Potential role of Jun activation domain-binding protein 1 and phosphorylated p27 expression in prognosis of glioma

Prognostic role of c-Jun activation domain-binding protein-1 in cancer: A systematic review and meta-analysis

c-Jun activation domain-binding protein-1 (Jab1) is aberrantly overexpressed in multiple cancers and plays an oncogenic role in cancer progression. We examined the association between Jab1 expression and prognosis in patients with cancer by conducting a meta-analysis. A comprehensive search strategy was performed using the PubMed, Web of Science, Ovid and EMBASE in July 2020. Eligible studies were enrolled according to definite criteria. Twenty-seven studies involving 2609 patients were enrolled in this meta-analysis. A significant association between high Jab1 expression and poor overall survival (pooled hazard ratio [HR] 2.344, 95% confidence interval [CI]: 2.037-2.696) was observed. Subgroup analyses of the type of cancer, sample size, follow-up period, Jab1 detection method and preoperative treatment did not alter the significance. On pooling data from Cox multivariate analyses, high Jab1 expression was found to be an independent prognostic indicator for overall survival. In addition, high Jab1 expression was found to be associated with advanced clinicopathological features such as clinical stage, lymphatic metastasis, histological grade and distant metastasis in cancers. Our meta-analysis is the first to demonstrate that high Jab1 expression may be a promising indicator of poor prognosis and has an independent prognostic value for overall survival in patients with cancer.

JAB1-STAT3 activation loop is associated with recurrence following 5-fluorouracil-based adjuvant chemotherapy in human colorectal cancer

Jun activation domain-binding protein 1 (JAB1) has been shown to have multiple roles in tumorigenesis, including the degradation of tumor suppressor proteins such as p53, Smad7, Runx3 and the cyclin-dependent kinase inhibitor p27Kip1, and the activation of oncogenic transcription factors, such as c-Jun and hypoxia-inducible factor-1α. In addition, our previous study revealed that JAB1 positively regulates signal transducer and activator of transcription 3 (STAT3) DNA-binding activity in human colon cancer cells. In turn, the oncogenic transcription factor STAT3 positively regulates JAB1 expression, indicative of a positive feedback loop. Furthermore, high JAB1 expression is associated with a poor prognosis in numerous malignant carcinomas. However, the association between JAB1 expression and prognosis in colorectal cancer remains unclear. The aim of the present study was to elucidate the association between JAB1 and STAT3 expression and recurrence in colorectal cancer. In the present study, it was found that high JAB1 expression in primary colorectal cancer tissues is an independent predictor of recurrence following 5-fluorouracil (5-FU)-based adjuvant chemotherapy in colorectal cancer patients, and that high expression of both JAB1 and STAT3 in primary colorectal cancer tissues is associated with a lower recurrence-free survival rate following 5-FU-based adjuvant chemotherapy compared to high expression of only JAB1 or STAT3. Overall, these results suggest that JAB1 is a novel predictive marker of recurrence following 5-FU-based adjuvant chemotherapy in colorectal cancer patients, and that the JAB1-STAT3 activation loop may be a potential therapeutic target in recurrent colorectal cancer following 5-FU-based adjuvant chemotherapy.

Cyclin-dependent kinase inhibitors, p16 and p27, demonstrate different expression patterns in thymoma and thymic carcinoma

OBJECTIVES

The role of cell cycle inhibitors in tumorigenesis has been proven in various neoplasms; however, their roles in thymic tumors are still unclear. We examined the expression of cell cycle inhibitors such as those of the Cip/Kip family (p21, p27, and p57) and the INK-4/ARF family (p16 and p14) in thymoma and thymic carcinoma.

METHODS

Samples from 41 thymoma and 14 thymic carcinoma patients, and 34 normal thymic tissue samples were prepared for the study. Immunohistochemical analysis using antibodies to p21, p27, p57, p16, and p14 was carried out, and the positivity for these inhibitors in each group was estimated in terms of their subcellular location and percentage of cells showing positive staining.

RESULTS

Nuclear p27 showed a stepwise decrease (p < 0.0001), and the cytoplasmic p27 showed a stepwise increase (p < 0.0001) in expression level with the increase in malignancy. p16 in both the nucleus and cytoplasm showed a stepwise increase (p < 0.0001) in expression level with the increase in malignancy. However, as for p21, p57, and p14, there was almost no nuclear or cytoplasmic expression in each group.

CONCLUSIONS

Our findings suggest that low nuclear and high cytoplasmic p27 expression levels, and high nuclear and cytoplasmic p16 expression levels may correlate with the increase in thymic malignancy.

p27 Is a critical prognostic biomarker in non-alcoholic steatohepatitis-related hepatocellular carcinoma

Non-alcoholic steatohepatitis (NASH) is a recently identified chronic liver disease, which progresses to liver cirrhosis and hepatocellular carcinoma (HCC). As the number of patients studied to date has been limited, clinically useful prognostic biomarkers of NASH-related HCC have not been available. In this study, we investigated the status of a cell-cycle regulator, p27, in NASH-related HCC. p27 has been regarded as a prognostic factor in various types of cancer patients. A total of 22 cases with NASH-related HCC were analyzed for p27 protein expression, and phosphorylation at threonine 157 (T157) and serine 10 (S10) by immunohistochemical analysis. The correlation of p27 with tumor characteristics, disease-free survival (DFS), and overall survival was analyzed. p27 expression was decreased in 13 HCCs (59%), and was significantly correlated with enlarged tumor size (p = 0.01) and increased cell proliferation (p < 0.01). Phospho-p27 at T157 and S10 was detected in four (18%) and seven (32%) cases, respectively, and patients positive for phospho-p27 (S10) showed reduced DFS (hazard ratio 7.623, p = 0.016) by univariate analysis. Further studies with more patients are required to verify the usefulness of p27 as a biomarker for predicting tumor recurrence in NASH patients.

Expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma: low p27 expression predicts poor prognosis

Prognosis of eyelid sebaceous gland carcinoma is largely unpredictable and there are few practically available markers for predicting patients' prognosis. Dysregulation of cell cycle progression is strongly associated with the development of cancer and the cancer prognosis. We investigated the expression of cell cycle regulatory proteins in eyelid sebaceous gland carcinoma and estimate their value as prognostic predictors. Forty-three cases of eyelid sebaceous gland carcinoma were included in this study. Immunohistochemistry for the p53, p21, p27, cyclin E, p16, cyclin D1, and phosphorylated Rb (pRb) proteins was performed using archival paraffin blocks. Correlations between clinical features and protein expression were evaluated statistically. Nine patients showed lymph node or distant metastasis, and the remaining patients showed localized disease. High expression of p21, p27, cyclin E, and p16 was found in the majority of tumor cell nuclei, whereas these proteins were rarely expressed in the normal sebaceous glands. However, pRb was focally lost in a subset of cases. Patients showing diffuse p27 expression developed metastasis less commonly than those with negative or focal p27 expression (log-rank test, p = 0.008). Aberrant expression of cell cycle regulatory proteins was observed in eyelid sebaceous gland carcinoma, suggesting that cell cycle dysregulation is involved in the pathogenesis of this tumor. Decreased p27 expression is a predictive biomarker of an unfavorable prognosis of eyelid sebaceous gland carcinoma.

Oncogenic role of SOX9 expression in human malignant glioma

SOX9 belongs to the SOX (Sry-related high-mobility group box) family and acts as a transcription factor that plays a central role in the development and differentiation of multiple cell lineages. Recent studies have demonstrated that SOX9 is required for the carcinogenesis in several cancer types. The aim of this study was to investigate the clinicopathological significance of SOX9 expression in human malignant glioma. SOX9 mRNA expression was detected by real-time quantitative RT-PCR assay in glioma and nonneoplastic brain tissues. Then, the association of SOX9 mRNA expression with clinicopathological factors or prognosis of glioma patients was statistically analyzed. In addition, the small interfering RNA was used to knockdown SOX9 expression in a glioma cell line and to analyze the effects of SOX9 inhibition on cell growth, cell cycle and apoptosis of glioma cell line. The expression level of SOX9 mRNA in glioma tissues was significantly higher than that in corresponding nonneoplastic brain tissues (P < 0.001). In addition, a high level of SOX9 mRNA expression was significantly more common in glioma tissues with advanced WHO grade than those with low grade (P = 0.02). The increased expression of SOX9 mRNA was also significantly correlated with low Karnofsky performance score (P = 0.008). Meanwhile, the disease-free and overall survival rates of patients with high SOX9 mRNA expression were obviously lower than those of patients with low SOX9 mRNA expression (both P = 0.01). Multivariate analysis showed that high SOX9 mRNA expression was an independent prognostic factor for glioma patients (P = 0.02). Moreover, the down-regulation of SOX9 could inhibit the cell growth, induce the cell arrest in G2/M phase of cell cycle and enhance the apoptosis in glioma cells. Our data suggest for the first time that the over-expression of SOX9 mRNA is closely associated with poor clinical outcome of patients with malignant gliomas, and targeting SOX9 may be a novel therapeutic strategy for this tumor.