LAT, HOXD3 and NFE2L3 identified as novel DNA methylation-driven genes and prognostic markers in human clear cell renal cell carcinoma by integrative bioinformatics approaches.

Background: Abnormal DNA methylation of is one of the important mechanisms leading to tumor pathogenesis. The purpose of this study was to explore differentially methylated genes that may drive the development of renal clear cell carcinoma through a comprehensive analysis of the TCGA database. Materials and methods: Methylation data and RNA-seq data for clear cell renal cell carcinoma were downloaded from The Cancer Genome Atlas (TCGA). Differentially methylated genes and the differential genes associated with survival were then screened by MethylMix R package and univariate Cox proportional-hazards model, respectively. Their common genes were then intersected and obtained for further analysis. Correlation of gene expression and methylation levels, gene set enrichment analysis (GSEA) enrichments, survival curve, and ROC curve plotting for DNA methylation-driven genes were finally performed. The methylation alterations of the three genes were validated via two GEO datasets (GSE70303 and GSE113501), and the genes expression level was verified through two GEO datasets (GSE6344 and GSE53757). Results: Three novel DNA methylation-driven genes LAT, HOXD3 and NFE2L3 were identified in clear cell renal cell carcinoma. Expression analysis further revealed that hypomethylation levels of LAT and NFE2L3 showed higher gene expression levels, while HOXD3 exhibited opposite methylation-expression pattern. The CpG sites of LAT (cg16462073), HOXD3 (cg24000528) and NFE2L3 (cg16882373) that may affect respective gene expressions were also identified. For the survival analysis, we found that hypomethylation and over-expression of LAT and NFE2L3 were correlated with poor survival, while hypermethylation and low-expression HOXD3 was correlated with poor survival of clear cell renal cell carcinoma patients. In addition, GSEA KEGG analysis and biological processes of these genes were also enriched for functional analysis. Kaplan-Meier survival and ROC analyses of these genes showed an average risk score of 0.9140593, AUC = 0.692, which suggested a good clinical application value. Finally, the opposite methylation-expression pattern of these three genes were verified in GEO datasets. Conclusions: In this study, we successfully exhibited the potential DNA methylation-driven genes LAT, HOXD3, and NFE2L3 involved in clear cell renal cell carcinoma. Moreover, gene functions and prognostic risk models were also elucidated, which facilitated the expansion of the current study on the role of methylation in the pathology process of clear cell renal cell carcinoma.

SU6668 modulates prostate cancer progression by downregulating MTDH/AKT signaling pathway.

Prostate cancer is the second leading cause of cancer deaths among men in Western counties and has increased in incidence also in China in recent years. Although diagnosis modalities for primary prostate cancer have markedly improved, there are still no effective therapies for metastatic prostate cancer. SU6668 is an inhibitor of the tyrosine kinase activity of three angiogenic receptors VEGFR2, PDGFRß and FGFR1. There is strong experimental evidence that SU6668 can induce growth inhibition of various primary tumors. However, the function and molecular mechanism of SU6668 in prostate cancer has not been fully elucidated. In the present study, we found that SU6668 inhibited the proliferation and invasion of prostate cancer cells. Functional studies also demonstrated that SU6668 inhibited epithelial-mesenchymal transition in DU145 and LNCap cells. After treatment with SU6668, MTDH protein, which has been reported to be significantly overexpressed in many human tumor tissues, was downregulated in DU145 and LNCap cells. siRNA-mediated silencing of MTDH in prostate cancer cells decreased their proliferation and invasive capabilities, suggesting that SU6668 may inhibit cell proliferation and invasion of prostate cancer cells partly through downstream targeting of MTDH. Mechanistic investigations showed that AKT signaling pathway was inhibited after SU6668 treatment in prostate cancer cells. Moreover, a combination of SU6668 and PI3K-AKT pathway inhibitor LY29004 resulted in increased inhibition of cell proliferation and invasion in DU145 cells. Taken together, our findings revealed that SU6668 suppressed prostate cancer progression by downregulating MTDH/AKT signaling pathway and identified a promising therapeutic strategy for prostate cancer.

[Crypotanshione reduces the expression of metadherin in DU145 prostate cancer cells].

OBJECTIVE: To investigate the effects of crypotanshinone (CPT) on the proliferation and apoptosis of DU145 prostate cancer cells as well as on the metadherin expression and the downstream PI3K/AKT signaling pathway in the DU145 cells. METHODS: We treated DU145 prostate cancer cells with different concentrations of CPT for 24, 48, and 72 hours followed by evaluation of the proliferation and apoptosis of the cells by MTT assay and TUNEL, respectively. We determined the expressions of metadherin protein and mRNA in the DU145 cells by Western blot and RT-PCR respectively at different time points after CPT treatment. We also detected the expressions of the proteins metadherin, AKT, p-AKT, and Bcl-2 in the CPT-treated DU145 cells at 48 hours. RESULTS: CPT significantly inhibited the proliferation of the DU145 cells in a dose- and time-dependent manner (P < 0.05). After treatment with 10 µmol/L CPT for 24, 48, and 72 hours, the apoptosis rates of the DU145 cells were (29.42 ± 4.51), (55.07 ± 5.67) and (70.84 ± 4.66)%, respectively, significantly higher than (3.1 ± 2.48)% in the control group (P < 0.05). The expression of metadherin was remarkably downregulated at the transcription and translation levels (P < 0.05) and the expressions of the AKT signaling pathway and the Bcl-2 protein were markedly inhibited in the DU145 cells after treated with 10 µmol/L CPT for 48 hours (P < 0.05). CONCLUSION: CPT can inhibit the proliferation and induce the apoptosis of DU145 prostate cancer cells, which may be associated with its suppression of the downstream PI3K/AKT signaling pathway by reducing the expression of metadherin in the DU145 cells.

MTDH/AEG-1-based DNA vaccine suppresses metastasis and enhances chemosensitivity to paclitaxel in pelvic lymph node metastasis.

OBJECTIVE: MTDH/AEG-1 could act as an oncogene by regulating cellular transformation, proliferation, invasion, metastasis, and angiogenesis. This study aims to explore the mechanism by which MTDH/AEG-1 inhibits cancer growth and metastasis and enhances chemosensitivity. METHODS: Mouse model was established using orally immunized mice exposed to attenuated Salmonella containing vectors carrying full length MTDH/AEG-1 gene, and we were able to enhance the immune response and inhibit the growth and metastasis of prostate cancer through activation of cellular and humoral immunities and induction of CD8+ T cells. Immunohistochemistry and TUNEL assay, CD4+ and CD8+ T cell analysis by flow cytometry, HE staining, RT-PCR analysis, Western-blot analysis and quantitative polymerase chain reaction were performed. RESULTS: The MTDH/AEG-1 gene vaccine induced the anti-tumor function of cytotoxic T lymphocytes and CD8+ T cells and inhibited tumor growth and metastasis of prostate cancer. In the therapy model, the MTDH/AEG-1 gene vaccine significantly enhanced chemosensitivity to paclitaxel, inhibited tumor growth, promoted tumor cell apoptosis, and prolonged the survival time of tumor-bearing mice without any apparent side effects. CONCLUSIONS: Our results demonstrated that MTDH/AEG-1-based DNA vaccines could used for the treatment of prostate cancer in terms of the inhibition of tumor growth, the lifespan of tumor-bearing animals. Combined with chemotherapy, MTDH/AEG-1-based DNA vaccines may produce highly favorable outcomes in the prevention and treatment of prostate cancer, suggesting the immune efficacy of MTDH/AEG-1-based DNA should be further analyzed in other cancers.

[Hypothermia combined with dexamethasone reduces ICAM1 expression and protects spermatogenesis after testicular torsion-detorsion].

OBJECTIVE: To investigate the protective effect of hypothermia combined with dexamethasone on spermatogenesis and the expression of intercellular adhesion molecule 1 (ICAM1) after testicular torsion-detorsion. METHODS: We made unilateral testicular torsion models in 100 pubertal male Sprague-Dawley rats by 720 degree torsion of the left testis and then randomly divided them into four groups of equal number to be treated with normal temperature + physiological saline (group A), hypothermia + physiological saline (group B), normal temperature + dexamethasone (group C), and hypothermia + dexamethasone (group D). After 48 hours, we collected the testes, observed pathological changes of the testicular tissue by HE staining under the light microscope, detected the apoptosis of spermatogenic cells by TUNEL, and determined the expression of ICAM1 by Western blot. RESULTS: HE staining showed different degrees of testicular tissue injury in the four groups of rats, most obvious in group A, but mild in the other three. The ICAM1 protein expression was significantly higher in group A (0.68 +/-0. 03) than in B (0. 49 +/- 0. 06, P <0. 05) , C (0. 46 +/- 0. 09, P < 0.05) , and D (0.17 +/- 0.08, P <0.01). The nuclei were deep brown or brown. Lots of apoptotic spermatogenic cells were seen in the torsion testis of group A, with a significantly higher apoptosis index ( [33. 13 +/- 3.21 ]%) than in B ( [ 17. 12 +/-5.23 ]%, P < 0.05), C ([14.13 +/- 2.03]%, P <0.05), and D ([9.05 +/- 1.03]%, P <0.01). CONCLUSION: Hypothermia combined with dexamethasone can protect the testis from injury as well as the reproductive function of the testis after testicular torsion-detorsion and reduce the expression of ICAM1.

[Effects of hypothermia plus dexamethasone on eNOS expression and spermatogenic cell apoptosis after testicular torsion reduction].

OBJECTIVE: To investigate the protective effects of hypothermia combined with dexamethasone on the testis of rats after testicular torsion reduction and on the expression of eNOS and apoptosis of spermatogenic cells. METHODS: We made unilateral testicular torsion models in 80 adolescent male Sprague-Dawley rats by 720 degrees torsion of the left testis, and then randomly divided them into four groups of equal number to be treated with normal temperature + physiological saline (group A), hypothermia + physiological saline (group B), hypothermia + dexamethasone (group C), and normal temperature + dexamethasone (group D). After 48 hours, we collected the testes, observed pathological changes of the testicular tissue by HE staining under the light microscope, determined the expression of eNOS by immunohistochemistry, and detected the apoptosis of spermatogenic cells by TUNEL. RESULTS: HE staining showed different degrees of testicular tissue injury in all the four groups of rats, most obvious in group A, while protective effect was observed in the other three groups. Immunohistochemistry revealed significantly more positive cells and higher positive staining intensity in the torsion (left) testis in group A than in B (P < 0.05), C (P < 0.01) and D (P < 0.01). The nuclei were deep brown or brown. Lots of apoptotic spermatogenic cells were seen in the torsion testis of group A, with a significantly higher apoptosis index (31.12 +/- 4.68) than in B (16.58 +/- 6.22) (P < 0.05), C (8.60 +/- 1.15) (P < 0.01) and D (13.52 +/- 3.06) (P < 0.01). CONCLUSION: Ischemia-reperfusion injury after testicular torsion reduction can increase the apoptosis of spermatogenic cells and decrease testicular reproductivity. Hypothermia combined with dexamethasone can protect the testis from injury as well as the reproductive function of the testis after testicular torsion reduction.

MTDH/AEG-1-based DNA vaccine suppresses lung metastasis and enhances chemosensitivity to doxorubicin in breast cancer.

The gene MTDH/AEG-1 is overexpressed in more than 40% of breast cancer patients, and it is associated with poor clinical outcomes. Previous studies have indicated that MTDH/AEG-1 could promote metastatic lung-seeding and enhance chemoresistance. Therefore, MTDH/AEG-1 could be a candidate target against breast cancer lung metastasis. We demonstrated that MTDH/AEG-1-based DNA vaccine, delivered by attenuated Salmonella typhimurium, could evoke strong CD8(+) cytotoxic-T-cell mediated immune responses against breast cancer. This vaccine showed anti-tumor growth and metastasis efficacy in a prophylactic setting. Importantly, in a therapeutic model, MTDH/AEG-1 vaccine was proved to increase chemosensitivity to doxorubicin and inhibit breast cancer lung metastasis. This vaccine could also prolong the life span of tumor-bearing mice without significant side effects in vivo. These results suggested that this novel DNA vaccine was effective in the inhibition of breast cancer growth and metastasis, and this vaccine in combination with chemotherapies offered new strategies for the clinical therapeutics of breast cancer metastasis.