Altered Expression of DDR1 in Clear Cell Renal Cell Carcinoma Correlates With miR-199a/b-5p and Patients' Outcome.

BACKGROUND/AIM: Accumulating evidence suggests that discoidin domain receptor tyrosine kinase 1 (DDR1) has an oncogenic role. Therefore, the aim of this study was to evaluate the potential utility of DDR1 and its post-transcriptional repressors, miR-199a-5p and miR-199b-5p, as prognostic factors in clear cell renal cell carcinoma (ccRCC). PATIENTS AND METHODS: The expression of DDR1 in tumor and normal renal tissues of 56 patients with ccRCC was assessed by reverse transcription quantitative polymerase chain reaction, western blotting and immunohistochemistry. Renal cancer cells were transfected with specific RNA sequences to validate DDR1 as a putative miR-199a/b-5p target. RESULTS: Decreased DDR1 mRNA and protein, as well as miR-199a/b-5p levels were found in ccRCC. Low DDR1 protein was associated with higher nuclear grade and shorter overall survival. DDR1 immunoreactivity was elevated in the nuclei and unchanged in the membrane/cytoplasmic compartment of tumor cells. DDR1 levels correlated with those of miR-199a/b-5p. In addition, we validated DDR1 as a target gene for miR-199a/b-5p in renal cancer cell lines. CONCLUSION: DDR1 expression is altered in ccRCC, but our findings do not support its oncogenic role. In-depth investigation will be necessary to elucidate the exact role and potential utility of miR-199a/b-5p in ccRCC.

IKBKB expression in clear cell renal cell carcinoma is associated with tumor grade and patient outcomes.

Inhibitor of nuclear factor kappa B kinase subunit B (IKBKB or IKKß) is a key activator of the nuclear factor κB transcription factor pathway. Increased expression and/or aberrant activity of IKBKB have been observed in various types of human cancer. Three independent techniques, reverse transcription­quantitative polymerase chain reaction, western blotting and immunohistochemistry, were used to demonstrate that IKBKB expression is decreased in clear cell renal cell carcinoma (ccRCC). Notably, the patients with upregulated IKBKB protein expression were characterized by higher nuclear grade tumors and significantly shorter survival. The findings indicate that IKBKB protein may be of clinical relevance in ccRCC, serving as a marker of poor prognosis and as potential target for adjuvant chemotherapies. Further studies are required to validate the prognostic and predictive value of IKBKB.

Decreased Expression of SATB2 Associates with Tumor Growth and Predicts Worse Outcome in Patients with Clear Cell Renal Cell Carcinoma.

BACKGROUND/AIM: SATB2 (special AT-rich sequence-binding protein 2) is a DNA-binding protein that is involved in transcriptional regulation and chromatin remodeling. SATB2 protein has been described as a promising novel marker in several human cancers. PATIENTS AND METHODS: This study compared SATB2 expression in tumor and matched unchanged renal tissues collected from 57 patients with clear cell renal cell carcinoma (ccRCC). SATB2 mRNA levels were determined by quantitative polymerase chain reaction, while SATB2 protein expression was estimated by immunohistochemistry. Moreover, the associations between SATB2 expression in ccRCC samples and clinicopathological and survival data of the patients were investigated. RESULTS: The mRNA level of SATB2 was lower in tumor tissues than in samples of corresponding unchanged kidney. Although the average immunoreactivity of SATB2 protein did not differ significantly between cancer cells and epithelial cells of proximal convoluted tubules, the decreased SATB2 expression in tumor specimens inversely correlated with the size of primary tumor and predicted worse patients' outcome. CONCLUSION: The results of the presented study suggest the tumor-suppressing function of SATB2 and that the expression level of this protein can be considered a potential prognostic factor in ccRCC.

Expression of the EP300, TP53 and BAX genes in colorectal cancer: Correlations with clinicopathological parameters and survival.

E1A binding protein P300 (EP300), tumor protein P53 (TP53) and BCL2 associated X, apoptosis regulator (BAX) genes encode proteins which cooperate to regulate important cellular processes. The present study aimed to determine the expression levels of EP300, TP53 and BAX in colorectal cancer (CRC) and to investigate their prognostic value and association with the progression of CRC. Tumor and matched unchanged colorectal tissues were collected from 121 CRC patients. Quantitative polymerase chain reaction and immunohistochemistry were used to assess the mRNA and protein levels of the studied genes. Altered expression of the studied genes in CRC tissues was observed at both the mRNA and protein levels. The depth of invasion was associated with TP53 mRNA levels and was correlated negatively with BAX mRNA expression. Moreover, a relationship between tumor location and BAX mRNA content was noted. BAX immunoreactivity was correlated positively with the intensity of p300 immunostaining and was associated with lymph node involvement and tumor-node-metastasis (TNM) disease stage. Univariate regression analysis revealed that overexpression of p53 and BAX in CRC tissues was associated with poor patient outcome. In conclusion, dysregulation of the expression of the studied genes was found to contribute to CRC pathogenesis. The association between p300 and BAX levels suggests the existence of an interdependent regulatory mechanism of their expression. Moreover, BAX expression may be regulated alternatively, in a p53-independent manner, since the lack of correlations between expression of these factors was observed.

Expression and Prognostic Significance of EP300, TP53 and BAX in Clear Cell Renal Cell Carcinoma.

BACKGROUND: Histone acetyltransferase E1A-binding protein p300 (EP300), tumor protein p53 (TP53) and B-cell lymphoma-2-associated X protein (BAX) contribute to the regulation of the cell cycle and apoptosis, cellular processes that are often impaired in cancer cells. The aim of this study was to determine the expression levels of EP300, TP53 and BAX genes and their respective proteins in clear cell renal cell carcinoma (ccRCC) and evaluate the value of these factors as prognostic factors. MATERIALS AND METHODS: EP300, TP53 and BAX expression at the transcript and protein levels were determined by quantitative polymerase-chain reaction (QPCR) and immunohistochemistry (IHC) in paired tumor and kidney specimens from 31 patients with ccRCC. RESULTS: Levels of EP300, TP53 and BAX transcripts were found increased in tumor tissues. Immunoreactivity for TP53 was elevated in cancer cells when compared to unchanged kidney, while EP300 and BAX immunoexpression in ccRCC did not differ from that of normal renal tissue. Immunoreactivity for TP53 was positively associated with larger tumor size. In contrast, stronger BAX immunoexpression correlated with smaller tumor diameters. The average immunoreactivity for BAX was higher in localized, kidney-confined tumor than in advanced/recurrent tumors. None of the analyzed transcripts or proteins correlated with the overall survival of patients. CONCLUSION: Although TP53 and BAX immunoreactivity levels were associated with some clinicopathological parameters of the patients, the expression of EP300, TP53 and BAX did not reveal any prognostic significance in ccRCC.

SATB1 is Down-regulated in Clear Cell Renal Cell Carcinoma and Correlates with miR-21-5p Overexpression and Poor Prognosis.

BACKGROUND: Altered expression of special AT-rich sequence binding protein 1 (SATB1) was reported in several types of human cancers. This study aimed to determine the expression levels of SATB1, as well as miR-21-5p -the post-transcriptional repressor of SATB1 expression- in clear cell renal cell carcinoma (ccRCC) and to investigate their association with the progression of ccRCC. MATERIALS AND METHODS: Immunohistochemistry and quantitative polymerase chain reaction were used to assess the expression of SATB1 protein and mRNA as well as miR-21-5p in tumor and matched normal kidney tissues collected from 56 ccRCC patients. RESULTS: Nuclear SATB1 immunoreactivity was elevated in ccRCC cells while its cytoplasmic expression was decreased. SATB1 mRNA level was down-regulated in ccRCC tissue and inversely correlated with the content of miR-21-5p. Down-regulation of SATB1 mRNA and up-regulation of miR-21-5p were associated with shorter patient survival. CONCLUSION: Decreased expression of SATB1 in ccRCC may result from over-expressed miR-21-5p. Our data suggest that SATB1 may have a potential value as a prognostic marker in ccRCC.

PLAGL1 (ZAC1/LOT1) Expression in Clear Cell Renal Cell Carcinoma: Correlations with Disease Progression and Unfavorable Prognosis.

BACKGROUND: Pleiomorphic adenoma gene-like 1 (PLAGL1) protein was originally shown to induce cell-cycle arrest and promote apoptosis in several types of human tumors and therefore it was considered a candidate tumor suppressor. The involvement of PLAGL1 gene in the etiology and pathogenesis of clear cell renal cell carcinoma (ccRCC) has not been evaluated. The purpose of the present study was to determine the expression level of PLAGL1 in ccRCC and to investigate its potential utility as a prognostic factor. MATERIALS AND METHODS: We applied quantitative real-time polymerase chain reaction (QPCR), western blotting and immunohistochemistry to measure PLAGL1 mRNA/protein contents in paired tumor and kidney specimens of 40 patients with ccRCC. RESULTS: PLAGL1 mRNA and protein levels were increased in tumor tissues as determined by QPCR and immunohistochemistry, respectively. The average content of PLAGL1 protein measured by western blotting did not differ between tumor and non-cancerous kidney tissues. However, increased PLAGL1 protein level in ccRCC tissue positively correlated with the presence of distant metastases and worse patient outcome. CONCLUSION: These results suggest an oncogenic role of PLAGL1 in the progression of ccRCC and its potential value as a prognostic marker.

Altered expression of the PLAGL1 (ZAC1/LOT1) gene in colorectal cancer: Correlations to the clinicopathological parameters.

Pleomorphic adenoma gene-like 1 gene (PLAGL1) encodes a zinc-finger nuclear transcription factor which promotes apoptosis and cell cycle arrest. Loss or downregulation of its expression has been observed in various human neoplasms. This study compared PLAGL1 expression in colorectal cancer (CRC) tissue and colon mucosa of healthy subjects at the mRNA and protein levels, and estimated its prognostic value. The PLAGL1 mRNA levels were also determined in CRC cell lines. We collected paired tumor tissue and unchanged mucosa of the large intestine from 121 CRC patients as well as 72 colon biopsies of healthy subjects obtained during screening colonoscopy. PLAGL1 mRNA levels were determined by quantitative PCR, while PLAGL1 protein expression was estimated by western blotting and immunohistochemistry. PLAGL1 mRNA level in tumor tissue was ~2-fold lower than in samples of corresponding unchanged tissues and biopsies of healthy colon mucosa. Downregulated expression of PLAGL1 mRNA was also observed in all tested CRC cell lines. Although the average content of PLAGL1 protein did not differ significantly between tumor and unchanged tissues of CRC patients or colon mucosa of healthy individuals, the decreased PLAGL1 protein levels in tumor specimens correlated with lymph node involvement, the presence of metastases and higher TNM disease stage. The PLAGL1 expression level did not correlate significantly with patient overall survival; however, the hazard ratio for patients whose tumor tissues showed reduced PLAGL1 immunohistochemical staining was twice higher than in patients with increased PLAGL1 immunoreactivity. In conclusion, these results suggest that dysregulation of PLAGL1 expression may be involved to some extent in the progression of CRC, but the so far collected patient survival data do not confirm applicability of the PLAGL1 expression level as a prognostic factor in CRC.

Divergent expression patterns of SATB1 mRNA and SATB1 protein in colorectal cancer and normal tissues.

Special AT-rich sequence-binding protein 1 (SATB1) is a 'genome organizer,' and it has been proposed as a factor that affects the development and progression of various human neoplasms, including colorectal cancer (CRC). This study aimed to compare SATB1 expression in a group of CRC patients and healthy subjects at the mRNA and protein levels. We collected paired tumor tissue and unchanged mucosa of the large intestine from 102 CRC patients as well as 53 biopsies of normal colon mucosa obtained from healthy patients during screening colonoscopy. Tissue samples were quantified for SATB1 mRNA by quantitative PCR, while SATB1 protein expression was determined by Western blotting and immunohistochemistry. SATB1 mRNA level in tumor tissues was over twofolds lower than in samples of corresponding unchanged tissues and fourfolds lower than in biopsies of healthy colon mucosa. Western blotting analysis revealed that SATB1 protein content in tumor and unchanged tissues of CRC patients was over sixfold and fivefolds higher than in biopsies of healthy colon mucosa, respectively. Immunohistochemical staining demonstrated higher nuclear and cytoplasmic SATB1 reactivity in the tumor tissue compared to unchanged mucosa of CRC patients. Despite these differences, SATB1 mRNA, protein, and immunoreactivity levels did not correlate with patients' clinicopathological data and their overall survival, but the latter analysis was limited by a relatively short period of follow-up. In conclusion, we suggest that some as yet unidentified posttranscriptional mechanisms that regulate SATB1 expression may be altered in the CRC tissue.