The melanoma differentiation-associated gene-7/interleukin-24 (MDA-7/IL-24) is a novel candidate of tumor suppressor, which can experimentally inhibit the proliferation of cancer cells and induce apoptosis of various human malignant cells.
Apoptosis ; Cell Proliferation ; Genetic Therapy ; methods ; Humans ; Interleukins ; biosynthesis ; genetics ; Neoplasms ; metabolism ; pathology ; therapy ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVE: To determine the effects of exogenous RASSF1A gene on the proliferation and expression of P65 and subunit of NF-kappaB, in lung adenocarcinoma cell line A549. METHODS: pcDNA3.0-RASSF1A and pcDNA3. 0 were introduced into A549 cell line by lipofectin transfection, and the A549 cells stably expressing RASSF1A gene were established by G418 selection. The expression of RASSF1A was detected by Western blotting. The cytobiologic characterizations of the positive clone were analyzed by methythiazoletertraolium (MTT) assay and cytometry. The expressing of P65 was analyzed by RT-PCR and Western blotting. RESULTS: A549 cells stably expressing RASSF1A protein were established by lipofection mediated transfection and selected for further study. Compared with the nontransfected and vector transfected cells, the positive clone cells grew more slowly. Flow cytometric data showed that more positive clone cells went into phase G0/G1 and fewer cells went into phase S. The expression of P65 in nuclear protein in positive clone cells was lower than that of the control group while there was no obvious difference between the expression of p65 mRNA and P65 protein in total protein among the 3 groups. CONCLUSION RASSF1A gene might suppress the proliferation of A549 cells through blocking the activity of P65 protein.
Adenocarcinoma ; genetics ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Humans ; Lung Neoplasms ; genetics ; pathology ; RNA, Messenger ; biosynthesis ; genetics ; Transcription Factor RelA ; biosynthesis ; genetics ; Transfection ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVETo study effects of alternative transcripts of ING1 transfection on human cancer cell lines.

METHODSp47/ING1A and p33/ING1B expression vehicles were constructed and introduced into a human breast cancer cell line MCF-7 and a human lung cancer cell line PAa, both expressing wild-type p53 protein. Growth characteristics of the transfectants and potentially related genes were analyzed.

RESULTSThe levels of p47/ING1A and p33/ING1B protein elevated respectively in tumor cells of MCF-7 and PAa after transfected with p47/ING1A and p33/ING1B, and the latter was much higher than that of the former. Ectopic overexpression of p33/ING1B effectively blocked tumor cell growth and arrested cells in the G(0) approximately G(1) phase of the cell cycle (P < 0.01), while p47/ING1A gave no effect on cell growth or cell cycle. Tumor cells overexpressing p33/ING1B contained more p21(WAF1) protein than that of the control cells, with undisturbed p53 protein level.

CONCLUSIONSExpression of two different transcripts of ING1 may have different effects on tumor cell growth. p33/ING1B may cooperate with p53 in stimulating expression of p21(WAF1) gene, thus to arrest cell cycle and to inhibit tumor cell growth. p33/ING1B may be considered to be a candidate as a partner of p53 in gene therapy.

Adenocarcinoma ; genetics ; metabolism ; pathology ; Alternative Splicing ; Breast Neoplasms ; genetics ; metabolism ; pathology ; Cell Cycle ; Cell Cycle Proteins ; Cell Division ; Cell Line, Tumor ; Cyclin-Dependent Kinase Inhibitor p21 ; Cyclins ; biosynthesis ; DNA-Binding Proteins ; Genes, Tumor Suppressor ; Humans ; Inhibitor of Growth Protein 1 ; Intracellular Signaling Peptides and Proteins ; Lung Neoplasms ; genetics ; metabolism ; pathology ; Nuclear Proteins ; Protein Biosynthesis ; Proteins ; genetics ; Transfection ; Tumor Suppressor Protein p53 ; biosynthesis ; Tumor Suppressor Proteins

To investigate the relationship between the expression of RASSF1A protein and promoter hypermethylation of RASSF1A gene, RASSF1A protein expression was measured by Western blotting in 10 specimens of normal bladder tissues and 23 specimens of bladder transitional cell carcinoma (BTCC). The promoter methylation in BTCC and normal bladder tissues was detected by methylation-specific PCR (MSP). The results showed that the expression level of RASSF1A protein was significantly lower in BTCC tissues than that in normal bladder tissues. However, it was not correlated with its clinical stages and pathological grades. The frequency of promoter methylation of RASSF1A gene was higher in BTCC tissues than that in normal bladder tissues. In 14 patients with the aberrant promoter methylation, 13 showed loss or low expression of RASSF1A protein. It is concluded that RASSF1A gene promoter methylation may contribute to the low level or loss of RASSF1A protein expression, the inactivation of RASSF1A gene and the genesis of BTCC. But, it may bear no correlation with its clinical stages and pathological grades.
Blotting, Western ; Carcinoma, Transitional Cell/metabolism ; DNA Methylation ; DNA Primers/chemistry ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Promoter Regions, Genetic ; Tumor Suppressor Proteins/*biosynthesis ; Tumor Suppressor Proteins/*genetics ; Urinary Bladder Neoplasms/*metabolism

Omics docking study for polygenic inheritance tumors has become an important strategy in oncology research. This review focuses on the conceptions and technologies of omics, and puts forward the central contents and omics docking for polygenic inheritance tumor to reveal the role of molecular changes at different stages of polygenic inheritance tumor at multidisciplinary and multilayer level. It is a new strategy to explore the mechanism of tumor carcinogenesis, and to regulate the network, key molecules, and drug target by combined biology effects.
Carrier Proteins ; biosynthesis ; genetics ; Genomics ; methods ; Glycoproteins ; biosynthesis ; genetics ; Humans ; Membrane Proteins ; biosynthesis ; genetics ; Multifactorial Inheritance ; genetics ; Neoplasms ; genetics ; metabolism ; Phosphoproteins ; biosynthesis ; genetics ; Proteomics ; methods ; Tumor Suppressor Proteins ; biosynthesis ; genetics

The gene for LPTS is originally cloned as a human liver-related putative tumor suppressor (LPTS) gene that encodes a full length protein of 328 amino acids (LPTS-L). LPTS-L is also identified as a telomerase inhibitor to regulate telomere length in the cells. To facilitate the functional and structural studies of LPTS-L protein, the cDNA for LPTS-L was cloned into the expression vector pET-24 in frame to generate a recombinant plasmid pET-24-LPTS. The LPTS-L protein was expressed in E. coli BL21 solublely, and purified by Ni Sepharose affinity chromatography which, however, is not fit for large scale protein purification. The gene of LITS-L was then PCR amplified to remove the 6 x His tag, and cloned into pET-24a. The non-fusion protein of LPTS-L was expressed in E. coli B21, and purified by phosphocellulose P11 chromatography. The purity of LPTS-L protein was about 55% after that procedure,and arrived at 80% after second purification by Sephadex G-100 chromatography. Western Blotting analysis showed that the band reflects the specific binding of anti-LPTS antiserum against the purified LPTS-L protein. The TRAP assay was performed to detect the telomerase inhibitory activity of LPTS-L protein in vitro. It was observed that the purified LPTS-L inhibited the activity of telomerase greatly, similarly with that of LPTS-L protein purified by Ni Sepharose 4B. Our results suggest that phosphocellulose P11 plus Sephadex G-100 chromatography could substitute for Ni Sepharose 4B affinity chromatography for preparation of purified LPTS-L protein. Through this study, a technique for preparation of LPTS-L protein in a large scale is established.
Animals ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Humans ; Recombinant Proteins ; biosynthesis ; genetics ; isolation & purification ; Recombination, Genetic ; Telomerase ; antagonists & inhibitors ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVETo study the expressions of p53 and Gadd45a proteins and their clinicopathological significance in human pancreatic cancer.

METHODSThe expression of p53 and Gadd45a proteins was detected with immunohistochemistry in a series of 59 pancreatic cancers. Their relationships with the clinicopathological parameters including gender, tumor site, TNM stage, histological differentiation, and the prognosis of pancreatic cancer patients were analyzed.

RESULTSThe positive expression rate of p53 protein was 67.8% (40/59) and that of Gadd45a protein was 42.4% (25/59). The positive expression rate of p53 protein is significantly higher in patients < 65 years than in patients > or = 65 years (chi squared = 4.711, P = 0.030). Gadd45a expression was not correlated to the age of the patients. No significant difference was found between the expression of p53 proteins and histological differentiation and TNM stage of the tumors. Gadd45a expression was correlated with histological differentiation of pancreatic cancer (chi squared = 10.052, P = 0.007), but not with TNM stage of the tumors. No significant differences in the prognosis were found between the groups with and without p53 expression (chi squared = 0.09, P = 0.764) and the groups with and without Gadd45a expression (chi squared = 0.14, P = 0.704).

CONCLUSIONSBoth p53 and Gadd45a are highly expressed in human pancreatic cancer and may be associated with biological features of pancreatic cancer. Their expression alone or co-expression may be not helpful to evaluate the prognosis of patients with pancreatic cancer.

Adult ; Aged ; Biomarkers, Tumor ; biosynthesis ; Carcinoma, Pancreatic Ductal ; metabolism ; pathology ; Cell Cycle Proteins ; biosynthesis ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Neoplasm Staging ; Nuclear Proteins ; biosynthesis ; Pancreatic Neoplasms ; metabolism ; pathology ; Tumor Suppressor Protein p53 ; biosynthesis

Adult ; Aged ; Biomarkers, Tumor ; biosynthesis ; genetics ; Carcinoma, Hepatocellular ; metabolism ; Cell Cycle Proteins ; biosynthesis ; genetics ; Cyclin-Dependent Kinase Inhibitor p27 ; Female ; Humans ; Liver Cirrhosis ; metabolism ; Liver Neoplasms ; metabolism ; Male ; Middle Aged ; Retinoblastoma Protein ; biosynthesis ; genetics ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVEResearch was done on the possible roles of beta-catenin, p53 and proliferating cell nuclear antigen (PCNA) in the carcinogenesis of colorectal adenoma (CRA).

METHODSbeta-catenin and p53 and PCNA expressions were studied with immunohistochemical stain in 77 specimens of CRA together with mild epithelial dysplasia (CRA-MD), CRA with moderate/severe epithelial dysplasia (CRA-D/SD) and CRA with cancerous changes (CRA-C).

RESULTSThe percentage of abnormal expression of beta-catenin increased during the transition from CRA-MD to CRA-D/SD to CRA-C (P < 0.01). The nuclear expressions of beta-catenin in CRA-D/SD and CRA-C were all significantly higher than that in CRA-MD. Expression of p53 and PCNA were increased from CRA-MD to CRA-D/SD to CRA-C, with the positive rates in these three groups of 10.3%, 43.8%, 75.0% for p53 and 17.2%, 62.5%, 87.5% for PCNA, respectively. 69.7% of cases with positive nuclear beta-catenin expression showed strong PCNA positivity which was much higher than the 36.4% of cases without nuclear beta-catenin expression (P < 0.05). The percentage of strong PCNA expression in the p53 positive cases was significant higher than that in cases with negative p53 expression (72.4% vs 37.5%, P < 0.05). Nuclear beta-catenin and p53 co-expression rates in CRA-C reached 50%.

CONCLUSIONbeta-catenin, p53 and PCNA may play important roles in the carcinogenesis of colorectal adenoma.

Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; biosynthesis ; Colorectal Neoplasms ; diagnosis ; metabolism ; Cytoskeletal Proteins ; biosynthesis ; Female ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Prognosis ; Proliferating Cell Nuclear Antigen ; biosynthesis ; Trans-Activators ; biosynthesis ; Tumor Suppressor Protein p53 ; biosynthesis ; beta Catenin

Adenocarcinoma ; genetics ; metabolism ; Adolescent ; Adult ; Aged ; Biomarkers, Tumor ; Child ; Child, Preschool ; DNA-Binding Proteins ; biosynthesis ; genetics ; Female ; Gastric Mucosa ; metabolism ; Genes, Tumor Suppressor ; Humans ; Male ; Middle Aged ; Nuclear Proteins ; biosynthesis ; genetics ; PTEN Phosphohydrolase ; biosynthesis ; genetics ; RNA, Messenger ; biosynthesis ; genetics ; Stomach Diseases ; genetics ; metabolism ; Stomach Neoplasms ; genetics ; metabolism ; Tumor Protein p73 ; Tumor Suppressor Proteins