Expression pattern and level of ING5 protein in normal and cancer tissues.

Inhibitor of growth family 5 (ING5) functions as a type-II tumor suppressor gene and exerts an important role in DNA repair, apoptotic induction, proliferative inhibition, chromatin remodeling and the invasion process. In the present study, immunohistochemistry was performed to characterize the expression profile of ING5 protein on a tissue microarray containing mouse and human normal tissues, and human cancer tissues, including hepatocellular (n=62), renal clear cell (n=62), pancreatic (n=62), esophageal squamous cell (n=45), cervical squamous cell (n=31), breast (n=144), gastric (n=196), colorectal (n=96), endometrial (n=96) and lung carcinoma (n=192). In the mouse tissues, ING5 expression was detected in the cytoplasm of neurons, the nephric tubule and glomerulus, alveolar epithelium, gastrointestinal glands, squamous epithelium of the skin and skeletal muscles. By contrast, ING5 was localized to the cell nucleus in breast tissues. In human tissues, ING5 protein was primarily localized in the cytoplasm. However, ING5 was detected in the cytoplasm and nucleus in various types of normal tissues, including the tongue, stomach, intestine, lung and breast. In total, ING5 expression was detected in 400/986 cancer tissues (40.6%). In the majority of cases, ING5 expression was observed to be restricted to the cytoplasm. However, ING5 was also detected in the nucleus in a number of cancer tissues, including gastric, colorectal and lung carcinoma. Notably, ING5 was more frequently expressed in breast (79.9%), colorectal (56.3%) and endometrial carcinoma (50.0%). The incidence of ING5 expression in hepatocellular carcinoma (14.5%) and pancreatic carcinoma (22.6%) was low. These findings indicate that ING5 may be involved in cell regeneration and be associated with colorectal carcinogenesis.

Effects and mechanism of STAT3 silencing on the growth and apoptosis of colorectal cancer cells.

Signal transducer and activator of transcription 3 (STAT3) have roles in various cellular processes, including angiogenesis, apoptosis, cell cycle progression, cell migration and drug resistance. To clarify the effects of STAT3 in colorectal cancer (CRC) cells and the underlying molecular mechanisms, STAT3 was directly silenced, and the effects of STAT3 silencing on cell proliferation, apoptosis and growth with phenotype-associated molecules were examined.pSH1-Si-STAT3 was successfully transfected into the CRC HCT-116 and SW480 cell lines, which was verified by GFP tagging under a fluorescence microscope. An MTT assay revealed that the proliferation of both cell lines that were transfected with pSH1-Si-STAT3 was significantly suppressed in comparison with the control and mock (P<0.05). Acridine orange/ethidium bromide staining and flow cytometry indicated that the transfected cell lines had a significantly higher rate of apoptosis than the control- and mock-treated cells (P<0.05). STAT3-silienced cells were also significantly arrested at the G2/M stage compared with the cells that were transfected with control and mock plasmids (P<0.05). At the mRNA level, the expression of STAT3 and survivin was significantly downregulated (P<0.05), but p53 and caspase-3 were significantly upregulated (P<0.05). The significantly different patterns of expression were observed in western blot analysis (P<0.05). The findings of the present study indicate that STAT3 silencing may suppress the proliferation and growth of CRC cells, and induce their apoptosis by upregulating the expression of survivin, p53 and caspase-3. Therefore, STAT3 may be a good candidate for CRC gene therapy.

Immunohistochemical profile of ING3 protein in normal and cancerous tissues.

The inhibitor of growth family, member 3 (ING3) protein may be capable of blocking the cell cycle via activating p53-transactivated promoters of p21 and Bcl2-associated X protein, and may induce apoptosis via a Fas/caspase-8-dependent signaling pathway. In the present study, immunohistochemistry was performed in order to characterize the expression profile of ING3 protein in tissue microarrays containing mouse and human normal tissue, human hepatocellular (n=62), renal clear cell (n=62), pancreatic (n=62), esophageal squamous cell (n=45), cervical squamous cell (n=31), breast (n=144), gastric (n=196), colorectal (n=96), ovarian (n=208), endometrial (n=96) and lung carcinoma (n=192). In mouse tissue, ING3 protein was positively detected in the cytoplasm of cardiomyocytes, kidney and skeletal muscle cells, and was additionally detected in the cytoplasm and nucleus of bronchial and alveolar epithelium, gastric and intestinal gland, and mammary gland cells. In human tissues, ING3 protein was principally distributed in the cytoplasm, but was observed in the cytoplasm and nucleus of tongue, esophagus, stomach, intestine, lung, skin, appendix, bladder, cervix and breast cells. ING3 immunoreactivity was strongly detected in the stomach, skin and cervical tissues, whereas a weak signal was detected in the cerebellum, brain stem, thymus, liver, skeletal muscle, testis and prostate. In total, ING3-positive specimens were identified in 424 of 1,194 tested cancer entities (35.5%). In a number of cases, ING3 expression was observed to be restricted to the cytoplasm and nucleus, excluding the cytoplasmic distribution identified in breast and hepatocellular carcinoma. Among these cases, ING3 was more frequently expressed in breast and gynecological types of cancer, including ovarian (59.2%), endometrial (47.9%), breast (38.9%) and cervical (35.5%) cancer. ING3-positive cases were more rare in renal clear cell (17.7%), hepatocellular (16.1%) and esophageal carcinoma (17.8%). It is suggested that ING3 may be involved in the repair and regeneration of organs or tissues, and may be closely associated with gynecological carcinogenesis.

BTG1 might be employed as a biomarker for carcinogenesis and a target for gene therapy in colorectal cancers.

Here, BTG1 overexpression inhibited proliferation, induced differentiation, autophagy, and apoptosis in colorectal cancer cells (p<0.05). BTG1 overexpression reduced mitochondrial membrane potential and caused senescence in HCT-116 transfectants (p<0.05). BTG1-induced G2 arrest might be related to Cyclin B1 and Cdc25B hypoexpression in HCT-15 transfectants, while G1 arrest in HCT-116 transfectants overexpressing p21 and p27. BTG1 overexpression decreased the expression of Bcl-2, Bcl-xL, XIAP, Akt1 or survivin and increased the expression of Bax or p53 in colorectal cancer cells. BTG1-induced autophagy was dependent on Beclin-1 expression. BTG1 overexpression might weaken ß-catenin pathway in colorectal cancer cells. The chemosensitivity of BTG1 transfectants to paclitaxel, cisplatin, MG132 or SAHA was positively correlated with its apoptotic induction. There was a lower expression level of BTG1 in cancer than matched non-neoplastic mucosa by RT-PCR (p<0.05), while versa for Western blot and immunohistochemical data (p<0.05). BTG1 overexpression significantly suppressed the growth of HCT-15 and HCT-116 via inhibiting proliferation, inducing apoptosis and autophagy in nude mice. Up-regulated BTG1 expression plays an important role in colorectal carcinogenesis as a potential biomarker. BTG1 expression might reverse aggressive phenotypes, so it might be employed as a target of gene therapy for colorectal cancer.

The down-regulated ING5 expression in lung cancer: a potential target of gene therapy.

ING5 can interact with p53, thereby inhibiting cell growth and inducing apoptosis. We found that ING5 overexpression not only inhibited proliferation, migration, and invasion, but also induced G2 arrest, differentiation, autophagy, apoptosis, glycolysis and mitochondrial respiration in lung cancer cells. ING5 transfection up-regulated the expression of Cdc2, ATG13, ATG14, Beclin-1, LC-3B, AIF, cytochrome c, Akt1/2/3, ADFP, PFK-1 and PDPc, while down-regulated the expression of Bcl-2, XIAP, survivin,ß-catenin and HXK1. ING5 transfection desensitized cells to the chemotherapy of MG132, paclitaxel, and SAHA, which paralleled with apoptotic alteration. ING5 overexpression suppressed the xenograft tumor growth by inhibiting proliferation and inducing apoptosis. ING5 expression level was significantly higher in normal tissue than that in lung cancer at both protein and mRNA levels. Nuclear ING5 expression was positively correlated with ki-67 expression and cytoplasmic ING5 expression. Cytoplasmic ING5 expression was positively associated with lymph node metastasis, and negatively with age, lymphatic invasion or CPP32 expression. ING5 expression was different in histological classification: squamous cell carcinoma > adenocarcinoma > large cell carcinoma > small cell carcinoma. Taken together, our data suggested that ING5 downregulation might involved in carcinogenesis, growth, and invasion of lung cancer and could be considered as a promising marker to gauge the aggressiveness of lung cancer. It might be employed as a potential target for gene therapy of lung cancer.

The upregulated α-catulin expression was involved in head-neck squamous cell carcinogenesis by promoting proliferation, migration, invasion, and epithelial to mesenchymal transition.

Rho signaling component, α-catulin, is a cytoskeletal linker protein and plays an important role in apoptotic and senescence resistance, cytoskeletal reorganization, mobility, invasion, and epithelial to mesenchymal transition (EMT) of cancer cells. Here, we transfected α-catulin-expressing plasmid into head and neck squamous cell carcinoma (HNSCC) cell and examined the phenotypes and relevant molecules. α-catulin expression was detected on tissue microarray containing squamous epithelium, dysplasia, and cancer of head and neck by immunohistochemistry. It was found that α-catulin overexpression resulted in faster growth, migration and invasion, lower apoptosis, G2/M progression, and EMT than the mock and control (P < 0.05). α-catulin overexpression increased the expression of Cyclin E1, cdc2, survivin, Bcl-2, MMP-2, MMP-9, and N-cadherin but decreased the expression of Caspase-3 and E-cadherin by real-time PCR (P < 0.05). α-catulin expression was stronger in primary cancers than those in normal squamous epithelium and dysplasia (P < 0.05), but not correlated with aggressive behaviors or adverse prognosis of HNSCC patients (P > 0.05). Multivariate survival analysis showed that distant metastasis and TNM staging were independent prognostic factors for overall survival of the HNSCC patients (P < 0.05). These data indicated that upregulated expression of α-catulin protein might have impact on the tumorigenesis of HNSCC possibly by reducing apoptosis, enhancing proliferation, cell cycle progression, migration, invasion, and EMT. It might be regarded as a potential marker for head and neck carcinogenesis or a target of gene therapy for HNSCCs.

The roles of parafibromin expression in ovarian epithelial carcinomas: a marker for differentiation and prognosis and a target for gene therapy.

Parafibromin is a protein encoded by hyperparathyroidism 2 (HRPT2) and its downregulated expression is involved in the pathogenesis of parathyroid, breast, gastric, colorectal, lung, head and neck cancers. We aimed to investigate the roles of parafibromin expression in tumorigenesis, progression, or prognostic evaluation of ovarian cancers. HRPT2-expressing plasmid was transfected into ovarian cancer cells with the phenotypes and related molecules examined. The messenger RNA (mRNA) and protein expression of parafibromin were also examined in ovarian normal tissue, benign and borderline tumors and cancers by reverse transcription-polymerase chain reaction (RT-PCR), Western blot, or immunohistochemistry respectively. It was found that parafibromin overexpression caused a lower growth, migration and invasion, higher sensitivity to cisplatin and apoptosis than the mock and control (P < 0.05). The transfectants showed the hypoexpression of phosphoinositide 3-kinase (PI3K), Akt, p70 ribosomal protein S6 kinase (p70s6k), Wnt5a, B cell lymphoma-extra large (Bcl-xL), survivin, vascular endothelial growth factor (VEGF) and matrix metallopeptidase 9 (MMP-9) than the mock and control at both mRNA and protein levels (P < 0.05). According to real-time PCR, parafibromin mRNA level was lower in ovarian benign tumors and cancers than normal ovary (P < 0.05), while parafibromin was strongly expressed in metastatic cancers in omentum than primary cancers by Western blot. Immunohistochemically, parafibromin expression was stronger in primary cancers than that in ovarian normal tissue (P < 0.05) but weaker than the metastatic cancers (P < 0.05) with a positive correlation with dedifferentiation, ki-67 expression and the lower cumulative survival rate (P < 0.05). These findings indicate that parafibromin downregulation might promote the pathogenesis, dedifferentiation and metastasis of ovarian cancers possibly by suppressing aggressive phenotypes, such as proliferation, cell cycle, apoptosis, migration and invasion.

The clinicopathological significances and biological functions of parafibromin expression in head and neck squamous cell carcinomas.

Downregulated parafibromin expression is involved in the pathogenesis and progression of parathyroid, breast, gastric, colorectal, and lung cancers. To investigate the roles of parafibromin expression in tumorigenesis, progression, and prognostic evaluation of head and neck squamous cell carcinomas (HNSCCs), we transfected parafibromin-expressing plasmid into HNSCC cell and examined the phenotypes and their relevant molecules. Parafibromin expression was detected on tissue microarray containing squamous epithelium, dysplasia, and carcinoma of head and neck by immunohistochemistry. Parafibromin overexpression was found to suppress growth, migration, and invasion, and induce apoptosis, S arrest, and mesenchymal to epithelial transition (EMT), compared with the mock and control (P < 0.05). Both overexpression of Cyclin E1, Bax, and E-cadherin and hypoexpression of c-myc, Bcl-xL, and slug were detected in B88 transfectants, in comparison to mock and control by real-time PCR. Parafibromin expression was weaker in primary cancers than those in normal squamous tissue and dysplasia (P < 0.05), but stronger than the metastatic cancers in lymph node (P < 0.05). Parafibromin expression was negatively correlated with lymph node metastasis, tumor-node-metastasis (TNM) staging, but positively with human papillomavirus (HPV) positivity (P < 0.05). The HNSCCs in tongue showed more parafibromin expression than those in larynx (P < 0.05). There was stronger parafibromin expression in moderately-than poorly-differentiated carcinomas (P < 0.05). The significantly positive correlation was observed between parafibromin expression and relapse-free survival rate by Kaplan-Meier curves (P < 0.05). Cox's proportional hazard model indicated that distant metastasis and parafibromin expression were independent prognostic factors for overall and relapse-free survival of HNSCC, respectively (P < 0.05). These findings suggest that downregulated expression of parafibromin protein plays an important role in the pathogenesis, differentiation, and metastasis of HNSCCs possibly by inducing apoptosis, suppressing proliferation, cell cycle progression, migration, invasion, and EMT. Parafibromin expression is an independent factor for relapse-free survival of HNSCCs.

BTG1 expression correlates with pathogenesis, aggressive behaviors and prognosis of gastric cancer: a potential target for gene therapy.

Here, we found that BTG1 overexpression inhibited proliferation, migration and invasion, induced G2/M arrest, differentiation, senescence and apoptosis in BGC-823 and MKN28 cells (p < 0.05). BTG1 transfectants showed a higher mRNA expression of Cyclin D1 and Bax, but a lower mRNA expression of cdc2, p21, mTOR and MMP-9 than the control and mock (p < 0.05). After treated with cisplatin, MG132, paclitaxel and SAHA, both BTG1 transfectants showed lower mRNA viability and higher apoptosis than the control in both time- and dose-dependent manners (p < 0.05) with the hypoexpression of chemoresistance-related genes (slug, CD147, GRP78, GRP94, FBXW7 TOP1, TOP2 and GST-π). BTG1 expression was restored after 5-aza-2'-deoxycytidine treatment in gastric cancer cells. BTG1 expression was statistically lower in gastric cancer than non-neoplastic mucosa and metastatic cancer in lymph node (p < 0.05). BTG1 expression was positively correlated with depth of invasion, lymphatic and venous invasion, lymph node metastasis, TNM staging and worse prognosis (p < 0.05). The diffuse-type carcinoma showed less BTG1 expression than intestinal- and mixed-type ones (p < 0.05). BTG1 overexpression suppressed tumor growth and lung metastasis of gastric cancer cells by inhibiting proliferation, enhancing autophagy and apoptosis in xenograft models. It was suggested that down-regulated BTG1 expression might promote gastric carcinogenesis partially due to its promoter methylation. BTG1 overexpression might reverse the aggressive phenotypes and be employed as a potential target for gene therapy of gastric cancer.

ING5 suppresses proliferation, apoptosis, migration and invasion, and induces autophagy and differentiation of gastric cancer cells: a good marker for carcinogenesis and subsequent progression.

Here, we found that ING5 overexpression increased autophagy, differentiation, and decreased proliferation, apoptosis, migration, invasion and lamellipodia formation in gastric cancer cells, while ING5 knockdown had the opposite effects. In SGC-7901 transfectants, ING5 overexpression caused G1 arrest, which was positively associated with 14-3-3 overexpression, Cdk4 and c-jun hypoexpression. The induction of Bax hypoexpression, Bcl-2, survivin, 14-3-3, PI3K, p-Akt and p70S6K overexpression by ING5 decreased apoptosis in SGC-7901 cells. The hypoexpression of MMP-9, MAP1B and flotillin 2 contributed to the inhibitory effects of ING5 on migration and invasion of SGC-7901 cells. ING5 overexpression might activate both ß-catenin and NF-κB pathways in SGC-7901 cells, and promote the expression of down-stream genes (c-myc, VEGF, Cyclin D1, survivin, and interleukins). Compared with the control, ING5 transfectants displayed drug resistance to triciribine, paclitaxel, cisplatin, SAHA, MG132 and parthenolide, which was positively related to their apoptotic induction and the overexpression of chemoresistance-related genes (MDR1, GRP78, GRP94, IRE, CD147, FBXW7, TOP1, TOP2, MLH1, MRP1, BRCP1 and GST-π). ING5 expression was higher in gastric cancer than matched mucosa. It was inversely associated with tumor size, dedifferentiation, lymph node metastasis and clinicopathological staging of cancer. ING5 overexpression suppressed growth, blood supply and lung metastasis of SGC-7901 cells by inhibiting proliferation, enhancing autophagy and apoptosis in xenograft models. It was suggested that ING5 expression might be employed as a good marker for gastric carcinogenesis and subsequent progression by inhibiting proliferation, growth, migration, invasion and metastasis. ING5 might induce apoptotic and chemotherapeutic resistances of gastric cancer cells by activating ß-catenin, NF-κB and Akt pathways.

The oncogenic role of JC virus T antigen in lens tumors without cell specificity of alternative splicing of its intron.

JC virus (JCV), a ubiquitous polyoma virus that commonly infects the human, is identified as the etiologic agent for progressive multifocal leukoencephalopathy and some malignancies. To clarify the oncogenic role of JCV T antigen, we established two transgenic mice of T antigen using either α-crystallin A (αAT) or cytokeratin 19(KT) promoter. Lens tumors were found in high-copy αAT mice with the immunopositivity of T antigen, p53, ß-catenin and N-cadherin. Enlarged eyeballs were observed and tumor invaded into the brain by magnetic resonance imaging and hematoxylin-and-eosin staining. The overall survival time of homozygous mice was shorter than that of hemizygous mice (p<0.01), the latter than wild-type mice (p<0.01). The spontaneous salivary tumor and hepatocellular carcinoma were seen in αAT5 transgenic mice with no positivity of T antigen. KT7 mice suffered from lung tumor although JCV T antigen was strongly expressed in gastric epithelial cells. The alternative splicing of T antigen intron was detectable in the lens tumor of αAT mice, gastric mucosa of KT mice, and various cells transfected with pEGFP-N1-T antigen. It was suggested that JCV T antigen might induce carcinogenesis at a manner of cell specificity, which is not linked to alternative splicing of its intron. Both spontaneous lens and lung tumor models provide good tools to investigate the oncogenic role of JCV T antigen.

The roles of BTG3 expression in gastric cancer: a potential marker for carcinogenesis and a target molecule for gene therapy.

BTG (B-cell translocation gene) can inhibit cell proliferation, metastasis and angiogenesis, cell cycle progression, and induce differentiation in various cells. Here, we found that BTG3 overexpression inhibited proliferation, induced S/G2 arrest, differentiation, autophagy, apoptosis, suppressed migration and invasion in MKN28 and MGC803 cells (p < 0.05). BTG3 transfectants showed a higher mRNA expression of p27, Bax, 14-3-3, Caspase-3, Caspase-9, Beclin 1, NF-κB, IL-1, -2, -4, -10 and -17, but a lower mRNA expression of p21, MMP-9 and VEGF than the control and mock (p < 0.05). At protein level, BTG3 overexpression increased the expression of CDK4, AIF, LC-3B, Beclin 1 and p38 (p < 0.05), but decreased the expression of p21 and ß-catenin in both transfectants (p < 0.05). After treated with cisplatin, MG132, paclitaxel and SAHA, both BTG3 transfectants showed lower viability and higher apoptosis than the control in both time- and dose-dependent manners (p < 0.05). BTG3 expression was restored after 5-aza-2'-deoxycytidine or MG132 treatment in gastric cancer cells. BTG3 expression was decreased in gastric cancer in comparison to the adjacent mucosa (p < 0.05), and positively correlated with venous invasion and dedifferentiation of cancer (p < 0.05). It was suggested that BTG3 expression might contribute to gastric carcinogenesis. BTG3 overexpression might reverse the aggressive phenotypes and be employed as a potential target for gene therapy of gastric cancer.