Jing-Ru Wang

Objectives: While dysregulation of DSCC1 (DNA Replication And Sister Chromatid Cohesion 1) has been established in breast cancer and colorectal cancer, its associations with other tumors remain unclear. Therefore, this study was launched to explore the role of DSCC1 in pan-cancer. Methodology: In this study, we investigate the biological functions of DSCC1 across 33 solid tumors, elucidating its role in promoting oncogenesis and progression in various cancers through comprehensive analysis of multi-omics data. Results: We conducted a comprehensive analysis of DSCC1 expression using RNA-seq data from TCGA and GTEx databases across 30 cancer types. Striking variations were observed, with significant overexpression of DSCC1 identified in numerous cancers. Elevated DSCC1 level was strongly associated with poorer prognosis, shorter survival, and advanced tumor stages in kidney renal papillary cell carcinoma (KIRP), liver hepatocellular carcinoma (LIHC), lung adenocarcinoma (LUAD), as indicated by Kaplan-Meier curves and GEPIA2 analysis. Further investigation into the molecular mechanisms revealed reduced DNA methylation in the DSCC1 promoter region in KIRP, LIHC, and LUAD, supporting enhanced RNA transcription. Protein expression analysis via the Human Protein Atlas (HPA) corroborated mRNA expression findings, showcasing elevated DSCC1 protein in KIRP, LIHC, and LUAD tissues. Mutational analysis using cBioPortal revealed alterations in 0.4% of KIRP, 17% of LIHC, and 5% of LUAD samples, predominantly characterized by amplification. Immune cell infiltration analysis demonstrated robust positive correlations between DSCC1 expression and CD8+ T cells, CD4+ T cells, and B cells, influencing the tumor microenvironment. STRING and gene enrichment analyses unveiled DSCC1’s involvement in critical pathways, emphasizing its multifaceted impact. Notably, drug sensitivity analysis highlighted a significant correlation between DSCC1 mRNA expression and responses to 78 anticancer treatments, suggesting its potential as a predictive biomarker and therapeutic target for KIRP, LIHC, and LUAD. Finally, immunohistochemistry staining of clinical samples validated computational results, confirming elevated DSCC1 protein expression. Conclusion: Overall, this study provides comprehensive insights into the pivotal role of DSCC1 in KIRP, LIHC, and LUAD initiation, progression, and therapeutic responsiveness, laying the foundation for further investigations and personalized treatment strategies.

Ubiquitin specific protease 4 (USP4) is a deubiquitinating enzyme with key roles in the regulation of p53 and TGFβ signaling, suggesting its importance in tumorigenesis. However, the mechanisms and regulatory roles of USP4 in cancer, including colorectal cancer, remain largely elusive. Here, we present the first evidence that USP4 regulates the growth, invasion, and metastasis of colorectal cancer. USP4 expression was significantly elevated in colorectal cancer tissues and was significantly associated with tumor size, differentiation, distant metastasis, and poor survival. Knockdown of USP4 diminished colorectal cancer cell growth, colony formation, migration, and invasion in vitro and metastasis in vivo. Importantly, we found that phosphatase of regenerating liver-3 (PRL-3) is indispensable for USP4-mediated oncogenic activity in colorectal cancer. Mechanistically, we observed that USP4 interacted with and stabilized PRL-3 via deubiquitination. This resulted in activation of Akt and reduction of E-cadherin, critical regulators of cancer cell growth and metastasis. Examination of clinical samples confirmed that USP4 expression positively correlates with PRL-3 protein expression, but not mRNA transcript levels. Taken together, our results demonstrate that aberrant expression of USP4 contributes to the development and progression of colorectal cancer and reveal a critical mechanism underlying USP4-mediated oncogenic activity. These observations suggest that the potential of harnessing proteolytic degradation processes for therapeutic manipulation may offer a much-needed new approach for improving colorectal cancer treatment strategies. Cancer Res; 76(1); 83–95. ©2015 AACR.

Correlation of RARγ expression with patients' clinicopathological variables in 91 cases of CRC (S1); Human RARγ shRNA target sequences (S2); Primers for qPCR (S3).

Legends for Supplementary Figures S1-S4

Correlation of RARγ expression with patients' clinicopathological variables in 91 cases of CRC (S1); Human RARγ shRNA target sequences (S2); Primers for qPCR (S3).

Supplementary Materials and Methods

Supplementary Materials and Methods

The Hippo–Yap pathway conveys oncogenic signals, but its regulation during cancer development is not well understood. Here, we identify the nuclear receptor RARγ as a regulator of the Hippo–Yap pathway in colorectal tumorigenesis and metastasis. RARγ is downregulated in human colorectal cancer tissues, where its expression correlates inversely with tumor size, TNM stage, and distant metastasis. Functional studies established that silencing of RARγ drove colorectal cancer cell growth, invasion, and metastatic properties both in vitro and in vivo. Mechanistically, RARγ controlled Hippo–Yap signaling to inhibit colorectal cancer development, acting to promote phosphorylation and binding of Lats1 to its transcriptional coactivator Yap and thereby inactivating Yap target gene expression. In clinical specimens, RARγ expression correlated with overall survival outcomes and expression of critical Hippo–Yap pathway effector molecules in colorectal cancer patients. Collectively, our results defined RARγ as tumor suppressor in colorectal cancer that acts by restricting oncogenic signaling by the Hippo–Yap pathway, with potential implications for new approaches to colorectal cancer therapy. Cancer Res; 76(13); 3813–25. ©2016 AACR.