators (ICOS) in human hepatocellular carcinoma HepG2 cells using a RNA interference (RNAi) technique. Methods A RNAi technique was used to knockdown the expression of ICOS. ICOS expression after knockdown was detected as mRNA and protein levels by RT-PCR and Western blot, respectively. A MTT colorimetric assay was used to detect cell proliferation, and the Transwell assay was used to detect cell invasion. Western blot was carried out to detect the level of Bcl-2, AKT, and PI3K protein expression in different groups. Results The proliferation of HepG2 cells were significantly decreased after ICOS siRNA transfection (EG group). Similarly, the results of the Transwell experiment showed that invasion of HepG2 cells in the EG group was clearly reduced compared to the negative control (NC) and blank control groups (CON). Western blot analysis showed that knockdown of ICOS expression reduced the levels of Bcl-2 and AKT, and also significantly up-regulated the level of PI3K phosphorylation (P < 0.01). Conclusion Down-regulating ICOS expression in HepG2 cells suppressed cell proliferation and invasion. The underlying mechanism may be related to the expression of the downstream factor, PI3K/AKT.

Detection of B cell lymphoma 2, tumor protein 53, and FAS gene transcripts in blood cells of patients with breast cancer.

Background: Proteins encoded by FAS, BCL-2 and TP53 genes are major regulators of cellular survival and apoptosis. Results of recent investigations show remarkable biological features of these factors, which propose their role in the course of cancer. Therefore, it is plausible to test whether transcripts of these genes could be detected in the peripheral blood cells of patients with breast cancer. Materials and Methods: Real-time polymerase chain reaction assay was performed to detect FAS, BCL-2, and TP53 gene transcripts in the peripheral blood samples of 50 women with histologically confirmed infiltrative ductal carcinoma of the breast. Gene expression of patients was compared with 40 healthy women without history of malignancies or autoimmune disorders. Results: The relative overexpression of BCL-2 in the blood cells from patients of early stages (I and II), nonmetastatic and low-grade tumors compared with healthy individuals, was shown by measuring the gene transcript. Similarly, 3-4-fold higher expression of FAS was found in those patients. The measurement of TP53 transcripts also showed higher levels of gene expression in patients compared with healthy controls. BCL-2 gene expression showed a significant correlation with FAS, while such a correlation was not observed between BCL-2 and TP53 . Conclusion: It seems tumor cells overexpress BCL-2 to inhibit apoptosis and guarantee their cell survival. As a physiologic response, FAS and TP53 could be upregulated to suppress tumors. However, these pathways at early stages of disease may be inadequate and cause progressive malignancy.

Serum levels of bcl-2 and cellular oxidative stress in patients with viral hepatitis.

PURPOSE: This study was conducted to investigate the presence of bcl-2 protein in the serum of patients with viral hepatitis and to find out if there is any correlation between bcl-2 protein levels and cellular oxidative stress in the pathogenesis of viral hepatitis. METHODS: This study was carried out on 130 patients with viral hepatitis, 70 with chronic hepatitis, 30 with liver cirrhosis and 30 with hepatocellular carcinoma (HCC) in addition to 20 healthy persons as the control. Serum bcl-2 protein was estimated by enzyme-linked immunosorbent assay, serum malondialdehyde (MDA), nitric oxide (NO) and antioxidant enzymes (GSH, GSH-px, GR and SOD) were measured using spectrophotometric analysis. RESULTS: bcl-2 protein level was significantly elevated in the serum of HCC, cirrhosis and chronic hepatitis groups as compared to control group. There were significant positive correlations between higher bcl-2 protein level and viral hepatitis markers (HBsAg, anti-HCV antibodies) in HCC and cirrhotic patients as compared to chronic hepatitis group. An increase in oxidative stress markers (MDA, NO) and a decrease in antioxidant enzyme activities (SOD, GSH and GSH-px) were observed. However, there was a negative correlation between bcl-2 levels and GR in all studied patient groups. CONCLUSIONS: The release of oxidative free radicals, deficiency in antioxidant enzymes and the expression of bcl-2 protein might play a role in the pathogenesis of viral hepatitis. The ability to measure bcl-2 protein in the serum could be useful as a prognostic marker of cancer patients.

Evaluation of p53, bcl-2 Proteins and DNA Ploidy in Squamous and Transitional Cell Carcinomas of Urinary Bladder

The study covered 33 urinary bladder carcinoma cases, where mutated p53 nuclear protein and bcl-2 gene products were evaluated. Image analysis proved the correlation between genopathologic alterations and DNA ploidy. Immunohistochemistiy technique and Feulgen stain methods were applied to paraffin embedded tissue sections. Squamous cell carcinoma [Squ.C.C.] was diagnosed in 19 biopsies and transitional cell carcinoma [T.C.C.] in 14 biopsies. In Squ.C.C group, 10 cases [52.6%] demonstrated nuclear accumulation of mutated p53 protein with significant correlation to the advanced stage and high grade tumors [p=0.03 and 0.0001, respectively]. On the contrary, cytoplasmic expression of bcl-2 was detected in 7 cases [36.8%]. Dual expression of both biomarkers was observed in 2 cases. In T.C.C group, a single case [7.1%] was positive for p53 nuclear reactivity and S cases [35.7%] demonstrated bcl-2 cytoplasmic expression. In both groups, all p53 positive carcinomas comprised significant correlation to aneuploid histograms of DNA distribution patterns. However, 11 out of 12 bcl-2 positive cases [91.6%] demonstrated poliferative diploid histograms with a wide S-phase. It was concluded that, p53 was significantly expressed in Squ C.C. versus T.C.C. and was associated with advanced stage, high grade and aneuploid DNA. On the other hand, bcl-2 expression displayed insignificant difference in both groups of tumor

Expression of cell regulatory proteins C-erb B-2 and Bcl-2 in epithelial ovarian tumors

Ovarian cancer remains the leading cause of death from gynecologic malignancy in many countries. Lack of symptoms in the early stages of disease with consequent delay in diagnosis continues to result in poor overall survival. The expression of cell regulatory proteins was studied in an attempt to find the role of these proteins in differential diagnosis and progression of ovarian tumors. Sixty five cases with epithelial ovarian tumors [35 serous, 24 mucinous, 4 cases endometroid carcinomas and 2 cases were undifferentiated tumors were evaluated for expression of c-erbB-2 and bcl-2 by immunohistochemical technique and correlated with clinical parameters such as type, grade, and stage-Expression of c-erbB2 was significantly differed among the various types of ovarian tumors [p=0.01], highly expressed in undifferentiated, high grade, and advanced stage tumors in contrast to its weak expression or loss in benign, variety. While the bcl-2 was significantly lost in more aggressive tumors but strong expression was observed in benign lesions .p=0.01. In ovarian tumors, proto-oncogene c-erbB-2 and antiapoptotic gene bcl-2 had a role in behavior and differentiation of these tumors